JP2007248969A - Sound producing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sound producing device in which sound wave emitted from a sounding body is emitted outside of a casing with high efficiency. <P>SOLUTION: A sound releasing hole 5a of a piezoelectric buzzer 5 is faced to a wall section 4a of the casing 4 of a combination meter 1, and an aperture section 4b is provided facing the sound releasing hole 5a on the wall section 4a. With this configuration, the sound wave emitted from the sound releasing hole 5a of the piezoelectric buzzer 5 is directly propagated to the aperture section 4b, and further emitted outside of the casing 4 from the aperture section 4b. Thereby, the combination meter 1 in which the sound wave emitted from the piezoelectric buzzer 5 is emitted outside of the casing from the aperture section 4b with high efficiency, is attained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sounding device configured to blow a sounding body mounted on a printed circuit board, and is suitable for use in, for example, a vehicle instrument.

  As a conventional sound generator, for example, a sound generator is arranged in a case, and a hole is provided in the case to release sound of the sound generator to the outside, thereby forming a guide space for guiding the sound of the sound generator to the hole. There exists a thing of the structure (refer patent document 1).

In this case, the guide space is separated by a reflecting wall provided to face the sounding body.
JP 2000-172273 A

  In the case of a conventional sounding device, the sounding part that is the sound outlet of the sounding body arranged in the case does not face the hole that is the sound outlet of the case.

  That is, the sound wave radiated from the sounding part of the sounding body does not go directly to the hole of the case, but first travels toward the reflecting wall and propagates through the guide space while being repeatedly reflected by the reflecting wall. It reaches the part and propagates to the outside through the hole.

  According to this configuration, the sound wave radiated from the sounding part of the sounding body is attenuated while being repeatedly reflected by the reflecting wall, and the energy of sound radiated from the hole of the case to the outside, that is, the sound pressure level is lowered.

For this reason, it is necessary to employ a larger sounding body in order to make the driver surely perceive the sound produced by the sounding device, in other words, to set the sound pressure level of the sound from the sounding device at the driver's seat to a predetermined value. There is a problem that it is difficult for the driver to hear this sound, which causes a problem that the sound generating device is enlarged.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a sounding device that can emit sound waves emitted from a sounding body to the outside of the case with high efficiency.

  In order to achieve the above object, the present invention employs the following technical means.

  The sound producing device according to claim 1 of the present invention is a sound producing device including a printed circuit board, a sound producing body mounted on the printed circuit board, and a casing for housing the printed circuit board and the sound producing body. A sound emitting hole is provided in the side wall substantially orthogonal to the substrate, and an opening is provided in the wall portion of the casing facing the side wall of the sounding body so as to face the sound emitting hole.

  According to the above configuration, the sound emitting hole of the sounding body and the opening of the side wall of the casing face each other. For this reason, the sound wave radiated | emitted from the sound emission hole of the sounding body propagates directly to an opening part, and is further radiated | emitted from the opening part outside a casing.

  As a result, it is possible to provide a sounding device that can radiate sound waves emitted from the sounding body to the outside of the case with high efficiency.

  The sound producing device according to claim 2 of the present invention is characterized by comprising a partition member surrounding a space formed between the sound emitting hole of the sound producing body and the opening of the wall.

  Sound waves are emitted in a substantially conical shape from the sound emitting holes of the sounding body. That is, it is radiated in a conical shape in a space formed between the sound emitting hole of the sounding body and the opening of the wall. There is an opening in the wall on the extension of the central axis of the cone.

  Most of the sound wave radiated from the sound emitting hole of the sounding body reaches the opening of the wall directly and is radiated to the outside. On the other hand, the sound wave that does not go directly to the opening, that is, travels in a direction deviating from the opening, is reflected by the partition member and travels toward the opening of the wall.

  Therefore, the sound wave traveling in the direction warped from the opening can be reflected toward the opening of the wall by installing the partition member so as to surround the space.

