Buffer-adjustable hydraulic cylinder and internal buffering method

Abstract

Buffer adjustable hydraulic cylinder and internal buffering method. The invention consists of: a hydraulic cylinder body, a piston rod assembly installed inside the hydraulic cylinder body, a cylinder cover installed on the top of the hydraulic cylinder body, the piston rod assembly extending from the middle of the cylinder cover and performing reciprocating motion, a limit block and a porous sleeve installed inside the hydraulic cylinder body, and the bottom of the hydraulic cylinder body sealed by a screw plug. The invention enables the hydraulic cylinder to obtain long-term stable and uniform buffering at the end during operation, and according to different use requirements, the buffering process of the hydraulic cylinder can be easily adjusted without disassembling the hydraulic cylinder. Ideal and effective buffering can reduce noise during the use of the hydraulic cylinder, inhibit the influence of transmission vibration on transmission accuracy, and prolong the service life of the hydraulic cylinder.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinders, specifically to a hydraulic cylinder with adjustable buffer and an internal buffering method. Background Technology

[0002] Hydraulic cylinders are an important component of hydraulic systems. During piston movement, they possess a certain speed. Prolonged impacts at high speeds against the cylinder body can significantly impact cylinder lifespan. Therefore, industrial applications often employ buffer devices to reduce this final impact velocity.

[0003] Currently, hydraulic cylinders mainly fall into two categories: one is an external buffer device, which uses flow control equipment or a throttle valve to control the entire hydraulic circuit, thereby achieving buffering control at the end of the cylinder. The other is an internal buffer structure, including plunger-type buffer structures, built-in buffer springs, or buffer rubber, which reduces the piston speed during its movement.

[0004] External buffer devices are less practical, requiring additional purchase of throttling control equipment and the provision of space for installation, thus limiting their application scenarios and significantly increasing costs.

[0005] Internal buffer devices are often used, but they also have some problems. Plunger-type buffers typically require additional space because a plunger for throttling needs to be installed at the piston end, and the cylinder needs a plunger groove. Furthermore, the buffering process is uneven because the flow area is significantly reduced when the plunger enters the groove, resulting in a noticeable stutter during buffering. Adjusting the speed variation during buffering requires disassembling the entire cylinder and replacing the plunger with one of different specifications. Internal buffer springs or rubber buffers result in low buffering stability because the properties of the springs or rubber change over time, affecting the buffering effect and making the buffering process completely uncontrollable. Summary of the Invention

[0006] The purpose of this invention is to provide a buffer-adjustable hydraulic cylinder and an internal buffering method, so that the hydraulic cylinder can obtain long-term stable and uniform buffering at the end of the operation process, and the buffering process of the cylinder can be conveniently adjusted without disassembling the cylinder according to different usage requirements.

[0007] The above objectives are achieved through the following technical solutions: An adjustable hydraulic cylinder includes: a hydraulic cylinder body, a piston rod assembly installed inside the hydraulic cylinder body, a cylinder cover mounted on the top of the hydraulic cylinder body, the piston rod assembly extending from the center of the cylinder cover and reciprocating, a limit block and a multi-hole sleeve installed inside the hydraulic cylinder body, and a screw plug sealing the bottom of the hydraulic cylinder body.

[0008] Furthermore, the hydraulic cylinder body is provided with oil port one and oil port two, and oil port one and oil port two are externally connected to hydraulic oil pumps. Oil port one is provided with a reservoir first, and oil port two is provided with a reservoir second.

[0009] Furthermore, the multi-hole sleeve is provided with a buffer hole group and a normal hole group, wherein the buffer hole group includes two sets of round through holes that are symmetrically distributed and have different sizes and heights, and the normal hole group consists of round through holes that are evenly distributed circumferentially.

[0010] Furthermore, the buffer hole group is provided with a guide groove on the through hole, the bottom of the guide groove is at the same horizontal line and is connected to the storage groove of the oil cylinder.

[0011] Furthermore, the ordinary hole group is connected to the storage tank.

[0012] Furthermore, the piston rod assembly includes a piston rod joint, which is connected to the piston rod. The piston rod is connected to the piston seat, and a buffer device is provided between the piston rod and the piston seat. The piston seat is provided with a retaining ring and an O-ring seal.

[0013] Furthermore, the piston rod assembly can freely adjust its rotation angle within the cylinder by rotating and fixing the joint. The piston seat is provided with a retaining ring in the shape of a waist and made of rubber. There is pressure between the two arc surfaces of the retaining ring and the porous sleeve.

[0014] Furthermore, the buffer device is a buffer pad or a buffer spring.

