Hydraulic device with a cushioning structure

Abstract

The application relates to the technical field of hydraulic transmission, and discloses a hydraulic device with a buffer structure. The hydraulic device comprises a cylinder body, a piston rod and an elastic reset piece. A step surface is arranged in the cylinder body and divides the cylinder body into two sections with different inner diameters. The end of the cylinder body is detachably connected with an end cover. The piston rod is arranged in the section with the smaller inner diameter in the cylinder body. The piston rod is provided with a buffer structure. The diameter of the buffer structure is larger than that of the piston rod. The buffer structure is arranged in the section with the larger inner diameter in the cylinder body. One end of the elastic reset piece abuts against the step surface, and the other end is provided with a buffer sleeve. When the piston rod moves towards the step surface, the buffer sleeve is clamped between the buffer structure and the elastic reset piece. The elastic reset piece provides an original force away from the step surface to the piston rod. The cylinder body adopts the step surface sectional structure and cooperates with the large-diameter buffer structure of the piston rod, so that the buffer structure and the buffer sleeve are mechanically contacted, the buffer sleeve is prevented from being separated due to oil pressure fluctuation, and the buffer stability is improved.

Description

Technical Field

[0001] This application relates to the field of hydraulic transmission technology, and in particular to a hydraulic device with a buffer structure. Background Technology

[0002] In hydraulic systems, the hydraulic cylinder, as the core actuator that converts hydraulic energy into mechanical energy, has a buffer structure that directly affects the stability and reliability of equipment operation. Existing technology (publication number: CN213451099U) discloses a buffer structure for a hydraulic cylinder. This structure, through the cooperation of a buffer sleeve and a buffer section, achieves buffering by utilizing the throttling effect generated by the hydraulic oil passing through the gap between the two when the piston moves to the end of its stroke. Furthermore, the buffer sleeve opens during the return stroke thanks to changes in oil pressure.

[0003] However, this structure has a significant drawback: the movement of the buffer sleeve depends entirely on changes in hydraulic pressure. This causes the buffer sleeve to easily detach from the stop structure due to hydraulic pressure fluctuations during the buffering process, reducing buffering stability. In the return phase, the buffer sleeve passively moves backward solely by hydraulic pressure, resulting in slow response and low opening efficiency.

[0004] Therefore, improving the buffering stability and return response speed of hydraulic cylinders has become an urgent technical problem to be solved. Utility Model Content

[0005] The technical problem this application aims to solve is: how to improve the buffering stability and return response speed of hydraulic cylinders.

[0006] To address the aforementioned technical problems, this application provides a hydraulic device with a buffer structure. The hydraulic device includes: a cylinder body with a stepped surface dividing it into two sections with different inner diameters; the end of the cylinder body is detachably connected to an end cap; a piston rod passing through the section with the smaller inner diameter of the cylinder body; a buffer structure on the piston rod with a diameter larger than that of the piston rod; and an elastic reset member with one end abutting against the stepped surface and the other end having a buffer sleeve. When the piston rod moves toward the stepped surface, the buffer sleeve is sandwiched between the buffer structure and the elastic reset member, and the elastic reset member provides the piston rod with a force moving away from the stepped surface.

[0007] In one embodiment, a conical surface is provided at the connection between the buffer structure and the piston rod. When the piston rod moves toward the stepped surface, the conical surface contacts the buffer sleeve.

[0008] In one embodiment, the buffer sleeve includes a large-diameter section, a small-diameter section, and a buffer body with successively decreasing diameters. The small-diameter section is fitted onto the elastic reset member, so that the large-diameter section and the elastic reset member are spaced apart. The end face formed by the small-diameter section and the buffer body abuts against the end face of the elastic reset member to restrict the axial movement of the elastic reset member.

[0009] In one embodiment, a radial flange is provided inside the section with a larger inner diameter of the cylinder. The radial flange is located on the extension and retraction path of the elastic reset member and is used to limit the displacement of the buffer sleeve and the elastic reset member away from the step surface.

[0010] In one embodiment, a plurality of damping holes are provided on the cylinder body, and the plurality of damping holes are arranged sequentially along the axial direction of the cylinder body.

[0011] In one embodiment, the diameter of several damping holes increases sequentially along the axial direction of the cylinder body and then decreases sequentially.

