JP2003087884A - On-vehicle loudspeaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle loudspeaker system that can reproduce original sound with medium and high sound frequencies with fidelity. SOLUTION: In the on-vehicle loudspeaker system 10 for producing sound in a passenger compartment 102 in an automobile 100, an opening 110a is formed in the middle of a partition wall between the passenger compartment 102 and a baggage compartment 104, the opening 110a is closed by one-side wall 14 of a hollow enclosure 12 and center of piezoelectric diaphragms 22, 24, 26 is supported at the interior of the side wall 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle speaker system which produces sound in a passenger compartment of an automobile.

[0002]

2. Description of the Related Art Conventionally, a so-called car audio system which generates a sound in a passenger compartment of an automobile has been used. A speaker used in such a car audio system is a dynamic speaker that vibrates a cone paper by a voice coil, and is generally attached to a dashboard, a front door, a front pillar, a rear shelf, or the like.

[0003]

However, in the dynamic speaker, the magnet of the voice coil for vibrating the cone paper is very heavy, and it follows the audio signal input to the speaker especially in the middle and high range where acceleration is high. The original sound cannot be reproduced faithfully.

[0004] The present invention has a technical problem to solve the problems of the prior art, and an object thereof is to provide an in-vehicle speaker system capable of faithfully reproducing an original sound in a middle and high range.

[0005]

According to a first aspect of the present invention, in an in-vehicle speaker system for producing a sound in a passenger compartment of an automobile, an opening is provided at a central portion of a partition wall between the passenger compartment and the luggage compartment. A gist of a vehicle-mounted speaker system in which the opening is formed and closed by one side wall of a hollow enclosure, and a piezoelectric vibration plate is centrally supported on the inner surface of the side wall.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Referring to FIG. 1, a cross section of a rear bulkhead 110 as a partition wall between a passenger compartment 102 and a luggage compartment 104 of an automobile 100 is shown. In the center of the rear bulkhead 110, the passenger compartment 102
An opening portion 110a that connects the luggage compartment 104 and the luggage compartment 104 is formed, and the opening portion 110a is closed by the speaker system 10 attached to the luggage compartment 104 side of the rear bulkhead 110.

In addition, the passenger compartment 10 of the rear bulkhead 110
A rear seat assembly 108 is disposed on the second side, and the rear seat assembly 108 is a seat 108 on which a person sits.
a, a backrest 108b, and an armrest 108 disposed at a position corresponding to the opening 110a in the backrest 108b (see FIG. 2). Armrest 1
2 is a protrusion position indicated by a two-dot chain line in FIG.
It is rotatable about the rotation shaft 108a between itself and the storage position shown in FIG. Armrest 1 in protruding position
08 is the sheet 108 as indicated by the two-dot chain line in FIG.
It is arranged on the upper surface of a and the backrest 108 in the storage position.
It is arranged in b (see FIG. 2).

Referring to FIG. 3, the speaker system 10
Is provided with a hollow rectangular parallelepiped enclosure 12 and a piezoelectric vibrating body 20 arranged in the enclosure 12. The enclosure 12 is the speaker system 1
It has a side wall 14 that closes the opening 110a when 0 is attached to the rear bulkhead 110. The side wall 1
4 is preferably formed from a non-combustible foam material,
More preferably, it is formed by a plate member having a thickness of at least 10 mm. The piezoelectric vibrating body 20 includes a circular thin plate 22 made of metal such as brass or stainless steel, and the thin metal plate 22.
A piezoelectric vibrating plate having ceramic layers 24 and 26 adhered to both side surfaces of the side wall is centrally supported with respect to the inner surface of the side wall 14 via a column 30. An annular damper 28 is attached to the surface of the piezoelectric diaphragm opposite to the side wall 14.

The operation of this embodiment will be described below. By applying an audio signal to the piezoelectric diaphragm of the piezoelectric vibrating body 20 from an amplifier (not shown), the piezoelectric diaphragm vibrates according to the audio signal. At this time, when the piezoelectric diaphragm bends, the damper 28 acts as an inertial mass body, and at this time, therefore, the damper 28 tries to continue to stop in its original position due to the inertial force. The center of the moves in the front-back direction. The vibration of the piezoelectric diaphragm is transmitted through the support column 30 to the side wall 1
4 and transmitted from the side wall 14 to the opening 11 of the partition wall 110.
Sound waves are propagated as a sound wave forward in the passenger compartment 102 through 0a.

Since the piezoelectric diaphragm has a small inertial mass, it can faithfully follow the audio signal even if the frequency of vibration of the audio signal applied to the piezoelectric diaphragm becomes high.
The dynamic speaker can faithfully reproduce the original sound in the mid-high range where the sound quality deteriorates. In particular, recently, an audio system has been proposed which reproduces high-pitched sound exceeding 20 KHz, which is a human audible range. However, according to the speaker system of the present invention, even in such an audio system,
The piezoelectric diaphragm can faithfully follow an audio signal.

[0011]

Since the piezoelectric diaphragm has a small inertial mass,
Even if the frequency of the vibration of the audio signal applied to the piezoelectric diaphragm becomes high, it is possible to faithfully follow the audio signal, and the dynamic speaker can faithfully reproduce the original sound in the mid-high range where the sound quality deteriorates. is there.

Further, by forming the side wall to which the piezoelectric vibrating plate is attached with the foam material, it is possible to improve the bass characteristic of the speaker system using the piezoelectric vibrating body and to increase the sound pressure in the bass range.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a rear portion of an automobile.

FIG. 2 is a perspective view of a rear portion of a passenger compartment of an automobile.

FIG. 3 is a cross-sectional view of a speaker system according to a preferred embodiment of the present invention.

[Explanation of symbols]

10 ... Speaker system 12 ... Enclosure 14 ... Side wall 20 ... Piezoelectric vibrator 22 ... Metal thin plate 24 ... Ceramic layer 26 ... Ceramic layer 28 ... Damper 30 ... Prop 100 ... Car 102 ... guest room 104 ... luggage compartment 106 ... Rear seat assembly 108 ... Armrest 110 ... Rear bulkhead

Claims (3)

[Claims] 1. An in-vehicle speaker system for generating sound in a passenger compartment of an automobile, wherein an opening is formed in a central portion of a partition wall between the passenger compartment and the luggage compartment.
An in-vehicle speaker system in which the opening is closed by one side wall of a hollow enclosure, and a piezoelectric diaphragm is centrally supported on the inner surface of the side wall. 2. A side wall for closing the opening of the partition wall,
The vehicle-mounted speaker system according to claim 1, which is formed of a foam material. 3. A rear seat assembly of the automobile is disposed on the passenger compartment side of the partition wall, and in a backrest of the rear seat assembly, a portion corresponding to an opening of the partition wall rotates forward. The in-vehicle speaker system according to claim 1 or 2, wherein