Hydraulic cylinder with damping function

Abstract

The hydraulic cylinder with the damping function comprises a cylinder barrel, a front cover and a rear cover are arranged at the two ends of the cylinder barrel respectively, a piston and a piston rod are movably arranged in the cylinder barrel, the piston is fixedly connected with the piston rod, an inner cavity of the cylinder barrel is divided into a rod cavity and a rodless cavity by the piston, and the front end of the piston rod extends out of the front cover. A lining assembly is arranged at the front end of the piston rod and comprises an inner lining, an outer lining and a rubber sleeve which is arranged between the inner lining and the outer lining and enables the inner lining and the outer lining to be elastically connected, the outer lining is arranged on the outer wall of the inner lining in a sleeving mode in the radial direction and matched with the inner lining in an abutting mode, and the outer lining is arranged on the outer wall of the rubber sleeve in a sleeving mode in the radial direction and matched with the rubber sleeve in an abutting mode. The rubber sleeve and the outer bushing are integrally formed through vulcanization, and when the cab is turned over, the bushing assembly is adjusted through deformation of the rubber sleeve or rotation of the inner bushing; when the cab floats up and down, the lining assembly can absorb damping generated when the oil cylinder floats, and abnormal sound is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic cylinders, in particular to a hydraulic cylinder with a shock absorbing function. Background Art

[0002] In the field of medium and heavy trucks, some abnormal noises often occur during driving. The hydraulic cylinder is a key component used to drive the cab to flip, and it plays a vital role in the operation of the vehicle. These abnormal noises may affect the safety and stability of the cab, so they need to be paid enough attention.

[0003] The piston rod of the hydraulic cylinder is provided with a mounting point connected to the cab; the cab is the working environment of the truck driver, and its comfort and safety directly affect the driver's driving experience and work efficiency. When the vehicle cab is being repaired, the cab needs to be flipped frequently. When the piston rod of the hydraulic cylinder is fully extended, the cab is controlled to flip. In the existing technology, there are two main forms of the position design of the mounting point on the piston rod. The first form is as shown in the reference Fig.11 As shown, its structure includes a bracket 6', a mounting pin 5', a bolt 4', a polyurethane washer 2' and a nut 3'. The mounting pin 5' is connected to the bracket 6' through the bolt 4' and the nut 3'. At the mounting point, two polyurethane washers 2' or rubber rings are installed to play a shock-absorbing role. The second form is as shown in the reference Fig.12 As shown, some improvements are made on the basis of the first method, and a metal bushing 1' is added to solve the problem of unbalanced loading of the cylinder on the whole vehicle. However, the above two solutions have the following problems. First, when the cab is lifted, the cylinder will crush the polyurethane gasket 2', and the metal bushing 1' or the mounting pin 5' will rub against the upper part of the piston rod joint 7', causing abnormal noise; second, when the whole vehicle is traveling on an uneven road, if the polyurethane gasket 2' is too soft, it cannot prevent the cylinder bushing or the mounting pin 5' from colliding with the piston rod joint 7'; if the polyurethane gasket 2' is too hard, the damping force of the cylinder will be directly transmitted to the bottom plate of the cab, causing abnormal noise in the whole vehicle, and the polyurethane gasket 2' is more likely to cause abnormal noise after being crushed, so it is necessary to improve it. Utility Model Content

[0004] The purpose of the utility model is to provide a hydraulic cylinder with a shock-absorbing function in view of the defects and shortcomings of the prior art. The hydraulic cylinder has a simple and reasonable structure and is easy to operate. When the cab is flipped, due to the change in angle, the bushing assembly is adjusted by deformation of the rubber sleeve or rotation of the inner bushing; during driving, the bushing assembly can effectively absorb the damping when the cylinder floats to prevent abnormal noise.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The utility model discloses a hydraulic cylinder with a shock absorbing function, comprising a cylinder barrel, a front cover and a rear cover are respectively provided at both ends of the cylinder barrel, a piston and a piston rod are movably provided in the cylinder barrel, the piston is fixedly connected to the piston rod, the piston divides the inner cavity of the cylinder barrel into a rod cavity and a rodless cavity, the front end of the piston rod extends out of the front cover, a bushing assembly is provided at the front end of the piston rod, the bushing assembly comprises an inner bushing, an outer bushing and a rubber sleeve arranged between the inner bushing and the outer bushing and elastically connected therewith, the outer bushing is radially sleeved on the outer wall of the inner bushing and abuts against the inner bushing, the outer bushing is radially sleeved on the outer wall of the rubber sleeve and abuts against the rubber sleeve, and the rubber sleeve and the outer bushing are vulcanized into one piece.

