JP2005337480A - Configuration method of piezoelectric damping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To fix and mount a piezoelectric element P of a piezoelectric damping device to reduce the mechanical vibration and noise in a member of a machine or equipment on the member to continue the usage without machining the member surface or damaging the piezoelectric element. <P>SOLUTION: Guide members 12a, b are installed to provide at least a pair of slopes 14a, b inclining at a predetermined angle to a surface on the surface of the member 10 and mutually opposing toward the separating direction from the surface in a configuration method of the piezoelectric damping device on the member 10 of the machine. The piezoelectric element P having edges 16a, b in a shape capable of contacting the slopes between the opposite slopes is installed on the surface of the member via an adhesive A so as to make the edge face-contact the slopes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of reducing vibration and noise of a machine or device such as an automobile transmission using a piezoelectric element, and other machines or devices.

  In power devices (engines, motors, etc.) of machines such as automobiles, power transmission devices (transmissions, etc.) or other devices / machines, they are members that generate mechanical vibrations, and are in paths where vibrations are transmitted. Vibration or noise is reduced by attaching a piezoelectric (or piezo) element to a member or other member and absorbing vibration energy by the piezoelectric effect or canceling vibration deformation of the member. A method or apparatus for suppressing propagation is known (for example, see Patent Documents 1-3 below).

  In one of the vibration / noise reduction methods or apparatuses using such a piezoelectric element (Patent Document 1-2), a voltage having a phase opposite to the vibration of the member is applied to the piezoelectric element attached to the vibrating member. Thus, the piezoelectric element is deformed, and the deformation force cancels the deformation of the member, thereby suppressing the mechanical vibration of the member (active vibration damping method). When this active vibration control method is applied to, for example, a vehicle transmission, the frequency and phase of vibration generated in the transmission are monitored from the vehicle speed, the rotation speed of tires and shafts, the number of gear teeth, and the like. Therefore, the phase and frequency of the voltage applied to the piezoelectric element are controlled so that the piezoelectric element is deformed and strained in the opposite phase to the vibration of the monitored member.

  In another vibration / noise reduction method or apparatus using a piezoelectric element (Patent Document 3), a piezoelectric element attached to a vibrating member includes an electric resistance, a coil, and a capacitor via a pair of electrodes. Connected to the circuit (passive vibration control method). In this case, when the piezoelectric element is deformed and strained by the vibration of the member, a potential difference is generated between the electrodes connected to the piezoelectric element, and a current flows in the circuit due to the potential difference. . Since the circuit includes a resistor, heat is generated when a current flows through the resistor. That is, the vibration energy of the member is converted into electric energy in the piezoelectric element, and then the electric energy is converted into thermal energy in the resistance of the circuit and dissipated to the outside air, thereby reducing the vibration and noise of the member. It is like that.

One of the advantages of the vibration / noise reduction method or apparatus using the piezoelectric element as described above is that, after completion of the machine or the like whose vibration is to be reduced, an additional piezoelectric element and its associated circuit (hereinafter referred to as piezoelectric). It is a type that can be mounted). In particular, since the passive vibration damping type piezoelectric vibration damping device is completed with only a piezoelectric element and a simple electric circuit, in principle, for example, it can be arbitrarily applied to the surface of a resonated part of a completed machine or the like. A desired damping effect is expected only by mounting.
JP-A-5-133435 Japanese Utility Model Publication No. 6-32787 Japanese Patent Laid-Open No. 10-38029 JP-A-1-138898

  As described above, in principle, the piezoelectric vibration damping device should be simply to attach a piezoelectric element to an arbitrary surface of a member such as a machine. The shapes of the elements do not necessarily match, and the piezoelectric elements on the surface of the member may not be brought into close contact with each other, and the usable range of the piezoelectric damping device is limited. For example, a case or housing of a rotary machine such as an engine or transmission has a curved surface, and the surface of a plate-like piezoelectric element that is normally used is a flat surface. Therefore, when a planar piezoelectric element is fixed to a curved part of a machine, the close contact is incomplete, thus reducing the piezoelectric conversion efficiency between the member and the element, and obtaining the expected vibration absorption or reduction effect. It will disappear.

