Sound detection device

Abstract

The present invention comprises a sensor unit (40) that outputs a detection signal corresponding to a sound, a case (10) in which the sensor unit (40) is disposed, and a cover part (70) that is assembled to the case (10) and protects the sensor unit (40). A discharge structure (94) for discharging foreign matter is formed in at least one of the case (10) and the cover part (70).

Description

Sound detection device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2023-108638, filed on June 30, 2023, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a sound detection device.

[0003] Conventionally, sound detection devices with a cover have been proposed (see, for example, Patent Document 1). Specifically, in this sound detection device, the cover is arranged so as to prevent foreign objects from reaching a sensor that outputs a detection signal in response to sound. The cover is made of a mesh or the like with holes formed therein, and is configured so that sound can be introduced through the holes.

[0004] Patent No. 5684793

[0005] However, such a sound detection device has the possibility of foreign matter such as water entering through the hole in the cover. For example, when the sound detection device is used as a detection unit that detects sound generated by a machine tool, the sound detection device is placed in an environment where foreign matter such as water or oil is likely to scatter, increasing the possibility of foreign matter entering through the hole in the cover. If foreign matter reaches the sensor unit, the detection accuracy of the sensor unit may decrease. The present disclosure aims to suppress a decrease in the detection accuracy of the sensor unit.

[0006] According to one aspect of the present disclosure, a sound detection device includes a sensor unit that outputs a detection signal in response to sound, a case in which the sensor unit is disposed, and a cover unit that is assembled to the case and protects the sensor unit, and at least one of the case and the cover unit is formed with an ejection structure that ejects foreign matter.

[0007] According to this, the discharge structure is formed on at least one of the case and the cover, which makes it easier to discharge foreign matter through the discharge structure and prevents foreign matter from reaching the sensor, thereby preventing a decrease in detection accuracy.

[0008] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below.

[0009] FIG. 1 is a cross-sectional view of a sound detection device in a first embodiment. FIG. 2 is a cross-sectional view of a sound detection device in a second embodiment. FIG. 3 is a cross-sectional view of a sound detection device in a third embodiment. FIG. 4 is a plan view of a cover part in a fourth embodiment. FIG. 5 is a cross-sectional view of the vicinity of the outer edge part of the lid part in a fifth embodiment. FIG. 6 is a cross-sectional view of a sound detection device in a sixth embodiment. FIG. 7 is a cross-sectional view for explaining the state when a foreign object has entered the inside of the cover. FIG. 8 is a cross-sectional view of a sound detection device in a seventh embodiment. FIG. 9 is a diagram showing the relationship between the size of the tapered part, the frequency of the sound applied, and the sound pressure. FIG. 10 is a diagram for explaining the relationship between the diameter of the bottom part and the size of the tapered part. FIG. 11 is a cross-sectional view of a sound detection device in a tenth embodiment. FIG. 12 is a cross-sectional view of a sound detection device in an eleventh embodiment. FIG. 13 is a cross-sectional view of a sound detection device in a twelfth embodiment. FIG. 14 is a cross-sectional view of a sound detection device in a thirteenth embodiment.

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the following embodiments, identical or equivalent parts will be denoted by the same reference numerals.

[0011] First Embodiment A first embodiment will be described with reference to the drawings. Note that a sound detection device S1 of this embodiment is suitably used as a detection unit that detects sound generated from a machine tool, for example.

[0012] As shown in FIG. 1, the sound detection device S1 includes a case 10, a wiring board 30, a sensor unit 40, a waterproof membrane 60, a cover unit 70, and the like.

[0013] The case 10 is configured by assembling a connector case 20 and a lid portion 50. The connector case 20 is generally cylindrical and made of, for example, a heat-resistant resin material such as PPS (i.e., polyphenylene sulfide) or a metal material such as SUS. The connector case 20 of this embodiment is configured with a step portion 23 between a first portion 21 at one end and a second portion 22 at the other end. Specifically, the circumferential length of the first portion 21 of the connector case 20 is longer than the circumferential length of the second portion 22. In other words, in a cross section of the connector case 20 taken along the axial direction, the length of the opposing side of the first portion 21 is longer than the length of the opposing side of the second portion 22. In FIG. 1 , the upper portion of the connector case 20 on the paper surface corresponds to the first portion 21, and the lower portion of the connector case 20 on the paper surface corresponds to the second portion 22. In FIG. 1 , the vertical direction on the paper surface corresponds to the axial direction, and the circumferential direction corresponds to the direction around the axial direction. The cross section along the axial direction is, for example, that shown in FIG.

[0014] The connector case 20 has a recess 24 formed in one surface 20a on one end side. In this embodiment, the one surface 20a of the connector case 20 is formed so that the normal direction to the one surface 20a (hereinafter simply referred to as the normal direction) coincides with the axial direction. The connector case 20 also has an annular groove 25 formed in a side surface 20b connected to the one surface 20a, and a sealing member 26 such as an O-ring is disposed in the groove 25. In this embodiment, the groove 25 is formed so as to go around the side surface 20b of the first portion 21 in the circumferential direction. The lid 50 constituting the case 10 will be described later.

[0015] The wiring board 30 is configured as a printed circuit board or the like having one surface 30 a and another surface 30 b. Although not specifically shown, the wiring board 30 of this embodiment has one-surface wiring formed on the one surface 30 a and another-surface wiring formed on the other surface 30 b, and through-hole wiring connecting the one-surface wiring and the other-surface wiring is appropriately formed. The wiring board 30 is then placed in the recess 24 with the other surface 30 b facing the bottom surface of the recess 24.

[0016] Furthermore, through holes 31 are formed in the outer edge of the wiring board 30, penetrating between one surface 30a and the other surface 30b, and terminals 27 are inserted into the through holes 31. The wiring board 30 is connected to the terminals 27 by arranging a conductive member 32, such as solder, in the through holes 31. The terminals 27 are, for example, rod-shaped and arranged in the connector case 20. Specifically, the terminals 27 are arranged in the connector case 20 so that the ends of the terminals 27 on the wiring board 30 side are exposed from the recess 24 and the ends of the terminals 27 opposite the wiring board 30 side are exposed from predetermined positions on the connector case 20. The ends of the terminals 27 opposite the wiring board 30 side are connected to an external circuit, thereby connecting the wiring board 30 to the external circuit.