[0007] Furthermore, a valve cavity is formed in the rear cover, and the rear cover is provided with an oil receiving port A and an oil receiving port B respectively connected to the valve cavity. A hydraulic control valve is provided in the valve cavity, and the valve cavity is connected to the rodless cavity through the hydraulic control valve. An oil pipe for connecting the valve cavity and the rod cavity is also provided outside the cylinder.

[0008] Furthermore, the cylinder barrel and the rear cover are welded together, one end of the oil pipe is welded to the cylinder barrel, and the other end of the oil pipe is welded to the rear cover.

[0009] Furthermore, the cylinder is provided with a small diameter barrel section and a large diameter barrel section in sequence from front to back along the axial direction, and the outer wall of the piston is sleeved with a piston sealing ring, the outer wall of the piston sealing ring is sealed with the inner wall of the small diameter barrel section, and the outer wall of the piston sealing ring is gap-fitted with the inner wall of the large diameter barrel section.

[0010] Furthermore, a limiting groove is provided in the front end of the cylinder, a wire retaining ring is provided in the limiting groove, and the front cover is limitedly matched with the wire retaining ring along the axial direction.

[0011] Furthermore, the rubber sleeve is arranged in a hollow shape.

[0012] Furthermore, the rubber sleeve and the inner liner are integrally formed by vulcanization.

[0013] Furthermore, the rubber sleeve is provided with a plurality of buffer holes along the circumferential direction and penetrating the rubber sleeve along the axial direction.

[0014] Furthermore, the rubber sleeve is arranged in a solid shape.

[0015] Furthermore, the rubber sleeve and the inner bushing are in clearance fit, and the inner bushing can rotate relative to the rubber sleeve.

[0016] The beneficial effects of the utility model are as follows: the hydraulic cylinder with shock absorption function described in the utility model controls the cab to flip when the piston rod of the hydraulic cylinder is fully extended. When flipping, due to the change in angle, the bushing assembly is adjusted by deformation of the rubber sleeve or rotation of the inner bushing; during driving, the piston rod will float with the shaking of the cab. When the cab floats down, the piston rod will float down with it, and the hydraulic oil inside the cylinder will generate an upward reverse force transmitted to the bushing assembly. At this time, the inner bushing will absorb the reaction force by deformation to prevent this force from pushing up the bottom plate of the cab, thereby avoiding abnormal noise; when the cab floats up, the piston rod will float up with it, and the hydraulic oil inside the cylinder will generate a downward reverse force transmitted to the bushing assembly. At this time, the inner bushing will absorb the reaction force by deformation to prevent this force from pulling down the bottom plate of the cab, thereby avoiding abnormal noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0018] Figure 2 It is a schematic diagram of the cross-sectional structure of the utility model;

[0019] Figure 3 yes Figure 2 A schematic diagram of the enlarged structure at A in the middle;

[0020] Figure 4 yes Figure 2 A schematic diagram of the enlarged structure at B in the middle;

[0021] Figure 5 yes Figure 2 Schematic diagram of the enlarged structure at C in the middle;

[0022] Figure 6 It is a schematic diagram of the structure when the piston runs to the small diameter barrel section;

[0023] Figure 7 It is a schematic diagram of the structure when the bushing assembly is connected to the piston rod joint;

[0024] Figure 8 is a schematic diagram of the structure of the bushing assembly;

[0025] Fig. 9 is a schematic diagram of the cross-sectional structure of the bushing assembly;

[0026] Fig.10 It is a schematic diagram of the structure of the rubber sleeve;

[0027] Fig.11 It is a schematic cross-sectional structure diagram of the first form of mounting point on the piston rod in the prior art;

[0028] Fig.12It is a schematic cross-sectional structure diagram of the second form of the mounting point on the piston rod in the prior art.

[0029] Figure 1-12 Middle: 1', metal bushing; 2', polyurethane gasket; 3', nut; 4', bolt; 5', mounting pin; 6', bracket; 7', piston rod joint; 1, cylinder barrel; 11, front cover; 12, rear cover; 121, oil inlet A; 1211, oil inlet joint A; 122, oil inlet B; 1221, oil inlet joint B; 13, rod chamber; 14, rodless chamber; 15, small diameter barrel section; 16, large diameter barrel section; 17, limit groove; 171, Wire retaining ring; 2. Piston; 21. Piston sealing ring; 3. Piston rod; 31. Piston rod joint; 4. Bushing assembly; 41. Inner bushing; 42. Outer bushing; 43. Rubber sleeve; 431. Buffer hole; 5. Hydraulic control valve; 51. Valve core member; 511. Valve core sealing ring; 512. Extension; 52. Valve core seat; 521. Valve hole; 53. Steel ball; 54. Valve core spring; 55. Fixed seat; 551. Connecting hole; 6. Oil pipe; 7. Dust ring. DETAILED DESCRIPTION

[0030] The utility model is further described below in conjunction with the accompanying drawings.

