JP6307378B2 - Linear actuator - Google Patents

Description

  The present invention relates to a linear actuator provided with a magnetic drive mechanism.

  In the field of mobile phone, etc., a device for notifying an incoming call by vibration is used, and as such a device, a linear actuator for driving a movable body provided with a permanent magnet by a coil provided on a fixed body has been proposed. (See Patent Documents 1 and 2). According to such a linear actuator, the intensity and frequency of vibration can be varied by the drive signal supplied to the coil.

JP 2012-135755 A JP 2006-7161 A

  In a linear actuator provided with a magnetic drive mechanism, it is necessary to apply a sufficient thrust to a movable body in order to make the strength and frequency of vibration variable by the drive signal supplied to the coil. When the coil is arranged around the support shaft and the permanent magnet is arranged around the coil as in the configuration described in (1), a large thrust cannot be obtained. However, when a plurality of permanent magnets are arranged in the axial direction, the number of parts increases and the cost of the linear actuator increases. Further, the linear actuator described in Patent Document 2 has a problem in that the number of parts is large because the movable body is supported by a support shaft that penetrates the movable body. Furthermore, the configuration described in Patent Document 2 has a problem that when the movable body vibrates, the movable body resonates depending on the frequency of vibration.

  In view of the above problems, an object of the present invention is to provide a linear actuator that can generate an appropriate vibration in a movable body with a small number of parts.

  In order to solve the above-described problems, a linear actuator according to the present invention includes a movable body having one cylindrical permanent magnet, a fixed body having a coil bobbin surrounding the permanent magnet on the outside in the radial direction, and the movable body. And a spring member connected to the coil bobbin so that the movable body is supported so as to be movable in the axial direction relative to the coil bobbin, and the movable body is wound together with the permanent magnet in the axial direction. And a gel damper member sandwiched between the fixed body and the movable body in the axial direction.

In the present invention, the magnetic drive mechanism is used to drive the movable body, and the spring member is connected between the movable body and the fixed body, so the propulsive force of the magnetic drive mechanism and the biasing force of the spring member are used. Thus, the movable body can be driven in the axial direction. The movable body is provided with a cylindrical permanent magnet. In the fixed body, a coil is wound around a coil bobbin that surrounds the permanent magnet on the outer side in the radial direction. For this reason, since a permanent magnet and a coil can be enlarged in diameter, a big thrust can be given to a movable body also with a simple structure that there is one permanent magnet. Further, resonance of the movable body can be suppressed with a simple configuration in which the gel-like damper member is sandwiched between the fixed body and the movable body in the axial direction. Further, since the movable body is supported by the spring member on the outer side in the radial direction of the permanent magnet, the movable body is unlikely to be inclined even if the movable body is not supported by the support shaft. Therefore,
According to the present invention, it is possible to configure a linear actuator with a small number of parts and to generate appropriate vibrations in the movable body.

  In the present invention, the coil bobbin includes a bottom plate portion that overlaps on one side in the axial direction with respect to the movable body, a cylindrical portion that protrudes from the bottom plate portion to the other side in the axial direction and surrounds the permanent magnet on a radially outer side, In the bottom plate portion, when viewed in the axial direction, slits are formed at a plurality of locations in the circumferential direction so as to overlap gaps formed between the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the movable body. Preferably it is. According to this configuration, when assembling the linear actuator, a jig such as a shim can be arranged from the slit to provide an appropriate gap between the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the movable body. Accordingly, since the gap width can be set appropriately at any location in the circumferential direction, the movable body is unlikely to be inclined even if the movable body is not supported by the support shaft.

  In the present invention, the movable body includes a first core that overlaps the permanent magnet on one side in the axial direction, and a second core that overlaps the permanent magnet on the other side in the axial direction. Preferably, the gap is larger than the permanent magnet, and the gap is located between the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the first core. According to this configuration, it is easier to position the outer peripheral surface of the movable body and the inner peripheral surface of the cylindrical portion than when positioning between the outer peripheral surface of the permanent magnet and the inner peripheral surface of the cylindrical portion.

  In the present invention, it is preferable that the fixed body includes a fixed plate that overlaps the opposite side of the movable body with respect to the bottom plate portion. According to such a configuration, since one side in the axial direction can be closed by the fixed plate, foreign matter is unlikely to enter between the outer peripheral surface of the movable body and the inner peripheral surface of the cylindrical portion.

  In the present invention, the fixed plate preferably closes the slit from the side opposite to the movable body. According to such a configuration, the air damper acts between the movable body and the coil bobbin or between the movable body and the fixed plate. For this reason, compared with the case where only a gel-like damper member is utilized, the resonance of a movable body can be suppressed more reliably. In addition, since the air damper acts between the movable body and the coil bobbin, or between the movable body and the fixed plate, it is possible to relax the requirements for the gel-like damper member.

