ACTUATOR

An actuator includes a movable body, a support body having a coil holder, a connection body connected with the movable body and the support body, and a magnetic drive circuit having a coil held by the coil holder and a magnet for vibrating the movable body. The coil holder has a plate part which surrounds at least a part of the coil, and the movable body has a yoke holding the magnet. The plate part has a coil holding part along an outer edge of the coil and a connection body fixing part whose plate thickness is thinner than that of the coil holding part. The connection body includes at least one of a first connection body connecting a first facing part of the yoke with the connection body fixing part and a second connection body connecting a second facing part of the yoke with the connection body fixing part.

CROSS REFERENCE TO RELATED APPLICATION

The present invention claims priority under 35 U.S.C. § 119 to Japanese Application No. 2022-136505 filed Aug. 30, 2022, and the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

At least an embodiment of the present invention may relate to an actuator which vibrates a movable body.

BACKGROUND

In Japanese Patent Laid-Open No. 2020-162393 (Patent Literature 1), an actuator is disclosed which includes a movable body having a magnet and a support body having a coil, and which is structured to vibrate the movable body with respect to the support body by supplying a drive current to the coil. Such an actuator uses an elastic body or a viscoelastic body as a connection body which connects the movable body with the support body. In the actuator described in Patent Literature 1, a gel state member such as silicone gel is used as the connection body.

In Patent Literature 1, the support body includes a case made of metal which defines an outer shape of the actuator and a coil holder made of resin. A coil is an air core coil and is disposed in a coil arrangement hole provided in the coil holder. The movable body includes a first yoke which faces the coil from one side in its thickness direction and a second yoke which faces the coil from an opposite side to the first yoke, and a magnet is fixed to each face facing the coil of the first yoke and the second yoke.

In Patent Literature 1, the coil holder is attached with a first plate which covers a plate part formed with the coil arrangement hole from one side in a plate thickness direction, and a second plate which covers the plate part from the other side in the plate thickness direction. The connection body is disposed at a position where the first plate and the first yoke face each other and a position where the second plate and the second yoke face each other. When an electric current is supplied to the coil, the movable body vibrates in a direction intersecting a direction in which the coil and the magnet face each other. In this case, the connection body which connects the first plate with the first yoke and the connection body which connects the second plate with the second yoke are deformed in a shearing direction.

In the actuator, in order to increase acceleration when the movable body vibrates, a gap between the magnet and the coil is required to reduce. However, in the structure described in Patent Literature 1, when a gap between the magnet and the coil is reduced, a thickness of the connection body (gel state member) is also reduced. In a case that a gel state member is shear-deformed, when a thickness of the gel state member is made too small, stable vibration may not be attained. For example, in a case that a thickness of a gel state member is smaller than an amplitude of a movable body, the gel state member may peel off from its joined surface.

SUMMARY

In view of the problem described above, at least an embodiment of the present invention may advantageously provide an actuator in which a gap between a magnet and a coil can be reduced and, in addition, a thickness of a connection body can be secured.

According to at least an embodiment of the present invention, there may be provided an actuator including a movable body, a support body having a coil holder, a connection body which is connected with the movable body and the support body, and a magnetic drive circuit which includes a coil held by the coil holder and a magnet facing the coil in a first direction and is structured to vibrate the movable body with respect to the support body in a second direction intersecting the first direction. The coil holder is provided with a plate part which surrounds at least a part of the coil, the movable body includes a yoke which holds the magnet, the yoke includes a first facing part which faces the coil from one side in the first direction and a second facing part which faces the coil from the other side in the first direction, and the magnet is fixed to at least one of the first facing part and the second facing part. The plate part is provided with a coil holding part along an outer edge of the coil and a connection body fixing part whose plate thickness in the first direction is thinner than a plate thickness of the coil holding part, and the connection body includes at least one of a first connection body which connects the first facing part with the connection body fixing part and a second connection body which connects the second facing part with the connection body fixing part.

According to at least an embodiment of the present invention, a coil holder which structures a support body of an actuator is provided with a plate part surrounding the coil, and the plate part is provided with a connection body fixing part whose plate thickness is thinner than that of the coil holding part provided along an outer edge of the coil. The connection body which connects a movable body with the support body is disposed at a position where the connection body fixing part whose plate thickness is made thin and a yoke face each other. As described above, when a plate thickness of a portion where the connection body is disposed is made thin, even in a case that a gap between a magnet fixed to the yoke and the coil is reduced, a thickness of the connection body is restrained from becoming small because a thickness of the connection body fixing part is made thinner, and a sufficient thickness of the connection body can be secured. Therefore, acceleration when the movable body vibrates can be increased by reducing the gap between the magnet and the coil and, in addition, a situation can be avoided that a thickness of the connection body becomes too small and the connection body is unable to vibrate stably.

In the present invention, it is preferable that, when a direction intersecting the first direction and the second direction is referred to as a third direction, the coil holding part surrounds one side in the third direction of the coil and the other side in the third direction of the coil, the connection body fixing part includes one side fixing part provided on the one side in the third direction with respect to the coil and the other side fixing part provided on the other side in the third direction with respect to the coil, and the one side fixing part and the other side fixing part are respectively connected with the first facing part and the second facing part through the first connection body and the second connection body. According to this structure, both end portions in the third direction of the coil holder are respectively connected with the yoke through the connection bodies from both sides in the first direction. Therefore, the movable body can be stably supported.

In the present invention, it is preferable that the plate part is provided with a first recessed part which is recessed to the other side in the first direction and a second recessed part which is recessed to the one side in the first direction on an opposite side in the first direction with respect to the first recessed part, the connection body fixing part is a thin wall part whose surfaces are a bottom face of the first recessed part and a bottom face of the second recessed part, the first connection body connects the first facing part with the bottom face of the first recessed part, and the second connection body connects the second facing part with the bottom face of the second recessed part. According to this structure, distances in the first direction with respect to the yoke are respectively widened by depths of the recessed parts on both sides in the first direction of the plate part. Therefore, even in a case that a gap between the coil and the magnet facing the coil from the one side in the first direction and a gap between the coil and the magnet facing the coil from the other side in the first direction are narrowed, a situation can be avoided that a thickness of the connection body becomes too small and the movable body is unable to vibrate stably. In the present invention, it is preferable that the support body includes a first plate made of metal which is overlapped with the coil and the coil holding part from the one side in the first direction, and a second plate made of metal which is overlapped with the coil and the coil holding part from the other side in the first direction, and the connection body fixing part is exposed from the first plate and the second plate. According to this structure, the coil can be protected by the first plate and the second plate and thus, even when a gap between the magnet and the coil is narrowed, the coil is less likely to be damaged due to a collision with the magnet. Further, the connection body fixing part is exposed from the first plate and the second plate and thus, a height in the first direction of an arrangement space of the connection body does not become lower. Therefore, a thickness of the connection body can be secured.

In the present invention, it is preferable that the first plate is provided with a first fixing part which is bent from both ends in the second direction to the other side in the first direction and is engaged with a side face in the second direction of the coil holding part, and the second plate is provided with a second fixing part which is bent from both ends in the second direction to the one side in the first direction and is engaged with the side face in the second direction of the coil holding part. According to this structure, the first plate, the second plate, the coil holder and the coil are assembled to be capable of being handled as a coil assembly. Therefore, even when the coil holder is divided into two members, the actuator can be easily assembled.

In the present invention, it is preferable that, when a direction intersecting the first direction and the second direction is referred to as a third direction, the coil holder includes a first holder member disposed on one side in the third direction with respect to the coil and a second holder member disposed on the other side in the third direction with respect to the coil, the coil holding part includes a first coil holding part provided at an end part on the other side in the third direction of the first holder member, and a second coil holding part which is provided at an end part on the one side in the third direction of the second holder member, and the connection body fixing part includes one side fixing part which is provided on the one side in the third direction of the first coil holding part, and the other side fixing part which is provided on the other side in the third direction of the second coil holding part. As described above, the coil holder is divided into two members and thus, portions covering both sides in the second direction of the coil can be omitted. As a result, a size in the second direction of the movable body can be reduced and a size in the second direction of the actuator can be attained.

In the present invention, it is preferable that, when a direction intersecting the first direction and the second direction is referred to as a third direction, the coil holder is provided with a first holder side plate part which is extended in the first direction at an end part on one side in the third direction of the coil holder, a board is fixed to the first holder side plate part, the plate part is provided with a groove in which a coil wire extended from the coil is disposed, and the groove is extended to a cut-out part, which is formed by cutting out the first holder side plate part in the first direction, through surfaces of the coil holding part and the connection body fixing part. According to this structure, when a coil wire is to be extended to the board, the coil wire can be extended without interfering with the connection body.

According to the present invention, the coil holder which structures the support body of the actuator is provided with the plate part surrounding the coil, and the plate part is provided with the connection body fixing part whose plate thickness is thinner than that of the coil holding part provided along an outer edge of the coil. The connection body which connects the movable body with the support body is disposed at a position where the connection body fixing part whose plate thickness is thin and the yoke face each other. As described above, when a plate thickness of the portion where the connection body is disposed is made thinner, even in a case that a gap between the magnet fixed to the yoke and the coil is reduced, a thickness of the connection body is restrained from becoming small because a thickness of the connection body fixing part is made thinner, and a sufficient thickness of the connection body can be secured. Therefore, acceleration when the movable body is vibrated can be increased by reducing the gap between the magnet and the coil and, in addition, a situation can be avoided that a thickness of the connection body becomes too small and the connection body is unable to vibrate stably.

DETAILED DESCRIPTION

An embodiment of an actuator to which the present invention is applied will be described below with reference to the accompanying drawings.

