Coil assembly and voice coil motor

Abstract

To provide a coil assembly component and a voice coil motor in which an air core coil is appropriately cooled even in the vicinity of a refrigerant outlet.SOLUTION: In a coil assembly component including a housing having an annular housing space in which an air-core coil is housed, the housing includes a plurality of projections 23 that are formed with an inlet and an outlet for a refrigerant that communicate with the housing space, are provided on the inner wall that forms the housing space, and guide the flow F of the refrigerant, and the number of projections increases as approaching from the inlet to the outlet.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a coil assembly and a voice coil motor including the coil assembly. [Background technology]

[0002] Voice coil motors, for example, have become widespread. These motors have a permanent magnet and a coil disposed within the magnetic field of the permanent magnet, and the permanent magnet and coil act as a stator and a mover, respectively. In such voice coil motors, when current is applied to the coil, a thrust force is generated in the coil in a direction transverse to the magnetic field, based on Fleming's left-hand rule.

[0003] However, when a current flows through the coil, Joule heat is generated in the coil, and this heat causes thermal deformation in the members surrounding the coil, which may reduce the positioning accuracy of the voice coil motor.

[0004] In contrast to this, Patent Document 1 discloses a voice coil motor that has a housing with a space inside to accommodate an air-core coil, and cools the air-core coil by injecting a refrigerant into the space inside the housing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-299338 Summary of the Invention [Problem to be solved by the invention]

[0006] In the voice coil motor described above, the refrigerant flows into the space from the inlet of the housing and comes into contact with the air-core coil to cool it. As a result, the temperature of the refrigerant rises as it approaches the outlet, which not only prevents the air-core coil from being properly cooled near the outlet, but also causes temperature unevenness between the inlet and outlet, which may affect surrounding components.

[0007] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a coil assembly and a voice coil motor that can properly cool the air-core coil even near the refrigerant outlet and suppress the occurrence of temperature unevenness at the inlet and outlet. [Means for solving the problem]

[0008] The coil assembly member according to the present invention is a coil assembly member comprising a housing having an annular storage space in which an air-core coil is housed, wherein the housing is formed with an inlet and an outlet for a refrigerant that communicate with the storage space, and the housing has a plurality of protrusions on the inner wall that forms the storage space to guide the flow of the refrigerant, the number of protrusions increasing as one approaches from the inlet to the outlet.

[0009] In the present invention, the number of protrusions that guide the flow of the refrigerant increases as the distance from the inlet to the outlet increases, so the distance the refrigerant flows is longer at the outlet side than at the inlet side. Therefore, the refrigerant contacts the air core coil for a longer period at the outlet side than at the inlet side, ensuring sufficient cooling time for the air core coil.

[0010] In the coil assembly member according to the present invention, the distance between the projections narrows from the entrance to the exit.

[0011] In the present invention, the distance between the projections narrows as one approaches the outlet from the inlet, so the refrigerant flows longer at the outlet side than at the inlet side, and therefore the refrigerant contacts the air core coil for a longer period at the outlet side than at the inlet side, ensuring sufficient cooling time for the air core coil.

[0012] In the coil assembly member according to the present invention, the plurality of protrusions are formed on at least one inner wall that faces the air core coil in the axial direction of the air core coil.

[0013] In the present invention, the multiple protrusions are formed on at least one of the inner walls forming the storage space that faces the air core coil in the axial direction of the air core coil, and the flow of the refrigerant is guided and changed by the protrusions.

[0014] In the coil assembly member of the present invention, the one inner wall is a hollow rectangle, and the multiple protrusions include a first protrusion provided on the inner edge of the one inner wall and extending toward the outer edge of the one inner wall, and a second protrusion provided on the outer edge of the one inner wall and extending toward the inner edge, and the first protrusion or the second protrusion is provided on the inlet side, and the first protrusion and the second protrusion are provided alternately on the outlet side.

