Bidirectional cushion cylinder structure

Abstract

The utility model relates to a kind of two-way buffer oil cylinder structure, belong to fluid pressure actuator technical field.The utility model will realize the throttle valve (namely retract throttle valve and extend throttle valve) of buffering function, realize the one-way valve (namely retract one-way valve and extend one-way valve) of quick start is built-in installed on cylinder bottom and guide sleeve, without external buffering structure or control system, reduce the cost of oil cylinder, while simplifying the overall design of oil cylinder, save the installation and use space of oil cylinder, and the buffering function of oil cylinder is completely by throttle valve flow control, than the hydraulic oil cylinder of conventional rely on buffer part gap to control flow more accurate, more stable, in the hydraulic system of multiple oil cylinder parallel installation operation, consistency is better, especially suitable for small space, small flow, high-precision use environment.

Description

Technical Field

[0001] This utility model relates to a bidirectional buffer cylinder structure, belonging to the technical field of fluid pressure actuators. Background Technology

[0002] Hydraulic cylinders, as actuators that convert hydraulic energy into mechanical energy, are widely used in various industrial fields. In traditional hydraulic cylinders, when the piston reaches the end of its stroke, due to the large flow rate and high speed, the piston will mechanically collide with the guide sleeve or the bottom of the cylinder, generating enormous impact force and noise. This is particularly noticeable under high pressure and high flow conditions. This impact force can have serious effects on the cylinder itself and even the entire hydraulic system. For example, long-term repeated rigid impacts can cause fatigue damage, loosening, or even breakage of the cylinder's parts, welds, and connected components, shortening the service life of the cylinder and the hydraulic system. A sudden stop of the piston will cause the oil flow to be momentarily cut off, generating pressure peaks in the oil circuit, which may damage the hydraulic pump, hydraulic valves, and related sealing components in the hydraulic system. Strong impact forces will cause severe vibration of the cylinder, producing harsh noise and deteriorating the working environment.

[0003] To overcome the above problems, it is necessary to reduce the running speed of the cylinder piston at the end of its stroke, i.e., an end-stroke buffering function is required. The buffering function designed by existing technology can meet the operating conditions of most buffer cylinders, but there are still some shortcomings and defects: for example, the buffering design scheme that controls the flow rate by the gap of the buffering parts is not effective in small-flow hydraulic cylinders.

