JPH06144093A - Car vibration reducer - Google Patents

Abstract

PURPOSE:To provide a car vibration reducer that is able to effectively reduce a car vibration ascribed to a high frequency input without using any expensive system. CONSTITUTION:When a signal showing a vibrational state in a car is detected by an acceleration sensor 6, it is inputted into an engine control unit 7 in which an actuator signal voltage VfVA showing a reverse vibration to be produced in a seat part 13 is operated, and inputted into two driving parts 15, 17. In this case, these driving parts 15, 17 select two control valves 10 and 18 in a damper unit 8, thereby producing the reverse vibration in the seat part 13, and car vibrations are reduced in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle vibration reducing device for effectively reducing vehicle vibration caused by road surface conditions.

[0002]

2. Description of the Related Art Conventionally, as one of the devices of this type, there is one that electronically controls the damping force of a shock absorber.
As an example, a damping force control device applying the so-called skyhook theory, which controls the damping force based on the sprung speed dX and the sprung-unsprung relative speed dY (relative speed between the sprung member and the unsprung member), is provided. There is (for example, Japanese Patent Laid-Open No. 3-1
No. 04726). In this device, the opening area of the oil passage is adjusted (the damping coefficient is determined by the product of the sprung speed dX and the sprung-unsprung relative speed dY, that is, the sign of the sprung speed dX and the sprung-unsprung relative speed dY. Adjust) to change the damping force.

[0003]

However, as shown in FIG. 1, when the damping coefficient is increased in order to reduce the vehicle vibration in the vicinity of the vehicle input frequency of 2-3 Hz (the sprung resonance frequency), the The vehicle vibration becomes large in the high frequency region where the input frequency is near 10 Hz (spring resonance frequency) or higher. The vehicle input frequency is 2
Even if the vehicle is running on a road surface of ~ 3 Hz with a large damping coefficient, especially when there is a single high-frequency input due to road surface projection called a harshness shock,
When the control cannot catch up and the control is started, the vibration has already propagated to the occupant, and the discomfort cannot be eliminated. In order to solve such a problem, JP-A-61-2
Although there is a method of detecting the road surface condition by remote sensing as in Japanese Patent No. 44614, there are drawbacks that accurate sensing is very difficult and the system becomes expensive.

Further, in the device disclosed in Japanese Patent Application Laid-Open No. 62-74728, a suspension mechanism is arranged between the floor and the seat, and the damping force is varied in the suspension mechanism, so that vibration to the occupant is generated. Although the transmission is controlled, in this device, since the spring-mass system is formed between the floor and the seat, the relationship between the vehicle input frequency and the transfer function when the damping force is variable is as shown in FIG. . As can be seen from FIG. 7, by varying the damping force, the transfer function is made smaller with respect to the vehicle input frequency in the frequency region higher than the frequency f _A (generally, a frequency somewhat higher than the resonance frequency on the spring), and vibration is generated. Transmission can be reduced. However, in the frequency region around the frequency f _A or lower, the transfer function does not become smaller than 1, so that the vibration transfer cannot be reduced.

Therefore, the present invention has been made in view of the above problems, and is capable of effectively reducing the vehicle vibration caused by any vehicle frequency input without using an expensive system. The purpose is to provide.

[0006]

In order to achieve the above object, the present invention is a device for reducing vibrations by generating vibrations of opposite phase to the vibrations of a vehicle, such as a vehicle suspension portion and its mounting portion. A vibration state detecting means for detecting a vibration state of the vehicle installed in the vehicle, a setting means for estimating a transmission delay time to the seat portion based on the vehicle vibration and calculating an anti-phase signal with respect to the vehicle vibration, and a reverse operation from the setting means. It is characterized in that it is provided with a driving means for actually driving based on the phase signal.

[0007]

In the vibration reducing device configured as described above,
A vibration state input from the road surface and transmitted from the tire to the suspension is detected by the vibration state detecting means. This vibration generates an anti-phase vibration that estimates the transmission delay time to the seat portion, so that the vibration input to the seat portion from the road surface can be canceled.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. [First Embodiment] FIG. 2 shows the overall construction of the first embodiment.
In the case of a strut type suspension, the vehicle suspension part is composed of a coil spring 2, a shock absorber 3, an upper support 1 and a tire 4 as main components,
The vibration input from the road surface protrusion 14 is transmitted from the tire 4 to the coil spring 2 and the shock absorber 3, and reaches the upper support 1. An acceleration sensor 6 as a vibration state detecting means is arranged on the upper support 1.

