KR100461387B1 - posture control system of vehicle - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle attitude control system, and includes a cylinder (2) consisting of an outer cylinder (2a) and an inner cylinder (2b), and a piston (3) and a piston rod (4) linearly moved up and down in the cylinder (2). A shock absorber (10) comprising a, a magnetic coil (21) wound around a predetermined section and installed on an outer circumferential surface of the inner cylinder (2b), and a permanent magnet (22) press-fitted to the outer circumferential surface of the piston rod (4). ), A signal converter used to apply the magnetorheological fluid 23 filled in the cylinder 2 and the induced electromotive force generated by the linear reciprocation of the piston rod 4 to the magnetorheological fluid 23. It consists of a 24 and an amplifier 25, to control the posture of the vehicle according to the situation quickly and correctly when the length of the shock absorber 10 is compressed (BUMP) or extended (REBOUND) in accordance with the change in the attitude of the vehicle Can help you to drive safely. Not only will the allow the sunshine to improve the ride quality.

Description

Posture control system of vehicle

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle attitude control system. In particular, when the length of a shock absorber is compressed (BUMP) or extended (REBOUND) according to a change in the attitude of a vehicle, it is possible to quickly control the vehicle attitude according to a situation. A vehicle attitude control system.

In general, the suspension system is an important device for promoting the ride comfort and driving stability of the vehicle, and the main components thereof include a spring for absorbing the shock during the bump / rebound of the wheel, and the impact as described above. There is a shock absorber that absorbs the vibration and quickly attenuates the vibration of the spring and maintains a constant garage.There is a strut method that connects these springs and the shock absorber integrally to the knuckle and installs them in different positions. There are many different types of suspensions, including the way.

There are many types of shock absorbers as described above. Looking at the basic structure of the McPherson strut shock absorber 10, as shown in FIG. 1, the outer cylinder 2a and the inner side of the cover 1 connected to the vehicle body side are shown. A cylinder (2) consisting of an inner cylinder (2b), a piston (3) and a piston rod (4) connected to the vehicle body side together with the cover (1), moving up and down in the cylinder (2), and the piston ( 3) the base valve (5) provided at the lower side of the piston valve (3a) and the cylinder (2) provided to switch the communication state between the reservoir (2c) and the cylinder (2) between the inner cylinder (2a) and the outer cylinder (2b); And oil (6) filled in the cylinder (2).

Here, the piston (3) is formed with a plurality of orifices (not shown), the orifice is installed in each of the leaf springs are spaced apart at minute intervals, the orifice and the leaf springs are collectively referred to as a piston valve (3a). .

In this shock absorber 10, when the piston rod 4 moves downward at the time of compression, the space under the piston 3 becomes high pressure, and the oil 6 pushes the non-return valve of the piston valve 3a. While raising, the piston 3 is easily moved downward with almost no resistance. At this time, the volume of oil in which the piston rod 4 is pushed into the cylinder opens the damping force generating valve of the base valve 5 and opens the outer cylinder 2b. Damping force is generated as it flows out into the reservoir 2c, which is a space between the inner cylinder 2a and the inner cylinder 2a, and when the piston rod 4 moves upward during expansion, the upper portion of the piston 3 becomes a high pressure piston valve 3a. At this time, the flow resistance of the oil (6) becomes a damping force to stop the vibration of the spring quickly, and the oil (6) that flowed out into the reservoir (2c) is the field of the base valve (5) Through the return valve almost without resistance of the cylinder It is to be recovered in the space.

However, the conventional shock absorber 10 as described above has a problem in that the posture cannot be controlled as the overall length is actively changed according to the vibration state of the vehicle body.

For example, if the attitude of the vehicle does not change when the overall length of the shock absorber 10 is compressed according to the vibration state of the vehicle body, the compressed state does not itself extend. Shock absorber 10 has a problem that can not actively cope with the attitude of the vehicle.

In order to solve the above problems, a variable orifice type shock absorber using a step motor has been recently used to absorb vibration by changing the viscosity of oil according to the attitude of a vehicle. However, the variable orifice type shock absorber is a device. Because of the complicated and expensive parts, there is a problem that it is not only mounted on high-end vehicles, but also has a problem that it is not suitable for active posture control due to the slow response of system according to the situation.

Accordingly, the present invention has been made to solve the above problems, and equipped with a shock absorber using a magneto-rheological fluid whose viscosity changes according to the magnitude of the induced electromotive force, and according to the vibration state of the vehicle body It is an object of the present invention to provide a vehicle attitude control system capable of controlling the vehicle attitude as the overall length of the absorber is actively changed.

