JP7627282B2 - Vehicle sound generator - Google Patents

Description

The present invention relates to a sound generator for vehicles.

JP 9-327082 A discloses a car-mounted speaker device in which a grill (protector) is attached to the opening on the front of the speaker box. In simple terms, the grill of the speaker device has a rib extending in a substantially horizontal direction and a shielding portion formed integrally with the rib. Although this conventional technology can prevent the speaker diaphragm from being directly exposed to water, the shape of the grill's sound emission holes in a front view is longer horizontally in the vertical center area than in the areas at both ends, for example, and the multiple sound emission holes are not structured to have the same resonance frequency, so there is room for improvement in terms of ensuring acoustic performance.

In contrast, the prior art disclosed in Patent Publication No. 6,337,669 attempts to obtain high sound pressure over a wide frequency range by providing multiple resonance chambers with different resonance frequencies along the sound passage, while at the same time making the sound passage into a maze structure to prevent the speaker's diaphragm (vibration plate) from being directly exposed to water.

However, the prior art disclosed in Patent Publication No. 6,337,669 has a complex structure and may lead to an increase in the size of the device.

Taking into consideration the above facts, the present disclosure provides a sound generator for vehicles that can ensure acoustic performance with a compact configuration while preventing or effectively suppressing direct exposure of the speaker diaphragm to water.

The vehicle sound generator of the first aspect of the present disclosure includes a speaker that generates sound by vibrating a diaphragm, a case that houses the speaker and forms a rear chamber rearward of the diaphragm and has an opening formed therethrough at a distance forward of the diaphragm, and a protector that is attached to the opening and forms a front chamber forward of the diaphragm together with the case, and has multiple ports that form flow paths for gas inside and outside the front chamber. Each of the multiple ports is formed with a shielding portion that shields an area that overlaps with the flow path of the port with respect to the front chamber when viewed from the front of the port, and the multiple ports have the same resonance frequency.

According to the above configuration, the speaker generates sound by vibrating the diaphragm. A rear chamber is formed by the case on the rear side of the diaphragm, and a front chamber is formed by the case and the protector on the front side of the diaphragm. The protector also has a number of ports formed on the front side of the diaphragm that form flow paths for gas inside and outside the front chamber. As a result, sound generated by vibration of the diaphragm is transmitted to the outside through the front chamber and further through the ports.

Here, each of the multiple ports is formed with a shielding portion that shields the area that overlaps with the flow path of the port relative to the antechamber when viewed from the front of the port. Therefore, the shielding portion can prevent or effectively suppress water moving straight from the front side of the port toward the antechamber from directly infiltrating into the antechamber. In addition, the multiple ports have the same resonance frequency. This allows the target frequency band to be specified and acoustic performance to be adjusted, so that the sound pressure level of the target frequency band can be reliably increased. In addition, since the structure ensures acoustic performance using the antechamber and ports, the size of the vehicle sounder can be suppressed.

The second aspect of the present disclosure is a sound generator for a vehicle, in the configuration of the first aspect, in which the shapes of the multiple ports are identical to each other or are line-symmetrical with respect to an imaginary line in the fore-and-aft direction passing through the center of the protector.

According to the above configuration, the shapes of the multiple ports are identical or line-symmetric to each other, making design easy.

The third aspect of the present disclosure relates to a sound generator for a vehicle, and in the configuration of the first or second aspect, the port is configured to include a flat plate portion arranged opposite the diaphragm in the protector, an inner rib portion protruding from the flat plate portion toward the diaphragm and forming part of the flow path, and an outer component portion protruding from the flat plate portion toward the opposite side to the diaphragm and forming part of the flow path.

According to the above configuration, the port is configured to include an inner rib portion and an outer component portion, so the amount of protrusion of the port to the outside is suppressed while the flow path length of the port is secured. This makes it possible to obtain the desired acoustic performance while further suppressing the increase in size of the vehicle sound generator.

The fourth aspect of the present disclosure relates to a sound generator for a vehicle, and in the configuration of the third aspect, the outer component has an L-shaped curved wall portion, and the shielding portion is formed in the curved wall portion.