[0004] For example, Chinese patent document CN218564065U discloses a one-way buffer mechanism for a hydraulic cylinder, including a cylinder barrel, a piston, a guide sleeve, a piston rod, and a cylinder bottom. The cylinder bottom is fixedly mounted to one end of the cylinder barrel, and the guide sleeve is fixedly mounted to the other end of the cylinder barrel. The inner wall of the guide sleeve mates with the piston rod, and a piston rod seal is provided on the mating surface of the inner wall of the guide sleeve with the piston rod. One end of the piston rod extending into the cylinder barrel is fixedly connected to the piston. The outer surface of the piston mates with the inner wall of the cylinder barrel, and a piston seal is provided between the mating surface of the outer surface of the piston and the inner wall of the cylinder barrel. The cylinder barrel is connected to the guide sleeve. A first oil port communicating with the cylinder cavity is fixedly provided on the outer wall of one end, and a second oil port communicating with the cylinder cavity is provided on the outer side of the cylinder bottom. Both the cylinder bottom end and the front guide sleeve end are provided with one-way buffer mechanisms. The one-way buffer mechanism at the front guide sleeve end includes a first buffer sleeve, a first retaining ring, a first buffer spacer ring, and a first buffer spacer ring. The first buffer sleeve is fixedly provided on the piston rod and located at the piston end near the front guide sleeve. A first positioning step surface is provided on the inner wall of the front guide sleeve at the piston end. The first retaining ring is fixedly installed on the inner wall of the front guide sleeve at the piston end. The first positioning step surface and the end face of the first retaining ring are also provided. The first adjusting cavity is formed by combining the first buffer spacer and the inner wall of the guide sleeve. Both the first buffer spacer and the first buffer spacer are fitted onto the piston rod and disposed within the first adjusting cavity. The first buffer spacer is located closer to the first retaining ring. The first adjusting cavity provides space for the axial movement of the first buffer spacer and the first buffer spacer. The outer surface of the first buffer spacer is fitted to the inner wall of the guide sleeve. The inner surface of the first buffer spacer has a radial clearance with the outer surface of the first buffer sleeve. The inner surface of the first buffer spacer is fitted to the outer surface of the first buffer sleeve, and a first gradient oil groove is provided between their mating surfaces. The length direction of the first gradient oil groove is arranged along the length direction of the piston rod, and the cross-sectional area of ​​the first gradient oil groove decreases in the direction from the front guide sleeve to the bottom of the cylinder; there is a radial gap between the outer circular surface of the first buffer ring and the inner sidewall of the front guide sleeve; a cylinder seal is provided between the outer circular surface of the front guide sleeve and the mating surface of the cylinder inner wall, and the cylinder seal is located on both sides of the first oil port; a first oil hole is provided in the area between the two sets of cylinder seals of the front guide sleeve, and the first oil hole connects the outer circular surface and the inner circular surface of the front guide sleeve; the opening formed by the first oil hole on the inner circular surface of the front guide sleeve is located on the side of the first adjustment chamber away from the piston;The one-way buffer mechanism at the cylinder bottom end includes a second buffer spacer, a second buffer spacer pressure ring, a second retaining ring, and a second buffer sleeve. The second buffer sleeve is fixedly mounted on the piston rod and located at the piston end near the cylinder bottom. A cylinder bottom buffer hole is provided on the inner end face of the cylinder bottom. A second positioning step surface is provided on the inner side wall of the cylinder bottom buffer hole at the piston end. The second retaining ring is fixedly installed on the inner side wall of the cylinder bottom buffer hole at the piston end. The second positioning step surface, the end face of the second retaining ring, and the inner side wall of the cylinder bottom buffer hole together form a second adjustment cavity. The second buffer spacer and the second buffer spacer pressure ring are both sleeved on the piston rod and located in the second adjustment cavity. The second buffer spacer pressure ring is located on the side closer to the second retaining ring. The second adjustment cavity has a spacer for the second buffer spacer and the second buffer spacer pressure ring. The space for axial movement includes a second buffer spacer ring whose outer circular surface is adapted to the inner wall of the cylinder bottom buffer hole, a second buffer spacer ring whose inner circular surface has a radial clearance with the outer circular surface of the second buffer sleeve, a second gradually changing oil groove between the mating surfaces of the two, the length direction of the second gradually changing oil groove being arranged along the length direction of the piston rod, and the cross-sectional area of ​​the second gradually changing oil groove decreasing from the cylinder bottom to the front guide sleeve; a radial clearance between the outer circular surface of the second buffer spacer ring and the inner wall of the cylinder bottom buffer hole; a second oil hole connecting the second oil port and the cylinder bottom buffer hole is provided at the cylinder bottom, and the opening formed by the second oil hole on the inner circular surface of the cylinder bottom buffer hole is located on the side of the second adjustment chamber away from the piston. The above-mentioned solution mainly achieves the buffering effect through the oil passage clearance of each component in the areas where the first and second regulating chambers are located. However, when applied to small-flow hydraulic cylinders, it typically presents challenges in machining and assembly, as well as insufficient precision in controlling the buffering function. Furthermore, in hydraulic systems with multiple cylinders installed and operating in parallel, consistency needs further improvement. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a bidirectional buffer cylinder structure that is suitable for small flow hydraulic cylinders. It makes the structure simple and reliable, easy to process and assemble, and the buffer function is more precise and stable. In a hydraulic system in which multiple cylinders are installed and operated in parallel, the consistency is better.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a bidirectional buffer cylinder structure, including a cylinder barrel, a piston, a guide sleeve, a piston rod, and a cylinder bottom. The cylinder bottom is fixedly assembled to one end of the cylinder barrel, and the guide sleeve is fixedly assembled to the other end of the cylinder barrel to form the cylinder cavity. The inner circumferential surface of the outer end of the guide sleeve is sealed to the outer circumferential surface of the piston rod. The end of the piston rod that extends into the cylinder barrel is fixedly connected to the piston. The piston divides the cylinder cavity into a rodless cavity and a rod cavity. A buffer pin is coaxially fixedly assembled on the piston rod near the rodless cavity. A first main oil passage for the buffer pin to be inserted is provided at the inner end of the cylinder bottom. A cylinder bottom oil port is provided at the cylinder bottom, and the cylinder bottom oil port is connected to the rodless cavity through the first main oil passage. A buffer sleeve is coaxially sealed and fixedly assembled on the piston rod near the rod cavity. A second main oil passage for the buffer sleeve to be inserted is provided at the inner end of the guide sleeve. A cylinder oil port is provided on the outer wall of the cylinder barrel. A cylinder seal is provided between the outer circular surface of the guide sleeve and the mating surface of the inner wall of the cylinder barrel. The cylinder seal is located on both sides of the cylinder oil port. A set of guide sleeves is provided on each side. A guide sleeve oil port is provided in the area between the two sets of cylinder seals. The cylinder oil port connects to the rod chamber sequentially through the guide sleeve oil port and the second main oil passage. A buffer pin seal is provided on the outer circumference of the buffer pin to form a sealing fit with the first main oil passage, and a buffer sleeve seal is provided on the outer circumference of the buffer sleeve to form a sealing fit with the second main oil passage. Between the cylinder bottom oil port and the rodless chamber, a first one-way starting oil passage and a first throttling oil passage are provided parallel to the first main oil passage. The first one-way starting oil passage is equipped with an extended one-way valve, which opens from the cylinder bottom oil port towards the rodless chamber. A retractable throttling valve is installed in the first throttling oil passage. Between the guide sleeve oil port and the rod chamber, a second one-way starting oil passage and a second throttling oil passage are provided parallel to the second main oil passage. The second one-way starting oil passage is equipped with a retractable one-way valve, which opens from the guide sleeve oil port towards the rod chamber. An extended throttling valve is installed in the second throttling oil passage.

