JPH0366948A - Viscosity variable fluid sealed control type vibro-isolating body - Google Patents

Abstract

PURPOSE:To avoid collision of a movable plate against peripheral members even when there is a vibration of large amplitude from an engine caused by oscillation after cranking in concert with an engine start operation and an engine stop, by applying a control voltage to an electrode plate provided to a rattle element for a specified time after an ignition key is put on or off. CONSTITUTION:Reduction of vibration through thorough usage of an orifice function is performed by applying a control voltage to each of electrode members 44b, 52 in accordance with the number of rotation of an engine and the speed, for example, by locking a movable plate 42 inside a rattle element 40 by way of heightening the viscosity of an electric rheology fluid inside the rattle element 40 at the time of idling of the engine. Subsequently, when an ignition current is fed into the the primary side of an ignition coil at the time of starting of a car, the fluid comes to be in stick state by way of heightening the viscosity of the fluid inside the rattle element 40, the movable plate 42 stored in the rattle element 40 is locked, collision against its peripheral members is avoided and generation of hammering noise is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a variable viscosity fluid filled control type that is capable of tuning a plurality of vibration damping frequencies by filling the inside with a fluid whose viscosity changes depending on the applied voltage. This relates to vibration isolators.

BACKGROUND ART This type of controlled vibration damping body filled with a variable viscosity fluid is disclosed in Japanese Patent Laid-Open No. 57-84220, in which a main fluid whose volume changes as a support elastic body deforms. In addition to the orifice that communicates the chamber with the auxiliary fluid chamber whose volume changes accordingly, a play member having a movable member that is moved in response to pressure changes in the main fluid chamber is provided.

By the way, a fluid-filled control type vibration isolator provided with such a backlash member normally communicates the main fluid chamber and the sub-fluid chamber against input vibrations in a relatively low frequency range such as idle vibration or engine shake. By changing the flow state of the fluid in the orifice, vibrations input to the vehicle body are reduced,
In addition, with respect to input vibration in a relatively high frequency range that causes muffled noise, the muffled sound inside the vehicle interior is reduced by vibrating the rattling member.

Therefore, the movable member of the play member must be sufficiently moved when the high-frequency vibration occurs, and must be prevented from moving when the low-frequency vibration occurs in order to utilize the orifice.

Therefore, the amount of movement of the movable member is regulated to be small in accordance with the small amplitude during high frequency vibration, and the movement of the movable member is prevented during low frequency vibration where the amplitude is relatively large. .

Problems to be Solved by the Invention However, in such a conventional variable viscosity fluid-filled controlled vibration isolator, even if the input vibration is a low frequency vibration, if an idle vibration with a relatively small amplitude is input, the mainstream vibration is There is a problem in that the pressure within the body chamber escapes to the backlash element side, and sufficient liquid movement within the orifice is no longer generated.

Furthermore, even when the amplitude is large such as engine shake, the pressure change in the main fluid chamber is reduced due to the backlash (movement) of the backlash element, making it impossible to fully demonstrate the effect of the orifice. was there.

Furthermore, in the case of the above vibration isolator, the fluid inside the vibration isolator flows violently due to vibrations caused by cranking when the engine is started and large amplitude vibrations caused by the shaking of the engine when the engine is stopped. As the fluid flows, the movable members within the backlash element collide with surrounding members, producing a banging sound.
There is a problem in that this hitting sound is transmitted as noise into the vehicle interior.

Therefore, the present invention solves the problems that the conventional variable viscosity fluid-filled control type vibration isolators have, and enables the vibration isolators to be fixed even when low-frequency vibrations or high-frequency vibrations are input. It is an object of the present invention to provide a vibration isolator which can fully utilize the functions of the orifice and the play element, and which does not generate knocking noises caused by the movable members within the play element even when the engine is started and stopped. It is something to do.

