Oil cylinder buffer mechanism

Abstract

A buffer mechanism of an oil cylinder includes a piston, a buffer sleeve, and a spring; a buffer cavity with a circular cross-section is provided at the rear side of the piston, and the rear side of the buffer cavity is open; the buffer sleeve includes a first part and a second part, the first part is located in the buffer cavity and slidably cooperates with the buffer cavity, the second part extends backward beyond the rear side of the piston, a through hole penetrating the buffer sleeve is provided in the buffer sleeve, and the through hole is composed of a first hole, a second hole, and a third hole with decreasing diameters in sequence, a throttling hole penetrating the buffer sleeve is provided at the buffer sleeve corresponding to the second hole, a valve core is provided in the second hole, the valve core is a cylindrical body, the front side of the valve core is sealed, and the rear side is open, the valve core and the second hole are slidably cooperated, a conical head is provided at the front side of the valve core and forms a conical surface seal with the rear side of the second hole, a through hole penetrating the inside and outside of the valve core is provided in the axial direction of the valve core, and the spring is provided in the buffer cavity, the front side of the spring is connected to the bottom of the buffer cavity, and the rear side of the spring is against the rear side of the first hole. The mechanism has good buffering effect, simple structure, reliable performance, and low cost.

Description

Technical Field

[0001] The invention relates to an oil cylinder buffer mechanism. Background Art

[0002] There will be obvious impact when the piston cylinder extends and retracts to the end, resulting in poor stability of the cylinder. There are currently two solutions. One is to install two buffer sleeves on the cylinder bottom and the piston, and use the gap between the two buffer sleeves to achieve the buffering effect. The disadvantage of this structure is that the oil does not flow smoothly when the piston is extended, and there is a throttling scene. A one-way valve structure must be added, resulting in a complex structure and a high failure rate. In addition, the traditional cylinder buffer requires the installation of buffer sleeves on the cylinder bottom and the piston. There is a high coaxiality requirement between the cylinder bottom and the piston, and the cylinder bottom is purchased as a welded structure, so the coaxiality is difficult to guarantee. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an oil cylinder buffer mechanism, which has good buffer effect, simple structure, reliable performance and low cost.

[0004] In order to solve the above technical problems, the present invention provides an oil cylinder buffer mechanism, including a piston, a buffer sleeve, and a spring;

[0005] The side of the piston axially away from the cylinder bottom is assumed to be the front, and the side close to the cylinder bottom is assumed to be the rear. A buffer cavity with a circular cross-section is provided at the rear side of the piston, and the rear side of the buffer cavity is open.

[0006] The buffer sleeve includes a first part and a second part which are coaxially arranged front and back and are both cylindrical. The diameter of the first part is larger than that of the second part. The first part is located in the buffer cavity and slides with the buffer cavity. The second part extends backward and exceeds the rear side of the piston. A through hole is provided in the buffer sleeve which penetrates the buffer sleeve along the axial direction. The through hole is composed of a first hole, a second hole and a third hole which are connected in sequence from front to back and are coaxial. The diameters of the first hole, the second hole and the third hole decrease in sequence. A conical transition section is provided between the second hole and the third hole. A throttling hole which penetrates the buffer sleeve along the radial direction is provided at the position of the buffer sleeve corresponding to the second hole. A valve core is provided in the second hole. The valve core is a cylindrical body arranged along the axial direction of the first hole. The front side of the valve core is sealed and the rear side is open. The axial length of the valve core is smaller than the axial length of the second hole. The valve core slides with the second hole. A conical head is provided on the front side of the valve core. The conical head and the conical transition section are conically sealed. A through hole which penetrates the inside and outside of the valve core along the radial direction is provided in the axial direction of the valve core.

[0007] The spring is arranged in the buffer cavity along the axial direction of the piston, the front side of the spring is connected to the bottom of the buffer cavity, and the rear side of the spring is against the rear side of the first hole.

[0008] For the purpose of simple explanation, the oil cylinder buffer mechanism described in the present invention is referred to as this mechanism below.

