JPS6013529A - Preparation of hollow component part - Google Patents

Abstract

PURPOSE:To obtain a hollow component part easy to control its weight as a float at a shorter preparng time by a method wherein internal joints and external joints that are formed concentrically with the same shape are brought into contact with each other through communicating groove and synthetic resin is injected into this groove. CONSTITUTION:Half member 10 is made from synthetic resin and concave step portion 12 forming an external joint is provided around the end of external shell portion 11. This concave step step portion 12 is bonded with concave step portion 12' at the end of the other half member 10' with the same shape to provide the external joint. A pair of the half members 10, 10' with such structure are inserted into molds 21, 22 to bring them face to face and to arrange the concave step portions 12, 12' and joints 14, 14' in direct contact. Synthetic resin injected from nozzle 23 reaches the inner joint 14 through a long hole having ends 15a, 15a' as inlets. In this way, the joining surfaces of both half members 10, 10' are bonded tightly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing hollow-shaped parts such as automobile gasoline tank floats, carburetor floats, oil stove floats, and the like.

Generally, this type of industrial float must have excellent oil resistance and heat resistance due to its use, which limits the materials that can be used, and currently, foamed phenol, foamed nylon, etc. are used. There are various methods of manufacturing this 70-tooth, and various shapes are required depending on the usage situation of the float.

In addition, as an industrial float, the above-mentioned durability is necessary, but the other most important factor is the weight of 70 tons to obtain a predetermined buoyancy. Controlling this weight is the most important point in the float manufacturing process, and there is a need to simplify this weight control.

Conventionally, industrial floats are manufactured using foamed phenol, foamed nylon, etc., and at this time, the weight of the float is controlled by a blowing agent contained in the foamed phenol. FIG. 1 shows a cross section of a float 1 formed by foaming. A rotating arm (not shown) of a level detector is inserted into the hole 2 in the center.

Controlling the weight of the float 10 using foaming agents such as foamed phenol and foamed nylon is extremely unstable and difficult to manage, and the foaming ratio (apparently density) is restricted. Therefore, in order to form an industrial float that is stable at a predetermined weight without being restricted by the foaming state of the blowing agent, we assume that the float is formed using only synthetic resin.
It will look like the figure. This is done by calculating the weight from the specific gravity of the synthetic resin used for a certain predetermined shape, and then removing an excessive amount of weight from the inside of that shape based on the desired float weight to form the hollow part 4. float 30
It's weight. However, it is necessary for the float 3 to have a hole 5 in the center in order to insert the rotating arm, and when the float 3 is formed only from synthetic resin, it is symmetrical as shown in Fig. 3. The formed hollow parts 6 and 7 must be connected in some way, and in order to make a completely closed hollow part, the outer parts 9, 9' and the inner parts 8, 8! must be joined, and that direction is the third
In either direction of figure X-X and Y-Y, internal 8, 8/
It is quite difficult to join. Furthermore, a conventional float using a blowing agent requires a much longer time to form than a general composite product made of synthetic resin. For example, foaming generally requires 2 to 3 times longer time to form than synthetic resin.
The longer the forming time, the lower the productivity.On the other hand, if the forming time is shortened, foaming occurs from within the surface of the part (referred to as post-foaming) immediately after forming, which poses a problem.

Therefore, the present invention was made in order to eliminate the above-mentioned drawbacks, and the purpose of the present invention is to use a synthetic resin with excellent oil resistance and heat resistance, which is especially necessary for industrial floats, and to The present invention provides a method for manufacturing hollow shaped parts that allows easy weight control and shortens manufacturing time.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings from FIG. 4 onwards.

In the figure, 10 is a half member, and this half member 1o is made of synthetic resin and has a substantially cup-shaped outer shell portion 11. A four-step portion 12 is formed on the outer periphery of the end portion of this outer shell portion 11, and forms an external joint portion 13, which will be described later. Note that this recessed step 12 is joined to a recessed step 12' at the end of the other half member 10' having the same shape to form an external joint 13. Further, 14 is an internal joint formed concentrically with the external joint 13, and the internal joint 14 and the external joint 13 are connected to two or more (four in this embodiment). Concave groove 15・
They are connected by... 16 is a carefully formed through hole in the half member 10, into which a rotating arm (not shown) of a level detector is inserted. Reference numeral 17 denotes a groove portion for locking the rotating arm, and reference numeral 18 denotes a plurality of cavities separated from the outside by the outer shell portion 11 and the wall surface 20 having the groove 15 formed at the end thereof.