[0007] A further preferred embodiment is that: the retractable throttle valve is fixed to the end of the first throttle passage near the rodless chamber by an interference fit; the extended check valve is fixed to the end of the first one-way start passage near the rodless chamber by an interference fit.

[0008] A further preferred embodiment is that the extension throttle valve is fixed to one end of the second throttle passage near the rod chamber by an interference fit; and the retractable check valve is fixed to one end of the second one-way start passage near the rod chamber by an interference fit.

[0009] A further preferred embodiment is that the retractable throttle valve includes a retractable throttle valve body, the retractable throttle valve body has a central flow channel, and a throttle orifice is provided at the end face of the central flow channel near the bottom oil port of the cylinder, and a filter screen is provided inside the central flow channel.

[0010] A further preferred embodiment is that the extended throttle valve includes an extended throttle valve body, the extended throttle valve body has a central flow channel, and a throttle hole is provided at the end face of the central flow channel near the guide sleeve oil port, and a filter screen is provided inside the central flow channel.

[0011] A further preferred method is to weld the cylinder bottom to the cylinder barrel.

[0012] A further preferred embodiment is that the guide sleeve is detachably fixed to the cylinder by a snap ring.

[0013] A further preferred embodiment is that the axis of the cylinder bottom oil port is arranged radially along the cylinder bottom, the axis of the first one-way starting oil passage and the axis of the first throttling oil passage are both parallel to the axis of the first main oil passage, and the first one-way starting oil passage and the first throttling oil passage are respectively located on both sides of the first main oil passage.

