vibrator unit

Abstract

The present invention provides a vibrator unit that appropriately dampens vibrations in a magnetic circuit. [Solution] The transducer unit 1D comprises a housing having a cylindrical housing body 221 and a top plate 211 connected to the voice coil 3; a magnetic circuit consisting of a yoke 43, a magnet 41 and a plate 42 located above the magnet, which is arranged to float within the housing on the central axis P; an annular first support member 35A located between the top plate 211 and the cylindrical portion 432 of the yoke 43; and a disc-shaped second support member 35B located between the bottom surface of the housing body 221 and the bottom plate portion 431 of the yoke 43.

Description

Technical Field

[0001] The present invention relates to a vibrator unit.

Background Art

[0002] A vibration unit that makes a person feel vibration is known (see Patent Document 1). In the vibrator unit described in Patent Document 1, a magnetic circuit structure is supported by a support member in a case, and when an electric current flows through a coil attached to the case, the magnetic circuit structure vibrates.

[0003] The vibrator unit described in Patent Document 1 includes a cylindrical housing connected to a built-in voice coil, a magnet, a plate and a pole yoke that face each other with the magnet interposed therebetween and constitute a magnetic gap for the voice coil, and a magnetic circuit structure that is coaxially arranged in a floating state inside the housing, and a plurality of support members that support the magnetic circuit structure inside the housing and support the vibration of the magnetic circuit structure.

[0004] In particular, the support member described in Patent Document 1 is fixed to the magnetic circuit structure and the housing using an adhesive.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, it is difficult to uniformly apply the adhesive to a predetermined position, and depending on the application state of the adhesive, variations may occur in the vibration attenuation characteristics.

[0007] Such oscillator units require good responsiveness to electrical signals; that is, they must not only transmit vibrations of the magnetic circuit components appropriately but also attenuate them appropriately.

[0008] One example of a problem that this invention aims to solve is the problem of variability in vibration damping characteristics that occurs in the conventional technology described above. [Means for solving the problem]

[0009] The present invention relates to a vibrator unit comprising a housing having a cylindrical housing body and a top plate, a magnetic circuit located inside the housing consisting of a yoke, a magnet and a plate located above the magnet, and a first support member located between the top plate and the magnetic circuit, wherein the first support member is annular in shape. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view showing a vibrator unit according to a first embodiment of the present invention. [Figure 2] This is an exploded perspective view of the aforementioned oscillator unit. [Figure 3] This is a diagram illustrating the manufacturing method of the vibrator unit. [Figure 4] This is a cross-sectional view showing a vibrator unit according to a second embodiment of the present invention. [Figure 5] This is a cross-sectional view showing a vibrator unit according to a third embodiment of the present invention. [Figure 6] This is a cross-sectional view showing a vibrator unit according to a fourth embodiment of the present invention. [Figure 7] This is a cross-sectional view showing a vibrator unit according to a fourth embodiment of the present invention. [Modes for carrying out the invention]

[0011] One embodiment of the present invention is described below. The transducer unit according to this embodiment of the present invention comprises a housing having a cylindrical housing body and a top plate connected to a voice coil, a magnetic circuit consisting of a yoke, a magnet and a plate located above the magnet, and arranged coaxially in a floating state within the housing, a first support member located between the top plate and the magnetic circuit, and a second support member located between the bottom surface of the housing body and the magnetic circuit. That is, the first support member is held sandwiched between the top plate and the magnetic circuit, and the second support member is held sandwiched between the bottom surface of the housing body and the magnetic circuit. With this, the first support member and the second support member can be positioned appropriately without using adhesive. Therefore, unlike the prior art, it is possible to suppress variations in vibration damping characteristics due to the application state of adhesive, while appropriately damping the vibration of the magnetic circuit by positioning the first support member and the second support member appropriately.

[0012] Furthermore, even when adhesive is applied to the upper and lower surfaces of the first and second support members, or to either of these surfaces, the adhesive serves as an auxiliary fixing means for positioning and maintaining these members. Since these members can hold themselves in place by their elasticity, the application state of the adhesive has little effect on the damping characteristics. In this way, even when adhesive is used, vibrations of the magnetic circuit can be appropriately dampened.

