JPH02240427A - Control type engine mount - Google Patents

Abstract

PURPOSE:To effectively reduce vibration by selecting the first or second voltage applying means in accordance with an input vibrative condition and, applying voltage to an electrode orifice to control viscosity of electric rheology fluid in accordance with the respective condition. CONSTITUTION:A selecting means (k), in accordance with an input vibrative condition, selects the first or second voltage applying means (i) or (j) applying voltage to an electrode orifice (e) changing viscosity of electric rheology fluid between main and subfluid chambers (d), (f) and a damping rate. The first voltage applying means (i), being based on a signal of a car body movement detecting means (g) and an in-orifice fluid movement detecting means (h), applies predetermined voltage when the first to third conditions, judging a car body (a) and fluid movement direction, fluid speed, car body speed, are satisfied. While the second voltage applying means (j) applies fixed voltage lower than the above described predetermined voltage. Thus, a reducing effect can be substantially improved of a transmitting rate of vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to an electrorheological fluid whose viscosity changes depending on an applied voltage, and which changes the fluid viscosity within an orifice provided between a main fluid chamber and a sub-fluid chamber. This invention relates to a controlled engine mount that allows variable

BACKGROUND ART As this type of controlled engine mount, for example, there is a control type engine mount disclosed in Japanese Patent Application Laid-open No. 104828/1983. ) Main fluid chamber (upper chamber) formed within
and a sub-fluid chamber (lower chamber) defined by an elastic wall are communicated through an electrode orifice, that is, an orifice provided with an electrode plate, and a variable viscosity fluid is provided in these main and sub-fluid chambers and the orifice. By enclosing an electrorheological fluid and changing the voltage applied to the electrode plate in response to the input vibration, the flow state of the fluid in the orifice is changed, thereby making it possible to adjust the vibration transmission state as appropriate. It is now possible to do so.

Problems to be Solved by the Invention However, in such conventional controlled engine mounts, vibrations transmitted between the vehicle body and the power unit via the engine mount are transmitted via the supporting elastic body itself. Inputs from these supporting elastic bodies,
Since the phase with the input from the expansion elasticity changes due to the action of a dynamic vibration absorber using the fluid in the orifice as a mass, sufficient vibration transmissibility can be achieved even if the controlled engine mount is simply controlled as a vibration model with one degree of freedom. There was a problem in that it was not possible to reduce the

Therefore, in view of such conventional problems, the present invention detects the state of input vibration and the flow state of the fluid in the orifice, and adjusts the viscosity of the electrorheological fluid in the orifice according to the change in the vibration state amount for each vehicle. It is an object of the present invention to provide a controlled variable engine mount that greatly improves the effect of reducing vibration transmission rate through control.

Means for Solving the Problems In order to achieve this object, the invention of claim 1, as shown in FIG. A main fluid chamber d which is arranged in parallel with C and whose volume can be changed by input vibration, and a auxiliary fluid chamber f whose volume is variable and which is communicated with the main fluid chamber d through an electrode orifice e, and these main and auxiliary fluid chambers d , f and an electrode orifice e, in which an electrorheological fluid whose viscosity changes depending on the applied voltage is sealed, and the damping rate in the electrode orifice e is changed. a vehicle body motion detection means g that detects the movement of the fluid in the electrode orifice e; and an orifice fluid motion detection means that detects the movement of the fluid in the electrode orifice e; The first condition is to determine the movement direction of the fluid in the vehicle body a and the electrode orifice e based on the first condition, and the second condition is to determine the velocity of the fluid in the orifice to a predetermined value.
A third condition for determining the condition and the magnitude of the vehicle speed based on a predetermined value B is determined, and these first. Second. a first voltage applying means i that applies a predetermined voltage value to the electrode orifice e when a third condition is satisfied; and a constant voltage value lower than the predetermined voltage value output from the first pressure applying means i. , a second voltage applying means j that applies to the electrode orifice e, and a first voltage applying means i that applies the voltage to the electrode orifice e according to the input vibration conditions.
Alternatively, the selection means for selecting the second voltage application means j and applying a voltage to the electrode orifice e is provided.

