CN113153860B

CN113153860B - Telescopic reciprocating mechanism

Info

Publication number: CN113153860B
Application number: CN202110497825.9A
Authority: CN
Inventors: 王立峰; 王秀强; 冷长庚; 吴龙龙; 尹伟科
Original assignee: Weifang Lichuang Electronic Technology Co Ltd
Current assignee: Weifang Lichuang Electronic Technology Co Ltd
Priority date: 2021-05-08
Filing date: 2021-05-08
Publication date: 2022-07-08
Anticipated expiration: 2041-05-08
Also published as: CN113153860A

Abstract

The invention provides a telescopic reciprocating mechanism which comprises a cylinder body, a piston rod, a rotary return mechanism and a reciprocating return mechanism, wherein the rotary return mechanism is arranged on the cylinder body and is used for applying return torque to the piston rod, and the reciprocating return mechanism is used for enabling the piston rod to axially return; the periphery of the piston is provided with a spiral ring groove and a spiral fluid groove communicated with a fluid pressure cavity between the piston and the cylinder body; the cylinder body is provided with a fluid inlet hole, a fluid outlet hole and a fixing pin; the spiral fluid groove is selectively communicated with the fluid inlet hole or the fluid outlet hole; under the action of fluid in the fluid pressure cavity and the reciprocating return mechanism, the spiral ring groove is matched with the fixing pin to enable the piston rod to do rotary telescopic motion and enable the rotary return mechanism to generate return torque; when the piston rod extends forwards or retracts backwards to the right position, the piston rod changes the current steering direction under the action of the return torque, and the communication state of the spiral fluid groove and the fluid inlet hole and the fluid outlet hole is switched. The invention can realize automatic reciprocating motion without adding a reversing mechanism, and has simple structure and low manufacturing cost.

Description

Telescopic reciprocating mechanism

Technical Field

The invention belongs to the technical field of reciprocating mechanisms, and particularly relates to a telescopic reciprocating mechanism.

Background

There are many mechanisms for realizing the reciprocating motion, such as a crank link mechanism, a linear screw mechanism, a cam mechanism, a hydraulic push rod mechanism, and the like. In a hydraulic system, a hydraulically-driven reciprocating mechanism is common, the structure generally needs a reversing mechanism such as a reversing valve besides a cylinder body, a piston and a piston rod, and the reversing mechanism is used for changing the direction of oil inlet and outlet to realize the reciprocating motion of the piston; although the reciprocating motion can be realized, the reciprocating motion is unstable, the reciprocating stroke cannot be well controlled, and the using effect is poor.

In view of this, some hydraulic automatic reciprocating motions without a reversing mechanism are produced, for example, chinese patent specification CN10915436A discloses a reciprocating hydraulic driving device, which is specifically disclosed in paragraphs [0021] to [0022] of the specification and fig. 2 "comprising a hydraulic cylinder body, a hydraulic piston, a piston rod and a flow distribution mechanism, wherein the hydraulic cylinder body is provided with a first oil injection port, a second oil injection port and a pressure relief oil port, the hydraulic piston is arranged between the two oil injection ports and divides the hydraulic cylinder body into a first oil injection chamber and a second oil injection chamber; the flow distribution mechanism comprises a flow distribution block which is arranged in the first oil injection cavity and can generate axial reciprocating movement and a driving mechanism which is matched with the piston rod and used for driving the flow distribution block, a pressure relief oil port is also arranged on the hydraulic cylinder body, an oil injection channel for opening and closing the first oil injection hole and the first oil injection cavity and a pressure relief channel for opening and closing the pressure relief oil hole and the first oil injection cavity are arranged on the flow distribution block, and the communication between the pressure relief channel and the pressure relief oil port and the communication between the oil injection channel and the first oil injection hole are realized through the axial reciprocating movement switching of the flow distribution block; when first oiling mouth and oiling passageway intercommunication, the hydraulic piston of oiling in the first oiling chamber moves to the right, moves to certain extent when hydraulic piston and piston rod and drives actuating mechanism motion for actuating mechanism can drive and join in marriage a class piece and move to the right, to first oiling chamber pressure release when moving pressure release hydraulic fluid port and pressure release passageway intercommunication, first oiling mouth and oiling passageway do not communicate this moment, and the automatic leftward movement of hydraulic piston under the pressure of second oiling chamber oiling, so, form reciprocating motion process.

