Vehicle sound generator

Abstract

A vehicle sound emitter has: a speaker; a case part that accommodates the speaker and forms a rear chamber on the rear side of a vibration plate, an opening being formed that passes through the case part and is separated to the rear side from the vibration plate; and a protector attached to the opening, the protector forming a front chamber on the front side of the vibration plate together with the case, and a plurality of ports that form a flow path for a gas inside and outside the front chamber being formed in the protector. Shield parts that, in front view from the front of the ports, shield a region of the ports overlapping the flow paths in relation to the front chamber are formed in each of the plurality of ports, and the plurality of ports have the same resonance frequency.

Description

[Technical field]

[0001] The present invention relates to a sound generator for a vehicle. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 9-327082 discloses a speaker device for vehicle use in which a grill (protector) is attached to the opening on the front of the speaker box. Briefly, the grill of the speaker device includes a rib extending in a substantially horizontal direction and a shielding portion integrally formed with the rib. Although this conventional technology can prevent the speaker diaphragm from being directly exposed to water, the shape of the sound emission holes of the grill when viewed from the front is longer in the left-right direction in the vertical center area than in the areas on the upper and lower ends, 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.

[0003] In contrast, the prior art disclosed in Patent No. 6337669 attempts to obtain high sound pressure over a wide frequency band by providing multiple resonance chambers with different resonance frequencies in the sound path, while at the same time making the sound path a maze structure to prevent the speaker's diaphragm (vibration plate) from being directly exposed to water. Summary of the Invention [Problem to be solved by the invention]

[0004] However, the prior art disclosed in Japanese Patent No. 6337669 has a complex structure, which may lead to an increase in the size of the device.

[0005] In consideration of the above, the present disclosure provides a sound generator for a vehicle that can ensure acoustic performance with a small configuration while preventing or effectively suppressing direct exposure of the speaker diaphragm to water. [Means for solving the problem]

[0006] A sound generator for a vehicle according to a first aspect of the present disclosure includes a speaker that generates sound by vibrating a diaphragm, a case portion 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 together with the case portion forward of the diaphragm and has a plurality of ports that form flow paths for gas inside and outside the front chamber. Each of the plurality of 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 in a front view from the front of the port, and the plurality of ports have the same resonance frequency.

[0007] 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 is also formed with a plurality of ports 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.

[0008] Here, the multiple ports are each 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. Therefore, the shielding portion can prevent or effectively suppress water that flows straight from the front side of the port toward the front chamber from directly entering the front chamber. In addition, the multiple ports have the same resonance frequency. This allows the target frequency band to be specified and the 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 front chamber and the port, the vehicle sound generator can be prevented from becoming large.

[0009] In a sound generator for a vehicle according to a second aspect of the present disclosure, in the configuration of the first aspect, the shapes of the multiple ports are identical to each other or are line-symmetrical with respect to an imaginary line passing through the center of the protector in the front-rear direction.

[0010] According to the above configuration, the shapes of the multiple ports are identical to one another or are line-symmetrical, making design easy.

[0011] A third aspect of the present disclosure is a sound generator for a vehicle, in the configuration of the first or second aspect, wherein the port includes 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 to the side opposite the diaphragm and forming part of the flow path.

[0012] According to the above-mentioned configuration, since the port is configured to include the inner rib portion and the outer component portion, the amount of protrusion of the port to the outside is suppressed while the flow path length of the port is secured, thereby making it possible to obtain the desired acoustic performance while further suppressing the increase in size of the sound generator for a vehicle.

[0013] A fourth aspect of the present disclosure provides a sound generator for a vehicle according to the third aspect, wherein the outer constituent portion includes an L-shaped curved wall portion, and the shielding portion is formed on the curved wall portion.

[0014] 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, thereby making it possible to more effectively prevent water traveling straight from the front side of the port toward the antechamber from directly infiltrating into the antechamber.

[0015] A fifth aspect of the present disclosure provides a sound generator for a vehicle according to any one of the first to fourth aspects, wherein an R-shaped chamfer is formed at both end openings of the port from the opening ends toward the inside of the port.

[0016] With this configuration, when gas flows through the port, the R-shaped chamfered portion suppresses the occurrence of a flow velocity difference near both end openings of the port, thereby making it possible to suppress the occurrence of air noise caused by the flow velocity difference of the gas.

