JP2565584Y2 - Back cavity structure of embedded speaker for hatchback car - Google Patents

Description

[Detailed description of the invention] [Overview] The present invention extends the path of sound leaking from the back of the speaker to the surface of the tray board, and adds acoustic impedance to this path. Due to the cavity structure, sound leaking from the back of the speaker can be effectively utilized because the low-frequency characteristics are improved and the radiation efficiency is improved.

[Industrial applications]

The present invention relates to a back cavity structure of an embedded speaker for a hatchback vehicle used to reduce a spring action of a closed cabinet.

In particular, the present invention refers to the improvement of the characteristics of sound leaking from the back cavity on the back of the speaker and the effective use of the sound.

[Conventional technology]

FIG. 3 is a view showing the back cavity structure of a conventional embedded speaker for a hatchback vehicle. Note that the same components are denoted by the same reference numerals or symbols throughout the drawings. The configuration of this drawing will be described. As shown in this figure, the structure of the back cavity of an embedded speaker of a body type hatchback car having a tailgate such as a wagon while retaining the basic form as a passenger car includes a tailgate 1 serving as a rear tail and the tailgate. A tray board 2 that is adjacent to 1 and moves up and down with the back position as a fulcrum when loading and unloading luggage;
A rear seat 3 at the front of the tray board 2 and a floor 4 facing the tray board 2 form a space behind a speaker 5 embedded in the tray board 2,
It also has the role of a trunk as a space for luggage.

Next, the operation will be described. In the back cavity structure of the embedded speaker for a hatchback vehicle shown in this figure, the tailgate 1, the tray board 2, the rear seat 3 and the floor 4 are connected to the speaker 5
Construct a closed cabinet. Since the back cavity inside the closed type cabinet is shared with the luggage storage space, the spring action of expanding or compressing the air in response to the vibration of the speaker 5 is relatively widened, and the speaker action is driven by the relaxation of the spring action. To improve the low-frequency response of the speaker 5.

[Problems to be solved by the invention]

However, in the conventional back cavity structure of the hatchback-dedicated embedded speaker, air leaks into the front space of the speaker 5 due to the lack of airtightness of the cavity formed on the back surface of the speaker 5, which is the back space of the tray board 2. As a matter of course, the bass cannot be reproduced, so that there is a problem that the sense of volume at low temperatures is lacking. This air leak is mainly caused by a structurally insidious gap formed between the tailgate 1 and the tray board 2, and further between the tray board 2 and the rear seat, since the tray board 2 is movable at the time of loading and unloading (see FIG. Arrow C) occurs.

In addition, if the sound due to air leakage is to be used positively, the tightness and the feeling of tightness are alienated due to the deflection of the tray board 2 and the volume of the cavity is also the volume of the trunk portion. There was a problem that the radiation efficiency was not good.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a back cavity structure of an embedded speaker for a hatchback vehicle that can effectively utilize sound leaking from the back of the speaker in view of the above problems.

[Means for solving the problem]

In order to solve the above-mentioned problem, the present invention has an acoustic transformer in a back cavity structure of an embedded speaker for a hatchback vehicle.

The acoustic transformer has one end fixed to the tray board and surrounds the back of the speaker, the other open end is spaced apart from the floor and has a taper between the ends.

Bass sound from the back of the speaker leaking out through the gap between the tray board and the tailgate and the gap between the tray board and the rear seat passes through the other open end of the acoustic transformer.

[Action]

According to the back cavity structure of the embedded speaker for a hatchback vehicle of the present invention, the sound from the rear surface of the speaker by the acoustic transformer goes out of the gap of the tray board through the back cavity through the acoustic transformer, so that the path is long. Therefore, interference with sound from the front of the speaker is reduced. Further, the acoustic impedance of the rear surface of the speaker is increased by the acoustic conversion unit, and the low-impedance back cavity is connected to the rear surface of the speaker in a stepwise manner, so that the radiation efficiency from the rear surface of the speaker into the acoustic conversion unit increases. The taper provided in the acoustic transformer prevents cavity resonance. Therefore, the sound leaking from the gap of the tray board has an improved distortion characteristic in a low frequency range and a high radiation efficiency, so that it can be effectively used in the same manner as the sound from the front of the speaker.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a back cavity structure of an embedded speaker for a hatchback vehicle according to a first embodiment of the present invention. The configuration of this drawing will be described. The back cavity structure of the embedded speaker for a hatchback vehicle shown in the figure is a tailgate 1 and a tray board 2 adjacent to the tailgate 1.
A rear seat 3 in front of the tray board 2; a floor 4 facing the tray board 2;
The speaker 5 embedded in the speaker 5 and one end (6A) are fixed to the tray board 2 to surround the rear surface of the speaker 5, and the other open end (6B) is spaced from the floor 4 by a predetermined distance. D
(Approximately 1 cm) and includes an acoustic transformer 6 having a taper between both ends. The size of the acoustic conversion section 6 is selected so that the volume of the trunk section on the back of the speaker 5 is appropriate for the aperture of the speaker 5 and the stiffness (compliance) of the vibration system.

