JPS6128467Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a vehicle acoustic device that utilizes various vehicle panel members as acoustic diaphragms.

Conventional car audio equipment, such as speakers, is a type of speaker unit equipped with a diaphragm such as a paper cone, and is used as a single full-range type or as a two-way type in combination with multiple speakers.
These completed speakers are installed as either embedded or standing speakers in predetermined positions, such as in the front panel, front door, rear side, or rear parcel shelf.

However, in order to fully reproduce low frequencies below 200 Hz with a normal speaker unit made of paper cone, etc., a speaker unit with a diameter of nearly 20 cm is required, and a large number of various parts are integrated. In vehicles, the size of the speaker unit that can be mounted is limited due to its mounting position, etc., so with the exception of some large vehicles, it is generally difficult to use large-diameter speakers such as the one described above. be. Furthermore, if such a large-diameter speaker is forcibly placed on the rear parcel shelf, a problem arises in that it obstructs the rear view.

Therefore, in practice, speaker units with a diameter of about 5 to 10 cm are mainly used, and therefore the reproduction of low frequency ranges is insufficient.

Therefore, the present applicant has previously developed an acoustic excitation driver for various panel members such as plywood, iron plates, and synthetic resin plates used in various parts of vehicles, such as rear parcel shells, door trims, door inner panels, and head linings. The present invention has proposed an acoustic device for a vehicle in which the excitation force is transmitted to the panel member so that the panel member itself acts as an acoustic diaphragm and generates vibration sound. According to this, since it is small and does not occupy space in the vehicle interior, and a large vibration area can be obtained, it is possible to reproduce low frequency sounds comparable to a large-diameter speaker.

By the way, as mentioned above, the rear parcel shelf used as a diaphragm is generally rigidly fixed at the outer edge, etc., so when the mid-to-high range reaches a certain level, split vibration occurs and distortion occurs. It becomes a sound. Therefore, when considering sound quality, it is necessary to use a normal speaker unit for medium and high frequency reproduction in addition to the panel type speaker using the above-mentioned excitation driver, and also to prevent distorted medium and high frequencies from being reproduced from the panel type speaker. In this case, it is necessary to input signals separated into respective predetermined frequency bands using a channel divider. Therefore, there is a risk that the audio unit will become complicated and expensive.

In view of the above points, this idea includes an elastic member that damps and blocks predetermined medium and high frequency vibrations, for example, between the panel member and the acoustic vibration driver, or in the transmission path of the vibration force inside the vibration driver. By interposing it, it forms a kind of low-pass filter and prevents the generation of distorted mid-to-high frequencies without performing electrical signal processing, so that only good bass can be obtained from this panel speaker. This is what I did.

Hereinafter, an embodiment in which this invention is applied to a rear parcel shelf of an automobile will be described in detail with reference to the drawings.

Figures 1 and 2 show an example in which a rubber sheet is used as an elastic member for blocking mid- and high-frequency sounds, and 1 shows a rear parcel inner which is a rigid non-vibrating member whose outer edge is joined to a vehicle body member 2. This rear parcel inner panel 1 has a rib 4 on its outer edge, and has a normal speaker unit 5, such as a moving coil type speaker unit, equipped with cone paper as a diaphragm on both left and right sides. , 6 are installed for medium and high frequency reproduction.
Reference numeral 7 denotes a rear parcel shelf used as an acoustic diaphragm, which is formed by, for example, hardboard as a core material and a surface material such as carpet attached thereto. Synthetic resin covers 8, 8 with slits formed therein.
is installed. A rubber sheet 9 is attached to the entire rear surface of the rear parcel shelf 7, which is a transmission path for the excitation force. At the same time, a vibration driver 11 is attached to the center of the back surface of the rubber sheet 9 via the rubber sheet 9.

FIG. 3 shows the configuration of the vibration driver 11, in which 12 is a magnet for forming a magnetic field between the pole piece 13 and the yoke plate 14;
15 is a coil placed in the magnetic field, 16 is a vibrating plate on which a bobbin 17 is fixed to support this coil 15, and the above-mentioned pole piece 13, yoke plate 14, and magnet 12 are integrated. It is elastically supported by a cover 19 via an elastic ring 18, and the cover 19, together with the vibrating plate 16, is fixed to the rear parcel shelf 7 via the rubber sheet 9.

Therefore, when a signal current flows through the coil 15, the pole piece 13 etc. supported via the elastic ring 18 and the vibration plate 16 vibrate relative to each other, causing the rear parcel to which the vibration plate 16 is attached to vibrate. Excite Shelf 7. In response to this vibration input, the rear parcel shelf 7 vibrates around the fixed outer edge as nodes, and as a result reproduces sound in the same way as a normal speaker unit. Here, since an elastic rubber sheet 9 is interposed between the vibration plate 16 and the rear parcel shelf 7, when the frequency of the signal current becomes high, the rubber sheet 9 attenuates the vibration force. Because of this, the rear parcel shelf 7 does not vibrate. In other words, only a predetermined low frequency range is reproduced from the panel type speaker using the rear parcel shelf 7 as a diaphragm. Therefore, there is no need to separate the frequency bands of the respective signals for the speaker units 5, 6 and the vibration driver 11. Furthermore, by attaching the rubber sheet 9 to the entire rear surface of the rear parcel shelf 7 as described above, it is possible to prevent chattering noise caused by interference with the rear parcel inner panel 1, vehicle body members 2, etc.

