JPH07156020A - Arm member for machine tool and wire electric discharge machining device using the same - Google Patents

Abstract

PURPOSE:To enhance the rigidity and reduce the coefficient of thermal expansion of an arm member for a machine tool by using a pipe-like composite material compact containing reinforcing fibers and epoxy resin. CONSTITUTION:Carbon fiber is woven and formed into a roll base material, when as wire guide holding arm for a wire guide electric discharge machining device is produced. This base material is continuously immersed in a laminating epoxy resin composition unit, and is passed through a drying tower for evaporating a solvent in the laminating epoxy resin composition and promoting curing of the resin at the same time, and prepreg is formed. Subsequently, this prepreg is cut into the preset dimension and is laminated so that they are arranged in the weft direction of a specification. The cured laminated body is pulled out from a mandrel by means of a mandrel removing device. Then, the outside surface is ground by a grinder for deriving the outer circumference dimension of the laminated body, and then, both ends are cut for deciding the length dimension of the laminated body. In addition, the laminated body is coated with a resin for surface treatment and is dried, and consequently, provided as a compact 1 for the arm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine tool arm member and a wire electric discharge machine using the arm member as a wire guide holding arm.

[0002]

2. Description of the Related Art Conventionally, a large number of machine tools such as wire electric discharge machines and industrial robots having arm parts have been used. For example, FIG. 13 is an overall view of a conventional wire electric discharge machine, and FIG. 12 shows the A part of FIG. 13 in detail. In FIG. 12, (10) is a wire electrode for machining a work, (11) is a working fluid (using water) for cooling the wire electrode (10) and the workpiece (14) to be machined, (12) is a wire guide for guiding the wire electrode (10) to the workpiece, and (15) is a wire guide ( It is a wire guide holding arm that fixes 12). Here, conventionally, iron-based low expansion castings have been used as the material of the wire guide holding arm (15). Also (13)
Is a surface plate for holding the work (14). FIG. 1 is a schematic view showing a wire guide holding arm.

Next, the operation will be described. The workpiece (14) to be machined is attached to the surface plate (13) in the wire electric discharge machine. The wire electrode (10) is also guided to the upper part of the machine through the wire guide holding arm (15) and the wire guide (12). At this time, the wire electrode (10) is
It is introduced into 4) and the work (14) is melted and processed by the electric discharge effect. At this time, the working liquid (11) is used for the purpose of reducing heat generated during working.

[0004]

Since the conventional wire guide holding arm (15) is constructed as described above, it is necessary to increase the rigidity of the arm in order to improve the processing accuracy of the work (14). This is necessary, which causes a problem that the weight of the arm becomes heavy. Further, since the temperature of the machining liquid rises due to electric discharge during machining, it is necessary to use an expensive material having a small coefficient of thermal expansion as a material for the arm. Further, the water used as the working liquid may cause electrolytic corrosion, and if it is used as it is, it may cause an accident such as breakage. Therefore, it is necessary to take measures such as applying a corrosion resistant coating.

The present invention has been made in order to solve the above-mentioned problems, and improves the rigidity of the machine tool arm member and reduces the coefficient of thermal expansion, thereby improving the machining accuracy of the arm. A machine tool arm member capable of improving the assembling property by reducing the occurrence of electrolytic corrosion and further reducing the weight of the arm member, and a wire electric discharge machine using the arm member as a wire guide holding arm. The purpose is to provide.

[0006]

An arm member for a machine tool according to the present invention is characterized by comprising a pipe-shaped composite material molded body composed of reinforcing fibers and an epoxy resin.

Further, the wire electric discharge machine according to the present invention is characterized in that the machine tool arm member is used as a wire guide holding arm, whereby the rigidity of the wire guide holding arm is increased and the thermal expansion coefficient is increased. Can be made smaller, and the machining accuracy of the work is improved. In addition, by reducing the weight of the arm member, it is possible to improve the assemblability.

