JPH04302739A - Mount for power unit - Google Patents

Abstract

PURPOSE:To provide a mount device for power unit which can suppress the vibration of the power unit, especially a large vibration of the power unit in a cranking effectively, as a mount for power unit to hold the power unit to the car body. CONSTITUTION:While an actuator 6 to operate in the operation of an engine and to suppress the vibration of the engine is provided between an installing bracket 1a at the power unit side and a member 2 at the car body side, a control means to start the operation of the actuator 6 when a starter switch to start the engine is turned ON is also provided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power unit mount that is placed between a vehicle body and a power unit to suppress vibrations of the power unit.

0002

2. Description of the Related Art In automobiles, a mounting device having anti-vibration rubber or the like is placed between a power unit consisting of an engine, a transmission, etc., and the vehicle body. configured to inhibit transmission. Furthermore, for example, according to Japanese Patent Application Laid-Open No. 59-23140, a vibration-proof rubber member and a laminate of electrostrictive elements whose thickness changes when energized are arranged in series between the engine as a vibration source and the vehicle body. A mounting device (vibration absorption method) has been disclosed in which the electrostrictive element is synchronized with engine vibrations and vibrates in an opposite phase, thereby suppressing engine vibrations.

0003

[Problems to be Solved by the Invention] By the way, the above-mentioned mounting device suppresses the vibration of the power unit during idling or normal driving, and the transmission of the vibration to the vehicle body. When the engine is started, that is, during cranking, large vibrations (fluctuations) occur, and the transmission of this vibration to the vehicle body becomes significant. Therefore, the challenge is how to suppress the large vibrations of the power unit during cranking.

SUMMARY OF THE INVENTION Therefore, the present invention provides a power unit mount device which is used as a power unit mount disposed between a vehicle body and a power unit and is capable of effectively suppressing vibrations of the power unit, particularly large vibrations of the power unit during cranking. The purpose is to provide

[0005]

[Means for Solving the Problems] In order to solve the above problems, the present invention is characterized by the following structure.

First, the invention according to claim 1 of the present application (hereinafter referred to as
In a power unit mount that supports a power unit on a vehicle body, an actuator that is disposed between the vehicle body and the power unit and operates while the engine is operating to suppress vibrations of the engine;
The present invention is characterized by further comprising a control means for starting operation of the actuator when a starter switch for starting the engine is turned on.

[0007] Furthermore, the invention according to claim 2 of the present application (hereinafter,
A second invention) is characterized in that, in addition to the configuration of the first invention, a gain correction means is provided for increasing the gain of the output voltage to the actuator while the starter switch is in the ON state.

Furthermore, the invention according to claim 3 of the present application (hereinafter,
In the configuration of the first aspect, the actuator is constituted by a stack of piezoelectric elements, and a temperature sensor for detecting the temperature around the actuator installation part, and a temperature detected by the temperature sensor are provided. The actuator is characterized by further comprising an output voltage correction means for correcting the output voltage to the actuator when the temperature is below a predetermined temperature.

[0009]

[Operation] In any of the first to third inventions, the actuator starts operating when the starter switch is turned on, that is, when the engine is cranking, thereby suppressing vibrations of the power unit during engine cranking. It turns out.

In particular, according to the second invention, while the starter switch is in the ON state, that is, during cranking when the power unit vibrates greatly, the gain of the output voltage to the actuator is increased. , large vibrations of the power unit during cranking can be more effectively suppressed.

[0011] Furthermore, in the third aspect of the invention, the actuator is constituted by a laminate of piezoelectric elements whose plate thickness changes depending on the voltage, but this piezoelectric element is easily affected by temperature and is When the outside temperature is low, or when the engine room is not sufficiently warmed before the engine starts, the amount of change in plate thickness, that is, the strain rate, tends to decrease. However, in the third invention, the output voltage to the actuator is temperature-compensated, which makes it difficult to suppress the vibration of the power unit during cranking due to an insufficient amount of plate thickness change. Also, the reduction in the amount of change in the thickness of the piezoelectric element constituting the actuator is compensated for, and vibration of the power unit during cranking can be reliably suppressed.

0012

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

As shown in FIGS. 1 and 2, a plurality of power unit mounts 3...3 are provided between a power unit 1 consisting of an engine, a transmission, etc., and a vehicle body side member 2.
The mount 3 has a rubber 4 as an elastic body and an actuator 6 made of a laminate of a large number of piezoelectric elements 5...5 whose plate thickness changes when energized.
A mounting bolt 8 is integrally mounted to the upper mounting member 7 fixed to the upper surface of the actuator 6, and a mounting bolt 10 is integrally mounted to the lower mounting member 9 fixed to the lower surface of the actuator 6. The power unit mount 3 is coupled to the vehicle body side member 2 and the power unit 3 by fastening bolts 8, 10 to the mounting bracket 1a integrated with the power unit 1 and the vehicle body side member 2 via nuts 8a, 10a. Further, in the actuator 6, the plate thickness of the piezoelectric elements 5...5 changes by applying a predetermined voltage between the piezoelectric elements 5...5, thereby changing the overall thickness of the actuator 6, i.e. ,
The total height of the actuator 6 is changed. A G sensor 11 is attached to the mounting member 1a for detecting the vertical acceleration of the power unit 1 and detecting the vibration state of the power unit 1 based on this. A stroke sensor 13 that detects displacement between the power unit 1 and the vehicle body side member 2 is arranged between the partition member 12 coupled to the rubber 4 and the actuator 6 and the mounting bracket 1a.