Although the reciprocating hydraulic driving device can realize automatic reciprocating motion without a reversing valve, the reciprocating hydraulic driving device has a complex structure and high manufacturing cost, and the response speed of the reciprocating motion can be influenced by utilizing the linkage of a plurality of parts in the hydraulic cylinder body to realize reversing, so that the reciprocating hydraulic driving device is not beneficial to popularization and application.

Disclosure of Invention

The invention aims to overcome the problems in the prior art, and aims to provide a telescopic reciprocating mechanism which can realize automatic reciprocating motion without additionally arranging a reversing valve, and has the advantages of simple structure, low manufacturing cost and high reciprocating motion response speed.

In order to solve the problems in the prior art, an embodiment of the present invention provides a telescopic reciprocating mechanism, which includes a cylinder, a piston disposed in the cylinder, and a piston rod connected to one end of the piston, wherein a fluid pressure chamber is formed between the other end of the piston and the cylinder; the piston rod resetting mechanism is arranged on the cylinder body and used for applying resetting torque to the piston rod; the periphery of the piston is provided with a spiral ring groove and a spiral fluid groove which have the same spiral line direction, and the spiral fluid groove is communicated with the fluid pressure cavity; the cylinder body is provided with a fluid inlet hole, a fluid outlet hole and a fixing pin with one end extending into the spiral annular groove; the spiral fluid slot is selectively communicated with the fluid inlet hole or the fluid outlet hole;

under the action of fluid in the fluid pressure cavity and the reciprocating return mechanism, the spiral ring groove is matched with the fixing pin to enable the piston rod to do rotary telescopic motion relative to the cylinder body and enable the rotary return mechanism to generate return torque; when the piston rod extends out in place in a forward rotation mode or retracts back in place in a reverse rotation mode, the current rotation direction of the piston rod is changed under the action of the return torque, and the communication state of the spiral fluid groove and the fluid inlet hole and the fluid outlet hole is switched.

As a further improvement, the spiral ring groove comprises two spiral groove sections and two transverse groove sections connected between the two spiral groove sections; the spiral line direction of the spiral groove section is the same as that of the spiral fluid groove;

the spiral groove section is used for being matched with the fixing pin to realize the rotary extending or rotary retracting movement of the piston rod; the transverse groove section is used for being matched with the fixing pin to realize the communication between the spiral fluid groove and the fluid inlet hole or the fluid outlet hole.

As a further improvement, the periphery of the piston is symmetrically provided with two spiral ring grooves and two spiral fluid grooves;

one of the spiral fluid slots is selectively communicated with the fluid inlet hole or the fluid outlet hole; the cylinder body is provided with two fixing pins, and the fixing pins correspond to the spiral annular grooves one to one.

As a further improvement, the rotary return mechanism comprises an installation seat and a deflector rod, the installation seat is fixedly connected with the cylinder body, the deflector rod is axially connected with the piston rod in a sliding and synchronous rotating manner, and the deflector rod is axially limited on the installation seat;

an arc-shaped groove unit is arranged on the mounting seat and comprises two arc-shaped guide grooves which are symmetrically arranged, and the circle center of each arc-shaped guide groove is concentric with the rotation center of the piston rod; each arc-shaped guide groove is internally provided with a sliding piece, a return elastic piece is arranged between the two sliding pieces, and one end part of the shifting lever is clamped between the two sliding pieces.

As a further improvement, the sliding piece is provided with a limiting structure for preventing the sliding piece from axially shifting on the mounting seat.

As a further improvement, the mounting seat comprises two limiting plates which are detachably connected and have the same structure; the arc-shaped groove unit is arranged on the limiting plate;

the slider is including being located two spacing axial region between the limiting plate with set up in the slip axial region of spacing axial region both sides, and two the slip axial region respectively with correspond on the limiting plate arc guide way looks adaptation.