[0008]

The arm member for machine tools in the present invention is a pipe-shaped composite material molded body composed of reinforcing fibers and epoxy resin, and the longitudinal elastic modulus of the composite material molded body is the iron-based low expansion coefficient currently used. It is more than twice as good as that of castings. In addition, the specific gravity of the iron-based low expansion casting is 7.8, while that of the composite material is 1.6, and the weight is about 1/5.
It is reduced to the extent. Further, since the pipe-shaped composite material molded body is composed of the reinforcing fiber and the epoxy resin, it has a large specific resistance and can improve electrolytic corrosion.

The composite material used in the arm member for machine tools of the present invention is composed of 40 to 65% by volume of reinforcing fiber and 60 to 35% by volume of epoxy resin. Here, if the proportion of the reinforcing fibers is less than 40% by volume, that is, the proportion of the epoxy resin exceeds 60% by volume, the rigidity is lowered, which is not preferable, and the proportion of the reinforcing fibers exceeds 65% by volume, that is, the proportion of the epoxy resin. Is less than 35% by volume, defects are increased and strength is lowered, which is not preferable.

As the reinforcing fiber, carbon fiber, aramid fiber, glass fiber, alumina fiber, silicon nitride fiber, silicon carbide fiber or the like can be used. These can be used alone or in combination of two or more kinds. You may. For example, by using mainly carbon fiber as the internal reinforcing fiber of the pipe-shaped composite material molded body and using glass fiber as the reinforcing fiber of the surface layer portion, the high rigidity of the carbon fiber and the insulating property of the glass fiber are utilized. Further, by using mainly aramid fiber as the internal reinforcing fiber and using glass fiber as the reinforcing fiber of the surface layer portion, the excellent performance of the aramid fiber, the insulating property of the glass fiber, and the resistance It can be configured to make the most of the hygroscopicity. In addition,
Since aramid fibers have high hygroscopicity, when aramid fibers are used, it is preferable to use fibers having excellent hygroscopicity resistance such as glass fibers in the surface layer portion.

As the epoxy resin, a laminated epoxy resin composition such as an epoxy varnish can be used. The epoxy resin composition for lamination which can be used in the present invention is, for example,

[Chemical 8] (In the formula, R is H or CH ₃ , and n is 0 or an integer of 1 to 5) and 20 to 80% by weight of a polyfunctional epoxy compound and two epoxy groups in one molecule. The composition (A) containing 80 to 20% by weight of the epoxy compound has an aromatic hydrogen content of 0.3 to 0.8 equivalent per 1 equivalent of the epoxy group terminal in the composition (A). To 100 parts by weight of the composition (B) containing the diamino compound,
0.5-10 parts by weight of dicyandiamide and 1-100
It is a blend of parts by weight of a linear polymer. Epoxy resin has various excellent properties as a structural adhesive and has relatively low water absorption, so it is used in a state of contact with water such as a wire guide holding arm of a wire electric discharge machine. In use, it is possible to provide the arm member with excellent dimensional stability due to water absorption.

In the above-mentioned epoxy resin composition for lamination, aromatic diamino compounds include diaminodiphenyl ether, diaminodiphenylmethane, diaminodiphenylsulfone, diaminobenzanilide, p-phenylenediamine, m-phenylenediamine, dibromodiaminodiphenylmethane, Examples thereof include dichlorodiaminophenylmethane, diaminobenzoguanamine, and tetrabromodiaminodiphenylmethane.

Examples of the linear polymer include polyether sulfone, polysulfone, polyetherimide, polyphenylene sulfide, polyester, phenoxy resin and the like having a molecular weight of 3,000 or more.

