KR20000061218A - Damping device for automobile seat - Google Patents

Abstract

PURPOSE: A buffer of a seat for a vehicle is provided to improve a ride in heavy vehicle with poor seat cushion by controlling seat buffering according to the road condition. CONSTITUTION: A buffer of a seat for a vehicle comprises: a spring(19) to be mounted to make elastic force between a X-type link(13) and a seat(11); a damper(18) to be mounted to make damping force between the seat and a body(12), with magnetic induction fluid or electric induction fluid; acceleration sensors(14)(15) to be respectively mounted on the seat and the body, and to generate signals according to variations of accelerations; a displacement sensor(16) to be mounted between the seat and the body, generate signals according to variations of relative displacements; a controller(26) to receive signals of the acceleration sensors and the displacement sensor, and to generate an output to adjust a damper(18); an operation output device to receive output signals of the control and to vary current or voltage of the damper.

Description

Damping device for vehicle seats {DAMPING DEVICE FOR AUTOMOBILE SEAT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorber for a vehicle seat, and more particularly, to a shock absorber for a vehicle seat, which improves a riding comfort by adjusting a buffer according to a state of a road surface while driving a large vehicle having a relatively poor seat cushion.

As the development of automobiles is rapidly growing, facilities for the passenger's convenience are relatively important. Especially, the improvement of the passenger's riding comfort is one of the most important factors, but the design for actual development and commercialization is one of the most important factors. There is difficulty.

Various types of shock absorbers are used to reduce the vibrations and shocks generated from the engine and the road surface while driving the vehicle to improve ride comfort. The most common suspension system is a spring and a damper installed between the axle and the body connected to the tire of the car. It primarily reduces vibrations and shocks transmitted to the body.

However, because the suspension alone is not able to completely block the vibration and shock, there is also a case where another seat suspension is installed between the vehicle body and the seat to ensure a sufficient comfort of the occupant.

In particular, large vehicles such as buses, trucks, heavy equipment, and jeeps use an integrated suspension system, so that vibrations and shocks caused by the road surface are not completely absorbed and are transmitted to the driver, adding to the fatigue of the driver who requires a long driving.

Conventionally, as a suspension device for a vehicle seat to absorb the vibration of the vehicle is composed of an X-shaped link structure between the vehicle body and the seat frame, the height of the entire seat frame can be adjusted while each end moves in accordance with the change of load, It was buffered by the air spring in the center and the damper damper.

At this time, most of the dampers are hydraulic or pneumatic dampers, and the pressure is controlled by the stepped opening of the valve which changes the amount of fluid and air according to the condition of the road or the load. It can maintain and always have a certain ride quality.

However, the air spring and the hydraulic pneumatic damper adjust the damping coefficient only by stepwise opening / closing control of the valve according to the state of the road surface and the load change that change in real time, so it is difficult to block the vibration sufficiently due to the discontinuous absorption of energy and the road surface of the vehicle. When the vibration and the load displacement change rapidly, the change in the damping coefficient for the damping force against the vibration of the hydraulic and pneumatic dampers is large, and the response to the buffer is inadequately delayed.

In addition, in the case of using the hydraulic pressure damper, there is a problem in that it requires structural facilities such as a pressure regulating mechanism, a compressor, and the like, resulting in structural complexity, thereby affecting reliability, durability, and serviceability of the operation.

Therefore, an object of the present invention is to solve the above problems, and provides a cushioning device for a vehicle seat which improves the riding comfort by adjusting the cushioning according to the state of the road surface while driving a large vehicle having a relatively poor seat cushion.

1 is a block diagram showing the arrangement of main parts of the apparatus according to the present invention;

2 is a block diagram showing a circuit configuration for operating an apparatus according to the present invention;

3 is a flowchart showing the operating sequence of the apparatus according to the present invention;

Figure 4 is a graph showing the measurement of the vibration transmission ratio of the device according to the invention.

Explanation of symbols on the main parts of the drawings

11: sheet 11a: frame

12: body 13: X-type link

14, 15: acceleration sensor 16: displacement sensor

17: drive output 18: damper

19: spring 20: controller

In order to achieve this object, the present invention provides an automobile having a seat 11 mounted on a vehicle body 12 via an X-shaped link 13 having a fixed end and a free end: A spring 19 mounted to exert an elastic force between the sheets 11; A damper (18) mounted to apply a damping force between the seat (11) and the vehicle body (12), and having a magnetorheological fluid or an electric fluid fluid; Acceleration sensors (14) (15) mounted on the seat (11) and the vehicle body (12), respectively, for generating a signal in accordance with a change in acceleration; A displacement sensor 16 mounted between the seat 11 and the vehicle body 12 to generate a signal according to a change in relative displacement; A controller 20 which receives inputs of the acceleration sensors 14 and 15 and the displacement sensor 16 and generates an output for adjusting the damper 18; And it is characterized in that it comprises a drive output unit 17 for varying the operating current or voltage of the damper 18 in response to the output signal of the controller 20.

