Shock absorber with negative stiffness characteristic and vehicle adopting shock absorber

Abstract

The shock absorber with the negative stiffness characteristic comprises a cylinder barrel, a piston rod, a piston and a bottom valve, a stretching valve and a one-way valve are arranged on the piston, a compression valve and a one-way valve are arranged on the bottom valve, a valve element of the compression valve is connected to a valve element of the stretching valve through a spring, and a limiting device of the valve element of the stretching valve is arranged on the piston or the piston rod. Damping force values of the compression valve and the stretching valve are both controlled by the stroke of the piston and the acting force of the spring. In the stretching process of the shock absorber, when the spring is in a pressed state, the stretching valve forms damping force, and the shock absorption effect is achieved. The larger the compression stroke (compression force value) of the spring is, the larger the tensile damping value of the shock absorber is. In the compression process of the shock absorber, when the spring is in a pulled state, the compression valve forms damping force, and the shock absorption effect is achieved. The larger the stretching stroke (stretching force value) of the spring is, the larger the compression damping value of the shock absorber is.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of shock absorbers, and is particularly suitable for single-cylinder or double-cylinder shock absorbers. BACKGROUND

[0002] The damping force values of the common hydraulic cylinder shock absorber extension valve and compression valve are usually related to the extension or compression speed of the shock absorber, that is, the faster the extension or compression speed of the shock absorber, the greater the damping, and the smaller the extension or compression speed, the smaller the damping. A small number of high-performance active shock absorbers can adjust the damping force value of the shock absorber in real time by measuring the road surface undulations in front of the vehicle in advance. However, the damping force value cannot be accurately controlled according to the actual stress of the vehicle.

[0003] The performance of the existing shock absorber is usually represented by a indicator diagram, which cannot accurately reflect the damping performance of the shock absorber, and there is no specific matching method between the shock absorber and the vehicle support spring (23) to guide the selection relationship between the shock absorber and the support spring (23).

[0004] In addition, the common shock absorber needs to set the extension liquid flow channel and the compression liquid flow channel (one-way valve channel) on the shock absorber piston at the same time, which results in a small installation space of the one-way valve and a small effective diameter, and in the process of rapid compression, the liquid flow speed is large, the damping of the liquid flow entering the rod cavity through the one-way valve is large, and cavitation effect is formed, which greatly affects the damping effect of the shock absorber.

[0005] Technical problems solved by the present application:

[0006] 1. The damping performance of the shock absorber has no quantitative standard and cannot be quantified.

[0007] 2. The performance of the shock absorber is matched with the support spring and the vehicle load to solve the selection problem.

[0008] 3. The extension damping and compression damping force values of the shock absorber are associated with the extension or compression stroke of the shock absorber, so as to automatically adjust the damping force value of the shock absorber.

[0009] 4. A simple structure and better performance of the shock absorber are provided.

[0010] 5. The influence of the speed of the shock absorber during extension or compression on the damping value of the shock absorber is reduced, so that the effect of the shock absorber is better.

[0011] 6. For a long time, the related technical personnel of the shock absorber have always taken the extension speed and vibration (extension) frequency of the shock absorber as the basis for adjusting the damping force value of the shock absorber. The present application takes the extension stroke position or the compression stroke position of the shock absorber as the main basis for controlling the damping force value of the shock absorber, which overcomes the bias of the traditional method of taking the speed and the extension frequency of the shock absorber as the basis for controlling the damping force value of the shock absorber.

[0012] 7、The damper of this scheme can provide a damper with negative stiffness damping characteristics whose absolute value of stiffness is equal or similar to the stiffness of the vehicle support spring.

[0013] 8、The damper piston rod cavity end stretch liquid flow channel and compression liquid flow channel (one-way valve channel) can share one part, effectively increasing the liquid flow path into the rod cavity, reducing the liquid flow damping into the rod cavity, and avoiding or reducing cavitation effects caused by insufficient liquid supply.

[0014] 9、Effectively overcome the influence of temperature change on the damping value of the damper, so that the damping force value of the damper is not affected by temperature change. SUMMARY

[0015] Scheme A, a damper with negative stiffness characteristics, including: cylinder, piston rod, piston, one-way valve, stretch valve or / and compression valve and other components. When the stretch valve is provided, the stretch valve is provided on the piston; when the compression valve is provided, the bottom valve is also provided, and the compression valve is provided on the bottom valve; the damper cylinder of this scheme is provided with a spring in the rodless cavity, and the end of the spring is connected with a stretch valve (9) or / and a compression valve (19), the spring force value controls the damping force value of the stretch valve or / and the compression valve, when the damper is stretched or compressed, the piston goes up to stretch or goes down to compress, so that the spring bears tension or pressure, the tension or pressure of the spring (13) changes with the position of the piston, and the tension or pressure of the spring is loaded on the compression valve or / and the stretch valve, thereby controlling the stretch damping force value or / and the compression damping force value of the damper, so as to form a stretch damping force or / and a compression damping force with a negative stiffness coefficient, so that the damper has a damping force value corresponding to the position of the damper stroke. That is, when the piston goes up to stretch or goes down to compress, the distance change between the piston and the bottom of the cylinder controls the stretch amount or / and the compression amount change of the spring (13), and the stretch amount or / and the compression amount change of the spring controls the damping force value of the stretch valve or / and the compression valve of the damper, so that the stretch damping force value or / and the compression damping force value of the damper is in a certain proportional relationship with the piston stroke in the set range (the set range refers to the stroke range of L1~L2, L2~L3, L3~L4 in FIG. 5, FIG. 8, FIG. 9, part of the value of the stroke range can be set by changing the free length of the spring), that is, the stretch damping force value of the damper is proportional to the compression force value of the spring, or / and the compression damping force value of the damper is proportional to the stretch force value of the spring, and the damper has a stretch damping force value or / and a compression damping force value corresponding to the position of the damper stroke at any stroke position.

