Spring with variable rigidity

Abstract

The utility model discloses a spring with variable rigidity, and relates to the technical field of automobile chassis development and test, one end of a spiral compression spring is connected with an air bag, the other end of the spiral compression spring is a free end, and one end of the air bag far away from the spiral compression spring is horizontally arranged on an air bag seat; a spring assembly formed by the air bag and the spiral compression spring can change along with the change of the inflation pressure of the air bag, so that the matching and adjusting work of the suspension spring can be conveniently carried out; meanwhile, the air bag and the spiral compression spring are connected in series, the spring deformation in the stress direction is the superposition amount of spring unit deformation, and the radial size is reasonable.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile chassis development and testing, and specifically relates to a spring with variable stiffness. Background Technique

[0002] During the development of vehicle chassis, the matching and tuning of suspension springs is one of the important tasks. If the stiffness of the spring is too small, it will cause serious roll of the vehicle during steering, which has a very adverse impact on the handling of the vehicle and even endangers driving safety. However, when the stiffness is increased, it will lead to more severe bumps and affect the comfort. Therefore, it is necessary to carry out the matching and tuning of suspension springs to select the most suitable suspension spring to ensure the performance of the vehicle. At present, when carrying out the matching and tuning work of spring stiffness, it is necessary to manufacture spring samples with different stiffnesses, which not only has a high cost but also requires a certain production cycle, and can no longer meet the rapid needs of automobile chassis development.

[0003] The patent document with the name of "A Variable Stiffness Spring" (document number CN 219962384 U) discloses a technical solution that the mean diameter of the linear helical steel spring is slightly larger than the diameter of the laminated inflatable airbag, that is, the linear helical steel spring surrounds the outer periphery of the laminated inflatable airbag. Since the diameter of the laminated inflatable airbag will become larger during the pressing process while the mean diameter of the linear helical steel spring hardly changes, there is a risk of extrusion and friction between the spring body and the outer wall of the airbag. If we want to avoid the friction between the two, it is necessary to design that the mean diameter of the linear helical steel spring is still larger than the diameter of the laminated inflatable airbag at the maximum deformation, and at this time, the outer diameter of the linear helical steel spring needs to be designed larger, which puts new requirements on the layout space of the variable stiffness spring on the vehicle. Content of the Utility Model

[0004] The purpose of the utility model is to provide a spring with variable stiffness, in which the deformation amount of the spring in the force direction is the superposition amount of the deformation of spring units and the radial dimension is reasonable.

[0005] The utility model can be realized by the following technical solutions: A spring with variable stiffness, one end of the helical compression spring is connected to the airbag, and the other end is a free end. The end of the airbag far from the helical compression spring lies horizontally on the airbag seat.

[0006] Compared with the prior art, the utility model has the following beneficial effects:

[0007] By connecting the airbag in series with the helical compression spring, the overall stiffness of the spring assembly composed of the airbag and the helical compression spring will also change with the change of the internal inflation pressure of the airbag, which facilitates the matching and tuning work of the suspension spring. At the same time, after being connected in series, the airbag and the helical compression spring have the spring deformation amount in the force direction as the superposition amount of the spring unit deformations. And when pressing the spring assembly composed of the airbag and the helical compression spring, the diameter of the airbag will become larger without requiring the mean diameter of the helical compression spring to be set very large in advance, so that the rationality of the radial dimension of the spring assembly composed of the airbag and the helical compression spring can be ensured. Brief Description of the Drawings

[0008] Figure 1 It is a schematic structural diagram of each component assembled in the present utility model;

[0009] Figure 2 It is a schematic structural diagram of each component before assembly in the present utility model. Detailed Embodiment

[0010] Please refer to Figure 1-2 As shown, for a spring with variable stiffness, one end of the helical compression spring 30 is connected to the airbag 10, and the other end is a free end. One end of the airbag 10 far from the helical compression spring 30 lies on the airbag seat 20. The free end of the helical compression spring 30 can be directly installed on the suspension support point of the vehicle frame or body, and the bottom end of the airbag seat 20 is connected to components such as the control arm and steering knuckle of the suspension. The helical compression spring 30 is a spring with a fixed stiffness, and the airbag 10 is equivalent to a spring with variable stiffness. It can be understood that the airbag 10 is a pneumatic spring because the overall stiffness of the airbag 10 changes with the change of the internal inflation pressure of the airbag 10. Since the airbag 10 is connected in series with the helical compression spring 30, the overall stiffness of the spring assembly composed of the airbag 10 and the helical compression spring 30 will also change with the change of the internal inflation pressure of the airbag 10. In this way, during the vehicle chassis development process and when matching and tuning the suspension spring, the stiffness of the spring assembly can be changed by changing the internal inflation pressure of the airbag 10, so as to carry out the spring stiffness evaluation work of the actual vehicle. At the same time, since the airbag 10 is connected in series with the helical compression spring 30, the spring deformation amount in the force direction is the superposition amount of the spring unit deformations. And when pressing the spring assembly composed of the airbag 10 and the helical compression spring 30, the diameter of the airbag 10 will become larger without requiring the mean diameter of the helical compression spring 30 to be set very large in advance, so that the rationality of the radial dimension of the spring assembly composed of the airbag 10 and the helical compression spring 30 can be ensured.

