Air buffering type air cylinder

Abstract

The utility model discloses an air buffering type air cylinder which comprises a cylinder body and a center shaft, the center shaft is arranged at the front end of the cylinder body in an axial telescopic mode, a piston is sleeved on the center shaft, and the piston is attached to the inner wall of the cylinder body and arranged in an axial sliding mode. The front end cover and the rear end cover of the cylinder body are respectively provided with an air inlet and outlet pipe connector, and the air inlet and outlet pipe connectors are communicated with an inner cavity of the cylinder body through transition air cavities. The end face of the piston is provided with a plugging structure matched with the communication opening in a protruding mode, when the plugging structure and the plugging structure are matched in a plugging mode, a buffer space is formed between the end face of the piston and the inner end face of the corresponding end cover, the buffer space is communicated with the transition air cavity through a buffer air channel, and the buffer air channel is provided with an on-off adjusting valve. And the central shaft is connected with the inner wall of the cylinder body through a rotary limiting structure. Air buffering is adopted, and the problem that buffering of a small-size air cylinder cannot be achieved by installing a buffering screw is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of cylinder structures, in particular to an air buffer type cylinder. Background Art

[0002] The cylinder is a common linear motion actuator. Due to the fast movement speed of its central axis, buffer screws are often installed to buffer the internal piston in order to increase its service life. However, since the buffer screws need to occupy a certain internal space, the overall size of the cylinder is limited. Therefore, buffering cannot be achieved by installing buffer screws in some small cylinders. Summary of the invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art, the utility model provides an air-buffered cylinder, which adopts air buffering to solve the problem that a small-volume cylinder cannot achieve buffering by installing buffer screws.

[0004] Technical solution: To achieve the above-mentioned purpose, the utility model provides an air-buffered cylinder, comprising a cylinder body and a central axis, wherein the central axis is axially telescopically arranged at the front end of the cylinder body, a piston is mounted on the central axis, and the piston is axially slidably arranged in contact with the inner wall of the cylinder body; the front and rear end covers of the cylinder body are respectively provided with inlet and outlet air pipe interfaces, and the inlet and outlet air pipe interfaces are connected with the inner cavity of the cylinder body through a transition air cavity, and the connecting port between the transition air cavity and the inner cavity of the cylinder body is located on the inner end face of the end cover; a sealing structure is protruded on the end face of the piston and cooperates with the connecting port, and when the two are sealed and cooperated, a buffer space is formed between the end face of the piston and the inner end face of the corresponding end cover, and the buffer space is connected with the transition air cavity through a buffer air path, and the buffer air path is provided with an on-off regulating valve; the central axis is connected to the inner wall of the cylinder body through a rotation limiting structure.

[0005] Furthermore, the transition air cavity is arranged as an annular cavity around the central axis, the connecting port is opened on the inner end surface of the end cover around the central axis, and the sealing structure is arranged as a plunger structure adapted to the inner diameter of the annular cavity, and the plunger structure is fixedly mounted relative to the central axis.

[0006] Furthermore, the buffer gas path includes a buffer hole parallel to the axial direction of the cylinder body and a bottom hole arranged along the radial direction of the cylinder body, and the buffer hole is connected to the middle part of the bottom hole; the on-off regulating valve includes a valve core movably arranged in the bottom hole.

[0007] Furthermore, the valve core is a stop screw, and the stop screw is threadably matched with the inner wall of the bottom hole.

[0008] Furthermore, the rotation limiting structure includes a polygonal shaft fixedly connected to the center of the rear end cover of the cylinder body, the polygonal shaft is extended along the axis direction of the cylinder body, and the end of the central shaft is slidably sleeved relative to the polygonal shaft.

[0009] Furthermore, a bushing is provided between the central shaft and the polygonal shaft, the bushing is fixedly plugged into the end mounting hole of the central shaft, and the inner cavity of the bushing is configured as a polygonal guide hole adapted to the polygonal shaft.

[0010] Beneficial effects: The utility model provides an air-buffered cylinder, which realizes air buffering by opening a transition air cavity and a buffer air path on the original cylinder end cover, arranging an adaptive blocking structure on the piston, and utilizing the piston movement in coordination with the valve core movement of the on-off regulating valve. Structurally, no excessively large structure is added, and the internal space of the cylinder body is small. Functionally, buffering can be achieved without installing buffer screws, solving the problem that small-volume cylinders cannot achieve buffering by installing buffer screws. Through the mutual cooperation of the non-rotating bushing and the multi-faceted shaft, a low-cost anti-axis rotation function is achieved, avoiding waste of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Attached Figure 1 The utility model is a schematic diagram of the overall structure of an embodiment. DETAILED DESCRIPTION

[0012] The utility model is further described below in conjunction with the accompanying drawings.

