CN110497476B

CN110497476B - Emergency stop protection method for pneumatically driven reciprocating saw

Info

Publication number: CN110497476B
Application number: CN201910804139.4A
Authority: CN
Inventors: 魏大平; 张勤
Original assignee: Lu'an Yongzhen Grizzly Electrical And Mechanical Technology Co ltd
Current assignee: Lu'an Yongzhen Grizzly Electrical And Mechanical Technology Co ltd
Priority date: 2019-08-28
Filing date: 2019-08-28
Publication date: 2021-04-20
Anticipated expiration: 2039-08-28
Also published as: CN110497476A

Abstract

The invention provides an emergency stop protection method of a pneumatic drive reciprocating saw, which comprises the following steps: firstly, the gas supply device conveys high-pressure gas of a gas source to the input end of a pneumatic driving device, the pneumatic driving device receives the high-pressure gas and drives a linkage rod in a saw body to reciprocate up and down along the vertical direction, and the linkage rod drives a saw blade to reciprocate up and down and saw wood on a workbench; in the sawing process, if the saw blade is accidentally broken, the saw breaking protection mechanism is switched to a blocking state, the high-pressure air source is cut off to be communicated with an air distribution inlet in the pneumatic driving device, and the pneumatic driving device stops driving the saw blade to reciprocate up and down; in the sawing process, if the saw blade needs to be emergently braked, a user manually switches the emergency stop switch to a closed state, the high-pressure air source is cut off from being communicated with an air distribution inlet in the pneumatic driving device, and the pneumatic driving device stops driving the saw blade to reciprocate up and down.

Description

Emergency stop protection method for pneumatically driven reciprocating saw

Technical Field

The invention relates to a saw, in particular to an emergency stop protection method of a pneumatic drive reciprocating saw.

Background

The wood cutting treatment in daily life generally adopts a saw to cut, the saw mainly comprises two types, one type is a manual saw, the other type is an electric saw, the manual saw mainly comprises a saw blade and a saw body, the saw blade and the saw body are formed by irregularly arranged saw teeth, the saw is light, convenient and low in cost, but has obvious defects, for example, the saw has low cutting efficiency, wastes time and labor, when the saw blade is accidentally broken, splashing is easily generated due to the inertia effect to endanger the life and health of workers, the electric saw drives the saw blade to circularly operate through a motor to realize the cutting of wood, the saw has the advantages of high cutting efficiency and certain defects, when the saw blade is accidentally broken, the motor continuously drives the saw blade to operate, the saw blade generates centrifugal motion to endanger the life of the workers, the saw blade cannot be stopped suddenly, and the safety performance is low, in order to overcome the defects, the invention designs the emergency stop protection method of the pneumatic driving reciprocating saw, which has the advantages of ingenious structure, simple principle, high safety performance and high cutting efficiency, and can realize emergency stop when the saw is broken.

Disclosure of Invention

In order to solve the defects of the prior art, the invention aims to provide the emergency stop protection method of the pneumatic driving reciprocating saw, which has the advantages of ingenious structure, simple principle, high safety performance and high cutting efficiency, and can realize emergency stop when the saw is broken.

In order to achieve the technical purpose, the technical scheme adopted by the invention is as follows.

A sudden stop protection method of a pneumatic drive reciprocating saw comprises the following steps:

a normal sawing stage;

s1: the gas supply protection device conveys gas source high-pressure gas to the input end of the pneumatic driving device, the pneumatic driving device receives the high-pressure gas and drives a linkage rod in the saw body to reciprocate up and down along the vertical direction, and the linkage rod drives a saw blade to reciprocate up and down and saw wood on the workbench;

the saw body comprises a mounting column which is fixedly mounted on the top of an upper arm and vertically arranged, a strip-shaped top frame which is positioned right above the upper arm and is parallel to the upper arm is movably sleeved on the mounting column, one end of the top frame along the length direction is sleeved on the mounting column, the top frame and the mounting column form sliding guide fit along the vertical direction, a linkage rod which vertically extends downwards and sequentially and movably penetrates through the upper arm, a workbench and a lower arm to extend to the lower part of the lower arm is fixedly arranged at the middle position of the top frame along the length direction, a strip-shaped bottom frame which is positioned below the lower arm and is parallel to the length direction of the lower arm is fixedly arranged at the bottom end of the linkage rod, one end of the bottom frame departing from the linkage rod is vertically corresponding to one end of the top frame departing from the mounting column, an upper mounting rod which is parallel to the axial direction of the linkage rod and vertically extends downwards and movably penetrates through the suspension end of the upper arm is arranged at one end of, the upper mounting rod and the lower mounting rod are coaxially arranged, and the saw blade is detachably mounted between the upper mounting rod and the lower mounting rod;

the bottom end of the upper mounting rod and the top end of the lower mounting rod are both provided with a gap for movably clamping a saw blade, a bolt and a nut which are matched are movably arranged in the gap along the width direction of the gap in a penetrating manner, the lower mounting rod and the underframe form sliding guide fit along the vertical direction, the outer circular surface of the lower mounting rod close to the bottom end of the lower mounting rod is provided with a threaded section, the threaded section is positioned below the underframe, the threaded section of the lower mounting rod is sleeved with a tightening knob which is in threaded connection fit with the threaded section, the tightening knob is abutted against the underframe, the outer circular surface of the lower mounting rod is fixedly provided with a limiting ring positioned above the underframe, the outer part of the lower mounting rod is sleeved with a first buffer spring, one end of the first buffer spring is abutted against the limiting ring, the other end of the first buffer spring is abutted;

sliding guide assemblies are arranged between the upper mounting rod and the upper arm and between the lower mounting rod and the lower arm, each sliding guide assembly comprises a guide groove which is formed in the excircle of the upper mounting rod/the lower mounting rod and is parallel to the axial direction of the upper mounting rod/the lower mounting rod, and a guide block which is arranged on the upper arm/the lower arm and is matched with the guide groove, and the guide grooves and the guide blocks form sliding guide fit along the vertical direction;

(II) automatic protection stage of cutting off the saw;

s2: if the saw blade is accidentally broken, the broken saw protection mechanism is switched to a blocking state, the high-pressure air source is cut off from being communicated with an air distribution inlet in the pneumatic driving device, and the pneumatic driving device stops driving the saw blade to reciprocate up and down;

the gas supply protection device comprises a first gas supply conduit, a second gas supply conduit and a third gas supply conduit which are sequentially connected in series, wherein an emergency stop switch for controlling the on-off of the first gas supply conduit and the second gas supply conduit is arranged between the first gas supply conduit and the second gas supply conduit, a saw breaking protection mechanism for controlling the on-off of the second gas supply conduit and the third gas supply conduit is arranged between the second gas supply conduit and the third gas supply conduit, the input end of the first gas supply conduit is connected and communicated with a high-pressure gas source, the output end of the third gas supply conduit is connected and communicated with a gas distribution inlet, the emergency;

specifically, the broken saw protection mechanism comprises an air guide cylinder fixedly arranged at one end of the top frame, which is far away from the mounting column, and the two ends of the air guide cylinder are arranged in an opening way, the air guide cylinder is positioned above the upper mounting rod and is coaxially arranged with the upper mounting rod, the opening way at the upper end of the air guide cylinder is provided with an end cover which is in sealing connection and matching with the air guide cylinder, a floating plug which is in sealing sliding guide and matching with the air guide cylinder is coaxially arranged in the air guide cylinder, the diameter of the floating plug is larger than that of the opening way at the lower end of the air guide cylinder, a variable-volume air guide inner cavity is formed between the floating plug and the end cover, the lower end surface of the floating plug is coaxially and fixedly connected with the upper end of the upper mounting rod, a floating spring is movably arranged in the air guide cylinder, one end of the floating spring is abutted against the floating, the outer part of the air guide cylinder is provided with a first transition conduit and a second transition conduit which are connected and communicated with the air guide inner cavity, the first transition conduit is used for guiding high-pressure gas into the air guide inner cavity, the second transition conduit is used for guiding the high-pressure gas out of the air guide inner cavity, the connection part of the first transition conduit and the air guide inner cavity and the connection part of the second transition conduit and the air guide inner cavity are both positioned above the floating plug in an initial state, the connection part of the first transition conduit and the air guide inner cavity is positioned above the connection part of the second transition conduit and the air guide inner cavity, and the connection part of the first transition conduit and the air guide inner cavity is arranged close to the end cover, if the saw blade is broken, the floating spring pushes the floating plug to slide upwards and seals the;

the upper arm is fixedly provided with a first columnar airtight barrel body which is vertically arranged in the axial direction, the lower arm is fixedly provided with a second columnar airtight barrel body which is vertically arranged in the axial direction, the first airtight barrel body and the second airtight barrel body are coaxially arranged, the linkage rod is coaxially and movably arranged in the first airtight barrel body and the second airtight barrel body in a penetrating mode, the linkage rod and the first airtight barrel body form sealed sliding guide fit along the vertical direction, the linkage rod and the second airtight barrel body form sealed sliding guide fit along the vertical direction, an annular sealed cavity I is formed between the first airtight barrel body and the linkage rod, an annular sealed cavity II is formed between the second airtight barrel body and the linkage rod, the length of the first sealed cavity and the second sealed cavity along the vertical direction is larger than the stroke of the linkage rod in up-and-down reciprocating motion, a first air guide channel and a second air guide channel are formed in the linkage rod in parallel to the axial direction, and, The lower end of the air guide channel II is connected and communicated with the first closed cavity, the upper end of the air guide channel II is connected and communicated with the output end of the second transition guide pipe, the lower end of the air guide channel II is connected and communicated with the second closed cavity, the output end of the second air supply guide pipe is connected and communicated with the first closed cavity, and the third air supply guide pipe is connected and communicated with the second closed cavity;

when the saw breaking protection mechanism works, the emergency stop switch is in an open state, high-pressure gas is output by a high-pressure gas source and sequentially passes through the first gas supply conduit, the emergency stop switch, the second gas supply conduit, the first closed cavity, the first gas guide channel, the first transition conduit, the inner gas guide cavity, the second transition conduit, the second gas guide channel and the second closed cavity to be conveyed to the third gas supply conduit, the third gas supply conduit conveys the high-pressure gas to a gas distribution inlet, the pneumatic driving device normally operates and drives the linkage rod to reciprocate up and down, if saw breaking accidents happen to saw blades, the floating spring of the saw blades pushes the floating plug to slide upwards and seals the connection part of the first transition conduit and the inner gas guide cavity, so that the interior of the saw breaking protection mechanism is disconnected, further gas supply to the gas distribution inlet is cut off;

