JP5724637B2 - Linear actuator - Google Patents

Description

  The present invention provides a linear spring including a leaf spring that supports an inner core and an outer core that are provided inside and outside in the radial direction so as to have the same axial center, and elastically supports the outer core so as to reciprocate in the axial direction with respect to the inner core. It relates to an actuator.

  Conventionally, there are many types of linear actuators that reciprocate a mover in one direction with respect to a stator by the action of magnetism. Among them, a linear actuator having a configuration shown in Patent Document 1 below is known.

  This is a type called an outer movable type in which the mover is arranged outside the stator, and the outer core as the mover has the same axial center as the outer core as the stator. In addition, a permanent magnet is provided outside the inner core, and a magnetic pole part is provided inside the outer core. The permanent magnet and the magnetic pole part are placed close to each other with a certain distance therebetween, and the magnetic field formed between them is electrically The outer core is reciprocated in the axial direction of the shaft center by being controlled to be changed.

  The configuration of the linear actuator will be described in detail. The inner core is supported in the radial direction of the shaft by a shaft that passes through a through hole provided in the shaft center, and the outer periphery of the shaft is sandwiched between the inner core and the inner core. A pair of leaf springs is provided, and the outer core is elastically supported with respect to the axial direction of the shaft by being connected from the front surface and the rear surface by the pair of leaf springs. The leaf spring is formed in an “8” shape when viewed from the axial direction of the shaft, and a through hole is provided at the central intersection, and the shaft is simultaneously inserted into the through hole provided in the inner core and the through hole. As a result, the inner core and the leaf spring are arranged coaxially, and the outer core connected to the leaf spring can also be arranged coaxially with the inner core.

  In addition, a large-diameter portion that cannot pass through the through hole is formed on one end portion side of the shaft, and a male screw is formed on the other end portion side, and the leaf spring and the inner core are formed as described above. The position of the leaf spring or the inner core can be fixed with respect to the shaft by screwing the nut after inserting the through hole.

  In such a linear actuator, it is important to maintain a predetermined gap while appropriately facing the permanent magnet and the magnetic pole portion in order to maintain the characteristics as the linear actuator. For this purpose, the positions of the inner core and the outer core are determined. Various techniques for regulating the relationship have been proposed.

  For example, in Patent Document 1 described above, a groove portion is provided on the outer periphery of the leaf spring and a shaft portion is provided on the outer core, and the positional relationship between the leaf spring and the outer core is regulated by engaging the groove portion and the shaft portion. Indirectly, the positional relationship between the outer core and the inner core is regulated.

  Moreover, in patent document 2, while forming a shaft into a polygonal shape and making the through-hole of an inner core and a leaf | plate spring corresponding to this in a polygonal shape, the circle | round | yen between an inner core and a leaf | plate spring via a shaft is formed. The positional deviation in the circumferential direction is suppressed. Thereby, the positional relationship between the inner core and the outer core is also indirectly regulated.

  Further, in Patent Document 3, when the inner core and the outer core are relatively displaced in the radial direction, the inner core and the outer core are contacted to function as a stopper by contacting the permanent magnet and the magnetic pole portion before contacting each other. It is formed between. The contact portion also regulates the positional relationship between the inner core and the outer core during operation.

JP 2010-226874 A JP 2010-279161 A JP 2010-104126 A

  However, in the linear actuator according to the above-described prior art, a device for improving the ease of assembly while simplifying each component for reducing the manufacturing cost is still insufficient.

  For example, if a shaft formed in a columnar shape as in Patent Document 1 or Patent Document 3 is used and the shaft is inserted into a through hole of a leaf spring or an inner core and a nut is screwed to the tip, the nut is given. A rotational force acts on the leaf spring, and the position of the leaf spring is displaced in the circumferential direction with respect to the inner core. As a result, the positional relationship between the magnetic pole portion provided on the outer core and the permanent magnet provided on the inner core is increased. By changing, the magnetic field characteristic changes, and there is a possibility that the operation characteristic as a linear actuator may change.

  In order to prevent such misalignment during assembly, it may be possible to carefully assemble while using a dedicated assembly jig. However, the manufacturing cost of the jig increases and the number of assembly steps increases, Production costs may increase.

  Moreover, the shaft is made into a polygonal shape as in Patent Document 2, or a key or a flat portion is provided on a part of a cylindrical shape, and a leaf spring or inner core that is fitted to the outer periphery of the shaft is made to have a shape corresponding to them. Therefore, it is also conceivable to suppress the positional deviation in the circumferential direction. However, such processing may lead to an increase in manufacturing cost.

  As means for drastically solving the circumferential displacement between the leaf spring and the inner core during assembly as described above, the leaf spring and the inner core are pressed in the axial direction of the shaft without using a screw during assembly. Thus, it can be considered that the position of each member is regulated. Specifically, with a leaf spring and an inner core inserted through the outer periphery of the shaft, a fixed collar fixed by a tightening swivel is press-fitted in the axial direction by means such as a hydraulic cylinder instead of a nut at the tip of the shaft. A possible configuration is possible. With this configuration, the shaft does not require complicated processing such as screws, key grooves, and flat portions, so that the device configuration can be made simple and inexpensive, and can be easily assembled. Nevertheless, since no circumferential force is applied during assembly, no positional deviation occurs between the leaf spring and the inner core.

  However, in the configuration in which the fixed collar is press-fitted into the outer periphery of the shaft as described above, the position regulation in the axial direction of the leaf spring and the inner core by the fixed collar may be insufficient depending on the use environment. Specifically, when used in an environment where the temperature changes drastically and the shaft temperature rises significantly higher than the temperature of the inner core, the fixed collar is positioned relative to the leaf spring or inner core due to the elongation of the shaft. It will shift. Further, when the temperature of the shaft is significantly lower than the temperature of the inner core, the position of the fixed collar is shifted due to the shaft contracting in the axial direction.

  In these cases, the position restriction in the axial direction between the inner core fitted to the outer periphery of the shaft and the leaf spring is insufficient, and a gap is generated. When such a phenomenon occurs, even if the outer core is operated with respect to the inner core, it is conceivable that the operation stroke is shortened or the responsiveness is deteriorated by the gap. In addition, since the support state of the leaf spring changes, it may lead to a change in device characteristics as a linear actuator such as a natural frequency.

  An object of the present invention is to effectively solve such a problem. Specifically, the inner core and the outer core can be easily assembled without shifting in the circumferential direction, and the temperature change is severe. It is an object of the present invention to provide a linear actuator having stable device characteristics even under a use environment.

  In order to achieve this object, the present invention takes the following measures.