A pair of half members 10 and 10' configured as described above are placed in a mold 2.
1.22 and the two molds 21.22 are butted together so that the recessed portions 12.12' formed at the ends of the two half members 10.10' and the joint portions 14.14' are in contact with each other. Place it in In addition, at this time, each of the four grooves 15
......15/... Outer shell part 11 (
11') end portions 15a and 15a' are brought into contact with each other to form a long hole. A synthetic resin injection nozzle 23 is disposed in this mold 21, 22, and this nozzle 23
For example, a synthetic resin 19 of the same quality as the synthetic resin forming the half member 1° (1σ) is injected.

This injected composite 11t has an external joint 13 formed by a recessed step 12.12' and a recessed groove 15.1.
It reaches the inner joint part 14 through a long hole whose entrance is at each end 15a, 15a' of 5/. As a result, the joint surfaces of both half members 1o, 10' are fixed. Then, the four spaces 18 are completely cut off from the outside air. In addition, since the internal joint portion 14 is in contact and fixed by the synthetic resin 19, even if the liquid is filled from the through hole 16, the space portion 1
It will never fall within 8.

FIG. 9 shows a float A manufactured by the method for manufacturing hollow-shaped parts according to the present invention. This float A has a plurality of sealed spaces 18, which are controlled to occupy a predetermined volume to obtain a predetermined buoyancy.

In the above embodiment, four grooves 15 (1s') are provided, but it goes without saying that the number of grooves 15 may be one or more.

The present invention is constructed as described above, and includes forming a groove in the end portions of the two parts, which communicates the internal joint part and the external joint part;
Both parts are brought into contact within the formwork, and then synthetic resin is injected into the groove to fix the inner and outer joints, so synthetic resin can be attached to the inner and outer joints, so for example, two parts It is possible to form a hollow-shaped component having a sealed space and having an insertion hole for a rotary arm such as a level detector. That is, according to the present invention, since a foaming agent is not used as in the conventional method, the weight of the hollow shaped part can be easily controlled, the volume of the space can be accurately obtained, and a predetermined buoyancy can be generated. Also, because it uses synthetic resin! ! It is possible to shorten the waiting time for manufacturing and improve work efficiency. Furthermore, since half-parts of the same shape are fixed using synthetic resin of approximately the same quality as the half-parts injected into the joints between the inside and outside, hollow-shaped parts are manufactured, which reduces mold manufacturing costs and makes management easier. It is also effective.

[Brief explanation of the drawing]

Figures 1 to 3 show conventional floats, Figure 1 is a cross-sectional view of a foam molded float, Figure 2 is a cross-sectional view of a float molded with synthetic resin, and Figure 3 shows the manufacturing process of the same float. The explanatory drawings and FIG. 4 and subsequent figures show embodiments of the present invention,
Fig. 4 is a left side view of a half member of the float, Fig. 5 is a right side view thereof, Fig. 6 is a sectional view of the half member, Figs. 7 and 8 are a front view and a sectional view showing the manufacturing process, FIG. 9 is a front view of the float. 10.1o/... Half member, 13... External joint, 14... Internal joint, ]5.1
5'...Groove (concave groove), 18...Space, 19...Synthetic resin, 21.22...
・Formwork (mold), A...Float Fig. 1 Fig. 2
Figure 3 Figure 4 Figure 5 Figure 6 @ 0 Figure 7 Figure 8 tM': rS 91r<1

Claims (1)

[Claims] In a method for manufacturing a hollow-shaped part formed by combining at least two parts, one or more grooves connecting an inner joint part and an outer joint part each formed concentrically are formed at the ends of the two parts. 1. A method for manufacturing a hollow-shaped part, comprising forming both parts into abutment in a mold, and then injecting a synthetic resin into the groove to fix the inner and outer joints.