JPH0624261A - Seat device for automobile - Google Patents

Abstract

PURPOSE:To provide a seat device for an automobile wherein a damping coefficient corresponding to a road surface condition is set so as to effectively improve riding comfortableness. CONSTITUTION:Air bags 15, 16 are respectively buried in a seat cushion 12 and a seat bag 13, of a seat 11. These air bags 15, 16 are connected to accumulators 21, 22 respectively through pipes 19, 20, and circulating air amounts between the bags and accumulators are controlled by valve mechanisms 23, 24, so as to variably set damping coefficients of the air bags 15, 16. The valve mechanisms 23, 24 are controlled corresponding to front wheel sprung acceleration by a control unit 25, so as to set the damping coefficient in accordance with a road surface condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle seat device for effectively setting a riding comfort corresponding to a traveling road surface condition.

[0002]

2. Description of the Related Art Particularly in passenger cars, many attempts have been made to improve riding comfort by improving seats. For example, as shown in Japanese Patent Laid-Open No. 62-74728, an elastic body and a shock absorber are interposed between the seat side and the floor of the vehicle body. For example, the damping force (damping coefficient) of the shock absorber is adjusted according to the road surface condition. C) is variably adjusted.

Further, in the seat device disclosed in Japanese Patent Laid-Open No. 61-181730 or the like, an air bag is embedded inside the seat, and the seat device responds to a detection signal from a sensor for detecting a driving condition of the vehicle. It has been considered that the air pressure (spring constant K) in the airbag is controlled by the above. That is, the feeling or body pressure distribution of the person sitting on this seat is adjusted.

However, in the seat device for adjusting the damping force of the shock absorber that supports the seat, since the shock absorber is set between the seat and the vehicle body floor, this shock absorber is arranged. The space needs to be set between the seat and the body floor. Therefore, it can be attached to a large vehicle such as a bus or a truck that can set an extra space below the seat, but it can be used for vehicles such as passenger cars that do not have enough space below the seat. Can not.

Further, in the seat device for controlling the air pressure of the airbag set inside the seat, if the air pressure in the airbag, that is, the spring constant is greatly changed in order to improve the riding comfort of the occupant, it is inevitable. The occupant's sitting posture will change. In such a situation, the occupant feels uncomfortable, and there is a problem in that the air pressure in the airbag is substantially changed to improve the riding comfort.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and can be effectively applied to a vehicle such as a passenger car having no space below the seat. In particular, it is an object of the present invention to provide a vehicle seat device that can easily and surely adjust not the spring constant, but the damping coefficient, for example, according to the road surface condition on which the vehicle travels, and the ride comfort is effectively improved. To do.

[0007]

A vehicle seat device according to the present invention sets a damping force variable member inside the seat and variably adjusts the damping coefficient of the damping force variable member by a driving means. The damping force variable member is constituted by a bag filled with a fluid set inside the seat, the bag communicates with an accumulator containing the fluid, and is set between the bag and the accumulator by the driving means. The valve mechanism is controlled to adjust the flow rate. Here, a sprung acceleration detecting means for detecting sprung acceleration of the automobile is provided, and a detection signal from the sprung acceleration detecting means is supplied to the control unit, and this sprung acceleration and a set threshold value are set. The driving means is controlled on the basis of the comparison result.

[0008]

In the seat device of the automobile constructed as above, the fluid filled in the bag set in the seat is
It can freely flow to and from the accumulator via a valve mechanism. Therefore, when the valve mechanism is wide open, the fluid in the bag easily flows into the accumulator with the seat load applied, and the damping coefficient is set to a small state.
On the other hand, when the amount of fluid flowing to the valve mechanism is limited by the drive mechanism, the outflow of fluid in the bag is limited even if a load is applied to the seat, and the damping coefficient is set to a large state. Therefore, for example, if the amount of fluid passing through the valve mechanism is variably adjusted according to the vertical acceleration of the vehicle that changes depending on the road surface condition, the damping coefficient of the seat is variably adjusted according to the road surface condition, and The vibration transmitted to the vehicle is reduced and the riding comfort is improved. In this case, the bag filled with the fluid can be easily embedded in the seat and can be easily applied to passenger cars. Further, by comparing the sprung acceleration with a set threshold value and controlling the driving means based on the result, a damping coefficient is set according to the acceleration state acting on the human body, and the riding comfort is improved. Be improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall structure of a seat 11 used in, for example, a passenger car. The seat 11 includes a seat cushion 12, a seat bag 13, and a headrest 14.
Composed by. Airbags 15 and 16 are embedded in the seat cushion 12 and the seat bag 13, respectively.

