JPH07186264A - Manufacture of resin molded article - Google Patents

Abstract

PURPOSE:To obtain a resin molded article which is welded without generating strain due to injection molding and has good welding quality by a method in which a pair of resin molding members, which are injection molded, are set in a vibration welder together with split molds without removing them from respective split molds of a mold. CONSTITUTION:Resin molding members 1, 2 are injection molded respectively in split molds 3a, 4a of a mold. The split molds 3a, 4a with the members 1, 2 are set in a vibration welder 10 to weld welding parts 1a, 2a. In this way, the members 1, 2 which are removed from the split molds 3a, 4a are prevented from shrinking and warping, and both welding faces are in accordance with each other, giving a good welding condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a resin molded body by welding a resin molded member by vibration welding.

[0002]

2. Description of the Related Art Conventionally, a resin molding having a shape which is difficult to integrally mold has been manufactured by individually molding resin molding members by injection molding, and combining them and welding the abutting surfaces by vibration welding. .

[0003]

According to the conventional manufacturing method, both resin molding members are molded in a molding die of an injection molding machine, taken out from the molding die, and then vibration welded using a jig or the like. It was attached to the machine and welded.

According to this manufacturing method, since the resin molding member to be welded is taken out from the injection molding die, it is deformed by contraction or warpage. Therefore, the two welding surfaces to be vibration-welded do not coincide with each other, or the surface pressure varies depending on the parts of the abutting surfaces, so that the welding quality becomes unstable. Further, since the warp of the molded product is forcibly corrected by the pressing force at the time of vibration welding, residual stress remains particularly in the welded portion, and the strength becomes weak as a whole.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a resin molding member to be welded is molded by a separate injection molding machine and its welding surface is exposed without removing it from a molding die of the injection molding machine. Then, vibration welding is performed in the state of being left in the molding die.

[0006]

According to this manufacturing method, both resin molding members are in the cavity of the molding die, and neither shrinkage nor warpage occurs. Therefore, the welded surfaces of both resin molded members do not have dimensional inconsistencies or surface non-adhesion. Therefore, the shapes of the welding surfaces are the same, and the welding can be performed with a uniform surface pressure.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention is shown in FIGS. 1, 2, 3 and 4. The resin-molded parts 1 and 2 are injection-molded in the cavities 5 and 6 of the molding dies 3 and 4 mounted in separate injection molding machines (not shown). Mold 3 is split mold 3
a resin molded body 1 made of a and 3b and having a circular disk-shaped cavity surface 5b formed in the split mold 3b and having a disc-like shape
The rib-shaped portion 1a is formed on the. The rib-shaped portion 1a forms a welding margin with the welding surface of the welding portion of the resin molded body 1 to be vibration-welded.

The resin molding 2 is a cylindrical box having one end open and the other end closed, and is molded by the split dies 4a and 4b of the molding die 4 and has an annular groove 6b formed in the split die 4b.
Thus, the open peripheral edge portion 2a is formed, and the welding surface and the welding margin of the welding portion of the resin molded body 2 are formed.

[0009] Each injection molding machine, when releasing the molding die,
The split molds 3b and 4b are removed so that the resin moldings 1 and 2 remain on the cavity surfaces 5a and 6a of the split molds 3a and 4a, respectively. This can be easily set by the shape of the split surface of the split mold. Therefore, the welded portions 1a and 2a of the molded resin members 1 and 2 are exposed from the split surfaces of the split molds 3a and 4a.

Next, the split dies 3a and 4a are moved as indicated by arrows A and B (FIG. 3) by a transfer mechanism (not shown) attached to the injection molding machine, and mounted on the table of the vibration welding machine 10 to cure the split molds. The tools 11 and 12 are set at a predetermined position for welding. Next, the jigs 11 and 12 are pressed in the direction of arrow C to bring the welded portions 1a and 2a of the resin molded members 1 and 2 into contact with each other and vibrate in the direction of arrow D to weld the welds 1a and 2a.

Next, the pressing of the arrow C is stopped and the jigs 11 and 12 are
The hollow resin molded body 7 (FIG. 4) can be taken out by retreating. The manufacturing method of the present invention can be applied without restricting the shape of resin molding, but a resin molded member to be welded such as a hollow molded body, a thin molded body having a complicated shape is likely to cause shrinkage or warpage after injection molding. The thing is especially effective.

FIG. 5 shows a schematic view of the apparatus of this manufacturing method.
The injection molding machines 15 and 16 are split molds 17a and 17b, respectively.
And molding dies 17, 18 composed of split dies 18a, 18b
The resin molded members 19 and 20 are molded with. FIG. 5 shows a state in which the molding dies 17 and 18 are opened after molding, and
Resin molded members 19 and 20 are placed in a and 18a. A vibration welding machine 21 is installed between the injection molding machines 15 and 16, and the split molds 17a and 18a are installed by the conveyors 22 and 23.
Is moved and attached to a predetermined position of the vibration welding machine 21. After the resin molding members 19 and 20 are welded by the vibration welding machine 21 to form a resin molding (not shown),
The split molds 17a and 18a retract and the resin molded body is taken out. After that, the split molds 17a and 18a are transferred to the conveyors 22 and 23.
Is returned to a predetermined position of the injection molding machine 15, 16. Thus, one cycle of this manufacturing method is completed.

[0013]

In this manufacturing method, the injection-molded resin molded body is welded while it is left in one of the split molds of the molding die, so that there is no deformation such as shrinkage or warpage after injection molding, and the welding surfaces do not match. There is no unevenness in contact pressure and surface pressure, and good welding quality is obtained. In addition, there is no residual stress on the welded surface due to strain,
A resin molded product having high strength as a whole can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a molded state of a resin molded member of an example.

FIG. 2 is a diagram showing a molding state of the other resin molding member of the embodiment.

FIG. 3 is a diagram showing a state of vibration welding according to the embodiment.

FIG. 4 is a diagram of a resin molded body obtained according to an example.

FIG. 5 is a schematic diagram of an example of a device used in an embodiment.

[Explanation of symbols]

 1, 2 resin molding member 3, 4 molding die 5, 6 cavity 3a, 3b, 4a, 4b split mold 1a, 2a welded portion 7 resin molding

Claims (1)

[Claims] 1. A method for manufacturing a resin molded body, wherein a pair of resin molded members formed by injection molding are combined and both abutting surfaces are welded by vibration welding. Molded in the mold, the resin mold member is left in the cavity of one of the mold halves of each mold with at least its welded portion exposed, and the other mold is removed to remove the resin. Move both split molds in which the molding members are placed, mount them facing the vibration welding machine, and weld the resin molding members by vibration welding to form a resin molding, then remove both split molds Body manufacturing method.