Means for Solving the Problems In order to achieve the above object, the present invention includes a support elastic body disposed between a vehicle body and a power unit, and a main stream disposed in parallel with the support elastic body whose volume changes due to input vibration. a body chamber, a variable volume sub-fluid chamber communicating with the main fluid chamber through an orifice having an electrode plate facing inside, and a sub-fluid chamber having a variable volume and facing inside the main fluid chamber, and configured to change the pressure within the main fluid chamber. a backlash element configured by a movable member that is moved in accordance with the movement of the movable member, and a case member that regulates the amount of movement of the movable member within a predetermined range and has an electrode plate facing inside, the main fluid chamber and the case member. In a variable viscosity fluid-filled controlled vibration isolator in which a variable viscosity fluid is sealed in which the viscosity changes depending on an applied voltage, first, according to claim 1, an electrode plate provided in the orifice and the backlash element is provided with an engine rotation speed. , a controlled vibration damping device filled with a variable viscosity fluid, which applies a control voltage according to the vehicle speed and also applies a control voltage to an electrode plate provided on the backlash element for a predetermined period of time after the ignition key is turned on or off. According to claim 2, the predetermined time is the time from when the ignition key is turned on and from when the ignition key is turned off until the vibration input due to engine shaking converges. be.

According to the variable viscosity fluid-filled controlled vibration isolator of the present invention configured as described above, by applying a control voltage corresponding to the engine rotation speed and vehicle speed to the electrode plate provided in the orifice and the backlash element, , the viscosity of the electrorheological fluid within the orifice and case member can be varied to adjust the stiffness and damping characteristics of the engine mount to appropriate values. That is, by applying a control voltage to each electrode member according to the engine rotation speed and vehicle speed, for example, when the engine is idling, the viscosity of the electrorheological fluid in the backlash element is increased, and the viscosity of the electrorheological fluid inside the backlash element is increased. It is possible to achieve vibration reduction by locking the movable parts and making full use of the orifice function, and also to reduce the engine speed when the vehicle speed is not within the range where engine shake occurs, or even when the vehicle speed is within the above range. In the rotation range where muffled noise occurs, the stiffness of the engine mount is reduced by lowering both the viscosity of the fluid in the orifice passage and the play element, and the dynamic spring constant is reduced mainly in the medium and high frequency range. , the sound vibration phenomenon that becomes a problem in this area is reduced. Further, when the vehicle speed is within a range where engine shake occurs, the viscosity of the fluid in the orifice passage and the play element is made highest over the entire region, thereby increasing the rigidity of the engine mount, By increasing the loss factor, it is possible to suppress engine vibration and reduce input vibration to the vehicle body.

Furthermore, when the ignition current is applied to the primary side of the ignition coil when the vehicle starts, by increasing the viscosity of the fluid in the play element, the fluid becomes stuck in the play element and is stored in the play element. The movable plate is locked, and even if there is large-amplitude vibration from the engine due to cranking that accompanies the subsequent engine starting operation, the movable plate will not collide with surrounding members, and this collision will be prevented. This prevents the occurrence of hitting sounds caused by

Furthermore, even when the ignition current applied to the primary side of the ignition coil is cut off when the vehicle is stopped, the viscosity of the fluid within the play element is increased within a predetermined period of time, causing the fluid to stick inside the play element. During the time it takes for the large-amplitude vibration input caused by the shaking of the engine to converge after the engine has stopped, the movable plate within the rattling element no longer collides with surrounding members, and the knocking noise caused by this collision is eliminated. occurrence is prevented.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

That is, FIGS. 1 and 2 show an embodiment of a fluid-filled engine mount 10 to which a variable viscosity fluid-filled controlled vibration isolator according to the present invention is applied. 12, and an outer cylinder 14 surrounding the inner R12.
and within these.

A support elastic body 16 made of rubber or the like is interposed between the outer cylinders 12 and 14.

The inner cylinder 12 is attached to one side of the vehicle body or a power unit (a combination of an engine, a transmission, etc.), and the outer cylinder 14 is attached to the other side of the vehicle body or power unit, and the static load of the power unit is It is supported on the vehicle body side via the body 16.

