JPS63140141A - Seat supporting device for vehicle using magnetic fluid - Google Patents

Abstract

PURPOSE:To obtain a seat supporting device to which vibration is not transmitted from a body by filling up the interior of a cylinder made of non-magnetic material, which is fixed to a car body with magnetic fluid, and disposing a permanent magnet fixed to a support rod of a frame in the magnetic fluid. CONSTITUTION:Cylinders 2, 3 made of non-magnetic material are fixed to a car body 1 by brackets 4, 5 and magnetic fluid 6 formed by dispersing magnetic fine grains such as magnetite or the like in a solvent such as oil or the like is filled up in the cylinders 2, 3. Permanent magnets 7, 8 are disposed spaced from the inner walls 9, 10 of the cylinders 2, 3 in the magnetic fluid 6, and the permanent magnets 7, 8 are firmly fixed to support rods 13, 14 fixed to a frame 12 of a seat cushion 11.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a support device which is a cushion device for a vehicle seat.

BACKGROUND OF THE INVENTION Conventional vehicle seats with adjustable cushioning properties include, for example, Japanese Patent Laid-Open No. 55-1
As shown in Japanese Patent No. 03813, a device whose spring characteristics can be adjusted is known.

Problems to be Solved by the Invention In all of the above-mentioned conventional vehicle seats in which the cushioning properties can be adjusted, the supporting members are in solid contact with each other, and vibration absorption is insufficient. can be,
In particular, it does not function at all in terms of absorbing small amplitude vibrations, and if the spring system is softened to improve vibration absorption performance, it has the disadvantage of worsening seat stability and vibration damping performance, and it also has the disadvantage of worsening the driving condition. It is difficult, if not impossible, to adjust the spring constant and damping coefficient accordingly.

Therefore, the present invention provides a vehicle seat support without solid contact, which can absorb and eliminate vibrations transmitted from the body to a negligible extent, and can automatically adjust the damping effect to the best condition in response to various driving conditions. The purpose is to provide equipment.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention has a cylinder made of a non-magnetic material fixed to a vehicle body filled with magnetic fluid, and a space between the inner wall of the cylinder and the magnetic fluid. A permanent magnet is disposed within the cylinder, and this permanent magnet is fixed to the support rod of the seat cushion frame.A coil capable of applying a magnetic field to the magnetic fluid is disposed outside the cylinder, and the coil has the following properties: The system employs a configuration in which it is connected to a power source that is controlled by a computer that selects the required current value based on detection signals from the sensor such as vehicle speed, steering angle, and throttle position.

Operation Since the present invention has the above-described configuration, the permanent magnet fixed to the seat cushion frame receives a self-centering action in the cylinder with the magnetic fluid attracted around it, and is positioned at the center of the cylinder. It is maintained in a state in which there is no solid contact.

For this reason, if the detected values of various sensors are below the set value to the computer, no coil current flows from the power supply, and the magnetic fluid maintains its viscosity when there is no magnetic field, and is permanently fixed to the seat cushion frame. The magnet is displaced in the magnetic fluid according to the load applied to the seat, and when the load is removed, it returns to the center of the cylinder due to the self-centering action described above and exhibits soft cushioning performance, so it absorbs vibrations transmitted from the body to the extent that it can be ignored. ,to erase.

The computer generates a magnetic field in advance to obtain the resistance value of the magnetic fluid against the displacement of the above-mentioned permanent magnet in the magnetic fluid, which is necessary to give the seat the best cushioning properties in response to various driving conditions. The current value to be used is stored.

Therefore, when the vehicle is running, the running conditions and operating conditions are detected by various sensors, and a current controlled according to the detected values flows through the coil, and a predetermined magnetic field is applied to the magnetic fluid to reduce the viscosity. As the permanent magnet moves upward, some resistance is generated to the displacement in the magnetic fluid, resulting in a vibration damping effect that is optimal for the driving conditions.