[0013] Furthermore, the first support member and the second support member may be formed such that their deformation amounts in response to a predetermined force are substantially equal. This ensures that there is no difference in vibration damping characteristics between the vertical and horizontal directions, and that vibrations of the magnetic circuit can be appropriately dampened.

[0014] Furthermore, the first support member and the second support member may be formed such that the areas of their upper and lower surfaces are approximately equal, and the areas of the surfaces of the first support member and the second support member may be approximately equal. This allows for appropriate damping of vibrations in the magnetic circuit.

[0015] Furthermore, at least one of the first support member and the second support member may be formed to have a trapezoidal cross-sectional shape. With this configuration, at least one of the first support member and the second support member will be compressed by the vibration shock of the magnetic circuit. However, as it is compressed, the resistance will gradually increase, thus preventing bottoming out (where the vibration force exceeds the limit of the damping amplitude and is transmitted directly to the housing).

[0016] Furthermore, if both the first support member and the second support member are formed to have a trapezoidal cross-sectional shape, the long side of the first support member and the long side of the second support member may be provided to contact the magnetic circuit, or the short side of the first support member and the short side of the second support member may be provided to contact the magnetic circuit.

[0017] Furthermore, the magnetic circuit is an external magnetic type magnetic circuit in which the yoke integrally comprises a disc-shaped bottom plate portion and a column portion formed to rise from the center of the bottom plate portion, and the first support member and the second support member may be provided above and below the yoke. With this, the first support member and the second support member can be positioned appropriately without using adhesive. Therefore, unlike the prior art, variations in vibration damping characteristics due to the application state of adhesive can be suppressed, and the vibration of the magnetic circuit can be appropriately damped by positioning the first support member and the second support member appropriately.

[0018] Further, the magnetic circuit is an internal magnetic type magnetic circuit in which the yoke integrally includes a disc-shaped bottom plate portion and a cylindrical tubular portion formed so as to rise from the outer edge of the bottom plate portion. The first support member may be formed in an annular shape and be located between the top plate and the tubular portion of the yoke. The second support member may be formed in a disc shape and be located between the bottom surface of the housing body and the bottom plate portion. According to this, the first support member and the second support member can be arranged at appropriate positions without using an adhesive. Therefore, while suppressing the occurrence of variations in the vibration damping characteristics due to the application state of the adhesive as in the prior art, the vibration of the magnetic circuit can be appropriately damped because the first support member and the second support member are arranged at appropriate positions.

[0019] Further, the inner diameter dimension of the first support member and the diameter dimension of the second support member may be formed to be substantially equal. According to this, the first support member and the second support member can be formed by a single pressing process, and the amount of end material can be reduced, so that the material yield can be improved.

Embodiment

[0020] (First Embodiment) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a cross-sectional view showing a vibrator unit 1 according to the first embodiment of the present invention. FIG. 2 is an exploded perspective view of the vibrator unit 1. The axial direction shown in FIG. 1 and the like is the vibration direction in which the vibrator unit 1 vibrates, and the radial direction is the direction orthogonal to the axis of the magnetic circuit 40. Among the axial directions, the side where the upper case 21 is located may be referred to as "upper", and the side where the lower case body 221 described later is located may be referred to as "lower". Further, the P direction shown in FIG. 1 and the like indicates the central axis of the vibrator unit 1.

[0021] As shown in FIGS. 1 and 2, the vibrator unit 1 includes a hollow and disc-shaped case 2 (housing) including an upper case 21 and a lower case 22, a voice coil 3 fixed to the upper case 21, a magnetic circuit portion 4 built in the case 2, and a damping portion 5 that damps the vibration of the magnetic circuit 40.

[0022] As shown in Figures 1 and 2, the upper case 21 comprises a disc-shaped upper case body 211 (top plate), a peripheral wall 212 erected downward from the periphery of the upper case body 211, and a terminal cover 213 (shown in Figure 2) that surrounds a hole (not shown) formed in the peripheral wall 212 and protrudes radially outward from the periphery of the hole in a rectangular tube shape. Note that the terminal cover 213 is omitted in Figure 1.