[0013] As attached Figure 1 The air-buffered cylinder comprises a cylinder body 1 and a central axis 2, wherein the central axis 2 is axially telescopically arranged at the front end of the cylinder body 1, and a piston 3 is mounted on the central axis 2, and the piston 3 is axially slidably arranged in contact with the inner wall of the cylinder body 1; the front and rear end covers of the cylinder body 1 are respectively provided with inlet and outlet air pipe interfaces 4, and the inlet and outlet air pipe interfaces 4 are connected with the inner cavity of the cylinder body 1 through a transition air cavity 5, and the connecting port between the transition air cavity 5 and the inner cavity of the cylinder body 1 is located on the inner end face of the end cover; a sealing structure 6 is protrudingly provided on the end face of the piston 3 and cooperates with the connecting port, and when the two are sealed and cooperated, a buffer space 7 is formed between the end face of the piston 3 and the inner end face of the corresponding end cover, and the buffer space 7 is connected with the transition air cavity 5 through a buffer air path 8, and the buffer air path 8 is provided with an on-off regulating valve 9; the central axis 2 is connected to the inner wall of the cylinder body 1 through a rotation limiting structure.

[0014] Based on the existing cylinder, this solution provides a transition air cavity directly connected to the inlet and outlet air pipe interfaces and a buffer air path connected to the inlet and outlet air pipe interfaces through an on-off regulating valve in the end cover. When the internal piston moves toward one end, the buffer air path in the end cover is closed, so that the gas in the cylinder directly enters the transition air cavity from the connecting port and is then discharged through the inlet and outlet air pipe interfaces, thereby realizing the movement of the central axis driven by the piston movement. When the piston approaches the end cover, the blocking structure protruding from the piston end face first cooperates with the connecting port to achieve the isolation between the cylinder body cavity and the transition air cavity. Since the buffer air path is also in a closed state, the buffer space formed is a sealed chamber, and the internal air is compressed and the air pressure is increased, which generates a reverse force on the piston, thereby achieving a buffering effect. Most of the structures required by the air buffer principle are realized by hollowing out the original cylinder structure, and the added solid structures are mostly located in the opened cavity. The volume of the cylinder is not increased as a whole, and the blocking structure protruding from the piston end face only occupies a very small space in the cylinder, avoiding affecting the cylinder stroke. Overall, the buffer cylinder structure is compact and easier to manufacture into a small-volume cylinder, solving the problem that buffer screws cannot be installed in small-volume cylinders.

[0015] At the same time, during the movement of the central axis, the buffer gas path in the end cover of the air inlet end can be opened, so that the gas entering from the air inlet and outlet pipe interfaces can not only act on the end face of the blocking structure through the transition air cavity, but also directly act on the piston end face through the buffer gas path, reducing the resistance caused by starting the piston. During the action, due to the flow and friction of the fluid, the piston rod will rotate 360 ​​degrees. By setting a rotation limit structure, the rotation of the central axis can be restrained, so that the central axis can smoothly perform axial linear motion.

[0016] The transition air cavity 5 is arranged around the central axis 2 as an annular cavity, the connecting port is arranged around the central axis 2 and is opened on the inner end surface of the end cover, and the plugging structure 6 is arranged as a plunger structure adapted to the inner diameter of the annular cavity, and the plunger structure is fixedly sleeved relative to the central axis 2. The internal structure of the cylinder body is made more symmetrical, and both the transition air cavity 5 and the plugging structure 6 are arranged around the central axis, which can make the cooperation process between the two more accurate and stable, and the structure is relatively simple and easy to process. An annular groove can be opened on the inner wall of the transition air cavity, and a buffer sleeve 51 can be embedded in the groove, which can better cooperate with the plugging structure to achieve a better plugging effect, reduce the direct friction contact between the plunger structure and the inner wall of the annular cavity, reduce mechanical friction resistance, reduce friction loss, and use the buffer sleeve as a consumable part, which can be flexibly replaced and used, thereby increasing the service life of the cylinder body structure.

[0017] The buffer gas path 8 includes a buffer hole 81 parallel to the axial direction of the cylinder body and a bottom hole 82 arranged along the radial direction of the cylinder body, wherein the buffer hole 81 is connected to the middle part of the bottom hole 82; the on-off regulating valve 9 includes a valve core 91 movably arranged in the bottom hole 82. The on-off of the buffer gas path is realized by adjusting the position of the valve core in the bottom hole. When the valve core blocks the port of the buffer hole, the buffer gas path is closed. When the valve core moves radially outward away from the port of the buffer hole, the buffer hole is connected to the transition air cavity through the bottom hole, and the buffer gas path is opened.

[0018] The valve core 91 is a stop screw, which is threadedly engaged with the inner wall of the bottom hole 82. The stop screw position can be adjusted from the outer port of the bottom hole on the end cover. After the central axis completes one axial movement and achieves air buffering, the stop screw is manually adjusted to open the buffer gas path, discharge the gas in the buffer space, and make the piston close to the end cover.

