JP2020175603A - Method for manufacturing fiber reinforced resin ring - Google Patents

Abstract

To provide a method for manufacturing a fiber reinforced resin ring capable of reducing the frictional resistance of an outer circumferential surface while not causing strength degradation.SOLUTION: A carbon fiber, being impregnated with an epoxy resin, is put into a semi-cured state to form a prepreg sheet 11, which is made into a ring shape to form a sleeve 12. A transfer film 21, in which a protrusion type pattern is formed, is wound on the outer circumferential surface of the sleeve so as to adhere it. After the sleeve 12 is heated and cured, the transfer film 21 is removed. Thereby, an annular carbon fiber reinforced resin ring 10 in which a groove 10a in correspondence with the pattern is formed on the outer circumferential surface is manufactured.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a fiber reinforced resin ring, and is extremely effective when applied to the manufacture of a holding ring for fixing a permanent magnet to the surface of the rotor core of a rotor of a surface magnet type synchronous machine.

In the surface magnet type synchronous machine (SPMSM) that attaches a permanent magnet to the surface of the rotor core of the rotor, when the rotor rotates at high speed, the permanent magnet may peel off from the surface of the rotor core due to centrifugal force and scatter. A holding ring is fitted on the surface of the rotor core to which the permanent magnet is attached to fix the permanent magnet to the rotor core.

Since such a holding ring is located on the outermost periphery of the rotor, eddy currents are generated by space harmonics due to the slots of the stator and time harmonics due to distortion of the current waveform, resulting in eddy current loss and a decrease in efficiency. Carbon fiber reinforced resin (CFRP), which has high strength and low conductivity, is used because heat generation may cause thermal demagnetization of adjacent permanent magnets.

This CFRP is very suitable as a material for a holding ring because its conductivity is overwhelmingly lower than that of titanium alloy (Ti-6Al-4V), which is a non-magnetic material and has high strength and low conductivity, and hardly causes loss. Is.

JP 2015-091202

Toshio Terabayashi et al., "Cutting of molds with fine wavy riblet structure", 24th Society of Precision Engineering Student Member Graduation Research Presentation Lecture Proceedings, Public Interest Incorporated Association Precision Engineering Society, March 6, 2017, p. 31-32

In the SPMSM, when the rotor rotates at a high speed, the air in the gap between the stator and the rotor becomes frictional resistance and causes loss. Therefore, the frictional resistance on the outer peripheral surface of the holding ring should be made as small as possible. Is strongly sought after.

For this reason, in the holding ring made of CFRP, which is more likely to have irregularities on the outer peripheral surface than the holding ring made of metal such as titanium alloy, and the outer peripheral surface shape is more likely to be uneven, the outer peripheral surface is machined by cutting or grinding. It is considered to reduce the frictional resistance of the outer peripheral surface.

However, when the outer peripheral surface of the holding ring made of CFRP is machined, not only the carbon fiber is broken, but also damage such as cracking and chipping is likely to occur, which may cause a decrease in strength.

Such a problem is not limited to the holding ring made of CFRP of SPMSM as described above, and can occur in the same manner as described above in the case of a fiber reinforced plastic (FRP) ring for which frictional resistance on the outer peripheral surface is desired to be reduced. Is.

For this reason, it is an object of the present invention to provide a method for manufacturing an FRP ring capable of reducing the frictional resistance of the outer peripheral surface without causing a decrease in strength.

In order to solve the above-mentioned problems, the method for manufacturing a fiber-reinforced resin ring according to the present invention has a convex or concave shape on the outer peripheral surface of an annular prepreg in which the reinforcing fibers are impregnated with a thermosetting resin to be in a semi-cured state. The transfer film on which the pattern is formed is wound so as to be in close contact with the prepreg, and then the transfer film is removed to reinforce the annular fiber in which the concave or convex pattern is formed on the outer peripheral surface. It is characterized by obtaining a resin.

Further, the method for manufacturing a fiber-reinforced resin ring according to the present invention is characterized in that, in the above-mentioned method for manufacturing a fiber-reinforced resin ring, the pattern of the transfer film has a riblet structure.

Further, the method for producing a fiber-reinforced resin ring according to the present invention is characterized in that the reinforcing fiber is a carbon fiber in the above-mentioned method for producing a fiber-reinforced resin ring.

