Sound pressure measurement device

Abstract

To provide a sound pressure measurement device which can reduce the number of components of a holding part and suppress the generation of a measurement error by making a sound sensor to be difficult for vibrating.SOLUTION: A sound pressure measurement device 100 that measures a sound pressure generated by a speaker 13 for a function inspection of the speaker 13, and transmits its measurement result to a railroad crossing device box 14 in radio, comprises: a sound pressure sensor 110; and a holding part 120 that holds the sound pressure sensor 110. The holding part 120 is constructed as an integrated component of a cross section L-character shape in which a first piece part 120a and a second piece part 120b are continuously bent. The sound pressure sensor 110 includes: a sound collection substrate S; and a housing 111 that builds the sound collection substrate S. A sensing housing 111 is fixed to the second piece part 120b. The sound pressure measurement device 100 is fixed so as to nip one part of a horn 13a of a speaker with the housing 111 and the first piece part 120a, and one part of the sensing housing 111 is contacted to an inner surface of the horn.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a sound pressure measurement device.

Background Art

[0002] A sound pressure measurement device is known that includes a sound pressure sensor that measures the sound pressure of sound emitted by a speaker, and a holding portion that sandwiches and holds a part of the opening edge side in the horn of the speaker and holds the sound pressure sensor facing the inside of the horn (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described sound pressure measurement device, the holding portion includes a clamp having a U-shaped cross section and a connecting plate fixed to the clamp, and the sound pressure sensor is attached to the connecting plate. For this reason, the number of parts constituting the holding portion increases, and the sound pressure sensor is likely to vibrate because it is attached away from the clamp, which may cause an error in the measured value of the sound pressure.

[0005] An object of the present invention is to provide a sound pressure measurement device capable of reducing the number of parts of the holding portion and suppressing the occurrence of measurement errors by making the sound pressure sensor less likely to vibrate.

Means for Solving the Problems

[0006] In order to solve the above problems, the sound pressure measurement device of the present invention includes a sound pressure sensor that measures the sound pressure of the sound emitted by a speaker, and a holding portion that holds the sound pressure sensor facing the inside of the horn of the speaker. The holding portion is composed of an integral part having a cross-sectional L-shape in which a first piece portion and a second piece portion are bent and continuous. The first piece portion is located outside the horn, and the second piece portion extends inwardly from the open end edge of the horn. The sound pressure sensor has a sensor body and a sensor housing that houses the sensor body. The sensor housing is fixed to the second piece portion, and is fixed so as to sandwich a part of the horn between the sensor housing and the first piece portion, and a part of the sensor housing is in contact with the inner surface of the horn.

[0007] According to the present invention as described above, the holding portion is composed of an integral part having a cross-sectional L-shape in which the first piece portion and the second piece portion are continuous, and the sound pressure sensor is fixed to the second piece portion. Therefore, there is no need to use components such as a connecting plate for attaching the sound pressure sensor, and accordingly, the number of parts of the holding portion can be reduced. The sound pressure measurement device is fixed so as to sandwich a part of the horn between the first piece portion of the holding portion and the sensor housing fixed to the second piece portion of the holding portion and having a part in contact with the inner surface of the horn. In this way, since the sensor housing constituting the sound pressure sensor is directly in contact with the horn, compared with a device having a configuration in which the sound pressure sensor is easily vibrated when it is attached away from the clamp, the generation of vibration in the sound pressure sensor can be suppressed. Therefore, it is possible to provide a sound pressure measurement device that can reduce the number of parts of the holding portion and suppress the occurrence of measurement errors by making the sound pressure sensor difficult to vibrate.

[0008] Also, at this time, it is preferable that the holding portion has a screw member that penetrates the first piece portion, and the screw member is tightened so that its tip presses against the outer surface of the horn, thereby being fixed to the horn. According to such a configuration, by tightening the screw member that penetrates the first piece portion, the tip of the screw member presses against the outer surface of the horn, and the holding portion can be fixed to the horn. Therefore, the sound pressure measuring device can be firmly attached to the speaker.

