JP2009122272A - Electric horn - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric horn capable of suppressing degradation of sound pressure, and capable of preventing intrusion of a foreign substance, such as waterdrop. <P>SOLUTION: In the electric horn 1, intrusion preventing plates 26 having permeability, which prevent that the foreign substance intrudes inside a ventilation path 25c (inside a trumpet 25), are arranged so as to face each other via a gap which is set at an output section 25b of the trumpet 25 beforehand. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric horn (alarm).

  The electric horn generates sound pressure by a diaphragm that vibrates due to electromagnetic force, and emits sound (such as a horn) through a trumpet. That is, the vibration of air generated by the diaphragm is transmitted to the outside of the electric horn through the ventilation path inside the trumpet.

  The electric horn is attached to a vehicle, for example. In this case, water droplets such as rain water, splashes during traveling, or water flow during high-pressure car washing may enter the inside of the trumpet from the outlet of the trumpet. If these foreign substances enter the trumpet, the sound pressure or the like may change, causing problems such as temporarily reducing the sound.

Therefore, Japanese Utility Model Laid-Open No. 5-71045 (Patent Document 1) discloses an air horn that can prevent intrusion of water droplets. This air horn has a configuration in which a plate-like cap having the same shape as the output end is covered at a predetermined interval on the output end of the resonator.
Japanese Utility Model Publication No. 5-71045

  However, in the air horn, since the plate-like cap is put on the output end, the opening of the outlet portion (output end) of the air passage is very small. That is, in the air horn, the cap itself is a large resistance for sound transmission. As a result, the generated sound pressure was greatly reduced by the cap. In particular, there is a problem that the sound pressure is significantly reduced in front of the output end cap.

  When an electric horn is used as a horn, a horn sound is very important in a transportation society, such as informing a danger. In other words, the decrease in sound pressure must be suppressed as much as possible. In addition, it is required to prevent water droplets and the like from entering.

  In the air horn, in order to reduce the decrease in sound pressure, it is conceivable to increase the distance between the output end and the cap. However, when the interval is increased, there is a problem that water droplets or the like easily enter.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electric horn that can suppress a decrease in sound pressure and prevent entry of foreign matters such as water droplets.

  The electric horn of the present invention includes a horn housing, a diaphragm having an outer peripheral end fixed to the horn housing, an outer peripheral end fixed to the horn housing, disposed opposite to the diaphragm, and having an opening at the center. A front cover, a trumpet that defines at least a part of an air passage whose one end is connected to the opening, and an inlet portion that includes one end of the air passage and an outlet portion that includes the other end, and the center portion of the diaphragm A movable iron core fixed to the movable iron core, a fixed iron core arranged opposite to the movable iron core, a coil that attracts the movable iron core to the fixed iron core, a fixed contact provided in the coil energization circuit, and a fixed contact support that supports the fixed contact A normally closed movable contact that normally closes to the fixed contact, a movable contact support plate that supports the movable contact, and a pressing portion that is provided on the movable contact and presses the movable contact support plate. Koi When the movable iron core is attracted to the fixed contact by the electromagnetic force of the electric horn, it is an electric horn that presses the movable contact support plate by the pressing portion and separates the movable contact from the fixed contact. An intrusion prevention plate for preventing intrusion into the air passage is arranged opposite to the outlet portion of the trumpet via a preset interval.

  The electric horn of the present invention has an intrusion prevention plate that is disposed to face the trumpet outlet portion at a predetermined interval. The intrusion prevention plate can prevent foreign matter from entering the trumpet. Furthermore, the intrusion prevention plate has air permeability, and the portion exhibiting the air permeability allows sound emitted from the outlet portion of the trumpet to pass therethrough, so that a decrease in sound pressure can be suppressed.

  Here, the foreign matter is one that reduces the sound pressure when entering the trumpet, and examples thereof include rainwater, splashes during traveling of the vehicle, and water droplets caused by water flow during high-pressure car washing.

  The intrusion prevention plate may be any material that has air permeability and prevents intrusion of foreign matter, for example, a member provided in a mesh shape (net shape), a fence shape, a lattice shape, or a plurality of small ventilation holes. Is mentioned. A combination of these may also be used.