[0015] Furthermore, the screw plug seal is provided with a raised limiting step, the height of which is higher than the ordinary hole group of the multi-hole sleeve.

[0016] An internal buffering method for the aforementioned adjustable hydraulic cylinder requires an external hydraulic pump to be connected to both oil ports one and two of the cylinder, including an extension phase and a retraction phase, wherein: The extension stage occurs when the hydraulic pump injects hydraulic oil through the port. The hydraulic oil enters the reservoir and then the rodless chamber of the cylinder, pushing the piston rod to extend outward. At this time, the hydraulic oil in the rod chamber is squeezed and flows out from the various buffer hole groups, flowing into the reservoir and then back into the return pump through the port. Specifically, when the retaining ring of the piston rod assembly has not yet moved to the buffer hole, the cylinder runs at normal speed until the retaining ring begins to gradually block the bottom through hole of the buffer hole group. Due to the reduced flow area, the speed of the piston rod gradually decreases, but the piston rod will still gradually extend outward, causing the retaining ring to block more buffer holes, thus further reducing the piston rod extension speed. At the end of the entire buffering process, due to the limiting and buffering effect of the limiting block, only the top row of buffer holes is not blocked, and the entire extension process ends. The retraction phase involves the hydraulic pump reversing the injection of oil. The hydraulic oil enters the oil reservoir through the oil port. Since only the top row of holes in the buffer hole group is not blocked by the retaining ring at this time, the hydraulic oil can initially enter from the top row of hydraulic oil holes in the buffer hole group, thereby pushing the piston rod to retract. As the piston rod gradually retracts, the blocked oil holes begin to connect until all buffer holes are filled with oil into the rod chamber. At this time, the speed is stable until the piston seat hits the limit block of the bottom screw plug.

[0017] The beneficial effects of this invention are: The present invention has a simple and compact structure, low maintenance cost, and the buffer can effectively reduce the vibration of the hydraulic cylinder during use, thereby improving the accuracy of the reciprocating transmission of the hydraulic cylinder and increasing the service life of the hydraulic cylinder.

[0018] This invention allows for free adjustment of speed changes during the buffering process to meet different usage requirements. Furthermore, the buffering process is smooth due to the gradual covering of the flow orifice, without any abrupt pauses.

[0019] This invention enables the hydraulic cylinder to achieve long-term, stable, and uniformly varied buffering at the end of its operation. Furthermore, the buffering process can be easily adjusted without disassembling the cylinder to meet different usage requirements. This ideal and effective buffering reduces noise during cylinder use, suppresses the impact of transmission vibration on transmission accuracy, and extends the cylinder's service life. Attached Figure Description

[0020] Appendix Figure 1 This is a schematic diagram of the structure of the present invention.

[0021] Appendix Figure 2 This is a schematic diagram of the piston rod assembly of the present invention.

[0022] Appendix Figure 3 This is a schematic diagram of the structure of the hydraulic cylinder body of the present invention.

[0023] Appendix Figure 4 This is a schematic diagram of the structure of the porous sleeve of the present invention.

[0024] In the diagram: 1: Piston rod assembly; 2: Cylinder head assembly; 3: Cylinder body; 4: Internal positioning block assembly 5: Multi-hole sleeve; 6: Bottom screw plug seal; 11: Connector; 12: Piston rod; 13: Spring washer; 14: Piston seat; 15: Retaining ring; 16: Sealing O-ring; 31: Storage tank one; 32: Oil port one; 33: Storage tank two; 34: Oil port two; 51: Buffer hole group; 52: Ordinary hole group. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1:

[0026] This invention provides a buffer-adjustable hydraulic cylinder, as shown in the attached figure. Figure 1 The device comprises: a hydraulic cylinder body 3, inside which a piston rod assembly 1 is installed, and a cylinder cover 2 is mounted on top. The piston rod assembly 1 extends from the center of the cylinder cover and can reciprocate. A limit block and a perforated sleeve 5 are installed inside the cylinder; the bottom of the cylinder is sealed with a screw plug.

[0027] As attached Figure 2 As shown, the piston rod assembly includes a piston rod joint 11, used to adjust and fix the rotation angle of the piston. This rotation angle ultimately determines the number of buffer holes blocked by the retaining ring 15 at the buffer end, thus affecting the speed change during buffering. It is required that the sealing area of ​​the retaining ring 15 be larger than the distribution area of ​​the buffer holes in the porous sleeve. The buffer device 13 is a buffer pad or buffer spring, used to ensure that after the buffering effect of the buffer holes has ended, the piston rod still has a relatively low residual speed, resulting in a soft contact between the piston seat 15 and the limiting block 4, avoiding direct collision between the two metal surfaces, and making the buffering process smoother.

