JPS5939291B2 - Manufacturing method for fiber reinforced plastic products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing products made of fiber reinforced plastics (hereinafter abbreviated as FRP), such as tennis racket frames. When molding with
) A protrusion is formed on the outer surface of the product corresponding to the so-called parting line part), and the outer surface of the protrusion is machined and deburred at the same time, thereby improving workability and productivity. This is what I did.

Generally, when molding this type of FRP product, such as a ratchet frame for tennis, using a split mold, burrs occur at the locations corresponding to the mold joints of the split mold due to problems with the FRP hot-press molding conditions and the accuracy of the split mold itself. Easy to do.

Conventionally, the deburring work of such FRP products is usually carried out manually or by mechanical cutting using a grinder, but as illustrated in Fig. 1,
For tennis racket frames 1, which have a structure in which FRP3 is used as an outer shell layer on the outer peripheral surface of the core material 2,
When finishing the burrs 4 generated on the outer surface of the FRP outer shell layer 3 by cutting with a grinder, relatively rough cutting is performed at high speed up to the initial cutting removal range a near the boundary between the FRP outer shell layer 3 and the burr 4. (For example, dimensional accuracy is low) Although it is possible, the remaining range must be cut carefully at low speed, and the overall workability is very poor.I hope that productivity will improve. I can't.

In addition, in order to increase productivity, if the entire burr 4 is carefully removed at high speed, the cutting finish accuracy will be low, so FR
There is a risk that the P outer shell layer 3 will be cut down and destroyed, which will have a negative impact on the strength of the tennis racket frame, and there will be a high probability of it becoming a defective product, and furthermore, there will be problems such as no hope of increasing the product value. . Therefore, in this invention, a protrusion is formed in advance on the outer surface of the FRP outer shell layer of the product corresponding to the mold joint of the split mold, and the burr generated on the outer surface of the protrusion is removed together with at least a part or all of the protrusion. By cutting and removing it, the above-mentioned conventional drawbacks are attempted to be overcome.

Next, the present invention will be explained based on the embodiments shown in FIG. 2 and subsequent figures.

2 to 4 show the manufacturing process of an FRP product according to the present invention, such as a tennis racket frame.
0 is a split mold, which consists of an upper mold 11, a lower mold 12, intermediate molds 13 and 14, and a cavity 1 shaped like the circumference of the racket frame.
5 are formed, and split molds 11, 12,
A recess 16 is formed along the circumferential direction of the racket frame on the inner wall surface of the capsule 15 corresponding to the mold joint where burrs 13 and 14 form (see FIG. 2).

For example, the core material 17 is made of foamed synthetic resin, and the outer peripheral surface thereof is made of FRP, which serves as an outer shell layer.
A frame forming member 19 covered with a molding material (bripreg sheet) 18 is placed (see FIG. 3), and after clamping the mold, hot pressure molding is performed and the mold is released to form a racket frame body 20 as shown in FIG. 4. It is made by molding. That is, the racket frame main body 20 molded through the above manufacturing process is formed from a foamed core 21 and an FRP outer shell layer 22, and has recesses provided at locations corresponding to the mold joints of the split molds 10. A protrusion 23 is provided on the outer surface of the FRP outer shell layer 22 corresponding to No. 16, and a burr 24 is generated on the outer surface of the protrusion 23. The burr 24 is cut by cutting in the area c including a part of the protrusion 23.
It is obtained by removing .

According to the manufacturing method described above, a protrusion is formed on the outer surface of the FRP outer shell layer of the product corresponding to the burr generation part by the split mold, and burr is generated on this protrusion during molding. During deburring work, even if a part of the protruding part is cut, there is no effect on the product itself, so high-speed cutting is possible even with low dimensional accuracy, greatly improving workability and productivity. In addition, the presence of protrusions that remain in the circumferential direction of the product body after cutting, especially in the case of racket frames, protects the product body from external forces and prevents wear. It has excellent effects such as: In the above embodiments, a tennis racket frame was used as an example of an FRP product, but the technical idea of the present invention can also be used in the manufacture of products such as pole vaulting poles, tube bodies, and ski boards. It is extremely versatile, especially in the production of hollow bodies that have a large effect on strength distribution due to dimensional irregularities.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram partially enlarging an example of conventional deburring processing for FRP products, and Figs. 2 to 4 show the manufacturing process of FRP products according to the present invention. A cross-sectional view of the split mold, Figure 3 is a cross-sectional view showing the molding state of the FRP product,
FIG. 4 is an explanatory diagram partially enlarging the deburring process of the FRP product after demolding. 10...split mold, 16...concavity, 20...
...Product, 22...FRP outer shell layer, 23
...Protrusion, 24...burr.

Claims (1)

[Claims] 1. When molding a product whose outer shell layer is made of fiber-reinforced plastic using a split mold, a recess is provided at a location corresponding to the mold joint of the split mold, and the outer shell of the product after molding corresponds to the recess. In addition to forming a protrusion on the outer surface of the layer, burrs are generated on the outer surface of the protrusion, and when removing burrs after mold release, cutting is performed in an area that includes at least a part of the protrusion. A manufacturing method for fiber-reinforced plastic products featuring: