Multi-stage electric control seat shock absorber and seat suspension system

Abstract

The multistage electric control seat shock absorber comprises a valve seat, a working cylinder, an outer barrel and a lower end cover, the outer barrel forms a cylindrical integral shell structure of the shock absorber, and the valve seat and the lower end cover receive the working cylinder and the outer barrel in a sleeved mode and are arranged at the upper end and the lower end of the working cylinder and the upper end and the lower end of the outer barrel respectively. An oil storage chamber used for adjusting hydraulic oil can be formed between the outer barrel and the working cylinder in a mutual sleeving mode. A first electromagnetic valve and a second electromagnetic valve which are used for opening and closing a hydraulic oil passage between the working cylinder and the oil storage chamber are arranged on two opposite side surfaces of the valve seat, and are detachably arranged in a first mounting chamber and a second mounting chamber reserved in the valve seat respectively; and the first electromagnetic valve and the second electromagnetic valve can select different models, so that the sizes of through holes between the first electromagnetic valve and the second electromagnetic valve are different.

Description

Technical Field

[0001] The present invention relates to the technical field of shock absorbers, and particularly to a multi-stage electronically controlled seat shock absorber and a seat suspension system. Background Art

[0002] Traditional automotive suspension systems are mainly responsible for absorbing and isolating impacts and vibrations from the road surface to ensure the driving stability and comfort of the vehicle. However, these systems often focus on the dynamic response of the entire vehicle and may not fully meet the personalized needs of passengers for seat comfort. In addition, there are limitations in the suspension system's ability to filter high-frequency vibrations, and these vibrations will ultimately be transmitted to the seat, affecting the passenger's riding experience.

[0003] To address the above problems, seat shock absorbers have been introduced as a supplementary technology. The seat is a basic device in various means of transportation and an important safety component. It connects the human body and the vehicle body and is directly related to the driving and riding comfort and safety of the passengers. The seat shock absorber acts directly on the part where the passenger contacts the seat and can more precisely control the vibration transmission from the seat to the passenger. Long hours of driving or riding may cause physical fatigue or even health problems for passengers. By reducing the impact of vibrations on the passenger's spine, the seat shock absorber helps to relieve physical fatigue, improve riding comfort, and also conforms to the design principles of ergonomics. This way of shock absorption acting directly on the passenger contact point can effectively reduce the vibrations felt by the passenger and enhance riding comfort.

[0004] Currently, the vast majority of seat shock absorbers have non-adjustable hardness, or can only be adjusted manually. Non-adjustable passive shock absorbers cannot take into account different vibration conditions and affect seat comfort. Although manually adjustable shock absorbers can adjust the hardness according to the driver's personal preference and improve a part of the riding comfort, frequent manual adjustment is extremely likely to cause driver fatigue and pose a safety hazard. In addition, in the case of random vibrations, it is very difficult for the driver to make timely adjustments.

[0005] CN107989950A provides a shock absorber for a seat with adjustable damping, which includes an oil storage cylinder assembly, a working cylinder, a piston rod guide seat, an oil seal, an auxiliary return valve assembly, a piston rod, a piston, a piston nut, a compression valve system, a return valve system, and a regulating valve system. The lower section of the piston rod is of a hollow structure and is symmetrically provided with lateral oil holes. A sleeve is sleeved on the piston rod. The regulating valve system consists of a regulator, a valve plate, and a limiting plate. The regulator is provided with an annular groove for accommodating the valve plate. The valve plate can linearly move within the annular groove. A limiting plate for restricting the valve plate within the annular groove is arranged at the opening of the annular groove. First and second oil guiding grooves corresponding to and having the same height as the lateral oil holes are arranged at the bottom of the groove. The sleeve can drive the regulator, the valve plate, and the limiting plate to rotate synchronously, so as to conduct or close the first and second oil guiding grooves with the lateral oil holes, and it can achieve adjustable damping.

[0006] The shock absorber design in this patent adopts a mechanical adjustment mechanism to adjust the damping force by conducting or closing the first and second oil guiding grooves with the lateral oil holes. This design allows the driver to manually adjust the damping characteristics of the shock absorber according to the current road conditions to obtain better ride comfort and vehicle controllability. However, since its adjustment mechanism is based on the connection state between the oil guiding grooves and the oil holes, it actually provides two extreme damping states: when conducting, the shock absorber shows lower damping, and when closed, it provides higher damping. Although this binary adjustment method simplifies the operation, it also has some limitations. First, it may not be able to meet the fine adjustment requirements of damping characteristics under all driving conditions. Under variable road conditions, only two damping states may not be sufficient to provide the best ride experience and handling performance. Second, due to limited adjustment options, the driver may need to frequently manually adjust the shock absorber, which increases the complexity of the operation to a certain extent and may distract the driver's attention in some cases.

[0007] In addition, on the one hand, there are differences in the understanding of those skilled in the art; on the other hand, although the applicant studied a large number of documents and patents when making this invention, due to space limitations, all details and contents are not listed in detail. However, this does not mean that this invention does not possess the features of these prior arts. On the contrary, this invention already possesses all the features of the prior arts, and the applicant reserves the right to add relevant prior arts in the background art. Summary of the Invention

[0008] The firmness of existing seat shock absorbers can only be adjusted manually, and the adjustment range is limited. Non-adjustable passive shock absorbers cannot take into account different vibration conditions, affecting seat comfort. Although manually adjusting the shock absorber can adjust the firmness according to the driver's personal preference and improve a part of the riding real-time performance, frequent manual adjustment is extremely likely to cause driver fatigue and pose a safety hazard. In addition, in the case of random vibration, it is very difficult for the driver to make timely adjustments.

[0009] In view of the deficiencies of the prior art, the present invention provides a multi-stage electronically controlled seat shock absorber and a seat suspension system to solve at least part of the above technical problems.

[0010] The present invention relates to a multi-stage electronically controlled seat shock absorber, including a valve seat, a working cylinder, an outer cylinder and a lower end cover. The valve seat and the lower end cover accommodate the working cylinder and the outer cylinder in a sleeved form, and are respectively arranged at the upper and lower ends of the working cylinder and the outer cylinder. The outer cylinder and the working cylinder can form an oil storage chamber for adjusting hydraulic oil in a mutually sleeved manner. Two opposite side surfaces of the valve seat are provided with a first solenoid valve and a second solenoid valve for opening and closing the hydraulic oil passage between the working cylinder and the oil storage chamber. The two are respectively detachably installed in a first installation chamber and a second installation chamber reserved on the valve seat. Among them, the two solenoid valves can achieve multi-stage adjustment of the damping force by controlling the oil flow rate and flow direction according to different opening and closing times and different design characteristics.

[0011] By providing two independently controllable first solenoid valve and second solenoid valve, the shock absorber of the present invention can achieve multi-stage control of the oil flow rate. These two solenoid valves, based on the differences in their respective design characteristics, flexibly adjust the flow rate of the oil between the working cylinder and the oil storage chamber under the precise control of the opening and closing time, so as to achieve multi-stage adjustment of the damping force. Thanks to the precise control and detachable design of the solenoid valve, the seat shock absorber of the present invention can provide continuously adjustable multi-stage damping force from low to high. This multi-stage adjustment ability enables the seat to automatically or manually adjust to the most suitable damping state according to the vehicle driving state, road conditions and passenger needs, ensuring riding comfort and stability. Considering the possible future maintenance and upgrade requirements, the shock absorber of the present invention adopts a detachable design of the solenoid valve. This design allows users to easily perform multi-stage maintenance and upgrade operations when it is necessary to adjust the damping characteristics or replace the solenoid valve, without replacing the entire shock absorber, reducing the maintenance cost and difficulty.

[0012] According to a preferred embodiment, the valve seat can be buckled on the top of the working cylinder and the outer cylinder to form a housing structure at the top of the shock absorber. The valve seat is connected to the outer cylinder through a cylinder structure extending along the outer wall of the outer cylinder towards the bottom of the shock absorber. The valve seat seals the top opening of the working cylinder through a frustum structure that extends into the working cylinder along the inner wall of the working cylinder towards the bottom of the working cylinder. The buckling design of the valve seat forms a solid housing structure at the top of the shock absorber, enhancing the overall sealing performance and durability. Through the extending structures along the outer wall of the outer cylinder and the inner wall of the working cylinder, the valve seat is firmly connected to the outer cylinder and the working cylinder, forming a stable support structure. This design not only simplifies the assembly process but also improves the overall structural strength and sealing performance of the shock absorber.