  FIGS. 3A and 3B show examples of cross sections in a state in which the plate-like piezoelectric element P in such a conventional technique is mounted on a curved member. In these figures, the curved member 10 of the machine whose vibrations are to be reduced is, for example, a transmission case or cover which is a radiation source of automobile transmission noise (for clarity, the piezoelectric element is Only the site to be fixed is shown.) As is well known, planar electrodes are attached to the lower surface B (side bonded to the member surface) and the upper surface T (opposite the lower surface B) of the piezoelectric element, and lead wires ( (Not shown) is extended. The piezoelectric element P is fixed to the surface of the member 10 by the adhesive layer A.

  FIG. 3A shows a case where the piezoelectric element P is simply attached on the surface of the curved member. In this case, the central region PO of the piezoelectric element P is easily brought into contact with the surface of the member 10, but is separated from the surface of the member 10 at the edge PS. If the edge portion PS is further pressed to bring the edge portion PS into close contact with the member 10, the entire element P is curved. At this time, if the pressing force is too strong (compared to the strength of the element), the element will be cracked, and even if it is attached without cracking, a bending moment always acts as shown by the arrow in the figure. Therefore, there is a high possibility that the adhesive is peeled off during use or the element is damaged.

  FIG. 3B shows a case where the surface of the member is cut into a planar shape in order to make the shapes of the piezoelectric element P and the member surface coincide with each other. In this case, the case where the member surface can be processed as shown in the figure is limited (the place where the piezoelectric element P is applied is limited), and if the process as shown in the figure is performed, the sectional modulus of the processed part decreases, Since the rigidity is lowered, the vibration is increased and cracks or breakage is likely to occur at the processing site.

  As described above, if the piezoelectric element is forcibly adhered to the member so as to obtain the expected vibration absorption or reduction effect, an excessive force is applied during the mounting operation, and the piezoelectric element may be broken. In addition, even after attachment, the piezoelectric element is always subjected to stress at the time of attachment, which can easily be damaged during use. Further, if the shape of the surface of the member is machined in accordance with the shape of the piezoelectric element, one advantage of the piezoelectric vibration damping device that only has to be attached to an arbitrary part after completion of the machine is lost. Further, the part to which the piezoelectric element is to be attached is not always machined, and if machining such as cutting is performed, the rigidity (section modulus) of the member may be reduced and vibration may be increased.

  Thus, one problem to be solved by the present invention is to provide a piezoelectric element for a piezoelectric damping device that reduces mechanical vibration and noise in a machine or device member without requiring machining of the surface of the member. It is an object of the present invention to provide a structure or a manufacturing method of a piezoelectric vibration damping device, wherein the piezoelectric element is mounted on a member so that the piezoelectric element can be fixed and used without being damaged.

  The above-described problem is solved by a piezoelectric control including a piezoelectric element attached on the surface of the member in a state where mechanical vibration energy on the surface of the member can be converted into electric energy in order to reduce vibration of the member of the machine. A method of constructing a vibration device on the member, wherein at least a pair of inclined surfaces facing each other are inclined on the surface of the member at a predetermined angle and facing away from the surface. A guide member is provided, and a piezoelectric element having an edge capable of coming into contact with the inclined surface between the opposing inclined surfaces is placed on the surface of the member via an adhesive so that the edge comes into surface contact with the inclined surface. This is achieved by a method characterized in that it is attached to the head.

