CN102909710B

CN102909710B - Power tool

Info

Publication number: CN102909710B
Application number: CN201210166388.3A
Authority: CN
Inventors: 张士松; 庞晓丽; 钟红风
Original assignee: Positec Power Tools Suzhou Co Ltd
Current assignee: Positec Power Tools Suzhou Co Ltd
Priority date: 2011-08-06
Filing date: 2012-05-25
Publication date: 2015-04-22
Anticipated expiration: 2032-05-25
Also published as: CN104476472B; CN104385206A; CN102909679B; CN104801744B; CN202702199U; CN102909709B; CN102909677B; CN102909709A; CN202702201U; CN104385205A; CN102909677A; CN102909676B; CN102909679A; CN202702198U; CN102909701A; CN102909703B; CN104385206B; CN102909701B; CN102909710A; CN102909702A

Abstract

The invention relates to a power tool. The power tool comprises a case, a motor, an output shaft, a transmission mechanism, a working head supporting mechanism and a connecting shaft, wherein the motor is arranged in the case and outputs rotation power; the output shaft is provided with housing holes which are axially formed and are used for containing working heads; the working heads are provided with torque stressed parts with polygonal sections; the transmission mechanism is arranged between the motor and the output shaft and can transmit the rotation power output by the motor to the output shaft; the working head supporting mechanism is provided with a plurality of parallel housing spaces for supporting working heads; the connecting shaft is arranged in the case and can enable the working heads to be in working positions in the housing holes or in housing positions of the working head supporting mechanism; the housing holes comprise torque transmission parts and calibration parts; the torque transmission parts can limit the working heads to rotate relative to the output shaft; the output shaft is provided with elastic pressing devices; the elastic pressing devices at least partially extend into the calibration parts; and when entering the torque transmission parts from the calibration parts, the working heads can rotate relative to the output shaft under the action of the elastic pressing devices.

Description

Power tool

Technical Field

The invention relates to a power tool, in particular to a gun drill type power tool capable of realizing storage and quick replacement of a working head.

Background

Among the existing power tools of the gun drill type, electric drills, electric screwdrivers and impact drills are generally included.

A power screwdriver is a commonly used power tool for tightening screws onto a workpiece. When screws with different specifications need to be screwed down in the using process, different working heads, namely bits, need to be replaced according to the specifications of the screws, namely the originally installed working head needs to be taken down and then a working head with another structure is installed. In the use occasion that the working head needs to be replaced frequently, great inconvenience is brought to an operator, on one hand, the working head is troublesome to replace, and on the other hand, the taken-off working head is easy to lose everywhere. Although some of the hand tools can achieve storage and quick replacement of the working head, the hand tools are not suitable for use as professional tools in the industrial industry due to their inherent disadvantages, i.e., low torque and laborious operation, which makes the operator easily fatigued and inefficient.

Chinese utility model patent CN201086280Y discloses a multitool head electric tool, including electric tool main part and multitool head runner structure, multitool head runner structure includes a multitool head runner section of thick bamboo that can accept a plurality of tool bits, but multitool head runner section of thick bamboo endwise slip links to each other with the tool main part, when multitool head runner section of thick bamboo slides to the position of keeping away from the tool main part, thereby the rotatory multitool head runner section of thick bamboo of accessible selects the tool bit that needs. However, when the multi-cutter-head rotating-wheel cylinder is far away from the tool main body, the connecting shaft of the multi-cutter-head rotating-wheel cylinder is exposed outside, dust and powder can enter the inside of the electric tool or the inside of the multi-cutter-head rotating-wheel cylinder in the sliding process of the multi-cutter-head rotating-wheel cylinder, and the multi-cutter-head rotating-wheel cylinder cannot rotate to select the cutter head or directly cause the electric tool to be unusable after a long time. And the working head is propped against the workpiece when the tool works, so that the connecting shaft needs to bear the acting force in the opposite direction, and the connecting shaft can bring pressure to the transmission mechanism, so that the transmission mechanism can not transmit the torque to the connecting shaft.

In addition, because the electric tool is random in the using process, the angle of the cylinder wall of the connecting shaft for mounting the working head is uncertain when the electric tool is stopped, and the angle of the working head for retreating the rotary wheel cylinder is uncertain, so that the condition that the working head cannot enter the connecting shaft correctly and smoothly can occur due to the dislocation of the angle of the cylinder wall of the connecting shaft and the angle of the working head in the process of replacing the working head. The Chinese utility model patent CN201086280Y also discloses that the multi-cutter head rotary drum is linked with a switch, when the multi-cutter head rotary drum slides to a position far away from the tool main body, the multi-cutter head rotary drum can be rotated to select the required cutter head; when the multi-cutter head rotating wheel cylinder slides back to the tool main body, the multi-cutter head rotating wheel cylinder drives the linkage rod to move, the linkage rod can touch and press the switch to enable the motor to work, and the multi-cutter head rotating wheel cylinder rotates for a certain angle to enable the angle of the sleeve to be matched with the angle of the cutter head. On one hand, the frequent short-time starting of the motor is easy to cause the reduction of the service life of the motor or the damage of the motor; on the other hand, the linkage of the multi-cutter head rotating wheel cylinder and the switch needs to be accurately positioned and controlled, and the cost is higher.

Disclosure of Invention

In view of the deficiencies of the prior art, it is an object of the present invention to provide a power tool which is reliable in operation.

The technical scheme adopted by the invention for solving the technical problems is as follows: a power tool, comprising: a housing; a motor disposed in the housing and outputting rotational power; the output shaft is provided with an axially arranged accommodating hole for accommodating the working head, and the working head is provided with a torque stress part with a polygonal section; the transmission mechanism is arranged between the motor and the output shaft and can transmit the rotary power output by the motor to the output shaft; the working head supporting mechanism is arranged in the shell and is provided with a plurality of accommodating spaces which are arranged in parallel and used for supporting the working heads; the connecting shaft is arranged in the machine shell and can enable the working head to be positioned at a working position in the accommodating hole or at an accommodating position of the working head supporting mechanism; the accommodating hole comprises a torque transmission part and a correction part, the torque transmission part can limit the working head to rotate relative to the output shaft, the output shaft is provided with an elastic abutting device, at least part of the elastic abutting device extends into the correction part, and when the working head enters the torque transmission part from the correction part, the working head can rotate relative to the output shaft under the action of the elastic abutting device.