As a further improvement, the mounting seat is symmetrically provided with two arc-shaped groove units; correspondingly, the other end of the shifting lever is clamped between the two sliding pieces corresponding to the other arc-shaped groove unit.

As a further improvement, two return elastic pieces are arranged between two sliding pieces corresponding to the same arc-shaped groove unit, and the two return elastic pieces are respectively positioned on two sides of the mounting seat.

As a further improvement, the shifting lever comprises a connecting part and shifting parts arranged on two sides of the connecting part, the connecting part is provided with a waist-shaped hole, and the shifting parts are positioned between the two sliding parts;

the piston rod comprises a profiling rod part matched with the waist-shaped hole.

As a further improvement, the reciprocating return mechanism comprises a limiting frame fixed on the rotary return mechanism, a mounting rod fixedly connected with the piston rod and extending out of the limiting frame, and an axial return elastic piece sleeved on the mounting rod; one end of the axial return elastic piece is abutted against the inner wall of the limiting frame body, and the other end of the axial return elastic piece is abutted against a step surface formed between the mounting rod and the piston rod.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

the invention relates to a telescopic reciprocating mechanism, which comprises a cylinder body, a piston arranged in the cylinder body and a piston rod connected with one end of the piston, wherein a fluid pressure cavity is formed between the other end of the piston and the cylinder body; the reciprocating type piston rod resetting device is characterized by also comprising a rotary resetting mechanism and a reciprocating resetting mechanism, wherein the rotary resetting mechanism is arranged on the cylinder body and is used for applying a resetting torque to the piston rod, and the reciprocating resetting mechanism is used for enabling the piston rod to axially reset; the periphery of the piston is provided with a spiral ring groove and a spiral fluid groove with the same spiral line direction, and the spiral fluid groove is communicated with the fluid pressure cavity; the cylinder body is provided with a fluid inlet hole, a fluid outlet hole and a fixing pin with one end extending into the spiral ring groove; the spiral fluid slot is selectively in communication with either the fluid inlet or the fluid outlet. Under the action of fluid in the fluid pressure cavity and the pressure of the reciprocating return mechanism, the spiral ring groove is matched with the fixing pin to enable the piston rod to do rotary telescopic motion relative to the cylinder body and enable the rotary return mechanism to generate return torque; when the piston rod extends out in place in the forward rotation mode or retracts back in place in the reverse rotation mode, the piston rod changes the current steering direction under the action of the return torque, and the communication state of the spiral fluid groove and the fluid inlet hole and the fluid outlet hole is switched. When the piston rod extends out in place in a forward rotation mode, the piston rod rotates reversely under the action of return torque, the spiral fluid groove is switched from being communicated with the fluid inlet hole to being communicated with the fluid outlet hole, and the piston rod begins to rotate reversely and retract; when the piston rod reversely rotates and retracts to the right position, the piston rod rotates forwards under the action of return torque, the spiral fluid groove is switched from being communicated with the fluid outlet hole to being communicated with the fluid inlet hole, and the piston rod begins to rotate forwards and retract; thus, a reciprocating motion process is formed.

In conclusion, the automatic reciprocating motion of the piston rod can be realized without adding a reversing mechanism outside the cylinder body, the structure is simpler than the prior art, the manufacturing cost is greatly reduced, the number of parts involved in reversing is less, and the response speed of the reciprocating motion can be improved.

Drawings

FIG. 1 is a schematic structural view of a telescopic reciprocating mechanism of the present invention (the reciprocating return mechanism is omitted);

FIG. 2 is an exploded view of the structure of FIG. 1;

FIG. 3 is an axial cross-sectional view of the telescoping reciprocating mechanism of the present invention;

FIG. 4 is a sectional view taken along A _ A in FIG. 3;

FIG. 5 is a schematic plan-view development of the piston of FIG. 2;

FIG. 6 is an exploded view of the first embodiment of the swivel mechanism of FIG. 2;

FIG. 7 is a side view of a second embodiment of the swivel mechanism of FIG. 2;