[0009] Further, the sensor housing is provided with a first abutting portion located on the inner side of the horn and a second abutting portion located on the front side of the horn so as to be able to abut against the inner surface of the horn. It is preferable that the tip of the screw member abuts against the outer surface of the horn between the first abutting portion and the second abutting portion. According to such a configuration, the sound pressure measuring device can be supported with respect to the horn by three points (three ranges) of the first abutting portion, the tip of the screw member, and the second abutting portion from the inner side to the front side of the horn. Therefore, the state in which the sound pressure measuring device is fixed to the horn can be stably maintained.

[0010] Further, it is preferable that the sensor housing has a step such that the second abutting portion is located closer to the first piece portion side than the first abutting portion. According to such a configuration, by providing a step in the sensor housing, the first abutting portion and the second abutting portion located closer to the first piece portion side than the first abutting portion can be configured, so that the sensor housing can have a simple shape.

[0011] Further, the sensor housing preferably has a cover portion that covers the sensor body, and the cover portion abuts against the inner surface of the horn. According to such a configuration, since the sensor housing is provided with a cover portion that covers the sensor body, the cover portion can prevent water and dust from coming into contact with the sensor body. Further, since the cover portion abuts against the inner surface of the horn, the sound pressure measuring device can be fixed to the horn via this cover portion.

[0012] Further, it is preferable that a reinforcing rib for reinforcing the eaves portion is provided on the portion of the eaves portion facing the sensor body side. According to such a configuration, the eaves portion can be reinforced by the reinforcing rib, and its rigidity can be increased, so that the eaves portion can be made difficult to vibrate. Therefore, it is possible to suppress the occurrence of an error in the measured sound pressure value due to the vibration of the eaves portion. Further, since the reinforcing rib is provided on the portion of the eaves portion facing the sensor body side, the reinforcing rib is difficult to be exposed, and thereby it is possible to prevent water, dust, etc. from accumulating between the eaves portion and the reinforcing rib.

[0013] Also, it is also preferable that the speaker is an alarm installed at a railway crossing. According to such a configuration, by using the speaker as an alarm at a railway crossing where the demand for measuring the sound pressure at any time is high and the installation locations are numerous as an installation target of the sound pressure measurement device, the effect of reducing the above-mentioned number of parts can be effectively utilized, and a function inspection system for the alarm can be configured at low cost. Further, the speaker as an alarm at a railway crossing is likely to vibrate due to vibrations when a train or a vehicle passes by, rain, wind, speaker sound, etc., but the sound pressure measurement device of the present invention can make the sound pressure sensor difficult to vibrate as described above. Therefore, it is possible to reduce the resonance of the sound pressure sensor and suppress the measurement error of the sound pressure to configure a function inspection system for the alarm.

Advantages of the Invention

[0014] According to the present invention, it is possible to provide a sound pressure measurement device that can reduce the number of parts of the holding portion and suppress the occurrence of measurement errors by making the sound pressure sensor difficult to vibrate.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

[0016] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 6. The crossing 1 shown in Fig. 1 is a facility installed at various points on a railway line, and includes a pole-shaped object 11, a crossing gate 12, a speaker 13, a crossing tool box 14, and a sound pressure measuring device 100. The pole-shaped object 11 is a pole installed at the crossing 1, and supports the crossing gate 12 and the speaker 13. The crossing gate 12 is a traffic control device, and switches between restricting the intrusion of people and vehicles onto the tracks and releasing the restriction by raising or lowering the barrier 12a. The speaker 13 is an alarm device, and is installed on the upper end side of the pole-shaped object 11, and is configured to emit an alarm sound before and after a train passes. The crossing tool box 14 is a communication device, and is installed next to the pole-shaped object 11, and collects various information related to the monitoring of the crossing 1 and exchanges information with a predetermined monitoring server. The sound pressure measuring device 100 is a device for measuring sound pressure, and measures the sound pressure of the sound emitted by the speaker 13 in order to check the functionality of the speaker 13, and wirelessly transmits the measurement result to the crossing instrument box 14. Although not shown in Fig. 1, in addition to the crossing gate 12, the speaker 13, and the sound pressure measuring device 100, traffic signals, a display device that displays the passing status of trains, an emergency stop button device, and the like may be supported on the pillar-shaped object 11 of the crossing 1.