[0013] According to a preferred embodiment, a lower end cap is connected to the bottom of the outer cylinder. The lower end cap is connected to the outer cylinder through a cylinder structure that extends along the inner wall of the outer cylinder towards the top of the shock absorber. A bushing is provided at the bottom of the lower end cap as a connection node between the shock absorber and the seat support frame. The connection design between the bottom of the outer cylinder and the lower end cap realizes the sealing and fixation of the bottom of the shock absorber through the close fit of the cylinder structure of the lower end cap and the outer cylinder. The setting of the bushing as a connection node between the shock absorber and the seat support frame can not only effectively transmit and absorb vibrations but also improve the load-bearing capacity of the shock absorber for forces in different directions, enhancing the stability and durability of the entire seat suspension system.

[0014] According to a preferred embodiment, the shock absorber includes a piston rod and a piston valve assembly. The piston rod passes through the valve seat and partially extends into the working cylinder. The piston valve assembly is located at the end of the piston rod inside the working cylinder and divides the working cylinder into a compression chamber and a rebound chamber. Among them, the compression chamber is located on the side where the piston rod is connected to the piston valve assembly, and the rebound chamber is located on the other side of the piston valve assembly. The design of the piston rod and the piston valve assembly divides the working cylinder into a compression chamber and a rebound chamber. Such a space division provides a clear flow path for the hydraulic oil, optimizing the working cycle of the shock absorber. The piston rod partially extends into the working cylinder, and its connection with the piston valve assembly effectively controls the volume change of the compression chamber and the rebound chamber, thereby precisely adjusting the damping force and improving the riding comfort and shock absorption efficiency.

[0015] According to a preferred embodiment, the top of the oil storage chamber is closed by a valve seat, and the bottom is closed by a lower end cap to isolate the oil exchange between the working cylinder and the oil storage chamber when the shock absorber is not working. The valve seat and the upper end cap are configured with two corresponding through channels formed by removing materials at their coaxial positions to allow the piston rod to move upward and downward under the restriction of the through channels. When the piston rod moves upward or downward, the oil flow path between the valve seat and / or the lower end cap and the working cylinder is selectively opened to achieve the oil exchange between the working cylinder and the oil storage chamber. The design that the top and bottom of the oil storage chamber are respectively closed by the valve seat and the lower end cap isolates the oil exchange between the working cylinder and the oil storage chamber when the shock absorber is not working, preventing the reactive loss of hydraulic oil. When the piston rod moves, the selective opening of the oil flow path between the valve seat and the lower end cap and the working cylinder realizes the effective oil exchange between the working cylinder and the oil storage chamber, ensuring the oil supply and circulation of the shock absorber under different working conditions.

[0016] According to a preferred embodiment, an oil seal installation chamber for installing an oil seal is formed between the upper end cap and the valve seat. The oil seal installation chamber contains an oil seal member and an oil seal spring coaxially placed with the piston rod. The oil seal spring surrounds the outside of the piston rod, and one end of the oil seal spring is near the entrance of the through channel of the valve seat, and the other end is connected to the oil seal member. When the valve seat and the upper end cap are combined, the oil seal spring applies elastic force to the oil seal member through its compressed state, so that the oil seal member keeps in contact with the upper end cap and is fixed in the oil seal installation chamber. The oil seal installation chamber formed between the upper end cap and the valve seat provides a stable installation space for the oil seal member and the oil seal spring. The design of the oil seal spring ensures good contact between the oil seal member and the upper end cap, effectively prevents the leakage of hydraulic oil, maintains the pressure stability of the internal oil of the shock absorber, and thus improves the sealing performance and working reliability of the shock absorber.

[0017] According to a preferred embodiment, a fifth oil passage and a sixth oil passage for connecting the oil seal installation chamber and the oil storage chamber are provided in the valve seat. The fifth oil passage and the sixth oil passage can be arranged on both sides of the piston rod in a way that avoids the first oil passage and the third oil passage to recover the hydraulic oil brought out by the piston rod in the oil seal installation chamber back into the oil storage chamber. The fifth oil passage and the sixth oil passage provided in the valve seat, through a reasonable layout on both sides of the piston rod, avoid the main oil passages and realize the effective recovery of the hydraulic oil in the oil seal installation chamber. This design not only improves the utilization rate of hydraulic oil, but also helps to maintain the cleanliness of the internal oil of the shock absorber, extending the maintenance period and service life of the shock absorber.

[0018] According to a preferred embodiment, a first oil passage and a second oil passage are provided in the valve seat to be connected to the first installation chamber, and a third oil passage and a fourth oil passage are provided to be connected to the second installation chamber; the hydraulic oil in the restoration chamber flows to the first installation chamber via the first oil passage and flows to the oil storage chamber via the second oil passage; the hydraulic oil in the restoration chamber flows to the second installation chamber via the third oil passage and flows to the oil storage chamber via the fourth oil passage. Through the reasonable layout of the first oil passage to the fourth oil passage, the orderly flow of the hydraulic oil in the restoration chamber to the installation chamber and the oil storage chamber is realized. This design optimizes the distribution of the hydraulic oil, enabling the shock absorber to respond quickly as needed during operation, achieving precise adjustment of the damping force, and enhancing the performance and riding experience of the shock absorber.

[0019] The present invention also relates to a seat suspension system, including the aforementioned multi-stage electronically controlled seat shock absorber and a seat part. The seat part includes a seat support frame, a seat body, an elastic element, a first sensor, a second sensor, and a controller; the seat support frame is located below the seat body and is connected to the vehicle body ground, and the elastic element and the shock absorber are arranged on the seat support frame; the first sensor, the second sensor, and the first solenoid valve and the second solenoid valve in the shock absorption part are all connected to the controller for data. The controller can receive the displacement data collected from the first sensor and the second sensor and set the damping force for the shock absorber based on these data. The integrated design of the seat suspension system realizes the effective control of the seat vibration through the coordinated work of the multi-stage electronically controlled seat shock absorber with the seat support frame, the elastic element, the sensors, and the controller. The intelligent cooperation of the sensors and the controller can monitor and respond to the displacement changes of the seat in real time, automatically adjusting the damping force of the shock absorber, enabling the seat suspension system to adapt to different driving conditions and passenger needs, and providing a high degree of comfort and safety.

[0020] According to a preferred embodiment, the controller can be integrally arranged in the vehicle-mounted center console. The controller can realize the switching between the semi-active control mode and the manual control mode of the seat suspension system. In the case of switching from the semi-active control mode to the manual control mode, the controller is manually controlled by the passenger to selectively open and close the solenoid valves to adjust the damping magnitude of the seat suspension system. The integrated design of the controller enables the passenger to intuitively operate the seat suspension system through the vehicle-mounted center console, realizing the flexible switching from semi-active control to manual control. This design not only improves the user experience but also enables the passenger to make personalized settings according to personal preferences. Whether pursuing comfort or sportiness, the passenger can find a seat suspension mode suitable for themselves. Brief Description of the Drawings

[0021] Figure 1 is a cross-sectional view of the overall structure of a preferred shock absorber of the present invention;

[0022] Figure 2It is a preferred overall appearance diagram of the shock absorber of the present invention;

[0023] Figure 3 It is a preferred cross-sectional view of the valve seat of the present invention;

[0024] Figure 4 It is another preferred cross-sectional view of the valve seat of the present invention;

[0025] Figure 5 It is a preferred schematic diagram of the solenoid valve of the present invention;

[0026] Figure 6 It is a preferred schematic diagram of the seat suspension system of the present invention;

[0027] Figure 7 It is a Simulink modeling diagram of a preferred frequency identification controller for the seat suspension of the present invention;

[0028] Figure 8 It is a schematic diagram of the zero-crossing method frequency estimation for the seat suspension of the present invention;

[0029] Figure 9 It is a schematic diagram of the frequency identification result of the swept-frequency signal for the seat suspension of the present invention;

[0030] Figure 10 It is a schematic diagram of the design process of the frequency identification controller for the seat suspension of the present invention;

[0031] Figure 11 (a) It is a schematic diagram of the shock absorber gear shifting result under the high-frequency and small-amplitude working condition of the seat suspension of the present invention;

[0032] Figure 11 (b) It is a schematic diagram of the vibration frequency under the high-frequency and small-amplitude working condition of the seat suspension of the present invention;

[0033] Figure 12 (a) It is a comparison schematic diagram of the seat acceleration response (in the interval of 0 - 39 s) of the seat suspension of the present invention;

[0034] Figure 12 (b) It is a comparison schematic diagram of the seat acceleration response (in the interval of 36.5 - 39 s) of the seat suspension of the present invention;

[0035] Figure 12 (c) It is a schematic diagram of the seat acceleration RMS (in the interval of 0 - 39 s) of the seat suspension of the present invention;

[0036] Figure 13 (a) It is a schematic diagram of the shock absorber gear shifting result under the low-frequency and large-amplitude working condition of the seat suspension of the present invention;

[0037] Figure 13(b) is a schematic diagram of the vibration frequency of the seat suspension of the present invention under the condition of low frequency and large amplitude;

[0038] Figure 14 (a) is a comparative schematic diagram of the seat acceleration response (in the interval of 173 - 188 s) of the seat suspension of the present invention;

[0039] Figure 14 (b) is a comparative schematic diagram of the seat acceleration response (in the interval of 182.6 - 184.6 s) of the seat suspension of the present invention;

[0040] Figure 14 (c) is a schematic diagram of the seat acceleration RMS (in the interval of 173 - 188 s) of the seat suspension of the present invention;

[0041] Figure 15 is a curve graph of the change of the seat acceleration power spectral density (PSD) of the seat suspension of the present invention in the range of 0 - 20 Hz;

[0042] Figure 16 is a statistical schematic diagram of the PSD weighted root mean square acceleration (WRMSA) and the corresponding SEAT value of the seat suspension of the present invention in three modes.

