US20070052136A1

US20070052136A1 - Exclusive molding method for producing cloth-based parts of loudspeaker

Info

Publication number: US20070052136A1
Application number: US11/222,354
Authority: US
Inventors: Hiroshi Ohara
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-09-08
Filing date: 2005-09-08
Publication date: 2007-03-08

Abstract

An exclusive molding method for producing cloth-based parts of loudspeaker is employed to move a resin-dipped and dried cloth roll to pass intermittently through a heating device and a mold set in order, so that the cloth roll is preheated then molded into shape of parts and cut into the desired parts with a heightened working efficiency.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention relates to an exclusive molding method for producing cloth-based parts of loudspeaker, particularly to such a method capable of raising production efficiency of cloth-based parts by altering the manufacture flowchart thereof.
2. The Prior Arts
A typical structure of dynamic loudspeaker is usually composed of a power system, a piece of drum paper, and a suspension system, in which the power system further comprises a magnet, an electrode, an upper iron, a gap, and a voice coil; the drum paper is a diaphragm, which is mostly a conic or semi-spherical voice pot for moving air; and the suspension system is comprised of a damper and a suspension rim for guiding the diaphragm to move in a specific direction. The working principle is that an electromagnetic field perpendicular to the magnetic field created by a permanent magnet disposed on a loudspeaker is generated as soon as a current flows through the voice coil, such that a dynamic coil is forced to move in a gap reserved between the voice coil and the magnet. The mechanical force generated by the movement of the coil would drive the diaphragm attached on the voice coil to create vertical vibrations of sound frequencies and achieve the energy transference from electric energy to sound energy.
Several nonmetallic cloth-based parts, such as drum paper, damper, and even dust cover, are adopted for making a loudspeaker because of the elasticity and firmness of cloth after undergoing a special treatment. In the special treatment, a cloth roll is dipped first in a liquid resin, then taken out and rolled again for use. During manufacture of the damper, drum paper, etc., a cloth roll is carried by a conveyer to the position of a mold set for being depressed there between an upper half and a lower half mold of the mold set. Both the upper half and the lower half mold of the mold set are provided with respective heating devices such that cloth can be heated by those halve molds of the mold set concurrently which are heated by the heating devices which are heated by applying electric current when cloth is depressed, hence the damper, drum paper, etc., can be formed and cut into pieces as required.
The mold set depresses cloth and heats it up to 200° C. for 10 seconds every time, in other words, each mold set works on cloth for at least 10 seconds, so that 6 pieces of cloth-based parts could be obtained every one minute, or 360 pieces in one hour. Anyway, it is affirmable that the output per hour is less than 360 pieces when conveyance time of cloth is put into consideration, and it could be even worse under a lower temperature condition desired for keeping the quality of cloth.
As shown in FIG. 3, since a heating device C (an electric heater for example) must be arranged in both an upper half mold (A) and a lower half mold (B) of a mold set that would bring troubles to maintenance. For instance, during the maintenance of the heating device, the mold sets must temporarily cease operation, inevitably affecting the entire production line.