[0015] In the present invention, the first protrusions or the second protrusions are provided on the inlet side, and the first protrusions and the second protrusions are provided alternately on the outlet side, so that the refrigerant flow is more likely to bend on the outlet side, and the refrigerant flows a longer distance on the outlet side than on the inlet side. Therefore, the refrigerant contacts the air core coil for a longer period on the outlet side than on the inlet side, ensuring sufficient cooling time for the air core coil.

[0016] In the coil assembly member of the present invention, the housing has a flat rectangular parallelepiped shape, the inlet and the outlet are formed opposite each other on opposing side surfaces of the housing, and an obstruction protrusion is provided in the storage space between the inlet and the outlet to obstruct the flow of the refrigerant.

[0017] In the present invention, the inlet and the outlet are formed to face each other, and the accommodation space is provided with an obstructing protrusion between the inlet and the outlet to obstruct the flow of the refrigerant, so that the refrigerant flowing in through the inlet does not flow out directly through the outlet.

[0018] A voice coil motor according to the present invention includes any of the coil assembly members described above, and magnets arranged on both sides of the coil assembly member so as to face each other in the axial direction of the air-core coil.

[0019] In the present invention, when current is applied to the air-core coil, a thrust force is generated in a direction crossing the alternating magnetic field formed between the magnets, and the air-core coil is pushed in that direction. [Effects of the Invention]

[0020] According to the present invention, the air-core coil can be appropriately cooled even near the refrigerant outlet, and temperature non-uniformity at the inlet and outlet can be suppressed. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a diagram showing a voice coil motor according to an embodiment of the present invention; [Figure 2] 1 is a plan view of a voice coil motor according to an embodiment of the present invention; [Figure 3] 1 is a perspective view showing a mover of a voice coil motor according to an embodiment of the present invention; [Figure 4] FIG. 2 is a perspective view showing a housing of a mover according to an embodiment of the present invention. [Figure 5] FIG. 2 is a plan view of a housing of a mover according to an embodiment of the present invention. [Figure 6] FIG. 2 is a cross-sectional view of a housing of a mover according to an embodiment of the present invention. [Figure 7] FIG. 2 is a perspective view showing a cover body of a mover according to the embodiment of the present invention. [Figure 8] FIG. 2 is a plan view of a cover body of a mover according to the embodiment of the present invention. [Figure 9] FIG. 1 is an explanatory diagram showing a state in which a temperature sensor is attached to a mover of a voice coil motor according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] A coil assembly and a voice coil motor according to an embodiment of the present invention will be described in detail below with reference to the drawings.

[0023] Fig. 1 is a diagram showing a voice coil motor 100 according to an embodiment of the present invention. Fig. 1B is a front view of the voice coil motor 100, and Figs. 1A and 1C are side views of the voice coil motor 100. Fig. 2 is a plan view of the voice coil motor 100. For convenience, Fig. 2 shows a partial cross section taken along line II-II in Fig. 1.

[0024] The voice coil motor 100 includes a stator 10 and a mover 1 (coil assembly member). The stator 10 and the mover 1 are mounted on a base 30. The stator 10 has a housing shape with an open bottom on the side of the base 30. The stator 10 is fixed to the base 30 by a fixing jig 20 at a predetermined distance from the base 30. The mover 1 is covered by the stator 10, with only the lower end exposed to the outside.

[0025] The stator 10 has a pair of yokes 11 arranged opposite each other. Each yoke 11 is made of a ferromagnetic material (e.g., steel) and has a rectangular plate shape. Each yoke 11 is arranged so that one long side thereof faces the base 30. The pair of yokes 11 are arranged facing each other with a predetermined gap between them. A gap retaining plate 12 is provided between the yokes 11 to maintain the gap.

[0026] The spacing plates 12 are made of metal and have a rectangular plate shape. The length of the spacing plates 12 is the same as the width of the yoke 11. The spacing plates 12 are provided on both short sides of the yoke 11, and the main surfaces of the spacing plates 12 are flush with the side surfaces of the short sides of the yoke 11. For example, the spacing plates 12 are fastened to the yoke 11 with screws.