[0016] The damping force value of the damper changes with the position of the damper stroke, and the damping force value is basically not affected by the stretch speed or compression speed of the damper.

[0017] The uplink and downlink in the text are only for the description of the patent drawings to make it easy to understand, and are not limited to the actual orientation position relationship of the shock absorber. That is, the piston downlink corresponds to the compression process of the shock absorber, and the piston uplink corresponds to the stretching process of the shock absorber.

[0018] In general, the free length of the spring (13) should be less than the stroke of the shock absorber.

[0019] Scheme B, the shock absorber as described in Scheme A, comprising: a cylinder, a piston rod, a piston, a one-way valve provided on the piston, a valve hole provided on the piston and matched with a stretch valve spool, the valve hole being communicated with a rod cavity, the stretch valve spool being arranged in a rodless cavity, a spring being arranged between the valve core and the bottom of the cylinder or a bottom valve, when the spring (13) is compressed during the stretching process of the shock absorber, the stretch valve spool and the valve hole are affected by the compression force of the spring (13) to form a stretching damping valve. When the spring (13) is in a compressed state during the stretching process of the shock absorber, the stretch valve forms a damping force to achieve a damping effect. The greater the compression stroke (compression force value) of the spring (13), the greater the stretching damping value of the shock absorber. When the spring (13) is in a non-compressed state, the stretch valve is opened, and the stretching damping value is minimum. During the compression process of the shock absorber, the liquid flow in the rodless cavity mainly enters the rod cavity through the one-way valve on the piston. The shock absorber of the present scheme can be provided with a bottom valve or without a bottom valve.

[0020] Whether the spring (13) and the valve core, and the spring (13) and the bottom of the cylinder or the bottom valve are connected or not is not limited, and the connection mode is also not limited. That is, fixed connection, non-fixed connection, single-head fixed connection and other connection modes can be adopted.

[0021] Working principle: as shown in FIG. 1 and FIG. 2, the stretch valve spool is affected by the force of the spring (13) and matched with the valve hole to form a stretching damping valve. During the process that the piston is uplinked from L1 to L2, the spring (13) is transitioned from the forced compression state to the free state, and the damping of the stretching damping valve is changed from large to small, that is, the stretching damping force of the shock absorber is changed from large to small.

[0022] When the piston is uplinked to L2 (the free length position of the spring (13)), the damping reaches the minimum value, until the piston is uplinked to L3. When the piston is downlinked, the liquid flow flows from the rodless cavity to the rod cavity through the one-way valve on the piston.

[0023] Scheme C, the damper as described in Scheme A, comprising: cylinder, piston rod, piston, bottom valve, the bottom valve is provided with compression valve and check valve, compression valve spool is connected to the piston or piston rod by spring (13), so that the damping force value of compression valve is controlled by the stroke of piston and the tension of spring (13). When the spring (13) is in tension, the compression valve forms damping force during the compression of the damper, and the damping effect is achieved. The greater the extension stroke (tension value) of spring (13) is, the greater the compression damping value of the damper is. When the spring (13) is in free state and pressure state, the compression valve of the damper is opened, and the compression damping is in minimum state. The piston or piston rod of the present scheme can be replaced by a plunger.

[0024] Working principle:

[0025] As shown in Figure 2: the compression valve spool is matched with the compression valve hole to form a damping valve under the action of spring (13) tension, and the damping force of the damping valve changes from large to small during the process that the piston goes down from L4 position to L3 position, that is, the compression damping force value of the damper changes from large to small. When the piston goes down to L3 position (spring (13) free length position), the damping reaches the minimum value, and the piston goes down to L1 position. When the piston goes down from L2 position to L1 position, the spring (13) is under pressure, the compression valve spool is located at the lower part of the bottom valve, and the compression valve is in full open state.

[0026] Scheme D, the damper as described in Scheme A, comprising: cylinder, piston rod, piston, bottom valve, the piston is provided with stretch valve and check valve, the bottom valve is provided with compression valve and check valve, the stretch valve spool is connected to the spool of compression valve by spring (13), the piston or piston rod is provided with limiting device for limiting the stroke of stretch valve spool, the limiting device can adopt nut, pin, ring and other devices, and the damping force value of compression valve is controlled by the stroke of piston and the tension of spring (13) when the spring (13) is in tension during the compression of the damper. The damping force value of stretch valve is controlled by the stroke of piston and the compression force of spring (13) when the spring (13) is under pressure during the stretching of the damper.

[0027] That is, the stretch valve forms damping force when the spring (13) is in pressure state during the stretching of the damper, and the damping effect is achieved. The greater the compression stroke (compression value) of spring (13) is, the greater the stretching damping value of the damper is. The compression valve forms damping force when the spring (13) is in tension during the compression of the damper, and the damping effect is achieved. The greater the extension stroke (tension value) of spring (13) is, the greater the compression damping value of the damper is.