[0019] The rotation limiting structure includes a polygonal shaft 11 fixedly connected to the center of the rear end cover of the cylinder body 1, the polygonal shaft 11 is extended along the axis direction of the cylinder body 1, and the end of the central shaft 2 is slidably sleeved relative to the polygonal shaft 11. Since the buffer hole will inevitably act eccentrically on the piston surface, which may cause the rotation of the central shaft, the polygonal shaft is used to limit the central shaft, thereby avoiding the rotation of the central shaft and making the axial movement of the central shaft more stable.

[0020] A bushing 21 is provided between the central shaft 2 and the polygonal shaft 11. The bushing 21 is fixedly plugged into the end mounting hole of the central shaft 2. The inner cavity of the bushing 21 is provided as a polygonal guide hole adapted to the polygonal shaft 11. Due to the frequent reciprocating motion of the central shaft, wear is inevitable. By providing a bushing and providing both the bushing and the polygonal shaft with detachable and replaceable consumable parts, the service life of the central shaft can be effectively extended.

[0021] Among them, the polygonal shaft can be a square shaft, and the corresponding bushing is a copper liner with a circular outer diameter and a square inner diameter. The copper liner and the central shaft are relatively limited by a set screw, and the central shaft is non-rotating by the mutual cooperation of the copper liner and the square shaft. Compared with the existing method of realizing the non-rotating function of the piston rod by a polygonal piston rod and a polygonal sealing ring, the cost of this solution is lower. The reason is that the polygonal sealing ring needs to be molded and made, which is costly and easily causes waste of resources for small batch orders. This solution does not need to install a polygonal sealing ring, avoiding waste of resources.

[0022] Preferably, the center shaft 2 is made of PEEK, which is polyetheretherketone, a high-performance special engineering plastic with the characteristics of high temperature resistance, self-lubrication, easy processing, and high mechanical strength. It is often used to make precision parts and durable products, suitable for the processing of small cylinder center shafts, and meets the operating requirements of high temperature and high pressure environments; in addition, the material also has the properties of good compatibility, corrosion resistance, and stability, which can effectively extend the service life of the center shaft.

[0023] 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. An air-buffered cylinder, characterized in that: The invention comprises a cylinder body (1) and a central shaft (2), wherein the central shaft (2) is axially telescopically arranged at the front end of the cylinder body (1), and a piston (3) is mounted on the central shaft (2), and the piston (3) is axially slidably arranged in contact with the inner wall of the cylinder body (1); the front and rear end covers of the cylinder body (1) are respectively provided with inlet and outlet air pipe interfaces (4), and the inlet and outlet air pipe interfaces (4) are communicated with the inner cavity of the cylinder body (1) through a transition air cavity (5), and the transition air cavity (5) is connected to the inner cavity of the cylinder body (1). The connecting port is located on the inner end surface of the end cover; a blocking structure (6) cooperating with the connecting port is protruded on the end surface of the piston (3), and when the two are blocked and matched, a buffer space (7) is formed between the end surface of the piston (3) and the inner end surface of the corresponding end cover, and the buffer space (7) is connected to the transition air cavity (5) through a buffer air path (8), and the buffer air path (8) is provided with an on-off regulating valve (9); the central shaft (2) is connected to the inner wall of the cylinder body (1) through a rotation limit structure.

2. An air-cushioned cylinder according to claim 1, characterized in that: The transition air cavity (5) is arranged as an annular cavity around the central axis (2), the communication port is arranged around the central axis (2) and is opened on the inner end surface of the end cover, and the blocking structure (6) is arranged as a plunger structure adapted to the inner diameter of the annular cavity, and the plunger structure is fixedly sleeved relative to the central axis (2).

3. An air-cushioned cylinder according to claim 2, characterized in that: The buffer gas path (8) comprises a buffer hole (81) parallel to the axial direction of the cylinder body and a bottom hole (82) arranged along the radial direction of the cylinder body, wherein the buffer hole (81) is connected to the middle part of the bottom hole (82); the on-off regulating valve (9) comprises a valve core (91) movably arranged in the bottom hole (82).

4. An air-cushioned cylinder according to claim 3, characterized in that: The valve core (91) is a stop screw, and the stop screw is threadably matched with the inner wall of the bottom hole (82).

5. The air-cushioned cylinder according to claim 4, characterized in that: The rotation limiting structure comprises a polygonal shaft (11) fixedly connected to the center of the rear end cover of the cylinder body (1), the polygonal shaft (11) extending along the axial direction of the cylinder body (1), and the end of the central shaft (2) slidingly sleeved relative to the polygonal shaft (11).

6. An air-cushioned cylinder according to claim 5, characterized in that: A bushing (21) is sleeved between the central shaft (2) and the polygonal shaft (11); the bushing (21) is fixedly plugged into an end mounting hole of the central shaft (2); and the inner cavity of the bushing (21) is configured as a polygonal guide hole adapted to the polygonal shaft (11).

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