  The intrusion prevention plate is disposed to face the outlet portion of the trumpet with a gap. Due to this distance, a gap exists between the intrusion prevention plate and the outlet of the trumpet. The sound emitted from the exit portion passes through this gap. Thereby, as for the electric horn of this invention, the fall of a sound pressure is suppressed.

  Here, in the electric horn of the present invention, since the intrusion prevention plate has air permeability, the interval between the outlet portion and the intrusion prevention plate can be set smaller. That is, since the decrease in sound pressure is suppressed by the air permeability, the intrusion prevention plate can be arranged closer to the outlet portion of the trumpet. Therefore, the electric horn can be miniaturized. Furthermore, entry of foreign matter from a gap formed by the interval can be suppressed, and foreign matter can be further prevented from entering the ventilation path.

  In addition, the said space | interval can be suitably changed with the magnitude | size of an electric horn, an output, the structure of an intrusion prevention board, etc., and is not decided unconditionally. Preferably, it is 10 mm or less.

  Here, it is preferable that the intrusion prevention plate has a mesh portion. The mesh portion is a portion formed in a mesh shape (net shape). Since the mesh part is mesh-shaped, it has air permeability and prevents passage of foreign matter. When the intrusion prevention plate has a mesh portion, the mesh portion is preferably formed over substantially the entire surface of the intrusion prevention plate (the entire surface of the outlet portion).

  Here, the mesh size of the mesh part is more preferably 150 mesh or more. The mesh size is the number of meshes per square inch (unit: mesh / 2.54 cm). Thereby, the invasion of foreign matters can be prevented more reliably. As the mesh size becomes larger, the mesh becomes smaller, so that the passage of smaller foreign matters can be prevented.

  The mesh size of the mesh part is more preferably 300 mesh or less. As a result, the attenuation amount of the sound pressure becomes small. The smaller the mesh size, the larger the mesh area in the mesh portion, so the sound pressure attenuation by the mesh decreases. And since it becomes 250 mesh or less, the attenuation amount of a sound pressure can be 1 dB or less.

  Therefore, the mesh size of the mesh part is more preferably 150 mesh or more and 300 mesh or less. Thereby, the fall of a sound pressure can fully be suppressed and the penetration | invasion of a foreign material can be prevented more reliably. In addition, the said effect can be exhibited more reliably by making the mesh size of a mesh part into 200 meshes or more and less than 300 meshes.

  On the other hand, the intrusion prevention plate includes a plate-like first fence-like member having a plurality of first ventilation holes opened, and a plate-like second fence-like member having a plurality of second ventilation holes opened. The first fence-like member and the second fence-like member are arranged at an interval in a direction perpendicular to the direction in which the surface of the fence-like member spreads, with the first vent hole and the second vent hole not overlapping. May be good.

  As a result, the intrusion prevention plate has a configuration that does not have a portion penetrating in the vertical direction. In such a configuration, the foreign matter from the front hits a portion of the first fence-like member or the second fence-like member that is not a vent hole. As a result, the intrusion prevention plate can reliably prevent the intrusion of foreign matters from the front (vertical direction). And the clearance gap is provided between the 1st fence-shaped member and the 2nd fence-shaped member which each have a vent hole. Therefore, air can pass through each vent hole and interval of the intrusion prevention plate. That is, since the intrusion prevention plate has air permeability and can pass sound, it is possible to suppress a decrease in sound pressure.

  In this case, the first fence-like member and the second fence-like member may be formed by arranging a plurality of rod-like members so that their extending directions are parallel to each other. In this case, a space between adjacent rod-shaped members is a vent hole. Thereby, in addition to the said effect, an intrusion prevention board can be manufactured easily. According to this configuration, for example, in the production of the first fence-like member and the second fence-like member, it can be produced simply by arranging the rod-like members in parallel.

  As described above, the electric horn of the present invention is provided with the intrusion prevention plate, so that it is possible to suppress the decrease in sound pressure and more reliably prevent the entry of foreign matters.

