Earpiece

Abstract

To provide an earpiece which can be mounted in the ear comfortably for a long time.SOLUTION: An earpiece 1 comprises a hollow shaft part 2 in a cylindrical shape including a through hole 23 for transferring sounds and a cylindrical outer coat part 3 which extends in a first axial direction Z from a first end 21 to the side of a second end 22 in an axial direction of the hollow shaft part and covers the hollow shaft part. The outer coat part is formed in a circular truncated cone cylinder shape of which the radial dimension becomes larger toward a position in the first axial direction. An outer peripheral surface 3a of the outer coat part includes: a first outer peripheral region 3a1 which is positioned on the side of the first end and of which the tilt angle with respect to the axial direction is fixed; and a second outer peripheral region 3a2 which is positioned while being continued to the side of the second end with respect to the first outer peripheral region and of which the tilt angle at least at a position away from the first outer peripheral region is larger than that of the first outer peripheral region.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an earpiece. [Background technology]

[0002] Patent Document 1 discloses an earpiece for use with earphones that has a cylindrical inner skin (hollow shaft portion) and an outer skin (outer skin portion) that extends from one axial end of the inner skin and covers the outside of the inner skin. A sound guide tube of the earphone body is inserted into the inner skin. In the earpiece of Patent Document 1, part of the outer skin is formed in the shape of a tapered truncated cone. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 3218417 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is room for improvement in this type of earpiece in terms of wearing it comfortably in the ear for long periods of time.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide an earpiece that can be worn comfortably in the ear for a long period of time. [Means for solving the problem]

[0006] A first aspect of the present invention is an earpiece comprising: a cylindrical hollow shaft portion having a through hole for transmitting sound; and a tubular outer cover portion extending in a first axial direction from a first axial end of the hollow shaft portion toward a second axial end of the hollow shaft portion and covering the hollow shaft portion, wherein the outer cover portion is formed in a truncated conical shape whose diameter increases toward the first axial direction, and the outer surface of the outer cover portion has a first outer peripheral region located toward the first end and having a constant inclination angle with respect to the axial direction, and a second outer peripheral region located adjacent to the first outer peripheral region toward the second end, and where the inclination angle is larger than that of the first outer peripheral region at least in a position away from the first outer peripheral region.

[0007] A second aspect of the present invention is an earpiece comprising: a cylindrical hollow shaft portion having a through hole for transmitting sound; and a tubular outer cover portion extending in a first axial direction from a first axial end of the hollow shaft portion toward a second axial end of the hollow shaft portion and covering the hollow shaft portion, wherein the outer cover portion has a shape whose diameter increases along the first axial direction, and the earpiece has: an insertion portion located at the first end and to be inserted into the ear canal; and a fitting portion located adjacent to the insertion portion toward the second end and fitting tightly to an entrance of the ear canal. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an earpiece that can be worn comfortably in the ear for a long period of time. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view showing an earpiece according to a first embodiment of the present invention. [Figure 2] 2 is a diagram showing an example of the earpiece of FIG. 1 attached to an earphone body and then worn in the ear of a user. FIG. [Figure 3] 2 is a photograph showing an example of the earpiece of FIG. 1 being worn on the ear. [Figure 4] FIG. 4 is a cross-sectional view showing an earpiece according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view showing an earpiece according to a third embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view showing the earpiece of FIG. 5 attached to the earphone body. [Figure 7] FIG. 10 is a cross-sectional view showing an earpiece according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment Hereinafter, one embodiment of the present invention will be described with reference to FIGS. As shown in Fig. 1, the earpiece 1 of this embodiment is used by a user to listen to sound. The earpiece 1 is made of an elastic material that can be elastically deformed (e.g., silicone rubber), and includes a hollow shaft portion 2 and an outer cover portion 3.

[0011] The hollow shaft portion 2 is formed in a cylindrical shape that extends linearly. The hollow shaft portion 2 has a through hole 23 for transmitting sound. A sound conduit 201 (see FIG. 2) of the earphone main body 200, which will be described later, is inserted into the hollow shaft portion 2. The inner circumferential surface 2b of the hollow shaft portion 2, which forms the through hole 23, is formed with irregularities for holding the sound conduit 201. The thickness of the hollow shaft portion 2 is sufficiently greater than the thickness of the outer cover portion 3, which will be described later. For this reason, the rigidity of the hollow shaft portion 2 is greater than that of the outer cover portion 3. In other words, the hollow shaft portion 2 is less likely to deform elastically than the outer cover portion 3.

