Shock absorber for semi-active hydraulic suspension

Abstract

The invention discloses a shock absorber for a semi-active hydraulic suspension, and relates to the technical field of automobile shock absorbers. In order to reduce the occupation of a chassis space by an external oil way connecting structure of the shock absorber and effectively avoid the movement interference with peripheral parts, the following technical scheme is provided: the oil storage cylinder comprises an oil storage barrel and a working cylinder; the bottoms of the oil storage barrel and the working cylinder are hermetically connected with a barrel base; a piston and a piston rod are slidably arranged in the working cylinder, an oil seal is arranged at the top of the working cylinder, the piston rod is matched with the oil seal, and the working cylinder is divided into an upper cavity and a lower cavity by the piston; a damping valve system is arranged on the piston; an oil hole is formed in the side wall of the upper cavity; a single-pipe oil way connector is arranged on the cylinder base; the single-pipe oil way connector is in direct fluid communication with the lower cavity through an oil way formed in the barrel base, and a single external oil way connecting point integrated on the barrel base is formed. The space layout of the chassis is obviously optimized, the design freedom degree of the whole vehicle is improved, high integration of the vibration reduction function and the lifting function is achieved, and the system cost and complexity are greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile shock absorbers, in particular to a semi-active hydraulic suspension shock absorber. BACKGROUND

[0002] In the automotive industry, shock absorbers are key components of the suspension system, and their performance directly affects the ride comfort and handling stability of the vehicle. With technological advances, electronically controlled shock absorbers (such as CDC shock absorbers) and hydraulic suspension systems that can adjust damping force in real time are gradually being applied. In particular, semi-active hydraulic suspension systems adjust damping force through control valves, improving vehicle dynamic performance without significantly increasing costs.

[0003] However, existing semi-active hydraulic shock absorbers must have multiple independent external oil ports on the shock absorber cylinder or use a large bottom connecting block with multiple oil paths in order to connect to external hydraulic systems. These designs result in complex external connection structures, irregular profiles, and large space occupation of the shock absorber body. The resulting multiple oil pipes are disorganized, or the rigid connection parts are large in volume, making it difficult to plan in a crowded chassis layout and significantly restricting the compactness and low center of gravity trend of the chassis design. It is easy to cause static space conflicts or dynamic motion interference with components such as stabilizer bars, control arms, and drive shafts, significantly increasing the difficulty, cost, and long-term use of vehicle assembly and interference risks.

[0004] In addition, from the perspective of integrating vehicle system functions, traditional solutions typically separate shock absorption and vehicle body lifting functions: shock absorbers are only responsible for providing damping force, while vehicle body height adjustment (lifting / descending) requires the additional introduction of air springs or an independent hydraulic lifting system. This functionally separate architecture not only increases system complexity, occupies more chassis space, but also significantly increases manufacturing costs and maintenance difficulty.

[0005] Therefore, how to optimize the external oil path interface design of the shock absorber to make it more compact to solve the space interference problem and provide a deep integration path for shock absorption and lifting functions to simplify the system and reduce costs has become a technical problem that needs to be solved in the field. SUMMARY

[0006] The present application provides a semi-active hydraulic suspension shock absorber, which aims to reduce the space occupation of the shock absorber external oil path connection structure on the chassis, effectively avoid motion interference with surrounding components, and provide integration of shock absorption and lifting functions.

[0007] The technical solution of the present application to solve the above technical problems is as follows:

[0008] A semi-active hydraulic suspension shock absorber, comprising:

[0009] The oil storage cylinder and the working cylinder coaxially nested in the oil storage cylinder are provided; the bottom of the oil storage cylinder is sealingly connected with a cylinder base, and the bottom of the working cylinder is also sealingly arranged on the cylinder base; a piston and a piston rod fixedly connected with the piston are slidably arranged in the working cylinder, an oil seal is arranged at the top of the working cylinder, the extending end of the piston rod is in sliding cooperation with the oil seal, and the piston divides the working cylinder into an upper cavity and a lower cavity; a damping valve system for generating damping in a recovery stroke is arranged on the piston, and an oil hole communicating with the inner cavity of the oil storage cylinder is formed in the side wall of the upper cavity; a single-pipe oil way interface is arranged on the cylinder base; the single-pipe oil way interface is directly in fluid communication with the lower cavity through an oil channel formed in the cylinder base, thereby forming a single external oil way connecting point integrated in the cylinder base, and the single-pipe oil way interface is used for connecting an external hydraulic module, so that the lower cavity and the external hydraulic module form a hydraulic circuit for adjusting damping and realizing lifting.