  According to the electric horn of the present invention, it is possible to suppress a decrease in sound pressure and to prevent entry of foreign matters such as water droplets.

  Next, the present invention will be described in more detail with reference to embodiments. In this embodiment, a vehicle electric horn will be described as an example.

(First embodiment)
The electric horn 1 of the first embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view of the electric horn 1. FIG. 2 is a diagram showing the electric horn 1 viewed from the top of FIG. FIG. 3 is a view showing the intrusion prevention plate 26 viewed from the bottom of FIG.

  First, the overall configuration of the electric horn 1 will be described with reference to FIGS. 1 and 2. A horn housing 10 accommodates an electromagnet 12 that vibrates the diaphragm 11. In order to form part of the magnetic circuit of the electromagnet 12, the horn housing 10 and the diaphragm 11 are formed by pressing an iron-based magnetic material plate into a concave shape.

  The electromagnet 12 is provided with a coil 14 wound around a resin bobbin 13, and a lower part of a movable iron core 15 formed in a cylindrical shape is disposed in a central hole portion of the bobbin 13. The central portion of the diaphragm 11 is caulked and fixed to the small diameter portion 15 a at the top of the movable iron core 15. The outer peripheral end portion 11a of the diaphragm 11 is fastened and fixed to the flange portion 10a at the outer peripheral end portion of the horn housing 10 over the entire periphery.

  The outer peripheral end portion 24a of the front cover 24 is fastened and fixed to the flange portion 10a of the horn housing 10 so as to overlap the outer peripheral end portion 11a of the diaphragm 11 over the entire periphery. That is, the front cover 24 is disposed to face the diaphragm 11. An opening 24 a is provided at the center of the front cover 24.

  The lower outer peripheral end portion 25c of the trumpet 25 is fitted and fixed to the flange portion 10a of the horn housing 10 via the outer peripheral end portions 11a and 24a. The trumpet 25 is fixed to the front cover 24, and defines a ventilation path 25 c with the front cover 24. The trumpet 25 has an inlet portion 25a that defines a part of one end of the air passage 25c and an outlet portion 25b that defines the other end of the air passage 25c. The air passage 25c is partitioned in a spiral shape around the inlet 25a. The inlet 25a is connected to the opening 24a of the front cover 24, and the outlet 25b is opened outward from the inlet 25a.

  Therefore, the vibration of air transmitted from the opening 24a of the front cover 24 is transmitted outward through the air passage 25c. The air passage 25c has a so-called trumpet shape, and the flow passage cross-sectional area gradually increases from the inlet portion 25a toward the opening end of the outlet portion 25b. Further, an engagement groove (not shown) is provided on the outer peripheral surface of the outlet portion 25b of the trumpet 25. However, the shape and internal shape of the trumpet 25 are not limited to the above. Moreover, the exit part 25b may be opened toward the radial direction or axial direction of the spiral.

  The concave intermediate flat portion 10b of the horn housing 10 includes a protruding portion 13b protruding radially outward from the upper flange portion 13a of the bobbin 13, a movable contact support plate 17 made of a metal spring material, a fixed contact support plate 18, Insulating members 19 interposed between the two contact support plates 17 and 18 are laminated, and these members are caulked and fixed on the intermediate flat portion 10b by metal rivets 20.

  Here, the insulating member 19 is formed of a resin plate material, and is laminated on the upper surface of the movable contact support plate 17 over substantially the entire length of the movable contact support plate 17. The fixed contact support plate 18 is formed of a ferrous conductor metal that is relatively easily deformed, for example, a cold rolled steel plate (low carbon steel) plate material.

  A movable contact 17a is fixed to the movable contact support plate 17, and a fixed contact 18a is fixed to the fixed contact support plate 18, respectively. The movable contact 17a is a normally-closed contact that is crimped to the fixed contact 18a by a spring force generated by elastic deformation of the movable contact support plate 17 at normal times (when the coil 14 is not energized).

  A ring-shaped flange portion 15b protruding radially outward is integrally formed on the outer peripheral surface of the intermediate portion in the axial direction of the movable iron core 15 by cold forging or the like. The pressing part which presses the site | part near the horn center part among the movable contact support plates 17 is comprised.