  As a result, it is possible to provide a sounding device that can radiate sound waves emitted from the sounding body to the outside of the case with high efficiency.

  The sound producing device according to claim 3 of the present invention is characterized in that the partition member is installed in a portion from the sound emitting hole to the opening.

  Thereby, the sound wave emitted conically from the sound emitting hole of the sounding body can be advanced to the opening of the wall with high efficiency.

  In the sound producing device according to claim 4 of the present invention, the partition member is formed in a parabolic shape having an apex on the sound producing body side and opened toward the wall portion.

  According to such a configuration, it is possible to more effectively propagate the sound wave emitted from the sound emitting hole of the sounding body and traveling in the direction warped from the opening to the opening of the wall.

  In the sounding device according to claim 5 of the present invention, the sounding body includes a plate-like vibration element for generating sound waves, and the vibration element is parallel to the printed circuit board when the sounding body is mounted on the printed circuit board. It is characterized by that.

  According to such a configuration, the height of the sounding body on the printed circuit board, that is, the protruding length from the surface of the printed circuit board can be reduced, so that the physique of the casing, particularly the dimension in the thickness direction of the printed circuit board can be reduced. can do.

  In the sound producing device according to claim 6 of the present invention, the opening of the casing is arranged to face the vehicle interior wall surface.

  When the sounding device is mounted on a vehicle, it is necessary to arrange the sounding device to ensure that the sound emitted by the sounding device is heard by the driver. For example, when the sounding device is installed in a meter in front of the driver's seat of the vehicle, even if the opening of the casing is arranged facing the driver's seat, the dial of the instrument, a transparent cover, etc. Due to the arrangement, the sound waves from the sounding body are blocked by these obstacles, and the energy of the sound transmitted through them is greatly reduced.

  According to the configuration of the sound producing device according to claim 6 of the present invention, the sound wave radiated from the sound producing device can be reflected on the vehicle interior wall surface, and the reflected sound wave can be heard by the driver.

  As a result, even in a sounding device having a configuration in which the image projection member is placed outside the facing plate, the sound wave from the sounding body that has propagated to the surface side space of the dial is directed to the outside of the sounding device, that is, to the driver's seat. Can be propagated.

  As a result, it is possible to provide a sounding device that can radiate sound waves emitted from the sounding body to a predetermined location outside the case, that is, in the vehicle compartment with high efficiency.

  In the sound producing device according to claim 7 of the present invention, the casing is installed in front of the driver's seat of the vehicle, and the indoor wall surface is the side wall of the vehicle.

  According to such a configuration, the sound emitted by the sound producing device can be propagated with high efficiency so that the driver can hear it.

  Hereinafter, a case where the sounding device according to the present invention is applied to a combination meter 1 mounted on an automobile will be described with reference to the drawings.

  FIG. 1 is a partial front view of a combination meter 1 that is a sounding device according to an embodiment of the present invention, and shows a speedometer A section that displays the traveling speed of the automobile.

  2 is a cross-sectional view taken along line II-II in FIG. In FIG. 2, the left side is the driver's seat side, and the combination meter 1 is visually recognized from the left in FIG.

  3 is a cross-sectional view taken along line III-III in FIG.

  4 is a cross-sectional view taken along line IV-IV in FIG.

  The combination meter 1 is disposed in the instrument panel 10 in front of the driver's seat of the automobile so as to be visible from the driver, and displays various information related to the automobile including the running speed. The combination meter 1 also includes a piezoelectric buzzer 5 that is a sounding body. For example, when the state of an automobile needs to alert the driver, the combination meter 1 is electrically driven to emit sound waves. .

  Below, the structure of the combination meter 1 by one Embodiment of this invention is demonstrated.

