ACTUATOR

An actuator includes a magnetic drive circuit to vibrate a movable body relative to a support body. The magnetic drive circuit includes a magnet disposed in the movable body and a coil disposed in the support body. The support body includes a metal cover housing the movable body and a metal coil holder holding the coil. Two guide portions disposed on the coil holder are in surface contact with a first surface and a second surface of the cover. The heat generated when the coil is energized is transmitted from the coil holding portion to the guide portions and dissipated to the outside from the cover, which is in surface contact with the guide portions. Therefore, the temperature rise of the coil can be suppressed.

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention claims priority under 35 U.S.C. § 119 to Japanese Application No. 2021-013383 filed on Jan. 29, 2021, the entire content of which is incorporated herein by reference.

BACKGROUND

Field of the Invention

At least an embodiment of the present invention relates to an actuator that vibrates a movable body.

Description of the Related Documents

Japanese Unexamined Patent Publication No. 2020-203247 (JP 2020-203247) discloses an actuator used as a device to report information through vibration. The actuator of JP 2020-203247 includes a support body including a square cover, a movable body vibrating relative to the support body inside the cover, and a connecting member that connects the support body and the movable body. The movable body includes a permanent magnet and a yoke, and the support body includes a coil holder fixed to the cover and a coil held by the coil holder. The permanent magnet and the coil face each other inside the yoke in a direction orthogonal to the vibration direction of the movable body.

In the actuator of JP 2020-203247, the driving force of the magnetic drive circuit can be increased by increasing the amount of current flow to the coil, and strong vibration can be achieved. However, as the amount of current flow increases, the amount of heat generated by the coil increases. When the actuator is driven, it is necessary to energize the coil within the range in which the coil does not exceed the upper temperature limit. In order to suppress the temperature rise of the coil, it is necessary to release the heat of the coil to the outside, but with JP 2020-203247, it is difficult to dissipated heat of the coil because the coil is placed in a sealed space defined by first and second side plates of the coil holder and the cover. The only component in contact with the coil is the coil holder, which is composed of resin and has low thermal conductivity. Therefore, it is difficult to release a large amount of heat through the coil holder.

In view of the above problems, an object of at least an embodiment of the present invention is to improve the heat dissipation of heat generated by a coil in an actuator in which a magnetic drive circuit is housed inside a cover.

SUMMARY

To solve the issue described above, an actuator according to at least an embodiment of the present invention includes a movable body; a support body; a connecting member having at least one of elasticity and viscoelasticity and being connected to both the movable body and the support body; and a magnetic drive circuit including a magnet disposed in the movable body and a coil disposed in the support body, the support body including a metal cover enclosing the movable body and a metal coil holder housed inside the cover, the cover including a first surface extending in a first direction and a second surface facing the first surface in a second direction intersecting the first direction, the coil holder including a coil holding portion disposed between the first surface and the second surface and two guide portions disposed on both sides of the coil holding portion in the second direction, one of the two guide portions being in surface contact with the first surface, the other one of the two guide portions being in surface contact with the second surface.

According to at least an embodiment of the present embodiment, the coil holder holding the coil of the magnetic drive circuit is composed of metal, and the two guide portions disposed on the coil holder are in surface contact with the first surface and the second surface of the metal cover. Therefore, the two guide portions can guide the insertion of the coil holder into the cover and position the coil holder when the support body is assembled, and when the actuator is completed, the two guide portions constitute a heat transfer path that can transfer a large amount of heat through the surface contact between metal parts having high thermal conductivity. Since the heat of the coil can be dissipated from the entire cover, the dissipation of the heat generated at the coil can be enhanced, and the temperature rise of the coil can be suppressed.

In at least an embodiment of the present invention, it is preferred that the coil is an air-core coil include a coil wire wound around an opening, the coil holding portion include a coil contacting surface being in contact with the coil in a third direction intersecting the first direction and the second direction and a projecting portion protruding from the coil contacting surface in the third direction, the coil be positioned in the coil holding portion by fitting the projecting portion into the opening, and the outer circumferential surface of the projecting portion be in contact with the inner circumferential surface of the opening. In this way, since not only the end surface of the coil but also the inner circumferential surface of the opening is in direct contact with the coil holder, heat of the coil can be released from the inner circumferential surface of the opening. Therefore, the amount of heat dissipation can be increased.