[0031] like Figure 1-10 The hydraulic cylinder with a shock absorbing function shown in the figure comprises a cylinder barrel 1, a front cover 11 and a rear cover 12 are respectively provided at both ends of the cylinder barrel 1, a piston 2 and a piston rod 3 are movably provided in the cylinder barrel 1, the piston 2 is fixedly connected to the piston rod 3, the cylinder barrel 1 is filled with hydraulic oil, and the piston 2 divides the inner cavity of the cylinder barrel 1 into a rod cavity 13 and a rodless cavity 14, see Figure 7 The front end of the piston rod 3 extends out of the front cover 11, and the front end of the piston rod 3 is provided with a piston rod joint 31, and the piston rod joint 31 is connected to the bushing assembly 4, see Figure 8-10The bushing assembly 4 includes an inner bushing 41, an outer bushing 42 and a rubber sleeve 43 arranged between the inner bushing 41 and the outer bushing 42 and elastically connecting them. The inner bushing 41, the outer bushing 42 and the rubber sleeve 43 are all coaxially arranged. The center of the inner bushing 41 is provided with a through hole along the axial direction. The through hole is connected with a mounting pin and a bolt, and is connected to the cab of the car through the mounting pin and the bolt. The outer bushing 42 is radially sleeved on the outer wall of the inner bushing 41 and abuts against the inner bushing 41. The outer bushing 42 is radially sleeved on the outer wall of the rubber sleeve 43 and abuts against the rubber sleeve 43. The rubber sleeve 43 and the outer bushing 42 are vulcanized and integrally formed to prevent separation during use and affect use. By setting the bushing assembly 4, the damping of the cylinder floating during driving bumps can be absorbed, and the bushing assembly 4 will not be crushed during the lifting and falling process, which can well solve the problem of abnormal noise on the bottom plate of the cab when the whole vehicle is driving, thereby improving driving comfort and the overall performance of the vehicle.

[0032] When the vehicle's cab is being repaired, it is necessary to flip the cab. The hydraulic cylinder is a key component for driving the vehicle's cab to flip. Specifically, when the hydraulic cylinder is assembled on the vehicle, the two ends of the bushing assembly 4 are clamped by the lifting ears on the vehicle. When the piston rod 3 of the hydraulic cylinder is fully extended, the cab is controlled to flip. When flipping, due to the change in angle, the bushing assembly 4 is adjusted by deforming the rubber sleeve 43 or rotating the inner bushing 41. During driving, the piston rod 3 will float with the shaking of the cab. When the cab floats down, the piston rod 3 will float. When the cab floats up, the piston rod 3 floats up, and the hydraulic oil in the cylinder 1 generates an upward reverse force which is transmitted to the bushing assembly 4. At this time, the inner bushing 41 absorbs the reaction force by deformation to prevent this force from pushing up the cab floor, thereby avoiding abnormal noise; when the cab floats up, the piston rod 3 floats up, and the hydraulic oil in the cylinder 1 generates a downward reverse force which is transmitted to the bushing assembly 4. At this time, the inner bushing 41 absorbs the reaction force by deformation to prevent this force from pulling down the cab floor, thereby avoiding abnormal noise.

[0033] Preferably, in the present embodiment, there are two connection methods between the inner sleeve 41 and the rubber sleeve 43. Of course, in other embodiments, there may be other connection methods. In the first connection method, the rubber sleeve 43 is hollowed out. Specifically, the rubber sleeve 43 and the inner sleeve 41 are vulcanized and formed as one piece to prevent separation during use and affect use. In addition, the stiffness of the rubber sleeve 43 can be adjusted according to the damping value of the cylinder, which can effectively absorb the damping when the cylinder floats and prevent abnormal noise. At the same time, when the lifting and falling angle of the cab rotates, the inner sleeve 41 can twist and rotate accordingly and can return to its original state after rotation without causing damage, thereby improving its adaptability and durability.