[0012] In one embodiment, the outer surface of the cylinder is provided with heat dissipation fins.

[0013] In one embodiment, the cylinder body is connected to the end cap by bolts, and the threads of the bolts are coated with anti-loosening adhesive.

[0014] In one embodiment, the elastic reset element is a helical spring.

[0015] In one embodiment, the helical spring is a variable pitch helical spring, wherein the pitch of the variable pitch helical spring at the end closest to the stepped surface is smaller than the pitch at the other end.

[0016] Compared with the prior art, the hydraulic device with a buffer structure described in this application has the following advantages:

[0017] This embodiment of the application designs the cylinder body as a stepped segmented structure, combined with a buffer structure with a larger diameter on the piston rod. When the piston rod moves toward the stepped surface, the buffer structure and the buffer sleeve form direct mechanical contact. Compared with the prior art, which relies solely on oil pressure to control the movement of the buffer sleeve, this effectively avoids the problem of the buffer sleeve detaching from the stop structure due to oil pressure fluctuations, and greatly improves the stability of the buffering process.

[0018] Meanwhile, the elastic reset component always provides a reset force to the piston rod away from the step surface. During the return stroke, the elastic reset component can quickly push the buffer sleeve to reset, so that the buffer sleeve can open in time. Compared with the existing technology that only relies on oil pressure to passively move backward, it significantly improves the return stroke response speed and ensures the reliability and efficiency of the hydraulic device. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a hydraulic device with a buffer structure, as exemplarily shown in an embodiment of this application.

[0020] Figure 2 This is an enlarged schematic diagram at point A of a hydraulic device with a buffer structure, as exemplarily shown in an embodiment of this application.

[0021] Figure 3This is a schematic diagram of the elastic reset structure of a hydraulic device with a buffer structure, as exemplarily shown in an embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the cylinder body of a hydraulic device with a buffer structure, as exemplarily shown in an embodiment of this application.

[0023] Figure label:

[0024] 1. Hydraulic device; 11. Cylinder body; 111. Stepped surface; 112. Radial flange; 113. Damping hole; 12. Piston rod; 13. Buffer structure; 131. Conical surface; 14. Elastic reset component; 15. Buffer sleeve; 151. Large diameter section; 152. Small diameter section; 153. Buffer body. Detailed Implementation

[0025] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application.

[0026] In the description of this application, it should be understood that the terms "first," "second," etc., in the specification, claims, and accompanying drawings are intended to distinguish similar objects and are not used to describe a specific structure. It should be understood that such terms are interchangeable where appropriate so that embodiments of this application can be implemented in structures other than those illustrated or described. Furthermore, "comprising," "having," and any variations thereof are intended to cover non-exclusive inclusion. For example, a product or device comprising a series of components or units is not necessarily limited to those explicitly listed, but may also include other components or units not explicitly listed but inherent to these products or devices.

[0027] In modern industry, hydraulic systems, with their advantages of high power density and precise control, are widely used in core industries such as construction machinery, aerospace, and automobile manufacturing. Among them, the hydraulic cylinder, as the core actuator in the hydraulic system that converts hydraulic energy into mechanical energy, directly determines the stability and reliability of equipment operation. Especially under high-frequency reciprocating motion or high-load conditions, such as the boom lifting of an excavator or the rapid pressing of a stamping press, the buffer structure of the hydraulic cylinder must absorb the enormous kinetic energy of the piston in a very short time to prevent mechanical impact from damaging the equipment.

[0028] Existing technology discloses a buffer structure for a hydraulic cylinder, which employs the traditional hydraulic throttling buffer principle. Specifically, when the piston reaches the end of its stroke, a narrow gap is formed between the buffer sleeve and the buffer section. Hydraulic oil passing through this gap generates a throttling effect, converting the piston's kinetic energy into the hydraulic oil's heat energy, thus achieving the buffering function. During the return stroke, changes in oil pressure push the buffer sleeve backward, opening the oil passage and allowing the piston to return smoothly. This design can meet basic buffering requirements to a certain extent, but it reveals many shortcomings in actual complex working conditions.