[0043] List of reference numerals

[0044] 100: damping part; 101: piston rod; 102: upper end cover; 103: oil seal part; 104: oil seal spring; 105: valve seat; 106: piston valve assembly; 107: bottom valve assembly; 108: working cylinder; 109: outer cylinder; 110: lower end cover; 111: bushing; 112: first solenoid valve; 113: second solenoid valve; 114: first electromagnetic coil; 115: second electromagnetic coil; 116: recovery chamber; 117: compression chamber; 118: oil storage chamber; 119: limiting part; 120: oil seal installation chamber; 121: first installation chamber; 122: first oil passage; 123: second oil passage; 124: second installation chamber; 125: third oil passage; 126: fourth oil passage; 127: fifth oil passage; 128: sixth oil passage; 129: first boss; 130: second boss; 131: oil inlet; 132: oil outlet; 200: seat part; 210: seat support frame; 220: seat body; 230: elastic element; 240: first sensor; 250: second sensor; 260: controller; 261: frequency identification module; 262: frequency division control module. Detailed implementation manners

[0045] The following is a detailed description with reference to the drawings.

[0046] Example 1

[0047] The present invention relates to a multi - stage electronically controlled seat shock absorber.Figure 1 A longitudinal sectional view of a shock absorber (i.e., the shock absorption part 100) according to an embodiment of the present invention is shown, and the cutting plane is parallel to the axis of the shock absorption part 100. The shock absorption part 100 includes an outer cylinder 109 that forms its cylindrical integral housing structure, and a valve seat 105 received at the top of the outer cylinder 109 in a sleeved form. A working cylinder 108 with an outer diameter smaller than its inner diameter is coaxially installed inside the outer cylinder 109, and the two are sleeved with each other to form a stable hollow sandwich structure of the shock absorption part 100 between their circumferential side walls, that is, an oil storage chamber 118. The valve seat 105 located at the top of the two has a cylindrical structure extending along their circumferential side walls and towards the bottom direction, and it can be stably connected to the top of the two by clamping or welding. A plurality of oil passages communicating the working cylinder 108 and the oil storage chamber 118 are formed inside the valve seat 109, so that the hydraulic oil contained inside the working cylinder 108 can flow through the oil passages of the valve seat 109 and enter the oil storage chamber 118. The bottoms of the outer cylinder 109 and the working cylinder 108 are configured with a lower end cover 110 with an upward-opening concave surface in a sleeved form, which can be fixedly connected to the outer cylinder 109 by clamping or welding, and an installation space for a bottom valve assembly 107 with two check valves with opposite opening directions is reserved at the bottom of the working cylinder 108 by using its concave surface. The bottom valve assembly 107 provides a two-way flow channel for the hydraulic oil in the working cylinder 108 and the oil storage chamber 118 at the bottom position, that is, provides a second path for the hydraulic oil exchange between the two in addition to the oil passages built in the valve seat 105.

[0048] Preferably, as Figure 1 shown, the shock absorption part 100 includes a piston rod 101 passing through the valve seat 105 and partially extending into the working cylinder 108, and a piston valve assembly 106 located at the end of the piston rod 101. The size of the piston valve assembly 106 fits the inner diameter of the working cylinder 108, thereby dividing the working cylinder 108 into two independent chambers. Among them, the one on the side of the piston rod 101 is the recovery chamber 116; the one on the other side is the compression chamber 117. Driven by the piston rod 101, the piston valve assembly 106 can reciprocate on the inner wall of the working cylinder 108, and thus adjust the volumes of the compression chamber 117 and the recovery chamber 116 in a way that one increases while the other decreases. The piston valve assembly 106 is equipped with two check valves with different flow directions, and these check valves can be selectively opened when the piston rod 101 moves downward (compression stroke) or upward (recovery stroke) to form a hydraulic oil flow channel between the compression chamber 117 and the recovery chamber 116 inside the working cylinder 108.

[0049] Preferably, in combination with Figure 1 and Figure 2, the annular interlayer space between the outer cylinder 109 and the working cylinder 108 is called the oil storage chamber 118. The oil storage chamber 118 realizes the hydraulic oil regulation function of the shock absorber by temporarily storing the hydraulic oil flowing out of the working cylinder 108 or replenishing the hydraulic oil to the working cylinder 108. The top of the oil storage chamber 118 is closed by the valve seat 105, and the bottom is closed by the lower end cover 110. Such a setting can isolate the oil fluid communication between the working cylinder 108 and the oil storage chamber 118 when the shock absorber is not working. When the shock absorber is working (the piston rod 101 is compressed or the piston rod 101 is restored), the oil fluid flow path between the valve seat 105 and / or the lower end cover 110 and the working cylinder 108 is selectively opened, and the oil fluid communication between the working cylinder 108 and the oil storage chamber 118 is realized.

[0050] As Figure 1 shown, a bushing 111 is provided at the bottom of the lower end cover 110. The bushing 111 serves as a connection node between the shock absorber and the seat support frame 210 to transmit and absorb various forces and vibrations borne by the shock absorber. The bushing 111 is usually made of high-strength metal material and is designed as a solid circular ring structure to ensure that it has sufficient load-bearing capacity and durability to cope with various dynamic stresses and loads. Inside the circular ring structure, a rubber bushing can be embedded to improve its shock absorption performance. Since the lower end cover 110 is only connected to the outer cylinder 109, the external force applied to the shock absorption part 100 by the bushing 111 at the bottom of the lower end cover 110 will only be applied to the outer cylinder 109, reducing the degree of influence of this external force on the operation of the working cylinder 108 and extending the service life of the working cylinder 108.

[0051] Preferably, as Figure 1 shown, the annular interlayer space between the outer cylinder 109 and the working cylinder 108 is called the oil storage chamber 118. The oil storage chamber 118 realizes the hydraulic oil regulation function of the shock absorber by temporarily storing the hydraulic oil flowing out of the working cylinder 108 or replenishing the hydraulic oil to the working cylinder 108. The top of the oil storage chamber 118 is closed by the valve seat 105, and the bottom is closed by the lower end cover 110. Such a setting can isolate the oil fluid communication between the working cylinder 108 and the oil storage chamber 118 when the shock absorber is not working. When the shock absorber is working (the piston rod 101 is compressed or the piston rod 101 is restored), the oil fluid flow path between the valve seat 105 and / or the lower end cover 110 and the working cylinder 108 is selectively opened, and the oil fluid communication between the working cylinder 108 and the oil storage chamber 118 is realized.

[0052] Preferably, as Figure 1As shown, the valve seat 105 is in a closed state by fastening its top surface to the upper end cover 102. At the same time, two corresponding through channels formed by material removal are configured at the coaxial position between the two, allowing the piston rod 101 to move up and down under the restriction of these channels. A cavity for installing an oil seal, called the oil seal installation chamber 120, is formed between the upper end cover 102 and the valve seat 105, which contains an oil seal part 103 and an oil seal spring 104 placed coaxially with the piston rod 101. The oil seal spring 104 surrounds the outside of the piston rod 101, with one end near the entrance of the through channel of the valve seat 105 and the other end connected to the oil seal part 103. When the valve seat 105 is combined with the upper end cover 102, the oil seal spring 104 is in a compressed state, so it can apply a certain elastic force to the oil seal part 103 to keep the oil seal part 103 in close contact with the upper end cover 102 and fixed in the oil seal installation chamber 120. The function of the oil seal part 103 is to seal the gap between the upper end cover 102 and the piston rod 101 to prevent the hydraulic oil in the shock absorber from being carried out when the piston rod 101 moves upward. The materials used for the oil seal part 103 include nitrile rubber (NBR), fluororubber (FKM), acrylate rubber (ACM), etc. These materials are suitable for shock absorber application scenarios due to their excellent wear resistance and oil resistance properties.