[0014] Further preferred features include: the cylinder oil port and the guide sleeve oil port have the same axis (i.e., coaxial or parallel) and are both arranged along the radial direction of the cylinder; the axis of the second one-way starting oil passage and the axis of the second throttling oil passage are both parallel to the axis of the second main oil passage, and the second one-way starting oil passage and the second throttling oil passage are respectively located on both sides of the second main oil passage.

[0015] The working principle of this invention is as follows: When the cylinder extends to start, oil enters through the bottom port of the cylinder. At this time, the first main oil passage is sealed, but the oil can quickly reach the rodless chamber through the extended one-way valve, pushing the piston to move and allowing the cylinder to start quickly. During the piston rod extension process, when the buffer sleeve moves close to the guide sleeve, the buffer sleeve gradually inserts into the second main oil passage and seals it. The retracted one-way valve is always in a closed state, and the oil in the rod chamber can only slowly return to the cylinder port through the extended throttle valve, thereby reducing the piston movement speed and realizing the buffering function at the end of the extension.

[0016] When the hydraulic cylinder retracts and starts, oil enters through the cylinder port. At this time, the second main oil passage is sealed, but the oil can quickly reach the rod chamber through the retraction check valve, pushing the piston and starting the cylinder quickly. During the piston rod retraction process, when the buffer pin moves close to the bottom of the cylinder, the buffer pin gradually inserts into the first main oil passage and seals it. The extended check valve remains closed, and the oil in the rodless chamber can only slowly return to the bottom port through the retraction throttle valve, thereby reducing the piston speed and achieving the buffering function at the end of the retraction.

[0017] The beneficial effects of this utility model are as follows: The throttle valve (i.e., retractable and extended throttle valves) that realizes the buffering function, and the check valve (i.e., retractable and extended check valves) that realize rapid start-up are built into the cylinder bottom and guide sleeve. No external buffering structure or control system is required, reducing cylinder costs while simplifying the overall cylinder design and saving installation and usage space. Furthermore, the cylinder's buffering function is entirely controlled by the throttle valve for flow control, which is more precise and stable than conventional hydraulic cylinders that rely on the gaps between buffer components to control flow. In hydraulic systems with multiple cylinders installed and operating in parallel, consistency is better, making it particularly suitable for environments with small spaces, low flow rates, and high precision. Additionally, if the cylinder experiences buffering failure, slow start-up, or internal seal leakage during use, the guide sleeve fixed by the snap ring can be quickly disassembled, the entire piston rod assembly removed, the root cause of the problem located, and corresponding parts repaired or replaced, such as the buffer pin, buffer sleeve, throttle valve, check valve, and seals, without scrapping the entire cylinder, thus reducing operating costs. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the internal structure of the bidirectional buffer cylinder described in this utility model; Figure 2 This is a schematic diagram of the oil flow direction during the extension and start-up of the bidirectional buffer cylinder described in this utility model; Figure 3 This is a schematic diagram of the oil flow direction when the bidirectional buffer cylinder of this utility model extends to the buffer starting point position; Figure 4 This is a schematic diagram of the oil flow direction during the retraction and start-up of the bidirectional buffer cylinder described in this utility model; Figure 5 This is a schematic diagram of the oil flow direction when the bidirectional buffer cylinder of this utility model retracts to the buffer starting position; Figure 6 This is a three-dimensional structural schematic diagram of the throttle valve described in this utility model; Figure 7 This is a cross-sectional view of the throttle valve described in this utility model; Figure 8 This is a three-dimensional structural diagram of the one-way valve described in this utility model; Figure 9 This is a cross-sectional view of the one-way valve described in this utility model.