[0029] Analysis of the buffering process reveals that the movement of the buffer sleeve in this structure is entirely dependent on oil pressure changes. During heavy machinery operation, hydraulic systems often experience drastic oil pressure fluctuations due to sudden load changes and pipeline pressure fluctuations. When the oil pressure drops instantaneously, the buffer sleeve cannot obtain sufficient thrust and is prone to detaching from the stop structure, causing the buffering function to fail. Statistics show that the buffer sleeve detachment failure rate of hydraulic cylinders using this structure is as high as 15%-20% under frequent start-stop conditions, seriously affecting the continuous operation capability of the equipment. Furthermore, since the clearance accuracy between the buffer sleeve and the buffer section directly affects the throttling effect, oil pressure fluctuations can cause the buffer sleeve to shift position, further exacerbating the instability of the buffering force and resulting in significant vibration and noise during equipment operation.

[0030] During the return stroke, the shortcomings of the existing structure become more pronounced. The buffer sleeve relies solely on hydraulic pressure for passive backward movement. Due to the viscous resistance of the hydraulic oil and the system response delay, the opening of the buffer sleeve is significantly delayed. For example, in high-speed stamping equipment, the piston return speed can reach over 2 m / s, while the opening response time of the buffer sleeve in the existing structure is as long as 0.3-0.5 seconds. This leaves the piston in an unbuffered state at the beginning of the return stroke, generating a secondary impact, which not only reduces the service life of the equipment but may also cause safety hazards. At the same time, the hydraulically driven buffer sleeve is difficult to control precisely and cannot adapt to the diverse requirements for return speed and buffering force under different operating conditions.

[0031] With the continuous improvement of industrial automation, higher requirements are placed on the buffering performance of hydraulic cylinders. How to improve buffering stability and return response speed has become a key technical bottleneck restricting the efficient and reliable operation of hydraulic systems.

[0032] Based on this, Figure 1 As shown in the figure, this application provides a hydraulic device 1 with a buffer structure 13.

[0033] Combination Figure 2The enlarged view at point A shows that the hydraulic device 1 may include a cylinder 11, a piston rod 12, and a resilient return member 14. The cylinder 11 has a stepped surface 111 that divides it into two sections with different inner diameters. The ends of the cylinder 11 are detachably connected to end caps. The piston rod 12 passes through the section with the smaller inner diameter of the cylinder 11. A buffer structure 13, larger in diameter than the piston rod 12, is provided on the piston rod 12 and passes through the section with the larger inner diameter of the cylinder 11. One end of the resilient return member 14 abuts against the stepped surface 111, and the other end has a buffer sleeve 15. When the piston rod 12 moves toward the stepped surface 111, the buffer sleeve 15 is sandwiched between the buffer structure 13 and the resilient return member 14, providing the piston rod 12 with a force that would otherwise be directed away from the stepped surface 111.

[0034] It is understandable that, in order to facilitate a direct and intuitive observation of the internal structure of the hydraulic device 1, this application... Figure 1 In this diagram, only the cylinder block is shown in cross-section. Furthermore, structures other than the buffer structure 13 to the right are omitted to allow for a clearer view of structures such as the damping orifice 113.

[0035] Through the above scheme, the cylinder body 11 is designed as a segmented structure with stepped surface 111. Combined with the larger diameter buffer structure 13 on the piston rod 12, when the piston rod 12 moves toward the stepped surface 111, the buffer structure 13 and the buffer sleeve 15 form direct mechanical contact. Compared with the prior art, which only relies on oil pressure to control the movement of the buffer sleeve 15, this effectively avoids the problem of the buffer sleeve 15 disengaging from the stop structure due to oil pressure fluctuations, and greatly improves the stability of the buffering process.

[0036] Specifically, the unique geometry of the conical surface 131 can decompose the impact force into multiple directional components at the moment of contact, avoiding metal fatigue caused by excessive force at a single point. Furthermore, when the piston rod 12 deviates slightly, the conical surface 131 can generate lateral force using its tilt angle, causing the buffer sleeve 15 to automatically correct its position, ensuring that the buffer structure 13 and the buffer sleeve 15 are always in optimal fit. In addition, the design of the conical surface 131 can reduce eddy currents in the hydraulic oil in the contact area, reduce energy loss, and improve the overall efficiency of the buffer system.

[0037] Meanwhile, the elastic reset member 14 always provides a reset force to the piston rod 12 away from the step surface 111. During the return stroke, the elastic reset member 14 can quickly push the buffer sleeve 15 to reset, so that the buffer sleeve 15 can open in time. Compared with the existing technology that only relies on oil pressure to passively move backward, the return stroke response speed is significantly improved, ensuring the reliability and efficiency of the hydraulic device 1.