FIG.1Ais a perspective view showing an actuator1which is viewed from the “Z2” direction side in accordance with an embodiment of the present invention.FIG.1Bis a perspective view showing the actuator1which is viewed from the “Z1” direction side.FIG.2is a cross-sectional view showing the actuator1which is cut in a longitudinal direction and is a cross-sectional view showing the actuator1which is cut at the “A-A” position inFIG.1A.FIG.3is a cross-sectional view showing the actuator1which is cut in a direction perpendicular to the longitudinal direction and is a cross-sectional view showing the actuator1which is cut at the “B-B” position inFIG.1A.FIG.4is an exploded perspective view showing a movable body5and a coil assembly13which are viewed from the “Z2” direction side.FIG.5is an exploded perspective view showing the movable body5and the coil assembly13which are viewed from the “Z1” direction side.FIG.6is an exploded perspective view showing an assembly method of the coil assembly13.FIG.7is a perspective view showing the coil assembly13.

An actuator1is used as a tactile device which is structured to transmit information by vibration. As shown inFIGS.1A and1B, an outer shape of the actuator1is a rectangular parallelepiped shape. The actuator1generates vibration in a shorter direction of the outer shape. In the following descriptions, a shorter direction in which the vibration is generated is defined as an “X” direction (second direction), a direction which is a longitudinal direction of the actuator1and is perpendicular to the “X” direction is defined as a “Y” direction (third direction), and a direction which is a thickness direction (height direction) of the actuator1and is perpendicular to the “X” direction and the “Y” direction is defined as a “Z” direction (first direction). Further, one side in the “X” direction is referred to as an “X1” direction side, and the other side is referred to as an “X2” direction side. One side in the “Y” direction is referred to as a “Y1” direction side, and the other side is referred to as a “Y2” direction side. One side in the “Z” direction is referred to as a “Z1” direction side, and the other side is referred to as a “Z2” direction side.

As shown inFIGS.1A through3, the actuator1includes a support body3having a case2which defines an outer shape of the actuator1and a movable body5which is accommodated on an inner side of the case2. Further, the actuator1includes a connection body4which connects the support body3with the movable body5and a magnetic drive circuit6structured to relatively move the movable body5in the “X” direction with respect to the support body3.

The support body3includes the case2and a coil assembly13. As shown inFIGS.4through7, the coil assembly13includes a coil10, a coil holder17which surrounds the “Y1” side and the “Y2” side of the coil10, a first plate11overlapped with the coil10from the “Z1” direction side, and a second plate12overlapped with the coil10from the “Z2” direction side. The first plate11and the second plate12are made of nonmagnetic metal.

As shown inFIGS.2and3, the coil10is located at a center in the “Z” direction of the case2. The coil10is a flat air core coil whose thickness direction is directed in the “Z” direction. As shown inFIGS.4and5, the coil10is formed in an elliptical shape which is long in the “Y” direction and is provided with a pair of long side parts10aand10bwhich are extended in parallel with the “Y” direction. A center hole10cwhich is extended in the “Y” direction is provided between a pair of the long side parts10aand10b.

As shown inFIGS.4and5, the coil holder17is divided into two members. The coil holder17includes a first holder member15disposed on the “Y1” side with respect to the coil10, and a second holder member16which is disposed on the “Y2” side with respect to the coil10. The first holder member15and the second holder member16are made of resin.

The first holder member15is provided with a first plate part151which is extended in the “Y” direction on the “Y1” direction side with respect to the coil10, and a first holder side plate part152which is extended from an end on the “Y1” side of the first plate part151to the “Z1” direction side and the “Z2” direction side. The second holder member16is provided with a second plate part161which is extended in the “Y” direction on the “Y2” direction side with respect to the coil10, and a second holder side plate part162which is extended from an end on the “Y2” side of the second plate part161to the “Z1” direction side and the “Z2” direction side.

The coil holder17is provided with a plate part171whose plate thickness direction is directed in the “Z” direction. In this embodiment, the coil holder17is divided into two members, and the plate part171is structured of the first plate part151and the second plate part161. The plate part171is provided with coil holding parts173which surround an outer edge of the coil10on the “Y1” side and the “Y2” side with respect to the coil10. The coil holding part173includes a first coil holding part153provided at an end part on the “Y2” side of the first plate part151, and a second coil holding part163provided at an end part on the “Y1” side of the second plate part161. The coil10is disposed between the first coil holding part153and the second coil holding part163. The end part on the “Y2” side of the first coil holding part153and the end part on the “Y1” side of the second coil holding part163are formed in a circular arc shape along the outer edge of the coil10.