[0017] The sensor unit 40 includes a detection element that outputs a detection signal corresponding to the applied sound, and is disposed on one surface 30a of the wiring board 30 and electrically connected to the wiring board 30. This allows the sensor unit 40 to be connected to an external circuit via the wiring board 30 and the terminals 27. The detection element is not particularly limited, but may be, for example, a piezoelectric, electrostatic, or capacitor type. The sensor unit 40 may be a package in which the detection element is housed in a box-shaped container having an introduction hole for introducing sound, or may be composed of the detection element alone.

[0018] The lid 50 is made of a metal material such as SUS, and is shaped like a bottomed cylinder having a bottom 51 and a side 52. The lid 50 is assembled to the connector case 20 with the bottom 51 facing one surface 20a of the connector case 20 and the open end 52a of the side 52 crimped to the stepped portion 23 of the connector case 20 so that the sealing member 26 is crushed by the side 52. By assembling the lid 50 to the connector case 20 in this manner, an accommodation space 41 is defined between the lid 50 and the recess 24 of the connector case 20, and the sensor 40 is disposed in the accommodation space 41.

[0019] In the following description, the surface of the bottom 51 opposite to the sensor unit 40 will be referred to as one surface 51a of the bottom 51, and the surface on the sensor unit 40 side will be referred to as the other surface 51b of the bottom 51.

[0020] In the present embodiment, the lid 50 has a protrusion 53 formed in the center of the bottom 51, protruding toward the first surface 51a. In other words, the lid 50 has a step 54 formed in the outer edge of the bottom 51, recessed toward the second surface 51b. In other words, the first surface 51a and the second surface 51b of the bottom 51 in the present embodiment have their central portions protruding toward the first surface 51a more than their outer edges. The protrusion 53 is sized to accommodate a portion of the sensor unit 40 therein. The lid 50 is assembled to the connector case 20 so that a portion of the sensor unit 40 is accommodated within the protrusion 53.

[0021] Furthermore, a through-hole 55 is formed in the lid 50, penetrating between the one surface 51a and the other surface 51b, in a portion of the bottom 51 facing the sensor unit 40. As a result, sound is applied to the sensor unit 40 through the through-hole 55. In this embodiment, a convex portion 53 is formed in the center of the lid 50, and the through-hole 55 is formed in the convex portion 53. The space inside the through-hole 55 becomes a so-called acoustic space 56, and the size of the through-hole 55 is changed appropriately depending on the frequency of the sound to be detected, etc.

[0022] The lid portion 50 is formed with a first engaging fixing portion 501 for engaging with an inner cover portion 80 (described later) to fix the inner cover portion 80, and a second engaging fixing portion 502 for engaging with an outer cover portion 90 (described later) to fix the outer cover portion 90. In this embodiment, the first engaging fixing portion 501 is formed on the outer edge of the protrusion 53 and is a protrusion that protrudes along the surface direction of the one surface 51 a. The second engaging fixing portion 502 is formed on the outer edge of the step portion 54 and is a protrusion that protrudes along the surface direction of the one surface 51 a.

[0023] The waterproof membrane 60 is made of a porous material such as fluororesin. The waterproof membrane 60 is arranged so as to block the through-hole 55 of the lid portion 50. In this embodiment, the waterproof membrane 60 is arranged on one surface 51a of the bottom portion 51, but the waterproof membrane 60 may also be arranged on the other surface 51b of the bottom portion 51. In this embodiment, the waterproof membrane 60 corresponds to a protective membrane. Note that in this embodiment, the waterproof membrane 60 is arranged because it is assumed that water may infiltrate as a foreign object. However, in a situation where oil may infiltrate as a foreign object, an oil-proof membrane may be arranged instead of the waterproof membrane 60.

[0024] The cover unit 70 is attached to the case 10 to protect the sensor unit 40, and in this embodiment, is configured to include an inner cover unit 80 and an outer cover unit 90. The outer cover unit 90 is disposed so as to cover the inner cover unit 80.

[0025] Specifically, the inner cover portion 80 is made of a windscreen member made of a porous material such as sponge, and is hemispherical in shape with an outer surface 80a and an inner surface 80b. In this embodiment, the inner cover portion 80 is generally bowl-shaped with a recessed portion formed on the inside so that a cavity is formed on the inner surface 80b side. The inner cover portion 80 may also be made of a material that easily absorbs (i.e., attenuates) specific frequencies. For example, if it is desired to absorb sounds related to human voices, the inner cover portion 80 may be made of a material that easily absorbs sounds in the 3 to 4 kHz range.

[0026] Additionally, the inner cover portion 80 has third engaging fixing portions 81 formed on its inner surface 80b, which correspond to the first engaging fixing portions 501 of the lid portion 50. The inner cover portion 80 is fixed to the lid portion 50 by engaging the third engaging fixing portions 81 with the first engaging fixing portions 501 with the outer edge end of the inner cover portion 80 abutting against the stepped portion 54 of the lid portion 50. In this embodiment, the third engaging fixing portions 81 are recessed portions, and the protruding portions of the first engaging fixing portions 501 are snap-fitted into these recessed portions.

[0027] In this embodiment, the interior of the inner cover portion 80 is hollow. Therefore, when the inner cover portion 80 is fixed to the lid portion 50, an internal space 100 is formed between the inner cover portion 80 and the lid portion 50.

[0028] The outer cover portion 90 is made of a hard material such as a metal material or resin having a higher Young's modulus than the inner cover portion 80, and is formed with holes 91 through which foreign matter can more easily penetrate than in the inner cover portion 80. In this embodiment, the outer cover portion 90 is made of a mesh member formed by weaving metal wires into a net shape, a punched metal, or the like.

[0029] The outer cover portion 90 is formed in a semispherical shape with an arc-shaped cross section corresponding to the inner cover portion 80 so as to cover the inner cover portion 80. In the following description, the surface of the outer cover portion 90 facing the inner cover portion 80 will be referred to as the inner surface 90b, and the surface opposite the inner cover portion 80 will be referred to as the outer surface 90a.

[0030] The outer cover part 90 has a fourth engaging fixing part 92 formed on its outer edge. The outer cover part 90 is fixed to the lid part 50 by engaging the fourth engaging fixing part 92 with the second engaging fixing part 502. In this embodiment, the fourth engaging fixing part 92 is a convex part, and this convex part is snap-fitted to the convex part of the second engaging fixing part 502.