[0019] The components in the diagram are labeled as follows: 1-Cylinder bottom, 2-First main oil passage, 3-Retractable throttle valve, 4-Extending check valve, 5-Rodless chamber, 6-Buffer pin seal, 7-Buffer pin, 8-Piston, 9-Cylinder barrel, 10-Buffer sleeve, 11-Buffer sleeve seal, 12-Rod chamber, 13-Piston rod, 14-Retractable check valve, 15-Extending throttle valve, 16-Second main oil passage, 17-Guide sleeve, 18-Snap ring, 19-Rod head, 20-Cylinder bottom port, 21-Cylinder barrel port, 22-Cylinder barrel seal, 23-Filter screen, 24-Throttle orifice, 25-Spring, 26-Sealing ball. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] like Figure 1 As shown, the main structure of this utility model is the same as that of existing conventional technology, including a cylinder 9, a piston 8, a guide sleeve 17, a piston rod 13, and a cylinder bottom 1. The cylinder bottom 1 is fixedly assembled to one end of the cylinder 9, and the guide sleeve 17 is fixedly assembled to the other end of the cylinder 9 to form the inner cavity of the oil cylinder. That is, the cylinder 9, the guide sleeve 17, and the cylinder bottom 1 form a relatively closed inner cavity of the oil cylinder, which generally only has the necessary piston rod through hole and oil inlet and outlet channels. The inner circumferential surface of the outer end of the guide sleeve 17 is sealed to the outer circumferential surface of the piston rod 13. One end of the piston rod 13 that extends into the cylinder 9 is fixedly connected to the piston 8. The piston 8 divides the inner cavity of the oil cylinder into a rodless cavity 5 and a rod cavity 12. A buffer pin 7 is coaxially fixedly assembled on the side of the piston 8 near the rodless cavity 5. The inner end of the cylinder bottom 1 is provided with a first main oil passage 2 for the buffer pin 7 to be inserted. The cylinder bottom 1 is provided with A cylinder bottom oil port 20 is provided, which is connected to the rodless chamber 5 through the first main oil passage 2. The piston rod 13 is coaxially and sealed with a buffer sleeve 10 on the side of the piston 8 near the rod chamber 12 (that is, equivalent to a sealed fit between the inner circular surface of the piston rod 13 and the buffer sleeve 10, which can generally be achieved by adding a sealing ring between the two). The inner end of the guide sleeve 17 is provided with a second main oil passage 16 for the buffer sleeve 10 to be inserted. The outer wall of the cylinder 9 is provided with a cylinder oil port 21. The outer circular surface of the guide sleeve 17 is provided with a cylinder seal 22 between the mating surface with the inner wall of the cylinder 9. A set of cylinder seals 22 is provided on both sides of the cylinder oil port 21. The guide sleeve 17 is provided with a guide sleeve oil port in the area between the two sets of cylinder seals 22. The cylinder oil port 21 is connected to the rod chamber 12 through the guide sleeve oil port and the second main oil passage 16 in sequence. The cylinder bottom port 20 and cylinder barrel port 21 are used to connect to external hydraulic oil pipes, respectively; the piston rod 13 extending out of the cylinder barrel 9 is generally also fixedly connected to a rod head 19.

[0022] The key technical point of this utility model is that the outer peripheral surface of the buffer pin 7 is provided with a buffer pin seal 6 for forming a sealing fit with the first main oil passage 2, and the outer peripheral surface of the buffer sleeve 10 is provided with a buffer sleeve seal 11 for forming a sealing fit with the second main oil passage 16; a first one-way starting oil passage and a first throttling oil passage are also provided between the cylinder bottom oil port 20 and the rodless chamber 5, which are arranged in parallel with the first main oil passage 2. The first one-way starting oil passage is equipped with an extension one-way valve 4, and the opening direction of the extension one-way valve 4 is from the cylinder bottom oil port 20 to the rodless chamber 5. A retractable throttling valve 3 is installed in the first throttling oil passage; a second one-way starting oil passage and a second throttling oil passage are also provided between the guide sleeve oil port and the rod chamber 12, which are arranged in parallel with the second main oil passage 16. A retractable one-way valve 14 is installed in the second one-way starting oil passage, and the opening direction of the retractable one-way valve 14 is from the guide sleeve oil port to the rod chamber 12. An extension throttling valve 15 is installed in the second throttling oil passage.