In at least an embodiment of the present invention, it is preferred that the coil holder include a metal plate, the coil holding portion extend in a flat plate shape along the first direction and the second direction, and the projecting portion be formed by pressing, and the two guide portions extend in the first direction by bending in the third direction from both ends of the coil holding portion in the second direction. In this way, the coil holder can be manufactured by sheet metal processing, and thus the coil holder can be manufactured at low cost. The two guide portions are bent in the third direction and extend in a flat plate shape in the first direction, and thus, the contact area between the cover and the coil holder can be made wide. Therefore, the amount of heat dissipation can be increased.

In at least an embodiment of the present invention, it is preferred that the coil be fixed to the coil holder by a heat conductive adhesive agent. In this way, it is possible to avoid a decrease in the thermal conductivity due to the adhesive agent disposed between the coil and the coil holder. Therefore, the amount of heat dissipation can be increased.

In at least an embodiment of the present invention, the coil holder is preferably fixed to the cover via the two guide portions. In this way, the coil holder can be readily fixed to the cover because it is only necessary to fix the portion of the coil holder in surface contact with the cover. Since there is no need to provide a fixing portion separate from the guide portions, the shape of the component can be simplified. At this time, the two guide portions are preferably fixed to the cover by a heat conductive adhesive agent. In this way, it is possible to avoid a decrease in the thermal conductivity due to the adhesive agent disposed between the two guide portions and the cover. Therefore, the amount of heat dissipation can be increased.

In at least an embodiment of the present invention, the cover includes a first cover member disposed on a first side in the first direction and a second cover member disposed on a second side in the first direction, the first cover member and the second cover member being joined together; the first cover member includes a first flat plate portion and a first side plate portion extending from an edge of the first flat plate portion toward the second cover member; the second cover member includes a second flat plate portion and a second side plate portion, the second flat plate portion facing the first flat plate portion in the first direction, the second side plate portion extending from an edge of the second flat plate portion toward the second cover member; and the first surface includes the first side plate portion, and the second surface includes the second side plate portion. If, in this way, the cover is divided into two parts in the first direction and both of the parts have a surface in contact with the two guide portions, the cover can be assembled by installing the first cover member and the second cover member to the coil holder.

According to at least an embodiment of the present embodiment, the coil holder holding the coil of the magnetic drive circuit is composed of metal, and the two guide portions disposed on the coil holder are in surface contact with the first surface and the second surface of the metal cover. Therefore, the two guide portions can guide the insertion of the coil holder into the cover and position the coil holder when the support body is assembled, and when the actuator is completed, the two guide portions constitute a heat transfer path that can transfer a large amount of heat through the surface contact between metal parts having high thermal conductivity. Since the heat of the coil can be dissipated from the entire cover, the dissipation of the heat generated at the coil can be enhanced, and the temperature rise of the coil can be suppressed.

DETAILED DESCRIPTION

Embodiments of the present invention will now be described with reference to the accompanying drawings. In the following description, a first direction Y, a second direction X, and a third direction Z are directions that intersect each other. A first side in the second direction X is denoted as X1, a second side in the second direction X is denoted as X2. A first side in the first direction Y is denoted as Y1, and a second side in the first direction Y is denoted Y2. A first side in the third direction Z is denoted as Z1, and a second side in the third direction Z is denoted as Z2. The third direction Z, the second direction X, and the first direction Y are orthogonal to each other in the present embodiment. The second direction X is the vibration direction of a movable body6.

FIG. 1is an external view of an actuator1to which at least an embodiment of the present invention is applied.FIG. 2is a cross-sectional view of the actuator1taken along line A-A inFIG. 1.FIG. 3is a cross-sectional view of the actuator1taken along line B-B inFIG. 1.FIG. 4is an exploded view of the actuator1with a cover3disassembled.FIG. 5is an exploded view of the actuator1with the cover3and the movable body6disassembled.

Overall Configuration

As illustrated inFIG. 1, the actuator1is rectangular in shape with its longitudinal direction oriented in the first direction Y. The actuator1includes a support body2including the cover3defining the outer shape of the actuator1, and a movable body6supported inside the cover3so that it is movable in the second direction X relative to the support body2. The support body2includes a cover3, a coil holder4, and a coil5. The movable body6includes magnets7and a yoke8. The coil5and the magnets7face each other in the third direction Z, and constitute a magnetic drive circuit M that vibrates the movable body6in the second direction X. The movable body6is supported by the support body2via a connecting member9that is connected to both the movable body6and the support body2. The connecting member9includes at least one of elasticity and viscoelasticity, as described below.

