Buffer structure of oil cylinder
By setting buffer sleeves and guide sleeves at both ends of the cylinder piston, the overshoot problem during rapid cylinder movement is solved, achieving stable movement and buffering effect, extending the service life of the cylinder and reducing maintenance costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JUCHAO TECHNOLOGY (HUNAN) CO LTD
- Filing Date
- 2025-08-21
- Publication Date
- 2026-06-26
AI Technical Summary
Existing hydraulic cylinders, lacking an effective buffer structure, are prone to over-impact when moving rapidly. Furthermore, damage to external hydraulic components or improper control can cause the buffering effect to fail, shortening service life and increasing maintenance costs.
Buffer sleeves and guide sleeves are installed at both ends of the piston in the oil cylinder to form a buffer channel and an oil return chamber. The oil flows out or in slowly through the buffer channel, so as to achieve stable movement and buffering effect on the piston and avoid direct impact on the end cover.
It improves the service life of the hydraulic cylinder, reduces the frequency of inspection and maintenance, enhances the stability and uniformity of piston movement, and avoids direct damage to the end cap.
Smart Images
Figure CN224414017U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of injection molding equipment technology, and in particular to a buffer structure for a hydraulic cylinder. Background Technology
[0002] During the product processing, injection molding equipment needs to drive the mold with hydraulic cylinders to extrude and shape the injection molded product. However, when the hydraulic cylinder moves quickly, if there is no external force, it will hit the bottom directly because there is no internal braking. Therefore, many hydraulic cylinder designers and manufacturers use external hydraulic components to decelerate according to the position. The disadvantage is that external control may cause over-impact due to improper control, or the external hydraulic components may fail to provide a buffering effect due to damage. Utility Model Content
[0003] This utility model provides a buffer structure for a hydraulic cylinder, which solves the problem in the prior art that the cylinder cannot play a buffering role due to improper external control causing excessive impact or damage to external hydraulic components, resulting in short service life and high maintenance costs.
[0004] This utility model provides the following technical solution:
[0005] A buffer structure for a hydraulic cylinder includes a cylinder barrel, end caps, a piston rod, and a piston. The end caps include a front end cap and a rear end cap, which are respectively disposed at both ends of the cylinder barrel. Both the front end cap and the rear end cap are provided with oil return holes. A piston rod extending into the cylinder barrel is installed on the front end cap. A piston is installed on the end of the piston rod that extends into the cylinder barrel. The piston and the piston rod reciprocate together along the cylinder barrel. Both the front end cap and the rear end cap are provided with annular guide sleeves, which extend into the cylinder barrel and are interference-fitted with the cylinder barrel.
[0006] The piston has a piston body in the middle and buffer sleeves at both ends. The outer diameter of the buffer sleeve is adapted to the inner diameter of the guide sleeve. When the buffer sleeve extends into the guide sleeve, the end face of the piston body, the end face of the guide sleeve, the inner wall of the cylinder located between the two, and the outer wall of the guide sleeve form a buffer cavity. There is a buffer channel between the outer wall of the buffer sleeve and the inner wall of the guide sleeve. The buffer channel connects the oil return hole and the buffer cavity.
[0007] The advantages of this invention are that the inner cavity of the guide sleeve and the buffer sleeve form a return oil cavity. By setting buffer sleeves that are compatible with the end cover guide sleeve at both ends of the piston, the oil in the buffer cavity slowly flows out from the buffer channel under the action of the buffer channel, thereby making the buffer cavity buffer the piston. When the pressure in the return oil cavity is greater than the pressure in the buffer cavity, the oil will move along the buffer channel into the buffer cavity, increasing the force-bearing area of the piston, ensuring the uniformity of the force on the piston, and making the piston move more stably along the cylinder. When the pressure in the buffer cavity is greater than the pressure in the return oil cavity, the oil flows from the buffer channel into the return oil cavity, thereby buffering the piston and preventing direct impact on the end cover.
[0008] The buffer sleeve includes a frustum-shaped buffer sleeve body I and a cylindrical buffer sleeve body II, with buffer sleeve body I located on the side furthest from the piston. The lengths of both buffer sleeve body I and buffer sleeve body II are 10–50 mm. Preferably, the lengths of both buffer sleeve body I and buffer sleeve body II are 20–30 mm; more preferably, the lengths of both buffer sleeve body I and buffer sleeve body II are 22 / 25 / 28 mm. Using this range effectively ensures the buffering effect.
