JPS627530A - Fiber-reinforced structure and manufacture thereof - Google Patents

Abstract

PURPOSE:To form a fiber-reinforced structure with characteristics of high rigidity and high strength by a method wherein a fiber is wound under tension and at the same time the fiber is cured while being applied with further tension. CONSTITUTION:Firstly, bearing members 1 and 2, the diameters of which are different from each other, are connected to a connecting member 3. Secondly, a fiber 4, which is impregnated with resin and has extensibility, is wound around the outer periphery of said members 1, 2 and 3. Though gaps are developed between the fiber 4 and the connecting member 3 in the state as wound, the gaps are eliminated by applying external forces so as to bring the fiber 4 into close contact with the connecting member 3. In the state just mentioned above, the fiber is cured and bonded with adhesive such as resin so as to obtain a fiber 4'. The resultant fiber-reinforced structure is employed as the arm of an industrial robot.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fiber-reinforced structure and a method for manufacturing the same, and provides a fiber-reinforced structure having high rigidity and high strength properties.

(a) Industrial application field The fiber reinforced structure obtained by the present invention has high rigidity and strength, and is lighter than those obtained by conventional methods, so it can be used as an automobile member or an industrial robot member. Widely used.

(b) Prior Art Nine different methods have been proposed as methods for manufacturing fiber reinforced structures.

For example, (1) one in which fibers are arranged on the outside as shown in Publication No. 57-53114.

(2) Simply wrapped fibers.

(3) A combination of examples (1) and (2) in which fiber-reinforced members are simply glued together.

(4) A method of integrally molding a bearing member and its connecting member with a mold, as shown in "Molding and Processing of Carbon Fiber Composite Materials" published by Nikkiso Co., Ltd.

etc. are already known.

However, these have the following drawbacks.

(1) The boundary portion between the bearing member and the connecting member that connects the bearing member is bonded by adhesive.

Peeling occurs from the border during use.

(2) Since the fibers themselves should have a structure that generates stress in the structure, the strength of the structure is determined according to the amount of fibers, that is, the composite side.

(3) Due to the high cost of molding in mold molding, there is a limit to the size of the structure, which has hindered the industrial use of fiber-reinforced structures.

(c) In order to solve the drawbacks of the prior art that exceed the problems to be solved by the invention, the relationship between the drawbacks of the prior art and the present invention will be described.

(1) To solve the problem of easy peeling of multiple members due to adhesive bonding, we devised a way to connect multiple members under compressive stress by wrapping fibers around the outer periphery of the multiple members.

(2) It is well known that when stress is applied to a structure, the fatigue strength of the structure is generally higher in response to external forces than when no stress is applied. In conventional methods, fibers are simply arranged or molded using a mold, so stress is not actively generated in the structure. The present invention has made three improvements in this regard. The first point is.

A plurality of members were connected to each other by applying an external force, and extensible fibers were wrapped around the outer periphery of the members.

As for the second point, extensible fibers were wrapped around the outer periphery of the plurality of connected members with tension applied thereto.

The third point is the plurality of connected members and the plurality of them.

A gap is formed between the extensible fibers wrapped around the outer periphery of a number of parts, and the fibers are pressed and stretched so as to eliminate the gap, and the adhesive is cured using an adhesive. Therefore, it is necessary to create a compressive force in the connected members and a tensile force in the fibers.

(3) The following measures were taken to address the size limitations in mold molding.

That is, by connecting the separately manufactured members to each other,
Since the fibers are wrapped, bonded and cured with an adhesive, no mold is required.

(d) Means for solving the problems The features of the means for solving the problems of the present invention are as follows.

(1) A compressive stress is applied to a plurality of members 2, for example, two bearing members, and a connecting member provided between the two bearing members, and a fiber having extensibility is wound in a connected state.

(2) Wrapping fibers with extensibility by applying tensile stress.

(3) A gap is formed between the wound fibers and a plurality of members 1, such as a bearing member and a connecting member.

(4) applying an external force to eliminate the voids, and bringing the fibers into close contact with a plurality of members 2, such as a bearing member and a connecting member;
Adhesive 1: For example, resin is used to cure and adhere.

(E) Structure of the Invention An example in which the fiber-reinforced structure according to the present invention is implemented in an arm for an industrial robot will be explained in detail based on the drawings.

FIG. 1 shows the main configuration of the fiber-reinforced structure of the present invention using an arm for an industrial robot as an example.
1 and 2 are bearing members having different diameters, and are connected to a connecting member 3.

The outer periphery is wrapped with extensible fibers 4 impregnated with resin. In this state, the fiber 4 and the connecting member 3
There is a gap between the two.

The fibers 4' are hardened by applying an external force to the fibers 4 in close contact with the connecting member 3.

FIG. 2 shows an arrangement in which a gap is created between the fibers 4 and the connecting member 3.

The bearing members 1, 2 of equal diameter are connected to a connecting member 3 having a protrusion 5 in the center. The extensible fibers 4 impregnated with resin are still wound, and a gap is created between the fibers 4 and the connecting member 3.

The fibers 4' are hardened by applying an external force to the fibers 4 in close contact with the connecting member 3.

Next, an example in which the method for manufacturing a fiber-reinforced structure of the present invention is applied to an arm for an industrial robot will be described in detail based on the drawings.

FIG. 3 is an example of an arm for an industrial robot manufactured by the manufacturing method of the present invention. FIG. 4 is a cross section taken along the line XX in FIG. 3.