[0012] In the following description, the direction in which the central axis A1 (hereinafter simply referred to as axis A1) of the hollow shaft portion 2 extends will be referred to as the axial direction. The axial end of the hollow shaft portion 2 where one side of the through hole 23 opens will be referred to as the first end 21, and the axial end of the hollow shaft portion 2 where the other side of the through hole 23 opens will be referred to as the second end 22. The direction in the axial direction from the first end 21 toward the second end 22 of the hollow shaft portion 2 will be referred to as the first axial direction Z.

[0013] The outer cover 3 is formed contiguous with the first end 21 of the hollow shaft 2. The outer cover 3 is cylindrical and extends from the first end 21 of the hollow shaft 2 in the first axial direction Z to cover the hollow shaft 2. The outer cover 3 is formed in the shape of a truncated cone cylinder whose diameter increases from the first end 21 of the hollow shaft 2 in the first axial direction Z.

[0014] The outer peripheral surface 3a of the outer skin 3 has a first outer peripheral region 3a1 and a second outer peripheral region 3a2 arranged in order in the first axial direction Z. The first outer peripheral region 3a1 is located on the first end 21 side of the hollow shaft portion 2. The inclination angle of the first outer peripheral region 3a1 with respect to the axial direction (axis A1 of the hollow shaft portion 2) is constant. The second outer peripheral region 3a2 is located adjacent to the first outer peripheral region 3a1 on the second end 22 side of the hollow shaft portion 2. The inclination angle of the second outer peripheral region 3a2 with respect to the axial direction is larger than the inclination angle of the first outer peripheral region 3a1 at least at a position away from the first outer peripheral region 3a1. Specifically, the inclination angle of the second outer peripheral region 3a2 increases toward the first axial direction Z. The inclination angle of the second outer peripheral region 3a2 is equal to the inclination angle of the first outer peripheral region 3a1 at a boundary B1 (first boundary B1) with the first outer peripheral region 3a1. In this embodiment, the axial distance from the first end 21 of the hollow shaft portion 2 to the first boundary B1 between the first outer circumferential region 3a1 and the second outer circumferential region 3a2 is equal to or greater than half the total length of the outer shell portion 3 in the axial direction.

[0015] The outer skin portion 3 has a first outer skin portion 31 and a second outer skin portion 32 arranged in order in the first axial direction Z. The first outer skin portion 31 is located on the first end 21 side of the hollow shaft portion 2. The first outer skin portion 31 has a constant thickness. The second outer skin portion 32 is located adjacent to the first outer skin portion 31 on the second end 22 side of the hollow shaft portion 2. The thickness of the second outer skin portion 32 increases toward the first axial direction Z. The second outer skin portion 32 is provided at a position corresponding to at least the second outer peripheral region 3a2. In this embodiment, the distance in the axial direction from the first end 21 of the hollow shaft portion 2 to the boundary B2 (second boundary B2) between the first outer skin portion 31 and the second outer skin portion 32 is more than half the total length of the outer skin portion 3 in the axial direction.

[0016] 1, the second boundary B2 between the first outer skin portion 31 and the second outer skin portion 32 is located closer to the second end 22 of the hollow shaft portion 2 than the first boundary B1 between the first outer peripheral region 3a1 and the second outer peripheral region 3a2. Note that, for example, the positions of the first boundary B1 and the second boundary B2 in the axial direction may coincide, or the second boundary B2 may be located closer to the first end 21 of the hollow shaft portion 2 than the first boundary B1. The specific angle of inclination of the outer peripheral surface 3a of the outer shell 3 with respect to the axial direction, the specific thickness of the outer shell 3, and the specific positions of the first boundary B1 and the second boundary B2 in the axial direction may be set appropriately depending on factors such as the size of the earpiece 1. For example, the smaller the size of the earpiece 1, the smaller the angle of inclination of the outer peripheral surface 3a of the outer shell 3 may be set, or the first boundary B1 and the second boundary B2 may be positioned closer to the first end 21 of the hollow shaft portion 2.

[0017] As shown in Fig. 2, the outer cover part 3 has an insertion part 33 and a contact part 34. The insertion part 33 is located on the first end 21 side of the hollow shaft part 2. The insertion part 33 is the part of the outer cover part 3 that is inserted into the ear canal E1 of the ear E. The contact part 34 is located adjacent to the insertion part 33 on the second end 22 side of the hollow shaft part 2. The contact part 34 is the part that comes into contact with the entrance part E11 of the ear canal E1 when the insertion part 33 is inserted into the ear canal E1.

[0018] As shown in FIG. 2, the earpiece 1 of this embodiment, together with an earphone main body 200, constitutes an earphone 100 through which the user listens to sound. The earphone main body 200 has a cylindrical sound conduit 201 to which the earpiece 1 is attached. Although not shown, a driver unit (not shown) that converts an electrical signal (sound signal) into a sound wave is also provided inside the earphone main body 200. In the earphone main body 200, sound waves output from the driver unit are emitted to the outside from the open end of the sound conduit 201. The specific structures of the earphone main body 200 and the driver unit may be those disclosed in Patent Document 1, for example.

[0019] In the earphone 100, the sound conduit 201 of the earphone main body 200 is inserted into the hollow shaft portion 2 of the earpiece 1, thereby attaching the earpiece 1 to the earphone main body 200. In the earphone 100, when sound waves based on a sound signal are output from the driver unit of the earphone main body 200, the sound waves are transmitted from the sound conduit 201 to the inside of the hollow shaft portion 2 and are emitted to the outside from the first end 21 of the hollow shaft portion 2.

[0020] When the earpiece 1 is fitted to the user's ear E, the outer cover 3 is inserted into the ear canal E1 with the first end 21 of the hollow shaft portion 2 positioned at the tip side, and the insertion portion 33 of the outer cover 3 located on the first end 21 side of the hollow shaft portion 2 is inserted into the ear canal E1. The insertion portion 33 includes at least a portion of the outer cover 3 that corresponds to the first outer peripheral region 3a1, the first outer cover portion 31. When the insertion portion 33 of the outer cover 3 is inserted into the ear canal E1, the contact portion 34 of the outer cover 3, which has a larger diameter than the insertion portion 33, comes into contact with the entrance E11 of the ear canal E1. The contact portion 34 includes a portion of the outer cover 3 that corresponds to the second outer peripheral region 3a2, the second outer cover portion 32. As shown in FIG. 3 , when the earpiece 1 is fitted to the user's ear E, the contact portion 34 elastically deforms to come into contact with the entire periphery of the entrance E11 of the ear canal E1. The reason why the contact portion 34 elastically deforms and fits tightly around the entire periphery of the entrance E11 of the ear canal E1 is that, when the earpiece 1 is fitted to the ear E, the insertion portion 33 on the first end 21 side, which has a smaller diameter, does not come into contact with the ear canal E1, and only the contact portion 34 on the second end 22 side, which has a larger diameter than the insertion portion 33, fits tightly around the entrance E11 of the ear canal E1. The reason why the contact portion 34 elastically deforms and fits tightly around the entire periphery of the entrance E11 of the ear canal E1 is because the material of the earpiece 1 (particularly the outer cover 3) is silicone, urethane (low-resilience sponge), a hybrid of silicone and urethane, or the like, and because the thickness of the outer cover 3 is 0.4 mm to 1.0 mm.

[0021] In the example shown in Fig. 2, an earpiece 1 attached to an earphone main body 200 is worn on a user's ear E. In Fig. 2, the entire earphone main body 200 is located inside the auricle E2, but for example, part of the earphone main body 200 may protrude outside the auricle E2.

[0022] As described above, in the earpiece 1 of the first embodiment, the outer cover 3 is formed in the shape of a truncated cone cylinder whose diameter increases toward the first axial direction Z. The outer peripheral surface 3a of the outer cover 3 has a first outer peripheral region 3a1 located on the first end 21 side of the hollow shaft portion 2 and having a constant inclination angle with respect to the axial direction, and a second outer peripheral region 3a2 located adjacent to the first outer peripheral region 3a1 on the second end 22 side of the hollow shaft portion 2 and whose inclination angle increases toward the first axial direction Z.

