A valve-controlled constant damping adjustable fluid inertia suspension device

Abstract

The present invention discloses a valve-controlled constant damping adjustable fluid inertia suspension device, which is based on a double-rod hydraulic cylinder and realizes the switching of two fluid pipelines through a high-speed switch valve. The structural parameter design ensures that when the fluid flows through any fluid pipeline at high speed, the expected inertia force and damping force are generated, the adjustment of the inertia force and the damping force are independent of each other, and the damping force is constant. A spiral tube is provided, and the fluid flows from one side of the hydraulic cylinder barrel to the other side through the spiral tube to form a first fluid pipeline. A short straight tube with a damping hole is provided, and the fluid flows from one side of the hydraulic cylinder barrel to the other side through the short straight tube with the damping hole to form a second fluid pipeline. The present invention is suitable for the harsh working conditions of military vehicle suspension devices, and the two working pipelines can be switched through switch control to adjust the inertia and damping characteristics of the suspension, thereby greatly improving the vibration reduction performance of the suspension device, and has good application value.

Description

Technical Field

[0001] The invention relates to the technical field of vibration reduction and vehicle suspension, and in particular to a valve-controlled constant damping adjustable fluid inertia suspension device. Background Art

[0002] In 2002, Smith of Cambridge University proposed the concept of inertia vessel, and thus constructed a new vibration isolation theory system of "inertia vessel-spring-damper". Inertia vessel helps to solve common problems in the field of vibration reduction and noise reduction. The concept of fluid inertia vessel was first proposed in 2010. Fluid inertia vessel is a dynamic characteristic that makes the axial force proportional to the relative acceleration of the two ends by accelerating the flow of liquid in a spiral pipe. Fluid inertia vessel not only has sufficient load-bearing capacity, but also has a simple structure and high stability. It is regarded as the most potential form of inertia vessel for actual mass production. In addition, fluid inertia vessel has the advantages of large inertia coefficient and strong impact resistance, which is suitable for the harsh working conditions of military vehicle suspension devices. More importantly, due to the various self-contained damping effects generated by the liquid during the flow process, it has a structural expansibility that can combine multiple damping and inertia effects. For example, the damping of different topological structures can be increased by using the flow limiting valve and the piston oil hole to adjust the inertia and damping characteristics of the suspension, thereby greatly improving the comprehensive performance of the suspension. Therefore, the design of a fluid inertia vessel with a suitable structure has become a research hotspot and focus in the current field of inertia vessels.

[0003] Patent CN201510762454.7 proposes a dual-pipeline fluid inertia container with a variable inertia coefficient. The opening and closing of the pipeline is controlled by controlling the opening and closing of the valve, thereby adjusting the flow mode of the oil, and realizing a fluid inertia container device with three-level adjustable inertia coefficients of "large", "medium" and "small", which has the advantages of simple control and easy implementation. As mentioned above, a variety of damping effects will be generated in the process of fluid flowing through the pipeline at high speed, but like this patent, the existing literature only considers the inertia force and does not consider the influence of the damping force. However, in engineering practice, when the oil flows in pipelines of different diameters or (and) lengths, the damping force is often different. When the control valve described in patent CN201510762454.7 is opened and closed at high speed, the damping force will also produce large fluctuations in the process of adjusting the inertia coefficient. In this case, although the change of the inertia coefficient can improve the vibration reduction effect, the large fluctuation of the damping force will often reduce the vibration reduction efficiency. Therefore, under certain working conditions, the fluctuation of damping force will weaken the beneficial effects brought about by the adjustment of the inertia coefficient. Under certain extreme working conditions, the drastic fluctuation of damping force will make it impossible to quickly suppress resonance, and may even produce strong impact, resulting in poor vehicle ride comfort. It may also cause problems with handling stability, leading to extremely dangerous working conditions such as vehicle instability and steering failure. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention proposes a valve-controlled constant damping adjustable fluid inertia suspension device solution.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A valve-controlled constant damping adjustable fluid inertia suspension device is based on a double-rod hydraulic cylinder. The double-rod hydraulic cylinder comprises a hydraulic cylinder barrel (11) and a piston rod (12). The hydraulic cylinder outputs force externally. The left end point of the hydraulic cylinder barrel (11) and the right end point of the piston rod (12) are two interfaces of inertia force. The switching of two fluid pipelines is achieved through a high-speed switch valve (9). The structural parameter design ensures that when the fluid flows through any fluid pipeline at high speed, the expected inertia force and damping force are generated. The inertia force and the damping force are adjusted independently and the damping force remains constant. The first fluid pipeline is a linear inertia vessel and a nonlinear damper in parallel, and the second fluid pipeline is a linear inertia vessel and a nonlinear damper in parallel, and a nonlinear damper with a small hole throttling is superimposed.

