WO2020137415A1

WO2020137415A1 - Earplug

Info

Publication number: WO2020137415A1
Application number: PCT/JP2019/047593
Authority: WO
Inventors: 真史上村
Original assignee: 株式会社Ｊｖｃケンウッド
Priority date: 2018-12-25
Filing date: 2019-12-05
Publication date: 2020-07-02
Also published as: JP2023015356A; JP2022043367A; JP7192486B2; JP7439885B2

Abstract

This earplug (51) is provided with: a body part (1) which has a through hole (121) and which can be fitted into the external auditory canal (Ea); and an adjustment part (2) which is movably inserted to the through hole (121) from one end side and which is for performing control so as to select connection or non-connection between said one end side of the through hole (121) and an external space (Vg) in accordance with an insertion position with respect to the through hole (121).

Description

Earplug

The present disclosure relates to earplugs.

[Patent Document 1] describes an earplug in which the volume that communicates with the outside air can be increased or decreased by rotating the sound adjusting rotary plate to increase or decrease the number of openings and closings of the ventilation holes.

Japanese Patent Laid-Open No. 2003-091288

With the earplug described in Patent Document 1, the sound volume is adjusted by rotating the sound adjustment rotary plate. Since this rotating operation is difficult, it is not easy to adjust the volume.

The embodiments are intended to provide earplugs whose volume can be easily adjusted.

According to one aspect of the embodiment, a main body portion having a through hole that can be mounted on the ear canal, and movably inserted into the through hole from one end side thereof, the through hole of the through hole depending on the insertion position with respect to the through hole. An earplug is provided that includes an adjusting unit that selectively controls communication and non-communication between the one end side and an external space.

According to the embodiment, it is possible to obtain an effect that it can be used for various purposes.

FIG. 1 is a perspective view showing the external appearance of an earplug according to an embodiment. FIG. 2 is a sectional view for explaining the structure of the earplug. FIG. 3 is a plan view of the adjusting portion viewed from the tip end side of the screwing portion. FIG. 4 is a cross-sectional view showing the earplug in the first adjusted state mounted on the ear canal. FIG. 5 is a side view showing the external appearance of the earplug in the first adjustment state. FIG. 6 is a cross-sectional view showing the earplug in the second adjustment state, which is attached to the ear canal. FIG. 7 is a side view showing the external appearance of the earplug in the second adjustment state. FIG. 8 is a graph showing an example of sound pressure reduction characteristics of earplugs. FIG. 9 is a graph for explaining the sound pressure reduction adjustment for each frequency of earplugs. FIG. 10 is a cross-sectional view showing the earplug 51 in which the sound absorbing material is arranged. FIG. 11 is a graph showing the sound absorbing material addition characteristics. 12A and 12B are views showing an adjusting unit which is a modified example of the adjusting unit, FIG. 12A is a plan view seen from the tip side of the screwing unit, and FIG. 12B is a sectional view.

An earplug according to an embodiment of the present disclosure will be described. FIG. 1 is a perspective view showing the outer appearance of an earplug 51 according to this embodiment. The earplug 51 has a main body 1 and an adjusting portion 2 screwed to the main body 1. FIG. 2 is a cross-sectional view for explaining the configuration of the earplug 51, and is an assembly diagram showing a state before the adjusting portion 2 is screwed into the body portion 1. FIG. 3 is a plan view of the adjusting portion 2 viewed from the tip side of the screwing portion 22.

As shown in FIGS. 1 and 2, the main body 1 has a base 12 and a cushion 11. The base 12 is formed in a cylindrical shape having a through hole 121. The inner peripheral surface of the through hole 121 has a female screw portion 122 on at least one end side portion thereof. On the inner peripheral surface of the female screw portion 122, a screw thread forming a female screw is formed.

The base 12 is made of resin or metal. The resin is, for example, PC (polycarbonate). The metal is, for example, aluminum.

The cushion portion 11 has, for example, a substantially columnar outer shape that extends in the axial direction. The cushion portion 11 is made of a flexible material. The material is, for example, a sponge made of chloroprene rubber or the like, or a thermoplastic elastomer. When the cushion portion 11 is made of sponge, the cushion portion 11 is fitted and integrated with the base portion 12. When the cushion portion 11 is made of thermoplastic elastomer, the base portion 12 is made of resin and is integrally formed.

