JP2022086967A - Linear actuator - Google Patents

Abstract

To provide a linear actuator having a structure which enables a magnet to be provided in a case with sufficient bonding strength while suppressing harmful effect on magnetic characteristics of the magnet.SOLUTION: A linear actuator includes: a movable element 30 which may move in a predetermined first direction; a magnet 40 which is disposed facing the movable element 30 in a second direction orthogonal to the first direction; an elastic member 50 which elastically deforms to apply a force acting in the first direction to the movable element 30 in conjunction with movement of the movable element 30 in the first direction; and a case 20 which houses the movable element 30, the magnet 40, and the elastic member 50 and is made of a magnetic material. The magnet 40 is attached to an inner wall surface 26a of the case 20. The case 20 has hole parts 81, 82, 83, 84, penetrating through the case 20, at positions facing the magnet 40. Bonding adhesives 91, 92, 93, 94 are provided in the hole parts 81, 82, 83, 84.SELECTED DRAWING: Figure 5

Description

The present invention relates to a linear actuator.

A linear actuator with a mover that can move in a predetermined direction is known. For example, Patent Document 1 describes, as such a linear actuator, a linear vibration motor including a magnet and a coil housed inside a case.

Japanese Unexamined Patent Publication No. 2020-22349

In the linear actuator as described above, for example, a configuration in which a magnet is provided on the case with an adhesive can be considered. However, in this case, if a thermosetting adhesive is used, it is considered that the magnetic force characteristics of the magnet are adversely affected by heating. When a photocurable adhesive is used, it is considered that the adhesive is cured only at the outer peripheral portion of the magnet at the interface between the magnet and the case, and sufficient adhesive strength cannot be obtained.

The present invention has been made in consideration of the above points, and provides a linear actuator having a structure capable of providing a magnet to a case with sufficient adhesive strength while suppressing an adverse effect on the magnetic force characteristics of the magnet. Is one of the purposes.

One aspect of the linear actuator of the present invention is a movable element that can move in a predetermined first direction, a magnet that is arranged so as to face the movable element in a second direction orthogonal to the first direction, and the movable element. A case of a magnetic material that internally accommodates an elastic member that is elastically deformed with the movement of the child in the first direction and applies a force in the first direction to the mover, and the mover, the magnet, and the elastic member. The magnet is attached to the inner wall surface of the case, and the case has a hole portion penetrating the case at a position facing the magnet, and an adhesive is provided in the hole portion. There is.

According to one aspect of the present invention, in a linear actuator, a magnet can be provided on a case with sufficient adhesive strength while suppressing an adverse effect on the magnetic properties of the magnet.

FIG. 1 is a perspective view showing a linear actuator of one embodiment. FIG. 2 is a cross-sectional perspective view showing a linear actuator of one embodiment. FIG. 3 is a cross-sectional view showing a linear actuator of one embodiment. FIG. 4 is a cross-sectional perspective view showing a linear actuator of one embodiment, and is a diagram showing an IV-IV cross section in FIG. FIG. 5 is a cross-sectional view showing a linear actuator of one embodiment, and is a cross-sectional view taken along the line VV in FIG. FIG. 6 is a perspective view showing the magnetic field strength of the linear actuator of one embodiment. FIG. 7 is a diagram showing the thrust coefficient of the linear actuator when there is no hole in the case and when there is no hole. FIG. 8 is a cross-sectional view showing a modified example of the groove portion.

Hereinafter, a linear actuator according to an embodiment of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. Further, in the following drawings, in order to make each configuration easy to understand, the scale and number of each structure may be different from the actual structure.

Each figure shows an X-axis, a Y-axis orthogonal to the X-axis, and a Z-axis orthogonal to the X-axis and the Y-axis. In the following description, the direction parallel to the Z axis is referred to as "vertical direction Z", the direction parallel to the Y axis is referred to as "front-back direction Y", and the direction parallel to the X-axis is referred to as "horizontal direction X". .. The vertical direction Z, the front-back direction Y, and the left-right direction X are directions orthogonal to each other.

Of the vertical Z, the positive side (+ Z side) where the Z-axis arrow points is called the "upper side", and the negative side (-Z side) opposite to the side where the Z-axis arrow points is the "lower side". Called. Of the front-back direction Y, the positive side (+ Y side) where the Y-axis arrow points is called the "front side", and the negative side (-Y side) opposite to the side where the Y-axis arrow points is the "rear side". Called. Of the left-right directions X, the positive side (+ X side) where the X-axis arrow points is called the "right side", and the negative side (-X side) opposite to the side where the X-axis arrow points is called the "left side". Call.

In the following embodiments, the left-right direction X corresponds to the "first direction", the vertical direction Z corresponds to the "second direction", and the front-back direction Y corresponds to the "third direction". The vertical direction Z, the front-rear direction Y, and the left-right direction X, the upper side, the lower side, the front side, the rear side, the right side, and the left side are simply names for explaining the arrangement relationship of each part, and the actual arrangement. The relationship or the like may be an arrangement relationship or the like other than the arrangement relationship or the like indicated by these names. Further, in the present specification, the "parallel direction" includes a direction substantially parallel, and the "orthogonal direction" also includes a direction substantially orthogonal.

The linear actuator 10 of the present embodiment shown in FIG. 1 is a linear resonance actuator (Linear Resonant Actuator: LRA). The linear actuator 10 is mounted on an electronic device such as a smartphone, for example. As shown in FIG. 1, the linear actuator 10 includes a case 20 and a wiring member 60. As shown in FIGS. 2 and 3, the linear actuator 10 includes a mover 30, an elastic member 50, and a damper member 70. As shown in FIGS. 4 and 5, the linear actuator 10 includes a magnet 40.

As shown in FIG. 1, the case 20 has a substantially rectangular parallelepiped shape that is flat in the vertical direction Z and long in the horizontal direction X. As shown in FIGS. 2 to 4, the case 20 houses the mover 30, the magnet 40, the elastic member 50, a part of the wiring member 60, and the damper member 70 inside. In this embodiment, the material of the case 20 is a magnetic material. As shown in FIG. 4, the case 20 is configured such that the first case member 21 and the second case member 22 are fixed to each other in the vertical direction Z.

The first case member 21 is located below the second case member 22. The first case member 21 has a bottom wall portion 21a and a pair of side wall portions 21b and 21c. The bottom wall portion 21a has a rectangular plate shape in which the plate surface faces the vertical direction Z and is long in the horizontal direction X. The inner wall surface of the bottom wall portion 21a, that is, the upper surface, is a facing surface 26a facing the mover 30 in the vertical direction Z. The side wall portion 21b projects upward from the front side (+ Y side) edge portion of the bottom wall portion 21a. The side wall portion 21c projects upward from the rear (−Y side) edge portion of the bottom wall portion 21a. The side wall portions 21b and 21c have a plate shape in which the plate surface faces Y in the front-rear direction. The side wall portions 21b and 21c extend in the left-right direction X.

