CN114583919A - Linear actuator - Google Patents

Abstract

The invention provides a linear actuator. The linear actuator has: a movable element movable in a predetermined 1 st direction; a magnet disposed opposite to the movable element in a 2 nd direction perpendicular to the 1 st direction; an elastic member that elastically deforms in accordance with movement of the movable element in the 1 st direction and applies a force in the 1 st direction to the movable element; and a magnetic housing that houses the movable element, the magnet, and the elastic member therein. The magnet is attached to an inner wall surface of the housing, the housing has a hole penetrating the housing at a position facing the magnet, and an adhesive is provided in the hole.

Description

Linear actuator

Technical Field

The present invention relates to a linear actuator.

Background

Linear actuators having a movable member movable in a predetermined direction are known. For example, patent document 1 describes a linear vibration motor having a magnet and a coil housed in a housing as such a linear actuator.

Patent document 1: japanese patent laid-open No. 2020 and 22349

In the linear actuator as described above, for example, a structure in which a magnet is provided in a housing using an adhesive is 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 only the adhesive on the outer periphery of the magnet in the interface between the magnet and the case is cured, and sufficient adhesive strength cannot be obtained.

Disclosure of Invention

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a linear actuator having a structure in which a magnet can be provided in a housing with sufficient adhesive strength while suppressing adverse effects on magnetic characteristics of the magnet.

One embodiment of the present invention is a linear actuator including: a movable element movable in a predetermined 1 st direction; a magnet disposed opposite to the movable element in a 2 nd direction perpendicular to the 1 st direction; an elastic member that elastically deforms in accordance with the movement of the movable element in the 1 st direction and applies a force in the 1 st direction to the movable element; and a magnetic housing that houses the movable element, the magnet, and the elastic member therein, wherein the magnet is attached to an inner wall surface of the housing, the housing has a hole that penetrates the housing at a position facing the magnet, and an adhesive is provided in the hole.

According to one aspect of the present invention, in the linear actuator, the magnet can be provided in the housing with sufficient adhesive strength while suppressing adverse effects on the magnetic force characteristics of the magnet.

Drawings

Fig. 1 is a perspective view illustrating a linear actuator according to an embodiment.

FIG. 2 is a cutaway perspective view illustrating one embodiment of a linear actuator.

Fig. 3 is a sectional view illustrating a linear actuator according to an embodiment.

Fig. 4 is a sectional perspective view showing one embodiment of a linear actuator, which is a view showing an IV-IV section in fig. 1.

Fig. 5 is a sectional view showing a linear actuator according to an embodiment, and is a V-V sectional view of fig. 3.

Fig. 6 is a perspective view showing the magnetic field strength of the linear actuator of one embodiment.

Fig. 7 is a graph showing thrust coefficients of the linear actuator in the case where there is no hole portion and in the case where there is a hole portion in the housing.

Fig. 8 is a cross-sectional view showing a modification of the groove portion.

Description of the reference symbols

10: a linear actuator; 20: a housing; 26 a: an inner wall surface (opposed surface); 26 d: inner wall surfaces (opposed surfaces); 30: a movable member; 31: a movable member main body; 32: a coil; 40: a magnet; 41: 1 st magnet (magnet); 42: 2 nd magnet (magnet); 43: a 3 rd magnet (magnet); 44: a 4 th magnet (magnet); 50: an elastic member; 81. 82, 83, 84: a hole portion; 85. 86, 87, 88: a groove part; 91. 92, 93, 94: an adhesive; x: left-right direction (1 st direction); z: the up-down direction (2 nd direction).

Detailed Description

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. In the drawings below, in order to facilitate understanding of each structure, the actual structure may be different from the scale, the number, and the like of each structure.

In each figure, an X-axis, a Y-axis perpendicular to the X-axis, and a Z-axis perpendicular to the X-axis and the Y-axis are shown. In the following description, a direction parallel to the Z axis is referred to as "vertical direction Z", a direction parallel to the Y axis is referred to as "front-rear direction Y", and a direction parallel to the X axis is referred to as "left-right direction X". The vertical direction Z, the front-rear direction Y, and the left-right direction X are perpendicular to each other.

The positive side (+ Z side) of the Z axis in the up-down direction Z, which is indicated by an arrow, is referred to as "upper side", and the negative side (-Z side) opposite to the side indicated by the arrow, which is indicated by the Z axis, is referred to as "lower side". The positive side (+ Y side) of the Y axis in the front-rear direction Y, which is pointed by the arrow, is referred to as "front side", and the negative side (-Y side) opposite to the side pointed by the arrow of the Y axis is referred to as "rear side". A positive side (+ X side) of the X axis in the left-right direction X, which is pointed by an arrow, is referred to as "right side", and a negative side (-X side) opposite to the X axis, which is pointed by an arrow, is referred to as "left side".

In the following embodiments, the left-right direction X corresponds to the "1 st direction", the up-down direction Z corresponds to the "2 nd direction", and the front-back direction Y corresponds to the "3 rd 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 only names for explaining the arrangement of the respective parts, and the actual arrangement may be an arrangement other than the arrangement indicated by these names. In the present specification, the "parallel direction" also includes a substantially parallel direction, and the "perpendicular direction" also includes a substantially perpendicular direction.

The Linear Actuator 10 of the present embodiment shown in fig. 1 is a 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 has a housing 20 and a wiring member 60. As shown in fig. 2 and 3, the linear actuator 10 has a movable member 30, an elastic member 50, and a damping member 70. As shown in fig. 4 and 5, the linear actuator 10 has a magnet 40.

As shown in fig. 1, the housing 20 is a substantially rectangular parallelepiped box shape that is flat in the vertical direction Z and long in the left-right direction X. As shown in fig. 2 to 4, the case 20 internally houses the movable element 30, the magnet 40, the elastic member 50, a part of the wiring member 60, and the damper member 70. In the present embodiment, the material of the case 20 is a magnetic body. As shown in fig. 4, the case 20 is configured by fixing the 1 st case member 21 and the 2 nd case member 22 to each other in the vertical direction Z.