Further, as the epoxy resin composition for lamination, an epoxy resin is

[Chemical 9] (In the formula, R is H or CH ₃ , and m is 0 or an integer from 1 to 5).
₁ )

[Chemical 10] (In the formula, n is an integer of 0 or more, X is bromine or H,
a is an integer of 1 to 4) and a bisphenol A type epoxy resin (α ₂ ) represented by a weight ratio of 100: 0 to 30:
To the epoxy resin composition (α) blended with 70,

[Chemical 11] (In the formula, b is an integer of 1 to 4) Brominated bisphenol A (β) is added to the above-mentioned brominated bisphenol A (β) with respect to 1 equivalent of epoxy group terminal of the epoxy resin composition (α). A polyfunctional epoxy resin obtained by reacting a composition in which the hydroxyl groups of) are mixed in a proportion of 0.05 to 0.5 equivalents until the reaction rate of the epoxy groups and the hydroxyl groups becomes 80% or more.
(A) and a phenol resin (B) having a molecular weight of 1,000 or more and 10,000 or less, which is a polycondensation product of bisphenol A and formaldehyde, relative to 1 equivalent of the epoxy group terminal of the polyfunctional epoxy resin (A). A composition in which the above-mentioned phenolic resin (B) has a hydroxyl group of 0.7 to 1.2 equivalents
(I) A linear polymer having a molecular weight of 5,000 or more and 100,000 or less, which is compatible with the composition (I), relative to 100 parts by weight.
A mixture of 1 to 60 parts by weight of (II) can be used, whereby the pipe-shaped composite material molded body can be provided with moisture absorption resistance, water resistance, and low hygroscopic expansion.

As the linear polymer (II), the same ones as described above can be used.

Further, as the epoxy resin composition for lamination, an epoxy resin is

[Chemical 12] (Wherein R is H or CH ₃ , X is Br or H, and m is 0 or an integer from 1 to 5),

[Chemical 13] (In the formula, a is an integer of 1 to 4) and brominated bisphenol A (β ₁ ) and

[Chemical 14] The composition (β) containing at least one of bisphenol A (β ₂ ) represented by
The composition in which the hydroxyl group of the composition (β) is 0.05 to 0.5 equivalent to 1 equivalent of the epoxy group terminal of (α) has a reaction rate of the epoxy group and the hydroxyl group of 80% or more. A polyfunctional epoxy resin (A) obtained by reacting until the reaction is completed, and a phenol resin having a molecular weight of 1,000 or more and 10,000 or less, which is a polycondensation product of bisphenol A and formaldehyde.
In (B), the hydroxyl group of the phenolic resin (B) is 0. 1 with respect to 1 equivalent of the epoxy group terminal of the polyfunctional epoxy resin (A).
1 to 60 parts by weight of a linear polymer (II) having a molecular weight of 5,000 or more and 100,000 or less compatible with the composition (I) blended in a ratio of 7 to 1.2 equivalents is blended. It can be used, whereby the flame retardancy of the pipe-shaped composite material molded body can be improved.

The composite material molded body used in the arm member for a machine tool of the present invention is a pipe shape in which reinforcing fibers are laminated in a predetermined laminated structure by, for example, a sheet winding molding method using a prepreg or a filament winding molding method. It is a molded body of. The laminated structure of the reinforcing fiber is
It is not particularly limited.

The machine tool arm member of the present invention having the above-mentioned structure can be suitably used as, for example, a wire guide holding arm of a wire electric discharge machine, a robot arm, or an arm of another machine tool.

[0019]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of a wire guide holding arm of a wire guide electric discharge machine. The wire guide holding arm includes a pipe-shaped composite material molded body (1), a stainless steel flange (2), and a ceramic insulating plate (3). ). The stainless steel flange (2) and the ceramic insulating plate (3) are fixed to the composite material molded body (1) with an adhesive. Fig. 11 shows the state of attachment to the wire electric discharge machine
Shown in.

Next, a method for manufacturing a pipe-shaped composite material molded body by the sheet winding method will be described. First, carbon fiber is woven into a roll-shaped base material. This base material is continuously laminated with an epoxy resin composition [Claim 3
The aromatic diamino compound is diaminodiphenylmethane, the dicyandiamide content is 2.5 parts by weight per 100 parts by weight of the composition (B), and the phenoxy resin used as a linear polymer is Compounding amount is 6
Parts by weight] and evaporate the solvent of the epoxy resin composition for lamination through a drying tower, and at the same time, proceed with hardening of the resin to prepare a prepreg in a B state (semi-cured state).
Next, the prepreg in the B state is cut into a predetermined size so as to be in the specified grain direction. This prepreg is laminated by a conventional sheet winding molding device according to the specification. As shown in Fig. 2, the mandrel (4) that winds the prepreg is placed on two rolls (5, 6) and rotated. Then, the mandrel (4) and the rolls (5, 6) are laminated while applying pressure. A heat-shrink tape (for example, polyester tape) is evenly wound around this laminate, and then cured in a curing oven under conventional conditions. The heat-shrink tape is wound in order to improve the density of the laminate and make it uniform during curing due to the heat-shrink force of the tape.