That is, the linear actuator of the present invention has an inner core, a pair of leaf springs provided so as to sandwich the inner core from the front and rear in the axial direction, and the same axial center as the inner core while being supported by the pair of leaf springs. And an outer core provided radially outward of the inner core, wherein one of the inner core and the outer core is provided with a permanent magnet, and the other of the inner core and the outer core is fixed with the permanent magnet. The inner core and the pair of leaf springs are each formed with a through hole at the same axial center, and has a large diameter portion on one end side. A shaft is tightly inserted into each through hole from the other end side, and is fixed to the other end protruding from the through hole. Is provided by being press-fitted in the axial direction, and a spring member is provided on at least one of either the pair of leaf springs and the large diameter portion or the fixed collar, and the inner core and the pair of pairs A leaf spring is positioned between the large-diameter portion and the fixed collar while being biased in the axial direction of the shaft by the spring member , and the outer core is on both sides in the axial direction, and the shaft The stopper member is provided at a position corresponding to the large-diameter portion and the fixed collar, and each stopper member is disposed with a predetermined gap with respect to the outer periphery of the large-diameter portion and the fixed collar. The predetermined gap is made smaller than the interval between the permanent magnet and the magnetic pole .

  With this configuration, it is possible to easily assemble without causing a circumferential displacement between the inner core and the leaf spring, and when the shaft expands due to a temperature change or the shaft contracts. Even if the position of the fixed collar is shifted in the axial direction, the leaf spring and the inner core can be pressed in the axial direction without being changed by the biasing force of the spring member, so that an axial gap is generated inside. And the support condition of the outer core by the leaf spring hardly changes. Therefore, even when used under severe conditions where the temperature changes drastically, the characteristics as a linear actuator do not change and can be used stably.

Further, the outer core is provided with stopper members on both sides in the axial direction and at positions corresponding to the large-diameter portion of the shaft and the fixed collar, and each of the stopper members includes the large-diameter portion and the fixed collar. It has a hole arranged with a predetermined gap with respect to the outer periphery, and since the predetermined gap is smaller than the interval between the permanent magnet and the magnetic pole, A compact configuration can also be achieved while also having a function as a radial stopper for position restriction.

Further, in order to further enhance the above effect, it is preferable that the leaf spring is uniformly supported over the entire circumferential direction. For this purpose, the spring member is formed by a disc spring, and the inside of the disc spring is It is preferable that the circumference is fitted to the outer circumference of the shaft.

  Furthermore, when the stopper function is activated, it is possible to absorb the impact caused by the contact between the members, and even when these contact, the sliding resistance is small and the relative reciprocating operation can be continued. It is preferable that a resin collar is provided on at least one of the outer periphery of the large-diameter portion and the fixed collar, or the inner periphery of the stopper member corresponding to each of the outer periphery.

  Furthermore, in order to be able to easily attach the above-mentioned resin collar and to ensure that the function as a stopper can work regardless of which direction the outer core is displaced, the resin collar is arranged in the circumferential direction. A cutting portion is provided at one location, and the diameter can be increased or decreased, and the cutting portion is provided obliquely with respect to the axial direction, and at least at any location in the circumferential direction. It is preferable that the resin collar is formed so that a part of the resin collar is present.

  According to the present invention described above, it is possible to easily assemble without causing a circumferential displacement between the inner core and the outer core, and there is a gap in the interior even in an environment where the temperature changes rapidly. It does not occur, and the support condition of the outer core does not change, so that it is possible to provide a linear actuator that can maintain stable operation characteristics.

The perspective view of the linear actuator which concerns on one Embodiment of this invention. Sectional drawing of the linear actuator. The exploded perspective view of the linear actuator. The disassembled perspective view of the principal part of the linear actuator. Sectional drawing which shows the assembly method of the principal part of the linear actuator. The disassembled perspective view of the outer core which comprises the linear actuator. The disassembled perspective view of the stopper member which comprises the linear actuator. The disassembled perspective view of the leaf | plate spring which comprises the linear actuator. Sectional drawing and perspective view which show the principal part of the linear actuator. The schematic diagram which shows the form of the crimping part used with the linear actuator. Sectional drawing and perspective view which show the modification of a stopper member and resin-made collars. Sectional drawing and the perspective view which show the modification of the stopper member different from FIG. 11, and resin-made collars.

  Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the linear actuator of this embodiment includes an inner core 2 that is largely provided inside, an outer core 3 that is provided on the outer periphery of the inner core 2 so as to have the same axis, and the above-described linear actuator. The shaft 6 comprises a shaft 6, a pair of leaf springs 41, 42 that support the outer core 3 on the outer periphery of the shaft 6, and stopper members 51, 52 provided in the front-rear direction of the leaf springs 41, 42, respectively. Has been.

  This configuration will be described in more detail with reference to the central sectional view shown in FIG.

The shaft 6 is formed in a columnar shape extending from the rear end portion 63 on the right side in the drawing toward the front end portion 62 on the left side in the drawing, and a large diameter portion 61 is formed on the right side in the drawing from the center in the longitudinal direction. Yes.
From the end surface 61a of the large diameter portion 61 to the left end portion 62 in the drawing is inserted as an insertion portion 64 into the inner core 2 and the leaf springs 41 and 42. The insertion portion 64 and the large diameter portion 61 are formed coaxially.

  The leaf spring 42, the spacer 72, the inner core 2, the spacer 71, and the leaf spring 41 are sequentially fitted in the insertion portion 64 of the shaft 6, and the disc spring 73 as a spring member and a fixed collar are provided in the vicinity of the distal end portion 62 of the shaft 6. 74 is fitted. Thus, the position of the leaf springs 41 and 42 and the inner core 2 is restricted between the end surface 74 b of the fixed collar 74 and the end surface 61 a of the large diameter portion 61 while being urged in the axial direction by the disc spring 73. It is like that.

  Here, in the description of the present embodiment, the axial direction means the axial direction in the shaft 6, and the radial direction and the circumferential direction mean the radial direction and the circumferential direction in the shaft 6, respectively. It is synonymous with the direction with reference to the third axis, and this definition will be used in the following description unless otherwise specified.

  The inner core 2 is formed of laminated steel plates, and core covers 21 and 22 are provided so as to sandwich the inner core 2 from the front and rear in the axial direction, and coils 25 and 26 are provided outside the core covers 21 and 22. ing. By applying a current to these coils 25 and 26, a vertical magnetic field in the figure can be generated. Further, permanent magnets 23 and 24 are provided above and below the inner core 2, and the permanent magnets 23 and 24 are configured such that different magnetic poles are arranged in the axial direction, respectively, 24, the magnetic poles are arranged in different directions.

  Cylindrical spacers 71 and 72 are provided on the front and rear sides of the inner core 2 in the axial direction so that one end face is in contact with each other. 42 is provided so as to abut. The leaf springs 71 and 72 extend to the outer periphery of the inner core 2 and are configured to support the outer core 3 via the guide pins 93.