At this time, the controller 20 determines the road surface state by the input of the acceleration sensors 14 and 15, calculates the output value according to the product of the preset function and the gain, and if there is a collision between the ends of the seat 11, gain again. Then, the algorithm of increasing the output value to the driving output unit 17 is performed again.

The controller 20 has a function f (s) according to the displacement, a function f (s, v) according to the displacement and velocity, and a function f (s, v, a) according to the displacement, velocity and acceleration. do.

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

1 is a block diagram showing the arrangement of main parts of the apparatus according to the present invention.

The present invention relates to an automobile having a seat (11) mounted on a vehicle body (12) via an X-shaped link (13) composed of a fixed end and a free end. In the illustration, the frame 11a of the seat 11 shows an X-shaped link 13 having a free end and a fixed end of the frame 11, so that the present invention can be applied to other links in which the seat 11 is not completely restrained. It is possible to apply.

According to the present invention, a spring 19 is mounted to apply an elastic force between the X-type link 13 and the seat 11, and a magnetorheological fluid to apply a damping force between the seat 11 and the vehicle body 12. Or a damper 18 having an electric rheological fluid. The spring 19 supports the free end of the seat 11 and primarily attenuates vibrations. The lower end of the spring 19 can be fixed to the vehicle body 12 instead of the X-shaped link 13. The upper end of the spring 19 and the upper end of the damper 18 are fixed at the same point in the frame 11a of the seat 11. Magnetically deformable or electro-deformed dampers 18, unlike conventional hydraulic pneumatic dampers, change the physical properties of the fluid itself by electric force to control the damping force.

The magnetoresistive damper 18 is an oil filled with micro-polarized particles of magnetic polarity. When a magnetic field is applied, the polarized particles are arranged in chain form of anisotropic structure, and the stronger the strength of the magnetic field, the stronger the force. As a result, the yield shear stress to break the chain structure increases. Using the damper 18 of this type in the present invention, it is possible to change the yield shear stress of the magnetorheological fluid flowing through the orifice and to adjust the damping force by generating a magnetic field with the current flowing through the coil wound between the orifices therein.

The electric rheological damper 18 is composed of an electrode plate and an electric rheological fluid, which are devices for loading an electric field. An electrorheological fluid is generally a colloidal solution in which strong particles are dispersed in a non-conductive fluid. When an electric field is applied, conductive particles dispersed in a fluid form a chain structure, and the fluid has a yield stress. The higher the strength of the electric field, the stronger the chain structure, the higher the yield stress. Applying the damper 18 of this type to the present invention can apply a high voltage to the inner and outer cylinders to generate an electric field and to adjust the damping force as the yield stress changes.

Further, according to the present invention, the acceleration sensors 14 and 15, which generate signals according to the change in acceleration, are mounted on the seat 11 and the vehicle body 12, respectively, and the displacement which generates a signal according to the change in relative displacement. A sensor 16 is mounted between the seat 11 and the vehicle body 12. The vibration mode of the seat 11 is recognized through the first acceleration sensor 14 installed in the seat 11, and the second acceleration sensor 15 installed in the vehicle body 12 recognizes the vibration mode of the vehicle. The rougher the road surface, the lower frequency signal is detected by the acceleration sensors 14 and 15, and the amplitude of the signal detected by the displacement sensor 16 increases. The signal of the displacement sensor 16 may be used to generate data that limits the amplitude of the sheet 11.

In addition, according to the present invention, it is provided with a controller 20 which receives the inputs of the acceleration sensors 14 and 15 and the displacement sensor 16 and generates an output for adjusting the damper 18. The controller 20 may use an electrical control unit (ECU), which is a comprehensive controller of an automobile, as a microcomputer circuit including a microprocessor, a memory, an input / output interface, and the like.

In addition, according to the present invention is provided with a drive output 17 for varying the operating current or voltage of the damper 18 in response to the output signal of the controller 20. The driving output unit 17 includes a current control circuit or a voltage control circuit. When the analog signal through the D / A converter is output from the controller 20, the driving output unit 17 generates a current or voltage signal proportional thereto. By controlling the current or voltage through the drive output unit 17 can implement a variety of attenuation power and excellent durability because the configuration of the device for generating a magnetic or electric field is also simple.

2 is a block diagram showing a circuit configuration for operating an apparatus according to the present invention.

The first acceleration sensor 14, the second acceleration sensor 15, and the displacement sensor 16 input a digital signal to the microcomputer through the A / D converter of the controller 20, and the microcomputer is driven through the D / A converter. Output to the output unit 17. The controller 20 is connected to use a power source stored as a battery in the generator of the vehicle. The driving output unit 17 receives the AC power of the generator, amplifies it appropriately, and then changes the current to a desired current and voltage.

The controller 20 according to the present invention determines the road surface state by the input of the acceleration sensors 14 and 15, calculates the output value according to the product of the preset function and the gain, and if there is a collision at the end of the seat 11. The gain is increased again and the algorithm sends the calculated output value to the driving output unit 17 again.