A plate thickness in the “Z” direction of the coil holding part173(first coil holding part153and second coil holding part163) is thicker than a thickness in the “Z” direction of the coil10. The plate part171is provided with a connection body fixing part174whose plate thickness in the “Z” direction is thinner than that of the coil holding part173. The plate thickness in the “Z” direction of the connection body fixing part174is thinner than the thickness in the “Z” direction of the coil10. The connection body fixing part174includes one side fixing part154provided on the “Y1” side of the first coil holding part153and the other side fixing part164provided the “Y2” side of the second coil holding part163.

In the first holder member15, the “Y1” side of the first coil holding part153is provided with a first recessed part155which is recessed to the “Z1” direction side, and a second recessed part156which is recessed to the “Z2” direction side on an opposite side to the first recessed part155in the “Z” direction. Depths in the “Z” direction of the first recessed part155and the second recessed part156are equal to each other. The one side fixing part154is a thin wall part in which a bottom face of the first recessed part155is its “Z2” direction side face, and a bottom face of the second recessed part156is its “Z1” direction side face.

In the second holder member16, the “Y2” side of the second coil holding part163is provided with a first recessed part165which is recessed to the “Z1” direction side, and a second recessed part166which is recessed to the “Z2” direction side on an opposite side to the first recessed part165in the “Z” direction. Depths in the “Z” direction of the first recessed part165and the second recessed part166are equal to each other. The other side fixing part164is a thin wall part in which a bottom face of the first recessed part165is its “Z2” direction side face, and a bottom face of the second recessed part166is its “Z1” direction side face.

As shown inFIG.2, the connection body fixing part174(one side fixing part154and the other side fixing part164) faces yokes8which face from the “Z1” direction side and the “Z2” direction side. As described below, in this embodiment, the movable body5and the support body3are connected with each other through the connection body4(first connection body9A and second connection body9B) disposed between the connection body fixing part174and the yoke8.

The first holder member15is fixed with a power feeding board14. Electric power is supplied to the coil10through the power feeding board14. Two coil wires (not shown) extended from the coil10are disposed in two grooves141, which are formed on the “Z2” direction side face of the first plate part151, and are extended to the “Y1” direction side through a cut-out part158, which is formed by cutting out a center portion in the “X” direction of the first holder side plate part152to the “Z1” direction, and are connected with the power feeding board14which is fixed on the “Z1” direction side with respect to the cut-out part158.

In this embodiment, the first holder member15and the second holder member16have the same shape as each other, but they are disposed in reverse in the “Y” direction. The second holder side plate part162is formed with a cut-out part168having the same shape as the cut-out part158of the first holder side plate part152, and two grooves141are formed on the “Z2” direction side face of the second plate part161. Therefore, it may be structured that coil wires extended from the coil10to the “Y2” direction side are disposed in the grooves141of the second plate part161, and the coil wires are connected with a power feeding board14which is fixed to the second holder side plate part162instead of the first holder side plate part152.

The first plate11is provided with a first plate part111which is overlapped with the coil10from the “Z1” side and a pair of first bent parts112which are bent to the “Z2” direction side from both ends in the “X” direction of the first plate part111. The second plate12is provided with a second plate part121which is overlapped with the coil10from the “Z2” side and a pair of second bent parts122which are bent to the “Z1” direction side from both ends in the “X” direction of the second plate part121.

The first plate11is provided with first fixing parts113, which are bent to the “Z2” direction side from the first plate part111on the “Y1” side and the “Y2” side with respect to each of the first bent parts112. The second plate12is provided with second fixing parts123, which are bent to the “Z1” direction side from the second plate part121on the “Y1” side and the “Y2” side with respect to each of the second bent parts122.

When the first plate11and the second plate12are attached to the first plate part151and the second plate part161from both sides in the “Z” direction, as shown inFIG.7, the first bent parts112and the second bent parts122cover the long side parts10aand10bof the coil10from both sides in the “X” direction. Further, the first fixing part113of the first plate11and the second fixing part123of the second plate12are overlapped with each other on both sides in the “Y” direction with respect to the first bent part112and the second bent part122. The first fixing part113and the second fixing part123are fixed in the “Z” direction. Further, a claw part157provided on a side face of the first coil holding part153and a claw part167provided on a side face of the second coil holding part163are engaged with cut-out parts114provided in the first fixing parts113and cut-out parts124provided in the second fixing parts123.

(Assembly Method of Coil Assembly)

When the actuator1is to be manufactured, the coil assembly13is assembled by using the coil10, the first plate11, the second plate12, the first holder member15and the second holder member16. For example, as shown inFIG.6, the first coil holding part153and the second coil holding part163are fitted between a pair of the first fixing parts113from the “Z2” side at both ends in the “Y” direction of the first plate11, and the claw parts157and167are protruded from the cut-out parts114of the first fixing parts113to both sides in the “X” direction. As a result, the first holder member15and the second holder member16are assembled in a state that they do not disengage from the first plate11in the “Y” direction.

