JPH0367741A - Roof trim structure for car - Google Patents

Abstract

PURPOSE:To improve the sound quality especially in low-frequency region by keeping a roof trim away from a roof panel to form it into a vibrating plate for speakers which can vibrate up and down, and vibrating the roof trim by an exciting device in response to output signals from acoustic apparatuses. CONSTITUTION:A roof trim 3 is formed by a paper-honeycomb plate 3a containing a great many holes cover sheets 3b arranged on both upper and lower faces of the above plate, and a mesy surface skin 3c. The roof trim 3 is supported through a rubber member 6 on a roof rail 5 of the peripheral edge of a roof panel 2 with the hole kept away from the roof panel 2 so that it can vibrate up and down. Further, an exciting device 4 is fixed at the center part of a reinforcement 7 of the roof rail 5 to connect its exciting part to the center part of the roof trim 3. When on-board acoustic apparatuses are used, output signals in low-frequency region are provided to the exciting device 4, and thus the whole of the roof trim 3 is vibrated by the exciting device 4.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a roof trim structure for a vehicle.

(Prior Art) A vehicle in which a roof trim is provided inside the roof panel is generally known (see Japanese Utility Model Application No. 168142/1983). This roof trim is usually provided for the purpose of improving the appearance of the vehicle interior and absorbing noise inside the vehicle interior.

On the other hand, vehicles are sometimes equipped with audio equipment such as radios and tape decks, and in order to improve their acoustic characteristics, it is common practice to provide a speaker device independent of the audio equipment itself. Dynamic speakers are widely used as this speaker device.

(Problem to be Solved by the Invention) By the way, a speaker device is required to be able to reproduce sound over a wide frequency range from low frequencies to high frequencies, but in the case of a dynamic speaker, the reproduction characteristics of the sound in the low frequency range are Determined by the diameter (area) of the speaker. On the other hand, in a dynamic speaker installed in a vehicle interior, since the vehicle interior itself is generally narrow, the diameter of the speaker must be small, and therefore the characteristics in the low frequency range tend to deteriorate.

That is, an object of the present invention is to improve the acoustic characteristics in the vehicle interior, particularly the characteristics in the low frequency range.

(Means for Solving the Problems) The present invention solves these problems by making it possible to improve the acoustic characteristics in the low frequency range by using the roof trim of a vehicle as a speaker. It is.

That is, the means for this purpose is such that a roof trim that covers the roof panel of the vehicle from the inside constitutes a speaker diaphragm that is separated from the roof panel and can vibrate up and down, and that the roof trim is actuated by an output signal from an audio device to transmit the sound. This is a vehicle roof trim structure characterized in that a vibrator for vibrating the roof trim is attached.

(Function) In the roof trim structure described above, the exciter is activated by the output signal of the audio equipment, and the roof trim vibrates. In other words, the roof trim acts as a diaphragm for the speaker, and since the roof trim has a large area,
It becomes possible to construct a diaphragm with a wide area.

(Effects of the Invention) Therefore, according to the present invention, the roof trim is provided with a speaker vibrating section, and the vibrating section is equipped with an exciter operated by the output signal of the audio equipment. It is possible to supply sound to the occupants from above their heads, and to improve the sound quality in the low frequency range.

(Example) Embodiments of the present invention will be described below based on the drawings.

Example 1- This example is illustrated in FIGS. 1-3.

In a vehicle 1 shown in FIG. 1, 2 is a roof panel, 3 is a roof trim that covers the roof panel 2 from the inside (vehicle interior side), and a vibrator 4 is attached to this roof trim 3.

That is, as shown in FIG. 2, the roof trim 3 includes a paper honeycomb board 3a having a large number of holes penetrating the board surface in a vertical direction, and a paper honeycomb board 3a having holes on the upper surface (roof panel 2 side) of the honeycomb board 3a. The fixed cover sheet 13b and the mesh-like skin (
Cloth) 3c. The roof trim 3 is supported by a hard rubber member 6 on a roof rail 5 provided at the periphery of the roof panel 2 in a state separated from the roof panel 2 so that the entire roof trim 3 can vibrate up and down.

On the other hand, the vibrator 4 uses a giant magnetostrictive alloy whose strain changes with changes in the magnetic field, and is fixed to the center of the reinforcement 7, which is provided laterally in the center of the roof, and is used to excite vibrations. is connected to the center of the roof trim 3. Both ends of the reinforcement 7 are connected to the rain rails 5 on both sides.