[0023] As shown in Figures 1 and 2, the upper case body 211 comprises a central disc portion 214 located in the center and an annular portion 215 extending radially outward from the outer edge of the central disc portion 214. The central disc portion 214 is formed in a disc shape with a central axis P at its center. As shown in Figure 1, the central disc portion 214 is composed of substantially flat upper and lower surfaces, and is formed to have a substantially constant thickness. The central disc portion 214 is located below the annular portion 215. The upper end of the voice coil 3, which will be described later, is fixed to the outer peripheral end surface 214a of the central disc portion 214.

[0024] As shown in Figure 1, the peripheral wall 212 comprises a first peripheral wall 216 erected cylindrically downward from the outer peripheral edge of the annular portion 215, and a second peripheral wall 217 that is continuous with the lower peripheral edge of the first peripheral wall 216 and erected cylindrically downward. The inner diameter of the second peripheral wall 217 is formed to be larger than the inner diameter of the first peripheral wall 216. The lower end of the first peripheral wall 216 is provided with a surface (denoted as the lower end surface 216a) that extends in a direction perpendicular to the axis. A suspension 44 of the magnetic circuit portion 4, which will be described later, is sandwiched between the lower end surface 216a of the first peripheral wall 216 and the upper end surface 221a of the lower case body 221, which will be described later.

[0025] As shown in Figures 1 and 2, the lower case 22 comprises a lower case body 221 (housing body) formed in the shape of a tray (cylindrical or rectangular tube), an extending wall portion 222 extending radially outward from a position below the upper end surface 221a of the lower case body 221, and a cylindrical wall portion 223 erected cylindrically upward from the outer peripheral edge of the extending wall portion 222. In the lower case body 221, the second peripheral wall 217 of the upper case 21 is inserted between a part of the lower case body 221 (designated as reference numeral 221A), including the upper end surface 221a, and the cylindrical wall portion 223. Also, as shown in Figure 2, a notch 223a is formed in the cylindrical wall portion 223 at a position that overlaps with the hole of the upper case 21. A copper wire (not shown) drawn out from the voice coil 3, which will be described later, is inserted into the terminal cover 213 through the communicating hole and notch 223a and led out to the outside of the case 2.

[0026] Furthermore, case 2 has a locking part 23 that locks the upper case 21 and the lower case 22 together. The locking part 23 comprises a locking arm 232 having a locking portion 231, and a receiving portion 233 into which the locking portion 231 of the locking arm 232 engages. The locking arm 232 is provided on the cylindrical wall portion 223 of the lower case 22. The receiving portion 233 is a step at the boundary between the first circumferential wall 216 and the second circumferential wall 217 in the circumferential wall 212 of the upper case 21. With this locking part 23, the locking portion 231 of the locking arm 232 engages with the step that functions as the receiving portion 233 of the upper case 21 by inserting the second circumferential wall 217 of the upper case 21 between a portion 221A including the upper end surface 221a of the lower case body 221 and the cylindrical wall portion 223. In this way, the locking part 23 maintains the locked state of the upper case 21 and the lower case 22.

[0027] The voice coil 3 is composed of a cylindrical bobbin 31 and a coil portion 32 formed by winding copper wire 30 around the bobbin 31. A portion of the coil portion 32 is routed through a wire passage (not shown) formed in the annular body 215 and brought out to the outside of the case 2. Such a voice coil 3 is arranged in a floating state within a magnetic gap G (a place where magnetic flux is concentrated, shown in Figure 1) formed in the magnetic circuit 40.

[0028] The magnetic circuit section 4 is configured to include a disc-shaped magnet 41, a disc-shaped plate 42, and a yoke section 45, all of which are arranged coaxially on the central axis P of the case 2. The magnet 41, plate 42, and yoke 43 constitute the magnetic circuit 40.

[0029] The magnet 41 is made of neodymium magnet. The magnet 41 is located between the plate 42 and the bottom plate portion 431 of the yoke 43. The outer diameter of the magnet 41 is formed to be smaller than the inner diameter of the cylindrical portion 432 of the yoke 43, and also slightly smaller than the outer diameter of the plate 42. The plate 42 and the yoke 43 are each made of iron. The plate 42 and the yoke 43 are also provided to concentrate magnetic flux in the magnetic gap G.