[0027] As shown in Fig. 2, a magnet unit 50 is provided on each of the opposing surfaces 123 of the pair of yokes 11. For convenience, Fig. 2 shows only the magnet unit 50 provided on one of the yokes 11, but a similar magnet unit 50 is also provided on the other yoke 11. Each magnet unit 50 has its magnetic pole facing in the opposing direction of the pair of yokes 11 (hereinafter simply referred to as the opposing direction).

[0028] Each magnet unit 50 is made up of a magnet unit 50A and a magnet unit 50B. The magnet units 50A and 50B are arranged side by side at a predetermined interval in the longitudinal direction of the yoke 11, and each consists of a pair of permanent magnets. In the magnet units 50A and 50B, the pair of permanent magnets are arranged so that the magnetic poles of their surfaces (hereinafter referred to as surface magnetic poles) in the opposing direction have the same polarity. On the other hand, in the magnet units 50A and 50B, the surface magnetic poles are arranged so that the polarities are opposite. Note that the surface magnetic poles are reversed between the magnet unit 50 of one yoke 11 and the magnet unit 50 of the other yoke 11. In other words, the magnet unit 50 of one yoke 11 and the magnet unit 50 of the other yoke 11 form an alternating magnetic field.

[0029] A predetermined gap is formed between the magnet unit 50 of one yoke 11 and the magnet unit 50 of the other yoke 11, and the mover 1 is interposed in this gap. The mover 1 is provided with an air-core coil 3.

[0030] In the voice coil motor 100 according to the present invention, when current is applied to the air core coil 3, a thrust force is generated in a direction (indicated by the outline arrow in FIG. 1B) that crosses the alternating magnetic field formed between the magnet unit 50 of one yoke 11 and the magnet unit 50 of the other yoke 11, based on Fleming's left-hand rule, pushing the air core coil 3 in that direction. This causes the mover 1 to move.

[0031] A cover plate 13 is attached to the other long sides of the pair of yokes 11. The cover plate 13 is a rectangular plate whose length is the same as that of the yoke 11, and is made of the same metal as the spacing plate 12. That is, the side surface of the other long side of each yoke 11 is covered by the main surface of the cover plate 13, and the side surface of the long side of the cover plate 13 is flush with, for example, the outer main surfaces of the pair of yokes 11. Both long sides of the cover plate 13 are screwed to the pair of yokes 11, respectively.

[0032] FIG. 3 is a perspective view showing a mover 1 of a voice coil motor 100 according to an embodiment of the present invention. The mover 1 has a housing 6 in the shape of a flat rectangular parallelepiped. An accommodation space 5 is formed inside the housing 6, and an air core coil 3 is accommodated in the accommodation space 5 (see FIG. 2). A refrigerant is injected into the accommodation space 5, and the refrigerant cools the air core coil 3. The refrigerant is, for example, water.

[0033] The housing 6 includes a housing 4 having a housing shape with one main surface open, and a cover 2 having a substantially rectangular plate shape that covers the one main surface of the housing 4. That is, the housing 4 and the cover 2 are joined together to form an accommodation space 5 (housing 6). The cover 2 also has through holes 22 (see FIG. 7), which will be described later, formed in multiple locations in the center and on the periphery. Screws S are passed through the through holes 22 and screwed into screw holes 421 (see FIG. 4), which will be described later, in the housing 4, thereby fastening the cover 2 to the housing 4.

[0034] Fig. 4 is a perspective view showing the housing 4 of the mover 1 according to the embodiment of the present invention, and Fig. 5 is a plan view of the housing 4. For convenience, the air core coil 3 is not shown in Fig. 4, and is indicated by a dashed line in Fig. 5. Fig. 6 is a cross-sectional view of the housing 4. Fig. 6A is a cross-sectional view taken along line VIA-VIA in Fig. 5, and Fig. 6B is a cross-sectional view taken along line VIB-VIB in Fig. 5.