[0023] The working principle of this utility model is as follows: See Figure 2 When the cylinder extends to start, oil enters through the bottom oil port 20. At this time, the first main oil passage 2 is sealed, but the oil can quickly reach the rodless chamber 5 through the extended check valve 4, pushing the piston 8 to move and allowing the cylinder to start quickly.

[0024] See Figure 3 During the extension of the piston rod 13, when the buffer sleeve 10 moves close to the guide sleeve 17, the buffer sleeve 10 gradually inserts into the second main oil passage 16 and seals the second main oil passage 16. The retractable check valve 14 is always in a closed state, and the oil in the rod chamber 12 can only slowly return to the cylinder oil port 21 through the extension throttle valve 15, thereby reducing the movement speed of the piston 8 and realizing the buffer function at the end of the extension.

[0025] See Figure 4 When the hydraulic cylinder retracts and starts, oil enters through the cylinder oil port 21. At this time, the second main oil passage 16 is sealed, but the oil can quickly reach the rod chamber 12 through the retracting check valve 14, pushing the piston 8 to move and allowing the hydraulic cylinder to start quickly.

[0026] See Figure 5 During the retraction of piston rod 13, when buffer pin 7 moves close to cylinder bottom 1, buffer pin 7 gradually inserts into the first main oil passage 2 and seals the first main oil passage 2. The extended one-way valve 4 is always closed, and the oil in rodless chamber 5 can only slowly return to cylinder bottom oil port 20 through retraction throttle valve 3, thereby reducing the movement speed of piston 8 and realizing the retraction end buffer function.

[0027] The retractable throttle valve 3 and the extended throttle valve 15 of this utility model have the same main structure, differing only in their installation positions, and can be collectively referred to as "throttle valves"; the retractable one-way valve 14 and the extended one-way valve 4 have the same main structure, differing only in their installation positions, and can be collectively referred to as "one-way valves". An embodiment of one of them can be found in [reference needed]. Figure 8 and Figure 9 A check valve typically includes a valve body with a central flow channel. Within this central flow channel, a sealing ball 26 and a spring 25 are installed. Under normal conditions, the spring 25 causes the sealing ball 26 to seal the central flow channel. When the cylinder is activated, the hydraulic pressure pushes the sealing ball 26 to move, achieving one-way flow through the central flow channel. Both the aforementioned "throttle valve" and "check valve" can utilize existing standard components, which are then fixed to the cylinder bottom 1 and guide sleeve 17 according to the designed structure. No external buffer structure or control system is required, reducing cylinder costs, simplifying the overall cylinder design, and saving installation and usage space. Furthermore, the cylinder's buffering function is entirely controlled by the throttle valve, resulting in greater precision and stability than conventional hydraulic cylinders that rely on buffer component gaps for flow control. In hydraulic systems with multiple cylinders installed and operating in parallel, consistency is improved, making it particularly suitable for environments requiring small spaces, low flow rates, and high precision.

[0028] To further facilitate assembly, in the preferred embodiment, the retractable throttle valve 3 is fixed to one end of the first throttle oil passage near the rodless chamber 5 by an interference fit; the extended one-way valve 4 is fixed to one end of the first one-way start oil passage near the rodless chamber 5 by an interference fit.

[0029] To further facilitate assembly, in the preferred embodiment, the extended throttle valve 15 is fixed to one end of the second throttle oil passage near the rod chamber 12 by an interference fit; the retractable check valve 14 is fixed to one end of the second one-way start oil passage near the rod chamber 12 by an interference fit.

[0030] See Figure 6 and Figure 7 In some preferred embodiments, the retractable throttle valve 3 includes a retractable throttle valve body with a central flow channel and a throttle orifice 24 at the end face of the central flow channel near the bottom oil port 20. A filter screen 23 is disposed inside the central flow channel. By adding the filter screen 23, oil impurities can be filtered out, thereby effectively preventing impurities generated in the cylinder cavity from clogging the throttle orifice 24 of the retractable throttle valve 3. Similarly, the extended throttle valve 15 includes an extended throttle valve body with a central flow channel and a throttle orifice 24 at the end face of the central flow channel near the guide sleeve oil port. A filter screen 23 is disposed inside the central flow channel.

