JPH0249613B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method of manufacturing a coiled lightweight core material for reducing the weight of a ring-shaped rim portion of a steering wheel and obtaining a highly rigid ring reinforcing body.

[Prior art]

Conventionally, this type of ring reinforcing body has been disclosed by the applicant in Japanese Patent Application No. 59-79589 (Japanese Unexamined Patent Publication No. 60-222235).
The present invention is proposed in the method for manufacturing a steering wheel shown in Japanese Patent Publication No. That is, as shown in Fig. 7, this reinforcing body is made by braiding or winding a unidirectional reinforcing fiber roving prepreg 2 around a coiled lightweight core material 1 made of foamed urethane foam, etc. The unidirectional reinforcing fiber roving prepreg 2 is impregnated with a resin or the like, and the two ends are joined together as shown in FIG.

[Summary of the invention]

This invention involves filling a plurality of flexible tubes spirally wound around a cylindrical body with unfoamed hard urethane foam material from one end of each at the same time.
The purpose of the present invention is to provide a method for manufacturing a coiled lightweight core material that can manufacture a plurality of coiled lightweight core materials at once by cutting open a flexible tube after foaming of a urethane foam material is completed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Figures 1 to 3 show an apparatus for manufacturing a coiled lightweight core material, in which 3c, 3b, and 3c are flexible core materials with a circular cross section that are spirally wound around the outer peripheral surface of a cylindrical body 4 so as not to abut each other. They are tubes made of plastics such as vinyl chloride, polyethylene, polypropylene, and nylon, or these plastics reinforced with glass fibers or polyester fibers. 5 is each flexible tube 3a, 3 mentioned above.
5a is a screw for attaching the fixture 5 to the cylindrical body 4. 6 is a storage tank for urethane foam, 7 is a storage tank for hardening agent,
8 is a mixing section for mixing urethane foam and a curing agent, and 9 is a mixing motor. Reference numeral 10 denotes a branch pipe through which unfoamed hard urethane foam material made of urethane foam and curing agent mixed in the mixing section 8 is fed simultaneously from the lower end of each of the flexible tubes 3a, 3b, and 3c through a pipe 11 and a distributor 12. .

Next, a method for manufacturing the coiled lightweight core material will be explained. First, the unfoamed hard urethane foam material of urethane foam and curing agent sufficiently mixed in the mixing section 8 is transferred from the pipe 11 to the flexible tube 3 via the distributor 12 and the branch pipe 10.
It is fed into a, 3b, and 3c from the lower end. The urethane foam material is fed to 2/5 to 4/5 of the tube and then stopped. Thereafter, as shown in FIGS. 4 and 5, the urethane foam material 13 in each tube 3a, 3b, 3c starts foaming. Since the upper ends of each of the tubes 3a, 3b, and 3c are open in this way, the air inside the tubes is forced out with the foaming action of the urethane foam material, and the urethane foam material 13 foams and expands toward the top. It continues and overflows from the top of the tube. Eventually, after the foaming of the urethane foam material is completed, the fixture 5 is removed from the cylindrical body 4, each flexible tube 3a, 3b, 3c is removed, and finally each tube is cut open to form a coiled lightweight core material as shown in FIG. 1 can be manufactured at the same time. As shown in FIG. 7, the lightweight core material produced as described above is wound with unidirectional reinforcing fibers on its surface to obtain a ring-shaped ring reinforcement shown in FIG. 8.

In addition, in the embodiment of this invention, an example was explained in which three coiled lightweight core materials were manufactured at one time, but two
The number is arbitrary.

〔Effect of the invention〕

As explained above, according to the present invention, unfoamed hard urethane foam material is simultaneously filled from one end into a plurality of flexible tubes wound spirally around a cylindrical body, and after foaming of the urethane foam material is completed, the flexible tubes are The following effects can be achieved by cutting open the core material into a coiled lightweight core material.

(a) Multiple pieces of coiled lightweight core material can be manufactured at the same time through a single manufacturing process.

(b) Since unfoamed hard urethane foam is fed into one end of the flexible tube and foamed while pushing out the air inside the tube from the other end of the tube, a coiled lightweight core material of uniform material can be obtained.

(c) Since the flexible tube is supported in a spiral manner on the cylindrical body, the coil helix angle and coil inner diameter of the coiled lightweight core material are highly accurate.

(d) Since the inner wall of the flexible tube is filled with urethane foam material, the foaming pressure generates membrane force in the tube, resulting in a coiled lightweight core material with a uniform circular cross section.

(e) Can be used as core material for FRP coils.

(f) Because the equipment is simple, inexpensive coiled lightweight core material can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an apparatus for carrying out the method of manufacturing a coiled lightweight core material of the present invention, and FIG.
- Line enlarged sectional view of the figure, Figure 3 is also -
4 and 5 are cross-sectional views similar to those shown in FIGS. 2 and 3 showing a state in which the flexible tube is filled with urethane foam, and FIG. Figure 7 is a perspective view of a conventional coiled lightweight core material in which unidirectional reinforcing fibers are wound, and Figure 8 is a perspective view of a conventional coiled lightweight core material formed into a ring shape. be. 1... Coiled lightweight core material, 3a, 3b, 3c
...Flexible tube, 4...Cylindrical body, 5...
...Fixing tool, 6...Urethane foam tank, 7
...Curing agent tank, 8...Mixing section, 10
...Branch piping, 13...Urethane foam material. In the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A plurality of flexible tubes made of plastic such as vinyl chloride or plastic reinforced with glass fiber are wound and fixed in a spiral around the outer peripheral surface of a cylindrical body so that the tubes do not come into contact with each other. A predetermined amount of unfoamed hard urethane foam material is simultaneously filled into the flexible tube from one end using a feeding means, and after the foaming of the urethane foam material is completed, the flexible tube is removed from the cylindrical body. 1. A method for producing a coiled lightweight core material, which comprises cutting open a core material to obtain multiple coiled lightweight core materials at a time. 2. The feeding device according to claim 1, wherein the feeding means simultaneously feeds an unfoamed hard urethane foam material containing a mixture of urethane foam and a hardening agent into each flexible tube via branch piping. A method for manufacturing a coiled lightweight core material.