[0035] The housing 4 is made of, for example, glass resin, and has a rectangular recess 42 that follows the shape of the lid 2 and has a depth approximately equal to the thickness of the lid 2 formed on one side of the housing 4 to which the lid 2 is attached. The recess 42 is formed over approximately the entire area of the one side of the housing 4, and the lid 2 engages with the recess 42. The recess 42 has a reduced width portion 422 formed on one end side in the length direction, and screw holes 421 are formed at positions corresponding to each through-hole 22 in the lid 2.

[0036] At the bottom of the recess 42, a first space forming portion 41 is recessed over a wider area toward the center than each screw hole 421. The first space forming portion 41 is a recess that forms the accommodation space 5 and occupies most of the accommodation space 5. The first space forming portion 41 has a shape that corresponds to the air core coil 3, and is a hollow recess that is a rounded rectangle in a plan view. In other words, a rectangular recess that is a rounded rectangle in a plan view is formed at the bottom of the recess 42, and a protruding pillar 43 that is approximately rectangular in a plan view protrudes from the center of this rectangular recess in the thickness direction of the housing 4. In other words, the first space forming portion 41 is an annular space in the rectangular recess excluding the protruding pillar 43.

[0037] The air core coil 3 is housed in the first space forming portion 41. More specifically, the air core coil 3 is housed in the first space forming portion 41 so that one end face in the axial direction faces the bottom 411 of the first space forming portion 41 and is coaxial with the protruding pillar 43. At this time, the protruding pillar 43 is inserted into the hole inside the air core coil 3.

[0038] The distance L1 from the side surface of the protruding post 43 to the sidewall 413 of the first spatial component 41 (hereinafter referred to as the width of the first spatial component 41) is longer than the dimension L2 from the inner peripheral surface to the outer peripheral surface of the air core coil 3 (hereinafter referred to as the width of the air core coil 3). That is, when the air core coil 3 is housed in the first spatial component 41, a gap is formed between the outer peripheral surface of the air core coil 3 and the sidewall 413 of the first spatial component 41, and a gap is also formed between the inner peripheral surface of the air core coil 3 and the side surface of the protruding post 43. Furthermore, the depth of the first spatial component 41, i.e., the dimension in the thickness direction of the housing 4, is slightly smaller than the dimension in the axial direction of the air core coil 3. In the thickness direction of the housing 4, the tip surface of the protruding post 43 is located at the same height as the bottom of the recess 42 (see FIG. 6). A screw hole 421 corresponding to the through hole 22 of the cover 2 is formed in the center of the tip surface of the protruding post 43.

[0039] A plurality of land portions 412 are provided at predetermined intervals on the bottom 411 of the first spatial forming portion 41. On the bottom 411 of the first spatial forming portion 41, rectangular land portions 412 are provided on the linearly extending portion, and approximately L-shaped land portions 412 are provided on the bent portion. In the width direction of the first spatial forming portion 41, the width of the land portions 412 is narrower than the width of the air core coil 3.

[0040] Therefore, when the air core coil 3 is housed in the first spatial component 41, the one end face of the air core coil 3 abuts against the land portion 412. Therefore, a gap is formed between the bottom 411 of the first spatial component 41 and the air core coil 3.

[0041] Of the two side surfaces (hereinafter referred to as short side surfaces) on both short sides in the length direction of the housing 4, lead wire holes 46 through which the lead wires of the air core coil 3 pass are formed at both ends on one short side surface closer to the reduced width portion 422 of the recess 42. The lead wire holes 46 communicate with the first space forming portion 41.

[0042] Furthermore, in the housing 4, a refrigerant inlet 44 and an outlet 45 are formed on two side surfaces (hereinafter referred to as long side surfaces) adjacent to the one short side surface and facing each other on both long side surfaces. The inlet 44 and the outlet 45 are provided at the end of each long side surface closer to the one short side surface. More specifically, the inlet 44 and the outlet 45 open to face each other at a position on the side wall 413 of the first spatial component 41 corresponding to the narrowed portion 422 of the recess 42. The inlet 44 and the outlet 45 are connected to the first spatial component 41. That is, the refrigerant flows into the first spatial component 41 through the inlet 44 and flows out of the first spatial component 41 to the outside of the housing 4 through the outlet 45.

