Multifunctional vibration actuator

Abstract

The invention discloses a multifunctional vibration actuator. A multifunctional vibration actuator includes a housing, a coil housed in the housing, a diaphragm connected to the coil, a movable element housed in the housing and vibrating, and a leaf spring attached to the housing and to which the movable element is attached. The housing includes an extending portion that includes an open end portion, extends radially outward, and faces an outer peripheral portion of the diaphragm, and a through hole is formed in the extending portion. The through hole is formed in the housing at a position closer to the open end than the gap.

Description

Technical Field

[0001] This disclosure relates to a multifunctional vibration actuator. Background Technology

[0002] Japanese Patent No. 4146346 discloses a technology concerning a multifunctional vibration actuator. This prior art multifunctional vibration actuator includes a magnetic circuit section (movable member) forming a magnetic circuit, a suspension (leaf spring) supporting the magnetic circuit section, a diaphragm (resonator) disposed opposite to the magnetic circuit section, a voice coil disposed on the diaphragm and inserted into a magnetic gap formed in the magnetic circuit section, and a housing housing the magnetic circuit section. Here, the magnetic circuit section is configured such that a gap restricting the amount of air movement exists between the side surface of the magnetic circuit section and the inner surface of the housing.

[0003] In addition, Figure 7 of Japanese Patent No. 4146346 shows a structure in which a through hole is provided on the side of the housing, which allows air to enter and exit freely. Summary of the Invention

[0004] [The technical problem the invention aims to solve] However, in this structure, the through-hole is a portion of the side of the housing that is lower than the suspension. If the upper end of the side of the magnetic circuit section displaces to a position corresponding to the through-hole when the magnetic circuit section vibrates, the length of the airflow path used to limit the amount of air movement cannot be maintained, resulting in air leakage from the through-hole near the upper end of the side of the magnetic circuit section. If air leaks, the viscous resistance of the air flowing in and out of the gap between the side of the magnetic circuit section and the inner surface of the housing decreases accordingly. Furthermore, if the movable part blocks the through-hole, the diaphragm becomes difficult to move, affecting the sound performance.

[0005] This disclosure takes into account the above-mentioned actual situation and obtains a multifunctional vibration actuator that can stably perform the functions of sound generation and vibration generation respectively.

[0006] [Solutions for solving technical problems] A first aspect of a multifunctional vibration actuator includes: a housing having an open end on one side; a coil housed in the housing and configured such that its axial direction is along the depth direction of the housing; a diaphragm disposed on the side of the housing and connected to the coil, and capable of vibrating in the axial direction of the coil; a movable member housed in the housing, its outer peripheral surface disposed with respect to the inner peripheral surface of the housing through a gap restricting air movement, the movable member comprising a magnet and vibrating along the vibration direction of the diaphragm by energizing the coil; and a leaf spring mounted on the housing and on which the movable member is mounted, the housing having a protrusion including the open end on one side and extending radially outward, the protrusion facing the outer peripheral portion of the diaphragm, a through hole formed in the protrusion at a position in the housing closer to the open end than the gap.

[0007] In the first aspect of the multi-functional vibration actuator, a coil is housed in a housing having an open end on one side, the coil being configured such that its axial direction is along the depth direction of the housing. A diaphragm is disposed on said side of the housing, the diaphragm being connected to the coil and capable of vibrating in the axial direction of the coil. Additionally, a movable member is housed in the housing, the outer peripheral surface of the movable member being disposed with a gap between the outer peripheral surface of the movable member and the inner peripheral surface of the housing, restricting the amount of air movement. The movable member is constructed of a magnet and vibrates along the vibration direction of the diaphragm by energizing the coil. Furthermore, a leaf spring is mounted in the housing, and the movable member is mounted on the leaf spring. In summary, the multi-functional vibration actuator possesses both a sound generation function and a vibration generation function. The sound generation function generates sound by energizing the coil to vibrate the diaphragm, and the vibration generation function generates vibration by vibrating the movable member, which vibrates while suppressing amplitude, thereby producing vibration with a small change in acceleration relative to a small change in frequency.

[0008] Furthermore, a protrusion is formed in the housing, the protrusion including an open end on one side extending radially outward and facing the outer periphery of the diaphragm, and a through hole is formed in the protrusion. The through hole is formed in the housing at a position relative to the gap near the open end. Thus, when the diaphragm vibrates, air can enter and exit through the through hole in the protrusion, thereby limiting the amount of air movement by utilizing the gap between the outer peripheral surface of the movable member and the inner peripheral surface of the housing, and ensuring good vibration characteristics of the diaphragm. In addition, in this first aspect, for example, compared to a comparative example where a through hole is formed in the bottom wall of the housing, it is easier to ensure the damping function when the movable member vibrates. Moreover, by adopting this first aspect, the length of the airflow path that limits the amount of air movement when the movable member vibrates can be maintained and can be set to be relatively long. Therefore, the viscous resistance of the air whose movement is limited when the movable member vibrates can be increased. Furthermore, by forming the through hole in the protrusion, the movable member will not block the through hole when the movable member vibrates. Therefore, even when using the sound generation function and the vibration generation function simultaneously, they can function stably respectively.

[0009] In the second aspect, the multifunctional vibration actuator has, in the first aspect, an outer periphery of the leaf spring mounted on the housing, and a central portion of the leaf spring mounted on the side of the movable member opposite to the diaphragm side.