  In the electric horn 1, when the movable iron core 15 is attracted to the fixed contact 18 a by the electromagnetic force of the coil 14, the movable contact support plate 17 is pressed by the flange portion 15 b (pressing portion) of the movable iron core 15. 17a is separated from the fixed contact 18a. As the movable iron core 15 vibrates, the diaphragm 11 vibrates, and air vibration is transmitted from the opening 24a of the front cover 24 to the inside of the trumpet 25 (air passage 25c).

  In the center hole of the bobbin 13 of the electromagnet 12, the fixed iron core 21 is disposed to face the lower end surface of the movable iron core 15 with a predetermined suction interval. The fixed iron core 21 is fixed to the center portion of the bottom surface portion 10c of the horn housing 10 by means such as caulking. The fixed iron core 21 is integrally formed with a male screw portion 21a that protrudes to the outside of the bottom surface portion 10c of the horn housing 10, and a mounting stay 22 to the vehicle body is fastened and fixed to the male screw portion 21a by a nut 23.

  One end portion of the coil 14 is electrically connected to a terminal piece of a connector portion (not shown) disposed outside the horn housing 10, and the other end portion of the coil 14 is electrically connected to the movable contact support plate 17. . The fixed contact support plate 18 is electrically connected to the horn housing 10 via a metal rivet 20, and is further grounded to the vehicle body of the vehicle via a fixed iron core 21 and a mounting stay 22 fixed to the horn housing 10. It has become.

  An intrusion prevention plate 26 is attached to the outlet portion 25 b of the trumpet 25 by a fixing portion 27. Here, the intrusion prevention plate 26 will be described with reference to FIGS. As shown in FIG. 3, the intrusion prevention plate 26 includes a mesh portion 26a and a frame portion 26b. The mesh portion 26a is a substantially square plate having a mesh provided on the entire surface, and the mesh size is 250 mesh.

  The frame portion 26b includes a frame-shaped portion 26c and a cross-shaped portion 26d. The frame-shaped portion 26c is a substantially rectangular frame shape slightly larger than the opening of the outlet portion 25b, and each vertex of the inner peripheral edge is gently curved. The cross-shaped portion 26d has a cross-like plate shape and is integrally provided on the inner peripheral edge of the frame-shaped portion 26c. The mesh part 26a is supported by the frame part 26b by clamping and bonding between the curved four corners of the frame-like part 26c and the cross-like part 26d.

  As shown in FIG. 2, the fixing part 27 has a plate-like part 27a and a claw part 27b. The plate-like portion 27a is plate-shaped, one end is connected to the frame-like portion 26c, and the other end is integrally connected to the claw portion 27b. The claw portion 27b is composed of two plate-like members, and one plate-like member is provided with a claw that protrudes toward the other plate-like member. The fixing portion 27 is provided on each of two opposing sides of the frame-like portion 26c toward the outlet portion 25b.

  The claw portion 27b of the fixed portion 27 sandwiches the outlet portion 25b of the trumpet 25 with two plate-like members and engages with an engagement groove (not shown). That is, the intrusion prevention plate 26 is disposed to face the outlet portion 25b of the trumpet 25 with a preset interval. In the first embodiment, this interval is set to 10 mm. As shown in FIG. 2, the intrusion prevention plate 26 is disposed so as to face the entire opening end of the outlet portion 25b.

  The mesh portion 26a has an excellent net function that allows air (sound) to pass therethrough and prevents entry of foreign matters such as water droplets. Therefore, the intrusion prevention plate 26 has air permeability and prevents intrusion of foreign matter into the trumpet 25 (inside the air passage 25c).

  Here, an example of attachment of the electric horn 1 to the vehicle will be described. For example, the electric horn 1 is attached to the vehicle in a state where the mounting stay 22 is on the upper side and the outlet 25b of the trumpet 25 is on the lower side. In this case, in this embodiment, the exit part 25b opens toward the vehicle lower side.