[0043] Furthermore, an annular ridge 48 is formed at the bottom of the recess 42 between each screw hole 421 and the first space forming portion 41. The ridge 48 is formed along the edge of the first space forming portion 41.

[0044] Fig. 7 is a perspective view showing the lid body 2 of the mover 1 according to the embodiment of the present invention. Fig. 7A shows the front surface of the lid body 2, and Fig. 7B shows the back surface of the lid body 2. Fig. 8 is a plan view of the lid body 2. In Fig. 8, the flow F of the refrigerant on the back surface of the lid body 2 is indicated by dashed arrows.

[0045] The lid 2 is made of, for example, glass resin and has a generally rectangular plate shape. The lid 2 has narrow portions 28 at one end in the longitudinal direction, where the width is reduced, and the narrow portions 28 correspond to the reduced width portions 422 of the recessed portion 42. The lid 2 also has through holes 22 formed at multiple locations in the center and peripheral portion 27. The surface of the lid 2 also has counterbore holes formed around each through hole 22 (see FIG. 7A).

[0046] Furthermore, the cover 2 has a second space forming portion 21 recessed on the back surface thereof in a wider area toward the center than the four edge portions 27 on which the through holes 22 are formed. The second space forming portion 21 is a recess that forms part of the storage space 5. The second space forming portion 21 has a shape that corresponds to the first space forming portion 41 of the housing 4, and is a hollow, rounded rectangular recess in plan view. A protrusion 26 is protruded from the center of the second space forming portion 21. The protrusion 26 has the same rectangular shape as the protruding column 43 in plan view, and is plate-shaped.

[0047] The second spatial component 21 covers the air core coil 3 housed in the first spatial component 41. More specifically, when the air core coil 3 is housed in the first spatial component 41 so that the one end face of the air core coil 3 abuts against the land portion 412 of the first spatial component 41, the second spatial component 21 covers the other end face of the air core coil 3. At this time, the protrusion 26 is inserted into the hole inside the air core coil 3 from the other end face side of the air core coil 3.

[0048] A distance L3 (see FIG. 8) from the side surface of the protruding portion 26 to the side wall 211 of the second space forming portion 21 is the same as the width L1 of the first space forming portion 41. Therefore, when the second space forming portion 21 covers the other end surface of the air core coil 3, a gap is formed between the outer peripheral surface of the air core coil 3 and the side wall 211 of the second space forming portion 21, and a gap is also formed between the inner peripheral surface of the air core coil 3 and the side surface of the protruding portion 26. In the thickness direction of the lid 2, the tip surface of the protruding portion 26 is provided at the same height as the rear surface of the lid 2.

[0049] A plurality of protrusions 23 that guide the flow F of the refrigerant are formed on the bottom 24 (one inner wall) of the second spatial portion 21. That is, the plurality of protrusions 23 change the flow of the refrigerant that flows into the storage space 5 through the inlet 44 and flows out of the storage space 5 through the outlet 45. The positions of the inlet 44 and the outlet 45 provided on the housing 4 correspond to the ends of the narrow portion 28 of both long sides of the lid 2. In FIG. 8, the position corresponding to the position of the inlet 44 is indicated by a solid arrow, and the position corresponding to the position of the outlet 45 is indicated by a hollow arrow.

[0050] The protrusion 23 has a generally rectangular plate shape and is provided to protrude from the bottom 24 so that its thickness direction is the same as the thickness direction of the lid 2. The protrusion 23 includes a first protrusion 23A and a second protrusion 23B. More specifically, the bottom 24 of the second spatial component 21 has a hollow, rounded rectangular shape, and the first protrusion 23A is provided on the inner edge of the bottom 24, on the side surface of the protruding portion 26, and extends toward the outer edge of the bottom 24, i.e., toward the side wall 211 of the second spatial component 21. The second protrusion 23B is provided on the outer edge of the bottom 24, on the side wall 211 side, and extends toward the inner edge of the bottom 24, i.e., toward the side surface of the protruding portion 26.

