JP2002205331A - Blow molded object having welding flange - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly and certainly weld the welding flange integrally formed to a blow molded object to other plastic part and to enhance the strength of the welding flange itself. SOLUTION: The welding flange 13 is formed into a double wall hollow plate-shaped structure and reinforcing ribs 14 are formed between both opposed walls to connect them. Each of the reinforcing ribs 14 is the side wall of the part having a recessed shape continuously going from one wall 13a to the other wall 13b and the part having the recessed shape has a bottom 14a parallel to the other wall 13b and the bottom 14a reaches the other wall 13b to be bonded thereto under pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow molded article having a welding flange for welding and joining with other plastic parts.

[0002]

2. Description of the Related Art In an air-conditioning structure of an automobile, when a duct is attached to a frame member arranged at an outlet, a flange formed at an end of the duct and a frame member have been conventionally fixed with screws. Friction welding, ultrasonic welding, hot plate welding (place a hot plate between both members, press both members against the hot plate, pull out the hot plate when the contact area is heated and melted,
Then, the two members are often welded and joined by utilizing a method of pressing and welding the two members together. In this case, for example, as shown in FIG. 8, a blow molded body including a bellows-type duct main body 1 and a waste bag 2 integrally connected to an end thereof is formed, and the waste bag 2 is formed by a virtual line portion. As shown in FIG. 9, a frame member 4 made of plastic (injection molded product) is welded to the plate-shaped welding flange 3, as shown in FIG. 9.

[0003]

However, since the duct is a blow-molded body, the welding flange 3 is inevitably thinner toward the outer peripheral side, and it is inevitable that the thickness fluctuates around the periphery. Therefore, the pressing pressure of the welding jig is not constant on the surface of the welding flange 3, and it has been difficult to uniformly and surely weld necessary portions. Further, since the welding flange 3 has a thin plate shape, the strength of the welding flange 3 itself is insufficient.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to uniformly and reliably weld a welding flange integrally formed on a blow molded body to another plastic part by welding. An object of the present invention is to obtain a blow molded article that can be welded and has a large strength of a welding flange itself.

[0005]

According to the present invention, there is provided a blow molded article in which a welding flange for welding to another plastic part is integrally connected to a main body, wherein the welding flange has a double wall. It has a hollow plate shape, and is characterized in that a reinforcing rib for connecting it is formed between both opposing walls. The reinforcing rib is, for example, a side wall of a concave-shaped portion that is continuous from one wall toward the other wall, and the concave-shaped portion has a bottom parallel to the other wall. Reaches the other wall and is crimped to the other wall. In addition, the reinforcing ribs are, for example, side walls of a dent-shaped portion continuously facing the opposing wall from the opposing position of each wall, and the dent-shaped portions have bottoms parallel to each other, and They are crimped together at appropriate places between the opposing walls. The welding flange is formed all around or a part of the main body. The reinforcing rib is formed in an annular shape on the welding flange, and a plurality of the reinforcing ribs are desirably formed on the welding flange.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a blow molded article according to the present invention will be described more specifically with reference to FIGS. 1 to 7 taking a bellows type duct as an example. As shown in FIGS. 1 and 2, this duct comprises a duct main body 11 and a welding flange 13 integrally formed around the whole of the duct main body 11, and the welding flange 13 has a hollow plate shape having a uniform thickness. A plurality of annular reinforcing ribs 14 are formed between the opposing walls. The reinforcing ribs 14 are attached to the duct main body 11.
Side wall 13a is a side wall of a concave shape that is continuous from the side wall 13a toward the other side wall 13b, and has a bottom 14a parallel to the other side wall 13b, and the bottom 14a is connected to the other side wall 13b. And is crimped to the other wall 13b. The wall 13b on the other side is planar as a whole, but a plurality of dents are discontinuously formed on the wall 13a on the duct body side.

FIGS. 3 and 4 show a method of blow molding this duct. FIG. 3 shows main dies 16 and 17 and slide dies 18 and 19 from both sides of a parison 15 made of a thermoplastic resin.
Is closed, air is blown into the parison 15, and the slide dies 18, 19 are rising. FIG. 4 shows a state in which the slide dies 18 and 19 are finally closed, and a welding flange 13 in the form of a hollow plate is formed between the main dies 16 and 17 and the slide dies 18 and 19. In the part of the welding flange 13, a part of the parison 15 is formed by a plurality of protrusions 16 formed on the main dies 16 and 17.
A depression 17a is formed toward the wall 13b by being pressed by the a and 17a, and the bottom 14a is pressed against the wall 13b.

