JPH08166041A - Liquid sealed engine mount - Google Patents

Abstract

PURPOSE: To provide an engine mount for improving vibration isolation performance at high speed without effecting on vibration performance at low speed and reducing high frequency vibration such as high speed booming noise effectively and exhibiting improved vibration control effect in wide frequency area. CONSTITUTION: A main liquid chamber A taking an elastic member 1 as a wall and the volume of which is changed by deformation of the elastic member 1 and an auxiliary liquid chamber B divided by a diaphragm 2 from the main liquid chamber A taking an elastic member film 4 as a wall the volume of which is variable and an orifice 21 communicating with the main liquid chamber A and the auxiliary liquid chamber B are mounted on a mount. A part of the diaphragm 2 is a movable plate 22 and fixed by an actuator 7 when low frequency vibration is inputted and the vibration is effectively reduced by forcing the movable plate 22 vibrate at the same phase with the input vibration when high frequency vibration is inputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled type engine mount mounted on a vehicle such as an automobile, and more particularly to an engine mount effective for reducing high frequency vibration such as high-speed muffled noise.

[0002]

2. Description of the Related Art Generally, a liquid-filled engine mount is constructed by connecting a pair of liquid chambers, each of which has a rubber elastic body as a chamber wall and is partitioned by a partition plate, with an orifice. Then, by circulating the liquid between both liquid chambers through the orifice, it is possible to obtain an excellent effect in reducing a vibration region preset by the shape of the orifice, for example, a vibration at a relatively low frequency such as an engine shake (around 10 Hz). Is known to exert.

However, although the above-mentioned conventional engine mount is excellent in vibration damping performance at low speed, high-speed muffled noise (100 Hz to 200 Hz) generated at high speed, etc.
A sufficient effect was not seen in the vibration reduction in the higher frequency region. This is because the viscosity of the filled liquid increases with respect to high-frequency vibrations, the damping rate increases, and the vibration insulation performance deteriorates. For this reason, Japanese Patent Laid-Open No. 60-155027 discloses both liquids. A vibration isolation device has been proposed in which a partition plate that divides a chamber is provided so that it can vibrate slightly and the volume of the liquid chamber is changed to absorb high frequency vibration.

[0004]

However, if only the partition plate is movable as in the above-mentioned configuration, the partition plate is affected by the viscous resistance of the enclosed liquid, causing a time delay with respect to the vibration force. It does not work following vibration as expected. In this case, the pressure rise in the liquid chamber cannot be alleviated sufficiently,
There was a problem that the pressure difference between both liquid chambers became a force to transmit the vibration to the vehicle body.

Therefore, an object of the present invention is to improve the vibration insulation performance at high speeds without affecting the vibration suppression performance at low speeds and effectively reduce high frequency vibrations such as high-speed muffled noise. It is to provide an engine mount that exhibits excellent vibration damping effect in a wide frequency range.

[0006]

The structure of the present invention is shown in FIG. 1. In an engine mount, an elastic body 1 is used as a chamber wall, and a volume of the main liquid chamber A is changed by deformation of the elastic body 1. The liquid chamber A is partitioned by the partition plate 2 and is provided with an auxiliary liquid chamber B whose volume is variable and which has an elastic membrane 4 as a chamber wall, and an orifice 21 which connects the main liquid chamber A and the auxiliary liquid chamber B with each other. . In the present invention, a part of the partition plate 2 is used as the movable plate 22, the movable plate 22 is fixed when a low frequency vibration is input, and the movable plate 22 is in the same phase as the input vibration when a high frequency vibration is input. The driving means 7 for forcibly vibrating is provided (Claim 1). The drive means 7 is specifically constituted by a voice coil type actuator (claim 2).

[0007]

When the low frequency vibration is input, the movable plate 22 is fixed by the driving means 7 and the vibration is damped by viscous resistance when the liquid flows through the orifice 21. On the other hand, when high-frequency vibration is input, the movable plate 22 is vibrated in the same phase as the input vibration by the driving means 7. That is, the movable plate 2
Since No. 2 is always driven in the same direction as the exciting force, the internal pressure of the main liquid chamber A does not change. Further, the sub liquid chamber B constitutes a chamber wall with the elastic film 4, and its volume can be freely changed.
The movement of the movable plate 22 does not increase the pressure. Thus, there is no pressure difference between the liquid chambers A and B, and the vibration is insulated and prevented from being transmitted to the vehicle body.

Moreover, since the drive means 7 forcibly vibrates the movable plate 22 in a phase corresponding to the input vibration,
There is no fear that a response delay will occur and the vibration cannot be followed like a conventional movable plate that vibrates due to a change in hydraulic pressure.
At this time, if a voice coil type actuator is used as the driving means 7, a more accurate sine waveform can be generated as compared with, for example, a piezoelectric actuator, and a minute displacement can be easily generated. Therefore, high frequency vibration can be more reliably absorbed. It is possible. Further, there are advantages that control is easy and power consumption is low.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the thick rubber elastic body 1 has an umbrella shape that spreads downward, and the inside thereof serves as a main liquid chamber A. An annular metal side plate 11 is provided at the lower end opening edge of the rubber elastic body 1.
Are joined together, and below the side plate 11, the main liquid chamber A
A partition plate 2 is arranged so as to close the lower end opening of the partition plate 2.
The partition plate 2 has an outer periphery held by a container-shaped support plate 3, and is sandwiched between an annular holding member 31 protruding from the inner periphery of the upper end of the support plate 3 and the side plate 11. Further, below the partition plate 2, there is disposed a thin rubber elastic body film 4 whose outer periphery is held by an annular groove provided in the holding member 31, and the rubber elastic body film 4 and the above-mentioned A space surrounded by the partition plate 2 serves as a sub liquid chamber B.