(III) manual emergency stop protection stage;

s3: if the saw blade needs to be emergently braked, a user manually switches the emergency stop switch to a closed state, the connection between a high-pressure air source and an air distribution inlet in the pneumatic driving device is cut off, and the pneumatic driving device stops driving the saw blade to reciprocate up and down;

the emergency stop switch comprises a rectangular emergency stop valve body fixedly arranged at the edge of the upper end face of the workbench, the emergency stop valve body comprises a columnar emergency stop valve cavity with an opening vertically and upwards arranged, an input channel communicated with the emergency stop valve cavity and an output channel communicated with the emergency stop valve cavity, the input channel and the output channel are symmetrically arranged along the axial direction of the emergency stop valve cavity, the input channel is communicated with the output end of the first air supply guide pipe, the output channel is communicated with the input end of the second air supply guide pipe, a columnar emergency stop valve core which is in rotary sealing connection and matching with the emergency stop valve cavity is arranged in the emergency stop valve cavity, the emergency stop valve core can slide up and down along the emergency stop valve cavity, a through communication hole is radially arranged on the emergency stop valve core and is used for connecting and communicating the input channel and the output channel, a circular mounting groove is coaxially arranged at the lower end of, one end of the emergency stop spring is abutted against the bottom of the emergency stop valve cavity, the other end of the emergency stop spring is abutted against the groove bottom of the mounting groove, the elastic force of the emergency stop spring always points to the bottom of the mounting groove from the emergency stop valve cavity, the communication hole is positioned above the input channel in the initial state, the distance between the communication hole and the input channel is equal to the distance between the emergency stop valve core and the bottom of the emergency stop valve cavity, the communication hole and the input channel are staggered in the initial state, and the emergency stop switch is in;

the upper end face of the scram valve body is horizontally provided with a rectangular inner sinking groove in a horizontal opening mode, the scram valve cavity is communicated with the middle of the inner sinking groove, a rectangular valve end cover matched with the rectangular valve end cover is arranged at an opening of the inner sinking groove, the top end of the scram valve core extends into the inner sinking groove in an initial state, the distance between the top end of the scram valve core and the bottom of the inner sinking groove is equal to the distance between the scram valve core and the bottom of the scram valve cavity, a rectangular limiting frame is arranged in the inner sinking groove, the length direction of the limiting frame is parallel to the length direction of the inner sinking groove, the length direction of the limiting frame and the length direction of the inner sinking groove form sliding guide fit, a limiting spring is arranged between one end of the limiting frame in the length direction and the corresponding groove wall of the inner sinking groove, one end of the limiting spring is abutted against the groove wall of the inner sinking groove, the other end of the limiting frame is abutted, the distance between the inclined plane and the axis of the emergency stop valve core is gradually increased from bottom to top along the vertical direction, the limiting frame is abutted against the emergency stop valve core in the initial state, the upper end of the emergency stop valve core is coaxially and fixedly provided with a control main shaft which extends vertically upwards and movably penetrates through a valve end cover, the diameter of the control main shaft is smaller than that of the emergency stop valve core, and the top end of the control main shaft is coaxially and fixedly provided with a button;

an extending lug is fixedly arranged at one end of the limiting frame, which is far away from the limiting spring, the limiting lug movably penetrates through the emergency stop valve body and extends to the outside, a long-strip emergency stop handle is hinged on the valve end cover, the axial direction of a hinge shaft formed by the hinged position of the valve end cover and the emergency stop handle is parallel to the width direction of the emergency stop valve body, the emergency stop handle and the extending lug are positioned at the same side and above the extending lug, a pressing lug is fixedly arranged at the middle position of the emergency stop handle along the length direction of the emergency stop handle, and the pressing lug extends downwards and is movably abutted against one end, which is far away from the;

during the working process of the emergency stop switch, during the opening process, a user manually presses the button, the button drives the emergency stop valve core to vertically slide downwards to overcome the elastic force of the emergency stop spring, the emergency stop spring is gradually compressed and the elastic potential energy is increased until the emergency stop valve core is abutted against the bottom of the emergency stop valve cavity, at the moment, the emergency stop valve core slides to the lower part of the inner sunken groove and pushes the limit frame to slide and line up to the upper part of the emergency stop valve core, the limit frame limits and restricts the emergency stop valve core, the communication hole is in butt joint with the input channel and the output channel, the emergency stop switch is in an opening state, during the emergency closing process, if the user presses the emergency stop handle downwards, the emergency stop handle rotates downwards around the hinge shaft of the emergency stop handle and presses the extension lug to extrude the extension lug to enable the extension lug to retract towards the inner sunken groove, the limit frame slides and resets to overcome the elastic force of the limit, the limit frame releases the restraint on the emergency stop valve core, at the moment, the elastic potential energy of the emergency stop spring is released and pushes the emergency stop valve core to vertically slide upwards for resetting, the communication hole is staggered with the input channel and the output channel, and the emergency stop switch is switched to a closed state.

Compared with the prior art, the pneumatic saw blade cutting device has the advantages that the structure is ingenious, the principle is simple, the reciprocating motion of the saw blade is driven by the pneumatic power, the saw blade cutting efficiency is improved, meanwhile, when an accident happens under a normal condition, a user can manually and rapidly cut off the air supply to the pneumatic driving device, and under the condition of saw cutting failure, the air supply to the pneumatic driving device can be automatically cut off, so that the saw blade is suddenly stopped, and the safety of saw blade cutting is greatly improved.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic view of the overall structure of the present invention.

Fig. 3 is a schematic view of the overall structure of the present invention.

Fig. 4 is a schematic view of the overall structure of the present invention.

Fig. 5 is a schematic structural view of the base.

FIG. 6 is a schematic structural view of the base and the saw body.

Fig. 7 is a schematic structural view of the saw body.

Fig. 8 is a partial structural view of the saw body.

FIG. 9 is a view of the saw body coupled to a pneumatic drive.

Fig. 10 is a schematic structural view of the pneumatic driving device.

Fig. 11 is a schematic structural view of the reciprocating mechanism.

Fig. 12 is a cross-sectional view of the reciprocator.

Fig. 13 is a view of the valve and the reciprocating mechanism.

Fig. 14 is a schematic structural diagram of a gas distribution valve.

Fig. 15 is a schematic view of the internal structure of the gas distribution valve.

Fig. 16 is a partial structure diagram of the gas distribution valve.

Fig. 17 is a schematic structural view of the first check valve.

Fig. 18 is a schematic view of the internal structure of the first check valve.

Fig. 19 is an internal structural view of the first check valve.

Fig. 20 is a connection diagram of the discharge valve and the first check valve.

Fig. 21 is a partial structural view of the exhaust valve.

Fig. 22 is a partial structure view of the exhaust valve.

Fig. 23 is a partial structure view of the exhaust valve.

Fig. 24 is a view showing the exhaust valve and the reciprocating lever in cooperation.

Fig. 25 is a view showing the reversing mechanism and the exhaust valve.

Fig. 26 is a connection diagram of the reversing mechanism and the gas distribution valve.

Fig. 27 is a connection diagram of the second check valve and the gas distribution valve.

Fig. 28 is a diagram showing the cooperation of the gas supply protection device and the gas distribution valve.

Fig. 29 is an installation diagram of the first sealing cylinder and the second sealing cylinder.

FIG. 30 is a view of the linkage rod in cooperation with the saw guard mechanism.

FIG. 31 is a partial cross-sectional view of the saw guard mechanism.

Fig. 32 is a schematic structural view of the emergency stop switch.

Fig. 33 is a schematic structural view of the scram switch.

Fig. 34 is an internal structural diagram of the scram switch.

Fig. 35 is an internal structural diagram of the scram switch.

Fig. 36 is a partial structural schematic view of the scram switch.

Fig. 37 is a partial structural schematic view of the scram switch.

Detailed Description

a normal sawing stage;

s1: the gas supply protection device 400 transmits gas source high-pressure gas to the input end of the pneumatic driving device 300, the pneumatic driving device 300 receives the high-pressure gas and drives the linkage rod 203 in the saw body 200 to reciprocate up and down along the vertical direction, and the linkage rod 203 drives the saw blade 210 to reciprocate up and down and saw the wood on the workbench 120;

the saw body 200 comprises a mounting column 201 which is fixedly mounted at the top of an upper arm 111 and vertically arranged, a strip-shaped top frame 202 which is positioned right above the upper arm 111 and is parallel to the upper arm 111 is movably sleeved on the mounting column 202, one end of the top frame 202 in the length direction is sleeved on the mounting column 201, the top frame 202 and the mounting column form sliding guide fit in the vertical direction, a linkage rod 203 which extends vertically and downwards and sequentially and movably penetrates through the upper arm 111, a workbench 120 and a lower arm 112 to the lower arm 112 is fixedly arranged at the middle position of the top frame 202 in the length direction, a strip-shaped bottom frame 204 which is positioned below the lower arm 112 and is parallel to the length direction of the lower arm 112 is fixedly arranged at the bottom end of the linkage rod 203, one end of the bottom frame 204, which deviates from the linkage rod 203, corresponds to one end of the top frame 202, which deviates from the mounting column 201 up and down, an upper mounting rod 205 which is parallel to the axial, One end of the chassis 204, which is far away from the linkage rod 203, is provided with a lower mounting rod 206 which is parallel to the axial direction of the linkage rod 203, vertically extends upwards and movably penetrates through the suspension end of the lower arm 112, the upper mounting rod 205 and the lower mounting rod 206 are coaxially arranged, and a saw blade 210 is detachably mounted between the upper mounting rod 205 and the lower mounting rod 206;

the bottom end of the upper mounting rod 205 and the top end of the lower mounting rod 206 are both provided with a gap 207 for movably clamping the saw blade 210, a bolt 207a and a nut 207b which are matched are movably arranged on the gap 207 along the width direction of the gap, the lower mounting rod 206 and the bottom frame 204 form a sliding guide fit along the vertical direction, a threaded section is arranged on the outer circular surface of the lower mounting rod 206 close to the bottom end of the lower mounting rod and is positioned below the bottom frame 204, a tightening knob 208 which is in threaded connection and fit with the threaded section of the lower mounting rod 206 is sleeved on the threaded section of the lower mounting rod 206, the tightening knob 208 is abutted against the bottom frame 204, a limiting ring 209a positioned above the bottom frame 204 is fixedly arranged on the outer circular surface of the lower mounting rod 206, a first buffer spring 209b is sleeved outside the lower mounting rod 26, one end of the first buffer spring 209b is abutted against the limiting ring 209a, the other end of the first buffer spring 209b is abutted against the bottom frame 204, and the elastic force of the first buffer spring 209b always points to the limiting ring 209a from the bottom frame 204;

sliding guide assemblies are arranged between the upper mounting rod 115 and the upper arm 111 and between the lower mounting rod 206 and the lower arm 112, each sliding guide assembly comprises a guide groove which is formed in the excircle of the upper mounting rod 115/the lower mounting rod 206 and is parallel to the axial direction of the guide groove, and a guide block which is arranged on the upper arm 111/the lower arm 112 and is matched with the guide groove, and the guide grooves and the guide blocks form sliding guide fit along the vertical direction;