The side wall portion 21b has a guide portion 24a and a wall main body portion 21d. The guide portion 24a projects upward and diagonally forward from the front (+ Y side) edge of the bottom wall portion 21a. The guide portion 24a extends in the left-right direction X. The guide portion 24a has a guide surface 24c.
The guide surface 24c is a surface of the guide portion 24a that faces the inside of the case 20. The guide surface 24c extends in the left-right direction X. In the present embodiment, the guide surface 24c faces the rear side and the diagonally upper side. The wall main body portion 21d projects directly upward from the upper end portion of the guide portion 24a. The inner wall surface of the wall main body portion 21d, that is, the surface on the rear side (−Y side) is the facing surface 26b facing the mover 30 in the front-rear direction Y.

The side wall portion 21c is provided symmetrically with the side wall portion 21b in the front-rear direction Y. The side wall portion 21c has a guide portion 24b and a wall main body portion 21e. The guide portion 24b projects upward and diagonally to the rear side from the edge portion on the rear side (−Y side) of the bottom wall portion 21a. That is, the guide portion 24a and the guide portion 24b project from the bottom wall portion 21a in a direction away from each other in the front-rear direction Y toward the upper side. The guide portion 24b extends in the left-right direction X. The guide portion 24b has a guide surface 24d. The guide surface 24d is a surface of the guide portion 24b that faces the inside of the case 20. The guide surface 24d extends in the left-right direction X. In the present embodiment, the guide surface 24d faces the front side and the diagonally upper side. The wall main body portion 21e projects directly upward from the upper end portion of the guide portion 24b. The inner wall surface of the wall body portion 21e, that is, the front side (+ Y side) surface is the facing surface 26c facing the mover 30 in the front-rear direction Y.

The second case member 22 is located above the first case member 21. As shown in FIG. 1, the second case member 22 has a top wall portion 22a, a pair of side wall portions 22b, 22c, and a pair of guide portions 23a, 23b. The top wall portion 22a has a rectangular plate shape in which the plate surface faces the vertical direction Z and is long in the horizontal direction X. The top wall portion 22a and the bottom wall portion 21a are almost entirely overlapped with each other when viewed in the vertical direction Z. Both edges of the top wall portion 22a in the front-rear direction Y are in contact with the upper ends of the pair of side wall portions 21b and 21c. As shown in FIG. 4, the inner wall surface of the top wall portion 22a, that is, the lower surface is a facing surface 26d facing the mover 30 in the vertical direction Z.

As shown in FIG. 1, the side wall portion 22b projects downward from the right (+ X side) edge portion of the top wall portion 22a. The side wall portion 22c projects downward from the left (−X side) edge portion of the top wall portion 22a. The side wall portions 22b and 22c have a plate shape in which the plate surface faces the left-right direction X. The side wall portions 22b and 22c extend in the front-rear direction Y. The side wall portion 22b is in contact with the right end portion of the bottom wall portion 21a and the right end portion of the pair of side wall portions 21b, 21c. The side wall portion 22c is in contact with the left end portion of the bottom wall portion 21a and the left end portion of the pair of side wall portions 21b, 21c.

The pair of guide portions 23a and 23b are provided on both edges of the top wall portion 22a in the front-rear direction Y, respectively. The guide portion 23a is provided at the center portion in the left-right direction X at the front side (+ Y side) edge portion of the top wall portion 22a. The guide portion 23b is provided at the central portion in the left-right direction X at the edge portion on the rear side (−Y side) of the top wall portion 22a. The guide portions 23a and 23b extend in the left-right direction X.

As shown in FIG. 4, the guide portion 23a projects downward and diagonally forward from the front side (+ Y side) edge portion of the top wall portion 22a. The guide portion 23a is arranged to face the rear side (−Y side) of the wall main body portion 21d in the side wall portion 21b. The guide portion 23a is located above the guide portion 24a. The guide portion 23a and the guide portion 24a sandwich the front edge portion of the base portion 31a, which will be described later, in the vertical direction Z. The guide portion 23a and the guide portion 24a approach each other in the vertical direction Z toward the front side.

The guide portion 23a has a guide surface 23c. The guide surface 23c is a surface of the guide portion 23a that faces the inside of the case 20. The guide surface 23c extends in the left-right direction X. In the present embodiment, the guide surface 23c faces the rear side and diagonally downward side. The guide surface 23c sandwiches the front side (+ Y side) edge portion of the base portion 31a, which will be described later, in the vertical direction Z between the guide surface 23c and the vertical direction Z.

The guide portion 23b projects downward and diagonally to the rear side from the edge portion on the rear side (−Y side) of the top wall portion 22a. The guide portion 23b is arranged to face the front side (+ Y side) of the wall main body portion 21e in the side wall portion 21c. The guide portion 23b is located above the guide portion 24b. The guide portion 23b and the guide portion 24b sandwich the rear edge portion of the base portion 31a, which will be described later, in the vertical direction Z. The guide portion 23b and the guide portion 24b approach each other in the vertical direction Z toward the rear side.

The guide portion 23b has a guide surface 23d. The guide surface 23d is a surface of the guide portion 23b that faces the inside of the case 20. The guide surface 23d extends in the left-right direction X. In the present embodiment, the guide surface 23d faces the front side and the diagonally lower side. The guide surface 23d sandwiches the edge portion on the rear side (−Y side) of the base portion 31a, which will be described later, in the vertical direction Z between the guide surface 23d and the guide surface 24d in the vertical direction Z.

The guide surfaces 23c and 24c are arranged on the side (−Y side) closer to the mover 30 than the facing surface 26b in the front-rear direction Y. The guide surfaces 23d and 24d are arranged on the side (+ Y side) closer to the mover 30 than the facing surface 26c in the front-rear direction Y. The guide surfaces 23c and 23d are arranged on the side (−Z side) closer to the mover 30 than the facing surface 26d in the vertical direction Z. The guide surfaces 24c and 24d are arranged on the side (+ Z side) closer to the mover 30 than the facing surface 26a in the vertical direction Z.

As shown in FIG. 3, the case 20 has convex portions 25a, 25b, 25c, 25d. The convex portions 25a and 25b project to the left from the inner wall surface of the side wall portion 22b, that is, the left side (−X side) surface. The convex portion 25a and the convex portion 25b are provided at both ends of the side wall portion 22b in the front-rear direction Y. The convex portions 25c and 25d project to the right from the inner wall surface of the side wall portion 22c, that is, the surface on the right side (+ X side). The convex portion 25c and the convex portion 25d are provided at both ends of the side wall portion 22c in the front-rear direction Y. Each of the convex portions 25a, 25b, 25c, 25d is made, for example, by caulking a part of each of the provided side wall portions 22b, 22c in the left-right direction X.

In the present embodiment, the mover 30 extends in the left-right direction X. The mover 30 can move in the left-right direction X in the case 20. The mover 30 has a mover main body 31 and a coil 32. In the present embodiment, the mover 30 vibrates in the left-right direction X due to the electromagnetic force generated between the coil 32 and the magnet 40 when electric power is supplied to the coil 32 and the elastic force applied from the elastic member 50. .. The movable element main body 31 extends in the left-right direction X. The mover main body 31 has a base portion 31a and protrusions 31b and 31c. The base portion 31a is a portion where the coil 32 is held. As shown in FIG. 2, the base portion 31a is flat in the vertical direction Z and has a substantially rectangular parallelepiped shape extending in the horizontal direction X.