[0031] Furthermore, in this embodiment, the inner cover portion 80 and the outer cover portion 90 are fixed to the lid portion 50 with a predetermined space (i.e., gap) 110 between the inner cover portion 80 and the outer cover portion 90. Therefore, foreign matter that enters the interior through the hole 91 of the outer cover portion 90 is more likely to move along the inner surface 90b of the outer cover portion 90 than to move toward the inner cover portion 80. This prevents foreign matter from reaching the inner cover portion 80 and then the sensor portion 40 via the inner cover portion 80.

[0032] The above is the configuration of the sound detection device S1 in this embodiment. Such a sound detection device S1 is placed, for example, near a target part that emits the sound to be detected. The sensor part 40 outputs a detection signal corresponding to the sound when the sound generated by the target part passes through the cover part 70, the internal space 100, and the acoustic space 56 and is applied to the sensor part 40.

[0033] According to the present embodiment described above, the cover unit 70 is configured to include an outer cover unit 90 made of a hard material and an inner cover unit 80 made of a porous windscreen material. Therefore, even if a foreign object enters through the hole 91 in the outer cover unit 90, the inner cover unit 80 can prevent the foreign object from reaching the sensor unit 40, thereby preventing a decrease in detection accuracy. Furthermore, because the outer cover unit 90 is made of a hard material, impact resistance can also be improved.

[0034] (1) In this embodiment, a space 110 is defined between the inner cover portion 80 and the outer cover portion 90. Therefore, foreign matter that enters the interior through the hole 91 of the outer cover portion 90 is more likely to move along the inner surface 90b of the outer cover portion 90 than to move toward the inner cover portion 80. This prevents foreign matter from reaching the inner cover portion 80 and then the sensor portion 40 via the inner cover portion 80.

[0035] (2) In this embodiment, the waterproof film 60 is disposed so as to close the through-hole 55. This further prevents water as a foreign substance from reaching the sensor unit 40.

[0036] Second Embodiment A second embodiment will be described. This embodiment is different from the first embodiment in that the configurations of the inner cover portion 80 and the outer cover portion 90 are changed. As the rest of the configuration is the same as the first embodiment, a description thereof will be omitted here.

[0037] The noise detection device S1 of this embodiment is designed for a situation in which water may enter as a foreign object. As shown in Fig. 2, the inner cover part 80 has a water-repellent part 82 formed on its outer surface 80a. The outer cover part 90 has a water-repellent part 93 formed on its outer surface 90a. The water-repellent parts 82, 93 are made of, for example, an organic fluorine compound film or the like.

[0038] According to the present embodiment described above, the cover portion 70 is configured to include the outer cover portion 90 and the inner cover portion 80, and therefore, the same effects as those of the first embodiment can be obtained.

[0039] (1) In this embodiment, the water-repellent portion 82 is formed on the inner cover portion 80, and the water-repellent portion 93 is formed on the outer cover portion 90. This prevents water from accumulating as a foreign object in the cover portion 70, and further prevents the foreign object from reaching the sensor portion 40.

[0040] (Variation of the Second Embodiment) A variation of the second embodiment will be described. In the second embodiment, when the noise detection device S1 is used in a situation where oil as a foreign object may enter, the inner cover part 80 may be formed with an oil-repellent part instead of the water-repellent part 82, and the outer cover part 90 may be formed with an oil-repellent part instead of the water-repellent part 93. The oil-repellent part may be made of, for example, a fluorine-based polymer or the like.

[0041] In the second embodiment, the water-repellent portion 82 may be formed on the outer surface 80a and the inner surface 80b of the inner cover portion 80, and the water-repellent portion 93 may be formed on the outer surface 90a and the inner surface 90b of the outer cover portion 90. Furthermore, the water-repellent portion 82 may be formed only on the inner surface 80b of the inner cover portion 80, and the water-repellent portion 93 may be formed only on the inner surface 90b of the outer cover portion 90. Furthermore, only one of the water-repellent portion 82 of the inner cover portion 80 and the water-repellent portion 93 of the outer cover portion 90 may be formed.

[0042] Furthermore, in the second embodiment, the cover portion 70 may be composed of either the inner cover portion 80 or the outer cover portion 90, and one of these cover portions may be provided with the water-repellent portions 82, 93. When the cover portion 70 is composed of only the inner cover portion 80, the pores of the cover portion 70 are formed by the pores of the porous material that constitutes the inner cover portion 80.

[0043] Third Embodiment A third embodiment will be described. This embodiment is different from the first embodiment in that the configuration of the outer cover part 90 is changed. As the rest of the configuration is the same as the first embodiment, a description thereof will be omitted here.

[0044] As shown in FIG. 3 , the noise detection device S1 of this embodiment is configured such that the outer cover portion 90 includes a first outer cover portion 910 and a second outer cover portion 920. Specifically, the first outer cover portion 910 and the second outer cover portion 920 are arranged in this order from the side opposite the inner cover portion 80, and are integrated by sintering or the like. Therefore, in this embodiment, the outer surface 90a of the outer cover portion 90 is formed by the first outer cover portion 910, and the inner surface 90b of the outer cover portion 90 is formed by the second outer cover portion 920. Note that, although this embodiment describes an example in which the first outer cover portion 910 and the second outer cover portion 920 are integrated by sintering, the first outer cover portion 910 and the second outer cover portion 920 may also be integrated by an adhesive or the like.

[0045] The first outer cover portion 910 and the second outer cover portion 920 have a higher Young's modulus than the second outer cover portion 920. The first outer cover portion 910 has a hole 911 formed therein, and the second outer cover portion 920 has a hole 921 formed therein. However, the opening size of each of the holes 911, 921 is smaller in the second outer cover portion 920 than in the first outer cover portion 910. In other words, the opening area of ​​the hole 921 in the second outer cover portion 920 is smaller than that of the hole 911 in the first outer cover portion 910. That is, the hole 921 in the second outer cover portion 920 is sized to make it more difficult for foreign objects to enter than the hole 911 in the first outer cover portion 910. In this case, it is preferable that the hole 921 of the second outer cover portion 920 be sized to satisfy at least IP6X. IP6X is a size that prevents a substance with a diameter of 1 mm from entering. In this embodiment, the hole 91 of the outer cover part 90 is formed at the portion where the hole 911 of the first outer cover part 910 and the hole 921 of the second outer cover part 920 communicate with each other.

