JP2010002033A - Vibration reducing device and vibration reducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration reducing device and a vibration reducing method, eliminating influence of temperature and having a large vibration reducing effect. <P>SOLUTION: This vibration reducing device reduces vibration of an object 20 to be damped by an inertia mass actuator 10 including a piezo stacked body 11 fitted to the object 20 to be damped and having stacked piezo elements 11a and an inertia mass 12 provided on the opposite side to the fitting end of the piezo stacked body 11. The device includes: a vibrating state estimating means 90 for detecting voltage generated in some of piezo elements 11a-1 of the stacked piezo elements 11a and estimating the vibrating state based on the voltage; and a damping force control means 90 for expanding and contracting a second piezo element 11a-2 by applying a driving signal voltage set based on the estimated vibrating state to the second piezo element 11a-2 different from the some of piezo elements 11a-1 to apply the force to the inertia mass 12, and taking its reaction as damping force to damp the object 20 to be damped. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus and method for reducing vibrations generated in components constituting an engine.

Japanese Patent Application Laid-Open No. 2004-228561 discloses an actuator that applies a force to an inertial mass and uses the reaction to reduce the vibration of an object. This actuator uses a permanent magnet attached via an elastic body as an inertial mass, and applies an electromagnetic force generated by the permanent magnet and the electromagnetic coil to the permanent magnet. And the sensor which detects the transmission force transmitted from the elastic body which supports a permanent magnet, and the sensor which detects the speed of an actuator attachment point are provided, and the vibration of a target object is reduced based on the signal of these sensors.
JP 2002-79178 A

  However, the above-described conventional actuator may change its characteristics under the influence of temperature or the like, which may reduce the vibration reduction effect.

  The present invention has been made paying attention to such conventional problems, and an object of the present invention is to provide a vibration reduction device and a vibration reduction method that eliminates the influence of temperature and has a large vibration reduction effect.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.

  The present invention is provided on a side opposite to the mounting end of the piezoelectric laminate (11), and a piezoelectric laminate (11) having a piezoelectric element (11a) which is attached to the vibration damping object (20) and laminated. An inertial mass actuator (10) having an inertial mass (12) and a vibration reducing device for reducing vibrations of a vibration control target (20), wherein a part of the stacked piezoelectric elements (11a) A vibration state estimating means (90) for detecting a voltage generated in the element (11a-1) and estimating a vibration state based on the voltage, and a piezoelectric element different from the part of the piezoelectric elements (11a-1) Applying a drive signal voltage set based on the estimated vibration state to (11a-2) causes the piezo element (11a-2) to expand and contract to exert a force on the inertial mass (12), and its reaction Damping force control means (9) for damping the damping object (20) as the damping force 0).

  According to the present invention, the vibration state is estimated based on voltages generated in some of the stacked piezoelectric elements, and the drive signal voltage set based on the estimated vibration state is applied to another piezoelectric element. Applying a force acts on the inertial mass, and the vibration is controlled by using the reaction as a damping force, so a vibration reduction effect can be obtained without considering the temperature fluctuation characteristics of the piezo element. It is.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing a state in which the vibration reducing device according to the present invention is applied to a chain case.

  The engine body is vibrated by the vibration force when the piston descends or the vibration force input from a fuel injector or the like, which is transmitted to the chain case 20, and the plane portion of the chain case 20 vibrates as a radiation surface. Is emitted as sound. Therefore, the engine noise can be reduced by reducing the vibration on the radiation surface. Therefore, the engine mass is reduced by attaching the inertial mass actuator 10 to the chain case 20 to reduce the vibration of the chain case. The inertial mass actuator 10 is attached to the upper end of the chain case 20 so that a damping force can be applied in the direction perpendicular to the chain case 20.

  FIG. 2 is a diagram illustrating an inertial mass actuator.

  The inertial mass actuator 10 includes a piezoelectric laminate 11, an inertial mass 12, and a fastening bolt 13.

  The piezo laminate 11 is attached to a vibration control object (chain case 20 in this embodiment). The piezoelectric laminate 11 is configured by laminating thin plate-like piezoelectric elements (piezoelectric elements) 11a. In the present embodiment, the piezo element 11a is annular, and the piezo laminate 11 in which a large number of piezo elements 11a are laminated is cylindrical. The piezo element 11a is polarized so that, when a voltage is applied, an internal force is generated in the applied voltage range that causes elongation in the thickness direction that is substantially proportional to the voltage. That is, the piezo element 11a expands and contracts in the axial direction (vertical direction in FIG. 2) according to the applied voltage to generate a force. Therefore, a part of the piezo elements constituting the piezo laminate 11 is a force generating piezo element 11a-2, a force is applied to the inertial mass 12 by the piezo element 11a-2, and the reaction is used as a damping force to form a chain case. Damping 20 The force acting on the inertial mass 12 by the force generating piezo element 11 a-2 is given by the product of the vibration acceleration of the inertial mass 12 and the mass of the inertial mass 12.