[0007] Furthermore, a spiral tube (8) is provided, and the fluid flows from one side of the hydraulic cylinder barrel (11) to the other side through the spiral tube (8) to form a first liquid flow pipeline; a short straight tube (6) with a damping hole (7) is provided, and the fluid flows from one side of the hydraulic cylinder barrel (11) to the other side through the short straight tube (6) with the damping hole (7) to form a second liquid flow pipeline.

[0008] Furthermore, the damping force of the first liquid flow pipeline is changed by changing the bending radius of the spiral tube; the damping force of the second liquid flow pipeline is changed by changing the radius of the damping hole; the inertia force of the first liquid flow pipeline is changed by changing the length of the spiral tube, or the inner diameter of the spiral tube, or by changing both the length of the spiral tube and the inner diameter of the spiral tube; the inertia force of the second liquid flow pipeline is changed by changing the inner diameter of the short straight tube, or the length of the short straight tube, or by changing both the inner diameter of the short straight tube and the length of the short straight tube.

[0009] Furthermore, the damping force F of the first fluid pipeline is c The calculation method is as follows:

[0010]

[0011] in,

[0012]

[0013] z 1 is the displacement of one end point, z 2 is the displacement of the other end point, is the relative velocity of the two endpoints;

[0014] sign is the sign function;

[0015]

[0016] ρ is the oil density,

[0017] l ch is the length of the spiral tube, n is the number of turns of the helical tube, and h is the pitch of the helical tube;

[0018] r c is the inner diameter of the cylinder, r r is the piston rod radius, R is the spiral tube bending radius, r ch is the inner diameter of the spiral tube.

[0019] Furthermore, the damping force F of the second fluid pipeline is c The calculation method is as follows:

[0020]

[0021] in,

[0022]

[0023]

[0024] r c is the inner diameter of the cylinder, r r is the piston rod radius, C d is the flow coefficient, r k is the radius of the damping hole;

[0025] μ is the dynamic viscosity of the fluid, l is the length of the short straight tube, r h It is the inner diameter of the short straight pipe.

[0026] Furthermore, the calculation method of the inertia force b of the first fluid flow pipeline is as follows:

[0027]

[0028] Furthermore, the calculation method of the inertia force b of the second liquid flow pipeline is as follows:

[0029]

[0030] Furthermore, the fluid is water, non-toxic and harmless low-viscosity oil or magnetorheological fluid; the double-rod hydraulic cylinder consisting of the hydraulic cylinder barrel (11) and the piston rod (12) is made of steel, the short straight pipe (6) and the spiral pipe (8) are made of rubber, and the high-speed switch valve (9) uses a high-precision valve system structure.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention proposes a new type of single-tube fluid inertia suspension device, specifically a valve-controlled constant damping adjustable fluid inertia suspension device. Compared with the traditional fluid inertia container, the present invention adopts a single-tube fluid inertia container structure, with a spiral tube liquid flow pipeline and a short straight tube liquid flow pipeline, and can switch the working liquid flow pipeline through a high-speed switch valve, thereby realizing the adjustment of the inertia coefficient of the fluid inertia container.

[0033] 2. The valve-controlled constant damping adjustable fluid inertia suspension device has a structure that integrates multiple damping and inertia effects, which is used to adjust the inertia and damping characteristics of the suspension, and can greatly improve the comprehensive performance of the suspension. The device has sufficient load-bearing capacity, a large inertia coefficient, and strong impact resistance. It is suitable for the harsh working conditions of off-road vehicle suspension devices and has a high application value.

[0034] 3. The scheme of the present invention is concise and easy to understand, and the principle is reliable and easy to implement.

[0035] 4. The short straight tube can provide a smaller inertial force, and the damping force it generates is also smaller than that of the spiral tube. When the oil flow path switches between the spiral tube and the short straight tube, the damping force will fluctuate violently. The present invention adds a throttle hole device in the short straight tube, and by adjusting the size of the throttle hole, the damping force is kept approximately constant when the oil switches between the spiral tube and the short straight tube, thereby reducing the fluctuation of the damping force and greatly improving the vibration reduction efficiency of the suspension.

[0036] 5. The present invention achieves constant damping force during the switching process by setting the size of the damping hole, and has a simple structure, good processability and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of a valve-controlled constant damping adjustable fluid inertia suspension device of the present invention.

[0038] Figure 2 It is an equivalent principle diagram of the spiral pipe pipeline structure of a valve-controlled constant damping adjustable fluid inertia suspension device of the present invention.