  Next, an optimal test for the mesh size of the mesh portion 26a will be described with reference to FIGS. FIG. 4 is a diagram showing the relationship between the mesh size (mesh) of the mesh portion 26a and the sound pressure (dB (A)). FIG. 5 is a diagram showing the relationship between the mesh size (mesh) of the mesh portion 26a and the sound pressure attenuation amount (dB (A)).

  The optimum test is performed by changing the mesh size of the mesh portion 26a. First, the sound pressure (dB (A)) at each mesh size is measured. In this sound pressure measurement, the distance between the sound pressure measuring instrument and the opening end of the outlet portion 25b of the trumpet 25 is 2 m. The measured value of the sound pressure is shown as an average value of two measurements. Moreover, the space | interval of the intrusion prevention board 26 and the opening end of the exit part 25b is 10 mm. The measurement is performed under the same conditions as in the sound pressure measurement test prescribed for mounting on a vehicle.

  As shown in FIG. 4, the sound pressure without the intrusion prevention plate 26 is 111.5 (dB (A)). And in 150 mesh, it will be 111 (dB (A)). With 175 mesh, it is 110.9 (dB (A)). With 200 mesh, it is 110.75 (dB (A)). With 250 mesh, it is 110.65 (dB (A)). With 300 mesh, it is 110.1 (dB (A)). In the case of only the frame portion 26b (the state where there is no mesh portion 26a), the sound pressure is 111.19 (dB (A)). Thus, it can be seen that the sound pressure decreases as the mesh size increases.

  Here, the sound pressure attenuation amount in each mesh size is as shown in FIG. That is, in the case of only the frame portion 26b, it is 0.31 (dB (A)). With 150 mesh, it is 0.5 (dB (A)). With 175 mesh, it is 0.6 (dB (A)). With 200 mesh, it is 0.75 (dB (A)). With 250 mesh, it is 0.85 (dB (A)). With 300 mesh, it is 1.40 (dB (A)). Thus, it can be seen that the sound pressure attenuation increases as the mesh size increases.

  In addition, since the sound pressure is determined by legal regulations, it is desirable that the sound pressure attenuation amount due to the installation of the intrusion prevention plate 26 be as small as possible. Therefore, the mesh size of the mesh portion 26a is more preferably 250 mesh or less. Thereby, the sound pressure attenuation can be suppressed to 1 dB or less.

  Subsequently, a foreign substance intrusion test is performed at each mesh size. This test is performed by spraying a high-pressure water flow (80 MPa) toward the intrusion prevention plate 26 of the electric horn 1. The high-pressure water flow source is disposed opposite to the intrusion prevention plate 26 with an interval of 0.5 m. The penetration test is performed on the assumption that the foreign substance is most likely to be penetrated during high-pressure cleaning. Here, the nozzle of the high-pressure car wash machine is the high-pressure water flow source.

  According to this test, when the mesh size was 250 mesh or more, water droplets did not penetrate into the inside of the trumpet 25 (ventilation passage 25c), and foreign matter could be prevented more reliably. In addition, even if it was 150, 175, 200 mesh, the function which prevents the penetration | invasion of a foreign material was exhibited, and the prevention precision improved, so that it approached 250 mesh.

  As described above, according to the sound pressure measurement and the penetration test, the mesh size is preferably 300 mesh or less from the viewpoint of sound pressure attenuation, and is preferably 150 mesh or more from the viewpoint of preventing foreign matter penetration. That is, it is preferable to set the mesh size of the mesh portion 26a to 150 mesh or more and 300 mesh or less.

  More preferably, the mesh size is 200 mesh or more and 250 mesh or less. By doing so, a decrease in sound pressure is sufficiently suppressed and entry of foreign matter is more reliably prevented. Further, from FIG. 5, it is considered that there is a mesh size in which the sound pressure attenuation amount is 1 dB or less even when the mesh size is larger than 250 mesh and smaller than 300 mesh. In this case, the same effect as described above can be obtained. That is, the mesh size is more preferably around 250 mesh (200 mesh or more and less than 300 mesh). Here, in the intrusion prevention plate 26 of the first embodiment, the mesh size of the mesh portion 26a is 250 mesh, and it is possible to sufficiently suppress the decrease in sound pressure and more reliably prevent the entry of foreign matter.