FIG. 8 is an exploded view of a second embodiment of the swivel mechanism of FIG. 2;

FIG. 9 is a sectional view taken along line B _ B in FIG. 7;

fig. 10.1 and 10.2 are state reference diagrams of fig. 9 when a return torque is generated;

11.1-11.10 are schematic diagrams of the present invention implementing the reciprocating process;

in the figure: 1-cylinder body, 11-fluid inlet hole, 12-fluid outlet hole, 13-fixed pin, 2-piston, 21-spiral ring groove, 211-spiral groove section, 212-transverse groove section, 22-spiral fluid groove, 3-piston rod, 31-head, 32-profiling rod part, 4-fluid pressure chamber, 5-rotary return mechanism, 51-mounting seat, 511-limiting plate, 5111-avoiding hole, 512-arc groove unit, 5121-arc guide groove, 513-first sliding part, 514-second sliding part, 5141-limiting shaft part, 5142-sliding shaft part, 515-return elastic part, 516-snap spring, 517-bearing, 518-return elastic part mounting hole, 52-deflector rod, 521-connecting part, 5211-waist-shaped hole, 522-a shifting part, 6-a reciprocating return mechanism, 61-a limiting frame body, 62-an installation rod, 63-an axial return elastic part and a-a step surface.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments and orientations of "left", "right", "up", "down", etc. in the embodiments and examples described herein are merely illustrative and not restrictive.

The first embodiment is as follows:

as shown in fig. 1 to 4, the telescopic reciprocating structure disclosed in this embodiment includes a cylinder 1, a piston 2 disposed in the cylinder 1, and a piston rod 3 connected to one end of the piston 2, wherein a fluid pressure chamber 4 is formed between the other end of the piston 2 and the cylinder 1; the piston rod resetting mechanism further comprises a rotary resetting mechanism 5 and a reciprocating resetting mechanism 6, wherein the rotary resetting mechanism 5 is arranged on the cylinder body 1 and is used for applying a resetting torque to the piston rod 3, and the reciprocating resetting mechanism 6 is used for enabling the piston rod 3 to axially reset; the periphery of the piston 2 is provided with a spiral ring groove 21 and a spiral fluid groove 22 with the same spiral line direction, and the opening end of the spiral fluid groove 22 is communicated with the fluid pressure cavity 4; the cylinder body 1 is provided with a fluid inlet hole 11, a fluid outlet hole 12 and a fixing pin 13 with one end extending into the spiral ring groove 21; the spiral fluid slot 22 may alternatively be in communication with the fluid inlet aperture 11 or the fluid outlet aperture 12.

Under the action of fluid (flowing media such as hydraulic oil and gas) in the fluid pressure cavity 4 and the reciprocating return mechanism 6, the spiral annular groove 21 is matched with the fixing pin 13 to enable the piston rod 3 (and the piston 2) to do rotary telescopic motion relative to the cylinder body 1 and enable the rotary return mechanism 5 to generate return torque; when the piston rod 3 extends out of the position in the forward rotation mode or retracts back into the position in the reverse rotation mode, the piston rod 3 changes the current steering direction under the action of the return torque generated by the rotary return mechanism 5, and the communication state of the spiral fluid groove 22 with the fluid inlet hole 11 and the fluid outlet hole 12 is switched.

As shown in fig. 5, the spiral ring groove 21 in the present embodiment includes two spiral groove segments 211 and two transverse groove segments 212 connected between the two spiral groove segments 211; the spiral groove segment 211 follows the same spiral as the spiral fluid groove 22. Wherein, the spiral groove section 211 is used for cooperating with the fixed pin 13 to realize the rotary extending or rotary retracting movement of the piston rod 3; the transverse groove section 212 is used for being matched with the fixed pin 13 to realize the communication of the spiral fluid groove 22 and the fluid inlet hole 11 or the fluid outlet hole 12, and further realize the reversing of the reciprocating motion.

