Oil return structure, oil return method, oil return system and hydraulic equipment

Abstract

The invention provides an oil return structure, an oil return method, an oil return system and hydraulic equipment, the oil return structure comprises a first pressure relief part, a second pressure relief part and a driving part, the first pressure relief part blocks an oil outlet of a cylinder body, the first hydraulic part comprises a flow guide channel, and the second pressure relief part blocks the flow guide channel; one end of the driving part penetrates through the flow guide channel to abut against the second pressure relief part, the driving part can move back and forth along the flow guide channel, and after the driving part fixedly jacks the second pressure relief part to a preset height, part of the area can abut against the first pressure relief part, and the first pressure relief part is jacked up. According to the oil return structure, when a worker operates the oil return button to enable the driving piece to move to jack up the second pressure relief piece and the first pressure relief piece in sequence to enable the hydraulic equipment to return oil, the needed operation force can be greatly reduced, namely, the worker can complete oil return operation in a very labor-saving mode, meanwhile, the operation efficiency of the hydraulic equipment can be improved, and the working efficiency of the hydraulic equipment is improved. And the design of the hydraulic equipment is more reasonable.

Description

Technical Field

[0001] This application relates to the field of hydraulic equipment technology, and in particular to a return oil structure, return oil method, return oil system and hydraulic equipment. Background Technology

[0002] Hydraulic equipment is widely used in modern industry, especially in applications requiring enormous force output or precise pressure control, such as mechanical engineering and crimping tools. With the development of industrial technology, the demands on equipment output are constantly increasing, and the working system pressures of many high-performance hydraulic equipment have climbed to ultra-high pressure levels, such as 70 MPa or even higher. Under such ultra-high pressure conditions, the existing manual direct-trigger return oil method reveals significant defects and operational difficulties. When the hydraulic equipment pressure reaches 70 MPa, the manual operating force (pressing or levering force) required to overcome the enormous hydraulic pressure on the valve core is still very large. Operators need to expend a great deal of physical strength to complete a single return oil action, which not only leads to low operating efficiency but also easily causes muscle fatigue and even cumulative musculoskeletal damage. Summary of the Invention

[0003] In view of this, this application aims to provide an oil return structure, an oil return method, an oil return system, and a hydraulic device to solve the above-mentioned technical problems.

[0004] Based on the above objectives, this application provides an oil return structure disposed within the cylinder of a hydraulic device. The oil return structure includes: a first pressure relief component, a second pressure relief component, and a driving component. The first pressure relief component is sealed at the oil outlet of the cylinder. The first hydraulic component includes a flow guide channel. The second pressure relief component is sealed within the flow guide channel. One end of the driving component passes through the flow guide channel and abuts against the second pressure relief component. The driving component can reciprocate along the flow guide channel. When the driving component lifts the second pressure relief component to a preset height, a portion of it will abut against the first pressure relief component, thus lifting the first pressure relief component.

[0005] As a preferred technical solution for the oil return structure, the driving component includes an abutment portion, and the distance between the abutment portion and the bottom surface of the first pressure relief component is consistent with the preset distance. When the abutment portion abuts against the bottom surface of the first pressure relief component, the second pressure relief component is lifted to a preset height to perform a first-stage pressure relief on the hydraulic equipment.

[0006] As a preferred technical solution for the oil return structure, when the driving component moves, the abutting part lifts the first pressure relief component, and the hydraulic oil in the cylinder flows out from the oil outlet and the guide channel together, thus performing secondary pressure relief on the hydraulic equipment.

[0007] As a preferred technical solution for the oil return structure, the driving component includes a push rod and a connecting rod. One end of the push rod passes through the flow channel and abuts against the second pressure relief component, and the other end abuts against the connecting rod. When the connecting rod moves, it enables the push rod to reciprocate along the flow channel. The abutting part is provided on the push rod, so that the push rod lifts the second pressure relief component to the preset height and then lifts the first pressure relief component.

