Small self-locking air cylinder

Abstract

The utility model discloses a small self-locking air cylinder which comprises a cylinder body, an end cover for a central shaft to extend out is a front end cover, both the front end cover and a rear end cover are provided with air inlets and inner cavities, and the air inlets are communicated to an inner cavity of the cylinder body through the corresponding inner cavities; the front end cover is provided with a self-locking device, the end of a lock pin of the self-locking device abuts against the outer circle face of the center shaft, and the outer circle face, close to the piston, of the center shaft is provided with a matching section buckled with the lock pin. The lock pin is arranged in a driving cavity in a sliding mode, and the driving cavity is arranged in the radial direction of the center shaft. A driving ring on the outer side of the lock pin is in piston motion fit with the inner wall of the driving cavity, the far-shaft side of the driving ring is connected with the end face of the driving cavity through an elastic piece, an air inlet cavity is formed between the near-shaft side of the driving ring and the wall of the driving cavity, and the air inlet cavity is communicated with the inner cavity of the front end cover. The self-locking cylinder solves the problem that a self-locking device cannot be installed on a small-sized cylinder due to small space, so that the self-locking function is difficult to realize.

Description

Technical Field

[0001] The utility model relates to the technical field of cylinders, in particular to a small self-locking cylinder. Background Art

[0002] Cylinders are common reciprocating linear motion actuators with a wide range of applications. For some movements that need to stay in an extreme position for a period of time, the cylinders used are required to have a self-locking function. However, in some precision-matching structures, only small cylinders can be used for driving. Due to their small structure, they cannot be installed with existing self-locking structures with active driving capabilities, which makes it difficult for small cylinders to achieve reliable self-locking functions. Summary of the invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art, the utility model provides a small self-locking cylinder to solve the problem that the small cylinder cannot be installed with a self-locking device due to the small space, thus making it difficult to achieve the self-locking function.

[0004] Technical solution: To achieve the above-mentioned purpose, the utility model provides a small self-locking cylinder, including a cylinder body, the cylinder body is provided with a front end cover and a rear end cover, wherein the front end cover is provided for the central axis to extend, the inner end of the central axis is fixedly connected to the piston, and the piston is slidably matched with the inner wall of the cylinder body; the front end cover and the rear end cover are both provided with an air inlet and an inner chamber, and the air inlet is connected to the inner chamber of the cylinder body through the corresponding inner chamber; the front end cover is provided with a self-locking device, the end of the lock pin of the self-locking device is pressed tightly against the outer cylindrical surface of the central axis, and the outer cylindrical surface of the central axis close to the piston is provided with a matching section with a lock pin buckle; the lock pin is slidably arranged in a drive cavity, and the drive cavity is arranged radially along the central axis; the drive ring on the outer side of the lock pin is matched with the piston movement of the inner wall of the drive cavity, the far axis side of the drive ring is connected to the end face of the drive cavity through an elastic member, and an air inlet cavity is formed between the proximal axis side of the drive ring and the drive cavity wall, and the air inlet cavity is connected with the inner chamber of the front end cover.

[0005] Furthermore, the inner chamber is an annular cavity coaxial with the central axis, and the locking pin extends from the inner wall of the inner chamber of the front end cover.

[0006] Furthermore, both ends of the driving cavity are provided with through holes that are slidably matched with the ends of the locking pin, and the inner walls of the through holes are provided with self-lubricating bearings.

[0007] Furthermore, an annular groove is provided on the outer circumferential surface of the driving ring, and a sealing ring is embedded in the annular groove.

[0008] Furthermore, the air inlet cavity is connected to the inner chamber through an air hole, and a plurality of the air holes are symmetrically arranged relative to the locking pin.

[0009] Furthermore, a plunger structure cooperating with the inner chamber is arranged on the end surface of the piston.