  The outer core 3 is configured as an upper core 31 and a lower core 32, which are divided into two in the vertical direction in the figure, and are provided so that guide pins 93 and 93 are inserted therethrough, respectively. Positioning is performed in the radial direction via 41 and 42. Further, stopper members 51 and 52 are provided so as to sandwich the outer core 3 in the front and rear in the axial direction, and these are also positioned by the guide pins 93 and 93 in the same manner as the outer core 3. Further, in the state where the respective members are arranged in this manner, the bolts 91 and 91 and the nuts 92 and 92 are fixed in the axial direction.

  The shape and configuration of each part showing the above rough configuration will be described in detail below.

  If the structure between components is demonstrated again using the exploded perspective view shown in FIG. 3, the inner core 2 will be in the state inserted | pinched between the leaf | plate springs 41 and 42 in the axial direction through the spacers 71 and 72, These The inside of the through holes 2a, 41a, 42a is inserted through the insertion portion 64 of the shaft 6, and is configured to have a larger diameter than the disc spring 73 and the through holes 2a, 41a, 42a in the vicinity of the distal end portion 62 of the shaft 6. A fixed collar 74 is fitted. In this manner, the inner core 2 and the leaf springs 41 and 42 are positioned in the radial direction so as to have the same axis as the axis X of the shaft 6 and are positioned in the axial direction.

  Before fitting the outer periphery of the shaft 6 as described above, peripheral parts are attached to the inner core 2 as shown in FIG. The inner cores 2 are each formed of laminated steel plates whose axial direction is the thickness direction, and are integrated by being connected to each other by caulking portions 2j formed on the respective steel plates as will be described in detail later. The front surface 2b and the rear surface 2c in the axial direction are configured as flat surfaces, and a crimping portion 2j is provided as a convex portion in the axial direction on the front surface 2b, and a crimping portion (not shown) is provided as a concave portion in the rear surface 2c. It has been. A through hole 2a is formed in the center from the front surface 2b to the rear surface 2c, and the upper surface 2d and the lower surface 2e are formed so as to be almost close to a curved surface along the circumferential direction. Further, step portions 2f and 2g are formed as escape portions for winding the coils 25 and 26 at positions near the through hole 2a below the upper surface 2d and above the lower surface 2e, respectively.

  The spacers 71 and 72 that contact the inner core 2 so as to sandwich the inner core 2 in the front-rear direction are formed in a cylindrical shape, and caulking portions 71j and 72j are provided on these end surfaces as well as the inner core 2. For this reason, part of the caulking portion provided on the inner core 2 and the caulking portions 71j and 72j of the spacers 71 and 72 are engaged with each other, so that the positions are mutually regulated when pressed in the axial direction. Yes.

  Further, core covers 21 and 22 are provided so as to sandwich the inner core 2 in the axial direction, and almost all of the inner core 2 is covered thereby. The core covers 21 and 22 are provided with opening holes 21a and 22a, respectively. Since the opening holes 21a and 22a are formed larger than the outer diameter of the spacers 71 and 72, the end surfaces 71b of the spacers 71 and 72 are provided. 72c are completely exposed in the axial direction. With the core covers 71 and 72 attached to the inner core 2 in this way, the permanent magnets 23 and 24 are attached from above and below. The permanent magnets 23 and 24 are each configured to have a curved surface that protrudes radially outward, and the inner surfaces 23b and 24b are in contact with the upper surface 2d or the lower surface 2e of the inner core 2 while being guided by the core covers 21 and 22. It is attached in this way. Thus, the outer surfaces 23a and 24a are formed so as to be curved surfaces constituting a part of a cylindrical surface centering on the axis of the through hole 2a in a state of being attached to the inner core 2.

  Further, in a state where the core covers 21 and 22 are attached to the inner core 2, the coil 25 is provided at the positions of the step portions 21b, 21c, 22b and 22c of the core covers 21 and 22 corresponding to the step portions 2f and 2g of the inner core 2. 26 is formed. By applying a current to the coils 25 and 26, the magnetic field formed by the permanent magnets 23 and 24 can be changed.

  After the inner core 2, the core covers 21 and 22, the spacers 71 and 72, the permanent magnets 23 and 24, and the coils 25 and 26 are assembled in advance as described above, the other cores as shown in FIG. The linear actuator 1 is assembled together with the parts.

  Leaf springs 41 and 42 are provided so as to be adjacent to the spacers 71 and 72, respectively. The leaf springs 41 and 42 are connected to the frame portions 41e and 42e formed in a square shape, and the frame portions 41e and 42e in the vertical position in the drawing, and the spring portions 41f and 42f formed in the shape of "8". And ring-shaped attachment portions 41h and 42h provided at the center thereof. By being configured in this manner, the frame portions 41e and 42e can be elastically displaced in the axial direction by the deformation of the spring portions 41f and 42f in a state where the mounting portions 41h and 42h are fixed. Yes. One of the end surfaces of the attachment portions 41h and 42h is positioned in the axial direction so as to contact the spacers 71 and 72. The through holes 41a and 42a provided at the centers of the mounting portions 41h and 42h are arranged coaxially with the through hole 2a of the inner core 2 and the shaft 6 is inserted therethrough. Cutout portions 41b, 41b, 42b, and 42b are formed at the upper and lower positions in the figure of the frame portions 41e and 42e of the leaf springs 41 and 42 so as to be aligned with the center of the through hole 41a. At the time of assembly, the upper core 31 and the lower core 32 are positioned so that the guide pins 93 and 93 are inserted along the notches 41b, 41b, 42b and 42b from above and below in the drawing. . Further, bolt holes 41g to 41g and 42g to 42g are formed at the four corners of the frame portions 41 and 42, and the bolts 91 to 91 are inserted into the portions at the final stage of assembly. .

  Hereinafter, the detailed configuration of the leaf springs 41 and 42 will be described using the leaf spring 42 as an example. As shown in FIG. 8, the plate spring 42 is configured by laminating plate spring steel plates 42 </ b> P <b> 1 to 42 </ b> P <b> 5 formed by punching and connecting them to each other. Each of the leaf spring steel plates 42P1 to 42P5 has the same overall shape, and the formed bolt hole portions 42g1 to g5, the cutout portions 42b1 to b5, and the through hole portions 42a1 to a5 are integrated after being laminated. A single bolt hole 42g, a notch 42b, and a through hole 42a are formed as shown in FIG.

  Each frame portion 42e1 to e5 is provided with twelve crimping portions 42j1 to 42j5 in the circumferential direction, and each of the attachment portions 42h1 to h5 is provided with two crimping portions 42j1 to 42j5 in the left-right direction in the drawing. The caulking portions 42j1 to 42j5 are formed so as to have an inverted V-shaped cross section by pressing, and are convex toward the left in the drawing. Therefore, it has a concave shape of the same shape on the back surface with respect to the convex surface. Therefore, the concave portions and the convex portions can be engaged with each other by aligning the positions of the caulking portions 42j1 to 42j5 having such shapes. Further, by applying a pressing force in the laminating direction with a press or the like in the state where the thin plates are laminated in this way, the caulking portions 42j1 to 42j5 are slightly deformed and the mutual coupling force is strengthened and integrated. Is possible.