[0051] For example, the first protrusion 23A and the second protrusion 23B have the same shape and are slightly thinner than the thickness of the protruding portion 26. Hereinafter, the first protrusion 23A and the second protrusion 23B will also be referred to as protrusions 23.

[0052] In the voice coil motor 100 according to the present invention, as shown in FIG. 8, the number of protrusions 23 is small on the entrance 44 side (position indicated by the solid arrow in FIG. 8) and increases toward the exit 45 (position indicated by the hollow arrow in FIG. 8). The entrance side (entrance 44 side) and the exit side (exit 45 side) refer to two regions of the lid 2 separated longitudinally by a bisector (not shown) of the short side (line segment) of the lid 2. The entrance side refers to the side where the entrance 44 is located, and the exit side refers to the side where the exit 45 is located. For example, there is one protrusion 23 on the entrance 44 side, and three protrusions 23 on the exit 45 side (excluding the protrusion 23 located on the bisector provided on the short side surface of the protrusion 26). Furthermore, the spacing between the protrusions 23 narrows as one approaches the exit 45 from the entrance 44.

[0053] Specifically, in the voice coil motor 100 according to the present invention, only the first protrusion 23A is provided on the entrance 44 side of the cover 2, whereas the first protrusion 23A and the second protrusion 23B are provided alternately and at close intervals on the exit 45 side.

[0054] With this configuration, in the voice coil motor 100 according to the present invention, as shown in FIG. 8, near the bottom 24 of the second spatial forming portion 21, the curvature of the flow F increases as it approaches the exit 45 from the entrance 44, and the flow F becomes more serpentine as it approaches the exit 45. As a result, the distance the refrigerant flows on the exit 45 side is longer than the distance the refrigerant flows on the entrance 44 side (see flow F in FIG. 8). Here, the refrigerant flow F in Figure 8 indicates the main flow of the refrigerant, and is shown by dashed lines along the vicinity of the middle of the distance L3 from the protrusion 26 to the side wall 211, the vicinity of the middle of the line connecting the first protrusion 23A to the side wall 211, and the vicinity of the middle of the line connecting the second protrusion 23B and the protrusion 26.

[0055] As described above, the positions of the inlet 44 and the outlet 45 provided in the housing 4 correspond to the ends of the narrow portion 28 on both long sides of the lid 2. The inlet 44 and the outlet 45 are arranged opposite each other in the width direction of the lid 2 (see the solid arrow and the hollow arrow in FIG. 8).

[0056] In contrast, in the voice coil motor 100 according to the present invention, an obstructing protrusion 25 is provided in the narrow width portion 28 between the inlet 44 and the outlet 45 in the opposing direction of the inlet 44 and the outlet 45. The obstructing protrusion 25 has a generally rectangular plate shape with a width narrower than that of the protrusion 23, and extends from the side wall 211 of the second space forming portion 21 to the side surface of the protruding portion 26. The thickness of the obstructing protrusion 25 is slightly thinner than that of the protrusion 23. The obstructing protrusion 25 prevents the refrigerant that flows in from the inlet 44 from flowing along the air core coil 3 and instead from flowing directly toward the outlet 45 on the opposing side.

[0057] Furthermore, on the back surface of the lid 2, annular grooves 29 are formed between each through-hole 22 and the second spatial portion 21. The grooves 29 are formed along the edge of the second spatial portion 21. The position and shape of the grooves 29 correspond to the ridges 48 of the housing 4.

[0058] In the voice coil motor 100 according to the present invention, as described above, the accommodation space 5 is formed when the cover 2 is attached to the housing 4 and the first space forming portion 41 and the second space forming portion 21 are combined. The air core coil 3 is accommodated in the accommodation space 5, and at this time, the protruding pillar 43 of the first space forming portion 41 is inserted into the hole inside the air core coil 3, and the protruding portion 26 of the second space forming portion 21 is inserted into the hole inside the air core coil 3, so that the tip surface of the protruding pillar 43 and the tip surface of the protruding portion 26 abut against each other.