[0028] Working principle: as shown in Figure 3:

[0029] When the piston is compressed from top to bottom, the compression valve core is matched with the compression valve hole to form a damping valve under the action of the spring (13) tension, and the damping force of the damping valve changes from large to small, that is, the compression damping force value of the shock absorber changes from large to small, when the piston is down to L3 position (spring (13) free length position), the damping reaches the minimum value, until the piston is down to L1 position. When the piston is down from L2 to L1, the spring (13) is compressed, the compression valve core is located below the bottom valve, and the compression valve is in full open state.

[0030] When the piston is stretched from bottom to top, the stretching valve core is matched with the valve hole to form a damping valve under the action of the spring (13) force, and the damping of the stretching damping valve changes from large to small, that is, the stretching damping force of the shock absorber changes from large to small, when the piston is up to L2 position (spring (13) free length position), the damping reaches the minimum value, until the piston is up to L4 position.

[0031] When the piston is down, the liquid flows through the one-way valve on the piston from the rodless cavity to the rod cavity.

[0032] When the piston is up, the liquid in the liquid storage cylinder flows into the cylinder rodless cavity through the one-way valve on the bottom valve.

[0033] The foregoing Figure 3 The theoretical damping value of the shock absorber is calculated as follows:

[0034] The theoretical stretching damping calculation method in the above scheme is as follows:

[0035] When L1≤ L X ≤ L2, then ;

[0036] When L2<L X <L3, then ;

[0037] When L3≤ L X ≤ L4, then .

[0038] The theoretical stretching stiffness calculation method in the above scheme is as follows:

[0039] When L1≤ L X ≤ L2, then ;

[0040] When L2<L X <L3, then ;

[0041] When L3≤ L X ≤ L4, then .

[0042] Theoretical compression damping calculation method in the above scheme:

[0043] When L3≤ L X ≤ L4, then ;

[0044] When L2<L X <L3, then ;

[0045] When L1≤ L X ≤ L2, then .

[0046] Theoretical compression stiffness calculation method in the above scheme:

[0047] When L3≤ L X ≤ L4, then ;

[0048] When L2<L X <L3, then ;

[0049] When L1≤ L X ≤ L2, then .

[0050] F 拉实 =F 支 + F 拉

[0051] F 压实 =F 支 + F 压

[0052] F 拉 is the real-time tensile damping force value of the shock absorber

[0053] K 拉 is the tensile damping stiffness value of the shock absorber

[0054] F 压 is the real-time compression damping force value of the shock absorber

[0055] K 压 is the compression damping stiffness value of the shock absorber

[0056] S1 is the hydraulic cylinder barrel cross-sectional area

[0057] S2 is the piston rod cross-sectional area

[0058] S3 is the effective cross-sectional area of the tensile valve port

[0059] S4 is the effective cross-sectional area of the compression valve port

[0060] F 支 is the real-time force value of the support spring (23)

[0061] K 内 is the stiffness of the spring (13) in the shock absorber

[0062] F 拉实 is the real-time support force value of the combined force of the shock absorber and the support spring on the vehicle during the extension stroke of the shock absorber

[0063] F 压实 is the real-time support force value of the combined force of the shock absorber and the support spring on the vehicle during the compression stroke of the shock absorber

[0064] F 目 is the target support force value

[0065] Stroke position of the shock absorber:

[0066] L1 is the limit position of the compression stroke of the shock absorber

[0067] L2 is the critical position of the free length of the compression spring (critical position of the extension valve seal)

[0068] L3 is the critical position of the free length of the extension spring (critical position of the compression valve seal)

[0069] L4 is the limit position of the extension stroke of the shock absorber

[0070] L X any real-time position during the extension or compression of the shock absorber

[0071] L1~L2 is the effective stroke segment of the negative stiffness of the extension damping and the positive stiffness of the compression damping

[0072] L2~L3 is the minimum value stroke segment of the extension damping and the compression damping

[0073] L3~L4 is the effective stroke segment of the negative stiffness of the compression damping and the positive stiffness of the extension damping

[0074] In FIG. 8, S represents the corresponding stroke position, and F represents the vector force value.

[0075] Performance representation method of the shock absorber

[0076] The damping performance of the shock absorber is represented by the stiffness value corresponding to each stroke position of the extension stroke and the compression stroke of the shock absorber, or the position corresponding to each stiffness value. The stiffness value of the shock absorber includes the extension stiffness value and the compression stiffness value, and each stroke segment corresponds to its own stiffness value.

[0077] The negative value of the compression stiffness of the shock absorber indicates that the greater the compression stroke, the smaller the compression force value; the negative value of the tensile stiffness of the shock absorber indicates that the greater the tensile stroke, the smaller the tensile force value.

[0078] For example:

[0079] The tensile damping stiffness value of the tensile stroke L1~L2 is -n kgf / cm;

[0080] The tensile damping stiffness value of the tensile stroke L3~L4 is n kgf / cm;

[0081] The compression damping stiffness value of the compression stroke L1~L2 is n kgf / cm;

[0082] The compression damping stiffness value of the compression stroke L3~L4 is -n kgf / cm;

[0083] The stiffness value of the transition stroke L2~L3 is n kgf / cm;

[0084] The n in -n kgf / cm indicates the actual numerical value, for example, -5 kgf / cm indicates that the tensile damping decreases by 5 kgf of tensile force for every 1 cm of stroke in the tensile direction within the tensile stroke L1~L2.