[0009] Furthermore, an annular gap is formed between the outer wall of the buffer sleeve and the inner wall of the guide sleeve, and the annular gap serves as a buffer channel.
[0010] The annular gap is 0.2–5 mm. Preferably, the annular gap is 0.3–4.5 mm; more preferably, the annular gap is 0.5–2 mm. The annular gap can also be 0.8 / 1.0 / 1.2 / 1.5 mm. The annular gap within this range acts as a throttling mechanism, allowing the oil in the buffer chamber to flow slowly from the annular gap to the return oil chamber, thus achieving a buffering effect. An excessively large annular gap will result in an unsatisfactory or ineffective buffering effect; conversely, a gap smaller than this range will result in a loss of buffering effect, potentially leading to direct impact on the end cap.
[0011] Furthermore, a second groove is provided along the axial direction on the outer wall of the buffer sleeve and / or the inner wall of the guide sleeve, and the second groove is a buffer channel.
[0012] The depth of the second groove is 0.5–2 mm; the second grooves are evenly distributed on the inner wall and / or outer wall of the guide sleeve. The second grooves allow the oil in the buffer cavity to flow slowly from the annular gap to the return oil cavity, thereby achieving a buffering effect.
[0013] Furthermore, the length of the guide sleeve in the axial direction is greater than the length of the buffer sleeve. This allows the oil return cavity formed when the buffer sleeve enters the guide sleeve to avoid the end of the buffer sleeve directly impacting the bottom of the guide sleeve.
[0014] Furthermore, the piston rod is provided with a variable diameter section at the connection between the piston rod and the piston, and after the piston is installed, the buffer sleeve is flush with the outer diameter of the piston rod body.
[0015] The outer diameter of the variable diameter section is smaller than the outer diameter of the piston rod body, which facilitates the connection and installation between the piston and the piston rod. After installation, the end of the buffer sleeve is flush with the outer diameter of the piston rod body and remains on a plane, reducing the pressure of high-pressure oil on the end of the buffer sleeve and preventing damage to the buffer sleeve after long-term use.
[0016] Furthermore, a locking ring is provided at the connection between the variable diameter section and the piston, and an annular groove matching the locking ring is provided on the variable diameter section. The locking ring and annular groove are designed to improve the connection strength between the piston and the piston rod, preventing the piston from detaching from the piston rod.
[0017] Furthermore, a first sealing ring and a second sealing ring are provided at the connection between the end cover and the cylinder. The first sealing ring is located between the end cover and the end of the cylinder, and the second sealing ring is located between the guide sleeve and the inner wall of the cylinder.
[0018] The placement of the first and second sealing rings effectively improves the sealing effect. Furthermore, the fact that the first and second sealing rings are not aligned on the same straight line further enhances the sealing performance.
[0019] Furthermore, the piston is provided with a third sealing ring, and the two sides of the third sealing ring are provided with U-shaped grooves.
[0020] The third sealing ring and U-groove ensure a tight fit between the piston and the inner wall of the cylinder, improving the piston's movement efficiency.
[0021] Furthermore, the piston rod is fitted into the front end cover with a clearance fit, and a fourth sealing ring is provided at the fit. Two fourth sealing rings are provided to provide multiple sealing functions.
[0022] Furthermore, a first groove is provided on the end face of the guide sleeve near the piston; the depth of the first groove is 1-5mm. Preferably, the depth of the first groove is 2-4mm; more preferably, the depth of the first groove is 3mm. Providing a first groove on the guide sleeve can improve the buffering effect, and the depth of the first groove should not be too deep to affect the structural strength of the end cap; at the same time, it can prevent the piston from sticking to the end cap and avoid the problem of incomplete oil return.
[0023] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit the present invention.
[0024] In this invention, buffer sleeves are provided at both ends of the piston. When the piston moves to the end, the buffer sleeves cooperate with the end cap to achieve a buffering effect, avoiding direct impact of the piston on the end cap, reducing damage to the end cap, effectively improving the service life of the hydraulic cylinder, and reducing the frequency of hydraulic cylinder inspection and maintenance.