The 1 st housing part 21 is located on the underside of the 2 nd housing part 22. The 1 st case member 21 has a bottom wall portion 21a and a pair of side wall portions 21b, 21 c. The bottom wall portion 21a has a rectangular plate shape with a plate surface facing in the vertical direction Z and being long in the horizontal direction X. The inner wall surface of the bottom wall portion 21a, i.e., the upper surface, is an opposing surface 26a that opposes the movable element 30 in the vertical direction Z. The side wall portion 21b protrudes upward from the edge portion on the front side (+ Y side) of the bottom wall portion 21 a. The side wall portion 21c protrudes upward from the edge portion on the rear side (-Y side) of the bottom wall portion 21 a. The side wall portions 21b and 21c are plate-shaped with plate surfaces facing in the front-rear direction Y. The side wall portions 21b, 21c extend in the left-right direction X.

The side wall portion 21b has a guide portion 24a and a wall body portion 21 d. The guide portion 24a protrudes upward and obliquely forward from the edge portion on the front side (+ Y side) of the bottom wall portion 21 a. The guide portion 24a extends in the left-right direction X. The guide portion 24a has a guide surface 24 c. The guide surface 24c is a surface facing the inside of the housing 20 among the surfaces of the guide portion 24 a. The guide surface 24c extends in the left-right direction X. In the present embodiment, the guide surface 24c faces the rear side and obliquely upward. The wall body 21d protrudes from the upper end of the guide portion 24a directly upward. The inner wall surface of the wall body 21d, i.e., the surface on the rear side (-Y side), is an opposed surface 26b opposed to the movable element 30 in the front-rear direction Y.

The side wall portion 21c and the side wall portion 21b are provided symmetrically in the front-rear direction Y. The side wall portion 21c has a guide portion 24b and a wall body portion 21 e. The guide portion 24b protrudes upward and obliquely rearward from the edge portion on the rear side (-Y side) of the bottom wall portion 21 a. That is, the guide portions 24a and 24b project from the bottom wall portion 21a in directions away from each other in the front-rear direction Y as going toward the upper side. The guide portion 24b extends in the left-right direction X. The guide portion 24b has a guide surface 24 d. The guide surface 24d is a surface facing the inside of the housing 20 among the surfaces of the guide portion 24 b. The guide surface 24d extends in the left-right direction X. In the present embodiment, the guide surface 24d faces the front side and obliquely upward. The wall body 21e protrudes from the upper end of the guide portion 24b directly upward. The front side (+ Y side) surface, which is the inner wall surface of the wall body 21e, is an opposing surface 26c that opposes the movable element 30 in the front-rear direction Y.

The 2 nd case member 22 is located on the upper side of the 1 st case member 21. As shown in fig. 1, the 2 nd case member 22 has a top wall portion 22a, a pair of side wall portions 22b, 22c, and a pair of guide portions 23a, 23 b. The top wall portion 22a has a rectangular plate shape whose plate surface is oriented in the vertical direction Z and is long in the horizontal direction X. Substantially the entirety of the top wall portion 22a and the bottom wall portion 21a overlap each other when viewed in the up-down direction Z. Both edge portions of the top wall portion 22a in the front-rear direction Y contact the upper end portions of the pair of side wall portions 21b, 21 c. As shown in fig. 4, the lower surface, which is the inner wall surface of the top wall portion 22a, is an opposing surface 26d that opposes the mover 30 in the vertical direction Z.

As shown in fig. 1, the side wall portion 22b protrudes downward from the edge portion on the right side (+ X side) of the top wall portion 22 a. The side wall portion 22c protrudes downward from the edge portion on the left side (X side) of the ceiling wall portion 22 a. The side walls 22b and 22c are plate-shaped with plate surfaces facing in the left-right direction X. The side walls 22b and 22c extend in the front-rear direction Y. The side wall portion 22b is in contact with the right end of the bottom wall portion 21a and the right end of the pair of side wall portions 21b and 21 c. The side wall portion 22c is in contact with the left end of the bottom wall portion 21a and the left ends of the pair of side wall portions 21b and 21 c.

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

As shown in fig. 4, the guide portion 23a protrudes downward and obliquely forward from the edge portion on the front side (+ Y side) of the ceiling wall portion 22 a. The guide portion 23a is disposed to face the rear side (-Y side) of the wall body portion 21d in the side wall portion 21 b. The guide portion 23a is located on the upper side of the guide portion 24 a. The guide portion 23a and the guide portion 24a are spaced from the front edge of the base portion 31a described later in the vertical direction Z. The guide portion 23a and the guide portion 24a approach each other in the up-down direction Z as going toward the front side.

The guide portion 23a has a guide surface 23 c. The guide surface 23c is a surface facing the inside of the housing 20 among the surfaces of the guide portion 23 a. The guide surface 23c extends in the left-right direction X. In the present embodiment, the guide surface 23c faces the rear side and obliquely downward. The guide surface 23c is spaced apart from the edge on the front side (+ Y side) of the base portion 31a, which will be described later, in the vertical direction Z between the guide surface 24c and the vertical direction Z.

The guide portion 23b protrudes downward and obliquely rearward from the edge portion on the rear side (-Y side) of the ceiling wall portion 22 a. The guide portion 23b is disposed to face the front side (+ Y side) of the wall body 21e in the side wall portion 21 c. The guide portion 23b is located on the upper side of the guide portion 24 b. The guide portion 23b and the guide portion 24b are spaced from the rear edge 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 up-down direction Z as going toward the rear side.

The guide portion 23b has a guide surface 23 d. The guide surface 23d is a surface facing the inside of the housing 20 among the surfaces of the guide portion 23 b. The guide surface 23d extends in the left-right direction X. In the present embodiment, the guide surface 23d faces the front side and obliquely downward. The guide surface 23d is spaced apart from 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 24d and the vertical direction Z.

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

As shown in fig. 3, the housing 20 has projections 25a, 25b, 25c, 25 d. The protruding portions 25a and 25b protrude leftward from the inner wall surface of the side wall portion 22b, i.e., the left side (-X side). The convex portions 25a and 25b are provided at both ends of the side wall portion 22b in the front-rear direction Y. The protruding portions 25c and 25d protrude rightward from the inner wall surface of the side wall portion 22c, i.e., the right side (+ X side) surface. The convex portions 25c and 25d are provided at both ends of the side wall portion 22c in the front-rear direction Y. The projections 25a, 25b, 25c, and 25d are produced by, for example, pressure-bonding a part of the side walls 22b and 22c provided in the left-right direction X.