  According to the above method, the piezoelectric element can be stably fixed on the surface of the member even if the surface of the machine member does not match the surface shape of the piezoelectric element. In the above method, first, it should be noted that a pair of inclined surfaces on which the guide members face each other is formed on a member surface of the machine, and the piezoelectric elements are received and attached on the member surface by the inclined surfaces. It is to guide to the state that should be attached to the site. At least a pair of inclined surfaces are inclined at a predetermined angle with respect to the surface and are directed away from the surface. Therefore, the closer to the member, the closer to each other. Since the piezoelectric element prepared in the present invention has a shape in which the edge abuts the slope, it is thus received by the slope of the guide member, and the edge of the piezoelectric element is inclined to the slope of the guide member at a predetermined distance from the member surface. And is in contact with the surface. In addition, since the position of the member and the piezoelectric element is determined by the guide member, the adhesive can be filled between the member and the element without excess or deficiency, so that the mechanical vibration between the member and the element is excellent. Will be transmitted. Furthermore, due to the presence of the adhesive, the possibility of unnecessarily giving a bending moment to the element even if the element is pressed against the member is reduced as before (adhesives are generally, even before curing, It has a certain degree of viscosity.), Damage to the piezoelectric element is avoided, or durability during use is maintained.

  Thus, according to the method of the present invention as described above, the piezoelectric vibration damping includes a piezoelectric element attached to the surface of the member in a state where mechanical vibration energy can be converted into electric energy, and reduces vibration of the surface of the member. A machine member to which an apparatus is attached, wherein the piezoelectric element has a slope with end faces of at least a pair of edges facing the machine member when mounted on the surface of the machine member. A piezoelectric element mounted on the surface of a machine member through an adhesive in a state of being in surface contact with at least a pair of surfaces provided by a guide member provided on the surface of the machine member Are provided. It should be understood that the guide member may be removed from the surface of the machine member after mounting and fixing the piezoelectric element on the surface of the machine member, and that case is also within the scope of the present invention. The machine part may be, for example, a car transmission case or any other machine part where vibration and noise are a problem.

  In the above method, in order to fill the adhesive between the piezoelectric element and the member without excess or deficiency, the piezoelectric element is pressed toward the member, and excess adhesive is removed from between the piezoelectric element and the member. You may be supposed to. As already described, the position of the piezoelectric element and the member is determined by the guide member. Therefore, if a large amount of adhesive is applied before or after the piezoelectric element is received by the guide member, and then the piezoelectric element is pressed toward the member, the gap between the members can be completely filled. It becomes possible. It should be understood that the ability to fill the adhesive without excess or deficiency is very important in transmitting mechanical vibrations. If there is too much adhesive, the distance between the member and the piezoelectric element will be increased, and the vibration transmission rate will decrease.If there is too little adhesive, a gap will be created between the member and the piezoelectric element, and the vibration transmission rate will again be low. It will decline.

  In piezoelectric vibration control devices, a plurality of piezoelectric elements are often mounted on a machine member. Therefore, it is preferable to attach a plurality of piezoelectric elements in substantially the same state. Therefore, in the method of the present invention described above, the guide member may be an integral guide frame having at least a pair of inclined surfaces. If the guide member is an integral member, the interval between the opposing inclined surfaces can be determined in advance, so that the piezoelectric element is substantially always in the same state (if the shape of the member is the same). It can be mounted on the surface. In particular, it is advantageous when a plurality of piezoelectric elements are attached over the entire circumference of the rotating machine.

  Further, the guide member is configured as a guide frame, and the edge of the piezoelectric element and the inclined surface of the guide member are in contact with each other over the entire circumference of the piezoelectric element, and is closed by the piezoelectric element, the guide member, and the machine member. It is preferable to form an open space. This is because in this case, while the piezoelectric element is pressed toward the member, the hydraulic pressure of the adhesive (having fluidity) sealed in the closed space acts uniformly on the entire surface of the piezoelectric element, thereby This is because the bending deformation of the plate-like piezoelectric element can be avoided.