The above-mentioned damping effect is obtained by varying the flow resistance of the magnetic fluid between the inner wall of the cylinder and the permanent magnet. During sudden acceleration, sharp turns, high-speed driving, etc., the flow resistance of the magnetic fluid becomes large and the cushioning increases. The damping force and support force are increased, which stabilizes the seated posture.When all driving conditions are slow, the flow resistance of the magnetic fluid is automatically reduced, resulting in soft cushioning. Provides a comfortable sitting experience.

If this support device is installed not only between the floor and the seat cushion frame, but also between the side members of the vehicle body and the seat cushion frame, it will be effective in stabilizing the seat in the vehicle width direction during sharp turns. becomes.

Embodiment FIG. 1 is a circuit diagram showing an example of the embodiment from the side with a part cut away, in which a cylinder 2.3 made of a non-magnetic material is fixed to a vehicle body 1, which is a floor, with a bracket 4.5.
The cylinder 2.3 is filled with a known IIII fluid 6 in which magnetic fine particles such as magnetite (Fe304) with a dispersant adsorbed on the surface are dispersed in a solvent such as oil or water.

The magnetic fluid 6 described above has a property that its viscosity increases when a magnetic field is applied, and the change appears instantaneously.

Now, the viscosity when there is no magnetic field is η8, the viscosity when there is a magnetic field is η□, the magnetization of the magnetic particles is M, and the strength of the magnetic field is H, 1i
ft The shear rate of the fluid is γ, and the viscosity of the solvent is η. Curve A in Figure 3 shows the change in viscosity of the magnetic fluid 6 due to the magnetic field.
It becomes as shown in .

Figure 3 shows the ratio of the viscosity η in the presence of a magnetic field to the viscosity ηS in the absence of a magnetic field as γη. /MH, indicating that the viscosity changes in proportion to the strength of the magnetic field, and the present invention utilizes the above-mentioned characteristics of the magnetic fluid 6.

As shown in FIG. 1, a permanent magnet 7.8 is located within the magnetic fluid 6 filled in the cylinder 2.3.
3, and the permanent 6R
The stone 7.8 is fixed to a support rod 13.14 which is fixed to the seat cushion frame 12 of the seat cushion 11.

In the illustrated example, a plurality of permanent magnets 15.16, 17.18, . They are placed with a certain distance between them.

As a result, the magnetic fluid 6 is oriented around each permanent magnet 7,8°16.1
7. ．． 18, 19, etc., each permanent magnet is located at the center of the magnetic fluid 6 and is subjected to a self-centering action.

A coil 20.21 is arranged close to the outside of the cylinder 2.3, in the example shown at the bottom.

This coil 20 , 21 is a coil that applies a magnetic field to the magnetic fluid 6 and is connected to a power source 24 having a variable resistor 23 controlled by a computer 22 .

The computer 22 described above includes a vehicle speed sensor 25, a steering angle sensor 26, and a throttle position sensor 2.
7 detection signals are manually input and compared with preset values, and a current value is selected to obtain the magnetic fluid viscosity necessary to obtain the best cushioning performance in accordance with the various set running conditions. to operate the variable resistor 23 described above.

Reference numerals 28 and 29 in FIG. 1 designate an air spring device for supporting the seat, which is arranged in parallel with the cylinder 2.3 filled with the magnetic fluid 6.

FIG. 2 is a flowchart for adjusting the viscosity of the magnetic fluid 6 by the computer 22. When the vehicle is started, in step I, whether the steering angle measured by the steering angle sensor 25 is equal to or smaller than 50 degrees is determined. If YES, it is determined in step III whether the acceleration by the throttle position sensor 27 is equal to or smaller than 2.0 m/S 2, and if YES, further step V is performed.
In step V!, it is determined whether the vehicle speed measured by the vehicle speed sensor 25 is equal to or smaller than 120 km, and if YES, step V! In this case, control is performed in which no current is applied to the coils 20, 21 and no viscosity change occurs.