[0085] Other performance representation methods can also be used, as long as they can represent the stiffness performance of the shock absorber and the relationship between the stiffness and the position.

[0086] The shock absorber can be set to have different damping performance by changing the S1~S4 cross-sectional area, K 内 The stiffness of the spring (13) and the free length of the spring (13).

[0087] Matching method of the shock absorber and the supporting spring (23):

[0088] 1. Stiffness value matching method

[0089] Within the entire stroke range in which the supporting force of the supporting spring (23) on the vehicle is less than the target supporting force value, the closer the absolute value of the compression stiffness of the shock absorber in this stroke range to the stiffness value of the equivalent supporting spring (23), the better the damping effect; that is, the absolute value of the compression stiffness of the shock absorber (22) in this stroke range is equal to or close to the stiffness value of the equivalent supporting spring (23) as the matching standard.

[0090] In the range of all strokes of the support spring (23) where the support force of the vehicle exceeds the target support force value, the better the damping effect is, the closer the absolute value of the tensile stiffness of the damper in this range of strokes is to the stiffness value of the equivalent support spring (23); that is, the absolute value of the tensile stiffness of the damper (22) in this range of strokes is equal to or close to the stiffness value of the equivalent support spring (23) as the matching standard;

[0091] In the range of all strokes of the support spring (23) where the support force of the vehicle is equal to the target support force value, the better the damping effect is, the smaller the absolute value of the compression stiffness, the absolute value of the tensile stiffness and the damping value of the damper are; that is, the absolute value of the compression stiffness, the absolute value of the tensile stiffness and the minimum value of the damping of the damper (22) are the matching standards.

[0092] In the range of all strokes of the support spring (23) where the support force of the vehicle is less than the target support force value, the better the damping effect is, the smaller the tensile positive stiffness value and the tensile damping value of the damper in this range of strokes are;

[0093] In the range of all strokes of the support spring (23) where the support force of the vehicle exceeds the target support force value, the better the damping effect is, the smaller the compression positive stiffness value and the compression damping value of the damper in this range of strokes are.

[0094] For the case where there is both tensile negative stiffness and compression negative stiffness and the tensile negative stiffness value and the compression negative stiffness value are not the same, the absolute value of the value between the tensile negative stiffness and the compression negative stiffness value is selected as the matching value of the stiffness value of the equivalent support spring (23) for better damping effect.

[0095] The purpose of the above stiffness value matching is to make the resultant force of the support spring (23) and the damper equal to or close to the target support force value, so as to achieve the best damping effect.

[0096] 2. Force value matching method

[0097] In the tensile process of the damper, F 拉实 is equal to or close to F 目 In the compression process of the damper, F 压实 is equal to or close to F 目 is the best matching standard of the damper and the support spring (23), so as to achieve the best damping effect.

[0098] The equivalent support spring (23) refers to:

[0099] The spring that actually produces the support force of the vehicle is converted into an equivalent spring coaxial with the damper, and the equivalent spring has the same effect on the force of the vehicle as the original spring.

[0100] Target support force value (F 目 ) refers to:

[0101] The force value of the actual gravity value of the vehicle body acting on the equivalent support spring (23) as the target support force value;

[0102] Or the force of the vehicle at a certain speed acting on the vehicle body and the force of the vehicle body gravity acting on the corresponding equivalent support spring (23) as the target support force value;

[0103] Or the actual working condition of the force value as the target support force value, that is, considering the actual force value of the road slope, wind speed, vehicle speed, load acting on the equivalent support spring (23) as the target force value.

[0104] The stiffness value of the equivalent support spring (23) refers to:

[0105] The stiffness of the support spring (23) that will actually support the vehicle is converted into the stiffness value of the equivalent support spring (23) coaxial with the shock absorber.

[0106] The stiffness of the support spring (23) in this paper, without special identification, refers to the stiffness of the support spring (23) converted into the stiffness of the equivalent support spring (23) coaxial with the shock absorber.

[0107] Scheme E, any one of the shock absorbers as described in the foregoing schemes A~D, the one-way valve on the piston is mainly composed of a valve block (7), the valve block (7) and the cylinder wall of the shock absorber cylinder (14) form a sealing surface, the valve block (7) and the piston (6) have a liquid inlet passage (11) communicating with the rod cavity (4) and the rodless cavity (12), and the valve block (7) and the piston (6) can move relative to each other, so that the shock absorber is compressed or stretched to form an open or closed liquid inlet passage (11). That is, when the shock absorber is compressed, the liquid inlet passage (11) is opened to communicate the cylinder rodless cavity (12) and the rod cavity (4). When the shock absorber is stretched, the liquid inlet passage (11) is closed, so that the cylinder rodless cavity (12) and the rod cavity (4) are not communicated, and the liquid inlet passage (11) is closed, so that the stretch valve (9) forms a communication damping passage (10) between the rod cavity (4) and the rodless cavity (12). The piston (15) or the piston rod (3) has a structure or device for limiting the displacement of the valve block (7), so as to limit the relative displacement amount between the valve block (7) and the piston.

[0108] Working principle:

[0109] As shown in Fig. 1, when the shock absorber is compressed, the piston (6) goes down until the limiting structure or limiting device contacts the valve block (7) and drives the valve block (7) to go down together, so that a gap is formed between the valve block (7) and the piston, the rodless cavity and the rod cavity form a liquid inlet channel (11), and the liquid flows into the rod cavity (4) through the liquid inlet channel (11). When the shock absorber is stretched, the piston goes up until the valve block (7) contacts the sealing surface of the piston (6) and drives the valve block (7) to go up together, so that a sealing structure is formed between the piston (6) and the valve block (7), and the liquid cannot pass through the sealing surface between the piston (6) and the valve block (7). The liquid in the rod cavity (4) flows from the damping channel (10) to the rodless cavity (12) through the stretching damping valve.