After that, the coil10is arranged between the first coil holding part153and the second coil holding part163, and coil wires (not shown) are arranged in the grooves141and led out to the “Y1” side through the cut-out part158. Next, after an adhesive18(seeFIGS.2and3) is poured into a center hole10cof the coil10, the second plate12is attached so as to cover the coil10from the “Z2” side. In this case, a pair of the first fixing parts113is fitted between a pair of the second fixing parts123at both ends in the “Y” direction of the second plate12, and the claw parts157and167are protruded from the cut-out parts124of the second fixing parts123to both sides in the “X” direction.

As shown inFIG.7, when the coil assembly13has been assembled, the plate part171of the coil holder17is structured so that the coil holding part173(first coil holding part153and second coil holding part163) is covered by the first plate11and the second plate12, and the connection body fixing part174(one side fixing part154and the other side fixing part164) are exposed. The one side fixing part154is extended to the “Y1” side with respect to the first plate11and the second plate12, and the other side fixing part164is extended to the “Y2” side with respect to the first plate11and the second plate12.

The movable body5includes a magnet7and a yoke8. As shown inFIGS.2and3, the magnet7faces the coil10in the “Z” direction. The coil10and the magnet7structure the magnetic drive circuit6. The movable body5includes a first magnet71and a second magnet72as the magnet7. The first magnet71is located on the “Z1” direction side with respect to the coil10. The second magnet72is located on the “Z2” direction side with respect to the coil10. The first magnet71and the second magnet72are polarized into two pieces in the “X” direction. As shown inFIG.3, when the movable body5and the support body3are assembled, the long side parts10aand10bof the coil10face the first magnet71on the “Z1” direction side and face the second magnet72on the “Z2” direction side.

The yoke8is made of magnetic material. As shown inFIG.3, the yoke8includes a first facing part801which faces the coil10from the “Z1” direction side and a second facing part802which faces the coil10from the “Z2” direction side. The first magnet71is fixed to the first facing part801. The second magnet72is fixed to the second facing part802. Further, the yoke8includes a pair of connection parts803which are extended in the “Z” direction on both sides in the “X” direction with respect to the coil10. A pair of the connection parts803connects the first facing part801with the second facing part802.

When the yoke8is to be assembled, a pair of connecting plate parts805extended to the “Z1” direction side from both ends in the “X” direction of the second facing part802is press-fitted and fixed to inner sides of a pair of connecting plate parts804extended to the “Z2” direction side from both ends in the “X” direction of the first facing part801. As a result, a pair of the connection parts803is structured, and the yoke8is assembled in a shape so as to surround outer peripheral sides of the coil10, the first plate11and the second plate12. As shown inFIGS.4and5, in this embodiment, a length in the “Y” direction of the connecting plate part805is shorter than that of the connecting plate part804.

As shown inFIGS.2through5, the yoke8includes a first yoke81and a second yoke82. The first yoke81is structured of two members which are joined to each other, i.e., a first inner side member83overlapped with the coil10from the “Z1” direction side and a first outer side member84overlapped with the first inner side member83from the “Z1” direction side. The first magnet71is fixed to the first inner side member83. The first outer side member84is provided with a first flat plate part87overlapped with the first inner side member83from the “Z1” direction side, and a pair of the connecting plate parts804which are extended from both ends in the “X” direction of the first flat plate part87to the “Z2” direction side.

The second yoke82is structured of two members which are joined to each other, i.e., a second inner side member85overlapped with the coil10from the “Z2” direction side and a second outer side member86overlapped with the second inner side member85from the “Z2” direction side. The second magnet72is fixed to the second inner side member85. The second outer side member86is provided with a second flat plate part88overlapped with the second inner side member85from the “Z2” direction side, and a pair of the connecting plate parts805which are extended from both ends in the “X” direction of the second flat plate part88to the “Z1” direction side.

The first facing part801of the yoke8is structured by laminating the first flat plate part87of the first outer side member84and the first inner side member83in the “Z” direction. As shown inFIG.2, a length in the “Y” direction of the first inner side member83is the same as that of the first magnet71and is shorter than that of the first flat plate part87of the first outer side member84. Both ends in the “Y” direction of the first flat plate part87are provided with first connection body fixing parts806which are extended to the “Y1” side and the “Y2” side with respect to the first inner side member83and the first magnet71. Two first connection body fixing parts806respectively face the connection body fixing parts174(one side fixing part154and the other side fixing part164) of the coil assembly13in the “Z” direction.

The second facing part802of the yoke8is structured by laminating the second flat plate part88of the second outer side member86and the second inner side member85in the “Z” direction. As shown inFIG.2, a length in the “Y” direction of the second inner side member85is the same as that of the second magnet72and is shorter than that of the second flat plate part88of the second outer side member86. Both ends in the “Y” direction of the second flat plate part88are provided with second connection body fixing parts807which are extended to the “Y1” side and the “Y2” side with respect to the second inner side member85and the second magnet72. Two second connection body fixing parts807respectively face the connection body fixing parts174(one side fixing part154and the other side fixing part164) of the coil assembly13in the “Z” direction.