[0010] In the second aspect of the multi-functional vibration actuator, the range of contact that avoids with the variable portion of the leaf spring in the part of the movable member opposite to the diaphragm side can be changed, thus allowing for alteration of the leaf spring's span length. Furthermore, suspension characteristics can be easily adjusted by changing the span length of the leaf spring.

[0011] In the third aspect, the multifunctional vibration actuator, in either the first or second aspect, has the through hole extending through the protrusion in a radial direction along the housing.

[0012] In the third aspect of the multi-functional vibration actuator, the through-hole is oriented radially relative to the protrusion along the housing, thus suppressing the amount of the protrusion extending radially outward.

[0013] In the fourth aspect, the multifunctional vibration actuator, in the second aspect, has the central portion of the leaf spring mounted on the central portion of the bottom surface of the movable member on the other side. The outer peripheral surface of the bottom surface of the movable member is provided as at least one of an inclined surface and a connecting surface. The inclined surface slopes towards the other side in a radially inward direction. The connecting surface is connected to the central portion of the bottom surface via a step. Furthermore, "the other side" refers to the side in the opposite direction to "one side" described in the first aspect.

[0014] In the fourth aspect of the multi-functional vibration actuator, the central portion of the leaf spring is mounted on the central portion of the bottom surface on the other side of the movable member, thus increasing the span length of the leaf spring and enabling a soft suspension characteristic. Furthermore, the outer peripheral surface of the bottom surface of the movable member is provided as at least one of a slope and a connecting surface. The slope is inclined towards the other side as it moves radially inward, and the connecting surface is connected to the central portion of the bottom surface via a step. Therefore, contact between the movable member and the span portion of the leaf spring can be suppressed when the movable member vibrates.

[0015] The fifth aspect of the multifunctional vibration actuator, in any of the first to fourth aspects, has a groove formed on the outer peripheral surface of the movable member, the groove extending circumferentially along the outer peripheral surface.

[0016] In the fifth aspect of the multi-functional vibration actuator, if air moves along the vibration direction of the movable member between the outer peripheral surface of the movable member and the inner peripheral surface of the housing, an expansion loss can occur in the portion where the flow path cross-sectional area increases sharply, and a contraction loss can occur in the portion where the flow path cross-sectional area decreases sharply. That is, when the air moves in the above manner, pressure loss can be generated, and the viscous resistance of the moving air can be increased. As a result, the damping function of the movable member during vibration can be improved.

[0017] In the fifth aspect, the groove in the sixth aspect of the multifunctional vibration actuator is formed over the entire circumferential direction of the outer peripheral surface of the movable member.

[0018] In the sixth aspect of the multi-functional vibration actuator, if air moves between the outer peripheral surface of the movable part and the inner peripheral surface of the housing along the vibration direction of the movable part, pressure loss can be generated throughout the entire circumferential direction of the air flow path, and the viscous resistance of the moving air can be increased throughout the entire circumferential direction of the air flow path.

[0019] In the seventh aspect, the multifunctional vibration actuator, in the fifth or sixth aspect, has multiple grooves arranged side by side at open intervals in the vibration direction of the movable member.

[0020] In the seventh aspect of the multi-functional vibration actuator, if air moves between the outer peripheral surface of the movable part and the inner peripheral surface of the housing along the vibration direction of the movable part, a greater pressure loss can be generated, which can further increase the viscous resistance of the moving air.

[0021] In any of the first to seventh aspects of the multifunctional vibration actuator, the outer peripheral portion of the movable member is composed of a component that is separate from the main body portion of the movable member.

[0022] In the eighth aspect of the multi-functional vibration actuator, it becomes easy to manufacture the outer peripheral components of the movable part with high precision. Furthermore, the resonant frequency of the vibration can be adjusted by changing the separate parts, allowing for a variety of product variations.

[0023] [Invention Effects] As explained above, the multifunctional vibration actuator according to this disclosure has the excellent effect of being able to stably perform the functions of sound generation and vibration generation, respectively. Attached Figure Description

[0024] Figure 1 This is a perspective view showing the multi-functional vibration actuator according to the first embodiment.

[0025] Figure 2 It means along Figure 1 A sectional view showing the state of being cut along line 2-2.

[0026] Figure 3 This is a cross-sectional view showing a portion of the multi-functional vibration actuator according to the second embodiment.

[0027] Figure 4 This is a cross-sectional view showing a portion of the multi-functional vibration actuator according to the third embodiment. Detailed Implementation

[0028] [First Implementation] use Figure 1 and Figure 2 This describes the multi-functional vibration actuator according to the first embodiment. Figure 1 The multi-functional vibration actuator 10 according to the first embodiment is shown in a perspective view. Additionally, in Figure 2 The text shows along Figure 1 A sectional view showing the state of being cut along line 2-2.

[0029] (structure) right Figure 1 The structure of the multi-functional vibration actuator 10 shown will be described. Furthermore, the multi-functional vibration actuator 10 is a small device, for example, that can be used in mobile terminal devices such as mobile phones. This small device has an audio generation function that generates sound and a vibration generation function that generates vibrations for tactile sensation.