Such airbags 15 and 16 are set, for example, on the lower portion of the cushion pad 17 or on the support spring 18 as shown in FIG. Then, accumulators 21 and 22 are connected to the airbags 15 and 16 via pipes 19 and 20, respectively,
Airbag 15 and accumulator 21, and airbag 16
The common space formed by the accumulator 22 and the accumulator 22 is filled with air set to a predetermined pressure.

Here, a pipe 19 which connects the airbags 15 and 16 with the accumulators 21 and 22 respectively.
Valve mechanisms 23 and 24 are provided in and 20, respectively, and the valve mechanisms 23 and 24 variably adjust the amount of air flowing through the pipes 19 and 20, respectively.

The valve mechanisms 23 and 24 include a control unit 25.
The control unit 25 is supplied with the sprung acceleration signal detected by the front wheel sprung acceleration detector 26. That is, in the control unit 25, the valve mechanisms 23 and 24 are controlled to open and close based on the signal corresponding to the vertical vibration on the front wheel springs to control the flow amount of air between the airbags 15 and 16 and the accumulators 21 and 22. Variable control is performed so that the damping force set for each of the airbags 15 and 16 is variably adjusted.

FIG. 3 shows the structure of the control unit 25. The detection signal from the sprung acceleration detector 26 for the front wheels is input to the interface circuit 31 of the control unit 25.
The control unit 25 includes an arithmetic processing unit 32 and a storage unit 33 together with the interface circuit 31, and the control output Vt from the interface circuit 31 is supplied to the drive circuit 34. Then, the valve mechanisms 23 and 24 are controlled independently or commonly by a command from the drive circuit 34.

The arithmetic processing unit 32 is an interface circuit.
Filtering processing is performed based on the sprung acceleration detection signal supplied to 31 and the predetermined arithmetic processing is used to determine the unevenness of the road surface on which this vehicle is traveling, and the drive circuit corresponding to the determination. The drive signal Vt supplied to 34 is calculated. Then, the valve mechanisms 23 and 24 are controlled to be opened and closed according to the condition of the traveling road surface, and the damping coefficients set in the airbags 15 and 16 are variably adjusted.

The storage device 33 stores processing programs and the like necessary for the arithmetic processing in the arithmetic processing device 32, and stores the arithmetic result of the arithmetic processing device 32 in a sequentially designated storage area. I have to.

FIG. 4 shows the procedure of processing in the arithmetic processing unit 32. In step 100, the sprung acceleration signal detected by the sprung acceleration detector 26 is read, and in the filter processing step 101, for example, upper and lower fluffy components are added. Remove the corresponding signal component. Then, the sprung acceleration signal subjected to the filtering process is supplied to the determination step 102. In this determination step 102, when the sprung acceleration signal has a value larger than the threshold value Gt set to the specified value, for example, when the wheel gets over a projection on the road surface, the "projection overrun" is performed. Is determined.

In the filter processing step 101, a high-pass filter or band-pass filter centering on 10 to 15 Hz is used for the harshness, and a low-pass filter centering on 1 Hz is used to cope with the undulation of the road surface. Is used.

The output Vt from the determination step 102 is supplied to the drive circuit 34 as a drive command so that the valve mechanisms 23 and 24 are controlled before the large sprung mass acceleration corresponding to overcoming the protrusion is transmitted to the seat portion. To And
The damping coefficient of the airbags 15 and 16 set in the seat cushion 12 and the seat bag 13 is reduced.