A mount pedestal 12 made of a metal plate is joined to the upper surface of the rubber elastic body 1, and is fixed to a bracket 5 on the engine side by a bolt 13 protruding from the center of the upper surface of the pedestal 12. A bolt 32 is provided at the center of the lower surface of the support plate 3 so that the engine mount is fixed to the vehicle body 6.

The partition plate 2 has orifices 21 communicating with the main liquid chamber A and the sub liquid chamber B at a plurality of positions on the plate surface, and is enclosed in the liquid chambers A and B through the orifices 21. Incompressible fluids such as water, alkylene glycol, and silicone oil are made to flow. The central portion of the partition plate 2 is a circular movable plate 22, and the movable plate 22 is arranged in the support plate 3 below the rubber elastic film 4 by a connecting pin 23 fixed to the center of the lower surface. It is connected to a voice coil type actuator 7.

The actuator 7 includes a container body 71,
A lid 72 joined to the upper surface of the lid 72 via a support rubber 73 is provided, and the connecting pin 23 is fixed to the center of the upper surface of the lid 72. A ring-shaped permanent magnet 8 is arranged in the container body 71 while being retained by a yoke 74, and a magnetic field is formed in a ring-shaped gap 75 formed between the inner peripheral portion and the central portion of the yoke 74. Is formed. Further, the tubular portion 76 extending from the lower surface of the lid 72 is inserted into the gap 75, and the drive coil 9 wound around the tubular portion 76 crosses the magnetic field at a right angle. is there. Then, when the drive coil 9 is energized, a driving force corresponding to the current according to Fleming's law acts on the movable plate 22 via the lid 72 and the connecting pin 23, and the movable plate 22 can be moved up and down. Becomes The support rubber 73
A slit is provided on the outer periphery of the lid 72 so that the lid 72 can freely move up and down. Further, a guide pin 77 penetrating the central portion of the yoke 74 is provided on the lower surface of the lid body 72, and by smoothly sliding the guide pin 77 only in the vertical direction, the movable plate 22 is moved in a direction other than the vertical direction. Are regulated.

The drive coil 9 is connected to an external control circuit 10 by a lead wire 91, and the control circuit 1
A signal from a vibration detecting means installed on the vehicle body is input to 0. Therefore, calculate the gain and phase that this vibration signal decreases, for example, using adaptive control theory,
By amplifying a signal based on this by an amplifier (not shown) and inputting it to the actuator 7, the movable plate 22 can be forcibly vibrated so as to absorb the internal pressure of the main liquid chamber A. As the vibration detecting means, for example, acceleration detection by an acceleration sensor or speed detection by a search coil can be used.

In the above construction, during low speed operation, the drive coil 9 is not energized and the movable plate 22 is fixed. At this time, when the rubber elastic body 1 is largely deformed by the vibration from the engine, a pressure difference is generated between the main liquid chamber A and the sub liquid chamber B, and the filled liquid vigorously flows in the orifice 21. The viscous resistance acting on the filled liquid exerts good vibration damping characteristics. During high-speed operation, the movable plate 22 is driven in the same phase as the input vibration based on the signal from the control circuit 10 and forcedly vibrated so as to absorb the increase in the internal pressure of the main liquid chamber A. Therefore, there is no pressure difference between the liquid chambers A and B, and good insulation performance is exhibited.

In the above embodiment, the orifice 21 is formed in the partition plate 2 on the outer periphery of the movable plate 22, but the position or shape of the orifice 21 is not particularly limited. Orifices 21 may be formed by providing through holes in the surface.

[0016]

As described above, the liquid-filled engine mount of the present invention can effectively reduce low-frequency and high-frequency vibrations and exhibit high vibration absorption performance in a wide frequency range.

[Brief description of drawings]

FIG. 1 is an overall cross-sectional view of a liquid filled engine mount according to the present invention.

[Explanation of symbols]

 A main liquid chamber B sub liquid chamber 1 rubber elastic body 11 metal side plate 2 partition plate 21 orifice 22 movable plate 23 connecting pin 3 support plate 4 rubber elastic body film 7 voice coil type actuator (driving means) 8 permanent magnet 9 drive coil 10 Control circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazumasa Kuze, Toyota Town, Toyota City, Aichi Prefecture, 1st Toyota Motor Co., Ltd. (72) Kunio Saito, Toyota Town, Toyota City, Aichi Prefecture 1, Toyota Motor Co., Ltd.

Claims (2)

[Claims] 1. An elastic body serving as a chamber wall, a main liquid chamber whose volume changes due to the deformation of the elastic body, and a partition plate which separates the main liquid chamber from the main liquid chamber, and an elastic body membrane serving as a chamber wall, which has a variable volume. In a liquid chamber and an engine mount having an orifice that communicates the main liquid chamber and the sub liquid chamber, a part of the partition plate is a movable plate, and the movable plate is fixed when a low-frequency vibration is input, A liquid-filled engine mount, characterized in that drive means for forcibly vibrating the movable plate in the same phase as the input vibration when a high-frequency vibration is input is provided. 2. The liquid-filled engine mount according to claim 1, wherein the drive means is a voice coil type actuator.