Vehicle warning device and system

Abstract

A vehicle warning device and system. The vehicle warning device comprises a housing, a sound producing unit and a mesh cover; the sound producing unit is provided in the housing, and the sound producing unit comprises a diaphragm vibrating along the axis of vibration that extends front and back, the diaphragm having a front surface facing forwards and a back surface facing backwards; the mesh cover covers the front surface of the diaphragm, and the mesh cover comprises a fixing ring, a grating portion and a shielding portion, the fixing ring being connected to the housing; the grating portion is located between the fixing ring and the shielding portion, the fixing ring surrounds the grating portion, and the grating portion surrounds the shielding portion; the grating portion is provided with a plurality of grating holes for air to flow through, the middle portion of the shielding portion is provided with a middle hole for air to flow through, and a resonant cavity for changing the direction of a sound wave is formed between the shielding portion and the diaphragm. The vehicle warning device has high sensitivity to medium frequency.

Description

Vehicle warning device and system Cross-reference to related applications

[0001] This application claims priority to Chinese patent application No. CN 2024112305606, filed on September 3, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure belongs to the field of loudspeakers, and relates to a vehicle warning device, in particular, a vehicle warning device capable of emitting a pedestrian warning sound for an electric vehicle; and further relates to a vehicle warning system capable of generating a low-speed pedestrian warning sound and a horn sound. BACKGROUND

[0003] For new energy vehicles driven by batteries, such as electric vehicles, since no internal combustion engine is used, the vehicle is relatively quiet when driving at low speed. When the car drives behind the pedestrian, the pedestrian often fails to notice the presence of the car, increasing the probability of a car accident. Therefore, the vehicle warning device outside the car is an indispensable part of new energy vehicles, which is used to emit a pedestrian warning sound to remind pedestrians that the vehicle is approaching, especially when the vehicle is driving at low speed. Since the vehicle warning device outside the car is directly exposed to the outside of the car, it is easily disturbed by external environmental factors. For example, the applicant's patent CN208585167U discloses a pedestrian warning device with a mesh cover, which can protect the internal components of the pedestrian warning device and not affect the performance of the pedestrian warning device. However, the sound playback effect of the existing pedestrian warning device in the medium and high frequency bands still has room for improvement, and the performance needs to be optimized.

[0004] The above information disclosed in the background section is only intended to strengthen the understanding of the background of the present application, and therefore it can include information that does not constitute the prior art known to those of ordinary skill in the art. SUMMARY

[0005] The present disclosure relates to a vehicle warning device with high medium frequency sensitivity, which can serve as both a pedestrian warning device and a horn. The present disclosure also relates to a vehicle warning device that realizes both horn warning and pedestrian warning when the vehicle is driving at low speed through a single sound emitting unit.

[0006] The first aspect of the present disclosure provides a vehicle warning device, which comprises a housing, a sound generating unit arranged in the housing, the sound generating unit comprising a diaphragm vibrating along a front-rear extending vibration axis, the diaphragm having a front surface facing forward and a back surface facing backward, and a mesh cover covering the front surface of the diaphragm, the mesh cover comprising a fixing ring connected with the housing, a grating portion between the fixing ring and a shielding portion, the fixing ring surrounding the grating portion, the grating portion surrounding the shielding portion, the grating portion having a plurality of grating holes for air flow, and the shielding portion having a middle hole for air flow in a middle portion of the shielding portion, a resonance cavity being formed between the shielding portion and the diaphragm for changing the direction of sound waves.

[0007] In an embodiment, the ratio of the total width of the shielding portion to the diameter of the mesh cover is greater than 0.5 in the diameter direction of the mesh cover.

[0008] In an embodiment, the ratio of the total width of the shielding portion to the diameter of the mesh cover is 0.55-0.95. In another embodiment, the ratio of the total width of the shielding portion to the diameter of the mesh cover is 0.6-0.8.

[0009] In an embodiment, the middle hole extends along the vibration axis, the middle hole having an expanding section adjacent to the diaphragm and a uniform section away from the diaphragm, the hole diameter of the expanding section gradually decreasing from back to front along the vibration axis, and the hole diameter of the uniform section being equal to the minimum hole diameter of the expanding section.

[0010] In an embodiment, the middle portion of the diaphragm has a spherical top portion arched upward, the hole wall of the expanding section is located in front of the spherical top portion, and the shape of the hole wall is a part of a spherical surface matching the spherical top portion.