[0030] The yoke section 45 comprises a yoke 43 and a suspension 44 (maintenance member) connected to the yoke 43 and supporting the magnetic circuit 40.

[0031] The yoke 43 is configured with a disc-shaped base plate portion 431, a cylindrical portion 432 erected from the outer edge of the base plate portion 431 to position the magnet 41 and plate 42 inside it, and an extended portion 433 extending radially outward from the end (upper end) of the cylindrical portion 432 that is away from the base plate portion 431. The magnetic circuit 40 of this embodiment is an internal magnetic circuit configured with a yoke 43 comprising a disc-shaped base plate portion 431 and a cylindrical portion 432 erected from the outer edge of the base plate portion 431 to position the magnet 41 and plate 42 inside it.

[0032] When a signal current is input to the voice coil 3, the magnetic circuit 40 generates a force in the axial direction according to Fleming's left-hand rule. However, since the voice coil 3 is fixed to the case 2 and cannot move, the reaction force causes the magnetic circuit 40 to vibrate up and down.

[0033] As shown in Figures 1 and 2, the suspension 44 is formed in an annular shape and is composed of plate-shaped members. The suspension 44 is formed with different diameters and comprises a plurality of (three in the illustrated example) narrow annular sections 440A, 440B, and 440C (shown in Figure 2) arranged radially, and a plurality of connecting sections 444D (shown in Figure 2) that connect radially adjacent narrow annular sections 440A, 440B, and 440C.

[0034] As shown in Figure 1, of the narrow annular sections 440A, 440B, and 440C, the narrow annular section 440A, which is located closest to the central axis P (inner circumference), is equipped with a yoke support section 441 with a roughly C-shaped cross-section.

[0035] In this type of suspension 44, the extended portion 433 of the yoke 43 is inserted and supported by the yoke support portion 441 of the narrow annular portion 440A located at the inner end, and the narrow annular portion 440C located at the outer end is sandwiched and supported between the lower end surface 216a of the upper case 21 and the upper end surface 221a of the lower case 22.

[0036] The magnetic circuit 40 is supported coaxially with the central axis P by fixing the suspension 44 in a predetermined position on the yoke 43. When a signal current is input to the voice coil 3, it generates a force in one axial direction (upward) according to Fleming's left-hand rule. However, since the voice coil 3 is fixed to the case 2 and cannot move, vertical vibration is imparted to the case 2 via the suspension 44 due to the reaction force of the vibration of the magnetic circuit 40.

[0037] The damping section 5 is formed in a disc shape having a predetermined thickness and includes a pair of dampers 5A (first support member) and 5B (second support member) that absorb and dampen vibrations of the magnetic circuit 40. The pair of dampers 5A and 5B in this embodiment are made of urethane foam. These dampers 5A and 5B have substantially the same function or substantially the same configuration. That is, the pair of dampers 5A (first support member) and 5B (second support member) are configured such that the amount of deformation in response to a predetermined force is substantially equal.

[0038] Each damper 5A and 5B, as shown in Figure 2, is composed of an upper surface 51 made of a flat surface, a lower surface 52 facing the upper surface 51 and also made of a flat surface, and an outer peripheral surface 53 formed such that the distance from the center (central axis P) is approximately constant. The outer peripheral surface 53 is formed such that the distance from the center (central axis P) is approximately constant at any position in the vertical direction. That is, each pair of dampers 5A and 5B is formed such that the areas of the upper and lower surfaces 51 and 52 are approximately equal. The diameter of each damper 5A and 5B is formed to be larger than the shaft dimension. Damper 5A is sandwiched between the central disc portion 214 of the upper case 21 and the plate 42 of the magnetic circuit 40 in a natural state or slightly compressed state, while damper 5B is sandwiched between the lower case body 221 of the lower case 22 and the bottom plate portion 431 of the yoke 43 in a natural state or slightly compressed state. A pair of dampers 5A and 5B are positioned above and below the magnetic circuit 40. In this embodiment, damper 5A is sandwiched between the central disc portion 214 of the upper case 21 and the plate 42 of the magnetic circuit 40 without the use of adhesive, and damper 5B is sandwiched between the lower case body 221 of the lower case 22 and the bottom plate portion 431 of the yoke 43 without the use of adhesive.

