JPH01286832A - Tubular composite whose thickness varies and its manufacture - Google Patents

Abstract

PURPOSE:To make manufacturing simple and a material free from a loss and obtain uniform strength extending over the whole circumference, by a method wherein an angle to be made by a thread line constituting a reinforcement member with a lengthwise direction of a tubular composite is made large at a large-diameter part of a tubular composite and small at a small-diameter part. CONSTITUTION:The diameter is this at a grip part and that is large at a hitting part of the tip part, in a bat. The reinforcement member 1 is comprised by crossing thread lines 2 tilting to a lengthwise direction, an angle alpha1 to be formed by the thread line 2 with a lengthwise direction of a bat is large at its large-diameter part and its angle alpha2 becomes small at a small-diameter part. Then the angle is varying gradually from the alpha1 to the alpha2 at a tapered part connecting the large-diameter part with the small- diameter part. The angle of the thread line at the whole positions on the circumference of a composite member is uniform and the thread line possesses uniform strength extending over the whole circumference. Since a composite in a desired form is obtained by winding simply bias cloth around the large-diameter part of a core mold and running along a small-diameter part by extending the same, a manufacturing process is extremely simple and a material loss is little.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a tubular composite material whose thickness gradually changes and a method for manufacturing the same, and particularly relates to FRP for baseball.
The present invention relates to a tubular composite material suitable for manufacturing bats, golf club shafts, fishing rods, etc.

BACKGROUND ART Conventionally, known methods for manufacturing tubular composite materials include a filament winding method, a method of spirally winding a woven tape, and a method of winding a wide woven fabric.

Problems to be Solved by the Invention The above-mentioned filament winding method has few restrictions due to the shape of the molded product, and is widely used. It doesn't look good.

Furthermore, it is difficult to obtain a thin composite material with only one filament layer, and the surface needs to be polished in order to finally achieve the desired shape and dimensions.

In the tape winding method, the fibers are discontinuous along the length of the composite. Generally, tubular composite materials often require strength in the longitudinal direction, but it is difficult to obtain sufficient strength because the fibers in that direction are discontinuous.

Furthermore, the method of winding a wide woven fabric is suitable for obtaining a tubular composite material with a constant thickness, but is not suitable for obtaining a tubular composite material whose thickness varies.

In other words, if you try to wind a woven fabric around a mold with a shape that changes in thickness, you will wind it around the maximum diameter part of the mold, and there will be a gap between the surface of the mold and the inner surface of the fabric in the other small diameter parts. This causes the woven fabric to not be able to fit the pattern.Also, it is necessary to cut the woven fabric appropriately according to the change in the thickness of the pattern, and to wind it along the surface of the pattern while deforming the weave of the woven fabric. Although it is not impossible to do so, as the shape of the cut becomes complicated, loss occurs in the woven fabric, and in the tapered part where the thickness changes, the angles of the threads that make up the woven fabric on the circumference are uneven. Therefore, a composite material having uniform strength all around the circumference cannot be obtained.

The present invention has been made in view of the above circumstances, and is a composite material whose thickness changes, whose reinforcing member is made of a wide fabric, which is easy to manufacture, has no loss of material, and which is made of a composite material whose thickness changes. The object is to provide a tubular composite material having mutually equal strength.

Means for Solving the Problems In the tubular composite material of the present invention, the reinforcing member of the composite material crosses threads that are inclined with respect to the length direction of the tubular composite material. The present invention is characterized in that the angle that the yarn makes with respect to the longitudinal direction of the tubular composite material is large in the large diameter portion of the tubular composite material and small in the small diameter portion of the tubular composite material. The manufacturing method is to wrap a bias cloth around a core mold of varying thickness on the surface along the maximum diameter part of the core mold, and to separate the bias cloth and the core mold in parts other than the maximum diameter part. A gap is created between them, and then the bias cloth is stretched in the length direction of the core mold to shrink its diameter so as to fit along the part other than the maximum diameter part, and the bias cloth is used as a reinforcing member and composited with synthetic resin. It is characterized by encouraging people.

In addition, the term "tubular composite material" in the present invention does not mean that the inside is hollow, but it means that there is a tubular part made of the composite material at the outermost part. The core may be hollow or may be continuously made of a composite material, and also includes a core in which a tubular composite material is formed on the outer peripheral surface of another core.

Function: In the tubular composite material of the present invention, the angle that the threads constituting the reinforcing member make with respect to the longitudinal direction of the tubular composite material is large in the large diameter portion of the tubular composite material and small in the small diameter portion. It is possible to change the diameter while using the same number of threads.

In addition, in the manufacturing method of the present invention, a bias cloth is wound on the surface of a core mold of varying thickness along the maximum diameter part,
By stretching the bias cloth in the length direction of the core mold, the angle of the threads constituting the bias cloth becomes smaller, and the diameter of the bias cloth is contracted so that it can fit along the small diameter portion.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a reinforcing member for a baseball bat to which the present invention is applied. In a bat, the grip part has a narrow diameter, and the striking part at the tip has a large diameter. This reinforcing member 1 is formed by intersecting the threads 2 that are inclined with respect to the length direction, and the angle α1 between the threads 2 and the length direction of the bat is large in the large diameter part, and the small diameter part is large. The angle α2 is small in the section. In a portion of the taper connecting the large diameter portion and the small diameter portion, the angle gradually changes from α to α2.