In the present embodiment, the movable element 30 extends in the left-right direction X. The movable element 30 is movable in the left-right direction X within the housing 20. The mover 30 has a mover body 31 and a coil 32. In the present embodiment, the movable element 30 vibrates in the left-right direction X by an electromagnetic force generated between the coil 32 and the magnet 40 by supplying power to the coil 32 and an elastic force applied from the elastic member 50. The mover body 31 extends in the left-right direction X. The movable body 31 has a base 31a and protruding portions 31b, 31 c. The base 31a is a portion that holds the coil 32. As shown in fig. 2, the base portion 31a has a substantially rectangular parallelepiped shape which is flat in the vertical direction Z and extends in the left-right direction X.

The base 31a has a recess 31d recessed from the upper surface of the base 31a toward the lower side. The inner edge of the concave portion 31d is rectangular when viewed from above. As shown in fig. 4, the base 31a has a recess 31g recessed from the lower surface of the base 31a toward the upper side. The inner edge of the recess 31g is rectangular when viewed from the lower side. The concave portion 31d and the concave portion 31g are provided at positions overlapping each other when viewed in the up-down direction Z. The base 31a has a through hole 31e penetrating the base 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 31 g. As shown in fig. 2, the through hole 31e is a substantially circular hole. The coil 32 is fitted and held inside the through hole 31 e. Thereby, the coil 32 is attached to the movable element body 31.

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

The guided surface 34a is provided at an upper end portion of the edge portion on the front side (+ Y side) of the base portion 31 a. The guided surface 34a faces the front side and obliquely upward, and the guided surface 34a extends in the left-right direction X. The guided surface 34a is produced by chamfering a corner portion on the front side and the upper side of the base portion 31a, for example. The guided surface 34a is disposed opposite to the guide surface 23 c. The guided surface 34a can contact the guide surface 23 c.

The guided surface 34b is provided at a lower end portion of the edge portion on the front side (+ Y side) of the base portion 31 a. The guided surface 34b faces the front side and obliquely downward, and the guided surface 34b extends in the left-right direction X. The guided surface 34b is formed by chamfering a front and lower corner of the base 31a, for example. The guided surface 34b is disposed opposite to the guide surface 24 c. The guided surface 34b can contact the guide surface 24 c.

The guided surface 34c is provided at an upper end portion of the edge portion on the rear side (-Y side) of the base portion 31 a. The guided surface 34c faces the rear side and obliquely upward, and the guided surface 34c extends in the left-right direction X. The guided surface 34c is formed by chamfering the rear and upper corner of the base 31 a. The guided surface 34c is disposed opposite to the guide surface 23 d. The guided surface 34c can contact the guide surface 23 d.

The guided surface 34d is provided at the lower end portion of the edge portion on the rear side (-Y side) of the base portion 31 a. The guided surface 34d faces the rear side and obliquely downward, and the guided surface 34d extends in the left-right direction X. The guided surface 34d is formed by chamfering a rear lower corner of the base 31a, for example. The guided surface 34d is disposed opposite to the guide surface 24 d. The guided surface 34d can contact the guide surface 24 d.

The guided surface 34a and the guided surface 34b are arranged at a distance in the vertical direction Z. The guided surface 34a and the guided surface 34b approach each other in the up-down direction Z as going toward the front side (+ Y side). The guided surface 34a and the guided surface 34b are sandwiched between the guide surface 23c and the guide surface 24c in the vertical direction Z. In a state where the guided surface 34a is in contact with the guide surface 23c and the guided surface 34b is in contact with the guide surface 24c, the front end surface of the base portion 31a faces the facing surface 26b facing the front of the base portion 31a with a gap therebetween in the front-rear direction Y. That is, in the present embodiment, the movable element 30 is in contact with the guide surfaces 23c and 24c, and is in a state of facing the facing surface 26b with a gap therebetween in the front-rear direction Y. Thus, in the present embodiment, the movable element 30 does not contact the facing surface 26 b.

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 relationship is symmetrical 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, the movable element 30 is in a state where the facing surface 26c facing the rear side (-Y side) of the base portion 31a faces the rear side Y with a gap therebetween. Thus, in the present embodiment, the movable element 30 does not contact the facing surface 26 c.

In a state where the guided surface 34a is in contact with the guide surface 23c and the guided surface 34c is in contact with the guide surface 23d, the upper end surface of the base portion 31a faces the facing surface 26d facing the upper side of the base portion 31a with a gap therebetween in the vertical direction Z. That is, in the present embodiment, the movable element 30 is in contact with the guide surfaces 23c and 23d, and is in a state of facing the facing surface 26d with a gap in the vertical direction Z. Thus, in the present embodiment, the movable element 30 does not contact the facing surface 26 d. In a state where the guided surfaces 34b and 34d are in contact with the guide surfaces 24c and 24d, the movable element 30 is in a state of facing the facing surface 26a facing the lower side of the base portion 31a with a gap therebetween in the vertical direction Z. Thus, in the present embodiment, the movable element 30 does not contact the facing surface 26 a.

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

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

The mover body 31 has convex portions 33a, 33b, 33c, 33 d. The convex portions 33a and 33b protrude rightward (+ X) from both ends in the front-rear direction Y of the right end of the base portion 31 a. The convex portions 33a and 33b sandwich the protruding portion 31b in the front-rear direction Y. The protruding portions 33c and 33d protrude to the left side (-X) from both ends in the front-rear direction Y of the left end of the base portion 31 a. The convex portions 33c and 33d sandwich the protruding portion 31c in the front-rear direction Y. The convex portions 33a, 33b, 33c, 33d have, for example, a rectangular parallelepiped shape. The protruding heights of the convex portions 33a, 33b, 33c, 33d are smaller than the protruding heights of the protruding portions 31b, 31 c.

As shown in fig. 2, the mover body 31 has a groove portion 31 f. In the present embodiment, the groove 31f is provided across the base 31a and the front portion 31h of the projection 31 b. The groove 31f is recessed downward from the upper surface of the mover body 31 and extends in the left-right direction X. The left side (-X side) end of the groove 31f opens into the recess 31 d. The right (+ X side) end of the groove 31f opens at the right end face of the front portion 31 h. The groove 31f is provided on the front side (+ Y side) of the center of the movable element main body 31 in the front-rear direction Y.

The coil 32 is formed by winding a wire around a central axis J extending in the vertical direction Z. The central axis J is a suitably illustrated imaginary axis. For example, in a state where the movable element 30 is stationary, the central axis J passes through the center of the housing 20 in the left-right direction X and the center of the front-rear direction Y. The coil 32 has a substantially annular shape centered on the central axis J when viewed in the vertical direction Z. The coil 32 is fitted in the through hole 31e and fixed to the mover body 31. As shown in fig. 4, the upper end of the coil 32 protrudes upward beyond the through hole 31e, for example. The lower end of the coil 32 is located at the same position as the lower end of the through hole 31e in the vertical direction Z, for example. The coil 32 is supplied with electric power from the outside of the linear actuator 10 via the wiring member 60.