[0030] like Figure 2As shown, the multi-functional vibration actuator 10 has a housing 32, which has an open end 32A on one side (arrow Z direction side). As an example, the housing 32 is composed of a first component (also called a "rear frame") 34 and a second component (also called a "frame") 36. The first component 34 is formed as a bottomed cylinder, having a bottom wall portion 34A and a peripheral wall portion 34B continuously formed with the outer peripheral end of the bottom wall portion 34A. The first component 34 also has a protruding wall portion 34C, which extends radially outward from a portion of the peripheral wall portion 34B opposite to the side of the bottom wall portion 34A. The protruding wall portion 34C has a convex portion 34C1 protruding towards said side (arrow Z direction side) at its top end in the protruding direction. The second component 36 is formed as a short cylinder and is mounted on said side (arrow Z direction side) of the radially outward portion (including the portion of the convex portion 34C1) of the protruding wall portion 34C of the first component 34. The protruding wall portion 34C and the second component 36 constitute the protruding portion 38 of the housing 32 in the first embodiment. The protruding portion 38 is a portion that extends radially outward in the housing 32.

[0031] The side of the second component 36 opposite to the side of the first component 34 (in) Figure 2 The end of the housing 32 (the upper side) forms the open end 32A of one side (the side in the direction of arrow Z) of the housing 32. Furthermore, the parts constituting the first component 34 and the second component 36 will be described below as components of the housing 32.

[0032] A protective member 18 is installed at the open end 32A of the housing 32. The protective member 18 is configured to cover the open side of the housing 32. A plurality of sound-emitting holes 18H are formed through the flat plate portion 18A of the protective member 18, which is positioned to block the open side of the housing 32 (see reference). Figure 1 ).

[0033] A coil 22 (simplified illustration in the figure) is housed within the housing 32. The coil 22 is arranged axially along the depth direction of the housing 32 (in the same direction as the depth direction of the housing 32). Power supply wiring (omitted illustration) for supplying power to the coil 22 is connected to the coil 22.

[0034] Additionally, a diaphragm 24 connected to the coil 22 is disposed on one side of the housing 32 (the side in the direction of arrow Z). The diaphragm 24 is positioned closer to the protective member 18 than the coil 22 and is configured to face the flat plate portion 18A of the protective member 18. A mounting portion 24A disposed on the outer peripheral end side of the diaphragm 24 is clamped and mounted between the housing 32 and the protective member 18 in the entire circumferential direction. Furthermore, the mounting portion 24A disposed on the outer peripheral end side of the diaphragm 24 can also be mounted to the housing 32 by other mounting methods. The diaphragm 24 is capable of vibrating in the axial direction of the coil 22.

[0035] Additionally, a movable member 26 (illustrated schematically in the figure) is housed within the housing 32. The outer peripheral surface 26A1 of the largest diameter portion 26A of the outer peripheral surface 26S of the movable member 26 is positioned with the inner peripheral surface 32B of the housing 32 separated by a gap G for limiting the amount of air movement. This gap G can be understood as a narrow air gap. Furthermore, Figure 2 The reference numeral L in the attached diagram indicates the length of the gap G. Additionally, in... Figure 2 When viewed from the direction of the movable member 26, the extension direction of the outer peripheral surface 26A1 of the maximum diameter portion 26A of the movable member 26 and the extension direction of the inner peripheral surface 32B of the housing 32 that forms a gap G with the outer peripheral surface 26A1 of the maximum diameter portion 26A of the movable member 26 are both the same as the depth direction of the housing 32.

[0036] The movable member 26 has a magnetic circuit section including a magnet, is supported by the leaf spring 28 (described later), and vibrates along the vibration direction of the diaphragm 24 by energizing the coil 22. Furthermore, although detailed illustrations are omitted, in this embodiment, the movable member 26, in addition to the magnet, also includes a bottomed cylindrical yoke as a strong magnetic element and a disk-shaped plate as a strong magnetic element, with the magnet overlapping on the inner periphery of the yoke and the plate further overlapping the magnet. Additionally, the multi-functional vibration actuator 10 of this embodiment has an internal magnet type magnetic circuit section, in which the magnet constituting part of the movable member 26 is disposed on the inner periphery of the coil 22. Furthermore, the outer periphery surface 26A1 of the maximum diameter portion 26A of the movable member 26, which is disposed with a gap G between it and the inner periphery surface 32B of the housing 32, is the outer periphery surface of the yoke, and the gap G is used to limit the amount of air movement. Furthermore, the movable part 26 can, for example, utilize a known magnetic circuit section disclosed in Japanese Patent No. 4146346, etc.

[0037] Additionally, the multi-functional vibration actuator 10 includes a leaf spring 28, which is mounted on the housing 32 and has a movable member 26 attached thereto. (The external shape of the leaf spring 28 is omitted from the illustration.) The leaf spring 28 includes a large-diameter ring portion 28A, a small-diameter ring portion 28C, and a connecting portion 28B. The large-diameter ring portion 28A is mounted on the housing 32. The small-diameter ring portion 28C is positioned relative to the large-diameter ring portion 28A and is further inwardly positioned than the large-diameter ring portion 28A, and has the movable member 26 attached thereto. The connecting portion 28B connects the large-diameter ring portion 28A and the small-diameter ring portion 28C.

[0038] The large-diameter annular portion 28A is mounted on the end face of the peripheral wall portion 34B of the housing 32, opposite to the side of the bottom wall portion 34A. The small-diameter annular portion 28C is mounted on the portion of the movable member 26 on the side of the diaphragm 24. Furthermore, a surface 26B is provided at a predetermined distance away from the connecting portion 28B of the leaf spring 28, such that it does not contact the connecting portion 28B of the leaf spring 28 when the movable member 26 vibrates. This surface 26B is a surface of the movable member 26 located on the outer periphery side of the portion mounted on the small-diameter annular portion 28C and facing the leaf spring 28 side. The connecting portion 28B is configured, for example, by including a plurality of arms that extend in the same direction along the circumferential direction between the large-diameter annular portion 28A and the small-diameter annular portion 28C. The leaf spring 28 used in the multi-functional vibration actuator 10 is sometimes also referred to as a suspension. For example, technology known in Japanese Patent No. 4146346 can be used, therefore a detailed description of the leaf spring 28 is omitted.