According to the above configuration, a shielding portion is formed in the curved wall portion of the outer component part on the forward side of the port, so that water moving straight from the front side of the port toward the antechamber can be more effectively prevented from directly infiltrating into the antechamber.

The vehicle sound generator of the fifth aspect of the present disclosure, in the configuration described in any one of the first to fourth aspects, has an R-shaped chamfer formed at both end openings of the port from the opening end toward the inside of the port.

According to the above configuration, when gas flows through the port, the R-shaped chamfered portion suppresses the occurrence of a flow velocity difference near the openings at both ends of the port. This makes it possible to suppress the occurrence of air noise caused by the flow velocity difference of the gas.

The sixth aspect of the present disclosure is a sound generator for a vehicle, in the configuration described in any one of the first to fifth aspects, wherein the port has at least one bend between one end and the other end of the flow passage, and at least one corner of the bend on the inner surface of the flow passage of the port is formed with an R-shaped curved surface.

According to the above configuration, when gas flows through the port, the occurrence of flow velocity differences is suppressed by the R-shaped curved surface at at least one of the corners on the inner surface of the flow passage of the port. This also makes it possible to suppress the occurrence of air noise caused by flow velocity differences when gas flows through the port.

The seventh aspect of the present disclosure relates to a sound generator for a vehicle, which, in the configuration of the sixth aspect, has the curved surface portion formed only in the concave corner portion of the corner portion.

According to the above configuration, when high-pressure water enters obliquely from the front opening of the port, passing near the convex corner, it is easier to prevent the high-pressure water from entering because there is no curved portion (chamfered portion) in the convex corner.

In the vehicle sound generator of the eighth aspect of the present disclosure, in any of the configurations of the first to seventh aspects, the orientation of both end openings of all of the ports is aligned with the sound emission direction of the diaphragm.

The above configuration makes it possible to increase the sound pressure level in highly directional frequency bands.

The ninth aspect of the vehicle sound generator of the present disclosure is configured in any one of the first and eighth aspects, in which the case portion comprises a first case portion which forms the front chamber together with the protector, and a second case portion which is joined to the first case portion and forms the rear chamber together with a part of the first case portion, and a frame portion which supports the speaker and the first case portion are integrally formed to form a frame with a case.

According to the above configuration, since the frame portion and the first case portion are integrally formed, it is possible to prevent the occurrence of a situation in which water enters through the gap between the frame portion and the first case portion.

The vehicle sound device of the tenth aspect of the present disclosure is the same as the ninth aspect, except that the case frame has a connector portion formed in the first case portion, and a terminal is insert-molded in the connector portion, one end of which is exposed and the other end of which is exposed from the frame portion and is connected to the speaker.

According to the above configuration, the terminal is insert-molded into the case frame, and one end of the terminal is exposed in the connector portion formed in the first case portion, while the other end of the terminal is exposed from the frame portion and connected to the speaker. This eliminates the need for wiring holes, preventing the occurrence of situations such as water entering through the wiring holes.

As described above, the vehicle sound generator disclosed herein takes into account the above facts and has the excellent effect of ensuring acoustic performance with a compact configuration while preventing or effectively suppressing direct exposure of the speaker diaphragm to water.

FIG. 1 is a perspective view showing a sound generator for a vehicle according to an embodiment of the present disclosure. FIG. 2 is a perspective view showing a state cut along line 2-2 in FIG. FIG. 2 is a front view of a protector of the sound generator for a vehicle of FIG. 1 . 3 is an enlarged cross-sectional view showing a part of a protector of the sound generator for a vehicle shown in FIG. 2. FIG. 2 is a perspective view showing a frame with a case of the sound generator for a vehicle shown in FIG. 1 . 2 is a diagram showing curves of frequency-sound pressure level characteristics for the vehicle sounder of FIG. 1 and a comparative example. FIG.

A sound generator for a vehicle according to one embodiment of the present disclosure will be described with reference to Figures 1 to 6. Note that the arrow FR, as appropriate, shown in these figures indicates the forward direction in which the speaker 20 (see Figure 2) faces. Hereinafter, when the front-to-rear direction is used in the description, it refers to the front-to-rear direction when viewed from the speaker 20 as a reference, unless otherwise specified.