Preferably, the torque transmission part comprises at least one radial protrusion, and the at least one radial protrusion abuts against the torque bearing part and limits the working head to rotate relative to the output shaft.

Preferably, the torque transmission part comprises twelve radial protrusions which are uniformly arranged, the twelve radial protrusions are in contact with the torque bearing part and limit the working head to rotate relative to the output shaft, and the part of the elastic pressing device, which extends into the correction part, is aligned with the joint part of two adjacent radial protrusions in the twelve radial protrusions along an axial extension line.

Preferably, the torque transmission portion includes six radial protrusions, the six radial protrusions are twelve-pointed star-shaped, and the radially opposite six corners are uniformly arranged, and the portion of the elastic pressing device extending into the correction portion is aligned with an extension line of one of the six radial protrusions along the axial direction.

Preferably, every two radial protrusions of the six radial protrusions are in circular arc transition.

Preferably, the torque transmission part is a regular polygon with a cross section matched with that of the torque force-bearing part, and a part of the elastic pressing device extending into the correcting part is aligned with an extending surface of at least one surface of the torque transmission part along the axial direction.

Preferably, the cross section of the torque transmission part and the cross section of the torque bearing part are matched in a regular hexagon shape.

Preferably, the elastic pressing device comprises a pressing piece partially extending into the correcting portion and an elastic element, and the elastic element biases the pressing piece inwards along the radial direction of the output shaft.

Preferably, the elastic element is a C-shaped elastic sheet arranged around the output shaft, and the pressing pieces are arranged on two sides of an opening of the C-shaped elastic sheet.

Preferably, the elastic element is an elastic sheet arranged along the axial direction of the output shaft, one end of the elastic sheet is fixed relative to the casing, and the other end of the elastic sheet biases the pressing part.

Preferably, the elastic pressing device comprises an elastic element, the elastic element is provided with a pressing part extending into the correcting part, and the pressing part can move along the radial direction of the output shaft between the free state and the biased state of the elastic element.

Preferably, the elastic element comprises at least one C-shaped steel wire arranged around the output shaft, and the pressing parts are arranged on two sides of the opening of the C-shaped steel wire.

Preferably, the number of the C-shaped steel wires is two, and the two C-shaped steel wires are distributed at intervals along the axial direction of the output shaft.

Preferably, the two pressing parts of the two C-shaped steel wires are arranged in a staggered mode along the circumferential direction.

Preferably, the elastic element is an elastic sheet arranged along the axial direction of the output shaft, one end of the elastic sheet is fixed relative to the casing, and the pressing part is arranged at the other end of the elastic sheet.

Preferably, the connecting shaft is connected between a transmission mechanism and the output shaft, and the transmission mechanism transmits the rotary power output by the motor to the output shaft through the connecting shaft.

Compared with the prior art, the invention has the beneficial effects that: the power tool of the invention enables the working head to smoothly enter the output shaft in the process of replacing the working head through a simple structure, ensures higher reliability and reduces cost.

Drawings

Fig. 1 is a sectional view of a power tool in an operating state in a first preferred embodiment of the present invention.

Fig. 2 is a partially exploded perspective view of the power tool of fig. 1.

Fig. 3 is a partial sectional view taken along line E-E in fig. 1.

FIG. 4 is a schematic cross-sectional view of the working head of the power tool of the present invention.

Fig. 5 is a schematic right-side view of an output shaft portion of the power tool in the preferred first embodiment of the present invention, in which the working head has not yet entered the output shaft.

FIG. 6 is similar to FIG. 5 with the working head just entering the correcting portion of the output shaft.

Fig. 7 is similar to fig. 5, wherein the working head rotates relative to the output shaft under the action of the elastic pressing device.

Fig. 8 is similar to fig. 5 with the working head entering the torque transfer portion of the output shaft.

Fig. 9 is a schematic view of a torque transmitting portion formation of an output shaft of a power tool in a preferred second embodiment of the present invention, in which two regular hexagons are rotated 30 degrees relative to each other.

Fig. 10 is a schematic outline view of a torque transmission portion of an output shaft of a power tool in a preferred second embodiment of the present invention.

Fig. 11 is a schematic right-side view of an output shaft portion of a power tool in a preferred second embodiment of the present invention, in which the working head has not yet entered the output shaft.

FIG. 12 is similar to FIG. 11 with the working head just entering the correcting portion of the output shaft.

FIG. 13 is similar to FIG. 11 with the working head entering the torque transmitting portion of the output shaft.

Fig. 14 is a schematic outline view of a torque transmission portion of an output shaft of a power tool in a preferred third embodiment of the present invention.

Fig. 15 is a sectional view of a power tool in a state where the working head is replaced in the preferred second embodiment of the present invention.

Fig. 16 is a partial cross-sectional view taken along line F-F of fig. 15, wherein the working head has not yet entered the output shaft.

Fig. 17 is a schematic right view of an output shaft portion of a power tool in a preferred third embodiment of the present invention, in which the working head has just entered the correcting portion of the output shaft.

Fig. 18 is similar to fig. 17, wherein the working head is rotated relative to the output shaft by the elastic pressing device.

FIG. 19 is similar to FIG. 17 with the working head entering the torque transmitting portion of the output shaft.

Fig. 20 is a partial sectional view showing a power tool in an operating state in a fourth preferred embodiment of the present invention.

Fig. 21 is a partially exploded perspective view of the power tool of fig. 20.

Fig. 22 is a partial sectional view of a power tool in an operating state in a fifth preferred embodiment of the present invention.