In step I, if it is determined that the steering angle is greater than 50 degrees, step! Proceed to ■
It is determined whether the steering angle is equal to or smaller than 100 degrees, and if YES, it is determined in step IV whether the acceleration is equal to or smaller than 3.0 m/s2, and if YES, step V is performed. ! Control is performed to flow a predetermined current through the coils 20, 21 and adjust the magnetic fluid 6 to a corresponding viscosity.

If it is determined in step [I that the steering angle is 100 degrees that the dog is a dog, the process proceeds to step V+, where a large current flows into the coils 20 and 21 in order to stiffen the cushioning properties of the seat and stabilize the sitting posture. Then, the viscosity of the magnetic fluid 6 is controlled to be uniform.

If it is determined in step II+ that the dog is a dog based on the acceleration of 2.0 m/s2, the process proceeds to step IV and the same control as described above is performed.

In step IV, the acceleration is 3. If it is determined that it is larger than Om/s2, the process proceeds to step Vl and the above-mentioned control is performed.

If it is determined in step V that the vehicle is a dog because the vehicle speed is 120 m, the same control as when YES is determined in step IV is performed.

As is clear from the above explanation, the preferred seat support state is preset according to the respective driving conditions and running conditions during slalom, sharp turns, sudden acceleration, sudden braking, high speed driving, etc. The viscosity of the magnetic fluid 6 is adjusted to obtain a damping force of the seat support device.

The supporting force is increased to a predetermined value to provide a stable seating posture, and under other normal driving and driving conditions, the viscosity of the magnetic fluid 6 is kept low, automatically providing a soft and comfortable sitting position. can be obtained.

In the illustrated example, the support device according to the present invention is disposed between the floor and the seat cushion frame, but it is also possible to attach the support device according to the present invention between the side member of the vehicle body 1 and the seat cushion frame. , better seat cushioning properties can be obtained.

Also, as shown in FIG. 1, a plurality of permanent magnets 7.16.
1? , 8, 18, 19, . . . , the adjustment range of the damping force and supporting force is further expanded by the action of the magnetic fluid 6 within the space between the permanent magnets.

Effects The present invention has the above-described configuration 1, in which the permanent magnet fixed to the seat cushion frame is always kept suspended in the magnetic fluid, and the magnetic fluid is not applied to the peripheral surface of the permanent magnet. Due to the self-centering effect caused by attraction, the permanent magnet is always given a force that positions it at the center of the cylinder, and fixed contact between the vehicle body and seat sides is avoided, so vibrations transmitted from the vehicle body are absorbed to a negligible level. , produces an erasing and creeping effect.

Also, while driving, the current value is controlled to the magnetic fluid viscosity necessary to obtain the optimal seat cushioning characteristics for various driving conditions and driving conditions, based on detected values such as vehicle speed, steering angle, and throttle position. Therefore, it has the effect of providing optimal cushioning properties for automatic fishing during running.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a part of an example of implementation as a cross section and a side view, Fig. 2 is a flowchart of a computer used in the present invention, and Fig. 3 shows the relationship between the viscosity of the magnetic fluid and the magnitude of the current. FIG. 1: Vehicle body, 2.3 = cylinder, 6: Magnetic fluid, 7.8,
16, 17.18.19: Permanent magnet, 10: Inner wall, 12
; Seat cushion frame, 13.14: Support rod, 2
0, 21: Coil, 22: Computer, 25: Vehicle speed sensor, 26: Steering angle sensor, 27: Throttle position sensor.

Claims (1)

[Claims] A cylinder made of a non-magnetic material fixed to the vehicle body is filled with magnetic fluid, and a permanent magnet is placed within the magnetic fluid at a distance from the inner wall of the cylinder, and the permanent magnet is supported by the seat cushion frame. In addition to being fixed via a rod, a coil that can apply a magnetic field to the magnetic fluid is disposed outside the cylinder, and the coil operates based on detection signals from sensors such as vehicle speed, steering angle, and throttle position. , a vehicle seat support device that uses magnetic fluid and is connected to a power source that is controlled by a computer that calculates the required current value.