The base portion 31a has a recess 31d that is recessed downward from the upper surface of the base portion 31a. The inner edge of the recess 31d is rectangular when viewed from above. As shown in FIG. 4, the base portion 31a has a recess 31g recessed upward from the lower surface of the base portion 31a. The inner edge of the recess 31g is rectangular when viewed from below. The recess 31d and the recess 31g are provided at positions where they overlap each other when viewed in the vertical direction Z. The base portion 31a has a through hole 31e that penetrates the base portion 31a in the vertical direction Z. The through hole 31e penetrates from the bottom surface of the recess 31d to the bottom surface of the recess 31g. As shown in FIG. 2, the through hole 31e is a substantially circular hole. A coil 32 is fitted and held inside the through hole 31e. As a result, the coil 32 is attached to the mover main body 31.

As shown in FIG. 4, the base portion 31a is located inside surrounded by the bottom wall portion 21a, the top wall portion 22a, the guide portion 23a, the guide portion 23b, the guide portion 24a, and the guide portion 24b. The base portion 31a is movably supported in the left-right direction X by the guide portions 23a, 23b, 24a, 24b. As a result, the guide portions 23a, 23b, 24a, 24b guide the movement of the mover 30 in the left-right direction X. The base 31a has surfaces 34a, 34b, 34c, 34d to be guided. That is, the movable element main body 31 has the guided surfaces 34a, 34b, 34c, 34d.

The guided surface 34a is provided at the upper end portion of the front side (+ Y side) edge portion of the base portion 31a. The guided surface 34a faces the front side and the diagonally upper side, and extends in the left-right direction X. The guided surface 34a is formed, for example, by chamfering the front and upper corners of the base 31a. The guided surface 34a is arranged so as to face the guide surface 23c. The guided surface 34a can come into contact with the guide surface 23c.

The guided surface 34b is provided at the lower end of the front (+ Y side) edge of the base 31a. The guided surface 34b faces forward and diagonally downward, and extends in the left-right direction X. The guided surface 34b is formed, for example, by chamfering the front and lower corners of the base 31a. The guided surface 34b is arranged so as to face the guide surface 24c. The guided surface 34b can come into contact with the guide surface 24c.

The guided surface 34c is provided at the upper end of the rear (−Y side) edge of the base 31a. The guided surface 34c faces the rear side and the diagonally upper side, and extends in the left-right direction X. The guided surface 34c is formed by chamfering the rear and upper corners of the base 31a. The guided surface 34c is arranged so as to face the guide surface 23d. The guided surface 34c can come into contact with the guide surface 23d.

The guided surface 34d is provided at the lower end of the rear (−Y side) edge of the base 31a. The guided surface 34d faces rearward and diagonally downward, and extends in the left-right direction X. The guided surface 34d is formed, for example, by chamfering the rear and lower corners of the base 31a. The guided surface 34d is arranged so as to face the guide surface 24d. The guided surface 34d can come into contact with the guide surface 24d.

The guided surface 34a and the guided surface 34b are arranged at intervals in the vertical direction Z. The guided surface 34a and the guided surface 34b approach each other in the vertical direction Z toward the front side (+ Y side). The guided surface 34a and the guided surface 34b are sandwiched in the vertical direction Z by the guide surface 23c and the guide surface 24c. In a state where the guided surface 34a and the guide surface 23c are in contact with each other and the guided surface 34b and the guide surface 24c are in contact with each other, the front end surface of the base portion 31a has a gap with the facing surface 26b facing the front side of the base portion 31a. It becomes a state facing Y in the front-rear direction via. That is, in the present embodiment, the mover 30 is in contact with the guide surfaces 23c and 24c and is in a state of facing the facing surface 26b in the front-rear direction Y via a gap. As a result, in the present embodiment, the mover 30 does not come into contact with the facing surface 26b.

The relationship between the guided surface 34c and the guided surface 34d is the same as the relationship between the guided surface 34a and the guided surface 34b described above, except that the surface is symmetrical in the front-rear direction Y. The mover 30 faces the facing surface 26c facing the rear side (−Y side) of the base 31a via a gap in the front-rear direction Y in a state where the guided surfaces 34c and 34d are in contact with the guide surfaces 23d and 24d. It becomes a state. As a result, in the present embodiment, the mover 30 does not come into contact with the facing surface 26c.

In a state where the guided surface 34a and the guide surface 23c are in contact with each other and the guided surface 34c and the guide surface 23d are in contact with each other, the upper end surface of the base portion 31a has a gap with the facing surface 26d facing the upper side of the base portion 31a. It becomes a state facing each other in the vertical direction Z via the above. That is, in the present embodiment, the mover 30 is in contact with the guide surfaces 23c and 23d, and is in a state of facing the facing surface 26d in the vertical direction Z via a gap. As a result, in the present embodiment, the mover 30 does not come into contact with the facing surface 26d. Further, the mover 30 is in a state where the guided surfaces 34b and 34d are in contact with the guide surfaces 24c and 24d and are opposed to the facing surface 26a facing the lower side of the base portion 31a via a gap in the vertical direction Z. .. As a result, in the present embodiment, the mover 30 does not come into contact with the facing surface 26a.

As shown in FIG. 2, the protruding portion 31b protrudes to the right side (+ X side) from the base portion 31a. The protruding portion 31c protrudes to the left side (-X side) from the base portion 31a. The protrusions 31b and 31c are, for example, substantially rectangular parallelepiped. The dimension of the protrusions 31b and 31c in the front-rear direction Y is smaller than the dimension of the base 31a in the front-rear direction Y. In the present embodiment, the protruding portions 31b and 31c are provided at the central portion of the base portion 31a in the front-rear direction Y. Both ends of the protrusions 31b and 31c in the front-rear direction Y are located apart from both ends of the base 31a in the front-rear direction Y.

As shown in FIG. 3, the dimension of the front side portion 31h of the protrusion 31b in the left-right direction X is smaller than the dimension of the rear portion 31i of the protrusion 31b in the left-right direction X. The right end (+ X side) of the front side portion 31h is located on the left side (−X side) of the right end portion of the rear side portion 31i. The dimension of the front side portion 31h in the left-right direction X is smaller than, for example, the dimension of the protrusion 31c in the left-right direction X. The dimension of the rear side portion 31i in the left-right direction X is, for example, the same as the dimension of the protrusion 31c in the left-right direction X. In the present embodiment, the rear side portion 31i is a portion of the movable element main body 31 that overlaps with the third extending portion 66, which will be described later, when viewed in the vertical direction Z.

The mover main body 31 has convex portions 33a, 33b, 33c, 33d. The convex portions 33a and 33b project to the right (+ X) from each of both end portions in the front-rear direction Y at the right end portion of the base portion 31a. The convex portion 33a and the convex portion 33b sandwich the protruding portion 31b in the front-rear direction Y. The convex portions 33c and 33d project to the left (-X) from each of both end portions in the front-rear direction Y at the left end portion of the base portion 31a. The convex portion 33c and the convex portion 33d sandwich the protruding portion 31c in the front-rear direction Y. The protrusions 33a, 33b, 33c, 33d are, for example, rectangular parallelepiped. The protrusion height of the protrusions 33a, 33b, 33c, 33d is smaller than the protrusion height of the protrusions 31b, 31c.