Further, in the method for manufacturing a fiber reinforced resin ring according to the present invention, in the above-mentioned method for manufacturing a fiber reinforced resin ring, a holding ring for fixing a permanent magnet to the surface of the rotor core of a rotor of a surface magnet type synchronous machine is manufactured. It is a feature.

According to the method for manufacturing a fiber reinforced resin ring according to the present invention, a concave or convex pattern is formed on the outer peripheral surface of the fiber reinforced resin ring corresponding to the convex or concave pattern formed on the transfer film. Therefore, a fiber-reinforced resin ring having reduced frictional resistance on the outer peripheral surface can be obtained without relying on machining such as cutting or grinding, so that the frictional resistance on the outer peripheral surface is reduced without causing a decrease in strength. Since the fiber reinforced resin ring can be manufactured and it does not depend on machining, the process can be simplified and the cost can be reduced.

It is a procedure explanatory drawing of the main embodiment of the manufacturing method of the fiber reinforced resin ring which concerns on this invention. It is an external view of the holding ring manufactured by the method of FIG. It is an enlarged view of the surface of the holding ring of FIG.

An embodiment of a method for manufacturing a fiber reinforced plastic (FRP) ring according to the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments described based on the drawings.

<Main embodiment>
A main embodiment of the method for manufacturing an FRP ring according to the present invention will be described with reference to FIGS.

In the method for manufacturing an FRP ring according to the present embodiment, a transfer film having a convex pattern is brought into close contact with the outer peripheral surface of an annular prepreg in a semi-cured state by impregnating reinforcing fibers with a thermosetting resin. This is a method of obtaining an annular fiber reinforced resin in which the concave pattern is formed on the outer peripheral surface by winding and heat-curing the prepreg and then removing the transfer film. More specifically, it will be described below.

First, a prepreg sheet 11 is manufactured by impregnating a knitted fabric of reinforcing fibers such as carbon with a thermosetting resin such as epoxy and semi-curing it (FIG. 1A: prepreg manufacturing process).

Next, the prepreg sleeve (annular body) 12 is formed by winding the sheet 11 around a mandrel (core rod) 1 coated with a mold release agent with a roll 2 until the desired thickness is reached. (Fig. 1B: prototype manufacturing process). The sheet 11 is cut into the same width size or the target width size and wound around the mandrel 1 according to the width and the like of the sleeve 12 to be manufactured.

Subsequently, a strip-shaped transfer film 21 having a convex pattern such as a riblet shape forming a fine corrugation is spirally applied to the transfer film 21 so as to be brought into close contact with the outer peripheral surface of the sleeve 12. Winding at a specified pitch (Fig. 1C: film winding process).

Here, the transfer film 21 is made of, for example, a columnar mold in which an ultraviolet curable resin is applied on a base film and a concave groove such as a riblet structure having a fine corrugation is formed on an outer peripheral surface. It can be obtained by irradiating ultraviolet rays while rolling on the above (see, for example, Non-Patent Document 1 and the like).

Then, the sleeve 12 around which the transfer film 21 is wound is heated and cured (heat curing step), then cooled and removed from the mandrel 1 (FIG. 1D). At this time, if the mandrel 1 has a tapered outer peripheral surface having an outer diameter smaller than that of one end side, it can be easily removed from the mandrel 1.

Finally, the transfer film 21 is peeled off from the sleeve 12, various surface treatments are applied to the sleeve 12, and the sleeve 12 is cut along the radial direction at predetermined intervals in the axial direction to form a CFRP ring. 10 is manufactured (see FIG. 2).

The CFRP ring 10 manufactured in this manner corresponds to the convex pattern formed on the transfer film 21 and has a quadrangular groove 10a (see FIG. 3A) and a triangular groove 10b (see FIG. 3A) on the outer peripheral surface thereof. A riblet structure having a fine waveform such as (see 3B) will be formed.

Therefore, when the CFRP ring 10 is used as a holding ring for fixing a permanent magnet to the surface of the rotor core of the rotor of the SPMSM, even if the rotor rotates at a high speed, the riblet structure of the CFRP ring 10 causes the stator and the rotor. The frictional resistance of the air in the gap between the and is very small, and the loss can be significantly reduced.

Therefore, according to the present embodiment, the CFRP ring 10 having reduced frictional resistance on the outer peripheral surface can be obtained without machining such as cutting or grinding, so that the frictional resistance on the outer peripheral surface is not reduced. CFRP ring 10 can be manufactured.

Moreover, since it does not depend on machining, the process can be simplified and the cost can be reduced.