Note that this reinforcing member 1 is made of bias-shaped fabric,
It is preferable to change the angle of the bias to obtain the above-mentioned top formation.

This reinforcing member is impregnated with a synthetic resin such as an unsaturated polyester resin or an epoxy resin and cured to form a composite bat having a predetermined shape.

Depending on the use of the product to be manufactured, the composite material of the present invention may be a solid composite material to the inside, or may be a composite material coated on an appropriate core. When coating the core, only the surface may be thinly coated with a single layer of composite material, or may be coated with multiple layers. Further, the product may be made with the core coated as it is, or the product may be made of only the composite material by removing the core.

FIG. 2 shows a state in which a bat made of the composite material is manufactured. 3 is a core type, and has the shape of a bat. Then, a bias cloth 4 is wound around the surface of this core mold 3. At this time, the bias cloth 4 is wound along the surface of the large diameter portion 5 of the core mold 3, and a gap is formed between the bias cloth 4 and the core mold 3 in the small diameter portion 6 and the tapered portion 7. Ru. When the bias cloth 4 is wound around the core 3, it has a cylindrical shape with a diameter corresponding to the large diameter portion 5 of the core 3.

Next, when the bias cloth 4 wound around the core mold 3 is pulled in the direction of arrow A in the figure, the angle between the threads 2 constituting the bias cloth 4 and the length direction of the core mold 3 becomes smaller, and the bias cloth 4
extends in the direction of arrow A and reduces its diameter, along the tapered portion 7 and small diameter portion 6 of the core mold 3.

Thereafter, the bias cloth 4 impregnated with a synthetic resin is sandwiched between molds, and the synthetic resin is solidified to manufacture a composite bat.

Note that the bias cloth 4 may be impregnated with the synthetic resin after the bias cloth 4 is wound around the core mold 3, or the bias cloth 4 impregnated with synthetic resin in advance may be wound around the core mold 3. In the latter case, when the bias cloth 4 is wound multiple times around the core 3, if the bias cloth 4 has adhesive properties, it will be difficult to stretch even if the wound bias cloth 4 is pulled. Therefore, it is preferable to use a bias cloth 4 with a small amount of synthetic resin impregnated and low adhesiveness.

Further, the core mold 3 may remain wrapped in the bias cloth 4 to form the core of the bat, or it may be removed after the bias cloth 4 is wound or after the synthetic resin has been cured, and the core mold 3 may be removed from the bat made of only the composite material. It is also possible to do this.

Effects of the Invention According to the tubular composite material of the present invention, since the entire structure is made up of a single reinforcing member 1, there are few discontinuous parts in the threads 2 constituting the reinforcing member 1, and the strength is improved. It becomes a large composite material. In addition, since it can be composed of only one layer of a single reinforcing member, a sufficiently thin composite material can be obtained, and by stacking multiple layers of reinforcing members, it is possible to easily create a thick composite material. .

In addition, since the angle of the threads that make up the reinforcing member changes to follow changes in the thickness of the composite material, the angles of the threads at all positions on the circumference of the composite material are uniform, and It has uniform strength around the circumference.

Therefore, the composite material has no directionality and behaves uniformly in all directions, making it suitable for baseball bats, fishing rods, etc.
Furthermore, when used in golf club shafts, etc., there will be no variation in product performance.

In addition, especially in baseball bats, it is desirable that the batting part has strength in the circumferential direction since it directly receives the MS during impact, and the grip part is subjected to bending moment during impact, so it is desirable to have strength in the circumferential direction. It is desirable to have strength in the axial direction, but in the composite material of the present invention, the large diameter part has a large yarn angle and has relatively high strength in the circumferential direction, and the small diameter part has a relatively high strength in the circumferential direction. Since the angle is small and the strength in the axial direction is large, it has suitable performance as a bat.

According to the method of the present invention, a composite material having a desired shape can be obtained by simply winding the bias cloth around the large diameter part of the core and stretching it along the small diameter part. There is no need to cut the bias cloth in a complicated manner according to the shape, and the manufacturing process is extremely simple, and there is little loss of material, making it economical.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a baseball bat as an example of the composite material of the present invention, and FIG. 2 is a plan view showing the manufacturing process thereof. 1... Reinforcement member 2... Thread 3... Core type 4... Bias cloth 5... Large diameter portion 6...・・・
・Small diameter part 7... Part of the taper

Claims (1)

[Claims] 1. In a tubular composite material whose thickness changes, the reinforcing member (1) of the tubular composite material is made by intersecting threads (2) that are inclined with respect to the length direction of the tubular composite material. , the thread (2)
A tubular composite material of varying thickness, characterized in that the angle (α) formed by A bias cloth (4) is wound on the surface of the core mold (3) whose length changes along the maximum diameter portion (5) of the core mold (3), and the bias cloth (4) is wound around the surface of the core mold (3) along the maximum diameter portion (5). ,7)
In this case, a gap is created between the bias cloth (4) and the core mold (3), and then the bias cloth (4) is inserted into the core mold (3).
The bias cloth (4) is stretched in the length direction to contract its diameter so as to fit along the parts (6, 7) other than the maximum diameter part, and the bias cloth (4) is composited with a synthetic resin as a reinforcing member. , a method for manufacturing tubular composites of varying thickness.