[0046] In this embodiment, the second outer cover portion 920 has a thickness t2 that is thinner than the thickness t1 of the first outer cover portion 910 .

[0047] According to the present embodiment described above, the cover portion 70 is configured to include the outer cover portion 90 and the inner cover portion 80, and therefore, the same effects as those of the first embodiment can be obtained.

[0048] (1) In the present embodiment, the outer cover portion 90 is configured by integrating a first outer cover portion 910 and a second outer cover portion 920. The hole 921 of the second outer cover portion 920 is smaller than the hole 911 of the first outer cover portion 910. Therefore, compared to when the outer cover portion 90 is configured only by the first outer cover portion 910, it is possible to further prevent foreign matter from entering the interior, and it is possible to further prevent a decrease in detection accuracy.

[0049] (2) In the present embodiment, the thickness t2 of the second outer cover portion 920 is thinner than the thickness t1 of the first outer cover portion 910. Therefore, compared to when the thickness t2 of the second outer cover portion 920 is the same as the thickness t1 of the first outer cover portion 910, the attenuation of sound passing through the hole 921 can be reduced, thereby improving detection accuracy.

[0050] (3) In the present embodiment, the first outer cover portion 910 has a higher Young's modulus than the second outer cover portion 920. Therefore, compared to a case where the Young's modulus of the first outer cover portion 910 is the same as the Young's modulus of the second outer cover portion 920, it is possible to improve the impact resistance.

[0051] (Modification of Third Embodiment) A modification of the third embodiment will be described. In the third embodiment, the cover portion 70 may be configured with only the outer cover portion 90 without including the inner cover portion 80.

[0052] (Fourth embodiment) A fourth embodiment will be described. This embodiment is different from the first embodiment in that a discharge path is added to the outer cover part 90. As the other features are the same as those of the first embodiment, a description thereof will be omitted here.

[0053] As shown in Fig. 4, the noise detection device S1 of this embodiment has exhaust paths 94 formed in the outer surface 90a of the outer cover part 90. In this embodiment, the exhaust paths 94 are recesses formed in a location different from the hole parts 91, and are formed so as to extend radially from the center of the outer cover part 90 in the normal direction. Note that the hole parts 91 are not shown in Fig. 4. Also, "in the normal direction" can be rephrased as when viewed from the normal direction. In this embodiment, the exhaust paths 94 correspond to the exhaust structure.

[0054] In addition, similar to the second embodiment, this embodiment assumes a situation in which water as a foreign object may get in. The outer cover part 90 has a water-repellent part 93 formed in a part different from the discharge passage 94, similar to the second embodiment.

[0055] According to the present embodiment described above, the cover portion 70 is configured to include the outer cover portion 90 and the inner cover portion 80, and therefore, the same effects as those of the first embodiment can be obtained.

[0056] (1) In this embodiment, a discharge path 94 is formed in the outer cover portion 90. This makes it easier to discharge foreign matter from the outer cover portion 90 through the discharge path 94. For example, if the sound detection device S1 is positioned so that the connector case 20 is on the bottom side in the vertical direction and the outer cover portion 90 is on the top side in the vertical direction, foreign matter will flow to the outer edge of the outer cover portion 90 and be discharged, as indicated by arrow A. In contrast, if the sound detection device S1 is positioned so that the connector case 20 is on the top side in the vertical direction and the outer cover portion 90 is on the bottom side in the vertical direction, foreign matter will flow in the opposite direction to arrow A, gather at the center of the outer cover portion 90, and be discharged.

[0057] (2) In the present embodiment, the water-repellent portion 93 is formed in a portion of the outer cover portion 90 that is different from the discharge path 94. Therefore, in a situation where water may enter as a foreign object, the foreign object that reaches the outer cover portion 90 is more likely to be guided to the discharge path 94 and then discharged from the discharge path 94. Therefore, it is possible to prevent foreign objects from entering the interior of the outer cover portion 90.

[0058] (Variation of Fourth Embodiment) A variation of the fourth embodiment will now be described. In the fourth embodiment, as with the variation of the second embodiment, when the noise detection device S1 is used in a situation where oil as a foreign object may enter, an oil-repellent portion may be formed instead of the water-repellent portion 93.

[0059] In the fourth embodiment, the water-repellent portion 93 may also be formed in the discharge path 94. In other words, when the water-repellent portion 93 is formed, it is sufficient that the water-repellent portion 93 is formed in at least a portion different from the discharge path 94.

[0060] Furthermore, in the fourth embodiment, the cover portion 70 may not include the inner cover portion 80, and may be configured only with the outer cover portion 90. Also, in the fourth embodiment, the water-repellent portion 93 may not be formed. This type of noise detection device S1 can also make it easier to discharge foreign matter from the discharge path 94.

[0061] Fifth Embodiment A fifth embodiment will be described. This embodiment is different from the third embodiment in that the configuration of the outer cover part 90 is changed. As the rest of the configuration is the same as the third embodiment, a description thereof will be omitted here.

[0062] As shown in FIG. 5 , the noise detection device S1 of this embodiment is configured such that the outer cover portion 90 includes a first outer cover portion 910 and a second outer cover portion 920. In this embodiment, the outer edge of the second outer cover portion 920 terminates more inward than the outer edge of the first outer cover portion 910, and is positioned so that the outer edge is spaced apart from one surface 51 a of the bottom portion 51 of the lid portion 50. In other words, a predetermined gap G is formed between the outer edge of the second outer cover portion 920 and the one surface 51 a of the bottom portion 51 of the lid portion 50. Therefore, the hole 911 on the outer edge side of the first outer cover portion 910 is exposed from the second outer cover portion 920. In this embodiment, the shape of the second outer cover portion 920 corresponds to the exhaust structure. FIG. 5 corresponds to an enlarged view of area V in FIG. 3 .

[0063] In this embodiment, the lid portion 50 is configured to have the protrusion 53 and the step portion 54 as described above. The outer edge of the second outer cover portion 920 is positioned opposite the step portion 54 in the normal direction, and the gap G between the step portion 54 and the surface 51 a of the second outer cover portion 920 is shorter than the height of the protrusion 53. In other words, the outer edge of the second outer cover portion 920 is positioned closer to the step portion 54 than an imaginary plane along the surface 51 a of the protrusion 53. In yet another way, the outer edge of the second outer cover portion 920 is shaped to be positioned between the height of the portion of the surface 51 a where the through hole 55 is formed and the height of the portion of the first outer cover portion 910 that is assembled to the lid portion 50.