  In the present embodiment, the leaf spring 42 shown in FIG. 3 is the same as the leaf spring 41 configured as described above, and is assembled in the same direction when configured as the linear actuator 1.

  The plate springs 41 and 42 configured as described above are arranged so as to sandwich the inner core 2 via the spacers 71 and 72 as shown in FIG. 3, and the shaft 6 is inserted through the centers thereof. As described above, the core covers 21 and 22, the permanent magnets 23 and 24, and the coils 25 and 26 are attached to the inner core 2 in advance.

  When assembled in this way, the configuration is as shown in FIG. With the inner core 2 as the center, the plate spring 41, the spacer 71, the inner core 2, the spacer 72, and the plate spring 42 are arranged in this order from the left in the figure, and each of the through holes 41a, 71a, 2a, The insertion part 64 of the shaft 6 is inserted into the interior of 72a, 42a so that the end surface 61a of the large-diameter part 61 and the leaf spring 41 on the left side in the drawing sequentially contact each other in the axial direction. The inner diameter of each of the through holes 2 a, 71 a, 72 a, 41 a, 42 a provided in the center of the inner core 2, the spacers 71, 72 and the leaf springs 41, 42 is set to be substantially equal to the outer diameter of the insertion part 64. Is positioned in the radial direction by being tightly inserted. Further, with respect to the circumferential direction, position restriction is performed by engaging a part of the crimping portions 2j, 71j, 72j, 41j, and 42j (see FIGS. 3 and 4) formed on each member. It has become. In such a state, the disc spring 73 as the spring member and the fixed collar 74 are fitted into the insertion portion 64 of the shaft 6. A through hole 74a provided in the center of the fixed collar 74 has an inner diameter slightly smaller than the outer diameter of the insertion portion 64 of the shaft 6, and the fixed collar 74 uses a hydraulic cylinder or the like to form the tip end portion 62 of the shaft 6. Further, by press-fitting in the right direction in the figure, the position is firmly fixed by the inner peripheral surface of the through hole 74a gripping the outer peripheral surface of the insertion portion 64 after the press-fitting.

  When the fixed collar 74 is press-fitted, it is only pressed in the axial direction, and the circumferential force is not applied as in the case of tightening the screw. Therefore, the position of each member is not shifted in the circumferential direction when assembling. . Therefore, it is possible to easily perform the assembly without using special attention, and to reduce assembly defects.

  Since the outer diameter of the fixed collar 74 is configured to be larger than the through holes 2a, 71a, 72a, 41a, and 42a of the inner core 2, the spacers 71 and 72, and the leaf springs 41 and 42, the fixed collar 74 is Acts as a position restricting member in the axial direction. That is, the position of the inner core 2, the spacers 71 and 72, and the leaf springs 41 and 42 is restricted in the axial direction between the end surface 74 b of the fixed collar 74 and the end surface 61 a of the large diameter portion 61. When the fixed collar 74 is press-fitted as described above, the disc spring 73 is deformed so as to be compressed in the axial direction, so that the restoring force of the disc spring 73 is always the inner core 2, the spacers 71 and 72, the leaf spring 41, It acts on 42 in the axial direction. For this reason, the axial displacement of the inner core 2, the spacers 71 and 72, the leaf springs 41 and 42, and the stationary collar 74 due to the displacement of the stationary collar 74 in the axial direction due to the thermal contraction of the shaft 6 and the thermal expansion of the shaft 6 Even when the relative position is changed, the shape of the disc spring 73 is restored so that no gap is generated, and the inner core 2, the spacers 71 and 72, and the leaf springs 41 and 42 are always changed in the axial direction without changing. You can work the urging power of. As a result, no gap is generated in the axial direction on the outer periphery of the shaft 6, and the support conditions for the leaf springs 41 and 42 can be prevented from changing. Therefore, even if it is used under severe conditions where the temperature change is severe, the change in characteristics as the linear actuator 1 is reduced.

  Further, the disc spring 73 is used as a spring member for applying an axial urging force to the inner core 2, the spacers 71, 72, and the plate springs 41, 42, so that the inner peripheral surface of the disc spring 73 is connected to the shaft 6. It is possible to easily support with high positional accuracy simply by fitting it to the outer periphery, and to apply a biasing force uniformly in the circumferential direction. For this reason, the leaf springs 41 and 42 can be uniformly supported over the entire circumference without any directionality, thereby contributing to the stabilization of the characteristics as the linear actuator 1.

  Further, when the fixed collar 74 is press-fitted into the shaft 6, the end surface 74 b of the fixed collar 74 applies a pressing force in the axial direction to the inner core 2, the spacers 71 and 72 and the leaf springs 41 and 42. Therefore, as described above, a part of the caulking portions 2j, 71j, 72j, 41j, and 42j (see FIGS. 3 and 4) formed on each member that has been functioning as the positioning in the circumferential direction is an engagement portion. As a result of the slight deformation, the coupling force increases and integration is achieved.

  After the inner core 2, the spacers 71 and 72, the leaf springs 41 and 42, the disc spring 73, and the fixed collar 74 are assembled with the shaft 6 as a reference as described above, the upper core 31 and the lower core 31 are arranged in the form shown in FIG. 3. The side cores 32 are respectively attached from above and below in the drawing, and constitute the outer core 3. The outer core 3 constituted by the upper core 31 and the lower core 32 is provided so as to surround the inner core 2 on the outer side in the radial direction of the inner core 2, and is sandwiched in the axial direction by the frame portions 41 e and 42 e of the leaf springs 41 and 42. Provided. The outer core 3 has magnetic pole portions 31a and 32a formed on the inner surface thereof, and is configured to face the permanent magnets 23 and 24 with an appropriate gap therebetween. The upper core 31 and the lower core 32 are provided with guide pins 93 and 93 so as to be inserted into pin holes 31b and 32b provided outside the magnetic pole portions 31a and 32a, respectively. Is inserted into the notches 41b and 42b formed in the plate springs 41 and 42 described above, and can be incorporated while positioning.

  Since it has a positioning function using such guide pins 93, positioning can be performed so that the outer core 3 and the inner core have the same axis X at the time of assembly. 24 and the magnetic pole portions 31a and 32a are not caused to collide with each other to cause damage, and an appropriate gap can be formed between them. The upper core 31 and the lower core 32 are provided with through holes 31c, 31c, 32c, and 32c at positions corresponding to the bolt holes 41g to 41g and 42g to 42g provided in the leaf springs 41 and 42, respectively. Bolts 91 to 91 can be inserted at the final stage of assembly.

  The upper core 31 and the lower core 32 having the shapes as described above are configured in detail as follows. Hereinafter, the upper core 31 will be described as a representative.