As shown in FIGS. 1 to 3, the adjusting unit 2 has a disc-shaped picking portion 21 and a cylindrical screwing portion 22 projecting from the picking portion 21 along its axis. The adjustment unit 2 is made of resin or metal. The resin is, for example, PC (polycarbonate). The metal is aluminum, for example. The picking portion 21 is a portion to be picked by a finger, and a knurl 21a for preventing slippage is formed on the outer peripheral surface. The screwing portion 22 has a male screw portion 221. On the outer peripheral surface of the male screw portion 221, a screw thread forming a male screw is formed. Therefore, the male screw portion 221 can be screwed into the female screw portion 122 of the base portion 12 of the main body 1. The screwing part 22 of the adjusting part 2 has a slit part 23 as a ventilation part connected to the internal space of the through hole 121. The slit portion 23 extends from the front end surface 22a in the diametrical direction of the threaded portion 22, and is cut in the axial direction of the threaded portion 22 with a width da and a depth L23. The position (bottom) that is deepest in the slit portion 23 from the tip end surface 22a is located closer to the tip end surface 22a of the threaded portion 22 than the surface 21b of the knob portion 21 on the threaded portion 22 side. That is, as shown in FIG. 2, the depth L23 of the slit portion 23 is shorter than the distance L21 from the tip surface 22a to the surface 21b. In this example, the depth L23 is shorter than the length L22 of the threaded portion 22.

The adjusting part 2 is attached (inserted) from one end side to the through hole 121 in the main body part 1 in the direction indicated by the arrow DRa in FIG. Specifically, the adjusting portion 2 is screwed onto the female screw portion 122 of the base portion 12 of the body portion 1 and attached to the body portion 1. FIG. 1 shows a state in which the male screw portion 221 of the adjusting portion 2 is screwed to the female screw portion 122 of the main body portion 1 partway and a part of the slit portion 23 is exposed to the outside. As shown in FIG. 2, undercuts for removing incomplete threads are formed at both ends of the female screw portion 122 on the inner peripheral surface of the through hole 121. The escape portion has no threaded portion and has an inner diameter larger than that of the through hole 121.

When the adjusting portion 2 is screwed in the direction indicated by the arrow DRa in FIG. 2 with respect to the main body portion 1, the surface 21 b of the knob portion 21 on the screwing portion 22 side comes into contact with the base portion 12 of the main body portion 1. The screwing is restricted. In this way, the state in which the adjusting portion 2 is screwed to the innermost position with respect to the main body portion 1 is included in the first adjusting state described later. When the earplug 51 (adjustment unit 2) is in the first adjustment state, the adjustment unit 2 is in the first insertion position (insertion position) with respect to the through hole 121.

FIG. 4 is a cross-sectional view showing the earplug 51 in the first adjustment state attached (attached) to the external auditory meatus Ea, and FIG. 5 is a side view showing the appearance of the earplug 51 in the first adjustment state. As shown in FIG. 2, the depth L23 of the slit portion 23 is shorter than the distance L21 from the tip end surface 22a to the surface 21b of the knob 21. In the first adjustment state, the threaded portion 22 is inserted into the through hole 121 up to a depth of L23 or more. Therefore, the entire slit portion 23 is hidden (embedded) in the base portion 12 and is not exposed to the outside. That is, in the first adjustment state, the one end side of the through hole 121 is closed by the screwing portion 22 of the adjusting portion 2, and a ventilation path with the outside is not formed. Therefore, the effect of sound insulation by the earplug 51 is maximized in the first adjustment state.

FIG. 6 is a cross-sectional view showing the earplug 51 in the second adjusted state mounted (attached) to the external auditory meatus Ea, and FIG. 7 is a side view showing the appearance of the earplug 51 in the second adjusted state. As shown in FIG. 6, in the second adjustment state, the male screw portion 221 of the adjusting portion 2 is screwed into the female screw portion 122 of the main body portion 1, while the slit portion 23 is exposed to the outside. For example, the earplug 51 is moved from the first adjustment state by screwing the adjusting portion 2 in the first insertion position in the direction opposite to the arrow DRa in FIG. 2 and exposing the slit portion 23 to the outside. The second adjustment state is reached. When the earplug 51 (adjustment unit 2) is in the second adjustment state, the adjustment unit 2 is in the second insertion position with respect to the through hole 121.