Next, the cured laminated body is pulled out from the mandrel by a core removing machine. Next, in order to extract the outer peripheral dimension of the laminate, the outer surface is polished by a polishing machine, and then both ends are cut to determine the length dimension of the laminate. Furthermore,
This laminate is coated with a resin for surface treatment and dried in a drying oven to obtain a pipe-shaped composite material molded body. In addition,
The proportion of reinforcing fibers in the obtained molded body was 55% by volume,
The proportion of epoxy resin is 45% by volume.

The laminated structure according to this embodiment is shown in Table 1 and FIG. (Table 1) Stacking angle Stacking number Longitudinal elastic value Deflection (10kgf) 1st layer ± 10 degrees 8 2nd layer 90 degrees 1 28600kg / mm ² 13μm 3rd layer ± 10 degrees 8 4th layer 90 degrees 2

The dimensions of the obtained pipe-shaped composite material compact were 100.0 mm in outer diameter, 90.0 mm in inner diameter, and 5 in length.
It is 22 mm. This is a stainless steel flange (2)
Then, the wire guide holding arm having the shape shown in FIG. 1 was assembled by fixing it to the ceramic insulating plate (3) with an adhesive. The total weight of the obtained wire guide holding arm is 71.
It was 00 g. Since this arm sprays cooling water during wire electric discharge machining, a repeated pressure of about 10 kg is applied to the tip of the arm, causing the arm to bend. The bending amount of the wire guide holding arm component according to this embodiment is 1 in the vertical direction.
It was 3 μm. The bending amount of the iron-based low expansion casting currently used is 45 μm. Actually, since it is the direction of 90 degrees with respect to the vertical direction that affects the processing accuracy, it becomes smaller than the above value. FIG. 4 shows a test method in which this state is modeled as a cantilever load.

Further, although the temperature is controlled in the wire electric discharge machine, the liquid temperature is 1 to 2 due to the heat generated during normal machining.
It is unavoidable that the temperature fluctuates by about ℃. For example, when the machining fluid temperature fluctuates by 2 ° C, the coefficient of thermal expansion of the iron-based low expansion casting currently used (in the case of 500 mm length) is 5 × 10
^Since it is ^-6 / ° C, the arm length varies by 5 μm. On the other hand, the coefficient of thermal expansion of the pipe-shaped composite material molded body using carbon fiber as the reinforcing fiber is 3 × 10 ⁻⁶ / ° C., so that the change of 3 μm can be suppressed.

The machining accuracy of the wire electric discharge machine is obtained by adding the bending of the arm and the fluctuation of the liquid temperature as described above. However, for the wire electric discharge machine which requires the micron-order machining accuracy, this embodiment is used. Obviously, if the arm member is used as the wire guide holding arm, the machining accuracy of the product is significantly improved. Further, since the arm is formed of the pipe-shaped composite material molded body, the total weight is reduced from 22 kg of the iron-based low expansion casting to about 1/3, and the assembling workability is also improved at the same time.

Example 2. Next, a second embodiment will be described. The composition according to claim 4, wherein the epoxy resin composition for lamination is 6 parts by weight of the phenoxy resin based on 100 parts by weight of the composition (I).
The manufacturing method of the pipe-shaped composite material molded body was the same as in Example 1, but the laminated structure was changed as shown in Table 2 and FIG. 5 below.