Fig. 23 is a partial sectional view of a power tool in an operating state in a sixth preferred embodiment of the present invention.

Fig. 24 is a partial sectional view of a power tool in an operating state in which the working head has just entered the correcting portion of the output shaft in a seventh preferred embodiment of the present invention.

FIG. 25 is a view similar to FIG. 24 with the working head past the first retaining member.

FIG. 26 is similar to FIG. 24 with the working head passing over the second retaining member.

Fig. 27 is similar to fig. 24 with the connecting shaft passing over the first retaining member.

FIG. 28 is a view similar to FIG. 24, but with the output shaft in the reset position and the working head rotated.

Wherein,

1. casing 2, motor 3, transmission mechanism

4. Output shaft 6, battery 7, button switch

9. Working head 11, handle 13 and front shell

15. Guide groove 21, motor shaft 22, gear box

30. Pinion gear mechanism 31, planetary gear reduction mechanism 40, sleeve

41. 41a, 41b, receiving hole 42, radial protrusion 48, stop

51. Connecting shaft 50, fixing block 52 and storage clamp

53. Sliding cover 131, opening 221 and partition plate

223. Gear box cover plate 225, arch 301, first gear

302. Second gear 303, third gear 461, 461a, torque transmission part

462. 462a, a correction portion 463, 463a, a radial through hole 464. C-shaped elastic sheet

465. Pressing member 465a, projection 466, C-shaped steel wire

467. 467a spring 468, a bending 481, a first locking portion

482. First release portion 483, first receiving groove 484, first locking member

485. Second locking part 486, second releasing part 487, second containing groove

488. Second locking piece 489, elastic element 521, working head accommodating bin

531. Guide rail

Detailed Description

In the preferred embodiment of the power tool of the present invention, the power tool is a power screwdriver, which can be classified into a pneumatic screwdriver, a hydraulic screwdriver and an electric screwdriver according to the power source, and the electric screwdriver also has a dc component and an ac component.

Referring to fig. 1 to 3, the dc electric screwdriver includes a housing 1, a motor 2, a battery 6, a transmission mechanism 3, a connecting shaft 51, a working head support mechanism, and an output shaft 4. The casing 1 is assembled by folding two half shells which are symmetrical left and right by screws (not shown), and has a horizontal part and a handle 11 part which forms an obtuse angle with the horizontal part, and the preferred angle of the invention is between 100 degrees and 130 degrees, so that the handle 11 can be held comfortably during operation. The upper part of the handle 11 is provided with a button switch 7, the battery 6 is fixed at the rear part of the handle 11, and the transmission mechanism 3 is partially and fixedly accommodated in the horizontal part of the machine shell 1. As a preferred embodiment, the battery 6 may be a lithium ion battery. It should be noted that the lithium ion battery referred to herein is a generic term of a rechargeable battery in which a negative electrode material is a lithium element, and may be constructed in many systems, such as a "lithium manganese" battery, a "lithium iron" battery, and the like, depending on a positive electrode material. In the present embodiment, the lithium ion battery is a lithium ion battery having a rated voltage of 3.6V (volts). Of course, the battery 6 may also be of a nickel cadmium, nickel hydrogen, or the like, of a type well known to those skilled in the art.

The transmission mechanism 3 includes, from back to front (rear on the right side of the drawing), a planetary gear reduction mechanism 31 driven by the motor 2 and a pinion mechanism 30, wherein the pinion mechanism 30 is connected to a connecting shaft 51, and transmits the rotational motion of the motor 2 to the output shaft 4 through the connecting shaft 51. The working head supporting mechanism is used for storing different working heads, the working heads mainly refer to cross screwdriver heads, straight screwdriver heads, drill heads and the like commonly used by the electric screwdriver, and different working heads can be quickly replaced when the electric screwdriver screws or loosens different screws by operating the connecting shaft to axially move through the working head supporting mechanism or leave the working head supporting mechanism. According to the above composition of the electric screwdriver, the electric screwdriver can be divided into a motor part D provided with a motor, a transmission part C provided with the transmission mechanism 3, a storage part B provided with the working head support mechanism and an output part a provided with an output shaft in sequence from back to front (with the right side of the drawing as the back).

The motor in the preferred embodiment of the present invention is an electric motor 2, and the electric motor 2 has a motor shaft 21 extending forwardly from the motor housing. The motor 2 is fixed in the machine shell 1, a gear box 22 is fixed in the machine shell 1 and positioned at the front part of the motor 2, the gear box 22 is used for accommodating the planetary gear speed reducing mechanism 31 and the pinion mechanism 30, the planetary gear speed reducing mechanism 31 and the pinion mechanism 30 are separated by arranging a separating plate 221 between the planetary gear speed reducing mechanism 31 and the pinion mechanism 30, and a gear box cover plate 223 is arranged between the gear box 22 and the working head supporting mechanism, so that the transmission mechanism 3 and the working head supporting mechanism can be separated, namely, the transmission mechanism 3 and the working head supporting mechanism are independent. The pinion mechanism 30 includes a first gear 301 connected to the planetary gear reduction mechanism 31 so as to be capable of transmitting torque, a third gear 303 connected to the connecting shaft 51, and a second gear 302 meshing with the first gear 301 and the third gear 303, the second gear 302 transmitting the rotation of the first gear 301 to the third gear 303, both ends of each gear being supported by bushings. The middle part of the partition 221 is provided with a hole for the shaft of the first gear 301 to pass through, the end face of the partition 221 is provided with a groove for mounting a shaft sleeve, a rear shaft sleeve for supporting the pinion mechanism 30 is fixed on the partition 221, a front shaft sleeve is fixed on a gear box cover plate 223, and the gear box cover plate 223 is fixedly connected with the gear box 22 through screws, buckles and the like, so that the pinion mechanism 30 and the planetary gear speed reducing mechanism 31 can be separated and can be sealed at the same time, dust, powder and the like are prevented from entering the transmission mechanism 3, and the leakage of lubricating oil can also be prevented. In addition, the three gears are provided only to make the inner space of the tool more compact so as not to affect the external beauty. Of course, two gears may be provided as necessary, one being connected to the planetary gear speed reduction mechanism 31 and the other being connected to the connecting shaft 51. In addition, the transmission mechanism 3 is not limited to the above-described form, and the transmission mechanism 3 may include only the planetary gear speed reduction mechanism 31, or only the pinion gear mechanism 30, or other rotational motion transmission mechanisms such as a ratchet mechanism, a worm gear mechanism, and the like. The planetary gear reduction mechanism 31 has a three-stage reduction system, the motor shaft 21 extends to be meshed with the planetary gear reduction mechanism 31, the planetary gear reduction mechanism 31 transmits the rotation motion to the pinion mechanism 30, the pinion mechanism 30 drives the connecting shaft 51 to rotate, and the connecting shaft 51 drives the output shaft to rotate. When the motor 2 is operated, the output shaft 4 finally outputs the motor through the planetary gear reduction mechanism 31 and the pinion mechanism 30. It can be seen that the drive train in this embodiment is a motor-transmission-connecting shaft-output shaft, i.e. the connecting shaft is part of the drive train. In addition, the speed reducing mechanism is composed of a three-stage planetary speed reducing system and a two-stage parallel shaft speed reducing system to obtain the desired output speed, and in other embodiments, the speed reducing mechanism may only include a two-stage planetary speed reducing system or other speed reducing systems according to the required output speed.