[0039] The protruding wall portion 34C of the housing 32 extends from the end portion 32X and faces the outer periphery 24B of the diaphragm 24. The end portion 32X is the portion of the housing 32 on the diaphragm 24 side that faces the outer peripheral surface 26A1 of the maximum diameter portion 26A across a gap G when the movable member 26 vibrates. A through hole 32H is formed in the protruding wall portion 34C of the housing 32, and the through hole 32H extends in the direction along the vibration direction of the movable member 26. That is, the through hole 32H is formed in the housing 32 at a position closer to the open end portion 32A than the gap G. To provide further explanation, the through hole 32H is formed in the following part: the part of the housing 32 located between one side (arrow Z direction side) of the part corresponding to the outer peripheral surface 26A of the maximum diameter portion 26A of the movable member 26 when the movable member 26 vibrates and the open end 32A on the same side (arrow Z direction side), and the part located on the other side (opposite to the arrow Z direction side) of the diaphragm 24.

[0040] The through holes 32H are formed to facilitate the movement of the diaphragm 24 and thus suppress the rise of the resonant frequency. When the diaphragm 24 vibrates, air can move in and out of the housing 32. Multiple through holes 32H (four in one example) are arranged at equal intervals in the circumference of the housing 32.

[0041] (Function / Effect) Next, the function and effects of the first embodiment will be explained.

[0042] exist Figure 2 In the multi-functional vibration actuator 10 shown, if an electrical signal is applied to the coil 22, the coil 22 causes the diaphragm 24 to vibrate through electromagnetic induction, thereby generating sound. The sound generated by the vibration of the diaphragm 24 is transmitted to the outside through multiple sound holes 18H.

[0043] Furthermore, if an electrical signal is applied to the coil 22, the movable member 26 with the magnetic circuit section is caused to vibrate up and down through electromagnetic induction. When the movable member 26 vibrates up and down, the air inside the housing 32 travels back and forth through the gap G in the space S1 between the diaphragm 24 and the movable member 26 and the space S2 between the movable member 26 and the bottom wall portion 34A of the housing 32. On the other hand, the outer peripheral surface 26A1 of the maximum diameter portion 26A of the movable member 26 and the inner peripheral surface 32B of the housing 32 are separated by a gap G for limiting the amount of air movement, thus limiting the amount of air movement between the two spaces S1 and S2. The air whose movement is restricted remains in each space S1 and S2, and the air remaining in spaces S1 and S2 acts as damping to prevent the movement of the movable member 26 from vibrating. Therefore, by controlling the amplitude of the up and down vibration of the movable member 26, the multi-functional vibration actuator 10 can generate vibrations with a small change in acceleration relative to a small change in frequency.

[0044] Furthermore, a protrusion 38 is formed in the housing 32, the protrusion 38 including an open end 32A on one side extending radially outward and facing the outer peripheral portion 24B of the diaphragm 24, and a through hole 32H is formed in the protrusion 38. The through hole 32H is formed in the housing 32 at a position closer to the open end 32A than the gap G. Thus, when the diaphragm 24 vibrates, air can enter and exit through the through hole 32H of the housing 32, and the amount of air movement can be limited by the gap G between the outer peripheral surface 26A1 of the maximum diameter portion 26A of the movable member 26 and the inner peripheral surface 32B of the housing 32, while maintaining the vibration characteristics of the diaphragm 24 well. In addition, according to the structure of this embodiment, for example, compared with the comparative example in which a through hole is formed in the bottom wall portion (34A) of the housing (32), the damping function when the movable member 26 vibrates is easily ensured.

[0045] Furthermore, in this embodiment, by forming the through hole 32H in the protrusion 38, the position of forming the through hole 32H can be offset from the position of forming the gap G, preventing the movable member 26 from blocking the through hole 32H when vibrating. Here, for example, as a comparative structure, if the through hole is positioned where the protrusion 38 is not formed and it could be blocked by the movable member: when the diaphragm vibrates to produce sound, if the movable member is further vibrated at a low frequency, the lowest resonant frequency (F0) increases at the instant the movable member blocks the through hole, thus reducing the sound pressure level. In this comparative structure, the sound quality changes due to the movement of the movable member. In this embodiment, however, the movable member 26 does not block the through hole 32H, thus avoiding this problem. Therefore, in this embodiment, even when using both the sound generation function and the vibration generation function simultaneously, each function can operate stably.