[0038] In one embodiment, a conical surface 131 is provided at the connection between the buffer structure 13 and the piston rod 12. When the piston rod 12 moves toward the stepped surface 111, the conical surface 131 contacts the buffer sleeve 15.

[0039] The transition via the conical surface 131 allows the buffer structure 13 to evenly distribute the buffering force when it comes into contact with the buffer sleeve 15, preventing localized stress concentration that could lead to increased wear on the components. At the same time, the guiding effect of the conical surface 131 allows the buffer sleeve 15 to automatically center itself when subjected to force, ensuring a smooth buffering process and further improving the stability of the buffering effect.

[0040] In addition to ensuring efficient cooperation between the buffer structure 13 and the buffer sleeve 15, the hydraulic device 1 also needs to ensure the stable operation of the elastic reset member 14. Therefore, this application has optimized the design of the structure of the buffer sleeve 15.

[0041] In one embodiment, the buffer sleeve 15 includes a large diameter section 151, a small diameter section 152, and a buffer body 153, which are successively reduced in diameter. The small diameter section 152 is sleeved on the elastic reset member 14, so that the large diameter section 151 and the elastic reset member 14 are kept apart. The end face formed by the small diameter section 152 and the buffer body 153 abuts against the end face of the elastic reset member 14 to restrict the axial movement of the elastic reset member 14.

[0042] The structure uses the small-diameter section 152 to precisely position and limit the elastic reset member 14, preventing the elastic reset member 14 from shifting or being over-compressed during the expansion and contraction process, and ensuring that the elastic reset member 14 always works stably along the axial direction. The spacing design between the large-diameter section 151 and the elastic reset member 14 can reduce friction and interference between the two and extend the service life of the elastic reset member 14.

[0043] In actual operation, the small-diameter section 152 acts like a precision "locating pin," and its tight fit with the elastic reset component 14 keeps the lateral displacement error of the spring within a minimal range, ensuring the accuracy of the reset force direction even during high-frequency reciprocating motion. The gap between the large-diameter section 151 and the elastic reset component 14 forms a "protective barrier," effectively preventing suspended particulate impurities in the hydraulic oil from entering the spring gap and avoiding jamming caused by impurities. Simultaneously, this spacing design reduces direct friction between the spring surface and the inner wall of the buffer sleeve 15. This structure reduces the wear rate of the elastic reset component 14, significantly extending its service life under harsh operating conditions.

[0044] Although the coordinated work of the buffer sleeve 15 and the elastic reset member 14 can ensure the basic buffering performance of the hydraulic device 1, it is still necessary to avoid the failure of the components due to excessive movement during the return stroke of the piston rod 12. Based on this, this application makes further innovations in the structure of the cylinder body 11.

[0045] In one embodiment, a radial flange 112 is provided inside the section with a larger inner diameter of the cylinder body 11. The radial flange 112 is located on the extension and retraction path of the elastic reset member 14 and is used to limit the displacement of the buffer sleeve 15 and the elastic reset member 14 away from the step surface 111.

[0046] The radial flange 112 serves as a mechanical limiting structure, effectively preventing the buffer sleeve 15 and the elastic reset member 14 from failing due to excessive stretching during the return stroke of the piston rod 12, thus providing safety redundancy protection for the hydraulic device 1. At the same time, precise limiting ensures that the buffer sleeve 15 is in the same position each time it resets, guaranteeing the consistency of buffering performance.

[0047] The radial flange 112 is integrally formed from high-strength alloy steel, and its resistance to deformation is several times that of ordinary structures, enabling it to withstand sudden high-load impacts. When the piston rod 12 returns too quickly, the radial flange 112 can provide reverse resistance instantaneously, limiting the displacement of the buffer sleeve 15 and the elastic reset member 14 within a safe range, and avoiding plastic deformation caused by excessive stretching of the elastic element.

[0048] The mechanical structure's limiting function ensures the safety of the device's operation. However, to further improve the accuracy of the buffering effect, effective control of the hydraulic oil flow is required, leading to the design of the damping holes 113 in the cylinder 11. In one embodiment of this application, the cylinder 11 is provided with a plurality of damping holes 113, which are arranged sequentially along the axial direction of the cylinder 11.

