JPS58101848A - Insulator for car - Google Patents

Abstract

PURPOSE:To improve the efficiency of the molding work in an insulator consisting of a sound-insulating layer made of a heavy thermoplastic sheet and a porous mat by depositing the sound-insulating layer and the porous mat with each other at several spots by ultrasonic vibration. CONSTITUTION:Insulators are provided on partition walls in a car room and an engine room by attaching a sound-insulating layer 10 made of a heavy thermoplastic sheet to a porous mat 11 on the backside of the sound-insulating layer 10. For its manufacturing, for instance, the sound-insulating layer 10 and the porous mat 11 are at first placed in order on a lower mold 1 of an ultrasonic vibration device B and then covered by an upper mold 3 for closing. From several penetration holes 3b bored on the upper mold 3, the top of an ultrasonic horn 7 is inserted near to the sound-insulating layer 10, and vibrates an ultrasonic head 6 to melt members 10 and 11 for forming point-deposited parts H. This construction permits to combine both parts instantly without drying up adhesives and greatly improve the work efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulator for an automobile, and more particularly to an insulator in which the adhesion between a sound insulating layer and a porous mat is fixed by using an ultrasonic device.

The insulator is made by molding a sound insulation layer made of a heavy thermoplastic sheet such as vinyl chloride or rubber to match the shape of the car's floor surface, and pasting a porous mat such as felt, urethane, or Tsudo on the back side. There is.

For this bonding, adhesive is usually applied by flow coating to the surface of a porous mat that has been trim-cut to the same shape as the sound insulation layer, stacked on the back side of the sound insulation layer, and then press-formed. That's what I do. In this case, heat and pressure are applied to efficiently assimilate and dry the adhesive, but in this case, due to the insulation effect of felt or polyurethane foam, Because curing by heating the thermosetting resin contained in the felt itself takes a considerable amount of time, the molding cycle becomes extremely long, making it impossible to maintain takt time between each process. The aldehyde component evaporates, causing a deterioration of the working environment.

The present invention was made in view of the above-mentioned drawbacks, and during molding, the tip of an ultrasonic horn penetrates the above-mentioned porous mat and comes into contact with the back surface of the sound insulation layer, and the above-mentioned material is melted by ultrasonic vibration. The above-mentioned drawbacks are improved by welding the sound insulating layer and the porous mat together at multiple points.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an apparatus for carrying out this invention.
This mold includes a lower mold 1 having a mold surface 1a having a required curved surface, and an upper mold 3 that can be engaged with one side of the lower mold 1 via a hinge 2. A movable plate 5 is provided on the mold and can be raised and lowered by a cylinder 4, and a number of heads 6 each having a built-in ultrasonic transducer are mounted on the lower surface of the movable plate 5, and a number of heads 6 are installed on the lower surface of these heads 6. A large number of ultrasonic heads 7 are provided which reach the mold surface 18 of the upper mold 1 by passing through a large number of through holes 3b formed in the lower mold 3.

As shown at the right end in FIG. 1, each ultrasonic head 6 is always urged downward by a compression spring 8 provided between the head 6 and the movable plate 5. With the upper mold 3 engaged with the lower mold 1, the cylinder 4 is lowered and the movable plate 5 is located at the lowest position, and each ultrasonic head 7 has its tip abutted on the mold surface 1a of the lower mold 1. However, in this state, when the robot tries to descend further, the spring 8 works to prevent excessive pressing force from being generated.

A sound insulation layer 10 made of a heavy thermoplastic sheet is laminated on the mold surface 1a of the lower mold 1, and a porous mat 11 made of felt or the like is laminated on the sound insulation layer 10. The upper die 3 is closed, the movable plate 5 is then lowered, and the ultrasonic coils built into each head 6 are oscillated, so that the tip of the ultrasonic horn 7 is moved as shown in an enlarged view in FIG. The part compresses the porous mat 11 to reach the vicinity of the sound insulation layer 10, and at each stage, it is melted by ultrasonic vibration (the dark part in the middle of Fig. 2 is the welded part H). be). Therefore, in the automobile insulator constructed in this way, there is no need for the process of solidifying and drying the adhesive by heating and pressurizing, as in conventional insulators, and the sound insulation layer and the porous mat can be instantly welded at multiple points. By doing so, it is possible to join them together.

Although only a partial cross section is shown in the figure, good adhesion can be obtained by point welding only the main parts with an appropriate distribution according to the required shape of the insulator. Can be done.

In addition, a large number of ultrasonic heads 6°6... shown in FIG.
・In a welding device equipped with a welding device, each of the ultrasonic coils cannot be excited at the same time. For example, as shown in FIG. 3, if ultrasonic welding is performed while sequentially switching the output of the ultrasonic oscillator 20 to each ultrasonic coil 6'6' through the switching circuit 21, the power consumption will be reduced. Problems such as increase in noise and noise can be prevented as much as possible.

For example, in the case where the ultrasonic head 6 is single, the ultrasonic head 6 may be installed on a running rail movable in the XYh direction, and each part may be made into an ultrasonic groove while repeating the vertical movement. Of course, it is also possible to use a variety of device configurations.

It should be noted that the application of this type of ultrasonic welding to a sound insulating layer made of a heavy thermoplastic sheet has not been done in the past.
Normally, it is used for processing hard resin plates or metals, etc., but the fact that it can be applied to flexible sheets of III-III material means that the tip of the ultrasonic head 7, as shown in FIG. This can be achieved by compressing the tip of a porous mat made of felt or the like and fusing it in that state. In the insulator where each part is melted in this way, the adhesive bonding force between the porous mat and the sound insulation layer that constitutes the insulator is extremely large, and the bond between the sound insulation layer and the porous mat in the insulator obtained by the conventional method is extremely large. It is possible to obtain a bonding strength that is approximately comparable to the bonding strength.

As explained in detail in the examples above, in the automobile insulator according to the present invention, the sound insulating layer and the porous mat are welded together at multiple points by ultrasonic vibration, so that the bonding strength between the two is is comparable to using conventional adhesives or hot melt adhesives, and does not require materials such as adhesives. Compared to conventional bonding methods, it requires no heating time and has an extremely short molding cycle. It has the great advantage of being time consuming.

[Brief explanation of drawings]

FIG. 1 is an explanatory cross-sectional view showing an apparatus for carrying out the present invention, FIG. 2 is a partially enlarged cross-sectional view showing the state of bonding of the insulator in the area surrounded by circle line A in FIG. 1, and FIG. 3 is the same. FIG. 3 is an explanatory diagram of a circuit in the device. 10... Sound insulation layer 11... Porous mat

Claims (1)

[Claims] (1) A sound insulation layer made of a thermoplastic heavy fog sheet molded to match the floor shape of the partition wall that separates the engine room and the single room, and an insulator made of a porous mat bonded to the back side of this sound insulation layer. In this method, the tip of an ultrasonic horn is brought into contact with the back surface of the sound insulation layer by compressing the porous mat, and the sound insulation layer and the porous mat are melted by ultrasonic vibration and point-welded at multiple locations. Automotive insulator.