(Configuration of the embodiment)
Fig. 1 shows a perspective view of a sound generator 10 for a vehicle according to an embodiment of the present disclosure. Fig. 2 shows a perspective view of the vehicle in a cut state taken along line 2-2 of Fig. 1. First, a schematic configuration of the sound generator 10 for a vehicle will be described. The sound generator 10 for a vehicle is attached to the front and rear of an electric vehicle (e.g., an electric vehicle, a hybrid vehicle, etc.), and automatically generates a sound to alert pedestrians and the like of the approach of the electric vehicle when the electric vehicle is traveling at a low speed.

As shown in FIG. 2, the vehicle sound generator 10 has a speaker 20 that vibrates a diaphragm 22 to generate sound, and a case portion 30 that houses the speaker 20. The case portion 30 forms a rear chamber 14 on the rear side of the diaphragm 22. In addition, an opening 32A is formed through the case portion 30 at a distance from the front side of the diaphragm 22. A protector 40 is attached to the opening 32A of the case portion 30. The protector 40 is arranged to cover the opening 32A of the case portion 30, and together with the case portion 30, forms a front chamber 12 on the front side of the diaphragm 22. The protector 40 has a flat plate portion 42 arranged opposite the diaphragm 22, and a plurality of ports 50 that form a flow path A for gas inside and outside the front chamber 12. The port 50 is an element that can be understood as a sound emission hole.

Next, each component part of the vehicle sound generator 10 will be described in detail.

The diaphragm 22 of the speaker 20 is formed in a ring shape when viewed from the front, and the front side is curved in a concave shape. The material of the diaphragm 22 can be, for example, a resin material such as polyetherimide (PEI), polyimide (PI), polycarbonate (PC), etc., or a metal material such as an aluminum alloy, or a papermaking material such as pulp fiber. The diameter (outer diameter) of the diaphragm 22 is, for example, 80 mm. The outer periphery of the center cap 21, which is circular when viewed from the front, is joined to the front center side of the front of the diaphragm 22. The edge 23, which is made of an elastic material such as rubber, is joined to the outer periphery of the diaphragm 22. The edge 23 is formed in a ring shape when viewed from the front, and is joined to the shelf-like portion 24A of the frame portion 24 around the entire periphery.

The frame portion 24 is a component that supports the speaker 20. The frame portion 24 has an annular bottom wall portion 24B disposed on the rear side of the diaphragm 22, and a connecting portion 24C that connects the outer periphery of the bottom wall portion 24B and the inner periphery of the shelf-like portion 24A. The connecting portion 24C has an intermediate shelf portion 24C1 that is connected to the outer periphery of the bottom wall portion 24B via a step portion, and a connecting wall portion 24C2 that connects the outer periphery of the intermediate shelf portion 24C1 and the inner periphery of the shelf-like portion 24A. The connecting wall portions 24C2 are arranged at intervals in the circumferential direction of the frame portion 24 (see FIG. 5).

An opening is formed through the center of the bottom wall 24B of the frame 24, and the electric wire coil 25B of the voice coil 25 (shown in a simplified form in the figure) is disposed within the opening. The voice coil 25 comprises a bobbin 25A made of a cylindrical film, and an electric wire coil 25B formed by winding an electric wire around the outer periphery of the bobbin 25A. The bobbin 25A extends through the opening of the bottom wall 24B of the frame 24, and one end of the bobbin 25A is disposed near the center cap 21 and connected to the inner periphery of the diaphragm 22.

Inside the frame portion 24, a damper 26 is arranged on the outer periphery side of the middle part of the bobbin 25A in the axial direction. The damper 26 is a flexible thin plate member formed in a ring shape when viewed from the front and having a ripple-like corrugated plate part. The inner periphery of the damper 26 is joined to the outer periphery of the bobbin 25A. The outer periphery of the damper 26 is joined to the middle shelf part 24C1 of the frame portion 24. In other words, the voice coil 25 is connected to the frame portion 24 via the diaphragm 22 and the edge 23, and is also connected to the frame portion 24 via the damper 26, and is supported in a state in which it can vibrate along the axial direction of the bobbin 25A.