[0010] Beneficial effects: The utility model is a small self-locking cylinder, which realizes the self-locking function after the center axis is extended to the limit position by burying a specially designed self-locking device inside the front end cover of the original cylinder body, and occupies a small space; and by connecting the air intake cavity of the inner chamber, the gas that pushes the center axis to retract is used to drive the unlocking of the self-locking device, and there is no need to install other active driving devices, making the overall structure compact, which solves the problem that the small cylinder cannot be installed with an actively driven unlocking self-locking device due to the small space, thus making it difficult to realize the self-locking function. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Attached Figure 1 This is a schematic cross-sectional view of the overall structure of an embodiment of the utility model;

[0012] Attached Figure 2 This is a schematic diagram of the structure of a self-locking device according to an embodiment of the utility model;

[0013] Attached Figure 3 The figure is a schematic diagram of the front end cover structure of an embodiment of the utility model. DETAILED DESCRIPTION

[0014] The utility model is further described below in conjunction with the accompanying drawings.

[0015] As attached Figure 1-3 The small self-locking cylinder comprises a cylinder body 1, wherein the cylinder body 1 is provided with a front end cover 2 and a rear end cover 3, wherein the front end cover 2 is provided for the central shaft 4 to extend, the inner end of the central shaft 4 is fixedly connected to a piston 5, and the piston 5 is slidably matched with the inner wall of the cylinder body 1; the front end cover 2 and the rear end cover 3 are both provided with an air inlet 8 and an inner chamber 6, and the air inlet 8 is connected to the inner cavity of the cylinder body 1 through the corresponding inner chamber 6; the front end cover 2 is provided with a self-locking device 7, and the end of the locking pin 71 of the self-locking device 7 is pressed tightly against the outer wall of the central shaft 4 A matching section 41 which is snapped with a locking pin 71 is provided on the outer circular surface of the central axis 4 close to the piston 5; the locking pin 71 is slidably arranged in a driving cavity 72, and the driving cavity 72 is radially arranged along the central axis 4; a driving ring 73 on the outer side of the locking pin 71 cooperates with the piston movement of the inner wall of the driving cavity 72, and the distal side of the driving ring 73 is connected to the end face of the driving cavity 72 through an elastic member 74, and an air inlet cavity 75 is formed between the proximal side of the driving ring 73 and the driving cavity wall, and the air cavity 75 is connected to the inner cavity 6 of the front end cover.

[0016] This solution is based on the original cylinder structure, and the parts are processed and assembled on the end cover to form an embedded self-locking structure, which does not occupy the internal space of the cylinder body and does not increase the volume of the cylinder body. The elastic potential energy accumulated by the elastic member makes the lock pin press against the surface of the central axis, so that after the central axis is extended to a certain length, when the matching section corresponds to the position of the lock pin, the lock pin can be naturally buckled with the matching section under the action of the elastic force, thereby restricting the axial movement of the central axis and realizing self-locking. And when the central axis needs to retract, by introducing compressed gas from the front air inlet, the compressed gas acts on the piston and the drive ring at the same time, thereby pushing the lock pin out of the matching section to realize the unlocking function. Therefore, there is no need to install an additional unlocking drive device to drive the reset movement of the lock pin, so that the self-locking device has a simple and compact structure and occupies a small space. It will not occupy the original space of the cylinder and will not indirectly increase the volume of the cylinder. It effectively solves the problem that small cylinders cannot install self-locking devices due to small space, thus making it difficult to realize the self-locking function.

[0017] The inner chamber 6 is an annular cavity coaxial with the central axis 4, and an annular air distribution port is provided on the inner end face of the end cover, so that the compressed gas can act evenly on the piston end face; the end face of the piston 5 is provided with a plunger structure 51 that cooperates with the inner chamber 6. When the piston moves close to the end cover, the plunger structure will enter from the annular air distribution port to cooperate with the inner chamber 6, blocking the gas outlet channel, so that a closed annular space is formed between the piston and the end cover, and the buffering effect is achieved by compressing the internal air. At the same time, because the plunger structure blocks the annular air distribution port, when air is taken in from the front end cover air inlet, the input compressed gas will first enter the air inlet cavity, push the lock pin out of the matching section of the central axis, and achieve unlocking. At the same time, the gas acts on the end of the plunger structure, gradually pushing the plunger structure out of the inner chamber 6, so that the compressed gas can enter the cylinder body cavity to push the piston to move in the opposite direction, and achieve the retraction of the central axis. This effectively ensures that gas can enter the air inlet chamber to push the lock pin back to complete the unlocking action, making the self-locking device more reliable and avoiding the phenomenon of being locked and unable to retreat.