  In the present invention, the first core and the bottom plate portion are formed with a through hole in which the gel-like damper member is disposed inside, and the gel-like damper member has the fixed plate and the movable body in the axial direction. It is preferable to be sandwiched between According to such a configuration, it is possible to expand a space for arranging the gel-like damper member in the axial direction as compared with the case where the gel-like damper member is arranged between the permanent magnet and the coil bobbin. Therefore, since the gel-like damper member having a large dimension in the axial direction can be disposed, the resonance of the movable body can be more reliably suppressed.

  In the present invention, between the fixed plate and the movable body, an opening that opens radially outward extends in the circumferential direction, and the fixing plate has an adhesive member along the opening. Is preferably provided. According to such a configuration, it is difficult for foreign matter to enter between the outer peripheral surface of the movable body and the inner peripheral surface of the cylindrical portion.

  In this invention, it is preferable that the said adhesive member is arrange | positioned in the groove | channel formed in the surface of the other side of the axial direction of the said fixed plate. According to this configuration, a space for arranging the adhesive member can be easily secured.

  In the present invention, the gel damper member is made of, for example, a silicone gel.

  In the present invention, the magnetic drive mechanism is used to drive the movable body, and the spring member is connected between the movable body and the fixed body, so the propulsive force of the magnetic drive mechanism and the biasing force of the spring member are used. Thus, the movable body can be driven in the axial direction. The movable body is provided with a cylindrical permanent magnet. In the fixed body, a coil is wound around a coil bobbin that surrounds the permanent magnet on the outer side in the radial direction. For this reason, since a permanent magnet and a coil can be enlarged in diameter, a big thrust can be given to a movable body also with a simple structure that there is one permanent magnet. Further, resonance of the movable body can be suppressed with a simple configuration in which the gel-like damper member is sandwiched between the fixed body and the movable body in the axial direction. Further, the movable member is supported by the spring member on the radially outer side, such as being connected to a coil bobbin that surrounds the permanent magnet of the movable member on the radially outer side. For this reason, even if the movable body is not supported by the support shaft, the movable body is unlikely to be inclined. Therefore, according to the present invention, a linear actuator can be configured with a small number of parts, and appropriate vibrations can be generated in the movable body.

It is a perspective view of the linear actuator which concerns on Embodiment 1 of this invention. It is an exploded view of the linear actuator which concerns on Embodiment 1 of this invention. It is sectional drawing of the linear actuator which concerns on Embodiment 1 of this invention. In the linear actuator which concerns on Embodiment 1 of this invention, it is a perspective view which shows a mode that the spring member 8 was attached to the coil bobbin which wound the coil. It is the disassembled perspective view which looked at a mode that the spring member, coil bobbin, and coil which were used for the linear actuator which concerns on Embodiment 1 of this invention were decomposed | disassembled from the other side of the axial direction. It is explanatory drawing of the coil bobbin used for the linear actuator which concerns on Embodiment 1 of this invention. It is an expanded sectional view which expands and shows the state which inserted the jig | tool from the 1st slit of the coil bobbin used for the linear actuator which concerns on Embodiment 1 of this invention. It is sectional drawing of the linear actuator which concerns on Embodiment 2 of this invention.

  Embodiments of the present invention will be described with reference to the drawings. In the following description, the axis L is the central axis of the movable body 6, and the axis L passes through the center of gravity of the movable body 6. In the following description, in the direction (axial direction) in which the axis L extends, the side on which the movable body 6 is positioned is referred to as one side L1, and the side on which the fixed plate 4 of the fixed body 2 is positioned is described as the other side L2. To do.

[Embodiment 1]
(overall structure)
FIG. 1 is a perspective view of a linear actuator 1 according to Embodiment 1 of the present invention. FIG. 2 is an exploded view of the linear actuator 1 according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view of the linear actuator 1 according to the first embodiment of the present invention. FIGS. 3A, 3B, and 3C show the movable body 6 positioned on the other side L2 in the axis L direction. FIG. 6 is a cross-sectional view in a state where the movable body 6 is positioned at an intermediate position (origin position) in the axis L direction, and a cross-sectional view in a state where the movable body 6 is positioned on one side L1 in the axis L direction.

  As shown in FIGS. 1, 2, and 3 (b), the linear actuator 1 of the present embodiment includes a fixed body 2, a movable body 6, and a spring member 8 connected to the movable body 6 and the fixed body 2. The spring member 8 supports the movable body 6 so as to be movable in the direction of the axis L with respect to the fixed body 2. The linear actuator 1 has a magnetic drive mechanism 5 that drives the movable body 6 in the direction of the axis L.