[0023] For this reason, the inclination angle of the first outer peripheral region 3a1 with respect to the axial direction is smaller than the inclination angle of the second outer peripheral region 3a2. As a result, the diameter of the portion of the outer peripheral portion 3 corresponding to the first outer peripheral region 3a1 is smaller than the diameter of the portion of the outer peripheral portion 3 corresponding to the second outer peripheral region 3a2. As a result, when the portion of the outer peripheral portion 3 corresponding to the first outer peripheral region 3a1 is inserted into the ear canal E1 of the ear E, the portion of the outer peripheral portion 3 corresponding to the second outer peripheral region 3a2 can be brought into close contact with the entrance E11 of the ear canal E1 while preventing the portion of the outer peripheral portion 3 corresponding to the first outer peripheral region 3a1 from pressing against the ear canal E1. Furthermore, because the portion of the outer peripheral portion 3 corresponding to the second outer peripheral region 3a2 is in close contact with the entrance E11 of the ear canal E1, the earpiece 1 can be held stably in place in the ear E. Furthermore, by preventing or minimizing pressure on the ear canal E1 by the portion of the outer peripheral portion 3 inserted into the ear canal E1, discomfort felt when wearing the earpiece 1 can be reduced. As a result, the user can wear the earpiece 1 comfortably for long periods of time.

[0024] Furthermore, with the earpiece 1 of this embodiment, the distance in the axial direction from the first end 21 of the hollow shaft portion 2 to the first boundary B1 between the first outer peripheral region 3a1 and the second outer peripheral region 3a2 is equal to or greater than half the total axial length of the shell 3. This allows more than half of the shell 3 in the axial direction to be inserted into the ear canal E1, so the earpiece 1 can be held stably in the ear E.

[0025] Furthermore, in the earpiece 1 of this embodiment, the skin portion 3 has a first skin portion 31 that is located on the first end 21 side of the hollow shaft portion 2 and has a constant thickness, and a second skin portion 32 that is located adjacent to the first skin portion 31 on the second end 22 side of the hollow shaft portion 2 and whose thickness increases toward the first axial direction Z. For this reason, the rigidity of the skin part 3 at the second skin portion 32 gradually increases in the first axial direction Z. As a result, when the earpiece 1 is fitted to the user's ear E, the pressing force of the second skin portion 32 against the entrance E11 of the ear canal E1 increases the further the earpiece 1 goes into the ear canal E1. This makes it possible to further improve the adhesion of the skin part 3 to the entrance E11 of the ear canal E1. On the other hand, the thickness of the skin 3 at the first skin portion 31 inserted into the ear canal E1 is thinner than that of the second skin portion 32, thereby reducing the rigidity of the first skin portion 31. This effectively prevents the first skin portion 31 from compressing the ear canal E1 even when the first skin portion 31 is inserted into the ear canal E1.

[0026] Furthermore, with the earpiece 1 of this embodiment, the distance in the axial direction from the first end 21 of the hollow shaft portion 2 to the second boundary B2 between the first outer cover portion 31 and the second outer cover portion 32 is equal to or greater than half of the total axial length of the outer cover portion 3. This allows more than half of the outer cover portion 3 in the axial direction to be inserted into the ear canal E1, and therefore the earpiece 1 can be held stably in the ear E.

[0027] Furthermore, in the earpiece 1 of this embodiment, the outer cover 3 has a shape in which the diameter dimension increases toward the first axial direction Z. The outer cover 3 has an insertion section 33 located on the first end 21 side of the hollow shaft section 2 and inserted into the ear canal E1, and a fitting section 34 located adjacent to the insertion section 33 on the second end 22 side of the hollow shaft section 2 and fitting tightly to the entrance E11 of the ear canal E1.

[0028] For this reason, when the insertion portion 33, which has a relatively small diameter, is inserted into the ear canal E1, the fitting portion 34, which has a larger diameter than the insertion portion 33, can be brought into tight contact with the entrance E11 of the ear canal E1 while preventing the insertion portion 33 from pressing against the ear canal E1. The fitting portion 34 of the outer cover 3 fits tightly against the entrance E11 of the ear canal E1, thereby enabling the earpiece 1 to be held stably in the ear E. Furthermore, by preventing or reducing the insertion portion 33 of the outer cover 3 inserted into the ear canal E1 from pressing against the ear canal E1, discomfort when wearing the earpiece 1 can be reduced. As a result, the user can wear the earpiece 1 comfortably for long periods of time.