The casing 1 is slidably connected with a sliding cover 53, and the sliding cover 53 can drive the connecting shaft 51 to move axially. The edge of the sliding cover 53 is provided with a guide track 531, and correspondingly, the housing 1 is provided with a guide groove 15, and the sliding cover 53 is installed in the guide groove 15 through the guide track 531 and can slide axially relative to the housing 1. Of course, the sliding cover 53 may be provided with a guide groove, and the sliding cover may be moved by providing a guide rail on the housing 1.

The connecting shaft 51 is a hexagonal shaft, a fixing block 50 is axially and fixedly arranged on the connecting shaft 51, the rear end of the connecting shaft 51 can rotatably abut against the fixing block 50, and the sliding cover 53 can drive the connecting shaft 51 to move in a mode of being connected with the fixing block 50. Of course, there are many ways for the sliding cover 53 to drive the connecting shaft 51 to move, for example, a ring groove surrounding the periphery of the connecting shaft 51 may be provided on the connecting shaft 51, and the sliding cover 53 extends into the ring groove through a pin or a wire ring to connect with the connecting shaft 51, so that the rotation of the connecting shaft 51 is not affected, and the sliding cover 53 drives the connecting shaft 51 to move is also not affected. The front end of the connecting shaft 51 is provided with a magnet 511 for attracting the working head 9, when the working head 9 is selected, the sliding cover 53 can be operated to drive the connecting shaft 51 to pass through the working head supporting mechanism, the working head 9 is attracted by the magnet 511 on the connecting shaft 51, and leaves the working head supporting mechanism under the pushing of the connecting shaft 51 to enter the output shaft 4.

The housing 1 includes a front case 13 connected to a front end thereof, and a part of the working head support mechanism is housed in the front case 13 and the other part is covered by the slide cover 53 and exposed as the slide cover 53 moves. The preferred work head support mechanism of the present invention is a cylindrical storage clamp 52, which is convenient to rotate and occupies a small space, but can be square, triangular, strip-shaped, bracket-shaped, etc. When the electric screwdriver is operated, the sliding cover 53 abuts against the front housing 13, so that the storage clip 52 and the connecting shaft 51 can be closed. The gear box cover plate 223 is provided with a hole for the connecting shaft 51 to pass through, the gear box 22 extends around the axis of the connecting shaft 51 to form an arch 225, the arch 225 can be integrally or separately arranged with the gear box 22, the connecting shaft 51 can be partially sealed by the arrangement of the arch 225, when the working head 9 of the electric screwdriver is replaced, namely the sliding cover 53 moves to the rearmost position, the connecting shaft 51 cannot be exposed, and therefore dust, powder and the like can be prevented from entering the tool. Furthermore, the gearbox cover 223 extends to the end face of the arch 225, so that the transmission 3 is closed together in its entirety in the axial direction. In the working process, the sliding cover 53 can seal the storage clip 52, so that dust is prevented from entering, when the working head needs to be replaced, the sliding cover 53 is removed to expose the storage clip 52, different working heads are convenient to select, and thus the sliding cover 53 needs to have a certain length, when the sliding cover 53 moves to the working position abutted against the front shell 13, the sliding cover 53 is axially overlapped with the storage part B and the transmission part C, and when the sliding cover 53 moves to the position where the working head can be replaced, the sliding cover 53 is axially overlapped with the motor part D and is partially axially overlapped with the transmission part C. Of course, there are many ways to move the sliding cover 53, for example, the sliding cover 53 can be rotatably installed on the housing 1, and can rotate between two positions for covering the storage clip 52 and exposing the storage clip 52; or may be opened or closed in a manner similar to a sliding door; or pivotally connected to the housing 1, etc., to close the storage clamp 52 during operation and expose the storage clamp 52 when the working head needs to be replaced.

The storage clamp 52 is rotatably supported between the gear box cover plate 223 and the output shaft 4, a plurality of working head accommodating chambers 521 are uniformly distributed on the storage clamp 52 along the circumferential direction, that is, the working heads have a plurality of accommodating spaces, and the plurality of accommodating spaces are arranged in parallel along the rotation axis of the storage clamp 52. The working head accommodating bin 521 is partially closed along the axial direction of the storage clamp 52, and partially opened at the outer circumference, so that an operator can easily see the shape of the head of the working head 9 from the opened part when selecting the working head 9, and the operator can quickly select the required working head 9. Of course, it is easy for those skilled in the art to understand that the working head storage bin 521 can also be fully enclosed, and only the corresponding position needs to be marked, or the storage clip 52 can be made transparent directly, so that the identification can be facilitated. In addition, elastic positioning can be performed between the storage clamp 52 and the gear box cover plate 223, that is, a positioning groove 522 is arranged at a position, corresponding to the working head 9, on the end surface of the storage clamp 52 facing the gear box cover plate 223, the positioning groove 522 corresponds to the accommodating bin 521, and a steel cap or a spring plate pressed by a spring is arranged on the gear box cover plate 223, so that a prompt sound falling into the positioning groove 522 is given out when the storage clamp 52 rotates one working head 9, and an operator can avoid the rotation angle of the storage clamp 52 from being staggered with the connecting shaft 51 when selecting the working head 9.