[0017] A sixth aspect of the present disclosure provides a sound generator for a vehicle, in the configuration described in any of the first to fifth aspects, wherein the port has at least one bent portion between one end and the other end of the flow path, and at least one corner portion of the bent portion on the inner surface of the flow path of the port is formed with an R-shaped curved portion.

[0018] With the above configuration, when gas flows through the port, the R-shaped curved surface portion of at least one of the corners on the inner surface of the flow passage of the port suppresses the occurrence of a flow velocity difference. This also makes it possible to suppress the occurrence of air noise caused by a flow velocity difference when gas flows through the port.

[0019] A seventh aspect of the present disclosure provides a sound generator for a vehicle according to the sixth aspect, wherein the curved surface portion is formed only at a concave corner portion among the corner portions.

[0020] According to the above configuration, when high-pressure water enters obliquely from the front opening of the port and passes 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.

[0021] The sound generator for a vehicle according to an eighth aspect of the present disclosure has the configuration of any one of the first to seventh aspects, such that the openings at both ends of all of the ports are oriented in the sound emitting direction of the diaphragm.

[0022] According to the above configuration, it is possible to increase the sound pressure level in a frequency band having high directivity.

[0023] A ninth aspect of the vehicle speaker of the present disclosure, in the configuration of any one of the first to eighth aspects, includes 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.

[0024] 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 infiltrates through a gap between the frame portion and the first case portion.

[0025] A vehicle sound generator according to a tenth aspect of the present disclosure has the configuration of the ninth aspect, 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, for connection to the speaker.

[0026] 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 and the other end of the terminal is exposed from the frame portion to be connected to the speaker. This eliminates the need for wiring holes, making it possible to prevent the occurrence of situations such as water entering through the wiring holes. Effect of the Invention

[0027] As described above, the vehicle sound generator of the present disclosure, taking into account the above facts, has the excellent effect of being able to ensure acoustic performance with a compact configuration while preventing or effectively suppressing direct exposure of the speaker diaphragm to water. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a perspective view showing a sound generator for a vehicle according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a perspective view showing a state cut along line 2-2 in FIG. [Diagram 3] 2 is a front view of a protector of the sound generator for a vehicle in FIG. 1. [Figure 4] 3 is an enlarged cross-sectional view showing a part of a protector of the sound generator for a vehicle in FIG. 2. [Diagram 5] 2 is a perspective view showing a frame with a case of the sound generator for a vehicle shown in FIG. 1. [Figure 6]FIG. 2 is a diagram showing curves of frequency-sound pressure level characteristics for the sound generator for a vehicle of FIG. 1 and a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] A sound generator for a vehicle according to an embodiment of the present disclosure will be described with reference to Figures 1 to 6. Note that an arrow FR shown as appropriate in these figures indicates the forward direction in which the speaker 20 (see Figure 2) faces. Hereinafter, when the description is given simply using the front-rear direction, it will refer to the front and rear of the front-rear direction when viewed from the speaker 20 as a reference, unless otherwise specified.

[0030] (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 cut along line 2-2 in 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 notify pedestrians, etc. of the approach of the electric vehicle when the electric vehicle is traveling at a low speed.

[0031] As shown in FIG. 2, the sound generator 10 for a vehicle has a speaker 20 that vibrates a diaphragm 22 to generate sound, and a case section 30 that houses the speaker 20. The case section 30 forms a rear chamber 14 on the rear side of the diaphragm 22. An opening 32A is formed through the case section 30 at a distance from the front side of the diaphragm 22. A protector 40 is attached to the opening 32A of the case section 30. The protector 40 is arranged to cover the opening 32A of the case section 30, and together with the case section 30, forms a front chamber 12 on the front side of the diaphragm 22. The protector 40 is formed with a flat plate section 42 that is 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 are formed. The ports 50 are elements that can be understood as sound emission holes.

[0032] Next, each component of the sound generator 10 for a vehicle will be specifically described.

[0033] 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 center of the front of the diaphragm 22 over the entire circumference. The edge 23, which is made of an elastic material such as rubber, is joined to the outer periphery of the diaphragm 22 over the entire circumference. 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 over the entire circumference.