The actuator1reports information to a user through the body of the person using the actuator1or a device to which the actuator1is attached by vibrating the movable body6in the second direction X. The actuator1can be incorporated into, for example, an operation member of a game machine, an operation panel, a steering wheel or a chair of an automobile, etc., and can be used as a tactile device to provide a user with a sense of touch by vibration of the movable body6in the second direction X. When the actuator1is used as a tactile device, for example, the AC waveform applied to the coil5can be adjusted to cause a difference between the acceleration of the movable body6moving to the first side X1in the second direction X and the acceleration of the movable body6moving to the second side X2in the second direction X. In this way, the user can feel vibration having directionality in the second direction X.

Cover

As illustrated inFIGS. 2 and 3, the cover3defining the outline of the actuator1is divided into two parts in the first direction Y. The cover3includes a first cover member31positioned at the first side Y1in the first direction Y and a second cover member32positioned at the second side Y2in the first direction Y. The first cover member31and the second cover member32are composed of a non-magnetic metal, such as stainless steel.

As illustrated inFIGS. 2 and 4, the first cover member31includes a rectangular first flat plate portion33facing the movable body6on the first side Y1in the first direction Y, and a rectangular cylindrical first side plate portion34extending from an outer circumferential edge of the first flat plate portion33to the second side Y2in the first direction Y. The corner portion connecting the outer circumferential edge of the first flat plate portion33and the first side plate portion34is curved. The first side plate portion34has a first side plate portion first surface341and a first side plate portion second surface342facing each other in the second direction X, and a first side plate portion third surface343and a first side plate portion fourth surface344facing each other in the third direction Z.

The distal edge of the first side plate portion34has extending portions11extending to the second side Y2in the first direction Y. In more detail, the distal edge of the first side plate portion34has first comb teeth portions10each in which the extending portions11are arranged at regular intervals. In the present embodiment, the first comb teeth portions10are disposed at the distal edges of the first side plate portion third surface343and the first side plate portion fourth surface344. The first side plate portion first surface341and the first side plate portion second surface342each have one extending portion11. At the distal edge of the first side plate portion34, a notched portion12recessed toward the first side Y1in the first direction Y is disposed between adjacent extending portions11. The extending portions11and the notched portions12alternate each other in each of the first comb teeth portions10.

Each of the extending portions11and each of the notched portions12has a constant width in a direction orthogonal to the first direction Y. The edges13and14along the width direction of the two sides of each of the extending portions11constitute the inner edges along the width direction of each of the notched portions12, and extend parallel to the first direction Y. The distal edge15of each extending portion11and the proximal edge16of each notched portion12on the first side Y1in the first direction Y extend in a straight line in a direction orthogonal to the first direction Y.

The second cover member32includes a rectangular second flat plate portion35facing the movable body6on the second side Y2in the first direction Y, and a rectangular cylindrical second side plate portion36extending from an outer circumferential edge of second flat plate portion35to the first side Y1in the first direction Y. The corner portion connecting the outer circumferential edge of the second flat plate portion35and the second side plate portion36is curved. The second side plate portion36has a second side plate portion first surface361and a second side plate portion second surface362facing each other in the second direction X, and a second side plate portion third surface363and a second side plate portion fourth surface364facing each other in the third direction Z.

The distal edge of the second side plate portion36has extending portions21extending to the first side Y1in the first direction Y. In more detail, the distal edge of the second side plate portion36has second comb teeth portions20each in which the extending portions21are arranged at regular intervals. In the present embodiment, the second comb teeth portions20are disposed at the distal edges of the second side plate portion third surface363and the second side plate portion fourth surface364. The second side plate portion first surface361and the second side plate portion second surface362each have one extending portion21. At the distal edge of the second side plate portion36, a notched portion22recessed toward the second side Y2in the first direction Y is disposed between adjacent extending portions21. The extending portions21and the notched portions22alternate each other in each of the second comb teeth portions20.

Each of the extending portions21and each of the notched portions22has a constant width in a direction orthogonal to the first direction Y. The edges23and24along the width direction of the two sides of each of the extending portions21constitute the inner edges along the width direction of each of the notched portions22, and extend parallel to the first direction Y. The distal edge25of each extending portion21and the inner edge26of each notched portion22on the second side Y2in the first direction Y extend in a straight line in a direction orthogonal to the first direction Y.

As illustrated inFIG. 1, the cover3is welded together in such a manner that the first comb teeth portion10on the first cover member31interlocks with the second comb teeth portion20on the second cover member32. That is, the cover3is welded together with the extending portions11of the first cover member31fitting into the notched portions22of the second cover member32and the extending portions21of the second cover member32fitting into the notched portions12of the first cover member31.