[0009] The use status of this mechanism: when the piston moves backward to the end, the buffer sleeve will first contact the end face of the oil cylinder, and then the buffer chamber between the buffer sleeve and the piston will be pressurized, and the hydraulic oil in the buffer chamber will enter the valve core through the first hole and the second hole in turn, and then flow out through the through hole of the valve core and the throttling hole on the buffer sleeve into the cylinder. According to analysis and experiments, a throttling hole of appropriate size is selected to achieve the effect of piston deceleration, and then the oil cylinder will decelerate smoothly at the end, reducing the vibration of the oil cylinder. When the oil pressure drives the piston to move forward, the hydraulic oil enters the buffer sleeve from the third hole, pushes the valve core forward to open the conical seal, and enters the buffer chamber. At the same time, the spring rebound assists the buffer sleeve to reset. When the piston moves backward again, the hydraulic oil pushes the valve core backward, and the conical head of the valve core and the conical transition section form a conical seal again. When the piston moves backward to the end, the buffer mechanism acts on the piston again, and so on.

[0010] Advantages of this mechanism: This mechanism has good buffering effect, simple structure, reliable performance and low cost. In addition, since the buffering pressure of this mechanism is only between the piston and the buffer sleeve, it has no effect on other parts of the cylinder, especially the seals and welds, which can indirectly improve the performance and service life of the cylinder.

[0011] In order to achieve better use effect of this mechanism, the preferred scheme is as follows:

[0012] Preferably, an annular step is formed at the junction of the first part and the second part, and a retaining ring extending inwardly is provided at a position in the buffer cavity corresponding to the annular step, and the rear side of the annular step abuts against the retaining ring.

[0013] The retaining ring can prevent the buffer sleeve from slipping off from the rear side of the buffer cavity.

[0014] Preferably, the connection between the first hole and the second hole is a step transition, a washer matching the first hole is provided on the rear side of the first hole, and the rear side of the spring abuts against the washer.

[0015] The washer can increase the radial width of the step at the connection between the first hole and the second hole, thereby increasing the contact area with the spring and making the contact more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of this organization. DETAILED DESCRIPTION

[0017] See also Figure 1 , an oil cylinder buffer mechanism, comprising a piston 1, a buffer sleeve 2, and a spring 3;

[0018] Assume that the side of the piston 1 in the oil cylinder that is axially away from the cylinder bottom is the front, and the side that is close to the cylinder bottom is the rear. The rear side of the piston 1 is provided with a buffer cavity 11 with a circular cross-section shape, and the rear side of the buffer cavity 11 is open.

[0019] The buffer sleeve 2 includes a first part 21 and a second part 22 which are coaxially arranged front and back and are both cylindrical. The diameter of the first part 21 is larger than the diameter of the second part 22. The first part 21 is located in the buffer cavity 11 and slides with the buffer cavity 11. The second part 22 extends backward and exceeds the rear side of the piston 1. An annular step is formed at the connection between the first part 21 and the second part 22. A retaining ring 12 extending inward is provided at a position corresponding to the annular step in the buffer cavity 11, and the rear side of the annular step abuts against the retaining ring 12. A through hole is provided in the buffer sleeve 2 which penetrates the buffer sleeve 2 axially. The through hole is composed of a first hole 23, a second hole 24 and a third hole 25 which are connected in sequence from front to back and are coaxial. The diameters of the first hole 23, the second hole 24 and the third hole 25 decrease in sequence. A conical transition section 26 is provided between the second hole 24 and the third hole 25. A throttling hole 241 which penetrates the buffer sleeve 2 radially is provided at a position of the buffer sleeve 2 corresponding to the second hole 24. A valve core 4 is provided in the second hole 24. The valve core 4 is a cylindrical body arranged axially along the first hole 23. The front side of the valve core 4 is sealed and the rear side is open. The axial length of the valve core 4 is less than the axial length of the second hole 24. The valve core 4 and the second hole 24 are slidably matched. A conical head 42 is provided on the front side of the valve core 4. The conical head 42 and the conical transition section 26 are conically sealed. A through hole 41 which penetrates the inside and outside of the valve core 4 radially is provided in the axial direction of the valve core 4.