  The dial 2 is formed of a light-transmitting material, for example, a thin plate such as a transparent polycarbonate resin or acrylic resin. Further, as shown in FIG. 1, the dial 2 has a scale 2a and a character 2b of the speedometer A. The scale 2a and the character 2b are formed by printing or hot stamping on the front surface (left surface in FIG. 2) or back surface (right surface in FIG. 2) of the dial plate 2. That is, a non-transparent colored layer or a semi-transparent colored layer is provided in a portion other than the scale 2a and the character 2b, and the scale 2a and the character 2b are kept transparent, or a semi-transparent colored layer is provided. Has been processed. Therefore, when the light emitting diode 11 disposed on the back side of the dial 2 is turned on, the dial 2 is transmitted and illuminated by the light emitted from the light emitting diode 11, and the scale 2a and the character 2b are lit and displayed in a dark background.

  As shown in FIG. 2, a printed circuit board 3 is disposed on the back side of the dial 2 (right side in FIG. 2). The printed board 3 is made of, for example, a glass epoxy board or the like, and forms an electric circuit portion of the combination meter 1. The printed circuit board 3 is provided with an electric conductor (for example, copper foil) on the surface of the dial 2 side (left side in FIG. 2) to form an electric circuit.

  As shown in FIG. 2, a light emitting diode 11 that is a light source for transmitting and illuminating the dial 2 is mounted on the printed circuit board 3.

  On the back side of the dial 2, a movement 12 for rotating a pointer 13 described later is disposed. The movement 12 is composed of an electric actuator such as a stepping motor or a cross coil type rotating machine. The rotation shaft 12a of the movement 12 is extended to the front side (the left side in FIG. 2) of the dial 2 through the through hole 2c of the dial 2, and the pointer 13 is fixed to the tip thereof. The movement 12 is driven to rotate the shaft by an angle corresponding to the traveling speed calculated based on a detection signal from a speed sensor (not shown), and the pointer 13 indicates the traveling speed on the dial 2.

  The pointer 13 is formed of a translucent material, such as acrylic resin, is fixed to the tip of the rotating shaft 12a of the movement 12, and rotates integrally with the rotating shaft 12a. The pointer 13 is lit and displayed by light emitted from the light emitting diode 14 mounted on the printed circuit board 3. A light shielding cap 15 is attached to a portion of the pointer 13 that is fixed to the rotating shaft 12 a so as to cover the through hole 2 c of the dial 2. The light shielding cap 15 is formed by resin molding or the like, and prevents the light emitted from the light emitting diode 14 from directly entering the driver's eyes through the through hole 2c and dazzling the driver.

  The dial 2 and the printed circuit board 3 described above are accommodated and held in the casing 4 as shown in FIG. The casing 4 is formed from a resin material.

  A lower cover 8 is disposed on the back side of the casing 4 (on the right side in FIG. 2) so as to cover the printed circuit board 3, in other words, so as to cover the opening behind the casing 4.

  As shown in FIG. 2, a facing plate 9 is disposed on the front side of the dial 2 (left side in FIG. 2), that is, on the front side of the casing 4. As shown in FIG. 2, a transparent cover 10 is disposed on the front side (left side in FIG. 2) of the facing plate 9. The transparent cover 10 is formed in a plate shape from a colorless and transparent polycarbonate resin or acrylic resin. The transparent cover 10 and the lower cover 8 described above prevent foreign matters (dust, water droplets, etc.) from entering the casing 4 and keep the inside of the casing 4 clean.

  As shown in FIG. 2, a piezoelectric buzzer 5 as a sounding body is mounted on the printed circuit board 3. The piezoelectric buzzer 5 includes a vibration plate (not shown) formed by laminating a thin plate of a piezoelectric element and a thin plate of metal or resin, and generates a sound wave by applying a voltage to the piezoelectric element to vibrate the vibration plate. is there. As the piezoelectric element, for example, a thin plate of lead zirconate titanate (PZT) is used. When a voltage is applied to both the front and back surfaces of the piezoelectric element and the polarity of the voltage is switched, the piezoelectric element expands and contracts and the diaphragm vibrates accordingly.