  Contrary to the above case, when a piezoelectric element is attached to any part of the machine member having various shapes, depending on the shape of the part to be attached, the member and the piezoelectric element (particularly the end portion) It is preferable that the distance can be adjusted. For example, even if it is determined that the substantially central region of the piezoelectric element is positioned so as to contact the member surface, the distance between the end of the element and the member surface changes depending on the radius of the member surface. Therefore, in the above-mentioned present invention, the distance between the at least one pair of inclined surfaces on the surface of the member may be adjusted to adjust the distance between the surface of the piezoelectric element and the surface of the member. . Thereby, the range of the site | part which can attach a piezoelectric element will be expanded.

  In the past, it was difficult to “skillfully” attach the piezoelectric element when the surface of the member was curved. As already mentioned, if the attachment is forced, the piezoelectric element is damaged or its durability is lowered. Further, in order to avoid breakage and durability of the piezoelectric element, when a very strong force is not applied, one edge of the piezoelectric element may float from the member. In addition, the attached state also varied. The same applies to the case where the piezoelectric element is simply attached to an arbitrary planar member via an adhesive (Patent Document 4).

  On the other hand, according to the present invention, as described above, by positioning the piezoelectric element with the guide member, an excessive force is applied to the piezoelectric element even if the shape of the surface of the member and the piezoelectric element do not match. In addition, the adhesion between the piezoelectric element and the member surface can be stably performed so that vibration is better transmitted. At this time, since the distance between the piezoelectric element and the member surface can be adjusted, the piezoelectric element can be fixed so that vibration is transmitted most efficiently.

  In the present invention described above, it is necessary to process the edge of the piezoelectric element so as to contact the inclined surface of the guide member. However, as before, it is far more cost effective than machining the member surface to bring the piezoelectric element into close contact with the member surface. Moreover, when the member surface is machined, the rigidity of the member is lowered, and thus the durability of the member itself may be lowered. According to the present invention, such vibration should be removed. This is advantageous because it does not impair the durability of the object.

  Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention.

  The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings. In the figure, the same reference numerals indicate the same parts.

  In order to solve the problem in the conventional process of attaching the piezoelectric element as described above, in the present invention, as shown in FIG. 1, a guide member 12 is provided on the surface of the member 10, and the piezoelectric element on the member surface is provided. P is positioned and the piezoelectric element is fixed on the member surface.

  1A and 1B, similarly to FIG. 3, a plate-like piezoelectric element P is provided on a surface 10 of a transmission member serving as a radiation source of a transmission noise of an automobile, for example, a machine member whose vibration is to be reduced. In accordance with the teaching of the present invention, a schematic cross section of the member 10 and the piezoelectric element P in the process of attachment is shown (only the portion where the piezoelectric element is attached is shown for the sake of clarity). .

  Referring to FIG. 1A, in the method of the present invention, first, guide members 12a and 12b are arranged on the surface of a member 10 of a machine. As shown in the figure, the guide members 12a and 12b have a pair of inclined surfaces 14a and 14b that are inclined at a certain angle with respect to the surface of the member 10 and face each other. It gets shorter as you get closer. Further, since the guide member is removed after fixing the piezoelectric element on the member, it may be fixed on the member by any removable method. At this time, the lower surface of the guide member may be appropriately processed so as to be in close contact with the member surface of the machine.

  Next, the adhesive A is applied in a fluidized state on the surface of the member 10 between the guide members 12a, b, and from there, the piezoelectric element P is received into the space defined between the guide members 12a, b, As shown in FIG. 1B, the piezoelectric element P is pressed toward the surface of the member 10. Here, as shown in the drawing, both edges 16a and 16b of the piezoelectric element P that are in contact with the guide members 12a and 12b are processed into a shape that can abut (or preferably complementarily) the inclined surfaces 14a and 14b. It is preferable. In this case, as shown in the figure, when the piezoelectric element P approaches the surface of the member 10, the distance between both edges 16a and 16b of the piezoelectric element coincides with the distance between the inclined surfaces 14a and b at a certain position, and surface contact is made. It stops in the state, that is, it will be positioned. Since the distance between the member 10 and the piezoelectric element P is determined by positioning the piezoelectric element P in this way, it is avoided that the piezoelectric element P is damaged by, for example, pressing it forcibly. . That is, since the piezoelectric element P is supported by the guide member at the edge, it is possible to prevent the element from being bent by pushing the edge too much as before (see, for example, FIG. 3A).