[0110] Valve block: refers to a device that forms a sealing surface with the cylinder wall of the cylinder and can produce mutual displacement with the piston and form an openable and closable channel with the piston or piston rod, which can be composed of a separate valve block ring or together with auxiliary components such as sealing rings, sealing rings (8) installed on the valve block. The valve block can be a whole ring or a half ring structure, and its structure and composition are not limited.

[0111] Limiting device: used to limit the displacement between the valve block (7) and the piston. The structure of the limiting device is not limited. The limiting device can be a nut, a snap ring, a pin, etc., and can also be a limiting structure provided on the piston.

[0112] Scheme F, a vehicle characterized by adopting any one of the shock absorbers of schemes A to E.

[0113] Advantages

[0114] 1. The shock absorber has a corresponding optimal resistance force value for the compression stroke and the stretching stroke, so that the shock absorber achieves the best damping effect.

[0115] 2. The damping force value of the shock absorber during vehicle driving is automatically adjusted according to the feedback of the road surface and the support force of the vehicle.

[0116] 3. When the shock absorber is quickly compressed, the piston has a larger one-way valve diameter and smaller damping, effectively reducing or avoiding the cavitation effect caused by insufficient liquid supply of the shock absorber.

[0117] 4. The performance quantization problem of the shock absorber is solved, and the performance evaluation standard of the shock absorber is clear.

[0118] 5. The performance matching standard problem of the shock absorber and the vehicle support spring is solved, so that the performance matching of the shock absorber and the vehicle support spring has a performance quantization standard.

[0119] 6. The influence of temperature on the performance of the shock absorber can be effectively avoided, so that the performance of the shock absorber is basically not affected by the temperature of the oil in the shock absorber.

[0120] 7. This invention corrects the long-standing bias that the damping force of a shock absorber should be related to speed. The damping force of the shock absorber in this invention is only related to the stroke of the shock absorber and the force of the supporting spring, so that the damping force of the shock absorber is basically unaffected by the tensile and compressive speeds. Attached Figure Description

[0121] Figure 1: Partial cross-sectional view of a tension-damped controlled vibration damper

[0122] Figure 2: Schematic diagram of the stroke position of the tension-damped controlled vibration damper

[0123] Figure 3: Schematic diagram of a dual-controlled vibration damper with tensile and compressive damping (compression damping controlled position)

[0124] Figure 4: Schematic diagram of a dual-controlled vibration damper with tensile and compressive damping (controlled position for tensile damping)

[0125] Figure 5: Schematic diagram of the stroke position of a dual-controlled damper with tensile and compressive damping.

[0126] Figure 6: 3D schematic diagram of the bottom valve seat

[0127] Figure 7: 3D schematic diagram of piston and valve block

[0128] Figure 8: Correspondence between damper stroke and various force values

[0129] Figure 9: Schematic diagram showing the relationship between the shock absorber stroke and various force values.

[0130] (The central axes of the damper and the support spring in Figure 9 are not coaxial. This is only for the convenience of showing the spring, the damper and their resultant force relationship in the figure. In actual application, the stress relationship between the damper and the support spring should be calculated in an equivalent coaxial manner.)

[0131] Illustration Number and Name:

[0132] 1-Reservoir cylinder 2-Reservoir chamber 3-Piston rod 4-Rod chamber (tensioning chamber) 5-Guide belt 6-Piston 7-Valve block

[0133] 8-Sealing ring; 9-Tension valve; 10-Tension damping channel; 11-Compression inlet channel; 12-Rodless chamber (compression chamber)

[0134] 13-Spring 14-Cylinder (Hydraulic Cylinder) 15-Snap Ring 16-Spring Plate 17-Check Valve Plate 18-Bottom Valve Seat

[0135] 19-Compression valve 20-Compression damping channel 21-Tension inlet channel 22-Shock absorber 23-Support spring Detailed Implementation

[0136] Embodiments of the present invention

[0137] Preferred solution 1 (Fig. 1, Fig. 2):

[0138] A stretch-damping controlled shock absorber, comprising a cylinder (14), a piston rod (3), a piston (6); the piston (6) is provided with a one-way valve and a valve hole matched with a stretch valve spool, the valve hole is communicated with a rod cavity, the stretch valve (9) spool is arranged in a rodless cavity (12), a spring (13) is arranged between the stretch valve (9) spool and the bottom of the cylinder (14) or a bottom valve, the stretch valve (9) spool and the valve hole form a stretch damping valve under the action of the spring (13), and the stretch damping valve can achieve the damping effect when the shock absorber is stretched. That is, at any position in the spring compression stroke in the stretch stroke of the shock absorber, the stretch damping force value of the shock absorber is proportional to the compression force value of the spring.