<Other Embodiments>
In the above-described embodiment, the prepreg sheet 11 is manufactured (prepreg manufacturing step) by impregnating the woven fabric of the reinforcing fibers with a thermosetting resin and semi-curing it, and the sheet 11 is used as the mandrel 1. The case where the CFRP ring 10 is manufactured by the sheet winding method for manufacturing the prepreg sleeve 12 (prototype manufacturing process) by winding and laminating until the desired thickness is obtained while pressing with the roll 2 has been described. Is not limited to this, and as another embodiment, for example, a filament in which a plurality of reinforcing fibers such as carbon are bundled is run and immersed in a thermosetting resin bath to impregnate the filament with a thermosetting resin. While semi-curing to manufacture a prepreg filament (prepreg manufacturing process), the prepreg sleeve is manufactured by winding the filament around a mandrel until the desired thickness is obtained while applying tension to the filament. It is also possible to manufacture a CFRP ring by the filament winding method (prototype manufacturing process).

Further, in the above-described embodiment, the transfer film 21 having a convex pattern formed by irradiating an ultraviolet ray while rolling a columnar mold having a concave groove formed on the outer peripheral surface on an ultraviolet curable resin. The CFRP ring 10 having concave grooves 10a and 10b formed on the outer peripheral surface was manufactured by wrapping the sleeve 12 around the outer peripheral surface of the sleeve 12 and curing it by heating. For example, a transfer film in which a plurality of protrusion-shaped patterns are formed is manufactured by irradiating ultraviolet rays while rolling a cylindrical mold having a plurality of depressions formed on the outer peripheral surface on an ultraviolet-curable resin. As shown in FIG. 3C, a CFRP ring 10 having a plurality of recesses 10c formed on the outer peripheral surface can be manufactured by wrapping the sleeve around the outer peripheral surface and curing by heating, or a column having a plurality of protrusions formed on the outer peripheral surface. By irradiating ultraviolet rays while rolling the mold on an ultraviolet curable resin, a transfer film in which a plurality of concave patterns are formed is manufactured, and this is wound around the outer peripheral surface of the sleeve and cured by heating. As shown in FIG. 3D, it is also possible to manufacture a CFRP ring 10 having a plurality of protrusions 10d formed on the outer peripheral surface.

Further, in the above-described embodiment, the case of the CFRP ring 10 using carbon fiber (CF) has been described, but as another embodiment, for example, a glass fiber reinforced resin (GFRP) using glass fiber (GF) has been described. Even in the case of the GFRP ring according to the above, it can be applied in the same manner as in the case of the above-described embodiment.

Further, in the above-described embodiment, the case where it is applied to the production of a holding ring made of CFRP for fixing a permanent magnet to the surface of the rotor core of the rotor of the SPMSM has been described, but the present invention is not limited to this, and the FRP ring is not limited to this. In the case of manufacturing, it can be applied in the same manner as in the case of the above-described embodiment.

According to the method for manufacturing a fiber reinforced resin ring according to the present invention, a fiber reinforced resin ring having reduced frictional resistance on the outer peripheral surface can be obtained without machining such as cutting or grinding, and the outer circumference is not reduced in strength. A fiber-reinforced resin ring with reduced surface frictional resistance can be manufactured, the process can be simplified, and the cost can be reduced, so that it can be used extremely beneficially in industry.

1 Mandrel 2 Rolls 10 Carbon Fiber Reinforced Resin (CFRP) Rings 10a, 10b Grooves 10c Recesses 10d Protrusions 11 Sheets 12 Sleeves 21 Transfer Film

Claims (4)

A transfer film having a convex or concave pattern was wound around the outer peripheral surface of the annular prepreg in a semi-cured state by impregnating the reinforcing fibers with a thermosetting resin so as to adhere to the prepreg, and the prepreg was heat-cured. After that, a method for producing a fiber reinforced resin ring, which comprises removing the transfer film to obtain an annular fiber reinforced resin having the concave or convex pattern formed on the outer peripheral surface. The method for producing a fiber-reinforced resin ring according to claim 1, wherein the pattern of the transfer film has a riblet structure. The method for producing a fiber-reinforced resin ring according to claim 1 or 2, wherein the reinforcing fiber is a carbon fiber. The method for manufacturing a fiber reinforced resin ring according to any one of claims 1 to 3, wherein a holding ring for fixing a permanent magnet to the surface of a rotor core of a rotor of a surface magnet type synchronous machine is manufactured.

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