JPH04351342A - Vibration isolating device - Google Patents

Abstract

PURPOSE:To allow a vibration isolating device to work with optimum damping effect at all times by changing the vibration characteristics from time to time in compliance with varying natural frequency of a car resulting from change in the engine revolving speed. CONSTITUTION:When car vibration varies with the revolving speed of the engine, first an engine revolving speed sensing means 3 senses the change of the engine revolving speed and output a signal corresponding to the revolving speed to a control means 4, which performs control so that a voltage corresponding to the revolving speed is impressed on an electrofluidifying fluid. This fluid with voltage impressed receives an optimum viscosity for damping and absorption of the natural frequency of car corresponding to the revolving speed, and the elasticity modulus is changed, which allows the device to work with the optimum vibration damping performance at all times.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to a vibration isolator that can form a dynamic damper by interacting with heavy objects such as radiators and batteries, and in particular, it relates to a vibration isolator that can form a dynamic damper by interacting with heavy objects such as radiators and batteries. The present invention relates to a vibration isolator that can exhibit excellent performance.

0002

[Prior Art] Vibration isolation for heavy objects with a certain amount of mass (hereinafter referred to as mass flying), such as radiators and batteries in the engine room, by actively utilizing the mass to absorb vibrations generated from the engine. Various devices have been proposed. That is, as shown in FIG. 3, for example, this vibration isolator is composed of a vibration absorbing member 101 made of rubber or the like and attached to the vehicle body 100. The mass 102 constitutes a dynamic damper.
The large mass of the mass 102 can be used to attenuate and absorb vibrations.

By the way, in a dynamic bumper having such a structure, as shown in FIG.
By vibrating at a specific natural frequency f1, it is possible to reduce the natural vibration of the vehicle body. In other words, the vibration system using this dynamic damper has a mass of mass m
, If the elastic constant of the vibration absorbing member is k, then its natural frequency ω is uniquely determined by these parameters, and by selecting and using one with appropriate mass and elastic constant, Then, by using a mass and a vibration absorbing member that can forcibly generate an appropriate natural vibration that does not resonate with the natural vibration A accompanying engine vibration, it is possible to attenuate and absorb the natural vibration A. .

0004

[Problem to be Solved by the Invention] However, in the case of such a structure, once the mass and vibration absorbing member are attached to the vehicle body, these cannot be changed freely, so it is difficult to change the characteristics of the dynamic bumper itself. Vibration mode cannot be changed. However, the vibration mode of the car body changes from time to time depending on the engine speed, so conventional dynamic bumpers cannot follow the various vibrations of the car body and perform optimal vibration damping. This results in a significant decrease in damping performance. In view of the above-mentioned drawbacks of the conventional technology, the present invention provides a vibration damping system that can constantly change vibration characteristics in accordance with changes in the natural vibration of the vehicle due to changes in engine speed, and constantly exhibit optimal damping performance. The purpose is to provide a device.

[0005]

[Means for Solving the Problems] That is, the present invention is provided between a mass consisting of a heavy object such as a radiator or a battery in the engine room of a vehicle and a body in the engine room, and connected by an elastic body. a pair of mounts, a plurality of divided liquid chambers formed between the elastic body and the mount and filled with an electrorheological fluid, and at least one or more liquid chambers formed between the divided liquid chambers; An orifice communicating between these liquid chambers, and an orifice attached to this orifice,
and an electrode that applies a voltage to the fluid, and is configured to control the viscosity of the fluid by the applied voltage and damp and absorb vibrations from the engine that change depending on the engine rotation speed. .

[0006]

[Operation] When the vibration of the vehicle changes according to the engine rotation speed, the engine rotation speed detection means first detects the change in the engine rotation speed and outputs a signal corresponding to the rotation speed to the control means. The control means inputting the signal applies a predetermined voltage to the electrorheological fluid corresponding to the rotation speed, and the fluid to which this voltage is applied damps and absorbs the natural vibration of the vehicle corresponding to the rotation speed. The optimum viscosity is given to
This allows optimum vibration damping performance to be exhibited at all times.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a vibration isolator according to the present invention, which can constitute a dynamic damper with a mass 1, a vibration absorbing mechanism 2, an engine rotation speed detection means 3, and a mass 1. , a control means 4, and a power source 5, and is designed to attenuate and absorb vibrations of the vehicle body 6 caused by the operation of an engine (not shown). The mass 1 is designed to attenuate and absorb vibrations from the engine by forcibly generating unique vibrations, and a mass having a mass larger than a certain level is used. In this embodiment, a battery with mass m is used as mass 1. Furthermore, this mass is not particularly limited to this, and may be, for example, a radiator, etc., as long as it provides the same effect.

[0008] The vibration absorption mechanism 2 has a mass 1 mounted on the vehicle body 6 and is designed not only to prevent vibration of the mass 1, but also to actively attenuate and absorb vibrations from the engine using the mass 1. , a pair of mounts 7 and 8 arranged above and below
, an elastic body 9 such as rubber fixed between these mounts 7 and 8, an upper liquid chamber 10 and a lower liquid chamber 11 formed between this elastic body 9 and the mount 8, and these liquid chambers 10, It consists of an orifice 12 formed between 11 and electrodes 13 and 14 attached to this orifice 12. The mount 7 is adapted to fix the mass 1.