(II) automatic protection stage of cutting off the saw;

s2: if the saw blade 210 is accidentally broken, the broken saw protection mechanism 420 is switched to a blocking state, the high-pressure air source is cut off from being communicated with the air distribution inlet 333 in the pneumatic driving device 300, and the pneumatic driving device 300 stops driving the saw blade 210 to reciprocate up and down;

the air supply protection device 400 comprises an air supply conduit I401, an air supply conduit II 402 and an air supply conduit III 403 which are sequentially connected in series, wherein an emergency stop switch 410 for controlling the on-off of the air supply conduit I401 and the air supply conduit II 402 is arranged between the air supply conduit I401 and the air supply conduit II 402, an off-saw protection mechanism 420 for controlling the on-off of the air supply conduit II 402 and the air supply conduit III 403 is arranged between the air supply conduit II 402 and the air supply conduit III 403, the input end of the air supply conduit I401 is connected and connected with a high-pressure air source, the output end of the air supply conduit III 403 is connected and connected with an air distribution inlet 333, the;

specifically, the saw breaking protection mechanism 420 comprises an air guide cylinder 421 fixedly mounted on one end of the top frame 202 away from the mounting column 201, two ends of the air guide cylinder 421 are open and arranged, the air guide cylinder 421 is positioned above the upper mounting rod 205 and coaxially arranged with the upper mounting rod 205, an end cover 422 which is in sealing connection and matching with the air guide cylinder 421 is arranged at an upper end opening of the air guide cylinder 421, a floating plug 423 which is in sealing sliding guide and matching with the air guide cylinder 421 is coaxially arranged in the air guide cylinder 421, the diameter of the floating plug 423 is larger than that of a lower end opening of the air guide cylinder 421, an air guide inner cavity 424 with a variable volume is formed between the floating plug 423 and the end cover 422, the lower end surface of the floating plug 423 is coaxially and fixedly connected with the upper end of the upper mounting rod 205, a floating spring 425 is movably arranged in the air guide cylinder 421, one end of the floating spring 425 abuts against the floating plug 423, the other end abuts against a, the floating spring 425 is in a compressed state in an initial state, a first transition conduit 426 and a second transition conduit 427 which are communicated with the air guide cavity 424 are arranged outside the air guide cylinder 421, the first transition conduit 426 is used for guiding high-pressure air into the air guide cavity 424, the second transition conduit 427 is used for leading out high-pressure gas from the gas guide cavity 424, in an initial state, the connection position of the first transition conduit 426 and the gas guide cavity 424 and the connection position of the second transition conduit 427 and the gas guide cavity 424 are both positioned above the floating plug 423, the connection position of the first transition conduit 426 and the gas guide cavity 424 is positioned above the connection position of the second transition conduit 427 and the gas guide cavity 424, and the connection position of the first transition conduit 426 and the gas guide cavity 424 is arranged close to the end cover 422, if the saw blade 210 is broken, the floating spring 425 pushes the floating plug 423 to slide upwards and seals the connection position of the first transition conduit 426 and the gas guide cavity 424;

the upper arm 111 is fixedly provided with a first columnar closed cylinder body 113 which is vertically arranged in the axial direction, the lower arm 112 is fixedly provided with a second columnar closed cylinder body 114 which is vertically arranged in the axial direction, the first sealed closed body 113 and the second sealed cylinder body 114 are coaxially arranged, the linkage rod 203 is coaxially and movably arranged in the first sealed cylinder body 113 and the second sealed cylinder body 114, the linkage rod 203 and the first sealed cylinder body 113 form sealed sliding guide fit along the vertical direction, the linkage rod 203 and the second sealed cylinder body 114 form sealed sliding guide fit along the vertical direction, an annular first sealed cavity is formed between the first sealed cylinder body 113 and the linkage rod 203, an annular second sealed cavity is formed between the second sealed cylinder body 114 and the linkage rod 203, the length of the first sealed cavity and the second sealed cavity along the vertical direction is larger than the stroke of the linkage rod 203 for up-down reciprocating motion, the linkage rod 203 is internally provided with a first air guide channel 203a and a second air guide, the upper end of the first air guide channel 203a is connected and communicated with the input end of the first transition guide pipe 426, the lower end of the first air guide channel 203a is connected and communicated with the sealed cavity, the upper end of the second air guide channel 203b is connected and communicated with the output end of the second transition guide pipe 427, the lower end of the second air guide channel is connected and communicated with the second sealed cavity, the output end of the second air guide pipe 402 is connected and communicated with the sealed cavity, and the third air guide pipe 403 is connected and communicated with the second sealed cavity;

in the working process of the saw cutting protection mechanism 420, the emergency stop switch 410 is in an open state, high-pressure gas is output by a high-pressure gas source and is conveyed to the gas supply conduit III 403 through the gas supply conduit I401, the emergency stop switch 410, the gas supply conduit II 402, the closed cavity I, the gas guide channel I203 a, the transition conduit I426, the gas guide inner cavity 424, the transition conduit II 427, the gas guide channel II 203b and the closed cavity II in sequence, and the gas is delivered to the gas distribution inlet 333 from the gas supply conduit III 403, the pneumatic driving device 300 operates normally and drives the linkage rod 203 to reciprocate up and down, if the saw blade 210 has saw breakage accident, the saw blade floating spring 425 pushes the floating plug 423 to slide upwards and seals the connection part of the transition conduit I426 and the gas guide inner cavity 424, so that the inside of the saw breakage protection mechanism 420 is disconnected, and further air supply to the air distribution inlet 333 is cut off, and the pneumatic drive device 300 stops operating rapidly;

(III) manual emergency stop protection stage;

s3: if the saw blade 210 needs to be emergently braked, a user manually switches the emergency stop switch 410 to a closed state, the high-pressure air source is cut off from being communicated with the air distribution inlet 333 in the pneumatic driving device 300, and the pneumatic driving device 300 stops driving the saw blade 210 to reciprocate up and down;

the scram switch 410 comprises a rectangular scram valve body 411 fixedly installed at the edge of the upper end face of the workbench 120, the scram valve body 411 comprises a columnar scram valve cavity 413 with an opening arranged vertically upwards, an input channel 414a communicated with the scram valve cavity 413 and an output channel 414b communicated with the scram valve cavity 413, the input channel 414a and the output channel 414b are symmetrically arranged along the axial direction of the scram valve cavity 413, the input channel 414a is communicated with the output end of the first air supply conduit 401, the output channel 414b is communicated with the input end of the second air supply conduit 402, a columnar scram valve core 415 in rotary sealing connection and matching with the scram valve cavity 413 is arranged in the scram valve cavity 413, the scram valve core 415 can slide up and down along the scram valve cavity 413, a through communication hole 416 is formed in the scram valve core 415 along the radial direction, and the communication hole 416 is used for connecting and communicating the input channel 414a, the lower end of the emergency stop valve core 415 is coaxially provided with a circular mounting groove 417a, an emergency stop spring 417b is arranged in the mounting groove 417a, one end of the emergency stop spring 417b is abutted against the bottom of the emergency stop valve cavity 413, the other end of the emergency stop spring 417b is abutted against the groove bottom of the mounting groove 417a, the elastic force of the emergency stop spring 417b is always directed to the bottom of the mounting groove 417a from the emergency stop valve cavity 413, the communication hole 416 is positioned above the input channel 414a in an initial state, the distance between the two is equal to the distance between the emergency stop valve core 415 and the bottom of the emergency stop valve cavity 413, the communication hole 416 and the input channel 414a are staggered in the;

the upper end surface of the scram valve body 411 is horizontally provided with a rectangular inner sunken groove 418a, the scram valve cavity 413 is communicated with the middle position of the inner sunken groove 418a, the opening of the inner sunken groove 418a is provided with a rectangular valve end cover 412 matched with the inner sunken groove 418a, the top end of the scram valve core 415 extends into the inner sunken groove 418a in the initial state, the distance between the top end of the scram valve core 4135 and the bottom of the inner sunken groove 418a is equal to the distance between the scram valve core 415 and the bottom of the scram valve cavity 413, a rectangular limit frame 418b is arranged in the inner sunken groove 418a, the length direction of the limit frame 418b is parallel to the length direction of the inner sunken groove 418a, the limit frame 418a and the inner sunken groove 418a form sliding guide fit along the length direction of the limit frame, one end of the limit frame 418a and the groove wall of the inner sunken groove 418a are opposite, the other end of the limit frame 418a is opposite to the limit frame 418a, and the elastic force of the limit spring 418e is always directed to the limit The inner side surface of the limiting frame 418a, which is close to the limiting spring 418e, is provided with an inclined surface 418c, the distance between the inclined surface 418b and the axis of the emergency stop spool 415 is gradually increased from bottom to top along the vertical direction, the limiting frame 418b is abutted against the emergency stop spool 415 in the initial state, the upper end of the emergency stop spool 415 is coaxially and fixedly provided with a control main shaft 416a which extends vertically and upwards and movably penetrates through the valve end cover 412, the diameter of the control main shaft 416a is smaller than that of the emergency stop spool 415, and the top end of the control main shaft 416a is coaxially and fixedly provided with a button 416 b;

an extending bump 418b is fixedly arranged at one end of the limiting frame 418b, which is far away from the limiting spring 418e, the limiting bump 418b movably penetrates through the emergency stop valve body 411 to extend to the outside, an elongated emergency stop handle 419a is hinged to the valve end cover 412, the axial direction of a hinge shaft formed by the hinge joint of the valve end cover and the emergency stop handle is parallel to the width direction of the emergency stop valve body 411, the emergency stop handle 419a and the extending bump 418d are positioned at the same side and above the extending bump 418d, a pressing bump 419b is fixedly arranged at the middle position of the emergency stop handle 419a along the length direction thereof, and the pressing bump 419b extends downwards and is movably abutted against one end of the extending bump 418b, which is far away from the limiting spring 418;

during the operation of the emergency stop switch 410, during the opening process, when a user manually presses the button 416b, the button 416b will drive the emergency stop valve core 415 to vertically slide downwards against the elastic force of the emergency stop spring 417b, the emergency stop spring 417b gradually compresses and the elastic potential energy increases until the emergency stop valve core 415 abuts against the bottom of the emergency stop valve cavity 413, at this time, the emergency stop valve core 415 slides to the lower side of the inner sunken groove 418a and the limit spring 418e will push the limit frame 418b to slide and line up above the emergency stop valve core 415, the limit frame 418b carries out limit constraint on the emergency stop valve core 415, and the communication hole 416 is in butt joint with the input channel 414a and the output channel 414b, the emergency stop switch 410 is in the open state, during the emergency closing process, if the user presses the emergency stop handle 419a downwards, the emergency stop handle 419a will rotate downwards around the hinge shaft thereof and the pressing the bump 419b will press the extension bump 418b, the extension lug 418b retracts towards the inner sunken groove 418a, the limit frame 418b overcomes the elastic force of the limit spring 418e to slide and reset, the limit frame 418b releases the constraint on the scram valve core 415, at the moment, the elastic potential energy of the scram spring 417b is released and pushes the scram valve core 415 to slide and reset vertically and upwards, the communication hole 416 is staggered with the input channel 414a and the output channel 414b, and the scram switch 410 is switched to a closed state.