Further, the invention according to claim 2 is arranged such that the vehicle body acceleration detected by the vehicle body motion detecting means g is detected by the vehicle body motion detecting means g. The acceleration time integral value is determined, and the fluid movement detection means in the orifice detects the pressure change in the sub-fluid chamber f, and the pressure in the sub-fluid chamber f is set as X3 + pressure time differential value as ■3. In this case, (a) the first condition is ■1・X, <Q, (b) the second condition is one sentence, and 1<A father 1 ・ (・) the third condition is father 11・X・〉B.

Furthermore, in the invention according to claim 3, the voltage value output from the second voltage applying means j is set to be 20 to 20 with respect to the predetermined voltage value.
A constant voltage value is set within a range of 60%.

Furthermore, in the invention of claim 4, the selection of the first voltage application means i or the second voltage application means j by the selection means k,
This is done by comparing input vibrations within a certain sampling time.

Operation With the above-described configuration, the controlled engine mount of the invention as set forth in claim 1 has the following advantages: when a voltage is applied to the electrode orifice e by the first voltage application means i, the first, second, . A voltage is output when the third condition is satisfied, and the first condition determines the movement of the fluid in the vehicle body a and the electrode orifice e, and the second condition determines the magnitude of the velocity of the fluid in the orifice. Furthermore, since the third condition determines the speed of the vehicle body based on the predetermined value B, the state of the engine mount and the vibration state of the vehicle body can be comprehensively detected. Accurate electrorheological fluid viscosity control is achieved.

On the other hand, when a voltage is applied to the electrode orifice e by the second voltage application means j, by setting a constant voltage value lower than the above-mentioned predetermined voltage value, a controlled type When the engine mount is in an uncontrolled state, especially when the input vibration is random,
Vibration transmissibility is effectively reduced.

Therefore, by selecting the control by the first voltage application means i or the control by the second voltage application means j by the selection means k, fine control is possible under a wide range of vibration conditions, and vibration input to the vehicle body can be controlled. can be significantly reduced.

According to a second aspect of the invention, the first condition is defined as the vehicle body acceleration detected by the vehicle body motion detecting means g. The acceleration time integral value is set to be large, and the fluid movement detection means in the orifice detects the pressure change in the sub-fluid chamber f, the pressure in the sub-fluid chamber f is xs, and the pressure time differential value is set to 3. In this case, (a) the first condition is father yo・Xsku0 (b) the second condition is 1 large, 1〈A (・) the third condition is car・sentence, >B lx.

By doing so, it is possible to perform precise control and greatly improve the effect of reducing vehicle body vibration.

Furthermore, in claim 3, the voltage value output from the second voltage applying means j is set to be 20 to 20 with respect to the predetermined voltage value.
By setting a constant voltage value in the range of 60%, the fluid movement within the electrode orifice e is set to an optimal state for random vibrations.

Furthermore, in claim 4, the selection of the first voltage application means i or the second voltage application means j by the selection means k,
By comparing the input vibrations within a certain sampling time, the voltage value to be applied to the electrode orifice e can be easily and accurately selected.

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

That is, FIG. 2 shows a controlled engine mount 10 showing an embodiment of the present invention, and the controlled engine mount 10 is disposed between a vehicle body 12 and a power unit 14, and the power unit 14 is provided with a buffering effect on the vehicle body 12. I support it with.

The controlled engine mount 10 includes a first bracket 1'6 attached to the vehicle body 12 and a second bracket 18 attached to the power unit 14. A support elastic body 20 is attached between the second brackets 16, 18 by vulcanization adhesive or the like.