  The upper core 31 has a configuration as shown in FIG. 6, and is formed by integrating five core elements 31B1 to B5 arranged in the axial direction. Each of the core elements 31B1 to B5 is formed in a U shape and is formed by laminating thin steel plates each formed by punching. The method for connecting these thin plates is the same as the fastening method using the crimping portions 42j1 to 42j5 formed in the respective portions of the thin plates 42P1 to P5 described with reference to FIG.

  Returning to FIG. 6, the core elements 31 </ b> B <b> 1 to B <b> 5 have caulking portions 31 j <b> 1 to j <b> 5 at their respective portions, and the caulking portions 31 j <b> 1 to j <b> 5 Therefore, when the core elements 31B1 to B5 are overlapped, the crimping portions 31j1 to j5 are engaged to restrict the position. The core elements 31B1 to B5 are respectively formed with bolt hole portions 31c1 to 31c5 and pin hole portions 31b1 to b5, and when the core elements 31B1 to B5 are connected to form the upper core 31 as a unit, The bolt hole 31c and the pin hole 31b are respectively configured. Inside the pin hole 31 b, guide pins 93 are inserted in the axial direction, and both end portions of the guide pins 93 protrude from the upper core 31. Further, step portions 31d1 to d5 and 31e1 to e5 are formed at both ends of the U-shape of the core elements 31B1 to B5, respectively, and the lower core 32 after the portions are integrated as the upper core 31. It is configured to mesh with the same part (see FIG. 3).

  In the present embodiment, the lower core 32 shown in FIG. 3 has the same shape as the upper core 31 configured as described above, and is used with the upper core 31 upside down. is there.

  Returning to FIG. 3, after the upper core 31 and the lower core 32 are positioned between the leaf springs 41 and 42 while being positioned by the guide pins 93 and 93, the stoppers are further sandwiched from outside in the axial direction. The members 51 and 52 are assembled. The stopper members 51 and 52 are each configured to have a rectangular outer shape and are substantially the same as the outer shapes of the leaf springs 41 and 42 and the outer core 3. Each stopper member 51, 52 is provided with groove portions 51b, 51b, 52b, 52b on the upper and lower sides in the drawing, respectively, and these portions are fitted to both ends of guide pins 93, 93 protruding in the axial direction from the outer core 3. Thus, positioning is performed, and the axial center X of the shaft 6 and the central axis are made the same as in the outer core 3.

  The stopper members 51 and 52 are each formed in a shape of “8”, and holes 51 a and 52 a are provided at the center thereof. The inner diameters of these holes 51 a and 52 a are the above-described fixed collar 74. And the outer diameter of the large diameter portion 61 of the shaft 6 are set to be slightly larger. Therefore, the fixed collar 74 and the large diameter portion 61 do not interfere with the holes 51a and 52a. The stopper members 51 and 52 are respectively provided with bolt holes 51c to 51c and 52c to 52c at four corners.

  The stopper members 51 and 52 configured in such a shape have the following configuration in detail. Hereinafter, the stopper member 51 on the left side in the drawing will be representatively described.

  The stopper member 51 has a configuration as shown in FIG. 7, and is configured by connecting two stopper elements 51B1 and 51B2 in the axial direction. The stopper elements 51B1 and 51B2 are formed in a rectangular shape having substantially the same outer shape, but the stopper element 51B1 is formed in a “8” shape and the stopper element 51B2 is formed in a “O” shape. . These stopper elements 51B1 and 51B2 are each configured by laminating thin punched steel plates. These thin plates are connected by engaging the caulking portions 51j1 to 51j1 and 51j2 to 51j2 provided in each of them in the axial direction. The leaf springs 41 and 42, the inner core 2 and the core spring 2 shown in FIG. The outer core 3 is configured by the same method.

  The stopper member 51 is designed so that the caulking portions 51j1 to 51j1 in FIG. 7 do not protrude leftward in the drawing in order to prevent a convex portion from being generated in the axial direction when the stopper member 51 is assembled as the linear actuator 1. . This method will be described in detail later.

  The stopper member 52 (see FIG. 3) is also manufactured in the same manner as the stopper member 51 as described above, but differs from the stopper member 51 when assembled as the linear actuator 1 as shown in FIG. The crimping member (see FIG. 7) is formed in the direction in which the concave portion is formed with respect to the outside in the axial direction.

  The inner peripheral surfaces of the holes 51a and 52a provided at the centers of the stopper members 51 and 52 form gaps between the fixed collar 74 and the outer peripheral surfaces of the large-diameter portion 61 of the shaft 6, respectively. Further, a resin collar 75 is fitted on the outer periphery of the fixed collar 74 and a resin collar 76 is fitted on the outer periphery of the large-diameter portion 61a at positions facing the hole portions 51a and 52a. FIG. 2 shows gaps between the fixed collar 74 fitted with the resin collars 75 and 76 and the large-diameter portion 61 of the shaft 6 and the hole portions 51a and 52a of the stopper members 51 and 52 facing them. Are defined as δ2 and δ3, respectively. On the other hand, a gap between the permanent magnets 23 and 24 and the magnetic pole portions 31a and 32a is defined as δ1. In the present embodiment, δ2 and δ3 are set to have the same size, and are set to be smaller than δ1. Therefore, even when the inner core 2 and the outer core 3 are relatively displaced in the radial direction, before the permanent magnets 23 and 24 come into contact with the magnetic pole portions 31a and 32a, the resin collars 75 and 76 are connected to the stopper member 51, Since the contact with the inner peripheral surfaces of the hole portions 51a and 52a of the 52 functions as a stopper, the contact between the permanent magnets 23 and 24 and the magnetic pole portions 31a and 32a can be prevented.

  The resin collars 75 and 76 are attached to the fixed collar 74 and the large-diameter portion 61 of the shaft 6 as shown in FIGS. 9 (a) and 9 (b). FIG. 9B is a schematic diagram showing a simplified case assuming that parts such as the inner core 5 and the leaf springs 41 and 42 are removed from the shaft 6. Small diameter portions are formed as stepped portions 74c and 61b in the fixed collar 74 and the large diameter portion 61 of the shaft 6, respectively, and resin collars 75 and 76 are fitted into these portions.

  The resin collars 75 and 76 have the same shape, are each formed in a thin cylindrical shape, and are provided with cutting portions 75a and 76a at one place in the circumferential direction. For this reason, it is fitted into the stepped portions 74c and 74b so as to have a larger diameter than that portion, and the inner peripheral surface is brought into close contact with each other by the restoring force so that the position is fixed. The cutting portions 75a and 75b are provided obliquely with respect to the axial direction, and are configured to form the resin collars 75 and 76 at any location in the circumferential direction while being attached to the stepped portions 74c and 74b. The dimensions are set so that the part exists. Therefore, even if the inner core 2 and the outer core 3 are relatively displaced with respect to any radial direction, the function as a stopper remains unchanged.