[0011] In an embodiment, the ratio of the hole diameter of the uniform section to the total width of the shielding portion is less than 0.25.

[0012] In an embodiment, the shielding portion has an inner surface opposite to the front surface of the diaphragm, the inner surface of the shielding portion and the front surface of the diaphragm are parallel to each other, the shielding portion has an outer surface facing forward, and the outer surface is a plane perpendicular to the vibration axis.

[0013] In an embodiment, the diaphragm has a cone in the shape of a truncated cone, the inner surface is located in front of the cone, and the inner surface is a conical surface matching the shape of the cone.

[0014] In an embodiment, the ratio of the total width of the grating portion to the middle width of the shielding portion is less than 0.25 in the diameter direction of the mesh cover.

[0015] In an embodiment, the grid portion is provided with one or more rings of grid holes, the one or more rings of grid holes including a plurality of grid holes spaced along a circumferential direction of the grid portion.

[0016] In an embodiment, the housing includes a frame and a back cover, the magnetic drive assembly of the sound production unit is arranged on the frame, the back cover is connected to the frame and seals a rear end of the frame, a closed rear cavity is formed between the back cover and the frame, the rear cavity and an internal cavity of the sound production unit are in communication.

[0017] In an embodiment, the housing includes a frame and a back cover, the magnetic drive assembly of the sound production unit is arranged on the frame, the back cover is connected to the frame and seals a rear end of the frame, a closed rear cavity is formed between the back cover and the frame, the rear cavity and an internal cavity of the sound production unit are in communication.

[0018] In an embodiment, the sound production unit is a moving coil loudspeaker.

[0019] In an embodiment, the sound production unit is a moving coil loudspeaker, the sound production unit further includes a positioning support, the positioning support is connected between a voice coil of the sound production unit and the frame, the frame is provided with a ring of mounting protrusions extending forward or a plurality of mounting protrusions arranged in a ring shape, the positioning support is limited between the mounting protrusions.

[0020] In an embodiment, the frame is provided with a clamping groove, a front piece of the magnetic drive assembly is clamped in the clamping groove. The front piece is fixed to the frame by clamping, which is more beneficial to obtain better connection strength than the traditional bonding method.

[0021] A second aspect of the present disclosure provides a vehicle warning system, including a single vehicle warning device, and configured to emit a horn sound through the single vehicle warning device and emit a pedestrian warning sound when the vehicle is running at a low speed. For example, when the vehicle suddenly approaches, a pedestrian mistakenly enters the lane, the driver actively triggers the vehicle warning device to emit a horn sound; when the vehicle speed is low, the vehicle warning device automatically emits a pedestrian warning sound in response to the vehicle speed reduction, to remind pedestrians that there is a vehicle or the vehicle is approaching.

[0022] "Honking sound" is used to actively remind others of danger or emergency (such as a vehicle approaching suddenly, a pedestrian mistakenly entering the lane), which is common in emergency avoidance, overtaking reminder, blind area warning, etc., and is usually used at higher vehicle speed or in sudden situations. "Pedestrian warning sound" is used to passively remind pedestrians of the existence of vehicles, to make up for the problem of insufficient noise when electric vehicles / hybrid vehicles are running at low speed, and is usually automatically triggered when running at low speed (usually at a speed lower than 30km / h) in parking lots, residential areas, congested road sections, etc. In terms of triggering method, the honking sound is manually controlled by the driver (such as pressing the steering wheel button); the low-speed pedestrian warning sound is automatically triggered by the vehicle (without the intervention of the driver), and is usually associated with the vehicle speed, and is continuously or intermittently sounded at low speed. In terms of sound characteristics, the honking sound has a large volume (for example, 80-110 decibels), strong penetration, and the purpose is to quickly attract attention. The low-speed pedestrian warning sound has a low volume (about 50-70 decibels), and is mostly in the low-frequency band or simulates natural sound (such as white noise, engine sound).

[0023] The above scheme is adopted in the present disclosure, which has the following advantages:

[0024] The vehicle warning device and system of the present disclosure has a shielding part with a closed structure in the middle of the mesh cover, forming a resonance cavity between the shielding part and the diaphragm main body part (cone), the sound waves change the propagation direction in the resonance cavity, and resonance is formed in the resonance cavity, so that the medium-high frequency sound waves propagate in a relatively wide space, the sound field also changes, the sensitivity of medium-high frequency (1KHz~4KHz) is improved, and the pedestrian warning device and the honking horn can be combined, thereby saving the honking horn in the traditional vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the present disclosure, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art without creative labor.

[0026] Fig. 1 is a top view of a vehicle warning device according to an embodiment of the present disclosure.

[0027] Fig. 2 is a sectional view of A-A in Fig. 1.

[0028] Fig. 3 is a partial enlarged view of A in Fig. 2.

[0029] Fig. 4 is an exploded view of a vehicle warning device according to an embodiment of the present disclosure.

[0030] Fig. 5 is a perspective view of a mesh cover according to an embodiment of the present disclosure.

[0031] Fig. 6 is a front view of a mesh cover according to an embodiment of the present disclosure.

[0032] Fig. 7 is a sectional view of a mesh cover according to an embodiment of the present disclosure.

[0033] Fig. 8 is a structural diagram of a vehicle warning device of a comparative example.

[0034] Fig. 9 is a frequency response curve of vehicle warning devices of the embodiment and the comparative example.

[0035] In the above drawings,

[0036] 1 - housing; 11 - frame; 111 - hollowed part; 112 - mounting protrusion; 113 - clamping groove; 12 - rear cover; 13 - rear cavity;

[0037] 2 - sound emitting unit; 21 - diaphragm; 211 - spherical top; 212 - cone; 22 - voice coil; 23 - positioning tab; 24 - magnetic driving assembly; 241 - T iron; 2411 - cylindrical part; 2412 - groove; 2413 - through hole; 242 - magnetic steel; 243 - front piece;

[0038] 3 - mesh cover; 31 - fixing ring; 32 - grating part; 321 - grating hole; 33 - shielding part; 331 - recessed part; 34 - middle hole; 341 - hole wall;

[0039] 4 - resonance cavity. DETAILED DESCRIPTION

[0040] The preferred embodiments of the present disclosure will be described in detail with reference to the drawings, so that the advantages and features of the present disclosure can be more easily understood by those skilled in the art. It should be noted that the description of the embodiments is intended to help understand the present disclosure, and is not intended to limit the present disclosure. In addition, the technical features involved in the various embodiments of the present disclosure described below can be combined with each other as long as they do not conflict with each other.

[0041] In this document, "inner" and "outer" are defined with reference to the vibration axis (center line of the voice coil) of the vehicle warning device, and the position closer to the vibration axis is defined as inner, and vice versa. The words "front" and "rear" are intended to facilitate understanding of the structure of the vehicle warning device by those skilled in the art, and are not intended to limit the position of the vehicle warning device after installation (for example, in a vehicle).

[0042] The drawings of Figs. 1 to 7 are drawn to true scale, and in order to maintain the brevity of the specification, the scale of each element is not listed one by one, but the scale and position of each element should be considered as part of the content of the specification. EMBODIMENT

[0043] The embodiment provides a vehicle warning device, in particular a pedestrian warning device installed on a new energy vehicle, which is typically an electric vehicle driven by a battery. The vehicle warning device is used to emit one or more warning sounds, including a pedestrian warning sound played to pedestrians outside the vehicle when the vehicle is running at low speed, which is a simulated sound of a traditional vehicle engine. The vehicle warning device is generally installed outside the vehicle cabin (such as at the vehicle bumper) to radiate sound outside the vehicle. Further, the vehicle warning device of the embodiment also considers the function of a traditional whistle horn, and can emit whistle horn sound. Therefore, the vehicle warning device of the embodiment realizes the functions of playing pedestrian warning sound and whistle horn sound through the same sound emitting unit (speaker).

[0044] Referring to FIGS. 1-7, the vehicle warning device comprises a housing 1, a sound emitting unit 2 and a mesh cover 3. The sound emitting unit 2 is arranged in the housing 1, and the sound emitting unit 2 is specifically a moving coil speaker. The sound emitting unit 2 comprises a diaphragm 21 which vibrates along a front-rear extending vibration axis, and the vibration axis ideally coincides with the center line of a voice coil 22 of the sound emitting unit 2. The diaphragm 21 has a front surface facing forward and a back surface facing backward. The mesh cover 3 covers the front surface of the diaphragm 21, and the traditional function of the mesh cover 3 is to protect the relatively fragile internal components of the sound emitting unit 2. In the embodiment, the mesh cover 3 comprises a fixing ring 31, a grid part 32 and a shielding part 33 arranged in sequence from outside to inside. The fixing ring 31 is connected with the housing 1; the grid part 32 is located between the fixing ring 31 and the shielding part 33, the fixing ring 31 surrounds the grid part 32, and the grid part 32 surrounds the shielding part 33. The grid part 32 has a plurality of grid holes 321 for air flow; the middle part of the shielding part 33 is provided with a middle hole 34 for air flow. In the embodiment, a resonance cavity 4 changing the direction of sound waves is formed between the shielding part 33 and the diaphragm 21, and the sensitivity of sound playback in the medium and high frequency band can be improved through the arrangement of the resonance cavity 4.

[0045] In the diameter direction of the mesh cover 3, the ratio of the total width of the shielding part 33 to the diameter of the mesh cover 3 is greater than 0.5. Referring to FIG. 7, the total width of the shielding part 33 is W1+W2; that is, the total width of the shielding part 33 is twice the distance between the inner and outer edges of the shielding part 33. Preferably, the ratio of the total width of the shielding part 33 to the diameter of the mesh cover 3 is 0.55-0.95; further, 0.6-0.8.

[0046] The middle hole 34 extends along the vibration axis, and the middle hole 34 has an outward expanding section adjacent to the diaphragm 21 and a uniform section far from the diaphragm 21, the hole diameter of the outward expanding section gradually decreases from back to front along the vibration axis, and the hole diameter of the uniform section is equal to the minimum hole diameter of the outward expanding section. Specifically, the shape of the uniform section is a whole cylinder, and the outward expanding section is generally a horn structure with an outward expanding mouth. The ratio of the hole diameter of the uniform section to the total width of the shielding part 33 is less than 0.25; preferably, 0.1-0.2.

[0047] Further, the middle portion of the diaphragm 21 has a dome-shaped top portion 211 which is arched upward, and the hole wall 341 of the flared portion is located in front of the dome-shaped top portion 211, and the shape of the hole wall 341 is a part of a spherical surface which matches the dome-shaped top portion 211. The hole wall 341 of the flared portion and the dome-shaped top portion 211 are arranged substantially in parallel. The baffle 33 has an inner surface which is opposite to the front surface of the diaphragm 21, and the inner surface of the baffle 33 and the front surface of the diaphragm 21 are parallel to each other. The baffle 33 has an outer surface which faces forward, and the outer surface is a plane which is perpendicular to the vibration axis.

[0048] In this embodiment, the diaphragm 21 has a truncated cone-shaped cone portion 212, and the inner surface of the baffle 33 is located in front of the cone portion 212, and the inner surface is a conical surface which matches the shape of the cone portion 212. As shown in Fig. 6, the baffle 33 is provided with a plurality of recessed portions 331 which extend upward from the inner surface of the baffle 33, and in the case where the inner surface as a whole is a conical surface, the volume of the resonance chamber 4 is enlarged as much as possible.

[0049] The grid portion 32 is provided with one or more rings of grid holes 321. As shown in Fig. 5, two rings of grid holes 321 are provided in this embodiment, and the plurality of grid holes 321 of the outer ring are arranged at intervals in the circumferential direction of the mesh cover 3, and the plurality of grid holes 321 of the inner ring are arranged at intervals in the circumferential direction of the mesh cover 3, and the grid holes 321 are spaced apart from each other by connecting ribs. In the diameter direction of the mesh cover 3, the ratio of the total width of the grid portion 32 to the middle width of the baffle 33 is less than 0.25; preferably, it is 0.1 to 0.2.

[0050] The shell 1 specifically comprises a frame 11 and a back cover 12, the frame 11 comprising an outer cylinder and a support fixed to the inner side of the outer cylinder, and the back cover 12 being connected to the rear end of the outer cylinder and closing the rear end of the frame 11, so as to form a closed rear cavity 13 between the back cover 12 and the frame 11. The sound generating unit 2 is mounted on the support, and the outer edge of the mesh cover 3 is fixed to the upper end of the support and / or the outer cylinder, so as to clamp the outer edge (hanging edge) of the diaphragm 21 between the mesh cover 3 and the frame 11. Among them, the magnetic driving assembly 24 of the sound generating unit 2 is fixedly arranged in the support of the frame 11, for example, can be bonded by glue. The magnetic driving assembly 24 specifically comprises a T-shaped iron 241, a magnetic steel 242 and a front piece 243, and the frame 11 is provided with a clamping groove 113, and the front piece 243 of the magnetic driving assembly 24 is clamped in the clamping groove 113, and the two are fixedly connected. The magnetic steel 242 and the front piece 243 are fixedly connected, for example, bonded by glue. The T-shaped iron 241 and the magnetic steel 242 are fixedly connected, for example, bonded by glue. The T-shaped iron 241 of the magnetic driving assembly 24 has a cylindrical portion 2411 extending forward, and the rear end portion (coil portion) of the voice coil 22 is inserted into the gap between the front piece 243 and the cylindrical portion 2411. Further, the outer diameter of the front end portion of the cylindrical portion 2411 is smaller than the outer diameter of the main body of the cylindrical portion, so as to have an annular groove 2412, and the rear end portion of the voice coil 22 can be movably inserted in the annular groove 2412 in the front-rear direction. A through hole 2413 extending forward and backward is formed in the cylindrical portion 2411. The support of the frame 11 is provided with a plurality of hollow portions 111; the rear cavity 13 and the internal cavity of the sound generating unit 2 are communicated through the hollow portions 111 and the through hole 2413. Further, a short circuit ring (copper sleeve) can be placed in the annular groove 2412, so that the sensitivity of the sound generating unit 2 is higher.

[0051] The sound generating unit 2 further comprises a positioning support 23 connected between the voice coil 22 of the sound generating unit 2 and the frame 11. Further, the frame 11 is provided with a mounting protrusion 112, and the positioning support 23 is limited inside the mounting protrusion 112. Specifically, the mounting protrusion 112 surrounds the positioning support 23 once, forming a circular shallow groove, and the positioning support 23 is arranged in the shallow groove. In another embodiment, a plurality of mounting protrusions 112 are arranged along a ring shape, and the positioning support 23 is limited between the plurality of mounting protrusions 112. Comparative Example

[0052] As shown in FIG. 8, the shell and the sound generating unit of the vehicle warning device of the comparative example are the same as those of the embodiment, and the only difference is the mesh cover 3. In the comparative example, the mesh cover adopts a traditional louver structure, and the main body of the mesh cover is uniformly distributed with lattice holes. Performance Evaluation

[0053] Under the same test conditions (the same specifications of the sound emitting unit 2 and the same excitation signal), the sound emitting effect tests were performed on the two vehicle warning devices of the example and the comparative example. The frequency response curves are shown in FIG. 9. As can be seen from the figure, in the frequency band of 1KHz~4KHz, the average sensitivity of the frequency response curve of the vehicle warning device of the example is about 9dB higher than that of the comparative example.

[0054] The vehicle warning device of the example has the closed structure of the shielding part 33 in the middle part of the mesh cover 3, and a resonance cavity 4, i.e. a Helmholtz resonance cavity, is formed between the shielding part 33 and the main body part (cone 212) of the diaphragm 21. The sound waves change the propagation direction in the resonance cavity 4, and resonance is formed in the resonance cavity 4, so that the middle and high frequency sound waves propagate in a relatively wide space, the sound field is also changed, the sensitivity of the middle and high frequency (1KHz~4KHz) is improved, and the vehicle warning device can be used as a pedestrian warning device and a horn, thereby saving the horn in the traditional vehicle.

[0055] Further, a vehicle warning system is also provided, which includes a single vehicle warning device (single moving coil loudspeaker) and is configured to emit a horn sound and a pedestrian warning sound when the vehicle is running at a low speed through the single vehicle warning device. For example, when the vehicle suddenly approaches or a pedestrian mistakenly enters the lane, the driver actively triggers the vehicle warning device to emit a horn sound. When the vehicle speed is relatively low (less than 30km / h), the vehicle warning device automatically emits a pedestrian warning sound in response to the reduction of the vehicle speed, so as to remind the pedestrian that there is a vehicle or the vehicle is approaching.

[0056] The features of the embodiments of the present disclosure are stated in the following clauses:

[0057] Clause 1, a vehicle warning device, comprising a housing, a sound emitting unit and a mesh cover, the sound emitting unit is arranged in the housing, the sound emitting unit comprises a diaphragm which vibrates along a front-rear extending vibration axis, the diaphragm has a front surface facing forward and a back surface facing backward; the mesh cover covers the front surface of the diaphragm; the mesh cover comprises a fixing ring, a grid part and a shielding part, the fixing ring is connected with the housing; the grid part is located between the fixing ring and the shielding part, the fixing ring surrounds the grid part, the grid part surrounds the shielding part, the grid part has a plurality of grid holes for air flow; the middle part of the shielding part is provided with a middle hole for air flow; the shielding part and the diaphragm form a resonance cavity which changes the direction of sound waves.

[0058] Clause 2, the vehicle warning device according to clause 1, wherein, in the diameter direction of the mesh cover, the ratio of the total width of the shielding part to the diameter of the mesh cover is greater than 0.5.

[0059] Clause 3, the vehicle warning device according to Clause 2, wherein a ratio of the total width of the baffle portion to the diameter of the mesh cover is 0.55 to 0.95.

[0060] Clause 4, the vehicle warning device according to Clause 1, wherein the through-hole extends along the vibration axis, the through-hole has an expanded section adjacent to the diaphragm and a uniform section distal from the diaphragm, a hole diameter of the expanded section gradually decreases from back to front along the vibration axis, and a hole diameter of the uniform section is equal to a minimum hole diameter of the expanded section.

[0061] Clause 5, the vehicle warning device according to Clause 4, wherein a central portion of the diaphragm has a spherical top portion arched upward, a hole wall of the expanded section is located above the spherical top portion, and a shape of the hole wall is a part of a spherical surface matching the spherical top portion.

[0062] Clause 6, the vehicle warning device according to Clause 4, wherein a ratio of the hole diameter of the uniform section to the total width of the baffle portion is less than 0.25.

[0063] Clause 7, the vehicle warning device according to Clause 1, wherein the baffle portion has an inner surface opposite to a front surface of the diaphragm, the inner surface of the baffle portion and the front surface of the diaphragm are parallel to each other; the baffle portion has an outer surface facing forward, and the outer surface is a plane perpendicular to the vibration axis.

[0064] Clause 8, the vehicle warning device according to Clause 7, wherein the diaphragm has a truncated cone-shaped cone, the inner surface is located above the cone, and the inner surface is a conical surface matching a shape of the cone.

[0065] Clause 9, the vehicle warning device according to Clause 1, wherein in a diameter direction of the mesh cover, a ratio of the total width of the grid portion to the middle width of the baffle portion is less than 0.25; and one or more rings of grid holes are provided on the grid portion.

[0066] Clause 10, the vehicle warning device according to clause 1, wherein the housing comprises a frame and a back cover, the magnetic drive assembly of the sound production unit is arranged on the frame, the back cover is connected to the frame and seals the back end of the frame, a closed back cavity is formed between the back cover and the frame, the back cavity and the internal cavity of the sound production unit are communicated; the sound production unit further comprises a positioning support, the positioning support is connected between the voice coil of the sound production unit and the frame, the frame is provided with a mounting protrusion, and the positioning support is limited inside the mounting protrusion; the frame is provided with a clamping groove, and the front piece of the magnetic drive assembly is clamped in the clamping groove; the T iron of the magnetic drive assembly has a cylindrical portion extending forward, the outer diameter of the front end portion of the cylindrical portion is smaller than the outer diameter of the main body of the cylindrical portion, and a through hole extending forward and backward is formed in the cylindrical portion.

[0067] As shown in the specification and claims, the terms "comprise" and "include" only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements.

[0068] Those skilled in the art can understand that, unless specifically stated, the singular forms "a", "said" and "the" used herein also include the plural forms. It can be further understood that "a plurality of" in the present disclosure means two or more, and other quantifiers are similar.

[0069] It can be further understood that the terms "first", "second", and the like are used to describe various information, but these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other, and do not represent a specific order or importance. In fact, the expressions of "first", "second", etc. can be used interchangeably. For example, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information without departing from the scope of the present disclosure.

[0070] In the present disclosure, unless otherwise explicitly specified and limited, "on" or "under" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, "on", "above" and "above" of the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. "Below", "below" and "below" of the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

[0071] The above embodiments are only for illustrating the technical concept and characteristics of the present disclosure, and are preferred embodiments, and the purpose is to enable those skilled in the art to understand the content of the present disclosure and implement it, and cannot limit the protection scope of the present disclosure.