[0139] Working principle:

[0140] As shown in Fig. 1, the stretch valve (9) spool matched with the valve hole forms a stretch damping valve under the action of the spring (13), and the piston (6) is in the process of moving from L1 to L2, the spring (13) is in the process of transition from the forced compression state to the free state, the liquid flows from the rodless cavity (12) to the rod cavity (4) through the stretch damping channel (10), the damping of the stretch valve (9) changes from large to small, that is, the stretch damping force of the shock absorber changes from large to small. When the piston moves to the position above L2 (the free length position of the spring), the stretch valve (9) is in the open position, and the damping reaches the minimum value, until the piston moves to the position L3. In the process of moving from L3 to L2, the spring (13) is in the free state, the stretch valve (9) is in the open position, and the liquid flows from the rod cavity (4) to the rodless cavity through the compression damping channel (11) and the stretch damping channel (10). In the process of moving from L2 to L1, the spring (13) is in the compression state, the stretch valve (9) is in the closed position, and the liquid flows from the rod cavity (4) to the rodless cavity (12) through the compression damping channel (11), that is, through the one-way valve (7) to the rodless cavity (12).

[0141] The performance of the shock absorber can be represented as follows:

[0142] The stretch damping stiffness value of the stretch stroke L1~L2 is -n kgf / cm.

[0143] The compression damping stiffness value of the compression stroke L1~L2 is n kgf / cm.

[0144] The n in -n kgf / cm represents the actual numerical value, for example, -5 kgf / cm represents that the stretch damping decreases by 5 kgf in the stretch direction for every 1 cm stroke in the stretch stroke L1~L2.

[0145] Other performance representation methods can also be used as long as they can represent the damper stiffness performance and the relationship between each stiffness and position.

[0146] Matching scheme of damper and support spring (23):

[0147] In the range of all strokes where the support force of the support spring (23) to the vehicle is greater than the target support force value, the closer the absolute value of the damper's tensile stiffness is to the stiffness value of the equivalent support spring (23), the better the damping effect. That is, the stiffness of the equivalent support spring (23) is equal to or close to the absolute value of the damper's tensile stiffness is the selection standard. And the closer the damper's tensile or compression position is to L2 when the vehicle is driving straight on a flat road at a constant speed, the better the damping effect (limiting the tensile or compression position of the damper after initial installation), that is, the closer the damper's tensile or compression position is to L2 when the actual force of the support spring (23) is equal to the target support force value, the better the damping effect.

[0148] The closer the damper's tensile or compression position is to L2 when the vehicle is driving straight on a flat road at a certain speed and load, and the closer the absolute value of the damper's tensile stiffness in the range of L1~L2 is to the stiffness value of the equivalent support spring (23), the better the damping effect of the damper matched with the vehicle at this speed.

[0149] For example: when the vehicle is driving straight on a flat road at a speed of 60km / h and a load of 200kg, the equivalent support force value of the front left support spring (23) is 500kgf, and the stiffness of the support spring (23) is 25kgf / cm, then the closer the tensile or compression position of the front left damper matched with the vehicle is to L2 when the spring support force is 500kgf, and the closer the absolute value of the damper's tensile stiffness in the range of L1~L2 is to 25kgf / cm, the better the damping effect. Similarly, the damping effect of the damper matched with the vehicle at other positions is better. L2 can also be understood as the force balance critical point of the spring, that is, the L2 point of the damper is the force balance point of the vehicle driving straight on a flat road at a certain speed and load, L1~L2 is the case where the support force is too large, L2~L3 is the case where the support force is insufficient, and the closer L2 is to the force balance point and the closer the absolute value of the damper's tensile stiffness in the range of L1~L2 is to the stiffness of the support spring, the better the damping effect. Figure 2

[0150] Preferred scheme 2:

[0151] ​A compression damping controlled shock absorber, comprising: a cylinder, a piston rod, a piston, a bottom valve, a compression valve and a one-way valve are arranged on the bottom valve, the one-way valve on the bottom valve is composed of a one-way valve piece (17) and a spring piece (16), a compression valve spool is connected to the piston or the piston rod through a spring, so that the damping force value of the compression valve is controlled by the stroke of the piston and the tensile force of the spring, when the shock absorber is compressed and the spring is stretched, the greater the tensile force value of the spring, the greater the compression damping, so as to achieve the damping effect. The compression damping force value at any position in the spring tension stroke range in the compression stroke of the shock absorber is proportional to the tensile force value of the spring. In the compression stroke of the shock absorber, the compression damping force value of the shock absorber at any position in the spring compression stroke range is approximately the compression force value of the spring under compression.

[0152] Working principle:

[0153] As shown in FIG. 3: the compression valve spool (19) is subjected to the tension of the spring (13) and cooperates with the compression valve hole to form a damping valve. During the process of the piston moving from L4 position to L3 position, the spring (13) transits from the tensioned state to the free state, the damping force of the damping valve decreases, that is, the compression damping force value of the shock absorber decreases, and the liquid flows from the rodless chamber to the liquid storage chamber through the compression damping channel (20). When the piston moves below the L3 position (the free length position of the spring), the compression damping reaches the minimum value until the piston moves to the L1 position. When the piston moves from L2 position to L1 position, the spring is compressed, the compression valve spool is located at the lower part of the bottom valve, and the compression valve is in the fully open state. When the shock absorber is compressed, the liquid flows from the rodless chamber to the liquid storage chamber (2) through the compression damping channel (20).

[0154] Performance representation method of shock absorber:

[0155] The tensile damping stiffness value of the tension stroke L1~L2, L3~L4 is n kgf / cm.

[0156] The compression damping stiffness value of the compression stroke L4~L3 is -n kgf / cm.