[0029] Furthermore, with the earpiece 1 of this embodiment, when the earpiece 1 is worn on the user's ear E, the opening on the first end 21 side of the hollow shaft portion 2 is located deep inside the ear canal E1, away from the entrance E11 of the ear canal E1, i.e., near the eardrum. This allows sound waves that propagate inside the hollow shaft portion 2 and are emitted from the first end 21 of the hollow shaft portion 2 to efficiently reach the eardrum. Therefore, using the earpiece 1 of this embodiment also has the effect of allowing sounds to be heard clearly.

[0030] In the first embodiment, the inclination angle of the outer peripheral surface 3a of the outer skin portion 3 may vary discontinuously at the first boundary B1 between the first outer peripheral region 3a1 and the second outer peripheral region 3a2. For example, the inclination angle of the second outer peripheral region 3a2 may be constant within a range greater than the inclination angle of the first outer peripheral region 3a1. This configuration also achieves the same effect as the above-described configuration in which the inclination angle of the second outer peripheral region 3a2 increases toward the first axial direction Z.

[0031] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Fig. 4. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0032] As shown in Fig. 4, the earpiece 1C of the second embodiment further includes an annular protrusion 4 in addition to the hollow shaft portion 2 and outer cover portion 3 similar to those of the first embodiment. The annular protrusion 4 protrudes from the outer peripheral surface 2a of the hollow shaft portion 2 toward the inner peripheral surface 3b of the outer cover portion 3 at a second end portion 26 located on the second end 22 side of the hollow shaft portion 2. The tip of the annular protrusion 4 in the protruding direction is positioned with a gap between it and the inner peripheral surface 3b of the outer cover portion 3. The annular protrusion 4 is formed over the entire circumferential direction of the hollow shaft portion 2. The annular protrusion 4 is formed integrally with the hollow shaft portion 2 and is elastically deformable. 4, the annular protrusion 4 is curved in the radial direction from the outer peripheral surface 2a of the hollow shaft 2 toward the inner peripheral surface 3b of the outer cover 3 so as to extend in the first axial direction Z, but this is not limited thereto. For example, the annular protrusion 4 may extend linearly in the radial direction from the outer peripheral surface 2a of the hollow shaft 2 toward the inner peripheral surface 3b of the outer cover 3.

[0033] The outer skin 3 can be brought into contact with the tip 41 of the annular protrusion 4 by elastically deforming. Specifically, the outer skin 3 elastically bends and deforms radially inward, with the part connected to the first end 21 of the hollow shaft 2 as a fulcrum. This allows the inner circumferential surface 3b of the outer skin 3 to come into contact with the tip 41 of the annular protrusion 4, as shown by the two-dot chain line in Figure 4. When the outer skin 3 is in contact with the tip 41 of the annular protrusion 4, an air layer 43 is formed, surrounded by the outer circumferential surface 2a of the hollow shaft 2, the inner circumferential surface 3b of the outer skin 3, and the annular protrusion 4. In the earpiece 1C of the second embodiment, when the earpiece 1C is attached to the user's ear E (see FIG. 2), the outer cover 3 is inserted into the ear canal E1 and elastically deforms, causing the tip 41 of the annular protrusion 4 to come into contact with the outer cover 3, thereby forming the air layer 43 described above.

[0034] The earpiece 1C of the second embodiment provides the same effects as the first embodiment. Furthermore, when the earpiece 1C of the second embodiment is worn on the ear E of a user, sounds around the user (hereinafter referred to as environmental sounds) are blocked by the annular protrusion 4, preventing the environmental sounds from reaching the eardrum of the user. Note that arrow D1 in Fig. 4 shows an example of the direction in which environmental sounds travel toward the earpiece 1C worn on the ear E of the user.

[0035] Furthermore, when the earpiece 1C of the second embodiment is worn on the ear E of the user, an air layer 43 can be formed that is surrounded by the outer peripheral surface 2a of the hollow shaft portion 2, the inner peripheral surface 3b of the outer cover portion 3, and the annular protrusion 4. This allows environmental sound that has passed through the annular protrusion 4 to be attenuated in the air layer 43, more effectively preventing the environmental sound from reaching the eardrum of the user. Furthermore, with the earpiece 1C of the second embodiment, the structure can be simplified compared to when the air layer 43 is formed in advance in the earpiece alone.