  In the piezoelectric buzzer 5 of the combination meter 1 according to one embodiment of the present invention, a diaphragm (not shown) is arranged in parallel with the printed circuit board 3, and the diaphragm vibrates in a direction orthogonal to the printed circuit board 3. Thereby, the protrusion length from the printed circuit board 3 surface of the piezoelectric buzzer 5 can be made small.

  The piezoelectric buzzer 5 is electrically driven by a control circuit (not shown) to emit a sound wave when a situation in which the driver should take some measures is detected by various sensors (not shown) included in the vehicle while the vehicle is running. It plays a role to call attention.

  As the piezoelectric buzzer 5 of the combination meter 1 according to the embodiment of the present invention, a surface mounting type is used, and the shape thereof is a flat rectangular parallelepiped. As shown in FIG. 2, the piezoelectric buzzer 5 is provided with a sound emission hole 5 a for radiating sound waves generated by the vibration of the diaphragm to the outside. As shown in FIG. 3, the sound emitting hole 5 a is formed in the side wall 5 b of the piezoelectric buzzer 5 that is substantially orthogonal to the printed circuit board 3. As shown in FIG. 2, the sound emitting hole 5a is formed in a long and narrow rectangle along the outer diameter shape of the side wall 5b. In the combination meter 1 according to the embodiment of the present invention, the piezoelectric buzzer 5 is mounted with the sound emission hole 5a facing the wall portion 4a of the casing 4 of the combination meter 1 as shown in FIG. When the combination meter 1 is mounted on an automobile, the wall 4a of the casing 4 substantially faces the indoor wall surface 7 that is the right side wall of the automobile, as shown in FIG. An opening 4 b is provided in the wall 4 a of the casing 4 at a position facing the sound emission hole 5 a of the piezoelectric buzzer 5. That is, the sound emitting hole 5a of the piezoelectric buzzer 5 and the opening 4b of the casing 4 are both open in the left-right direction, which is the width direction of the automobile. Moreover, the shape of the opening part 4b is formed in the rectangle larger than the sound emission hole 5a. In FIG. 3, the space between the wall 4a of the casing 4 and the interior wall surface 7 communicates with the interior space of the automobile, for example, the space including the driver's seat.

  On the printed circuit board 3, a sound guide member 6, which is a partition member, is installed between the sound emission hole 5 a of the piezoelectric buzzer 5 and the opening 4 b of the wall portion 4 a.

  The sound guide member 6 is formed of, for example, a resin molded product or a metal plate pressed product. The sound guide member 6 is formed in a groove shape having a substantially U-shaped cross section, and the surfaces 6a and 6b, which are both side walls of the groove-like sound guide member 6, have a point P as shown in FIG. It is formed in a parabolic shape with the apex as the apex. As shown in FIG. 4, the sound guide member 6 has a point P, which is the apex of the parabola forming the surfaces 6a and 6b, on the printed circuit board 3 as the piezoelectric buzzer 5 side, and the side where the parabola is open is the wall 4a. On the side, a surface 6c corresponding to the bottom surface of the groove is arranged substantially parallel to the printed circuit board 3 as shown in FIG. Thereby, the space between the sound emission hole 5 a and the opening 4 b is surrounded by the sound guide member 6.

  Next, the characteristics of the combination meter 1 according to the embodiment of the present invention configured as described above, that is, the sound emission hole 5a of the piezoelectric buzzer 5 is opposed to the wall portion 4a of the casing 4 of the combination meter 1, and the wall The piezoelectric buzzer 5 is mainly used for the operational effect of the configuration in which the opening 4b is provided in the portion 4a so as to face the sound emission hole 5a and the sound guide member 6 is disposed in the space between the sound emission hole 5a and the opening 4b. The state of sound propagation will be described.