  When a force is applied to the piezo element 11a in the plate thickness direction (vertical direction in FIG. 2), a voltage corresponding to the force is generated. In the present embodiment, the vibration acceleration of the inertial mass 12 is detected using a part of the piezo elements constituting the piezo stack 11 as sensor piezo elements 11a-1 using this characteristic. Note that the sensor piezo element 11a-1 and the force generating piezo element 11a-2 are the same piezo element, and only the usage is different. Therefore, the sensor piezoelectric element 11a-1 and the force generating piezoelectric element 11a-2 have the same characteristics. The piezoelectric constant of the sensor piezoelectric element 11a-1 and the piezoelectric constant of the force generating piezoelectric element 11a-2 are the same.

  In the present embodiment, among the piezo elements 11a constituting the piezo laminate 11, the piezo elements at the upper and lower ends are referred to as sensor piezo elements 11a-1, and the other elements are referred to as force generating piezo elements 11a-2. The sensor piezo element 11a-1 and the force generating piezo element 11a-2 are connected to the controller 90 through signal lines.

  The inertia mass 12 is provided on the side opposite to the attachment end of the piezoelectric laminate 11. In FIG. 2, the inertial mass 12 is placed on the piezo laminate 11. The inertial mass 12 has a cylindrical shape with a ceiling, and a hole 12a is formed in the ceiling portion. The inertial mass 12 is placed on the piezo laminate 11.

  The fastening bolt 13 is a bolt that is inserted through the hole 12 a of the inertia mass 12 and is inserted into the cylindrical piezo laminate 11 and screwed into the chain case 20. The fastening bolt 13 screws the piezo laminate 11 and the inertia mass 12 to the chain case 20.

  The inertial mass actuator 10 has such a configuration. The piezo element 11a-1 detects the vibration acceleration of the inertial mass 12. The piezo element 11a-2 applies a force to the inertial mass 12, and controls the chain case 20 using the reaction as a damping force. That is, the controller 90 determines the control force based on a signal proportional to the acceleration of the inertial mass detected by the sensor piezo element 11a-1, and applies a voltage to the force generating piezo element 11a-2. Controls damping force.

  FIG. 3 is a diagram illustrating a model of an inertial mass actuator.

  For simplification, considering a model in which a plurality of sensor piezo elements 11a-1 are grouped together and arranged in series with a force generating piezo element 11a-2, the following equations (1-1) and (1-2) are obtained. It can be expressed by an equation of motion.

  The formulas (1-1) and (1-2) are summarized as follows.

  The vibration damping object of the present embodiment is a chain case 20 that is an engine component and transmits engine heat. In such a case, the temperature of the piezo laminate 11 is distributed almost linearly from the controlled object side to the mass side. As shown in FIG. 4 (A), the temperature of the piezo laminate 11 becomes higher toward the control object side. As shown in FIG. 4B, the piezoelectric laminate 11 has a high temperature on the controlled object side and a low temperature on the mass side.

  FIG. 5 is a diagram illustrating temperature characteristics of the piezoelectric element.

  The contraction force of the piezo element varies substantially linearly with the temperature of the piezo element. Therefore, if the average temperature of the piezoelectric element 11a-1 for sensor constituting the piezoelectric laminate 11 and the average temperature of the piezoelectric element 11a-2 for force generation are made equal, the characteristics of the piezoelectric element 11a-1 for sensor and the piezoelectric element for force generation are obtained. The characteristics of the element 11a-2 are equal.

  The vibration reduction device can be modeled as a one-degree-of-freedom vibration system that receives a forced displacement at the attachment point, and can be expressed by an equation of motion such as the following equation. That is, the following equation is a motion equation of displacement excitation.

  When the inertial mass acceleration is converted into the state space representation as an output, the following equations (4-1) and (4-2) are obtained.

  From this, it is possible to create an observer that estimates the inertial mass velocity, inertial mass displacement, and attachment point displacement from the acceleration of the inertial mass and the control force of the piezo laminate, and then to perform first-order differentiation of the estimated attachment point displacement. Can also estimate the attachment point speed.

  In this embodiment, the attachment point speed is multiplied by the gain G1 as shown in the following equation (5), and the force uv having the opposite sign is input to the chain case to be controlled, whereby the resonance of the chain case vibration is caused by the damping effect. Reduce the peak.

  Here, the control force u is expressed by the following equation (6) with respect to the force uv input to the chain case that is the object of vibration suppression.