[0017] The sound pressure measurement device 100 includes a sound pressure sensor 110, a holding unit 120, a control unit 130, and a relay cable 140. The sound pressure sensor 110 is a sensor that measures the sound pressure of the sound emitted by the speaker 13. The holding unit 120 holds the sound pressure sensor 110 facing the inside of the horn 13a of the speaker 13 as described later. The control unit 130 is installed at a position below the speaker 13 in the columnar object 11, supplies power to the sound pressure sensor 110, converts the output voltage of the sound pressure sensor 110 into a signal representing the sound pressure, and is configured to wirelessly transmit it to the level crossing equipment box 14. The relay cable 140 electrically connects the sound pressure sensor 110 and the control unit 130, and relays the power supply from the control unit 130 to the sound pressure sensor 110 and the voltage output from the sound pressure sensor 110 to the control unit 130. This relay cable 140 is fixed to the columnar object 11 by a predetermined fastening member 141 between the sound pressure sensor 110 and the control unit 130. The sound pressure measurement device 100 is generally configured as described above. Hereinafter, the sound pressure sensor 110 and the holding unit 120 in this sound pressure measurement device 100 will be described in detail.

[0018] FIG. 2 is a diagram showing the mounting state of the speaker 13 and the sound pressure measurement device 100. FIG. 3 is a perspective view of the sound pressure measurement device 100 viewed obliquely from above, and FIG. 4 is a perspective view of the sound pressure measurement device 100 viewed obliquely from below. FIG. 5 is a cross-sectional view taken along the line A-A in FIG. 2, and FIG. 6 is a cross-sectional view taken along the line B-B in FIG. 2.

[0019] In FIGS. 2 to 6, X, Y, and Z are directions that are orthogonal to each other. In this embodiment, the left - right direction of the sound pressure measuring device 100 is indicated by arrow X and is denoted as "left - right direction X". The left side of the left - right direction X is denoted as "left side X1", and the right side is denoted as "right side X2". Also, the height direction of the sound pressure measuring device 100 is indicated by arrow Y and is denoted as "height direction Y". One of the height directions Y is denoted as "sound collection side Y1", and the other is denoted as "reception side Y2". Further, the up - down direction of the sound pressure measuring device 100 is indicated by arrow Z and is denoted as "up - down direction Z". The upper side of the up - down direction Z is denoted as "upper side Z1", and the lower side is denoted as "lower side Z2". Note that these directions are for the convenience of explanation only and do not necessarily coincide with the front - back direction, left - right direction, and up - down direction in the actual use state of the sound pressure measuring device 100, nor do they limit the respective directions in the actual use state of the sound pressure measuring device 100.

[0020] The sound pressure sensor 110 is one in which a sound collection substrate S (sensor main body) is housed and fixed inside a sensor housing 111. The sensor housing 111 is a bottomed cylindrical shape with the sound collection side Y1 as the bottom 111a1, and includes a cylindrical portion 111a in which the sound collection substrate S is installed, a mounting flange 111b provided on the opening side (reception side Y2) of the cylindrical portion 111a, a back cover 121 that closes the openings of the cylindrical portion 111a and the mounting flange 111b, and an arcuate eaves portion 111c installed along the outer peripheral surface of the cylindrical portion 111a and covering the upper side Z1 (above) of the sound collection substrate S. This sound pressure sensor 110 is configured to be held by a holding portion 120 as shown in FIG. 2 with the bottom 111a1 of the cylindrical portion 111a facing the inside (sound collection side Y1) of the horn 13a. The cylindrical portion 111a is formed to extend in the height direction Y. A cap 112 is attached to the central portion of the bottom 111a1 of the cylindrical portion 111a. This cap 112 is a plug member that is fitted into a through - hole (not shown) penetrating in the plate - thickness direction of the bottom 111a1 and closes the through - hole from the sound collection side Y1.

[0021] The cap 112 is provided with a humidity-adjusting vent that communicates with the inside and outside of the sensor housing 111, and is configured to keep the humidity substantially the same inside and outside the sensor housing 111. At the edge of the receiving side Y2 of the through-hole into which the cap 112 is fitted, a sound-collecting substrate S is fixed so as to face the cap 112 in the height direction Y. That is, the sound-collecting substrate S is built into the sensor housing 111. The sound-collecting substrate S is a substrate on which a microphone element is mounted on the sound-collecting side Y1, and this microphone element is configured to detect sound propagated from the outside of the sensor housing 111. A cable connector 113 is attached to the lower side Z2 of the outer peripheral surface of the cylindrical portion 111a. This cable connector 113 is provided so as to be connected to the above-described relay cable 140, and an output voltage corresponding to the sound detected by the microphone element is sent to the control unit 130 via the relay cable 140.