[0008] As a preferred technical solution for the oil return structure, the push rod includes a first main body and a protrusion. The protrusion is movably positioned in the guide channel. The protrusion abuts against the second pressure relief component and is partially exposed. The exposed length of the protrusion is consistent with the preset height. The end of the first main body away from the protrusion abuts against the connecting rod. The transition surface between the first main body and the protrusion is opposite to the bottom surface of the first pressure relief component. The transition surface is the abutment portion.

[0009] As a preferred technical solution for the oil return structure, one end of the push rod passes through the flow guide channel and abuts against the second pressure relief component, and the other end abuts against the connecting rod. The side of the push rod near the first hydraulic valve is provided with a protrusion, and the distance between the protrusion and the first hydraulic valve is consistent with the preset height. The protrusion is the abutment part.

[0010] As a preferred technical solution for the oil return structure, the connecting rod is rotatably mounted in the hydraulic equipment, and the torque ratio of the connecting rod is 3:1 to 6:1.

[0011] As a preferred technical solution for the oil return structure, the ratio of the flow area of ​​the guide channel to the flow area of ​​the oil outlet is 10~12.

[0012] An oil return method, applied to the aforementioned oil return structure, the oil return method comprising the following steps: The control drive moves along the guide channel in the forward direction, lifting the second pressure relief component to a preset height; The control drive continues to move forward, lifting the first pressure relief component; The control drive moves in the reverse direction, causing the first and second pressure relief components to reset sequentially.

[0013] An oil return system includes the aforementioned oil return structure.

[0014] A hydraulic device includes the aforementioned return oil system.

[0015] As can be seen from the above, the beneficial effects of the oil return structure provided in this application are as follows: The oil return structure provided in this application uses a second pressure relief component to block the flow channel in the first pressure relief component. The area of ​​the flow channel is smaller than the area of ​​the oil outlet, making the volume of the second pressure relief component smaller than that of the first pressure relief component. In the hydraulic circuit, the effective area of ​​the hydraulic oil acting on the second pressure relief component is smaller than that acting on the first pressure relief component. Therefore, the downward pressure generated by the hydraulic circuit on the second pressure relief component is less than the downward pressure generated on the first pressure relief component. For the first pressure relief component, it is relatively easier to lift the second pressure relief component. During the process of raising the second pressure relief component to the preset height, some of the hydraulic oil in the hydraulic circuit can pass through... The hydraulic oil flows back into the tank through the guide channel, initially relieving pressure in the hydraulic circuit. The pressure inside the cylinder decreases, and when the drive component comes into contact with the first pressure relief component, the downward pressure exerted by the hydraulic oil on the first pressure relief component is significantly reduced. This makes it easier for the first pressure relief component to be lifted. When the operator operates the return oil button, the drive component moves to lift the second and first pressure relief components in sequence. This greatly reduces the operating force required when the hydraulic circuit returns oil, allowing the operator to complete the return oil operation with much less effort. At the same time, it also improves the operating efficiency of the hydraulic equipment and makes the design of the hydraulic equipment more rational. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a partial cross-sectional schematic diagram of the hydraulic equipment provided in the embodiments of this application; Figure 2 This is a schematic cross-sectional view of a hydraulic device provided in an embodiment of this application.

[0018] Figure label: 100. Hydraulic equipment; 101. Cylinder body; 102. Oil return button; 1. First pressure relief component; 11. Flow guide channel; 2. Second pressure relief component; 21. Sealing component; 22. Support component; 23. Elastic component; 3. Driving component; 31. Top rod; 311. First main body; 312. Protrusion; 32. Connecting rod; 33. Torsion spring. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0020] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] Hydraulic equipment is widely used in modern industry, especially in applications requiring immense force or precise pressure control, such as mechanical engineering and crimping tools. This type of equipment typically uses a hydraulic pump to drive hydraulic oil to establish system pressure, and various valves control the flow and direction of the oil, thereby driving actuators (such as cylinders) to perform work. At the end of a work cycle or when a position reset is required, a "return oil" operation is usually performed, which releases the pressure within the actuator cavity, allowing the oil to flow back to the tank or reservoir under control, facilitating the next operation or adjustment.