Next, FIGS. 4 and 5 show an embodiment in which a leaf spring is used as an elastic member for blocking middle and high frequency ranges, and the same parts as in the previous embodiment are given the same reference numerals. That is, in this embodiment, a strip-shaped leaf spring 21 is attached to the back surface of the rear parcel shelf 7 fixed to the rib 4 of the rear parcel inner panel 1 with screws 10.
is fixed at both ends with rivets 22 and is arranged in a slightly curved shape, and the vibration driver 11 is attached to the center of this leaf spring 21 which can vibrate vertically.

Therefore, as in the above embodiment, when the frequency of the signal current increases, the excitation force generated by the excitation driver 11 is attenuated and blocked by the action of the leaf spring 21.
This functions like a kind of low-pass filter, and only a predetermined low frequency range is reproduced from the panel speaker using the rear parcel shelf 7 as a diaphragm. Furthermore, by attaching the vibration driver 11 to a plate spring 21 which is an elastic member, the plate spring 21 functions as a heat sink, and the vibration driver 11 functions as a heat sink.
The heat generated by the first coil 15 can be quickly radiated.

In place of the leaf spring 21, as shown in FIG. A similar effect can be obtained by doing so.

Next, FIG. 7 shows an embodiment in which an elastic member for blocking middle and high frequency ranges is integrated into the vibration driver. This vibration driver 11' is particularly suitable for the cover 1.
9' is formed into two parts, a base 32 having a mounting flange 31 and a head 33, and a vibrating plate 16 having a coil 15 and a bobbin 17 is fixed to the head 33, and a magnet 12,
The pole piece 13 and the yoke plate 14 are integrally connected to the cover 1 via the elastic ring 18.
It is elastically supported by the head 33 of 9'. and,
The base 32 and head 33 of the cover 19' are connected via an annular rubber ring 34, which is an elastic member having a predetermined elasticity.

Therefore, the excitation force due to the relative vibration between the magnet 12 etc. and the coil 15 is transmitted from the head 33 of the cover 19' via the rubber ring 34 to the rear to which the base 32 of the cover 19' is fixed. When the frequency of the signal current becomes higher, the vibration in the head 33 is attenuated and blocked by the rubber ring 34, and the vibration is transmitted to the rear parcel shelf 7, as in each of the above embodiments. 7
is not transmitted.

Above, various embodiments have been described in which a rear parcel shelf is used as a vehicle panel member serving as an acoustic diaphragm. However, this invention is not limited to this, and can be applied to various panels such as door trims, head linings, instrument panels, etc. Applicable to members.

As is clear from the above explanation, according to this invention, the elastic member functions as a kind of low-pass filter, and there is no need for special signal processing such as separating frequency bands using a channel divider.
Only good low tones, excluding distorted middle and high tones, can be obtained as the sound reproduced from the panel member. Therefore, it is possible to obtain bass sound comparable to that of large-diameter speakers, which conventionally could not be installed in vehicles due to installation space, with comparable sound quality, and to solve problems that arise when audio units become complex. .

[Brief explanation of the drawing]

Figure 1 is a plan view of a rear parcel shelf showing an embodiment using a rubber sheet as the elastic member;
The figure is a cross-sectional view taken along the - line, Figure 3 is a cross-sectional view of the vibration driver, Figure 4 is a plan view of the main part of the rear parcel shelf showing an embodiment using a leaf spring as the elastic member, and Figure 5 is a cross-sectional view of the vibration driver. The figure is a cross-sectional view taken along the - line, Figure 6 is a cross-sectional view of the main part of a rear parcel shelf showing an example using an insulator as an elastic member, and Figure 7 is a sectional view of the elastic member integrated into the vibration driver. FIG. 2 is a cross-sectional view of a vibrating driver showing an example of the configuration. 1...Rear parcel inner panel, 5, 6...Speaker unit, 7...Rear parcel shelf, 9...
Rubber sheet, 11, 11'... Vibration driver, 12
...Magnet, 13...Pole piece, 15...Coil, 16...Vibration plate, 19, 19'...Cover, 21
...Plate spring, 23...Insulator, 34...Rubber ring.

Claims (1)

[Scope of utility model registration request] In a vehicle acoustic device, an acoustic excitation driver is attached to a panel member at an appropriate position of a vehicle, and the excitation force is transmitted to the panel member to cause the panel member itself to act as an acoustic diaphragm to vibrate and generate sound. 1. An acoustic device for a vehicle, characterized in that an elastic member is interposed in a transmission path to attenuate and block predetermined medium and high frequency vibrations.