Inside the supporting elastic body 20 on the first bracket 16 side,
Orifice structure 23 in which electrode orifice 22 is formed
A main fluid chamber 24 defined by
A side of the electrode orifice 22 opposite to the main fluid chamber 24 is covered with a diaphragm 26, and a sub-fluid chamber 28 is formed between the electrode orifice 22 and the diaphragm 26.

The first bracket 16 is composed of a tapered cylindrical body 16a and a dish-shaped cover 16b which is caulked and fixed to the lower end peripheral edge of the tapered cylindrical body 16a in the figure. The peripheral edges of the orifice structure 23 and the diaphragm 26 are each caulked and fixed to the caulked portion with the cover 16b.

Further, a space defined by the diaphragm 26 and the cover 16b is an air chamber 30.

The electrode orifice 22 has a main fluid chamber 24 and a sub fluid chamber 2.
A pair of electrode plates 22b and 22C are attached to vertically opposing walls of an orifice 22H that communicates with the orifice 8.

The main fluid chamber 24. An electrorheological fluid as a variable viscosity fluid is sealed within the sub-fluid chamber 28 and the electrode orifice 22 .

The electrorheological fluid has a property that the viscosity changes depending on the applied voltage, and the viscosity increases when a strong electric field is applied by the applied voltage.

Incidentally, the vehicle body 12 is provided with a vertical acceleration sensor 32 as a vehicle body motion detecting means.
2, the vertical displacement acceleration of the vehicle body 12 is detected.

Further, a pressure sensor 34 is provided in the sub-fluid chamber 28 at the lower end of the orifice structure 23 and serves as an intra-orifice fluid movement detecting means, which is attached facing the inside of the sub-fluid chamber 28. The pressure within the secondary fluid chamber 28 that is changed is detected.

In other words, the pressure inside the auxiliary fluid chamber 28 is reduced to the orifice 22a.
Fluid flowing in and out through (electrorheological fluid)
By detecting the pressure inside the sub-fluid chamber 28 with the pressure sensor 34, the orifice 22a
The movement of fluid within the tube will be detected.

Note that the state of movement of the fluid within the orifice 22a can also be obtained by detecting the pressure within the air chamber 30.

The acceleration signal and pressure signal detected by the vertical acceleration sensor 32 and the pressure sensor 34 are output to a controller 36 as a control means for calculating a control voltage, and the controller 36 based on these signals The control voltage to be output to the electrode orifices 22b, 22C is calculated.

The result calculated by the controller 36 is output to a voltage output section 38, and a control voltage according to the calculation result of the controller 36 is applied from the voltage output section 38 to the electrode plates 22b, 22c.

Inside the controller 36, a first voltage applying means 40 is provided.
, a second voltage application means 42, and a selection means 44 are provided.

The first voltage applying means 40 sets a first condition for determining the movement direction of the fluid in the vehicle body 12 and the electrode orifice 22 based on the detected values of the vertical acceleration sensor 32 and the pressure sensor 34, and the velocity of the fluid toward the orifice 22a. A second condition for determining the magnitude of the vehicle body 12 based on the predetermined value A and a third condition for determining the magnitude of the speed of the vehicle body 12 based on the predetermined value B are determined. Second. When the third condition is met,
A predetermined voltage value is applied to the electrode orifice 22.

On the other hand, the second voltage applying means 42 outputs a constant voltage value lower than the predetermined voltage value output from the first voltage applying means 40 to the electrode orifice 22.

Further, the selection means 44 includes the first voltage application means 40
Alternatively, the second @pressure applying means 42 is selected and the voltage value to be output to the electrode orifice 22 is determined.

FIG. 3 shows the control type engine mount IO and the vehicle body 12.
This is a model diagram of the vibration system of the entire vehicle including the power unit 14 and the unsprung portion 40, where Xl is the displacement amount of the vehicle body 12,
X3 indicates the amount of displacement of the fluid toward the orifice 22a, and further,
Xo shown in the figure is the amount of displacement of the unsprung part, for example, the suspension link, and X is the amount of displacement of the power unit 14.