As shown in FIG. 2, the movable element main body 31 has a groove portion 31f. In the present embodiment, the groove portion 31f is provided so as to straddle the base portion 31a and the front side portion 31h of the protruding portion 31b. The groove portion 31f is recessed downward from the upper surface of the movable element main body 31 and extends in the left-right direction X. The left end (−X side) end of the groove 31f is open in the recess 31d. The right end (+ X side) end of the groove 31f is open to the right end surface of the front side portion 31h. The groove portion 31f is provided closer to the front side (+ Y side) than the center of the movable element main body 31 in the front-rear direction Y.

The coil 32 is configured by winding a conducting wire around the central axis J extending in the vertical direction Z. The central axis J is a virtual axis as shown in the figure as appropriate. For example, in a state where the mover 30 is stationary, the central axis J passes through the center of the case 20 in the left-right direction X and the center in the front-back direction Y. The coil 32 is a substantially annular shape centered on the central axis J when viewed in the vertical direction Z. The coil 32 is fitted into the through hole 31e and fixed to the mover main body 31. As shown in FIG. 4, the upper end of the coil 32 projects upward from, for example, the through hole 31e. The lower end of the coil 32 is, for example, located at the same position in the vertical direction Z as the lower end of the through hole 31e. Electric power is supplied to the coil 32 from the outside of the linear actuator 10 via the wiring member 60.

As shown in FIG. 5, the magnet 40 is arranged inside the case 20 in the vertical direction Z orthogonal to the horizontal direction X so as to face the coil 32. A gap is provided between the magnet 40 and the coil 32 in the vertical direction Z. The magnet 40 has, for example, a rectangular plate shape in which the plate surface faces the vertical direction Z and is long in the front-rear direction Y. The magnet 40 includes a first magnet 41, a second magnet 42, a third magnet 43, and a fourth magnet 44.

The first magnet 41 and the second magnet 42 are located above the coil 32. The first magnet 41 and the second magnet 42 are arranged side by side in the left-right direction X. The second magnet 42 is located on the left side (−X side) of the first magnet 41. The first magnet 41 and the second magnet 42 are in contact with each other in the left-right direction X. For example, in a state where the mover 30 is stationary, the central axis J passes between the first magnet 41 and the second magnet 42 in the left-right direction X.

The third magnet 43 and the fourth magnet 44 are located below the coil 32. The third magnet 43 and the fourth magnet 44 are arranged side by side in the left-right direction X. The fourth magnet 44 is located on the left side (−X side) of the third magnet 43. The third magnet 43 and the fourth magnet 44 are in contact with each other in the left-right direction X. For example, in a state where the mover 30 is stationary, the central axis J passes between the third magnet 43 and the fourth magnet 44 in the left-right direction X.

The first magnet 41 and the third magnet 43 are arranged so as to sandwich the coil 32 in the vertical direction Z. The first magnet 41 and the third magnet 43 are arranged so as to overlap each other when viewed in the vertical direction Z. The second magnet 42 and the fourth magnet 44 are arranged so as to sandwich the coil 32 in the vertical direction Z. The second magnet 42 and the fourth magnet 44 are arranged so as to overlap each other when viewed in the vertical direction Z.

Each magnet 40 has a magnetic pole along the vertical direction Z. The first magnet 41 has a magnetic pole 41N, which is an N pole, on the upper side. The first magnet 41 has a magnetic pole 41S, which is an S pole, on the lower side. The second magnet 42 has a magnetic pole 42S which is an S pole on the upper side. The second magnet 42 has a magnetic pole 42N which is an N pole on the lower side. The third magnet 43 has a magnetic pole 43N which is an N pole on the upper side. The third magnet 43 has a magnetic pole 43S which is an S pole on the lower side. The fourth magnet 44 has a magnetic pole 44S which is an S pole on the upper side. The fourth magnet 44 has a magnetic pole 44N which is an N pole on the lower side.

The first magnet 41 and the second magnet 42 arranged adjacent to each other in the left-right direction X have their N poles and S poles reversed in the vertical direction Z. The third magnet 43 and the fourth magnet 44 arranged adjacent to each other in the left-right direction X have their N poles and S poles reversed in the vertical direction Z. The first magnet 41 and the third magnet 43 arranged so as to sandwich the coil 32 in the vertical direction Z have the same arrangement of the N pole and the S pole along the vertical direction Z. The second magnet 42 and the fourth magnet 44 arranged so as to sandwich the coil 32 in the vertical direction Z have the same arrangement of the N pole and the S pole along the vertical direction Z. The first magnet 41, the second magnet 42, the third magnet 43, and the fourth magnet 44 have the same dimensions in the vertical direction Z, dimensions in the front-rear direction Y, and dimensions in the left-right direction X.

The first magnet 41 and the second magnet 42 are attached to the inner wall surface of the top wall portion 22a, that is, the facing surface 26d. The first magnet 41 and the second magnet 42 are fixed to the facing surface 26d. The third magnet 43 and the fourth magnet 44 are attached to the inner wall surface of the bottom wall portion 21a, that is, the facing surface 26a. The third magnet 43 and the fourth magnet 44 are fixed to the facing surface 26a of the bottom wall portion 21a.

The case 20 has a hole portion and a groove portion at a position facing the magnet 40. More specifically, the second case member 22 has a hole portion 81 and a groove portion 85 at positions facing the first magnet 41. As shown in FIGS. 1, 4 and 5, the hole portion 81 penetrates the top wall portion 22a of the second case member 22 in the vertical direction Z. The hole 81 overlaps with the center of the magnetic pole of the first magnet 41 in the vertical direction Z. An adhesive 91 is provided in the hole 81. The groove portion 85 is recessed upward from the facing surface 26d of the top wall portion 22a and communicates with the hole portion 81. The maximum dimension of the groove 85 is larger than the maximum dimension of the hole 81. The groove portion 85 is provided with an adhesive 91. When viewed in the axial direction, the hole portion 81 and the groove portion 85 are coaxial circular shapes. The hole 81 and the groove 85 do not have to be arranged coaxially and circular if they overlap with the center of the magnetic pole of the first magnet 41 in the vertical direction Z, but are arranged eccentrically and have an ellipse or a polygon. There may be. At least one of the hole portion 81 and the groove portion 85 may be arranged in a plurality of regions including the magnetic pole center of the first magnet 41.

The second case member 22 has a hole portion 82 and a groove portion 86 at positions facing the second magnet 42. The hole portion 82 penetrates the top wall portion 22a of the second case member 22 in the vertical direction Z. The hole 82 overlaps the center of the magnetic pole of the second magnet 42 in the vertical direction Z. An adhesive 92 is provided in the hole 82. The groove portion 86 is recessed upward from the facing surface 26d of the top wall portion 22a and communicates with the hole portion 82. The maximum dimension of the groove 86 is larger than the maximum dimension of the hole 82. The groove portion 86 is provided with an adhesive 91. When viewed in the axial direction, the hole portion 82 and the groove portion 86 are coaxial circular shapes. The hole 82 and the groove 86 do not have to be arranged coaxially and circular if they overlap with the center of the magnetic pole of the second magnet 42 in the vertical direction Z, but are arranged eccentrically and have an ellipse or a polygon. There may be. At least one of the hole portion 82 and the groove portion 86 may be arranged in a plurality of regions including the magnetic pole center of the second magnet 42.