As illustrated inFIG. 1, the cover3has a first surface3A and a second surface3B facing each other in the second direction X. The first surface3A and the second surface3B extend parallel to each other in the first direction Y. The first surface3A includes the first side plate portion first surface341of the first cover member31and the second side plate portion first surface361of the second cover member32. The second surface3B is composed of the first side plate portion second surface342of the first cover member31and the second side plate portion second surface362of the second cover member32.

Coil Holder

As illustrated inFIG. 3, the coil holder4includes a rectangular coil holding portion41and two guide portions42and43extending in the first direction Y along the two sides of the coil holding portion41in the second direction X. The guide portion42has a flat straight portion44bent from an end edge of the flat coil holding portion41on the first side X1in the second direction X to the first side Z1in the third direction Z and extending along the YZ plane, and projecting portions45projecting from an edge of the straight portion44on the second side Z2in the third direction Z to the second side Z2. The projecting portions45are provided at two position on the two sides of the coil holding portion41in the first direction Y.

Similarly, the guide portion43has a flat straight portion46bent from an end edge of the flat coil holding portion41on the second side X2in the second direction X to the first side Z1in the third direction Z and extending along the YZ plane, and projecting portions47projecting from an edge of the straight portion46on the second side Z2in the third direction Z to the second side Z2. The projecting portions47are provided at two position on the two sides of the coil holding portion41in the first direction Y. The straight portions44and46extend parallel to each other in the first direction Y. Curved portions48that curve inwardly in the width direction (i.e., the second direction X) of the coil holder4are disposed at the two ends of each of the straight portions44and46in the first direction Y.

The coil holding portion41include projecting portions49projecting to the first side Z1in the third direction Z. The surface of the first side Z1of the coil holding portion41is a coil contacting surface41ato which the coil5contacts, and the projecting portions49protrude from the coil contacting surface41a. The coil holder4is a sheet metal member composed of a non-magnetic metal, such as stainless steel, and the projecting portions49are formed by press working. The coil5is a long, circular, air core coil, and the coil wire is wound around a long, an opening50. The projecting portions49are disposed two positions spaced apart in the first direction Y. As illustrated inFIG. 4, the projecting portions49are inserted into the opening50at the two ends in the first direction Y to position the coil5in a state in which two effective edges extending parallel to each other in the first direction Y are aligned in the second direction X. The projecting portions49are each circular in shape viewed from the third direction Z, and the outer circumferential surfaces of the projecting portions49are in contact with the inner circumferential surface of the opening50(seeFIGS. 4 and 5).

As illustrated inFIG. 5, the two guide portions42and43are in contact with the inner surface of the cover3in the second direction X and are fixed to the cover3by welding or an adhesive agent. In more detail, the guide portion42is in surface contact with the first surface3A of the cover3and is fixed to the first surface3A by welding or an adhesive agent. The guide portions43is in surface contact with the second surface3B of the cover3and is fixed to the second surface3B by welding or an adhesive agent. Fixing of the two guide portions42and43to the cover3fixes the coil5to the cover3via the coil holder4.

In the present embodiment, since the coil holder4and the cover3are composed of metal, the portion where the two guide portions42an,43and the first surface3A and the second surface3B of the cover3are in surface contact with each other serves as a heat transfer path for transferring heat of the coil5to the cover3through the coil holder4. As illustrated inFIG. 4, the coil5is fixed to the coil holding portion41by a heat-conductive adhesive agent51. The heat-conductive adhesive agent51is, for example, an adhesive agent mixed with a paste having high thermal conductivity, such as a silver paste. The heat generated when the coil5is energized is transmitted to the coil holding portion41through the heat-conductive adhesive agent51, is transmitted from the coil holding portion41to the guide portions42and43, and is dissipated to the outside through the cover3, which is in surface contact with the guide portions42and43.

Plate

As illustrated inFIGS. 4 and 5, the support body2includes a plate40that overlaps the coil5from the first side Z1in the third direction Z. As illustrated inFIG. 3, the plate40is a rectangular metal plate and is composed of a non-magnetic material. The plate40is fixed to the coil5with the heat-conductive adhesive agent51. The coil5is disposed between the coil holding portion41and the plate40. Therefore, when the actuator1is subjected to a shock due to a fall or the like and the movable body6moves significantly, the coil5is prevented from colliding with the magnets7and being damaged.