As shown in fig. 5, the magnet 40 is disposed inside the case 20 so as to face the coil 32 in the vertical direction Z perpendicular to the horizontal direction X. A gap is provided between the magnet 40 and the coil 32 in the vertical direction Z. The magnet 40 is, for example, a rectangular plate having a plate surface facing the vertical direction Z and long in the front-rear direction Y. The magnet 40 includes a 1 st magnet 41, a 2 nd magnet 42, a 3 rd magnet 43, and a 4 th magnet 44.

The 1 st magnet 41 and the 2 nd magnet 42 are located above the coil 32. The 1 st magnet 41 and the 2 nd magnet 42 are arranged in the left-right direction X. The 2 nd magnet 42 is positioned on the left side (-X side) of the 1 st magnet 41. The 1 st magnet 41 and the 2 nd magnet 42 are in contact in the left-right direction X. For example, in a state where the movable element 30 is stationary, the central axis J passes between the 1 st magnet 41 and the 2 nd magnet 42 in the left-right direction X.

The 3 rd magnet 43 and the 4 th magnet 44 are located at the lower side of the coil 32. The 3 rd magnet 43 and the 4 th magnet 44 are arranged in the left-right direction X. The 4 th magnet 44 is positioned on the left side (-X side) of the 3 rd magnet 43. The 3 rd magnet 43 and the 4 th magnet 44 are in contact in the left-right direction X. For example, in a state where the movable element 30 is stationary, the central axis J passes between the 3 rd magnet 43 and the 4 th magnet 44 in the left-right direction X.

The 1 st magnet 41 and the 3 rd magnet 43 are disposed across the coil 32 in the vertical direction Z. The 1 st magnet 41 and the 3 rd magnet 43 are disposed so as to overlap each other when viewed in the vertical direction Z. The 2 nd magnet 42 and the 4 th magnet 44 are disposed across the coil 32 in the vertical direction Z. The 2 nd magnet 42 and the 4 th magnet 44 are disposed 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 1 st magnet 41 has a magnetic pole 41N as an N pole on the upper side. The 1 st magnet 41 has a magnetic pole 41S as an S pole on the lower side. The 2 nd magnet 42 has a magnetic pole 42S as an S pole on the upper side. The 2 nd magnet 42 has a magnetic pole 42N as an N-pole on the lower side. The 3 rd magnet 43 has a magnetic pole 43N as an N-pole on the upper side. The 3 rd magnet 43 has a magnetic pole 43S as an S pole on the lower side. The 4 th magnet 44 has a magnetic pole 44S as an S pole on the upper side. The 4 th magnet 44 has a magnetic pole 44N as an N-pole on the lower side.

The N-pole and S-pole of the 1 st magnet 41 and the 2 nd magnet 42 arranged adjacent to each other in the left-right direction X are arranged opposite to each other in the up-down direction Z. The N-pole and S-pole of the 3 rd magnet 43 and the 4 th magnet 44 arranged adjacent to each other in the left-right direction X are arranged opposite to each other in the up-down direction Z. The 1 st magnet 41 and the 3 rd magnet 43 arranged with the coil 32 interposed therebetween in the vertical direction Z have the same arrangement of N-pole and S-pole along the vertical direction Z. The N-pole and S-pole arrangements along the vertical direction Z of the 2 nd magnet 42 and the 4 th magnet 44 arranged with the coil 32 interposed therebetween in the vertical direction Z are the same as each other. The 1 st magnet 41, the 2 nd magnet 42, the 3 rd magnet 43, and the 4 th magnet 44 have the same vertical dimension Z, the same longitudinal dimension Y, and the same horizontal dimension X.

The 1 st magnet 41 and the 2 nd magnet 42 are attached to the facing surface 26d which is the inner wall surface of the top wall portion 22 a. The 1 st magnet 41 and the 2 nd magnet 42 are fixed to the facing surface 26 d. The 3 rd magnet 43 and the 4 th magnet 44 are attached to the facing surface 26a which is the inner wall surface of the bottom wall portion 21 a. The 3 rd magnet 43 and the 4 th magnet 44 are fixed to the facing surface 26a of the bottom wall portion 21 a.

The case 20 has a hole and a groove at a position facing the magnet 40. More specifically, the 2 nd case member 22 has a hole 81 and a groove 85 at a position facing the 1 st magnet 41. As shown in fig. 1, 4, and 5, the hole 81 penetrates the top wall portion 22a of the 2 nd case member 22 in the vertical direction Z. The hole 81 overlaps the magnetic pole center of the 1 st magnet 41 in the vertical direction Z. The hole 81 is provided with an adhesive 91. The groove 85 is recessed upward from the facing surface 26d of the top wall 22a and communicates with the hole 81. The maximum dimension of the groove portion 85 is larger than the maximum dimension of the hole portion 81. The groove portion 85 is provided with an adhesive 91. The hole 81 and the groove 85 are circular and coaxial when viewed in the axial direction. The hole 81 and the groove 85 do not need to be coaxially arranged and circular, and may be eccentrically arranged and elliptical or polygonal, as long as they overlap the magnetic pole center of the 1 st magnet 41 in the vertical direction Z. At least one of the plurality of holes 81 and the groove 85 may be disposed in a region including the magnetic pole center of the 1 st magnet 41.

The 2 nd case member 22 has a hole 82 and a groove 86 at a position facing the 2 nd magnet 42. The hole 82 penetrates the top wall 22a of the 2 nd case member 22 in the vertical direction Z. The hole 82 overlaps the magnetic pole center of the 2 nd magnet 42 in the vertical direction Z. The hole 82 is provided with an adhesive 92. Groove 86 is recessed upward from facing surface 26d of top wall 22a and communicates with hole 82. The maximum dimension of the groove portion 86 is larger than the maximum dimension of the hole portion 82. The groove portion 86 is provided with an adhesive 91. The hole 82 and the groove 86 are circular and coaxial when viewed in the axial direction. The hole 82 and the groove 86 do not need to be coaxially arranged and circular, and may be eccentrically arranged and elliptical or polygonal, as long as they overlap the magnetic pole center of the 2 nd magnet 42 in the vertical direction Z. At least one of the plurality of holes 82 and the grooves 86 may be arranged in a region including the magnetic pole center of the 2 nd magnet 42.