[0022] Currently, the return oil operation of many hydraulic devices relies on direct manual triggering. Specifically, the operator needs to manually press or pull a dedicated "return oil button" or "unloading valve handle" to release pressure and return oil to the main oil circuit or the working chamber of the actuator. This direct manual triggering method is still within the ergonomically acceptable comfort range when the system operating pressure is low (e.g., below 10-20 MPa), and has the advantages of simple structure and low cost.

[0023] However, with the development of industrial technology and the increasing demands on equipment output, the working system pressure of many high-performance hydraulic equipment has climbed to ultra-high pressure levels, such as 70MPa or even higher. Under such ultra-high pressure conditions, the existing manual direct triggering method for oil return exposes significant defects and operational difficulties. When the hydraulic circuit pressure reaches 70MPa, the manual operating force (pressing force or lever force) required to overcome the enormous hydraulic pressure on the valve core is still very large. Operators need to expend a great deal of physical strength to complete a single oil return action. This not only leads to low operating efficiency but also easily causes muscle fatigue in operators and may even cause cumulative musculoskeletal damage.

[0024] like Figure 1 and Figure 2As shown, in some optional embodiments, this application provides an oil return structure disposed within the cylinder 101 of the hydraulic device 100. The oil return structure includes a first pressure relief component 1, a second pressure relief component 2, and a drive component 3. The first pressure relief component 1 blocks the oil outlet of the hydraulic circuit and includes a guide channel 11. The second pressure relief component 2 blocks the guide channel 11 to prevent oil return and pressure relief during operation of the actuator, ensuring stable operation of the actuator. One end of the drive component 3 passes through the guide channel 11 and abuts against the second pressure relief component 2. The drive component 3 can reciprocate along the guide channel 11. When the drive component 3 moves along the guide channel 11, it can lift the second pressure relief component 2, allowing the hydraulic oil in the hydraulic circuit of the hydraulic device 100 to flow out from the guide channel 11 back to the oil tank. This provides initial pressure relief to the hydraulic circuit, reducing the pressure within the cylinder 101. After the second pressure relief component 2 is lifted to a preset height, a portion of the drive component 3 will come into contact with the first pressure relief component 1. As the drive component 3 continues to move, it will lift the first pressure relief component 1. Since the oil outlet area is larger than the oil outlet area of ​​the guide channel 11, the hydraulic oil in the hydraulic circuit can flow out quickly from the oil outlet and the guide channel 11 and flow back into the oil tank, thus realizing the rapid oil return of the hydraulic equipment 100.

[0025] Since the second pressure relief component 2 is used to block the flow channel 11 in the first pressure relief component 1, and the area of ​​the flow channel 11 is smaller than the area of ​​the oil outlet, the volume of the second pressure relief component 2 is much smaller than the volume of the first pressure relief component 1. In the hydraulic circuit, the effective area of ​​the hydraulic oil acting on the second pressure relief component 2 is smaller than the effective area acting on the first pressure relief component 1. Therefore, the downward pressure generated by the hydraulic circuit on the second pressure relief component 2 is less than the downward pressure generated on the first pressure relief component 1. For the first pressure relief component 1, it is relatively easier to lift the second pressure relief component 2. During the process of raising the second pressure relief component 2 to the preset height, some of the hydraulic oil in the hydraulic circuit can return through the flow channel 11. The oil flows into the tank, initially relieving pressure in the hydraulic circuit. The pressure inside cylinder 101 decreases. When the drive component 3 comes into contact with the second pressure relief component 2, the downward pressure exerted by the hydraulic oil on the first pressure relief component 1 is significantly reduced. This makes it easier for the first hydraulic valve to be lifted. When the operator operates the return oil button 102, causing the drive component 3 to move and lift the second pressure relief component 2 and the first pressure relief component 1 in sequence, the required operating force for the hydraulic equipment 100 to return oil is greatly reduced. This means that the operator can complete the return oil operation with very little effort, while also improving the operating efficiency of the hydraulic equipment 100 and making the design of the hydraulic equipment 100 more rational.