When the actuator1is to be assembled, the movable body5is assembled so as to surround the coil assembly13, and the movable body5and the coil assembly13are connected with each other by the connection body4. In other words, the first connection body fixing part806and the connection body fixing part174(one side fixing part154and the other side fixing part164) facing in the “Z” direction are connected with each other through the first connection body9A, and the second connection body fixing part807and the connection body fixing part174(one side fixing part154and the other side fixing part164) facing in the “Z” direction are connected with each other through the second connection body9B.

As shown inFIG.2, the connection body4includes the first connection body9A and the second connection body9B. As shown inFIGS.4and5, the first connection body9A and the second connection body9B are formed in a cuboid shape which is long in the “X” direction. The first connection body9A is located on the “Z1” side with respect to the coil10. The second connection body9B is located on the “Z2” side with respect to the coil10. The first connection body9A is disposed at two positions on the “Y1” side and the “Y2” side with respect to the first magnet71and is structured of two members having the same shape. The second connection body9B is disposed at two positions on the “Y1” side and the “Y2” side with respect to the second magnet72and is structured of two members having the same shape. Each of the first connection body9A and the second connection body9B is provided with at least one of elasticity and viscoelasticity.

The first connection body9A is, as described above, sandwiched between the first facing part801of the yoke8and the connection body fixing part174of the coil holder17(one side fixing part154and the other side fixing part164) on both sides in the “Y” direction of the coil10. The first connection body9A is compressed in the “Z” direction between the first facing part801and the connection body fixing part174. The second connection body9B is, as described above, sandwiched between the second facing part802of the yoke8and the connection body fixing part174on both sides in the “Y” direction of the coil10. The second connection body9B is compressed in the “Z” direction between the second facing part802and the connection body fixing part174.

In this embodiment, the first connection body9A and the second connection body9B are gel state members made of silicone gel. More specifically, faces of the gel state member on the “Z1” direction side and the “Z2” direction side are stuck with a flexible film such as a PET sheet by adhesiveness of the gel state member itself, and the gel state member is joined to the movable body5and the support body3through the PET sheets. In this case, the PET sheet may be omitted. Silicone gel is a viscoelastic body whose spring constant when it deforms in an expansion and contraction direction is about three times of a spring constant when it deforms in a shearing direction. The viscoelastic body deforms in a pulled and extended direction when it deforms in a direction (shearing direction) intersecting a thickness direction and thus, the viscoelastic body has a deformation characteristic that a linear component is larger than a non-linear component. Further, the viscoelastic body has a deformation characteristic that a non-linear component is larger than a linear component when it is pressed in a thickness direction and is compressed and deformed and, on the other hand, when the viscoelastic body is pulled and extended in the thickness direction, it has a deformation characteristic that a linear component is larger than a non-linear component.

In accordance with an embodiment of the present invention, as the first connection body9A and the second connection body9B, the following material may be used; in other words, various rubber materials such as natural rubber, diene-based rubber (for example, styrene butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber and acrylonitrile butadiene rubber), non-diene-based rubber (for example, butyl rubber, ethylene propylene rubber, ethylene propylene diene rubber, urethane rubber, silicone rubber and fluorine-containing rubber) and thermoplastic elastomer, and their denatured materials.

As shown inFIGS.1A through3, the case2includes a first case member30and a second case member40which are overlapped in the “Z” direction. The first case member30is assembled to the coil assembly13from the “Z1” direction side. The second case member40is assembled to the coil assembly13and the first case member30from the “Z2” direction side.

The first case member30is provided with a first end plate part31in a substantially rectangular shape which faces the coil10from the “Z1” direction side, and a first side plate part32which is extended from an outer edge of the first end plate part31to the “Z2” direction side. The second case member40is provided with a second end plate part41in a substantially rectangular shape which faces the coil10from the “Z2” direction side, and a second side plate part42which is extended from an outer edge of the second end plate part41to the “Z1” direction side.

When the coil assembly13and the movable body5are to be accommodated into the case2, as shown inFIG.2, a tip end on the “Z1” direction side of the first holder side plate part152of the coil assembly13and a tip end on the “Z1” direction side of the second holder side plate part162are abutted with the first end plate part31from the “Z2” direction side. As a result, the coil assembly13is positioned in the “Z” direction with respect to the first case member30.

As shown inFIGS.4and5, the coil assembly13is provided with a first receiving part159, which is protruded to the “Y1” direction side from a “Y1” side face of the first holder side plate part152, and a second receiving part169which is protruded to the “Y2” direction side from a “Y2” side face of the second holder side plate part162. When the first case member30, the coil assembly13and the movable body5are to be covered by the second case member40from the “Z2” direction side, as shown inFIG.2, the second side plate part42of the second case member40is abutted with the first receiving part159and the second receiving part169from the “Z2” direction side. As a result, the second case member40is positioned in the “X” direction with respect to the first case member30through the coil assembly13.

