JPH0626858B2 - Method for forming tubular body by filament winding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention forms a tubular body by a filament winding method (hereinafter simply referred to as FW method) using reinforcing fibers such as carbon fibers, glass fibers, and aramid fibers. On how to do.

[Prior Art] The FW method is a method in which a continuous mandrel is impregnated with a resin and is wound around a rotating mandrel (often a cylindrical metal) at an appropriate wrapping angle to form a predetermined shape. Has the advantage that the strength and elastic modulus of the fiber can be maximized, and that the lamination direction is precise and highly reliable.

Therefore, it is necessary to appropriately select the winding angle (fiber orientation) of the fiber with respect to the mandrel in view of the characteristics required for the tubular product obtained by the FW method. Therefore, it is desirable that the winding angle can be arbitrarily selected within the range of 0 ° parallel to the mandrel axis to 90 ° perpendicular to the axis.

[Problems to be Solved by the Invention] However, when a tubular body is formed by the FW method using an ordinary mandrel, the winding angle of the fiber cannot be lowered too much due to the problem of thread slippage, and is limited to about 30 °. Met.

The inventors of the present invention have conducted various examinations and experiments to develop a molding method capable of further winding at a low angle, and as a result, have made the diameter of the mandrel shaft portion as small as possible, and the mandrel body has a sufficient diameter on both ends. A mandrel that achieves low-angle winding and a molding method using the mandrel have been completed by forming a different step (shoulder) and winding fibers around the step (separate pending application).

However, also in this winding method, as the winding angle approaches 0 ° or the mandrel step surface is formed into a curved surface in consideration of the breakage of the fiber, the slippage of the fiber becomes a problem. On the contrary, when the winding angle is increased when winding the stepped portion, the slipping of the fiber toward the mandrel center side may become a problem.

The present invention has been made in view of the above circumstances, and it is a first object of the present invention to provide a molding method capable of performing stable winding at any winding angle and easily obtaining a tubular body with required performance. To do. A second object of the present invention is also to provide a molding method capable of smoothly removing the mandrel from the molded body obtained after the winding molding.

[Means for Solving the Problems] A molding method according to the present invention for achieving the above object is to use a resin-impregnated continuous fiber around a mandrel to wind a mandrel and to form a tubular body. In the molding method in which a non-slip jig is attached to the fiber and the fiber is turned as if it passes through the anti-slip jig and wound at an appropriate angle, the anti-slip jig is fitted into the mandrel shaft and contacts the body end. A ring with a dried wood pin, characterized in that the molded body is cut at the position of the dried wood ring with a pin.

Furthermore, when pulling out the mandrel after completion of the winding molding, in the above step, the winding on one end side of the mandrel is finally made to have a large diameter, and after completion of the winding molding, the end portion of the molded body on the side opposite to the large diameter portion is removed. It is preferable to add a step of cutting and pulling out the mandrel from the cutting side, at the same time fitting a ring into the large diameter portion, pulling the molded body in the opposite direction and pulling out the mandrel.

[Operation] In the present invention, when the fiber is wound using the stepped portion of the mandrel, the fiber is not slipped even if the winding angle is set to any angle because the fiber is always wound on the anti-slip jig. It will be possible. In addition, when pulling out the mandrel from the molded body, it is possible to hold and fix the opposite end of the molded body while applying tensile force to the mandrel and pull it in the opposite direction, so that the smooth pulling out can be performed. Be seen.

Embodiments Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of a mandrel used in the molding method of the present invention, which comprises, for example, a body portion 1 and a shaft portion 2 (rotating shaft) integrally connected in the axial direction of both ends thereof. Has a diameter as small as possible so that a step portion 1a having a sufficient width is formed at the end portion of the body portion 1. A ring 3 with a pin having a hole 3a having substantially the same diameter as the shaft 2 is provided at both ends of the body of the mandrel.
Is installed.

The pin ring 3 functions as an anti-slip jig for the fiber to be wound, and as shown in FIG. 2, the diameter of the ring 3 is slightly larger than the diameter of the mandrel body 1 and is a donut shape. The peripheral edge portion is cut to give an R surface or an inclined surface, and a large number of pins 4 made of metal or the like are erected on the surface at a constant pitch and at an angle. The temperature of the heating step in the FW method (about 200 ° C)
Since it is required to have heat resistance to withstand and the property that can be easily cut at the time of cutting the molded body after winding and molding the fiber, it is made of a material such as dry wood.
Of course, if it has similar properties other than wood,
It can be used.

A case in which the FW method is carried out using a mandrel equipped with this ring with pin 3 will be described. Instead, attach the rings 3 with pins to both ends of the mandrel, taping the boundary between the mandrel body 1 and the ring 3, and then set the mandrel to a predetermined position.
Attached to the FW method, the resin-impregnated reinforcing fiber is fed, and for example, low-angle winding is performed. As shown in FIG. 3, the winding of the fiber around the mandrel is such that the fiber 5 wound around the body 1 and reaching the end passes through between the pins 4 of the pin ring 3 and through between the other pins through the ring step 3b. Then, it is performed by returning to the body portion 1 again and turning in the same manner toward the ring with a pin 3 on the other end side. After repeating this operation to finish winding the desired number of windings / layers, the resin is heat-cured to obtain the molded body 6. Next, the molded body 6 is cut at the position of the ring 3 with one pin.

Incidentally, FIG. 4 shows a molding state after heat curing. C indicates a cutting position, and one end of the molded body 6 is cut together with the pin ring 3 at this position, and then the molded body 6 is provided on one of the shaft portions 2 of the mandrel. The mandrel is pulled out by connecting the pulling mechanism to the notched portion 7. In the figure, the diameter of the end portion on the side opposite to the cut side of the molded body 6 is large, but this is the result of extra winding of this portion over the other portion when winding the fiber. By forming the large diameter portion 6a, the mandrel can be easily pulled out.

That is, in the case of ordinary mandrel drawing, at the same time as pulling the mandrel in the axial direction, the end face on the mandrel tension side of the molded body was pushed in the opposite direction. However, in this case, a compressive force toward the center acts on the end of the molded body on the side opposite to the mandrel tension side, and the molded body and the mandrel may rather come into strong contact and may not come out smoothly (the tighter the fiber, Strong tendency). On the other hand, when the annular jig 8 is fitted to the large diameter portion 6a as shown in FIG. 4 and the molded body is pulled in the direction opposite to the mandrel pulling direction by this, the compacted body does not generate the compressive force as described above, and it is easy to perform. The mandrel comes out.

After pulling out the mandrel, the other end of the molded product is cut and subjected to a predetermined end treatment and the like to obtain a product.

[Effects of the Invention] According to the molding method of the present invention described above, since the reinforcing fibers can be wound at any angle by utilizing both end steps of the mandrel, it becomes possible to create tubular bodies having various properties. , It is a great place to contribute to the industry. Further, if the winding on one end side of the mandrel is made to have a large diameter, the mandrel can be smoothly pulled out.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a mandrel used for carrying out the method of the present invention, FIGS. 2 (a) and 2 (b) are a plan view and a side view of a ring with a pin attached to the mandrel, and FIG. FIG. 4 is a cross-sectional view for explaining the method of the present invention and mandrel drawing, and FIG. 4 is a schematic view showing another example of mandrels for carrying out the method of the present invention. 1 ... Mandrel body, 2 ... Shaft, 3 ... Ring with pin, 4 ... Pin, 5 ... Continuous fiber, 6 ... Molded body, 7 ...
… Notch, 8… Ring jig

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-50-33263 (JP, A) JP-A-52-9552 (JP, A)

Claims (2)

[Claims] 1. A non-slip jig is attached to both end shafts of a mandrel body of a filament winding method in which resin-impregnated continuous fibers are wound around a mandrel to form a tubular body.
In a molding method in which the fiber is turned as it passes through the anti-slip jig and wound at an appropriate angle, a non-slip jig is fitted into the mandrel shaft and comes into contact with the body end with a pin ring made of dry wood. And a method for forming a tubular body by filament winding, which comprises cutting the formed body at the position of the dried wood ring with a pin. 2. When winding a fiber around a mandrel, the winding on one end side of the mandrel is finally made to have a large diameter, and after the winding and forming is completed, the end of the formed body on the side opposite to the large diameter portion is cut to form a mandrel. 2. The molding method according to claim 1, wherein the mandrel is pulled out by pulling the molded body in the opposite direction at the same time as pulling out from the cutting side and fitting a ring into the large diameter portion.