The holes 81 and the grooves 85, and the holes 82 and the grooves 86 are arranged line-symmetrically with respect to the center axis J in the left-right direction X. Hereinafter, the hole 82 and the groove 86 may not be described in the same configuration as the hole 81 and the groove 85 except for the point of line symmetry with respect to the central axis J.

Fig. 6 shows the magnetic field strength in the housing 20 in a state where no current flows through the coil 32. As shown in fig. 6, in the top wall portion 22a of the housing 20, the magnetic field strength of the 1 st magnet 41 is small at the position of the magnetic pole center of the 1 st magnet 41, and the magnetic field strength of the 2 nd magnet 42 is small at the position of the magnetic pole center of the 2 nd magnet 42. The hole 81 overlaps with the magnetic pole center of the 1 st magnet 41 in the vertical direction Z, and the hole 82 overlaps with the magnetic pole center of the 2 nd magnet 42 in the vertical direction Z, whereby even when the hole 81 and the hole 82 are provided in the ceiling wall portion 22a, the decrease in the magnetic field strength of the 1 st magnet 41 and the 2 nd magnet 42 can be suppressed.

As shown in fig. 7, the thrust coefficient in the linear actuator 10 is suppressed to be equal in the case where there is no hole portion in the housing 20 and in the case where there is a hole portion (for example, the reduction 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 thermosetting adhesives are used as the adhesives 91 and 92, the heat for curing the adhesives may adversely affect the magnetic characteristics of the 1 st magnet 41 and the 2 nd magnet 42. By using a photocurable adhesive as the adhesives 91 and 92, adverse effects on the magnetic characteristics of the 1 st magnet 41 and the 2 nd magnet 42 can be suppressed.

In the present embodiment, the adhesives 91 and 92 are ultraviolet-curable adhesives that are cured by irradiation of ultraviolet rays, for example. In a state where the 1 st magnet 41 is attached to the facing surface 26d of the top wall 22a, the adhesive 91 is injected into the hole 81 and the groove 85. Since the hole 81 is open above the top wall 22a, the adhesive 91 can be easily injected into the hole 81 and the groove 85 from above. The adhesive 91 injected into the hole 81 and the groove 85 contacts the 1 st 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 ultraviolet rays from above the hole 81 to the adhesive 91. The 1 st magnet 41 can be fixed to the top wall 22a by curing the adhesive 91 in the hole 81 and the groove 85. By providing the groove portion 85 having the maximum size larger than the maximum size of the hole portion 81, the 1 st magnet 41 can be effectively fixed to the top wall portion 22a with a large area. In order to effectively cure the adhesive 91 in the groove portion 85, the ultraviolet light may be irradiated at a large orientation angle or an incident angle at which the optical axis of the ultraviolet light is inclined with respect to the central axis J.

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

In the case where 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 in the case where the maximum dimension of the hole 81 in the front-rear direction Y exceeds 30% of the maximum dimension L2 of the first magnet 41 in the front-rear direction Y, there is a possibility that the magnetic field strength of the first magnet 41 decreases. By setting the maximum dimension of the hole 81 in the left-right direction X to 30% or less of the maximum dimension L1 of the 1 st magnet 41 in the left-right direction X and setting the maximum dimension of the hole 81 in the front-rear direction Y to 30% or less of the maximum dimension L2 of the 1 st magnet 41 in the front-rear direction Y, it is possible to suppress a decrease in the magnetic field strength of the 1 st magnet 41.

The 1 st case member 21 has a hole 83 and a groove 87 at a position facing the 3 rd magnet 43. The hole 83 penetrates the bottom wall 21a of the 1 st case member 21 in the vertical direction Z. The hole 83 overlaps the magnetic pole center of the 3 rd magnet 43 in the vertical direction Z. An adhesive 93 is provided in the hole 83. The groove 87 is recessed downward from the facing surface 26a of the bottom wall 21a and communicates with the hole 83. The maximum dimension of the groove 87 is larger than the maximum dimension of the hole 83. The groove 87 is provided with an adhesive 93. The hole 83 and the groove 87 are circular and coaxial when viewed in the axial direction. The hole 83 and the groove 87 do not need to be coaxially arranged and circular, and may be eccentrically arranged and elliptical or polygonal, as long as they overlap the magnetic pole center of the 3 rd magnet 43 in the vertical direction Z. At least one of the plurality of holes 83 and the grooves 87 may be arranged in a region including the magnetic pole center of the 3 rd magnet 43.

First case member 21 has hole 84 and groove 88 at a position facing second magnet 44. The hole 84 penetrates the bottom wall 21a of the 1 st case member 21 in the vertical direction Z. The hole 84 overlaps the magnetic pole center of the 4 th magnet 44 in the vertical direction Z. An adhesive 94 is provided in the hole portion 84. The groove 88 is recessed downward from the facing surface 26a of the bottom wall 21a and communicates with the hole 84. The maximum dimension of the groove portion 85 is larger than the maximum dimension of the hole portion 84. The groove portion 88 is provided with an adhesive 94. The hole portion 84 and the groove portion 88 are circular and coaxial when viewed in the axial direction. The hole 84 and the groove 88 do not need to be coaxially arranged and circular, and may be eccentrically arranged and elliptical or polygonal, as long as they overlap the magnetic pole center of the 4 th magnet 44 in the vertical direction Z. At least one of the plurality of holes 84 and the grooves 88 may be disposed in a region including the magnetic pole center of the 4 th magnet 44.

The holes 83 and the grooves 88, and the holes 84 and the grooves 88 are arranged line-symmetrically with respect to the center axis J in the left-right direction X. Hereinafter, the hole 84 and the groove 88 may not be described in the same configuration as the hole 83 and the groove 87 except for the point of line symmetry 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 3 rd magnet 43 is small at the position of the magnetic pole center of the 3 rd magnet 43, and the magnetic field strength of the 4 th magnet 44 is small at the position of the magnetic pole center of the 4 th magnet 44. Since hole 83 overlaps the magnetic pole center of 3 rd magnet 43 in vertical direction Z and hole 84 overlaps the magnetic pole center of 4 th magnet 44 in vertical direction Z, even when hole 83 and hole 84 are provided in bottom wall 21a, the decrease in magnetic field strength of 3 rd magnet 43 and 4 th magnet 44 can be suppressed.