The mount 8 is composed of an upper tube 15 that is open upward, and a lower tube 17 that is secured to the upper tube 15 by caulking with a diaphragm 16 sandwiched therebetween. Upper tube 15
A partition wall 15a is formed inside to divide the liquid chamber into upper and lower parts. The lower cylinder 17 has a diaphragm 1
The internal sealed space formed by 6 is the air chamber 17a.
It consists of The upper liquid chamber 10 and the lower liquid chamber 11 are filled and sealed with electrorheological fluid (ER fluid), and the fluid in this embodiment is, for example, 40 to 60% by weight.
of silicic acid, 30-50% by weight of a low-boiling organic phase, 50-50% by weight of a low-boiling organic phase,
A mixture of 10% by weight water and 5% by weight dispersion medium has been applied, for example isododecane (isododecane).
dekan) can be used. This electrorheological fluid has the viscosity of a normal hydraulic fluid when it is not energized, and when it is energized, its viscosity changes linearly in a linear manner depending on the strength of the electric field and becomes hard. Therefore, the viscosity can be easily and approximately accurately controlled by applying voltage.

The orifice 12 is formed at the center of the partition wall 15a, and the inner wall surface through which the electrorheological fluid passes is provided with an electrode 13 and an electrode 1 to which positive and negative potentials are respectively applied.
4 is installed. In addition, these electrodes 13, 14
A lead wire is drawn out and connected to the power source 5 through a hole (not shown) provided in the partition wall 15a. The engine rotation speed detection means 3 focuses on the fact that the vehicle body (especially the engine room) vibrates at a specific frequency depending on the engine rotation speed,
In order to generate optimal damping and absorption vibration in accordance with each natural frequency, the engine rotation speed is detected and output as information to the control means 4, and is connected to the input side of the control means 4. The control means 4 applies a predetermined voltage to the electrorheological fluid based on the information about the engine speed output from the engine speed detection means 3, and changes the natural vibration characteristics as needed according to changes in the viscosity of the fluid. death,
It is configured to be able to freely control the vibration mode that is optimal for damping and absorbing vibrations from the engine. The output side of the control means 4 is connected to the power supply 5, and the voltage applied to the electrodes 13 and 14 connected to the power supply 5 is controlled at any time by a control signal outputted from the control means 4. .

Next, the operation of this embodiment will be explained. Vibrations generated with the operation of the engine propagate into the engine room of the vehicle body 6, and the engine room vibrates in a predetermined mode depending on the rotation speed. At this time, the vibration absorbing mechanism 2 that has propagated the vibration has a portion of the vibration absorbed by internal friction in the elastic body 9, and also propagates to the electrorheological fluid in the liquid chambers 10 and 11. As a result, the fluid in the liquid chambers 10 and 11 moves up and down through the orifice 12, and vibrations are absorbed by the passage resistance during this movement. The vibrations absorbed in this way vary depending on the engine speed, and the vibration characteristics also vary over a wide range. In other words, with respect to vibrations occurring in the engine room depending on the engine rotation speed, the engine rotation speed detection means 3 first detects the rotation speed and sends a signal corresponding to the rotation speed to the control means 4.
Output to. The control means 4, which has received this signal, outputs a control signal to the power source 5 and applies an appropriate voltage to the fluid via the electrodes 13 and 14 in order to give the fluid the optimum viscosity for damping and absorbing the vibration. Apply. The viscosity of the fluid to which this voltage is applied changes according to the voltage, and the elastic constant is controlled at any time due to this viscosity change. Vibrations from the engine are effectively damped and absorbed through functional control.

0012

As explained above, according to the vibration isolating device according to the present invention, when the vibration from the vehicle changes depending on the engine speed, the engine speed detecting means first detects the engine speed. A signal corresponding to the detected rotational speed is output to the control means, and the control means imparts to the electrorheological fluid the optimum viscosity for damping and absorbing the natural vibration of the vehicle corresponding to the rotational speed. The elastic constant changes according to the viscosity of the fluid, and an appropriate vibration absorption mode is set according to the elastic constant, and optimal vibration damping performance is always achieved in response to changes in the vibration mode generated by the engine. As a result, the anti-vibration performance is dramatically improved.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a vibration isolating device according to the present invention.

FIG. 2 is a graph showing the correlation between the applied voltage in the electrorheological fluid and the natural frequency as a dynamic damper according to the present invention.

FIG. 3 is a configuration diagram showing a conventional vibration isolator.

FIG. 4 is a graph for explaining the drawbacks of a dynamic damper using a conventional vibration isolator.

[Explanation of symbols]

1 square 3 Engine speed detection means 4 Control means 6 Vehicle body 7,8 Mount 9 Elastic body 10, 11 Liquid chamber 12 Orifice 13,14 Electrode

Claims (1)

[Claims] 1. A pair of mounts connected by an elastic body and provided between a mass consisting of a heavy object such as a radiator or a battery in an engine room of a vehicle and a body in the engine room; A liquid chamber formed divided into a plurality of parts between the mount and filled with an electrorheological fluid, and an orifice formed at at least one or more places between the divided liquid chambers and communicating between these liquid chambers. , an electrode attached to the orifice and applying a voltage to the fluid, the viscosity of the fluid being controlled by the applied voltage,
A vibration isolating device characterized in that it is configured to attenuate and absorb vibrations from an engine that change depending on the engine speed.