This duct has a welding flange 13 in the shape of a hollow plate and a plurality of annular reinforcing ribs 14 formed between both walls, so that the duct itself has strength, and both sides are always sandwiched between molds. Since the meat that is formed and is protruded from the crimping portion is absorbed by the hollow portion, a uniform thickness can be ensured. Further, when the welding flange 13 is welded to the plastic frame member 4 by friction welding, ultrasonic welding, hot plate welding, or the like, the welding flange 13 has a uniform thickness, and the reinforcing ribs 14 are welded. Since the pressing pressure of the welding jig is received and transmitted, the pressing pressure of the welding jig is always constant on the surface of the welding flange 13, particularly on the welding rib 14 and in the vicinity thereof, so that the welding flange 13 and the frame member 4 can be evenly and uniformly. Welding can be performed reliably. In addition,
The welding rib 14 may be formed so as to continuously surround the entire circumference along the duct main body 11. However, from the viewpoint of the strength of the flange 13, it is more advantageous to form a plurality of annular welding ribs 14 that are smaller than the duct main body 11 discontinuously along the duct main body 11 as described above.

In the blow molding method for a duct shown in FIG. 5, a plurality of projections 26a, 27a are formed on main dies 26, 27, and projections 28a, 29a are formed at positions opposed to slide dies 28, 29. 3 and 4 in that
Is different from the method. As a result, the welding flange 23
The wall 23a on the duct body 21 side and the wall 23 on the other side
A portion having a concave shape is formed continuously from the opposing position to the opposing wall, and their parallel bottoms are pressed together between the opposing walls. The side wall of the concave portion serves as an annular reinforcing rib 24. In this case, a plurality of dents are discontinuously formed on both the wall 23a on the duct main body side and the wall 23b on the other side.

In the blow molding method of the duct shown in FIG. 6, the welding flange 33 is formed only by the main dies 36 and 37, and a protrusion 36a (one or a plurality) is provided at the end of the main die 37. The welding flange 33 is formed so that the duct body 3
1 and is integrally connected. In this case, for example, FIG.
In the form as shown in FIG.

[0011]

According to the present invention, when the welding flange integrally formed on the blow molded article is welded and joined to other plastic parts, it can be uniformly and reliably welded, and the strength of the welding flange itself can be reduced. Large blow molded articles can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a blow molded article according to the present invention and a welding form thereof.

FIG. 2 is a perspective view of a blow molded article.

FIG. 3 is a sectional view showing the molding method.

FIG. 4 is a sectional view showing the molding method.

FIG. 5 is a cross-sectional view showing another blow molded article according to the present invention and a molding method thereof.

FIG. 6 is a cross-sectional view showing another blow molded article according to the present invention and a molding method thereof.

FIG. 7 is a cross-sectional view showing the welding mode.

FIG. 8 is a cross-sectional view of a conventional blow-molded body (before cutting of a discarded bag).

FIG. 9 is a cross-sectional view illustrating a welding mode.

[Explanation of symbols]

4, 34 Frame member 11, 21 Duct main body 13, 23, 33 Welding flange 13a, 13b, 23a, 23b Wall 14 Reinforcement rib 14a Bottom 15 Parison 16, 17, 26, 27, 36, 37 Main mold 16a , 17a, 26a, 27a, 28a, 29a, 3
6a Projection 18, 19, 28, 29 Slide mold

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hideo Yokota 447, Shimoichi, Sanyo-cho, Akaiwa-gun, Okayama Prefecture F-term (reference) 4F202 AG24 AG28 AH17 CA15 CB01 CK52 4F208 AG24 AG28 AH17 LA01 LB01 LD06 LG19 LG22 LG40

Claims (4)

[Claims] 1. A blow molded article in which a welding flange for welding to another plastic component is integrally connected to a main body, wherein the welding flange has a double-walled hollow plate shape and faces each other. A blow-molded article characterized in that a reinforcing rib for connecting the ribs is formed between both walls. 2. The reinforcing rib is a side wall of a dent-shaped portion that is continuous from one wall toward the other wall, and the dent-shaped portion has a bottom parallel to the other wall. The blow molded article according to claim 1, wherein the bottom reaches the other wall and is crimped to the other wall. 3. The reinforcing rib is a side wall of a dent-shaped portion that continuously faces the opposing wall from an opposing position of each wall, and the dent-shaped portion has bottoms parallel to each other, The blow molded article according to claim 1, wherein the blow molded article is pressed against each other at an appropriate position between the opposing walls. 4. The welding flange is formed on the entire periphery or a part of the main body, and the reinforcing rib has an annular shape, and a plurality of the reinforcing ribs are formed on the welding flange. The blow molded article according to any one of 1 to 3.