[0157] The compression damping stiffness value of the compression stroke L1~L2 is n kgf / cm.

[0158] The stiffness value of L2~L3 is approximately n kgf / cm.

[0159] Spring matching method:

[0160] In all the range of travel where the support force of the support spring (23) to the vehicle is less than the target support force value, the closer the absolute value of the compression stiffness of the damper to the stiffness value of the equivalent support spring (23), the better the damping effect. That is, the stiffness of the equivalent support spring (23) is equal to or close to the absolute value of the damper stiffness as the selection standard. When the support force of the support spring (23) to the vehicle is equal to the target support force value, the extension and compression positions of the damper should be set between L2 and L3.

[0161] That is, the extension or compression position of the damper when the vehicle is driving straight at a constant speed on a flat road should be set between L2 and L3, and the closer the absolute value of the compression stiffness of the damper at L3 to L4 to the stiffness value of the equivalent support spring (23), the better the damping effect.

[0162] Preferred solution 3 (Fig. 3, Fig. 4, Fig. 5):

[0163] A double-controlled damper with extension damping and compression damping, comprising: a cylinder, a piston rod, a piston, a bottom valve, a piston provided with an extension valve and a one-way valve, a bottom valve provided with a compression valve and a one-way valve, the one-way valve on the bottom valve comprising a one-way valve piece (17) and a spring piece (16), the compression valve spool is connected to the spool of the extension valve through a spring, the piston or piston rod is provided with a position limiting device for the extension valve spool, limiting the displacement of the extension valve, so that the damping force values of the compression valve and the extension valve are controlled by the stroke of the piston and the extension force of the spring. When the damper is stretched or compressed, the extension damping force value or the compression damping force value changes with the stroke of the piston to achieve the damping effect. That is, at any position in the compression stroke of the spring in the extension stroke of the damper, the extension damping force value of the damper is proportional to the compression force value of the spring; at any position in the compression stroke of the spring in the compression stroke of the damper, the compression damping force value is proportional to the extension force value of the spring.

[0164] Working principle:

[0165] As shown in Fig. 3:

[0166] When the piston is compressed from top to bottom, the compression valve spool (19) is subjected to the tension of the spring (13) and cooperates with the compression valve hole to form a damping valve. During the process of the piston descending from L4 position to L3 position, the spring (13) transits from the tension state under force to the free state, and the damping force of the damping valve changes from large to small, that is, the compression damping force value of the damper changes from large to small. When the piston descends to L3 position (free length position of the spring), the damping reaches the minimum value until the piston descends to L1 position. When the piston descends from L2 position to L1 position, the spring is compressed, the compression valve spool is located at the lower part of the bottom valve, and the compression valve is in the fully open state.

[0167] When the piston is stretched from bottom to top, the stretching valve spool cooperates with the valve hole to form a damping valve under the action of spring force. During the process of the piston moving from L1 to L2, the spring transits from the compressed state to the free state, and the damping of the damping valve changes from large to small, i.e. the stretching damping force of the shock absorber changes from large to small. When the piston moves to L2 (the free length position of the spring), the damping reaches the minimum value, and then the piston moves to L4.

[0168] When the piston moves downward, the liquid flows from the rodless chamber to the rod chamber through the compression inlet channel (11), and the liquid in the rodless chamber flows into the liquid storage chamber through the compression damping channel (20).

[0169] When the piston moves upward, the liquid flows from the liquid storage chamber (2) to the rodless chamber (12) through the stretching inlet channel (21), and the liquid in the rodless chamber (4) flows into the rodless chamber (12) through the stretching damping channel (10).

[0170] Performance representation method of shock absorber:

[0171] The stretching damping stiffness value of the stretching stroke L1~L2 is -n kgf / cm.

[0172] The compression damping stiffness value of the compression stroke L1~L2 is n kgf / cm.

[0173] The stretching damping stiffness value of the stretching stroke L3~L4 is n kgf / cm.

[0174] The compression damping stiffness value of the compression stroke L3~L4 is -n kgf / cm.

[0175] The stretching and compression stiffness value of L2~L3 is about n kgf / cm.

[0176] n represents the actual numerical value of each stroke position.

[0177] Stiffness matching method:

[0178] In the range of all strokes (L3~L4 stroke positions) where the support force of the support spring (23) on the vehicle is less than the target support force value, the closer the absolute value of the compression stiffness of the shock absorber in this stroke range to the stiffness value of the equivalent support spring (23), the better the damping effect.

[0179] In the range of all strokes (L1~L2 stroke positions) where the support force of the support spring (23) on the vehicle is greater than the target support force value, the closer the absolute value of the stretching stiffness of the shock absorber in this stroke range to the stiffness value of the equivalent support spring (23), the better the damping effect.

[0180] The absolute values of the compression stiffness, the extension stiffness and the damping value of the shock absorber are smaller the better when the support force of the support spring (23) on the vehicle is near the target support force value (L2~L3 stroke position).

[0181] Force value matching method:

[0182] In the extension process of the shock absorber, F 拉实 is equal to or close to F 目 As the best matching standard of the shock absorber and the support spring (23), in the compression process of the shock absorber, F 压实 is equal to or close to F 目 As the best matching standard of the shock absorber and the support spring (23).

[0183] That is, in the range of all strokes (L3~L4 stroke position) where the support force of the support spring (23) on the vehicle is less than the target support force value, the minimum extension damping force value is taken as the matching standard when the shock absorber is in the extension state, so that F 拉实 is as close as possible to F 目 ; and the minimum compression damping force value is taken as the matching standard when the shock absorber is in the compression state, so that F 压实 is as close as possible to F 目 As the compression damping force value matching standard.