[0026] In some optional embodiments, the driving member 3 includes an abutment portion, the distance between the abutment portion and the bottom surface of the first pressure relief member 1 being consistent with a preset distance. When the driving member 3 moves along the guide channel 11, the second pressure relief member 2 is lifted up as the driving member 3 moves. When the abutment portion abuts against the first pressure relief member 1, the second pressure relief member 2 is lifted to a preset height. During the process of the second pressure relief member 2 being lifted, the hydraulic oil in the hydraulic circuit flows back to the oil tank through the guide channel 11, performing initial pressure relief on the hydraulic circuit. At this time, the oil return structure completes the first stage of pressure relief on the hydraulic circuit, reducing the pressure inside the cylinder 101, thereby reducing the force on the first pressure relief member 1.

[0027] In some alternative embodiments, when the drive member 3 continues to move, and the second pressure relief member 2 is pushed to a preset height, the hydraulic circuit completes the initial pressure relief, the pressure inside the cylinder 101 decreases, the pressure acting on the first pressure relief member 1 decreases, and the drive member 3 can lift the first pressure relief member 1 with less effort. At this time, the hydraulic oil in the cylinder 101 can flow out from the guide channel 11 and the oil outlet together, and flow back to the oil tank or oil bladder, performing secondary pressure relief on the hydraulic circuit, realizing rapid oil return of the hydraulic equipment 100, and improving the oil return efficiency of the hydraulic equipment 100.

[0028] In some optional embodiments, the second pressure relief component 2 includes a sealing component 21, a supporting component 22, and an elastic component 23. The sealing component 21 is used to block the flow channel 11. The supporting component 22 is placed in the oil return channel opposite to the first pressure relief component 1 and is abutted by the sealing component 21. The elastic component 23 is connected to the supporting component 22 and is opposite to the first pressure relief component 1. The driving component 3 abuts against the sealing component 21. When the driving component 3 moves along the flow channel 11, it lifts the sealing component 21 and the supporting component 22, causing the hydraulic oil in the cylinder 101 to flow out from the flow channel 11, thus reducing the pressure inside the cylinder 101. As the sealing component 21 and the supporting component 22 are lifted, and as the driving component 3 continues to move, the first pressure relief component 1 is lifted, causing the hydraulic oil in the cylinder 101 to flow out rapidly from the flow channel 11 and the oil outlet. During the movement of the driving component 3, the elastic element 23 is continuously compressed, providing support throughout the process and reducing the risk of misalignment of the blocking component, the supporting component 22, and the first pressure relief component 1 during the lifting process. Simultaneously, when the operator stops pressing the return oil button 102, the elastic element 23 allows the first pressure relief component 1, the second pressure relief component 2, and the driving component 3 to automatically reset. The elastic element 23 can be a spring.

[0029] In some optional embodiments, the drive component 3 includes a push rod 31 and a connecting rod 32. One end of the push rod 31 passes through the guide channel 11 and abuts against the second pressure relief component 2, and the other end abuts against the connecting rod 32. The return oil button 102 in the hydraulic device 100 is connected to the connecting rod 32. Pressing the return oil button 102 can move the connecting rod 32. When the connecting rod 32 moves, it can lift the push rod 31, causing the push rod 31 to move back and forth along the guide channel 11. The abutting part is provided on the push rod 31, so that the push rod 31 can lift the second pressure relief component 2 to a preset height and then lift the first pressure relief component 1 during the movement, realizing first-level and second-level pressure relief of the hydraulic circuit, so that the hydraulic device 100 can be operated with effortless speed and return oil quickly.

