JPH0149107B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Field of the Invention>> The present invention mainly relates to an insulator installed in an engine room and a method for manufacturing the same.

Various insulators are used in the engine room of an automobile, such as an insulator hood attached to a hood panel, or an insulator darts front attached to a darts panel that separates the engine room from the passenger compartment. The insulator prevents noise and vibrations from the engine room from leaking into or outside the vehicle.

However, these insulators use felt, glass wool, etc. as a sound absorbing material, and their upper and lower surfaces are covered with a heat-resistant skin material and a water-repellent nonwoven fabric, but these insulators are generally manufactured using the following method. This is obtained by

That is, a sound-absorbing material such as semi-cured felt or glass wool is placed at the center, and a skin material and a nonwoven fabric are arranged on the upper and lower surfaces, and this is carried into the upper and lower molds of a hot press. Thereafter, the sound absorbing material such as felt was cured by heating with this hot press, and trimming and piercing were simultaneously performed to obtain the material by hot compression molding.

However, according to such a molding method,
Since the sound-absorbing material is compressed, there is a problem in that although its shape-retaining performance is improved, its sound-absorbing performance is reduced. On the other hand, in order to maintain sound absorption performance, excessive compression is not possible, and as a result, after molding, the sound absorbing material such as felt protrudes from the ends of the skin material and nonwoven fabric, so it is necessary to cut the ends after molding. Furthermore, there were other problems such as water entering through the felt.

Further, according to the above manufacturing method, since the sound absorbing material such as felt is cured by heating, the molding cycle becomes longer, which inevitably increases the manufacturing cost. Additionally, since it was heat compression molded, heat and odor wafted into the workplace, creating a poor working environment.

≪Object of the invention≫ The first object of the present invention is to provide an insulator that maintains shape-retaining performance, improves sound absorption performance, eliminates the need for terminal treatment, and prevents water from entering. be.

A second object of the present invention is to provide a manufacturing method that shortens the molding cycle and improves the working environment.

≪Structure of the Invention≫ This invention has been made to achieve the above-mentioned objects, and the first invention of the invention is to center a sound absorbing material made of felt or the like, and to cover the upper and lower surfaces thereof with a skin material and a nonwoven fabric. In the coated insulator, the skin material and the nonwoven fabric are pressure-bonded at least on the outer periphery,
The present invention is characterized in that the above-mentioned skin material has a portion maintained in an uncompressed state.

Further, the second aspect of the present invention is provided with a cold press type upper mold having a lower mold and a recessed portion on the lower surface and a vacuum hole communicating with the recessed portion, and a nonwoven fabric and a cured material are placed on the lower mold. a step of positioning and fixing the sound absorbing material, a step of arranging a preheated skin material between the upper and lower molds, and a step of lowering the upper mold to process the skin material between the upper and lower molds and at least the outer periphery of the nonwoven fabric. This method is characterized by comprising the step of simultaneously driving a vacuum suction device to suction the air in the upper mold recess at the same time as pressure bonding.

<<Description of Examples>> Figs. 1A, B, and C are explanatory cross-sectional views showing the manufacturing process of the method of the present invention, in which 1 is a lower die for cold pressing, and 2 is a mold with recesses 2a, 2a on the lower surface. A pair of guide pins 3, 3 are provided on both sides of the lower mold 1. Vacuum holes 2b are branched and provided in the recess 2a of the upper mold, and these vacuum holes 2b are connected to a vacuum suction device 4.
It is designed to vacuum the air inside.

Reference numeral 5 indicates a non-woven fabric used for the insulator dart front, and this non-woven fabric 5 is provided with holes 5a for penetrating the shaft, pedals, etc. and holes 5a for penetrating attachment parts in the engine room. At the same time, guide holes 6, 6 are provided on both sides of this nonwoven fabric 5 to fit with the guide pins 3, 3, and an adhesive 8 is applied to the outer periphery of this nonwoven fabric 5 and around the holes 5a. .

A sound absorbing material 9 is provided with guide holes 10, 10 for positioning, various through holes 9a, 9a similar to the nonwoven fabric 5, and an adhesive 9b is applied around the through holes 9a, 9a. shows,
This sound absorbing material 9 is formed to have a substantially similar shape to the nonwoven fabric 5, and is slightly smaller than the nonwoven fabric 5, and is cured with felt or glass wool. 11a is the lower heater;
11b indicates an upper heater, and these upper and lower heaters 11
A heat-resistant sheet, such as EPDM, is placed between a and 11b.
A skin material 12 made of rubber is placed on a conveyor 13, preheated by the upper and lower heaters, and transported between the upper and lower molds 1 and 2.