[0034] Preferably, in this embodiment, refer to Fig.10The rubber sleeve 43 is provided with a plurality of buffer holes 431 penetrating the rubber sleeve 43 along the circumferential direction. Preferably, in the present embodiment, the buffer holes 431 penetrate the rubber sleeve 43 along the axial direction. Preferably, in the present embodiment, the buffer holes 431 are arranged in an arc shape, which can better disperse the pressure when subjected to external force, thereby improving its impact resistance. The buffer holes 431 can easily form a low-rigidity portion and improve the softness, so that it can show better elasticity and deformation ability when dealing with different pressures and impacts.

[0035] Preferably, in this embodiment, four buffer holes 431 are provided on the rubber sleeve 43, and the four buffer holes 431 are symmetrically arranged in pairs relative to the rubber sleeve 43, which is not only beautiful but also can achieve uniform distribution when subjected to force, and effectively disperse the pressure to all directions. Preferably, in this embodiment, the cross-sectional area of ​​two of the symmetrically arranged buffer holes 431 is smaller than the cross-sectional area of ​​the other two symmetrically arranged buffer holes 431, and the performance of the rubber sleeve 43 can be adjusted according to actual needs to adapt to different usage environments and requirements. Of course, in other embodiments, the number and cross-sectional area of ​​the buffer holes 431 can be adjusted accordingly according to actual needs.

[0036] In the second connection method, the rubber sleeve 43 is solid, so that the structure of the rubber sleeve 43 is more stable, and it can better resist external impact and pressure during use and is not easily crushed. Specifically, the rubber sleeve 43 and the inner sleeve 41 are clearance-matched, and the inner sleeve 41 can rotate relative to the rubber sleeve 43, so that the inner sleeve 41 can flexibly respond to the damping changes of the cylinder. At the same time, the rubber stiffness can be adjusted according to the damping value of the cylinder, which can effectively absorb the damping when the cylinder floats to prevent abnormal noise.

[0037] Preferably, in the present embodiment, a valve cavity is formed in the rear cover 12, and the rear cover 12 is provided with an oil receiving port A121 and an oil receiving port B122 respectively connected to the valve cavity. Specifically, the oil receiving port A121 is threadedly connected with an oil port joint A1211, and the oil receiving port B122 is threadedly connected with an oil port joint B1221. A hydraulic control valve 5 is provided in the valve cavity, and the valve cavity is connected with the rodless cavity 14 through the hydraulic control valve 5. An oil pipe 6 for connecting the valve cavity with the rod cavity 13 is also provided outside the cylinder barrel 1. Preferably, in the present embodiment, the cylinder barrel 1 and the rear cover 12 are welded together to enhance the stability of the structure. One end of the oil pipe 6 is welded to the cylinder barrel 1, and the other end of the oil pipe 6 is welded to the rear cover 12. The connection relationship is firm, which avoids loosening or leakage problems that may occur during use.

[0038] Preferably, in this embodiment, the cylinder 1 is provided with a small diameter cylinder section 15 and a large diameter cylinder section 16 in sequence from front to back along the axial direction, and the outer wall of the piston 2 is provided with a piston sealing ring 21, see Figure 6 The outer wall of the piston seal ring 21 is sealed with the inner wall of the small diameter barrel section 15, see Figure 3 The outer wall of the piston sealing ring 21 and the inner wall of the large diameter barrel section 16 are in a clearance fit. It should be noted that the small diameter barrel section 15 and the large diameter barrel section 16 mean that the diameter of the large diameter barrel section 16 is larger than the diameter of the small diameter barrel section 15. When the piston 2 runs to the small diameter barrel section 15, the outer wall of the piston sealing ring 21 and the inner wall of the small diameter barrel section 15 are in a sealing fit, and the oil between the rod chamber 13 and the rodless chamber 14 cannot be directly connected. When the piston 2 runs to the large diameter barrel section 16, the outer wall of the piston sealing ring 21 and the inner wall of the large diameter barrel section 16 are in a clearance fit, and the oil between the rod chamber 13 and the rodless chamber 14 can be directly connected.