[0039] In this embodiment, the yoke portion 45 is formed by insert molding, as shown in Figures 3(A) to (G). For insert molding of the yoke portion 45, a mold M is used, as shown in Figures 3(A) to (G). The mold M consists of male and female molds M10 and M11 that can be opened in the axial direction. Inside the mold M, a yoke portion housing M1 capable of housing the yoke portion 45 is formed. The yoke portion housing M1 has a molding projection M2 that is inserted into the cylindrical portion 432 of the yoke 43, a suspension housing M3 formed in an annular shape centered on the molding projection M2 and capable of housing the suspension 44, and a yoke housing M4 capable of housing the yoke 43.

[0040] First, as shown in Figures 3(A) and 3(B), with the male and female molds M10 and M11 open, the yoke 43 is set on the molding projection M2 of the yoke housing M4. Then, as shown in Figure 3(C), the molds M10 and M11 are brought close together and the molds M10 and M11 are closed. After this, as shown in Figures 3(D) and 3(E), molten resin is filled into the yoke housing M1. After the molten resin hardens, the male and female molds M10 and M11 are opened as shown in Figure 3(F). In this way, the yoke section 45, in which the yoke 43 and suspension 44 are integrated, is manufactured. Because the yoke section 45 is manufactured by insert molding, the yoke 43 and suspension 44 can be integrated in advance without using adhesives or supports, thus reducing the number of parts and the steps required to assemble the yoke 43 and suspension 44.

[0041] In this type of vibrator unit 1, the damper 5A (first support member) is held between the upper case body 211 (top plate) and the magnetic circuit 40, and the damper 5B (second support member) is held between the bottom surface of the lower case body 221 (housing body) and the magnetic circuit 40. With this configuration, the damper 5A (first support member) and the damper 5B (second support member) can be positioned appropriately without using adhesive. Therefore, unlike in the prior art, variations in vibration damping characteristics due to the application of adhesive can be suppressed, and the vibration of the magnetic circuit 40 can be appropriately damped by positioning the damper 5A (first support member) and the damper 5B (second support member) appropriately.

[0042] Furthermore, since the damper 5A (first support member) is held in place between the upper case body 211 (top plate) and the magnetic circuit 40, and the damper 5B (second support member) is held in place between the bottom surface of the lower case body 221 (enclosure body) and the magnetic circuit 40, the dampers 5A (first support member) and 5B (second support member) are positioned appropriately without the need for adhesive or fasteners to supplement adhesive fixation. This reduces the number of parts and the number of steps required to assemble the yoke 43 and suspension 44.

[0043] It should be noted that the present invention is not limited to the embodiments described above, and includes other configurations that can achieve the objectives of the present invention, and the following modifications are also included in the present invention.

[0044] In the first embodiment, the dampers 5A and 5B (first support member and second support member) were held in place without the use of adhesive, but the present invention is not limited thereto. The first support member and the second support member may have adhesive applied to their upper and lower surfaces, or to either of these surfaces. That is, even when adhesive is applied to the upper and lower surfaces, or to either of these surfaces, the adhesive is merely an auxiliary fixing means for positioning and maintaining these members, and the elasticity of these members allows them to hold themselves in place, so the state of adhesive application has little effect on the damping characteristics. In this way, even when adhesive is used, the vibrations of the magnetic circuit 40 can be appropriately dampened.

[0045] Furthermore, in the first embodiment, each damper 5A, 5B (first support member and second support member) has substantially the same function or substantially the same configuration, but the present invention is not limited thereto. One of the first support member and the second support member may be made of a relatively hard material, and the other may be made of a material that is more flexible than the other. In this case, the radial area of ​​one may be made smaller than that of the other so that the amount of deformation under a predetermined force is substantially equal.