Principal Operations and Effects of this Embodiment

As described above, the actuator1in this embodiment includes the movable body5, the support body3having the coil holder17, the connection body4which is connected with the movable body5and the support body3, and the magnetic drive circuit6which includes the coil10held by the coil holder17and the magnet7facing the coil10in the “Z” direction (first direction) and is structured to vibrate the movable body5with respect to the support body3in the “X” direction (second direction) intersecting the “Z” direction. The coil holder17is provided with the plate part171(first plate part151and second plate part161) which surrounds an end part on the “Y1” direction side (one side in the third direction) of the coil10and an end part on the “Y2” direction side (the other side in the third direction) of the coil10. The movable body5includes the yoke8which holds the magnet7, and the yoke8includes the first facing part801which faces the coil10from the “Z1” direction side (one side in the first direction), and the second facing part802which faces the coil10from the “Z2” direction side (the other side in the first direction). The magnet7includes the first magnet71fixed to the first facing part801and the second magnet72fixed to the second facing part802. The plate part171of the coil holder17is provided with the coil holding part173(first coil holding part153and second coil holding part163) along an outer edge of an end part on the “Y1” direction side of the coil10and an outer edge of an end part on the “Y2” direction side of the coil10, and the connection body fixing part174(one side fixing part154and the other side fixing part164) whose plate thickness in the “Z” direction is thinner than that of the coil holding part173. The connection body4includes the first connection body9A, which connects the first facing part801with the connection body fixing part174(one side fixing part154and the other side fixing part164), and the second connection body9B which connects the second facing part802with the connection body fixing part174(one side fixing part154and the other side fixing part164).

In this embodiment, the connection body4is disposed at a position where the coil holder17and the yoke8face each other in the “Z” direction. The coil holder17is structured so that a plate thickness in the “Z” direction of the connection body fixing part174where the connection body4is disposed is thinner than that of the coil holding part173provided along an outer edge of the coil10. Therefore, even when a gap between the magnet7fixed to the yoke8and the coil10is reduced, since a thickness of the connection body fixing part174is also reduced, a thickness of the connection body4is restrained from becoming small and a sufficient thickness of the connection body4can be secured. Therefore, acceleration when the movable body5is vibrated can be increased by setting the gap between the magnet7and the coil10to be small and, in addition, a situation can be avoided that a thickness of the connection body4becomes too small and the connection body4is unable to vibrate stably. Further, when a thickness of the connection body4is set to be a dimension not less than an amplitude of the movable body5, the movable body5can be stably supported and a stable vibration characteristic is attained. In this embodiment, a thickness of the connection body4is set to be two times or more of the amplitude of the movable body5.

In this embodiment, the coil holding part173(first coil holding part153and second coil holding part163) surrounds the “Y1” direction side and the “Y2” direction side of the coil10, and the connection body fixing part174is provided with the one side fixing part154provided on the “Y1” direction side with respect to the coil10and the other side fixing part164provided on the “Y2” direction side with respect to the coil10. The one side fixing part154and the other side fixing part164are respectively connected with the first facing part801and the second facing part802through the first connection body9A and the second connection body9B. As described above, both side portions on the “Y1” direction side of the coil holder17are respectively connected with the yoke8on both sides in the “Z” direction through the connection body4(first connection body9A and second connection body9B) and thus, the movable body5can be stably supported.

In this embodiment, the plate part171of the coil holder17is provided with the first recessed part (the first recessed part155of the first plate part151and the first recessed part165of the second plate part161) which is recessed to the “Z1” direction side, and the second recessed part156which is recessed to the “Z2” direction side on an opposite side to the first recessed part155in the “Z” direction, and the second recessed part166which is recessed to the “Z2” direction side on an opposite side to the first recessed part165in the “Z” direction. The connection body fixing part174is the one side fixing part154, which is a thin wall part whose surfaces are a bottom face of the first recessed part155and a bottom face of the second recessed part156, and the other side fixing part164which is a thin wall part whose surfaces are a bottom face of the first recessed part165and a bottom face of the second recessed part166. The first connection body9A connects the first facing part801with the bottom faces of the second recessed parts156and166. The second connection body9B connects the second facing part802with the bottom faces of the first recessed parts155and165. As described above, both faces in the “Z” direction of the plate part171are respectively formed with the recessed parts and thus, a distance in the “Z” direction with respect to the yoke8is widened by a depth of the recessed part on both sides in the “Z” direction of the plate part171. Therefore, even when a gap between the coil10and the first magnet71facing the coil10from the “Z1” direction side is narrowed and, in addition, even when a gap between the coil10and the second magnet72facing the coil10from the “Z2” direction side is narrowed, a situation is avoided that a thickness of the connection body4(first connection body9A and second connection body9B) becomes so small that the connection body4is unable to vibrate stably.

