JP2005305353A - Mounting structure of electromechanical converting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting structure of an electromechanical converting element having high reinforcing/bonding strengths, excellent in transferability of the expansion motion of the electromechanical converting element, and allowing a change in shape and the dispersion of positioning to be coped as occasions demand. <P>SOLUTION: In a driver 1 provided with the electromechanical converting element 10, a static member 20 for statically supporting the electromechanical converting element and a drive member 30 for driving a transfer member 40 in an expansion direction of the electromechanical converting element by friction engagement with the transfer member, at least one of a first peripheral part of a first end face joint part and both sides of it and a second peripheral part of a second end face joint part and both sides of it is covered with a composite reinforcing means, and the composite reinforcing means comprises a sheet-like substrate 52 having a through hole 55, an impregnation adhesive 56 with which the through hole is impregnated and a reinforcing bonding layer 58 disposed between the sheet-like substrate and the peripheral part for bonding the two. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electromechanical conversion element mounting structure, and more particularly, to an electromechanical conversion element mounting structure in which a stationary member and a drive member are coupled at both ends of an electromechanical conversion element.

  2. Description of the Related Art A driving device is known that applies a voltage to an electromechanical conversion element in which a stationary member and a driving member are coupled at both ends thereof, and moves a moving member frictionally engaged with the driving member in an expansion / contraction direction. Both end portions of the electromechanical conversion element, that is, the end surface coupling portion between the electromechanical conversion element and the stationary member and the end surface coupling portion between the electromechanical conversion element and the driving member are adhesively bonded by an end surface adhesive.

  However, the electromechanical conversion element, the stationary member, and the driving member, which are objects to be combined, are usually small rod-shaped members having a small diameter. In the bonding between such rod-shaped members, it is difficult to obtain sufficient bonding strength because the bonding area is small.

  In general, the electromechanical transducer is driven by applying a high-frequency sawtooth pulse voltage of several tens of kHz. When a high-frequency pulse voltage is repeatedly applied over a long period of time and the electromechanical conversion element is repeatedly expanded and contracted, the adhesive strength at the above-mentioned adhesive bond end face is lowered and peeling is likely to occur.

  Therefore, the applicant of the present application has already filed a patent application by proposing a roll-type electromechanical conversion element in which the end face coupling portion and its peripheral portion are covered with a reinforcing member in order to increase the bonding area and increase the bonding strength. (See Patent Document 1).

JP-A-8-286093

  In the electromechanical conversion element of Patent Document 1, in addition to the above-described end face coupling portion being adhesively bonded, a non-permeable reinforcing member such as metal, plastic, rubber, and the like (that is, an electromechanical conversion element or The stationary member and the driving member are adhesively bonded by an adhesive layer. Since the adhesive does not penetrate into the impermeable reinforcing member, the reinforcing member is substantially constituted by a reinforcing layer made of the non-permeable reinforcing member and an adhesive layer made of the adhesive. The desired bonding strength is obtained mainly by the reinforcing layer made of the impermeable reinforcing member. Therefore, the greater the thickness of the reinforcing member, the greater the bond strength. However, as the thickness of the reinforcing member increases, the mass of the reinforcing member increases, and there is a problem that the transmission of the expansion and contraction motion of the electromechanical conversion element is hindered.

  Further, the reinforcing member in Patent Document 1 is composed of a member that is relatively rigid and has shape retention, and is formed in advance into a shape that can accept the end of the object to be joined. Therefore, every time the shape of the object to be joined is changed in design, it is necessary to separately prepare a reinforcing member that conforms to the new shape. In addition, when the attachment position of the object to be combined is displaced, the reinforcing member cannot accommodate the object to be combined well. Moreover, if the clearance between the reinforcing member and the object to be joined is increased, a large amount of adhesive is required. As described above, when the reinforcing member is relatively rigid and has shape retention, there is a problem that it is not possible to respond flexibly to changes in the shape and position of the objects to be joined.

  Therefore, the technical problem to be solved by the present invention is that it has high reinforcement and adhesive strength, is excellent in the transferability of the expansion and contraction motion of the electromechanical conversion element, and responds flexibly to shape changes and positioning variations. It is to provide an electromechanical conversion element mounting structure that can be used.