The pole portion 27A of the yoke 27 is inserted into the inside of the bobbin 25A from the side opposite the center cap 21. The yoke 27 is made of a ferromagnetic material. The yoke 27 also has a plate portion 27B that protrudes from the end of the pole portion 27A opposite the center cap 21.

A magnet 28 and a metal plate 29 are disposed between the plate portion 27B and the bottom wall portion 24B of the frame portion 24. The magnet 28 is formed in an annular shape and is disposed adjacent to and spaced apart from the outer periphery of the pole portion 27A of the yoke 27, and is disposed on the plate portion 27B. The plate 29 is formed in an annular shape from a ferromagnetic material and is disposed adjacent to and spaced apart from the outer periphery of the bobbin 25A, and is disposed between the bottom wall portion 24B of the frame portion 24 and the magnet 28.

On the other hand, the case part 30 housing the speaker 20 includes a first case part 32 which forms the front chamber 12 together with the protector 40, and a second case part 34 which is joined to the first case part 32 and forms the rear chamber 14 together with a part of the first case part 32. The first case part 32 may be referred to as the upper case part, and the second case part 34 may be referred to as the lower case part.

The second case portion 34 is configured to include a bottom wall portion 34A and a peripheral wall portion 34B erected from the outer peripheral end portion of the bottom wall portion 34A. A flange-shaped protruding portion 34C is formed on the open end side of the peripheral wall portion 34B. A ventilation hole 34H is formed through the protruding portion 34C. The ventilation hole 34H is blocked by an air pressure control material (e.g. Gore-Tex (registered trademark)). The air pressure control material is waterproof and breathable, and suppresses the volume expansion of the rear chamber 14. Note that by suppressing the volume expansion of the rear chamber 14, damage to the diaphragm 22 is prevented.

A groove-shaped insertion portion 34D into which the rear end 32B (the end opposite the opening 32A) of the first case portion 32 is inserted is formed around the entire circumference of the end of the projection 34C of the second case portion 34. An engagement protrusion 34E (see the right side in FIG. 2) is formed on a part of the outer wall of the insertion portion 34D, and an engagement portion 32C that engages with the engagement protrusion 34E is formed on the rear portion of the first case portion 32.

In this embodiment, the frame portion 24 and the first case portion 32 are integrally formed to form the case frame 38. FIG. 5 shows a perspective view of the case frame 38. As shown in FIG. 5, the case frame 38 has a connector portion 32D formed on the outer periphery of the first case portion 32, and a terminal arrangement wall portion 24D that is continuous with the rear surface of the shelf portion 24A of the frame portion 24. The terminals T1 and T2 are insert molded into the case frame 38. One end portion T1A and T2A of the terminals T1 and T2 are exposed at the connector portion 32D. The other end portions T1B and T2B of the terminals T1 and T2 are exposed from the terminal arrangement wall portion 24D of the frame portion 24 and are connected to the speaker 20 (see FIG. 2). That is, the other ends T1B, T2B of the terminals T1, T2 are connected to a part of an electric wire (not shown) extending from the electric wire coil 25B of the voice coil 25 of the speaker 20 shown in FIG.

Next, the protector 40 will be described. Figure 3 shows a front view of the protector 40, and Figure 4 shows an enlarged cross-sectional view of a portion of the protector 40 shown in Figure 2.

As shown in FIG. 3, the protector 40 is formed in a substantially circular shape when viewed from the front, and a large number of ribs are formed. As an example, a total of ten ports 50 are formed in the protector 40. The shapes of these ten ports 50 are the same as each other, or as shown in FIG. 4, they are symmetrical with respect to a virtual line PL in the front-rear direction passing through the center of the protector 40, and these ten ports 50 have the same resonance frequency. The ports 50 are elongated holes in order to prevent the intrusion of foreign objects such as pebbles. The specific size (opening area and flow path length) of the ports 50 is appropriately set according to the frequency band in which the sound pressure level is to be increased (in other words, the target frequency band). In this embodiment, as an example, the target frequency band is set to 300 Hz to 1 kHz.