[0053] Preferably, as Figures 1 to 3 shown, special installation grooves are provided on both sides of the valve seat 105 by machining technology to accommodate the first solenoid valve 112 and the second solenoid valve 113. These solenoid valves are designed to be detachable for easy maintenance or replacement, and are partially embedded in a special-shaped installation cavity reserved in the valve seat 105 to achieve a stable assembly. Among them, the first solenoid valve 112 is placed in the first installation chamber ±21 formed by machining inside the valve seat 105, and the second solenoid valve 113 is placed in the second installation chamber 124. These installation chambers can be made by high-precision stamping process to ensure the accuracy and repeatability of the dimensions. Each installation chamber is designed as a space where two parts are interconnected to meet the size requirements of the solenoid valve. The part close to the piston rod 101 is called the head space, which has a smaller volume to reduce the interference with the piston movement. The part far from the piston rod 101 is called the tail space, which has a larger volume to provide enough space to accommodate the main body part of the solenoid valve and related electrical connections.

[0054] Preferably, as Figure 1 、 Figure 3As shown, two pairs of oil passage systems are precisely designed and machined inside the valve seat 105, which are respectively used to control and regulate the flow direction of hydraulic oil. The first oil passage 122 and the second oil passage 123 communicate with the head space of the first installation chamber 121, providing a flow passage for hydraulic oil. Specifically, the first oil passage 122 constitutes a fluid passage, which guides hydraulic oil from the recovery chamber 116 to the head space of the first installation chamber 121 where the first solenoid valve 112 is located during the operation of the shock absorber. At the same time, the second oil passage 123 provides a fluid passage from the head space of the first installation chamber 121 to the oil storage chamber 118, allowing hydraulic oil to flow back to the oil storage chamber 118 when the first solenoid valve 112 is in the open state, ensuring the balance of the internal pressure of the shock absorber and the recycling of hydraulic oil. In the corresponding part of the second installation chamber 124, a third oil passage 125 and a fourth oil passage 126 are also provided. The third oil passage 125 allows hydraulic oil to flow from the recovery chamber 116 into the head space of the second installation chamber 124 where the second solenoid valve 113 is located during the operation of the shock absorber, while the fourth oil passage 126 realizes the function of returning hydraulic oil from the second installation chamber 124 to the oil storage chamber 118 when the shock absorber is working.

[0055] Preferably, as Figure 1 shown, the solenoid valves (including the first solenoid valve 112 and the second solenoid valve 113) are both designed to have annular flanges, namely the first boss 129 and the second boss 130, to ensure that the solenoid valves are firmly fixed in their corresponding installation chambers (the first installation chamber 121 and the second installation chamber 124). The outer diameter of the first boss 129 is precisely matched with the inner diameter of the head space of the installation chamber, and stable engagement is achieved through plug-in fit to ensure no loosening even in a high-vibration environment. At the same time, the second boss 130 is designed to have the same outer diameter as the first boss 129 and is located at the boundary line between the head space and the tail space of the installation chamber. Its function is to prevent the hydraulic oil in the head space from leaking to the tail space through contact sealing, maintaining the sealing performance of the shock absorber and the pressure stability of the hydraulic oil. To realize the switching of the hydraulic oil flow path, the first solenoid valve 112 and the second solenoid valve 113 are each equipped with an electromagnetic coil around their outer periphery, namely the first electromagnetic coil 114 and the second electromagnetic coil 115 respectively. When the electromagnetic coil is energized, the generated magnetic field acts on the magnetic components inside the valve body, thereby opening or closing the solenoid valve to control the flow of hydraulic oil and then precisely adjusting the magnitude of the damping force. To protect and stabilize the electromagnetic coil, a specially designed housing is provided around it, and the geometric shape and size of the housing are adapted to those of the tail space of the installation chamber to achieve firm positioning of the electromagnetic coil. Through this design, the solenoid valve can achieve stable three-point positioning and installation in the installation chamber by relying on the first boss 129, the second boss 130 and the outer housing, not only realizing detachable installation but also ensuring its reliability and durability under various working conditions.

[0056] Preferably, as Figure 1, Figure 5 As shown, on the end face of the first solenoid valve 112 located within the headspace of the first installation chamber 121, there is an oil inlet 131 configured, and this oil inlet 131 precisely corresponds to the first oil passage 122. Meanwhile, on the circumferential surface of the first solenoid valve 112, there is an oil outlet 132 opened, and this oil outlet 132 is connected to the second oil passage 123 to ensure the smooth flow of hydraulic oil. The spool of the first solenoid valve 112 is designed to be movable between two key positions: one is the open position, at this time the oil between the first oil passage 122 and the second oil passage 123 can be freely communicated; the other is the closed position, at this time the fluid communication between the first oil passage 122 and the second oil passage 123 is restricted, thereby controlling the flow path of the hydraulic oil. When the first solenoid valve 112 is in the open state, the hydraulic oil in the restoration chamber 116 flows into the oil inlet 131 through the first oil passage 122. Subsequently, the hydraulic oil flows out from the oil outlet 132 through the flow channel inside the first solenoid valve 112 and enters the headspace of the first installation chamber 121. Then, the hydraulic oil is guided to the oil storage chamber 118 through the second oil passage 123 to complete the circulating flow of the hydraulic oil.

[0057] Preferably, as Figure 1 , Figure 5 shown, the second solenoid valve 113 is installed on the end face of the headspace of the second installation chamber 124, and on this end face, there is a dedicated oil inlet 131 provided. This oil inlet 131 is aligned with the interface of the third oil passage 125. In addition, on the circumferential surface of the second solenoid valve 113, there is also an oil outlet 132, and this oil outlet 132 is directly connected to the fourth oil passage 126 to facilitate the discharge of the hydraulic oil. The spool of the second solenoid valve 113 has two main functional positions: one is the open position, at this time the free flow of oil between the third oil passage 125 and the fourth oil passage 126 is allowed; the other is the closed position, at this time the fluid passage between the third oil passage 125 and the fourth oil passage 126 is interrupted. By precisely controlling the movement of the solenoid valve, the flow state of the hydraulic oil can be adjusted. When the second solenoid valve 113 is in the open state, the hydraulic oil from the restoration chamber 116 can flow into the oil inlet 131 through the third oil passage 125. After that, the hydraulic oil passes through the flow channel in the valve body, is discharged from the oil outlet 132, enters the headspace of the second installation chamber 124, and finally flows to the oil storage chamber 118 through the fourth oil passage 126 to complete its circulation.

[0058] Preferably, in order to further finely control the pressure of the hydraulic oil in the shock absorber, an overflow valve may be arranged in front of the oil inlets 131 of the first solenoid valve 112 and the second solenoid valve 113. Such an arrangement makes the first solenoid valve 112 and the second solenoid valve 113 serve as pilot valves of the overflow valve, thereby playing a role in controlling the back pressure of the overflow valve. The addition of the overflow valve further enhances the pressure stability and adjustability of the shock absorber. By controlling the pilot valve, the opening pressure of the overflow valve can be adjusted to protect the shock absorber from overloading pressure and maintain the pressure balance for the normal operation of the shock absorber.

[0059] Preferably, as Figure 4 shown, inside the valve seat 105, in addition to the existing oil circuit configuration, a fifth oil circuit 127 and a sixth oil circuit 128 are additionally provided. These two oil circuits are designed to connect the oil seal installation chamber 120 and the oil storage chamber 118 to form an independent hydraulic oil circuit. To ensure the independence of the oil circuit and avoid cross-interference with other main oil circuits (such as the first oil circuit 122 and the third oil circuit 125), the fifth oil circuit 127 and the sixth oil circuit 128 are precisely arranged on both sides of the piston rod 101. By utilizing the spatial separation of the piston rod 101, a separated layout of the oil circuits is achieved. The main function of the fifth oil circuit 127 and the sixth oil circuit 128 is to recover the hydraulic oil carried out of the oil seal installation chamber 120 due to the movement of the piston rod 101. When the piston rod 101 squeezes out the hydraulic oil in the oil seal installation chamber 120 during movement, this hydraulic oil can be effectively guided back to the oil storage chamber 118 through the fifth oil circuit 127 and the sixth oil circuit 128, thereby maintaining the oil quantity balance and hydraulic stability of the shock absorber. This design reduces the waste of oil fluid and ensures the long-term stable operation of the shock absorber.