(Configuration of movable body 6)
The movable body 6 has one permanent magnet 53 that constitutes the magnetic drive mechanism 5. Permanent magnet 53
Is a cylindrical shape having the axis L as the central axis, and is magnetized into the N pole and the S pole in the direction of the axis L. The movable body 6 includes a first core 71 that overlaps the permanent magnet 53 on one side L1 in the axial direction, and a second core 72 that overlaps the permanent magnet 53 on the other side L2 in the axial line L direction.

  The first core 71 has an annular shape centered on the axis L, and has a through hole 710 at the center. Further, the outer diameter of the first core 71 is slightly larger than the outer diameter of the permanent magnet 53, and the outer peripheral surface 715 of the first core 71 projects outward in the radial direction from the outer peripheral surface 535 of the permanent magnet 53. The first core 71 is fixed to the surface of the permanent magnet 53 on the one side L1 in the axis L direction by a method such as adhesion.

  The second core 72 includes an end plate portion 721 that overlaps the permanent magnet 53 on the other side L2 in the axis L direction, and a cylindrical side plate portion 722 that extends from the outer edge of the end plate portion 721 to the one side L1 in the axis L direction. It has. Moreover, it has the convex part 723 for stopper which protruded in the radial direction inner side at the edge part of the one side L1 of the axis line L direction of the side-plate part 722. FIG. In this embodiment, the second core 72 is composed of three magnetic plates (a first magnetic plate 76, a second magnetic plate 77, and a third magnetic plate 78).

  The first magnetic plate 76 includes a circular end plate portion 761 that overlaps the permanent magnet 53 on the other side L2 in the axis L direction, and a cylindrical side plate that extends from the outer edge of the end plate portion 761 to the one side L1 in the axis L direction. Part 762. The second magnetic plate 77 has a disk shape slightly smaller than the end plate portion 761 of the first magnetic plate 76, and is stacked on the end plate portion 761 of the first magnetic plate 76 on one side L1 in the axis L direction. . In this state, the second magnetic plate 77 is welded to the end plate portion 761 of the first magnetic plate 76 using the edge of the hole 773 or the like. Therefore, the end plate portion 721 of the second core 72 is constituted by the end plate portion 761 of the first magnetic plate 76 and the second magnetic plate 77. Therefore, the thickness of the end plate portion 721 of the second core 72 corresponds to the sum of the plate thickness of the end plate portion 761 of the first magnetic plate 76 and the plate thickness of the second magnetic plate 77. It is larger than the plate thickness. A step portion 774 is formed along the outer peripheral edge of the surface of the second magnetic plate 77 on the other side L2 in the axis L direction.

  The third magnetic plate 78 has a cylindrical body portion 781, and the end portion of the other side L2 of the body portion 781 in the axis L direction is one side L1 of the side plate portion 762 of the first magnetic plate 76 in the axis L direction. It is connected to the end of this by welding or the like. Therefore, the side plate portion 722 of the second core 72 is constituted by the side plate portion 762 of the first magnetic plate 76 and the body portion 781 of the third magnetic plate 78. Here, notches 763 are formed at a plurality of positions in the circumferential direction at the end of one side L1 of the side plate 762 of the first magnetic plate 76 in the axis L direction, and the side plate 762 of the first magnetic plate 76 is formed. And the body 781 of the third magnetic plate 78 are connected by welding or the like, the notch 763 holds a movable body side connecting portion 82 of the spring member 8 described later. The third magnetic plate 78 has an annular portion 782 that is bent radially inward at one end L1 of the trunk portion 781 in the axis L direction, and the annular portion 782 serves as a stopper for the second core 72. A convex portion 723 is formed. In the second core 72 configured as described above, the second magnetic plate 77 is fixed to the surface of the other side L2 of the permanent magnet 53 in the axis L direction by a method such as adhesion.

(Configuration of fixed body 2)
FIG. 4 is a perspective view showing a state where the spring member 8 is attached to the coil bobbin 3 around which the coil 55 is wound in the linear actuator 1 according to Embodiment 1 of the present invention, and FIGS. These are the perspective view which looked at the coil bobbin 3 from the other side L2 of the axis line L direction, and the perspective view which looked at the coil bobbin 3 from the one side L1 of the axis line L direction. FIG. 5 is an exploded perspective view of the state in which the spring member 8, the coil bobbin 3, and the coil 55 used in the linear actuator 1 according to Embodiment 1 of the present invention are disassembled, as viewed from the other side L2 in the axis L direction. 6 is an explanatory diagram of the coil bobbin 3 used in the linear actuator 1 according to the first embodiment of the present invention. FIGS. 6 (a), 6 (b), 6 (c), and 6 (d) show the coil bobbin 3 as an axis. A plan view of the L direction from the other side L2, a bottom view of the coil bobbin 3 from the one side L1 in the axis L direction, a side view of the coil bobbin 3, and a state in which the slit of the coil bobbin 3 is viewed from the other side L2 in the axis L direction. It is explanatory drawing shown.