[0010] Further, a guide sleeve for guiding the axial movement of the piston rod is further arranged at the top of the working cylinder, and a zerks seal is arranged in the guide sleeve and in sliding cooperation with the extending end of the piston rod.

[0011] Further, an oil seal seat and a screw cap are further arranged at the top of the working cylinder; the oil seal is arranged in the oil seal seat, the screw cap is connected with the oil storage cylinder and tightly fixes the guide sleeve and the oil seal seat, a sealing ring is arranged between the oil seal seat and the oil storage cylinder, and an oil seal gasket is arranged between the screw cap and the oil seal seat.

[0012] Further, a switch valve interface is further arranged on the cylinder base.

[0013] Further, the cylinder base and the bottom of the oil storage cylinder are fixedly connected in a welding mode.

[0014] Further, the single-pipe oil way interface is a quick connector or a threaded interface.

[0015] Further, a spring disc is arranged outside the oil storage cylinder.

[0016] The present application has the following beneficial effects:

[0017] The present application significantly optimizes the layout of the chassis space and improves the design freedom of the whole vehicle. By integrating the external oil way into the single interface on the cylinder base, the space redundancy and the complex protrusion caused by the traditional multi-way external connection or the large bottom connecting block are eliminated. The profile of the shock absorber at the bottom is extremely simple, and only one oil pipe needs to be planned, so that the moving parts in the chassis can be easily avoided, the problem of space interference is solved, and the freedom and reliability of the layout of the whole vehicle chassis are significantly improved.

[0018] Meanwhile, the application realizes high integration of damping and lifting functions, greatly reduces system cost and complexity. There are mainly two kinds of traditional schemes for realizing vehicle body height adjustment: air suspension or completely independent hydraulic lifting system. The application directly uses the lower cavity of the working cylinder of the shock absorber as the lifting oil cylinder, and uses the piston rod as the lifting piston. When the external hydraulic pump pumps high-pressure oil into the lower cavity of the working cylinder through the oil pipe, the high-pressure oil will push out the piston rod, realizing lifting. The lifting and damping share the same oil circuit, the same cylinder body and the same working medium. A set of independent execution mechanism is saved. When descending, no additional energy is consumed, only the hydraulic pump needs to be closed, and the piston rod is compressed by the weight of the vehicle body, and the lower cavity oil is pressed back to the oil can, which is energy-saving and reliable. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Figure 1 is a structural schematic diagram of a semi-active hydraulic suspension shock absorber according to the application.

[0020] Figure 2 Figure 2 is a partial enlarged view of A in figure 1. Figure 1

[0021] Figure 3 Figure 3 is a partial enlarged view of B in figure 1. Figure 1

[0022] Figure 4 Figure 4 is a partial enlarged view of C in figure 1. Figure 1

[0023] Figures 1 to 4 The reference signs shown in the drawings respectively represent: 1-piston rod; 2-screw cover; 3-oil seal gasket; 4-oil seal; 5-oil seal seat; 6-guide sleeve; 7-separation sleeve; 8-fixing ring; 9-working cylinder; 91-upper cavity; 92-lower cavity; 93-oil hole; 10-oil storage cylinder; 11-spring disc; 12-piston; 13-damping oil; 14-cylinder bottom seat; 15-single-pipe oil circuit interface; 16-switch valve interface; 17-threaded cylinder. DETAILED DESCRIPTION

[0024] The application will be further described below in combination with the drawings and examples as follows:

[0025] Please refer to Figures 1-4 ​​​The present embodiment describes a semi-active hydraulic suspension damper, which comprises an oil storage cylinder 10 and a working cylinder 9 coaxially nested in the oil storage cylinder 10; the bottom of the oil storage cylinder 10 is sealingly connected with a cylinder base 14, and the bottom of the working cylinder 9 is also sealingly arranged on the cylinder base 14; a piston 12 and a piston rod 1 fixedly connected with the piston 12 are slidably arranged in the working cylinder 9, the top of the working cylinder 9 is provided with an oil seal 4, the piston rod 1 is in sliding fit with the oil seal 4, and the piston 12 divides the working cylinder 9 into an upper chamber 91 and a lower chamber 92; an oil hole 93 is formed in the side wall of the upper chamber 91 and communicates with the inner cavity of the oil storage cylinder 10; the piston 12 is provided with a damping valve system for generating damping in the rebound stroke; a single-pipe oil way interface 15 is arranged on the cylinder base 14; the single-pipe oil way interface 15 is in direct fluid communication with the lower chamber 92 through an oil channel formed in the cylinder base 14, and constitutes a single external oil way connection point integrated in the cylinder base 14; the single-pipe oil way interface 15 is used for connecting an external hydraulic module, so that the lower chamber 92 and the external hydraulic module form a hydraulic circuit for adjusting damping and realizing lifting.