[0060] Preferably, as Figure 1 shown, at the bottom region of the working cylinder 108, a bottom valve assembly 107 is designed. The bottom valve assembly 107 is firmly fixed to the working cylinder 108 in a coaxial manner. The bottom valve assembly 107 forms a contact fit with the lower end cover 110 at its bottom end. The bottom valve assembly 107 is configured with two one-way valves, and these one-way valves allow the hydraulic oil to flow only in a specific direction, thereby establishing two hydraulic oil passages with different flow directions between the bottom of the working cylinder 108 and the bottom of the oil storage chamber 118. This configuration allows the hydraulic oil to flow efficiently and orderly between the working cylinder 108 and the oil storage chamber 118, realizing the one-way delivery of the oil fluid according to the working state of the shock absorber. Through the functions of these two one-way valves, on the one hand, when the working cylinder 108 needs oil fluid replenishment, the hydraulic oil can be delivered from the oil storage chamber 118 to the working cylinder 108, and the one-way valve ensures that the oil fluid can only flow from the oil storage chamber 118 to the working cylinder 108; on the other hand, when the pressure in the working cylinder 108 increases and part of the oil fluid needs to be released, the other one-way valve allows the oil fluid to flow back from the working cylinder 108 to the oil storage chamber 118 and does not allow reverse flow.

[0061] Preferably, if Figure 1 As shown, on the opposite end faces of the piston valve assembly 106 and the bottom valve assembly 107, there are limiters 119. These limiters 119 can play a key role in the structure when the piston rod 101 is pressed down (i.e., the shock absorber is in the compression stroke). As the piston rod 101 is pressed down, the limiters 119 on the piston valve assembly 106 will gradually approach the limiters 119 on the bottom valve assembly 107. When the limiters 119 of the two finally contact and abut, they will prevent the piston rod 101 from being further pressed down, thereby limiting the maximum movement distance of the piston rod 101. The design of this limiter 119 has multiple advantages: first, it clearly defines the volume ratio of the compression chamber 117 and the recovery chamber 116, which is crucial to maintaining the performance and response characteristics of the shock absorber. Second, by limiting the movement range of the piston rod 101, the limiter 119 effectively prevents direct collision between the piston valve assembly 106 and the bottom valve assembly 107, which may cause structural damage or performance degradation. Finally, the provision of the limiter 119 also helps to protect the entire shock absorber from potential failures caused by excessive compression, thereby ensuring safety and reliability.

[0062] The outer cylinder 109 constitutes the cylindrical overall shell structure of the vibration damping part 100, which is formed in the form of casting, for example. When the vibration damping part 100 is assembled, the valve seat 105 and the lower end cover 110 receive the working cylinder 108 and the outer cylinder 109 in a set form, and the vibration damping part 100 is formed into a sealed tank body that is hollow and cylindrical as a whole by being respectively arranged at the upper end and the lower end of the working cylinder 108 and the outer cylinder 109. The circumferential surface of the valve seat 105 is respectively equipped with a first solenoid valve 112 and a second solenoid valve 113. By controlling the opening and closing states of the two solenoid valves, the shock absorber can flexibly adjust the on-off conditions of multiple oil circuits, thereby realizing multi-level precise adjustment of the damping force.

[0063] Preferably, Figure 1 FIG1 shows a vertical cross-sectional view of the shock absorber of the embodiment of the present invention. In the compression stroke of the shock absorber, the piston rod 101 drives the piston valve assembly 106 at its end to move toward the bottom of the working cylinder 108, causing the volume of the compression chamber 117 to decrease, thereby causing the oil pressure to rise. At this time, the oil in the compression chamber 117 flows in two parts: one part flows into the oil storage chamber 118 through the one-way valve on the bottom valve assembly 107, and the other part flows into the recovery chamber 116 through the piston valve assembly 106. Referring to FIG1 showing a cross-sectional view of the interior of the valve seat of the embodiment of the present invention Figure 3 The oil in the recovery chamber 116 then enters the first oil passage 122 and the third oil passage 125 respectively. Figure 5The oil inlets 131 of the first solenoid valve 112 and the second solenoid valve 113 shown. The oil quantity ratio relationship between the two parts depends on the pre-tightening pressure of the bottom valve assembly 107 and the piston valve assembly 106. If the pre-tightening force of the bottom valve assembly 107 is too large, more oil will enter the solenoid valve through the piston valve assembly 106 and flow back to the oil storage chamber 118. Conversely, more oil will enter the oil storage chamber 118 through the bottom valve assembly 107. During this process, the first oil passage 122 and the third oil passage 125 can be regarded as part of the restoration chamber 116 and are always filled with oil.

[0064] According to the state of the solenoid valve, the oil flow path in the restoration chamber 116 and the damping state of the compression chamber 117 will be different:

[0065] 1. When both the first solenoid valve 112 and the second solenoid valve 113 are open, a part of the oil in the restoration chamber 116 can enter the oil inlets 131 of these two solenoid valves and flow into the oil storage chamber 118 through their respective oil outlets 132 via the second oil passage 123 and the fourth oil passage 126 respectively. In this case, the oil pressure in the compression chamber 117 is relatively low, resulting in the shock absorber being in a small compression damping state.

[0066] 2. If one of the first solenoid valve 112 and the second solenoid valve 113 is open and the other is closed, a part of the oil in the restoration chamber 116 will enter the oil inlet 131 of the open solenoid valve through the first oil passage 122 or the third oil passage 125 and flow into the oil storage chamber 118 through the oil outlet 132 and the second oil passage 123 or the fourth oil passage 126. At this time, the oil pressure in the compression chamber 117 is at a medium level, corresponding to the shock absorber being in a medium compression damping state.

[0067] 3. When both the first solenoid valve 112 and the second solenoid valve 113 are closed, the oil in the restoration chamber 116 cannot pass through these two solenoid valves, resulting in an increase in the oil pressure in the compression chamber 117, making the shock absorber in a large compression damping state.

[0068] By precisely controlling the opening and closing of the first solenoid valve 112 and the second solenoid valve 113, the throttling effect of the solenoid valve on the oil can be adjusted, thereby achieving fine multi-stage adjustment of the compression damping force of the shock absorber. This design allows the damping characteristics of the shock absorber to be adjusted according to different working conditions and requirements, improving its adaptability and performance.

[0069] During the rebound stroke of the shock absorber, that is, the piston rod 101 drives the piston valve assembly 106 to move towards the top of the working cylinder 108, resulting in the reduction of the volume of the rebound chamber 116 and the increase of the oil pressure, while the volume of the compression chamber 117 expands and the oil pressure decreases. Due to the pressure change, part of the oil in the oil storage chamber 118 flows back into the compression chamber 117 through the check valve on the bottom valve assembly 107. At the same time, part of the oil in the rebound chamber 116 flows into the compression chamber 117 through the check valve configured on the piston valve assembly 106, and the other part flows to the oil inlets 131 of the two solenoid valves through the first oil passage 122 and the third oil passage 125.

[0070] Specifically, regarding the working state of the solenoid valves:

[0071] 1. If both the first solenoid valve 112 and the second solenoid valve 113 are in the open state, part of the oil in the rebound chamber 116 will enter the oil inlets 131 of these two solenoid valves through the first oil passage 122 and the third oil passage 125, and flow to the oil storage chamber 118 along the second oil passage 123 and the fourth oil passage 126 through the oil outlets 132 of the solenoid valves. In this configuration, the oil pressure in the rebound chamber 116 is relatively low, making the shock absorber in a small rebound damping state.

[0072] 2. When only one of the first solenoid valve 112 and the second solenoid valve 113 is open and the other is closed, part of the oil in the rebound chamber 116 can enter the oil inlet 131 of the open solenoid valve through the first oil passage 122 or the third oil passage 125, and flow to the oil storage chamber 118 through its oil outlet 132 communicating with the second oil passage 123 or the fourth oil passage 126. In this case, the oil pressure in the rebound chamber 116 is at a medium level, corresponding to the shock absorber being in a medium rebound damping state.

[0073] 3. If both the first solenoid valve 112 and the second solenoid valve 113 are closed, the oil in the rebound chamber 116 will not be able to flow through these solenoid valves. At this time, the oil pressure in the rebound chamber 116 is relatively high, making the shock absorber enter a large rebound damping state.

[0074] By precisely controlling the opening and closing of the first solenoid valve 112 and the second solenoid valve 113, the throttling degree of the solenoid valves on the oil can be changed, realizing fine multi-level adjustment of the rebound damping force of the shock absorber.