Means and actions / effects for solving the problem

  In order to solve the above technical problem, according to the present invention, the following electromechanical transducer mounting structure is provided.

  That is, the electromechanical transducer mounting structure according to the present invention includes an electromechanical transducer that expands and contracts when a voltage is applied, and is coupled to the base end surface of the electromechanical transducer via the first end surface coupling portion. The stationary member that statically supports the mechanical conversion element and the distal end surface of the electromechanical conversion element are coupled to the terminal surface of the electromechanical conversion element via the second end surface coupling portion, and the electromechanical conversion element expands and contracts by frictional engagement with the moving member. A driving member that drives the moving member, wherein at least one of the first end surface coupling portion and the first peripheral portions on both sides thereof, and the second end surface coupling portion and the second peripheral portions on both sides thereof. The composite reinforcing means is covered between the sheet-like base material having a through hole, the impregnated adhesive impregnated in the through-hole, and the sheet-like base material and the peripheral portion. Adhesive layer that bonds the two together Characterized in that it is composed of.

  In the mounting structure of the electromechanical conversion element, the composite reinforcing means for connecting and reinforcing the objects to be combined includes a sheet-like base material having through holes, an impregnating adhesive impregnated in the through holes, and a sheet. It is comprised from the adhesive base material which interposes between a base material and a peripheral part, and adhere | attaches both. Although sufficient strength cannot be obtained with a sheet-like base material alone, sufficient reinforcing strength can be obtained by forming a composite structure in which a through-hole of the sheet-like base material is impregnated with an adhesive and cured. . Since the substrate is in the form of a sheet, the shape can be freely changed. Therefore, it is possible to respond flexibly to changes in the shape and position of the objects to be combined. Furthermore, since the base material is a thin sheet body, it is very lightweight. Therefore, the transmission efficiency of the expansion / contraction motion of the electromechanical conversion element is improved, and the drive member can be greatly displaced.

  The sheet-like substrate can take various forms, but is preferably fibrous. The fiber form includes natural fibers of plant fibers (cotton, hemp, bamboo, pulp, etc.) and animal fibers (wool, silk, etc.), regenerated fibers (rayon, cupra) and chemical fibers of semi-synthetic fibers (acetate), Nylon (polyamide fiber), polyester (polyester fiber), acrylic (polyacrylonitrile fiber), vinylon (polyvinyl alcohol fiber), polypropylene (polypropylene fiber), vinylidene (polyvinylidene chloride fiber), polyurethane (polyurethane) Synthetic fibers), Western paper, Japanese paper, kenaf fibers, or inorganic fibers such as metal fibers, glass fibers, and carbon fibers can be used. The fibrous sheet-like substrate may be a woven fabric or a non-woven fabric.

  Moreover, it is preferable that a sheet-like base material is porous. In the porous sheet-like base material, holes having a size enough to be impregnated with a liquid adhesive are formed. A single hole communicates from the front surface to the back surface, or a plurality of holes continue from the front surface to the back surface. For example, a porous polymer sheet can be used.

  The sheet-like substrate has translucency, and the impregnated adhesive and the reinforcing adhesive layer are photocurable.

  According to the above configuration, by irradiating the sheet-like substrate with light from the outside, the light-curing impregnation adhesive and the reinforcing adhesive layer absorb the light transmitted through the translucent sheet-like substrate, and impregnated. The adhesive and the reinforcing adhesive layer can be cured. This is particularly effective when the driving device includes a member having low heat resistance.

  A pair of connection electrodes are provided on the side surface of the electromechanical conversion element, and a pair of electrode openings for introducing the pair of power supply members are provided on the side surface of the sheet-like base material. The members can be configured to be electrically connected by abutting against a pair of connection electrodes via corresponding electrode openings.

  After the pair of power supply members are positioned on the pair of connection electrodes through the pair of electrode openings before the adhesive is cured, the pair of power supply members are pressed against the pair of connection electrodes when the adhesive is cured. Are electrically connected. As a result, the electrical connection process can be simplified, and the number of parts of the electrical connection member can be reduced.

  Hereinafter, the mounting structure of the electromechanical transducer 10 and the driving apparatus 1 according to the first embodiment of the present invention will be described in detail with reference to FIGS. The mounting structure of the electromechanical conversion element 10 and the driving device 1 according to the present invention can be applied to a driving mechanism for a lens holding frame in a camera, or can be applied to driving and positioning of a moving member in various precision instruments. .