The inner periphery of the supporting elastic body 16 is vulcanized and bonded to the inner cylinder 12, and the outer periphery of the supporting elastic body 16 is vulcanized and bonded to the inner periphery of the outer cylinder 14 through a thin rubber layer 18. Outer cylinder 14
It is press-fitted inside and fixed.

In the support elastic body 16, a main fluid chamber 20 is formed in the upper part in the figure with the inner cylinder 12 as a boundary, and a partition wall on the inner cylinder 12 side is configured as a diaphragm 22 with a space S in the lower part in the figure. A sub-fluid chamber 24 is formed.

Further, an annular groove 26 is formed in the outer circumferential portion of the support elastic body 16 with a width in the central axis direction (left-right direction in FIG. 2) of the main and sub-fluid chambers 20.24. An annular orifice arrangement 28 is fitted.

At this time, the outer peripheral sides of the main fluid chamber 20 and the auxiliary fluid chamber 24 are open into the annular groove 26, and the auxiliary fluid chamber 24
The opening of the main fluid chamber 20 is closed by the orifice structure 28, and the opening of the main fluid chamber 20 is closed by the orifice structure 28.
8 and a play element described later.

In the orifice structure 28, two orifice passages 30.32 of equal length in the left-right direction in FIG. Openings 30a and 32a communicating with the body chamber 20 are formed, and openings 30b and 32b communicating with the auxiliary fluid chamber 24 are formed at the other end (lower side in FIG. 1), and the main fluid chamber 20 and The secondary fluid chamber 24 is connected to the orifice passage 30. 3
They communicate with each other via 2.

The main fluid chamber 20. The auxiliary fluid chamber 24 and the orifice passage 30.32 are filled with electrorheological fluid whose viscosity changes in response to changes in applied voltage, and the engine mount 10 of this embodiment is also configured as a controlled engine mount. Ru.

That is, the above-mentioned control type engine mount is an engine mount that changes the vibration transmission rate by adjusting the fluid viscosity in the orifice passage 30, 32 using a control voltage, and is disclosed in, for example, Japanese Patent Laid-Open No. 104828/1983. There is.

Therefore, the orifice passages 30 and 32 are provided with electrode plates 34.34a and 36.36a, and by applying a control voltage to the electrode plates 34, 348 and 36, 36a, the orifice passages 30.32 are The fluid (
The viscosity of the electrorheological fluid (electrorheological fluid) is changed.

The viscosity of the above-mentioned electrorheological fluid changes depending on the applied voltage, but this viscosity change has a property that the viscosity is set low when no voltage is applied, and the viscosity is set extremely high when a high voltage is applied. have.

The electrode plates 34 and 36 are connected to the orifice passage 30.
32, and a positive voltage is applied from a control circuit (not shown), and the electrode plates 34a and 36a are installed on the outer diameter side of the orifice passage 30, 32, and a negative voltage is applied thereto. .

By the way, in this embodiment, the orifice passages 30, 32
The resonant frequency determined by the fluid mass in the main fluid chamber 20 and the expansion elasticity of the main fluid chamber 20 is set to about 35 to 50 Hz, and the resonance frequency is set to about 35 to 50 Hz.
) is tuned to obtain low dynamic spring characteristics in the vicinity of 20 to 30H2, which is the second-order component of
(See dynamic spring characteristic A in the figure).

In general, in the case of an internal/external cylinder type engine mount as shown in this embodiment, the expansion elasticity determined by the spring constant of the support elastic body 16 is approximately to-15 kg/nn, and the mount dimensions are approximately 100 mm and 100 mm. Since the width dimension is approximately 80 mm, two orifice passages 30 and 32 are required as disclosed in this embodiment in order to obtain the above-mentioned resonance frequency.

By the way, the orifice structure 28 is connected to the main fluid chamber 2.
0 is cut out, and the backlash element 40 is placed in that part.

The backlash element 40 is composed of a movable plate 42 and a case member 44 that accommodates the movable plate 42.
An opening 46.46a is formed which is slightly smaller than the outer shape of the movable plate 42, and the upper and lower plates 44a,
44b, a gap (approximately 0.1 to 0.3 mm) is provided that is slightly larger than the amplitude of high-frequency vibrations that cause muffled noise.