A multi-stage protection pneumatic reciprocating saw comprises a rectangular floor base 100, wherein a supporting arm 110 extending vertically and upwards is arranged at the top of the base 100, an upper arm 111 arranged horizontally is fixedly arranged at the top end of the supporting arm 110, a lower arm 112 arranged horizontally is fixedly arranged at the bottom end of the supporting arm 110, the lower arm 112 and the upper arm 111 are arranged correspondingly, a horizontal workbench 120 fixedly connected with the base 100 is arranged between the upper arm 111 and the lower arm 112, the workbench 120 is arranged close to the lower arm 112, a saw body 200 is movably arranged between the upper arm 111 and the lower arm 112, the saw body 200 comprises a saw blade 210 which is vertically arranged and movably penetrates through the workbench 120, a pneumatic driving device 300 for driving the saw blade 210 to reciprocate up and down along the vertical direction and an air supply protection device 400 which is communicated between a high-pressure air source and the input end of the pneumatic driving device 300 and is used for controlling the, the gas supply protection device 400 comprises an emergency stop switch 410 and a saw breaking protection mechanism 420.

The saw body 200 comprises a mounting column 201 which is fixedly mounted at the top of an upper arm 111 and vertically arranged, a strip-shaped top frame 202 which is positioned right above the upper arm 111 and is parallel to the upper arm 111 is movably sleeved on the mounting column 202, one end of the top frame 202 in the length direction is sleeved on the mounting column 201, the top frame 202 and the mounting column form sliding guide fit in the vertical direction, a linkage rod 203 which extends vertically and downwards and sequentially and movably penetrates through the upper arm 111, a workbench 120 and a lower arm 112 to the lower arm 112 is fixedly arranged at the middle position of the top frame 202 in the length direction, a strip-shaped bottom frame 204 which is positioned below the lower arm 112 and is parallel to the length direction of the lower arm 112 is fixedly arranged at the bottom end of the linkage rod 203, one end of the bottom frame 204, which deviates from the linkage rod 203, corresponds to one end of the top frame 202, which deviates from the mounting column 201 up and down, an upper mounting rod 205 which is parallel to the axial, One end of the chassis 204, which is far away from the linkage rod 203, is provided with a lower mounting rod 206 which is parallel to the axial direction of the linkage rod 203, extends vertically upwards and movably passes through the suspension end of the lower arm 112, the upper mounting rod 205 and the lower mounting rod 206 are coaxially arranged, and the saw blade 210 is detachably mounted between the upper mounting rod 205 and the lower mounting rod 206.

Specifically, in order to facilitate the installation and replacement of the saw blade 210, a gap 207 for movably clamping the saw blade 210 is formed at the bottom end of the upper installation rod 205 and the top end of the lower installation rod 206, a bolt 207a and a nut 207b matched with each other are movably inserted into the gap 207 along the width direction of the gap, an installation hole at the end of the saw blade 210 is sleeved in the bolt 207a, then the nut 207b is matched with the bolt 207a to complete the installation of the saw blade 210, in order to tighten the saw blade 210, the lower installation rod 206 and the chassis 204 form a sliding guide fit along the vertical direction, a thread section is formed on the outer circular surface of the lower installation rod 206 near the bottom end thereof and is located below the chassis 204, a tightening knob 208 which is in threaded connection and fit with the thread section of the lower installation rod 206 is sleeved on the thread section, the tightening knob 208 is abutted against the chassis 204, and in order to buffer the tightening of the saw blade 210, the outer circular surface of the lower mounting rod 206 is fixedly provided with a limiting ring 209a positioned above the bottom frame 204, the outer portion of the lower mounting rod 26 is sleeved with a first buffer spring 209b, one end of the first buffer spring 209b is abutted against the limiting ring 209a, the other end of the first buffer spring 209b is abutted against the bottom frame 204, and the elastic force of the first buffer spring 209b is always directed to the limiting ring 209a from the bottom frame 204, so that the lower mounting rod 206 vertically slides downwards and tightens the saw blade 210 through rotating the tightening knob 208.

More specifically, in order to avoid the twisting and breaking of the saw blade 210 caused by the rotation of the upper mounting rod 205 and the lower mounting rod 206 around their axes, sliding guide assemblies are respectively arranged between the upper mounting rod 115 and the upper arm 111 and between the lower mounting rod 206 and the lower arm 112, each sliding guide assembly comprises a guide groove which is opened on the outer circle of the upper mounting rod 115/the lower mounting rod 206 and is parallel to the axial direction thereof, and a guide block which is arranged on the upper arm 111/the lower arm 112 and is matched with the guide groove, and the guide grooves and the guide block form a sliding guide fit along the vertical direction.

During the operation of the saw body 200, the air supply protection device 400 delivers air source high-pressure air to the input end of the pneumatic driving device 300, the pneumatic driving device 300 receives the high-pressure air and drives the linkage rod 203 to reciprocate up and down along the vertical direction, the linkage rod 203 drives the top frame 202 and the bottom frame 204 to move synchronously, the top frame 202 drives the upper mounting rod 205 to move synchronously and the bottom frame 204 drives the lower mounting rod 206 to move synchronously, the upper mounting rod 205 and the lower mounting rod 206 drive the saw blade 210 to reciprocate up and down along the vertical direction and saw an object to be cut on the worktable 120, during the sawing process, if the saw blade 210 needs to be braked emergently, a user manually switches the emergency stop switch 410 to a closed state, switches off the high-pressure air source and the pneumatic driving device 300, and the pneumatic driving device 300 stops driving the saw blade 210 to reciprocate up and down; if the saw blade 210 is accidentally broken, the broken saw protection mechanism 420 is switched to a blocking state, the high-pressure air source is switched off to be connected with the pneumatic driving device 300, the pneumatic driving device 300 stops driving the saw blade 210 to reciprocate up and down, multi-stage protection of the saw body 200 in the sawing process is achieved, and safety of the saw blade 210 in the sawing process is improved.

In order to drive the linkage rod 203 to reciprocate up and down, the pneumatic driving device 300 comprises a mounting plate 310 which is fixedly arranged in the base 100 and is vertically arranged, a reciprocating mechanism 320, an air distribution valve 330, an exhaust valve 350 and a reversing mechanism 360 are fixedly arranged on the mounting plate 310, the reciprocating mechanism 320 comprises a cylinder body 321 which is fixedly arranged on the mounting plate 310 and is coaxially arranged with the linkage rod 203, the upper end opening and the lower end opening of the cylinder body 321 are respectively provided with an upper sealing cover 322 which is in sealing connection and matching with the cylinder body, the lower end opening of the cylinder body is provided with a lower sealing cover 323 which is in sealing connection and matching with the cylinder body, a piston 324 is coaxially and movably arranged in the cylinder body 321, the piston 324 and the cylinder body 321 form sealing sliding guide and matching along the axial direction, a reciprocating rod 325 is coaxially and fixedly arranged on the piston 324, and the, The lower sealing cover 323 penetrates through the lower sealing cover, the upper end of the reciprocating rod 325 is coaxially and fixedly connected with the bottom end of the linkage rod 203, an upper air chamber 326 with a variable volume is formed between the piston 324 and the upper sealing cover 322, a lower air chamber 327 with a variable volume is formed between the piston 324 and the lower sealing cover 323, the air distribution valve 330 is used for distributing air in the upper air chamber 326/the lower air chamber 327, the exhaust valve 350 is used for exhausting the compressed air in the upper air chamber 326/the lower air chamber 327 outwards, the reversing mechanism 360 receives part of the air exhausted by the exhaust valve 350 and enables the air distribution valve 330 to distribute air in the upper air chamber 326 and the lower air chamber 327 alternately, and the reciprocating rod 325 is driven to reciprocate up and down to drive the linkage rod 203.

In order to distribute air to the upper air chamber 326/the lower air chamber 327, the air distribution valve 330 includes an air distribution valve body 331 having a cylindrical air distribution valve cavity 322 therein, the air distribution valve body 331 is located at one side of the cylinder body 321 and is fixedly connected to the mounting plate 310, an axial direction of the air distribution valve cavity 332 is parallel to an axial direction of the reciprocating rod 325, an air distribution inlet 333 communicated with an output end of the air supply protection device 400 is opened at a middle position of the air distribution valve cavity 332 along a length direction thereof, the axial direction of the air distribution inlet 333 is arranged along a radial direction of the air distribution valve cavity 332, the air distribution valve cavity 332 is further provided with an upper air distribution outlet 334 and a lower air distribution outlet 335 communicated with an external part, the upper air distribution outlet 334 and the lower air distribution outlet 335 are arranged opposite to the air distribution inlet 333, the upper air distribution outlet 334 and the lower air distribution outlet 335 are arranged vertically symmetrically along the axial direction of the air distribution inlet 333, in order to connect and, or the air distribution inlet 333 is communicated with the lower air distribution outlet 335, and the lower air distribution outlet 335 distributes air to the lower air chamber 327, the air distribution valve cavity 332 is internally provided with an air distribution valve core 336 which forms a sealed sliding guide fit with the air distribution valve core, the air distribution valve core 336 comprises a columnar upper core body 336a and a columnar lower core body 336b which are consistent in shape, size and structure, a connecting rod 336c used for fixing the upper core body 336a and the lower core body 336b is arranged between the upper core body 336a and the upper end of the air distribution valve cavity 332, the maximum distance between the lower core body 336b and the lower end of the air distribution valve cavity 332 is equal to the distance between the lower air distribution outlet 335 and the lower end of the valve cavity 332, the upper core body 336a is used for plugging the upper air distribution outlet 334, and the lower core body 336b is used for plugging the lower air distribution outlet 335.