  The adhesive that is interposed between the piezoelectric element P and the member 10 and fixes the piezoelectric element P may be, for example, an epoxy resin, and when the piezoelectric element P is positioned by the guide member, An amount sufficient to fill the space between the members 10 should be provided. In this regard, by providing an appropriate escape path (not shown) from the space 18 defined by the guide members 12a and 12b, the piezoelectric element P and the member 10, an adhesive is first applied on the surface of the member 10. When the piezoelectric element P is pressed toward the member 10 by increasing the amount, excess adhesive may be extruded from the escape passage. Thus, the adhesive is filled in the space 18 without excess or deficiency. Further, even when the escape path is not provided, when the piezoelectric element P is continuously pressed against the member 10, the piezoelectric element edges 16 a and b and the inclined surfaces 14 a and b are completely in surface contact with each other. The fluid adhesive is discharged through between the edges 16a, b and the slopes 14a, b.

  Thus, as the adhesive is cured, the piezoelectric element P is fixed, for example, with the central region PO in contact with the member 10 as shown in FIG. 1B. Here, since the guide members 12a and 12b maintain the height of the edge of the piezoelectric element until the adhesive A is cured, even if the shape of the member 10 is curved as illustrated, the piezoelectric element P is deformed. It should be understood that it can be stably fixed without In the case of the conventional method, the piezoelectric element P is displaced while the adhesive A is cured (one edge is lifted), or by applying force until it is cured, the piezoelectric element P However, according to the present invention, such a problem does not occur. In the figure, the adhesive A is applied on the member 10 before the piezoelectric element P is placed on the guide members 12a and 12b, but the piezoelectric element P is applied on the guide members 12a and 12b. It should be understood that after placement, it may be injected between them, and such cases are also within the scope of the present invention. After the adhesive is cured, the guide members 12a, b may be removed.

  By the way, the guide member for receiving and positioning the piezoelectric element P achieves the above-described object of the present invention by providing at least a pair of opposing slopes as shown in FIG. 1, but preferably the piezoelectric element as shown in FIG. 2A. It may be like a guide frame 20 that provides a slope 22 that engages the edge of the piezoelectric element P over the entire circumference of P. In this case, the piezoelectric element P is also provided with an oblique angle so that the edge is in surface contact with the inclined surface 22 over the entire circumference. When an inclined surface is provided so as to surround the entire circumference of the piezoelectric element P, the piezoelectric element P is pressed against the surface of the member 10 via a fluid adhesive, and the edge starts to come into surface contact with the inclined surface. The pressure of the adhesive that opposes the pressurization holds the piezoelectric element P with an equal force, which is advantageous in avoiding the deformation of the piezoelectric element P. Moreover, if the dimension of the guide member (and the amount of adhesive) is set appropriately, the piezoelectric element P can be stably fixed on the member 10 without being deformed or damaged. In this regard, if the guide frame 20 is used, a plurality of piezoelectric elements can be mounted on the surface of the member 10 in the same state, that is, so that the positional relationship with the member is always constant. It is.

  Further, when mounting the piezoelectric element on the member surface of the machine having various different curvatures, the distance or position between the piezoelectric element P and the member 10 is arbitrarily adjusted by adjusting the interval between the inclined surfaces 14a and 14b of the guide member. You can adjust the relationship. For example, when the curvature is large compared to the case of FIG. 1 (when the radius of curvature is small), as shown in FIG. It will be attached to.