  FIG. 1 is a diagram illustrating an attachment structure for an electromechanical transducer 10 according to a first embodiment of the present invention. FIG. 2 is an enlarged explanatory view of the second composite reinforcing member 50 of FIG.

  As shown in FIG. 1, the drive device 1 is fixed to a chassis 3 that is a support member.

  In the drive device 1, the stationary member 20, the electromechanical conversion element 10, and the drive member 30 are arranged in order from the base side fixed to the chassis 3 toward the end side.

  The stationary member 20 fixed to the chassis 3 is located on the proximal end side, and positions the stationary position of the electromechanical transducer 10 at a predetermined position. The stationary member 20 has a cylindrical shape or a prismatic shape, and can be composed of various materials such as an insulating material and a conductive material.

The electromechanical conversion element 10 has a cylindrical shape or a prismatic shape, and is a piezoelectric element in which a sheet body is wound in a roll shape or a piezoelectric element in which a plurality of thin plates are stacked. As a material of the piezoelectric element, for example, piezoceramics mainly composed of lead zirconate titanate, that is, PZT (PbZrO ₃ · PbTiO ₃ ), or polyvinylidene fluoride (PVDF) is used. A pair of connection electrodes is formed on both end surfaces or the outer peripheral surface of the piezoelectric element. When a voltage is applied to the pair of connection electrodes, the roll-shaped piezoelectric element performs an expansion / contraction movement in the longitudinal direction of the shaft, and the piezoelectric element in which a plurality of thin plates are stacked performs an expansion / contraction movement in the thickness direction.

  The drive member 30 is a member that is located on the distal side, and that moves the moving member 40 in the axial longitudinal direction in accordance with the expansion and contraction motion transmitted from the electromechanical transducer 10. The drive member 30 has a columnar shape or a prismatic shape, and can be composed of various materials such as an insulating material and a conductive material.

  The moving member 40 is a block-shaped member that moves a moving object (for example, a lens holding frame) attached to the moving member 40. The drive member 30 is inserted in a movable state with respect to the moving member 40. That is, a large-diameter insertion hole is formed in the moving member 40, and a gap is formed between the upper surface of the drive member 30 and the inner surface of the insertion hole of the moving member 40 in this insertion hole. A pressure contact pad 42 that contacts the upper surface of the drive member 30 is inserted into the gap. A downward elastic force (toward the drive member 30) is applied by the pressure contact pad 42. With such a configuration, the moving member 40 including the pressure contact pad 42 is in pressure contact with the drive member 30 and frictionally engaged.

  For various adhesive bonds related to the objects to be joined (the stationary member 20, the electromechanical transducer 10 and the drive member 30), an adhesive optimal for the object to be joined is used. Although an organic adhesive is mainly used, an inorganic adhesive can also be used. As the organic adhesive, various adhesives such as epoxy, urethane, and cyanoacrylate can be used.

  The stationary member 20 and the electromechanical conversion element 10 and the electromechanical conversion element 10 and the drive member 30 are respectively bonded and fixed in advance. That is, the distal end surface of the stationary member 20 and the proximal end surface of the electromechanical transducer 10 are bonded and fixed by the first end surface adhesive 21 (first end surface coupling portion). Further, the end surface 11 of the electromechanical conversion element 10 and the base end surface 31 of the drive member 30 are bonded and fixed by a second end surface adhesive 13 (second end surface coupling portion).

  As shown in FIG. 1, the first end surface adhesive 21 (first end surface coupling portion) and the first peripheral portions 12 and 24 on both sides thereof, the second end surface adhesive 13 (second end surface coupling portion) and both sides thereof. The second peripheral portions 14 and 32 are covered with the first composite reinforcing member 60 and the second composite reinforcing member 50, respectively. Therefore, since the adhesion area between the objects to be joined is increased by the composite reinforcing members 50 and 60, the adhesion strength is improved. In addition, the structure covered with the composite reinforcement member may be sufficient as any one site | part.