In the process of distributing air to the upper air chamber 326/the lower air chamber 327, if the air distribution valve core 336 slides to the upper end of the air distribution valve cavity 332, the lower core body 336b seals the lower air distribution outlet 335, at this time, the upper air distribution outlet 334 is connected and communicated with the air distribution inlet 333, the upper air distribution outlet 334 distributes air to the upper air chamber 326, if the air distribution valve core 336 slides to the lower end of the air distribution valve cavity 332, the upper core body 336a seals the upper air distribution outlet 334, at this time, the lower air distribution outlet 335 is connected and communicated with the air distribution inlet 333, the lower air distribution outlet 335 distributes air to the lower air chamber 327, and when the piston 324 moves to the upper end/lower end point of the cylinder 321, the reversing mechanism 360 automatically controls the air distribution valve core 336 to slide upwards/downwards to the end position of the air distribution valve cavity 332, so that the air distribution valve 330 alternatively distributes air to the upper air chamber 326/.

In order to facilitate the connection between the upper air distribution outlet 334 and the upper air chamber 326, and the connection between the lower air distribution outlet 335 and the lower air chamber 327, the air distribution valve 330 further includes two first check valves 340, one first check valve 340 is disposed between the upper air distribution outlet 334 and the upper air chamber 326, the other first check valve 340 is disposed between the lower air distribution outlet 335 and the lower air chamber 327, the first check valve 340 includes a check valve body 341 having a cylindrical inner cavity therein, an input conduit 342 for connecting and connecting the upper air distribution outlet 334 and the lower air distribution outlet 335 is disposed between the input end of the inner cavity of the check valve body 341 and the upper air distribution outlet 334/the lower air distribution outlet 335, an output conduit 343 for connecting and connecting the check valve body 341 and the upper air chamber 326/the lower air chamber 327 is disposed between the input end of the inner cavity of the check valve body 341 and the upper seal cover 322/the lower seal cover 323, the inner cavity of the check valve body 341 is coaxially disposed with an internal annular table 344 near, a sealing cylinder 345 which forms a sealing sliding guiding fit with the one-way valve body 341 is further arranged in the inner cavity of the one-way valve body 341, one end of the sealing cylinder 345, which is close to the output end of the one-way valve body 341, is open and arranged, one end of the sealing cylinder is close to the input end of the one-way valve body 341, is closed and arranged, a sealing spring 346 is movably arranged in the sealing cylinder 345, one end of the sealing spring 346 abuts against the built-in annular table 344, the other end of the sealing spring is abutted against the closed end of the sealing cylinder 345, the elastic force of the sealing spring 346 is always directed to the closed end of the sealing cylinder 345 by the built-in annular table 344, the output end of the input conduit 342 is inserted into the inner cavity of the one-way valve body 341, and the closed end of the sealing cylinder 345 is abutted against the output end of the input, the butt joint holes 347 are arranged in a plurality and are arranged in an array along the circumferential direction of the sealing cylinder 345, an annular butt joint groove 348 is coaxially opened in the inner cavity of the check valve body 341, the groove width of the annular butt joint groove 348 is larger than the diameter of the butt joint hole 347, and the distance between the sealing cylinder 345 and the built-in annular table 344 is equal to the distance between the annular butt joint groove 348 and the butt joint hole 347.

During the operation of the first check valve 340, high-pressure gas enters the input conduit 342 from the upper gas distribution outlet 334/the lower gas distribution outlet 335 and enters the input end of the check valve body 341, the pressure of the high-pressure gas overcomes the elastic force of the sealing spring 346 to push the sealing cylinder 345 to move towards the built-in annular table 344, the sealing spring 346 is gradually compressed and retracts into the sealing cylinder 345 until the sealing cylinder 345 abuts against the built-in annular table 344, at this time, the annular abutting groove 348 is aligned with the abutting hole 347, the first check valve 340 is switched to the conducting state, the high-pressure gas flows into the output conduit 343 through the annular abutting groove 348, the abutting hole 347 and the sealing cylinder 345 in sequence, the delivery conduit 343 outputs the high-pressure gas into the upper gas chamber 326/the lower gas chamber 327, and if the high-pressure gas delivery to the input conduit 342 is cut off by the upper gas distribution outlet 334/the lower gas distribution outlet 335, the elastic potential energy of the sealing spring 346 is gradually released and pushes the sealing cylinder 345 to slide and reset, the abutment hole 347 will be offset from the annular abutment groove 348 and the first non return valve 340 will switch to the blocking position.

In order to discharge the compressed gas in the upper/lower air chambers 326, 327 and discharge a part of the compressed gas to the reversing mechanism 360, for this purpose, the exhaust valve 350 is set to an open state and a closed state and is set to an open state at an initial state, the exhaust valve 350 in the open state is used for discharging the compressed gas in the upper/lower air chambers 326, 327 to the air, the exhaust valve 350 in the closed state is used for discharging the compressed gas in the upper/lower air chambers 326, 327 to the reversing mechanism 360, the exhaust valve 350 includes a bottom plate 351 fixedly installed on the installation plate 310, the bottom plate 351 is located on the side of the cylinder block 321 away from the distribution valve 330, the bottom plate 351 is fixedly provided with exhaust valve bodies 352 symmetrically arranged up and down, the upper exhaust valve body 352 is aligned with the upper sealing cover 322, and the lower exhaust valve body 352 is aligned with the lower sealing cover 323, an exhaust valve core 354 used for controlling the on-off of the inside of the exhaust valve body 352 is arranged between the two exhaust valve bodies 352, the exhaust valve core 354 can control the on-off of the two exhaust valve bodies 352, the exhaust valve body 352 positioned above is used for discharging the compressed gas in the upper air chamber 326 outwards, and the exhaust valve body 352 positioned below is used for discharging the compressed gas in the lower air chamber 327 outwards.

Specifically, a cylindrical inner cavity penetrating up and down is formed in the exhaust valve body 352, the axial direction of the inner cavity is parallel to the axial direction of the reciprocating rod 325, an exhaust inlet 353a communicated with the inner cavity is formed in one end, away from the bottom plate 351, of the exhaust valve body 352, an exhaust outlet 353b communicated with the inner cavity is formed in one end, close to the bottom plate 351, of the exhaust valve body 352, the exhaust inlet 353a and the exhaust outlet 353b are symmetrically arranged along the axial direction of the inner cavity of the exhaust valve body 352, a butt joint guide pipe 359 used for connecting and communicating the exhaust inlet 353a and the inner cavity of the one-way valve body 341 on the same side is arranged between the exhaust inlet 353a and the inner cavity of the one-way valve body 341, the input end of the butt joint guide pipe 359 is connected and communicated with the one-way valve body 341, the communication position is located between the built-in annular table 344 and the annular butt joint, the exhaust valve core 354 is arranged into a rod-shaped structure which is axially parallel to the axial direction of the reciprocating rod 325, the end position of the exhaust valve core 354 is movably inserted into an inner cavity of the exhaust valve core 352, the exhaust valve core 354 and the exhaust valve core 354 form sealed sliding guide fit along the axial direction of the exhaust valve core 354, a communication flat groove 354a which is arranged in a penetrating way along the radial direction of the exhaust valve core is clamped on the outer circular surface of the axial end position of the exhaust valve core 354, the communication flat groove 354a is aligned with and communicated with the exhaust inlet 353a and the exhaust outlet 353b in the initial state, the communication flat groove 354a is staggered with the exhaust inlet 353a and the exhaust outlet 353b by enabling the exhaust valve core 354 to slide downwards, the interior of the exhaust valve body 352 which is positioned below is disconnected, and the communication flat groove 354a is staggered with the exhaust inlet 353a and the exhaust outlet 353b by enabling the exhaust valve.

Specifically, in order to keep the exhaust valve 350 in an open state in an initial state, that is, the interior of the exhaust valve body 352 is conducted, the exhaust valve core 354 is fixedly sleeved with an external boss 354b along the outer circumferential surface of the axial middle position of the exhaust valve core 354, a return spring 354c is movably sleeved on the exhaust valve core 354, two return springs 354c are arranged, one return spring 354c is located between the exhaust valve body 352 and the external boss 354b at the lower part, the other return spring 354c is located between the exhaust valve body 352 and the external boss 354b at the upper part, one end of the return spring 354c is abutted against the exhaust valve body 352, the other end of the return spring is abutted against the external boss 354b, the elastic force of the return spring 354c is always directed to the external boss 354b from the exhaust valve body 352, the elastic forces of the two return springs 354c are balanced with each other in the initial state and the, the exhaust valve body 352 is internally opened by sliding the exhaust valve body 354 upward/downward against the elastic force of the spring 354c to displace the flat abutting groove 354a from the exhaust inlet 353a and the exhaust outlet 353 b.

More specifically, the exhaust valve 350 firstly discharges a part of the compressed gas in the upper/lower air chambers 326, 327, and then switches from an open state to a closed state and discharges the remaining compressed gas into the reversing mechanism 360, so that the exhaust valve 350 needs to be switched to the closed state before the piston 324 slides along the cylinder body 321 to an upper end point/a lower end point, for this purpose, a rectangular fixing plate 355a is fixedly disposed near one end surface of the cylinder body 321 by the external boss 354b, the fixing plate 355a is vertically disposed in the length direction and the fixing plate 355a is fixedly connected to the external boss 354b at the middle position along the length direction, trigger plates 355b bent ninety degrees toward the cylinder body 321 are fixedly disposed at the end positions along the length direction of the fixing plate 355a, and the distance between the trigger plates 355b symmetrically disposed up and down is smaller than the distance between the upper and lower sealing covers 322 323, in order to drive the upward/downward sliding of the exhaust valve core 354 by driving the upward/downward movement of the trigger plate 355b, a linkage frame 357 is fixedly sleeved on the end position of the reciprocating rod 325, a trigger projection 358 is fixedly arranged on the linkage frame 357 and the trigger projection 358 is positioned between two trigger plates 355b which are symmetrically arranged, and the trigger plate 355b is pushed to move upward/downward by the trigger projection 358, so that the exhaust valve 350 is switched to the closed state.