  In the state where the stopper members 51 and 52 are formed and assembled as described above, the bolt holes 51c to 51c and 52c to 52c provided in the stopper members 51 and 52 are bolt holes 41g provided in the leaf springs 41 and 42, respectively. ˜41 g, 42 g to 42 g and the bolt holes 31 c, 31 c, 32 c, 32 c provided in the outer core 3 are continuous in the axial direction. Therefore, the bolts 91 to 91 are inserted in the state in which the stopper members 51 and 52 have been assembled, and the nuts 92 to 92 are tightened at the tips thereof, so that the stopper members 51 and 52, the leaf springs 41 and 42, and the outer core 3 are pivoted. Can be fastened in the direction.

  At this time, the convex portions and the concave portions constituting the stopper members 51 and 52, the leaf springs 41 and 42, and the caulking portions 51j, 52j, 41j, 42j, 31j, and 32j formed on the outer core 3 are respectively engaged in the axial direction. Further, when a pressing force is further applied, minute deformation occurs, and a stronger fastening force is generated.

  After fastening in the axial direction in this way, the outer core 3 can operate integrally with the frame bodies 41e and 42e of the leaf springs 41 and 42 and the stopper members 51 and 52. The linear actuator 1 shown in FIG.

  Here, the method for mutually connecting the laminated steel plates used for constituting the inner core 2, the outer core 3, the spring members 41 and 42, and the stopper members 51 and 52 described above will be described in detail. FIG. 10A shows an example schematically showing the structure of the caulking portion.

  In this example, a case where five thin plates 81a to 81e are connected is shown. The thin plates 81c to e are formed with convex portions as described above as caulking portions 82c to 82e, respectively. The convex portion is formed in a reverse V-shape with a notch parallel to two sides of the side, that is, the depth of the paper surface and the near side, while the notch is directed to one side (left direction in the figure). It is a deformed one. Since the convex portion forms a concave portion in the back surface direction (right direction in the figure), when the thin plates 81c to e are overlapped, the crimping portions 82c to 82e are engaged so that the concave and convex portions overlap. In this example, rectangular openings are formed in the thin plates 82a and 82b as the caulking portions 82a and 82b. The portion can be engaged so that a convex portion as a caulking portion 82c formed on the thin plate 81c is inserted. When the crimping portions 82a to 82e are engaged in this manner and pressed in the stacking direction, the crimping portions 82a to 82e are slightly deformed to generate a fastening force.

  In the configuration example of the caulking portions 82a to 82e, since the caulking portions 82a and 82b of the thin plates 81a and 81b on the left side in the drawing are rectangular openings, even when the thin plates 81a to 82e are stacked and connected, It is possible to prevent a convex portion from being formed on the left side of the drawing from the surface of the thin plate 81a. However, it is not essential to configure some of the crimped portions 82a and 82b as openings in this manner, and all the crimped portions may be formed in the same shape as the inverted V shape. Is possible. Among the above, the stopper member 51 shown in FIG. 3 is configured by a method of providing openings in some of the caulking portions 82a and 82b. All the caulking portions have the same inverted V shape and project outward. The stopper member 52, the inner core 2, the outer core 3, and the leaf spring 42 are formed so as to generate a portion that becomes. As described above, the plate spring 41 is configured such that only the caulking portion that contacts the disc spring 73 does not form a convex portion, and the other portions are configured such that a convex portion is generated.

  In this way, each member can be easily formed using a laminated steel sheet with crimped portions, and the fastening force between the members can be increased by applying pressure in the stacking direction while using these crimped portions as engaging portions. It is possible to work.

  Moreover, it is also possible to comprise a crimping part like the example of FIG.10 (b). In this example, the caulking portions 182a to 182e are formed in a circular shape when viewed from the axial direction, and do not have a cut on the side unlike the inverted V type in FIG. 10 (b), the caulking portions 182a to 182e formed on the thin plates 181b to 181e constitute a circular convex portion in the left direction in the drawing, and the right side in the drawing which is the back surface. Form a circular recess. Further, the caulking portion 182a in the thin plate 181a is configured as the same circular hole. These caulking portions 182a to 182e are engaged when the thin plates 181a to 181e are stacked, and a fastening force can be generated between them by applying a pressing force in the axial direction.

  As described above, the linear actuator 1 configured as shown in FIGS. 1 and 2 operates as follows. Hereinafter, description will be made with reference to FIG.

  Since the linear actuator 1 in the present embodiment is used for fixing the shaft 6, the linear actuator 1 is fitted into the outer periphery (insertion portion) 64 of the shaft 6 and is positioned in the axial direction by the fixed collar 74 and the disc spring 73. The inner core 2 functions as a so-called stator. Similarly, the outer core 3 provided on the radially outer side of the inner core 2 and having the same axis by the leaf springs 41 and 42 supported by the shaft 6 functions as a mover. The outer core 3 is elastically supported by the plate springs 41 and 42 so that the outer core 3 can be displaced in the plate thickness direction, that is, the axial direction of the shaft 6.

  Permanent magnets 23 and 24 are provided on the upper and lower sides of the inner core 2 in the drawing, and magnetic pole portions 31a and 32a are provided on the inner surface of the outer core 3 so as to face the permanent magnets 23 and 24, respectively. And a gap δ1 is formed between them. As described above, the permanent magnets 23 and 24 are provided with different magnetic poles in the axial direction, and a magnetic field is generated around these magnetic poles. The positional relationship between the permanent magnets 23 and 24 and the magnetic pole portions 31 a and 32 a is an important factor that determines the characteristics of the linear actuator 1, and a positional deviation occurs in the circumferential direction between the leaf springs 41 and 42 and the inner core 2. This leads to a decrease in efficiency. Therefore, as in the present embodiment, the configuration as a device that can be assembled without pressing the force in the circumferential direction by simply press-fitting the fixed collar 74 in the axial direction makes it possible to improve the characteristics as a device. There is no loss.

  By applying a current to the coils 25 and 26 provided so as to be wound around the inner core 2, a magnetic field can be biased in the axial direction. In a state where no current is applied, the magnetic pole portions 31a and 32a are disposed so as to face the axial center portions of the permanent magnets 23 and 24, respectively. An axial thrust can be applied to the portions 31a and 32a. In this way, the outer core 3 can be displaced in the axial direction, and the outer core 3 can be vibrated with an arbitrary acceleration and frequency by changing the current in a sine wave shape in the forward and reverse directions. It is also possible to use it as an active vibration damper by utilizing such a function.