[0046] Furthermore, in the first embodiment, the magnetic circuit 40 was described as an internal magnetic type, in which the yoke 43 comprises a bottom plate portion 431 formed in the shape of a disc and a cylindrical portion 432 erected in a cylindrical shape from the outer edge of the bottom plate portion 431 and positioning the magnet 41 and plate 42 inside it. However, the present invention is not limited thereto. The magnetic circuit may also be an external magnetic type, in which the yoke 43 comprises a bottom plate portion 431 formed in the shape of a disc and a columnar portion erected in a columnar shape from approximately the center of the bottom plate portion 431 and positioning the annular magnet 41 and annular plate 42 on its radially outer side. In that case, the damping portion may comprise a pair of dampers having substantially the same function or substantially the same configuration as in the first embodiment. One of the pair of dampers may be held in a natural state or slightly compressed between the central disc portion 214 of the upper case 21 and the upper surface of the column portion of the yoke 43, and the other of the pair of dampers may be held in a natural state or slightly compressed between the lower case body 221 (housing body) of the lower case 22 and the bottom plate portion 431 of the yoke 43. That is, the pair of dampers may be provided in positions that are arranged vertically on either side of the yoke 43. Even if the magnetic circuit is an external magnetic circuit, substantially the same effects as in the first embodiment will be achieved.

[0047] Furthermore, in the first embodiment, the suspension 44 (maintenance member) is formed with different diameters and comprises a plurality of (three in the illustrated example) annular body parts 440A, 440B, and 440C (shown in Figure 2) arranged radially, and a plurality of connecting parts 444D (shown in Figure 3) that connect radially adjacent annular body parts 440A, 440B, and 440C. However, the present invention is not limited thereto. The maintenance member may be formed in an annular shape using, for example, an elastic material, and may be continuously formed in the circumferential direction from the radial inner edge to the outer edge. That is, the maintenance member may have the edge shape of a speaker, and any configuration is acceptable as long as it can support the magnetic circuit 40.

[0048] Furthermore, in the first embodiment, the yoke portion 45 is formed by insert molding. That is, the yoke portion 45, in which the yoke 43 and suspension 44 are integrated, is manufactured by insert molding. However, the yoke 43 and suspension 44 may be manufactured separately and integrated by applying adhesive at appropriate positions.

[0049] Such vibrator units can be attached to pillows, chair cushions, etc., and used in various ways, such as tactile sound drive units, vibration drive units, massage drive units, and sound-generating vibration drive units.

[0050] Furthermore, the vibrator unit may have a control unit that receives input information from input devices such as remote controls, smartphones, and various sensors, and may vibrate the vibrator. The control unit may be provided in a separate control device from the vibration unit, and the vibration unit and the control device may be connected by wire or wireless.

[0051] (Second example) Next, a transducer unit according to a second embodiment of the present invention will be described with reference to Figure 4. Parts having substantially the same configuration or function as those in the first embodiment described above are denoted by the same reference numerals and their descriptions are omitted. The difference between the transducer unit according to the second embodiment and the transducer unit according to the first embodiment lies in the shape of the housing. Figure 4 is a cross-sectional view showing the transducer unit according to the second embodiment of the present invention.

[0052] As shown in Figure 4, the transducer unit 1A includes a hollow, disc-shaped case 102 (housing) comprising an upper case 121 and a lower case 122, a voice coil 3 fixed to the upper case 121, a magnetic circuit section 4 having a magnetic circuit 40 built into the case 102, and a damping section 5 that dampens the vibration of the magnetic circuit 40.

[0053] The upper case 121 comprises a disc-shaped upper case body 211, a peripheral wall 212 erected downward from the periphery of the upper case body 211, and a terminal cover 213 that surrounds a hole (not shown) formed in the peripheral wall 212 and protrudes radially outward from the periphery of the hole in a rectangular tubular shape. Note that the terminal cover 213 is omitted in Figure 4.

[0054] The upper case body 211 comprises a central disc portion 214 located in the center and an annular portion 215 extending radially outward from the outer edge of the central disc portion 214. The central disc portion 214 is formed in a disc shape with a central axis P at its center. The central disc portion 214 is provided with a damper mounting surface 214A, which is formed in a disc shape and has a damper 5A installed on its lower surface. The damper mounting surface 214A is composed of a curved surface whose projection increases as it approaches the center (central axis P). The central disc portion 214 is located below the annular portion 215.

[0055] The lower case 22 comprises a lower case body 221 formed in the shape of a tray, an extending wall portion 222 extending radially outward from a position below the upper end surface of the lower case body 221, and a cylindrical wall portion 223 erected in a cylindrical shape upward from the outer peripheral edge of the extending wall portion 222. The lower case body 221 is provided with a damper mounting surface 221A formed in the shape of a disc, on which a damper 5B is installed. The damper mounting surface 221A is composed of a curved surface whose projection increases as it approaches the center (central axis P).