In order to equalize the forces applied to the piston 2 to ensure the stable reliability of the reciprocating motion; in the embodiment, the piston 2 is further optimized, and two spiral ring grooves 21 and two spiral fluid grooves 22 are symmetrically arranged on the circumference of the optimized piston 2; one of the spiral fluid slots 22 is selectively in communication with either the fluid inlet aperture 11 or the fluid outlet aperture 12. Correspondingly, two fixing pins 13 are arranged on the cylinder body 1, and the fixing pins 13 correspond to the spiral ring grooves 21 one by one. When the fixing pin 13 is set to the dot-dash position, the rotary return mechanism 5 is set to the neutral position.

As shown in fig. 6, in the present embodiment, the rotary return mechanism 5 includes an installation seat 51 and a shift lever 52 which are integrated into a whole, the installation seat 51 is fixedly connected with the cylinder 1, the shift lever 52 is axially slidably and synchronously connected with the piston rod 3, and the shift lever 52 is axially limited on the installation seat 51; the installation seat 51 is provided with an arc-shaped groove unit 512, the arc-shaped groove unit 512 comprises two arc-shaped guide grooves 5121 which are symmetrically arranged, and the circle center of each arc-shaped guide groove 5121 is concentric with the rotation center of the piston rod 3; each arc-shaped guide groove 5121 is provided with a sliding member (referred to as a first sliding member 513), a return elastic member 515 (preferably a spring) is disposed between the two first sliding members 513, and one end of the shift lever 52 is sandwiched between the two first sliding members 513. In the free state of the return elastic member 515, the distance between the two first sliding members 513 is S, and the width of one end of the shift lever 52 is S. Regardless of whether the plunger 52 (piston rod 3) rotates clockwise or counterclockwise, the plunger 52 and the piston rod 3 will receive a return torque to the neutral position by the return elastic member 515.

In this embodiment, a bearing 517 is disposed on the mounting seat 51, a cylindrical mounting portion is disposed on the shift lever 52, the cylindrical mounting portion is mounted in the bearing 517, and the purpose that the shift lever 52 is axially limited on the mounting seat 51 and rotates relative to the mounting seat is achieved by the bearing 517.

In some embodiments, the center of the mounting seat 51 is provided with an annular hole, the shifting rod 52 is provided with a cylindrical portion corresponding to the annular hole, and the cylindrical portions at two sides of the mounting seat 51 are provided with limiting members, so that the purpose that the shifting rod 52 is axially limited on the mounting seat 51 and rotates relatively is achieved; the structures for realizing axial limit are many, and are not listed here.

In this embodiment, in order to prevent the first sliding member 513 from moving axially on the mounting base 51, a limiting structure (such as a clamp spring 516) may be disposed on a portion of the first sliding member 513 extending out of two sides of the mounting base 51.

In order to further ensure the stable reliability of the structure, the present embodiment is further optimized based on the above structure, and two arc-shaped slot units 512 are symmetrically arranged on the mounting seat 51; accordingly, the other end portion of the shift lever 52 is sandwiched between the two first sliding members 513 corresponding to the other arc-shaped slot unit 512.

In order to ensure that the rotary return mechanism 5 applies an effective return torque to the piston rod 3; in this embodiment, a further improvement is that two return elastic members 515 are disposed between two first sliding members 513 corresponding to the same arc-shaped slot unit 512, and the two return elastic members 515 are respectively located at two sides of the mounting base 51, that is, the portions of the first sliding members 513 extending out of the two sides of the mounting base 51 are both provided with return elastic member mounting holes 518.

In this embodiment, the reciprocating return mechanism 6 includes a limiting frame 61 fixed on the rotary return mechanism 5, an installation rod 62 fixedly connected with the piston rod 3 and extending out of the limiting frame 61, and an axial return elastic member 63 (preferably a spring) sleeved on the installation rod 62; one end of the axial return elastic member 63 abuts against the inner wall of the stopper frame 61, and the other end abuts against a stepped surface a formed between the mounting rod 62 and the piston rod 3.

Example two:

the second embodiment has substantially the same structure as the first embodiment, except that the rotary return mechanism 5 is adopted, so that the rotary return mechanism 5 in the second embodiment is more convenient to assemble and has a simple assembly mode. Only the differences will be described in detail below.