The attitude control system of the present invention for achieving the above object is a shock absorber comprising a cylinder consisting of an outer cylinder and an inner cylinder and a piston and a piston rod linearly moved up and down in the cylinder, and the outer peripheral surface of the inner cylinder. Magnetic coils are wound around the magnetic coil, and the permanent magnets are press-fitted to the outer circumference of the piston rod, the magnetorheological fluid filled in the cylinder, and the induced electromotive force generated by the linear reciprocating movement of the piston rod. It is characterized by consisting of a signal converter and an amplifier used for applying to the fluid.

1 is a longitudinal sectional view of a shock absorber generally used;

2 is a schematic configuration diagram of an attitude control system according to the present invention;

3 to 6 are longitudinal cross-sectional views and flowcharts for explaining the concept of the posture control system according to the present invention.

<Description of Symbols for Main Parts of Drawings>

2-cylinder 2a-outer cylinder

2b-inner cylinder 3-piston

4-Piston Rod 10-Shock Absorber

21-Magnetic Coil 22-Permanent Magnet

23-magnetorheological fluid 24-signal transducer

25-amplifier

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a schematic configuration diagram of a posture control system according to the present invention, will be described with the same reference numerals to the same parts as the conventional structure.

As shown in FIG. 2, the vehicle posture control system according to the present invention includes a cylinder 2 including an outer cylinder 2a and an inner cylinder 2b inside the cover 1 connected to the vehicle body side, and the cylinder ( 2) the piston (3) and the piston rod (4) which moves up and down in the vehicle and is connected to the vehicle body side together with the cover (1), and the piston valve (3a) and the cylinder (2) provided in the piston (3) It is configured to include a McPherson strut shock absorber (10) which is provided on the lower side and comprises a reservoir (2c) between the inner cylinder (2a) and the outer cylinder (2b) and a base valve (5) for switching the communication state of the cylinder (2). .

In addition, the attitude control system of the vehicle according to the present invention is a magnetic coil 21 is installed wound around a certain section on the outer peripheral surface of the inner cylinder (2b), and the permanent magnet 22 is pressed into the outer peripheral surface of the piston rod (4) ), A signal converter used to apply the magnetorheological fluid 23 filled in the cylinder 2 and the induced electromotive force generated by the linear reciprocation of the piston rod 4 to the magnetorheological fluid 23. 24 and an amplifier 25 are further included.

On the other hand, the magnetic coil 21 has a structure that is installed while being wound at equal intervals on the outer circumferential surface of the inner cylinder (2b) located to the lower side of the piston 3 in the shock absorber 10 is not applied to the load.

In addition, the permanent magnet 22 has a constant height from the bottom end of the piston rod (4) connected to the piston valve (3a) is pressed into the outer peripheral surface of the piston rod (4) is installed.

On the other hand, a brief feature of the magnetorheological fluid 23 to be filled in the cylinder (2) is as follows.

The magneto-rheological fluid (23) is a non-colloidal solution in which particles having a magnet size of microns are dispersed in a non-conductive solvent such as silicone oil or mineral oil, and dynamic characteristics thereof are changed by magnetic field load. As a fluid, a solution in which paramagnetic particles are dispersed in a solvent having a low permeability, and the magnetorheological fluid 23 is a Newtonian fluid having a random structure at no load without a magnetic field. However, once the magnetic field is loaded, the magnetically dispersed particles cause polarization, forming a chain-like fibrous structure in a direction parallel to the loaded magnetic field, thereby reducing the shear force or flow resistance, that is, the shear strain. It is a fluid that is transformed into a Bingham fluid without constant yield shear stress.

In addition, the magnetorheological fluid 23 exhibits isotropic properties due to free movement of particles dispersed in the fluid under no electric field, but induced dispersion of particles dispersed in the fluid when the electric field is applied to the electrosensitive fluid. It is a kind of controllable fluid that has a characteristic of exhibiting anisotropic behavior by forming a plurality of fibrous tissues facing the electrode, and thus exhibiting resistance to fluid flow or force from external load. The advantages of the fast response speed of electro-rheological fluids are those that have the disadvantages of low yield stress, narrow operating temperature range, and especially susceptibility to impurities.

Hereinafter, an operation process of the vehicle attitude control system according to the present invention will be described in detail with reference to FIGS. 2 to 6.