[0184] Similarly, in the range of all strokes (L1~L2 stroke position) where the support force of the support spring (23) on the vehicle is greater than the target support force value, F 拉实 is as close as possible to F 目 As the extension damping matching standard, the minimum compression damping force value is taken as the matching standard when the shock absorber is in the compression state, so that F 压实 is as close as possible to F 目。

[0185] Preferred solution 4 (Fig. 1, Fig. 3):

[0186] As in several shock absorbers in the foregoing preferred solutions, the feature is that the one-way valve on the piston comprises a valve block (7). The valve block (7) forms a sealing surface with the cylinder wall of the shock absorber hydraulic cylinder, the valve block (7) forms a passage with the piston that connects the rod cavity and the rodless cavity, the relative movement between the valve block (7) and the piston makes the passage open or closed, when the passage is open, the rodless cavity and the rod cavity of the cylinder are connected, when the passage is closed, the rodless cavity and the rod cavity of the cylinder are not connected. There is a structure or device on the piston or piston rod that limits the displacement of the valve block (7), thereby limiting the relative displacement amount of the valve block (7) and the piston.

[0187] Working principle:

[0188] As shown in Fig. 1, when the shock absorber is compressed, the piston (6) goes down until the limiting structure or limiting device contacts the valve block (7) and drives the valve block (7) to go down together, so that a gap is formed between the piston (6) and the valve block (7), the rodless chamber (12) and the rod chamber (4) form a liquid inlet channel (11) in communication, and the liquid flows from the rodless chamber (12) to the rod chamber (4) through the compression liquid inlet channel (11). When the shock absorber is stretched, the piston (6) goes up until the valve block (7) contacts the sealing surface of the piston (6) and drives the valve block (7) to go up together, so that a sealing structure is formed between the piston (6) and the valve block (7), and the liquid flow cannot pass through the sealing surface between the piston (6) and the valve block (7). The liquid flow in the rod chamber (4) can only flow to the rodless chamber (12) through the stretching valve.

[0189] Preferred solution 5:

[0190] A vehicle, i.e. a vehicle using any one of the shock absorbers described in preferred solutions 1-4.

Claims

1. A vibration damper having a negative stiffness characteristic, comprising: The shock absorber cylinder (14), the piston rod (3), the piston (6), the one-way valve, the stretch valve or / and the compression valve, characterized in that: the spring (13) is arranged in the rodless cavity (12) of the shock absorber cylinder, and the end of the spring is connected with the stretch valve (9) or / and the compression valve (19), and the distance between the piston (6) and the bottom of the cylinder (14) changes when the shock absorber is stretched or compressed, thereby controlling the stretch or / and compression of the spring (13), and the damping force value of the stretch valve (9) or / and the compression valve (19) of the shock absorber is controlled.

2. A vibration damper having a negative stiffness characteristic according to claim 1, characterized in that: The piston (6) is provided with an upper one-way valve, and the piston (6) is further provided with a valve hole matched with the valve core of the stretch valve (9), the valve hole is communicated with the rod cavity (4), the valve core of the stretch valve (9) is arranged in the rodless cavity (12), and the spring (13) is arranged between the valve core of the stretch valve (9) and the bottom valve, when the spring (13) is in a compressed state during the stretching process of the shock absorber, the valve core of the stretch valve (9) is compressed by the spring (13), and the stretch damping valve is formed.

3. A vibration damper having a negative stiffness characteristic according to claim 1, characterized in that The bottom valve (18) is provided with the compression valve (19) and the one-way valve, the valve core of the compression valve (19) is connected to the piston (6), the plunger or the piston rod (3) through the spring, and when the spring (13) is in a tension state during the compression process of the shock absorber, the damping force value of the compression valve (19) is controlled by the stroke of the piston (6) and the stretching force of the spring (13).

4. A vibration damper having a negative stiffness characteristic as defined in claim 1, characterized in that The piston (6) is provided with the stretch valve (9) and the one-way valve, the bottom valve (18) is provided with the compression valve (19) and the one-way valve, the valve core of the stretch valve (9) is connected to the valve core of the compression valve (19) through the spring (13), the piston (6) or the piston rod (3) is provided with a limiting device for limiting the stroke of the valve core of the stretch valve (9), when the spring (13) is in a tension state during the compression process of the shock absorber, the damping force value of the compression valve (19) is controlled by the stroke of the piston (6) and the stretching force of the spring (13), and when the spring (13) is in a compression state during the stretching process of the shock absorber, the damping force value of the stretch valve (9) is controlled by the stroke of the piston (6) and the compression force of the spring (13).

5. A vibration damper having a negative stiffness characteristic according to any one of claims 1 to 4, characterized in that: The one-way valve on the piston (6) is mainly composed of a valve block (7), the valve block (7) and the cylinder wall of the shock absorber cylinder (14) form a sealing surface, there is a liquid inlet channel (11) between the valve block (7) and the piston (6) and communicated with the rod cavity (4) and the rodless cavity (12), and the valve block (7) and the piston (6) can move relative to each other, so that the liquid inlet channel (11) is opened or closed when the shock absorber is compressed or stretched.

6. A vehicle characterized by The shock absorber with negative stiffness characteristics is adopted.

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