Referring to fig. 4, the cross section of the handle of the standard working head is a regular hexagon, that is, the handle forms a torque bearing part of the working head, the output shaft 4 has an axially penetrating receiving hole 41, the receiving hole 41 is in the form of a hexagonal hole matched with the torque bearing part of the working head, and the working head is mounted in the receiving hole to be in a working position, so that torque transmission is realized. Of course, the working head may be non-standard, that is, the cross section of the torque bearing part is polygonal, and the corresponding receiving hole is set to be polygonal matched with the torque bearing part, so that the torque transmission can be realized. The output shaft 4 is supported in the axial opening 131 of the front housing 13 by a bushing 40. the bushing 40 provides radial support for the output shaft 4, although radial support of the output shaft 4 may be provided by bearings. The connecting shaft 51 is also hexagonal, the third gear 303 is internally provided with a hexagonal hole which is used for being matched and connected with the connecting shaft 51 and transmitting the rotating power to the connecting shaft 51, so that the connecting shaft 51 is inserted into the output shaft 4 to drive the output shaft 4 to rotate, and the output shaft 4 drives the working head 9 to rotate, thus the standard working head 9 can be used, a hole for accommodating the working head 9 is not required to be formed in the connecting shaft 51, and the phenomenon that the diameter of the connecting shaft 51 is too large and the weight and the volume of the whole machine are increased is avoided. Therefore, the working head 9 is directly driven to rotate to form an output shaft, the torque transmission distance is shortened, and the tool is more reliable to use. However, it is easy for those skilled in the art to substitute other transmission methods, for example, the connecting shaft directly drives the working head to rotate, that is, the connecting shaft is directly connected to the working head in a manner of transmitting torque, or the output shaft is directly driven by a gear, and the connecting shaft is only used for pushing out the working head and driving the working head to return to the storage clip.

When the working head 9 enters the output shaft 4 under the driving of the connecting shaft 51, if the hexagonal shape of the working head 9 is staggered with the angle of the hexagonal hole in the output shaft 4, the working head 9 is clamped and cannot enter the output shaft 4, which brings great inconvenience to an operator. In order to prevent the situation, the elastic abutting device is arranged on the output shaft 4, and the relative position of the working head 9 and the output shaft is adjusted by the elastic abutting device in the process that the working head 9 enters the output shaft, so that the working head 9 smoothly enters the output shaft.

Fig. 1 to 8 show a first embodiment of the elastic pressing device of the present invention, referring to fig. 3 to 5, the receiving hole 41 of the output shaft 4 includes a torque transmitting portion 461 driving the working head to rotate and a correcting portion 462 facilitating the working head to enter, the correcting portion 462 is a circular hole, the torque transmitting portion 461 is a hexagonal hole, so as to facilitate the working head 9 to enter the receiving hole 41, the elastic pressing device is disposed at a position corresponding to the correcting portion 462, and includes a radial through hole 463 communicating with the receiving hole 41, a pressing member 465 received in the radial through hole 463, and a C-shaped elastic sheet 464 covering the output shaft 4 and radially biasing the pressing member 465, the pressing member 465 at least partially extends into the correcting portion 462 of the receiving hole 41 under the action of the C-shaped elastic sheet 464, and the pressing member 465 is disposed at a position axially corresponding to an extending surface of one of the hexagonal hole of the torque transmitting portion 461, so that when the working head 9 enters the correcting portion 462, if one plane in the hexagonal outer peripheral surface of the working head 9 axially corresponds to the pressing part 465, the working head 9 can directly enter the torque transmission part 461; referring to fig. 6 to 8, a plane in the hexagonal outer peripheral surface of the working head 9 is axially staggered from the pressing part 465, so that the working head 9 enters the correction portion 462 and radially presses the pressing part 465, the pressing part 465 presses the C-shaped elastic sheet 464 to elastically deform, meanwhile, the pressing part 465 also receives a reverse acting force of the C-shaped elastic sheet 464, the pressing part 465 presses the working head 9 under the reverse acting force of the C-shaped elastic sheet 464, so that the working head 9 and the output shaft 4 rotate relatively, a plane in the hexagonal outer peripheral surface of the working head 9 axially corresponds to the pressing part 465, at this time, the working head 9 is matched with the torque transmission portion 461, so that the working head 9 can smoothly enter the torque transmission portion 461, and the C-shaped elastic sheet 464 returns to an.

Fig. 9 and 13 show a second embodiment of the present invention, in which the correction portion 462a of the output shaft 4 is provided as a square hole, the torque transmission portion 461a is provided as a twelve-pointed star shape, the twelve-pointed star shape in this embodiment being formed by two regular hexagons having a phase difference of 30 degrees, so that the torque transmission portion 461a has twelve inwardly projecting radial protrusions 42, and the radial protrusions 42 can abut against the torque receiving portions of the hexagonal working heads 9 and restrict the working heads 9 from rotating relative to the output shaft 4. Thus, the pressing part 465 can be arranged at a position aligned with the axial extension line of the joint part of two adjacent radial protrusions, so that when the working head 9 enters the correcting part 462a, if one plane in the hexagonal outer peripheral surface of the working head 9 axially corresponds to the pressing part 465, the working head 9 can directly enter the torque transmission part 461 a; referring to fig. 12 and 13, a plane in the hexagonal outer peripheral surface of the working head 9 is axially staggered from the pressing member 465, so that the working head 9 rotates relative to the output shaft 4 under the action of the pressing member 465 and the C-shaped elastic sheet 464 until the radial protrusion 42 is attached to one surface of the working head 9, and then the torque transmission part 461a can enter. With the above arrangement, it is easy for those skilled in the art to think that at least one radial protrusion 42 is provided to achieve the rotation of the working head driven by the output shaft, and such radial protrusions 42 may also be provided in a pair, which are diametrically opposite to each other along the circumferential direction, i.e. symmetrically distributed, so that the working head is driven by the output shaft 4 to rotate with uniform force, and of course, two or three pairs, where two of each pair are diametrically opposite to each other, and the radial protrusion 42 can abut against one of the faces of the hexagonal working head 9 and limit the rotation of the working head 9 relative to the output shaft 4, etc.