The hole portion 81 and the groove portion 85, and the hole portion 82 and the groove portion 86 are arranged line-symmetrically with respect to the central axis J in the left-right direction X. Hereinafter, the description of the hole portion 82 and the groove portion 86 may be omitted for the same configuration as the hole portion 81 and the groove portion 85 except that the hole portion 81 and the groove portion 85 are line-symmetrical with respect to the central axis J.

FIG. 6 shows the magnetic field strength in the case 20 in a state where no current is passed through the coil 32. As shown in FIG. 6, in the top wall portion 22a of the case 20, the magnetic field strength of the first magnet 41 is small at the position of the magnetic pole center of the first magnet 41, and the magnetic field strength of the second magnet 42 is the second magnet 42. It is small at the position of the center of the magnetic pole. The hole 81 overlaps the magnetic pole center of the first magnet 41 in the vertical direction Z, and the hole 82 overlaps the magnetic pole center of the second magnet 42 in the vertical direction Z. Even when the above is provided, it is possible to suppress a decrease in the magnetic field strength of the first magnet 41 and the second magnet 42.

As shown in FIG. 7, the thrust coefficient in the linear actuator 10 when the case 20 has no hole and when the case 20 has a hole is suppressed to the same level (for example, the decrease in the thrust coefficient is 1% or less).

The adhesives 91 and 92 are photocurable adhesives that are cured by irradiation with energy light. When a thermosetting adhesive is used as the adhesives 91 and 92, the heat for curing the adhesive may adversely affect the magnetic properties of the first magnet 41 and the second magnet 42. By using a photocurable adhesive as the adhesives 91 and 92, it is possible to suppress adverse effects on the magnetic properties of the first magnet 41 and the second magnet 42.

In the present embodiment, the adhesives 91 and 92 are, as an example, ultraviolet curable adhesives that are cured by irradiation with ultraviolet rays. The adhesive 91 is injected into the hole 81 and the groove 85 with the first magnet 41 attached to the facing surface 26d of the top wall portion 22a. Since the hole portion 81 is open on the upper side of the top wall portion 22a, the adhesive 91 can be easily injected into the hole portion 81 and the groove portion 85 from the upper side. The adhesive 91 injected into the hole 81 and the groove 85 comes into contact with the first magnet 41 facing the hole 81 and the groove 85.

The adhesive 91 provided in the hole 81 and the groove 85 is cured by irradiating the adhesive 91 from above the hole 81 with ultraviolet rays. The first magnet 41 can be fixed to the top wall portion 22a by curing the adhesive 91 of the hole portion 81 and the groove portion 85. By providing the groove portion 85 having the maximum dimension larger than the maximum dimension of the hole portion 81, the first magnet 41 can be effectively fixed to the top wall portion 22a in a large area. In order to effectively cure the adhesive 91 of the groove portion 85, the irradiation of ultraviolet rays may be performed at a large orientation angle or an incident angle at which the optical axis of the ultraviolet rays is inclined with respect to the central axis J.

The maximum dimension (diameter) of the hole 81 is 0.6 mm or more. When the maximum dimension of the hole portion 81 is 0.6 mm or more, the workability when forming the hole portion 81 in the top wall portion 22a can be ensured. As shown in FIG. 1, the maximum dimension of the hole portion 81 in the left-right direction X is 30% or less of the maximum dimension L1 of the first magnet 41 in the left-right direction X. The maximum dimension of the hole 81 in the front-rear direction Y is 30% or less of the maximum dimension L2 of the first magnet 41 in the front-rear direction Y.

When the maximum dimension of the hole 81 in the left-right direction X exceeds 30% of the maximum dimension L1 of the first magnet 41 in the left-right direction X, or the maximum dimension of the hole 81 in the front-rear direction Y is the first in the front-rear direction Y. If it exceeds 30% of the maximum dimension L2 of the magnet 41, the magnetic field strength of the first magnet 41 may decrease. The maximum dimension of the hole 81 in the left-right direction X is 30% or less of the maximum dimension L1 of the first magnet 41 in the left-right direction X, and the maximum dimension of the hole 81 in the front-rear direction Y is the maximum of the first magnet 41 in the front-rear direction Y. By setting the dimension to 30% or less of L2, it is possible to suppress a decrease in the magnetic field strength of the first magnet 41.

The first case member 21 has a hole portion 83 and a groove portion 87 at positions facing the third magnet 43. The hole portion 83 penetrates the bottom wall portion 21a of the first case member 21 in the vertical direction Z. The hole 83 overlaps with the center of the magnetic pole of the third magnet 43 in the vertical direction Z. An adhesive 93 is provided in the hole 83. The groove portion 87 is recessed downward from the facing surface 26a of the bottom wall portion 21a and communicates with the hole portion 83. The maximum dimension of the groove 87 is larger than the maximum dimension of the hole 83. The groove portion 87 is provided with an adhesive 93. When viewed in the axial direction, the hole portion 83 and the groove portion 87 are coaxial circular shapes. The hole 83 and the groove 87 do not have to be arranged coaxially or circularly if they overlap with the center of the magnetic pole of the third magnet 43 in the vertical direction Z, but are arranged eccentrically and have an ellipse or a polygon. There may be. At least one of the hole portion 83 and the groove portion 87 may be arranged in a plurality of regions including the magnetic pole center of the third magnet 43.

The first case member 21 has a hole portion 84 and a groove portion 88 at positions facing the fourth magnet 44. The hole portion 84 penetrates the bottom wall portion 21a of the first case member 21 in the vertical direction Z. The hole portion 84 overlaps with the center of the magnetic pole of the fourth magnet 44 in the vertical direction Z. An adhesive 94 is provided in the hole 84. The groove portion 88 is recessed downward from the facing surface 26a of the bottom wall portion 21a and communicates with the hole portion 84. The maximum dimension of the groove 85 is larger than the maximum dimension of the hole 84. The groove portion 88 is provided with an adhesive 94. When viewed in the axial direction, the hole portion 84 and the groove portion 88 are coaxial circular shapes. The hole 84 and the groove 88 do not have to be arranged coaxially and circular if they overlap with the center of the magnetic pole of the fourth magnet 44 in the vertical direction Z, but are arranged eccentrically and have an ellipse or a polygon. There may be. At least one of the hole portion 84 and the groove portion 88 may be arranged in a plurality of regions including the magnetic pole center of the fourth magnet 44.

The hole 83 and the groove 88 and the hole 84 and the groove 88 are arranged line-symmetrically with respect to the central axis J in the left-right direction X. Hereinafter, the description of the hole portion 84 and the groove portion 88 may be omitted for the same configuration as the hole portion 83 and the groove portion 87 except that the hole portion 83 and the groove portion 87 are line-symmetrical with respect to the central axis J.