  According to the electric horn 1 of the first embodiment, by providing the intrusion prevention plate 26 at the outlet portion 25b of the trumpet 25, the decrease in sound pressure is suppressed and the intrusion of foreign matter into the air passage 25c is prevented. be able to.

  In addition, the arrangement | positioning method of the intrusion prevention board 26 is not restricted above. In other words, the fixing portion 27 may be any member as long as the intrusion prevention plate 26 is disposed so as to be opposed to the outlet portion 25b through a predetermined interval. Further, for example, the intrusion prevention plate 26 may be fixed to the outlet portion 25b. In this case, the fixing part 27 is formed in the outlet part 25b. Even in this case, the same effects as described above can be obtained.

  In addition, the interval between the intrusion prevention plate 26 and the opening end of the outlet portion 25b can be changed by setting. Since the intrusion prevention plate 26 has air permeability, the interval can be reduced. Therefore, it is possible to reduce the size of the electric horn 1 and further prevent foreign substances from entering.

(Second embodiment)
The electric horn of the second embodiment is obtained by changing the shape of the intrusion prevention plate 26 of the electric horn 1 of the first embodiment. Therefore, it is the same as that of the electric horn 1 except for the intrusion prevention plate. Here, the intrusion prevention plate 126 of this embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a view similar to FIG. 7 is a cross-sectional view taken along line AA in FIG.

  As shown in FIGS. 6 and 7, the intrusion prevention plate 126 includes a first fence-like member 130, a second fence-like member 140, and a connection portion 150. The first fence-like member 130 is a plate-like member having a plurality of first vent holes 132 opened. Specifically, the first fence-like member 130 is formed such that the extending directions of the rod-shaped members 131 are parallel in a state where the plurality of strip-shaped rod-shaped members 131 are equally spaced at the same interval as the width of the strips. . The second fence-like member 140 is a plate-like member having a plurality of second ventilation holes 142 opened, and is formed in the same manner as the first fence-like member 130.

  The connection part 150 consists of two parallel rod-shaped members 151 and 152, and is fixing the 1st fence-shaped part 130 and the 2nd fence-shaped part 140 in the state which spaced apart. Specifically, one rod-like member 151 fixes one end side (the upper side in FIG. 6) of the first fence-like member 130 and one end side (the upper side in FIG. 6) of the second fence-like member 140, and the other rod-like member. 152 fixes the other end side (lower side in FIG. 6) of the first fence-like member 130 and the other end side (lower side in FIG. 6) of the second fence-like member 140. That is, the first fence-like member 130 and the second fence-like member 140 are arranged to face each other with an interval so that the rod-like members 131 and 141 are parallel to each other.

  Furthermore, the first vent hole 132 and the second vent hole 142 are arranged so as not to overlap each other in a direction perpendicular to the direction in which the surface of the first fence-shaped member 130 spreads (the vertical direction in FIG. 7). That is, in the direction perpendicular to the first fence member 130, the first vent hole 132 faces the rod member 141, and the second vent hole 142 faces the rod member 131. Here, it is more preferable that the rod-shaped member 131 and the rod-shaped member 141 partially overlap in a direction perpendicular to the first fence-shaped member.

  In addition, in 2nd embodiment, the fixing | fixed part 27 is provided in the rod-shaped member 131 of the both ends of the 1st fence-shaped member 130. As shown in FIG. And the fixing | fixed part 27 is fixing the intrusion prevention board 126 to the exit part 25b similarly to 1st embodiment.

  Thereby, the intrusion prevention plate 126 completely blocks the opening in a direction facing the opening of the outlet portion 25b, and more reliably prevents the intrusion of foreign matter. In particular, it exhibits an excellent intrusion prevention effect against the intrusion of foreign matter from the vertical direction of the intrusion prevention plate 126.

  Further, the intrusion prevention plate 126 can allow air to pass through the first vent hole 132, the second vent hole 142, and the distance between the first fence-like member 130 and the second fence-like member 140. Therefore, the intrusion prevention plate 126 has air permeability and can suppress a decrease in sound pressure.