  As shown in FIG. 2, the second composite reinforcing member 50 includes a sheet-like base material 52 having a through-hole 56 and having flexibility, an impregnating adhesive 55 impregnated in the through-hole 56, and a sheet-like base. The reinforcing adhesive layer 58 is interposed between the material 52 and the second peripheral portions 14 and 32 on both sides and bonds them together. The second composite reinforcing member 50 has a composite structure in which a sheet-like base material 52 is impregnated with an impregnating adhesive 55. The first composite reinforcing member has substantially the same configuration as the second composite reinforcing member 50.

  In the second composite reinforcing member 50 of FIG. 1, since the outer dimensions are almost the same between the stationary member 20 and the electromechanical conversion element 10 and are in a so-called flush state, the sheet-like base material and the electromechanical conversion element A reinforcing adhesive layer 58 having substantially the same thickness is formed in the gap between the two.

  In the first composite reinforcing member 60 of FIG. 1, there is a difference in outer dimension between the stationary member 20 and the electromechanical transducer 10, and there is a step between both outer surfaces. The reinforcing adhesive layer 58 is filled in the gap with the electromechanical transducer 10. Therefore, the filled reinforcing adhesive layer 58 contributes to the improvement of the adhesive strength.

  The end face adhesives 21 and 13 and the reinforcing adhesive layer 58 can use the same type of adhesive, or can use different types of adhesive.

  The sheet-like base material 52 shown in FIG. 2 has a fibrous shape. Through complex intertwining of the fibers, a through hole 56 that allows the outer surface and the inner surface to communicate with each other and be impregnated with a liquid adhesive is formed. The sheet-like base material 52 is pressed against the liquid adhesive preliminarily applied to the proximal and distal peripheral portions, and the liquid adhesive is put into the fibrous through holes 56 of the sheet-like base material 52. Impregnate. Thereafter, the adhesive is cured to form the impregnated adhesive 55 and the reinforcing adhesive layer 58. Alternatively, a liquid adhesive is supplied from the outside to the sheet-like base material 52 wound in advance around the proximal and distal peripheral portions. Then, the impregnated adhesive 55 and the reinforcing adhesive layer 58 are formed by impregnating the liquid adhesive into the fibrous through-holes 56 of the sheet-like substrate 52 and then curing the adhesive.

  The adhesive is cured by heating or light irradiation. Since the sheet-like base material 52 is thin fibrous material, it has translucency. By irradiating the fibrous sheet-like base material with light from the outside, the light curable impregnating adhesive and the reinforcing adhesive layer absorb the light transmitted through the translucent sheet-like base material, and the impregnating adhesive and The reinforcing adhesive layer is cured. The photocurable adhesive is particularly effective when the driving device includes a member having low heat resistance.

  Examples of the fibrous sheet-like base material 52 include natural fibers of plant fibers (cotton, hemp, bamboo, pulp, etc.), animal fibers (wool, silk, etc.), regenerated fibers (rayon, cupra), and semi-synthetic fibers (acetate). Chemical fiber, nylon (polyamide fiber), polyester (polyester fiber), acrylic (polyacrylonitrile fiber), vinylon (polyvinyl alcohol fiber), polypropylene (polypropylene fiber) and vinylidene (polyvinylidene chloride fiber) In addition, synthetic fibers such as polyurethane (polyurethane fibers), paper, Japanese paper, kenaf fibers, or inorganic fibers such as metal fibers, glass fibers, and carbon fibers can be used. The fibrous sheet-like substrate 52 may be a woven fabric or a non-woven fabric.

  Since the composite reinforcing members 50 and 60 have a strong composite structure and the bonding area is increased, the composite reinforcing members 50 and 60 contribute to the improvement of the bonding strength between the objects to be joined. Since the sheet-like base material 52 is made of a fibrous material, it is very lightweight and does not hinder the transmission of the expansion and contraction motion of the electromechanical transducer. Furthermore, even if there is a shape difference or positioning variation among the stationary member 20, the electromechanical conversion element 10, and the drive member 30, which are the objects to be combined, the flexible sheet-like base material 52 is flexible. And it can respond flexibly.

  Next, the mounting structure of the electromechanical transducer 10 and the drive device 1 according to the second embodiment of the present invention will be described with reference to FIG. Since the second embodiment is substantially the same as that of the first embodiment described above, the difference between the two will be mainly described.