[0039] Figure 3 It is an equivalent principle diagram of a short straight pipe structure of a valve-controlled constant damping adjustable fluid inertia suspension device of the present invention.

[0040] Figure 4 It is a schematic diagram of a specific embodiment of a valve-controlled constant damping adjustable fluid inertia suspension device of the present invention.

[0041] Figure 5 It is an equivalent principle diagram of a specific embodiment of a valve-controlled constant damping adjustable fluid inertia suspension device of the present invention.

[0042] In the figure, 1. first end point, 2. left chamber, 3. right chamber, 4. second end point, 5. first oil port, 6. short straight pipe, 7. damping hole, 8. spiral tube, 9. high-speed switching valve, 10. second oil port, 11. hydraulic cylinder, 12. piston rod. DETAILED DESCRIPTION

[0043] In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The present invention can be implemented in many different forms, and the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. On the contrary, the purpose of illustrating in conjunction with the drawings and embodiments is to make the disclosure of the present invention clearer and easier to understand.

[0044] like Figure 1 As shown, a valve-controlled constant damping adjustable fluid inertia suspension device includes: a first end point 1, a second end point 4, a left oil chamber 2, a right oil chamber 3, a first oil port 5, a second oil port 10, a short straight pipe 6, a damping hole 7, a spiral pipe 8, a high-speed switch valve 9, a hydraulic cylinder 11, and a piston rod 12. The valve-controlled constant damping adjustable fluid inertia suspension device includes a double-rod hydraulic cylinder, which is composed of a hydraulic cylinder 11 and a piston rod 12, and outputs force to the outside. The cylinder 11 has an end point 1 on the left side, and the piston rod 12 has an end point 4 on the right side. End point 1 and end point 4 are two interfaces for inertia force. During the operation, the valve-controlled constant damping adjustable fluid inertia suspension device will generate inertia force and damping force, and includes two fluid pipeline combinations. The high-speed switch valve 9 is controlled by a switch control method to realize the switching of the working pipeline of the fluid inertia suspension device. The oil chambers 2, 3, oil ports 5, 10 and spiral tube 8 constitute the first type of liquid flow pipeline; the oil chambers 2, 3, oil ports 5, 10, short straight tube 6 and damping hole 7 constitute the second type of liquid flow pipeline. The high-speed switch valve 9 can control the on-off of the spiral tube 8 and the short straight tube 6, so as to switch the working modes of the two liquid flow pipelines. When the fluid flows through the two liquid flow pipelines at high speed, inertial force and damping force will be generated. When the end points 1 and 4 move relative to each other, the oil is forced to flow back and forth at high speed between the liquid flow pipelines, so as to achieve the encapsulation of the inertial force. The on-off of the spiral tube 8 and the short straight tube 6 is controlled by the high-speed switch valve 9, and the two working modes of the liquid flow pipelines are switched, so as to achieve the adjustment of the inertia coefficient of the fluid inertia suspension. The oil chambers 2, 3, oil ports 5, 10 and spiral tube 8 constitute the first type of liquid flow pipeline. When the fluid flows through the first type of fluid pipeline, it provides inertial force and generates a large parasitic damping force. Its mechanical characteristics are equivalent to the parallel connection of a linear inertia container and a nonlinear damper. Figure 2As shown. According to the dynamic requirements of the suspension, the optimal combination of inertia coefficient and damping coefficient can be obtained by optimizing the structural parameters of the spiral tube 8. The oil chambers 2, 3, the oil ports 5, 10, the short straight tube 6, and the damping hole 7 constitute the second fluid flow pipeline. When the fluid flows through the second fluid flow pipeline, its mechanical characteristics are equivalent to the parallel connection of a linear inertia container and a nonlinear damper, and a nonlinear damper with a small hole throttling is superimposed, as shown in FIG. Figure 3 As shown, the combination of small inertia coefficient and large damping coefficient can be achieved simultaneously through the additional small hole throttling effect. The fluid can be water, non-toxic and harmless low-viscosity oil or magnetorheological fluid. The high-speed switch valve 9 uses a high-precision valve system structure. The device has sufficient load-bearing capacity, a large inertia coefficient, and strong impact resistance, and is suitable for the harsh working conditions of off-road vehicle suspension devices.

[0045] The following further provides the working principle of the valve-controlled constant damping adjustable fluid inertia suspension device, the mechanical characteristics calculation method and the implementation scheme of the valve-controlled constant damping adjustable fluid inertia suspension device. The scheme is concise and easy to understand, and the principle is reliable and easy to implement.

