JPH03190722A - Winding and forming method of filament - Google Patents

Abstract

PURPOSE:To prevent the irregularity of the fibrous orientation of a cut surface and the floating of fibers even when a molded form is cured and shrunk by removing both terminal sections cut from a mandrel and curing the molded form unified with the mandrel under a state in which clamping force is displayed at all times by a clamping member. CONSTITUTION:A filament is wound and molded, and sections inner than engaging members (pin rings) 3 at both end sections of the molded form 4 are clamped and latched from an outer circumference by a clamping member 6 capable of continuously working clamping force even when the diameter of the molded form is shrunk. The molded form 4 is cut at a cut section between the clamping member 6 and the engaging member 3, and both terminal sections 7 cut are removed from a mandrel 1. The molded form 4 unified with the mandrel 1 is cured under the state in which it is clamped by the clamping member 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a filament winding forming method,
Specifically, the present invention relates to a filament winding molding method that prevents fibers at both ends from coming apart when a filament winding molded product is cured.

[Conventional technology]

In recent years, in order to reduce the weight of automobiles and the like, there has been a demand for high-strength, lightweight components, and the development of various composite materials has become active. Among them, the filament winding molding method is widely known as the FRP molding and casting method for cylindrical bodies suitable for mass production. This involves winding a roving made of a bundle of reinforcing fibers such as glass fibers impregnated with resin around a molding core called a mandrel at a constant tension.
By laminating, it is relatively easy to obtain the required strength and directionality of the molded product. For example, in the case of a cylindrical type, by selecting the angle at which the roving is wound around the axis of the mandrel, the orientation of the fibers can be determined as required.

Generally, when the winding angle is 45 degrees or less, a pin ring with a large number of pins arranged radially is often used to fold back the roving at the end of the mandrel. Examples of devices in which a pin ring is attached to a mandrel are disclosed in Japanese Utility Model Application Publication No. 58-120016 and Japanese Patent Application Laid-open No. 50-332.
It is described in Publication No. 63.

[Problem to be solved by the invention]

By the way, the filament winding molded body wound and laminated around a mandrel is separated from the pin ring before it is heated and hardened if the pin ring is to be used repeatedly. However, since the tension applied to the roving is applied to each pin during wind day jigging, when the fibers of the molded body are separated near the pin ring, that tension disappears, and the fiber orientation in the area where it is separated becomes irregular. The end face may be disturbed. As a result, not only does the quality of the molded product itself deteriorate, but it also becomes difficult to remove the mandrel after heat curing, and in some cases, local buckling may occur in areas where the surface pressure is high, or even larger scale damage may occur. There is also a concern that buckling may occur and molding quality may be impaired. Therefore, it has sometimes been necessary to provide an excess margin at the end of the molded body.

The present invention has been developed in consideration of these circumstances, and has been developed to continuously and stably exert a binding force even when the resin is squeezed or shrinks when cured or when the filament winding molded body is cut from the pin ring or when cured. To provide a filament winding molding method which prevents uneven fiber orientation on cut surfaces, lifting of fibers, etc., and prevents occurrence of uneven cut surfaces.

[Means for Solving the Problems] The present invention is applied to a method of filament winding forming by hooking resin-impregnated rovings on locking members provided at both ends of a mandrel and folding them back, and in order to solve the above problems. After filament winding molding, parts of the molded body inside the locking member at both ends are tightened from the outer periphery using a tightening member that can continuously apply a tightening force even when the diameter of the molded body is reduced. The molded body is then cut at the cutting site between the tightening member and the locking member, and after removing both cut end portions from the mandrel, the molded body is integrated with the mandrel. The molded body is hardened while being tightened with the tightening member.

〔Effect of the invention〕

In the filament winding molding method of the present invention, after filament winding molding, the molded product shrinks at a portion inside a locking member provided for hooking and folding the resin-impregnated roving. After the molded body is tightened and latched from the outer periphery by a tightening member that can continuously apply a tightening force even when the molded body is diameter, the molded body is cut at the cutting site between the tightening member and the above-mentioned locking member. Unnecessary terminal parts can be easily removed.

In addition, after removing both cut end portions from the mandrel, the molded body that is integrated with the mandrel is cured while the tightening force is constantly exerted by the tightening member, so even if the molded body Even when the material hardens and shrinks, it eliminates irregular fiber orientation and lifting of the fibers on the cut surface, prevents uneven cut surfaces, and dramatically improves molding quality. be able to.

〔Example] The present invention will be described in detail below based on examples thereof.

The filament winding molding method shown in this example is a method that prevents fibers from coming apart at the cut surfaces at both ends when curing a filament winding molded product for forming an FRP propeller shaft for a vehicle such as an automobile. And it is done as follows.

As shown in FIG. 1, first, both ends 2 (
The resin-impregnated roving is hooked onto the locking member 3 provided on the left side (only shown in the figure), and while folded back, the portions inside the locking member 3 at both ends 5 of the molded body 4 formed by filament winding are held. A tightening member 6 (second
(See Figures (a) and (b)), tighten and latch from the outer periphery. Then, the molded body 4 is cut at the cutting site 9 between the tightening member 6 and the locking member 3, and both cut end portions 7 are removed from the mandrel 1 together with the locking member 3. The molded body 4, which is integrated with the molded body 4, is thermally hardened while being tightened with the tightening member 6.

In this manner, by restraining both ends 5 of the molded body 4 with the tightening members 6, both end portions 7 can be easily cut, and the fibers can be prevented from coming apart. During thermosetting, the tightening force of the clamping member 6 that always acts on the molded body 4 squeezes the resin, increases the fiber density, and improves the quality characteristics of the molded body 4, especially at both ends 5. In addition to improving the quality, it is also possible to prevent the fibers from coming apart so that the quality is not compromised.