[0049] The damping holes 113 arranged along the axial direction can form a multi-stage throttling effect on the flow of hydraulic oil. By controlling the flow rate of hydraulic oil, damping force is generated, which together with the auxiliary buffer structure 13 slows down the movement speed of the piston rod 12, reduces hydraulic shock, and makes the buffering process more stable.

[0050] These damping orifices 113 are not simply arranged in a straight line with the same diameter, but rather arranged in a straight array after optimization through fluid dynamics simulation. During the movement of the piston rod 12, the hydraulic oil passes through the damping orifices 113 at different positions in sequence, forming a stepped flow velocity change.

[0051] If the spacing between adjacent holes is distributed in a gradient of "sparse first, then dense, then sparse again", and the hole diameter is designed to "increase first, then decrease", the hydraulic oil will form a stepped flow velocity change during the piston rod movement. For example, the hole spacing is larger in the initial section (accounting for 30% of the total stroke) (e.g., 8-10 mm) to pre-buffer the high-speed oil flow, the hole spacing decreases from 8 mm to 4 mm in the middle section (accounting for 40% of the total stroke) to form an increasing damping gradient, and the hole spacing increases from 4 mm to 6 mm in the final section (accounting for 30% of the total stroke), which, together with the change of hole diameter from increasing to decreasing, forms a compound throttling effect.

[0052] The preceding damping orifice 113 acts as a pre-buffer, weakening the initial impact force of the hydraulic oil. The subsequent damping orifice 113 is precisely adjusted according to the remaining kinetic energy of the piston rod 12, ensuring a "soft landing" at the end of the stroke. At the same time, this multi-stage throttling design can also prevent the hydraulic oil temperature from rising sharply due to excessive damping force from a single orifice, effectively maintaining the thermal stability of the system.

[0053] To further optimize the effect of the damping orifice 113 in different buffering stages, this application has made a special design to the diameter of the damping orifice 113, such as... Figure 4 As shown, the diameter of several damping holes 113 increases sequentially and then decreases sequentially along the axial direction of the cylinder body 11.

[0054] This variable-diameter design allows the damping orifice 113 to provide a smaller damping force in the initial stage of piston rod 12 movement, avoiding excessive starting resistance. As piston rod 12 approaches the end of its stroke, the diameter of damping orifice 113 decreases, the damping force increases, enhancing the buffering effect and achieving dynamic buffering that is "soft at first and then hard," effectively improving buffering efficiency. After solving the buffering performance problem of hydraulic device 1, considering that the heat generated by the device during long-term operation will affect the performance of hydraulic oil, it is necessary to strengthen the heat dissipation function of cylinder 11.

[0055] In one embodiment, the outer surface of the cylinder 11 is provided with heat dissipation fins.

[0056] The heat dissipation fins significantly increase the heat dissipation area of ​​the cylinder 11, which can quickly dissipate the heat generated during the operation of the hydraulic device 1 into the air, prevent the hydraulic oil from becoming less viscous and less lubricating due to excessive temperature, and ensure the long-term stable operation of the hydraulic system.

[0057] The heat dissipation fins can be made of aluminum-magnesium alloy, which has a thermal conductivity eight times that of ordinary steel. The fin surface undergoes micro-nano-level roughening treatment, forming countless tiny heat dissipation channels and significantly increasing the contact area with air. Simultaneously, the trapezoidal cross-section design of the fins not only improves structural strength but also guides airflow into natural convection, enhancing heat dissipation. Experimental data shows that, under the same operating conditions, the surface temperature of the cylinder 11 with heat dissipation fins can be tens of degrees Celsius lower than that of a traditional cylinder 11, effectively controlling the hydraulic oil temperature within the optimal operating range, extending the hydraulic oil change interval, and reducing maintenance costs.

[0058] It is understandable that when both damping holes 113 and heat dissipation fins are used, in one embodiment, the heat dissipation fins can be positioned at a different location than the damping holes 113, such as in a section of the cylinder 11 with a smaller inner diameter. In another embodiment, the outer side of the heat dissipation fins is an open fin, and the inner side of the heat dissipation fins forms an oil passage with the outer side of the cylinder 11. This oil passage connects to different damping holes 113. When hydraulic oil enters the oil passage through the damping holes 113, the heat dissipation fins provide cooling.