  As shown in FIGS. 2, 3 (b), 4, 5 and 6, the fixed body 2 has a coil bobbin 3 around which the coil 55 of the magnetic drive mechanism 5 is wound. The coil bobbin 3 includes a bottom plate portion 31 that overlaps the movable body 6 on one side L1 in the axis L direction, and a cylindrical portion 32 that protrudes from the bottom plate portion 31 to the other side L2 in the axis L direction. Encloses the permanent magnet 53 radially outward between the permanent magnet 53 and the side plate portion 722 of the second core 72. The fixed body 2 includes a fixed plate 4 that overlaps with the bottom plate portion 31 of the coil bobbin 3 on the side opposite to the movable body 6 (one side L1 in the axis L direction).

  In the coil bobbin 3, the cylindrical portion 32 includes an annular body 321 around which the coil 55 is wound, and an annular shape whose diameter is expanded radially outward from an end portion on one side L <b> 1 in the axis L direction of the tubular body 321. The first flange portion 322 has an annular second flange portion 323 that is expanded radially outward from the cylindrical body portion 321 on the other side L2 in the axis L direction with respect to the first flange portion 322. .

  Here, when viewed from the direction of the axis L, the second flange portion 323 has a larger diameter than the first flange portion 322. Accordingly, in a state where the coil 55 is wound around the cylindrical body portion 321, the first flange portion 322 slightly protrudes radially outward from the outer peripheral surface of the coil 55, whereas the second flange portion 323 is The coil 55 protrudes greatly outward in the radial direction from the first flange portion 322 from the outer peripheral surface of the coil 55.

  In the coil bobbin 3, a bottom plate portion 31 is provided radially inward from an end on one side L <b> 1 in the axis L direction of the cylindrical portion 32, and a through hole 310 is formed in the center of the bottom plate portion 31. The second flange portion 323 is provided on one side L1 in the direction of the axis L from the distal end surface 328 of the cylindrical body portion 321.

  As shown in FIGS. 2 and 3, the fixed plate 4 includes a disc portion 41 that overlaps with the bottom plate portion 31 of the coil bobbin 3 on the side opposite to the movable body 6 (one side L1 in the axis L direction), and a disc And a rectangular substrate support portion 42 protruding radially outward from one circumferential portion of the portion 41. A wiring board 46 is supported on the board support portion 42, and ends 551 and 552 of the coil 55 are connected to the wiring board 46.

(Configuration of the spring member 8)
As shown in FIGS. 2, 3 (b), 4 and 5, the spring member 8 includes a fixed body side connecting portion 81 connected to the fixed body 2 (coil bobbin 3) and the movable body 6 (second core 72). ) And a plurality of arm portions 83 connected to the fixed body side connecting portion 81 and the movable body side connecting portion 82. In the present embodiment, the fixed body side connecting portion 81 has an annular shape and is located on the radially inner side from the movable body side connecting portion 82 and the arm portion 83. Here, the fixed body side connecting portion 81 is formed with a hole 819 into which a protrusion 329 protruding from the tip end surface 328 of the cylindrical body portion 321 of the coil bobbin 3 to the other side L2 in the axis L direction is fitted. The fixed body side connecting portion 81 and the tip end surface 328 of the cylindrical body portion 321 are connected.

  The movable body side connecting portion 82 is divided into three in the circumferential direction, and an arm portion 83 extends in the circumferential direction from each of the three movable body side connecting portions 82. As described with reference to FIG. 1 and FIG. 2, the three movable body side connecting portions 82 are each formed by welding the side plate portion 762 of the first magnetic plate 76 and the body portion 781 of the third magnetic plate 78. When connecting, it is held in the notch 763.

(Configuration of the first slit 311 of the bobbin 3)
FIG. 7 shows a coil bobbin 3 used in the linear actuator 1 according to the first embodiment of the present invention.
It is an expanded sectional view which expands and shows the state which inserted the jig | tool 30 from the 1st slit 311 of.

  As shown in FIGS. 4 and 5, in the coil bobbin 3, the bottom plate portion 31 has first slits 311 formed in an arc shape at a plurality of locations in the circumferential direction, and when viewed from the direction of the axis L, the first slit 311. Is a gap G between the inner peripheral surface 325 of the cylindrical body 321 (the inner peripheral surface 325 of the cylindrical portion 32) and the outer peripheral surface 715 of the first core 71 of the movable body 6 (see FIG. 3B and FIG. 7). It is in a position that overlaps. More specifically, as shown in FIG. 7, when viewed from the direction of the axis L, the outer peripheral edge 311a of the first slit 311 is the inner peripheral surface 325 of the cylindrical body 321 (the inner peripheral surface 325 of the cylindrical portion 32). The inner peripheral edge 311 b of the first slit 311 is in a position overlapping the outer peripheral surface 715 of the first core 71. As a result, the positions of the permanent magnet 53 of the movable body 6 and the coil 55 of the fixed body 2 are set with high accuracy.