On the opposite side of the backlash element 40 from the main fluid chamber 20, a diaphragm 48 is formed by peeling off the thin rubber layer 18 adhered to the inside of the outer cylinder 14 from the outer cylinder i'j14.
A separate room 50 is provided with the backlash element 4 as a partition wall.
The main fluid chamber 20 and the separate chamber 50 are communicated through the main fluid chamber 20 and the separate chamber 50, and the electrorheological fluid in the main fluid chamber 20 is sealed inside the case member 44 of the play element 40 and the separate chamber 50.

The lower plate 44b of the case member 44 is integrally formed with an electrode plate 36a to which the negative voltage of the orifice passage 32 is applied, and the lower plate 44b itself is used as an electrode member, and The other electrode member 52 is attached to the periphery of the opening 46 on the inside of the upper plate 44a (lower side in the figure), and the electrode member 52 receives an electric current from the control circuit to the electrode plate 34.36. A positive control voltage different from the control voltage is applied.

With the above-described configuration, in the fluid-filled engine mount 10 of this embodiment, when relative vibration is generated between the power unit and the vehicle body, the inner cylinder 12 and the outer cylinder 14 are mutually displaced and supported accordingly. The elastic body 16 is deformed, and the main fluid chamber 2
The volume within 0 is changed.

Then, the electrorheological fluid in the main fluid chamber 20 is
The movable plate 4 of the play element 40 is about to be moved to and from the secondary fluid chamber 24 via the orifice passage 30.32.
2 is moved, pressure is about to be transferred between it and the separate chamber 50.

However, when the orifice passages 30, 32 and the backlash element 40 are operated together in this way, the fluid movement within the orifice passages 30, 32 is not sufficiently performed, so in this embodiment, the control shown in Table 1 is performed. Voltage is in orifice passage 3
It is output to the electrode plates 34 and 36 of 0.32 and the electrode member 52 of the backlash element 40. The above-mentioned control all voltage is determined by a control unit (not shown) using vehicle speed and engine rotational speed as factors, and is applied to each electrode member.

Table 1 Note that the electrode plate 34a of the orifice passage 30.32.

36a and the electrode member 44b of the backlash element 40, the negative ground voltage is always applied (when the ignition switch is turned on).
time) is applied.

That is, as for the above-mentioned control voltage, first, when the vehicle is idling in a stopped state, the voltage is stopped (OFF) L to the electrode plate 34.36 on the orifice passage 30.32 side, and the voltage is applied to the electrode member 52 on the backlash element 40 side. is applied (ON).

Then, the viscosity of the electrorheological fluid in the case member 44 of the play element 40 increases and
4, and the movable plate 42 housed in the case member 44 is locked.

Therefore, the fluid in the main fluid chamber 20 is moved between the secondary fluid chamber 24 exclusively through the orifice passage 30.32, and liquid column resonance occurs within the orifice passage 30.32. By doing so, the dynamic spring constant of the secondary frequency component of the idle rotation speed (usually 20 to 30 Hz) is lowered, and as shown in characteristic A in Figure 3, the transmission of vibration to the vehicle body is effectively reduced. Ru.

In addition, when engine shake occurs due to power unit resonance when driving at a constant speed, voltage is turned on to the backlash element side.
In this state, the voltage is also applied to the orifice passage side, causing the fluid in the orifice passages 30 and 32 to stick.

Then, the fluid in the main fluid chamber 20 is confined, and this confined fluid becomes a rigid body and prevents the deformation of the supporting elastic body 16, so the spring constant of the engine mount 10 itself is extremely high (see Figure 3, Characteristics). (see B), thereby suppressing the rocking of the power unit and reducing input vibration to the vehicle body.

Furthermore, under operating conditions other than the above-mentioned idling and engine shake occurrence, while the voltage to the orifice passage side is turned off, the voltage to the backlash element side is also turned off.
Make it.