(Table 2) Lamination Angle Lamination Number Longitudinal Elasticity Deflection (10 kgf) 1st layer 0 degrees 5 2nd layer 90 degrees 2 3rd layer 0 degrees 5 32,000kg / mm ² 12 μm 4th layer 90 degrees 2 5th Layer 0 degree 5 6th layer 90 degree 2

When this laminated structure is adopted, even if the carbon fibers are made of the same material, the longitudinal elastic modulus is
28,600 kg / mm ² to 32,000 kg / mm ²
To improve. As a result, the amount of deflection measured under the same conditions as in Example 1 is further improved to 12 μm. Therefore, when the shape of the pipe-shaped composite material molded body is the same as that of the embodiment, the product accuracy at the time of wire electric discharge machining is further improved. If the product precision is the same as that of the first embodiment, it is possible to use inexpensive carbon fiber. In addition,
The proportion of reinforcing fibers in the obtained molded body was 55% by volume,
The proportion of epoxy resin is 45% by volume.

Example 3. In this example, a pipe-shaped composite material molded body laminated by the sheet winding method of the above-mentioned Example 1 was further laminated with a prepreg based on a glass fiber woven fabric excellent in electric insulation as a base material. Is. According to this laminated structure shown in Table 3 and FIG.
The resin coating used as the surface treatment in Example 1 can be omitted, and the cost of the product can be reduced.

(Table 3) Lamination angle Lamination number Longitudinal elasticity Flexure (10kgf) 1st layer ± 45 degrees 2 2nd layer ± 10 degrees 8 3rd layer 90 degrees 1 28,600kg / mm ² 13μm 4th layer ± 10 degrees 8 5th layer 90 degrees 2

Example 4. In this example, in the same laminated structure as in Example 1 above, the reinforcing fibers were alumina fibers. In this example, the epoxy resin composition for lamination is the composition according to claim 5,
A mixture of 6 parts by weight of a phenoxy resin and 100 parts by weight of the composition (I) was used. The layered structure for this example is set forth in Table 4 below and in FIG.

(Table 4) Lamination Angle Lamination Number Longitudinal Elasticity Deflection (10kgf) 1st layer ± 10 degrees 8 2nd layer 90 degrees 1 3rd layer ± 10 degrees 8 23,900kg / mm ² 16μm 4th layer 90 degrees 2

In this embodiment, by using alumina fiber having high rigidity, excellent bending characteristics can be obtained, and at the same time, because of the ceramic fiber, the specific resistance is 10 ¹⁴ Ω · cm.
Therefore, it is not necessary to dispose glass fiber for electrical insulation treatment on the surface layer portion as in Example 3, and excellent electrolytic corrosion resistance can be obtained.

Example 5. In this example, in the same laminated structure as in Example 1 above, the reinforcing fibers were silicon nitride fibers. In this example, fibers having a diameter of 5 to 20 μm made of polycarbosilane as a starting material were used. The specific resistance is about 10 ¹⁶ Ω · cm. Further, in this example, the same epoxy resin composition for lamination as that used in Example 1 was used. The layered structure for this example is set forth in Table 5 below and in FIG.

(Table 5) Stacking angle Stacking number Longitudinal elastic value Deflection (10kgf) 1st layer ± 10 degrees 8 2nd layer 90 degrees 1 3rd layer ± 10 degrees 8 12,600kg / mm ² 30μm 4th layer 90 degrees 2

Example 6. In this example, in the same laminated structure as in Example 1, silicon carbide fibers were used as the reinforcing fibers. In this example, fibers having a diameter of 5 to 20 μm made of polycarbosilane as a starting material were used. However, since the specific resistance was about 10 ² Ω · cm, insulation treatment was applied to the surface layer portion as in Example 3. In this example, the same epoxy resin composition for lamination as that used in Example 2 was used. The layered structure for this example is set forth in Table 6 and FIG. 9 below.

(Table 6) Lamination Angle Lamination Number Longitudinal Elasticity Deflection (10kgf) 1st layer ± 45 degrees 2 2nd layer ± 10 degrees 8 3rd layer 90 degrees 1 12,600kg / mm ² 30μm 4th layer ± 10 degrees 8 5th layer 90 degrees 2

Example 7. In Example 3, when a pipe-shaped composite material molded body was prepared by using aramid fiber as the reinforcing fiber, it was possible to obtain a molded body excellent in moisture absorption resistance while taking advantage of the excellent characteristics of aramid fiber. .