[0026] The semi-active hydraulic suspension damper provided by the present application adopts a single-cylinder double-chamber layout in the main body structure. Specifically, it mainly comprises an oil storage cylinder 10 as a shell. In the inside of the oil storage cylinder 10, a working cylinder 9 is coaxially nested. The annular space between the working cylinder 9 and the oil storage cylinder 10 constitutes an oil storage cavity. The oil storage cylinder 10 has sufficient wall thickness to withstand the system burst pressure and provides a stable foundation for the externally welded spring disc 11 and other components.

[0027] The piston 12 cooperates with the inner wall of the working cylinder 9 to slidably divide the inner cavity of the working cylinder 9 into an upper chamber 91 and a lower chamber 92. On the piston 12, a damping valve system is arranged. When the piston rod 1 moves relative to the working cylinder 9, a pressure difference is generated between the upper chamber 91 and the lower chamber 92 on both sides of the piston 12, and the oil liquid is forced to pass through the damping valve system on the piston 12, thereby generating a damping force that hinders the movement, which is passive damping. The oil hole 93 formed in the side wall of the upper chamber 91 is in communication with the inner cavity of the oil storage cylinder 10. Figure 2 The oil hole 93 formed in the side wall of the upper chamber 91 is in communication with the inner cavity of the oil storage cylinder 10. The oil hole 93 is used to adapt to the change of the amount of oil liquid caused by the change of the volume of the upper chamber 91 when the piston rod 1 moves, and to realize the flow of oil liquid between the oil storage cavity of the oil storage cylinder 10 and the upper chamber 91 of the working cylinder 9.

[0028] The piston 12 itself integrates the function of a recovery valve. A dedicated oil way and valve system are arranged on the piston 12 for controlling the flow of oil liquid from the upper chamber 91 of the working cylinder to the lower chamber 92 in the rebound stroke and generating a rebound damping force.

[0029] The single-tube oil port interface 15 is connected to an independent damping module through an external oil line. The damping module integrates a compression valve system and an electromagnetic regulating valve. The compression valve system is used to control the flow and damping generation of oil flowing out of the lower chamber 92 of the working cylinder during the compression stroke; the electromagnetic regulating valve is used to receive electronic control signals to adjust the flow area or pressure of the oil line in real time. In addition, the damping module is also connected with a hydraulic accumulator for absorbing pulsation, stabilizing pressure and providing oil supply and return lines for the external hydraulic pump.

[0030] In the normal driving state, the external hydraulic pump does not provide active pressure to the lifting circuit.

[0031] Compression stroke: the piston rod 1 moves downward under pressure, the volume of the lower chamber 92 decreases, and the oil pressure rises. The oil is pushed to the external damping module through the single-tube oil port interface 15 and the external oil line. In this module, the oil first flows through the compression valve system. The electromagnetic regulating valve is in a normally closed state when no control current is input, and at this time the oil mainly or only generates damping through the compression valve system, and its working mode is equivalent to that of a traditional passive damper. When the vehicle control system inputs control current to the electromagnetic regulating valve according to sensor signals, the electromagnetic regulating valve is opened accordingly, forming a parallel or bypass oil line. By continuously adjusting the current size, the opening of the electromagnetic valve can be changed, so that the flow through the parallel oil line can be adjusted in real time and continuously, realizing continuous variable compression damping (CDC function). The adjusted oil finally enters the accumulator and the low-pressure circuit.

[0032] Recovery stroke: the piston rod 1 moves upward, and the pressure in the upper chamber 91 rises. At this time, the oil pushes the recovery valve integrated on the piston 12 to open, flows to the lower chamber 92, and generates a recovery damping force. This process is mainly completed inside the damper.

[0033] In this mode, the system only dissipates and adjusts damping energy, and does not output lifting force.

[0034] The bottom key component of the damper is the cylinder base 14. The cylinder base 14 is an integrated functional component, and its upper part is sealed and connected to the bottom of the oil tank 10 by welding. At the same time, the bottom of the working cylinder 9 can be connected to the cylinder base 14 by interference press fitting sealing. The cylinder base 14, the bottom of the working cylinder 9 and the bottom of the oil tank 10 together form a sealed lower cover structure.