[0034] The frame portion 24 is a component that supports the speaker 20. The frame portion 24 includes 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 includes 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).

[0035] An opening is formed through the center of the bottom wall 24B of the frame 24, and an electric wire coil 25B (shown in a simplified form in the drawing) of the voice coil 25 is disposed within the opening. The voice coil 25 includes a bobbin 25A formed by turning a film into a cylindrical shape, and an electric wire coil 25B formed by winding an electric wire around the outer periphery of the bobbin 25A. The bobbin 25A extends so as to pass 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.

[0036] A damper 26 is disposed on the inner side of the frame portion 24 on the outer periphery side of the intermediate portion in the axial direction of the bobbin 25A. The damper 26 is a flexible thin plate member formed in an annular shape when viewed from the front and having a ripple-like corrugated plate portion formed thereon. 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 intermediate shelf portion 24C1 of the frame portion 24. That is, 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.

[0037] A pole portion 27A of a yoke 27 is inserted into the bobbin 25A from the side opposite to the center cap 21. The yoke 27 is made of a ferromagnetic material. The yoke 27 also includes a plate portion 27B that protrudes from the end of the pole portion 27A opposite to the center cap 21.

[0038] 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 but spaced apart on the outer circumferential side of the pole portion 27A of the yoke 27, and is also disposed on the plate portion 27B. The plate 29 is formed in an annular shape from a ferromagnetic material and is disposed adjacent to but spaced apart on the outer circumferential side of the bobbin 25A, and is also disposed between the bottom wall portion 24B of the frame portion 24 and the magnet 28.

[0039] On the other hand, the case part 30 that houses the speaker 20 includes a first case part 32 that forms the front chamber 12 together with the protector 40, and also includes a second case part 34 that 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 an upper case part, and the second case part 34 may be referred to as a lower case part.

[0040] 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. An air vent 34H is formed through the protruding portion 34C. The air vent 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 volumetric expansion of the rear chamber 14. Note that by suppressing the volumetric expansion of the rear chamber 14, damage to the diaphragm 22 is prevented.

[0041] A groove-shaped inserted portion 34D into which rear end 32B (the end opposite to opening 32A) of first case portion 32 is inserted is formed around the entire periphery at the end in the projecting direction of projecting portion 34C of second case portion 34. An engaging protrusion 34E (see the right side in FIG. 2) is formed on a part of the outer wall portion of inserted portion 34D, and an engaging portion 32C that engages with engaging protrusion 34E is formed on the rear portion of first case portion 32.

[0042] In this embodiment, the frame portion 24 and the first case portion 32 are integrally formed to form a frame with case 38. FIG. 5 shows a perspective view of the frame with case 38. As shown in FIG. 5, the frame with case 38 has a connector portion 32D formed on the outer periphery of the first case portion 32, and a wall portion 24D for mounting a terminal 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 in the frame with case 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 wall portion 24D for mounting a terminal 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.

[0043] Next, a description will be given of the protector 40. Fig. 3 shows a front view of the protector 40, and Fig. 4 shows an enlarged cross-sectional view of a portion of the protector 40 shown in Fig. 2.

[0044] 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, 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 matter 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.

[0045] The ports 50 are arranged with their longitudinal directions in the same direction when viewed from the front of the protector 40. In the following description, for convenience, the longitudinal direction of the ports 50 is referred to as a first direction (the direction of the arrow X in the drawing), 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 a second direction (the direction of the arrow Y in the drawing).

[0046] 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 portions on both ends of the protector 40 in the second direction (arrow Y direction).

[0047] The orientation of the openings 50A, 50B at both ends of all ports 50 shown in Fig. 4 is aligned with the sound emission direction (the same direction as the direction of the arrow FR) of the diaphragm 22 (see Fig. 2). As shown in the partially enlarged view of Fig. 4, the openings 50A, 50B at both ends of the port 50 are formed with R-shaped chamfers R1, R2 extending from the open ends toward the inside of the port.

[0048] The port 50 is formed 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 bent portion formed between one end and the other end of the flow path A.