[0046] Assuming that the oil volume conservation and liquid density remain unchanged during the operation of the fluid inertia container, the influence of potential energy, heat energy loss and temperature change on the oil flow is not considered, and the damping force F of the oil flowing through the two liquid flow pipelines is considered. c and inertial force F b , the force analysis of the piston can obtain the equivalent schematic diagrams of the two fluid pipeline structures, such as Figure 2 and Figure 3 shown.

[0047] The force F at both ends of the fluid inertia container is:

[0048] F=F c +F b (1)

[0049] Inertial force F b for

[0050]

[0051] Where: is the relative acceleration of the two end points, and the damping force F is quantitatively analyzed c and inertial force F b The size of the two liquid flow pipelines flowing through the spiral tube 8 and the short straight tube 6 + damping hole 7 are compared and analyzed in detail, as shown in the following table, where: is the relative speed, sign is the sign function, and the definitions of other structural dimensions are shown in the table below.

[0052]

[0053]

[0054] As shown in the table above, when the fluid flows through the spiral tube 8, it provides inertial force and generates a large parasitic damping force. Its mechanical characteristics are equivalent to the parallel connection of a linear inertia container and a nonlinear damper. When the fluid flows through the combined pipeline of "short straight tube 6 + damping hole 7", it is equivalent to the parallel connection of a linear inertia container and a nonlinear damper, and a nonlinear damper with a small hole throttling is superimposed. The function of the damping hole is to ensure that the damping force is approximately constant during the switching process.

[0055] It can be found from the calculation formula in the above table that in the spiral tube fluid flow circuit, the dynamic viscosity μ of the fluid and the bending radius R of the spiral tube only affect the magnitude of the damping force and have nothing to do with the magnitude of the inertial force. Therefore, by adjusting the dynamic viscosity μ of the fluid and the bending radius R of the spiral tube, the inertial force and the damping force of the spiral tube 8 can be decoupled. Similarly, by adjusting the dynamic viscosity μ of the fluid and the radius r of the damping hole 7 k It is also possible to decouple the inertial force and damping force flowing through the "short straight pipe 6 + damping hole 7 combination". Therefore, by optimizing the ρ,r of the first liquid flow pipeline c ,r ch ,r r ,l ch , and ρ,r for the second flow line c ,r h ,r r ,l can get the required inertia coefficient, because it involves ρ,r c ,r r , so by optimizing r ch ,l ch and r h ,l achieves the purpose of adjusting the inertia force of the two fluid pipelines; on the basis of determining the inertia coefficient, adjust R or r k The optimal damping force can be achieved without affecting the optimized inertia coefficient. Therefore, this method can obtain the optimal inertia coefficient and damping coefficient at the same time by adjusting the structural dimensions of the fluid inertia container.

[0056] A valve-controlled constant damping adjustable fluid inertia suspension device is specifically implemented as follows Figure 4 As shown, a specific embodiment of a valve-controlled constant damping adjustable fluid inertia suspension device is equivalent to the schematic diagram as shown in Figure 5As shown. In this suspension scheme, the upper and lower arms adopt a double wishbone structure; the upper and lower arms and the kingpin form a steering knuckle; the single-tube fluid inertia container is arranged on the inner side of the wheel, and its upper end is connected to the vehicle body through an upper hinge, and the lower end is connected to the lower arm through a lower hinge; because the cylinder will change during the suspension compression or recovery stroke, the single-tube fluid inertia container connects the spiral tube and the short straight tube through a rubber hose, which serves as a channel for the fluid to reciprocate between the two hydraulic cylinders; using the switch control method, the high-speed switch valve controls the on and off of the spiral tube and the short straight tube to switch between the two fluid pipeline working modes, thereby realizing the adjustment of the inertia coefficient of the inertia container. This suspension model is equivalent to a parallel structure of three elements: adjustable inertia, spring, and damping, in which the adjustable inertia is provided by flowing through different pipelines, the spring adopts a spiral spring, and the damping is the viscous damping generated by flowing through the pipeline, and the damping of each pipeline is constant.

[0057] Specifically, when the vehicle encounters bumps during driving, the single-acting hydraulic cylinder is in a compressed or stretched state, and the wheel moves upward or downward relative to the vehicle body. In order to prevent the wheel from generating excessive dynamic load and to reduce the longitudinal displacement of the vehicle body, the inertial force generated by the fluid inertia container should be small, that is, the inertia coefficient of the fluid inertia container should be small, which can ensure that the wheel can move faster relative to the fluid inertia container, and absorb the kinetic energy generated by the wheel movement through the flow of the fluid in the inertia container, thereby reducing the longitudinal displacement of the vehicle body and exerting a vibration reduction effect. From the above calculation method of the inertia coefficient, it can be seen that in order to achieve the purpose of reducing the inertia coefficient, the high-speed switch valve needs to be connected to a short straight pipe + damping hole combination pipeline to reduce the inertia coefficient of the inertia container and increase the damping coefficient.