When viewed from the front of the protector 40, the ports 50 are arranged with their longitudinal directions in the same direction. In the following description, for convenience, the longitudinal direction of the ports 50 is referred to as the first direction (the direction of the arrow X in the figure), and the direction perpendicular to the longitudinal direction of the ports 50 when viewed from the front of the protector 40 is referred to as the second direction (the direction of the arrow Y in the figure).

The multiple ports 50 are formed symmetrically with respect to a first imaginary center line CL1 indicating the center position of the protector 40 in the first direction (arrow X direction). The multiple ports 50 are also formed symmetrically with respect to a second imaginary center line CL2 indicating the center position of the protector 40 in the second direction (arrow Y direction). In the middle of the protector 40 in the second direction (arrow Y direction), two ports 50 are lined up in series in the first direction (arrow X direction), and four ports 50 are lined up in parallel in the second direction (arrow Y direction). In addition, one port 50 is formed in the center of the first direction (arrow X direction) at each of the two end portions of the protector 40 in the second direction (arrow Y direction).

The orientation of both end openings 50A, 50B shown in Figure 4 of all ports 50 is aligned with the sound emission direction (the same direction as the arrow FR direction) of the diaphragm 22 (see Figure 2). As shown in the partially enlarged view of Figure 4, the openings 50A, 50B at both ends of the port 50 are formed with R-shaped chamfers R1, R2 extending from the opening end toward the inside of the port.

The port 50 is formed by penetrating the flat plate portion 42 of the protector 40, and includes an inner rib portion 52 formed on the front chamber 12 side of the flat plate portion 42, a through portion 54 penetrating the flat plate portion 42, and an outer component portion 56 formed on the outer side of the flat plate portion 42. The inner rib portion 52, the through portion 54, and the outer component portion 56 each form a part of the flow path A. In addition, the port 50 has at least one bend portion formed between one end and the other end of the flow path A.

The inner rib portion 52 is formed in a rectangular tube shape that protrudes from the flat plate portion 42 toward the vibration plate 22 (see FIG. 2) in a direction perpendicular to the surface direction. The through portion 54 is formed so as to extend the flow path on the inner rib portion 52 side. The outer component portion 56 is formed so that its flow path is L-shaped. Specifically, as shown in the partial enlarged view of FIG. 4, the outer component portion 56 includes a bent wall portion 56A that is erected from a portion of the flat plate portion 42 that overlaps with one side wall portion 52A of the inner rib portion 52 in a front view and then bent into an inverted L shape to cover the through portion 54, and an upright rib portion 56B that is erected from a portion of the flat plate portion 42 opposite the through portion 54 side with respect to the other side wall portion 52B of the inner rib portion 52 in a front view. In this manner, an L-shaped bent portion is formed by the bent wall portion 56A, and an inverted L-shaped bent portion is formed by the part 58B of the flat plate portion 42 and the upright rib portion 56B facing the bent wall portion 56A.

2 and 3, the ports 50 having the above configuration are each formed with shielding portions 58A, 58B that are formed in an area that overlaps with the flow path A of the port 50 with respect to the front chamber 12 when viewed from the front of the port 50 and partially shield the port 50. As shown in FIG. 4, in this embodiment, the length of the shielding portions 58A, 58B in the second direction (arrow Y direction) and the length of each of the openings 50A, 50B at both ends of the port 50 in the second direction (arrow Y direction) are set to be equal. In addition, the protruding amount of the upright rib portion 56B from the flat plate portion 42 and the protruding amount of the bent wall portion 56A from the flat plate portion 42 are set to be equal.

As shown in the partially enlarged view of Figure 4, among the corners C1, C2, C3, and C4 (hereinafter abbreviated as "corners C1 to C4") on the inner surface of the flow passage of the port 50, only the concave corners C2 and C4 have R-shaped curved surface portions R3 and R4. Among the corners C1 to C4 on the inner surface of the flow passage of the port 50, the convex corners C1 and C3 form right angles.

