JP2533104Y2 - Cylinder cushion device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushion device for reducing the speed of a piston at the end of a stroke in a hydraulic cylinder used for operating various machines in order to reduce an impact.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional cylinder cushion device. Slide block inside cylinder tube 31
32 is slidably fitted, and an end block 33 is fixed to an end of the cylinder tube 31. A throttle hole 34 is opened at both ends of the slide block (piston) 32, and a throttle packing 35 is provided in an annular groove at the opening of the throttle hole 34. Port that opens to the outside on end block 33
A needle valve with a check valve (not shown) is provided in a passage communicating the port 36 with the vicinity of the circumference of the inner surface of the end block 33. At the center of the inner surface of the end block 33, a cylindrical drawing mandrel 37 is provided.
Is fixed substantially perpendicularly to the inner surface of the end block, and the inside of the throttle mandrel 37 and the port 36 are communicated by a passage in the end block 33.

In the conventional cylinder cushion device, when the slide block 32 moves to the cushion section, the throttle mandrel 37 enters the throttle hole 34, and the space between the exhaust side chamber and the passage in the throttle mandrel 37 becomes the throttle packing 35. Cut off by The discharge of air in the exhaust side chamber is adjusted by the needle valve of the needle valve with check valve, and the slide block 32
The air in the exhaust-side chamber is compressed by the kinetic energy of the table 38 and the load, and the energy of the thrust, the pressure is increased, and the deceleration force is exerted. In the conventional cylinder cushion device, it is necessary to absorb both kinetic energy and energy due to thrust in the cushion section, so that the amount of energy to be absorbed is large. Further, since the throttle holes 34 are provided on both sides of the slide block 32, the piston becomes large.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned disadvantages of the related art. In the cushion section, the effective thrust area of the piston is reduced, the energy generated by the thrust is reduced, and the cushion load is reduced. It is another object of the present invention to reduce the size of the piston by making the two throttle holes of the piston a common throttle hole (hollow hole).

[0005]

According to the present invention, in order to achieve the above object, in a cylinder cushion device, communication holes are formed at both ends of a hollow piston, and a small piston is slidable in the hollow hole of the hollow piston. The hollow throttle mandrel fixed to the head cover is disposed so as to be freely inserted into the communication hole and the hollow hole, the through hole of the hollow throttle mandrel is communicated to the outside, and the head cover inner surface opening and the outside are connected. Is communicated through a needle valve with a check valve. In addition,
Working medium used in the shea cylinder cushion device of the present devised not only air, includes any kind of fluid.

[0006]

When the hollow piston enters the cushion section, the hollow throttle mandrel is inserted into the communication hole and the insertion hole to contact the small piston, and the movement of the small piston is stopped, so that the effective thrust area of the piston is reduced. . At the same time, the communication between the through hole of the hollow throttle mandrel communicating with the atmosphere and the exhaust side chamber is cut off, and the flow rate of the fluid flowing out of the exhaust side chamber is adjusted by the needle valve with the check valve. Back pressure increases, and the moving speed of the hollow piston is reduced.

[0007]

1 to 3 show a cylinder cushion device according to an embodiment of the present invention, and only one of the cylinder cushion devices installed at both ends of an air cylinder is shown. A rodless hollow piston 6 is slidably fitted in the cylinder tube 3, and the head cover 1 is fixed to both ends of the cylinder tube 3. The hollow piston 6 has a cylindrical piston body 15 with a small diameter portion, and a sleeve 10 is fitted on the inner surface of the piston body 15. The small piston 5 is slidably fitted on the inner surface of the sleeve 10, and the opening of the piston body 15 is closed by a lid 17 having a communication hole . Communication holes 18 and 19 each having a diameter smaller than the inner diameter of the sleeve 10 are respectively formed in the perforated bottom portion 16 and the lid 17 of the piston body 15, and an annular first throttle is provided in an annular concave portion on the inner surface of the communication holes 18 and 19. packing 7 and second throttle packing 9 is disposed, respectively. The annular groove of the circumference near the both side surfaces of the small piston 5 annular packing 4A, 4B are mounted is <br/> each packing 4A abuts the inner surface of the perforated bottom 16, the packing 4B lid It is in a position where it comes into contact with the inner surface of the body 17.

The head cover 1 has a port opening to the outside.
A needle valve 11 with a check valve is provided in a first passage 20 which is formed with a port 13 and communicates with the port 13 and the vicinity of the circumference of the inner surface of the head cover 1. At the center of the inner surface of the head cover 1, a bottomed cylindrical hollow throttle mandrel 8 is fixed substantially perpendicularly to the inner surface of the head cover 1 (the opening of the hollow throttle mandrel 8 faces the head cover 1). The inside of the mandrel 8 and the port 13 are communicated by a second passage 21 in the head cover 1. The hollow throttle mandrel 8 is slidably inserted into the first throttle packing 7 and the sleeve 10 of the hollow piston 6, and the hollow throttle mandrel 8 and the first throttle packing 7 are slidably inserted in a hermetically sealed state. A plurality of through holes 12 are formed near the tip (right end in the figure) of the mandrel 8.
An annular damper 2 is disposed in an annular groove on the inner surface of the head cover 1, and the damper 2 is a bottom portion of the hollow piston 6 having a hole.
16 Ru Tei is contactable to an outer surface of the.