As shown in FIGS. 6 and 7, in the second adjustment state, a part of the slit portion 23 is opened to the outside as an opening portion 23w having a width da and a length L. The opening 23w opens to the outside, for example, in the front-back direction in FIG. As shown in FIG. 6, the ventilation path D is formed in the second adjustment state. The ventilation path D is formed by the through hole 121 and the slit portion 23, and connects the external space Vg and the internal space Ve in the external auditory meatus Ea.

The opening area to the internal space Ve in the ventilation path D is the opening area of the through hole 121 and is constant. On the other hand, the opening area of the ventilation path D to the external space Vg, that is, the opening area S of the opening 23w is represented by width da×length L×2. It should be noted that the calculation of the opening area S takes into consideration that the opening 23w is open at two positions, the front side and the back side of the paper surface of FIG.

The length L of the opening area S of the opening 23w changes as the adjusting unit 2 moves back and forth. That is, the opening area S can be adjusted. The opening area S is reduced by screwing (advancing) the adjusting portion 2, and has a minimum value 0 (zero) in the first adjusting state in which the opening 23w is hidden by the base 12. In addition, the opening area S is increased by screwing (retracting) the adjustment unit 2 in the second adjustment state. The opening area S is set to a maximum length Lmax of the opening 23w and a maximum opening area Smax of the opening area S, which are upper limits, by providing a restricting structure (not shown) for restricting the screwing back of the adjusting portion 2. it can. This restricting structure (not shown) can be formed, for example, by forming the base 12 into a two-part structure. For example, it is assumed that the base 12 has a structure in which it is divided into two parts on a plane including the axis, and when the two divided base parts are combined and integrated, the accommodating part that accommodates the adjusting part 2 is formed in a bag shape. .. Then, the base portion divided into two is integrated so as to fit the adjusting portion 2 in the accommodating portion. In this case, the bag-shaped accommodating portion regulates the movement of the adjusting portion 2 in the axial direction.

As described above, the earplug 51 selectively controls “communication” and “non-communication” between the internal space Ve and the external space Vg in a state of being attached to the external auditory meatus Ea. Further, this selective control is performed according to the insertion position of the adjusting unit 2. Specifically, the through hole 121 communicates with the external space Vg through the opening 23w by adjusting the position of the adjustment unit 2 so that a part of the slit portion 23 is exposed as the opening 23w in the external space Vg. Further, by adjusting the position of the adjusting portion 2 so that the tip end surface 22a of the screwing portion 22 is located in the region on the far side of the through hole 121, the slit portion 23 is not in communication with the external space Vg. As a result, the through hole 121 does not communicate with the external space Vg. Here, the region on the back side means a region in which the slit portion 23 of the adjustment unit 2 and the external space Vg are maintained in non-communication.

The earplug 51 has an adjustment unit 2 that is movable in the axial direction with respect to the main body unit 1. Therefore, the opening area S of the ventilation path D can be changed according to the axial position of the adjusting portion 2. When the opening area S is 0 (zero), the sound pressure reducing effect is maximized. Further, when the adjusting portion 2 is retracted (moved) in the axial direction in the direction opposite to the arrow DRa shown in FIG. 2 with respect to the main body portion 1, the opening area S is gradually increased and the sound pressure reducing effect is obtained. Gradually weakens. That is, the volume can be adjusted by moving the adjusting unit 2 along the axial direction.

In this way, the opening area S increases or decreases as the adjustment unit 2 moves in the axial direction. On the other hand, it is easy to increase the change width of the opening area S by increasing the moving stroke of the adjusting unit 2. That is, when the user wears the earplug 51 on his/her ear, the sound pressure reduction adjustment range of the external sound heard by the user can be increased.

Further, by adopting a structure in which the adjusting portion 2 is screwed into the main body portion 1, it is possible to increase/decrease the opening area S due to the axial movement of the adjusting portion 2 by moving the adjusting portion 2 forward and backward. .. Therefore, it is possible to slightly increase or decrease the opening area S by rotating the adjusting unit 2 by a slight angle, and when the user puts the earplugs 51 on his ears, the external sound heard by the user is the sound pressure of which sound is blocked. In the reduced state, fine adjustment of volume adjustment is easier. However, the structure that allows the adjustment unit 2 to move in the axial direction with respect to the main body unit 1 is not limited to the screw engagement by the above-described screw thread, but a spiral cam mechanism or a sliding engagement structure between the inner cylinder and the outer cylinder. A well-known structure such as can be applied.

