JPH07189836A - Manufacture of intake manifold - Google Patents

Abstract

PURPOSE:To dispense with a core and to improve productivity so as to reduce costs. CONSTITUTION:A manufacturing method for an intake manifold consists of a process in which plural pieces 2, 3 formed by dividing a hollow part. 1 serving as an intake passage into at least two parts in the longitudinal direction are molded of a resin material, a process in which these pieces 2, 3 are adhered and integrated together by means of fusion or silicon rubber, a process in which the integrated pieces 2, 3 are set into the inside of an injection molding die 10 so that the hollow part 1 is closed, and a process in which a resin material is injected onto the outer circumferential faces of the plural pieces 2, 3 inside the injection molding die 10 so as to be fused and integrated with the plural pieces 2, 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an intake manifold, that is, an intake manifold used for an engine of an automobile or the like.

[0002]

2. Description of the Related Art Conventional intake manifolds have been manufactured by casting aluminum. In the casting of aluminum, a hollow part was formed by molding molten aluminum into a sand core and removing the core after cooling.

Recently, resin intake manifolds have been manufactured to reduce the weight. In the case of manufacturing with a resin material, a core made of a low melting point alloy such as tin-bismuth alloy is used as the core for forming the hollow part, and after such a core is set in the molding die. A so-called lost wax method has been adopted in which a resin material is injection-molded, and a core made of a tin-bismuth alloy is melted and removed after molding.

[0004]

In any of the above-mentioned conventional examples, a great number of man-hours are required to make the core, and also the man-hours are required to remove the core, resulting in cost increase and large-scale equipment. It was.

Therefore, the present invention does not require a core,
An object of the present invention is to provide a method for manufacturing an intake manifold that can improve productivity and reduce costs.

[0006]

In order to achieve the above object, the present invention relates to a step of molding a plurality of pieces of a hollow material, which becomes an intake passage, into two or more parts at least in the longitudinal direction, and molding the pieces with a resin material. A step of fusing or adhering the pieces via silicon rubber to integrate them, a step of setting the integrated pieces in the injection mold so as to close the hollow portion, and a step of setting a plurality of pieces in the injection mold. A step of injecting a resin material onto the outer peripheral surface of the piece to melt-integrate the plurality of pieces and the resin material.

[0007]

According to the present invention, a plurality of pieces obtained by dividing the hollow portion to be the intake passage into at least two pieces in the longitudinal direction are formed in advance, these pieces are integrated, and the integrated piece is placed in the injection molding die. Set to close,
Since the resin material is injected around these pieces to fuse them together, the core becomes unnecessary, the number of manufacturing steps can be reduced, and the cost can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a hollow portion 1 serving as an intake passage.
A plurality of pieces 2 and 3 obtained by dividing at least two in the longitudinal direction are molded in advance with a resin material. These pieces 2 and 3 are integrated by fusing or adhering through silicon rubber. These integrated pieces 2 and 3 are used in the injection mold 1
The hollow part 1 is set in 0 so as to be closed. A cavity 11 is formed on the outer circumference of each of the pieces 2 and 3. A resin material is injected into the cavity 11 from the injection path 12 of the molding die 10 to melt and integrate the plurality of pieces 2, 3 and the resin material. There are various ways to divide the molding die 10 shown in FIG. At this time, the hollow portion 1 is closed by a split mold so that the resin material does not flow into this portion. The protrusions of the split mold are fitted into the openings of both ends of the hollow portion 1 of the integrated pieces 2 and 3, and the hollow portion 1 is closed. Further, cavities for forming flanges are formed at both ends of the cavity 11.

The state before the cross section of the pieces 2 and 3 when viewed from the arrow A direction is as shown in FIG. 2, and the similar shape when viewed from the arrow B direction is as shown in FIG. The pieces 2 and 3 are also formed by an injection molding die using a molding die different from the molding die 10 shown in FIG. These pieces 2, 3
It is preferable to use a material having excellent gasoline resistance, for example, high-density polyethylene, as the resin material for molding. Further, as the resin material molded on the outer peripheral side of these pieces 2 and 3, a material having excellent strength, for example, nylon 6.6 or the like is preferable.

As described above, pieces 2 and 3 obtained by dividing the hollow portion 1 serving as the intake passage into two in the longitudinal direction are molded in advance with a resin material, and these pieces 2 and 3 are placed in the injection molding die. 1 is set so as to be closed, and the resin material and the pieces 2 and 3 are melt-integrated by injection-molding a resin material on the outer peripheral surfaces of the set pieces 2 and 3 as shown in FIG. The flange 4 is formed at both ends. Further, the outer peripheral portion 5 has a molding die 1 as shown in FIG.
When injection-molded by 0, the split surfaces of the pieces 2 and 3 are covered with the resin of the outer peripheral portion 5, so that the mechanical reliability is higher and the strength is superior to that of a usual welded product. Further, in the case where the pieces 2 and 3 are bonded and integrated with each other through silicone rubber, the sealing property is improved.

[0012]

As described above, according to the present invention, since the core is not required, the number of manufacturing steps is greatly reduced, the manufacturing is facilitated, and the cost can be reduced. Further, since the pre-molded pieces and the outer peripheral portion which is injection-molded around these pieces are fused, the mechanical strength is also improved, and each is required by changing the resin material of the inside and the outside. It is also possible to manufacture the one most suited to the performance required.

[Brief description of drawings]

FIG. 1 is a sectional view showing a preferred embodiment of the present invention.

FIG. 2 is a view of the piece viewed from the direction of arrow A in FIG.

FIG. 3 is a view of the piece viewed from the direction of arrow B in FIG.

FIG. 4 is a cross-sectional view of the manufactured intake manifold.

[Explanation of symbols]

 1 Hollow part 2 and 3 pieces 5 Peripheral part 10 Mold

Claims (1)

[Claims] 1. A step of molding a plurality of pieces in which a hollow portion serving as an intake passage is divided into at least two in the longitudinal direction with a resin material, and a step of adhering these pieces by fusion bonding or silicone rubber to integrate them. And the step of setting the integrated piece in the injection molding die so that the hollow part is closed, and the resin material is injected onto the outer peripheral surface of the plurality of pieces in the injection molding die to A method for producing an intake manifold, comprising: a step of melting and integrating the material.