[0059] Furthermore, when the air core coil 3 is accommodated in the accommodation space 5, both end faces of the air core coil 3 are clamped by the land portions 412 and the protrusions 23. Therefore, a gap is formed between one end face of the air core coil 3 and the bottom 411 of the first space forming portion 41, and a gap is also formed between the other end face of the air core coil 3 and the bottom 24 of the second space forming portion 21. Gaps are also formed between the outer circumferential surface of the air core coil 3 and the side wall 413 of the first space forming portion 41 and the side wall 211 of the second space forming portion 21, and gaps are also formed between the inner circumferential surface of the air core coil 3 and the side surface of the protruding pillar 43 and the side surface of the protrusion 26.

[0060] The refrigerant that flows into the storage space 5 through the inlet 44 flows to the outlet 45 through gaps between both end faces of the air core coil 3 and the bottom 411 of the first space forming portion 41 and the bottom 24 of the second space forming portion 21, gaps between the outer circumferential surface of the air core coil 3 and the side wall 413 of the first space forming portion 41 and the side wall 211 of the second space forming portion 21, and gaps between the inner circumferential surface of the air core coil 3 and the side surface of the protruding column 43 and the side surface of the protruding portion 26. At this time, the refrigerant flowing at least through the gaps between the other end face of the air core coil 3 and the bottom 24 of the second space forming portion 21 flows as shown by flow F in FIG. 8 .

[0061] Generally, the refrigerant flows into the accommodating space 5 from the inlet 44 and flows through the accommodating space 5 toward the outlet 45, where it comes into contact with the air core coil 3 and cools it. As a result, the temperature of the refrigerant rises as it approaches the outlet 45, making it impossible to adequately cool the air core coil 3 near the outlet 45. This also leads to temperature unevenness between the inlet 44 and the outlet 45. Such temperature unevenness can affect surrounding components and cause malfunctions.

[0062] In contrast, in the voice coil motor 100 according to the present invention, as described above, the length of the flow F on the outlet 45 side is longer than the length of the flow F on the inlet 44 side, that is, the length increases as the flow approaches from the inlet 44 to the outlet 45. Because of this configuration, the voice coil motor 100 according to the present invention has a longer time during which the refrigerant is in contact with the air-core coil 3 as the flow approaches from the inlet 44 to the outlet 45.

[0063] That is, the contact time between the refrigerant and the air core coil 3 near the outlet 45, where the refrigerant temperature is relatively high, is set to be longer than the contact time between the refrigerant and the air core coil 3 near the inlet 44, where the refrigerant temperature is relatively low. This ensures sufficient time for cooling the air core coil 3 near the outlet 45, and the air core coil 3 is appropriately cooled. Therefore, the occurrence of temperature unevenness between the inlet 44 and the outlet 45 can be prevented in advance.

[0064] Furthermore, in the voice coil motor 100 according to the present invention, as described above, the protrusions 23 are provided within the housing space 5, and vortices of the refrigerant are generated near the protrusions 23. This increases the contact time between the refrigerant and the air core coil 3, thereby improving the cooling effect. Furthermore, as described above, the number of protrusions 23 increases as one moves from the inlet 44 to the outlet 45, so the cooling effect of the air core coil 3 can be further improved.

[0065] When the lid 2 is attached to the housing 4 and the storage space 5 is completed, the ridges 48 of the housing 4 engage with the grooves 29 of the lid 2. As a result, the ridges 48 and the grooves 29 form a so-called labyrinth structure, which reliably prevents refrigerant from leaking from the storage space 5.

[0066] FIG. 9 is an explanatory diagram showing a state in which a temperature sensor 60 is attached to the mover 1 of the voice coil motor 100 according to the present invention. A temperature sensor 60 for detecting the temperature inside the housing 4 (accommodation space 5) is attached to the other surface of the housing 4 of the mover 1 opposite to the surface to which the lid 2 is attached. That is, the temperature sensor 60 detects the temperature of the air-core coil 3 or the temperature of the refrigerant.