[0022] The mounting flange 111b is a flange provided on the opening side (receiving side Y2) of the cylindrical portion 111a. This mounting flange 111b has side walls 111b1 extending in the height direction Y and is formed in a hollow thick plate shape that is substantially rectangular in a front view. At the four corners of the plate surface of the mounting flange 111b facing the height direction Y, holes (or female threads) 111b2 penetrating in the plate thickness direction are respectively formed, and through these holes 111b2, the mounting flange 111b is fixed to the back cover 121 by a fixing member such as a screw.

[0023] The back cover 121 is a member that closes the opening on the receiving side Y2 of the cylindrical portion 111a and the mounting flange 111b, and is formed in a rectangular plate shape. The dimension of the back cover 121 in the left-right direction X is set to be substantially the same as the dimension of the mounting flange 111b in the left-right direction X. The dimension of the back cover 121 in the up-down direction Z is set to be substantially the same as the dimension of the second piece portion 120b described later in the up-down direction Z. By fixing the mounting flange 111b to the back cover 121 as described above, the opening of the sensor housing 111 is closed. Therefore, this back cover 121 functions as a lid for preventing dust after installing the sound collecting substrate S inside the sensor housing 111, and for preventing sound diffraction and blocking sound transmission from the receiving side Y2 of the sound collecting substrate S. Female threads 121a penetrating in the plate thickness direction are formed at the four corners of the plate surface facing the height direction Y of the back cover 121, and a male screw member 122 is screwed into the female threads 121a via the second piece portion 120b.

[0024] In this embodiment, the eaves portion 111c is formed in an arc shape that is semi-circular when viewed from the front, and is disposed on the upper side Z1 of the cylindrical portion 111a. This eaves portion 111c extends in the height direction Y along the outer peripheral surface of the cylindrical portion 111a from the plate surface on the sound collecting side Y1 of the mounting flange 111b, and the dimension in the height direction Y thereof is set to be larger than the dimension in the height direction Y of the cylindrical portion 111a. With this configuration, the tip of the eaves portion 111c protrudes from the bottom 111a1 of the cylindrical portion 111a toward the sound collecting side Y1, and the eaves portion 111c functions as an eaves to prevent water and dust from entering the cylindrical portion 111a and contacting the sound collecting substrate S. Note that the shape of the eaves portion 111c is not limited to the arc shape that is semi-circular when viewed from the front as in this embodiment, and both ends in the left-right direction X may be continuous up to the lead-out portion of the cable connector 113, or may be a cylindrical shape that covers the entire outer peripheral surface of the cylindrical portion 111a. That is, the shape of the eaves portion 111c may be any eaves shape that can prevent rain and snow accumulation with respect to the humidity adjustment vent of the cap 112.

[0025] Side walls 111c1 having outer wall surfaces facing outward in the left-right direction X are formed at the left end X1 and the right end X2 of the eaves portion 111c. As shown in FIG. 6, the dimension W1 in the left-right direction X from the outer wall surface of the left side wall 111c1 to the outer wall surface of the right side wall 111c1 is formed to be smaller than the dimension W2 in the left-right direction X from the outer wall surface facing the left side X1 of the side wall 111b1 of the mounting flange 111b to the outer wall surface facing the right side X2. Thereby, a step 114 in the left-right direction X is formed between the side wall 111b1 of the mounting flange 111b and the side wall 111c1 of the eaves portion 111c.

[0026] On the central part in the left - right direction X of the wall surface facing the lower side Z2 of the eaves part 111c, there is a reinforcing rib 111c2 that protrudes toward the lower side Z2 and reinforces the eaves part 111c. That is, the reinforcing rib 111c2 is provided on the part of the eaves part 111c facing the sound - collecting substrate S side. The reinforcing rib 111c2 is a part that reinforces the eaves part 111c, increases its rigidity, and makes the eaves part 111c difficult to vibrate. Two reinforcing ribs 111c2 are formed at intervals in the left - right direction X. As shown in FIG. 4, they extend in the height direction Y from the bottom 111a1 of the cylindrical part 111a to the end of the sound - collecting side Y1 of the eaves part 111c. Since the reinforcing rib 111c2 is provided on the lower side Z2 of the eaves part 111c, it is difficult for the reinforcing rib 111c2 to be exposed outside the eaves part 111c. As a result, it is difficult for water, dust, etc. to accumulate between the eaves part 111c and the reinforcing rib 111c2, or between one reinforcing rib 111c2 and the other reinforcing rib 111c2.

[0027] It is desirable to set the protruding directions of one reinforcing rib 111c2 and the other reinforcing rib 111c2 to be parallel to each other and parallel to the vertical direction Z. For example, if the reinforcing ribs 111c2 are arranged to protrude radially, that is, in the radial direction, with respect to the center of the bottom 111a1 of the cylindrical part 111a, the reinforcing ribs 111c2 will be inclined with respect to the vertical direction Z, and rainwater, dust, etc. may accumulate on the inclined part. Also, it is more desirable to install the reinforcing rib 111c2 above the upper side Z1 in the vertical direction Z than the above - mentioned cap 112. With such a configuration, the reinforcing rib 111c2 can also function as an eaves, such as preventing rain from entering the above - mentioned humidity - adjusting vent.

[0028] A part of the sensor housing 111 configured as described above comes into contact with the inner surface of the horn 13a when the sound pressure measuring device 100 is fixed to the speaker 13. Specifically, as shown in FIG. 6, the outer wall surface of the side wall 111c1 on the left side X1 of the eaves portion 111c is such that when the sound pressure measuring device 100 is fixed to the speaker 13, the portion located on the sound collecting side Y1 (the back side) of the horn 13a can come into contact with the inner surface of the horn 13a, and this portion constitutes the first contact portion A. Also, the upper side Z1 and the lower side Z2 of the outer wall surface of the side wall 111b1 of the mounting flange 111b facing the left side X1 are located on the receiving side Y2 (the front side) of the horn 13a when the sound pressure measuring device 100 is fixed to the speaker 13, and can come into contact with the inner surface of the horn 13a, and this portion constitutes the second contact portion B. That is, the sensor housing 111 is provided with a first contact portion A located on the sound collecting side Y1 (the back side) of the horn 13a and a second contact portion B located on the receiving side Y2 (the front side) of the horn 13a so as to be able to come into contact with the inner surface of the horn 13a.

[0029] Note that due to the relationship between the above-described dimension W1 and dimension W2, the second contact portion B is located on the left side X1 (the side of the first piece portion 120a described later) rather than the first contact portion A. For this reason, the above-described step 114 is a step such that the second contact portion B is located on the left side X1 (the first piece portion 120a side) rather than the first contact portion A. Also, due to the above-described positional relationship between the first contact portion A and the second contact portion B, when the sound pressure measuring device 100 is attached to the speaker 13, as shown in FIG. 5, the sound pressure measuring device 100 is supported with respect to the horn 13a by three points (three ranges), namely, the second contact portion B, the first contact portion A, and the second contact portion B, extending from the upper side Z1 to the lower side Z2 of the horn 13a. Also, as shown in FIG. 6, the sound pressure measuring device 100 is supported with respect to the horn 13a by three points (three ranges), namely, the first contact portion A, the tip portion 124a (the tip) of the hexagonal bolt 124 (screw member) described later, and the second contact portion B, extending from the sound collecting side Y1 to the receiving side Y2 of the horn 13a.

[0030] The holding part 120 is an integral part with an L-shaped cross-section formed by bending and connecting a plate-shaped first piece part 120a extending in the height direction Y and a plate-shaped second piece part 120b extending in the left-right direction X. The first piece part 120a is formed in a rectangular shape that is long in the up-down direction Z, and as shown in FIG. 2, it is provided so as to be located outside the horn 13a when the sound pressure measuring device 100 is fixed to the speaker 13. The plate surface of the first piece part 120a facing the right side X2 is opposed to the left side X1 part of the sensor housing 111 in the left-right direction X. At the center of the first piece part 120a in the up-down direction Z and between the above-described first contact part A and second contact part B in the height direction Y, as shown in FIGS. 3 and 4, a female screw 120a1 having the same screw size as a later-described hexagonal bolt 124 that penetrates in the left-right direction X (plate thickness direction) is formed to penetrate. A nut 123 having a female screw with substantially the same diameter as the female screw 120a1 is arranged at the edge on the left side X1 in the penetration direction of the female screw 120a1, and the hexagonal bolt 124 is tightened to this nut 123. That is, by combining the hexagonal bolt 124, the female screw 120a1 of the first piece part 120a, and the nut 123, it functions as a double nut for preventing loosening of the hexagonal bolt 124.

