JPH04331879A - Method of manufacturing hollow assembly - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing a part such as a valve seat or an assembly, which can reduce the manhours for assembly with no defects during assembly, in the case of the necessity of clamping the part or the assembly during manufacture. CONSTITUTION:At least one of left and right split halves 5, 7 formed during a primary injection is left inward of die, and a separately molded part having a cross-sectional shape the same as that of the split halves and having a cylindrical external shape is inserted into the die, and then one end of one of the split halves and the cylindrical part 8 is simultaneously mated with the other end of the other of the split halves and the cylindrical part 8 upon die registration, and secondary molten resin 9 for joint is charged into the abutting part therebetween.

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 a hollow assembly in which an interior component or an assembly thereof is sandwiched and fixed between hollow half bodies.

0002

[Prior Art and its Problems] Oil strainers and filtration valves are manufactured as parts manufactured by incorporating a valve body or a filter inside a hollow body.Usually, as shown in FIG. 4, the filter member 11 is opened. A supply cylinder 1 attached to the opening of the intermediate cylinder 3 and a discharge cylinder 2 having a filter member 21 similarly attached to the opening thereof abut against both ends of an intermediate cylinder 3, which has a valve body 31, and the abutting parts are welded. It is common to form However, the process of molding the three parts separately, assembling them, and welding the joints requires a large number of assembly steps, making it unsuitable for automatic assembly using robots, etc., and the process of molding the three parts separately, assembling them, and welding the joints. etc. may enter the valve seat and cause malfunction.

0003

[Problem to be Solved by the Invention] Therefore, in these days when robot technology is becoming widely used, it is necessary to reduce the assembly man-hours when it is necessary to manufacture parts or assemblies such as the above-mentioned valve seats by enclosing them in the middle of a hollow body. An object of the present invention is to provide a manufacturing method that is free from defects during assembly.

0004

[Means for Solving the Problems] The present invention has been made with the focus on the fact that the above problems can be solved by applying a two-stage molding technique to the method for manufacturing hollow assemblies. , the mold is opened with at least one of the two halves molded by primary injection left in the deep part of the mold, and a separately molded part having a cylindrical outer shape with the same cross-sectional shape as the half body is inserted into the mold. , one divided body and one end of the cylindrical part are abutted simultaneously, and the other divided body and the other end of the cylindrical part are abutted simultaneously by mold matching, and secondary molten resin for joining is injected into both abutting parts. A method for manufacturing a hollow assembly, the gist of which is to solidify the hollow assembly.

[0005] The two-stage molding technique adopted in the present invention is disclosed in Japanese Patent Application No. 2-2-2001, which was developed by the present applicant and has already been filed.
In addition to the rotary slide molding method of No. 08720, there are also methods in which the mold is slid linearly, such as JP-A No. 6
The methods described in No. 2-87315 and JP-A No. 63-237917 may be employed. After injection molding, either one of the halves may be left in the inner part of the mold, but both halves may be left. Since the cylindrical part inserted into the mold forms the middle part of the hollow body, it needs to have the same cross-sectional shape as the half body, and is preferably manufactured from the same material. Particularly suitable are cylindrical valve assemblies with a valve seat and a valve body.

[0006]

[Operation] With at least one of the two halves molded by primary injection placed deep inside the mold, interior parts, etc. are inserted into the mold, and then the left and right halves are abutted against both ends of the interior part. Then, when the secondary molten resin is injected into both abutting parts and solidified to form a hollow body, the interior parts can be simultaneously completed as intermediate members into the hollow body using the two-stage molding process. .

[0007]

EXAMPLES The present invention will be explained in detail below based on examples. Figure 1 is a cross-sectional view showing the state of primary injection molding, which is the first step when the method of the present invention is carried out using a die sliding two-stage molding technique, and Figure 2 is a cross-sectional view of a filter valve used as an interior component. 3 is a sectional view showing the state of secondary injection molding, which is the second step.