[0020] The spring 3 is arranged in the buffer chamber 11 along the axial direction of the piston 1, and the front side of the spring 3 is connected to the bottom of the buffer chamber 11. The connection between the first hole 23 and the second hole 24 is a step transition. A gasket 231 matching the first hole 23 is provided on the rear side of the first hole 23, and the rear side of the spring 3 is against the gasket 231.

[0021] The use status of this mechanism: when the piston 1 moves backward to the end, the buffer sleeve 2 will first contact the end face of the oil cylinder, and then the buffer chamber 11 between the buffer sleeve 2 and the piston 1 will be pressurized, and the hydraulic oil in the buffer chamber 11 will enter the valve core 4 through the first hole 23 and the second hole 24 in turn, and then flow out through the through hole 41 of the valve core 4 and the throttling hole 241 on the buffer sleeve 2 into the cylinder barrel. According to analysis and experiments, a throttling hole 241 of a suitable size is selected to achieve the effect of decelerating the piston 1, and then the oil cylinder will decelerate smoothly at the end, reducing the vibration of the oil cylinder. When the oil pressure drives the piston 1 to move forward, the hydraulic oil enters the buffer sleeve 2 from the third hole 25, pushes the valve core 4 forward to open the conical seal, and enters the buffer chamber 11. At the same time, the spring 3 rebounds to assist the buffer sleeve 2 to reset. When the piston 1 moves backward again, the hydraulic oil pushes the valve core 4 backward, and the conical head 42 of the valve core 4 and the conical transition section 26 form a conical seal again. When the piston 1 moves backward to the end, the buffer mechanism acts on the piston 1 again, and this cycle repeats.

[0022] Advantages of this mechanism: This mechanism has good buffering effect, simple structure, reliable performance and low cost. In addition, since the buffering pressure of this mechanism is only between the piston 1 and the buffer sleeve 2, it has no effect on other parts of the cylinder, especially the seals and welds, which can indirectly improve the performance and service life of the cylinder.

[0023] The retaining ring 12 can prevent the buffer sleeve 2 from slipping off from the rear side of the buffer cavity 11 .

[0024] The washer 231 can increase the radial width of the step at the connection between the first hole 23 and the second hole 24, thereby increasing the contact area with the spring 3 and making the contact more stable.

Claims

1. A cylinder buffer mechanism, characterized in that: Including piston, buffer sleeve and spring; The side of the piston axially away from the cylinder bottom is assumed to be the front, and the side close to the cylinder bottom is assumed to be the rear. A buffer cavity with a circular cross-section is provided at the rear side of the piston, and the rear side of the buffer cavity is open. The buffer sleeve includes a first part and a second part which are coaxially arranged front and back and are both cylindrical. The diameter of the first part is larger than the diameter of the second part. The first part is located in the buffer cavity and slides with the buffer cavity. The second part extends backward and exceeds the rear side of the piston. A through hole is provided in the buffer sleeve which penetrates the buffer sleeve along the axial direction. The through hole is composed of a first hole, a second hole and a third hole which are sequentially connected and coaxial from front to back. The diameters of the first hole, the second hole and the third hole decrease in sequence. A conical transition section is provided between the second hole and the third hole. A throttling hole which penetrates the buffer sleeve along the radial direction is provided at the position of the buffer sleeve corresponding to the second hole. A valve core is provided in the second hole. The valve core is a cylindrical body arranged along the axial direction of the first hole. The front side of the valve core is sealed and the rear side is open. The axial length of the valve core is smaller than the axial length of the second hole. The valve core slides with the second hole. A conical head is provided on the front side of the valve core. The conical head and the conical transition section are conically sealed. A through hole which penetrates the inside and outside of the valve core along the radial direction is provided in the circumference of the valve core. The spring is arranged in the buffer cavity along the axial direction of the piston, the front side of the spring is connected to the bottom of the buffer cavity, and the rear side of the spring is against the rear side of the first hole; An annular step is formed at the junction of the first part and the second part, and a retaining ring extending inward is provided at a position in the buffer cavity corresponding to the annular step, and the rear side of the annular step abuts against the retaining ring; The connection between the first hole and the second hole is a step transition, a washer matching the first hole is arranged on the rear side of the first hole, and the rear side of the spring abuts against the washer.

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