Although not shown, in the bottom wall portion 21a of the case 20, the magnetic field strength of the third magnet 43 is small at the position of the magnetic pole center of the third magnet 43, and the magnetic field strength of the fourth magnet 44 is the magnetic field strength of the fourth magnet 44. It is small at the position of the center of the magnetic pole. The hole 83 overlaps the magnetic pole center of the third magnet 43 in the vertical direction Z, and the hole 84 overlaps the magnetic pole center of the fourth magnet 44 in the vertical direction Z, so that the hole 83 and the hole 84 are formed in the bottom wall portion 21a. Even when the above is provided, it is possible to suppress a decrease in the magnetic field strength of the third magnet 43 and the fourth magnet 44.

The adhesives 93 and 94 are photocurable adhesives like the adhesives 91 and 92. By using the adhesives 93 and 94 as the photocurable adhesive, it is possible to prevent heat from adversely affecting the magnetic properties of the third magnet 43 and the fourth magnet 44, as in the case of using a thermosetting adhesive. can.

The adhesive 93 is injected into the hole 83 and the groove 87 with the third magnet 43 attached to the facing surface 26a of the bottom wall 21a. Since the hole 83 is open to the lower side of the bottom wall portion 21a, the adhesive 93 can be easily injected into the hole 83 and the groove 87 from the lower side. The adhesive 93 injected into the hole 83 and the groove 87 comes into contact with the third magnet 43 facing the hole 83 and the groove 87.

The adhesive 93 provided in the hole 83 and the groove 87 is cured by irradiating the adhesive 93 with ultraviolet rays from the lower side of the hole 83. The third magnet 43 can be fixed to the bottom wall portion 21a by curing the adhesive 93 of the hole portion 83 and the groove portion 87. By providing the groove portion 87 having the maximum dimension larger than the maximum dimension of the hole portion 83, the third magnet 43 can be effectively fixed to the bottom wall portion 21a in a large area. In order to effectively cure the adhesive 93 of the groove portion 87, the irradiation of ultraviolet rays may be performed at a large orientation angle or an incident angle at which the optical axis of the ultraviolet rays is inclined with respect to the central axis J.

Similar to the hole portion 81, the maximum dimension (diameter) of the hole portion 83 is 0.6 mm or more. When the maximum dimension of the hole portion 83 is 0.6 mm or more, the workability when forming the hole portion 83 in the bottom wall portion 21a can be ensured. Although not shown, the maximum dimension of the hole 83 in the left-right direction X is 30% or less of the maximum dimension of the third magnet 43 in the left-right direction X. The maximum dimension of the hole 83 in the front-rear direction Y is 30% or less of the maximum dimension of the third magnet 43 in the front-rear direction Y.

The maximum dimension of the hole 83 in the left-right direction X is 30% or less of the maximum dimension of the third magnet 43 in the left-right direction X, and the maximum dimension of the hole 83 in the front-rear direction Y is the maximum dimension of the third magnet 43 in the front-rear direction Y. By setting it to 30% or less of the above, it is possible to suppress a decrease in the magnetic field strength of the third magnet 43.

The elastic member 50 is a member that elastically deforms as the mover 30 moves in the left-right direction X and applies a force in the left-right direction X to the mover 30. As shown in FIG. 3, in the present embodiment, the elastic member 50 is a coil spring extending in the left-right direction X. The elastic member 50 includes a first elastic member 51, a second elastic member 52, a third elastic member 53, and a fourth elastic member 54.

The first elastic member 51 and the second elastic member 52 are located on the right side (+ X side) of the mover 30. In the present embodiment, the first elastic member 51 and the second elastic member 52 are located between the mover 30 and the side wall portion 22b in the left-right direction X. The first elastic member 51 and the second elastic member 52 are arranged so as to sandwich the protruding portion 31b in the front-rear direction Y. The first elastic member 51 is located on the front side (+ Y side) of the protruding portion 31b. The second elastic member 52 is located on the rear side (−Y side) of the protrusion 31b. The right end of the first elastic member 51 and the right end of the second elastic member 52 are in contact with the side wall portion 22b of the case 20. The left end (−X side) end of the first elastic member 51 and the left end portion of the second elastic member 52 are in contact with the base portion 31a of the mover main body 31. Convex portions 25a and 33a are inserted into both ends of the first elastic member 51 in the left-right direction X, respectively. Convex portions 25b and 33b are inserted into both ends of the second elastic member 52 in the left-right direction X, respectively. As a result, the positions of the first elastic member 51 and the second elastic member 52 are suppressed from being displaced in the vertical direction Z and the front-rear direction Y.

In the present embodiment, the first elastic member 51 and the second elastic member 52 are located on the right side (+ X side) of the mover main body 31, and are wiring members in the front-rear direction Y orthogonal to both the left-right direction X and the up-down direction Z. It corresponds to a pair of elastic members 50 arranged with 60 in between.

The third elastic member 53 and the fourth elastic member 54 are located on the left side (-X side) of the mover 30. The third elastic member 53 and the fourth elastic member 54 are located between the movable element 30 and the side wall portion 22c in the left-right direction X. The third elastic member 53 and the fourth elastic member 54 are arranged so as to sandwich the protruding portion 31c in the front-rear direction Y. The third elastic member 53 is located on the front side (+ Y side) of the protruding portion 31c. The fourth elastic member 54 is located on the rear side (−Y side) of the protrusion 31c. The left end of the third elastic member 53 and the left end of the fourth elastic member 54 are in contact with the side wall portion 22c of the case 20. The right end (+ X side) end of the third elastic member 53 and the right end portion of the fourth elastic member 54 are in contact with the base portion 31a of the mover main body 31. Convex portions 25c and 33c are inserted into both ends of the third elastic member 53 in the left-right direction X, respectively. Convex portions 25d and 33d are inserted into both ends of the fourth elastic member 54 in the left-right direction X, respectively. As a result, the position of the third elastic member 53 and the position of the fourth elastic member 54 are suppressed from being displaced in the vertical direction Z and the front-rear direction Y.

The first elastic member 51 and the third elastic member 53 are arranged so as to sandwich a portion of the base portion 31a located on the front side (+ Y side) of the protruding portions 31b and 31c in the left-right direction X. The second elastic member 52 and the fourth elastic member 54 are arranged so as to sandwich a portion of the base portion 31a located on the rear side (−Y side) of the protruding portions 31b and 31c in the left-right direction X.

When the mover 30 moves to the right side (+ X side) from the position shown in each figure, the first elastic member 51 and the second elastic member 52 are compression-elastically deformed in the left-right direction X. As a result, the first elastic member 51 and the second elastic member 52 apply an elastic force to the mover 30 in a direction away from the side wall portion 22b, that is, toward the left side (−X side).

On the other hand, when the mover 30 moves to the left side (-X side) from the position shown in each figure, the third elastic member 53 and the fourth elastic member 54 are compression-elastically deformed in the left-right direction X. As a result, the third elastic member 53 and the fourth elastic member 54 apply an elastic force to the mover 30 in a direction away from the side wall portion 22c, that is, toward the right side (+ X side).