[0035] On the side or bottom of the cylinder base 14, only one single pipe oil port 15 is provided. The single pipe oil port 15 is the only external connection point for the shock absorber to exchange oil with the external hydraulic system. The single pipe oil port 15 establishes a direct fluid communication relationship with the lower chamber 92 of the working cylinder 9 through the oil channel formed inside the cylinder base 14. All the oil that needs to enter or leave the lower chamber 92 of the working cylinder 9 must pass through the single pipe oil port 15 integrated on the cylinder base 14. The form of the traditional multi-oil pipe external connection or large and complex joint at the bottom is changed, so that the profile of the shock absorber bottom is simple, and the problem of space interference with chassis components caused by the disorderly layout of oil pipes and the protruding joint is fundamentally avoided.

[0036] The structure of the upper chamber 91 and the lower chamber 92 of the working cylinder 9 is described in detail below. Figures 2-3 The shock absorber of the present application integrates the vehicle body height adjustment function while optimizing the spatial layout. The implementation principle is as follows:

[0037] Vehicle body lifting working condition:

[0038] When the vehicle body needs to be lifted, the vehicle control system starts the external hydraulic pump and sends a command to lock or open the electromagnetic regulating valve in the damping module at a very small opening, while pumping high-pressure oil.

[0039] The high-pressure oil enters the lower chamber 92 of the working cylinder through the damping module, the single pipe oil port 15 and the oil channel in the cylinder base 14. Since the electromagnetic regulating valve is controlled to be in a high resistance state, and the compression valve system itself has a high opening pressure, the leakage path to the external low-pressure circuit is effectively blocked.

[0040] At the same time, on the piston 12, due to the design characteristics of the recovery valve (which allows oil to flow from the upper chamber to the lower chamber, but the reverse flow is greatly inhibited or completely prevented), the high-pressure oil also cannot leak in large quantities to the upper chamber 91 through the piston.

[0041] Therefore, the lower chamber 92 quickly establishes a high pressure, which acts on the bottom surface of the piston 12 to push the piston rod 1 to extend upward as a whole, thereby achieving the lifting of the vehicle body.

[0042] Vehicle body lowering working condition:

[0043] When the vehicle body needs to be lowered, the hydraulic pump stops supplying pressure, and the control system switches the electromagnetic regulating valve in the damping module to a larger opening.

[0044] The weight of the vehicle body causes the suspension to compress, and the piston rod 1 is forced to retract, squeezing the oil in the lower chamber 92.

[0045] The oil flows back into the oil pot through the now unblocked oil path (through the single pipe oil port 15, the electromagnetic valve in the damping module and the compression valve system), achieving a smooth descent of the vehicle body.

[0046] Therefore, by the single oil path interface 15 and the integrated external damping module, the semi-active damping adjustment (CDC) and the active body lifting are combined in a simple system. The piston 12 of the shock absorber body is responsible for restoring damping and acts as a lifting piston; the external module is responsible for compression damping adjustment, lifting locking and flow control. They share the same oil path and the same working cylinder lower cavity as the pressure acting cavity, realizing high reuse of hardware and deep integration of functions.

[0047] When the vehicle is normally running, the piston 12 and the damping module connected with the oil pipe form a normal damping function, and the size of the damping can be adjusted in real time by controlling the electromagnetic valve through the current.

[0048] The piston 12 can make the oil in the lower cavity 92 slowly enter the oil in the upper cavity 91. If the upper cavity oil is full at this time, the high oil pressure of the lower cavity 92 cannot make the oil continue to enter the upper cavity 91, so it will push the piston 12 up. The piston rod 1 is limited by the guide sleeve 6 and the spacer sleeve 7 on it to avoid pulling off. When the shock absorber is connected with the entire hydraulic suspension system, software can be used to calibrate the lifting height of the shock absorber, and the control system will not exceed the stroke during lifting, which can avoid damage to mechanical limiting.

[0049] Further, the top of the working cylinder 9 is also provided with a guide sleeve 6 for guiding the axial movement of the piston rod 1, and a stator seal is arranged in the guide sleeve 6. The stator seal and the extending end of the piston rod 1 are used in a slidable manner. In order to guide the stable axial movement of the piston rod 1 in the working cylinder 9 and prevent radial movement, the guide sleeve 6 is arranged at the top of the working cylinder 9, and a stator seal is arranged in the guide sleeve 6. The stator seal cooperates with the piston rod 1, and the guide sleeve 6 can guide the axial movement of the piston rod 1. The stator seal can effectively block the high-pressure oil in the shock absorber from flowing out and prevent leakage.