In the model diagram shown in FIG. 3 above, the vehicle body mass MS as a mass body is supported by the unsprung mass 40 via the suspension spring KS, and the control type is connected between the vehicle body mass MS and the power unit mass MP. Engine mount IO is located.

At this time, the control type engine mount 10 has a fluid mass M in the orifice 22a in order to suppress resonance caused by the power unit mass MP, the vertical springs of the support elastic body 20 itself, and the expansion springs KP+KO.
O, the expansion spring KO of the main fluid chamber 24, and the orifice 22
The fluid resonance within the orifice 22a due to the cross-sectional area ratio R of a acts as a dynamic vibration absorber, so that the fluid resonance frequency within the orifice 22a is set at 10 (see FIG. 4, which will be described later).

With the above configuration, the controlled engine mount 1 of this embodiment
0, when vibration is input from the vehicle body 12, the support elastic body 20 is deformed and the volume inside the main body chamber 24 is changed,
Due to the pressure change according to the expansion spring of the support elastic body 20 that constitutes the side wall of the main fluid chamber 24, the viscosity variable fluid in the main fluid chamber 24 flows between it and the sub fluid chamber 28 through the orifice 22a of the electrode orifice 22. will be moved.

At this time, fluid vibration occurs in the electrode orifice 22,
At a specific frequency of input vibration, the movable fluid (electrorheological fluid) in the orifice 22a is defined as a mass (fluid mass MO), and the expansion elasticity of the supporting elastic body 20 is defined as a spring (expansion spring K).
A resonance phenomenon occurs.

At this time, the electrode plates 22b, 2 of the electrode orifice 22
By applying a high voltage to 2c, the orifice 22a
The viscosity of the electrorheological fluid in the orifice 22a increases, and the viscous resistance of the fluid (electrorheological fluid) passing through the orifice 22a becomes thicker (thus, the damping coefficient of the controlled engine mount 10 can be controlled).

Diagram M4 shows the displacement transmission rate (l) of the vehicle body 12 when the unsprung mass 40 is vibrated in the vibration system model shown in
It is known that the displacement transmissibility has different characteristics depending on the magnitude of the damping coefficient CO of the fluid mass MO, and when not controlled,
The shape of the orifice 22a and the expansion elasticity are set so that the optimum characteristic C is achieved in this uncontrolled state.

In the controlled engine mount 10 of this embodiment, the voltage application to the electrode orifice 22 in FIG. 4 is stopped (OV
), the resonance curve a1 voltage value is maximum (predetermined voltage value)
It is set so that a resonance curve is obtained when the viscosity of the electrorheological fluid is set to a solidified state, and a resonance curve C is obtained when an appropriate voltage value (a constant voltage value lower than a predetermined voltage value) is applied.

Here, when vibration in a relatively low frequency range, for example, engine shake, is manually applied to the control type engine mount 10 from the power unit 14 or the vehicle body side, the supporting elastic body 20 is elastically deformed by the excitation force, and the main fluid The pressure within the chamber 24 is changed so that the first bracket 16 and the second bracket 18
The displacement transmission force (vibration damping force) between the two is changed.

In this case, due to the phase delay characteristics of vibration, the orifice 22a
When the fluid mass (MO) in the power unit 14 is vibrating at a frequency lower than the resonance frequency f0, it moves in approximately the same phase as the relative displacement (X, -Xl) of the power unit 14, and when it is resonating, it moves in the same phase as the relative displacement (X, -Xl) of the power unit 14. It moves with a phase difference of 90 degrees from the relative displacement, and furthermore, if it is vibrated at a frequency exceeding the resonance frequency f0, it moves with a substantially opposite phase (180' delay) from the relative displacement.

In each of these states, the acceleration sensor 32 detects the acceleration on the vehicle body side, and the pressure sensor 34
The pressure in the sub-fluid chamber 28 (a value proportional to the displacement X of the fluid) is constantly detected, and the controller 36 grasps each state change and phase information of the vibration system based on the detected information.