  In such a configuration, in the assembly process of the linear actuator 1, the fixed body side connecting portion 81 is fixed to the coil bobbin 3, and then the movable body side connecting portion 82 of the spring member 8 is fixed to the second core 72 from the first slit 311. A jig 30 (shim) is inserted, and the gap G between the inner peripheral surface 325 of the cylindrical body 321 (the inner peripheral surface 325 of the cylindrical portion 32) and the outer peripheral surface 715 of the first core 71 is inserted into the jig 30. By positioning the movable body 6 and the coil bobbin 3, the movable body 6 and the coil bobbin 3 are positioned. In this state, the movable body side connecting portion 82 of the spring member 8 is fixed to the second core 72.

  As shown in FIGS. 4 and 6, the bottom plate portion 31 of the coil bobbin 3 has a second slit 312 formed radially inward from the first slit 311. The second slit 312 is formed when the fixing plate 4 is fixed to the bottom plate portion 31 of the coil bobbin 3 with an adhesive (not shown) after the movable body 6 is attached to the coil bobbin 3 via the spring member 8. The positioning of the coil bobbin 3 and the fixed plate 4 is performed by fitting the positioning plate 43 cut and raised from the position.

  In this way, when the fixing plate 4 is fixed to the bottom plate portion 31 of the coil bobbin 3 with an adhesive, the first slit 311 and the second slit 312 are closed by the adhesive, so that the inside of the fixed body 2 The movable body 6 and the fixed body 2 communicate with the outside only by the opening 20 that opens toward the radially outer side. Accordingly, the space between the movable body 6 and the fixed body 2 functions as an air damper.

  In the first slit 311 and the second slit 312, tapered surfaces 311 t and 312 t are formed at the opening edge on one side L <b> 1 in the axis L direction. Therefore, the jig 30 and the positioning plate 43 can be easily inserted into the first slit 311 and the second slit 312. In addition, the adhesive easily flows toward the first slit 311 and the second slit 312.

(Configuration of adhesive member 45)
As shown in FIGS. 1, 2, and 3, the fixing plate 4 is provided with an adhesive member 45 along the opening 20. In this embodiment, the pressure-sensitive adhesive member 45 is a pressure-sensitive adhesive tape fixed to the surface of the other side L <b> 2 in the axis L direction of the fixed plate 4 or a coated material having adhesiveness. In this embodiment, the adhesive member 45 is formed in an annular shape along the position overlapping the outer edge of the first flange portion 322 of the coil bobbin 3 in the fixed body 4 when viewed from the axis L direction.

(Configuration of the reinforcing rib 33 of the bobbin 3)
In the linear actuator 1 of this embodiment, an external force is applied between the movable body 6 and the fixed body 2 by the outer peripheral end portion 327 of the second flange portion 323 that faces the inner peripheral surface 727 of the second core 72 radially inward. Thus, the first stopper is configured to restrict the movable range of the movable body 6 when the movable body 6 moves in the direction orthogonal to the axis L. Further, the movable body 6 is movable between the movable body 6 and the fixed body 2 when the movable body 6 moves to the other side L2 of the axis L by an external force by the convex portion 723 and the second flange portion 323 of the second core 72. A second stopper that restricts the movable range of the body 6 is configured.

  However, the second flange portion 323 is a thin annular portion and has insufficient strength for a stopper. Therefore, in this embodiment, a reinforcing rib 33 connected to the second flange portion 323 is formed on the other side L2 in the axis L direction from the second flange portion 323 in the outer peripheral surface of the cylindrical portion 32 of the coil bobbin 3. In this embodiment, the outer peripheral surface 330 of the reinforcing rib 33 overlaps with the outer peripheral end portion 327 of the second flange portion 323 when viewed from the axis L direction.

  Here, the reinforcing rib 33 is provided at a position shifted in the circumferential direction from the connection position 820 of the arm portion 83 with the movable body side connecting portion 82. Further, the reinforcing rib 33 is a slope 335 inclined from the connecting position 820 of the arm part 83 to the movable body side connecting part 82 toward the one side L1 from the other side L2 in the axis L direction along the extending direction of the arm part 83. Is directed to the other side L2 in the direction of the axis L. That is, the reinforcing rib 33 has a circumferential dimension that is short on the other side L2 in the axis L direction and long on one side L1 in the axis L direction, and the longest part is connected to the second flange portion 323.