[0011] One end of the air duct 21 penetrating the circumferential side wall of the airbag seat 20 is connected to the interior of the airbag 10, and the other end of the air duct 21 located outside the airbag seat 20 is provided with a valve 22; the air duct 21 is used to deliver external gas into the airbag 10, or to discharge the gas inside the airbag 10, and the valve 22 is used to open and close the pipeline of the air duct 21. When the valve 22 is closed, it can prevent the internal gas of the airbag 10 from leaking out, and when the valve 22 is opened, the gas can be allowed to enter or be discharged.

[0012] The middle diameter of the helical compression spring 30 is a conical spring with a large end and a small end, and the small middle diameter end is connected to the airbag 10; the shape of the helical compression spring 30, firstly, it can be compressed more strongly and can provide a greater compression force than a standard spring, which is suitable for the scenario of matching and adjusting the suspension spring; secondly, the conical spring has higher lateral stability, which helps to reduce the lateral movement that may occur when subjected to force, and increases the stability of the overall structure.

[0013] Two connecting ears 23 for fixing the airbag seat 20 are symmetrically arranged on the outer peripheral surface of the airbag seat 20; a threaded hole is opened at the top of the connecting ear 23 to pass through from top to bottom. When in use, the connecting ear 23 is connected to the control arm or steering knuckle of the suspension by screws to complete the connection between the airbag seat 20 and the control arm or steering knuckle of the suspension.

[0014] A recess 24 for accommodating the airbag 10 is provided at the top of the airbag seat 20; the recess 24 provides space for the installation of the airbag 10, reduces the length of the spring assembly consisting of the airbag 10 and the helical compression spring 30 in the force direction, and thus reduces the layout space of the spring assembly on the vehicle.

[0015] A connecting block 11 for connecting the helical compression spring 30 is provided on the top of the airbag 10; the airbag 10 is connected to the helical compression spring 30 via the connecting block 11, which facilitates the installation of the helical compression spring 30 on the airbag 10 and also improves the stability of the two after connection.

[0016] When the spring assembly of the present application is matched and adjusted, the following steps are specifically included:

[0017] The first step is to release the air pressure in the spring assembly consisting of the airbag 10 and the helical compression spring 30, and install it on the whole vehicle, and then place the whole vehicle on the wheel load meter to obtain the initial weight m0 of the single wheel;

[0018] Step 2: Inflate the airbag 10 by increasing the pressure by 10 kPa each time, obtain different wheel load data, and finally obtain a relationship table between the inflation pressure of the airbag 10 and the wheel load;

[0019] Step 3: Data processing: According to the formula (where k represents stiffness, ΔF represents the changed spring load, and z represents spring displacement), it can be obtained that when the inflation pressure of the airbag 10 is known to be zero, the stiffness of the spring assembly is k0. If the inflation pressure of the air introduced is p, the load at this time can be obtained by looking up the table as m, then the corresponding stiffness of the spring assembly at this time is

[0020] Step 4: Real vehicle tuning and matching: Adjust the inflation pressure of the airbag 10 according to the pre-expected stiffness value and carry out the spring stiffness evaluation work of the real vehicle.

Claims

1. A spring with variable stiffness, characterized in that: One end of the helical compression spring (30) is connected to the airbag (10), and the other end is a free end. One end of the airbag (10) away from the helical compression spring (30) lies on the airbag seat (20).

2. The variable stiffness spring according to claim 1, characterized in that: One end of an air guide tube (21) penetrating the circumferential side wall of the air bag seat (20) is communicated with the interior of the air bag (10), and the other end of the air guide tube (21) located outside the air bag seat (20) is provided with a valve (22).

3. The variable stiffness spring according to claim 1, characterized in that: The spiral compression spring (30) has a conical spring with a large middle diameter at one end and a small middle diameter at the other end, and the small middle diameter end is connected to the air bag (10).

4. The variable stiffness spring according to claim 1, characterized in that: Two connecting ears (23) for fixing the airbag seat (20) are symmetrically arranged on the outer peripheral surface of the airbag seat (20).

5. The variable stiffness spring according to claim 1, characterized in that: The top of the airbag seat (20) is provided with a recess (24) for accommodating the airbag (10).

6. The variable stiffness spring according to claim 1, characterized in that: A connecting block (11) for connecting a helical compression spring (30) is arranged on the top of the airbag (10).

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