[0064] According to the present embodiment described above, the cover portion 70 is configured to include the outer cover portion 90 and the inner cover portion 80, and therefore, the same effects as those of the first embodiment can be obtained.

[0065] (1) In this embodiment, the second outer cover portion 920 is positioned so that its outer edge is spaced apart from one surface 51 a of the bottom portion 51 of the lid portion 50. Therefore, if a foreign object enters the inner surface 90 b of the outer cover portion 90 and moves along the inner surface 90 b to the outer edge, the foreign object will be transferred from the second outer cover portion 920 to the first outer cover portion 910. Furthermore, the hole 911 of the first outer cover portion 910 is larger than the hole 921 of the second outer cover portion 920. Therefore, it is expected that the foreign object that reaches the first outer cover portion 910 will be discharged through the hole 911 to the outer surface 90 a of the first outer cover portion 910. This prevents foreign objects from accumulating inside the cover portion 70.

[0066] (2) In this embodiment, the lid unit 50 has a protrusion 53 and a step 54. The outer edge of the second outer cover unit 920 is positioned opposite the step 54 in the normal direction, and the gap G between the second outer cover unit 920 and the surface 51 a of the step 54 is shorter than the height of the protrusion 53. This prevents foreign matter from reaching the surface 51 a of the protrusion 53 and further prevents foreign matter from reaching the sensor unit 40 through the through-hole 55.

[0067] (Modification of Fifth Embodiment) A modification of the fifth embodiment will be described. In the fifth embodiment, the cover portion 70 may be configured with only the outer cover portion 90 without including the inner cover portion 80.

[0068] Sixth Embodiment A sixth embodiment will be described. This embodiment differs from the first embodiment in that it does not include the inner cover portion 80. As the rest of the configuration is the same as the first embodiment, a description thereof will be omitted here.

[0069] 6, the noise detection device S1 of this embodiment does not include an inner cover portion 80. In other words, in this embodiment, the cover portion 70 is configured as an outer cover portion 90.

[0070] In this type of noise detection device S1, if a foreign object penetrates the inner surface of the outer cover portion 90, there is a possibility that the foreign object will reach one surface 51a of the bottom portion 51 of the lid portion 50. However, in this embodiment, the bottom portion 51 is configured to have a convex portion 53 and a step portion 54 formed thereon. Therefore, if a foreign object reaches the bottom portion 51, the foreign object W flows toward the step portion 54 as shown by arrow B in FIG. 7 , thereby preventing the foreign object W from accumulating near the through-hole 55. Therefore, the foreign object W can be prevented from reaching the sensor portion 40 through the through-hole 55. Note that FIG. 7 does not illustrate the cover portion 70, etc. Furthermore, in this embodiment, the shape of the bottom portion 51 corresponds to the discharge structure.

[0071] According to the present embodiment described above, the bottom 51 is configured to have the protrusion 53 and the step 54, which prevents foreign matter from reaching the sensor unit 40 through the through-hole 55 and prevents a decrease in detection accuracy. Note that this effect can also be obtained when the inner cover 80 is provided as in the first embodiment.

[0072] (Modification of Sixth Embodiment) A modification of the sixth embodiment will be described. In the sixth embodiment, the cover portion 70 may be configured with an inner cover portion 80 without including the outer cover portion 90 .

[0073] Seventh Embodiment A seventh embodiment will be described. This embodiment differs from the sixth embodiment in that a tapered portion is formed on the bottom 51 of the lid 50. As the remaining features are the same as those of the sixth embodiment, a description thereof will be omitted here.

[0074] As shown in Fig. 8 , in the noise detection device S1 of this embodiment, the bottom 51 of the lid 50 has a reference position where the portion of the protrusion 53 where the through hole 55 is formed, and is tapered such that the surface 51a approaches the connector case 20 from this reference position toward the outer edge. In other words, the portion of the bottom 51 where the through hole 55 is formed protrudes the most, and the surface 51a is shaped to slope toward the connector case 20 from this portion toward the outer edge. Hereinafter, the portion of the surface 51a that slopes toward the connector case 20 will be described as a tapered portion 511. Note that Fig. 8 does not illustrate the cover 70, etc. Furthermore, in this embodiment, the shape of the bottom 51 corresponds to the exhaust structure.

[0075] In such a noise detection device S1, if a foreign object penetrates the inner surface of the outer cover part 90, there is a possibility that the foreign object will reach one surface 51a of the bottom part 51 of the lid part 50. However, in this embodiment, the bottom part 51 has a reference position where the through hole 55 is formed, and the one surface 51a is tapered from this reference position toward the outer edge part so that it approaches the connector case 20. Therefore, if a foreign object reaches the bottom 51, the foreign object will flow toward the outer edge part as shown by arrow C in Figure 8, and therefore it is possible to prevent the foreign object from reaching the sensor part 40 through the through hole 55.

[0076] According to the present embodiment described above, the portion of the bottom 51 where the through hole 55 is formed is set as a reference position, and the surface 51a is tapered from this reference position toward the outer edge toward the connector case 20. This makes it possible to prevent foreign matter from reaching the sensor unit 40 through the through hole 55, and to prevent a decrease in detection accuracy.

[0077] (1) In this embodiment, the bottom portion 51 has a reference position where the through hole 55 is formed, and the surface 51a of the bottom portion 51 tapers from this reference position toward the outer edge toward the connector case 20. This prevents foreign matter from reaching the sensor unit 40, thereby preventing a decrease in detection accuracy. The inventors conducted extensive research into the relationship between the size of the tapered portion 511, the frequency of the applied sound, and the sound pressure (i.e., the detection signal), and obtained the results shown in FIG. 9A . The size of the tapered portion in FIG. 9A is the ratio of the radial length Rb of the tapered portion 511 to the diameter Ra of the lid portion 50 (i.e., (Rb / Ra) × 100) shown in FIG. 9B . Also, FIG. 9A illustrates the result when the angle θ of the tapered portion 511 shown in FIG. 9B is 45° and the tapered portion 511 is formed in a ring shape around the through hole 55. As shown in Figure 9A, it has been confirmed that when the frequency of the applied sound is in the range of 15,000 Hz or less, the sound pressure remains almost unchanged even when the size of the tapered portion 511 is changed. Note that in the range of 15,000 Hz or less in Figure 9A, the results are almost the same and overlap, so the solid line without the tapered portion is mainly shown, but in reality, it has been confirmed that the sound pressure remains the same even when the size of the tapered portion is changed. In other words, with the sound detection device S1 of this embodiment, when the frequency of the applied sound is 15,000 Hz or less, the characteristics do not change and foreign matter is prevented from reaching the sensor unit 40, thereby preventing a decrease in detection accuracy.