The port 50 of this embodiment described above has a structure that can be understood as a maze structure, but is designed in a shape that can be easily molded using upper and lower molds.

(Actions and Effects of the Embodiments)
Next, the operation and effects of the above embodiment will be described.

2, when an electric signal is applied to the electric wire coil 25B, the bobbin 25A vibrates the diaphragm 22 by electromagnetic induction to generate sound. A rear chamber 14 is formed by the case part 30 on the rear side of the diaphragm 22, and a front chamber 12 is formed by the case part 30 and a protector 40 on the front side of the diaphragm 22. In addition, the protector 40 has a plurality of ports 50 formed on the front side of the diaphragm 22 that form a flow path A for gas inside and outside the front chamber 12. As a result, sound generated by the vibration of the diaphragm 22 is transmitted to the outside through the front chamber 12 and further through the ports 50.

2 and 3, the ports 50 are each formed with shielding portions 58A and 58B that shield the area of the port 50 that overlaps with the flow path A of the port 50 relative to the front chamber 12 when viewed from the front of the port 50. Therefore, the shielding portions 58A and 58B can prevent or effectively suppress the water moving straight from the front side of the port 50 toward the front chamber 12 from directly entering the front chamber 12. Also, as shown in FIG. 2, the port 50 forms a flow path A bent in a crank shape by providing the shielding portions 58A and 58B, so that even if high-pressure water enters the port 50, the water will move in a zigzag manner inside the port 50, and as a result, the water pressure will be attenuated. Therefore, even if high-pressure water enters the port 50, damage to the diaphragm 22 can be significantly reduced.

In addition, the multiple ports 50 have the same resonant frequency. This allows the target frequency band to be specified and the acoustic performance to be adjusted, so the sound pressure level of the target frequency band can be reliably increased. In addition, the shapes of the multiple ports 50 are the same, making design easy. Furthermore, since the structure ensures acoustic performance using the front chamber 12 and the ports 50 (Kelton-type enclosure structure), the size of the vehicle sound generator 10 can be prevented from increasing.

Here, the frequency-sound pressure level characteristics of the vehicle sound device 10 of this embodiment will be explained using Figure 6. Figure 6 shows schematic curves of the frequency-sound pressure level characteristics for the vehicle sound device 10 of this embodiment and a comparison example. The comparison example is a vehicle sound device that does not have a protector (40) and has no front chamber (12). In Figure 6, the solid line diagram shows the results for the vehicle sound device 10 of this embodiment, and the two-dot chain line diagram shows the results for the comparison example.

As shown in Figure 6, in the comparative example, the sound pressure level in the specified frequency band (300 Hz to 1 kHz) is not sufficiently increased. In contrast, in the case of the vehicle sound generator 10 of this embodiment, there are two peaks, and the sound pressure level in the specified frequency band (300 Hz to 1 kHz) is increased to near the desired sound pressure level RL, showing a bandpass frequency characteristic.

In the above embodiment, as shown in Fig. 4, the port 50 is configured to include an inner rib portion 52 that protrudes from the flat plate portion 42 of the protector 40 toward the diaphragm 22 (see Fig. 2) and forms part of the flow path A. This ensures the flow path length of the port 50 while minimizing the amount of protrusion of the port 50 to the outside. This makes it possible to obtain the desired acoustic performance while further minimizing the increase in size of the sound generator 10 for a vehicle.

In the above embodiment, the openings 50A and 50B at both ends of the port 50 are formed with R-shaped chamfered portions R1 and R2 extending from the opening end toward the inside of the port 50, and the predetermined corners C2 and C4 on the inner surface of the flow passage of the port 50 are formed with R-shaped curved portions R3 and R4. Therefore, when gas flows through the port 50, the R-shaped chamfered portions R1 and R2 suppress the occurrence of a flow velocity difference near the openings 50A and 50B at both ends of the port 50, and the R-shaped curved portions R3 and R4 suppress the occurrence of a flow velocity difference at the predetermined corners C2 and C4 on the inner surface of the flow passage of the port 50. As a result, when gas flows through the port 50, the occurrence of air noise caused by the flow velocity difference can be suppressed.

