JPH0137260B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a hollow body made of FRP, and more particularly, to a method for manufacturing a hollow body made of FRP, for example, a hollow body made of FRP having connection members such as metal fittings for power transmission at both ends of a drive shaft of an automobile.
This invention relates to an improvement in the manufacturing method of hollow bodies.

Equipped with connection members such as power transmission fittings on both ends
A so-called FRP drive shaft made of an FRP hollow body is currently in the development stage, and the following methods have been proposed.

(i) After passing the fiber through a resin impregnating tank and winding it around a mold using a filament winding or spiral winding machine, the fiber is hardened to form a hollow cylinder, and then this hardened
A method of attaching power transmission fittings to both ends of an FRP cylinder using adhesive.

(ii) In advance, power transmission fittings are continuously and integrally machined on both ends of a thin-walled metal cylinder, and then resin impregnation is applied to the outer periphery of the thin-walled metal cylinder so as to include the ends of the metal fittings. How to wrap it and harden it.

(iii) The power transmission fitting is divided into a power transmission part and a mounting sleeve beforehand, the mounting sleeves are positioned at both ends, and the resin-impregnated thread is wound around them, and then the parts are cured. According to
Mounting sleeves are integrally attached to both ends.
A method of forming an FRP cylindrical body and then attaching the power transmission part to each mounting sleeve by welding or the like.

However, each of the above-mentioned manufacturing methods has the following drawbacks. In other words, in method (a) (i), the power transmission fittings are hardened.
2 on the inner surface of the cylinder for attaching to the FRP cylinder
The subsequent processing becomes complicated, and the adhesive strength is unstable, resulting in reliability problems.

Although the method (b) and (ii) improves the reliability described above, it not only complicates the manufacturing process but also has problems such as an increase in weight and a weakening of the effect of FRP.

(c) In method (iii), the power transmission fittings must be processed separately into the power transmission part and the mounting sleeve, but the processing of the mounting sleeve is especially complicated, and further welding and trim work are required. Become.

As mentioned above, all of the manufacturing methods that have been proposed so far have complex processing steps that not only make it impossible to mass-produce, but also have problems with their performance, especially for low-cost, high-performance automotive parts. The current situation is that it has not yet been put into practical use in fields that require this.

The present invention was developed as a result of studies to solve the above-mentioned problems.

Therefore, an object of the present invention is to eliminate the need for secondary processing for attaching connection members such as power transmission fittings,
Moreover, it is an object of the present invention to provide an excellent method for manufacturing FRP hollow bodies that can mass-produce highly reliable and lightweight FRP hollow bodies.

Hereinafter, the present invention will be explained in detail by way of examples with reference to the drawings.

In this embodiment, first, as shown in FIG. 1a, prepreg cloth 5 is wound around a cylindrical mandrel 4 in a spiral manner. This prepreg cloth 5 is generally a unidirectional prepreg, and when winding it in a spiral shape around the mandrel 4 as described above, the winding body 6 of the prepreg cloth 5 is rotated to the right while rotating the mandrel 4 in one direction. Or move to the left and wrap the layers alternately at a predetermined angle predetermined by the structural design until a predetermined number or thickness is reached, and the wrapping angle is not only one type but also multiple. Adopt seeds.

After this winding operation is completed, the mandrel 4 is pulled out as shown in FIG. 1b to obtain an unvulcanized FRP cylinder 2a formed into a cylindrical shape. In this mandrel drawing step, in order to facilitate drawing of the mandrel 4, the mandrel 4 is surface-treated or the surface of the mandrel 4 is covered with a release paper or a resin film.

Subsequently, the unvulcanized FRP cylinder 2a obtained in the previous step is cut into a required length by the cutting device 7 to obtain an unvulcanized FRP cylinder 2b (see FIG. 1c).
The cutting device 7 is a push cutter, but other than a rotary blade, a water jet, a laser, and the like are not particularly limited. Any method may be used as long as it can be cut without disturbing the threads.

Next, the uncured material obtained in the above-mentioned cutting process is
Into the FRP cylinder body 2b, as shown in FIG. 1d, an expanding/contracting middle mold D consisting of a shaft 8 and an expanding/contracting bladder 9 is inserted, and this is inserted into the upper and lower molds 10a of the forming outer mold E as shown in FIG. 1e. , 10b to form the uncured FRP cylinder 2b.

This forming outer mold E consists of an upper mold 10a and a lower mold 10b that are formed into relatively the same shape as shown in FIG.
In this example, compression claws 12 are provided at both ends of the body portion 11 to press both ends of the FRP cylinder body _2b , that is, the connection member mounting portion 22 from the periphery, and an expansion ring 13 is provided outside of the compression claws 12 to expand and contract the compression claws. It is configured by providing.

