Vehicle-mounted headrest

Abstract

The present invention provides a vehicle-mounted headrest, comprising a headrest body and loudspeaker modules. Each loudspeaker module comprises a housing fixed to the headrest body and a sound production device accommodated in the housing; the sound production device comprises a diaphragm used for vibrating to produce sound; a sound outlet through hole is formed in the housing; the diaphragm and the housing define a coupled rear cavity not communicated with the sound outlet through hole; a back sound outlet hole communicated with the coupled rear cavity is further provided in the housing; and the loudspeaker module further comprises an acoustic phase reversing tube accommodated in the coupled rear cavity. The loudspeaker module of the present invention is provided with the coupled rear cavity, so that the sound radiated outwards by the vehicle-mounted headrest due to passive vibration can be reduced, and the acoustic privacy effect of the vehicle-mounted headrest can be improved, the acoustic phase reversing tube can transmit the sound radiated backwards by the sound production device to the outside of the speaker module, so that the low-frequency performance of the loudspeaker module can be improved, the sound quality of the vehicle-mounted headrest is improved, and thus, the acoustic experience of the vehicle-mounted headrest is optimized.

Description

A vehicle headrest Technical Field

[0001] The invention belongs to the technical field of automobile accessories, and in particular relates to a vehicle-mounted headrest. Background Art

[0002] Currently, the degree and breadth of intelligent vehicle cockpits are increasing. As a key component of in-car entertainment systems, audio systems are becoming increasingly important to consumers. Headrest speakers are increasingly being equipped in a growing number of models. These not only provide enhanced near-field surround sound but also offer a degree of independent navigation, calling, and voice interaction for the driver's seat. It's safe to say that headrest speakers will gradually become standard equipment in intelligent cockpits.

[0003] In related technologies, on the one hand, headrest speakers are limited by the size of the headrest space, resulting in relatively small sizes of the sound units or sound modules, and a huge gap in sound quality compared to the whole vehicle speakers; on the other hand, one of the original intentions of the design of headrest speakers was to provide passengers with a relatively independent and private sound area, but traditional design solutions cannot achieve better sound zoning or sound isolation effects, resulting in a poor user experience.

[0004] Therefore, it is necessary to provide a new vehicle-mounted headrest. Technical issues

[0005] The purpose of the present invention is to provide a vehicle headrest that can solve the technical problems of poor sound quality and privacy in the related art. Technical Solutions

[0006] The technical solution of the present invention is as follows: A vehicle headrest includes a headrest body having an accommodating cavity and a speaker module at least partially accommodated in the accommodating cavity, the speaker module including a shell fixed to the headrest body and a sound-generating device accommodated in the shell, the sound-generating device including a diaphragm for vibrating and producing sound, the shell being provided with a sound outlet hole, and sound waves generated by the vibration of the diaphragm being transmitted to the outside through the sound outlet hole, the diaphragm and the shell enclosing a coupling rear cavity that is not connected to the sound outlet hole, the shell being further provided with a rear sound outlet hole communicating with the coupling rear cavity, the speaker module further including a sound reflection tube accommodated in the coupling rear cavity, the sound reflection tube being provided with a first opening and a second opening at both ends thereof, the first opening being communicated with the rear sound outlet hole, and the second opening being communicated with the coupling rear cavity, the headrest body being provided with a first sound outlet hole extending therethrough, the first sound outlet hole being communicated with the rear sound outlet hole.

[0007] Optionally, the shell is completely accommodated in the accommodating cavity, and the shell includes a front cover and a rear cover that are relatively spaced apart, and a side wall connecting the front cover and the rear cover, the sound outlet hole is provided in the front cover, and the back-facing sound outlet hole is provided in the rear cover, and the headrest body is also provided with a second sound outlet hole that is arranged opposite to the sound outlet hole, and the sound waves generated by the diaphragm are transmitted to the outside world through the sound outlet hole and the second sound outlet hole.

[0008] Optionally, the diaphragm is fixed to the front cover and covers the sound outlet hole, and the sound outlet hole is arranged opposite to the diaphragm along the vibration direction of the diaphragm.