  That is, according to the electric horn of the second embodiment, the intrusion prevention plate 126 can suppress a decrease in sound pressure and can further prevent foreign matter from entering the trumpet 25.

(Deformation)
Here, as an intrusion prevention plate of the electric horn 1, an intrusion prevention plate formed by combining the intrusion prevention plate 26 of the first embodiment and the intrusion prevention plate 126 of the second embodiment may be disposed. This may be a combination of the mesh portion 26a and the fence-like members 130 and 140.

  For example, an intrusion prevention plate formed by overlapping the intrusion prevention plate 26 and the intrusion prevention plate 126 may be used. Alternatively, the intrusion prevention plate may include the mesh portion 26 a and the first fence-like member 130, and the mesh portion 26 a may be provided in the first vent hole 132. The combination method is not limited to the above.

  Even in these modified forms, the electric horn 1 can suppress a decrease in sound pressure and can prevent foreign matter from entering the trumpet 25.

1 is a cross-sectional view of an electric horn 1. It is a figure which shows the electric horn 1 seen from the top of FIG. It is a figure which shows the intrusion prevention board 26 seen from the bottom of FIG. It is a figure which shows the relationship between the mesh size of the mesh part 26a, and sound pressure. It is a figure which shows the relationship between the mesh size of the mesh part 26a, and sound pressure attenuation amount. It is the figure shown similarly to FIG. It is sectional drawing in the AA of FIG.

Explanation of symbols

1: Electric horn,
10: Horn housing, 11: Diaphragm, 12: Electromagnet, 13: Bobbin, 14: Coil,
15: movable iron core, 17: movable contact support plate, 17a: movable contact, 18: fixed contact support plate,
18a: fixed contact, 19: insulating member, 20: metal rivet, 21: fixed iron core,
22: mounting stay, 23: nut, 24: front cover, 24a: opening,
25: trumpet, 25a: inlet part, 25b: outlet part,
26: Intrusion prevention plate, 26a: Mesh portion, 26b: Frame portion, 27: Fixed portion,
126: Intrusion prevention plate,
130: first fence-like member, 131: rod-like member, 132: first vent hole,
140: second fence-like member, 141: rod-like member, 142: second vent hole

Claims (4)

A horn housing,
A diaphragm having an outer peripheral end fixed to the horn housing;
A front cover having an outer peripheral end fixed to the horn housing, disposed opposite to the diaphragm, and having an opening at the center,
A trumpet that defines at least a part of a vent path whose one end is connected to the opening, and that defines an inlet portion formed from one end of the vent path and an outlet portion formed from the other end,
A movable iron core fixed to the center of the diaphragm;
A fixed iron core disposed opposite to the movable iron core,
A coil for sucking the movable iron core into the fixed iron core;
A fixed contact provided in the energization circuit of the coil;
A fixed contact support plate for supporting the fixed contact;
A normally closed movable contact that normally closes to the fixed contact;
A movable contact support plate for supporting the movable contact;
A pressing portion provided on the movable contact and pressing the movable contact support plate;
When the movable iron core is attracted to the fixed contact by the electromagnetic force of the coil, an electric horn that presses the movable contact support plate by the pressing portion and separates the movable contact from the fixed contact. ,
An electric horn characterized in that an intrusion prevention plate having air permeability and preventing foreign matter from entering the air passage is disposed opposite to the outlet portion of the trumpet with a predetermined interval. .   The electric horn according to claim 1, wherein the intrusion prevention plate has a mesh portion. The intrusion prevention plate is
A plate-like first fence-like member having a plurality of first ventilation holes opened;
A plate-like second fence-like member having a plurality of second ventilation holes opened;
Have
In a direction perpendicular to the direction in which the surface of the first fence-like member spreads, the first fence-like member and the second fence-like member are in a state where the first ventilation hole and the second ventilation hole do not overlap. The electric horn according to claim 1 or 2, wherein are arranged at intervals. 4. The electric horn according to claim 3, wherein the first fence-like member and the second fence-like member are formed by arranging a plurality of rod-like members in a state where their extending directions are parallel to each other.

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