[0030] In some optional embodiments, the push rod 31 includes a first main body 311 and a protrusion 312. The protrusion 312 is movably positioned in the flow channel 11, abuts against the second pressure relief member 2, and is partially exposed. The exposed length of the protrusion 312 is consistent with a preset height. One end of the first main body 311 opposite to the protrusion 312 abuts against the connecting rod 32. The transition surface between the first main body 311 and the protrusion 312 is opposite to the bottom surface of the first pressure relief member 1. Thus, when the connecting rod 32 moves and causes the push rod 31 to move upward, the push rod 31 first lifts the second pressure relief member 2, initially relieving pressure in the hydraulic circuit. Since the length of the protrusion 312 exposed in the guide channel 11 is consistent with the preset height, after the second pressure relief component 2 is lifted to the preset height, the transition surface between the protrusion 312 and the first main body 311 abuts against the first pressure relief component 1. As the push rod 31 continues to move, it lifts the first pressure relief component 1, allowing the hydraulic oil in the hydraulic equipment 100 to quickly flow back into the oil tank. The first main body 311 and the protrusion 312 can be configured separately or as a single unit; no specific limitation is made here.

[0031] In some alternative embodiments, one end of the push rod 31 passes through the guide channel 11 and abuts against the second pressure relief component 2, while the other end abuts against the connecting rod 32. A protrusion is provided around the side of the push rod 31 near the first hydraulic valve, and the distance between the protrusion and the first hydraulic valve is consistent with a preset height. When the connecting rod 32 moves, the push rod 31 moves upward, lifting the second pressure relief component 2 and initially relieving pressure in the hydraulic circuit. After the second pressure relief component 2 is lifted to a preset height, the protrusion abuts against the first pressure relief component 1. As the push rod 31 continues to move upward, the first pressure relief component 1 is lifted, and the hydraulic oil in the hydraulic equipment 100 can quickly flow back to the oil tank.

[0032] In some optional embodiments, the drive component 3 further includes a reset torsion spring 33, wherein the connecting rod 32 is disposed inside the housing of the hydraulic device 100, one end of the reset torsion spring 33 is connected to the housing, and the other end is connected to the connecting rod 32. When the operator stops pressing the return oil button 102, the connecting rod 32 can automatically reset under the action of the torsion spring 33.

[0033] In some alternative embodiments, the first pressure relief component 1 includes a positioning groove, a flow guiding channel 11 is disposed in the positioning groove, a sealing component 21 is used to block the flow guiding channel 11, and a support component 22 is partially placed in the positioning groove and fits against the inner wall of the positioning groove. During the process of the driving component 3 lifting the sealing component 21 and the support component 22, the positioning groove can play a certain limiting and guiding role.

[0034] In some optional embodiments, the first pressure relief component 1 includes a second main body and a sealing part. A positioning groove is disposed in the second main body, and the sealing part seals the oil outlet. The circumferential surface of the sealing part is inclined and fits against the inner wall of the oil outlet. Thus, as the push rod 31 lifts the first pressure relief component 1, the hydraulic oil in the hydraulic circuit will gradually flow out from the oil outlet. As the height of the first pressure relief component 1 gradually increases, the area of ​​the oil outlet being sealed gradually decreases, the flow rate of the hydraulic oil gradually increases, and the operator's operation gradually becomes less strenuous, until the first pressure relief component 1 is completely pushed out of the oil outlet, and the return flow rate of the hydraulic oil in the hydraulic circuit reaches its maximum.