[0078] (Modification of Seventh Embodiment) A modification of the seventh embodiment will be described. In the seventh embodiment, the cover portion 70 may be configured to have an inner cover portion 80, similar to the first embodiment. Also, in the seventh embodiment, the cover portion 70 may be configured with only the inner cover portion 80, without including the outer cover portion 90.

[0079] Eighth Embodiment An eighth embodiment will be described. This embodiment differs from the first embodiment in that guide holes are formed in the inner cover portion 80. As the remaining features are the same as those of the first embodiment, a description thereof will be omitted here.

[0080] 10 , in the noise detection device S1 of the present embodiment, an induction hole 83 that penetrates between the outer surface 80a and the inner surface 80b is formed in the inner cover part 80. In this embodiment, the induction hole 83 is formed so that its axis coincides with the axis of the through hole 55. In other words, the induction hole 83 is formed directly above the through hole 55.

[0081] According to the present embodiment described above, the cover portion 70 is configured to include the outer cover portion 90 and the inner cover portion 80, and therefore, the same effects as those of the first embodiment can be obtained.

[0082] (1) In this embodiment, the guide holes 83 are formed in the inner cover portion 80. Therefore, when sound passes through the inner cover portion 80, sound attenuation can be suppressed in the area of ​​the guide holes 83. This can improve detection accuracy. Furthermore, by forming the guide holes 83, sound attenuation in the area of ​​the guide holes 83 can be suppressed, and therefore, directionality can be imparted to the detection direction.

[0083] (Modification of Eighth Embodiment) A modification of the eighth embodiment will be described. In the eighth embodiment, the portion where the guide hole 83 is formed can be changed as appropriate depending on the desired direction of directionality. Furthermore, in the eighth embodiment, the cover portion 70 may be configured with an inner cover portion 80 without including the outer cover portion 90.

[0084] Ninth Embodiment A ninth embodiment will be described. This embodiment is different from the first embodiment in that the configuration of the inner cover portion 80 is changed. As the rest of the configuration is the same as the first embodiment, a description thereof will be omitted here.

[0085] 11 , in the sound detection device S1 of this embodiment, the inner cover part 80 does not have a cavity formed on the inner surface 80b side. The inner cover part 80 is also positioned so as to abut against one surface 51a of the protrusion 53 and close the through-hole 55. For this reason, in this embodiment, an internal space 100 is not formed between the inner cover part 80 and the lid part 50. Furthermore, because the inner cover part 80 is positioned so as to close the through-hole 55, a waterproof membrane 60 is not provided.

[0086] According to the present embodiment described above, the cover portion 70 is configured to include the outer cover portion 90 and the inner cover portion 80, and therefore, the same effects as those of the first embodiment can be obtained.

[0087] (1) In the present embodiment, the inner cover portion 80 is disposed so as to abut against the one surface 51 a of the protrusion 53. This makes it difficult for a space to exist between the inner cover portion 80 and the protrusion 53, thereby suppressing sound scattering between the inner cover portion 80 and the protrusion 53.

[0088] (Modification of the ninth embodiment) A modification of the ninth embodiment will be described. In the ninth embodiment, the waterproof membrane 60 may be provided. Also, in the ninth embodiment, the cover portion 70 may be configured with an inner cover portion 80 without including the outer cover portion 90.

[0089] Tenth Embodiment A tenth embodiment will be described. This embodiment differs from the first embodiment in that a filler member is provided. As the other features are the same as those of the first embodiment, a description thereof will be omitted here.

[0090] 12 , in the sound detection device S1 of this embodiment, a filler member 120 made of gel or the like is disposed in the housing space 41 between the inner cover part 80 and the connector case 20. However, the filler member 120 is disposed in a part of the sensor part 40 that is different from the part that overlaps with the through-hole 55 in the normal direction. In other words, the filler member 120 is disposed in a part of the sensor part 40 that is different from the part to which sound is likely to be applied through the through-hole 55.

[0091] According to the present embodiment described above, the cover portion 70 is configured to include the outer cover portion 90 and the inner cover portion 80, and therefore, the same effects as those of the first embodiment can be obtained.

[0092] (1) In this embodiment, the filling member 120 is disposed in the accommodation space 41 between the inner cover portion 80 and the connector case 20. This prevents sound from entering the accommodation space 41 and prevents sound from reverberating within the accommodation space 41. This improves detection accuracy. The filling member 120 is disposed in a portion of the sensor unit 40 that is different from the portion that overlaps with the through-hole 55 in the normal direction. This prevents the filling member 120 from impeding sound transmission to the sensor unit 40.

[0093] (Modification of Tenth Embodiment) A modification of the tenth embodiment will be described. In the tenth embodiment, the cover portion 70 may be composed of one of the inner cover portion 80 and the outer cover portion 90.

[0094] Eleventh Embodiment An eleventh embodiment will be described. This embodiment differs from the first embodiment in that a protective member is provided. As the rest of the configuration is the same as the first embodiment, a description thereof will be omitted here.

[0095] 13, in the sound detection device S1 of this embodiment, a protective member 130 is disposed at the portion where the lid portion 50 is crimped to the connector case 20. The protective member 130 is made of, for example, potting resin or the like.

[0096] According to the present embodiment described above, the cover portion 70 is configured to include the outer cover portion 90 and the inner cover portion 80, and therefore, the same effects as those of the first embodiment can be obtained.

[0097] (1) In this embodiment, the protective member 130 is disposed at the portion where the lid 50 is crimped to the connector case 20. This prevents foreign matter from entering between the connector case 20 and the lid 50 and prevents excess stress from being generated in the crimped portion. This allows for a longer lifespan of the noise detection device S1.

[0098] (Modification of Eleventh Embodiment) A modification of the eleventh embodiment will be described. In the eleventh embodiment, the cover portion 70 may be composed of one of the inner cover portion 80 and the outer cover portion 90.