[0075] Further, in order to expand the range of damping adjustment in the compression stroke and the extension stroke, the shock absorber can be selectively installed with a first solenoid valve 112 and a second solenoid valve 113 having different design characteristics. The design characteristics can include the through-hole size of the spool, the time required for opening and closing, the degree of opening and closing, etc. Taking the difference in through-hole size as one of the key design characteristics, this differential design endows the two solenoid valves with unique flow control performance. By precisely adjusting the through-hole size, the two solenoid valves can exhibit distinct flow characteristics, thereby providing a wider range of choices and higher flexibility for the adjustment of damping force and realizing the function of multi-stage adjustment. Specifically, the advantage of this flexible adjustment can be reflected when only one of the two solenoid valves is opened. Taking the example that the through-hole size of the spool of the selected first solenoid valve 112 is larger than that of the second solenoid valve 113, when only the first solenoid valve 112 is opened, due to its larger through-hole size of the spool, more oil is allowed to pass through in a short time, thereby reducing the resistance of the oil flowing through this solenoid valve, that is, reducing the throttling effect. This means that in the compression stroke or the rebound stroke, when the first solenoid valve 112 works alone, the oil in the rebound chamber 116 can flow into the oil storage chamber 118 more smoothly, resulting in a relatively rapid decrease in the oil pressure in the rebound chamber 116, and further reducing the damping force of the shock absorber at this stage, making the shock absorber exhibit a lower damping characteristic. On the contrary, when only the second solenoid valve 113 is opened, due to its smaller through-hole size of the spool, the resistance of the oil passing through increases, and the throttling effect is significant. This will cause the oil flow velocity to slow down, and the oil pressure in the rebound chamber 116 will decrease relatively slowly, thereby increasing the damping force of the shock absorber at this stage and making the shock absorber exhibit a higher damping characteristic.

[0076] In summary, by selecting different models of the first solenoid valve 112 and the second solenoid valve 113 and combining their opening and closing states, more refined and diversified multi-stage adjustment of the damping force can be achieved in the compression stroke and the rebound stroke. This design not only expands the range of damping adjustment, but also improves the adaptability of the shock absorber to different working conditions and requirements, making the shock absorption performance more optimized and personalized. For example, in occasions where rapid response and low damping are required, only the first solenoid valve 112 can be selected to be opened; while in occasions where better stability and high damping are required, only the second solenoid valve 113 can be opened or both solenoid valves can be opened but their opening degrees can be adjusted according to specific requirements.

[0077] Embodiment 2

[0078] This embodiment is a further improvement of Embodiment 1, and the repeated content will not be elaborated.

[0079] The present invention also relates to a seat suspension system, aiming to improve the riding comfort and handling stability of vehicle seats. As Figure 6As shown, the system includes a seat portion 200 and the shock absorber in the foregoing embodiment. Setting the shock absorber under the seat is the most obvious and intuitive for improving the driver's feeling. Moreover, the vibration frequency of the seat surface is much lower than that of the vehicle suspension. Therefore, the requirement for the response time of the shock absorber is lower than that of the conventional shock absorber provided in the vehicle suspension, and it is easier to control. The seat portion 200 includes a seat support frame 210, a seat body 220, an elastic element 230, a first sensor 240, a second sensor 250, and a controller 260.

[0080] Preferably, the seat portion 200 includes a seat support frame 210 for supporting the seat body 220. The seat support frame 210 is fixedly connected to the vehicle body ground to provide a fixed position for the seat. An elastic element 230, such as a spring or an airbag, is installed on the seat support frame 210, which is designed to adjust the default height of the seat in the unloaded state and provide a basic shock absorption function. A shock absorption portion 100 is also configured on the seat support frame 210, which is used to reduce the vibration caused by the uneven road surface and improve the seat comfort.

[0081] Preferably, the system is equipped with two sensors - a first sensor 240 and a second sensor 250. The first sensor 240 is installed on the bottom surface of the seat body 220, and the second sensor 250 is installed on the vehicle ground. The cooperation of the two is used to monitor the vertical displacement of the seat. Both sensors are designed as high-precision displacement sensors, which can accurately measure and monitor the distance change of the seat relative to the vehicle body ground.

[0082] Preferably, the first sensor 240, the second sensor 250, and the first solenoid valve 112 and the second solenoid valve 113 in the shock absorption portion 100 are data-connected to the controller 260, so that the controller 260 can receive the displacement data collected from the first sensor 240 and the second sensor 250, and set the appropriate damping force of the shock absorber according to these data to achieve the best shock absorption effect. In order to optimize the response strategy, the controller 260 can divide the displacement amount into four levels in advance from small to large, from level one (the smallest displacement amount) to level four (the largest displacement amount). This hierarchical response mechanism allows the system to quickly and accurately adjust the damping characteristics of the seat suspension system according to the real-time change of the seat displacement amount, ensuring that passengers can still enjoy the best comfort under different road conditions. Through this intelligent control, the seat suspension system can significantly improve the riding experience and reduce the impact and vibration felt by passengers.

[0083] When the seat body 220 moves vertically downward, that is, when entering the compression stroke of the shock absorber, the first sensor 240 and the second sensor 250 detect the downward displacement of the seat body 220 relative to the vehicle body ground. The controller 260 receives these displacement data and processes them, and judges the impact level of the seat according to the displacement amount:

[0084] 1. If the displacement of the seat body 220 is at the first level, indicating a relatively light impact, the controller 260 will instruct the first solenoid valve 112 and the second solenoid valve 113 to open fully, and the shock absorber will provide the minimum compression damping, facilitating a greater movement range of the seat and providing a gentle riding experience for the passengers.

[0085] 2. When the displacement of the seat body 220 reaches the second level, indicating an increase in the degree of impact, the controller 260 will open the solenoid valve with a larger through-hole size and close the smaller one, causing the shock absorber to generate medium compression damping to balance comfort and stability.

[0086] 3. If the displacement of the seat body 220 is at the third level, indicating a further increase in the degree of impact, the controller 260 will open the solenoid valve with a smaller through-hole and close the larger one, thereby providing higher compression damping, reducing the movement range of the seat, and enhancing riding stability.

[0087] 4. If the displacement of the seat body 220 is at the fourth level, that is, when a severe impact is suffered, the controller 260 will close all solenoid valves, and the shock absorber will reach the maximum compression damping to limit the movement of the seat and ensure riding stability under extreme conditions.

[0088] When the seat body 220 moves vertically upward, that is, when entering the rebound stroke of the shock absorber, the two sensors will detect the displacement of the seat body 220 away from the vehicle body ground. At this time, the controller 260 will also receive the displacement data and judge the impact level according to a predetermined algorithm:

[0089] 1. If the displacement of the seat body 220 is at the first level, the controller 260 will instruct the solenoid valves to open fully, and the shock absorber will be in the minimum rebound damping state, allowing the seat to rise smoothly and providing a gentle riding experience.

[0090] 2. When the displacement of the seat body 220 reaches the second level, the controller 260 will open the solenoid valve with a larger through-hole size and close the smaller solenoid valve to provide medium rebound damping and control the rising speed of the seat to avoid excessive rebound.

[0091] 3. If the displacement of the seat body 220 is at the third level, the controller 260 will open the solenoid valve with a smaller through-hole and close the larger solenoid valve to provide enhanced rebound damping and ensure the stability of the rising process.

[0092] 4. If the displacement of the seat body 220 is at the fourth level, the controller 260 will close all solenoid valves, and the shock absorber will provide the maximum rebound damping to suppress the movement of the seat and ensure stability under severe jolts.

[0093] Through this hierarchical control mechanism, the controller 260 can semi-actively adjust the damping force to respond to different levels of displacement, providing optimized comfort and stability while avoiding unnecessary over-compression or rebound reactions and extending the service life of the shock absorber.

[0094] Preferably, the controller 260 can be integrally disposed in the in-vehicle center console, enabling passengers to manually operate the center console to switch the seat suspension system from the semi-active control mode to the manual control mode, thereby making personalized settings according to their own preferences rather than the feedback data of the first sensor 240 and the second sensor 250. For example, for passengers who prefer a harder seat, the passengers can set the system to maintain a higher damping force by closing both solenoid valves simultaneously or only opening the solenoid valve with a smaller through-hole; while for passengers who prefer a softer seat, the passengers can set the system to maintain a lower damping force by opening both solenoid valves simultaneously or only closing the solenoid valve with a smaller through-hole.

[0095] Embodiment 3

[0096] This embodiment is a further improvement on the foregoing embodiment, and repeated content will not be elaborated.

[0097] Prior studies in the prior art have pointed out that during vehicle driving, the body vibration frequency is closely related to the road surface excitation frequency, and the swept-frequency simulation also shows that the vibration frequencies of the two are similar. Therefore, the road surface excitation frequency can be reflected by the vibration frequency of the seat suspension. Further, by adaptively adjusting the damping coefficient of the seat suspension according to the change of the road surface frequency, the suspension system can achieve optimal vibration damping performance in the entire frequency range.

[0098] In theoretical research or simulation processes, an intelligent predictive state observer based on predictive control can be designed to estimate vehicle state parameters and road surface conditions by using multiple sensors combined with complex predictive algorithms. However, in actual engineering applications, due to the significant nonlinear characteristics of the vehicle body and suspension system, the limited performance and cost of in-vehicle sensors and control units, and problems such as signal transmission delay, it is difficult to achieve real-time prediction of complex road conditions and vehicle body dynamics, and thus it is difficult to effectively identify the road surface excitation frequency.