Specifically, as shown in the flow chart shown in FIG. 5, the applied voltage value output to the electrode plates 22b and 22G of the electrode orifice 22 is controlled.

In the above flowchart, the method for controlling the voltage applied to the electrode orifice 22 is as follows:
) and the second voltage application means 42 (control (2)), and the selection means 44 selects the more effective method depending on the running condition.

That is, in the above flowchart, first step 100-
Control I is performed for T8 seconds in step 102, and averaging of vehicle body vibrations X and A during this time is performed in step 103. Next, control I is performed in steps 104 to 106 for T8 seconds.
This is carried out for 1 second, and the vehicle body vibration XIB during this period is averaged.

Then, in the next step 108, the set time is set to "0" and the process proceeds to step 109, in which the control by the selection means 44 is executed, and the vehicle body vibration XIA averaged for a certain period of time in the step 103 and the step 107 is And by comparing X and B, X I A < X
Determine t s.

If rYEsj is determined in step 109 above,
Proceeding to steps 110-111, T.

Execute control I for seconds.

On the other hand, if the determination in step 109 is "NO", the process proceeds to steps 112 and 113, where the control is performed for T9 seconds.
Execute.

By the way, the above control 11, that is, the first voltage application means 40
The control is performed by the algorithm shown in Fig. 6,
The control (2) will be explained below.

That is, in the above algorithm, first, the internal pressure pb of the auxiliary fluid chamber 28 detected by the pressure sensor 34 is input as the fluid displacement 1 is input.

Then, the time differential value of the fluid displacement
is further passed through an integrator 121 to obtain a time integral value statement.

The above four values X31 Statement 3. Father 89, together with preset predetermined values A and B, is the first . Second. A third condition is determined.

By the way, the above 1. Second. The third condition is (a) the first condition is set as ■1・X3〈0 (b) the second condition is set as 1 sentence, 1〈A, and the judgment circuit 122 determines that all three conditions are satisfied. If the three conditions are satisfied, a signal for applying a voltage is output to the voltage output section 38, and the voltage output section 38 outputs a signal to the electrode orifice 2.
While a predetermined voltage value (high voltage of several KV) is applied to 2,
If at least one of the three conditions is not met, a signal for cutting off the applied voltage is output to the voltage output section 38.

Above 1st. Second. The applied voltage is turned on and off depending on the third condition.
When FF control is performed, when a sine wave input from the unsprung area is applied, the applied voltage is approximately ON for vibrations in a frequency range smaller than the resonance frequency f0 of the fluid facing the orifice 22a.
occupied by the state of

In this state, the movement of the fluid mass becomes slow due to an increase in viscous resistance within the orifice 22a, and the fluid mass MO cannot function as a dynamic vibration absorber, and the resonance phenomenon of the power unit 14 seen from the vehicle body 12 side becomes noticeable. Become.

However, in a frequency range smaller than the resonance frequency f0, the phase difference between the vehicle body displacement X and the power unit displacement X does not exceed 900, so the resonance phenomenon of the power unit 14 acts as a dynamic vibration absorber for the vehicle body 12. As a result, the vibrations on the vehicle body 12 side that are excited from the unsprung portion 40 are significantly reduced (for example, the resonance curve at this time has the characteristic shown in FIG. 4).

On the other hand, for vibrations in a frequency range larger than the resonance frequency f0, the applied voltage is approximately OFF, and the viscous resistance of the fluid facing the orifice 22a decreases, causing the fluid mass M
O now works as a dynamic vibration absorber, and power unit 1
4 is suppressed, and the vibration of the vehicle body 12 is also reduced (for example, the resonance curve at this time is characteristic a in FIG. 4).

In addition, the control of the vibrating hood in the frequency range near the resonance frequency f0 is performed by switching the applied voltage ON and OFF,
The vibration input to the vehicle body 12 is controlled to be small.