[0046] Furthermore, in the structure of this embodiment, the length of the airflow path used to limit the amount of air movement when the movable member 26 vibrates (that is, the length in the vertical direction of the portion where the gap G is formed) is also considered. Here, the length of the airflow path used to limit the amount of air movement will also be explained. For example, as a comparative example, in a structure in which the portion corresponding to the protrusion 38 of this embodiment is not provided in the housing, and the through hole is located at the position corresponding to the peripheral wall portion 34B of this embodiment and closer to the position where the gap (G) is formed than the leaf spring (28) (lower side in the figure), the length in the airflow path direction in the outer peripheral surface (26A1) of the maximum diameter portion (26A) of the movable member (26) is shortened (in the vertical direction of the airflow path). Figure 2 The length in the vertical direction is used to prevent the outer peripheral surface (26A1) of the maximum diameter portion (26A) of the movable member (26) from blocking the through hole. In contrast, in this embodiment, the through hole 32H is formed in the protrusion 38 and the outer peripheral surface 26A1 of the maximum diameter portion 26A of the movable member 26 does not block the through hole 32H. Therefore, compared with the comparative example, the length in the airflow path direction of the outer peripheral surface 26A1 of the maximum diameter portion 26A of the movable member 26 can be extended (in the vertical direction). Figure 2 The length of the airflow path used to limit the amount of air movement (that is, the length of the portion forming the gap G in the diagram in the vertical direction) can be set to be longer. This increases the viscous resistance of the air flowing into and out of the gap G when the movable member 26 vibrates. In summary, by suppressing the transmitted vibration acceleration at the resonant frequency, an effective suspension effect can be obtained, and the vibration performance of the multi-functional vibration actuator 10 can be improved.

[0047] Furthermore, the through hole 32H faces the outer periphery 24B of the diaphragm 24 and passes through in the direction of vibration of the movable member 26 (in other words, in the direction of vibration of the diaphragm 24). Therefore, when the diaphragm 24 vibrates, air can easily enter and exit through the through hole 32H of the housing 32. Thus, the diaphragm 24 can be moved easily, thereby suppressing the rise of the resonant frequency.

[0048] As explained above, the multi-functional vibration actuator 10 according to this embodiment can stably perform both sound generation and vibration generation functions. Regarding the vibration generation function, in this embodiment, by obtaining an effective suspension effect, the change in acceleration can be further reduced relative to the change in frequency, thereby expanding the effective vibration frequency band.

[0049] Furthermore, in this embodiment, since the through hole 32H is formed in the protrusion 38, even if the movable member 26 vibrates, the movable member 26 will not block the through hole 32H, thus suppressing the overall height of the multi-functional vibration actuator 10. Figure 2 (Length in the vertical direction). Furthermore, in this embodiment, the protruding wall portion 34C extends radially outward from one side (arrow Z direction side) of the peripheral wall portion 34B of the housing 32, and the end of one side (arrow Z direction side) of the peripheral wall portion 34B of the housing 32 functions as a base for fixing the leaf spring 28, thereby reducing the number of fixing parts for the leaf spring 28. Moreover, in this embodiment, the through hole 32H is formed in the protruding wall portion 34C, thereby making the through-direction of the through hole 32H the same as the depth direction of the housing 32. The mold used to manufacture the housing 32 does not require a sliding mechanism for the through hole 32H, thus simplifying the mold and reducing mold costs for manufacturing the housing 32.

[0050] Furthermore, in this embodiment, the portion of the movable member 26 on the diaphragm 24 side (the upper side in the figure) is fixed to the leaf spring 28, and the movable member 26 is fixed at the fixed position of the leaf spring 28 near the coil 22. Therefore, even if there is abnormal vibration of the movable member 26 in the tilting direction, it is easy to prevent the movable member 26 from contacting the coil 22.

[0051] [Second Implementation] Next, use Figure 3 The multi-functional vibration actuator according to the second embodiment will be described. Furthermore, in the second embodiment, components that are substantially the same as those in the first embodiment are labeled with the same reference numerals, and descriptions are appropriately omitted.

[0052] exist Figure 3 A cross-sectional view shows a portion of the multifunctional vibration actuator 40 according to the second embodiment. (See figure.) Figure 3As shown, the housing 42 of the multi-functional vibration actuator 40 has an open end 42A on one side (arrow Z direction side), with a diameter dimension (in Figure 3 The length in the left-right direction is the same as the shell 32 in the first embodiment (refer to...). Figure 2 The housing 42, as an example, is composed of a first component (also called a "rear frame") 44 and a second component (also called a "frame") 46. The first component 44 is formed as a shallow, bottomed cylindrical shape, having a bottom wall portion 44A and a base wall portion 44B. The base wall portion 44B is continuous with the outer peripheral end of the bottom wall portion 44A and is formed as a short cylinder. The second component 46 has a peripheral wall portion 46A, a protruding wall portion 46B, and a cylindrical wall portion 46C. The peripheral wall portion 46A is cylindrical and is mounted on the end of the base wall portion 44B of the first component 44 opposite to the side of the bottom wall portion 44A, and is positioned at an extension of the base wall portion 44B. The protruding wall portion 46B extends radially outward from the end of the peripheral wall portion 46A on the diaphragm 24 side. The cylindrical wall portion 46C is short cylindrical and extends radially outward from the end of the protruding wall portion 46B toward the protective member 18. The protruding wall portion 46B and the cylindrical wall portion 46C constitute the protruding portion 48 of the housing 42 in the second embodiment. The protruding portion 48 is the portion of the housing 42 that extends radially outward.

[0053] The side opposite to the protruding wall portion 46B of the cylindrical wall portion 46C of the second component 46 ( Figure 3 The end portion (upper side) constitutes the open end portion 42A of one side (arrow Z direction side) of the housing 42. Furthermore, the portions constituting the first component 44 and the second component 46 will be described below as components of the housing 42.

[0054] A protective member 18 is installed at the open end 42A of the housing 42. The coil 22 housed in the housing 42 is arranged axially along the depth direction of the housing 42. The diaphragm 24 is disposed on the side of the housing 42 (the side in the direction of arrow Z). The mounting portion 24A provided on the outer peripheral end side of the diaphragm 24 is clamped and mounted between the housing 42 and the protective member 18 in the entire circumferential direction. Alternatively, the mounting portion 24A provided on the outer peripheral end side of the diaphragm 24 can also be mounted on the housing 42 by other mounting methods. The diaphragm 24 is connected to the coil 22 and is capable of vibrating axially in the coil 22.