First, the piston 3 of the shock absorber 10, which is not loaded, is positioned so that its tip is coincident with the top of the magnetic coil 21, as shown in FIG. 2, in which case the piston rod 4 ) Is not linearly moved along the cylinder (2), so no induced electromotive force is generated.

On the other hand, the state of the shock absorber 10 in which no induced electromotive force is generated while no load is applied is referred to as a reference state (zero state) in the embodiment of the present invention.

In the above state, when a constant load is applied in an eccentric state as shown in FIG. 3, the shock absorber 10 supporting the left wheel 3l of the vehicle performs a compression (BUMP) action, on the contrary, the right side. The shock absorber 10 supporting the wheel 32 is extended (REBOUND).

Here, the state of the shock absorber 10 that acts as a compression (BUMP) is shown in Figure 4, the piston 3 and the piston rod 4 is passed through the reference state (C) by a constant load cylinder (2) When the reciprocating movement while moving in the lower direction of), the induced electromotive force is generated by the interaction of the magnetic coil 21 and the permanent magnet 22, and the induced electromotive force is generated by the signal converter 24 and the amplifier 25 ) Is sequentially applied to the magnetorheological fluid 23 enclosed in the cylinder (2).

When the voltage of the induced electromotive force is applied to the magnetorheological fluid 23, the viscosity of the magnetorheological fluid 23 is increased. At this time, the viscosity of the piston 3 and the piston rod 4 of the cylinder 2 is increased. When moved to the bottom, it is changed to the maximum.

As such, when the viscosity of the magnetorheological fluid 23 is increased, the viscosity of the magnetorheological fluid 23 passing through the base valve 5 is increased, which causes energy for the downward movement of the piston rod 4. As damping force is absorbed, it is possible to actively control the change of attitude of the vehicle.

On the other hand, the state of the shock absorber 10 that performs the extension (REBOUND) action, such as the shock absorber 10 for supporting the right wheel 32 is shown in Figure 6, the piston 3 and the piston rod ( 4) is a state away from the reference state (C) and spaced apart from the magnetic coil 21 at a predetermined interval, wherein the viscosity of the magnetorheological fluid 23 has a shock absorber (10) as described above with reference to FIG. In the reference state (C) to which the load is not applied), the viscosity of the magnetorheological fluid 23 is reduced.

Here, the viscosity of the magnetorheological fluid 23 is gradually reduced by the distance that the piston 3 and the piston rod 4 is moved to the upper side of the cylinder (2).

In this manner, when the viscosity of the magnetorheological fluid 23 decreases from the viscosity of the reference state C, to which no load is applied, when the piston 3 and the piston rod 4 are moved to the upper side of the cylinder 2, The viscosity of the magnetorheological fluid 23 passing through the base valve 5 is reduced, which causes the piston rod 4, which has been raised and lowered along the cylinder 2, to receive the force to be lowered again. It will be able to control accordingly.

Therefore, when the shock absorber 10 using the magnetorheological fluid 23 is mounted on each wheel of the vehicle according to the present invention, the length of the shock absorber 10 is compressed (BUMP) according to the change in the attitude of the vehicle. It is possible to actively change its length when it is REBOUND, which allows the vehicle to control the posture correctly.

In addition, the posture control system according to the present invention is able to help the vehicle's safe operation by the responsiveness of the system according to the situation, and also has the advantage that can help improve the ride comfort.

As described above, according to the present invention, when the length of the shock absorber is compressed (BUMP) or extended (REBOUND) according to the change in the attitude of the vehicle, it is possible to quickly and correctly control the attitude of the vehicle according to the situation. This not only helps to drive safely but also helps to improve ride comfort.

Claims (2)

A shock absorber (10) comprising a cylinder (2) consisting of an outer cylinder (2a) and an inner cylinder (2b), a piston (3) and a piston rod (4) linearly moved up and down in the cylinder (2); The magnetic coil 21 is wound around the outer circumferential surface of the inner cylinder (2b) and is installed, the permanent magnet 22 is pressed into the outer circumferential surface of the piston rod (4), and the magnets filled in the cylinder (2) A vehicle composed of a rheological fluid 23 and a signal converter 24 and an amplifier 25 used to apply an induced electromotive force generated by the linear reciprocation of the piston rod 4 to the magnetorheological fluid 23. Attitude control system. The method of claim 1, wherein the magnetic coil 21 is installed on the outer circumferential surface of the inner cylinder (2b) which is located below the piston (3) in the shock absorber (10) which is not applied to the load is installed at equal intervals. Vehicle attitude control system.