Therefore, based on the above control I (by changing the attenuation value in the electrode orifice 22 at the timing),
In response to a sine wave input from the unsprung area, it is now possible to effectively utilize the power unit mass (MP) and fluid mass (MO) to reduce vehicle body vibration across the entire frequency range. The transmission factor can be obtained from the d characteristic shown in FIG.

In addition, in the above characteristic d, compared to characteristic C during non-control, 7 to
It is possible to reduce vibration by 1 odB.

By the way, the effect of the control I mentioned above is exhibited when the unsprung vibration is a sine wave, and when the unsprung vibration is a sine wave, a normal fluid mount that is non-controlled for random vibration (for a sine wave input, the 4th (corresponding to characteristic C in the figure) may provide better characteristics.

Therefore, in response to such random vibrations, control is performed to exhibit the characteristics of a normal fluid mount.
This is controlled by the second voltage application means 42.

That is, in the above control (2), a constant voltage value lower than the predetermined voltage value output from the first voltage applying means 40 is output by the above control (2), and in this way, the low constant voltage value causes the electrode orifice to be By appropriately setting the viscosity of the fluid (electrorheological fluid) in 22 to make it movable, the controlled engine mount 10 of this embodiment exhibits the characteristics as a normal fluid mount.

Further, the constant voltage value output from the second voltage output section 42 at this time is desirably set within a range of 20 to 60% of the predetermined voltage value output from the first voltage output section 40. .

Of course, in the above control ■, as well as in the above control I,
The applied voltage value output to the electrode orifice 22 is determined by sending a corresponding signal from the second voltage applying means 42 to the voltage output section 3.
8, and the actual voltage value is applied to the electrode orifice 22 from the voltage output section 38.

Therefore, the control type engine mount 1 of the present embodiment described above
0, the voltage value applied to the electrode orifice 22 is controlled using two control patterns, Control I and Control II, so that the input from the unsprung area is sine wave vibration and random vibration. Even if there is a problem, the control range can be covered, and vehicle body vibration can be effectively reduced under all driving conditions.

In this embodiment, as shown in the flowchart of FIG. 5, the selection of the 17115th voltage applying means 40 or the second voltage applying means 42 is performed at a certain sampling rate, which is performed under the control I and the control II, respectively. By comparing input vibrations over time, the voltage value to be applied to the electrode orifice 22 can be easily and accurately selected.

As described in detail, the controlled engine mount of the present invention comprises:
In claim 1, the first
When the voltage applying means or the second voltage applying means is selected and a voltage is applied to the electrode orifice by the first voltage applying means, the first. Voltage is generated when the second and third conditions are met. The first condition determines the direction of movement of the vehicle body and the fluid in the electrode orifice, and the second condition determines the magnitude of the velocity of the fluid in the orifice. Since the judgment is made based on the predetermined value A, and the third condition is the magnitude of the vehicle speed based on the predetermined value B, it is possible to comprehensively detect the state of the engine mount and the vibration state of the vehicle body. In particular, it is possible to perform accurate viscosity control of an electrorheological fluid with respect to input of sinusoidal vibration.

On the other hand, when a voltage is applied to the electrode orifice by the second voltage application means, by setting the voltage to a constant voltage value lower than the predetermined voltage value, the fluid movement within the electrode orifice is set in a non-controlled state, In particular, it is possible to effectively reduce the vibration transmissibility with respect to random vibration input.

Therefore, the control by the first voltage applying means or the second
By selecting the control by the voltage application means by the selection means, fine control is possible under a wide range of vibration conditions, and vehicle body vibration can be significantly reduced and vehicle ride comfort can be significantly improved.

According to a second aspect of the present invention, the first condition is (1) that the vehicle body acceleration detected by the vehicle body motion detecting means is 1.

When the acceleration time integral value is 5c1, and the fluid movement detection means in the orifice detects the pressure change in the auxiliary fluid chamber, the pressure in the auxiliary fluid chamber is Xs, and the pressure time differential value is Xs, (a) By setting the first condition as ■1. can be improved.