3 is a flowchart showing the sequence of operation of the apparatus according to the invention.

When the vehicle is started, the program is started and the signal of the displacement sensor 16 is input in step S10. This signal depends on the weight of the driver and the controller 20 stores it as an initial value for the movement of the seat 11. In steps S11 and S12, the signals of the acceleration sensors 14 and 15 are input to use the data for recognizing the road surface condition of the road in a later step.

In step S13, it is determined whether the car is traveling on the highway, and if yes, the gain G1 is determined (step S14), and the output signal P1 is calculated (step S15). If no, the flow goes to step S16 to determine whether the current road condition is unpaved. If yes, the gain G3 is determined (step S17) and the output signal P3 is calculated (step S18), but if no, another gain G2 is determined if it is a general road rather than a highway or unpaved road (step S19), and the output signal P2 Is calculated (step S20).

At this time, the function of the output signal of the controller 20 is a function f (s) according to the displacement, a function f (s, v) according to the displacement and velocity, and a function f (s, v according to the displacement, velocity and acceleration). and a). Although the function can be calculated to some extent by theory, it is preferable to obtain the function by experiment with actual vehicle. The speed used in the above function may be obtained by integrating the signals of the acceleration sensors 14 and 15 or by differentiating the signals of the displacement sensor 16, but it is also possible to add a separate speed sensor.

In step S21, if the end of the seat 11 collides, and if the maximum displacement (stroke) of the damper 18 mounted on the seat is exceeded due to the momentary change of the road surface, the impact by the end of the damper 18 remains the driver. This is to prevent it from being delivered to. If yes in step S21, the gain is increased at a constant rate (step S22), and then the flow returns to the above-described step S13 to generate a new output signal, and then in step S23, the output signal is sent to the drive output unit 17 and the above-mentioned step S11 is returned. do. If the gain is further increased in step S22, the damper 18 is made harder and can be prevented from colliding at the end of the seat 11.

The microcomputer of the controller 20 stores the gains G1, G2, G3 and the functions f (s), f (s, v), f (s, v, a) in memory and are described by the microprocessor. Since the operation step is performed at a rapid cycle, the reaction speed of the damping force control through the damper 18 is fast even when the road condition is changed.

Since the damping force is adjusted by changing the viscosity of the damper 18 by the electric force by the controller 20 and the driving output 17, it is possible to quickly and sufficiently block the vibration period and acceleration that the occupant can feel.

Figure 4 is a graph showing the measurement of the vibration transfer ratio of the device according to the present invention.

The dotted line indicates that the damper 18 does not receive power through the drive output unit 17, for example, when the drive output unit 17 fails, and at a low frequency of about 4 kHz, the transmissibility is 1.7. This results in poor buffering.

The portion indicated by the dashed-dotted line indicates that the damper 18 receives the maximum input power through the drive output unit 17, and there is no rapid increase in the vibration transfer ratio and the buffering action is improved as compared with the case described above.

On the other hand, the portion indicated by the solid line is a state in which the damper 18 receives an input power that is properly adjusted through the controller 20 and the drive output device 17, and the vibration transmission ratio is generally lower than the two cases described above. At about 4 kHz or more, the vibration transmission ratio is lowered to 1 or less, thereby performing the best buffering action.

The shock absorber of the vehicle seat according to the present invention having the above configuration and action has the effect of improving the riding comfort by adjusting the cushioning according to the state of the road surface while driving a large vehicle having a relatively poor cushion of the seat.

Claims (3)

In an automobile having a seat 11 mounted on a vehicle body 12 via an X-shaped link 13 composed of a fixed end and a free end: A spring 19 mounted to exert an elastic force between the X-link 13 and the seat 11; A damper (18) mounted to apply a damping force between the seat (11) and the vehicle body (12), and having a magnetorheological fluid or an electric fluid fluid; Acceleration sensors (14) (15) mounted on the seat (11) and the vehicle body (12), respectively, for generating a signal in accordance with a change in acceleration; A displacement sensor 16 mounted between the seat 11 and the vehicle body 12 to generate a signal according to a change in relative displacement; A controller 20 which receives inputs of the acceleration sensors 14 and 15 and the displacement sensor 16 and generates an output for adjusting the damper 18; And And a driving output unit (17) for varying the operating current or voltage of the damper (18) in response to the output signal of the controller (20). The method of claim 1, The controller 20 determines the road surface state by the input of the acceleration sensors 14 and 15, calculates the output value according to the product of the preset function and the gain, and if there is a collision at the end of the seat 11, gains again. A cushioning device for a vehicle seat, characterized in that for carrying out an algorithm for increasing and then again outputting the calculated output value to the drive output unit (17). The method of claim 2, The controller 20 has a function f (s) according to the displacement, a function f (s, v) according to the displacement and velocity, and a function f (s, v, a) according to the displacement, velocity and acceleration. A shock absorber for a vehicle seat, characterized in that.