A damper unit 8 as a driving means is arranged between the seat 13 and the seat support portion 5. The damper unit 8 includes a cylinder 11 divided into an upper chamber and a lower chamber by a piston 16, and the cylinder 1
1, a hydraulic pump 9 for supplying hydraulic oil, a reservoir 12 for storing the hydraulic oil discharged from the cylinder 11, and a control valve 10 for switching the supply / discharge of the hydraulic oil to the upper chamber and the lower chamber. The control valve 10 is adapted to be switched by a drive unit 15. Specifically, when the control valve 10 is at the position A shown in FIG. 2, the hydraulic pump 9 and the upper chamber communicate with each other, and the reservoir 12 and the lower chamber communicate with each other, so that hydraulic oil is supplied to the upper chamber. Hydraulic oil is discharged from the lower chamber. On the other hand, the control valve 10
Is in the B position, the hydraulic pump 9 communicates with the lower chamber and the reservoir 12 communicates with the upper chamber, so that the hydraulic oil is supplied to the lower chamber and the hydraulic oil is discharged from the upper chamber.

Further, the flow rate of the hydraulic oil from the pump 9 can be changed.
Is provided with a flow rate control valve 18 that drives the control valve 18.
The switching operation is performed by the portion 17.
In the acceleration sensor 6, the vibration level is converted into voltage and this
An electronic control device (hereinafter referred to as EC
(Referred to as U) 7 and the arithmetic processing is performed in the ECU 7.
After that, the actuators are sent to the drive unit 15 and the drive unit 17.
Signal voltage V_f, V _AIs output.

Next, the internal configuration of the ECU 7 and the flow of calculation are shown in FIG. The input signal X from the acceleration sensor 6 is determined by the determination unit 2
Input to 0. This ECU 7 together with the determination unit 20
It is provided with a setting unit 21, and a signal from the setting unit 21 is output to the driving unit 15.

The judging section 20 first extracts the vibration amplitude X _X to be reduced by the band pass filter 22 set in the frequency region (aHz to bHz) to be reduced, and the comparing section 2
Whether or not the vibration amplitude X _X extracted in 3 should be reduced is compared with a predetermined value X ₀ . When the vibration amplitude X _X should be reduced to a value greater than the predetermined value X ₀ , the time t at that time is stored as t _{0 in} the time storage unit 24. The above 22 to 24 make up the determination unit.

After the time is stored in the time storage unit 24,
The calculation unit 25 calculates the amplitude A of the anti-phase vibration to be generated, the anti-phase frequency ω, and the delay time Δtd. In particular,

[0014]

## EQU1 ## A = f ₁ (X _Xmax ) (where X _xmax is the maximum value of the vibration amplitude X _x after X _x > X _0, and f ₁ is a function having X _xmax as a variable.)

[0015]

## EQU2 ## ω = (a + b) / 2

[0016]

Δt d = f ₂ (X _xmax , ω) (where f ₂ is a function having X _xmax and ω as variables).
Given in. Next, it is determined whether or not the current time t is within the time at which the anti-phase wave should be emitted by the comparison unit 26. In particular,

[0017]

## EQU4 ## It is determined whether or not it is within the range of t ₀ + Δtd <t <t ₀ + Δtd + Δtm (where Δtm is a predetermined time for outputting the antiphase wave).

When the time t is within the above range, the signal voltage calculator 27 calculates the actuator signal voltages V _f and V _A corresponding to the anti-phase wave. In particular,

[0019]

V _f = C _f · ω / 2π where C _f is a predetermined coefficient.

[0020]

## EQU6 ## V _A = C _A Asin (ω (t−t0 −Δtd
)) (However, C _A is a predetermined coefficient.)

If either of the comparison units 23 and 26 determines that the result is negative, the signal voltage calculation unit 28 sets the actuator signal voltages V _f and V _A to zero. The above 25 to 28 configure the setting unit 21.