[0056] According to the embodiment described above, the upper case 121 and the lower case 122 are each formed with damper mounting surfaces 214A and 221A, which are curved surfaces whose projection increases as they approach the center (central axis P). As a result, damper 5A is held in a slightly compressed state between the central disc portion 214 of the upper case 121 and the plate of the magnetic circuit 40, and damper 5B is held in a slightly compressed state between the lower case body 221 of the lower case 122 and the bottom plate portion 431 of the yoke 43. Therefore, even without adhesive, or even with a small amount of adhesive used, or even if it is not applied uniformly, dampers 5A and 5B can be maintained in a stable state, and vibrations of the magnetic circuit 40 can be appropriately dampened.

[0057] (Third embodiment) Next, a transducer unit 1B according to a third embodiment of the present invention will be described with reference to Figure 5. Note that parts having substantially the same configuration or function as those in the first embodiment described above are denoted by the same reference numerals and their descriptions are omitted. The difference between the transducer unit 1B according to the third embodiment and the transducer unit 1 according to the first embodiment lies in the different shapes of the first and second support members. Figure 5 is a cross-sectional view showing the transducer unit 1B according to the third embodiment of the present invention.

[0058] A pair of dampers 15A (first support member) and 15B (second support member) are each formed in the shape of a disc having a predetermined thickness, and absorb and dampen vibrations of the magnetic circuit 40. These dampers 15A and 15B are made of urethane foam and have substantially the same function or substantially the same configuration. That is, the pair of dampers 15A (first support member) and 15B (second support member) are formed so that the amount of deformation in response to a predetermined force is substantially equal. Each damper 15A and 15B has an upper surface 51A made of a flat surface, a lower surface 52A made of a flat surface facing the upper surface 51A, and an outer peripheral surface 53A that is inclined so that the diameter decreases as it progresses in one direction in the axial direction, and is formed so that the cross-sectional shape is an isosceles trapezoid (trapezoidal). In this type of damper 15A, the long side (bottom surface 52A) is in contact with the plate 42 of the magnetic circuit 40, and in damper 15B, the long side (top surface 51A) is in contact with the bottom plate portion 431 of the yoke 43 of the magnetic circuit 40. That is, the long sides 51A and 52A of each damper 15A and 15B are in contact with the magnetic circuit.

[0059] In the embodiment described above, both damper 15A (first support member) and damper 15B (second support member) are formed to have a trapezoidal cross-sectional shape, and the long sides 51A and 52A of each damper 15A and 15B are in contact with the magnetic circuit 40. With this configuration, each damper 15A and 15B is gradually compressed by the vibration shock of the magnetic circuit 40, and as it is compressed, the resistance of each damper 15A and 15B gradually increases, thereby suppressing bottoming out (where the vibration force exceeds the limit of the damping amplitude and is transmitted directly to the housing).

[0060] (Fourth embodiment) Next, a vibrator unit according to a fourth embodiment of the present invention will be described with reference to Figure 6. Note that parts having substantially the same configuration or function as those in the third embodiment described above are denoted by the same reference numerals and their descriptions are omitted. The difference between the vibrator unit according to the fourth embodiment and the vibrator unit according to the third embodiment lies in the way the first and second support members are installed. In the third embodiment, the long sides 51A and 52A of the cross-section of each damper 25A and 25B are in contact with the magnetic circuit 40, whereas in the fourth embodiment, the short sides 51B and 52B of the cross-section of each damper 25A and 25B are in contact with the magnetic circuit 40. This provides substantially the same effects as the third embodiment.

[0061] (Fifth example) Next, a transducer unit 1D according to the fifth embodiment of the present invention will be described with reference to Figure 7. Parts having substantially the same configuration or function as those in the first embodiment described above are denoted by the same reference numerals and their descriptions are omitted. The difference between the transducer unit 1D according to the fifth embodiment and the transducer unit 1 according to the first embodiment lies in the shape and installation position of the first and second support members. Figure 7 is a cross-sectional view showing the transducer unit 1D according to the fifth embodiment of the present invention.