The actuator 6 is entirely covered by a retractable cover 14 provided between the partition member 12 and the lower mounting member 10.

As shown in FIG. 3, a control unit 15 for controlling the operation of the actuator 6 is provided, and this control unit 15 has the following functions:
A signal from the G sensor 11, a signal from the stroke sensor 13, a signal from the starter switch 16, a signal from the rotation sensor 17 that detects the engine rotation speed, and the vicinity of the installation position of the power unit mount 3. At the same time, the control unit 15 receives a signal from the temperature sensor 18 that detects the temperature of the G-sensor 11, and cuts off signals indicating low-frequency vibrations among the signals from the G-sensor 11, and cuts high-frequency vibrations exceeding a predetermined frequency. a high-pass processing section 19 that passes a signal indicating vibration; and a calculation section 20 that receives signals from the high-pass processing section 19 and signals from the sensors 13, 16, and 17 and calculates an output voltage to the actuator 6. , and a temperature correction section 21 that corrects the output voltage calculated by the calculation section based on the signal from the temperature sensor 18, and the actuator 6 is actuated by the control signal output from the temperature correction section 21. It's about to be controlled.

Next, the control operation of the actuator 6 by the control unit 15 will be explained based on the flow chart shown in FIG. Determine whether the engine is starting, that is, cranking, and select YES.
When it is determined that cranking is in progress, the stroke sensor 13 is activated in step S2.
The gain value of the output voltage to the actuator 6, that is, the stroke gain Kst and the stroke speed gain ΔKst, which are set based on the signal from the actuator 6, is increased.

This stroke gain Kst is calculated based on the vehicle speed v detected by the rotation sensor 17 and the stroke sensor 1.
With the displacement amount st detected by 3 as a parameter,
The characteristics shown in FIG. 5 are set in advance, and a plurality of stroke gains Kst are set so that the gain value increases as the vehicle speed v increases, and these are recorded in the control unit 15 as a map. . Also,
The stroke speed gain ΔKst is preset to the characteristics shown in FIG. 6 using the vehicle speed v and the displacement speed Δst detected by the stroke sensor 13 as parameters, and is set such that the gain value increases as the vehicle speed v increases. A plurality of stroke speed gains ΔKst are set,
These are recorded in the control unit 15 as a map.

On the other hand, when the determination in step S1 is NO, that is, in an operating state other than cranking, the engine speed n is read in step S3 based on the signal from the rotation sensor 17, and in step S4, the engine speed n is read. It is determined whether the rotation speed n is lower than a predetermined rotation speed nx for low rotation determination set in advance, and when the determination is YES, that is, when the rotation is low, the stroke is determined in step S5 as in the case of step S2 above. The gain value of the output voltage to the actuator 6 that is set based on the signal from the sensor 13, that is, the stroke gain Kst and the stroke speed gain ΔKst, is increased.

When the determination in step S4 is NO, that is, when the engine speed is high, the value (n-ny) obtained by subtracting the engine speed ny read in the previous cycle from the current engine speed n in step S6; That is, it is determined whether the amount of increase in the engine rotational speed is greater than a preset increased rotational speed na for acceleration determination, and when the determination is YES, that is, at the time of acceleration, the above-mentioned step S2 is performed in step S7.
.

Furthermore, when the determination in step S6 is NO, that is, when it is determined that the acceleration state is not present, the value obtained by subtracting the engine rotation speed ny read in the previous cycle from the current engine rotation speed n is determined in step S8. (n-ny
), that is, it is determined whether the amount of decrease in the engine rotation speed is greater than a preset decrease rotation speed nb for deceleration determination,
When the determination is YES, that is, when decelerating, step S
In step S9, the signal from the G sensor 11 that has been high-pass processed is read in the high-pass processing unit 19, and then in step S10, the gain value of the output voltage to the actuator 6 is set based on the signal from the G sensor 11, that is, Increase acceleration gain KG.

This acceleration gain KG is preset to the characteristics shown in FIG. 7 using the vehicle speed v and the vertical acceleration (frequency) G of the power unit 1 detected by the G sensor 11 as parameters, and is set in advance to have the characteristics shown in FIG. A plurality of acceleration gains KG are set so that the gain value increases in accordance with the acceleration gain KG, and these are recorded in the control unit 15 as a map.