[0067] On the other side of the housing 4, a generally L-shaped recess 47 is formed in the peripheral portion near the side where the lead wire hole 46 is formed, and a temperature sensor 60 is screwed into the recess 47. The temperature sensor 60 has two elongated terminals to which electric wires (not shown) are connected. The electric wires are connected to an external control device, for example, via a wiring port 49 formed on the side of the housing 4.

[0068] Alternatively, a copper or brass plate (not shown) may be attached to the heat-sensitive portion of temperature sensor 60 and inserted into housing 4 (accommodation space 5) so that it comes into direct contact with the refrigerant. In this case, the temperature of the refrigerant is transmitted to temperature sensor 60 via the copper or brass plate, which has excellent thermal conductivity, thereby increasing the sensitivity of temperature sensor 60.

[0069] In the above, an example has been described in which the first protrusions 23A and the second protrusions 23B have the same shape, but this is not limiting and they may have different shapes. Furthermore, all of the first protrusions 23A and all of the second protrusions 23B are not limited to having the same shape and the first protrusions 23A or the second protrusions 23B may have different shapes.

[0070] Furthermore, in the above, an example has been described in which the voice coil motor 100 has only the first protrusion 23A provided on the entrance 44 side of the lid body 2, but this is not limited to this, and only the second protrusion 23B may be provided on the entrance 44 side.

[0071] In the above description, an example has been given in which the number of protrusions 23 on the inlet 44 side of the lid 2 is one and the number of protrusions 23 on the outlet 45 side is three, but the present invention is not limited to this. Any configuration may be used as long as the number of protrusions 23 on the inlet 44 side is fewer than that on the outlet 45 side, and the number of protrusions 23 increases as one gets closer to the outlet 45.

[0072] In the above description, the protrusion 23 is formed only on the cover 2 (the bottom 24 of the second spatial portion 21), but this is not limiting. The protrusion 23 may be provided on the first spatial portion 41 (the side wall 413 or the bottom 411) of the housing 4, for example.

[0073] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0074] 1. Movable element (coil assembly component) 3 Air-core coil 5. Containment space 6. Housing 23 Protrusion 23A 1st protrusion 23B 2nd protrusion 24 Bottom (one inner wall) 25 Obstruction protrusion 44 Entrance 45 Exit 50 Magnet Unit 100 Voice Coil Motor F Refrigerant flow

Claims

1. A coil assembly member including a housing having an annular housing space for housing an air-core coil, The housing is formed with an inlet and an outlet for a refrigerant that communicate with the storage space, a plurality of protrusions provided on an inner wall of the storage space to guide the flow of the refrigerant; A coil assembly member in which the number of protrusions increases from the entrance to the exit.

2. 2. The coil assembly according to claim 1, wherein the distance between the projections decreases from the entrance to the exit.

3. 3. The coil assembly member according to claim 1, wherein the plurality of protrusions are formed on at least one inner wall that faces the air core coil in the axial direction of the air core coil.

4. The one inner wall is a hollow rectangle, the plurality of protrusions include a first protrusion provided on an inner edge of the one inner wall and extending toward an outer edge of the one inner wall, and a second protrusion provided on the outer edge of the one inner wall and extending toward the inner edge, The first protrusion or the second protrusion is provided on the inlet side, The coil assembly member according to claim 3 , wherein the first projections and the second projections are alternately provided on the outlet side.

5. The housing has a flat rectangular parallelepiped shape, The inlet and the outlet are formed opposite to each other on opposite side surfaces of the housing, The coil assembly member according to any one of claims 1 to 4, wherein the accommodation space is provided with an obstructing protrusion between the inlet and the outlet for obstructing the flow of the refrigerant.

6. The coil assembly member according to any one of claims 1 to 5; and magnets arranged on both sides of the coil assembly member so as to face each other in the axial direction of the air-core coil.

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