The above-mentioned is the way that the radial bulge 42 of the output shaft 4 contacts with the working head 6 surface to drive the working head 9 to rotate, so that the stress of the working head 9 is uniform and the stress of the unit area is small. Of course, the radial protrusion 42 of the output shaft 4 in line contact with the working head 9 can also drive the working head 9 to rotate, such as: the angle of the radial protrusion 42 is not limited, as long as the working head 9 can be driven to rotate, and the pressing member 465 is arranged at a position corresponding to the axial direction of the extending portion of the radial protrusion 42, so that the working head 9 can smoothly enter the output shaft 4. The pressing parts are steel balls, steel columns and the like, two steel balls can be arranged, and only one steel ball axially corresponds to the radial protrusion 42, so that the working heads can smoothly enter the output shaft 4 through symmetrical or asymmetrical distribution.

In the above embodiment, the hexagonal shape of the working head 9 and the torque transmission portion of the output shaft 4 need to be completely matched regardless of whether the torque transmission portion is hexagonal or dodecagonal star-shaped, and if there is a slight deviation, the working head 9 cannot smoothly enter the output shaft 4. In order to solve the problem, fig. 14 to 19 show a third embodiment of the present invention, the torque transmission portion only takes an odd number or an even number of twelve radial protrusions, so that the torque transmission portion has six radial protrusions, each two radial protrusions 42 are transited through an arc, the pressing member 465 is disposed at a position aligned with an axial extension of one of the radial protrusions, referring to fig. 17, when the hexagonal shape of the working head 9 is staggered from the torque transmission portion, the working head 9 is blocked by the pressing member 465, the working head 9 continues to advance, the pressing member 465 forces the C-shaped elastic sheet 464 to elastically deform, and meanwhile, the C-shaped elastic sheet 464 elastically acts on the pressing member 465 to relatively rotate the working head 9 and the output shaft 4, referring to fig. 18, until one surface of the hexagonal shape of the working head 9 is attached to one of the radial protrusions, referring to fig. 19, the working head 9 can smoothly enter the torque transmission portion of the output shaft, in fact, the working head 9 and the output shaft 4 only need to rotate relatively for a small angle, and the circular arc transition can be arranged to leave enough space for the relative rotation of the working head 9 and the output shaft 4. Meanwhile, as long as the edge part of the hexagonal shape of the working head 9 is a torque transmission part which can directly enter the output shaft corresponding to the arc part, that is, the angle K corresponding to the arc part is the non-interference angle range of the working head 9 entering the output shaft, in the embodiment, K is 30 degrees, so that the six arcs are 180 degrees, that is, the working head enters the torque transmission part of the output shaft with a general probability and directly enters without correction, so that the service life of the elastic pressing device can be prolonged.

Fig. 20 to 21 show a fourth embodiment of the present invention, in which the elastic pressing device includes a radial through hole 463a provided on the output shaft 4 and located at the position of the correcting portion 462 to communicate with the receiving hole 41, an annular steel wire 466 having an opening is sleeved on the output shaft 4 at the position of the radial through hole 463a, the annular steel wire 466 is provided with a protrusion 465a, the protrusion 465a is received in the radial through hole 463a and partially extends into the correcting portion 462, in this embodiment, the radial through hole 463a is preferably a waist-shaped hole, and the length direction thereof extends along the circumferential direction of the output shaft, so as to reduce the length of the output shaft 4, thereby making the structure more compact, and of course, the elastic pressing device may be provided as a circle, a square, etc. according. When the working head 9 enters the correcting portion 462, if one of the hexagonal outer peripheral surfaces of the working head 9 circumferentially corresponds to the projecting portion 465a, the working head 9 may directly enter the torque transmitting portion 461; on the other hand, if one of the hexagonal outer peripheral surfaces of the working heads 9 is circumferentially staggered from the protruding portion 465a, the working heads 9 are rotated relative to the output shaft 4 under the action of the annular steel wire 466 so that the hexagonal shape of the working heads 9 is matched with the torque transmitting portion 461 and the working heads 9 can smoothly enter the output shaft 4.

In the above embodiment, two radial through holes 463a and two corresponding annular steel wires 466 are preferably provided and spaced apart along the axial direction of the output shaft 4, so as to further strengthen the guiding of the working head 9 into the output shaft 4. In addition, the two radial through holes 463a may be circumferentially staggered, that is, the relative phase difference between the two radial through holes 463a is less than 30 degrees, that is, the positive and negative 60 degrees of the interval angle between the two radial through holes 463a is the relative phase difference, so that even if one of the edges of the working head 9 in the hexagonal shape is directly opposite to the protruding portion of one of the annular steel wires, the protruding portion of the other annular steel wire can be just staggered with the other edges of the working head in the hexagonal shape, so that the working head 9 can be guided to match the shape of the working head 9 with the torque transmission portion 461 when entering the correction portion 462 at any angle.