In this embodiment, the support body3includes the first plate11made of metal, which is overlapped with the coil10and the coil holding part173(first coil holding part153and second coil holding part163) from the “Z1” direction side, and the second plate12made of metal which is overlapped with the coil10and the coil holding part173from the “Z2” direction side. The connection body fixing part174(one side fixing part154and the other side fixing part164) is exposed from the first plate11and the second plate12. Therefore, the coil10can be protected by the first plate11and the second plate12and thus, even when a gap between the magnet7and the coil10is narrowed, the coil10is less likely to be damaged due to a collision with the magnet7. Further, the connection body fixing part174(one side fixing part154and the other side fixing part164) is exposed from the first plate11and the second plate12and thus, a height in the “Z” direction of an arrangement space of the connection body4(first connection body9A and second connection body9B) is not reduced and a thickness of the connection body4can be secured.

In this embodiment, the first plate11is provided with the first fixing part113which is bent in the “Z” direction from both ends in the “X” direction (second direction) and is engaged with a side face in the “X” direction of the coil holding part173(first coil holding part153and second coil holding part163). The second plate12is provided with the second fixing part123which is bent in the “Z” direction from both ends in the “X” direction (second direction) and is engaged with a side face in the “X” direction of the coil holding part173(first coil holding part153and second coil holding part163). As a result, the first plate11, the second plate12, the coil holder17and the coil10are assembled to be capable of handling as the coil assembly13and thus, even when the coil holder17is divided into two members, i.e., the first holder member15and the second holder member16, the actuator1can be easily assembled.

In this embodiment, the coil holder17includes the first holder member15disposed on the “Y1” direction side with respect to the coil10and the second holder member16disposed on the “Y2” direction side with respect to the coil10. The coil holding part173includes the first coil holding part153, which is provided at an end part on the “Y2” direction side of the first holder member15, and the second coil holding part163which is provided at an end part on the “Y1” direction side of the second holder member16. The connection body fixing part174includes one side fixing part154provided on the “Y1” direction side with respect to the first coil holding part153and the other side fixing part164provided on the “Y2” direction side with respect to the second coil holding part163. As described above, the coil holder17is divided into two members and thus, portions covering both sides in the “X” direction of the coil10can be omitted. As a result, a size in the “X” direction of the movable body5can be reduced, and a size in the “X” direction of the actuator1can be reduced.

In this embodiment, the coil holder17is provided with the first holder side plate part152which is extended in the “Z” direction at an end part on the “Y1” direction side, and the power feeding board14is fixed to the first holder side plate part152. The plate part171is provided with the groove141in which a coil wire extended from the coil10is disposed, and the groove141is extended to the cut-out part158, which is formed by cutting out the first holder side plate part152in the “Z” direction, through the faces of the first coil holding part153and the one side fixing part154. Therefore, when the coil wire is to be extended to the power feeding board14, the coil wire can be extended without interfering with the connection body4(second connection body9B).

Modified Embodiments

(1) In the embodiment described above, the coil holder17is divided into two members, i.e., the first holder member15and the second holder member16. However, the coil holder17may be structured of one member. For example, it may be structured that a portion is provided which is extended in the “Y” direction on both sides in the “X” direction of the coil10to connect the first holder member15with the second holder member16so that the entire periphery of the coil10is surrounded by the coil holder17.

(2) The coil holder17in the embodiment described above is structured so as to surround the “Y1” side and the “Y2” side of the coil. However, the coil holder17may be structured to surround other portions of the coil. For example, the coil holder17may be formed in a shape so as to surround the “X1” side and the “X2” side of the coil. Further, in the embodiment described above, the connection body fixing part174is disposed at two positions, i.e., on the “Y1” side and the “Y2” side with respect to the coil. However, the connection body fixing part174may be arranged in another position. For example, the connection body fixing part174may be disposed on the “X1” side and the “X2” side with respect to the coil10.

(3) In the embodiment described above, the plate part171of the coil holder17is provided with the first recessed parts155and165, which are recessed to the “Z1” direction side, and the second recessed parts156and166which are recessed to the “Z2” direction side and thereby, a height of a space where the connection body4is disposed is increased on both sides in the “Z” direction of the plate part171. However, only one of the first recessed parts155and165, and only one of the second recessed parts156and166may be provided.

(4) In the embodiment described above, the first magnet71and the second magnet72are provided as the magnet7. However, only one of the first magnet71and the second magnet72may be provided.

(5) In the embodiment described above, the first connection body9A and the second connection body9B are provided as the connection body4. However, only one of the first connection body9A and the second connection body9B may be provided. Further, the first connection body9A and the second connection body9B are respectively disposed at two positions, but may be disposed at one position or three or more positions.

(6) In the embodiment described above, the yoke8is structured so that each of the first yoke81and the second yoke82is laminated of an inner side member and an outer side member. However, each of the first yoke81and the second yoke82may be structured of only an outer side member.