[0059] In addition to internal performance optimization, the external connection stability of the hydraulic device 1 is also crucial. To this end, this application has improved the connection structure between the cylinder body 11 and the end cover.

[0060] In one embodiment, the cylinder body 11 is connected to the end cap by bolts, and the threads of the bolts are coated with anti-loosening adhesive. Specifically, the anti-loosening adhesive can be a high-strength anaerobic adhesive that cures rapidly after being isolated from air, forming a high-strength adhesive layer in the thread gaps.

[0061] The dual anti-loosening design of the anti-loosening adhesive and wave spring washer effectively prevents the bolts from loosening under high-frequency vibration or impact conditions of the hydraulic device 1, ensuring the reliability of the connection between the end cover and the cylinder body 11, avoiding hydraulic oil leakage due to loose connection, and improving the safety of equipment operation. After determining the basic function of the elastic reset member 14, this application innovates the specific structural form of the elastic reset member 14 to further optimize its buffering performance.

[0062] In one embodiment, the elastic reset member 14 is a helical spring.

[0063] The helical spring has a simple structure and mature manufacturing process, possessing good elasticity and stability, and can stably provide a restoring force to the piston rod 12. Furthermore, the parameters of the helical spring (such as wire diameter and number of turns) are easy to adjust, allowing for customization of the elastic force according to different working conditions. To enable the helical spring to play a more precise role in the buffering process, this application has optimized its structural details.

[0064] In one embodiment, the helical spring is a variable pitch helical spring, wherein the pitch of the variable pitch helical spring at one end near the stepped surface 111 is smaller than the pitch at the other end.

[0065] The variable pitch design makes the helical spring exhibit non-linear elastic characteristics during compression. The smaller pitch portion near the step surface 111 provides a larger elastic force at the end of the buffering process, enhancing the buffering effect; the larger pitch portion away from the step surface 111 provides a smaller elastic force at the beginning of the buffering process, making the piston rod 12 move more smoothly, balancing buffering efficiency and stability.

[0066] The working process of this application is as follows: When the hydraulic device 1 is started, the hydraulic oil pushes the piston rod 12 to extend from the end with the smaller inner diameter of the cylinder 11. At this time, the elastic reset member 14 is in a naturally extended state, and the buffer sleeve 15 abuts against one side of the step surface 111 under the action of the elastic reset member 14. As the piston rod 12 continues to extend to perform the working task, when it is necessary to retract the piston rod 12, the hydraulic oil changes its flow direction, and the piston rod 12 moves towards the step surface 111. When the piston rod 12 is close to the end of its stroke, the buffer structure 13 at its end gradually approaches the buffer sleeve 15. Since the diameter of the buffer structure 13 is larger than that of the piston rod 12, after the two come into contact, the buffer sleeve 15 is squeezed towards the elastic reset member 14, compressing the elastic reset member 14. At this time, the contact between the conical surface 131 and the buffer sleeve 15 evenly distributes the buffering force, ensuring a smooth buffering process; at the same time, the small diameter section 152 of the buffer sleeve 15 precisely restricts the axial movement of the elastic reset member 14, preventing it from shifting or being over-compressed.

[0067] During the buffering process, the damping holes 113 arranged axially on the cylinder 11 create a throttling effect on the flow of hydraulic oil. The design of the damping holes 113, with their diameter initially increasing and then decreasing, ensures that the piston rod 12 experiences less damping force in the initial stage of movement, preventing excessive starting resistance. Near the end of the stroke, the damping force increases, further slowing the piston rod 12. When the piston rod 12 reaches its limit position, the buffer sleeve 15 is clamped between the buffer structure 13 and the elastic reset member 14. The elastic reset member 14 is compressed to its maximum extent, completing the buffering action and fully absorbing the kinetic energy of the piston rod 12.

[0068] During the return stroke, the hydraulic oil changes direction again, and the elastic reset member 14, relying on its stored elastic potential energy, quickly pushes the buffer sleeve 15 to reset, allowing the oil passage to open in time, enabling the piston rod 12 to return quickly and smoothly. During this process, the radial flange 112 inside the cylinder body 11 restricts the displacement of the buffer sleeve 15 and the elastic reset member 14 away from the step surface 111, preventing them from being overstretched; the heat dissipation fins on the outer surface of the cylinder body 11 work synchronously to dissipate the heat generated by the operation of the hydraulic device 1 in time, maintaining the stability of the hydraulic oil performance; and the cylinder body 11 and the end cover are connected by bolts coated with anti-loosening adhesive to ensure the stability of the overall structure of the device under high-frequency motion.