[0035] In some optional embodiments, the connecting rod 32 is rotatably mounted in the hydraulic device 100, and the torque ratio of the connecting rod 32 is 3:1 to 6:1. When the operator presses the return oil button 102, the connecting rod 32 rotates, thereby causing the push rod 31 to move upward, sequentially lifting the second pressure relief component 2 and the first pressure relief component 1 to achieve oil return. Designing the torque ratio of the connecting rod 32 to be 3:1 to 6:1 reduces the force required to press the return oil button 102 to 1 / 3 to 1 / 6 of the downward force exerted by the hydraulic oil on the second pressure relief component 2 when the connecting rod 32 rotates and lifts the second pressure relief component 2 upward via the push rod 31, making the oil return operation easier for the operator. Preferably, the torque ratio of the connecting rod 32 can be 5:1. The connecting rod 32 is a conventional component in the hydraulic device 100, and its specific structure can be designed with reference to existing common knowledge; no specific limitations are imposed here.

[0036] In some optional embodiments, the ratio of the flow area of ​​the guide channel 11 to the flow area of ​​the outlet oil is 10 to 12. The second pressure relief component 2 is used to block the guide channel 11, and the first pressure relief component 1 is used to block the return oil channel. The volume of the first pressure relief component 1 is designed based on the flow area of ​​the guide channel 11, and the volume of the second pressure relief component 2 is designed based on the flow area of ​​the outlet oil. The pressure inside the cylinder 101 acts on the effective area of ​​the first pressure relief component 1, which is 10 to 12 times that of the second pressure relief component 2. Therefore, the force required to lift the first pressure relief component 1 is 10 to 12 times the force required to lift the second pressure relief component 2. Compared to existing technologies that use only a valve core matching the oil outlet area to block the oil outlet, this application uses only 1 / 10 to 1 / 12 of the force to lift the second pressure relief component 2, allowing the hydraulic oil in the cylinder 101 to flow out and reducing the pressure inside the cylinder 101. Subsequently, the first pressure relief component 1 can be lifted with relatively less effort, achieving rapid oil return from the hydraulic equipment 100. The flow area of ​​the oil outlet can be 11 times the flow area of ​​the guide channel 11.

[0037] In some alternative embodiments, this application provides an oil return method applied to the above-described oil return structure, wherein the oil return method includes the following steps.

[0038] The control drive unit 3 moves forward along the guide channel, lifting the second pressure relief component 2 to a preset height. During the process of the second pressure relief component 2 being lifted, the hydraulic oil in the hydraulic circuit can flow out along the guide channel 11 and eventually return to the oil tank. At this time, the drive unit 3 moves the first pressure relief stroke, and the oil return structure completes the first stage of pressure relief for the hydraulic circuit.

[0039] The drive unit 3 continues to move forward, lifting the first pressure relief component 1. The drive unit 3 is provided with an abutment part. When the first pressure relief component 1 is lifted to a preset height, the abutment part abuts against the first pressure relief component 1. As the drive unit 3 continues to move, the first pressure relief component 1 is lifted and gradually moves away from the oil outlet. The hydraulic oil in the hydraulic circuit flows out quickly from the oil outlet and the guide channel 11 and flows back into the oil tank. At this time, the drive unit 3 moves to the second pressure relief stroke, and the oil return structure completes the two-stage pressure relief of the hydraulic circuit, realizing the rapid oil return of the hydraulic equipment 100.

[0040] The control drive 3 moves in the reverse direction, causing the first pressure relief component 1 and the second pressure relief component 2 to reset sequentially. When the hydraulic equipment 100 completes the return oil, the operator no longer presses the return oil button 102, the external force acting on the return oil button 102 is removed, and under the action of the elastic component 23, the drive 3 moves in the reverse direction. At this time, the first hydraulic component and the second pressure relief component 2 can reset sequentially.

[0041] In some alternative embodiments, when the second pressure relief element 2 is lifted to a preset height, the hydraulic oil in the hydraulic circuit flows back from the guide channel 11 to the oil tank.

[0042] When the driving component 3 lifts the first pressure relief component 1, the hydraulic oil in the hydraulic circuit flows out from the oil outlet and the guide channel 11, flows into the return oil pipeline, and flows back to the oil tank.