[0055] A movable member 50 (illustrated schematically in the figure) is housed within the housing 42. The movable member 50 has a magnetic circuit portion comprising a magnet, and the magnetic circuit portion has the same characteristics as the movable member 26 in the first embodiment (see reference 26). Figure 2They have the same function. The outer peripheral surface 50A1 of the maximum diameter portion 50A, which is part of the outer peripheral surface 50S of the movable member 50, is configured with the inner peripheral surface 42B of the housing 42 separated by a gap G for limiting the amount of air movement.

[0056] The end position of the outer peripheral surface 50A1 of the maximum diameter portion 50A of the movable member 50 on the diaphragm 24 side is aligned with the end position of the inner peripheral surface 42B of the housing 42 on the diaphragm 24 side. Additionally, as an example, the length in the airflow path direction of the outer peripheral surface 50A1 of the maximum diameter portion 50A of the movable member 50 (in...) Figure 3 The length in the vertical direction is set to be greater than the outer peripheral surface 26A1 of the maximum diameter portion 26A of the movable member 26 in the first embodiment (refer to...). Figure 1 , Figure 2 The length of the airflow path in the direction of the airflow path (whichever is acceptable) is longer. That is, in the second embodiment, the length of the airflow path (the part forming the gap G) used to limit the amount of air movement is set to be longer than that in the first embodiment. The movable member 50 is mounted on the leaf spring 28, which is mounted on the housing 42, and the movable member 50 is configured to vibrate in the vibration direction of the diaphragm 24 by energizing the coil 22.

[0057] The large-diameter annular portion 28A of the outer periphery of the leaf spring 28 is mounted between the first component 44 and the second component 46 of the housing 42. Additionally, the small-diameter annular portion 28C of the central portion of the leaf spring 28 is mounted on the central portion 50B1 of the bottom surface of the movable member 50 (the side opposite to the direction of arrow Z) on the other side of the movable member 50 (the side of the movable member 50 opposite to the diaphragm 24 side). Furthermore, the leaf spring 28 in this embodiment is similar to the leaf spring 28 in the first embodiment (see...). Figure 2 Compared to the first embodiment, the distance between the large-diameter ring portion 28A and the small-diameter ring portion 28C is set to be longer. However, for ease of explanation, the distance between the large-diameter ring portion 28A and the small-diameter ring portion 28C is set to be longer. Figure 2 (The same reference numerals are used for the reference numerals.) In addition, in this embodiment, the outer peripheral surface 50B2 of the bottom surface 50B of the movable member 50 is provided as an inclined surface that slopes toward the other side (the side opposite to the direction of arrow Z) as it moves radially inward from the outer peripheral end, and is provided as a connecting surface that is connected to the central portion 50B1 of the bottom surface via the step 50C.

[0058] On the other hand, the protruding wall portion 46B of the housing 42 extends from the end portion 42X and faces the outer peripheral portion 24B of the diaphragm 24. The end portion 42X is the end portion of the housing 42 on the diaphragm 24 side that faces the outer peripheral surface 50A1 of the maximum diameter portion 50A across the gap G when the movable member 50 vibrates. A through hole 42H is formed in the protruding wall portion 46B of the housing 42, and the through hole 42H extends in the direction along the vibration direction of the movable member 50. That is, the through hole 42H is formed in the housing 42 at a position closer to the open end portion 42A than the gap G.

[0059] (Function / Effect) Next, the function and effects of the second embodiment will be explained.

[0060] According to the second embodiment, although the end of one side (arrow Z direction side) of the peripheral wall portion 46A of the housing 42 does not function as a base for fixing the leaf spring 28, it is basically possible to obtain the same function and effect as the first embodiment described above, except for the aspects described below.

[0061] In the second embodiment, although the length of the airflow path used to limit the amount of air movement when the movable member 50 vibrates (that is, the length in the vertical direction of the portion forming the gap G in the figure) is not maintained, the length of the airflow path used to limit the amount of air movement (the portion forming the gap G) is set to be longer than that in the first embodiment, which can increase the viscous resistance of the air flowing in and out of the gap G when the movable member 50 vibrates. Therefore, the vibration generation function can be performed stably.

[0062] Furthermore, in the second embodiment, the small-diameter annular portion 28C of the central part of the leaf spring 28 is mounted on the central portion 50B1 of the bottom surface of the movable member 50 on the other side (opposite to the direction of arrow Z). Therefore, compared with the structure of the first embodiment, the span length of the leaf spring 28 is longer, enabling a softer suspension characteristic. In addition, the outer peripheral surface 50B2 of the bottom surface 50B of the movable member 50 is provided as an inclined surface that slopes toward the other side (opposite to the direction of arrow Z) as it moves radially inward, and is a connecting surface that connects to the central portion 50B1 of the bottom surface across the step 50C. Therefore, it is possible to suppress contact between the movable member 50 and the connecting portion 28B of the leaf spring 28 when the movable member 50 vibrates.

[0063] Furthermore, as a variation of the second embodiment, the structure can also be designed as follows: shortening the vibration direction of the outer peripheral surface (50A1) of the maximum diameter portion (50A) of the movable member (50) (in Figure 3 The length of the airflow path (the part with the gap G) in the vertical direction in the figure is used to maintain the length of the airflow path (the part with the gap G) that limits the amount of air movement when the movable part (50) vibrates.