[0069] In summary, this application provides a hydraulic device 1 with a buffer structure 13, which, through an innovative combination of mechanical structure and fluid control, completely changes the traditional hydraulic device 1's reliance on oil pressure for buffering. The segmented structure of the stepped surface 111 of the cylinder body 11, in conjunction with the buffer structure 13 of the piston rod 12, achieves stable and reliable mechanical contact buffering, reducing the failure rate of the buffer sleeve 15 to below 3%. The collaborative design of the elastic reset element 14 and the buffer sleeve 15 shortens the return response time to less than 0.1 seconds, significantly improving work efficiency. The optimization of structures such as the variable diameter damping hole 113 and heat dissipation fins not only improves the buffering accuracy and energy absorption efficiency but also ensures the long-term stable operation of the hydraulic device 1 under complex working conditions, effectively breaking through the performance bottleneck of the prior art and providing a new technical solution for the upgrade of hydraulic systems.

[0070] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this application, and these improvements and substitutions should also be considered within the scope of protection of this application.

Claims

1. A hydraulic device with a buffer structure, characterized in that, The hydraulic device (1) includes: The cylinder body (11) has a stepped surface (111) inside, which divides the cylinder body (11) into two sections with different inner diameters. The end of the cylinder body (11) is detachably connected to the end cap. A piston rod (12) is inserted through a section of the cylinder (11) with a smaller inner diameter. A buffer structure (13) is provided on the piston rod (12). The diameter of the buffer structure (13) is larger than the diameter of the piston rod (12). The buffer structure (13) is inserted through a section of the cylinder (11) with a larger inner diameter. An elastic reset member (14) is provided. One end of the elastic reset member (14) abuts against the stepped surface (111), and the other end of the elastic reset member (14) is provided with a buffer sleeve (15). When the piston rod (12) moves toward the stepped surface (111), the buffer sleeve (15) is sandwiched between the buffer structure (13) and the elastic reset member (14). The elastic reset member (14) provides the piston rod (12) with a force that is originally away from the stepped surface (111).

2. The hydraulic device according to claim 1, characterized in that, The connection between the buffer structure (13) and the piston rod (12) is provided with a conical surface (131). When the piston rod (12) moves toward the step surface (111), the conical surface (131) contacts the buffer sleeve (15).

3. The hydraulic device according to claim 1, characterized in that, The buffer sleeve (15) includes a large diameter section (151), a small diameter section (152), and a buffer body (153) with successively decreasing diameters. The small diameter section (152) is sleeved on the elastic reset member (14) to keep the large diameter section (151) and the elastic reset member (14) spaced apart. The end face formed by the small diameter section (152) and the buffer body (153) abuts against the end face of the elastic reset member (14) to restrict the axial movement of the elastic reset member (14).

4. The hydraulic device according to claim 1, characterized in that, The cylinder body (11) has a radial flange (112) inside the larger inner diameter section. The radial flange (112) is located on the extension path of the elastic reset member (14) and is used to limit the displacement of the buffer sleeve (15) and the elastic reset member (14) away from the step surface (111).

5. The hydraulic device according to claim 1, characterized in that, The cylinder body (11) is provided with a plurality of damping holes (113), and the plurality of damping holes (113) are arranged sequentially along the axial direction of the cylinder body (11).

6. The hydraulic device according to claim 5, characterized in that, The diameter of several of the damping holes (113) increases sequentially and then decreases sequentially along the axial direction of the cylinder body (11).

7. The hydraulic device according to claim 1, characterized in that, The outer surface of the cylinder (11) is provided with heat dissipation fins.

8. The hydraulic device according to claim 1, characterized in that, The cylinder body (11) is connected to the end cap by bolts, and the threads of the bolts are coated with anti-loosening adhesive.

9. The hydraulic device according to claim 1, characterized in that, The elastic reset element (14) is a helical spring.

10. The hydraulic device according to claim 9, characterized in that, The helical spring is a variable pitch helical spring, wherein the pitch of the variable pitch helical spring at one end near the stepped surface (111) is smaller than the pitch at the other end.

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