[0043] The oil return structure is installed in the oil return system within the hydraulic equipment. The composition of the oil return system can be referenced from existing technologies, and no specific limitations are made here.

[0044] In some alternative embodiments, this application provides an oil return system including the above-described oil return structure, which enables the oil return system to return oil quickly and effortlessly.

[0045] In some optional embodiments, this application provides a hydraulic device 100, including the aforementioned return oil system. The hydraulic device 100 provided in this embodiment allows operators to press the return oil button 102 more effortlessly to complete the return oil operation, enabling them to operate the hydraulic device 100 more efficiently and conveniently. The hydraulic device 100 can be a hydraulic clamp.

[0046] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A return oil structure, installed inside the cylinder of a hydraulic device, characterized in that, The oil return structure includes: a first pressure relief component, a second pressure relief component, and a driving component. The first pressure relief component is sealed at the oil outlet of the cylinder. The first hydraulic component includes a flow guide channel. The second pressure relief component is sealed in the flow guide channel. One end of the driving component passes through the flow guide channel and abuts against the second pressure relief component. The driving component can reciprocate along the flow guide channel. When the driving component lifts the second pressure relief component to a preset height, a portion of it will abut against the first pressure relief component, thus lifting the first pressure relief component.

2. The oil return structure according to claim 1, characterized in that, The driving component includes an abutting part, and the distance between the abutting part and the bottom surface of the first pressure relief component is the same as the preset distance. When the abutting part abuts against the bottom surface of the first pressure relief component, the second pressure relief component is lifted to a preset height to perform a first-stage pressure relief on the hydraulic equipment.

3. The oil return structure according to claim 2, characterized in that, When the drive component moves, the abutment part lifts the first pressure relief component, and the hydraulic oil in the cylinder flows out from the oil outlet and the guide channel together, performing secondary pressure relief on the hydraulic equipment.

4. The oil return structure according to claim 2, characterized in that, The driving component includes a push rod and a connecting rod. One end of the push rod passes through the flow channel and abuts against the second pressure relief component, and the other end abuts against the connecting rod. When the connecting rod moves, it enables the push rod to reciprocate along the flow channel. The abutting part is provided on the push rod, so that the push rod lifts the second pressure relief component to the preset height and then lifts the first pressure relief component.

5. The oil return structure according to claim 4, characterized in that, The push rod includes a first main body and a protrusion. The protrusion is movably positioned in the flow channel. The protrusion abuts against the second pressure relief component and is partially exposed. The exposed length of the protrusion is consistent with the preset height. The end of the first main body away from the protrusion abuts against the connecting rod. The transition surface between the first main body and the protrusion is opposite to the bottom surface of the first pressure relief component. The transition surface is the abutment portion.

6. The oil return structure according to claim 4, characterized in that, One end of the push rod passes through the flow channel and abuts against the second pressure relief component, while the other end abuts against the connecting rod. A protrusion is provided around the side of the push rod near the first hydraulic valve. The distance between the protrusion and the first hydraulic valve is consistent with the preset height, and the protrusion is the abutment part.

7. The oil return structure according to claim 4, characterized in that, The connecting rod is rotatably mounted in the hydraulic equipment, and the torque ratio of the connecting rod is 3:1 to 6:

1.

8. The oil return structure according to any one of claims 1-7, characterized in that, The ratio of the flow area of ​​the guide channel to the flow area of ​​the oil outlet is 10~12.

9. A method for oil return, characterized in that, Applied to the oil return structure as described in any one of claims 1-8, the oil return method includes the following steps: The control drive moves along the guide channel in the forward direction, lifting the second pressure relief component to a preset height; The control drive continues to move forward, lifting the first pressure relief component; The control drive moves in the reverse direction, causing the first and second pressure relief components to reset sequentially.

10. An oil return system, characterized in that, Includes the oil return structure as described in any one of claims 1-8.

11. A hydraulic device, characterized in that, Includes the oil return system as described in claim 10.

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