  In 2nd embodiment, the sheet-like base material 52 which comprises a composite reinforcement member is porous. As shown in FIG. 3, the first end surface adhesive 21 (first end surface coupling portion) and the first peripheral portions 12 and 24 on both sides thereof, the second end surface adhesive 13 (second end surface coupling portion) and both sides thereof. The second peripheral portions 14 and 32 are covered with a first composite reinforcing member 60 and a second composite reinforcing member 50, respectively. Therefore, since the adhesion area between the objects to be joined is increased by the composite reinforcing members 50 and 60, the adhesion strength is improved. In addition, the structure covered with the composite reinforcement member may be sufficient as any one site | part.

  The first and second composite reinforcing members 50 and 60 are each made of a porous sheet-like base material having flexibility, an impregnating adhesive impregnated in the through-holes, a sheet-like base material, and second on both sides. It is comprised from the reinforcement adhesive layer which interposes between the peripheral parts 14 and 32, and adhere | attaches both. As described above, the first and second composite reinforcing members 50 and 60 have a composite structure in which the sheet-like base material is impregnated with the impregnating adhesive.

  In the porous sheet-like base material, holes having a size enough to be impregnated with a liquid adhesive are formed. A single hole communicates from the front surface to the back surface, or a plurality of holes continue from the front surface to the back surface.

  As the porous sheet-like base material, a porous molded body, a porous sintered body, and a porous film can be used. Preferably, a porous molded body obtained by injection molding or blow molding a resin is used. .

  The adhesive is cured by heating or light irradiation. Since the sheet-like substrate is thin and porous, it has translucency. By irradiating the porous sheet-like substrate with light from the outside, the light curable impregnating adhesive and the reinforcing adhesive layer absorb the light transmitted through the translucent sheet-like substrate, and the impregnating adhesive and The reinforcing adhesive layer is cured. The photocurable adhesive is particularly effective when the driving device includes a member having low heat resistance.

  Since the composite reinforcing members 50 and 60 have a strong composite structure and the bonding area is increased, the composite reinforcing members 50 and 60 contribute to the improvement of the bonding strength between the objects to be joined. Since the sheet-like substrate is made of a flexible porous material, it is very lightweight and does not hinder the expansion and contraction of the electromechanical transducer. Furthermore, since the porous sheet-like base material has a certain degree of shape retention, positioning of the binding object is easy. Furthermore, even if there is a shape difference or positioning variation among the stationary member 20, the electromechanical conversion element 10, and the drive member 30, which are the objects to be combined, the flexible sheet-like base material 52 is flexible. And it can respond flexibly.

  Next, a power feeding structure in the electromechanical transducer 10 and the driving apparatus 1 according to the third embodiment of the present invention will be described with reference to FIGS. In addition, since it is based on 2nd embodiment mentioned above, the characteristic part regarding electric power feeding is demonstrated.

  A pair of connection electrodes 16 are formed on the upper and lower portions of the outer peripheral surface of the electromechanical transducer 10 so as to be separated from each other. A pair of notches are formed in the upper and lower portions on the end side of the first composite reinforcing member 60 so as to be separated from each other. Through the cutouts, lead wires 22 as power supply members are provided to the pair of connection electrodes 16.

  The adhesive is applied to at least one of the outer surface of the electromechanical transducer 10 or the inner surface of the first composite reinforcing member 60 so that the adhesive does not enter the portion where the connection electrode 16 and the lead wire 22 are pressure-bonded. Is done. After positioning the pair of lead wires 22 between the pair of connection electrodes 16 of the electromechanical conversion element 10 and the first composite reinforcing member 60, the electromechanical conversion element 10 is placed in the first composite reinforcing member 60. Fit into. As a result, as shown in FIG. 5A, the pair of lead wires 22 are pressed against and electrically connected to the corresponding connection electrodes 16. Then, an electrical signal from a drive circuit (not shown), that is, a high-frequency sawtooth pulse of several tens of kHz is applied to the connection electrode 16 via the lead wire 22.

  As the power supply member, in addition to the lead wire 22, a metal thin piece, conductive resin, conductive rubber, a flexible substrate including these conductive members, or the like can be used.