[0058] When the vehicle travels from a bumpy road to a flat road, the vehicle suspension will return to a normal state. The inertia container should have a larger inertia force, that is, a larger inertia coefficient, to reduce or avoid the impact caused by the wheels pressing back to the ground and keep the vehicle body stable. In order to achieve the purpose of increasing the inertia coefficient, the high-speed switch valve needs to be connected to the spiral pipe line to increase the inertia coefficient of the inertia container and obtain an appropriate damping coefficient. Through the switch control of the fluid pipeline, the optimal vibration reduction performance of the valve-controlled adjustable fluid inertia suspension device can be achieved under different working conditions.

[0059] The above embodiments are only used to illustrate the design ideas and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, any equivalent changes or modifications made based on the principles and design ideas disclosed by the present invention are within the protection scope of the present invention.

Claims

1. A valve-controlled constant damping adjustable fluid inertia suspension device, based on a double-rod hydraulic cylinder, the double-rod hydraulic cylinder comprising a hydraulic cylinder barrel (11) and a piston rod (12), which outputs force to the outside, the left end point of the hydraulic cylinder barrel (11) and the right end point of the piston rod (12) are two interfaces of inertia force, characterized in that: The switching of the two fluid pipelines is realized by a high-speed switch valve (9), and the structural parameter design ensures that when the fluid flows through any fluid pipeline at high speed, the expected inertia force and damping force are generated, the inertia force and the damping force are adjusted independently of each other, and the damping force is constant, wherein the first fluid pipeline is a linear inertia container and a nonlinear damper in parallel, and the second fluid pipeline is a linear inertia container and a nonlinear damper in parallel, and a nonlinear damper with a small hole throttling is superimposed; A spiral tube (8) is provided, and fluid flows from one side of the hydraulic cylinder barrel (11) to the other side through the spiral tube (8) to form a first fluid flow pipeline; a short straight tube (6) with a damping hole (7) is provided, and fluid flows from one side of the hydraulic cylinder barrel (11) to the other side through the short straight tube (6) with the damping hole (7) to form a second fluid flow pipeline; The magnitude of the damping force of the first liquid flow pipeline is changed by changing the bending radius of the spiral tube; the magnitude of the damping force of the second liquid flow pipeline is changed by changing the radius of the damping hole; the magnitude of the inertia force of the first liquid flow pipeline is changed by changing the length of the spiral tube, or the inner diameter of the spiral tube, or by changing the length of the spiral tube and the inner diameter of the spiral tube at the same time; the magnitude of the inertia force of the second liquid flow pipeline is changed by changing the inner diameter of the short straight tube, or the length of the short straight tube, or by changing the inner diameter of the short straight tube and the length of the short straight tube at the same time.

2. A valve-controlled constant damping adjustable fluid inertia suspension device according to claim 1, characterized in that: Damping force F of the first fluid flow line c The calculation method is as follows: in, z1 is the displacement of one endpoint, z2 is the displacement of the other endpoint, is the relative speed of the two endpoints; sign is the sign function; ρ is the oil density, l ch is the length of the spiral tube, n is the number of turns of the helical tube, and h is the pitch of the helical tube; r c is the inner diameter of the cylinder, r r is the piston rod radius, R is the spiral tube bending radius, r ch is the inner diameter of the spiral tube.

3. A valve-controlled constant damping adjustable fluid inertia suspension device according to claim 2, characterized in that: Damping force F of the second fluid flow line c The calculation method is as follows: in, r c is the inner diameter of the cylinder, r r is the piston rod radius, C d is the flow coefficient, r k is the radius of the damping hole; μ is the dynamic viscosity of the fluid, l is the length of the short straight tube, r h It is the inner diameter of the short straight pipe.

4. A valve-controlled constant damping adjustable fluid inertia suspension device according to claim 3, characterized in that: The inertia force b of the first fluid flow line is calculated as follows:

5. A valve-controlled constant damping adjustable fluid inertia suspension device according to claim 4, characterized in that: The calculation method of the inertia force b of the second liquid flow pipeline is as follows:

6. A valve-controlled constant damping adjustable fluid inertia suspension device according to any one of claims 1 to 5, characterized in that: The fluid is water, non-toxic and harmless low-viscosity oil or magnetorheological fluid, and the high-speed switch valve (9) adopts a high-precision valve system structure.

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