The damper member 70 is fixed to the inner wall surface of the case 20. The damper member 70 faces the movable element main body 31 in the left-right direction X. The damper member 70 is a member that attenuates the kinetic energy of the collided object. The damper member 70 is made of rubber, for example. The damper member 70 has, for example, a square shape when viewed in the left-right direction X. In the present embodiment, the damper member 70 includes a first damper member 71 and a second damper member 72.

The first damper member 71 is fixed to the inner wall surface of the side wall portion 22b, that is, the surface on the left side (-X side) of the side wall portion 22b. In the present embodiment, the first damper member 71 is located on the rear side (−Y side) of the side wall portion 22b from the center in the front-rear direction Y. The first damper member 71 is located on the right side (+ X side) of the rear side portion 31i of the protrusion 31b.

The second damper member 72 is fixed to the inner wall surface of the side wall portion 22c, that is, the surface on the right side (+ X side) of the side wall portion 22c. In the present embodiment, the second damper member 72 is located on the rear side (−Y side) of the side wall portion 22c from the center in the front-rear direction Y. The second damper member 72 is located on the left side (-X side) of the rear side portion of the protrusion 31c. The first damper member 71 and the second damper member 72 are arranged so as to sandwich the movable element main body 31 in the left-right direction X.

The wiring member 60 is electrically connected to the coil 32 on the upper side of the mover main body 31. The wiring member 60 is a flexible member. The wiring member 60 is, for example, a flexible printed substrate. In the present embodiment, the wiring member 60 is strip-shaped. The width direction of the band-shaped wiring member 60 is the front-rear direction Y orthogonal to both the left-right direction X and the up-down direction Z. Hereinafter, in the description of the wiring member 60, the dimension in the front-rear direction Y may be simply referred to as “width”.

As shown in FIG. 2, the wiring member 60 includes a coil connection portion 61, a first extension portion 62, a first connection portion 63, a second extension portion 64, a second connection portion 65, and a third extension portion. 66 and. The wiring member 60 is configured by connecting the coil connecting portion 61, the first stretching portion 62, the first connecting portion 63, the second stretching portion 64, the second connecting portion 65, and the third stretching portion 66 in this order. In the coil connecting portion 61, the first stretching portion 62, the second stretching portion 64, the second connecting portion 65, and the third stretching portion 66, the thickness direction is the vertical direction Z. In the first connecting portion 63, the thickness direction is orthogonal to the front-rear direction Y and intersects the vertical direction Z.

The coil connecting portion 61 is one end of the wiring member 60. The coil connection portion 61 has a rectangular shape with rounded corners long in the front-rear direction Y when viewed from above. The coil connecting portion 61 is fixed to a portion of the bottom surface of the recess 31d located on the right side (+ X side) of the coil 32. The coil leader wires 32a and 32b drawn to the right side from the coil 32 are electrically connected to the coil connection portion 61. As a result, the coil 32 and the wiring member 60 are electrically connected.

The first extending portion 62 is located above the movable element main body 31 and extends in the left-right direction X.
The first extending portion 62 extends from the portion of the coil connecting portion 61 closer to the front side (+ Y side) to the right side (+ X side). The first stretched portion 62 passes through the groove portion 31f and extends to the right side of the front side portion 31h of the protruding portion 31b.

In the present embodiment, the first stretched portion 62 has a wide portion 62a extending to the right side (+ X side) from the coil connecting portion 61 and a narrow portion 62b connected to the right side of the wide portion 62a. The wide portion 62a passes through the groove portion 31f and extends to the right side of the front side portion 31h of the protruding portion 31b.
The width of the wide portion 62a is larger than the width of the narrow portion 62b and the width of the first connecting portion 63. The front (+ Y side) edge of the wide portion 62a protrudes forward from the front edge of the narrow portion 62b. The rear edge (-Y side) of the wide portion 62a is located at the same position as the rear edge of the narrow portion 62b in the front-rear direction Y.

The first connecting portion 63 is connected to the right end (+ X side) of the first extending portion 62, that is, the right end of the narrow portion 62b. In the present embodiment, the first connecting portion 63 is a portion bent downward with respect to the first extending portion 62. The first connection portion 63 is in a state of being elastically deformed. As shown in FIG. 5, the first connecting portion 63 is bent into an arc shape that is convex to the right side when viewed from the rear side (−Y side), for example. In the present embodiment, the first connecting portion 63 is bent in an arc shape from the upper side of the movable element main body 31 to the lower side of the movable element main body 31 through the right side of the front side portion 31h of the protruding portion 31b. The lower end of the first connecting portion 63 is connected to the right end of the second extending portion 64. As a result, the first connecting portion 63 connects the right end portion of the first stretched portion 62 and the right end portion of the second stretched portion 64.

The second stretched portion 64 is a portion that sandwiches the movable element main body 31 with the first stretched portion 62 in the vertical direction Z and extends in the horizontal direction X. The second stretched portion 64 extends from the lower end portion of the first connecting portion 63 to the left side (−X side). The left side portion of the second stretched portion 64 is located below the front side portion 31h of the protruding portion 31b. The second stretched portion 64 is arranged on the facing surface 26a.

As shown in FIG. 3, the second connecting portion 65 connects the left end (−X side) end of the second stretched portion 64 and the left end portion of the third stretched portion 66. The second connection portion 65 has, for example, a substantially rectangular shape that is long in the front-rear direction Y when viewed in the vertical direction Z. The second connecting portion 65 is arranged so as to straddle the lower side of the protruding portion 31b and the lower side of the base portion 31a. The second connecting portion 65 is arranged so as to straddle the lower side of the front side portion 31h and the lower side of the rear side portion 31i. The second connecting portion 65 projects to the rear side (−Y side) of the second extending portion 64. The second connection portion 65 is arranged on the facing surface 26a.

As shown in FIG. 5, the second connecting portion 65 is supported from the left side by the convex portion 27 provided on the inner wall surface of the case 20. As a result, the wiring member 60 is prevented from shifting to the left side in the case 20. The convex portion 27 projects upward from the upper surface of the bottom wall portion 21a, that is, the facing surface 26a. The convex portion 27 is made, for example, by caulking a part of the bottom wall portion 21a upward.

As shown in FIG. 3, the third stretched portion 66 is arranged side by side with the second stretched portion 64 in the front-rear direction Y orthogonal to both the left-right direction X and the vertical direction Z. The third extending portion 66 extends from the rear portion of the second connecting portion 65 to the right side (+ X side). The third stretched portion 66 is pulled out to the right side of the movable element main body 31. The third stretched portion 66 penetrates the side wall portion 22b in the left-right direction X and is pulled out to the outside of the case 20. The third stretched portion 66 extends to the right from the case 20, for example. The portion of the third stretched portion 66 located inside the case 20 is arranged on the facing surface 26a. An external power source (not shown) is connected to the third stretched portion 66. The electric power of the external power source is supplied to the coil 32 via the wiring member 60.

