JPH0730805B2 - Corrugated ring spring made of fiber reinforced composite material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a corrugated ring spring made of a fiber-reinforced composite material (hereinafter referred to as FRP). More specifically, the present invention relates to a corrugated ring spring made of FRP that is used under repeated load. This one has performance that could not be achieved with the FRP coil spring.

[Prior art and problems]

With the high specific elastic modulus of FRP drawing attention, its application to springs is gradually spreading due to its weight-saving effects.

While the FRP of the leaf spring is promoted, the F of the coil spring is
The reason why RP is not progressing slowly is as follows. That is, the mechanical property required for the coil spring is that the transverse elastic coefficient is high, and therefore the reinforcing fiber must be formed at ± 45 ° with respect to the axis of the coiled wire. Therefore, in order to manufacture this, it was necessary to further wind the wire in which the reinforcing fiber was wound at ± 45 ° around the core material selected arbitrarily for coiling. In addition to this annoyance, winding the reinforcing fiber around the core material is usually performed in a straight state of the core material, so that the core material is bent at the time of coiling to cause wrinkles, which often becomes a defect.

In addition, for reducing the weight of the spring itself, the effect cannot be sufficiently obtained unless the strand is a hollow body. Therefore, a hollow fiber in which the reinforcing fiber is oriented at ± 45 ° with respect to the axis of the coil strand is used. Fabrication of coil springs is needed to reduce weight. However, it is very difficult to mold such a coil spring, and at present, no molding method suitable for mass production has been found.

[Object, Structure and Effect of Invention]

Since the coil spring using the fiber reinforced material is difficult to form and has a manufacturing problem, the inventors of the present invention have conducted earnest studies to solve this problem. As a result, the problem cannot be solved as long as the shape of the coil spring is followed, and the corrugated ring spring having ridges and valleys in the circumferential direction is suitable for the purpose, easy to mold and lighter than the coil spring. We found that the effect was great.

That is, the present invention is as follows.

A ring-shaped material made of a fiber-reinforced composite material in which reinforcing fibers are oriented in the circumferential direction, the ring surface forming a corrugated shape composed of a plurality of radial ridges and valleys, and a load perpendicular to an imaginary plane of the ring. On the other hand, a corrugated ring spring made of a fiber-reinforced composite material to be used under repeated load, characterized in that a corrugated ring having a spring function is used as a spring element by bending and deforming a circumferentially inclined portion.

As is well known, when a coil spring receives a load, the strand mainly receives a torsion load. On the other hand, in the case of the corrugated ring spring, a bending load is applied, so that the reinforcing fibers should be oriented in the circumferential direction of the rig. Therefore, the corrugated ring spring can be molded very easily by the filament wind method, the compression molding method, or the like.

In the present invention, the reinforcing fiber of FRP is a highly elastic fiber such as carbon fiber, glass fiber, aromatic polyamide fiber, and the filament of carbon fiber is particularly preferable from the viewpoint of vibration damping property, high specific elasticity and high specific strength. Further, these fibers can be used alone or in combination. When used in combination, different reinforcing material fibers are arranged in layers,
It can also be arranged in a so-called hybrid structure.

The matrix resin of the fiber reinforcement is epoxy resin, vinyl ester resin, unsaturated polyester resin, furan resin, phenol resin, polyimide resin, or the like.

The orientation of the reinforcing fibers in the present invention needs to be oriented substantially in the circumferential direction of the ring. As mentioned earlier, this is because the coil spring receives a torsional load,
This is because the wave spring of the present invention has a ring shape and is subjected to a bending load.

However, although the spring action portion of the reinforcing fiber is oriented in the circumferential direction, some fibers may be oriented at a slight angle with respect to the circumferential direction in order to prevent the occurrence of cracks in the circumferential reinforcing fiber portion. it can.

In the present invention, the virtual plane means an imaginary plane parallel to the horizontal plane, which shares each ridge of the corrugated ring spring when the corrugated ring spring of the present invention is placed on the horizontal plane.

In the present invention, the ridges and valleys need to be radially formed toward the center of the ring.