In Examples 1 to 7, the 90-degree layers were arranged at regular intervals. This is for relaxing internal stress during sheet winding molding and avoiding molding cracks, and for pipe-shaped composite material moldings. This is to give crushing strength.

Example 8. FIG. 10 is a diagram showing a molding method of a pipe-shaped composite material molded body by the filament winding method. Reinforcing fiber roving (7) with resin bath (8)
While being impregnated with the epoxy resin composition for lamination (the same as in Example 1), the mandrel (9) is wound and molded, and after curing, the mandrel (9) is removed to obtain a molded body. In this example, the laminated structure was the same as in Example 1, but it has a feature that a high-performance molded body having a high fiber content and high reliability can be obtained.

In the above embodiment, the flange portion is shown as a square plate, but it may have another shape such as a disk, and the material is an inexpensive material such as cast iron if the corrosion resistance is taken into consideration. It is also possible to use. Further, although an example of alumina ceramics is shown as the ceramic insulating plate fixed to the tip of the pipe-shaped composite material molded body, it is a composite material using other insulating ceramics or glass fibers as reinforcing fibers. Good.

[0042]

As described above, according to the present invention, by using the pipe-shaped composite material molded body containing the reinforcing fiber and the epoxy resin as the arm member for the machine tool, the rigidity is increased and the thermal expansion coefficient is increased. Can be reduced, and, for example, when the member is used for the wire guide holding arm of the wire electric discharge machine, the accuracy at the time of wire electric discharge machining can be improved. Further, since it is an insulating structure, it has an effect of improving electrolytic corrosion resistance. Further, by using the composition according to any one of claims 3 to 5 as the epoxy resin composition for lamination, the arm has excellent water absorption resistance, low hygroscopic expansion, flame retardancy, etc. depending on the application of the arm member for machine tools. It can be applied to a member. Further, by adopting the configuration described in claim 7, it is possible to provide a machine tool arm member having excellent electrical insulation at a low cost without applying a resin coating to the surface of the viscous composite material molded body. it can. Further, with the structure described in claim 8, it is possible to provide an arm member for a machine tool using aramid fiber, which has high hygroscopicity but is particularly excellent in other properties. Further, according to the present invention, since the weight of the arm member is significantly reduced, the workability at the time of assembly is improved and the load on the entire machine is reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing a configuration of a wire guide holding arm for a wire electric discharge machine.

FIG. 2 is a diagram showing a configuration of a mandrel and a roll in a sheet winding molding apparatus.

3 is a cross-sectional view showing a laminated structure of a pipe-shaped composite material molded body according to Example 1. FIG.

FIG. 4 is a cantilever load model diagram of a wire guide holding arm.

5 is a cross-sectional view showing a laminated structure of a pipe-shaped composite material molded body according to Example 2. FIG.

6 is a cross-sectional view showing a laminated structure of a pipe-shaped composite material molded body according to Example 3. FIG.

7 is a cross-sectional view showing a laminated structure of a pipe-shaped composite material molded body according to Example 4. FIG.

8 is a cross-sectional view showing a laminated structure of a pipe-shaped composite material molded body according to Example 5. FIG.

FIG. 9 is a cross-sectional view showing a laminated structure of a pipe-shaped composite material molded body according to Example 6.

FIG. 10 is a schematic view of a filament winding molding device.

FIG. 11 is a view showing a mounting state of the wire guide holding arm according to the present invention.

FIG. 12 is a view showing a mounting state of a conventional wire guide holding arm.

FIG. 13 is an overall view of a wire electric discharge machine.