Movable Body

As illustrated inFIGS. 3, 4, and 5, the present embodiment includes a first permanent magnet71and a second permanent magnet72as the magnets7. The first permanent magnet71faces the coil5at the first side Z1in the third direction Z, and the second permanent magnet72faces the coil5at the second side Z2in the third direction Z. The first permanent magnet71and the second permanent magnet72are respectively magnetized to different poles on the first side X1in the second direction X and on the second side X2in the second direction X.

The yoke8is composed of a magnetic metal and holds the magnets7. As illustrated inFIG. 4, the yoke8is composed of two members, a first yoke member81and a second yoke member82, assembled together. The first yoke member81has a flat first plate portion83. The second yoke member82has a second plate portion84facing the first plate portion83in the third direction Z. The first plate portion83and the second plate portion84has a substantially rectangular shape with the first direction Y as the longitudinal direction. As illustrated inFIGS. 4 and 5, the first permanent magnet71is held on a surface of the first plate portion83on the second side Z2in the third direction Z. The second permanent magnet72is held on a surface of the second plate portion84on the first side Z1in the third direction Z.

The yoke8has two connecting portions85that connect the first plate portion83and the second plate portion84at two positions separated in the second direction X. The two connecting portions85face each other in the second direction X across the coil5and the magnets7. The connecting portions85are plate portions orthogonal to the second direction X. Here, the first yoke member81has two first yoke side comb teeth portions86that bend from the two ends of the first plate portion83in the first direction Y to the second side Z2in the third direction Z and project to the second side Z2. Here, the second yoke member82has two second yoke side comb teeth portions87that bend from the two ends of the second plate portion84in the first direction Y to the first side Z1in the third direction Z and project to the first side Z1. In the present embodiment, each of the connecting portions85is joined into a plate by interlocking and welding the first yoke side comb teeth portions86of the first yoke member81and the second yoke side comb teeth portions87of the second yoke member82.

As illustrated inFIG. 5, the width in the second direction X of the yoke8and the magnets7is smaller than the spacing of the two guide portions42and43in the second direction X. Therefore, the movable body6is disposed between the two guide portions42and43in a state in which it can vibrate in the second direction X.

Connecting Element

The movable body6is supported in such a manner that it is movable in the second direction X by a connecting member9disposed between the movable body6and the support body2. In the present embodiment, the connecting member9includes a first connecting sub-member91disposed on the first side Y1of the movable body6in the first direction Y and a second connecting sub-member92disposed on the second side Y2of the movable body6in the first direction Y. The first connecting sub-member91connects the first flat plate portion33of the cover3constituting the support body2and the corresponding connecting portion85of the yoke8on the first side Y1at the portion where these face each other in the first direction Y. The second connecting sub-member92connects the second flat plate portion35of the cover3and the corresponding connecting portion85of the yoke8on the second side Y2at the portion where these face each other in the first direction Y.

The two sides of the first connecting sub-member91and the two sides of the second connecting sub-member92in the first direction Y are connected to the movable body6and the support body2by adhesion or the like. The first connecting sub-member91and the second connecting sub-member92are in a state of being compressed in the first direction Y between the support body2and the movable body6. That is, the first connecting sub-member91is compressed in the first direction Y between the first flat plate portion33and the connecting portion85on the first side Y1of the yoke8. The second connecting sub-member92is compressed in the first direction Y between the second flat plate portion35and the connecting portion85on the second side Y2of the yoke8.

The connecting member9has at least one of elasticity and viscoelasticity. In the present embodiment, the connecting member9is a viscoelastic member. For example, the connecting member9(viscoelastic member) is a gelatinous member composed of silicone gel or the like. In the present embodiment, the connecting member9is composed of a silicone gel having a needle penetration of 10 to 110 degrees. Needle penetration is specified in JIS-K-2207 and JIS-K-2220, and the smaller this value is, the harder the material is. Examples of materials of the connecting member9having viscoelasticity include various rubber materials such as natural rubber, diene-based rubber (e.g., styrene-butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber, acrylonitrile butadiene rubber), non-diene-based rubber (e.g., butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, urethane rubber, silicone rubber, fluororubber), thermoplastic elastomers, and modified materials thereof.

The connecting member9has linear or non-linear stretching characteristics depending on the stretching direction. For example, the stretching characteristics of compressive deformation of the connecting member9in the thickness direction (axial direction) has a non-linear component (spring modulus) larger than the linear component (spring modulus), whereas the stretching characteristics of elongation of the connecting member9in the thickness direction (axial direction) has a linear component (spring modulus) larger than the non-linear component (spring modulus). When the deformation characteristic of the connecting member9in a direction (shear direction) intersecting the thickness direction (axial direction) has a linear component (spring modulus) larger than a nonlinear component (spring modulus) because the deformation is in the direction the connecting member9is being pulled and stretched, regardless of the direction of movement of the connecting member9.