Then, as shown in FIG.
Connected via 0. Further, an auxiliary speaker 11 is connected to the output device 8 via an amplifier 12.

Therefore, in the above roof trim structure, when the audio equipment is not used, the honeycomb plate 3a of the roof trim 3 is
By attenuating and absorbing sound vibrations,
In-vehicle noise will be reduced. When the audio equipment is turned on, a signal in the low frequency range outputted from the output device 8 via the low-pass filter 9 is transmitted to the amplifier 1.
The signal is amplified by 0 and applied to the vibrator 4, and the operation of the vibrator 4 causes the entire roof trim 3 to vibrate and emit sound. On the other hand, the auxiliary speaker 11 contributes to the reproduction of high-frequency sounds that are difficult to reproduce with the roof trim 3.

Therefore, the roof trim 3 has contradictory functions of sound absorption and sound production, but since the cover sheet 3b is provided on the honeycomb board 3a, the sound absorption effect of each independent hole of the honeycomb board 3a is not impaired. The roof trim 3 can function as a diaphragm for the speaker, and the above sound absorption and sound production can be achieved at the same time.

Embodiment 2 - This embodiment is shown in FIGS. 4 and 5, in which the air layer 14 between the roof panel 2 and the roof trim 13 can be used for sound absorption.

First, as shown in FIG. 4, in this example, the mounting structure of the roof trim 13 is similar to that of the embodiment f141, but the roof trim 13 is not a honeycomb but a porous plate. And roof panel 2 and roof trim 13
A sheet 15 capable of covering the entire upper surface of the roof trim 13 is provided between the roof trim 13 and the seat 15 so as to be movable up and down by a plurality of solenoid type up and down movement means 16.

That is, the vibrator 4 is fixed to the reinforcement 7 as in the first embodiment, and is activated in response to an output signal from the audio equipment, and its vibrator is attached to the sheet on the roof trim 13. are connected via. The vertical movement means 16 is attached to the front and rear roof rails 17, and the tip (lower end) of the movable rod 16a is connected to the edge of the seat 15. It is designed to move up and down between a contact position where the portion is brought into contact with the upper surface of the roof trim 13 and a separated position where the portion is separated upward from the roof trim 13.

Further, the vertical movement means 16 is configured to stop operating in conjunction with the audio equipment.

Therefore, in this example, as shown in FIG. 5, when the operating switch of the audio equipment is not on, the solenoid type vertical movement means 16 is also off (step S1*82).

In this state, the seat 15 is separated from the roof trim 13, and vibrations caused by sound inside the vehicle are transmitted through the holes in the roof trim 13 to the air layer 1 between the roof trim 13 and the seat 15.
This air layer 14 works together with the roof trim 13 to produce a sound absorbing effect. Then, when the audio equipment is turned on, the vertical movement means 16 is turned on, and the seat 15 moves and comes into close contact with the upper surface of the roof trim 13 (step S3.S
4). Thereby, the roof trim 13 vibrated by the vibrator 4 transmits sound into the vehicle interior.

Therefore, in this example, the roof trim 13 and the seat 1
When using the roof trim 13 as a speaker, while utilizing the air layer 14 between the air layer 1 and the roof trim 13 for sound absorption,
4, it is possible to prevent a decrease in sound pressure.

Note that in the roof trim structure of the first embodiment as well, the cover sheet 3b may be moved up and down in the same manner as in the second embodiment.

[Brief explanation of drawings]

The drawings show embodiments of the present invention, and FIGS. 1 to 3 relate to Embodiment 1, in which FIG. 1 is a perspective view of a vehicle, FIG. 2 is a sectional view showing a roof trim structure, and FIG. 3 is an audio equipment. Fig. TS4 is a sectional view showing the roof trim structure of the second embodiment, and Fig. 5 is a flowchart of seat operation control. 1... Vehicle 2... Roof panel 3.13... Roof trim 4... Vibrator idiot 2 people

Claims (1)

[Claims] (1) A roof trim that covers the roof panel of a vehicle from the inside is separated from the roof panel and constitutes a speaker diaphragm that can vibrate vertically, and the roof trim is actuated by an output signal from an audio device to vibrate the roof trim. A roof trim structure for a vehicle, characterized in that a vibration exciter is attached to the roof trim structure.