The adhesives 93 and 94 are photocurable adhesives as in the case of the adhesives 91 and 92. By using the photo-curable adhesives as the adhesives 93 and 94, it is possible to suppress adverse effects of heat on the magnetic characteristics of the 3 rd magnet 43 and the 4 th magnet 44 as in the case of using a thermosetting adhesive.

In a state where the 3 rd magnet 43 is attached to the facing surface 26a of the bottom wall 21a, the adhesive 93 is injected into the hole 83 and the groove 87. Since hole 83 is open on the lower side of bottom wall 21a, adhesive 93 can be easily injected into hole 83 and groove 87 from the lower side. The adhesive 93 injected into the hole 83 and the groove 87 contacts the 3 rd 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 light from below the hole 83. By curing adhesive 93 in hole 83 and groove 87, 3 rd magnet 43 can be fixed to bottom wall 21 a. By providing the groove 87 having the maximum size larger than the maximum size of the hole 83, the 3 rd magnet 43 can be effectively fixed to the bottom wall 21a with a large area. In order to effectively cure the adhesive 93 in the groove 87, the ultraviolet light may be irradiated at a large orientation angle or an incident angle at which the optical axis of the ultraviolet light is inclined with respect to the central axis J.

The maximum size (diameter) of the hole 83 is 0.6mm or more, as in the case of the hole 81. When the maximum size of the hole 83 is 0.6mm or more, workability in forming the hole 83 in the bottom wall 21a can be ensured. Although not shown, the maximum size of the hole 83 in the left-right direction X is 30% or less of the maximum size of the 3 rd 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 3 rd magnet 43 in the front-rear direction Y.

By setting the maximum dimension of the hole portion 83 in the left-right direction X to 30% or less of the maximum dimension of the 3 rd magnet 43 in the left-right direction X and setting the maximum dimension of the hole portion 83 in the front-rear direction Y to 30% or less of the maximum dimension of the 3 rd magnet 43 in the front-rear direction Y, a decrease in the magnetic field strength of the 3 rd magnet 43 can be suppressed.

The elastic member 50 is a member that elastically deforms in accordance with the movement of the movable element 30 in the left-right direction X, and applies a force in the left-right direction X to the movable element 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 1 st elastic member 51, a 2 nd elastic member 52, a 3 rd elastic member 53, and a 4 th elastic member 54.

The 1 st elastic member 51 and the 2 nd elastic member 52 are located on the right side (+ X side) of the movable piece 30. In the present embodiment, the 1 st elastic member 51 and the 2 nd elastic member 52 are positioned between the movable element 30 and the side wall portion 22b in the left-right direction X. The 1 st elastic member 51 and the 2 nd elastic member 52 are disposed across the protruding portion 31b in the front-rear direction Y. The 1 st elastic member 51 is located on the front side (+ Y side) of the protruding portion 31 b. The 2 nd elastic member 52 is located on the rear side (-Y side) of the projection 31 b. The right end of the 1 st elastic member 51 and the right end of the 2 nd elastic member 52 contact the side wall portion 22b of the housing 20. The left-side end portion (X-side) of the 1 st elastic member 51 and the left-side end portion of the 2 nd elastic member 52 are in contact with the base portion 31a of the movable piece main body 31. The convex portions 25a and 33a are inserted into both end portions of the 1 st elastic member 51 in the left-right direction X, respectively. The convex portions 25b and 33b are inserted into both end portions of the 2 nd elastic member 52 in the left-right direction X, respectively. This suppresses the 1 st elastic member 51 and the 2 nd elastic member 52 from being displaced in the vertical direction Z and the front-rear direction Y.

In the present embodiment, the 1 st elastic member 51 and the 2 nd elastic member 52 correspond to a pair of elastic members 50 located on the right side (+ X side) of the mover body 31 and arranged across the wiring member 60 in the front-rear direction Y perpendicular to both the left-right direction X and the up-down direction Z.

The 3 rd elastic member 53 and the 4 th elastic member 54 are located on the left side (-X side) of the movable member 30. The 3 rd elastic member 53 and the 4 th elastic member 54 are located between the movable element 30 and the side wall portion 22c in the left-right direction X. The 3 rd elastic member 53 and the 4 th elastic member 54 are disposed with the protruding portion 31c interposed therebetween in the front-rear direction Y. The 3 rd elastic member 53 is located on the front side (+ Y side) of the protruding portion 31 c. The 4 th elastic member 54 is located on the rear side (-Y side) of the protruding portion 31 c. The left end of the 3 rd elastic member 53 and the left end of the 4 th elastic member 54 contact the side wall portion 22c of the housing 20. The right-side (+ X side) end of the 3 rd elastic member 53 and the right-side end of the 4 th elastic member 54 are in contact with the base 31a of the movable piece main body 31. The convex portions 25c and 33c are inserted into both end portions of the 3 rd elastic member 53 in the left-right direction X, respectively. The 4 th elastic member 54 has projections 25d and 33d inserted into both ends in the left-right direction X. This suppresses the 3 rd elastic member 53 and the 4 th elastic member 54 from being displaced in the vertical direction Z and the front-rear direction Y.

The 1 st elastic member 51 and the 3 rd elastic member 53 are disposed across the front side (+ Y side) of the protruding portions 31b and 31c in the base portion 31a in the left-right direction X. The 2 nd elastic member 52 and the 4 th elastic member 54 are disposed across the portions of the base portion 31a on the rear side (-Y side) of the protruding portions 31b and 31c in the left-right direction X.

When the movable element 30 moves to the right side (+ X side) from the position shown in each drawing, the 1 st elastic member 51 and the 2 nd elastic member 52 are compressively elastically deformed in the left-right direction X. Thereby, the 1 st elastic member 51 and the 2 nd elastic member 52 apply an elastic force to the mover 30 in a direction of separating the mover 30 from the side wall portion 22b, that is, in a left direction (the (-X-side direction).

On the other hand, when the movable element 30 moves to the left side (-X side) from the position shown in the drawings, the 3 rd elastic member 53 and the 4 th elastic member 54 are compressed and elastically deformed in the left-right direction X. Thereby, the 3 rd elastic member 53 and the 4 th elastic member 54 apply elastic force to the movable element 30 in a direction of separating the movable element 30 from the side wall portion 22c, that is, in a right direction (+ X side direction).

The damping member 70 is fixed to an inner wall surface of the casing 20. The damping member 70 faces the mover body 31 in the left-right direction X. The damping member 70 is a member that attenuates the kinetic energy of the colliding object. The damping member 70 is made of rubber, for example. For example, the damping member 70 has a square shape when viewed in the left-right direction X. In the present embodiment, the damping member 70 includes the 1 st damping member 71 and the 2 nd damping member 72.