[0009] Optionally, the diaphragm is fixed to the side wall, and the diaphragm, the side wall and the front cover are arranged to form a sound-conducting front cavity connected to the sound outlet hole, and the sound outlet hole is staggered with the diaphragm along the vibration direction of the diaphragm.

[0010] Optionally, the headrest body is provided with a second sound outlet hole passing through the headrest body, the shell partially extends out of the accommodating cavity through the second sound outlet hole, and the sound outlet through hole is provided outside the accommodating cavity.

[0011] Optionally, the shell includes a front cover and a rear cover arranged relatively spaced apart, and a side wall connecting the front cover and the rear cover, the front cover and part of the side wall extend outside the accommodating cavity through the second sound outlet hole, and the sound outlet through hole is provided on the side wall.

[0012] Optionally, a raised portion is provided on one side of the front cover close to the rear cover, and the diaphragm is fixed to the raised portion and the side wall respectively. The diaphragm, the side wall and the raised portion surround and form a sound-conducting front cavity connected to the sound outlet hole.

[0013] Optionally, the phase of the sound radiated from the back-facing sound outlet hole and the phase of the sound radiated from the sound outlet through hole have a preset phase difference, and the value range of the preset phase difference is:

[0014] Optionally, the sound radiated from the back-facing sound outlet hole and the sound radiated from the sound outlet through hole satisfy the following relationship:

[0015] Among them, U l is the volume velocity of the radiation from the back-to-sound hole, Us is the volume velocity of the radiation from the sound outlet hole, r l is the acoustic resistance of the acoustic inverting tube, M l is the acoustic mass of the acoustic inverting tube, r b is the acoustic impedance of the coupling cavity, C b is the acoustic capacity of the coupled rear cavity, ω is the angular frequency of the sound wave, and j is an imaginary unit. Beneficial effects

[0016] The beneficial effects of the present invention are as follows: because the speaker module is provided with a coupled rear cavity, the mechanical vibrations generated by the sound-generating device during operation are weakened by the structural member forming the coupled rear cavity, and the air vibrations generated by the sound-generating device during operation are isolated by the coupled rear cavity, reducing the vibration transmission to the headrest body, thereby reducing the sound radiated outward by the passive vibration of the vehicle headrest; moreover, the sound radiated in the forward direction by the sound-generating device is directly transmitted to the user's ear at the location of the vehicle headrest through the sound outlet hole, and the sound radiated in the reverse direction by the sound-generating device is isolated by the coupled rear cavity and will not be transmitted to the reverse side of the vehicle headrest or other directions, thereby improving the acoustic privacy effect of the vehicle headrest. In addition, because an acoustic reflection tube is provided in the coupled rear cavity, the acoustic reflection tube can transmit the sound radiated in the reverse direction of the sound-generating device to the outside of the speaker module, thereby improving the low-frequency performance of the speaker module, improving the sound quality of the vehicle headrest, and thus optimizing the acoustic experience of the vehicle headrest. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a schematic diagram of the overall structure of a speaker module in a vehicle headrest provided by the present invention, which is a positive sound-emitting structure;

[0018] FIG2 is a front view of the vehicle headrest in Example 1 provided by the present invention;

[0019] FIG3 is a cross-sectional view taken along the line AA in FIG2 ;

[0020] FIG4 is an enlarged view of detail B in FIG3 ;

[0021] FIG5 is a front view of a vehicle headrest according to Example 2 of the present invention;

[0022] FIG6 is a cross-sectional view taken along the CC line in FIG5 ;

[0023] FIG7 is an enlarged view of detail D in FIG6 ;

[0024] FIG8 is a schematic diagram of the overall structure of the vehicle headrest in Example 3 provided by the present invention;

[0025] FIG9 is a front view of a vehicle headrest according to Example 3 of the present invention;

[0026] FIG10 is a cross-sectional view taken along line EE in FIG9 ;

[0027] FIG11 is an enlarged view of detail F in FIG10 ;

[0028] FIG12 is a schematic diagram showing a comparison of the acoustic performance of a vehicle headrest speaker module when no acoustic reflection tube is provided in the coupling rear cavity and when an acoustic reflection tube is provided in the coupling rear cavity;

[0029] FIG13 is a schematic diagram comparing the acoustic isolation effects of a vehicle headrest with a speaker module and a vehicle headrest without a speaker module;

[0030] FIG14 is a schematic diagram of the assembly of the vehicle headrest, the first microphone and the second microphone in the vehicle. Modes for Carrying Out the Invention

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] Referring to Figures 1 to 10 , the present invention provides a vehicle headrest 30 comprising a headrest body 1 having an accommodating cavity 11 and a speaker module 2 housed within the accommodating cavity 11. The speaker module 2 comprises a housing 21 secured to the headrest body 1 and a sound-generating device 22 housed within the housing 21. The sound-generating device 22 is an electroacoustic transducer that converts electrical signals into acoustic signals. The specific structure of the sound-generating device 22 can be designed based on actual usage requirements.

[0033] Referring to Figures 4, 7, and 10, in the embodiment provided by the present invention, the sound-generating device 22 includes a diaphragm 221 for vibrating and producing sound. The housing 21 is provided with a sound outlet hole 214. The sound waves generated by the vibration of the diaphragm 221 are transmitted to the outside world through the sound outlet hole 214. The diaphragm 221 and the housing 21 together form a coupling rear cavity 215 that is not connected to the sound outlet hole 214. The housing 21 is also provided with a rear sound outlet hole 216 that communicates with the coupling rear cavity 215. The speaker module 2 also includes an acoustic reflection tube 23 housed within the coupling rear cavity 215. The acoustic reflection tube 23 has a first opening 231 and a second opening 232 at its ends. The first opening 231 communicates with the rear sound outlet hole 216, and the second opening 232 communicates with the coupling rear cavity 215. The headrest body 1 is provided with a first sound outlet hole 12 extending therethrough, communicating with the rear sound outlet hole 216.

[0034] Since the speaker module 2 is provided with a coupling rear cavity 215, the mechanical vibration generated by the sound-generating device 22 when it is working will be weakened by the structural parts forming the coupling rear cavity 215, and the air vibration generated by the sound-generating device 22 when it is working will be isolated by the coupling rear cavity 215, reducing the vibration transmission to the headrest body 1, thereby reducing the sound radiated outward due to passive vibration of the vehicle headrest 30; moreover, the sound radiated forward by the sound-generating device 22 will be directly transmitted to the ears of the user at the location of the vehicle headrest 30 through the sound outlet hole 214, and the sound generated by the back radiation of the sound-generating device 22 will be isolated by the coupling rear cavity 215 and will not be transmitted to the back or other directions of the vehicle headrest 30, thereby improving the acoustic privacy effect of the vehicle headrest 30. In addition, since the acoustic reflection tube 23 is set in the coupling rear cavity 215, the acoustic reflection tube 23 can transmit the sound radiated backward by the sound-emitting device 22 to the outside of the speaker module 2, thereby improving the low-frequency performance of the speaker module 2, improving the sound quality of the vehicle headrest 30, and further optimizing the acoustic experience of the vehicle headrest 30.

[0035] It should be noted that in actual application scenarios, the sound outlet hole 214 is close to the human ear side, and the back-facing sound outlet hole 216 is far away from the human ear side; reducing the passive vibration effect of the vehicle headrest 30 can also improve its pillow comfort.

[0036] In some embodiments, one or more speaker modules 2 may be disposed within the headrest body 1. For example, as shown in FIG3 , two symmetrically distributed speaker modules 2 may be disposed within the headrest body 1. One or more acoustic reflection tubes 23 may be disposed within the coupling rear cavity 215. For example, as shown in FIG3 , one acoustic reflection tube 23 may be disposed within the coupling rear cavity 215.

[0037] It should be understood that, as shown in Figures 1 and 8, the vehicle headrest 30 is U-shaped. When two speaker modules 2 are provided in the headrest body 1, the two speaker modules 2 are respectively provided at the ends of the headrest body 1 and are symmetrically arranged along the central axis of the vehicle headrest 30. When the user rests his head on the vehicle headrest 30, the human ears correspond to the two speaker modules 2 respectively, which further improves the sound quality and acoustic privacy effect of the vehicle headrest 30.

[0038] The speaker module 2 in the vehicle headrest 30 provided by the present invention can be a front sound-emitting structure or a side sound-emitting structure, which will be described in detail in conjunction with the following embodiments.

[0039] Example 1:

[0040] The speaker module 2 in the vehicle headrest 30 provided in this embodiment is a positive sound-emitting structure.

[0041] Referring to Figures 1 to 4 , the housing 21 is completely housed within the accommodating cavity 11 . The housing 21 includes a front cover 212 and a rear cover 213 spaced apart from each other, as well as a sidewall 211 connecting the front and rear covers 212 and 213 A sound outlet 214 is provided in the front cover 212 , and a back-facing sound outlet 216 is provided in the rear cover 213 The headrest body 1 also includes a second sound outlet 13 , located opposite the sound outlet 214 . Sound waves generated by the diaphragm 221 are transmitted to the outside world through the sound outlet 214 and the second sound outlet 13 . Multiple second sound outlets 13 are provided and arranged in an array.

[0042] Please refer to FIG. 4 . The diaphragm 221 is fixed to the front cover 212 and covers the sound outlet hole 214 . The sound outlet hole 214 is arranged opposite to the diaphragm 221 along the vibration direction of the diaphragm 221 .

[0043] By using the loudspeaker module 2 provided in this embodiment, the path of sound radiation propagation can be shortened, thereby reducing the attenuation of the sound radiation propagation process.

[0044] Example 2:

[0045] Please refer to Figures 5, 6 and 7. The speaker module 2 in the vehicle headrest 30 provided in this embodiment is also a positive sound-emitting structure. Unlike Example 1, the diaphragm 221 is fixed to the side wall 211, and the diaphragm 221, the side wall 211 and the front cover 212 are arranged to form a sound-conducting front cavity 217 connected to the sound-emitting through hole 214. The sound-emitting through hole 214 is staggered with the diaphragm 221 along the vibration direction of the diaphragm 221.

[0046] By using the speaker module 2 provided in this embodiment, the relative position between the second sound outlet 13 and the human ear can be adjusted through the sound-conducting front cavity 217, so that the second sound outlet 13 is closer to the position of the human ear, thereby increasing the coupling between the sound position of the vehicle headrest 30 and the human ear, thereby achieving the effect of improving the privacy of the vehicle headrest 30.

[0047] Example 3:

[0048] The speaker module 2 in the vehicle headrest 30 provided in this embodiment is a side sound-emitting structure.

[0049] Referring to Figures 8 to 11 , the headrest body 1 is provided with a second sound outlet hole (not shown) extending therethrough. The housing 21 partially extends outside the accommodating cavity 11 via the second sound outlet hole, and a sound outlet hole 214 is provided outside the accommodating cavity 11. The housing 21 includes a front cover 212 and a rear cover 213 spaced apart from each other, and a side wall 211 connecting the front cover 212 and the rear cover 213. The front cover 212 and a portion of the side wall 211 extend outside the accommodating cavity 11 via the second sound outlet hole. The sound outlet hole 214 is provided in the side wall 211, and the axial extension direction of the sound outlet hole 214 is not aligned with the vibration direction of the diaphragm 221.

[0050] Please refer to Figure 11. A raised portion 2121 is provided on one side of the front cover 212 close to the rear cover 213. The diaphragm 221 is fixed to the raised portion 2121 and the side wall 211. The diaphragm 221, the side wall 211 and the raised portion 2121 are surrounded to form a sound-conducting front cavity 217 connected to the sound-emitting through hole 214. The relative position between the sound-emitting through hole 214 and the human ear can be adjusted through the sound-conducting front cavity 217, so that the sound-emitting through hole 214 is closer to the position of the human ear, thereby increasing the coupling between the sound-emitting position of the vehicle headrest 30 and the human ear, thereby achieving the effect of improving the privacy of the vehicle headrest 30.

[0051] It should be noted that, in other examples, the diaphragm 221 may be fixed to the side wall 111 and cover the sound outlet hole 214 provided on the side wall 211 , so that the sound waves generated by the vibration of the diaphragm 221 can be directly transmitted to the outside through the sound outlet hole 214 .

[0052] Please refer to Figure 12, which shows a schematic comparison of the acoustic performance of the speaker module 2 in the vehicle headrest 30 before and after improvements. The "before" curve refers to the absence of the acoustic reflection tube 23 within the coupling rear cavity 215, as shown in curve a; the "after" curve refers to the presence of the acoustic reflection tube 23 within the coupling rear cavity 215, as shown in curve b. Both curves a and b are frequency response curves measured at the user's ear with an input voltage of 1W and the microphone positioned within the vehicle headrest 30. This comparison reveals that the speaker module 2 with the acoustic reflection tube 23 within the coupling rear cavity 215 exhibits significantly improved low-frequency performance.

[0053] Please refer to Figures 13 and 14. Figure 13 shows a schematic diagram comparing the acoustic isolation of a vehicle headrest 30 equipped with a speaker module 2 (curve c) and without the speaker module 2 (curve d). The difference in the acoustic frequency response measured by the first microphone 10 and the second microphone 20 represents the acoustic isolation of the vehicle headrest 30 in the primary driver's seat. Figure 14 shows the assembly of the vehicle headrest 30, the first microphone 10, and the second microphone 20 in a vehicle. The vehicle headrest 30 is installed on the seat in the primary driver's seat, with the first microphone 10 installed at the primary driver's seat and the second microphone 20 installed at the passenger seat. The comparison shows that the acoustic isolation of the vehicle headrest 30 equipped with the speaker module 2 is significantly better than that of the vehicle headrest 30 without the speaker module 2.

[0054] In some embodiments, the phase of the sound radiated from the back sound outlet 216 and the phase of the sound radiated from the sound outlet through hole 214 have a preset phase difference, and the value range of the preset phase difference is: For example: Etc., thereby generating acoustic cancellation between the back-facing sound outlet hole 216 and the sound outlet through hole 214 , reducing the sound leakage radiated forward by the sound-emitting device 22 , and further improving the privacy effect of the vehicle headrest 30 .

[0055] It should be noted that acoustic cancellation refers to adjusting the structure of the coupling rear cavity 215 and the acoustic inverting tube 23 so that there is a certain phase difference between the phase of the sound radiated back to the sound outlet 216 and the phase of the sound radiated from the sound outlet through hole 214, thereby making the amplitude of the sound after the superposition of the two smaller.

[0056] Specifically, the sound radiated from the sound outlet hole 214 and the sound radiated from the back sound outlet hole 216 satisfy the following relationship:

[0057] Wherein, Us is the volume velocity of the sound outlet hole 214, U l is the volume velocity radiated back to the sound outlet 216, r l is the acoustic resistance of the acoustic inverting tube 23, M l is the acoustic mass of the acoustic inverting tube 23, r b is the acoustic impedance of the coupling rear cavity 215, C b is the acoustic capacity of the coupled rear cavity 215, ω is the angular frequency of the acoustic wave, and j is an imaginary unit.

[0058] By reasoning and transforming the above formula, we can get the following relationship:

[0059] Among them, w c is the resonance angular frequency of the coupling rear cavity 215 and the acoustic inverting tube 23.

[0060] From this we can see that is a complex number and is not always in phase; a phase difference φ exists between them. By adjusting the structure of the coupling rear cavity 215 and the acoustic phase-reversing tube 23, this phase difference φ can be adjusted, reducing the amplitude of the sound radiated from the back of the sound outlet 216 and the sound radiated from the sound outlet through hole 214. This achieves an acoustic cancellation effect, thereby improving the acoustic privacy of the vehicle-mounted needle.

[0061] Specifically, the structure of the coupling rear cavity 215 and the acoustic reflection tube 23 can be adjusted by adjusting the length, opening size, and opening shape of the acoustic reflection tube 23, and adjusting the shape, size, and internal filling of the coupling rear cavity 215. For example:

[0062] In a specific example, the sound-generating device 22 can be a dynamic rectangular loudspeaker with a size of 30mm x 60mm x 18mm, and the volume of the coupled rear cavity 215 can be 15cc. As shown in Figures 3 and 4, one end of the acoustic reflection tube 23 is fixed to the back cover 213, and the other end extends toward the sound-generating device 22. The length of the acoustic reflection tube 23 can be 3cm, and the diameter of the end of the acoustic reflection tube 23 connected to the shell 21 can be 2cm.

[0063] The above description is only an embodiment of the present invention. It should be pointed out that those skilled in the art can make improvements without departing from the creative concept of the present invention, but these improvements all fall within the scope of protection of the present invention.

Claims

1. A vehicle headrest, comprising a headrest body having an accommodating cavity and a speaker module at least partially accommodated in the accommodating cavity, the speaker module comprising a shell fixed to the headrest body and a sound-generating device accommodated in the shell, the sound-generating device comprising a diaphragm for vibrating and producing sound, the shell being provided with a sound-emitting through-hole, the sound waves generated by the vibration of the diaphragm being transmitted to the outside through the sound-emitting through-hole, the diaphragm and the shell enclosing a coupled rear cavity that is not connected to the sound-emitting through-hole, characterized in that: The housing is further provided with a rear sound outlet hole communicating with the coupling rear cavity, the speaker module further includes an acoustic reflection tube accommodated in the coupling rear cavity, the acoustic reflection tube is provided with a first opening and a second opening at both ends thereof, the first opening is communicated with the rear sound outlet hole, and the second opening is communicated with the coupling rear cavity, the headrest body is provided with a first sound outlet hole running therethrough, the first sound outlet hole is communicated with the rear sound outlet hole, the sound phase radiated by the rear sound outlet hole and the sound phase radiated by the sound outlet hole have a preset phase difference, and the value range of the preset phase difference is:

2. The vehicle headrest according to claim 1, characterized in that: The shell is completely accommodated in the accommodating cavity, and includes a front cover and a rear cover that are relatively spaced apart, and a side wall connecting the front cover and the rear cover. The sound outlet hole is provided in the front cover, and the back-facing sound outlet hole is provided in the rear cover. The headrest body is also provided with a second sound outlet hole that is arranged opposite to the sound outlet hole. The sound waves generated by the diaphragm are transmitted to the outside world through the sound outlet hole and the second sound outlet hole.

3. The vehicle headrest according to claim 2, characterized in that: The diaphragm is fixed to the front cover and covers the sound outlet hole. The sound outlet hole is arranged opposite to the diaphragm along the vibration direction of the diaphragm.

4. The vehicle headrest according to claim 2, characterized in that: The diaphragm is fixed to the side wall. The diaphragm, the side wall and the front cover are arranged to form a sound-conducting front cavity connected to the sound-emitting through hole. The sound-emitting through hole is staggered with the diaphragm along the vibration direction of the diaphragm.

5. The vehicle headrest according to claim 1, characterized in that: The headrest body is provided with a second sound outlet hole penetrating therethrough, the shell partially extends out of the accommodating cavity via the second sound outlet hole, and the sound outlet through hole is provided outside the accommodating cavity.

6. The vehicle headrest according to claim 5, characterized in that: The housing includes a front cover and a rear cover that are relatively spaced apart, and a side wall connecting the front cover and the rear cover. The front cover and part of the side wall extend outside the accommodating cavity through the second sound outlet hole. The sound outlet through hole is provided on the side wall.

7. The vehicle headrest according to claim 6, characterized in that: A raised portion is provided on one side of the front cover close to the rear cover, and the diaphragm is fixed to the raised portion and the side wall respectively. The diaphragm, the side wall and the raised portion surround and form a sound-conducting front cavity connected to the sound outlet hole.

8. The vehicle headrest according to claim 1, characterized in that: The sound radiated from the back-facing sound outlet and the sound radiated from the sound outlet through hole satisfy the following relationship: Among them, U l is the volume velocity of the radiation from the back-to-sound hole, Us is the volume velocity of the radiation from the sound outlet hole, r l is the acoustic resistance of the acoustic inverting tube, M l is the acoustic mass of the acoustic inverting tube, r b is the acoustic impedance of the coupling cavity, C b is the acoustic capacity of the coupled rear cavity, ω is the angular frequency of the sound wave, and j is an imaginary unit.

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