Then, the movable plate 42 of the backlash element 4o becomes freely movable, and the movable plate 42 is moved in accordance with the pressure change in the main fluid chamber 2o, thereby improving the flow of fluid between the separate chamber 5o and the main fluid chamber 20. As a result, the internal pressure of the main fluid chamber 20 becomes the same as when it is released to the atmosphere, and the rigidity of the engine mount 10 is significantly reduced.Characteristic C in Figure 3), the generation of muffled sounds and noise during acceleration is significantly reduced. can be reduced or prevented.

On the other hand, the control voltage output to the i-electrode plate 3436 of the orifice passage 30.32 and the electrode member 52 of the backlash element 40 is controlled to change depending on the position of the ignition key. In other words, when the driver turns the ignition key when starting the vehicle to apply ignition current to the primary side of the ignition coil, in other words, when the battery and engine ignition device are connected, the above-mentioned play element 4
A predetermined voltage is applied to the electrode member 52 on the 0 side, while no voltage is applied to the electrode plate 34.36 on the orifice passage 30.32 side. Then, similar to the control during idling, the viscosity of the electrorheological fluid in the case member 44 of the rattling element 4o increases, the fluid becomes stuck in the case member 44, and the movable plate housed in the case member 44 increases. 42 is locked, the movable plate 42 in the backlash element 40 will not collide with the case member 44 even if there is large-amplitude vibration from the engine due to cranking during a subsequent engine starting operation. , generation of hitting sounds due to this collision is prevented.

Next, if you want to stop the engine rotation after stopping, the 4th
As shown in the figure, when the driver turns the ignition key to cut off the ignition current applied to the primary side of the ignition coil at time To, the ignition current applied to the electrode member 52 on the backlash element 40 side is also applied. The current voltage vo is not immediately reduced to zero, but is maintained for a predetermined period of time 1. Later, by lowering this applied voltage to below {circle around (2)}, the application of voltage to the electrode members 52 of the 40 backlash elements is substantially stopped at time T, and the case of the backlash elements 40 is substantially stopped within the above-mentioned time t1. The electrorheological fluid within member 44 may be stuck within case member 44 .

Above time 1. As shown in the figure, Vl is the time required for the large amplitude vibration input caused by the vibration M of the engine to converge after the engine is stopped, and Vl is the time required for the vibration input of the vibration element 40
This is the minimum voltage value required to regulate the stick state.

Therefore, within the above time t, the movable plate 42 in the rattling element 40 does not collide with the case member 44,
It is possible to prevent the occurrence of hitting sounds due to this collision.

FIG. 5 is a flowchart showing an example of the above control,
This flowchart starts at every predetermined cycle period of the microcomputer constituting the control circuit when the ignition key is activated.

First, when the driver operates the ignition key in step 101 when starting the vehicle to apply ignition current to the primary side of the ignition coil, in step 102 the electrode plates 34, 36 on the orifice passage 30, 32 side are Then, the voltage application is stopped (OFF), and the voltage is applied (ON) to the electrode member 52 on the backlash element 40 side. Then, as described above, only the viscosity of the fluid on the side of the play element 40 becomes high, and as described above, the fluid becomes stuck inside the case member 44 of the play element 40, and the movable plate 42 is locked, and the subsequent engine Even if there is large-amplitude vibration from the engine due to cranking during a starting operation, the movable plate 42 in the rattling element 40 will not collide with the case member 44, and the generation of knocking noise due to this collision will be prevented. be done.

Next, in step 103, the ignition key is turned on to start the engine.

In step 104, it is detected whether or not the vehicle speed V is zero, and if YES, that is, the vehicle speed V is zero, step 10 is detected.
Proceeding to step 5, the voltage applied to the 1i electrode plates 34 and 36 on the orifice passages 30 and 32 side is turned off, and the voltage applied to the electrode member 52 on the backlash element 40 side is turned on. Then, as described above, the viscosity of the fluid on the side of the play element 40 increases and the viscosity of the fluid inside the orifice passage 30, 32 is kept low, so that the fluid in the main fluid chamber 20 escapes to the side of the play element 40. is prevented and the orifice passages 30, 32
The dynamic spring constant of the vibration isolator is reduced due to the resonance of the low-viscosity fluid inside the vehicle, thereby reducing the vibration input to the vehicle body during idling.