That is, in FIG. 1, 4 is a first slide mold for molding the left half body 5, and has a female part 41 and a male part 42, while 6 is a mold for molding the right half body 7. A slide mold for molding, which has a male mold part 61 and a female mold part 62 corresponding to the first slide mold 4, and the female mold part 41 of the first slide mold 4 and the second slide mold The male mold part 61 of the mold 6 is mold-matched, while the male mold part 42 of the first slide mold 4 and the male mold part 62 of the second slide mold 6 are mold-matched to form a cavity C1 and A first resin is injected into C2, and the left half body 5 and the right half body 7 are primary injection molded.

Next, the first slide mold 4 and the second slide mold 6 are opened, and filters 83 and 84 are fitted into both ends of a cylindrical valve body 82 having a valve seat 81 shown in FIG. The cylindrical filter valve 8 is inserted into the female mold part 41 of the first slide mold 4 into which the left half body 5 is inserted deep,
Half of it protrudes outside. This protruding part is shown in the second section below.
At the time of mold clamping, the right half body 7 in the second slide mold 6 is inserted into the entrance portion of the female mold part 62 inserted deep inside.

That is, the cylindrical valve body 82 has a portion of its outer periphery cut out at both ends, while the left and right halves 5 and 7 have a portion of their outer periphery cut out at the abutting portions 51 and 71. Annular grooves 52, 72 are formed, and small diameter openings 53, 73 are formed on the opposite side. therefore,
By matching the first and second slide molds 4 and 6, the left half body 5 into which the filter valve 8 is inserted
When and the right half body 7 are brought together with the cylindrical valve body 8 in between,
Cavities C3 and C4 are formed between both ends of the cylindrical valve body 8 and the left and right half bodies 5 and 7. Therefore, when the molten resin 9 is injected into the cavities C3 and C4 and solidified, the left and right halves 5 and 7 are brought into contact with each other in a hollow body with the filter valve 8 sandwiched therebetween, thereby producing the half body.

[0011]

Effects of the Invention As is clear from the above explanation, according to the present invention, two halves molded by primary injection are abutted at their ends in a mold, and the abutment portions are coated with secondary molten resin. In the method of manufacturing a hollow body by injecting and solidifying, when the mold is opened after the primary injection, a separately manufactured cylindrical part or assembly is inserted into one of the molds, leaving a half body in the inner part. Then, by abutting both halves against both ends of the cylindrical part and clamping the mold, and by injecting molten resin into the abutting part and solidifying it, the joining of both halves can be used to form intermediate parts, etc. Since the clamping into the hollow body is completed at the same time, the number of assembly steps can be reduced, and there is no need for a welding process, which prevents welding debris and dirt from entering the inside of the hollow body, unlike conventional methods. Without,
It will not cause defects in the assembly equipment. Furthermore, since the cylindrical part protrudes outside the mold, handling by a robot or the like is easy.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the state of primary injection molding, which is the first step when the method of the present invention is carried out using a die-sliding two-stage molding technique.

FIG. 2 is a sectional view of a filter valve used as an interior component.

FIG. 3 is a cross-sectional view showing the state of secondary injection molding, which is the second step.

FIG. 4 is a cross-sectional view of a hollow assembly manufactured by a conventional method.

[Explanation of symbols]

4, 6...Sliding mold, 5...Left half body, 7...Right half body, 8... Cylindrical part, 9... Molten resin.

Claims (2)

[Claims] Claim 1: The mold is opened with at least one of the two half bodies molded by primary injection left in the deep part of the mold, and a part having a cylindrical outer shape with the same cross-sectional shape as the separately molded half body is placed in the mold. one end of the cylindrical part and the other end of the cylindrical part are simultaneously abutted by mold matching, and a secondary material for joining is inserted into both abutting parts. A method for manufacturing a hollow assembly, characterized by injecting and solidifying molten resin. 2. The method of manufacturing a hollow assembly according to claim 1, wherein the cylindrical part is a valve assembly having a valve seat and a valve body.