The bearing members 1.2 have outer diameters of 97 mm and 52 m, respectively.
An aluminum vibrator with a length of 50+ am was used, but other materials (copper alloy, plastic) were used.

etc.) but it doesn't matter.

The connecting member 3 has a box structure manufactured by pultrusion made of glass fiber and resin with a wall thickness of 3II11, but the fiber and resin do not need to be specified, and the pultrusion was made because it is used as an arm. This is to allow flexibility in length.

It is characterized by the ability to produce long pieces with the same cross section. If a long piece can be obtained, other manufacturing methods may be used, and the shape is free.

However, both ends of the connecting member 3 are processed into a half-moon shape to facilitate connection with the bearing member 1.2.

The thickness of the wrapped fiber was 1fi.

Fig. 5 shows the shape before the bearing members 1, 2 and the connecting member 3 are connected, and Fig. 6 shows the shape of the bearing members 1, 2 before they are connected to the connecting member 3, and fibers impregnated with extensible resin are wound around the bearing members 1, 2 and the connecting member 3. Shows the state in which it is installed.

FIG. 7 shows a manufacturing method of the present invention using a dedicated device. A groove 10 is formed in the upper part of the rotatable table 7, and the support tables 8 and 9 are inserted into the groove 10 and can be moved from side to side. The bearing members 1a and 2a are inserted into the upper part of the support stand 8°9.

Next, the connecting member 3a is sandwiched between the bearing members 1a and 2a,
The zero-order screw 11 moves the support base 8 in the direction of the support base 9.
By rotating the support base 8, the support base 8 can be pressed in the direction of the support base 9.

In manufacturing the arms shown in FIGS. 3 and 4, the force for pinching the connecting member 3a was set to 0.5 to 1.0 kg/ms+'' with respect to the projected cross section of the bearing member 2a.

Next, fibers 4 having extensibility and impregnated with resin are wrapped around the outer circumferences of the bearing members 1a and 2a. In order to prevent the fibers 4 from protruding, a guide lid 12 is inserted into the bearing members 1a, 2a from above.

The bearing member 1 is rotated by rotating the turntable 7 while applying a tension of 0.1 to 0.6 kg/van to the fiber 4.
It is wound while tightening a and 2a.

The thickness of the fiber 4 after winding was 1 piece.

Next, using the plate 6 shown in FIG. 8, the fibers 4 were compressed by pressing in a vise in the direction of the arrow until there was no gap between them and the connecting member 3, thereby forming fibers 4'. The pressing force at this time was 1 to 2 kg/la'', and the entire piece was placed in a furnace in this state and cured. For example, in the case of impregnating unsaturated polyester, 2 hours at 80°C is good.

After the resin has hardened, it is removed from the furnace and the manufacturing process is complete.

Although the example in which the number of bearing members is two is shown above, it is also possible to manufacture three bearing members using the same method.

(F) Effects of the Invention The characteristics of the arm manufactured by the method shown in the embodiments are significantly different from those manufactured by the conventional method. Table 1 shows a comparison between the conventional method and the present invention.

5. As mentioned above, when manufacturing a fiber-reinforced structure, we have proposed a method in which the structure is created in a state where compressive stress is applied to the structure.

In order to apply compressive stress, (1) the bearing and the bearing member press the connecting member in a compressed state from the beginning; (2) Tension is further applied to the fibers and the fibers are wound in that state. (3) In order to make it stronger, we propose a new method by creating a gap between the fiber and the connecting member, which is completely different from the conventional method of applying external force to eliminate this gap. It is.

The effects produced by this creation are: (1) The strength of the structure is significantly greater than that produced by conventional methods, as shown in Table 1. (2) Furthermore, while the conventional method was to adhere the bearing part to the connecting part, one proposed method involves joining by winding fibers, which has a remarkable effect on the strength compared to the conventional method. (3) Furthermore, it is clear that this method significantly advances the method of manufacturing fiber-reinforced structures without being limited by the size of the structure to be manufactured.

[Brief explanation of drawings]

FIG. 1 is a side view of an embodiment of the fiber-reinforced structure of the present invention in an arm for an industrial robot. FIG. 2 is a side view of another embodiment in which the fiber-reinforced structure of the present invention is implemented in an arm for an industrial robot. FIG. 3 is a side view of an arm manufactured by the method for manufacturing a fiber reinforced structure of the present invention. FIG. 4 is a sectional view taken along the line X--X in FIG. 3. FIG. 5 is a diagram showing the shape of the bearing member and the connecting member before they are connected. FIG. 6 is a diagram showing a state in which fibers are wound. FIG. 7 shows a manufacturing method according to the present invention using a dedicated device. FIG. 8 shows a method of pressing fibers against a member in the method of manufacturing a fiber-reinforced structure of the present invention. Patent applicant Komatsu Ltd. Patent attorney Oka 1) Waki Kaya 1 Diagram 2 Figure 3 Figure 4 Concave

Claims (1)

[Scope of Claims] 1. A gap is formed between a plurality of mutually connected members and extensible fibers wrapped around the outer periphery of the plurality of members,
A fiber-reinforced structure characterized in that the fibers are pressed and stretched so as to eliminate the voids, and the fibers are adhered and hardened to the member using an adhesive. 2. Connecting a plurality of members to each other, wrapping a stretchable fiber around the outer periphery of the member so as to form a gap between the members, and further pressing and elongating the fiber from the outside, A method for producing a fiber-reinforced structure, which comprises curing the fibers in close contact with the member using an adhesive under pressure so as to eliminate the voids.