In the present embodiment, the connecting member9deform in the shear direction when the movable body6vibrates in the second direction X. Therefore, when the movable body6vibrates in the second direction X in the connecting member9, the vibration can be generated with subtle nuances because the reproducibility of the vibration acceleration in response to the input signal can be improved through use of a spring element in the shear direction.

Actuator Assembly Method

FIG. 6illustrates an assembly method of the cover3. (a) ofFIG. 6illustrates a state in which the first side Y1portions of the coil holder4and the movable body6are inserted into the first cover member31, and (b) ofFIG. 6illustrates a state in which the second side Y2portions of the coil holder4and the movable body6are inserted into the second cover member32and the first comb teeth portion10and the second comb teeth portion20are engaged.

When the actuator1is to be assembled, first, the coil holder4, the coil5, and the plate40are assembled, and then the movable body6is assembled to the state illustrated inFIG. 2. When the coil holder4, the coil5, and the plate40are assembled, the projecting portions49are fitted into the opening50of the coil5so that the coil5come into contact with the coil contacting surface41a, and then the plate40is disposed in contact with the coil5from the first side Z1in the third direction Z. As illustrated inFIG. 4, the heat-conductive adhesive agent51is applied between the coil contacting surface41aand the end face of the coil5, and between the end face of the coil5and the plate40. This fixes the coil5to the coil holding portion41. The plate40is fixed to the coil holder4via the coil5. Note that the inside of the opening50may be filled with the heat-conductive adhesive agent51.

After that, the first permanent magnet71fixed to the first yoke member81faces the plate40from the first side Z1in the third direction Z, and the second permanent magnet72fixed to the second yoke member82faces the coil holding portion41from the second side Z2in the third direction Z. The yoke8is then assembled by interlocking and welding the first yoke side comb teeth portions86and the second yoke side comb teeth portions87. In this way, the movable body6is assembled so as to be movable in the second direction X relative to the coil holder4, and the magnet7and the coil5constitute the magnetic drive circuit M.

Next, the support body2is assembled, and the movable body6is connected with the support body2by the connecting member9. The connecting member9is preliminarily fixed to the cover3or preliminarily fixed to the yoke8before the coil holder4, the first cover member31, and the second cover member32are assembled. In the present embodiment, the first connecting sub-member91is preliminarily joined to the first flat plate portion33, and the second connecting sub-member92is preliminarily joined to the second flat plate portion35. The coil holder4is then inserted into the first cover member31from the second side Y2in the first direction Y. The movable body6is inserted into the first cover member31together with the coil holder4. As illustrated in (a) ofFIG. 6, the movable body6is inserted so that it comes into contact with the first connecting sub-member91, and the movable body6is fixed to the first connecting sub-member91with an adhesive agent or the like, thereby connecting the movable body6to the support body2by the first connecting sub-member91.

As illustrated in (a) ofFIG. 6, when the coil holder4is inserted into the first cover member31, the two guide portions42and43come into contact with the first side plate portion first surface341and the first side plate portion second surface342from the inside, so that the insertion of the coil holder4into the first cover member31is guided. The coil holder4is inserted into the first cover member31until the curved portions48provided at the distal ends of the two guide portions42and43on the first side Y1strike the corner portion at which the first flat plate portion33and the first side plate portion34are connected.

Subsequently, the second cover member32is brought closer to the first cover member31from the second side Y2in the first direction Y, and the coil holder4and the movable body6are inserted into the second cover member32to interlock the first comb teeth portion10and the second comb teeth portion20. At this time, the two guide portions42and43come into contact with the second side plate portion first surface361and the second side plate portion second surface362from the inside, so that the insertion of the coil holder4into the second cover member32is guided.

The first comb teeth portion10and the second comb teeth portion20engage in a slidable state in the first direction Y because the extending portions11slidably fit into the notched portions22and the extending portions21slidably fit into the notched portions12. As illustrated in (b) ofFIG. 6, the second cover member32is slid to the first side Y1until the second connecting sub-member92fixed to the second cover member32comes into contact with the movable body6, and the movable body6is fixed to the second connecting sub-member92by an adhesive agent or the like. This connects the movable body6and the support body2by the second connecting sub-member92.