The operation of the embodiment of the present invention will be described.
1 shows a state before the hollow piston 6 enters the cushion section, FIG. 2 shows an initial state of the cushion section, and FIG. 3 shows a state where the hollow piston 6 has reached the stroke end. In the state shown in FIG. 1, compressed air is supplied to the filling side (right side) chamber of the hollow piston 6 and the pressure is P1, and the exhaust side (left side) chamber of the hollow piston 6 has the first passage 20 and the through hole 12.
-It is communicated with the atmosphere through the second passage 21 and the port 13, and the pressure is P2. The pressure P1 also acts on the filling side of the small piston 5, and the small piston 5 is the left end (forward end) in the hollow piston 6.
Located position, the small piston 5 packings 4A is perforated bottom 16
Is pressed against and sealed to the inner surface of the. The piston 6 advances toward the exhaust side chamber at a predetermined speed (moves to the left).
doing.

When the piston 6 moves forward and moves to the cushion section, as shown in FIG. 2, the hollow throttle mandrel 8 enters into the communication hole 18 of the hollow piston 6, the first throttle packing 7, and the sleeve 10, and becomes hollow. The tip of the throttle rod 8 is a small piston 5
, The hollow throttle mandrel 8 receives a force acting on the small piston 5. Therefore, the thrust acting on the hollow piston 6 is “(effective thrust (pressure receiving) area A2 of small piston 5) A2 ×
(Pressure P1 of the filling side of the hollow piston 6) - (outer径断area A3 of the hollow diaphragm mandrel 8) × (the pressure of the exhaust side of the hollow piston 6
P2) "only, the conventional thrust" (effective thrust area A1) × the hollow piston 6 [(pressure P1 of the filling side of the hollow piston 6) -
(Pressure P2 of the exhaust side of the hollow piston 6)] "is smaller than. At the same time, the communication between the through hole 12 of the hollow throttle mandrel 8 and the exhaust side chamber is interrupted by the outer surface of the hollow throttle mandrel 8 and the first throttle packing 7, and the discharge of air from the exhaust side chamber is adjusted by the needle valve with the check valve. You. The air in the exhaust-side chamber is compressed by the kinetic energy of the load connected to the hollow piston 6 and the energy by the thrust, and the pressure in the exhaust-side chamber increases, and the hollow piston 6 is decelerated. Thus, the energy and the kinetic energy due to the remaining thrust are absorbed before reaching the stroke end of the hollow piston 6.

In the cushion section, the hollow piston 6 is decelerated, and as shown in FIG. 3, the outer surface of the perforated bottom 16 of the hollow piston 6 comes into contact with the damper 2 and reaches the stroke end. At this time, a small gap is set between the filling side (right side) side surface of the small piston 5 and the inner side surface of the lid 17, and collision between the small piston 5 and the lid 17 occurs. Absent. When the exhaust side changes to the filling side by switching the directional control valve, compressed air flows into the sleeve 10 through the port 13, the second passage 21, and the through hole 12, and the small piston 5 moves rightward.
And is pressed against the inner side surface of the lid 17. Further, the compressed air flows into the filling side (left side) chamber through the port 13, the first passage 20, and the needle valve 11 with a check valve, and acts on the outer surface of the perforated bottom 16 of the hollow piston 6. Accordingly, the hollow piston 6 starts moving rightward in the figure. Since a cylinder cushion device similar to that described above is disposed on the opposite side of the head cover 1 of the cylinder tube 3, the hollow piston 6 also receives a cushioning effect similar to that described above at the right end of the cylinder tube 3.

[0012]

[Effect of the invention] In the present invention , a small hole is inserted into the insertion hole of the hollow piston.
Since the piston is slidably fitted and the small piston always abuts the hollow throttle mandrel in the cushion section, the effective thrust area of the hollow piston is reduced, and the generation of energy by the thrust is reduced. Therefore, the load on the cushion is reduced, and the moving distance required for the cushion can be reduced. In addition, in the present invention, it communicates inside the hollow piston.
The holes are connected to form an insertion hole with a diameter larger than the communication hole.
When the hollow throttle mandrel is inserted into the communication hole and the insertion hole of the hollow piston and abuts on the small piston in the insertion hole, the small piston moves. Therefore, the inside of the insertion hole of the hollow piston becomes a common space for the hollow throttle mandrel fixed to both ends of the cylinder tube, and the miniaturization of the piston and an increase in the effective stroke are brought about.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a cylinder cushion device (in a state immediately before a piston enters a cushion section) according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the cylinder cushion device (in a state immediately after the piston enters a cushion section) according to the embodiment of the present invention;

FIG. 3 is a longitudinal sectional view of the cylinder cushion device (in a state where the piston has arrived at the stroke end) according to the embodiment of the present invention;

FIG. 4 is a longitudinal sectional view of a conventional cylinder cushion device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Head cover 3 Cylinder tube 5 Small piston 6 Hollow piston 8 Hollow throttle mandrel 11 Needle valve with check valve 12 Communication hole 18 Communication hole 19 Communication hole

Claims (1)

(57) [Scope of request for utility model registration] 1. A head cover is provided at both ends of a cylinder tube.
Is fixed and the hollow piston slides in the cylinder tube.
The hollow piston is movably fitted, communication holes are formed at both ends of the hollow piston, and the communication holes are connected in the hollow piston.
Also formed the insertion hole of the large diameter, hollow diaphragm mandrel which is fixed to the f Ddokaba is slidably is provided in the communicating hole and the insertion hole
Is, freely small piston middle empty piston insertion hole sliding
And fitted so as to be contact with the leading end of the hollow diaphragm mandrel, hollow diaphragm through-hole of the mandrel is communicated with the port opening to the outside, also communicates with the side opening and the outside in the head cover through with check valve needle valve Cylinder cushion device.