[0025] A first groove is provided on the side of the end cap near the piston, which effectively improves the buffering effect of the buffer section on the piston; at the same time, it can prevent the piston from sticking to the end cap and avoid the problem of incomplete oil return.
[0026] By setting up a buffer channel, when the pressure inside the buffer chamber is greater than the pressure inside the return oil chamber, the oil slowly enters the return oil chamber through the buffer channel to play a buffering role, thereby reducing the direct impact of high-pressure oil on the end cover and improving the service life of the end cover. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the structure of this utility model;
[0028] Figure 2 for Figure 1 Right view of the middle structure;
[0029] Figure 3 for Figure 2 Sectional view of AA;
[0030] Figure 4 This is an enlarged cross-sectional view of the rear cover of another structure of this utility model;
[0031] Figure 5 This is an enlarged cross-sectional view of the front cover of another structure of this utility model;
[0032] Figure 6 This is a cross-sectional view of the piston;
[0033] 1. Rear end cap; 2. Screw; 3. Front end cap; 4. Piston rod; 5. Bolt; 6. Cylinder; 7. Oil return hole; 8. Buffer sleeve body I; 9. Buffer sleeve body II; 10. Piston; 11. Fourth sealing ring; 12. First sealing ring; 13. Second sealing ring; 14. Locking ring; 15. Third sealing ring; 16. Oil return chamber; 17. First groove; 18. Buffer channel; 19. Buffer cavity; 20. Second groove. Detailed Implementation
[0034] The embodiments of the present invention will now be described with reference to the accompanying drawings.
[0035] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection" and "installation" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, "connection" can be a direct connection or an indirect connection through an intermediate medium. "Fixed" means that the relative positional relationship remains unchanged after the connection. The directional terms mentioned in the embodiments of this utility model, such as "inner," "outer," "top," and "bottom," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of this utility model, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.
[0036] In this embodiment of the invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.
[0037] In this embodiment of the utility model, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.
[0038] References to "one embodiment" or "some embodiments" as used in this specification mean that one or more embodiments of the present invention include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.
[0039] Example
[0040] Reference Figures 1-6A buffer structure for a hydraulic cylinder includes a cylinder barrel 6, end caps, a piston rod 4, and a piston 10. The end caps include a front end cap 3 and a rear end cap 1, which are respectively disposed at both ends of the cylinder barrel 6. Both the front end cap 3 and the rear end cap 1 are provided with oil return holes 7. The piston rod 4, which extends into the cylinder barrel 6, is mounted on the front end cap 3. The piston 10 is mounted on the end of the piston rod 4 that extends into the cylinder barrel 6. The piston 10 and the piston rod 4 reciprocate together along the cylinder barrel 6. Both the front end cap 3 and the rear end cap 1 are provided with annular guides. The piston 10 has a piston body in the middle and buffer sleeves at both ends. The outer diameter of the buffer sleeve is adapted to the inner diameter of the guide sleeve. When the buffer sleeve is inserted into the guide sleeve, the end face of the piston body, the end face of the guide sleeve, the inner wall of the cylinder 6 located between the two, and the outer wall of the guide sleeve form a buffer cavity 19. There is a buffer channel 18 between the outer wall of the buffer sleeve and the inner wall of the guide sleeve. The buffer channel 18 connects the oil return hole 7 and the buffer cavity 19.
[0041] An annular gap is formed between the outer wall of the buffer sleeve and the inner wall of the guide sleeve, serving as a buffer channel 18. The annular gap is 0.2–5 mm. Preferably, the annular gap is 0.3–4.5 mm; more preferably, it is 0.5–2 mm. Most preferably, in this embodiment, the annular gap is 0.8 mm. This range of annular gap serves a throttling function, allowing the oil in the buffer cavity 19 to flow slowly from the annular gap to the return oil cavity 16, thereby achieving a buffering effect. An excessively large annular gap will result in an unsatisfactory or ineffective buffering effect, while a gap smaller than this range will lead to a loss of buffering effect and a direct impact on the end cap.