Next, in step 104, if NO1, that is, the vehicle speed V is not zero, the process advances to step 106, and this car i! It is detected whether or not v is between vehicle speeds V and V at which engine shake occurs. here! If IO2, that is, the vehicle speed V is not between vl and V, the process proceeds to step 108, where the voltage applied to each electrode plate 34, 36 on the orifice passage 30, 32 side is turned off, and the electrode member on the backlash element 40 side is turned off. The voltage applied to 44b is turned off. Then, the viscosity of the fluid sealed in the vibration isolator becomes the lowest, reducing the rigidity of the engine mount IO, and lowering the dynamic spring constant mainly in the medium and high frequency range, thereby reducing vibration in this range.

If YES in the step 106, that is, the vehicle speed V is between the vehicle speeds vl and V, the process proceeds to step 107, in which the engine speed ``is detected and the engine speed r is normally muffled. It is detected whether or not the engine speed at which the sound is generated is between ``, and r''.
If the number of revolutions r is between rl and r, the process proceeds to step 108, where the above-mentioned control is carried out;
9, each electrode plate 3 of said orifice passage 30.32
Turn on the voltage applied to 4.36, and also turn on the voltage applied to the electrode member 44b on the backlash element 40 side. Then, the viscosity of the fluid sealed inside the vibration isolator becomes the highest over the entire area, increasing the rigidity of the engine mount, suppressing the rocking of the power unit, and reducing input vibration to the vehicle body. .

Next, in step 110, the ignition key is turned off, thereby stopping the rotation of the engine.

Next, in step 111, a timer set to time t is started, and in step 112, the orifice passage 30
．． The applied voltage to the electrode plate 34 and 36 on the 32 side is turned off, and the applied voltage to the electrode member 52 on the backlash element 40 side is turned on.

Then, for at least the time t set by the timer, the electrorheological fluid in the case member 44 of the play element 40 can be kept in a stick state within the case member 44, and the movable plate 42 in the play element 40 can be There is no possibility of collision with the case member 44, and generation of tapping noise due to this collision is prevented. Further, in step 113, it is determined whether or not the set time of the timer is longer than the time tl.

As explained in FIG. 4 above, this time tl is the time until the large-amplitude vibration input caused by the vibration M of the engine converges after the engine is stopped. NO in this step 113.

That is, if the set time t of the timer is shorter than the time tl, the process returns to step 111, and the same control as above is continued, and the answer in step 113 is YES.

That is, if the set time t of the timer is longer than the time tl, in step 114 the voltage applied to the electrode plate 34.36 on the orifice passage 30.32 side is turned off, and the backlash element 40 is turned off.
By turning off the voltage applied to the electrode member 52 in the example, the viscosity of the fluid sealed within the vibration isolator becomes the lowest, the rigidity of the engine mount 10 is reduced, and the control is terminated.

In addition, in the current F, F (front engine front drive) cars, such an internal and external cylindrical engine mount 10
Since it is widely used, it has the advantage of being able to be repurposed without major design changes.

As described in detail, the variable viscosity fluid-filled controlled vibration isolator according to the present invention includes a support elastic body disposed between the vehicle body and the power unit, and a support elastic body disposed in parallel with the support elastic body. a main fluid chamber whose volume is changed by input vibration; a sub-fluid chamber whose volume is variable and communicated with the main fluid chamber through an orifice having an electrode plate facing inside; and a backlash element configured by a movable member that is moved in response to pressure changes in the main fluid chamber, and a case member that regulates the amount of movement of the movable member within a predetermined range and has an electrode plate facing inside. In the variable viscosity fluid-filled controlled vibration damping body in which the main fluid chamber and the case member are filled with a variable viscosity fluid whose viscosity changes depending on the applied voltage, first, according to claim 1, the orifice and the backlash element are provided with A control voltage corresponding to the engine rotation speed and vehicle speed is applied to the electrode plate that has been set, and a control voltage is applied to the electrode plate that is considered to be the backlash element for a predetermined period of time after the ignition key is turned on or off. According to claim 2, the predetermined period of time is such that vibration input due to engine vibration occurs when the ignition key is turned on and after the ignition key is turned off. Since the time taken to converge is set, the following effects are brought about.