An example of the present invention will be described with reference to the drawings.

FIG. 1 illustrates the spring element of the corrugated ring spring of the present invention. FIG. 2 shows a plan view of the spring element, and FIG. 3 shows a side view of the spring element. 1 to 3, 1 is a spring body, 2 is a ridge, 3 is a valley, 4 is an inner peripheral end of a ring, and 5 is an outer peripheral end. The cross section of the spring body of FIG. 1 shows an example of a rectangle, but the cross section is not necessarily limited to a rectangle, and may be a circle, an ellipse, a square, or a modification thereof. Further, it is not necessary that the whole has the same cross-sectional area. The number and size of the rings and the number of ridges and valleys per ring are not limited by the drawings. The shape from the ridge to the valley may be linear or curved, but it is necessary to consider so as not to cause stress concentration during loading.

It is generally known that when a bending load is applied, the apparent longitudinal elastic modulus decreases due to the influence of shearing as the ratio between the fulcrum distance and the member thickness decreases. Therefore, it is necessary to consider this point also in the corrugated ring spring, and the pitch length of the corrugation is 5 with respect to its thickness.
It is desirable to be above. Then, when trying to increase the spring constant, it is theoretically more effective to increase the ring thickness than to increase the width of the ring.

However, in this case, there is also a relationship with the strength, so it is necessary to set the thickness and width in a well-balanced manner according to the load actually applied.

FIG. 4 is a side view of a spring structure in which eight spring elements of the present invention shown in FIG. 1 are stacked. FIG. 5 is a side view of a filament winding mold used for molding the spring element shown in FIG.

The corrugated ring spring element as shown in FIG.
Produced by the wind method. That is, the mold as shown in FIG.
Carbon fiber with epoxy resin pre-impregnated in the gap
-Yeon's Bethfight HTA-7-6000)
The mold was removed after heat curing. The main molding is very easy
It was confirmed that The outer diameter of the ring is φ130 mm and the inner diameter is
φ100 mm and its thickness 2.8 mm
When the number was measured, it was 8 kgf / mm.

The weight of the spring was compared with the case where the same spring constant was obtained with a conventional coil spring whose center diameter was 115 mm, which is the same as that of the corrugated ring spring. The weight of the entire corrugated ring spring is the product of the weight of one ring and the number of rings, and the weight of the entire coil spring is the product of the weight of one coil and the number of turns. Were compared. Table 1 shows the results of a comparison between three types of materials used: iron, glass fiber reinforced plastics, and carbon fiber reinforced plastics, and also when the coil springs are solid and hollow.

The reinforcing fibers of the fiber reinforcement shall be oriented at ± 45 ° to the coil wire, and the hollow coil has a wall thickness of 1/10 of the outer diameter.
The case is shown.

The weight in the table shows the weight of one coil spring, all of which weigh 25 g of one corrugated ring spring.
Is getting heavy against. It was confirmed that the corrugated ring spring is easy to mold and has a great effect of reducing the weight.

[Brief description of drawings]

FIG. 1 illustrates the spring element of the present invention. FIG. 2 shows a plan view of the spring element of FIG. FIG. 3 shows a side view of the spring element of FIG. FIG. 4 shows a side view of a spring structure in which eight spring elements of FIG. 1 are stacked. FIG. 5 is a side view of a filament winding mold used for molding the spring element shown in FIG. 1 to 3, 1 is a spring body, 2 is a ridge, 3 is a valley, 4 is an inner peripheral end of a ring, and 5 is an outer peripheral end.

Claims (2)

[Claims] 1. A ring-shaped material made of a fiber-reinforced composite material in which reinforcing fibers are oriented in the circumferential direction, wherein the ring surface forms a corrugated shape composed of a plurality of radial ridges and valleys, and the ring is imaginary. A corrugated ring spring made of a fiber-reinforced composite material to be used under repeated load, characterized in that a corrugated ring having a spring function is used as a spring element by bending and deforming a circumferential inclined portion with respect to a load perpendicular to a plane. 2. The corrugated ring spring according to claim 1, wherein the reinforcing fibers are carbon fibers.