[0031] To ensure a simple and reliable structure, the cylinder bottom 1 and cylinder barrel 9 are generally fixed by welding.

[0032] In some preferred embodiments, the guide sleeve 17 is detachably fixed to the cylinder 9 by a retaining ring 18. In practice, the retaining ring 18 can be used with retaining ring pliers to facilitate the easy assembly and disassembly of the cylinder, making it convenient for subsequent maintenance of internal parts of the cylinder, such as throttle valves, check valves, and seals.

[0033] To ensure structural simplicity and reliability, in some preferred embodiments, the axis of the cylinder bottom port 20 is arranged radially along the cylinder bottom 1. The axes of the first one-way starting oil passage and the first throttling oil passage are both parallel to the axis of the first main oil passage 2. The first one-way starting oil passage and the first throttling oil passage are respectively located on both sides of the first main oil passage 2. That is, the retractable throttle valve 3 is located on the side near the outer end of the cylinder bottom port 20, and the extended one-way valve 4 is located on the side near the inner end of the cylinder bottom port 20, symmetrical with respect to the cylinder axis; or the extended one-way valve 4 is located on the side near the outer end of the cylinder bottom port 20, and the retractable throttle valve 3 is located on the side near the inner end of the cylinder bottom port 20, symmetrical with respect to the cylinder axis.

[0034] To ensure structural simplicity and reliability, in some preferred embodiments, the axes of the cylinder oil port 21 and the guide sleeve oil port are aligned (i.e., coaxial or parallel), and both are arranged radially along the cylinder 9. The axes of the second one-way starting oil passage and the second throttling oil passage are both parallel to the axis of the second main oil passage 16, and the second one-way starting oil passage and the second throttling oil passage are located on opposite sides of the second main oil passage 16. This is equivalent to the extended throttle valve 15 being positioned near the cylinder oil port 21, and the retractable one-way valve 14 being positioned symmetrically with respect to the cylinder axis on the side away from the cylinder oil port 21; or the retractable one-way valve 14 being positioned near the cylinder oil port 21, and the extended throttle valve 15 being positioned symmetrically with respect to the cylinder axis on the side away from the cylinder oil port 21.