To explain in detail, the main body of the mandrel 1 on which the formed bodies 4 are wound and laminated is formed into a solid round bar shape from a metal material such as steel, stainless steel, aluminum alloy, etc., and the outer periphery of both ends 2 of the mandrel 1 has a hexagonal shape. A secondary mandrel 8 having an outer peripheral surface of
is fitted, and the locking member 3 is attached to the outer periphery of the sub mandrel 8.
A bottle ring is fitted thereon and fixed with bolts 11, respectively. Although not shown, the mandrel 1 has both ends 2 rotatably supported on a trolley,
The mandrel 1 is rotated by a driving means, and the mandrel 1 is carried into a heating furnace together with the cart, and the molded body 4 is thermally hardened while being rotated. After heat curing,
Although not shown, the molded body 4 is demolded from the mandrel 1,
A universal joint yoke made of aluminum alloy or steel is fitted and fixed to both ends 2 of the hexagonal shape.

The bottle ring 3 fitted and fixed to the sub-mandrel 8 has stopper pins 13 radially planted therein for hanging the folded portion of the roving (not shown) forming the molded body 4, and is used repeatedly. It is something. A circumferential groove 15 is formed in the secondary mandrel 8 at a portion immediately inside the bottle ring 3 to allow use of a cutting tool such as scissors when cutting the molded product 4 before heat curing. ing. The purpose of providing this circumferential groove 15 is to keep the cutting positions of the fibers constant and to prevent variations in the cut surfaces between products. That is, both ends 5 of the wound molded body 4 are integrated with the bin ring 3 which is fitted and fixed to the sub-mandrel 8, as described above. Therefore, in order to use this bottle ring 3 again, it is necessary to remove the molded body 4 before heat curing. Therefore, such a circumferential groove 15 is bored and formed, and that part is used as the cutting part 9. The molded body 4 is cut. Stopper bin 1 installed in this bin ring 3
3 are arranged in a single line as described in the embodiment, but may also be arranged in multiple lines depending on the required specifications.

In this embodiment, before thermosetting, a tightening member such as the one shown in FIGS. The half rings 6 are fitted to restrain both ends 5 of the molded body 4 from the outer periphery, minimizing lifting of the fibers and disturbance of fiber orientation near the cut site 9 after cutting, and ensuring that the cut surface is straight. I try not to make it look uneven. This half ring 6 consists of a pair of magnetic bodies 10, 10 formed in a hexagonal shape so that the inner surface closely corresponds to the outer surface of the molded body 4.
When this is fitted into the molded body 4, its magnetic force constantly tightens the fibers. Therefore, not only when cutting the molded body 4 at the cutting site 9, but also during thermosetting, ・ At both ends 5 of the molded body 4,
Tightening allows force to be applied stably and continuously.

Therefore, it is possible to avoid molding defects due to fibers coming loose, which often occurs near the cut surface when heat curing is performed with both ends of the molded object unrestrained, as in the past. . That is, at the initial stage of thermosetting,
If the cut surface is not restrained, molding defects are likely to occur due to resin dripping due to a decrease in resin viscosity and changes in the diameter of the molded product due to curing shrinkage. However, in this example, as described above, half The tightening of the ring 6 is done by the action
This problem has been resolved.

Furthermore, by squeezing out excess resin during thermosetting and improving the fiber content, this half ring 6 can be used to improve the strength and rigidity of molded products, especially those that require strength and rigidity for attaching joint members, as described above. It is also possible to improve the quality characteristics of both ends 5 of 4.

FIGS. 3(a) and 3(b) show different embodiments of the half ring 6, in which a pair of opposing half ring bodies 21° 21
Two circumferential grooves 22 are bored and formed in the circumferential groove 22.22.
A ring-shaped spring 23, 23 is wound around the
It is configured so that it can exert a tightening force by hanging it, and as in the case of the half ring 6 made of magnetic material 10゜O in the previous embodiment, constant tightening force is applied to the outer surface of both ends 5 of the molded body 4. It is designed so that it can be made to work.

Although not shown, the tightening member may include a rubber magnet wound around the outer periphery, in addition to the above embodiments,
Alternatively, the ring component may be divided into three or more parts and connected to each other by a tensile force such as a spring. In short, any material may be used as long as it can always tighten the ends 5 of the molded body 4 from its outer periphery.

As described above, according to the method of the present invention, in the filament winding molding method in which the bottle ring is reused, the quality characteristics of the molded product, especially at both ends, can be dramatically improved by using a simple tightening member. Stable and
can be improved.

[Brief explanation of drawings]

Fig. 1 is a partial sectional view showing the state in which the end of the filament winding molded body formed in close contact with the outer periphery of the mandrel is tightened with a tightening member; Fig. 2(a) is a front view of the half ring; 2(b) is a side view thereof, FIG. 3(a) is a front view showing a different embodiment of the half ring, and FIG. 3(b) is a side view thereof. 1--mandrel, 2-one end, 3-locking member (pin ring), 4-molded body, 5-one end, 6-tightening member,
7-terminal portion, 9-- Cutting site. Figure 2 (a) Figure (b) Figure (a) Figure (b)

Claims (1)

[Claims] (1) A method of filament winding molding by hooking resin-impregnated rovings on locking members provided at both ends of a mandrel and folding them back, the method comprising: after filament winding molding, the locking members at both ends of the molded body. The inner part is tightened and latched from the outer periphery by a tightening member that can continuously apply a tightening force even if the molded body is reduced in diameter, and then the tightening member and the locking member are connected to each other. After cutting the molded body at the cutting site between them and removing both cut end portions from the mandrel, the molded body integrated with the mandrel is hardened while being tightened with the above-mentioned tightening member. This is a filament winding molding method.