By arranging the first stretched portion 62, the first connecting portion 63, the second stretched portion 64, the second connecting portion 65, and the third stretched portion 66 as described above, the wiring member 60 is the mover main body 31. It extends from the upper side of the movable element body 31 through the right side (+ X side) of the movable element main body 31 to the lower side of the movable element main body 31, and is pulled out from the lower side of the movable element main body 31 to the right side of the movable element main body 31. That is, the wiring member 60 is provided with the right side portion of the movable element main body 31 sandwiched in the vertical direction Z, and is pulled out to the right side of the movable element main body 31. Therefore, the wiring member 60 is less likely to interfere with the movable element main body 31 as compared with the case where the wiring member 60 is wound around the movable element main body 31 and arranged. In addition, it is possible to prevent the wiring member 60 from becoming long. As a result, it is possible to prevent the case 20 accommodating the movable element main body 31 and the wiring member 60 from becoming larger than the case where the wiring member 60 is wound around the movable element main body 31 and arranged. Therefore, the coil 32 can be provided on the mover 30 while suppressing the increase in size of the linear actuator 10.

According to the present embodiment, the case 20 has holes 81, 82, 83, 84 penetrating the case 20 at positions facing the magnet 40, and the adhesives 91, 92 are formed in the holes 81, 82, 83, 84. , 93, 94 are provided. Therefore, even when a photocurable adhesive is used, the magnet 40 can be adhered to the case 20 with at least the opening areas of the holes 81, 82, 83, 84. As a result, the magnet 40 can be fixed to the case 20 with sufficient adhesive strength without adversely affecting the magnetic force characteristics of the magnet 40 as in the case of using a thermosetting adhesive.

According to the present embodiment, the case 20 has groove portions 85, 86, 87, 88 communicating with the recessed holes 81, 82, 83, 84 from the inner wall surface at a position facing the magnet 40. Therefore, the magnet 40 can be adhered to the case 20 in a larger area. As a result, the magnet 40 can be fixed to the case 20 with sufficient adhesive strength.

According to the present embodiment, the holes 81, 82, 83, 84 overlap with the magnetic pole center of the magnet 40 in the vertical direction Z. Therefore, even when the holes 81, 82, 83, and 84 are provided, the decrease in the magnetic field strength in the case 20 can be suppressed. As a result, the magnet 40 can be fixed to the case 20 with sufficient adhesive strength while suppressing a decrease in the magnetic field strength in the case 20.

According to the present embodiment, the maximum dimensions of the holes 81, 82, 83, 84 are 30% or less of the maximum dimensions of the magnet 40 in the left-right direction X, and 30% or less of the maximum dimensions of the magnet 40 in the front-rear direction Y. Is. Therefore, even when the holes 81, 82, 83, and 84 are provided, the decrease in the magnetic field strength in the case 20 can be suppressed. As a result, the magnet 40 can be fixed to the case 20 with sufficient adhesive strength while suppressing a decrease in the magnetic field strength in the case 20.

Further, according to the present embodiment, the material of the case 20 is a magnetic material. Therefore, when electric power is supplied to the coil 32, a magnetic flux also flows in the case 20, so that a magnetic circuit passing through the coil 32 and the magnet 40 is more preferably configured. As a result, the electromagnetic force generated between the coil 32 and the magnet 40 can be improved. Therefore, the mover 30 can be more preferably moved in the left-right direction X.

Here, for example, when the magnet 40 is provided in the mover 30 and the coil 32 is provided in the case 20, the magnet 40 is attracted to the magnetic case 20 by a magnetic force, and the mover 30 is the case 20. May rub against the inner wall surface of the magnet. In this case, it becomes difficult for the mover 30 to move in the left-right direction X.

On the other hand, according to the present embodiment, the coil 32 is provided on the mover 30, and the magnet 40 is fixed to the case 20 made of a magnetic material. Therefore, it is possible to prevent the movable element 30 from being sucked into the case 20. As a result, it is possible to prevent the mover 30 from rubbing against the inner wall surface of the case 20. Therefore, it is possible to prevent the mover 30 from becoming difficult to move in the left-right direction X.

Although the preferred embodiments according to the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above examples. The various shapes and combinations of the constituent members shown in the above-mentioned example are examples, and can be variously changed based on design requirements and the like within a range not deviating from the gist of the present invention.

Although the configuration in which one groove portion is provided for one hole portion is exemplified, the configuration in which the groove portion is not provided and only the hole portion is provided or the configuration in which two or more groove portions are provided may be used. For example, as shown in FIG. 8, a groove portion 85A communicating with the lower end of the recessed hole portion 81 from the facing surface 26d at a position facing the first magnet 41 of the top wall portion 22a, and a maximum dimension larger than the maximum dimension of the groove portion 85A. A groove portion 85B having a size and recessing from the facing surface 26d and communicating with the hole portion 81 and the groove portion 85A may be provided. FIG. 8 illustrates a configuration in which two groove portions 85A and groove portions 85B are provided at positions facing the first magnet 41, but two groove portions are provided at positions facing the second magnet 42, the third magnet 43, and the fourth magnet 44. Needless to say, it may be provided, and three or more grooves may be provided.

Further, at least a part of the hole portion and the groove portion may be provided with irregularities by surface treatment such as shot blasting to increase the contact area with the adhesive and increase the adhesive strength. In this case, it is also possible to apply the above surface treatment to the inner peripheral surface of the hole portion without providing the groove portion.

In the above embodiment, the configuration in which the magnets 40 are provided on both sides of the movable element 30 in the vertical direction Z is exemplified, but since the material of the case 20 is a magnetic material, the magnets are provided only on the upper side or the lower side of the movable element 30. It may be configured to provide 40.

10 ... Linear actuator, 20 ... Case, 26a ... Inner wall surface (opposing surface), 26d ... Inner wall surface (opposing surface), 30 ... Movable element, 31 ... Movable element main body, 32 ... Coil, 40 ... Magnet, 41 ... First Magnet, 42 ... 2nd magnet (magnet), 43 ... 3rd magnet (magnet), 44 ... 4th magnet (magnet), 50 ... elastic member, 81, 82, 83, 84 ... hole, 85, 86, 87, 88 ... Grooves, 91, 92, 93, 94 ... Adhesive, X ... Left-right direction (first direction), Z ... Vertical direction (second direction)

Claims (6)

A movable element that can move in a predetermined first direction,
A magnet arranged facing the mover in a second direction orthogonal to the first direction, and a magnet.
An elastic member that elastically deforms with the movement of the mover in the first direction and applies a force in the first direction to the mover.
A magnetic case that houses the mover, the magnet, and the elastic member inside.
Equipped with
The magnet is attached to the inner wall surface of the case.
The case has a hole penetrating the case at a position facing the magnet.
A linear actuator in which an adhesive is provided in the hole. The case has a groove portion that is recessed from the inner wall surface and communicates with the hole portion at a position facing the magnet.
The linear actuator according to claim 1. The hole portion overlaps the magnetic pole center of the magnet in the second direction.
The linear actuator according to claim 1 or 2. The maximum dimension of the hole in the inner wall surface is
It is 30% or less of the maximum dimension of the magnet in the first direction and the maximum dimension of the magnet in the third direction orthogonal to the first direction and the second direction, respectively.
The linear actuator according to any one of claims 1 to 3. The magnets are attached to the inner wall surface of the case on both sides of the movable element in the second direction.
The linear actuator according to any one of claims 1 to 4. The mover has a coil.
The linear actuator according to any one of claims 1 to 5.

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