[0050] Further, the top of the working cylinder 9 is also provided with an oil seal seat 5 and a screw cap 2; the oil seal 4 is arranged in the oil seal seat 5, the screw cap 2 is connected with the oil storage cylinder 10 through a threaded cylinder 17, and the guide sleeve 6 and the oil seal seat 5 are pressed and fixed, a sealing ring is arranged between the oil seal seat 5 and the oil storage cylinder 10, and an oil seal washer is arranged between the screw cap 2 and the oil seal seat 5. The oil seal seat 5 provides a positioning and mounting base for the oil seal 4 and is adjacent to the guide sleeve 6. The oil seal 4 is a dynamic sealing element and is arranged in the oil seal seat 5, used for preventing the shock-absorbing oil 13 in the working cylinder 9 from leaking along the piston rod 1 and blocking external contaminants. An oil seal pressing washer 3 is arranged on the axial side of the oil seal 4, used for ensuring that the oil seal 4 is uniformly pressed during assembly and maintains stable sealing contact. The threaded cylinder 17 is welded on the upper end of the oil storage cylinder 10, the screw cap 2 is connected with the threaded cylinder 17 through threads, and finally the guide sleeve 6, the oil seal seat 5, the oil seal 4 and the oil seal pressing washer 3 and other parts inside are pressed and fixed to form a reliable sealing assembly. In assembly, the spacer sleeve 7 can be used to adjust the axial clearance of each part according to the needs.

[0051] To further improve the transportability, sealing and safety of the shock absorber as an independent component, a switch valve interface 16 is arranged on the cylinder base 14 adjacent to the single-pipe oil way interface 15, and one installation mode of the switch valve interface 16 is shown in FIG. 6. Figure 4 The switch valve interface 16 is not directly connected with the external oil pipe, but is used for installing a switch valve (such as a ball valve, a needle valve, etc.). The switch valve is configured to control the opening and closing of the internal oil passage connected with the single-pipe oil way interface 15. When the shock absorber is not installed on the vehicle or is not connected with the external hydraulic pipe, a switch valve in a closed state can be installed on the switch valve interface 16, so as to completely close the lower cavity 92 of the working cylinder 9 and prevent the shock-absorbing oil 13 in the shock absorber from leaking. When the shock absorber needs to be installed on the vehicle system, the switch valve can be opened, or in another embodiment, a special joint for communication can be directly installed instead of the switch valve, so as to restore the smoothness of the oil passage. This design ensures the sealing integrity of the shock absorber during storage and transportation, and is convenient for production line assembly and after-sales maintenance.

[0052] The cylinder base 14 and the bottom of the oil storage cylinder 10 are preferably fixedly connected through welding to ensure that the connection part will not loosen or leak under the long-term working condition of bearing oil pressure and vibration. The welding method can be laser welding, electric arc welding, etc., which can form a firm metallurgical bond.

[0053] As a preferred mode, the single-pipe oil way interface 15 is a quick connector or a threaded interface. The specific type of the single-pipe oil way interface 15 can be selected according to actual needs, for example, in the scene of frequent disassembly and assembly or rapid assembly on the production line, a quick connector with self-locking and sealing functions can be selected. In the case of pursuing high connection strength and high pressure resistance, a threaded interface can be selected and combined with a sealing washer or an O-ring for sealing.

[0054] Further, the outer part of the oil reservoir 10 is provided with a spring plate 11 as a mounting support and force transmission interface of the coil spring. In order to integrate the shock absorber of the present application into the vehicle suspension system, a general connecting and bearing part is added to the outer part. The spring plate 11 can be welded to the outer wall of the oil reservoir 10 as a mounting support of the coil spring to transmit the spring force; or a bracket mounting point for connecting the knuckle or control arm can be provided on the oil reservoir 10. The external mounting part is a conventional design to realize the vehicle assembly function of the shock absorber, and the specific form and position can be adjusted according to the vehicle suspension architecture.

[0055] Working principle

[0056] In the passive damping working condition of vehicle driving, the shock absorber of the present application has the same working principle as the ordinary hydraulic shock absorber: the road impact is transmitted through the wheel, causing the piston rod 1 to move relative to the working cylinder 9, the damping valve system on the piston 12 generates damping force to consume vibration energy, and the oil flows between the upper chamber 91, the lower chamber 92 and the oil reservoir chamber to compensate.