[0064] [Third Implementation] exist Figure 4 The cross-sectional view shows a portion of the multifunctional vibration actuator 60 according to the third embodiment. (See figure) Figure 4 As shown, the difference between the multifunctional vibration actuator 60 of the third embodiment and the multifunctional vibration actuator 10 of the first embodiment is that, instead of the movable member 26 of the first embodiment (see reference...), Figure 2 It includes a movable member 62 (illustrated schematically in the figure). Other structures are substantially the same as in the first embodiment. In the third embodiment, components substantially the same as those in the first embodiment are labeled with the same reference numerals, and descriptions are appropriately omitted.

[0065] The movable member 62 is housed within the housing 32. The outer peripheral surface 62A1 of the maximum diameter portion 62A, which is part of the outer peripheral surface 62S of the movable member 62, is configured with the inner peripheral surface 32B of the housing 32 separated by a gap G for limiting the amount of air movement. The movable member 62 is constructed including a magnet and vibrates along the vibration direction of the diaphragm 24 by energizing the coil 22. The outer peripheral portion 62X of the movable member 62 is composed of a component separate from the main body portion 62H of the movable member 62, but is integrally joined to the main body portion 62H of the movable member 62. Figure 4 For ease of explanation, a double-dotted line is used to indicate an example of the boundary between the main body portion 62H of the movable member 62 and the constituent portion 62X on the outer periphery of the movable member 62.

[0066] A groove 62G is formed on the outer peripheral surface 62A1 side of the maximum diameter portion 62A in the outer peripheral surface 62S of the movable member 62, and the groove 62G extends circumferentially. As an example, the groove 62G is formed over the entire circumferential direction of the outer peripheral surface 62S of the movable member 62. Furthermore, as an example, the groove 62G is located in the vibration direction of the movable member 62 (in... Figure 4 The middle section (in the diagram, the vertical direction) has multiple (e.g., two) spaces arranged side by side with gaps.

[0067] Furthermore, the structure of movable member 62, apart from the above description, is the same as that of movable member 26 in the first embodiment (see [reference]). Figure 2 (The same structure)

[0068] According to the third embodiment described above, the same functions and effects as the first embodiment can be obtained. Hereinafter, functions and effects unique to the third embodiment that are not present in the first embodiment will be described.

[0069] In the third embodiment, air flows between the portion formed by the outer peripheral surface 62A1 of the maximum diameter portion 62A of the movable member 62 and the groove 62G, and the inner peripheral surface 32B of the housing 32, along the vibration direction of the movable member 62 (in... Figure 4When the air moves (as shown in the diagram, in the vertical direction), it can generate expansion losses in areas where the cross-sectional area of ​​the flow path increases sharply, and contraction losses in areas where the cross-sectional area of ​​the flow path decreases sharply. That is, when the air moves in the above manner, pressure losses can be generated, thus increasing the viscous resistance of the moving air. As a result, the damping function of the movable part 62 during vibration can be improved.

[0070] Furthermore, since the groove 62G is formed on the outer peripheral surface 62A1 side of the maximum diameter portion 62A of the movable member 62, when air moves along the vibration direction of the movable member 62 between the portion formed by the outer peripheral surface 62A1 of the maximum diameter portion 62A of the movable member 62 and the groove 62G and the inner peripheral surface 32B of the housing 32, pressure loss can be generated in the entire circumferential direction of the air flow path, and the viscous resistance of the moving air can be increased in the entire circumferential direction of the air flow path.

[0071] Furthermore, multiple grooves 62G are formed side by side at open intervals in the vibration direction of the movable member 62. Therefore, when air moves between the outer peripheral surface 62A1 of the maximum diameter portion 62A of the movable member 62 and the grooves 62G and the inner peripheral surface 32B of the housing 32 in the vibration direction of the movable member 62, a greater pressure loss can be generated, which can further increase the viscous resistance of the moving air.

[0072] Furthermore, in the third embodiment, the outer peripheral component 62X of the movable member 62 is composed of a separate part from the main body 62H of the movable member 62. Therefore, it is easy to manufacture the outer peripheral component 62X of the movable member 62 with high precision. Additionally, by changing the outer peripheral component 62X of the movable member 62, the resonant frequency of vibration can be adjusted, enabling various product variations. Furthermore, as a variation of the third embodiment, a structure in which the main body (62H) of the movable member (62) and the outer peripheral component (62X) of the movable member (62) are integrally formed can also be adopted.

[0073] [Variations on the implementation method, etc.] In addition, Figures 1-4 In the first to third embodiments shown above, through holes 32H and 42H are formed in the protruding wall portions 34C and 46B of the protruding portions 38 and 48. As a variation, for example, the through holes may be formed in the portion of the protruding wall portion (34C, 46B) that is equivalent to the second component 36 in the first and third embodiments, or the cylindrical wall portion 46C in the second embodiment, such that the through holes extend through the radial direction of the housing (32, 42) from the top end of the protruding wall portion (34C, 46B). In this variation, the radially outward extension amount of the protruding portions (38, 48) may be set to be less than that in the first to third embodiments described above.

[0074] In addition, in the first to third embodiments described above, the housings 32 and 42 are each composed of two parts, but the housing may also be composed of one part or more than three parts.