[0036] Third Embodiment Next, a third embodiment of the present invention will be described with reference to Figures 5 and 6. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0037] As shown in Fig. 5, the earpiece 1D of the third embodiment further includes a tubular protrusion 5 in addition to the hollow shaft portion 2 and outer cover portion 3 similar to those of the first embodiment. The tubular protrusion 5 protrudes from the inner circumferential surface 3b of the outer cover portion 3 and is formed in the shape of a truncated cone whose diameter decreases in the first axial direction Z. The tip of the tubular protrusion 5 in the protruding direction is located away from the second end 22 of the hollow shaft portion 2 in the first axial direction Z. The tubular protrusion 5 is formed integrally with the outer cover portion 3 and is elastically deformable.

[0038] 5, the diameter at the tip of the cylindrical protrusion 5 is larger than the diameter of the outer periphery of the hollow shaft portion 2, but this is not limited to this. The diameter at the tip of the cylindrical protrusion 5 only needs to be large enough to allow at least the sound conduit 201 (see FIG. 6) of the earphone main body 200 inserted into the hollow shaft portion 2 to pass through the inside of the cylindrical protrusion 5.

[0039] 6 , when the earpiece 1D of the third embodiment is attached to the earphone main body 200, the opening on the tip side of the tubular protrusion 5 can be blocked by the earphone main body 200. This forms an air layer 53 surrounded by the outer circumferential surface 2a of the hollow shaft portion 2, the inner circumferential surface 3b of the outer cover portion 3, the tubular protrusion 5, and the earphone main body 200.

[0040] The earpiece 1D of the third embodiment provides the same effects as the first embodiment. Furthermore, when the earpiece 1D of the third embodiment is attached to the user's ear E (see FIG. 2), sounds around the user (hereinafter referred to as environmental sounds) are blocked by the cylindrical protrusion 5, preventing the environmental sounds from reaching the user's eardrum. Note that the arrow D2 in FIG. 6 shows an example of the direction in which environmental sounds travel toward the earpiece 1D attached to the user's ear E.

[0041] 6, when the earpiece 1D is attached to the earphone main body 200, an air layer 53 can be formed that is surrounded by the outer peripheral surface 2a of the hollow shaft portion 2, the inner peripheral surface 3b of the outer cover portion 3, the tubular protrusion 5, and the earphone main body 200. This allows environmental sound that passes through the tubular protrusion 5 to be attenuated in the air layer 53, more effectively preventing the environmental sound from reaching the user's eardrum. Furthermore, with the earpiece 1D of the third embodiment, the structure can be simplified compared to when the air layer 53 is formed in advance in the earpiece alone.

[0042] Fourth Embodiment Next, a fourth embodiment of the present invention will be described with reference to Fig. 7. In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0043] As shown in FIG. 7 , the earpiece 1F of the fourth embodiment further includes a connecting portion 7 in addition to the hollow shaft portion 2 and outer cover portion 3 similar to those of the first embodiment. The connecting portion 7 connects a first end portion 25 of the hollow shaft portion 2 located on the first end 21 side to a portion of the outer cover portion 3 that faces the first end portion 25 of the hollow shaft portion 2 in the radial direction. The connecting portion 7 is formed integrally with the hollow shaft portion 2 and the outer cover portion 3, and is elastically deformable. A plurality of connecting portions 7 are arranged at intervals in the circumferential direction of the hollow shaft portion 2. Note that the connecting portion 7 may be formed, for example, over the entire circumferential direction of the hollow shaft portion 2, i.e., may be formed in a ring shape.

[0044] The first end 25 of the hollow shaft 2 connected to the connecting part 7 is a portion from the first end 21 of the hollow shaft 2 to a predetermined position P1 away from the first axial direction Z. Similarly, the portion of the outer cover 3 connected to the connecting part 7 is a portion from the first end 21 of the hollow shaft 2 to a predetermined position P2 away from the first axial direction Z. These predetermined positions P1 and P2 only need to be located away from the second end 22 of the hollow shaft 2 and the end of the outer cover 3 corresponding to the second end 22 at least in the axial direction. Furthermore, the predetermined position P2 is preferably located closer to the first end 21 of the hollow shaft 2 than, for example, the second outer peripheral region 3a2 of the outer cover 3 or the second outer cover portion 32 (see FIG. 1 ). In FIG. 7, the predetermined position P1 on the hollow shaft portion 2 and the predetermined position P2 on the outer cover portion 3 coincide in the axial direction, but these predetermined positions P1 and P2 may be positioned, for example, offset from each other in the axial direction.