[0099] In this embodiment, the displacement sensors (i.e., the first sensor 240 and the second sensor 250) are configured to output relative displacement data of the suspension system, which includes relative velocity information of the seat suspension movement. Compared with the acceleration signal, the relative velocity signal oscillates less and has accurate values. Therefore, this signal can be used as the input of the controller 260. Based on this, the system vibration frequency can be approximately estimated and corresponding control strategies can be designed. In theory, the shift shock can be reduced and the vibration damping effect of the system in the time domain and frequency domain can be improved.

[0100] Based on the above theoretical basis, in this embodiment, a Frequency Identification Controller (FIC) 260 is designed to implement a semi-active seat suspension control strategy based on frequency identification.

[0101] As Figure 6 shown, the core of the controller 260 includes a frequency identification module 261 and a frequency division control module 262.

[0102] The frequency identification module 261 identifies the vibration frequency of the suspension through an algorithm and outputs the identification result to the frequency division control module 262. The controller 260 selects an appropriate gear according to the current vibration frequency (including 1st gear large damping, 2nd gear medium damping, and 3rd gear small damping), and outputs the on-off signals of the first solenoid valve 112 and the second solenoid valve 113. The controller 260 outputs the damping force at different gears according to this signal and the shock absorber speed. The Simulink modeling of the frequency identification module 261 is as Figure 7 shown.

[0103] For the frequency identification module 261 in the controller 260, in this embodiment, the zero-crossing method is adopted to estimate the main frequency of the relative speed signal of the seat suspension. As Figure 8 shown, the curve in the figure represents the relative speed curve of the seat suspension. T a and T b represent the moments when the curve is zero. The two adjacent dotted lines represent the minimum sampling period (t 2 -t 1 ). When the product of the relative speeds A 1 and A 2 at two adjacent sampling time points is less than 0, it represents that the curve generates a zero point, and the time T a at this moment is recorded. The algorithm continues to find zero points, and the moment when the third zero point is collected is recorded as T b . Then, the main frequency f of this part of the relative speed curve can be approximately obtained, that is, f = 1 / (T b -T a ).

[0104] Use the "chirp" sweep frequency function in MATLAB to generate a 1-20 Hz sine frequency signal, import it into the frequency identification module 261 of the controller 260 for algorithm verification, and the obtained results are as Figure 9 shown. It can be seen from the figure that the algorithm identification result is relatively accurate and has a certain reliability.

[0105] Considering that the dynamic stroke of the suspension is relatively large in most cases during low-frequency vibration, a relatively large damping is required at this time to reduce displacement changes and prevent the suspension system from hitting the stop block due to excessive stroke, resulting in abnormal vibration and damaging the performance of the suspension system, which affects ride comfort. When it comes to high-frequency vibration, the dynamic stroke of the suspension usually changes little and violently. At this time, the shock absorber needs a small damping to absorb vibration energy, attenuate high-frequency vibration, and improve system smoothness. Therefore, in the frequency division control module 262, the estimated frequencies are sorted and classified, and the shift critical frequencies are set as u 1 and u 2 . When the relative speed frequency of the seat suspension is less than u 1 , the controller 260 sends a signal, and the shock absorber switches to the first gear with large damping; when the relative speed frequency of the seat suspension is greater than u 2 , the shock absorber switches to the third gear with small damping; the middle damping of the second gear is maintained at other times. For the selection of the critical frequencies u 1 and u 2 , considering that the seat generates relatively large adverse vibrations near the resonance point, which will have a negative impact on both the system and the human body. Therefore, in this embodiment, the shift critical frequencies are set near the seat resonance frequency, and the optimal critical point is finally determined through multiple simulations. At this time, u 1 = 3 Hz and u 2 = 6 Hz. The seat resonance frequency is obtained through the seat suspension sweep frequency test, and its value is 1 - 2 Hz, while the resonance frequencies of the main human organs are 2 - 8 Hz, which can verify that the selection of the critical frequencies meets the theoretical research. The design process of the frequency identification controller is as shown in Figure 10 .

[0106] According to the road surface classification, the test data from 0 to 39 s that can best reflect the high-frequency small-amplitude road surface are intercepted, and the control effect of the semi-active seat suspension under the high-frequency small-amplitude condition is analyzed. The gear shift results under frequency division control are as shown in Figure 11 (a), and the main vibration frequency of the seat suspension under this condition obtained by the frequency identification algorithm is as shown in Figure 11 (b).

[0107] As can be seen from Figure 11 (b), at this time, the input of the seat suspension is mostly high-frequency excitation, which is consistent with the road surface classification, and a small damping gear should be used for vibration filtering. The gear shift results show that the third gear is used most frequently under this condition, which is in line with the actual situation, proving the effectiveness of the frequency division control strategy. The acceleration on the upper surface of the vehicle seat under frequency division control is compared with the acceleration on the upper surface of the seat of the original passive seat suspension, and the results are as shown in Figure 12 (a) and Figure 12 (b). In order to more intuitively compare its vibration reduction effect, on this basis, the root mean square value (RMS) of the seat acceleration is calculated, and the statistical results are as shown in Figure 12 (c).

[0108] As can be seen fromFigure 12 As can be seen from (a), under the high-frequency and small-amplitude working conditions, the seat surface acceleration of the passive seat suspension in the "soft" mode and the seat suspension under semi-active control is small globally, and there is no abnormal mutation in the acceleration. The reason is that the number of damper gear shifts under the control of this algorithm is small, and the switching timing is mostly near the zero point of the relative speed of the seat suspension. Therefore, the jerks caused by gear shifting during the operation of the seat suspension system are effectively suppressed. Refer to Figure 12 From (b), it can be clearly observed that the seat acceleration under semi-active control converges quickly, and the attenuation of high-frequency small-amplitude vibrations is obvious; while for the middle and large damping gears of the original damper, due to the too large damping coefficient, the vibration environment will be deteriorated under this working condition, and a large amount of high-frequency vibrations will have an adverse impact on the human bones, organs and nerves. Figure 12 (c) (i.e., the RMS value statistical chart) can indirectly confirm the above time-domain analysis results.

[0109] According to the road surface classification, the test data from 173 to 188 s that can best reflect the low-frequency and large-amplitude road surface are intercepted to analyze the control effect of the semi-active seat suspension under low-frequency and large-amplitude working conditions. The gear shifting results under frequency division control are as Figure 13 shown in (a), and the main vibration frequency of the seat suspension under this working condition obtained by the frequency identification algorithm is as Figure 13 shown in (b).

[0110] From Figure 13 (b), it can be seen that at this time, the input of the seat suspension is mostly low-frequency excitation, which is consistent with the road surface classification. A large damping gear should be used for vibration filtering. The gear shifting results show that the first gear is used most frequently under this working condition, which conforms to the actual situation and proves the effectiveness of the frequency division control strategy. Comparing the acceleration of the upper surface of the vehicle seat under frequency division control with the acceleration of the upper surface of the seat of the original passive seat suspension, the results are as Figure 14 (a), Figure 14 (b) shown. In order to more intuitively compare its vibration reduction effect, on this basis, the root mean square value (RMS) of the seat acceleration is calculated, and the statistical results are as Figure 14 (c) and Table 1 shown.

[0111] Table 1 Time-domain evaluation (low-frequency and large-amplitude)

[0112]

[0113] Combined with the acceleration comparison in Figure 14 , it can be known that under this working condition, the input excitation frequency is low and the amplitude changes violently. At this time, the seat surface acceleration of the seat suspension under semi-active control is similar to the passive "hard" and "medium" modes globally, and is significantly better than the passive "soft" damping mode. It can be clearly seen from the local enlarged view that when the damping is too small, the seat suspension system loses the ability to suppress large-amplitude vibrations, and the difference between the peak and valley values of the acceleration reaches 28.6 m / s 2, at this time, the difference between the peak and valley values of acceleration under the other two damping modes and semi-active control is less than 5 m / s 2 . And the "top-touching" phenomenon was observed during the experiment, that is, the stretching damping force of the shock absorber was insufficient, resulting in excessive stretching of the piston rod and frequent impact of the seat suspension slide rail on the limit block. This phenomenon not only greatly reduces the riding comfort of the driver, but also causes irreversible damage to the seat suspension system and shortens the service life. At the same time, the semi-active controlled seat suspension of the present application can accurately identify this condition adaptively and increase the damping coefficient to avoid the "top-touching" phenomenon. The RMS statistical value can indirectly prove the above time-domain analysis results. Referring to Table 1, the time-domain analysis results show that under the low-frequency and large-amplitude conditions, the passive "medium" and "hard" damping modes and semi-active control have good effects.