Furthermore, the curved surfaces R3 and R4 are formed only on the concave corners C2 and C4 among the corners C1 to C4. Therefore, when high-pressure water enters obliquely from the front opening 50B of the port 50, passing near the convex corners C1 and C3, the intrusion of high-pressure water is easier to prevent since the convex corners C1 and C3 do not have curved surfaces (chamfered portions).

In the above embodiment, the openings 50A and 50B at both ends of all ports 50 are aligned with the sound emission direction (the same direction as the arrow FR direction) of the diaphragm 22 (see FIG. 2). This makes it possible to increase the sound pressure level in a highly directional frequency band.

As described above, the vehicle sound generator 10 of this embodiment can ensure acoustic performance with a compact configuration while preventing or effectively suppressing direct exposure of the diaphragm 22 of the speaker 20 to water.

In addition, in the above embodiment, as shown in FIG. 2, the frame portion 24 and the first case portion 32 are integrally formed, thereby preventing the occurrence of a situation in which water enters through the gap between the frame portion 24 and the first case portion 32.

Furthermore, in the above embodiment, the terminals T1, T2 shown in Fig. 5 are insert molded into the cased frame 38, and one end T1A, T2A of the terminals T1, T2 are exposed in the connector portion 32D formed in the first case portion 32, while the other end T1B, T2B of the terminals T1, T2 are exposed from the frame portion 24 and connected to the speaker 20 (see Fig. 2). This eliminates the need for wiring holes, preventing the occurrence of situations such as water entering through the wiring holes. Also, wiring work can be eliminated.

(Supplementary explanation of the embodiment)
In the above embodiment, the target frequency band is 300 Hz to 1 kHz, but the target frequency band can be set appropriately within the range (160 Hz to 5 kHz) defined by the international standard (UN-R138). When the target frequency band is changed from 300 Hz to 1 kHz, the size of the port 50 shown in FIG. 2 is changed, for example.

To provide additional explanation, when increasing the upper limit frequency of the target frequency band (for example, 300 Hz to 1100 Hz), the opening area of the port 50 is increased or the flow path length of the flow path A of the port 50 is shortened. When decreasing the upper limit frequency of the target frequency band (for example, 300 Hz to 900 Hz), the opening area of the port 50 is decreased or the flow path length of the flow path A of the port 50 is increased. On the other hand, when decreasing the lower limit frequency of the target frequency band (for example, 200 Hz to 1 kHz), the volume of the rear chamber 14 shown in FIG. 2 is increased. When increasing the lower limit frequency of the target frequency band (for example, 400 Hz to 1 kHz), the volume of the rear chamber 14 is decreased.

In addition, in the above embodiment, the number of ports 50 is 10, but the number of ports can be set appropriately. If the number of ports is increased, the amount of air flowing through each port decreases accordingly, so air noise can be reduced.

In addition, in the above embodiment, the shapes of the multiple ports 50 are substantially identical to each other, but as a modified example of the above embodiment, the shapes of the multiple ports (50) may not be identical to each other, but the multiple ports (50) may have the same resonant frequency to each other.

In addition, in the above embodiment, the port 50 shown in Figure 4 etc. is configured to include an inner rib portion 52, but as a modified example of the above embodiment, the port may be configured not to have an inner rib portion (52).

In the above embodiment, the port 50 has the upright rib portion 56B on the outer component 56, but as a modification of the above embodiment, the port may have no upright rib portion (56B). In the above embodiment, the amount of protrusion of the upright rib portion 56B from the flat plate portion 42 matches the amount of protrusion of the curved wall portion 56A from the flat plate portion 42, but as a modification of the above embodiment, the amount of protrusion of the upright rib portion (56B) from the flat plate portion (42) may not match the amount of protrusion of the curved wall portion (56A) from the flat plate portion (42).