Further, similar to the nonwoven fabric 5 and the sound absorbing material 9, the skin material 12 is formed with various through holes (not shown) facing each other, and its size and shape are the same as those of the nonwoven fabric 5.

Then, the guide pins 3, 3 of the lower mold 1 pass through the guide holes 6, 6 of the nonwoven fabric 5, and are positioned and set at a predetermined position of the lower mold 1, and the sound absorbing material 9 is placed on the nonwoven fabric 5 through the guide holes. 10, 10 (see FIG. 1A).
Next, the skin material 12 preheated by the upper and lower heaters 11a and 11b is placed between the upper and lower molds via the conveyor device 13 (see FIG. 1B), and in this state, the upper mold 2 is lowered and At least the outer circumferences of the skin material 12 and the nonwoven fabric 5 are pressurized. At the same time, when the suction device 4 is operated, the vacuum hole 2
The air in the upper mold recess 2a provided with the upper mold 1 is suctioned, and the skin material 12 is suctioned toward the recess 2a of the upper mold 1.

That is, according to the manufacturing method described above, the outer circumference of the skin material 12 and the nonwoven fabric 5 are at least pressurized, so that they are fixed by the adhesive 8, while the sound absorbing material 12 in the upper die recess 2a is not subjected to the pressing process. Since it is not pressurized at all, it maintains an uncompressed state.

In addition, when designing the upper mold, the recess 2a
It is natural that the sound absorbing material 9 is designed so as not to pressurize it as much as possible.

What is shown in FIG. 2 shows an insulator obtained by the method of the present invention. As shown in the figure, the outer periphery of the insulator is bonded under pressure by the above-mentioned pressing process, but the sound absorption inside the upper mold recess 2a is Since the material is not compressed, it retains enough thickness to act as a sound absorbing layer. Furthermore, the results of experiments revealed that sufficient shape retention was achieved by the skin material.

<<Effects of the Invention>> As is clear from the above description, the insulator according to the present invention maintains its shape-retaining performance and maintains the thickness of the sound-absorbing material layer sufficiently by the mold recesses. , the sound absorption performance can be significantly improved compared to the conventional method. In addition, since sufficient pressure can be obtained on the outer periphery of the sound-absorbing material, ignoring the sound-absorbing performance, the edges of the sound-absorbing material do not protrude outside, eliminating the need for end treatment, and using sound-absorbing materials such as felt. This has the effect of preventing water from entering.

In addition, since the method of the present invention is obtained by cold press molding, the molding cycle can be significantly shortened compared to conventional foot presses, and there is no heat or odor, which improves the working environment. It has the following effects.

[Brief explanation of drawings]

1A, B, and C are explanatory cross-sectional views showing the manufacturing process of the method of the present invention, and FIG. 2 is a cross-sectional view of an insulator obtained by the method of the present invention. 1...Lower mold, 2...Upper mold, 2a...Upper mold recess,
2b... Vacuum hole, 5... Nonwoven fabric, 9... Sound absorbing material, 12... Skin material, 11a... Lower heater, 1
1b...Upper heater.

Claims (1)

[Scope of Claims] 1. An insulator consisting of a sound-absorbing material made of felt or the like, whose upper and lower surfaces are covered with a skin material and a nonwoven fabric, wherein the skin material and the nonwoven fabric are bonded under pressure at least on the outer periphery thereof. An insulator characterized by having a portion of the skin material that is held in an uncompressed state. 2. A step of positioning and fixing the nonwoven fabric and the cured sound absorbing material on the lower mold, comprising a lower mold and an upper mold of a cold press type having a recess on the lower surface and a vacuum hole communicating with the recess. , placing a preheated skin material between the upper and lower molds, lowering the upper mold, pressurizing and bonding the skin material between the upper and lower molds and at least the outer periphery of the nonwoven fabric, and at the same time applying a vacuum suction device. A method for manufacturing an insulator, comprising the step of: driving the upper mold recess to suck air in the upper mold recess.