[0114] The frequency-domain analysis is represented by the change curve of the seat acceleration power spectral density (PSD) from 0 to 20 Hz, as Figure 15 . On this basis, referring to the ISO-10326 evaluation standard, the weighted root mean square acceleration (WRMSA) of PSD and the corresponding seat suspension SEAT value under semi-active control and passive control in three modes are calculated, and the statistical results are as Figure 16 shown.

[0115] From Figure 15 , it can be seen that in the low-frequency band, the effects of semi-active control and passive control are not much different. Among them, the "medium" and "hard" damping modes of passive control have the best control effects, and the "soft" damping mode has the worst control effect. Referring to the standard GBT13441.1-2007, when the WRMSA value is between 0.8 and 1.6, the human body feels significantly uncomfortable; when the WRMSA value is between 1.6 and 2.5, the human body feels very uncomfortable. The calculation results show that the WRMSA value under semi-active control is slightly larger than the passive control results under the "medium" and "hard" damping modes. At this time, the human body can feel obvious discomfort without obvious difference; but compared with the passive "soft" damping mode, the WRMSA value has a larger decrease, which can reduce the great discomfort of the human body. The lateral comparison results of different seat SEAT values are basically the same as the WRMSA value, and the maximum decrease in the semi-active seat SEAT value can reach 22.92%. It can be seen that in the case of low-frequency and large-amplitude vibration, the seat moves greatly, and the shock absorber needs large damping to limit the relative movement of the seat and absorb vibration energy to reduce the discomfort of the human body. The semi-active seat suspension can adaptively switch to the large-damping state according to the road conditions. However, due to the structural characteristics of the MDC shock absorber itself, its maximum damping force is slightly smaller than that of the original shock absorber, and the effect of suppressing large-amplitude vibration is limited, but it can also successfully avoid the "top-touching" impact phenomenon in the passive "soft" damping mode.

[0116] It should be noted that the above specific embodiments are exemplary. Those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also fall within the scope of the disclosure of the present invention and within the protection scope of the present invention. Those skilled in the art should understand that the description and drawings of the present invention are illustrative and do not constitute a limitation on the claims. The protection scope of the present invention is defined by the claims and their equivalents. The description of the present invention contains multiple inventive concepts. Phrases such as "preferably" or "according to a preferred embodiment" indicate that the corresponding paragraphs disclose an independent concept. The applicant reserves the right to file divisional applications based on each inventive concept. Throughout the text, the features guided by "preferably" are only optional and should not be understood as being required to be provided. Therefore, the applicant reserves the right to waive or delete the relevant preferred features at any time.

Claims

1. A multi-stage electrically controlled seat shock absorber, characterized in that: The invention comprises a valve seat (105), a working cylinder (108), an outer tube (109) and a lower end cover (110); the valve seat (105) and the lower end cover (110) receive the working cylinder (108) and the outer tube (109) in a set-type manner and are respectively arranged at the upper end and the lower end of the working cylinder (108) and the outer tube (109); the outer tube (109) and the working cylinder (108) can be mutually sleeved to form an oil storage chamber (118) for adjusting hydraulic oil therebetween. A first solenoid valve (112) and a second solenoid valve (113) for opening and closing the hydraulic oil passage between the working cylinder (108) and the oil storage chamber (118) are disposed on two opposite sides of the valve seat (105), and the first solenoid valve (112) and the second solenoid valve (113) are detachably mounted in a first installation chamber (121) and a second installation chamber (124) reserved in the valve seat (105), respectively. The two solenoid valves can be opened and closed under the control of the on / off signal sent by the controller (260) to control the oil flow rate and flow direction to output the damping force at different gears.

2. The shock absorber according to claim 1, characterized in that The valve seat (105) can be snapped onto the top of the working cylinder (108) and the outer cylinder (109) to form a shell structure at the top of the shock absorber. The valve seat (105) is connected to the outer cylinder (109) via a cylinder structure extending along the outer wall of the outer cylinder (109) toward the bottom of the shock absorber. The valve seat (105) blocks the top opening of the working cylinder (108) by extending into the platform structure of the working cylinder (108) along the inner wall of the working cylinder (108) toward the bottom of the working cylinder (108).

3. The vibration absorber according to claim 1 or 2, characterized in that: The bottom of the outer cylinder (109) is connected to the lower end cover (110), and the lower end cover (110) is connected to the outer cylinder (109) through a cylinder structure extending along the inner wall of the outer cylinder (109) toward the top of the shock absorber. A bushing (111) is provided at the bottom of the lower end cover (110) as a connection node between the shock absorber and the seat support frame (210).

4. The vibration absorber according to any one of claims 1 to 3, characterized in that: The shock absorber comprises a piston rod (101) and a piston valve assembly (106), wherein the piston rod (101) passes through the valve seat (105) and partially extends into the working cylinder (108), and the piston valve assembly (106) is located at the end of the piston rod (101) in the working cylinder (108), and divides the working cylinder (108) into a compression chamber (117) and a recovery chamber (116), wherein the compression chamber (117) is located on a side where the piston rod (101) is connected to the piston valve assembly (106), and the recovery chamber (116) is located on the other side of the piston valve assembly (106).

5. The vibration absorber according to any one of claims 1 to 4, characterized in that: The top of the oil storage chamber (118) is closed by a valve seat (105), and the bottom is closed by a lower end cover (110) to isolate the oil exchange between the working cylinder (108) and the oil storage chamber (118) when the shock absorber is not working. The valve seat (105) and the upper end cover (102) are provided with two corresponding through-channels formed by removing materials at coaxial positions thereof to allow the piston rod (101) to move upward and downward under the restriction of the through-channels. When the piston rod (101) moves upward or downward, the oil flow passage between the valve seat (105) and / or the lower end cover (110) and the working cylinder (108) is selectively opened to achieve oil exchange between the working cylinder (108) and the oil storage chamber (118).

6. The shock absorber according to any one of claims 1 to 5, characterized in that: An oil seal installation chamber (120) for installing an oil seal is formed between the upper end cover (102) and the valve seat (105), wherein the oil seal installation chamber (120) contains an oil seal (103) and an oil seal spring (104) coaxially arranged with the piston rod (101), wherein the oil seal spring (104) surrounds the outer side of the piston rod (101), and one end of the oil seal spring (104) is located near the entrance of the through channel of the valve seat (105), and the other end is connected to the oil seal (103); When the valve seat (105) is combined with the upper end cover (102), the oil seal spring (104) applies elastic force to the oil seal (103) through its compressed state, so that the oil seal (103) maintains contact with the upper end cover (102) and is fixed in the oil seal installation chamber (120).

7. The vibration absorber according to any one of claims 1 to 6, characterized in that: The valve seat (105) is provided with a first oil passage (122) and a second oil passage (123) to be connected to the first installation chamber (121), and a third oil passage (125) and a fourth oil passage (126) to be connected to the second installation chamber (124); The hydraulic oil in the recovery chamber (116) flows to the first installation chamber (121) via the first oil passage (122), and flows to the oil storage chamber (118) via the second oil passage (123); The hydraulic oil in the recovery chamber (116) flows to the second installation chamber (124) via the third oil passage (125), and flows to the oil storage chamber (118) via the fourth oil passage (126).

8. The vibration absorber according to any one of claims 1 to 7, characterized in that: A fifth oil circuit (127) and a sixth oil circuit (128) for connecting the oil seal installation chamber (120) with the oil storage chamber (118) are arranged in the valve seat (105); the fifth oil circuit (127) and the sixth oil circuit (128) can be arranged on both sides of the piston rod (101) in a manner avoiding the first oil circuit (122) and the third oil circuit (125) so as to recover the hydraulic oil in the oil seal installation chamber (120) brought out by the piston rod (101) into the oil storage chamber (118).

9. A seat suspension system, comprising the shock absorber according to any one of claims 1 to 8 and a seat portion (200), wherein the seat portion (200) comprises a seat support frame (210), a seat body (220), an elastic element (230), a second sensor (240), a second sensor (250) and a controller (260); The seat support frame (210) is located below the seat body (220) and is connected to the vehicle body ground, and the elastic element (230) and the shock absorber are arranged on the seat support frame (210); The first sensor (240), the second sensor (250), and the first solenoid valve (112) and the second solenoid valve (113) in the shock absorber are all data-connected to the controller (260). The controller (260) is capable of receiving displacement data collected from the first sensor (240) and the second sensor (250), and setting a damping force for the shock absorber based on the data.

10. The seat suspension system according to claim 9, characterized in that The controller (260) can realize the switching of the seat suspension system between a semi-active control mode and a manual control mode. When switching from the semi-active control mode to the manual control mode, the controller (260) is manually controlled by the passenger to selectively open and close the solenoid valve to adjust the damping size of the seat suspension system.

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