[0045] The earpiece 1F of the fourth embodiment provides the same effects as the first embodiment. Furthermore, with the earpiece 1F of the fourth embodiment, the connecting portion 7 can prevent the outer cover 3 from separating from the first end 25 of the hollow shaft portion 2. This suppresses or prevents the outer cover 3 from turning inside out relative to the connecting portion 7, thereby extending the product life of the earpiece 1F.

[0046] The connecting portion 7 of the fourth embodiment is also applicable to the earpiece 1C of the second embodiment that includes the annular projection 4 and the earpiece 1D of the third embodiment that includes the cylindrical projection 5.

[0047] Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. [Explanation of symbols]

[0048] DESCRIPTION OF SYMBOLS 1, 1C, 1D, 1F...earpiece, 2...hollow shaft portion, 2a...outer peripheral surface of hollow shaft portion 2, 3...outer cover portion, 3a...outer peripheral surface of outer cover portion 3, 3a1...first outer peripheral region, 3a2...second outer peripheral region, 3b...inner peripheral surface of outer cover portion 3, 4...annular protrusion, 5...cylindrical protrusion, 7...connecting portion, 21...first end, 22...second end, 23...through hole, 25...first end, 26...second end, 31...first outer cover region, 32...second outer cover region, 33...insertion portion, 34...contact portion, B1...first boundary, B2...second boundary, E11...entrance portion, Z...first axial direction

Claims

1. a cylindrical hollow shaft portion having a through hole for transmitting sound; a cylindrical outer cover portion that extends in a first axial direction from a first axial end of the hollow shaft portion toward a second axial end of the hollow shaft portion and covers the hollow shaft portion, The outer skin portion is formed in a truncated conical cylindrical shape whose diameter increases along the first axis direction, The outer peripheral surface of the outer skin portion is a first outer peripheral region located on the first end side and having a constant inclination angle with respect to the axial direction; a second outer peripheral region positioned adjacent to the first outer peripheral region on the second end side, and in which the inclination angle is larger than that of the first outer peripheral region at least at a position away from the first outer peripheral region.

2. The earpiece according to claim 1 , wherein the inclination angle of the second outer circumferential region increases toward the first axis direction.

3. The earpiece according to claim 1 , wherein a distance from the first end to a boundary between the first outer peripheral region and the second outer peripheral region in the axial direction is equal to or greater than half of an overall length of the outer shell portion in the axial direction.

4. The outer skin portion is a first skin portion located on the first end side and having a constant thickness; a second outer skin portion located adjacent to the first outer skin portion on the second end side and having a thickness that increases toward the first axis direction; The earpiece according to claim 1 , wherein the second outer cover portion is provided at a position corresponding to at least the second outer peripheral region.

5. The earpiece according to claim 4 , wherein a distance from the first end to a boundary between the first outer cover portion and the second outer cover portion in the axial direction is equal to or greater than half of an entire length of the outer cover portion in the axial direction.

6. a second end portion of the hollow shaft portion located on the second end side thereof, the second end portion including an annular protrusion that protrudes from an outer peripheral surface of the hollow shaft portion toward an inner peripheral surface of the outer cover portion, the annular protrusion having a tip end in a protruding direction spaced apart from the inner peripheral surface of the outer cover portion; The earpiece according to claim 1 , wherein the outer cover portion is capable of contacting the tip of the annular projection by elastically deforming.

7. a cylindrical protrusion formed in a truncated cone shape that protrudes from an inner circumferential surface of the outer skin portion and whose diameter decreases in the first axial direction; The earpiece according to claim 1 , wherein a tip end of the cylindrical projection in a protruding direction is positioned away from the second end of the hollow shaft portion in the first axial direction.

8. 6. The earpiece according to claim 1, further comprising a connecting portion that connects a first end portion of the hollow shaft portion that is located on the first end side to a portion of the outer cover portion that faces the first end portion in the radial direction.

9. a cylindrical hollow shaft portion having a through hole for transmitting sound; a cylindrical outer cover portion that extends in a first axial direction from a first axial end of the hollow shaft portion toward a second axial end of the hollow shaft portion and covers the hollow shaft portion, The outer cover portion has a shape whose diameter increases toward the first axis, and the earpiece has an insertion portion located on the first end side that is inserted into the ear canal, and a fitting portion located adjacent to the insertion portion on the second end side that fits tightly against the entrance of the ear canal.

Images