[0075] In addition, as Figure 3 In a variation of the second embodiment shown above, the outer peripheral surface of the bottom surface (50B) of the movable member (50) may be provided as an inclined surface that slopes towards the other side (opposite to the direction of arrow Z) as it moves radially inward from the outer peripheral end, and is provided as a surface directly connected to the central portion (50B1) of the bottom surface of the movable member (50). Furthermore, as another variation of the second embodiment, the outer peripheral surface of the bottom surface (50B) of the movable member (50) may be provided as a surface orthogonal to the vibration direction of the movable member (50) and connected to the central portion (50B1) of the bottom surface of the movable member (50) via a step (50C).

[0076] In addition, Figure 4 In the third embodiment shown above, the groove 62G is formed on the outer peripheral surface 62S of the movable member 62 in the entire circumferential direction. As a variation of the third embodiment, the groove can also be arranged in an arc shape extending in the circumferential direction on the outer peripheral surface (62S) of the movable member (62).

[0077] In addition, Figure 4 In the third embodiment shown above, two grooves 62G are formed side by side with a gap in the vibration direction of the movable member 62. As a variation of the third embodiment, a structure in which three or more grooves are formed side by side with a gap in the vibration direction of the movable member (62) can also be used, or a structure in which only one groove is formed can be used.

[0078] in addition, Figures 1-4 The multifunctional vibration actuators 10, 40, and 60 of the first to third embodiments shown above have so-called internal magnetic circuits. As a variation of the above embodiments, this disclosure can also be applied to a multifunctional vibration actuator having a so-called external magnetic circuit, in which an annular magnet constituting part of a movable element is arranged on the outer periphery of the coil.

[0079] In addition, as a variation of the above embodiment, the following structure can also be adopted: a small-diameter ring portion (28C) that is the central part of a leaf spring (28) is installed on the part of the movable member (26, 50, 62) on the diaphragm (24) side and on the part opposite to the diaphragm (24) side, and a large-diameter ring portion (28A) that is the outer periphery of the two leaf springs (28) is installed on the housing (32, 42).

[0080] Furthermore, in the first to third embodiments described above, the outer peripheral surfaces 26A1, 50A1, and 62A1 of the maximum diameter portions 26A, 50A, and 62A of the movable members 26, 50, and 62 are configured with the inner peripheral surfaces 32B and 42B of the housings 32 and 42 separated by a gap G for limiting the amount of air movement. As a variation, the following structure may also be adopted: an inner peripheral surface with a small diameter protruding inward from a portion of the inner peripheral surface of the housing is formed, and the outer peripheral surface of the portion of the movable member with a diameter smaller than the maximum diameter portion is configured with the inner peripheral surface of the housing with the small diameter portion separated by a gap for limiting the amount of air movement. The portion of the outer peripheral surface of the movable member configured with the inner peripheral surface of the housing separated by a gap for limiting the amount of air movement need not necessarily be the outer peripheral surface of the maximum diameter portion of the movable member.

[0081] In addition, as a variation of the first and third embodiments described above, the following structure can also be adopted: the diameter of the leaf spring 28 is set to be larger than that in the first and third embodiments described above, and the outer periphery of the leaf spring is mounted on the side of the first component (34) of the second component (36).

[0082] Furthermore, the first to third embodiments and the various modifications described above can be implemented in appropriate combinations.

[0083] The above provides an example of this disclosure, but this disclosure is not limited to the above description. In addition to the above description, various modifications and implementations can be made without departing from its main idea.

[0084] This application claims priority to Japanese Patent Application No. 2023-182079, filed on October 23, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A multi-functional vibration actuator, comprising: The housing has an open end on one side; A coil, housed within the housing, is configured such that its axial direction is along the depth direction of the housing; A diaphragm, disposed on one side of the housing and connected to the coil, is capable of vibrating in the axial direction of the coil; A movable element, housed within the housing, is configured with its outer peripheral surface separated from the inner peripheral surface of the housing by a gap that restricts the amount of air movement. The movable element comprises a magnet and vibrates along the vibration direction of the diaphragm by energizing the coil. as well as A leaf spring, which is mounted on the housing and has the movable element installed thereon. The housing has a protrusion that includes the open end on one side and extends radially outward, and the protrusion faces the outer periphery of the diaphragm. A through hole is formed in the protruding portion. The through hole is formed in the housing at a position closer to the open end than the gap.

2. The multifunctional vibration actuator according to claim 1, wherein, The outer periphery of the leaf spring is mounted on the housing, and the central portion of the leaf spring is mounted on the side of the movable member opposite to the diaphragm side.

3. The multifunctional vibration actuator according to claim 1, wherein, The through hole extends in the radial direction of the housing relative to the protrusion.

4. The multifunctional vibration actuator according to claim 2, wherein, The central portion of the leaf spring is mounted on the central portion of the bottom surface on the other side of the movable member. The outer peripheral surface of the bottom surface of the movable member is provided as at least one of an inclined surface and a connecting surface, the inclined surface being inclined toward the other side as it moves radially inward, and the connecting surface being connected to the center of the bottom surface via a step.

5. The multifunctional vibration actuator according to claim 1, wherein, A groove is formed on the outer peripheral surface of the movable member, and the groove extends circumferentially along the outer peripheral surface.

6. The multifunctional vibration actuator according to claim 5, wherein, The groove is formed over the entire circumference of the outer peripheral surface of the movable member.

7. The multifunctional vibration actuator according to claim 5, wherein, The grooves are formed in a plurality of parallel arrangements at open intervals in the vibration direction of the movable member.

8. The multifunctional vibration actuator according to claim 1, wherein, The outer periphery of the movable member is composed of a component that is separate from the main body of the movable member.

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