Next, with reference to FIGS. 8 and 9, the sound pressure reducing effect which is the sound insulating effect of the earplug 51 will be described. FIG. 8 is a graph showing an example of the sound pressure reduction characteristics of the earplug 51, and FIG. 9 is a graph explaining the sound pressure reduction adjustment at some frequencies.

FIG. 8 shows the earplug characteristic C which is the sound pressure reduction characteristic of the earplug 51. The earplug characteristic C is acquired as follows. First, a model ear canal is created as a model corresponding to the ear canal Ea, and a microphone is installed in the model ear canal. Further, a speaker is arranged outside the model external auditory meatus and at a position facing the model external auditory meatus, and the speaker and the model external auditory canal are covered with a sound insulation box to acoustically cut off from the outside of the sound insulation box. In this state, the sound in the audible frequency band is swept out from the speaker and picked up by the microphone to obtain the frequency-sound pressure characteristic.

In the above sound collection, the frequency-sound pressure characteristics collected without the earplugs 51 attached to the model external auditory meatus are referred to as open ear characteristics Cn. The bare ear characteristic Cn is indicated by a broken line in FIG. Further, the frequency-sound pressure characteristic obtained by collecting the earplug 51 in the model external auditory meatus is referred to as earplug characteristic C. The earplug characteristic C was acquired each time the axial position of the adjustment unit 2 with respect to the main body unit 1 was changed stepwise. In FIG. 8, the earplug characteristic C is shown by a solid line as the earplug characteristic Cm in the first adjustment state in which the opening 23w is not exposed, and the earplug characteristic Cm in the second adjustment state in which the opening 23w is exposed to some extent. It is shown by a chain line as the characteristic Cm1.

As shown in FIG. 8, the earplug characteristic Cm has a substantially uniform sound pressure reduction of about 3 dB in the band of about 200 Hz or less with respect to the bare ear characteristic Cn. On the other hand, in the earplug characteristic Cm, in a band exceeding 200 Hz, the higher the frequency, the greater the degree of sound pressure reduction. For example, in the vicinity of 1 kHz, a sound pressure reduction of about 16 dB is recognized with respect to the bare ear characteristic Cn, and in the vicinity of 3 kHz, a sound pressure reduction of about 35 dB is recognized.

From the first adjustment state in which the opening 23w is closed, as the adjusting portion 2 is screwed back to increase the opening area S of the opening 23w, the earplug characteristic Cm approaches the bare ear characteristic Cn and the sound pressure is reduced. The action is suppressed. In FIG. 8, the earplug characteristic Cm1 indicated by the chain line is the characteristic at the position where the adjusting portion 2 is screwed back about 4 turns from the position where the earplug characteristic Cm was obtained. By further rotating and adjusting the adjustment unit 2 to increase the opening area S of the opening 23w, the earplug characteristic Cm1 can be adjusted to a characteristic closer to the bare ear characteristic Cn.

9(a) to 9(c), in three different frequencies at which the sound pressure reducing effect is obtained, the adjustment unit 2 is rotated from the first adjustment state in the direction opposite to the arrow DRa in FIG. 2 in the axial direction. It is a graph showing a change in sound pressure from 0 (zero) rotations to 4 rotations when retreated. Specifically, (a) is the sound pressure change characteristic Cma at 400 Hz, (b) is the sound pressure change characteristic Cmb at 800 Hz, and (c) is the sound pressure change Cmc at 1.25 kHz.

As is clear from FIGS. 9A to 9C, as the number of rotations of the adjusting unit 2 from the first adjustment state (zero number of rotations) increases, the degree of sound pressure reduction decreases at any frequency. Pressure gradually increases. The increase in one rotation is about 3 to 5 dB. Therefore, by rotating the adjusting unit 2 by, for example, 1/4 rotation (90°), fine adjustment of the sound pressure of about 0.8 to 1.2 dB is possible.

Further, as shown in FIG. 8, for example, at a frequency of 1 kHz, the sound pressure of the earplug characteristic Cm1 when the adjusting unit 2 is rotated four times and moved in the axial direction is the sound pressure of the bare ear characteristic Cn. It is about 97 dB, which is about half the difference between about 105 dB and the sound pressure of the earplug characteristic Cm in the first adjusted state of about 89 dB.

