JP2656723B2 - Bent tubular body made of resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bent tubular body made of resin, and more particularly to a bent tubular body having a flange at at least one end.

[0002]

2. Description of the Related Art A bent tubular body having a flange at one end is formed of two pieces.
In the case of combining the divided bodies, usually,
As disclosed in Japanese Patent No. 37692, a method has been proposed in which the entire body including a flange is divided into two parts, left and right, and these parts are joined by vibration welding at dividing lines. In addition, since the above-mentioned method causes welding burrs, Japanese Utility Model Publication No. 5-18132 proposes an improved plan in which the dividing line is vertically endless, and the dividing line has an endless loop shape except for the vicinity of the opening, and this is vibration welded. .

[0003]

However, such a vibration welding method has a drawback that it lacks mass productivity and that sufficient bonding strength cannot be obtained. Therefore, it is proposed to use a two-stage forming method in which a half body is formed by primary forming and a joining portion is joined by secondary forming. Not only is required, but also a disadvantage that the flange portion is particularly susceptible to damage occurs. Therefore, an object of the present invention is to provide a resin product in which a bent tubular body is formed by joining a pair of half bodies without dividing a flange portion.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a tubular body having excellent joining strength and reliability can be mass-produced by a two-stage molding method by forming an intermediate portion forming a bent tubular body, except for a flange, into a vertical half body. It is a resin tubular body having a flange at at least one end and a bent middle portion, except for the flange, where the middle portion is divided vertically along the bending direction. And the flange is integrally formed at one end of the half, and the two halves abut at the joint portion divided in the longitudinal direction of the intermediate portion and the flange neck. A resin bent tubular body characterized by being joined with a secondary resin in a fitted state.

[0005]

According to the present invention, the flange can be integrally formed on one of the half bodies by forming the intermediate portion forming the bent tubular body into a vertical half body.
As a result, there is no flange joint portion which is easily damaged when the bent body is manufactured by joining the half bodies. In addition, since the ends of the other half-pieces are joined by the secondary resin in an abutting fitting state in the integrally formed flange neck, cracks are less likely to occur from the ends of the half-pieces, and damage to the flange is prevented. In combination with the fact that it is unlikely to occur, a highly reliable bent tubular body is obtained. Further, in the present invention, a pair of vertical halves are molded with a primary resin using a die slide injection method as a two-stage molding method, and the two halves are abutted without being extracted from a molding die. Since the joining portion is joined with a secondary resin and the tubular body can be formed by injection molding, mass productivity is high.

[0006]

FIG. 1 shows a bent tubular body 1 used for an intake manifold of an automobile engine.
0 and 20 with two bolt holes 31 at each end.
a, 31a and a second flange 32 having one bolt hole 32a.

As shown in FIG. 2, the upper and lower vertical half bodies 10 and 20 have an intermediate portion vertically divided into two parts except for first and second flanges at both ends, and the first and second flanges 31 and 32 are provided. Are integrally formed at both ends of the lower half body 20.

As shown in FIG. 5 (C) of the two halves 10, 20, the intermediate portions 11, 21 are engaged with each other so that the inner side of the upper halves 10 extends in the longitudinal direction along the dividing line. On the other hand, the lower half body 20 has first notches 12 and 22 formed in the longitudinal direction along the dividing line on the outside and a second notch formed in the longitudinal direction on the outside of the dividing line. The notches 13 and 23 constitute the concave groove 4 filled with the second resin W2, and as shown in FIGS.
The neck portion 2 is formed so as to have semicircular concave grooves 51 and 52 filled with the secondary resin W2. Therefore, the upper and lower half halves 10 and 20 are molded with the primary resin in the first stage of the two-stage molding,
1, 21 and the grooves 4 and 51, 52
By injecting and joining the next resin W2, the bent tubular body 1 having flanges at both ends is manufactured.

Hereinafter, a manufacturing method by the DSI method will be described. FIG. 3 shows a forming process on the first flange side, and FIG.
Shows a molding process on the second flange side, and FIG. 5 shows a molding process on the intermediate portion. In each figure (A), the lower mold 61 after the first molding of the upper half body 10 is slid off to remove the upper half body 10 from the upper mold 6.
0 shows a state of being mounted. On the other hand, each figure (B) shows a state in which the upper mold 62 after the first molding of the lower half body 20 is slid off, and the lower half body 20 is mounted on the lower mold 63. The upper mold 60 having the upper half body 10 attached thereto and the lower mold 63 having the lower half body 20 attached thereto are slid together as shown in FIG. The split body 20 is brought into an abutting engagement state at its joints 11 and 21, and the concave grooves 4 and 51,
When the secondary resin W2 is filled in the second molding 52, the upper and lower halves 10 and 20 are joined by the secondary resin W2.

[Brief description of the drawings]

FIG. 1 is a perspective view of a bent tubular body 1 used for an intake manifold of an automobile engine.

FIG. 2 is a sectional view taken along line XY of FIG.

FIG. 3 is a process explanatory view showing a forming process on a first flange side of the bent tubular body of FIG. 1;

FIG. 4 is a process explanatory view showing a forming process of the bent tubular body of FIG. 1 on a second flange side.

FIG. 5 is a process explanatory view showing a forming process of an intermediate portion of the bent tubular body of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Bending tubular body 10 ... Upper half body 20 ... Lower half body 11, 21 ... Joint part 4, 51, 52 ... Joint groove

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-230924 (JP, A) JP-A-62-87315 (JP, A) JP-B-63-37692 (JP, B1) 18132 (JP, Y2)

Claims (2)

(57) [Claims] 1. A resin tubular body having a flange at at least one end and a bent middle portion, except for the flange, wherein the middle portion is a vertical half body vertically divided along a bending direction. The flange is integrally formed at one end of the half body, and the two halves are joined to the secondary resin in an abutting fitting state at the joint portion divided in the longitudinal direction of the intermediate portion and the flange neck portion. A bent tubular body made of resin, characterized by being joined together. 2. The resin-bent tubular body according to claim 1, wherein the pair of half halves are formed of a primary resin by die slide injection, and both halves are joined with a secondary resin.