[0039] When controlling the cab to flip, the piston 2 and the piston rod 3 are located in the small diameter barrel section 15. When the piston 2 runs to the small diameter barrel section 15 and the high pressure oil is input through the oil receiving port A121, the high pressure oil opens the hydraulic control valve 5 and enters the rodless chamber 14. The oil in the rod chamber 13 flows back to the oil receiving port B122 through the oil pipe 6. At this time, the rodless chamber 14 is injected with high pressure oil, and the rod chamber 13 is connected to the low pressure oil. The piston 2 and the piston rod 3 move forward to control the piston rod 3 to extend; when the high pressure oil is input through the oil receiving port B122, the high pressure oil enters the rod chamber 13 through the oil pipe 6, and at the same time opens the hydraulic control valve 5. The oil in the rodless chamber 14 flows back to the oil receiving port A121. At this time, the rod chamber 13 is injected with high pressure oil, and the rodless chamber 14 is connected to the low pressure oil. The piston 2 and the piston rod 3 move backward to control the piston rod 3 to retract.

[0040] During the driving of the vehicle, the piston 2 and the piston rod 3 are located in the large diameter barrel section 16. When the piston 2 runs to the large diameter barrel section 16 and moves forward slowly, the oil in the rod chamber 13 can flow into the rodless chamber 14 through the gap between the piston sealing ring 21 and the large diameter barrel section 16. When the piston 2 runs to the large diameter barrel section 16 and the piston 2 moves forward at a faster speed, the oil in the rod chamber 13 cannot flow into the rodless chamber 14 in time, and the oil pressure in the rod chamber 13 increases. At this time, a part of the oil opens the hydraulic control valve 5 through the oil pipe 6, and the external oil enters the rodless chamber 14 through the oil inlet A121 to supplement the cavity formed by the rapid forward movement of the piston 2. In addition, the oil in the rod chamber 13 will also form a reverse pulling force on the piston 2 and the piston rod 3 to act on the bushing assembly 4. The bushing assembly 4 absorbs the force by deformation to prevent the force from acting on the bottom plate of the cab, thereby avoiding abnormal noise. When the piston 2 runs to the large diameter barrel section 16 and moves slowly backward, the oil in the rodless chamber 14 can flow into the rod chamber 13 through the gap between the piston sealing ring 21 and the large diameter barrel section 16. When the piston 2 runs to the large diameter barrel section 16 and the piston 2 moves backward at a faster speed, the oil in the rodless chamber 14 cannot flow into the rod chamber 13 in time, and the volume of oil that needs to be discharged from the rodless chamber 14 is larger than the cavity formed by the rod chamber 13. The oil pressure in the rodless chamber 14 increases, and the oil pressure directly acts on the bottom of the piston 2, forming a forward thrust on the piston rod 3 and acting on the bushing assembly 4. The bushing assembly 4 absorbs the force by deformation to prevent this force from acting on the floor of the cab, thereby avoiding abnormal noise. At the same time, the oil in the rod chamber 13 will also flow back to the oil receiving port B122 through the oil pipe 6 to open the hydraulic control valve 5, so that part of the oil in the rodless chamber 14 flows out from the oil receiving port A121 through the hydraulic control valve 5.

[0041] Specifically, the hydraulic control valve 5 includes a valve core member 51, a valve core seat 52, a steel ball 53, a valve core spring 54 and a fixed seat 55. The valve core member 51 divides the valve cavity into a first cavity and a second cavity. The outer wall of the valve core member 51 is provided with a valve core sealing ring 511. The outer wall of the valve core sealing ring 511 is sealed with the inner wall of the first cavity. The valve core seat 52 is arranged in the second valve cavity. The rear end of the valve core seat 52 is axially provided with a valve hole 521. The front end of the valve core seat 52 is provided with a fixed seat 55. The fixed seat 55 is axially provided with a connecting hole 551 connected to the rodless cavity 14. The valve core seat 52 is provided with an oil channel for connecting the valve hole 521 and the connecting hole 551, and a valve core spring 54 and a steel ball 53 are provided in the oil channel. One end of the valve core spring 54 is against the steel ball 53, and the other end of the valve core spring 54 is against the fixed seat 55. The valve core spring 54 has a movement tendency to make the steel ball 53 seal the valve hole 521. The front end of the valve core member 51 is provided with an extension portion 512 extending into the valve hole 521. There is a clearance fit between the extension portion 512 and the valve hole 521, and the front end of the extension portion 512 is against the steel ball 53.

[0042] When high-pressure oil is input into the oil connecting port A121, the high-pressure oil pushes the steel ball 53 through the gap between the extension part 512 and the valve hole 521 to open the hydraulic control valve 5, allowing the high-pressure oil to enter the rodless chamber 14. When high-pressure oil is input into the oil connecting port B122, the high-pressure oil pushes the valve core member 51, so that the extension part 512 at the front end of the valve core member 51 pushes the steel ball 53 to open the hydraulic control valve 5, and the oil in the rodless chamber 14 flows back to the oil connecting port A121.