[0031] The hexagonal bolt 124 is configured such that by adjusting the tightening degree with respect to the female thread 120a1 of the first piece portion 120a, its tip 124a can be brought closer to or separated from the left side X1 portion of the sensor housing 111. Since the position where the female thread 120a1 is formed is as described above, when the sound pressure measuring device 100 is fixed to the speaker 13, as shown in FIG. 6, between the first contact portion A and the second contact portion B, the tip of the hexagonal bolt 124 abuts against the outer surface of the horn 13a and presses against the outer surface. And by this pressing, the holding portion 120 is fixed to the horn 13a. The shape of the tip 124a of the hexagonal bolt 124 may be formed in a so-called R shape such as a socket nut or a round tip, or may be configured to have a flat surface and thus have a so-called flat shape. However, by configuring it to have a flat surface, it becomes possible to bring the outer periphery of the tip 124a into line contact with the outer surface of the horn 13a, and the pressing force of the hexagonal bolt 124 can be increased. Therefore, from the viewpoint of stably maintaining the state where the sound pressure measuring device 100 is fixed to the horn 13a, it is desirable to have a flat shape. And after the sound pressure measuring device 100 is fixed to the horn 13a, by tightening the nut 123, a reliable fixing without looseness can be performed with respect to the horn 13a.

[0032] The second piece portion 120b is formed in a rectangular shape that is long in the left-right direction X, and is arranged such that the plate surface facing the sound collecting side Y1 is parallel to the plate surface facing the receiving side Y2 of the mounting flange 111b. As shown in FIG. 2, this second piece portion 120b extends inward in the left-right direction X from the opening edge 13b of the horn 13a in a state where the sound pressure measuring device 100 is fixed to the speaker 13. A female thread (not shown) is formed in the second piece portion 120b at a position coaxial with the female thread 121a formed in the back cover 121, and a male thread member 122 is screwed into this female thread from the receiving side Y2. The sound pressure sensor 110 is fixed to the holding portion 120 configured in this way via the back cover 121.

[0033] In the sound pressure measurement device 100 described above, the holding part 120 integrated with the sound pressure sensor 110 is attached to the horn 13a of the speaker 13 by tightening the hexagon bolt 124. At this time, the sound pressure measurement device 100 is fixed to the speaker 13 by sandwiching the horn 13a between the first piece part 120a of the holding part 120 and the sensor housing 111. Specifically, a part 13c of the opening edge 13b of the horn 13a in the speaker 13 is pressed at three points (three ranges), namely, the tip part 124a of the hexagon bolt 124, the first contact part A, and the second contact part B, and the sound pressure measurement device 100 is fixed to the speaker 13 in a state of being supported at these three points. Then, as shown in FIG. 1, the control unit 130 fixed to the columnar object 11 and the sound pressure sensor 110 held by the holding part 120 are connected by the relay cable 140, and the relay cable 140 is fixed to the columnar object 11 by the fastening member 141. Through these series of operations, the installation of the sound pressure measurement device 100 is completed.

[0034] According to the sound pressure measurement device 100 of the present embodiment, the holding part 120 is composed of an integral part with an L-shaped cross section where the first piece part 120a and the second piece part 120b are continuous, and the sound pressure sensor 110 is fixed to the second piece part 120b. For this reason, there is no need to use parts such as a connecting plate for attaching the sound pressure sensor 110, and the number of parts of the holding part 120 can be reduced accordingly. And the sound pressure measurement device 100 is fixed by sandwiching a part 13c of the opening edge 13b of the horn 13a between the first piece part 120a of the holding part 120 and the sensor housing 111 fixed to the second piece part 120b of the holding part 120 and having a part in contact with the inner surface of the horn 13a. In this way, since the sensor housing 111 constituting the sound pressure sensor 110 is directly in contact with the horn 13a, compared with a device having a structure in which the sound pressure sensor 110 is likely to vibrate when it is attached away from the clamp, the generation of vibration in the sound pressure sensor 110 can be suppressed. Therefore, it is possible to provide the sound pressure measurement device 100 that can reduce the number of parts of the holding part 120 and suppress the occurrence of measurement errors by making the sound pressure sensor 110 less likely to vibrate.