(Configuration of Gel Damper Member 9)
As shown in FIGS. 2 and 3, in the linear actuator 1 of this embodiment, a gel-like damper member 9 is disposed between the fixed body 2 and the movable body 6 at a position on the axis L.

  More specifically, in the fixed body 2, the fixed plate 4 includes the through hole 710 of the first core 71 and the bottom plate portion 31 of the bobbin 3 on one side L <b> 1 in the axis L direction with respect to the movable body 6 (permanent magnet 53). The cylindrical gel damper member 9 is disposed between the permanent magnet 53 and the fixed plate 4 in the axis L direction. Here, in the gel-like damper member 9, the surface on one side L <b> 1 in the axis L direction is fixed to the fixing plate 4 with an adhesive, and the surface on the other side L <b> 2 is fixed to the permanent magnet 53 with an adhesive. In this state, the gel damper member 9 penetrates the inside of the through hole 710 of the first core 71 and the inside of the through hole 310 of the bottom plate portion 31 of the bobbin 3.

  In this embodiment, the gel-like damper member 9 is made of a silicone gel having a penetration of 90 to 110 degrees. The penetration is a depth at which a 1/4 cone needle with a total load of 9.38 g at 25 ° C. enters 5 seconds as defined in JIS-K-2207 and JIS-K-2220. Is a value expressed in units of 1/10 mm, and the smaller this value is, the harder it is.

(Operation and main effect of this form)
As described above, in the linear actuator 1 according to the present embodiment, during the period when the energization to the coil 51 is suspended, the movable body 6 has the mass of the movable body 6 and the spring member 8 as shown in FIG. The holding force (biasing force) is balanced at the origin position. In this state, when a sine wave, an inversion pulse, or the like is supplied to the coil 51, first, the movable body 6 receives a propulsive force by the magnetic drive mechanism 5, and the urging force of the spring member 8 as shown in FIG. Against this, it moves to one side L1 in the direction of the axis L. The amount of movement at that time is defined by the current value supplied to the coil 51 and the biasing force of the spring member 8. And after returning to an origin position with the urging | biasing force of the spring member 8, as shown to Fig.3 (a), it opposes the urging | biasing force of the spring member 8, and the direction of an axis L direction receives it. Move to the other side L2. In this way, the movable body 6 is vibrated in the direction of the axis L. The amount of movement at that time is defined by the current value supplied to the coil 51 and the biasing force of the spring member 8. The frequency of vibration is defined by the frequency of the current supplied to the coil 51. For this reason, vibration intensity and frequency are variable.

Here, the movable body 6 is provided with one cylindrical permanent magnet 53, and in the fixed body 2, the coil 55 is wound around the coil bobbin 3 that surrounds the permanent magnet 53 on the outer side in the radial direction. For this reason, the permanent magnet 53 and the coil 55 can be increased in diameter. In addition, since the movable body 6 includes the first core 71 and the second core 72 on both sides of the permanent magnet 53 in the axis L direction, the magnetic flux density linked to the coil 55 is high. Therefore, even with a simple configuration in which the number of permanent magnets 53 is one, a large thrust can be applied to the movable body 6.

  Further, the spring member 8 is supported by the spring member 8 on the radially outer side of the permanent magnet 53, such as being connected to a coil bobbin 3 that surrounds the permanent magnet 53 of the movable body 6 on the radially outer side. For this reason, since the movable body 6 is stably supported by the spring member 8, even if the movable body 6 is not supported by the support shaft, the movable body 6 is unlikely to be inclined. Therefore, according to this embodiment, the linear actuator 1 can be configured with a small number of parts, and appropriate vibration can be generated in the movable body 6.

  In the second core 72, since the first magnetic plate 76 and the second magnetic plate 77 are laminated, even if the thickness is limited due to the restriction during the drawing process on the first magnetic plate 76, The end plate portion 721 of the two cores 72 can be made sufficiently thick. For example, the thickness of the end plate portion 721 of the second core 72 (the sum of the plate thickness of the end plate portion 762 and the plate thickness of the second magnetic plate 77) is larger than the plate thickness of the first core 71. Therefore, since the magnetic flux density linked to the coil 55 can be increased, a large thrust can be applied to the movable body 6.