[0043] Preferably, in this embodiment, a limiting groove 17 is provided in the front end of the cylinder 1, and a wire retaining ring 171 is provided in the limiting groove 17. The front cover 11 is limitedly matched with the wire retaining ring 171 along the axial direction. Specifically, the wire retaining ring 171 is arranged at the front end of the front cover 11, which can effectively prevent the front cover 11 from slipping out and affecting the use. Preferably, a dust ring 7 is also provided at the front end of the wire retaining ring 171 to prevent dust and other fine particles from entering the interior of the cylinder 1, thereby protecting the internal components from pollution and extending the service life of the equipment.

[0044] The above description is only a preferred embodiment of the present utility model, so all equivalent changes or modifications made according to the structure, features and principles described in the scope of the present utility model patent application are included in the scope of the present utility model patent application.

Claims

1. A hydraulic cylinder with a shock absorbing function, comprising a cylinder barrel (1), wherein two ends of the cylinder barrel (1) are respectively provided with a front cover (11) and a rear cover (12), wherein a piston (2) and a piston rod (3) are movably provided in the cylinder barrel (1), wherein the piston (2) and the piston rod (3) are fixedly connected, wherein the piston (2) divides the inner cavity of the cylinder barrel (1) into a rod cavity (13) and a rodless cavity (14), wherein the front end of the piston rod (3) protrudes from the front cover (11), and wherein: A bushing assembly (4) is provided at the front end of the piston rod (3), the bushing assembly (4) comprising an inner bushing (41), an outer bushing (42), and a rubber sleeve (43) disposed between the inner bushing (41) and the outer bushing (42) to elastically connect them, the outer bushing (42) being radially sleeved on the outer wall of the inner bushing (41) and abutting against the inner bushing (41), the outer bushing (42) being radially sleeved on the outer wall of the rubber sleeve (43) and abutting against the rubber sleeve (43). ) are abutted against each other, the rubber sleeve (43) and the outer bushing (42) are vulcanized and integrally formed, the cylinder barrel (1) is provided with a small diameter barrel section (15) and a large diameter barrel section (16) in sequence from front to back along the axial direction, the outer wall of the piston (2) is sleeved with a piston sealing ring (21), the outer wall of the piston sealing ring (21) is sealingly matched with the inner wall of the small diameter barrel section (15), and the outer wall of the piston sealing ring (21) is gap-matched with the inner wall of the large diameter barrel section (16).

2. A hydraulic cylinder with a shock absorbing function according to claim 1, characterized in that: A valve cavity is formed in the rear cover (12), and an oil receiving port A (121) and an oil receiving port B (122) are provided on the rear cover (12) and are respectively connected to the valve cavity. A hydraulic control valve (5) is provided in the valve cavity, and the valve cavity is connected to the rodless cavity (14) through the hydraulic control valve (5). An oil pipe (6) for connecting the valve cavity and the rod cavity (13) is also provided outside the cylinder barrel (1).

3. A hydraulic cylinder with a shock absorbing function according to claim 2, characterized in that: The cylinder barrel (1) and the rear cover (12) are welded together, one end of the oil pipe (6) is welded to the cylinder barrel (1), and the other end of the oil pipe (6) is welded to the rear cover (12).

4. The hydraulic cylinder with shock absorbing function according to claim 1, characterized in that: A limiting groove (17) is provided in the front end of the cylinder barrel (1), a wire retaining ring (171) is provided in the limiting groove (17), and the front cover (11) is limitedly matched with the wire retaining ring (171) along the axial direction.

5. The hydraulic cylinder with shock absorption function according to claim 1, characterized in that: The rubber sleeve (43) is arranged in a hollow shape.

6. A hydraulic cylinder with a shock absorbing function according to claim 5, characterized in that: The rubber sleeve (43) and the inner liner sleeve (41) are integrally formed by vulcanization.

7. The hydraulic cylinder with shock absorption function according to claim 5, characterized in that: The rubber sleeve (43) is provided with a plurality of buffer holes (431) along the circumferential direction and penetrating the rubber sleeve (43) along the axial direction.

8. The hydraulic cylinder with shock absorption function according to claim 1, characterized in that: The rubber sleeve (43) is arranged in a solid shape.

9. The hydraulic cylinder with shock absorbing function according to claim 8, characterized in that: The rubber sleeve (43) and the inner sleeve (41) are clearance-matched, and the inner sleeve (41) can rotate relative to the rubber sleeve (43).

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