As shown in fig. 7 to 9 and fig. 10.1 and 10.2, the optimized mounting seat 51 has a split structure, and includes two limiting plates 511 (circular limiting plates) detachably connected by a pin and having the same structure; the two arc-shaped groove units 512 are arranged on the limiting plate 511; a slider (referred to as a second slider 514) is disposed in each of the arc-shaped guide grooves 5121. The second slider 514 is axially restrained by means of two restraining plates 511; the second sliding member 514 includes a limiting shaft portion 5141 located between the two limiting plates 511 and sliding shaft portions 5142 disposed at two sides of the limiting shaft portion 5141, the two sliding shaft portions 5142 are respectively matched with the arc-shaped guiding grooves 5121 of the corresponding limiting plates 511, and the portions of the sliding shaft portions 5142 extending out of the arc-shaped guiding grooves 5121 of the corresponding limiting plates 511 are provided with return elastic member mounting holes 518.

In this embodiment, the shift lever 52 includes a connecting portion 521 and a shift portion 522 disposed at two sides of the connecting portion 521, the connecting portion 521 is provided with a waist-shaped hole 5211, and the shift portion 522 is located between the two second sliding members 514 in the same arc-shaped slot unit 512; the piston rod 3 comprises a head 31 fixedly connected with the piston 2 and a profiled rod part 32 which is matched with the waist-shaped hole 5211 to realize axial sliding and synchronous rotating connection. The limiting plate 511 is provided with an avoiding hole 5111 matched with the connecting part 521 in the center.

In other embodiments, the shift lever 52 and the piston rod 3 are connected in an axially sliding and synchronous rotating manner through other structures such as a key connection structure or a linear bearing structure; and will not be described herein.

The working principle of the method is briefly explained based on the above description:

shown collectively in fig. 3, 5, 11.1 through 11.10; for ease of understanding, the up-and-down motion directions shown in fig. 11.1 to 11.10 correspond to the axial reciprocating motion of the piston rod 3 and the piston 2 in the implementation application; the corresponding left and right movements in the figure correspond to the rotational movements of the piston rod 3 and the piston 2 in the implementation application. Fig. 11.1-11.6 are views of the movement of piston 2 against the pressure of axially return resilient member 63 under the action of the pressure generated by the fluid in fluid pressure chamber 4; fig. 11.7-11.10 are views of the movement of the piston 2 under the force of the axial return spring 63.

Here, as shown in fig. 11.1, when the rotary return mechanism 5 is at the neutral position, the return torque is zero, and the spiral fluid groove 22 is communicated with the fluid inlet hole 11. As shown in fig. 11.2 to 11.4, under the action of the fluid in the fluid pressure chamber 4 and the pressure of the axial return elastic element 63 in the reciprocating return mechanism 6, one spiral groove section 211 in the spiral annular groove 21 cooperates with the fixing pin 13 to make the piston rod 3 (piston 2) perform a forward rotation and extension movement relative to the cylinder 1 (in the schematic direction in the figure, the piston 2 moves downward and leftward relative to the cylinder 1, and the axial return elastic element 63 is compressed), and make the rotary return mechanism 5 generate a return torque (rightward). As shown in fig. 11.5 to 11.6, when the piston rod 3 is extended forward to a certain position, i.e. the fixing pin 13 is located in one of the transverse groove sections 212, under the action of the return torque of the rotary return mechanism 5, the piston rod 3 changes the current direction of rotation to start reverse rotation (the piston 2 moves to the right relative to the cylinder 1 in the direction indicated in the figure), the spiral fluid groove 22 is switched from communicating with the fluid inlet hole 11 to communicating with the fluid outlet hole 12, and the fixing pin 13 is located at the end of the other spiral groove section 211.