More specifically, the trigger lug 358 reciprocates up and down along with the reciprocating rod 325, the trigger lug 358 collides and contacts with the trigger plate 355b, then the trigger plate 355b is pushed to move downwards/upwards, in order to buffer the collision between the trigger lug 358 and the trigger plate 355b, a buffer guide rod 356 is movably penetrated through the trigger plate 355b, the axial direction of the buffer guide rod 356 is parallel to the axial direction of the reciprocating rod 325, the buffer guide rod 356 and the trigger plate 355b form sliding guide fit along the axial direction parallel to the reciprocating rod 325, one end of the two buffer guide rods 356, which is far away from each other, is coaxially and fixedly provided with a first limiting circular truncated cone 356a, the diameter of the first limiting circular truncated cone 356a is larger than that of the buffer guide rod 356, one end of the two buffer guide rods 356, which is close to each other, is coaxially and fixedly provided with a second limiting circular truncated cone 356b, the diameter of the second limiting circular truncated cone 356 is larger than that of the buffer guide rod, one end of the second buffer spring 356c abuts against the second limit circular truncated cone 356b, the other end of the second buffer spring 356c abuts against the trigger plate 355b, the elastic force of the second buffer spring 356c always points to the second limit circular truncated cone 356b from the trigger plate 355b, the trigger bump 358 is located between the second limit circular truncated cone 356b, in the buffering process, the trigger bump 358 collides with the second limit circular truncated cone 356b and compresses the second buffer spring 356c, the second buffer spring 356c buffers the collision of the second limit circular truncated cone 356b from the trigger bump 358 until the second buffer spring 356c is completely compressed, and then the trigger bump 359 drives the trigger plate 355b to move upwards/downwards.

During operation of the exhaust valve 350, when the gas distribution valve 330 distributes gas to the upper gas chamber 326, the piston 324 slides down along the cylinder 321 and compresses gas inside the lower gas chamber 327, the compressed gas in the lower gas chamber 327 enters the exhaust inlet 353a through the first docking conduit 359 and is exhausted to the air through the first communication flat groove 354a and the exhaust outlet 353b, during this process, the piston 324 drives the reciprocating rod 325 to synchronously move downward, the reciprocating rod 325 drives the trigger lug 358 to synchronously move downward, the trigger lug 358 drives the trigger block 355b located below to move downward, the trigger plate 355 drives the valve core 354 to move downward and make the first communication flat groove 354a staggered with the exhaust inlet 353a and the exhaust outlet 354b, the exhaust valve 350 is switched to the closed state, and thereafter, the piston 324 slides further downward and the compressed gas in the lower gas chamber 327 is exhausted to the reversing mechanism 360 through the first docking conduit 359, until the piston 324 moves to the lower end of the cylinder body 321, the reversing mechanism 360 is automatically triggered and switches the gas distribution valve 330 to distribute gas to the lower gas chamber 327, the piston 324 slides upwards along the cylinder body 321 and compresses the gas inside the upper gas chamber 327, and the process of discharging the compressed gas inside the upper gas chamber 327 outwards is the same as that of discharging the compressed gas inside the lower gas chamber 326 outwards, and the process is not repeated.

If the gas distribution valve 330 needs to be switched to distribute gas to the upper gas chamber 326/the lower gas chamber 327, the gas distribution valve core 336 needs to be pushed to slide downwards to the lower end of the gas distribution valve cavity 332 or upwards to the upper end of the gas distribution valve cavity 332, for this reason, the reversing mechanism 360 is used for receiving gas at the output end of the gas exhaust valve 350 and pushing the gas distribution valve core 336 to slide upwards/downwards along the inner cavity of the gas distribution valve body 331, two reversing mechanisms 360 are arranged, one reversing mechanism 360 is communicated between a lower butt joint conduit 359 and the upper end of the gas distribution valve cavity 332, the other reversing mechanism 360 is communicated between an upper butt joint conduit 359 and the lower end of the gas distribution valve cavity 332, the reversing mechanism 360 comprises a second one-way valve 361, a butt joint conduit II 362, an outer discharge conduit 363, and a plurality of exhaust pores communicated with the interior of the outer discharge conduit 363, the input end 364 of the butt, the output section of the second butt joint conduit 362 is connected and communicated with the input end of the second check valve 361, the output end of the second check valve 361 is connected and communicated with the lower end/upper end of the exhaust valve cavity 322, the second check valve 361 is consistent with the first check valve 340 in structure, size, shape and internal connection relation, the input end of the outer discharge pipe 363 is connected and communicated with the inner cavity of the check valve body 341 in the second check valve 361, and the communicated position is located between the built-in annular table 344 and the annular butt joint groove 348 in the second check valve 361.

In the working process of the reversing mechanism 360, when the gas distribution valve core 336 slides to the upper end of the gas distribution valve cavity 332, the gas distribution valve 330 distributes gas to the upper gas chamber 326 and the gas in the lower gas chamber 327 is compressed, the compressed gas in the lower gas chamber 327 is firstly discharged to a part of the air by the gas discharge valve 350, then the gas discharge valve 350 is switched to the closed state, the gas discharge valve 350 discharges the residual compressed gas to the input end of the second one-way valve 361 through the butt joint conduit two 362, the second one-way valve 361 is automatically switched to the conducting state under the action of the gas pressure and discharges the compressed gas to the upper end of the gas distribution valve cavity 332, the gas distribution valve core 336 is pushed to vertically slide downwards along the gas distribution valve cavity 332 under the action of the gas pressure until the gas distribution valve core 336 slides to the lower end of the gas distribution valve cavity 332, when the gas distribution valve core 336 slides to the lower end of the gas distribution valve cavity 332, the gas distribution valve 330 distributes gas to the lower gas chamber 327 and the gas in the upper gas chamber 326 is, the compressed gas in the lower gas chamber 327 is discharged to a part of the air from the exhaust valve 350, then the exhaust valve 350 is switched to the closed state, the exhaust valve 350 discharges the residual compressed gas to the input end of the second one-way valve 361 through the second butt joint conduit 362, the second one-way valve 361 is automatically switched to the conducting state under the action of the gas pressure, the compressed gas is discharged to the lower end of the gas distribution valve cavity 332, the gas distribution valve core 336 is pushed to vertically slide upwards along the gas distribution valve cavity 332 under the action of the gas pressure until the gas distribution valve core 336 slides to the upper end of the gas distribution valve cavity 332, and the operation is repeated in such a way, so that the gas distribution valve 330 alternately distributes gas to the upper gas chamber 326 and the lower gas chamber 327.

The air supply protection device 400 comprises a first air supply conduit 401, a second air supply conduit 402 and a third air supply conduit 403 which are sequentially connected in series, an emergency stop switch 410 for controlling the on-off of the first air supply conduit 401 and the second air supply conduit 402 is arranged between the second air supply conduit 402 and the third air supply conduit 403, a saw breaking protection mechanism 420 for controlling the on-off of the first air supply conduit 401 and the second air supply conduit 403 is arranged between the first air supply conduit 401 and the third air supply conduit 403, the input end of the first air supply conduit 401 is connected and connected with a high-pressure air source, the output end of the third air supply conduit 403 is connected and connected with an air distribution inlet 333, the emergency stop.

Specifically, the saw breaking protection mechanism 420 comprises an air guide cylinder 421 fixedly mounted on one end of the top frame 202, which is far away from the mounting column 201, and openings at two ends of the air guide cylinder 421 are arranged, the air guide cylinder 421 is positioned above the upper mounting rod 205 and is coaxially arranged with the upper mounting rod, an end cover 422 which is hermetically connected and matched with the air guide cylinder 421 is arranged at an opening at the upper end of the air guide cylinder 421, a floating plug 423 which is hermetically sliding and guiding and matched with the air guide cylinder 421 is coaxially arranged in the air guide cylinder 421, in order to prevent the floating plug 423 from sliding downwards and falling off from the air guide cylinder 421, the diameter of the floating plug 423 is larger than that of an opening at the lower end of the air guide cylinder 421, a variable-volume air guide inner cavity 424 is formed between the floating plug 423 and the end cover 422, the lower end surface of the floating plug 423 is coaxially and fixedly connected with the upper, The other end of the air cylinder is abutted against the lower end opening of the air guide cylinder 421, the elastic force of the floating spring 425 always points to the floating plug 423 from the lower end opening of the air cylinder 421, the floating spring 425 is in a compressed state in an initial state, a first transition conduit 426 and a second transition conduit 427 which are communicated with the air guide cavity 424 are arranged outside the air cylinder 421, the first transition conduit 426 is used for guiding high-pressure gas into the air guide cavity 424, the second transition conduit 427 is used for guiding the high-pressure gas out from the air guide cavity 424, the communication position of the first transition conduit 426 and the air guide cavity 424 and the communication position of the second transition conduit 427 and the air guide cavity 424 are both positioned above the floating plug 423 in the initial state, the communication position of the first transition conduit 426 and the air guide cavity 424 is positioned above the communication position of the second transition conduit 427 and the air guide cavity 424, and the communication position of the first transition conduit 426 and, if the saw blade 210 is broken, the floating spring 425 pushes the floating plug 423 to slide upwards and seal the connection between the first transition conduit 426 and the air guide cavity 424, so that the inside of the saw breaking protection mechanism 420 is disconnected, the air supply protection device 400 stops supplying air to the air distribution inlet 333, and the pneumatic driving device 300 stops operating.

More specifically, in order to connect and connect the first transition duct 426 with the output end of the second air supply duct 402 and connect the second transition duct 427 with the input end of the third air supply duct 403, the first upper arm 111 is fixedly provided with a first cylindrical sealing cylinder 113 arranged vertically in the axial direction, the second lower arm 112 is fixedly provided with a second cylindrical sealing cylinder 114 arranged vertically in the axial direction, the first sealing closing body 113 and the second sealing cylinder 114 are arranged coaxially, the linkage rod 203 is coaxially and movably inserted into the first sealing cylinder 113 and the second sealing cylinder 114, the linkage rod 203 and the first sealing cylinder 113 form a sealed sliding guide fit in the vertical direction, the linkage rod 203 and the second sealing cylinder 114 form a sealed sliding guide fit in the vertical direction, an annular first cavity is formed between the first sealing cylinder 113 and the linkage rod 203, an annular second sealing cavity is formed between the second sealing cylinder 114 and the linkage rod 203, and the length of the first sealing cavity and the second sealing cavity in the vertical direction is greater than the stroke of the linkage rod 203 in the up-, the air guide channel I203 a and the air guide channel II 203b are arranged in the linkage rod 203 in parallel to the axial direction of the linkage rod, the upper end of the air guide channel I203 a is connected and communicated with the input end of the transition guide pipe I426, the lower end of the air guide channel I203 b is connected and communicated with the closed cavity, the upper end of the air guide channel II 203b is connected and communicated with the output end of the transition guide pipe II 427, the lower end of the air guide channel II 203b is connected and communicated with the closed cavity II, the output end of the air supply guide pipe II 402 is connected and communicated with the closed cavity, and the air supply guide pipe III 403 is connected and communicated with the closed cavity II, during air supply, high-pressure air is sequentially conveyed to the air guide inner cavity 424 through the air supply guide pipe II 402, the closed cavity I, the air guide channel I203 a, the transition guide pipe I426, the air guide inner cavity 424, the transition guide pipe II 427, the air guide channel, the saw breakage preventing mechanism 420 can connect and connect the second air supply duct 402 and the third air supply duct 403 at all times.