As shown in FIG. 10, the sound absorbing material 31 may be installed in the through hole 121 of the earplug 51. Further, the sound absorbing material 32 may be installed in a part or the whole of the slit portion 23.
That is, either the sound absorbing material 31 or the sound absorbing material 32 may be installed in a part of the ventilation path D. Known sound absorbing materials can be used for the

sound absorbing materials

31 and 32. The sound absorbing material is, for example, glass wool.

By installing the

sound absorbing materials

31, 32 as shown in FIG. 11, the sound absorbing material additional characteristics CA1, CA2 shown in FIG. 11 are obtained in the first adjustment state. Specifically, the sound absorbing material addition characteristic CA1 is a characteristic when only the sound absorbing material 31 is installed, and the sound absorbing material addition characteristic CA2 is a characteristic when both the sound absorbing material 31 and the sound absorbing material 32 are installed. When the sound absorbing material 31 is used, as shown by the sound absorbing material addition characteristic CA1, the sound pressure in a wide frequency band including a low sound range of 200 Hz or less is reduced by about 10 dB with respect to the bare ear characteristic Cn. When the sound absorbing material 31 and the sound absorbing material 32 are used together, as shown in the sound absorbing material addition characteristic CA2, the sound pressure in a wide frequency band including a low sound range of 200 Hz or less is about 33 dB with respect to the bare ear characteristic Cn. Will be reduced. Even when the

sound absorbing materials

31 and 32 are used, the bare ear characteristics Cn can be obtained by retracting the adjusting portion 2 in the axial direction from the first adjusting state in the direction opposite to the arrow DRa in FIG. The characteristics can be adjusted so as to approach.

As described above, the earplug 51 has a large sound pressure reduction range, and a large sound insulation effect is obtained. In addition, the earplugs 51 can easily finely adjust the amount of sound pressure reduction. That is, the user of the earplug 51 has a large adjustment range of the volume of the external sound to be listened to, and can easily perform fine adjustment.

The embodiments described in detail above are not limited to the above-mentioned configurations, and may be modified examples that are modified without departing from the gist of the present invention.

As shown in FIGS. 12(a) and 12(b), instead of the slit portion 23 which is the ventilation portion of the screwing portion 22, the adjusting portion 2 is provided with a groove portion 23A extending in the axial direction on the peripheral surface of the screwing portion 22A. The adjusting portion 2A may be a ventilation portion. 12A is a front view of the adjusting unit 2A, and FIG. 12B is a side view. The number of slits 23 and grooves 23A formed and the shape such as width and depth are not limited, and may be set freely. A plurality of groove portions 23A having different widths and depths may be formed, or the slit portion 23 and the groove portion 23A may be arranged in parallel.

Markers may be provided for visually recognizing the axial position of the adjusting part 2 with respect to the main body part 1. For example, a cut extending in the axial direction may be provided on the outer peripheral surface of the threaded portion 22 of the adjusting unit 2, and a plurality of marks may be formed on the bottom surface of the cut at a predetermined pitch in the axial direction. As a result, the volume reduction amount from the axial position of the adjustment unit 2 can be set with higher accuracy than the size of the opening 23w can be visually determined depending on which of the plurality of marks is hidden by the base 12 of the main body 1. Can be grasped.

The disclosure of the present application relates to the subject matter described in Japanese Patent Application No. 2018-241109 filed on Dec. 25, 2018, the entire disclosures of which are incorporated herein by reference.

Claims

A body portion having a through hole and attachable to the ear canal,
An adjusting unit that is movably inserted into the through hole from one end side, and selectively controls communication and non-communication between the one end side of the through hole and an external space according to an insertion position with respect to the through hole. Prepared earplugs.
The adjustment unit,
A ventilation part that connects the one end side of the through hole and the external space at a first insertion position with respect to the through hole;
The said ventilation part is covered with the said main-body part, and is not connected to the said external space in the 2nd insertion position nearer the one end side of the said through hole than the said 1st insertion position with respect to the said through hole. Earplugs.
The earplug according to claim 2, wherein an area of an opening communicating with the external space in the ventilation portion changes according to an insertion position of the adjusting portion with respect to the through hole.
The earplug according to claim 2 or 3, wherein at least one of the through hole and the ventilation portion has a sound absorbing material.
The earplug according to any one of claims 1 to 4, wherein the adjustment portion is screwed into the through hole and is movable.