The 1 st damping member 71 is fixed to the inner wall surface of the side wall portion 22b, i.e., the left side (-X side) surface of the side wall portion 22 b. In the present embodiment, the 1 st damping member 71 is located on the rear side (-Y side) of the center of the side wall portion 22b in the front-rear direction Y. The 1 st damping member 71 is located on the right side (+ X side) of the rear side portion 31i in the protruding portion 31 b.

The 2 nd damping member 72 is fixed to the inner wall surface of the side wall portion 22c, i.e., the right side (+ X side) surface of the side wall portion 22 c. In the present embodiment, the 2 nd damping member 72 is located on the rear side (-Y side) of the center of the side wall portion 22c in the front-rear direction Y. The 2 nd damping member 72 is located on the left side (-X side) of the rear side portion in the projection 31 c. The 1 st damping member 71 and the 2 nd damping member 72 are disposed across the mover 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 body 31. The wiring member 60 is a member having flexibility. The wiring member 60 is, for example, a flexible printed circuit board. In the present embodiment, the wiring member 60 has a strip shape. The width direction of the tape-shaped wiring member 60 is the front-rear direction Y perpendicular 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 has a coil connecting portion 61, a 1 st extending portion 62, a 1 st connecting portion 63, a 2 nd extending portion 64, a 2 nd connecting portion 65, and a 3 rd extending portion 66. The wiring member 60 is configured by connecting a coil connecting portion 61, a 1 st extending portion 62, a 1 st connecting portion 63, a 2 nd extending portion 64, a 2 nd connecting portion 65, and a 3 rd extending portion 66 in this order. The thickness direction of the coil connecting portion 61, the 1 st extending portion 62, the 2 nd extending portion 64, the 2 nd connecting portion 65, and the 3 rd extending portion 66 is the vertical direction Z. In the 1 st connecting portion 63, the thickness direction is a direction perpendicular to the front-rear direction Y and intersecting the vertical direction Z.

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

The 1 st extending portion 62 is a portion located on the upper side of the mover body 31 and extending in the left-right direction X. The 1 st extending portion 62 extends rightward (+ X side) from a portion near the front side (+ Y side) in the coil connecting portion 61. The 1 st extending portion 62 extends to the right side of the front portion 31h of the protruding portion 31b through the groove portion 31 f.

In the present embodiment, the 1 st extending portion 62 has a wide portion 62a extending rightward (+ X side) from the coil connecting portion 61 and a narrow portion 62b continuous with the right side of the wide portion 62 a. The wide portion 62a passes through the groove portion 31f and extends to the right of the front portion 31h of the protrusion 31 b. The width of the wide portion 62a is larger than the width of the narrow portion 62b and the width of the 1 st connecting portion 63. The front edge (+ Y side) of the wide portion 62a protrudes forward beyond the front edge of the narrow portion 62 b. The rear (Y-side) edge 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 1 st connecting portion 63 is connected to the end portion on the right side (+ X side) of the 1 st extending portion 62, i.e., the end portion on the right side of the narrow width portion 62 b. In the present embodiment, the 1 st connecting portion 63 is a portion bent downward with respect to the 1 st extending portion 62. The 1 st connecting portion 63 is elastically deformed. As shown in fig. 5, for example, the 1 st connecting portion 63 is bent in an arc shape convex to the right side when viewed from the rear side (-Y side). In the present embodiment, the 1 st 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 by the right side of the front portion 31h of the protruding portion 31 b. The end of the lower side of the 1 st connecting portion 63 is connected to the end of the right side of the 2 nd extending portion 64. Thereby, the 1 st connecting portion 63 connects the end portion on the right side in the 1 st extending portion 62 and the end portion on the right side in the 2 nd extending portion 64.

The 2 nd extending portion 64 is a portion that extends in the left-right direction X with the movable element main body 31 sandwiched therebetween in the up-down direction Z with the 1 st extending portion 62. The 2 nd extending portion 64 extends from the end portion of the lower side of the 1 st connecting portion 63 to the left side (-X side). The left side portion of the 2 nd extending portion 64 is located on the lower side of the front side portion 31h in the protruding portion 31 b. The 2 nd extension part 64 is disposed on the facing surface 26 a.

As shown in fig. 3, the 2 nd connecting portion 65 connects the end portion on the left side (the (-X side) in the 2 nd extending portion 64 and the end portion on the left side in the 3 rd extending portion 66. For example, the 2 nd connecting portion 65 has a substantially rectangular shape elongated in the front-rear direction Y when viewed in the vertical direction Z. The 2 nd connecting portion 65 is disposed across the lower side of the protruding portion 31b and the lower side of the base portion 31 a. The 2 nd connecting portion 65 is disposed across the lower side of the front portion 31h and the lower side of the rear portion 31 i. The 2 nd connecting part 65 protrudes to the rear side (-Y side) than the 2 nd extending part 64. The 2 nd connecting portion 65 is disposed on the facing surface 26 a.

As shown in fig. 5, the 2 nd connecting portion 65 is supported from the left side by the convex portion 27 provided on the inner wall surface of the housing 20. This can suppress the wiring member 60 from shifting to the left in the housing 20. The protruding portion 27 protrudes upward from the facing surface 26a, which is the upper surface of the bottom wall portion 21 a. The convex portion 27 is formed by, for example, pressing a part of the bottom wall portion 21a upward.

As shown in fig. 3, the 3 rd extending portion 66 is arranged in the front-rear direction Y perpendicular to both the left-right direction X and the up-down direction Z with the 2 nd extending portion 64. The 3 rd extending portion 66 extends rightward (+ X side) from the rear side portion of the 2 nd connecting portion 65. The 3 rd extending portion 66 is drawn out to the right side than the mover body 31. The 3 rd extending portion 66 penetrates the side wall portion 22b in the left-right direction X and is drawn out to the outside of the housing 20. The 3 rd extension 66 extends, for example, rightward from the housing 20. The 3 rd extending portion 66 is disposed on the opposing surface 26a, which is located inside the housing 20. An external power supply, not shown, is connected to the 3 rd extending portion 66. The power of the external power supply is supplied to the coil 32 via the wiring member 60.