  Therefore, as shown in FIG. 6, the controller Cont determines the force uv input to the chain case by the equation (5) from the attachment point speed estimated by the observer, and the inertia mass speed, inertia mass displacement, attachment point estimated from the force uv. The control force u is determined from the speed and the attachment point displacement by the equation (6), and a desired control force is generated from the piezoelectric laminate by applying a voltage. That is, since the inertia mass acceleration signal is input to the observer, the inertia mass acceleration signal is input to the controller Cont to determine and output the control force u. Further, since the voltage of the sensor piezo element 11a-1 is used as the acceleration sensor of the inertia mass, the sensor output voltage Vs shown in the following equation (7) proportional to the contraction force Fs of the sensor piezo element 11a-1 is used. Is output.

  Since the value obtained by dividing the sensor contraction force by the inertia mass mass is substantially equal to the inertia mass acceleration signal, the inertia mass acceleration can be expressed by the following equation (8).

  Similarly, the force generation piezo element 11a-2 generates a contraction force u proportional to the force generation drive voltage Vu shown in the following equation (9).

  Therefore, the voltage Vu applied to the force generating piezo element 11a-2 is expressed by the following equation (10).

  In the present embodiment, among the piezo elements 11a constituting the piezo laminate 11, the piezo elements at the upper and lower ends are piezo elements 11a-1 for sensors, and the other elements are piezo elements 11a-2 for force generation. Therefore, the average temperature of the sensor piezoelectric element 11a-1 and the average temperature of the force generating piezoelectric element 11a-2 are substantially equal regardless of the temperature fluctuation of the vibration suppression object (chain case). It becomes substantially equal to Au (T) and can be canceled by the numerator denominator, and the following equation (11) is obtained.

  Therefore, control is possible without considering the temperature fluctuation characteristics of the piezo element, and a vibration reduction effect can be obtained.

  By performing the control as described above, a large vibration reduction effect can be obtained at the main resonance frequency of the chain case.

  FIG. 7 is a diagram for explaining the effect.

  When the inertial mass actuator of the present embodiment is not attached to the chain case and controlled, vibration deterioration occurs due to resonance of the inertial mass, as shown by a one-dot chain line in FIG. Also, the resonance frequency of the chain case is lowered.

  On the other hand, when the inertial mass actuator of the present embodiment is attached to the chain case and controlled, the force transmitted to the chain case is only a force equivalent to a damping force proportional to the speed, and therefore is affected by the inertial mass actuator as a vibration system. Thus, vibration deterioration due to resonance of the inertia mass and reduction of the chain case resonance frequency do not occur. Thereby, according to this embodiment, since it does not affect the resonance frequency of the structure that had been conventionally, even if there was something that was tuned to the resonance frequency, such as a dynamic vibration absorber, There is no need to retune.

  In the inertial mass actuator of the present embodiment, the controller does not have the vibration characteristics to be controlled as a model, and only the characteristics of the inertial mass actuator of the present embodiment are modeled. Even if the object to be shaken is changed, the controller only changes the gain at the attachment point speed and the displacement. What is necessary is just to determine these so that a desired attenuation | damping provision effect and a rigid improvement effect may be acquired. As a result, the chain case vibration can be reduced as shown in FIG.

(Second Embodiment)
FIG. 8 is a diagram showing a second embodiment of the vibration reducing apparatus according to the present invention.

  In the following description, parts having the same functions as those described above are denoted by the same reference numerals, and redundant description is omitted as appropriate.

  In the inertial mass actuator 10 of the present embodiment, among the piezo elements 11a constituting the piezo laminate 11, the central piezo element is a sensor piezo element 11a-1, and the other elements are force generating piezo elements 11a-2. .

  Even in this case, the average temperature of the sensor piezoelectric element 11a-1 is equal to the average temperature of the force generating piezoelectric element 11a-2. Therefore, the characteristics of the sensor piezoelectric element 11a-1 and the force generating piezoelectric element 11a are the same. -2 characteristics are equal.

(Third embodiment)
FIG. 9 is a diagram for explaining a third embodiment of the vibration reducing apparatus according to the present invention.

  In the present embodiment, the proportion of piezoelectric elements used for sensors or force generation is changed according to the engine output. Specifically, the higher the engine output, the higher the ratio of the force generating piezo elements 11a-2 and the lower the ratio of the sensor piezo elements 11a-1. This is because the higher the engine output, the greater the vibration, and a greater force is required to reduce the vibration. Further, the lower the engine output is, the smaller the vibration is, and it is desirable to reduce even a slight vibration with high accuracy. Therefore, the lower the engine output is, the more the ratio of the piezoelectric element for sensor 11a-1 is increased. The proportion of the force generating piezo element 11a-2 may be reduced.