[0022] Then, each of the above steps S1, S3, S6
, S8, the stroke gain Kst, stroke speed gain ΔKst, and acceleration gain KG are set to the values in the previous control cycle without being changed in step S11. After that, in step S12, each of the steps S2, S5, S
The gain value set in step 7, S9, or S11 is corrected by the temperature correction section 21. This is because, as shown in FIG. 8, the rate of change in the plate thickness of the piezoelectric element 5 that constitutes the actuator 6, that is, the strain rate, is easily affected by temperature, and when the outside temperature is low such as in winter, or before starting the engine. In a low-temperature state where the engine room is not sufficiently warmed, the amount of change in plate thickness, that is, the strain rate, tends to decrease. Therefore, in a low-temperature state, the amount of change in the plate thickness of the piezoelectric element 5 tends to be insufficient. Become. Therefore, the applied voltage is corrected according to the characteristics shown in FIG. 9 so that the strain rate is constant regardless of temperature.

Thereafter, in step S13, a control signal (applied voltage) that has been temperature-corrected so as to have a predetermined gain value is output to the actuator 6.

In this manner, when the power unit 1 vibrates, the actuator 6 is driven based on the signals from the G sensor 11, the stroke sensor 13, and the rotation sensor 16, so that the vibration of the power unit 1 is effectively suppressed. That will happen.

[0025] Then, when the starter switch 16 is turned on,
That is, the operation of the actuator 6 is started when the engine is cranked, thereby effectively suppressing vibrations of the power unit 1 during cranking of the engine, and in particular, when the starter switch 16 is turned on.
During the N state, that is, during cranking when the power unit 1 vibrates greatly, the gain of the output voltage to the actuator 6 is increased, thereby making the large vibrations of the power unit 1 more effective during cranking. will be suppressed.

Furthermore, the output voltage to the actuator 6 is temperature-corrected, thereby compensating for a decrease in the amount of change in the plate thickness of the piezoelectric element 5 constituting the actuator 6 even in a low temperature state, and thereby increasing the power unit 1 during cranking. vibration can be reliably suppressed.

[0027]

As described above, in any of the first to third inventions, the operation of the actuator is started when the starter switch is turned on, that is, when the engine is cranking. Vibration of the power unit will be suppressed.

In particular, according to the second invention, while the starter switch is in the ON state, that is, during cranking when the power unit vibrates greatly, the gain of the output voltage to the actuator is increased. , large vibrations of the power unit during cranking can be more effectively suppressed.

Furthermore, in the third aspect of the invention, the output voltage to the actuator is temperature-compensated, thereby compensating for the decrease in the amount of change in the thickness of the piezoelectric element that constitutes the actuator even in low-temperature conditions. The vibration of the power unit can be reliably suppressed.

[Brief explanation of drawings]

FIG. 1 is an overall front view showing the arrangement of a power unit mount.

[Fig. 2] An enlarged vertical cross-sectional view of the power unit mount.

[Fig. 3] An overall system diagram of the control system of the actuator that constitutes the power unit mount.

FIG. 4 is a flowchart showing the control operation of the actuator by the control unit.

FIG. 5 is a map showing the characteristics of stroke gain.

FIG. 6 is a map showing the characteristics of stroke speed gain.

FIG. 7 is a map showing the characteristics of acceleration gain.

[Fig. 8] Strain characteristic diagram of the piezoelectric element.

FIG. 9 is a graph showing the output characteristics of the voltage applied to the piezoelectric element.

[Explanation of symbols]

1 Power unit 3 Mount for power unit 5 Piezoelectric element 6 Actuator 15 Control unit 16 Starter switch 18 Temperature sensor

Claims (3)

[Claims] 1. A power unit mount for supporting a power unit on a vehicle body, comprising: an actuator disposed between the vehicle body and the power unit and activated during engine operation to suppress vibrations of the engine; An engine mount for a power unit, comprising: control means for starting operation of an actuator when a starter switch for starting the engine is turned on. 2. A power unit mount for supporting a power unit on a vehicle body, the actuator being disposed between the vehicle body and the power unit and operating during engine operation to suppress vibrations of the engine; The actuator is characterized by being equipped with a control means for starting operation of the actuator when a starter switch is turned ON, and a gain correction means for increasing the gain of the output voltage to the actuator while the starter switch is ON. Engine mount for power unit. 3. A mount for a power unit that supports a power unit on a vehicle body, the stack comprising a piezoelectric element that is disposed between the vehicle body and the power unit and is activated during engine operation to suppress vibrations of the engine. an actuator, a control means for starting the operation of the actuator when the starter switch for starting the engine is turned on, a temperature sensor for detecting the temperature around the actuator installation part, and a temperature detected by the temperature sensor at a predetermined temperature. An engine mount for a power unit, comprising output voltage correction means for correcting the output voltage to the actuator when the temperature is below .