[0042] The buffer sleeve includes a frustum-shaped buffer sleeve body I8 and a cylindrical buffer sleeve body II9, with buffer sleeve body I8 located on the side away from the piston 10. The lengths of both buffer sleeve body I8 and buffer sleeve body II9 are 10–50 mm. Preferably, the lengths of both buffer sleeve body I8 and buffer sleeve body II9 are 20–30 mm; more preferably, in this embodiment, the lengths of both buffer sleeve body I8 and buffer sleeve body II9 are 25 mm. This range effectively ensures the buffering effect, and the shape of buffer sleeve body I8 guides the buffer sleeve to enter the guide sleeve.
[0043] In this invention, the inner cavity of the guide sleeve and the buffer sleeve form a return oil cavity 16. The length of the guide sleeve in the axial direction is greater than the length of the buffer sleeve, so that the return oil cavity 16 formed when the buffer sleeve enters the guide sleeve can prevent the end of the buffer sleeve from directly hitting the bottom of the guide sleeve. By setting buffer sleeves that are adapted to the end cover guide sleeve at both ends of the piston 10, the oil in the buffer cavity 19 slowly flows out from the buffer channel 18 under the action of the buffer channel 18 during use, so that the buffer cavity 19 plays a buffering role on the piston 10. When the pressure in the return oil cavity 16 is greater than the pressure in the buffer cavity 19, the oil will move along the buffer channel 18 into the buffer cavity, increasing the force-bearing area of the piston 10, ensuring the uniformity of the force on the piston 10, and making the piston 10 move more stably along the cylinder 6. When the pressure in the buffer cavity 19 is greater than the pressure in the return oil cavity 16, the oil flows from the buffer channel 18 into the return oil cavity 16, thereby playing a buffering role on the piston 10 and preventing direct impact on the end cover.
[0044] A first groove 17 is provided on the end face of the guide sleeve near the piston 10. The first groove 17 is arc-shaped and evenly spaced on the end cap. In this embodiment, the first groove 17 is arranged in a circle on the end cap, thereby improving the buffering effect of the buffer section and effectively preventing the piston 10 from sticking tightly to the end cap. The depth of the first groove 17 is 1-5mm. Preferably, the depth of the first groove 17 is 2-4mm; more preferably, in this embodiment, the depth of the first groove 17 is 3mm. Providing the first groove 17 on the guide sleeve can improve the buffering effect. The depth of the first groove 17 should not be too deep, as this would affect the structural strength of the end cap. At the same time, it can prevent the piston 10 from sticking tightly to the end cap, avoiding the problem of incomplete oil return.
[0045] In another embodiment, the difference is that a second groove 20 is provided along the axial direction on the outer wall of the buffer sleeve and / or the inner wall of the guide sleeve. The second groove 20 is a buffer channel 18, and the depth of the second groove 20 is 0.5 to 2 mm. The outer wall of the buffer sleeve is provided with a second groove 20, the depth of which is 0.6mm. Four second grooves 20 are arranged in a circular pattern on the buffer sleeve body II9; or the inner wall of the guide sleeve is provided with a second groove 20, the depth of which is 0.8mm. Three second grooves 20 are arranged in a circular pattern at equal intervals on the guide sleeve; or two second grooves 20 are provided on both the outer wall of the buffer sleeve and the inner wall of the guide sleeve, the depth of which is 1.5mm. The second grooves 20 on the outer wall of the buffer sleeve and the inner wall of the guide sleeve are staggered. The second grooves 20 on the outer wall of the buffer sleeve penetrate the buffer sleeve body I8 and the buffer sleeve body II9, thereby ensuring that the oil in the buffer cavity 19 flows slowly from the buffer channel 18 to the return oil cavity 16, thus achieving the buffering effect.
[0046] In this embodiment, both the front end cover 3 and the rear end cover 1 are provided with oil return holes 7 communicating with the oil return chamber 16. The oil return holes 7 are used for oil return or high-pressure oil delivery to ensure the movement of the piston 10 within the cylinder 6. The cylinder 6 has a cylindrical structure, the outer side of the end cover has a rectangular structure, and the inner side of the end cover is provided with a guide sleeve that matches the cylinder 6. The front end cover 3 and the rear end cover 1 are connected and fastened to both ends of the cylinder 6 by a long screw 2. This method is used to improve the sealing effect of the cylinder 6. Preferably, the oil return hole 7 in the rear end cover 1 is L-shaped; the oil return hole 7 on the front end cover 3 is set perpendicular to the piston rod 4, and the piston rod 4 needs to pass through the front end cover 3. The purpose of this design is to avoid misalignment during the installation of the piston rod 4 and improve the convenience of installation and design.