The actuator signal voltages V _f and V _A calculated by the ECU 7 are input to the driving units 15 and 17 of FIG. 2, and the control valve 1 is based on these signal voltages V _f and V _A.
By switching between 0 and 18, hydraulic oil is supplied or discharged into the cylinder 11 and the piston 16 is moved up and down. Since the piston 16 is connected to the seat 13, a vertical movement y is generated in the seat 13, and the vibration x propagated from the suspension portion to the vehicle body 5 and cancelled in the seat support portion 5 is canceled.

When the vibration reduction control of this embodiment is performed, the relationship between the vehicle input frequency and the transfer function is as shown in FIG. As shown by the solid line, the broken line, and the alternate long and short dash line in FIG. 6, by generating an antiphase wave according to the vehicle input frequency, the transfer function can be 1 or less in all frequency regions,
It is possible to reduce vehicle vibration caused by any frequency input that could not be reduced by conventional suspension control.

Further, in this embodiment, the acceleration sensor 6 for detecting the vibration state provided on the suspension portion and the seat 13 are provided.
Can be controlled with a sufficient margin because is sufficiently separated. Furthermore, since the damper unit 8 does not form a spring-mass system, it is possible to reduce vibration in a wide frequency range without being affected by the resonance frequency of the spring-mass system.

[Second Embodiment] It is also possible to embed the damper portion 8 of the first embodiment in the seat 13 as shown in FIG. In this case, since the driving units 15 and 17 do not need to move the seat 13 up and down, energy can be saved compared to the first embodiment.

[Third Embodiment] The damper portion 8 and the driving portions 15 and 17 of the first embodiment have a torque motor 19 as shown in FIG.
It is also possible to replace with electrical means such as.

[0027]

As described above in detail, according to the present invention, since the anti-phase vibration with respect to the vehicle vibration is generated in the seat portion, the unpleasant vibration which could not be dealt with due to the control characteristic of the suspension control or the control delay is generated. It is possible to reduce the ride quality and improve the riding comfort.

[Brief description of drawings]

FIG. 1 is a characteristic diagram illustrating a relationship between a frequency input to a vehicle from a road surface and a transfer function.

FIG. 2 is a configuration diagram showing a configuration of a first embodiment.

FIG. 3 is a diagram showing a configuration in an ECU 7 and a flow of calculation.

FIG. 4 is a configuration diagram showing a main configuration of a second embodiment.

FIG. 5 is a configuration diagram showing a main configuration of a third embodiment.

FIG. 6 is a characteristic diagram showing a relationship between a frequency input to a vehicle from a road surface and a transfer function in the first embodiment.

FIG. 7 is a characteristic diagram showing a relationship between a frequency input to a vehicle from a road surface and a transfer function in the related art.

[Explanation of symbols]

 6 Acceleration sensor 7 ECU 8 Damper unit 15 Drive unit 17 Drive unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayuki Nagai, 1-1, Showa-cho, Kariya city, Aichi Prefecture, Nihon Denso Co., Ltd. (72) Inventor, Hiroshi Ishikawa, 1-1, Showa-cho, Kariya city, Aichi prefecture Co., Ltd. (72) Inventor Shunichi Doi, 41, Nagachote, Nagakute-cho, Aichi-gun, Aichi-gun 1 in Toyota Central Research Institute, Inc. (72) Inventor, Rikuo Ishiguro, 41, Nagakute-cho, Aichi-gun, Aichi-gun 1 Toyota Central Research Institute Co., Ltd. (72) Inventor Kazuyoshi Takei 41, Nagakute-cho, Aichi-gun, Aichi Prefecture

Claims (2)

[Claims] 1. A vibration state detecting means for detecting a vibration state of a vehicle; a setting means for estimating a transmission delay time to a seat portion based on the vehicle vibration to calculate an anti-phase signal for the vehicle vibration; A vehicle vibration reduction device, comprising: a drive unit that drives the seat portion based on a reverse-phase signal from the unit. 2. The vehicle vibration reduction device according to claim 1, wherein the drive means is housed in a seat.