SUMMARY OF THE INVENTION

The primary objective of this invention is to improve the conventional molding method for producing cloth-based parts of loudspeaker that needs a long processing time with poor production efficiency.
Another object of this invention is to provide an improved exclusive molding method for producing cloth-based parts of loudspeaker, which uses a mold set provided with a heating device that can be maintained easily to press and heat a cloth roll simultaneously.
The primary technical characteristic of this invention is that a resin-dipped cloth roll is first preheated then molded in same production line, so that the molding operation will not be affected by the heating process, thereby, raising the production efficiency.
Another technical characteristic of this invention is to install the heating device and the mold set separately, so that the maintenance or replacement of the heating device can be performed more easily in comparison with the conventional method.
Yet another technical characteristic of this invention is that a leveling device is arranged preceding the mold set, for leveling a cloth roll after passing through the heating device in order to make the cloth flush.
The molding method of this invention is to move a resin-dipped and dried cloth roll intermittently through a heating device then a mold set, and a leveling device of rollers or the like could be interpolated therebetween if deem necessary. After a roll of cloth has being heated by the heating device and leveled by the leveling device, a flush cloth roll is molded by the mold set, then cut into pieces to obtain cloth-based parts and heighten the production efficiency thereof.
For more detailed information regarding advantages or features of this invention, at least one example of preferred embodiment will be described below with reference to the annexed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The related drawings in connection with the detailed description of this invention to be made later are described briefly as follows, in which:
FIG. 1 is a schematic view showing raw cloth being dipped in resin, then dried and rolled for preparation
FIG. 2 is a schematic plane view showing cloth passing through a heating device, a leveling device, and a forming mold; and
FIG. 3 is a schematic plane view showing a heating device being arranged in both an upper half and a lower half mold of a mold set for pressing and heating cloth simultaneously.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Before forming cloth-based parts of loudspeaker, dip a raw cloth roll 5 into a liquid resin 6 as shown in FIG. 1, in which the cloth roll 5 is dragged by a driving machine to pass through and absorb the liquid resin 6. After cloth roll 5 has absorbed liquid resin after passing through driving machine, it is then dried in a dryer to become a cylindrical cloth roll 4 rich in resilience and firmness prepared for a follow-up procedure.
FIG. 2 shows the resin-dipped cloth roll 4 being moved intermittently to pass in order through a heating device 1 and a mold set 3, in which cloth roll 4 is preheated in the heating device 1 to soften the contained resin, then carry cloth roll 4 to mold set 3 for forming and cutting to produce parts of loudspeaker, such as damper, drum paper, etc.
The foregoing heating device 1 could be an electro-thermal chamber or the like, and an electric heater is usually installed inside in the case of an electro-thermal chamber so that heat is generated when electric power is applied. Also an inlet and an outlet are arranged at both ends of the chamber respectively to provide a transportation channel for cloth roll 4. Generally speaking, a suitable temperature range for heating cloth-based parts is around 150° C.˜200° C., with a preferred preheating time period of 10˜15 seconds. An over-high heating temperature or an overlong heating time may damage the quality of cloth; similarly, a too-low heating temperature or a too-short heating time will results in an insufficient preheat that may affect the follow-up forming operation. While cloth roll 4 is dragged through the heating device 1, cloth roll 4 is heated up to get the contained resin therein to soften in order to obtain plasticity. Afterwards, it is further dragged to arrive at the position of mold set 3, therein cloth roll 4 is clenched by an upper half 31 and lower half 32 to produce desired parts.
Since cloth roll 4 has been preheated by heating device 1 in advance, hence, no heaters are required to be installed in mold set 3, as long as the molding operation is held under room temperature. Under these conditions and compared with the conventional way, a suitable pressure is sufficient in molding process by the mold set, therefore, a longer heating time is not required in the procedure of combining two halves of the mold set together, thereby raising production efficiency considerably. Besides, as the heating device 1 is independent of the mold set 3, maintenance is easier and the cost thereof is relatively low. A short period of time is needed for the mold set 3 to process the cloth roll 4, an intermittent manner of conveyance must be adopted to transport the cloth through the heating device 1 and the mold set 3. At this point, since the machinery required for transportation isn't included in the range of our appeals, hence, it won't be reiterated herein.
A leveling device 2 is interpolated between the heating device 1 and the mold set 3, such that a cloth roll 4 can be leveled after passing through the heating device 1 and before being molded in the mold set 3 for appearance purposes. The leveling device 2 is composed at least of a pair of rollers 21 for pinching and leveling the cloth roll 4 in this embodiment.
Combining previously mentioned embodiment, it will not only significantly cut short the time for producing cloth parts of loudspeakers, raising production, it also help makes maintenance for mold set 3 much easier.
The above descriptions list the preferred embodiment in detail, with reference to the drawings annexed. Modifications may be made without departing from the true nature and scope thereof, as set forth in the claims below.

Claims

1. An exclusive molding method for producing cloth-based parts of loudspeaker, comprising:

(a) Providing a resin-dipped and dried cloth roll;

(b) Moving the cloth roll to pass through a heating device and a mold set intermittently in order, such that the cloth roll is preheated by the heating device then molded to show the shape of parts; and

(c) Cutting the molded cloth into pieces to obtain the desired cloth-base parts.

2. The exclusive molding method according to claim 1, in which, after passing through the heating device, the cloth roll is leveled by a leveling device before been moved to the mold set.

3. The exclusive molding method according to claim 2, the leveling device comprises at least of a pair of rollers for pinching and flushing the cloth roll.

4. The exclusive molding method according to claim 1 or claim 2, in which the preheating temperature provided by the heating device is in the range of 150° C.˜200° C.

5. The exclusive molding method according to claim 1 or claim 2, in which the preheating time is in the range of 10˜15 seconds.

6. The exclusive molding method according to claim 1 or claim 2, in which cloth-based parts are formed by the mold set under room temperature.