  In the above figure, the slope of the guide member and the edge of the piezoelectric element that are in surface contact with each other are both flat surfaces, but may have other shapes as long as the piezoelectric element is received and positioned. Should be understood. Similarly, it should be understood that the inclined surfaces of the guide members facing each other need not be arranged in parallel as long as the piezoelectric elements can be received and positioned.

  Although the above description has been made in relation to the embodiment of the present invention, many modifications and changes can be easily made by those skilled in the art, and the present invention is limited to the embodiment exemplified above. It will be apparent that the invention is not limited and applies to various devices without departing from the inventive concept.

FIG. 1 shows a schematic cross-sectional view of a piezoelectric element fixed on a member of an arbitrary machine according to an embodiment of the present invention. FIG. 1A shows a state where an adhesive is applied and the piezoelectric element is received by the guide member, and FIG. 1B shows a state where the piezoelectric element is pressed toward the member 10 and its edge is in surface contact with the inclined surface of the guide member. It is. FIG. 2A is a schematic perspective view of a guide frame according to an embodiment of the present invention. FIG. 2B is a view similar to FIG. 1B, and shows a mounting state of the piezoelectric element when the curvature of the machine member is larger than that of FIG. 1B. The typical sectional view in the state where the piezoelectric element in the prior art was stuck on the member of the machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Machine member 12a, b ... Guide member 14a, b ... Slope 16a, b ... Edge of piezoelectric element 20 ... Guide frame 22 ... Slope P ... Piezoelectric element A ... Adhesive

Claims (8)

A piezoelectric vibration damping device including a piezoelectric element mounted on a surface of the member in a state where mechanical vibration energy on the surface of the member can be converted into electrical energy in order to reduce vibration of the member of the machine. A method of configuring above,
A guide member is provided on the surface of the member to provide at least a pair of inclined surfaces that are inclined at a predetermined angle with respect to the surface and face away from the surface, and between the opposing inclined surfaces, A method of attaching a piezoelectric element having an edge capable of coming into contact with a slope to the surface of the member through an adhesive so that the edge comes into surface contact with the slope.   The method according to claim 1, wherein the piezoelectric element is pressed toward the member, and excess adhesive is pushed out from between the piezoelectric element and the member to be removed.   2. The method of claim 1, wherein the guide member is an integral guide frame having the at least one pair of slopes.   The method according to claim 1, wherein a distance between the at least one pair of inclined surfaces on the surface of the member is adjusted to adjust a distance between the surface of the piezoelectric element and the surface of the member. Method. A piezoelectric vibration damping device including a piezoelectric element mounted on a surface of the member in a state where mechanical vibration energy on the surface of the member can be converted into electrical energy in order to reduce vibration of the member of the machine. A method of configuring above,
A step of providing a guide member for receiving the piezoelectric element on the surface of the member and positioning the piezoelectric element with respect to the surface of the member; and a step of positioning the piezoelectric element by the guide member and attaching the piezoelectric element on the surface of the member. A method comprising the steps of:   6. The method of claim 5, wherein the guide member positions the piezoelectric element relative to a surface of the member by supporting an edge of the piezoelectric element. A machine member having a piezoelectric element attached to a surface of a member in a state in which mechanical vibration energy can be converted into electric energy and having a piezoelectric vibration damping device attached to reduce the vibration of the surface of the member,
When the piezoelectric element is mounted on the surface of the machine member, the end face of at least one pair of edge portions has a slope facing the machine member, and the slope is provided on the surface of the machine member. A machine member comprising a piezoelectric element attached on a surface of a member of the machine via an adhesive in a state of being in surface contact with at least a pair of surfaces provided by the guide member. 8. The machine member according to claim 7, wherein the guide member is removed from the surface of the machine member after the piezoelectric element is mounted and fixed on the surface of the machine member. Element.

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