Fig. 22 shows a fifth embodiment of the present invention, in which the elastic pressing device includes a radial through hole 463 disposed on the output shaft 4 and communicating with the receiving hole 41 at the position of the calibration portion 462, a pressing member 465 received in the radial through hole 463, and an elastic sheet 467 radially biasing the pressing member 465, where the elastic sheet 467 is a sheet spring extending along the axial direction of the output shaft 4, one end of the elastic sheet 467 is fixed between the output shaft 4 and the casing 1, and the other end is a free end abutting against the pressing member 465, and the free end of the elastic sheet 467 can be bent, so as to increase the elastic force of the elastic sheet 467 against the pressing member 465. The principle of guiding the working head 9 into the output shaft 4 in this embodiment is the same as that in the first embodiment, and will not be described again.

Fig. 23 shows a sixth embodiment of the present invention, in which the elastic pressing device includes a radial through hole 463 disposed on the output shaft 4 and communicating with the receiving hole 41 at the position of the correction portion 462, and an elastic piece 467a partially received in the radial through hole 463 and extending into the correction portion 462, one end of the elastic piece 467a is fixed between the output shaft 4 and the housing 1, and the other end is a free end having a bending portion 468, wherein the bending portion 468 extends into the correction portion 462, and the bending portion 468 here is equivalent to a pressing member, i.e. the pressing member and the elastic member are integrally disposed to achieve the function of guiding the working head.

Fig. 24 to 28 show a seventh embodiment of the present invention, in which the output shaft 4 has a receiving hole 41b provided in the axial direction, the receiving hole 41b is a circular hole, the output shaft 4 is provided with a first receiving groove 483 communicating with the receiving hole 41b, the first receiving groove 483 receives a first locking member 484 partially extending into the receiving hole 41b, and the first locking member 484 abuts against one surface of the working head received in the receiving hole 41b in the circumferential direction to restrict the rotation of the working head relative to the output shaft 4. When the working head 9 enters the output shaft 4, as long as one surface of the working head 9 with the hexagonal shape corresponds to the first locking member 484, the working head 9 can smoothly enter the output shaft 4, so that the output shaft 4 drives the working head to rotate through the first locking member 484.

The output shaft 4 drives the working head 9 to rotate by arranging the first accommodating groove 483 and the first locking piece 484, namely, if the output shaft is directly driven to rotate by a gear, the working head can smoothly enter the output shaft. In order to enable the connecting shaft 51 to drive the output shaft 4 to rotate, a second receiving groove 487 may be disposed on the output shaft 4 at an interval from the first receiving groove 483, a second locking member 488 partially extending into the receiving hole 41a is received in the second receiving groove 487, and one surface of the hexagonal shape of the connecting shaft 51 extending into the receiving hole 41b abuts against the second locking member 488 to drive the output shaft 4 to rotate. That is, as long as one of the surfaces of the connecting shaft 51 having the hexagonal shape corresponds to the first locking member 484, the connecting shaft 51 can smoothly enter the output shaft 4, so that the connecting shaft 51 drives the output shaft 4 to rotate through the second locking member 488.

However, when the peripheral surface of the hexagonal shape of the working head 9 is staggered from the first locking member 484, the working head 9 entering the output shaft 4 is blocked by the first locking member 484, so that the first locking member 484 can be arranged to move radially, which allows the working head 9 to enter the output shaft 4, and the output shaft 4 can drive the working head 9 to rotate through the first locking member 484. Specifically, a limiting member 48 may be disposed between the output shaft 4 and the front housing 13, the output shaft 4 may be capable of moving axially relative to the limiting member 48, the first locking member 484 is allowed to move or limited in radial direction by the limiting member 48 along with the axial movement of the output shaft 4, a first locking portion 481 and a first releasing portion 482 are disposed on the limiting member 48 along the axial direction, the first locking member 484 may be capable of engaging with the first releasing portion 482 when allowed to move in radial direction, the first locking member 484 may be engaged with the first locking portion 481 when limited in radial direction, an elastic element 489 may be disposed between the output shaft 4 and the limiting member 48, the elastic element 489 may be compressed by the axial movement of the output shaft 4, and after the working head 9 enters the output shaft 4, the output shaft 4 may return to a position where the first locking member 484 engages with the first locking portion 481 under the elastic force, so.

Similarly, in order to prevent the connecting shaft 51 from being blocked by the second locking member 488 when entering the output shaft 4, a second releasing portion 486 and a second locking portion 485 may be axially disposed on the limiting member 48 at a position corresponding to the second locking member 488, when one of the surfaces of the connecting shaft 51 having the hexagonal shape is aligned with the second locking member 488, the connecting shaft 51 may not be blocked and may be smoothly inserted into the output shaft 4, and the second locking member 488 may function as a hexagonal hole to lock the connecting shaft 51 to rotate together. When the hexagonal edge of the connecting shaft 51 is aligned with the second locking member 488 and blocked by the second locking member 488, the connecting shaft 51 drives the second locking member 488 and the output shaft 4 to move forward against the elastic force, and when the connecting shaft 51 is turned on, the straight edge of the connecting shaft 51 rotates to correspond to the second locking member 488, the second locking member 488 moves radially to be engaged with the second releasing portion 486, the connecting shaft 51 smoothly enters the output shaft 4, and when the connecting shaft 51 is turned on, the output shaft 4 drives the second locking member 488 to return to a position where the second locking member 485 is engaged with the second locking portion 488 under the action of the elastic force.

The specific working process is as follows, when the straight surface of the hexagonal shape of the working head 9 is aligned with the first locking member 484, the straight surface of the hexagonal shape of the working head 9 is not blocked and can be smoothly inserted into the output shaft 4, if one surface of the hexagonal shape of the connecting shaft 51 is also aligned with the second locking member 488, the connecting shaft 51 can also be smoothly inserted into the output shaft 4, when rotating, the connecting shaft 51 drives the output shaft 4 to rotate through the second locking member 488, and the output shaft 4 drives the working head 9 to rotate together through the first locking member 484. If one side of the connecting shaft 51 in the hexagonal shape is staggered from the second locking member 488, the connecting shaft 51 drives the second locking member 488 and the output shaft 4 to move forward by overcoming the elastic force until the second locking member 488 is disengaged from the second locking portion 485 of the limiting member 48, the second locking member 488 moves radially and is engaged with the second releasing portion 486, the connecting shaft 51 smoothly enters the output shaft 4, after the power-on operation, the connecting shaft 51 is driven to rotate, the limiting member 48 presses against the second locking member 488 under the action of the elastic force, the second locking member 488 moves radially and is disengaged from the second releasing portion 486, the output shaft 4 drives the second locking member 488 to move axially together under the action of the elastic force, the second locking member 488 returns to the position engaged with the second locking portion 485, and the connecting shaft 51 can drive the output shaft 4 to rotate through the second locking member 488.