[0099] (Twelfth Embodiment) A twelfth embodiment will be described. This embodiment differs from the first embodiment in that the shape of the connector case 20 is changed and an attachment member is added. As the rest of the configuration is the same as the first embodiment, a description thereof will be omitted here.

[0100] 14 , in the noise detection device S1 of the present embodiment, the second portion 22 of the connector case 20 has a shape that widens from the first portion 21 side toward the opposite side of the first portion 21. In other words, the second portion 22 of the connector case 20 has a tapered shape in a cross section along the axial direction, in which the length of the opposing side surface gradually increases from the first portion 21 side toward the opposite side of the first portion 21.

[0101] Furthermore, in the sound detection device S1, a magnet 140 is disposed as an attachment member at the other end of the second portion 22 opposite to the first portion 21 side.

[0102] According to the present embodiment described above, the cover portion 70 is configured to include the outer cover portion 90 and the inner cover portion 80, and therefore, the same effects as those of the first embodiment can be obtained.

[0103] (1) In the present embodiment, the second portion 22 of the connector case 20 has a fan-shaped configuration that widens from the first portion 21 side toward the opposite side from the first portion 21 side. Therefore, when attaching the second portion 22 side of the sound detection device S1 to a mounting member such as a machine tool, the mounting area can be widened, making the mounting easier. Furthermore, in the present embodiment, a magnet 140 is further disposed as a mounting member at the other end of the second portion 22 side. Therefore, if the mounting location of the mounting member is made of metal or the like, the sound detection device S1 can be easily attached using the magnet 140. In other words, the sound detection device S1 of the present embodiment can improve the mountability to the mounting member.

[0104] (Modification of Twelfth Embodiment) A modification of the twelfth embodiment will be described. In the twelfth embodiment, the cover portion 70 may be composed of one of the inner cover portion 80 and the outer cover portion 90.

[0105] (Thirteenth embodiment) A thirteenth embodiment will be described. This embodiment is different from the first embodiment in that a control unit is added. As the other aspects are the same as the first embodiment, a description thereof will be omitted here.

[0106] 15, the sound detection device S1 of this embodiment is equipped with a control unit 200 that is connected to the sensor unit 40 via a terminal 27 or the like. The control unit 200 is made up of a microcomputer or the like that includes a CPU and a storage unit that is made up of non-transient physical storage media such as ROM, RAM, flash memory, and HDD. Note that CPU is an abbreviation for Central Processing Unit, ROM is an abbreviation for Read Only Memory, RAM is an abbreviation for Random Access Memory, and HDD is an abbreviation for Hard Disk Drive.

[0107] The control unit 200 realizes various control operations by having the CPU read and execute programs (i.e., the routines described below) from a storage unit such as a ROM. The storage unit such as a ROM pre-stores various data (e.g., initial values, look-up tables, maps, etc.) to be used when executing the programs.

[0108] Specifically, when the control unit 200 is provided in a machine tool serving as a mounted member, for example, the control unit 200 determines whether there is an abnormality in the machine tool based on the detection signal detected by the sensor unit 40. The control unit 200 also performs a self-diagnosis determination of the sensor unit 40 based on the detection signal detected by the sensor unit 40. For example, if a foreign object enters the sensor unit 40 or if damage occurs due to mechanical stress or the like, the detection signal of the sound detection device S1 changes even when the machine tool is not operating. For this reason, in this embodiment, the self-diagnosis determination is performed based on the detection signal when the machine tool is not operating, for example. The control unit 200 is connected to an alarm unit or the like (not shown) and transmits a determination signal indicating the determination result to the alarm unit. As a result, the alarm unit notifies the operator of the content corresponding to the determination signal.

[0109] According to the present embodiment described above, the cover portion 70 is configured to include the outer cover portion 90 and the inner cover portion 80, and therefore, the same effects as those of the first embodiment can be obtained.

[0110] (1) In this embodiment, the control unit 200 is provided and performs a self-diagnosis determination of the sensor unit 40. Therefore, it is possible to prevent an abnormality determination of the machine tool from being made when the sound detection device S1 is abnormal.

[0111] (2) In this embodiment, the control unit 200 is disposed outside the case 10. This makes it easy to change the control of the control unit 200 depending on the application.

[0112] (Modification of the Thirteenth Embodiment) A modification of the thirteenth embodiment will be described. In the thirteenth embodiment, the cover portion 70 may be composed of one of the inner cover portion 80 and the outer cover portion 90.

[0113] Furthermore, the control unit 200 may be incorporated into the wiring board 30, for example, rather than being disposed outside the case 10. This allows the noise detection device S1 to be made smaller than when the control unit 200 is externally attached.

[0114] (Other Embodiments) While the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0115] In each of the above embodiments, the configuration of the case 10 can be changed as appropriate. For example, in the above first embodiment, the case 10 may be configured as a connector case 20, and the inner cover portion 80 and the outer cover portion 90 may be fixed to the connector case 20.

[0116] In each of the above-described embodiments, for example, in the first embodiment, the bottom 51 may not have the convex portion 53 formed thereon, and one surface 51a may be flat.

[0117] Furthermore, in each of the above-described embodiments, the wiring board 30 may not be provided, and the sensor unit 40 may be directly connected to the terminals 27 and the like.

[0118] The above embodiments may also be combined as appropriate. For example, the second embodiment may be combined as appropriate to include water-repellent portions 82, 93. The third embodiment may be combined as appropriate to include the outer cover portion 90 including a first outer cover portion 910 and a second outer cover portion 920. The fourth embodiment may be combined as appropriate to include a discharge path 94. The fifth embodiment may be combined as appropriate to include the first outer cover portion 910 and the second outer cover portion 920, and when the first outer cover portion 910 and the second outer cover portion 920 are included, the positional relationship of the second outer cover portion 920 may be adjusted. The sixth embodiment may be combined as appropriate to include the cover portion 70 including the outer cover portion 90. The seventh embodiment may be combined as appropriate to include a tapered surface 51a of the lid portion 50. The eighth embodiment may be combined as appropriate to include a guide hole 83 in the inner cover portion 80. The ninth embodiment may be combined as appropriate to include the inner cover portion 80 abutting against the surface 51a surrounding the through-hole 55. The tenth embodiment may be combined as appropriate to include a filling member 120. The eleventh embodiment may be appropriately combined to provide the protective member 130. The twelfth embodiment may be appropriately combined to provide the second portion 22 with a flared shape and the magnet 140. The thirteenth embodiment may be appropriately combined to provide the control unit 200.