Furthermore, in claim 3, the voltage value output from the second voltage applying means is set to be 20 to 6 % with respect to the predetermined voltage value.
By setting a constant voltage value in the range of 0%, fluid movement within the electrode orifice can be set to an optimum state with respect to random vibrations.

Furthermore, in claim 4, the selection of the first voltage application means or the second voltage application means by the selection means is performed by comparing input vibrations within a certain sampling time, so that the voltage applied to the electrode orifice is This provides various excellent effects such as being able to easily and accurately select the voltage value to be applied and simplifying the control circuit.

[Brief explanation of drawings]

FIG. 1 is a claim correspondence diagram showing the concept of the present invention, FIG. 2 is a sectional view showing an embodiment of the present invention, and FIG. 3 is a shape model diagram showing the vibration system of the entire vehicle to which the present invention is applied. Fig. 4 is a characteristic diagram of the vibration transmissibility that changes depending on the control mode, Fig. 5 is a flowchart showing an example of processing for executing a program for controlling the present invention, and Fig. 6 is a flow chart of the present invention. Invention number 11! This is an algorithm used in one embodiment of control by the pressure applying means. 10... Control type engine mount, 12... Vehicle body,
14... Power unit, 20... Support elastic body, 2
2... Electrode orifice, 22a... Orifice, 2
2b, 22C... Electrode plate, 24... Main fluid chamber, 28
... Sub-fluid chamber, 32... Vertical acceleration sensor (vehicle body movement detection means), 34... Pressure sensor (orifice internal fluid movement detection sensor), 36... Controller, 38...
Voltage output section, 40...first voltage application means, 42...
Second voltage application means, 44... selection means. Figure 1 2 people outside Figure Frequency (Hz) Figure 5 Figure 6 Voltage ON Voltage OFF

Claims (4)

[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 a main fluid chamber communicating with the main fluid chamber via an electrode orifice. A sub-fluid chamber whose volume is variable, and an electrorheological fluid whose viscosity changes depending on the applied voltage is sealed in these main and sub-fluid chambers and the electrode orifice, so that the attenuation rate within the electrode orifice is changed. In the controlled engine mount, a vehicle body motion detecting means for detecting vertical movement of the vehicle body, an orifice fluid motion detecting means for detecting fluid motion within an electrode orifice, and these vehicle body motion detecting means and orifice fluid motion detecting means. A first condition for determining the movement direction of the vehicle body and the fluid in the electrode orifice based on the detected value of the means; a second condition for determining the magnitude of the velocity of the fluid in the orifice based on a predetermined value A; and a second condition for determining the magnitude of the velocity of the vehicle body. A third step for determining the
A first step that applies a predetermined voltage value to the electrode orifice when the first, second, and third conditions are satisfied.
a voltage applying means; a second voltage applying means for applying a constant voltage value lower than a predetermined voltage value outputted from the first voltage applying means to the electrode orifice; A controlled engine mount comprising: a selection means for selecting either the voltage application means or the second voltage application means and applying a voltage to the electrode orifice. (2) The vehicle body acceleration detected by the vehicle body motion detection means is
_1, the acceleration time integral value is X_1, the fluid movement detection means in the orifice detects the pressure change in the sub-fluid chamber, the pressure in the sub-fluid chamber is X_3, and the pressure time differential value is ■_3, ( a) The first condition is ■_1・X_3<0 (b) The second condition is |■_3|<A (c) The third condition is (■_1/|■_1|)・■_1>B
The controlled engine mount according to claim 1, characterized in that: (3) The voltage value output from the second voltage applying means,
2. The controlled engine mount according to claim 1, wherein the voltage is set at a constant voltage within a range of 20 to 60% of the predetermined voltage. (4) The controlled engine according to claim 1, wherein the selection means selects the first voltage application means or the second voltage application means by comparing input vibrations within a certain sampling time. mount.