That is, by increasing the viscosity of the fluid in the backlash element when the engine is idling, it is possible to lock the movable members in the backlash element and achieve vibration reduction by fully utilizing the orifice function, as well as to reduce vehicle speed. If the engine speed is not within the range where engine shake occurs, or if the engine speed is within the range where muffled noise occurs even if the vehicle speed is within the above range, check the viscosity of the fluid in the orifice passage and play element. By lowering both, the rigidity of the engine mount is reduced, and the dynamic spring constant mainly in the medium and high frequency range is lowered, thereby making it possible to reduce the sound vibration phenomenon that becomes a problem in this range. Furthermore, when the vehicle speed is within the range where engine shake occurs, the viscosity of the fluid in the orifice passage and play element is made the highest over the entire region, increasing the rigidity of the engine mount and reducing loss. By increasing the factor, it is possible to suppress engine vibration and reduce input vibration to the vehicle body.

On the other hand, when the ignition current is applied to the primary side of the ignition coil when the vehicle starts, and after the ignition current is cut off to the ignition coil when the vehicle is stopped, a large amplitude vibration input due to engine vibration occurs. During the time until convergence, the viscosity of the fluid in the rattle element is increased, causing the fluid to become stuck inside the rattle element, and the movable plate housed in the rattle element is therefore locked, preventing the engine starting operation. Even if there is large-amplitude vibration from the engine due to accompanying cranking and shaking after the engine is stopped, the movable plate will not collide with surrounding members, and the generation of knocking noise due to this collision will be prevented. This brings about the effect that the noise caused by the hitting sound is not transmitted into the vehicle interior.

[Brief explanation of drawings]

Fig. 1 is a sectional front view showing an embodiment of the present invention, Fig. 2 is a sectional view taken along the line ■-n in Fig. 1, and Fig. 3 is a dynamic spring constant and loss achieved by an embodiment of the present invention. A characteristic diagram of the factors, FIG. 4 is a graph showing an example of applied voltage when the vehicle is stopped, and FIG. 5 is a flowchart showing an example of control according to the present invention. IO... Fluid-filled engine mount (variable viscosity fluid-filled control type vibration isolator), 12... Inner cylinder, 14... Outer cylinder, 16... Support elastic body, 20... Main fluid chamber , 24・
...Subfluid chamber, 28...Orifice structure, 30.3
2... Orifice passage (orifice), 34.36.
...electrode plate, 40...backlash element, 42...movable plate,
44... Case member, 44b, 52... Electrode member. Figure 3 Figure 4

Claims (2)

[Claims] (1) A supporting elastic body disposed between the vehicle body and the power unit, a main fluid chamber disposed in parallel with the supporting elastic body whose volume changes due to input vibration, and an orifice having an electrode plate facing inside. a sub-fluid chamber with a variable volume that communicates with the main fluid chamber; a movable member that is provided facing the main fluid chamber and is moved in response to a change in pressure within the main fluid chamber; and an amount of movement of the movable member. and a case member having an electrode plate facing inside and regulating the viscosity within a predetermined range, and a viscosity variable fluid whose viscosity changes according to an applied voltage is provided in the main fluid chamber and the case member. In the encapsulated variable viscosity fluid-filled control type vibration isolator, a control voltage is applied to the electrode plate provided in the orifice and the backlash element according to the engine speed and the vehicle speed, and after the ignition key is turned on or off, A control type vibration isolator filled with a variable viscosity fluid, characterized in that a control voltage is applied to an electrode plate provided on the backlash element for a predetermined period of time. (2) The predetermined time period is the time period from when the ignition key is turned on and from when the ignition key is turned off until the vibration input caused by engine shaking converges. Controlled vibration isolator filled with variable viscosity fluid.