In addition, in the above embodiment, R-shaped chamfered portions R1, R2 are formed at both end openings 50A, 50B of the port 50, but as a modified example of the above embodiment, a configuration in which the R-shaped chamfered portions (R1, R2) are not formed at one or both end openings (50A, 50B) of the port (50) may also be adopted.

As a modified example of the above embodiment, an R-shaped curved surface portion may be formed only at one of the corner portions (C1 to C4) on the inner surface of the flow passage of the port (50). As another modified example, an R-shaped curved surface portion may be formed at all of the corner portions (C1 to C4) on the inner surface of the flow passage of the port (50). As yet another modified example, an R-shaped curved surface portion may not be formed at any of the corner portions (C1 to C4) on the inner surface of the flow passage of the port (50).

In addition, in the above embodiment, the orientation of the openings 50A, 50B at both ends of all ports 50 is aligned with the sound emission direction of the diaphragm 22 (see Figure 2), but it is also possible to adopt a configuration in which, for example, the orientation of the openings (50A, 50B) at both ends of some ports (50) is not aligned with the sound emission direction of the diaphragm (22).

In addition, in the above embodiment, as shown in Figure 5 etc., the frame portion 24 and the first case portion 32 are formed integrally, but it is also possible to adopt a configuration in which the frame portion (24) and the first case portion (32) are formed separately and then joined to each other.

In addition, in the above embodiment, the terminals T1 and T2 are insert molded into the case frame 38, but it is also possible to form holes for wiring through the case frame (38) and arrange the terminals therein.

The above embodiments and the various modified examples described above can be implemented in appropriate combinations.

The above describes one example of the present invention, but the present invention is not limited to the above, and it goes without saying that it can be implemented in various modifications within the scope of the spirit of the present invention.

Claims (10)

A speaker that generates sound by vibrating a diaphragm;
a case portion that houses the speaker and defines a rear chamber on the rear side of the diaphragm, and has an opening formed therethrough and spaced apart on the front side of the diaphragm;
a protector attached to the opening and forming a front chamber in front of the diaphragm together with the case, the protector having a plurality of ports formed therein that form flow paths for gas inside and outside the front chamber;
a shielding portion that shields an area that overlaps with the flow path of the port with respect to the front chamber when viewed from the front of the port, and the plurality of ports have the same resonant frequency. The sound generator for a vehicle according to claim 1, wherein the shapes of the multiple ports are identical to each other or are symmetrical with respect to an imaginary line in the fore-and-aft direction passing through the center of the protector. The sound generator for a vehicle according to claim 1 or 2, wherein the port is configured to include a flat plate portion disposed opposite the diaphragm in the protector, an inner rib portion protruding from the flat plate portion toward the diaphragm and forming part of the flow path, and an outer component portion protruding from the flat plate portion toward the opposite side to the diaphragm and forming part of the flow path. The sound generator for a vehicle according to claim 3, wherein the outer component has an L-shaped curved wall portion, and the shielding portion is formed in the curved wall portion. A sound generator for a vehicle according to any one of claims 1 to 4, wherein an R-shaped chamfer is formed on both end openings of the port from the opening end toward the inside of the port. The port includes at least one bend between one end and the other end of the flow path,
The sound generator for a vehicle according to any one of claims 1 to 5, wherein an R-shaped curved surface portion is formed in at least one corner portion of the bent portion on the flow passage inner surface of the port. The sound generator for a vehicle according to claim 6, wherein the curved surface portion is formed only in the concave corner portion of the corner portion. A sound generator for a vehicle as described in any one of claims 1 to 7, wherein the orientation of both end openings of all the ports is aligned with the sound emission direction of the diaphragm. the case portion includes a first case portion that forms the front chamber together with the protector, and a second case portion that is joined to the first case portion and forms the rear chamber together with a part of the first case portion,
9. The sound generator for a vehicle according to claim 1, wherein a frame portion supporting the speaker and the first case portion are integrally formed as a frame with a case. The sound generator for a vehicle as described in claim 9, wherein the case frame has a connector portion formed in the first case portion, and a terminal is insert-molded in the connector portion, one end of which is exposed and the other end of which is exposed from the frame portion and is connected to the speaker.