[0028] The piston seat is equipped with a sealing O-ring and a flow-through hole retaining ring. The O-ring serves a sealing function, while the flow-through hole retaining ring is designed in a waist shape. The entire piston rod can rotate freely within the hydraulic cylinder. By adjusting the rotation angle of the piston rod and fixing this angle through an external connector before performing the reciprocating motion of the hydraulic cylinder, the number of flow-through holes that can be blocked when the piston extends to its final position can be controlled, thereby adjusting the speed change during the buffering process.

[0029] The waist-shaped flow passage retainer ring only functions during the buffering phase, while the overall cylinder speed remains unaffected during the preceding movement.

[0030] As attached Figure 3 As shown, the hydraulic cylinder body 3 is provided with a first flow hole 32 and a second flow hole 34, and is connected to an external hydraulic oil pump. When the piston rod extends, hydraulic oil enters through the second flow hole 34 and flows out through the first flow hole 32; when the piston rod retracts, hydraulic oil enters through the first flow hole 32 and flows out through the second flow hole 34, thus forming a reciprocating cycle. The two oil ports 32 and 34 are respectively located on the first reservoir 31 and the second reservoir 33.

[0031] As attached Figure 4 As shown, the porous sleeve 5 has a buffer hole group 51 and a regular hole group 52. The buffer hole group 51 has two symmetrically distributed groups of circular holes of varying sizes and heights. Each group has a guide groove on its through hole, with the bottom of the guide groove at the same horizontal level, and it connects to the first reservoir 31 of the hydraulic cylinder. Similarly, the through hole group 52 also connects to the second reservoir 33. This invention only discusses buffering in one direction. If needed, the regular hole group 52 can be designed as a buffer hole group, and a waist-shaped retaining ring can be added on the other side of the O-ring seal on the piston seat 14, thus achieving buffering for reciprocating processes in both directions.

[0032] The perforated sleeve is a thin-walled cylinder with multiple holes. The bottom of each guide channel is provided with a chamfered slope to facilitate outflow, and the height of the outflow slope at the bottom is at the same horizontal line.

[0033] Preferably, the screw plug seal 6 is used for sealing the bottom of the cylinder. A raised limiting step is provided on the screw plug seal, the height of which needs to be slightly higher than the through-hole assembly 52 of the porous sleeve. When the piston retracts, this step restricts the final position of the piston seat, preventing the piston seal ring from blocking the through-hole assembly 52 and thus preventing hydraulic oil from flowing in again. Example 2:

[0034] The internal cushioning method of the adjustable hydraulic cylinder according to Example 1 includes: First, an external hydraulic pump needs to be connected to the oil port 32 and oil port 34 of the hydraulic cylinder, including the extension and retraction phases. The extension stage occurs when the hydraulic pump injects hydraulic oil through port 34, the hydraulic oil enters reservoir 33 and then the rodless chamber of the cylinder, thus pushing the piston rod 12 to extend outward. At this time, the hydraulic oil in the rod chamber is squeezed and flows out from each buffer hole group 51, flowing into the reservoir 31 together, and then flowing into the return pump through port 32. Specifically, when the retaining ring 15 of the piston rod assembly 1 has not yet moved to the buffer hole, the cylinder runs at normal speed until the retaining ring 15 begins to gradually block the bottom through hole of the buffer hole group 51. Due to the reduction of the flow area, the speed of the piston rod 12 will gradually decrease, but at this time the piston rod 12 will still gradually extend outward, so that the retaining ring 15 blocks more buffer holes, thus further reducing the extension speed of the piston rod 12. When the entire buffering process ends, due to the limiting and buffering effect of the limiting block 4, only the top row of buffer holes is not blocked, and the entire extension process ends. The retraction stage involves the hydraulic pump reversing the oil flow. The hydraulic oil enters the oil reservoir 31 through the oil port 32. Since only the uppermost row of holes in the buffer hole group 51 is not blocked by the retaining ring 15, the hydraulic oil initially enters the uppermost row of hydraulic oil holes in the buffer hole group 51 from the oil reservoir 31, thereby pushing the piston rod 12 to retract. As the piston rod 12 gradually retracts, the blocked oil holes begin to connect until all the buffer holes are filled with oil into the rod chamber. At this point, the speed is stable until the piston seat hits the limit block of the bottom screw plug.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for internal buffering of an adjustable hydraulic cylinder, characterized in that, The method uses a buffer-adjustable hydraulic cylinder comprising: a hydraulic cylinder body (3), a piston rod assembly (1) installed inside the hydraulic cylinder body (3), a cylinder cover (2) mounted on the top of the hydraulic cylinder body (3), the piston rod assembly (1) extending from the center of the cylinder cover (2) and reciprocating, a limit block (4) and a multi-hole sleeve (5) installed inside the hydraulic cylinder body (3), and the bottom of the hydraulic cylinder body (3) sealed by a screw plug (6); The method includes: First, the oil port one (32) and oil port two (34) of the oil cylinder need to be connected to an external hydraulic oil pump, including the extension stage and the retraction stage, wherein: The aforementioned extension stage occurs when the hydraulic oil pump injects hydraulic oil from port two (34), the hydraulic oil enters reservoir two (33) and then enters the rodless chamber of the cylinder, thereby pushing the piston rod (12) to extend outward; at this time, the hydraulic oil in the rod chamber is squeezed and flows out from each buffer hole group (51), and flows into reservoir one (31) together, and then flows into the return oil pump through port one (32); When the retaining ring (15) of the piston rod assembly (1) has not yet moved to the buffer hole, the cylinder runs at normal speed until the retaining ring (15) begins to gradually block the bottom through hole of the buffer hole group (51). Due to the reduction of the flow area, the speed of the piston rod (12) will gradually decrease. However, at this time, the piston rod (12) will still gradually extend outward, so that the retaining ring (15) blocks more buffer holes, thereby further reducing the extension speed of the piston rod (12). When the entire buffering process ends, due to the limiting and buffering effect of the limiting block (4), only the top row of buffer holes is not blocked, and the entire extension process ends. The retraction stage is when the hydraulic pump injects oil in reverse. The hydraulic oil enters the reservoir 1 (31) through the oil port 1 (32). Since only the uppermost hole of the buffer hole group (51) is not blocked by the retaining ring (15), the hydraulic oil initially enters the uppermost hydraulic oil hole of the buffer hole group (51) from the reservoir 1 (31), thereby pushing the piston rod (12) to retract. As the piston rod (12) gradually retracts, the blocked oil holes begin to connect until all the buffer holes inject oil into the rod chamber. At this time, the speed is stable until the piston seat hits the limit block of the bottom screw plug.

2. The internal buffering method for an adjustable hydraulic cylinder according to claim 1, characterized in that, The hydraulic cylinder body (3) is provided with oil port one (32) and oil port two (34). The oil port one (32) and the oil port two (34) are connected to a hydraulic oil pump. The oil port one (32) is provided with a reservoir one (31) and the oil port two (34) is provided with a reservoir two (33).

3. The internal buffering method for an adjustable hydraulic cylinder according to claim 2, characterized in that, The multi-hole sleeve (5) is provided with a buffer hole group (51) and a normal hole group (52). The buffer hole group (51) includes two sets of round through holes that are symmetrically distributed and have different sizes and heights. The normal hole group (52) consists of round through holes that are evenly distributed in the circumference.

4. The internal buffering method for an adjustable hydraulic cylinder according to claim 3, characterized in that, The buffer hole group (51) is provided with a guide groove on the through hole. The bottom of the guide groove is at the same horizontal line and is connected to the storage groove (31) of the oil cylinder.

5. The internal buffering method for an adjustable hydraulic cylinder according to claim 4, characterized in that, The ordinary hole group (52) is connected to the second storage tank (33).

6. The internal buffering method for an adjustable hydraulic cylinder according to claim 5, characterized in that, The piston rod assembly (1) includes a piston rod joint (11), which is connected to the piston rod (12). The piston rod (12) is connected to the piston seat (14). A buffer device (13) is provided between the piston rod (12) and the piston seat (14). The piston seat is provided with a retaining ring (15) and an O-ring seal (16).

7. The internal buffering method for an adjustable hydraulic cylinder according to claim 6, characterized in that, The piston rod assembly (1) can be rotated and fixed by rotating the piston rod joint (11) to freely adjust the rotation angle in the cylinder. The piston seat (14) is provided with a retaining ring (15) in the shape of a waist and made of rubber. The two arc surfaces of the retaining ring (15) have pressure between them and the porous sleeve (5).

8. The internal buffering method for an adjustable hydraulic cylinder according to claim 7, characterized in that, The buffer device (13) is a buffer pad or a buffer spring.

9. The internal buffering method for an adjustable hydraulic cylinder according to claim 8, characterized in that, The screw plug (6) is provided with a raised limiting step, the height of which is higher than the ordinary hole group (52) of the multi-hole sleeve (5).

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