  When such a linear actuator 1 is used in a place where the temperature changes drastically, the characteristics may generally change due to a dimensional change in the axial direction of the shaft 6. Specifically, when the temperature of the shaft 6 rises relative to other members and relatively expands, or when the temperature of the shaft 6 falls below other members, the fixed collar 74 is pushed out in the axial direction. In this way, the position may be shifted to the left in the figure. In such a case, the inner core 2 and the plate attached to the outer periphery are increased by the relative dimension between the end surface 74b of the fixed collar 74 and the end surface 61a of the large-diameter portion 61 increasing relative to other members. The support condition of the outer core 3 is changed so that the spring length is apparently increased due to an axial gap with respect to the springs 41 and 42 and the spacers 71 and 72, or due to weak fixation of the leaf spring 41. Leads to. However, in the linear actuator 1 according to the present embodiment, since the disc spring 73 is provided in a compressed state adjacent to the fixed collar 74, the influence of a slight dimensional change of the shaft 6 and a positional deviation of the fixed collar 74 is provided. Is absorbed by the compression scissors of the disc spring 73 and is positioned against the inner core 2, the leaf springs 41 and 42, and the spacers 71 and 72 that are positioned between the end surface 74 b of the fixed collar 74 and the end surface 61 a of the large-diameter portion 61. The biasing force always works in the axial direction. Therefore, the characteristic as the linear actuator 1 does not change when a gap is generated in the axial direction of the shaft 6 or the support condition of the outer core 3 is changed.

  In addition, when the length of the shaft 6 is contracted relative to the inner core 2 as described above, the generation of excessive stress on the shaft 6 or the inner core 2 is suppressed by shifting the position of the fixed collar 74. It is possible to prevent damage to each member.

  Further, in order to increase the thrust with the same electric power and improve the efficiency, it is useful to reduce the gap δ1 between the permanent magnets 23 and 24 and the magnetic pole portions 31a and 32a to reduce the leakage magnetic flux. However, in such a method, there is a possibility that the permanent magnets 23 and 24 collide with the magnetic pole portions 31a and 32a. Since the permanent magnets 23 and 24 are generally made of a fragile material, the permanent magnets 23 and 24 may be damaged by collision with the magnetic pole portions 31a and 32a and become inoperable. In addition, even when the gap δ1 is sufficiently large and the permanent magnets 23 and 24 and the magnetic pole portions 31a and 32a are not in contact with each other, if the radial relative displacement is too large, the leaf springs 41 and 42 may be plastically deformed. If it is damaged, it may not function as an effective spring and may lose characteristics necessary for the linear actuator 1.

  In the linear actuator 1 of the present embodiment, in order to prevent the above problems, δ1 is set to a small size for improving efficiency, and stopper members 51 and 52 are provided in front and rear in the axial direction. Before the inner peripheral surfaces of the holes 51a and 52a formed in the core and the outer peripheral surfaces of the fixed collar 74 and the large-diameter portion 61 of the shaft 6 contact the permanent magnets 23 and 24 and the magnetic pole portions 31a and 32a. It comes into contact and functions as a stopper. Therefore, gaps δ2 and δ3 between the inner peripheral surfaces of the holes 51a and 52a and the outer peripheral surfaces of the fixed collar 74 and the large-diameter portion 61 of the shaft 6 are set smaller than δ1. The gaps δ2 and δ3 are sufficiently small for the purpose of preventing damage and deformation of the leaf springs 41 and 42.

  As described above, the fixed collar 74 and the large-diameter portion 61 regulate the position of the inner core 2, the leaf springs 41 and 42, and the spacers 71 and 72 between the end faces 74 b and 61 a, and the biasing force of the disc spring 73. In addition to acting as a base point for working the magnetic field, it can also serve as a stopper for preventing contact between the permanent magnets 23 and 24 and the magnetic pole portions 31a and 32a. For this reason, it is possible to achieve compactness with a simple configuration.

  In addition, resin collars 75 and 76 are fitted on the outer periphery of the fixed collar 74 and the large-diameter portion 61. When the resin collars 75 and 76 function as stoppers, the resin collars 75 and 76 serve as holes in the stopper members 51 and 52, respectively. It abuts on the inner peripheral surfaces of the portions 51a and 52a. Therefore, the impact when abutting can be absorbed by the resin material, the generation of noise can be suppressed, and the sliding resistance is reduced by functioning as a sliding bearing while abutting, thereby reducing the relative displacement in the axial direction. It is also possible to continue the movement of the outer core 3 in the axial direction while operating the stopper function. Furthermore, the shaft 6 and the fixed collar 74 are made of metal, and the above effects can be exhibited only by providing the thin resin collars 75 and 76 thereon. As a result, it can be easily installed and the gaps δ2, δ3 can be configured uniformly and accurately over the entire circumference.

  As described above, the linear actuator 1 according to the present invention includes the inner core 2, the pair of leaf springs 41 and 42 provided so as to sandwich the inner core 2 from the front and rear in the axial direction, and the pair of leaf springs 41 and 42. An outer core 3 provided on the radially outer side of the inner core 2 so as to have the same axial center as the inner core 2 while being supported, and the inner core 2 is provided with permanent magnets 23 and 24, The outer core 3 is formed with magnetic pole portions 31a and 32a facing the permanent magnets 23 and 24 at a predetermined interval, and the inner core 2 and the pair of leaf springs 41 and 42 are located at the same axial center position. Each of the through holes 2a, 41a, and 42a is formed, and the shaft 6 having the large diameter portion 61 on the one end portion 63 side is connected to each of the through holes 2a, A fixed collar 74 is axially press-fitted to the other end 62 protruding from the through holes 2a, 41a, 42a after being tightly inserted into the la, 42a, and the leaf spring 41 A spring member 73 is provided between the fixed collar 74 and the inner core 2 and the pair of leaf springs 41 and 42 between the large-diameter portion 61 and the fixed collar 74 by the spring member 73. The position of the shaft 6 is restricted while being given an urging force in the axial direction.

  With this configuration, the assembly can be easily performed without causing a circumferential displacement between the inner core 2 and the leaf springs 41 and 42, and the shaft 6 is stretched by heat. Even when the position of the fixed collar 74 is shifted in the axial direction, the urging force of the spring member 73 acts and the leaf springs 41 and 42 and the inner core 2 can always be pressed in the axial direction. In addition, there is no gap in the axial direction inside, and the support condition of the outer core 3 by the leaf springs 41 and 42 does not change. Therefore, even if it is used under severe conditions where the temperature changes drastically, the characteristics as the linear actuator 1 do not change and can be used stably.

  Further, since the spring member 73 is formed by a disc spring, and the inner circumference of the disc spring 73 is configured to be fitted to the outer circumference of the shaft 6, the plate springs 41 and 42 and the inner core 2 are configured. Since the axial pressing force acting on the shaft 6 can be generated uniformly in the circumferential direction of the shaft 6, the support of the leaf springs 41 and 42 can be made more stable, and the characteristics as the linear actuator 1 can be obtained. Can be further stabilized.

  Further, the outer core 3 includes stopper members 52 and 51 at positions corresponding to the large-diameter portion 61 of the shaft 6 and the fixed collar 74 on both sides in the axial direction, respectively. Includes holes 52a and 51a disposed with a predetermined gap with respect to the outer circumference of the large-diameter portion 61 and the fixed collar 74, and the predetermined gap is the permanent magnets 23 and 24 and the magnetic pole 31a. , 32a, the leaf spring 41 has the above-described effect while having the same function as an axial positioning function and a radial stopper. , 42 and the permanent magnets 23, 24 can be simply and compactly configured.