Claims

1. A vehicle warning device, comprising: a housing; a sound emitting unit arranged in the housing, the sound emitting unit comprising a diaphragm vibrating along a front-rear extending vibration axis, the diaphragm having a front surface facing forward and a back surface facing backward; and a mesh cover covering the front surface of the diaphragm, the mesh cover comprising a fixing ring, a grating portion and a shielding portion, the fixing ring being connected with the housing, the grating portion being located between the fixing ring and the shielding portion, the fixing ring surrounding the grating portion, the grating portion surrounding the shielding portion, the grating portion having a plurality of grating holes for air flow, the shielding portion having a middle hole for air flow in a middle portion of the shielding portion, a resonance cavity changing direction of sound waves being formed between the shielding portion and the diaphragm.

2. The vehicle warning device of claim 1, wherein A ratio of a total width of the shielding portion to a diameter of the mesh cover is greater than 0.5 in a diameter direction of the mesh cover.

3. The vehicle warning device of claim 2, wherein The ratio of the total width of the shielding portion to the diameter of the mesh cover is 0.55-0.

95.

4. A vehicle warning device according to any preceding claim, characterised in that, The middle hole extends along the vibration axis, the middle hole having an expanding section adjacent to the diaphragm and a uniform section far from the diaphragm, a hole diameter of the expanding section gradually decreasing from rear to front along the vibration axis, the hole diameter of the uniform section being equal to a minimum hole diameter of the expanding section.

5. The vehicle warning device of claim 4, wherein A middle portion of the diaphragm has a spherical top portion arched forward, a hole wall of the expanding section being located in front of the spherical top portion, and the hole wall being in the shape of a part of a spherical surface matched with the spherical top portion.

6. The vehicle warning device of claim 4, wherein A ratio of the hole diameter of the uniform section to the total width of the shielding portion is less than 0.

25.

7. A vehicle warning device according to any preceding claim, characterised in that, The shielding portion has an inner surface opposite to the front surface of the diaphragm, the inner surface of the shielding portion and the front surface of the diaphragm being parallel to each other, the shielding portion having an outer surface facing forward, the outer surface being a plane perpendicular to the vibration axis.

8. The vehicle warning device of claim 7, wherein The diaphragm has a cone in the shape of a truncated cone, the inner surface being located in front of the cone, and the inner surface being a conical surface matched with the shape of the cone.

9. A vehicle warning device according to any preceding claim, characterised in that, A ratio of a total width of the grating portion to a middle width of the shielding portion is less than 0.25 in a diameter direction of the mesh cover.

10. A vehicle warning device according to any preceding claim, characterised in that, The grating portion is provided with one or more rings of grating holes, the one or more rings of grating holes comprising a plurality of grating holes arranged at intervals along a circumferential direction of the grating portion.

11. A vehicle warning device according to any preceding claim, characterised in that, The housing comprises a frame and a rear cover, a magnetic driving assembly of the sound emitting unit being arranged on the frame, the rear cover being connected with the frame and sealing a rear end of the frame, a closed rear cavity being formed between the rear cover and the frame, the rear cavity being in communication with an inner cavity of the sound emitting unit.

12. The vehicle warning device of claim 11, wherein The sound emitting unit is a moving coil loudspeaker, the sound emitting unit further comprising a positioning support sheet connected between a voice coil of the sound emitting unit and the frame, the frame being provided with a ring of mounting protrusions extending forward or a plurality of mounting protrusions arranged in a ring shape, the positioning support sheet being limited between the mounting protrusions.

13. The vehicle warning device of claim 11 or 12, wherein The frame is provided with a clamping groove, a front sheet of the magnetic driving assembly being clamped in the clamping groove.

14. The vehicle warning device of claim 11 or 12 or 13, wherein, The T-shaped iron of the magnetic driving assembly has a forwardly extending cylindrical portion, the outer diameter of the front end of the cylindrical portion is smaller than the outer diameter of the main body of the cylindrical portion, and a through hole extending forwardly and rearwardly is formed in the cylindrical portion.

15. A vehicle warning system comprising a single vehicle warning device as claimed in any one of claims 1 to 14 and configured to emit a horn sound and a pedestrian warning sound when the vehicle is travelling at a low speed by means of the single vehicle warning device.

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