Therefore, as mentioned above, the uncured FRP cylinder body 2b
When forming, use the forming outer mold E.
As mentioned above, uncured FRP is placed between the upper and lower molds 10a, 10b of
After inserting the cylindrical body 2b, first expand the diameter of the expansion/contraction bladder 9 of the medium size D, and then insert the uncured FRP cylindrical body 2b.
is pressed against the inner circumferential wall of the forming outer mold E to form it into a desired shape, and after a predetermined period of time, the expansion/contraction bladder 9 of the middle mold D is reduced in diameter and extracted.

In this embodiment, the expandable/retractable medium D uses an expandable/retractable bladder to facilitate its insertion and removal, but it goes without saying that other expandable/retractable mechanisms may be used.

Thereafter, as shown in FIG. 1f, the connection members 3, such as power transmission fittings, which have been pretreated for adhesion, are inserted into the connection member attachment portions ₂₂ in the unhardened state described above. An FRP hollow body 1a is molded. In this embodiment, as shown in FIG. 1e and f, each connection member mounting portion 2 ₂ is in an uncured state
In order to facilitate the insertion of the connecting member 3 into the connecting member 3, the diameter of each connecting member mounting portion ₂₂ is previously molded to be slightly larger than the diameter of the insertion portion of the connecting member 3 in a pre-process.

Although the method of inserting the connecting member 3 will not be described in detail, the distance,
Of course, this can be done using a holding/inserting mechanism from both ends so as to match the position and axis, or it can also be done in combination with an automatic machine. After inserting the connecting member 3 into each connecting member mounting portion 2 ₂ in this way, move the expansion ring 13 and retract the compression claw 12 to attach each connecting member mounting portion 2 ₂ to the joint surface of the connecting member 3. While pressing and preventing the connection member 3 from falling off, it also improves forming in the next process.

Note that the connection member 3, such as a power transmission fitting used here, is provided with a hole that communicates with the inside of the FRP hollow body 1a. The connecting member 3 is made of a material such as metal or synthetic resin and is formed into a desired shape to suit the purpose of use.

After the connecting member is crimped as described above, the forming outer mold E is opened and the uncured FRP hollow body 1a is taken out.

After that, this uncured FRP hollow body 1a,
It is placed in a heating mold G and heated and cured while pressurized fluid is forced into the inside through the hole of the connecting member 3.

That is, in this embodiment, as shown in FIG.
While holding the uncured FRP hollow body 1a
, close the curing mold 14, and then remove the holding jig 16.
A compressed gas body is injected from a or 16b to form a hollow body 1.
A is inflated and pressed against the inner surface of the curing mold 14, and then steam, hot water, etc. are introduced into the heating medium passage 15 to perform curing.

After curing, it is taken out, and the exposed resin is trimmed and finished as shown in FIG. 1h to obtain the final product, that is, the FRP hollow body 1. Note that, due to the characteristics of the resin, it is not particularly limited to performing secondary curing in an oven or the like after primary curing.

As described above, in the present invention, prepreg cloth is laminated on a mandrel to form an uncured FRP cylinder, the mandrel is removed, and then the FRP
An uncured FRP hollow body is formed by inserting the connecting members into the connecting member attachment parts at both ends of the cylinder.
After that, this uncured FRP hollow body was heated and cured while pressurizing it from the inside and outside. (a) By using prepreg, it was possible to highly control the resin ratio and improve the stability of quality. can be achieved.

(b) After molding an uncured FRP hollow body with a connecting member attached to the connecting member attachment part, this was heated and hardened while applying pressure from the inside and outside, which resulted in stable quality and also the ability to conduct intermediate quality checks. It becomes possible.

(c) In particular, since the uncured connecting member attachment part is crimped onto the connecting member and hardened, the effect can be maximized even if vertical grooves or corrugated processing is used on the connecting member to improve bonding strength. It is possible to easily fix the material so that it will work properly, and not only can the quality be further improved, but also the productivity can be significantly improved.

Therefore, the present invention can provide an excellent method for manufacturing an FRP hollow body that does not require secondary processing for attaching a connecting member and can mass-produce a highly reliable and lightweight FRP hollow body. .

[Brief explanation of drawings]

FIGS. 1a to 1h are explanatory diagrams showing each manufacturing process of the FRP hollow body of the present invention. 1...FRP hollow body manufactured according to the present invention,
1a... uncured FRP hollow body, 2a, 2b...
...Unhardened FRP cylinder, 2 ₁ ...Body of FRP cylinder,
2 ₂ ... Connecting member attachment part of FRP cylinder body, 3... Connecting member.

Claims (1)

[Claims] 1 After laminating the prepreg cloth on a mandrel to form an uncured FRP cylinder, the mandrel is pulled out, and the connecting members are inserted into the connecting member attachment parts at both ends of this FRP cylinder.
A method for manufacturing an FRP hollow body, characterized by forming an FRP hollow body, and then heating and hardening the unhardened FRP hollow body while pressurizing it from the inside and outside.