[0047] In this embodiment, to ensure the sealing performance of the hydraulic cylinder, a first sealing ring 12 and a second sealing ring 13 are provided at the connection between the end cover and the cylinder 6. The first sealing ring 12 is located between the end cover and the end of the cylinder 6, and the second sealing ring 13 is located between the guide sleeve and the inner wall of the cylinder 6. The arrangement of the first sealing ring 12 and the second sealing ring 13 effectively improves the sealing effect. Furthermore, by positioning the first sealing ring 12 and the second sealing ring 13 on different lines, the sealing effect is further enhanced. Preferably, the guide sleeves on the front end cover 3 and the rear end cover 1 are 3-5 cm long; in this embodiment, the guide sleeve is 3 cm long; a second sealing ring 13 is provided on the guide sleeve to form a first sealing line, and a first sealing ring 12 is provided between the end of the front end cover 3 and one end of the cylinder 6, and between the end of the rear end cover 1 and the other end of the cylinder 6, to form a second sealing line; when the end cover and the cylinder 6 are installed tightly, the end of the end cover and the end of the cylinder 6 will be tightly connected to form a third sealing line; the sealing effect is ensured by multiple sealing lines; a third sealing ring 15 is provided on the piston 10, and U-shaped grooves are provided on both sides of the third sealing ring 15. The setting of the third sealing ring 15 and the U-shaped grooves makes the piston 10 fit tightly against the inner wall of the cylinder 6, improving the movement effect of the piston 10.
[0048] In this embodiment, a variable-diameter section is provided on the piston rod 4 at the connection between the piston rod 4 and the piston 10. After the piston 10 is installed, the buffer sleeve is flush with the outer diameter of the piston rod 4 body. The outer diameter of the variable-diameter section is smaller than the outer diameter of the piston rod 4 body, which facilitates the connection and installation between the piston 10 and the piston rod 4. After installation, the end of the buffer sleeve is flush with the outer diameter of the piston rod 4 body, keeping it on the same horizontal plane, reducing the pressure of high-pressure oil on the end of the buffer sleeve, and preventing damage to the buffer sleeve after long-term use. A locking ring 14 is provided at the connection between the variable-diameter section and the piston 10, and an annular groove matching the locking ring 14 is provided on the variable-diameter section. The locking ring 14 and the annular groove are provided to improve the connection strength between the piston 10 and the piston rod 4, preventing the piston 10 from detaching from the piston rod 4.
[0049] The piston rod 4 is fitted through the front end cover 3 with a clearance fit, and a fourth sealing ring 11 is provided at the fit; two fourth sealing rings 11 are provided to provide multiple sealing functions; in order to improve the installation convenience of the oil cylinder, the front end cover 3 is provided with bolts 5 and threaded holes that match the bolts 5 for installing the oil cylinder.
[0050] In this invention, buffer sleeves are provided at both ends of the piston 10. When the piston 10 moves to the end, the buffer sleeves cooperate with the end cap to achieve a buffering effect, preventing the piston 10 from directly impacting the end cap, reducing damage to the end cap, effectively improving the service life of the hydraulic cylinder, and reducing the frequency of hydraulic cylinder maintenance. A first groove 17 is provided on the side of the end cap near the piston 10, which effectively improves the buffering effect of the buffer section on the piston 10; at the same time, it can prevent the piston 10 from sticking tightly to the end cap, avoiding the problem of incomplete oil return. By providing a buffer channel 18, when the pressure in the buffer chamber 19 is greater than the pressure in the return oil chamber 16, the oil slowly enters the return oil chamber 16 through the buffer channel 18 to play a buffering role, alleviating the direct impact of high-pressure oil on the end cap, and improving the service life of the end cap.