[0035] Further, according to the present embodiment, by tightening the hexagon bolt 124 (screw member) penetrating the first piece portion 120a, the tip portion 124a (tip) of the hexagon bolt 124 can be pressed against the outer surface of the horn 13a, and the holding portion 120 can be fixed to the horn 13a. Therefore, the sound pressure measurement device 100 can be firmly attached to the speaker 13. Further, the sensor housing 111 is provided with a first contact portion A located on the sound collecting side Y1 (rear side) of the horn 13a and a second contact portion B located on the receiving side Y2 (front side) of the horn 13a so as to be able to contact the inner surface of the horn 13a. On the other hand, the tip portion 124a of the hexagon bolt 124 penetrating the first piece portion 120a is in contact with the outer surface of the horn 13a between the first contact portion A and the second contact portion B. Therefore, the sound pressure measurement device 100 can be supported with respect to the horn 13a by three points (three ranges) of the first contact portion A, the tip portion 124a of the hexagon bolt 124, and the second contact portion B from the sound collecting side Y1 to the receiving side Y2 of the horn 13a, so that the state in which the sound pressure measurement device 100 is fixed to the horn 13a can be stably maintained.

[0036] Further, by providing the step 114 in the sensor housing 111, the first contact portion A and the second contact portion B located on the first piece portion 120a side with respect to the first contact portion A can be configured, so that the sensor housing 111 can have a simple shape. For this reason, for example, when the sensor housing 111 is resin molded, it can be formed in a shape without an undercut, and the mold used for molding the sensor housing 111 can be a simple one such as an upper and lower mold that does not require a slide.

[0037] Further, the sensor housing 111 is provided with a shielding portion 111c that covers the sound collecting substrate S (sensor body), so that the shielding portion 111c can prevent water and dust from entering the cylindrical portion 111a and contacting the sound collecting substrate S. Further, since the shielding portion 111c is in contact with the inner surface of the horn 13a, the sound pressure measurement device 100 can be fixed to the horn 13a via the shielding portion 111c.

[0038] Also, at the center in the left - right direction X of the wall surface facing the lower side Z2 of the eaves portion 111c, two reinforcing ribs 111c2 that protrude toward the lower side Z2 and reinforce the eaves portion 111c are formed at intervals in the left - right direction X. Therefore, the eaves portion 111c can be reinforced by the two reinforcing ribs 111c2, and its rigidity can be increased, so that the eaves portion 111c can be made less likely to vibrate. Thus, it is possible to suppress the occurrence of an error in the measured value of the sound pressure due to the vibration of the eaves portion 111c. Further, since this reinforcing rib 111c2 is provided at a portion of the eaves portion 111c facing the sound - collecting substrate S side, it is difficult for the reinforcing rib 111c2 to be exposed, and it is possible to prevent water, dust, etc. from accumulating between the eaves portion 111c and the reinforcing rib 111c2 or between one reinforcing rib 111c2 and the other reinforcing rib 111c2.

[0039] Furthermore, as described above, by using the speaker 13 as an alarm for the level crossing 1, where the demand for measuring the sound pressure at any time is high and the installation locations are numerous, as an object for installing the sound - pressure measuring device 100, the effect of reducing the above - mentioned number of parts can be effectively utilized, and an alarm function inspection system can be configured at low cost. Also, the speaker 13 is likely to vibrate due to vibrations when a train or a vehicle passes by, rain, wind, speaker sound, etc. However, since the sound - pressure measuring device 100 of the present invention can make the sound - pressure sensor 110 less likely to vibrate as described above, the resonance of the sound - pressure sensor 110 can be reduced, the measurement error of the sound pressure can be suppressed, and an alarm function inspection system can be configured.