  First, in the structure of the conventional sound producing device, the sound emitting hole of the sound producing body is not provided facing the hole of the case, and the sound wave radiated from the sound producing part does not go directly to the hole of the case. First, the light travels toward the reflection wall in the case, propagates while repeating reflection on the reflection wall, reaches the hole of the case, and propagates to the outside through the hole. According to this configuration, the sound wave radiated from the sounding part of the sounding body is attenuated while it is repeatedly reflected by the reflecting wall, and the energy of the sound emitted from the hole of the case to the outside, that is, the sound pressure level is reduced. There's a problem.

  On the other hand, in the combination meter 1 according to the embodiment of the present invention, the sound emitting hole 5a of the piezoelectric buzzer 5 is opposed to the wall portion 4a of the casing 4 of the combination meter 1, and the wall portion 4a is opposed to the sound emitting hole 5a. The opening 4b is provided.

  With such a configuration, the sound wave radiated from the sound emitting hole 5a of the piezoelectric buzzer 5 propagates directly to the opening 4b as shown by an arrow in FIG. 3, and is further radiated from the opening 4b to the outside of the casing 4. The

  Therefore, the combination meter 1 that can radiate sound waves emitted from the piezoelectric buzzer 5 from the opening 4b to the outside of the casing with high efficiency can be realized.

  In the combination meter 1 according to the embodiment of the present invention, the sound guide member 6 is formed on the printed circuit board 3 so as to surround the space between the sound emitting hole 5a of the piezoelectric buzzer 5 and the opening 4b of the wall 4a. Is installed. Further, two opposing surfaces of the sound guide member 6 are formed in a parabolic shape, the surface 6a and the surface 6b, and the surface 6a and the surface 6b have a parabola vertex at the piezoelectric buzzer 5 side and a parabola open side as a wall portion. Arranged as the 4a side.

  Thus, the sound wave traveling in a direction other than the direction toward the opening 4b of the wall 4a among the sound radiated in a conical shape from the sound emitting hole 5a of the piezoelectric buzzer 5 is indicated by an arrow in FIG. Moreover, it can be reflected by the sound guide member 6 and can be advanced toward the opening 4b. In particular, by forming the surfaces 6a and 6b in a parabolic shape, as shown in FIG. 4, the sound waves emitted from the sound emitting holes 5a of the piezoelectric buzzer 5 and incident on the surface 6a or the surface 6b are emitted from the sound emitting holes 5a. Can be reflected in a direction parallel to the direction connecting the opening 4b. Further, among the sounds radiated in a conical shape from the sound emission holes 5a of the piezoelectric buzzer 5, sound waves that travel in directions other than the direction toward the opening 4b of the wall 4a are indicated by arrows in FIG. The light can be reflected by the surface 6c of the sound guide member 6 and the printed circuit board 3 and can be advanced toward the opening 4b.

  Thereby, the combination meter 1 which can radiate | transmit the sound wave emitted from the piezoelectric buzzer 5 out of the casing from the opening part 4b with high efficiency is realizable.

  Moreover, in the combination meter 1 by one Embodiment of this invention, the opening part 4b provided in the wall part 4a of the casing 4 is arrange | positioned facing the indoor wall surface 7 which is a right side wall of a motor vehicle. That is, the space sandwiched between the wall portion 4a of the casing 4 and the indoor wall surface 7 communicates with the indoor space of the automobile, for example, the space including the driver's seat.

  Therefore, the sound wave emitted from the piezoelectric buzzer 5 and emitted from the opening 4b to the outside of the combination meter 1 is reflected by the indoor wall surface 7 as indicated by an arrow in FIG. Proceed to

  Thereby, the sound wave emitted from the piezoelectric buzzer 5 can be propagated to the driver with high efficiency.

  Moreover, in the combination meter 1 by one Embodiment of this invention, both the sound emission hole 5a of the piezoelectric buzzer 5 and the opening part 4b of the casing 4 are opened in the left-right direction which is the width direction of a motor vehicle.