When the straight surface of the hexagonal shape of the working head 9 is staggered with the first locking member 484 and is blocked by the first locking member 484, the working head 9 can drive the first locking member 484 and the output shaft 4 to move forwards by overcoming the elastic force until the first locking member 484 is disengaged from the first clamping portion 481 of the limiting member 48, the first locking member 484 moves radially and is engaged with the first releasing portion 482, the working head 9 smoothly enters the output shaft 4, at this time, the second locking member 488 is disengaged from the second clamping portion 485, the connecting shaft 51 can smoothly enter the output shaft no matter whether one of the straight surfaces of the hexagonal shape of the connecting shaft 51 is aligned with the second locking member 488, after the machine is started, the connecting shaft 51 is driven to rotate, the working head 9 can also rotate by a small angle under the action of the magnet 511 of the connecting shaft 51, the limiting member 48 presses the first locking member 484 and the second locking member 488 under the elastic force, and along with the rotation of the, the first locking member 484 and the second locking member 488 of the output shaft 4 return to the position engaged with the first locking portion 481 and the second locking portion 485, so that the connecting shaft 51 can drive the output shaft 4 to rotate through the second locking member 488, and the output shaft 4 can also drive the working head 9 to rotate together through the first locking member 484.

The above definitions of the various elements are not limited to the various specific configurations or shapes mentioned in the embodiments, and may be easily and commonly replaced by those skilled in the art. For example, the motor can be a gasoline engine or a diesel engine and the like to replace the motor; the working head can be a polygon with any regular cross section; in addition, in the above embodiment, the relative axial movement between the connecting shaft and the working head storage clamp may also be that the connecting shaft is fixed, and the working head storage clamp can move axially and also rotate, and the connecting shaft may also be arranged coaxially with the motor shaft, and so on. In addition, the elastic pressing device is mainly used for guiding the relative position of the working head and the torque transmission part, has no special requirement on the structure, can change the configuration correspondingly according to different internal patterns, can add new elements and can reduce unnecessary elements.

Claims

1. A power tool, comprising:

a housing;

a motor disposed in the housing and outputting rotational power;

the output shaft is provided with an axially arranged accommodating hole for accommodating the working head, and the working head is provided with a torque stress part with a polygonal section;

the transmission mechanism is arranged between the motor and the output shaft and can transmit the rotary power output by the motor to the output shaft;

the working head supporting mechanism is arranged in the shell and is provided with a plurality of accommodating spaces which are arranged in parallel and used for supporting the working heads;

the connecting shaft is arranged in the machine shell and can enable the working head to be positioned at a working position in the accommodating hole or at an accommodating position of the working head supporting mechanism;

the method is characterized in that: the accommodating hole comprises a torque transmission part and a correction part, the torque transmission part can limit the working head to rotate relative to the output shaft, the output shaft is provided with an elastic abutting device, at least part of the elastic abutting device extends into the correction part, and when the working head enters the torque transmission part from the correction part, the working head can rotate relative to the output shaft under the action of the elastic abutting device.

2. The power tool of claim 1, wherein: the torque transmission part comprises at least one radial protrusion, and the at least one radial protrusion abuts against the torque stress part and limits the working head to rotate relative to the output shaft.

3. The power tool of claim 1 or 2, wherein: the torque transmission part comprises twelve radial protrusions which are uniformly arranged, the twelve radial protrusions are in contact with the torque stress part and limit the working head to rotate relative to the output shaft, and the part of the elastic pressing device, which extends into the correction part, is aligned with the joint part of two adjacent radial protrusions in the twelve radial protrusions along the axial extension line.

4. The power tool of claim 1 or 2, wherein: the torque transmission part comprises six radial protrusions, the six radial protrusions are twelve-pointed star-shaped, and the six radially opposite and uniformly arranged angles, and the part of the elastic pressing device extending into the correction part is aligned with one of the six radial protrusions along an axial extension line.

5. The power tool of claim 4, wherein: and every two radial bulges of the six radial bulges are in circular arc transition.

6. The power tool of claim 1, wherein: the elastic pressing device comprises a pressing piece partially extending into the correcting part and an elastic element, and the elastic element radially and inwards biases the pressing piece along the output shaft.

7. The power tool of claim 6, wherein: the elastic element is an elastic sheet arranged along the axial direction of the output shaft, one end of the elastic sheet is fixed relative to the shell, and the other end of the elastic sheet biases the pressing piece.

8. The power tool of claim 1, wherein: the elastic pressing device comprises an elastic element, the elastic element is provided with a pressing part extending into the correcting part, and the pressing part can move along the radial direction of the output shaft between a free state and a biasing state of the elastic element.

9. The power tool of claim 8, wherein: the elastic element comprises at least one C-shaped steel wire arranged around the output shaft, and the abutting parts are arranged on two sides of the opening of the C-shaped steel wire.

10. The power tool of claim 9, wherein: the C-shaped steel wires are arranged in two numbers and are distributed at intervals along the axial direction of the output shaft.

11. The power tool of claim 10, wherein: and the two pressing parts of the two C-shaped steel wires are arranged in a staggered manner along the circumferential direction.

12. The power tool of claim 8, wherein: the elastic element is an elastic sheet arranged along the axial direction of the output shaft, one end of the elastic sheet is fixed relative to the shell, and the pressing part is arranged at the other end of the elastic sheet.