The airbags 15 and 16 and the accumulators 21 and 22, respectively, have valve mechanisms 23 and 24, respectively.
Via the valve mechanism 23 and the occupant's seated state so that the internal air flow is maintained in an equilibrium state.
The air in the airbags 15 and 16 is in and out via 24. Therefore, the damping coefficient of the airbags 15 and 16 is changed by changing the amount of air flowing in and out of the airbags 15 and 16 by the valve mechanisms 23 and 24, and the amount of air flowing in and out is limited. This reduces the damping coefficient of the airbags 15 and 16.

The damping coefficient can be variably controlled according to the road surface condition based on the above-described calculation processing, and the ride comfort can be improved under all road surface conditions, and the occupant's driving posture can be improved. It has no effect.

FIG. 5 shows the vibration transmission characteristics between the case where the damping coefficient of such a seat is variably controlled and the conventional seat where such a control is not performed. By lowering the damping coefficient of the seat, for example, It was confirmed that the rugged vibration above the vibration frequency of 5 Hz was effectively reduced. In particular, it was confirmed that the vibration in the high frequency region of 10 Hz or higher was reduced by about 10 dB over the entire region.

In the description of the embodiment, the control when the wheel has passed over the protrusion on the road surface has been described as an example, but the present invention is not limited to such a case, and low frequency components such as a swell road surface are By extracting the sprung acceleration signal, when such a swell road surface is extracted, the damping coefficient of the airbags 15 and 16 is increased, contrary to the embodiment, and the riding comfort of the swell road surface can be effectively improved. .

Further, in the embodiment, the description has been given on the condition that the airbags 15 and 16 are set in the seat cushion 12 and the seat bag 13, respectively, and these airbags 15 and 16 are controlled simultaneously. However, it is not limited to such a structure at times, for example, an airbag in the seat cushion 12.
The same effect can be achieved by controlling only 15.

Further, in the embodiment, an air bag in which air is filled as a fluid is used, and the damping coefficient is variably controlled. However, what is filled is not limited to air, but a viscous fluid such as oil may be used, and the flow rate of oil may be variably controlled by the valve mechanism.

[0025]

As described above, according to the vehicle seat device of the present invention, the damping coefficient inside the seat can be variably controlled, and the seat elasticity corresponding to the road surface condition can be set. Then, the damping coefficient of the seat elasticity is controlled by a simple control of the valve mechanism, an arbitrary damping coefficient corresponding to the running condition of the vehicle is set, and the riding comfort is effectively improved. Moreover, such a variable adjustment mechanism of the damping coefficient can be effectively applied to a passenger car or the like having no room under the seat.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration for explaining a seat device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an internal structure of the seat device.

FIG. 3 is a configuration diagram illustrating a control unit of the seat device.

FIG. 4 is a diagram for explaining the flow of operations in the control unit.

FIG. 5 is a diagram showing the states of the damping coefficients of the seat device shown in the embodiment and a conventional seat in comparison.

[Explanation of symbols]

11 ... Seat device, 12 ... Seat cushion, 13 ... Seat bag, 14 ... Headrest, 15, 16 ... Air bag, 19, 20
… Pipe, 21, 22… Accumulator, 23, 24… Valve mechanism, 25… Control unit, 26… Front wheel sprung acceleration detector.

Claims (3)

[Claims] 1. A damping force variable member set inside a seat, drive means for variably setting a damping force of the damping force variable member, and at least the drive means so that at least an elastic damping coefficient of a seat cushion is variably controlled. A vehicle seat device, comprising: a control unit for controlling the vehicle. 2. The damping force varying member comprises a bag in which fluid is filled in the seat, the bag communicates with an accumulator containing the fluid, and the driving means comprises the bag. The seat device for an automobile according to claim 1, wherein the seat device for the automobile is configured by a valve mechanism that is set between the accumulator and the accumulator and controls the amount of fluid that flows. 3. A sprung acceleration detection means for detecting sprung acceleration of an automobile is provided, and a detection signal from the sprung acceleration detection means is supplied to the control unit, and the detected sprung acceleration is set. 2. The vehicle seat device according to claim 1, wherein the drive means is controlled based on a result of comparison with the threshold value.