  According to this configuration, foreign matters such as dust and water droplets are less likely to enter the piezoelectric buzzer 5 as compared with the case where the opening and the sound emission hole are opened upward of the automobile.

  Therefore, foreign matter such as dust and water droplets can be prevented from entering the piezoelectric buzzer 5 through the opening 4b and the sound emission hole 5a.

  In addition, in the combination meter 1 by one Embodiment of this invention demonstrated above, although the surface 6a and the surface 6b of the sound guide member 6 are formed in the parabola shape, it is not necessary to limit to a parabola shape, Other shapes For example, it may be formed linearly. In this case, the surface 6a and the surface 6b may be arranged in parallel to each other or so that the distance between the surfaces 6a and 6b increases from the piezoelectric buzzer 5 toward the opening 4b of the casing 4 (for example, in a C shape).

  Moreover, in the combination meter 1 by one Embodiment of this invention demonstrated above, although the sound guide member 6 is formed in groove shape, that is, it is formed so that it may be provided with three surfaces 6a, 6b, 6c, It is not necessary to limit to groove shape, and it is good also as a structure provided with at least 1 among the surface 6a, the surface 6b, and the surface 6c.

  In the combination meter 1 according to the embodiment of the present invention described above, the piezoelectric buzzer 5 using a piezoelectric element is used as a sounding body. However, the present invention is not limited to this type, and other types of sounding bodies. It may be. For example, an electromagnetic buzzer or a small speaker may be used.

  Further, in the above-described embodiment and modification of the present invention, the case where the sounding device according to the present invention is applied to the combination meter 1 of an automobile has been described as an example. For example, you may apply to a navigation apparatus etc. The sounding device according to the present invention may be applied to various consumer devices other than those for automobiles and vehicles.

It is a partial front view of the combination meter 1 which is a sounding device by one Embodiment of this invention, and shows the speedometer A part which displays the driving speed of the said motor vehicle. It is the II-II sectional view taken on the line in FIG. It is the III-III sectional view taken on the line in FIG. It is the IV-IV sectional view taken on the line in FIG.

Explanation of symbols

1 Combination meter (sound generator)
2 Dial 2a Scale 2b Character 2c Through-hole 3 Printed circuit board 4 Casing 4a Wall 4b Opening 5 Piezoelectric buzzer (sounding body)
5a Sound emission hole 6 Sound guide member (screen member)
6a surface (parabolic)
6b surface (parabolic)
6c surface 7 indoor wall surface 8 lower cover 9 turnover plate 10 transparent cover 11 light emitting diode 12 movement 12a rotating shaft 13 pointer 14 light emitting diode 15 light shielding cap A speedometer P point (vertex)

Claims (7)

A printed circuit board,
A sounding body mounted on the printed circuit board;
A sounding device comprising the printed circuit board and a casing for housing the sounding body,
A sound emitting hole is provided in a side wall substantially orthogonal to the printed circuit board of the sound generator,
The sound generating device according to claim 1, wherein an opening is provided in a wall portion of the casing facing the side wall so as to face the sound emitting hole.   The sounding device according to claim 1, further comprising a partition member surrounding a space formed between the sound emitting hole of the sounding body and the opening of the wall portion.   The sounding device according to claim 2, wherein the partition member is installed in a portion from the sound emitting hole to the opening.   The sounding device according to claim 2 or 3, wherein the partition member is formed in a parabolic shape having a vertex on the sounding body side and opening toward the wall portion. The sounding body includes a plate-like vibration element for generating sound waves,
5. The sound generating device according to claim 1, wherein the vibration element is parallel to the printed circuit board in a state where the sound generating body is mounted on the printed circuit board.   The sounding device according to any one of claims 1 to 5, wherein the opening of the casing is arranged to face a vehicle interior wall surface.   The sound generator according to claim 6, wherein the casing is installed in front of a driver's seat of the vehicle, and the indoor wall surface is a side wall of the vehicle.

Images