  Further, since the resin collars 76 and 75 are provided on the outer periphery of the large-diameter portion 61 and the fixed collar 74, even when these function as radial stoppers, the impact at the time of contact is absorbed. In addition, since the sliding resistance can be reduced, the relative operation of the inner core 2 and the outer core 3 can be continuously performed.

  Further, the resin collars 75 and 76 are provided with cutting portions 75a and 76a at one place in the circumferential direction so that the diameter can be increased, and the cutting portions 75a and 76a are provided obliquely with respect to the axial direction. The resin collars 75 and 76 having the above-described effects can be easily obtained because at least a part of the resin collars 75 and 76 exists at any location in the circumferential direction. The inner core 2 and the outer core 3 can reliably function as a stopper even if the inner core 2 and the outer core 3 are displaced in any radial direction.

  The specific configuration of each unit is not limited to the above-described embodiment.

  For example, the resin collars 75 and 76 described with reference to FIG. 9 are not limited to this form, and are provided on the hole portions 151a and 152a side of the stopper members 151 and 152 as shown in FIGS. 11 (a) and 11 (b). It is also possible to deform it. Even if it does in this way, the effect similar to the above of the impact reduction at the time of contact between the hole parts 151a and 152a, the fixed collar 174, and the large diameter part 161 of the shaft 106 and reduction of sliding resistance can be acquired. In this case, the dimension of the resin collar 175 (176) is set to be longer than the thickness of the stopper member 151 (152) in the axial direction, and flanges 175b and 175b (176b and 176b) are provided at both ends in the axial direction. The cutting portion 175c (176c) is formed in a part of the circumferential direction. After being deformed so as to be reduced in diameter by the cutting portion 175c (176c) and inserted into the hole 151a (152a), the inner surface of the hole 151a (152a) is utilized by using a restoring force. Adhere closely. After mounting in this manner, the position is restricted in the axial direction by the flanges 175b and 175b (176b and 176b).

  Further, the resin collar 275 (276) can be configured as shown in FIGS. 12 (a) and 12 (b). In this case, the resin collar 275 (276) is formed in a simple ring shape having a cut part 275c (276c) in part, and the hole 251a (252a) provided in the stopper member 251 (252) is concentric inside. A groove portion 251b (252b) is formed, and the resin collar 275 (276) is inserted so as to fit in the groove portion 251b (252b). When these function as a stopper, the inner surface of the resin collar 275 (276) comes into contact with the fixed collar 174 and the large-diameter portion 161 of the shaft 106.

  Further, in the above embodiment, the inner core 2 is configured as a stator and the outer core 3 is configured as a movable element. However, it may be reversed.

  Furthermore, in the above embodiment, the permanent magnets 23 and 24 and the coils 25 and 26 are provided on the inner core 2 and the magnetic pole portions 31a and 32a are formed on the outer core 3. However, it is also possible to reverse this.

  In the above embodiment, the insertion portion 64 (164) of the shaft 6 (106) is configured to have a round cross section, but the inner core 2 and the outer core 3 are supported so as to have the same axis. As long as the fixed collar 75 (175, 275) can be press-fitted after the disc spring 73 is fitted, it is not essential to have a round cross section, a flat portion is provided on a part of the outer periphery, It may be configured to have an elliptical or polygonal cross section. Further, the insertion portion 64 (164) into which the inner core 2, the spacers 71 and 72, the leaf springs 41 and 42, the disc spring 73, and the fixed collar 75 (175, 275) are fitted has an outer diameter or It is not essential to have the same cross-sectional shape, and it is possible to support each member fitted on the outer periphery so as to have the same axis, and the axial pressure between these members It is also possible to vary the outer diameter and the cross-sectional shape of the insertion portion 64 (164) according to the portion to which each member is attached as long as it can be transmitted sequentially.

  In the above embodiment, the disc spring 73 as a spring member is attached between the fixed collar 74 (174) and the leaf spring 41. However, as long as it is possible to apply a biasing force in the axial direction, It can be provided at any position between the large-diameter portion 61 (161) of the shaft 6 and the fixed collar 74 (174). For example, it is also suitable to provide between the large diameter portion 61 (161) of the shaft 6 (106) and the leaf spring 42. Further, a disc spring 73 may be attached between the fixed collar 74 (174) and the leaf spring 41 and between the large diameter portion 61 (161) and the leaf spring 42.

  Other configurations can be variously modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Linear actuator 2 ... Inner core 3 ... Outer core 6 ... Shaft 21, 22 ... Core cover 23, 24 ... Permanent magnet 25, 26 ... Coil 31, 32 ... Split core 33, 34 ... Magnetic pole part 41, 42 ... Plate spring 51, 52 ... Stopper member 71, 72 ... Spacer 73 ... Belleville spring (spring member)
74 ... Fixed collar 75, 76 ... Resin collar 91 ... Bolt 92 ... Nut 93 ... Guide pin

Claims (4)

An inner core, a pair of leaf springs provided so as to sandwich the inner core from the front and rear in the axial direction, a radius of the inner core so as to have the same axis as the inner core while being supported by the pair of leaf springs An outer core provided on the outer side in the direction, one of the inner core and the outer core is provided with a permanent magnet, and the other of the inner core and the outer core is formed with a magnetic pole portion facing the permanent magnet at a predetermined interval. In the linear actuator, the inner core and the pair of leaf springs are each formed with a through hole at the same axial center position, and the shaft having a large diameter portion on one end side is formed on the shaft from the other end side. A fixed collar is axially press-fitted to the other end protruding from the through hole after being closely inserted into each through hole. And at least one of the pair of leaf springs and at least one of the large-diameter portion or the fixed collar is provided, and the inner core and the pair of leaf springs are connected to the large-diameter portion and the The position is restricted while being given an urging force in the axial direction of the shaft by the spring member between the fixed collar ,
Further, the outer core is provided with stopper members on both sides in the axial direction and at positions corresponding to the large-diameter portion of the shaft and the fixed collar, and each of the stopper members includes the large-diameter portion and the fixed collar. A linear actuator comprising a hole portion having a predetermined gap with respect to an outer periphery, wherein the predetermined gap is made smaller than an interval between the permanent magnet and the magnetic pole . The linear actuator according to claim 1, wherein the spring member is formed of a disc spring, and an inner periphery of the disc spring is fitted to an outer periphery of the shaft. Said large diameter portion and said fixed outer circumferential color or according to claim 1 or 2, characterized in that a resin collar on at least one of the inner circumference of the stopper member corresponding to each of these outer periphery, Linear actuator. The resin collar is provided with a cutting portion at one place in the circumferential direction, and the diameter can be increased or reduced, and the cutting portion is provided obliquely with respect to the axial direction. The linear actuator according to claim 3 , wherein the linear actuator is formed so that at least a part of the resin collar is present at any position in the direction.

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