The saw breaking protection mechanism 420 is characterized in that the emergency stop switch 410 is in an open state, high-pressure gas is output by a high-pressure gas source and is conveyed to the gas supply conduit III 403 through the gas supply conduit I401, the emergency stop switch 410, the gas supply conduit II 402, the sealed cavity I, the gas guide channel I203 a, the transition conduit I426, the gas guide inner cavity 424, the transition conduit II 427, the gas guide channel II 203b and the sealed cavity II in sequence, and the gas is delivered to the gas distribution inlet 333 from the gas supply conduit III 403, the pneumatic driving device 300 operates normally and drives the linkage rod 203 to reciprocate up and down, if the saw blade 210 has saw breakage accident, the saw blade floating spring 425 pushes the floating plug 423 to slide upwards and seals the connection part of the transition conduit I426 and the gas guide inner cavity 424, so that the inside of the saw breakage protection mechanism 420 is disconnected, and further air supply to the air distribution inlet 333 is cut off and the pneumatic drive device 300 is rapidly stopped.

In order to rapidly and manually cut off the air supply to the air distribution inlet 333, the emergency stop switch 410 includes a rectangular emergency stop valve body 411 fixedly installed at the edge of the upper end face of the workbench 120, the emergency stop valve body 411 includes a cylindrical emergency stop valve cavity 413 with an opening arranged vertically upwards, an input channel 414a connected and communicated with the emergency stop valve cavity 413, and an output channel 414b connected and communicated with the emergency stop valve cavity 413, the input channel 414a and the output channel 414b are symmetrically arranged along the axial direction of the emergency stop valve cavity 413, the input channel 414a is connected and communicated with the output end of the first air supply conduit 401, the output channel 414b is connected and communicated with the input end of the second air supply conduit 402, in order to control the connection and disconnection of the input channel 414a and the output channel 414b, a cylindrical emergency stop valve core 415 in rotary sealing connection and matching with the emergency stop valve cavity 413 is arranged in the emergency stop valve cavity 413, and the emergency, the scram valve core 415 is provided with a through communication hole 416 along the radial direction, the communication hole 416 is used for connecting and communicating an input channel 414a and an output channel 414b, the lower end of the scram valve core 415 is coaxially provided with a circular installation groove 417a, an scram spring 417b is arranged in the installation groove 417a, one end of the scram spring 417b is abutted against the bottom of the scram valve cavity 413, the other end of the scram spring 417b is abutted against the groove bottom of the installation groove 417a, the elastic force of the scram spring 417b is always directed to the bottom of the installation groove 417a from the scram valve cavity 413, the communication hole 416 is positioned above the input channel 414a in an initial state, the distance between the communication hole 416 and the scram valve cavity 413 is equal to the distance between the scram valve core 415 and the bottom of the scram valve cavity 413, the communication hole 416 and the input channel 414a are staggered in the initial state, the scram switch 410, thereby bringing the communication hole 416 into butt-contact with the input passage 414a and the output passage 414b, and further switching the scram switch 410 to the on state.

Specifically, in order to overcome the elastic force of the emergency stop spring 417b to restrain the emergency stop valve spool 413 in contact with the bottom of the emergency stop valve chamber 413, a rectangular inner sunken groove 418a is horizontally arranged on the upper end surface of the emergency stop valve body 411, the emergency stop valve chamber 413 is communicated with the middle position of the inner sunken groove 418a, a rectangular valve end cover 412 matched with the opening of the inner sunken groove 418a is arranged at the opening of the inner sunken groove 418a, the top end of the emergency stop valve spool 415 in an initial state extends into the inner sunken groove 418a, the distance between the top end of the emergency stop valve spool 4135 and the bottom of the inner sunken groove 418a is equal to the distance between the emergency stop valve spool 415 and the bottom of the emergency stop valve chamber 413, in order to limit the emergency stop valve spool 415, a rectangular limit frame 418b is arranged in the inner sunken groove 418a, the length direction of the limit frame 418b is parallel to the length direction of the inner sunken groove 418a, the limit frame 418a is in sliding guide fit along the length direction of the inner sunken groove 418a, and a limit spring 418e is One end of a limiting spring 418e is abutted against the groove wall of the inner sunken groove 418a, the other end of the limiting spring 418e is abutted against the limiting frame 418a, the elastic force of the limiting spring 418e always points to the limiting frame 418a from the groove wall of the inner sunken groove 418a, the inner side surface of the limiting frame 418a close to the limiting spring 418e is provided with an inclined surface 418c, the distance between the inclined surface 418b and the axis of the emergency stop valve core 415 is gradually increased from bottom to top along the vertical direction, the limiting frame 418b is abutted against the emergency stop valve core 415 in the initial state, in order to press the emergency stop valve core 415, the upper end of the emergency stop valve core 415 is coaxially and fixedly provided with a control main shaft 416a which extends vertically and upwards and movably penetrates through the valve end cover 412, the diameter of the control main shaft 416a is smaller than that of the emergency stop valve core 415, the top end of the control main shaft 416a is coaxially and fixedly provided with a button 416b, the limit spring 418e will push the limit frame 418b to slide and line up above the scram spool 415, so as to restrain the scram spool 415 and maintain the scram switch 410 in an open state.

More specifically, in order to enable the emergency stop switch 410 to be rapidly switched to the closed state, that is, the limit frame 418b is required to rapidly release the constraint of the emergency stop valve core 415, for this reason, an end of the limit frame 418b, which is away from the limit spring 418e, is fixedly provided with an extension bump 418b, the limit bump 418b movably penetrates through the emergency stop valve body 411 and extends to the outside, the valve end cover 412 is hinged with an elongated emergency stop handle 419a, an axial direction of a hinge shaft formed by the hinge joint of the valve end cover and the emergency stop handle is parallel to the width direction of the emergency stop valve body 411, the emergency stop handle 419a and the extension bump 418d are located on the same side and above the extension bump 418d, the middle position of the emergency stop handle 419a along the length direction thereof is fixedly provided with a pressing bump 419b, and the pressing bump 419b is arranged to extend downward and movably abut against an end of the extension.

Claims

1. A sudden stop protection method of a pneumatic drive reciprocating saw comprises the following steps:

a normal sawing stage;

(II) automatic protection stage of cutting off the saw;

s2: if the saw blade is accidentally broken, the broken saw protection mechanism is switched to a blocking state, the high-pressure air source is cut off from being communicated with an air distribution inlet in the pneumatic driving device, and the pneumatic driving device stops driving the saw blade to reciprocate up and down; an air supply protection device for controlling the on-off of the high-pressure air is arranged between the high-pressure air source and the input end of the pneumatic driving device and comprises an emergency stop switch and a saw breaking protection mechanism;

(III) manual emergency stop protection stage;

2. The emergency stop protection method of the pneumatically driven reciprocating saw as claimed in claim 1, wherein the upper arm is fixedly provided with a first axially vertically arranged cylindrical sealing cylinder, the lower arm is fixedly provided with a second axially vertically arranged cylindrical sealing cylinder, the first sealing cylinder and the second sealing cylinder are coaxially arranged, the linkage rod is coaxially and movably inserted into the first sealing cylinder and the second sealing cylinder, the linkage rod and the first sealing cylinder are in sealing sliding guiding fit along the vertical direction, the linkage rod and the second sealing cylinder are in sealing sliding guiding fit along the vertical direction, an annular first sealing cavity is formed between the first sealing cylinder and the linkage rod, an annular second sealing cavity is formed between the second sealing cylinder and the linkage rod, the length of the first sealing cavity and the second sealing cavity along the vertical direction is greater than the stroke of the linkage rod in vertical reciprocating motion, the linkage rod is internally provided with a first air guide channel and a second air guide channel in parallel with the axial direction thereof, the upper end of the air guide channel I is connected and communicated with the input end of the transition guide pipe I, the lower end of the air guide channel I is connected and communicated with the sealed cavity, the upper end of the air guide channel II is connected and communicated with the output end of the transition guide pipe II, the lower end of the air guide channel II is connected and communicated with the sealed cavity II, the output end of the air supply guide pipe II is connected and communicated with the sealed cavity I, the air supply guide pipe III is connected and communicated with the sealed cavity II, and high-pressure air is conveyed to the air supply guide pipe III through the air supply guide pipe II, the sealed cavity I, the air guide channel I, the transition guide pipe I, the air guide inner cavity, the transition guide pipe II, the.

3. The emergency stop protection method of the pneumatically driven reciprocating saw as claimed in claim 2, wherein the upper end face of the emergency stop valve body is horizontally provided with a rectangular inner sinking groove, the emergency stop valve cavity is communicated with the middle position of the inner sinking groove, the opening of the inner sinking groove is provided with a rectangular valve end cover matched with the rectangular inner sinking groove, the top end of the emergency stop valve core extends into the inner sinking groove in the initial state, the distance between the top end of the emergency stop valve core and the bottom of the inner sinking groove is equal to the distance between the emergency stop valve core and the bottom of the emergency stop valve cavity, the inner sinking groove is internally provided with a rectangular limit frame, the length direction of the limit frame is parallel to the length direction of the inner sinking groove, the two limit frames form a sliding guide fit along the length direction, a limit spring is arranged between one end of the limit frame along the length direction and the corresponding groove wall of the inner sinking groove, one end of the limit spring is abutted against the groove wall of the inner sinking groove, the other end of the limit frame is, the inner side face, close to the limiting spring, of the limiting frame is arranged to be an inclined face, the distance between the inclined face and the axis of the emergency stop valve core is gradually increased from bottom to top along the vertical direction, the limiting frame is abutted to the emergency stop valve core in the initial state, a control main shaft which extends vertically upwards and movably penetrates through a valve end cover is coaxially and fixedly arranged at the upper end of the emergency stop valve core, the diameter of the control main shaft is smaller than that of the emergency stop valve core, and a button is coaxially and fixedly arranged at the top end of the control main shaft.

4. The emergency stop protection method of the pneumatic reciprocating saw as claimed in claim 3, wherein an extending protrusion is fixedly disposed at an end of the position-limiting frame away from the position-limiting spring, the position-limiting protrusion movably extends to the outside through the emergency stop valve body, the valve end cover is hinged with an elongated emergency stop handle, an axial direction of a hinge shaft formed at a hinge joint of the valve end cover and the emergency stop handle is parallel to a width direction of the emergency stop valve body, the emergency stop handle and the extending protrusion are located at the same side and above the extending protrusion, the emergency stop handle is fixedly disposed with a pressing protrusion along a middle position of a length direction thereof, and the pressing protrusion extends downward and movably abuts against an end of the extending protrusion away from the position-limiting spring.