Before the first cover member31and the second cover member32are welded and permanently fixed, a distance D1between the first flat plate portion33and the movable body6(see (b) ofFIG. 6) and a distance D2between the second flat plate portion35and the movable body6(see (b) ofFIG. 6) are adjusted so that the first connecting sub-member91and the second connecting sub-member92are compressed as designed. In the present embodiment, since the first comb teeth portion10and the second comb teeth portion20are engaged in a state slidable in the first direction Y, the first cover member31and the second cover member32can adjust the amount of engagement of the first comb teeth portion10and the second comb teeth portion20. The distances D1and D2are adjusted so that the spring force applied to the movable body6from the first connecting sub-member91and the spring force applied to the movable body6from the second connecting sub-member92are balanced.

For example, the coil5is energized and the vibration characteristics of the movable body6are measured while the first cover member31and the second cover member32temporarily fixed. The amount of engagement between the first comb teeth portion10and the second comb teeth portion20is adjusted so that the vibration characteristics as designed are achieved. If the vibration characteristics are as designed, it is determined that the distances D1and D2have the dimensions as designed. The first cover member31and the second cover member32are then welded and permanently fixed in the arrangement that achieves the vibration characteristics as designed. Note that in place of measuring the vibration characteristics of the movable body6, the distances D1and D2may be measured using a contact displacement meter or the like to adjust the amount of engagement of the first comb teeth portion10and the second comb teeth portion20.

FIG. 7illustrates welded portions of the first comb teeth portion10and the second comb teeth portions20. In the present embodiment, as a result of adjusting the relative positions of the first cover member31and the second cover member32to achieve the vibration characteristics as designed, the first comb teeth portion10and the second comb teeth portion20have gaps S in the first direction Y between the distal edges15of the extending portions11and the inner edges26of the notched portions22, and between the distal edges25of the extending portions21and the inner edges16of the notched portion12. The gaps S vary in accordance with variations in the dimensions of the cover3, the yoke8, and the connecting member9.

The first cover member31and the second cover member32are joined by welding the portions at which the widthwise edges13and14of the extending portions11and the widthwise edges23and24of the notched portions22come into contact. As in the enlarged view inFIG. 7, weld marks W are formed on the cover3at the portions at which the widthwise edges13of the extending portions11come into contact with the edges23of the notched portions22, and at the portions at which the widthwise edges14of the extending portions11come into contact with the edges24of the notched portions22.

Note that in the present embodiment, as described above, the widthwise edges13and14of the extending portions11constitute the widthwise edges of the notched portions12, and the widthwise edges23and24of the notched portions22constitute the widthwise edges of the extending portions21. Therefore, the welded portions of the first cover member31and the second cover member32are the portions at which the widthwise edges23and24of the extending portions21and the widthwise edges13and14of the notched portions12come into contact.

Main Advantageous Effects of the Present Embodiment

As described above, the actuator1of the present embodiment includes a movable body6, a support body2, a connecting member9having at least one of elasticity and viscoelasticity and being connected to both the movable body6and the support body2, and a magnetic drive circuit M including a magnet7disposed in the movable body6and a coil5disposed in the support body2. The support body2includes a metal cover3enclosing the movable body6and a metal coil holder4housed inside the cover3. The cover3has a first surface3A extending in a first direction Y, and a second surface3B facing the first surface3A in a second direction X intersecting the first direction Y. The coil holder4includes a coil holding portion41disposed between the first surface3A and the second surface3B, and two guide portions42and43disposed on both sides of the coil holding portion41in the second direction X. One of the two guide portions42and43is in surface contact with the first surface3A, and the other one of the guide portions42and43are in surface contact with the second surface3B.

According to the present embodiment, the coil holder4holding the coil5of the magnetic drive circuit M is composed of metal, and the two guide portions42and43disposed on the coil holder4are in surface contact with the first surface3A and the second surface3B of the metal cover3. Therefore, the two guide portions42and43can guide the insertion of the coil holder4into the cover3and position the coil holder4when the support body2is assembled. When the actuator1is completed, the metal parts having high thermal conductivity come into surface contact with each other to constitute a heat transfer path that can transfer a large amount of heat. Since the heat of the coil5can be dissipated from the entire cover3, the dissipation of the heat generated at the coil5can be enhanced, and the temperature rise of the coil5can be suppressed. This reduces the risk of the coil5exceeding the upper temperature limit when a large current is applied, so that a large current can be applied and the driving force of the magnetic drive circuit M can be increased. Therefore, it is possible to obtain the actuator1capable of generating strong vibration. Furthermore, variations in vibration characteristics due to heat can be suppressed.