[0040] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention. For example, in the present embodiment, the back cover 121 that closes the opening of the sensor housing 111 is formed in a rectangular shape, and the dimension in the vertical direction Z thereof is set to be substantially the same as the dimension in the vertical direction Z of the second piece portion 120b of the holding portion 120. That is, the dimension in the vertical direction Z of the back cover 121 is set to be larger than the dimension in the vertical direction Z of the mounting flange 111b. Then, the sensor housing 111 is fixed to the holding portion 120 via the back cover 121. However, since the back cover 121 is not essential as a support function for supporting the sound pressure measuring device 100 when the sound pressure measuring device 100 is fixed to the speaker 13, the shape and size of the back cover 121 are not limited to the shape and size of the present embodiment.

[0041] For example, the mounting flange 111b may be formed in a cylindrical shape, a female thread may be provided on its inner peripheral surface, and the back cover 121 may be configured to have a male thread that engages with the female thread on its outer peripheral surface. Examples of such a back cover 121 include a screw-in cover in which the receiving side Y2 of the mounting flange 111b is flat. Further, a groove may be provided on one of the inner peripheral surface of the mounting flange 111b and the outer peripheral surface of the back cover 121, and a rib that fits into the groove may be provided on the other, and the opening of the sensor housing 111 may be closed with a cap-shaped back cover 121 that is fixed by the fitting of the groove and the rib.

[0042] Furthermore, it is also possible to omit the back cover 121 itself and directly fix the mounting flange 111b to the second piece portion 120b. However, the sound pressure measuring device 100 fixed to the speaker 13 as an alarm device for the level crossing 1 may be disassembled by separating the sensor housing 111 and the holding portion 120 for reasons such as changing the pulling-out direction of the cable connector 113 (in this embodiment, the lower side Z2) at the site where the level crossing 1 is installed. In this case, in the configuration where the back cover 121 is omitted, the inside of the sensor housing 111 communicates with the outside through the opening, and there is a risk that water and dust may come into contact with the microphone element of the sound collecting substrate S. Therefore, as a dust-proof measure for the inside of the sensor housing 111, it is desirable to provide the back cover 121.

Explanation of Signs

[0043] S Sound collecting substrate (sensor body) 100 Sound pressure measuring device 13 Speaker 13a Horn 13b Opening edge 13c Part (a part) 110 Sound pressure sensor 111 Sensor housing 120 Holding portion 120a First piece portion 120b Second piece portion

Claims

1. A sound pressure sensor that measures the sound pressure of the sound emitted by a speaker, and a holding part that holds the sound pressure sensor facing the inside of the horn of the speaker, characterized in that, the holding part is composed of an integral part having a cross-sectional L-shape in which a first piece part and a second piece part are bent and continuous, the first piece part is located outside the horn, and the second piece part extends inward from the opening edge of the horn, the sound pressure sensor has a sensor main body and a sensor housing that houses the sensor main body, and the sensor housing is fixed to the second piece part, the sensor housing and the first piece part are fixed so as to sandwich a part of the horn, and a part of the sensor housing is in contact with the inner surface of the horn. A sound pressure measurement device characterized by this.

2. The holding part has a screw member that penetrates the first piece part, and is fixed to the horn by tightening the screw member and pressing the tip thereof against the outer surface of the horn. The sound pressure measurement device described in 1.

3. The sensor housing is provided with a first contact part located on the back side of the horn and a second contact part located on the front side of the horn so as to be able to contact the inner surface of the horn, The sound pressure measurement device according to claim 2, characterized in that the tip of the screw member is in contact with the outer surface of the horn between the first contact part and the second contact part.

4. The sensor housing has a step such that the second contact part is located closer to the first piece part side than the first contact part. The sound pressure measurement device described in 3.

5. The sensor housing has a cover part that covers the sensor main body, and the cover part is in contact with the inner surface of the horn. The sound pressure measurement device according to any one of claims 1 to 4.

6. The sound pressure measurement device according to claim 5, characterized in that a reinforcing rib for reinforcing the cover part is provided on a part of the cover part facing the sensor main body side.

7. The sound pressure measurement device according to any one of claims 1 to 6, characterized in that the speaker is an alarm installed at a railway level crossing.

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