  In addition, the bottom plate portion 31 of the coil bobbin 3 has a first slit that overlaps a gap G formed between the inner peripheral surface 325 of the cylindrical portion 32 of the coil bobbin 3 and the outer peripheral surface of the movable body 6 when viewed from the direction of the axis L. 311 are formed at a plurality of locations in the circumferential direction. For this reason, when assembling the linear actuator 1, as described with reference to FIG. 7, a jig 30 such as a shim is disposed from the first slit 311, and the outer peripheral surface of the movable body 6 and the inner peripheral surface 325 of the cylindrical portion 32. An appropriate gap G can be provided between the surface and the surface. Therefore, since the width of the gap G can be set appropriately at any location in the circumferential direction, it is difficult for the movable body 6 to tilt even if the movable body 6 is not supported by the support shaft. Here, since the first core 71 has a larger diameter than the permanent magnet 53, the gap G is located between the inner peripheral surface 325 of the cylindrical portion 32 and the outer peripheral surface 715 of the first core 71. For this reason, it is easier to position the outer peripheral surface of the movable body 6 and the inner peripheral surface 325 of the cylindrical portion 32 than when positioning between the outer peripheral surface 535 of the permanent magnet 53 and the inner peripheral surface 325 of the cylindrical portion 32. .

  The frequency of vibration is defined by the frequency of the drive signal supplied to the coil 51. At this time, the movable body 6 may resonate at a frequency corresponding to the mass of the movable body 6 and the spring constant of the spring member 8. In this embodiment, the fixed plate 4 of the fixed body 2 and the permanent magnet of the movable body 6 are used. A gel-like damper member 9 is provided between the movable body 6 and the gel-like damper member 9 so as to absorb the vibration of the movable body 6 while deforming following the movement of the movable body 6. For this reason, resonance of the movable body 6 can be suppressed. Further, the gel-like damper member 9 has a penetration of 90 degrees to 110 degrees. For this reason, the gel-like damper member 9 has sufficient elasticity to exert a damper function, and it is difficult for the gel-like damper member 9 to break and scatter. Moreover, since the gel-like damper member 9 is bonded and fixed to both the movable body 6 and the fixed body 2, it is possible to prevent the gel-like damper member 9 from moving as the movable body 6 moves.

  The first core 71 and the bottom plate portion 31 of the coil bobbin 3 are formed with through holes 710 and 310 in which the gel-like damper member 9 is disposed on the inner side. The gel-like damper member 9 is a fixed plate in the axis L direction. 4 and the permanent magnet 53. For this reason, compared with the case where the gel-like damper member 9 is arrange | positioned between the movable body 6 and the coil bobbin 3, the space which arrange | positions the gel-like damper member 9 in the axis line L direction can be expanded. Therefore, since the gel damper member 9 having a large dimension in the direction of the axis L can be disposed, the resonance of the movable body 6 can be more reliably suppressed.

  Further, since the fixed body 2 includes the fixed plate 4 that overlaps the side opposite to the movable body 6 with respect to the bottom plate portion 31, even if the first slit 311 and the like are formed in the bottom plate portion 31, the axis L direction One side L <b> 1 can be closed with the fixing plate 4. Accordingly, it is difficult for foreign matter to enter between the outer peripheral surface 535 of the permanent magnet 53 and the inner peripheral surface 325 of the cylindrical portion 32. Further, since the fixed plate 4 closes the first slit 311 and the like, the space between the movable body 6 and the coil bobbin 3 or between the movable body 6 and the fixed plate 4 acts as an air damper. For this reason, compared with the case where only the gel-like damper member 9 is used, the resonance of the movable body 6 can be more reliably suppressed. Moreover, the request | requirement requested | required of the gel-like damper member 9 can be eased.

  Further, since the adhesive member 45 is provided along the opening 20 between the movable body 6 and the fixed plate 4 on the surface of the other side L2 in the axis L direction of the fixed plate 4, the movable body 6 extends from the opening 20. A foreign substance such as dust that is about to enter between the fixing plate 4 and the fixing plate 4 can be captured by the adhesive member 45. Accordingly, it is difficult for foreign matter to enter between the outer peripheral surface 535 of the permanent magnet 53 and the inner peripheral surface 325 of the cylindrical portion 32.

  Further, in this embodiment, the second flange portion 323 of the coil bobbin 3 is used as a stopper, but the reinforcing rib 33 is connected to the second flange portion 323. For this reason, since the 2nd flange part 323 has sufficient intensity | strength, a stopper can be comprised using the 2nd flange part 323. FIG. Further, since the reinforcing rib 33 is provided at a position shifted in the circumferential direction from the connection position 820 between the movable body side connecting portion 82 and the arm portion 83 of the spring member 8, even if the reinforcing rib 33 is provided on the coil bobbin 3, The reinforcing rib 33 and the arm portion 83 of the spring member 8 do not easily interfere with each other. Further, the reinforcing rib 33 is a slope 335 inclined from the connecting position 820 of the arm part 83 to the movable body side connecting part 82 toward the one side L1 from the other side L2 in the axis L direction along the extending direction of the arm part 83. Is directed to the other side L2 in the direction of the axis L. For this reason, the reinforcement rib 33 can be formed over a wide range in the circumferential direction while avoiding interference between the reinforcement rib 33 and the arm portion 83 of the spring member 8.

[Embodiment 2]
FIG. 8 is a cross-sectional view of the linear actuator 1 according to Embodiment 2 of the present invention. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  In the first embodiment, an adhesive tape or a coated product having adhesiveness is provided as the adhesive member 45 on the surface of the other side L2 in the axis L direction of the fixed plate 4, but in this embodiment, as shown in FIG. The adhesive member 45 may be disposed in the groove 48 formed on the surface of the other side L2 of the fixing plate 4 in the axis L direction. According to this configuration, it is possible to easily secure a space for arranging the adhesive member 45.

[Other embodiments]
In the above embodiment, the structure in which the gel-like damper member 9 is fixed with an adhesive is adopted. However, after the precursor for forming the gel-like damper member 9 is provided, the precursor is gelled, and the gel-like damper is formed. The gel-like damper member 9 may be fixed by the adhesive force of the member 9 itself. For example, in Embodiment 2, after providing a UV curable precursor for forming the gel-like damper member 9, the precursor is irradiated with UV to be gelled, and the adhesive force of the gel-like damper member 9 itself is used. The gel-like damper member 9 may be fixed.

  In the above embodiment, the columnar gel-like damper member 9 is provided on the axis L, but the gel-like damper member 9 may be further arranged around the axis L. Further, instead of on the axis L, the gel-like damper member 9 may be arranged around the axis L.

1 .... Linear actuator 2 .... Fixed body 3 .... Coil bobbin 4 .... Fixing plate 5 ....
Magnetic drive mechanism 6 Movable body 8 Spring member 9 Gel damper member 20 Opening 30 Jig 31 Bottom plate 32 Cylindrical part 33 ..Reinforcing ribs 45..Adhesive members 48..Grooves 51..Coils 53..Permanent magnets 55..Coils 71..First core 72..Second core 76..No. 1 magnetic plate, 77 .. second magnetic plate, 78 .. third magnetic plate, 81.. Fixed body side connecting portion, 82 .. movable body side connecting portion, 83 .. arm portion, 310 .. through hole in bottom plate portion 311 ··· First slit, 312 ··· Second slit, 322 ··· First flange portion, 323 ·· Second flange portion, 325 · · Inner circumferential surface of cylindrical portion, 335 ·· Inclined surface, 710 ··· 1 core through hole, 715 .. outer periphery of the first core, 721 .. end plate of the second core, 723 .. for stopper Convex part, 761 ..End plate part of first magnetic plate, 762 ..Side plate part of first magnetic plate, 820 ..Connection position of arm part to movable body side coupling part, G .. Gap, L. , L1 ... one side, L2 ... other side

Claims (9)

A movable body having one cylindrical permanent magnet;
A stationary body provided with a coil bobbin that surrounds the permanent magnet radially outside;
A spring member connected to the movable body and the coil bobbin, wherein the movable body is supported so as to be movable in the axial direction with respect to the coil bobbin;
A coil that is wound around the coil bobbin and constitutes a magnetic drive mechanism that drives the movable body in the axial direction together with the permanent magnet;
A gel-like damper member sandwiched between the fixed body and the movable body in the axial direction;
The linear actuator characterized by having. The coil bobbin includes a bottom plate portion that overlaps on one side in the axial direction with respect to the movable body, and a cylindrical portion that protrudes from the bottom plate portion to the other side in the axial direction and surrounds the permanent magnet on a radially outer side,
In the bottom plate portion, when viewed from the axial direction, slits are formed at a plurality of locations in the circumferential direction so as to overlap a gap formed between the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the movable body. The linear actuator according to claim 1. The movable body includes a first core that overlaps the permanent magnet on one side in the axial direction, and a second core that overlaps the permanent magnet on the other side in the axial direction.
The first core has a larger diameter than the permanent magnet,
The linear actuator according to claim 2, wherein the gap is located between an inner peripheral surface of the cylindrical portion and an outer peripheral surface of the first core.   The linear actuator according to claim 2, wherein the fixed body includes a fixed plate that overlaps with the bottom plate portion on a side opposite to the movable body.   The linear actuator according to claim 4, wherein the fixed plate blocks the slit from a side opposite to the movable body. In the first core and the bottom plate portion, a through hole in which the gel-like damper member is disposed inside is formed,
The linear actuator according to claim 4, wherein the gel-like damper member is sandwiched between the fixed plate and the movable body in the axial direction. Between the fixed plate and the movable body, an opening that opens outward in the radial direction extends in the circumferential direction,
The linear actuator according to claim 4, wherein the fixing plate is provided with an adhesive member along the opening.   The linear actuator according to claim 7, wherein the adhesive member is disposed in a groove formed on a surface on the other side in the axial direction of the fixed plate.   The linear actuator according to claim 1, wherein the gel-like damper member is made of silicone gel.

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