Next, the operation of the present embodiment will be described. The sound emitted from the front of the speaker 5 is the same as the conventional one, but the sound emitted from the back of the speaker 5 passes through the inside of the acoustic transformer 6. The acoustic impedance of the acoustic conversion section 6 is higher than the acoustic impedance of the external back cavity, because the gap between the open end (6B) and the floor 4 at a fixed interval serves as air resistance to the flow of air. For this reason, the radiation efficiency of the low sound passing through the inside of the acoustic conversion unit 6 from the diaphragm of the speaker 5 to the air increases. Furthermore, when the bass goes out of the acoustic transformer 6, the acoustic impedance changes stepwise from high to low, so that the bass efficiently exits the acoustic transformer 6, and furthermore, the tray board 2, the rear seat 3 and It goes out of the back cavity through a gap (arrow C in the figure) between the tray board 2 and the tailgate 1. Therefore, the bass is efficiently radiated out of the back cavity, and furthermore, a path extending from the back of the speaker 5 to the outside of the back cavity is longer than before, so that interference with sound from the front of the speaker 5 is reduced, Distortion at low frequencies is improved.

In other words, the acoustic transformer 6 adds acoustic impedance to the path from the back of the speaker 5 to perform acoustic impedance matching. That is, the acoustic transformer 6 is connected stepwise to a low-impedance space to increase the acoustic load on the back of the speaker 5 to reduce the low-frequency range. By increasing the radiation efficiency of the loudspeaker and lowering the distortion rate of the low-frequency component, it is possible to improve the volume and tightness of the bass sound for the air in the space behind the speaker 5.

Here, the reason why the taper is provided in the acoustic conversion section 6 is that if a simple cylinder is used, there is a possibility that cavity resonance may occur.

In addition, the sound conversion unit 6 may be attached to the tray board 2 with bolts and nuts common to the speaker 5 so that the attachment can be simplified.

FIG. 2 is a view showing a back cavity structure of an embedded speaker for a hatchback vehicle according to a second embodiment of the present invention. The acoustic transformer 6 shown in the figure has a shape in which the narrower frusto-conical openings are connected, and the same effect as that of the first embodiment can be obtained. In securing the tapered shape, the space occupancy is reduced, and the space can be effectively used.

In the first and second embodiments, the tray board 2 may be attached or detached with a buckle or the like when attaching the tray board 2 so that the luggage can be easily put in and out.

Further, a vibration damping material such as butyl rubber is attached to the acoustic conversion section 6 with a width of about 2 to 3 cm on the inner wall portion of the open end of the truncated cone near the floor 4 so as to prevent generation of unnecessary sound due to resonance. (If attached to the outer wall, the clothes may be stained when opening and closing the trunk.)

Further, the present invention can be applied to a vehicle type such as a sedan type.

[Effect of the invention]

As described above, according to the present invention, the path of the sound leaking from the back of the speaker to the surface of the tray board is lengthened, and the acoustic impedance is added to this path. The characteristics are improved and the radiation efficiency is improved and can be used effectively.

[Brief description of the drawings]

FIG. 1 is a diagram showing a back cavity structure of an embedded speaker for a hatchback vehicle according to a first embodiment of the present invention, and FIG. 2 is a back of an embedded speaker for a hatchback vehicle according to a second embodiment of the present invention. FIG. 3 is a diagram showing a cavity structure, and FIG. 3 is a diagram showing a back cavity structure of a conventional embedded speaker for a hatchback vehicle. In the figure, 1... Tail gate, 2... Tray board, 3... Rear seat, 4... Floor, 5.

Claims (1)

(57) [Scope of request for utility model registration] 1. A tailgate (1), a tray board (2) adjacent to the tailgate (1), a rear seat (3) in front of the trayboard (2), and the trayboard (2). ), A back cavity structure of an embedded speaker for a hatchback car having a speaker (5) embedded in the tray board (2), the speaker having a speaker (5) embedded in the tray board (2). ), And surrounds the back surface of the speaker (5), and has an acoustically modified portion (6) having the other open end at a fixed distance from the floor (4) and having a taper between both ends, The low temperature from the back surface of the speaker (5) leaking out from the gap between the tray board (2) and the tailgate (1) and the gap between the tray board (2) and the rear seat (3) is the sound. Metamorphosis section (6) and others Back cavity structure of an embedded speaker for a hatchback car, characterized by passing through the open end of the other.