Claims

1. A bidirectional buffer cylinder structure, comprising a cylinder barrel (9), a piston (8), a guide sleeve (17), a piston rod (13), and a cylinder bottom (1). The cylinder bottom (1) is fixedly mounted on one end of the cylinder barrel (9), and the guide sleeve (17) is fixedly mounted on the other end of the cylinder barrel (9) to form the cylinder cavity. The inner circumferential surface of the outer end of the guide sleeve (17) is sealed to the outer circumferential surface of the piston rod (13). One end of the piston rod (13) extending into the cylinder barrel (9) is fixedly connected to the piston (8). The piston (8) divides the cylinder cavity into a rodless cavity (5) and a rod cavity (12). A buffer pin (7) is coaxially fixedly mounted on the piston rod (13) on the side of the piston (8) near the rodless cavity (5). The inner end of the cylinder bottom (1) is provided with a first main oil passage (2) for the buffer pin (7) to be inserted. The cylinder bottom (1) is provided with a cylinder bottom oil port (20). The cylinder bottom oil port (20) is connected to the rodless chamber (5) through the first main oil passage (2); the piston rod (13) is coaxially sealed and fixedly fitted with a buffer sleeve (10) on the side of the piston (8) near the rod chamber (12); the inner end of the guide sleeve (17) is provided with a second main oil passage (16) for the buffer sleeve (10) to be inserted; the outer wall of the cylinder (9) is provided with a cylinder oil port (21); the outer circular surface of the guide sleeve (17) is provided with a cylinder seal (22) between the mating surface with the inner wall of the cylinder (9); a set of cylinder seals (22) is provided on both sides of the cylinder oil port (21); the guide sleeve (17) is provided with a guide sleeve oil port in the area between the two sets of cylinder seals (22); the cylinder oil port (21) is connected to the rod chamber (12) through the guide sleeve oil port and the second main oil passage (16) in sequence; the characteristic is that: The outer circumferential surface of the buffer pin (7) is provided with a buffer pin seal (6) for forming a sealing fit with the first main oil passage (2), and the outer circumferential surface of the buffer sleeve (10) is provided with a buffer sleeve seal (11) for forming a sealing fit with the second main oil passage (16); between the cylinder bottom oil port (20) and the rodless chamber (5), a first one-way starting oil passage and a first throttling oil passage are also provided in parallel with the first main oil passage (2), the first one-way starting oil passage is equipped with an extended one-way valve (4), and the extended one-way valve (4) is... The opening direction is from the bottom oil port (20) to the rodless chamber (5). A retractable throttle valve (3) is installed in the first throttle oil passage. A second one-way starting oil passage and a second throttle oil passage are also provided between the guide sleeve oil port and the rod chamber (12) and are arranged in parallel with the second main oil passage (16). A retractable check valve (14) is installed in the second one-way starting oil passage. The opening direction of the retractable check valve (14) is from the guide sleeve oil port to the rod chamber (12). An extension throttle valve (15) is installed in the second throttle oil passage.

2. The bidirectional buffer cylinder structure as described in claim 1, characterized in that: The retractable throttle valve (3) is fixed to one end of the first throttle oil passage near the rodless chamber (5) by an interference fit; the extended check valve (4) is fixed to one end of the first one-way start oil passage near the rodless chamber (5) by an interference fit.

3. The bidirectional buffer cylinder structure as described in claim 1, characterized in that: The extended throttle valve (15) is fixed to one end of the second throttle oil passage near the rod chamber (12) by an interference fit; the retractable check valve (14) is fixed to one end of the second one-way start oil passage near the rod chamber (12) by an interference fit.

4. The bidirectional buffer cylinder structure as described in claim 1, characterized in that: The retractable throttle valve (3) includes a retractable throttle valve body, which has a central flow channel and a throttle hole (24) is provided at the end face of the central flow channel near the bottom oil port (20). A filter screen (23) is provided inside the central flow channel.

5. The bidirectional buffer cylinder structure as described in claim 1, characterized in that: The extended throttle valve (15) includes an extended throttle valve body, which has a central flow channel and a throttle hole (24) is provided at the end face of the central flow channel near the guide sleeve oil port. A filter screen (23) is provided inside the central flow channel.

6. The bidirectional buffer cylinder structure as described in claim 1, characterized in that: The cylinder bottom (1) is welded and fixed to the cylinder barrel (9).

7. The bidirectional buffer cylinder structure as described in claim 1, characterized in that: The guide sleeve (17) is detachably fixed to the cylinder (9) by means of a snap ring (18).

8. The bidirectional buffer cylinder structure as described in any one of claims 1 to 7, characterized in that: The axis of the cylinder bottom oil port (20) is set along the radial direction of the cylinder bottom (1). The axis of the first one-way starting oil passage and the axis of the first throttling oil passage are both parallel to the axis of the first main oil passage (2). The first one-way starting oil passage and the first throttling oil passage are respectively located on both sides of the first main oil passage (2).

9. The bidirectional buffer cylinder structure as described in any one of claims 1 to 7, characterized in that: The cylinder oil port (21) and the guide sleeve oil port are aligned and are both arranged along the radial direction of the cylinder (9); the axis of the second one-way starting oil passage and the axis of the second throttling oil passage are both parallel to the axis of the second main oil passage (16), and the second one-way starting oil passage and the second throttling oil passage are respectively located on both sides of the second main oil passage (16).

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