[0049] The inner rib portion 52 is formed in a rectangular tube shape protruding from the flat plate portion 42 toward the diaphragm 22 (see FIG. 2) in a direction perpendicular to the surface direction of the flat plate portion 42. The through portion 54 is formed so as to extend the flow path on the side of the inner rib portion 52. The outer component portion 56 is formed so that the flow path is L-shaped. Specifically, as shown in the partial enlarged view of FIG. 4, the outer component portion 56 includes a curved wall portion 56A that stands upright 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 is then bent into an inverted L shape so as to cover the through portion 54, and an upright rib portion 56B that stands upright 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.

[0050] 2 and 3, the ports 50 having the above configuration are each formed with shielding portions 58A and 58B that are formed in an area overlapping with the flow path A of the port 50 with respect to the front chamber 12 in a front view 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 and 58B in the second direction (arrow Y direction) is set to be equal to the length of each of the openings 50A and 50B at both ends of the port 50 in the second direction (arrow Y direction). 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 to each other.

[0051] 4, R-shaped curved surface portions R3, R4 are formed only at concave corner portions C2, C4 among corner portions C1, C2, C3, C4 (hereinafter abbreviated as "corner portions C1-C4") on the inner flow passage surface of port 50. Note that convex corner portions C1, C3 among corner portions C1-C4 on the inner flow passage surface of port 50 form right-angled corner portions.

[0052] The port 50 of this embodiment described above has a structure that can be understood as a labyrinth structure, but is set in a shape that can be easily molded using upper and lower dies.

[0053] (Actions and Effects of the Embodiments) Next, the operation and effects of the above embodiment will be described.

[0054] 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, which 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.

[0055] Here, as shown in Fig. 2 and Fig. 3, the multiple ports 50 are each formed with shielding parts 58A and 58B that shield the area overlapping 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. Therefore, the shielding parts 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 the flow path A bent in a crank shape by providing the shielding parts 58A and 58B, so that even if high-pressure water enters the port 50, the water moves in a zigzag manner inside the port 50, and as a result, the water pressure is attenuated. Therefore, even if high-pressure water enters the port 50, damage to the diaphragm 22 can be significantly reduced.

[0056] 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 multiple ports 50 have the same shape, 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 sound generator 10 for a vehicle can be prevented from increasing.

[0057] Here, the frequency-sound pressure level characteristics of the sound generator 10 for vehicles of this embodiment will be described with reference to Fig. 6. Fig. 6 shows schematic curves of the frequency-sound pressure level characteristics of the sound generator 10 for vehicles of this embodiment and a comparative example. The comparative example is a sound generator for vehicles that does not have a protector (40) and does not have a front chamber (12). In Fig. 6, the solid line diagram shows the results of the sound generator 10 for vehicles of this embodiment, and the two-dot chain line diagram shows the results of the comparative example.

[0058] As shown in Fig. 6, in the comparative example, the sound pressure level in the predetermined frequency band (300 Hz to 1 kHz) is not sufficiently increased. In contrast, in the case of the sound generator 10 for a vehicle of this embodiment, there are two peaks, and the sound pressure level in the predetermined frequency band (300 Hz to 1 kHz) is increased to near the desired sound pressure level RL, showing a band-pass frequency characteristic.

[0059] 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 suppressing the amount of protrusion to the outside of the port 50. This makes it possible to obtain the desired acoustic performance while further suppressing the increase in size of the sound generator 10 for a vehicle.

[0060] In the above embodiment, R-shaped chamfered portions R1 and R2 are formed at both end openings 50A and 50B of the port 50 from the opening ends toward the inside of the port 50, and R-shaped curved portions R3 and R4 are formed at predetermined corner portions C2 and C4 on the inner surface of the flow passage of the port 50. 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 both end openings 50A and 50B of the port 50, and the R-shaped curved portions R3 and R4 suppress the occurrence of a flow velocity difference at predetermined corner portions 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.

[0061] Furthermore, the above-mentioned curved surfaces R3, R4 are formed only on the concave corners C2, C4 among the corners C1 to C4. Therefore, when high-pressure water enters obliquely from the opening 50B on the front side of the port 50 so as to pass near the convex corners C1, C3, the intrusion of the high-pressure water is easily prevented since the convex corners C1, C3 do not have curved surfaces (chamfered portions).

[0062] In the above embodiment, the openings 50A and 50B at both ends of all the 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 frequency band with high directivity.