5. The emergency stop protection method of a pneumatically driven reciprocating saw as claimed in claim 4, wherein the pneumatically driven device comprises a vertically disposed mounting plate fixedly mounted in the base, a reciprocating mechanism, an air distribution valve, an exhaust valve and a reversing mechanism are fixedly mounted on the mounting plate, the reciprocating mechanism comprises a cylinder body fixedly mounted on the mounting plate and coaxially disposed with the linkage rod, the upper and lower openings of the cylinder body are disposed, the upper opening is provided with an upper sealing cover in sealing connection with the cylinder body, the lower opening is provided with a lower sealing cover in sealing connection with the cylinder body, the cylinder body is coaxially and movably provided with a piston, the piston and the cylinder body are axially in sealing sliding guide engagement, the piston is coaxially and fixedly provided with a reciprocating rod, the upper and lower ends of the reciprocating rod respectively penetrate through the upper sealing cover and the lower sealing cover, and the upper end of the reciprocating rod is coaxially and fixedly connected with the bottom end of the linkage rod, an upper air chamber with variable volume is formed between the piston and the upper sealing cover, a lower air chamber with variable volume is formed between the piston and the lower sealing cover, the air distribution valve is used for distributing air to the upper air chamber/the lower air chamber, the exhaust valve is used for discharging the compressed air in the upper air chamber/the lower air chamber outwards, and the reversing mechanism receives part of the air discharged by the exhaust valve and prompts the air distribution valve to distribute air to the upper air chamber and the lower air chamber alternately.

6. The emergency stop protection method of the pneumatically driven reciprocating saw of claim 5, wherein the air distribution valve comprises an air distribution valve body having a cylindrical air distribution valve cavity therein, the air distribution valve body is located at one side of the cylinder body and is fixedly connected with the mounting plate, the axial direction of the air distribution valve cavity is parallel to the axial direction of the reciprocating rod, the middle position of the air distribution valve cavity along the length direction thereof is provided with an air distribution inlet communicated with the output end of the air supply protection device, the axial direction of the air distribution inlet is arranged along the radial direction of the air distribution valve cavity, the air distribution valve cavity is further provided with an upper air distribution outlet and a lower air distribution outlet communicated with the outside, the upper air distribution outlet and the lower air distribution outlet are arranged opposite to the air distribution inlet and are arranged vertically and symmetrically along the axial direction of the air distribution inlet, the air distribution valve cavity is internally provided with an air distribution valve core forming a sealed, The upper core body and the lower core body are in a columnar shape and have the same structure, a connecting rod used for fixing the upper core body and the lower core body is arranged between the upper core body and the lower core body, the maximum distance between the upper core body and the upper end of the gas distribution valve cavity is equal to the distance between the upper gas distribution outlet and the upper end of the gas distribution valve cavity, the maximum distance between the lower core body and the lower end of the gas distribution valve cavity is equal to the distance between the lower gas distribution outlet and the lower end of the gas distribution valve cavity, the upper core body is used for plugging the upper gas distribution outlet, and the lower core.

7. The emergency stop protection method of the pneumatically driven reciprocating saw as claimed in claim 6, wherein the air distribution valve further comprises two first check valves, one of the two first check valves is disposed between the upper air distribution outlet and the upper air chamber, the other one of the two first check valves is disposed between the lower air distribution outlet and the lower air chamber, the first check valve comprises a check valve body having a cylindrical inner cavity therein, an input conduit is disposed between the input end of the inner cavity of the check valve body and the upper air distribution outlet/the lower air distribution outlet for connecting and connecting the two, an output conduit is disposed between the input end of the inner cavity of the check valve body and the upper sealing cover/the lower sealing cover for connecting and connecting the check valve body and the upper air chamber/the lower air chamber, the inner cavity of the check valve body is coaxially disposed with a built-in annular table disposed near the output end thereof, a sealing cylinder forming a sealed sliding guide fit with the inner cavity of the check valve body, the sealing cylinder is arranged close to the opening at one end of the output end of the one-way valve body and is arranged close to one end of the input end of the one-way valve body, a sealing spring is movably arranged in the sealing cylinder, one end of the sealing spring is abutted against the built-in annular table, the other end of the sealing spring is abutted against the closed end of the sealing cylinder, the elastic force of the sealing spring always points to the closed end of the sealing cylinder from the built-in annular table, the output end of the input guide pipe is inserted in the inner cavity of the one-way valve body, and the, the outer circular surface of the sealing cylinder is provided with a butt joint hole which is arranged close to the closed end of the sealing cylinder, the butt joint holes are arranged in a plurality of circumferential direction arrays along the position of the sealing cylinder, an annular butt joint groove is coaxially formed in the inner cavity of the one-way valve body, the groove width of the annular butt joint groove is larger than the diameter of the butt joint hole, and the distance between the sealing cylinder and the built-in annular table is equal to the distance between the annular butt joint groove and the butt joint hole.

8. The emergency stop protection method for a pneumatically driven reciprocating saw as claimed in claim 7, wherein the exhaust valve is set to an open state and a closed state and the initial state is the open state, the open state exhaust valve is used to exhaust the compressed air in the upper/lower air chambers to the air, the closed state exhaust valve is used to exhaust the compressed air in the upper/lower air chambers to the reversing mechanism, the exhaust valve comprises a bottom plate fixedly installed on the installation plate and located on the side of the cylinder block away from the air distribution valve, the bottom plate is fixedly provided with vertically symmetrically arranged exhaust valve bodies, the upper exhaust valve body is aligned with the upper sealing cover, the lower exhaust valve body is aligned with the lower sealing cover, an exhaust valve core for controlling the on-off of the inside of the exhaust valve body is arranged between the two exhaust valve bodies, and the exhaust valve core can control the on-off of the two exhaust valve bodies, the upper exhaust valve body is used for discharging compressed gas in the upper air chamber outwards, and the lower exhaust valve body is used for discharging compressed gas in the lower air chamber outwards;

the exhaust valve body is provided with a cylindrical inner cavity which penetrates through the exhaust valve body up and down, the axial direction of the inner cavity is parallel to the axial direction of the reciprocating rod, one end of the exhaust valve body, which is far away from the bottom plate, is provided with an exhaust inlet which is communicated with the inner cavity of the exhaust valve body, one end of the exhaust valve body, which is close to the bottom plate, is provided with an exhaust outlet which is communicated with the inner cavity of the exhaust valve body, the exhaust inlet and the exhaust outlet are symmetrically arranged along the axial direction of the inner cavity of the exhaust valve body, a first butt joint guide pipe for connecting and communicating the exhaust inlet and the inner cavity of the one-way valve body on the same side is arranged between the exhaust inlet and the inner cavity of the one-way valve body, the input end of the first butt joint guide pipe is communicated with the one-way valve body, the communication position is positioned between the built-in annular platform and the annular, the outer circular surface of the exhaust valve core along the axial end position is clamped with a communicating flat groove which is arranged along the radial direction in a penetrating way, and the communicating flat groove is aligned with and communicated with the exhaust inlet and the exhaust outlet in the initial state;

the exhaust valve core is fixedly sleeved with an external boss along the outer circular surface of the middle position of the exhaust valve core in the axial direction, a first reset spring is movably sleeved on the exhaust valve core, the first reset spring is provided with two reset springs, one reset spring is positioned between the exhaust valve body and the external boss at the lower part, the other reset spring is positioned between the exhaust valve body and the external boss at the upper part, one end of the first reset spring is abutted against the exhaust valve body, the other end of the first reset spring is abutted against the external boss, the elastic force of the first reset spring is always directed to the external boss by the exhaust valve body, the elastic forces of the two first reset springs are mutually balanced in the initial state, and;

the fixed rectangle fixed plate that is provided with of external boss is close to cylinder body one terminal surface, the vertical arrangement of length direction of fixed plate and fixed plate along its length direction's middle part position and external boss fixed connection, the fixed plate is all fixed being provided with along its length direction's tip position and is the trigger plate that ninety degrees bending arrangement was arranged towards the cylinder body, and the distance between the trigger plate of upper and lower symmetrical arrangement is less than the distance between sealed lid and the sealed lid down, fixed cover is equipped with the linkage frame on the tip position of reciprocating lever, and the fixed lug that is provided with of linkage frame triggers and triggers the lug and be located between two trigger plates of symmetrical arrangement.

9. The emergency stop protection method of the pneumatically driven reciprocating saw of claim 8, wherein the trigger plate is movably inserted with a buffer guide rod, the axial direction of the buffer guide rod is parallel to the axial direction of the reciprocating rod, the buffer guide rod and the trigger plate form a sliding guide fit along the axial direction parallel to the reciprocating rod, one end of each of the two buffer guide rods, which is far away from each other, is coaxially and fixedly provided with a first limiting round platform, the diameter of the first limiting round platform is larger than that of the buffer guide rod, one end of each of the two buffer guide rods, which is close to each other, is coaxially and fixedly provided with a second limiting round platform, the diameter of the second limiting round platform is larger than that of the buffer guide rod, a second buffer spring is movably sleeved outside the buffer guide, the other end of the buffer spring II is abutted against the trigger plate, the elastic force of the buffer spring II is always directed to the second limiting round table from the trigger plate, and the trigger bump is positioned between the two second limiting round tables.

10. The emergency stop protection method of a pneumatically driven reciprocating saw as claimed in claim 9, wherein the reversing mechanism is configured to receive the gas at the output end of the exhaust valve and push the gas distribution valve core to slide upward/downward along the inner cavity of the gas distribution valve body, the reversing mechanism has two reversing mechanisms, one of the reversing mechanisms is connected between the lower first docking conduit and the upper end of the gas distribution valve cavity, the other reversing mechanism is connected between the upper first docking conduit and the lower end of the gas distribution valve cavity, the reversing mechanism includes a second one-way valve, a second docking conduit, and an outer discharge pipe, and the outer circumferential surface of the outer discharge pipe is formed with a plurality of exhaust pores communicated with the interior of the outer discharge pipe, the input end of the second docking conduit is connected and communicated with the docking conduit, the output section of the second docking conduit is connected and communicated with the input end of the second one-way valve, and the, the second one-way valve is consistent with the first one-way valve in structure, size, shape and internal connection relation, the input end of the external discharge pipe is connected and communicated with the inner cavity of the one-way valve body in the second one-way valve, and the communicated position is positioned between the built-in annular table and the annular butt-joint groove in the second one-way valve.