Under the elastic restoring force of the axial restoring elastic member 63, another spiral groove section 211 cooperates with the fixing pin 13 to start reverse retraction of the piston rod 3 (in the schematic direction, the piston 2 moves upward and rightward relative to the cylinder 1 in the figure) and generate a restoring torque (leftward) for the rotary restoring mechanism 5, as shown in fig. 11.7 to 11.9. As shown in fig. 11.10, when the piston rod 3 is reversely rotated and retracted to the right, i.e. the fixing pin 13 is located in the other transverse groove section 212, the piston rod 3 changes the current direction to start the forward rotation (the piston 2 moves leftwards relative to the cylinder 1 in the schematic direction in the figure) under the action of the return torque of the rotary return mechanism 5, and the spiral fluid groove 22 is switched from being communicated with the fluid outlet hole 12 to being communicated with the fluid inlet hole 11; the piston rod 3 starts to extend forwards (the state of fig. 11.1); thus, a reciprocating motion process is formed.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A telescopic reciprocating mechanism comprises a cylinder body, a piston arranged in the cylinder body and a piston rod connected with one end of the piston, wherein a fluid pressure cavity is formed between the other end of the piston and the cylinder body; the piston rod resetting device is characterized by further comprising a rotary resetting mechanism and a reciprocating resetting mechanism, wherein the rotary resetting mechanism is arranged on the cylinder body and used for applying a resetting torque to the piston rod, and the reciprocating resetting mechanism is used for enabling the piston rod to axially reset; the periphery of the piston is provided with a spiral ring groove and a spiral fluid groove which have the same spiral line direction, and the spiral fluid groove is communicated with the fluid pressure cavity; the cylinder body is provided with a fluid inlet hole, a fluid outlet hole and a fixing pin with one end extending into the spiral ring groove; the spiral fluid slot is selectively communicated with the fluid inlet hole or the fluid outlet hole;

2. The telescoping reciprocation mechanism of claim 1 wherein the helical ring groove includes two helical groove segments and two transverse groove segments connected between the two helical groove segments; the spiral line direction of the spiral groove section is the same as that of the spiral fluid groove;

3. The telescopic reciprocating mechanism according to claim 1 or 2, wherein two of the spiral ring grooves and two of the spiral fluid grooves are symmetrically provided on a circumference of the piston;

one of the spiral fluid slots is selectively communicated with the fluid inlet hole or the fluid outlet hole; the cylinder body is provided with two fixing pins, and the fixing pins correspond to the spiral ring grooves one to one.

4. The telescopic reciprocating mechanism according to claim 1, wherein the rotary return mechanism comprises a mounting seat and a shift lever, the mounting seat is fixedly connected with the cylinder body, the shift lever is axially slidably and synchronously rotatably connected with the piston rod, and the shift lever is axially limited on the mounting seat;

5. The telescoping reciprocating mechanism of claim 4, wherein the slider is provided with a stop structure for preventing axial play on the mount.

6. The telescopic reciprocating mechanism according to claim 4, wherein the mounting seat comprises two removably connected and identically structured limiting plates; the arc-shaped groove unit is arranged on the limiting plate;

7. The telescopic reciprocating mechanism according to any one of claims 4 to 6, wherein two arc-shaped groove units are symmetrically arranged on the mounting seat; correspondingly, the other end of the shifting lever is clamped between the two sliding pieces corresponding to the other arc-shaped groove unit.

8. The telescopic reciprocating mechanism according to claim 7, wherein two return elastic members are provided between two sliding members corresponding to the same arc-shaped groove unit, and the two return elastic members are respectively located on both sides of the mounting seat.

9. The telescopic reciprocating mechanism according to claim 4, wherein the shift lever comprises a connecting portion and a shifting portion disposed at both sides of the connecting portion, the connecting portion is provided with a kidney-shaped hole, and the shifting portion is located between the two sliding members;

10. The telescopic reciprocating mechanism of claim 1, wherein the reciprocating return mechanism comprises a limit frame fixed on the rotary return mechanism, a mounting rod fixedly connected with the piston rod and extending out of the limit frame, and an axial return elastic member sleeved on the mounting rod; one end of the axial return elastic piece is abutted against the inner wall of the limiting frame body, and the other end of the axial return elastic piece is abutted against a step surface formed between the mounting rod and the piston rod.