[0018] The locking pin 71 extends from the inner wall of the inner chamber 6 of the front end cover. Preferably, the matching section is configured as an annular groove. A plurality of self-locking devices can be evenly arranged in an annular shape, and simultaneously press against the surface of the center axis to balance the force on the center axis, thereby avoiding bending of the center axis due to unilateral pressure, which affects the service life of the cylinder.

[0019] Both ends of the driving cavity 72 are provided with through holes that are slidably matched with the ends of the locking pin 71, and the inner wall of the through hole is provided with a self-lubricating bearing 76. The outer end of the locking pin can be extended from the surface of the end cover, so that the state of the self-locking device can be observed intuitively, which is convenient for troubleshooting. The self-lubricating bearing is conducive to the sliding of the locking pin, avoiding the phenomenon of self-locking failure caused by being stuck and unable to pop out.

[0020] The outer circumferential surface of the driving ring 73 is provided with an annular groove, and a sealing ring 77 is embedded in the annular groove to prevent air leakage from affecting the effect of gas-driven unlocking. At the same time, the cavity where the spring is located is also a closed cavity. When the elastic member is compressed, the internal gas will also be compressed, so that the tightening force of the locking pin relative to the central axis is stronger, thereby avoiding the phenomenon of insufficient tightening force, the inability of the locking pin to pop out, and the failure of self-locking.

[0021] The air inlet cavity 75 is connected to the inner chamber 6 via an air hole 78. The plurality of air holes 78 are symmetrically arranged relative to the locking pin 71 to ensure that the compressed gas enters the air inlet cavity evenly and acts on the driving ring, so that the driving ring is subjected to uniform force, thereby avoiding damage to the locking pin and the driving ring structure caused by eccentric force and extending the service life of the self-locking device.

[0022] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A small self-locking cylinder, characterized in that: The invention comprises a cylinder body (1), wherein the cylinder body (1) is provided with a front end cover (2) and a rear end cover (3), wherein the front end cover (2) is provided for a central shaft (4) to extend out, the inner end of the central shaft (4) is fixedly connected to a piston (5), and the piston (5) is slidably matched with the inner wall of the cylinder body (1); the front end cover (2) and the rear end cover (3) are both provided with an air inlet (8) and an inner chamber (6), and the air inlet (8) is connected to the inner chamber of the cylinder body (1) through the corresponding inner chamber (6); the front end cover (2) is provided with a self-locking device (7), and the end of a locking pin (71) of the self-locking device (7) is pressed tightly against the outer circumferential surface of the central shaft (4). The central axis (4) is provided with a mating section (41) which is snap-fitted with a locking pin (71) on its outer circumferential surface close to the piston (5); the locking pin (71) is slidably arranged in a driving cavity (72), and the driving cavity (72) is radially arranged along the central axis (4); a driving ring (73) on the outer side of the locking pin (71) is matched with the piston movement of the inner wall of the driving cavity (72), the distal side of the driving ring (73) is connected to the end face of the driving cavity (72) through an elastic member (74), and an air intake cavity (75) is formed between the proximal side of the driving ring (73) and the wall of the driving cavity, and the air intake cavity (75) is connected to the inner cavity (6) of the front end cover.

2. A small self-locking cylinder according to claim 1, characterized in that: The inner chamber (6) is an annular cavity coaxial with the central axis (4), and the locking pin (71) extends from the inner wall of the inner chamber (6) of the front end cover.

3. A small self-locking cylinder according to claim 2, characterized in that: Both ends of the driving cavity (72) are provided with through holes that are slidably matched with the ends of the locking pin (71), and the inner walls of the through holes are provided with self-lubricating bearings (76).

4. A small self-locking cylinder according to claim 3, characterized in that: The outer circumferential surface of the driving ring (73) is provided with an annular groove, and a sealing ring (77) is embedded in the annular groove.

5. A small self-locking cylinder according to claim 4, characterized in that: The air inlet cavity (75) is connected to the inner chamber (6) via an air hole (78), and a plurality of the air holes (78) are symmetrically arranged relative to the locking pin (71).

6. A small self-locking cylinder according to claim 5, characterized in that: A plunger structure (51) that cooperates with the inner chamber (6) is provided on the end surface of the piston (5).

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