[0119] The controller and methods described herein may be implemented by a special-purpose computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the controller and methods described herein may be implemented by a special-purpose computer configured with a processor configured with one or more dedicated hardware logic circuits. Alternatively, the controller and methods described herein may be implemented by one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions in combination with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium.

[0120] [Disclosure of the Present Invention] The above-described present disclosure can be understood from the following perspectives, for example: [First Aspect] A sound detection device comprising: a sensor unit (40) that outputs a detection signal in response to sound, a case (10) in which the sensor unit is disposed, and a cover unit (70) that is assembled to the case and protects the sensor unit, wherein at least one of the case and the cover unit is formed with an ejection structure (50, 94, 920) that ejects foreign matter.

[0121] [Second Aspect] The noise detection device according to the first aspect, wherein the discharge structure is a discharge path (94) that serves as a passage for foreign matter and is formed on an outer surface (90b) of the cover portion opposite the sensor portion.

[0122] [Third Aspect] The noise detection device according to the second aspect, wherein the cover portion has a water-repellent portion (93) or an oil-repellent portion formed on the outer surface at least in a portion different from the discharge path.

[0123] [Fourth Aspect] The sound detection device according to any one of the first to third aspects, wherein the case comprises a connector case (20) in which a recess (24) is formed, and a lid (50) which has a bottom (51) with one surface (51 a) and another surface (51 b) opposite the one surface, the other surface facing the bottom surface of the recess, and which is assembled to the connector case so that the bottom closes the recess of the connector case, thereby forming an accommodation space (41) between itself and the case, wherein the sensor unit is disposed in the accommodation space, and wherein the lid unit has a through-hole (55) formed in a portion facing the sensor unit.

[0124] [Fifth Aspect] The sound detection device according to the fourth aspect, further comprising a prevention film (60) made of a porous material and arranged to block the through-hole.

[0125] [Sixth Aspect] The cover part is configured by joining a first outer cover part (910) having a hole (911) formed therein and a second outer cover part (920) having a hole (921) formed therein, and has a part where the hole of the first outer cover part and the hole of the second outer cover part communicate with each other; the hole formed in the second outer cover part has an opening size smaller than the hole formed in the first outer cover part; the first outer cover part and the second outer cover part are integrated with each other, with the second outer cover part arranged on the sensor part side and an outer edge part of the first outer cover part exposed from the second outer cover part; the outer edge part of the first outer cover part exposed from the second outer cover part is assembled to the lid part; and the outer edge part of the second outer cover part is arranged away from the lid part as the discharge structure.

[0126] [Seventh Aspect] The noise detection device according to the sixth aspect, wherein the second outer cover portion has an outer edge portion positioned between the height of a portion of the one surface where the through hole is formed and the height of a portion of the first outer cover portion that is attached to the lid portion.

[0127] [Eighth Aspect] The sound detection device according to any one of the fourth to seventh aspects, wherein the lid portion has a convex portion (53) as the discharge structure that protrudes on the side opposite the sensor portion at a portion of the bottom that faces the sensor portion, and a step portion (54) at a portion of the bottom that differs from the convex portion, the through hole is formed in the convex portion, and a portion of the sensor portion is disposed in a space within the convex portion.

[0128] [Ninth Aspect] The noise detection device according to any one of the fourth to seventh aspects, wherein, when a portion where the through hole is formed is taken as a reference position, one surface of the lid portion has a tapered shape that approaches the connector case as it moves from the reference position toward the outer edge end.

Claims

1. A sound detection device comprising: a sensor unit (40) that outputs a detection signal in response to sound; a case (10) in which the sensor unit is disposed; and a cover unit (70) that is assembled to the case and protects the sensor unit, wherein at least one of the case and the cover unit is formed with an exhaust structure (50, 94, 920) that exhausts foreign matter.

2. The sound detection device according to claim 1, wherein the exhaust structure is an exhaust passage (94) for allowing foreign matter to pass through, the exhaust passage (94) being formed on an outer surface (90b) of the cover portion opposite the sensor portion.

3. The sound detection device according to claim 2, wherein the cover portion has a water-repellent portion (93) or an oil-repellent portion formed on the outer surface at least in a portion different from the exhaust path.

4. The sound detection device according to any one of claims 1 to 3, wherein the case comprises a connector case (20) in which a recess (24) is formed, and a lid portion (50) which has a bottom (51) having one surface (51a) and another surface (51b) opposite the one surface, the other surface facing the bottom surface of the recess, and which is assembled to the connector case so that the bottom closes the recess of the connector case and forms an accommodation space (41) between the case and the lid portion, wherein the sensor portion is disposed in the accommodation space, and a through hole (55) is formed in the portion of the lid portion which faces the sensor portion.

5. A sound detection device according to claim 4, further comprising a preventive membrane (60) made of a porous material and arranged to block said through hole.

6. The sound detection device according to claim 4, wherein the cover part is configured by joining a first outer cover part (910) having a hole (911) formed therein and a second outer cover part (920) having a hole (921) formed therein, and has a part where the hole of the first outer cover part and the hole of the second outer cover part are connected to each other, the hole formed in the second outer cover part has an opening size smaller than that of the hole formed in the first outer cover part, the first outer cover part and the second outer cover part are integrated with the second outer cover part disposed on the sensor part side and an outer edge part of the first outer cover part exposed from the second outer cover part, the outer edge part of the first outer cover part exposed from the second outer cover part is assembled to the lid part, and the outer edge part of the second outer cover part is disposed away from the lid part as the exhaust structure.

7. A sound detection device as described in claim 6, wherein the outer edge of the second outer cover portion is located between the height of the portion of the one surface where the through hole is formed and the height of the portion of the first outer cover portion which is attached to the lid portion.

8. The sound detection device according to claim 4, wherein the lid portion has a convex portion (53) as the discharge structure that protrudes toward the opposite side to the sensor portion at a portion of the bottom that faces the sensor portion, and a step portion (54) different from the convex portion of the bottom, the through hole being formed in the convex portion, and a portion of the sensor portion is disposed in the space within the convex portion.

9. The sound detection device according to claim 4, wherein one surface of the lid portion, as the exhaust structure, is tapered so that, when a portion where the through hole is formed is taken as a reference position, the surface approaches the connector case as it moves from the reference position towards the outer edge end.

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