[0051] The working principle of this application is as follows: When in use, the oil cylinder is installed and fixed on the equipment by bolts 5 on the front end cover 3. The oil return hole 7 is connected to a high-pressure oil source through a pipeline. By controlling the oil pressure on both sides of the piston 10, the piston 10 is pushed to move back and forth along the cylinder 6. When the oil cylinder drives a strong pressure component or a heavy object, the pressure inside the oil cylinder is relatively large. When the piston 10 moves to the front end cover 3 or the rear end cover 1, the buffer cavity 19 formed by the guide sleeve end on the inner side of the end cover, the piston 10, the buffer sleeve and the inner wall of the cylinder 6 plays a buffering role on the piston 10. The high-pressure oil in the buffer cavity 19 flows slowly from the buffer channel 18 to the oil return cavity 16, thereby avoiding the piston 10 from directly hitting the front end cover 3 or the rear end cover 1 and reducing the damage to the end cover. In addition, the first groove 17 set on the guide sleeve increases the oil capacity in the buffer cavity 19, improves the buffering effect, and at the same time avoids the problem of the piston 10 sticking tightly to the end cover.
[0052] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. In the absence of conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. Therefore, the protection scope of this utility model should be determined by the scope of the claims.
Claims
1. A buffer structure for a hydraulic cylinder, comprising a cylinder barrel, end caps, a piston rod, and a piston, wherein the end caps include a front end cap and a rear end cap, which are respectively disposed at both ends of the cylinder barrel; both the front end cap and the rear end cap are provided with oil return holes; a piston rod extending into the cylinder barrel is mounted on the front end cap; a piston is mounted on the end of the piston rod that extends into the cylinder barrel; the piston and the piston rod reciprocate together along the cylinder barrel; characterized in that: Both the front end cover and the rear end cover are provided with annular guide sleeves, which extend into the cylinder and are interference-fitted with the cylinder. The piston has a piston body in the middle and buffer sleeves at both ends. The outer diameter of the buffer sleeve is adapted to the inner diameter of the guide sleeve. When the buffer sleeve extends into the guide sleeve, the end face of the piston body, the end face of the guide sleeve, the inner wall of the cylinder located between the two, and the outer wall of the guide sleeve form a buffer cavity. There is a buffer channel between the outer wall of the buffer sleeve and the inner wall of the guide sleeve. The buffer channel connects the oil return hole and the buffer cavity.
2. The buffer structure of the hydraulic cylinder according to claim 1, characterized in that: An annular gap is formed between the outer wall of the buffer sleeve and the inner wall of the guide sleeve, and the annular gap serves as a buffer channel.
3. The buffer structure of the hydraulic cylinder according to claim 1, characterized in that: A second groove is provided along the axial direction on the outer wall of the buffer sleeve and / or the inner wall of the guide sleeve. The second groove is a buffer channel.
4. The buffer structure of the hydraulic cylinder according to claim 1, characterized in that: The length of the guide sleeve in the axial direction is greater than the length of the buffer sleeve.
5. The buffer structure of the hydraulic cylinder according to claim 1, characterized in that: The piston rod is provided with a variable diameter section at the connection between the piston rod and the piston. After the piston is installed, the buffer sleeve is flush with the outer diameter of the piston rod body.
6. The buffer structure of the hydraulic cylinder according to claim 5, characterized in that: A locking ring is provided at the connection between the variable diameter section and the piston, and an annular groove matching the locking ring is provided on the variable diameter section.
7. The buffer structure of the hydraulic cylinder according to claim 6, characterized in that: The end cap and cylinder are provided with a first sealing ring and a second sealing ring. The first sealing ring is located between the end cap and the end of the cylinder, and the second sealing ring is located between the guide sleeve and the inner wall of the cylinder.
8. The buffer structure of the hydraulic cylinder according to claim 1, characterized in that: The piston is provided with a third sealing ring, and the third sealing ring has U-shaped grooves on both sides.
9. The buffer structure of the hydraulic cylinder according to claim 1, characterized in that: The piston rod is fitted through the front end cover with a clearance fit, and a fourth sealing ring is provided at the fit.
10. The buffer structure of the hydraulic cylinder according to claim 1, characterized in that: The guide sleeve has a first groove on its end face near the piston.