  When changing, the sensor piezoelectric element 11 a-1 and the force generating piezoelectric element 11 a-2 may be arranged symmetrically with respect to the center of the piezoelectric laminate 11. In this way, the average temperature of the sensor piezo element 11a-1 and the average temperature of the force generating piezo element 11a-2 become equal, and the characteristics of the sensor piezo element 11a-1 and the force generating piezo element 11a- This is because the characteristics of 2 are equal.

  Without being limited to the embodiments described above, various modifications and changes are possible within the scope of the technical idea, and it is obvious that these are also included in the technical scope of the present invention.

  For example, in each of the above embodiments, the case where the sensor piezo elements and the force generating piezo elements are arranged symmetrically from the center of the piezo stack 11 has been described as an example. The position may be made to coincide with the position of the center of gravity of the force generating piezo element. In this way, the average temperature of the sensor piezo element is equal to the average temperature of the force generating piezo element regardless of the temperature fluctuation of the vibration suppression object (chain case). This is because the characteristics of the force generating piezo element are equal.

  Further, the chain case has been described as an example of the vibration suppression object, but the same vibration reduction effect can be obtained even when used for an oil pan that is a radiation surface for engine noise or a vehicle panel that is a radiation surface for vehicle interior noise.

It is a figure which shows a mode that the vibration reduction apparatus by this invention was applied to the chain case. It is a figure which shows an inertial mass actuator. It is a figure which shows the model of an inertial mass actuator. It is a figure explaining the temperature distribution of a piezoelectric laminated body. It is a figure which shows the temperature characteristic of a piezoelectric element. It is a control block diagram of 1st Embodiment of the vibration reduction apparatus by this invention. It is a figure explaining an effect. It is a figure which shows 2nd Embodiment of the vibration reduction apparatus by this invention. It is a figure explaining 3rd Embodiment of the vibration reduction apparatus by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inertial mass actuator 11 Piezo laminated body 11a Piezo element 11a-1 Piezo element for sensors (some piezo elements)
11a-2 Piezo element for force generation (another piezo element)
12 Inertial mass 13 Fastening bolt 20 Chain case (object to be controlled)
90 controller

Claims (9)

A piezo laminate including a piezo element attached to a vibration suppression object and laminated;
An inertial mass provided on the opposite side of the mounting end of the piezo laminate;
A vibration reduction device that reduces vibration of a vibration suppression object by an inertial mass actuator having:
Vibration state estimation means for detecting a voltage generated in some of the stacked piezoelectric elements and estimating a vibration state based on the voltage;
By applying a drive signal voltage set based on the estimated vibration state to a piezo element different from the part of the piezo elements, the piezo elements are expanded and contracted to exert a force on the inertial mass and control the reaction. Damping force control means for damping the damping object as the shaking force;
A vibration reducing device comprising: The another piezo element has the same characteristics as the part of the piezo elements.
The vibration reducing apparatus according to claim 1, wherein The part of the piezo elements is provided at a position where an average temperature is equal to an average temperature of the other piezo elements regardless of the temperature of the vibration control object.
The vibration reduction device according to claim 1 or 2, wherein The partial piezo element has a centroid position in the piezo stack that matches a centroid position of the other piezo element.
The vibration reducing device according to any one of claims 1 to 3, wherein the vibration reducing device according to any one of claims 1 to 3. The part of the piezo elements are piezo elements located at both ends of the piezo stack.
The vibration reduction apparatus according to any one of claims 1 to 4, wherein the vibration reduction apparatus according to any one of claims 1 to 4 is characterized. The part of the piezo elements is a piezo element at the center of the piezo stack.
The vibration reduction apparatus according to any one of claims 1 to 4, wherein the vibration reduction apparatus according to any one of claims 1 to 4 is characterized. The vibration suppression object is a part constituting the engine,
The damping force control means applies a driving signal voltage to many piezoelectric elements as the engine output increases.
The vibration reducing apparatus according to any one of claims 1 to 6, wherein the vibration reducing apparatus according to any one of claims 1 to 6. The vibration suppression object is a component constituting the engine,
The damping force control means detects the voltage from many piezoelectric elements as the engine output decreases.
The vibration reducing apparatus according to any one of claims 1 to 7, wherein the vibration reducing apparatus according to any one of claims 1 to 7 is provided. Piezo-stacked body with piezo elements that are attached to the object to be controlled and stacked,
An inertial mass provided on the opposite side of the mounting end of the piezo laminate;
A vibration reduction method for reducing vibration of an object to be controlled by an inertial mass actuator comprising:
A vibration state estimation step of detecting a voltage generated in some of the stacked piezoelectric elements and estimating a vibration state based on the voltage;
A drive signal voltage set based on the estimated vibration state is applied to a piezo element different from the part of the piezo elements, and the piezo elements are expanded and contracted to exert a force on the inertial mass and control the reaction. A damping force control process for damping a damping object as a vibration force;
A vibration reduction method comprising:

Images