[0063] As described above, according to the sound generator 10 for a vehicle of this embodiment, it is possible to ensure acoustic performance with a small configuration while preventing or effectively suppressing direct exposure of the diaphragm 22 of the speaker 20 to water.

[0064] 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.

[0065] Furthermore, in the above embodiment, the terminals T1, T2 shown in Fig. 5 are insert-molded into the case-attached 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, and the other end T1B, T2B of the terminals T1, T2 are exposed from the frame portion 24 to be connected to the speaker 20 (see Fig. 2). This eliminates the need for wiring holes, making it possible to prevent the occurrence of a situation in which water seeps in through the wiring holes. Also, wiring work can be eliminated.

[0066] (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.

[0067] To give a supplementary explanation, when the upper limit frequency of the target frequency band is increased (for example, to 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 decreased. When the upper limit frequency of the target frequency band is decreased (for example, to 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 the lower limit frequency of the target frequency band is decreased (for example, to 200 Hz to 1 kHz), the volume of the rear chamber 14 shown in FIG. 2 is increased. When the lower limit frequency of the target frequency band is increased (for example, to 400 Hz to 1 kHz), the volume of the rear chamber 14 is decreased.

[0068] 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 that air noise can be reduced.

[0069] In addition, in the above embodiment, the shapes of the multiple ports 50 are substantially identical to each other. However, as a modification 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.

[0070] In addition, in the above embodiment, the port 50 shown in FIG. 4 etc. is configured to include the inner rib portion 52, but as a modification of the above embodiment, the port may be configured not to have the inner rib portion (52).

[0071] In the above embodiment, the port 50 has the upright rib portion 56B on the outer component portion 56, but as a modification of the above embodiment, a configuration in which the port does not have the upright rib portion (56B) can be adopted. 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, a configuration in which the amount of protrusion of the upright rib portion (56B) from the flat plate portion (42) does not match the amount of protrusion of the curved wall portion (56A) from the flat plate portion (42) can be adopted.

[0072] In addition, in the above embodiment, R-shaped chamfered portions R1, R2 are formed at both end openings 50A, 50B of the port 50. However, 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 of the end openings (50A, 50B) of the port (50) may also be adopted.

[0073] As a modification of the above embodiment, a configuration may be adopted in which a rounded curved portion is formed only at one of the corners (C1-C4) on the inner surface of the flow passage of the port (50). As another modification, a configuration may be adopted in which a rounded curved portion is formed at all of the corners (C1-C4) on the inner surface of the flow passage of the port (50). As yet another modification, a configuration may be adopted in which a rounded curved portion is not formed at any of the corners (C1-C4) on the inner surface of the flow passage of the port (50).

[0074] 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 FIG. 2). However, for example, a configuration may also be adopted in which 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).

[0075] 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.

[0076] In addition, in the above embodiment, the terminals T1, T2 are insert-molded into the case frame 38, but a configuration in which wiring holes are formed through the case frame (38) and the terminals are disposed therein may also be adopted.

[0077] The above-described embodiment and the multiple modified examples can be implemented in appropriate combinations.

[0078] While one example of the present invention has been described above, the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms without departing from the spirit and scope of the present invention.

Claims

1. 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 a 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.

2. 2. The sound generator for a vehicle according to claim 1, wherein the shapes of the plurality of ports are identical to one another or are symmetrical with respect to an imaginary line passing through a center of the protector in the front-rear direction.

3. 3. The sound generator for a vehicle according to claim 1, 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 a 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 a part of the flow path.

4. The sound generator for a vehicle according to claim 3 , wherein the outer component portion includes an L-shaped curved wall portion, and the shielding portion is formed on the curved wall portion.

5. 5. The sound generator for a vehicle according to claim 1, wherein an R-shaped chamfer is formed at both end openings of the port from the opening ends toward the inside of the port.

6. 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.

7. 7. The sound generator for a vehicle according to claim 6, wherein the curved surface portion is formed only at a concave corner portion of the corner portions.

8. 8. The sound generator for a vehicle according to claim 1, wherein the openings at both ends of all of the ports are oriented in a direction in which the diaphragm emits sound.

9. 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.

10. 10. The sound generator for a vehicle according to 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, the terminal having one end exposed and the other end exposed from the frame portion, the terminal being connected to the speaker.

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