In the present embodiment, the coil5is an air-core coil in which a coil wire is wound around the opening50, and the coil holding portion41includes the coil contacting surface41ato which the coil5comes into contact in the third direction Z intersecting the first direction Y and intersecting the second direction X, and the projecting portions49projecting from the coil contacting surface41ato the first side Z1in the third direction Z. The coil5is positioned in the coil holding portion41by the fitting of the projecting portions49into the opening50, and the outer circumferential surfaces of the projecting portions49are in contact with the inner circumferential surface of the opening50. In the present embodiment, since not only the end surface of the coil5but also the inner circumferential surface of the opening50is in direct contact with the coil holder4, heat of the coil5can be released not only from the end surface of the coil5but also from the inner circumferential surface of the opening50. Therefore, since the amount of heat dissipation is large, the temperature rise of the coil5can be suppressed.

In the present embodiment, the coil5is fixed to the coil holder4by the heat-conductive adhesive agent51. Therefore, it is possible to avoid a decrease in the thermal conductivity due to the adhesive agent disposed between the coil5and the coil holder4. Therefore, the amount of heat dissipation can be increased.

In the present embodiment, the coil holder4is fixed to the cover3via the two guide portions42and43. Therefore, the coil holder4can be readily fixed to the cover3because it is only necessary to fix the portion of the coil holder4in surface contact with the cover3. Since there is no need to provide a fixing portion separate from the guide portions42and43, the shape of the component can be simplified. The two guide portions42and43can be fixed to the first surface3A and the second surface3B by welding or an adhesive agent, but when an adhesive agent is used, the guide portions42and43are fixed to the cover3by the heat-conductive adhesive agent51. Therefore, it is possible to avoid a decrease in the thermal conductivity due to the adhesive agent disposed between the two guide portions42and43and the cover3. Therefore, the amount of heat dissipation can be increased.

In the present embodiment, the coil holder4is composed of a metal plate, and the coil holding portion41extends in a flat plate shape along the first direction Y and the second direction X. The projecting portions49are formed by pressing, and the guide portions42and43extend in the first direction Y by bending in the third direction Z from both ends of the second direction X of the coil holding portion41. The coil holder4can be manufactured by sheet metal processing, and therefore, the component cost of the coil holder4can be reduced. The two guide portions42and43are bent in the third direction Z and extend in a flat plate shape in the first direction Y, and therefore, the contact area between the cover3and the coil holder4is wide. Therefore, since the amount of heat dissipation is large, the temperature rise of the coil5can be suppressed.

In the present embodiment, the cover3includes the first cover member31disposed on a first side in the first direction Y and the second cover member32disposed on a second side in the first direction Y, and the first cover member31and the second cover member32are joined together. The first cover member31has the first flat plate portion33and the first side plate portion34extending from an edge of the first flat plate portion33toward the second cover member32. The second cover member32has the second flat plate portion35facing the first flat plate portion33in the first direction Y, and the second side plate portion36extending from an edge of the second flat plate portion35toward the second cover member32. The first surface3A and the second surface3B each includes the first side plate portion34and the second side plate portion36. If the cover3is divided into two parts in the first direction Y and both of the parts have a surface in contact with the two guide portions42and43, the cover3can be assembled by installing the first cover member31and the second cover member32to the coil holder4.

Modification

(1) In the configuration according to an above-described embodiment, the first connecting sub-member91and the second connecting sub-member92are disposed on both sides of the movable body6ithe first direction Y, and the portions of the movable body6and the cover3facing each other in the first direction Y are connected by connecting members (the first connecting sub-member91and the second connecting sub-member92). However, at least an embodiment of the present invention is applicable to a configuration in which the portion at which the movable body6and the cover3face each other in the third direction Z is connected by the connecting member9. That is, at least an embodiment of present invention is applicable to a configuration in which the portion where the first plate portion83of the yoke8faces the cover3and the portion where the second plate portion84of the yoke8faces the cover3are connected by the connecting member9.

(2) In an above-described embodiment, the magnets7(the first permanent magnets71and the second permanent magnets72) are disposed on both sides of the coil5in the third direction Z. However, at least an embodiment of the present invention is applicable to an actuator including a magnet7disposed only on a first side Z1or a second side Z2in the third direction Z relative to the coil5. At least an embodiment of the present invention applicable to an actuator including multiple pairs of coils5and magnets7facing each other in a third direction Z. When multiple pairs of coils5and magnets7are provided, it is preferable to provide projecting portions49at positions where the projecting portions49fit into the opening50of each coil5.