  Further, as shown in FIG. 5B, in the sheet-like base material of the first composite reinforcing member 60, the thin portions 64 can be provided on both side portions with the lead wire 22 as the center. By providing the thin portion 64, the sheet-like base material is easily elastically deformed, so that the electromechanical conversion element 10 can be easily inserted into the first composite reinforcing member 60.

  Furthermore, as shown in FIG. 6, a pair of electrode openings 62 may be formed separately on the upper and lower portions on the end side of the first composite reinforcing member 60. The electrode opening 62 is a through hole. A lead wire 22 as a power supply member is inserted from the electrode opening 62. By bending the inserted lead wire 22, the lead wire 22 is caught by the electrode opening 62, so that the lead wire 22 is difficult to be detached from the electrode opening 62.

  When inserting the electromechanical conversion element 10 into the first composite reinforcing member 60 while interposing the pair of lead wires 22 between the electromechanical conversion element 10 and the first composite reinforcing member 60, The lead wire 22 is not easily detached. In such a fitting structure, an adhesive is impregnated from the outside, an adhesive is injected from a previously formed injection hole or injection groove, or from the gap between the electromechanical transducer 10 and the first composite reinforcing member 60. An adhesive can be injected.

It is a figure explaining the attachment structure of the electromechanical transducer concerning a first embodiment of the present invention. FIG. 2 is an enlarged explanatory view of a composite reinforcing member used in the mounting structure of FIG. 1. It is a figure explaining the attachment structure of the electromechanical conversion element which concerns on 2nd embodiment of this invention. It is a figure explaining the attachment structure of the electromechanical conversion element which concerns on 3rd embodiment of this invention. It is sectional drawing explaining the electric power feeding structure to the electromechanical conversion element by a electric power feeding member. (A) is an insertion press contact type. (B) is an elastic pressure contact type. It is a figure explaining the other electric power feeding structure to the electromechanical conversion element by a power feeding member.

Explanation of symbols

1 Drive device 3 Chassis (support member)
10 Electromechanical transducer (piezoelectric element)
11 End surface 12 First peripheral portion 13 Second end surface adhesive (second end surface coupling portion)
14 Second peripheral portion 16 Connection electrode 20 Stationary member 21 First end surface adhesive (first end surface coupling portion)
22 Lead wire (power supply member)
24 First peripheral portion 30 Driving member 31 Base end surface 32 Second peripheral portion 40 Moving member 42 Pressure contact pad (elastic biasing member)
50 Second composite reinforcing member 52 Sheet-like base material 54 Fibrous member 55 Through hole 56 Impregnating adhesive 58 Reinforcing adhesive layer 60 First composite reinforcing member 62 Electrode opening 64 Thin wall portion

Claims (5)

An electromechanical transducer that expands and contracts by application of voltage;
A stationary member that is coupled to the base end surface of the electromechanical conversion element via the first end surface coupling portion and statically supports the electromechanical conversion element;
A driving member that is coupled to the terminal surface of the electromechanical conversion element via the second end surface coupling portion and drives the moving member in the expansion and contraction direction of the electromechanical conversion element by frictional engagement with the moving member;
In a drive device comprising:
At least one of the first end surface coupling portion and the first peripheral portions on both sides thereof, and the second end surface coupling portion and the second peripheral portions on both sides thereof are covered with composite reinforcing means,
The composite reinforcing means includes a sheet-like base material having a through-hole, an impregnating adhesive impregnated in the through-hole, and a reinforcing adhesive layer that is interposed between the sheet-like base material and the peripheral portion to bond them together. An electromechanical transducer mounting structure, characterized by comprising:   The mounting structure for an electromechanical transducer according to claim 1, wherein the sheet-like substrate is fibrous.   The mounting structure for an electromechanical transducer according to claim 1, wherein the sheet-like substrate is porous.   The electromechanical conversion element mounting structure according to claim 1, wherein the sheet-like base material has translucency, and the impregnating adhesive and the reinforcing adhesive layer are photocurable. A pair of connection electrodes are provided on the side surface of the electromechanical transducer,
On the side surface of the sheet-like substrate, a pair of electrode openings for introducing a pair of power supply members are provided,
The electromechanical conversion element mounting structure according to claim 1, wherein the pair of power supply members are electrically connected by abutting against the pair of connection electrodes via the corresponding electrode openings.

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