[0062] The first damper 35A (first support member) is formed in an annular shape with a predetermined thickness. The second damper 35B (second support member) is formed in a disc shape with a predetermined thickness. The inner diameter of the first damper 35A and the outer diameter of the second damper 35B are formed to be approximately equal in size, and these first dampers 35A and second dampers 35B are formed in a single press operation. The upper and lower surfaces of the first damper 35A and the upper and lower surfaces of the second damper 35B are formed to be approximately equal in size. The first damper 35A is held between the annular portion 215 of the upper case 21 and the extended portion 433 of the yoke 43 of the magnetic circuit 40 in a natural state or slightly compressed state, while the second damper 35B is held between the lower case body 221 of the lower case 22 and the bottom plate portion 431 of the yoke 43 in a natural state or slightly compressed state. In this embodiment, the second extension portion 444 of the suspension 44 is omitted.

[0063] According to the embodiment described above, the magnetic circuit 40 is an internal magnetic circuit in which the yoke 43 integrally comprises a disc-shaped bottom plate portion 431 and a cylindrical tube portion 432 formed to rise from the outer edge of the bottom plate portion 431. The first damper 35A (first support member) may be formed in an annular shape and located between the upper case body 211 (top plate) and the tube portion 432 of the yoke 43, and the second damper 35B (second support member) may be formed in a disc shape and located between the bottom surface of the lower case body 221 (housing body) and the bottom plate portion 431 of the yoke 43. With this configuration, the first damper 35A (first support member) and the second damper 35B (second support member) can be positioned appropriately without using adhesive. Therefore, unlike conventional technology, where variations in vibration damping characteristics occur depending on the application state of the adhesive, the vibration of the magnetic circuit 40 can be appropriately damped by positioning the first damper 35A (first support member) and the second damper 35B (second support member) appropriately.

[0064] Furthermore, the inner diameter of the first damper 35A (first support member) and the diameter of the second damper 35B (second support member) are formed to be approximately equal. This allows the first damper 35A (first support member) and the second damper 35B (second support member) to be formed in a single press operation, and reduces the amount of scrap material, thereby improving material yield.

[0065] Furthermore, while the best configurations and methods for carrying out the present invention are disclosed in the above description, the present invention is not limited thereto. That is, although the present invention is particularly illustrated and described with respect to specific embodiments, those skilled in the art can make various modifications to the embodiments described above in terms of shape, material, quantity, and other detailed configurations without departing from the technical idea and purpose of the present invention. Therefore, the limiting descriptions of shape, material, etc. disclosed above are provided as examples to facilitate understanding of the present invention and do not limit the present invention. Accordingly, descriptions of components with some or all of these limitations removed are included in the present invention. [Explanation of Symbols]

[0066] 1. Transducer Unit 2 cases (enclosures) 211 Upper case body (top panel) 221 Lower case body (main enclosure) 3 Voice coil 40 Magnetic Circuit 41 Magnets 42 plates 43 York 431 Bottom plate part 432 Cylinder part 5A, 15A, 25A dampers (first support member) 35A First damper (first support member) 5B, 15B, 25B dampers (second support members) 35B Second damper (second support member)

Claims

1. A cylindrical enclosure body and an enclosure having a top plate, A magnetic circuit located within the housing consists of a yoke, a magnet, and a plate located above the magnet, The system includes a first support member located between the top plate and the magnetic circuit, The first support member is annular. A vibrator unit characterized by the following features.

2. The magnetic circuit and the housing are coaxially positioned. The vibrator unit according to feature 1.

3. The magnetic circuit is an internal magnetic circuit in which the yoke comprises a disc-shaped bottom plate portion and a cylindrical tube portion formed to rise from the outer edge of the bottom plate portion. The transducer unit according to feature 1 or 2.

4. The magnetic circuit is an external magnetic circuit in which the yoke comprises a disc-shaped base plate portion, a column portion located approximately in the center of the base plate portion, and the magnet and plate located radially outside the column portion. The transducer unit according to feature 1 or 2.

5. The housing body further comprises a second support member located between the bottom surface of the housing body and the magnetic circuit. The transducer unit according to any one of claims 1 to 4.

Images