By arranging the 1 st extending portion 62, the 1 st connecting portion 63, the 2 nd extending portion 64, the 2 nd connecting portion 65, and the 3 rd extending portion 66 as described above, the wiring member 60 extends from the upper side of the movable piece main body 31 to the lower side of the movable piece main body 31 through the right side (+ X side) of the movable piece main body 31, and is drawn out from the lower side of the movable piece main body 31 to a position on the right side of the movable piece main body 31. That is, the wiring member 60 is provided across the right portion of the mover body 31 in the vertical direction Z, and is drawn out to the right side of the mover body 31. Therefore, the wiring member 60 is less likely to interfere with the mover body 31, as compared with a case where the wiring member 60 is disposed by being wound around the mover body 31. In addition, the wiring member 60 can be prevented from being lengthened. Accordingly, as compared with a case where the wiring member 60 is disposed by being wound around the mover body 31, the case 20 housing the mover body 31 and the wiring member 60 can be prevented from being increased in size. Therefore, the coil 32 can be provided to the movable element 30 while suppressing an increase in size of the linear actuator 10.

According to the present embodiment, case 20 has holes 81, 82, 83, and 84 penetrating case 20 at positions facing magnet 40, and adhesives 91, 92, 93, and 94 are provided in holes 81, 82, 83, and 84. Therefore, even when a photocurable adhesive is used, magnet 40 can be bonded to case 20 with at least the opening areas of holes 81, 82, 83, and 84. This makes it possible to fix the magnet 40 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, case 20 has grooves 85, 86, 87, and 88 recessed from the inner wall surface at positions facing magnet 40 and communicating with holes 81, 82, 83, and 84. Therefore, the magnet 40 can be bonded to the case 20 in a larger area. This enables the magnet 40 to be fixed to the case 20 with a more sufficient adhesive strength.

According to the present embodiment, holes 81, 82, 83, and 84 overlap the magnetic pole center of magnet 40 in vertical direction Z. Therefore, even when the holes 81, 82, 83, and 84 are provided, the decrease in the magnetic field strength in the housing 20 can be suppressed. This makes it possible to fix the magnet 40 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 size of the holes 81, 82, 83, 84 is 30% or less of the maximum size of the magnet 40 in the left-right direction X, and 30% or less of the maximum size of the magnet 40 in the front-rear direction Y. Therefore, even when the holes 81, 82, 83, and 84 are provided, the decrease in the magnetic field strength in the housing 20 can be suppressed. This makes it possible to fix the magnet 40 to the case 20 with sufficient adhesive strength while suppressing a decrease in the magnetic field strength in the case 20.

In addition, according to the present embodiment, the material of the case 20 is a magnetic body. Therefore, when power is supplied to the coil 32, magnetic flux also flows in the case 20, and thus a magnetic path passing through the coil 32 and the magnet 40 is more appropriately configured. This can increase the electromagnetic force generated between the coil 32 and the magnet 40. Therefore, the movable element 30 can be moved more appropriately in the left-right direction X.

Here, for example, when the magnet 40 is provided on the mover 30 and the coil 32 is provided on the housing 20, the magnet 40 may be attracted to the magnetic housing 20 by a magnetic force, and the mover 30 may be rubbed against the inner wall surface of the housing 20. In this case, the movable element 30 is difficult to move in the left-right direction X.

In contrast, according to the present embodiment, the coil 32 is provided on the movable element 30, and the magnet 40 is fixed to the magnetic housing 20. Therefore, the movable element 30 can be suppressed from being attracted by the case 20. This can suppress friction of the movable element 30 against the inner wall surface of the case 20. Therefore, the movable element 30 can be suppressed from being difficult to move in the left-right direction X.

While preferred embodiments of the present invention have been described above with reference to the drawings, it is needless to say that the present invention is not limited to these examples. The shapes, combinations, and the like of the respective constituent members shown in the above examples are examples, and various modifications can be made based on design requirements and the like without departing from the spirit of the present invention.

The structure in which one groove is provided for one hole is exemplified, but a structure in which only a hole is provided without providing a groove or a structure in which two or more grooves are provided may be employed. For example, as shown in fig. 8, a groove 85A recessed from the facing surface 26d and communicating with the lower end of the hole 81 and a groove 85B having a maximum size larger than the maximum size of the groove 85A and recessed from the facing surface 26d and communicating with the hole 81 and the groove 85A may be provided in the top wall portion 22a at a position facing the 1 st magnet 41. In fig. 8, the configuration in which two groove portions, i.e., the groove portion 85A and the groove portion 85B, are provided at positions facing the 1 st magnet 41 is exemplified, but it is needless to say that two groove portions and three or more groove portions may be provided at positions facing the 2 nd magnet 42, the 3 rd magnet 43, and the 4 th magnet 44.

Further, unevenness may be provided by surface treatment such as shot blasting on at least a part of the hole and the groove, and the contact area with the adhesive may be increased to increase the adhesive strength. In this case, the inner peripheral surface of the hole may be subjected to the surface treatment without providing the groove portion.

In the above embodiment, the configuration in which the magnets 40 are provided on both sides across the mover 30 in the vertical direction Z is exemplified, but the magnet 40 may be provided only on the upper side or the lower side of the mover 30 because the material of the case 20 is a magnetic material.

Claims (6)

1. A linear actuator having:

a movable element movable in a predetermined 1 st direction;

a magnet disposed opposite to the movable element in a 2 nd direction perpendicular to the 1 st direction;

an elastic member that elastically deforms in accordance with the movement of the movable element in the 1 st direction and applies a force in the 1 st direction to the movable element; and

a magnetic housing that houses the movable element, the magnet, and the elastic member therein,

the magnet is mounted on the inner wall surface of the housing,

the housing has a hole penetrating the housing at a position facing the magnet,

an adhesive is provided in the hole.

2. The linear actuator of claim 1,

the housing has a groove portion recessed from the inner wall surface at a position facing the magnet and communicating with the hole portion.

3. The linear actuator according to claim 1 or 2,

the hole portion overlaps with a magnetic pole center of the magnet in the 2 nd direction.

4. The linear actuator according to any one of claims 1 to 3,

maximum sizes of the hole portions on the inner wall surface are respectively 30% or less of a maximum size of the magnet in the 1 st direction and a maximum size of the magnet in the 3 rd direction perpendicular to the 1 st direction and the 2 nd direction.

5. The linear actuator according to any one of claims 1 to 4,

the magnets are attached to the inner wall surface of the housing on both sides of the movable element in the 2 nd direction.

6. The linear actuator according to any one of claims 1 to 5,

the movable member has a coil.

Images