[0057] When semi-active damping adjustment is needed, the external control system adjusts the electro-hydraulic valve connected to the single-pipe oil port 15 to change the oil flow or pressure into or out of the lower chamber 92 of the working cylinder, thereby adjusting the size of the damping force in real time.

[0058] When the vehicle body height needs to be adjusted, the injection and discharge of oil are controlled by the external hydraulic pump, so that lifting and lowering can be realized.

[0059] The present application integrates the multiple external oil ports or complex integrated blocks that may exist in the prior art into only one single-pipe oil port interface 15 provided on the cylinder base 14, so that the connection structure of the bottom of the shock absorber is greatly simplified, and the space interference problem caused by the multi-oil pipe layout is fundamentally avoided. Through the same single-pipe oil port interface 15, cooperating with the external control system, the present application can respectively realize the semi-active damping adjustment mode based on real-time oil path control and the vehicle body height adjustment mode based on oil injection / discharge, both of which share most of the hardware, realizing high integration.

[0060] In summary, the core control logic of the present application is that through the single physical oil port interface 15 integrated in the cylinder base 14, under the instruction of the vehicle control system, the external hydraulic module dynamically configures the on-off state, flow and pressure of the oil path. In the damping mode, the external module mainly adjusts the damping valve characteristics; in the lifting mode, the external module is converted to pump or release pressure oil to the lower chamber 92 of the working cylinder. Both modes share the same set of hydraulic circuit and actuator (working cylinder, piston), realizing high reuse of hardware and intelligent integration of functions.

[0061] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A shock absorber for a semi-active hydraulic suspension, characterized in that, include: An oil reservoir (10) and a working cylinder (9) coaxially nested therein; the bottom of the oil reservoir (10) is sealed to a cylinder base (14), and the bottom of the working cylinder (9) is also sealed on the cylinder base (14); A piston (12) and a piston rod (1) fixedly connected to the piston (12) are slidably arranged inside the working cylinder (9). An oil seal (4) is provided on the top of the working cylinder (9). The extended end of the piston rod (1) is slidably engaged with the oil seal (4). The piston (12) divides the working cylinder (9) into an upper chamber (91) and a lower chamber (92). An oil hole (93) communicating with the inner cavity of the oil reservoir (10) is opened on the side wall of the upper chamber (91). A damping valve system for generating damping during the recovery stroke is provided on the piston (12). A single-pipe oil circuit interface (15) is provided on the cylindrical base (14); the single-pipe oil circuit interface (15) is directly fluidly connected to the lower cavity (92) through an oil passage formed in the cylindrical base (14), forming a single external oil circuit connection point integrated in the cylindrical base (14); the single-pipe oil circuit interface (15) is used to connect an external hydraulic module, and the lower cavity (92) and the external hydraulic module form a hydraulic circuit for adjusting damping and realizing lifting.

2. The shock absorber for a semi-active hydraulic suspension according to claim 1, characterized in that, The top of the working cylinder (9) is also provided with a guide sleeve (6) for guiding the axial movement of the piston rod (1). The guide sleeve (6) is provided with a step seal, which slides in cooperation with the extended end of the piston rod (1).

3. The shock absorber for a semi-active hydraulic suspension according to claim 2, characterized in that, The top of the working cylinder (9) is also provided with an oil seal seat (5) and a screw cap (2); the oil seal (4) is located inside the oil seal seat (5), the screw cap (2) is connected to the oil storage cylinder (10), the guide sleeve (6) abuts against the oil seal seat (5), a sealing ring is provided between the oil seal seat (5) and the oil storage cylinder (10), and an oil seal gasket is provided between the screw cap (2) and the oil seal seat (5).

4. The shock absorber for a semi-active hydraulic suspension according to claim 1, characterized in that, The cylinder base (14) is also provided with a switch valve interface (16).

5. The shock absorber for a semi-active hydraulic suspension according to claim 1, characterized in that, The cylinder base (14) is fixedly connected to the bottom of the oil storage cylinder (10) by welding.

6. The shock absorber for a semi-active hydraulic suspension according to claim 1, characterized in that, The single-pipe oil circuit interface (15) is a quick connector or a threaded interface.

7. The shock absorber for a semi-active hydraulic suspension according to claim 1, characterized in that, A spring disc (11) is provided on the outside of the oil storage tank (10).

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