[Explanation of symbols]

 1 Pipe-shaped composite material molded body 2 Stainless steel flange 3 Ceramic insulating plate 4 Mandrel 5 Roll 6 Roll 7 Roving 8 Resin bath 9 Mandrel 10 Wire electrode 11 Working fluid 12 Wire guide 13 Surface plate 14 Work piece 15 Wire guide holding arm

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B32B 27/38 7421-4F // B29K 63:00 105: 08 B29L 23:00 (72) Inventor Chihiro Ikeda 325 Kamimachiya, Kamakura City Mitsubishi Electric Co., Ltd.Kamakura Factory (72) Inventor Hikhiro Tomo 325 Kamikura City Kamikura Factory 72 Mitsubishi Electric Corporation Kamakura Factory (72) Inventor Makoto Utsunomiya 325 Kamikura City Mitsubishi Electric Corporation Kamakura Factory

Claims (9)

[Claims] 1. An arm member for a machine tool, comprising a pipe-shaped composite material molded body composed of a reinforcing fiber and an epoxy resin. 2. The machine tool according to claim 1, wherein the reinforcing fiber is one kind or two or more kinds selected from the group consisting of carbon fiber, aramid fiber, glass fiber, alumina fiber, silicon nitride fiber and silicon carbide fiber. Arm member. 3. The epoxy resin is represented by: (In the formula, R is H or CH ₃ , and n is 0 or an integer of 1 to 5) and 20 to 80% by weight of a polyfunctional epoxy compound and two epoxy groups in one molecule. The composition (A) containing 80 to 20% by weight of the epoxy compound has an aromatic hydrogen content of 0.3 to 0.8 equivalent per 1 equivalent of the epoxy group terminal in the composition (A). To 100 parts by weight of the composition (B) containing the diamino compound,
0.5-10 parts by weight of dicyandiamide and 1-100
The arm member for a machine tool according to claim 1, which is an epoxy resin composition for lamination, which is obtained by blending parts by weight of a linear polymer. 4. The epoxy resin is represented by: (In the formula, R is H or CH ₃ , and m is 0 or an integer from 1 to 5).
_{For 1} ), (In the formula, n is an integer of 0 or more, X is bromine or H, and a is an integer of 1 to 4), and the weight ratio of the bisphenol A type epoxy resin (α ₂ ) is 100: 0 to
The epoxy resin composition (α) compounded at 30:70 was (In the formula, b is an integer of 1 to 4) Brominated bisphenol A (β) is added to the above-mentioned brominated bisphenol A (β) with respect to 1 equivalent of epoxy group terminal of the epoxy resin composition (α). A polyfunctional epoxy resin obtained by reacting a composition in which the hydroxyl groups of) are mixed in a proportion of 0.05 to 0.5 equivalents until the reaction rate of the epoxy groups and the hydroxyl groups becomes 80% or more.
(A) and a phenol resin (B) having a molecular weight of 1,000 or more and 10,000 or less, which is a polycondensation product of bisphenol A and formaldehyde, relative to 1 equivalent of the epoxy group terminal of the polyfunctional epoxy resin (A). A composition in which the above-mentioned phenolic resin (B) has a hydroxyl group of 0.7 to 1.2 equivalents
(I) A linear polymer having a molecular weight of 5,000 or more and 100,000 or less, which is compatible with the composition (I), relative to 100 parts by weight.
The arm member for a machine tool according to claim 1, which is an epoxy resin composition for laminating containing 1 to 60 parts by weight of (II). 5. The epoxy resin is represented by: (Wherein R is H or CH ₃ , X is Br or H, and m is 0 or an integer from 1 to 5), and a polyfunctional epoxy resin (α) Brominated bisphenol A (β ₁ ) represented by the formula (wherein a is an integer from 1 to 4) and The composition (β) containing at least one of bisphenol A (β ₂ ) represented by
The composition in which the hydroxyl group of the composition (β) is 0.05 to 0.5 equivalent to 1 equivalent of the epoxy group terminal of (α) has a reaction rate of the epoxy group and the hydroxyl group of 80% or more. A polyfunctional epoxy resin (A) obtained by reacting until the reaction is completed, and a phenol resin having a molecular weight of 1,000 or more and 10,000 or less, which is a polycondensation product of bisphenol A and formaldehyde.
In (B), the hydroxyl group of the phenolic resin (B) is 0. 1 with respect to 1 equivalent of the epoxy group terminal of the polyfunctional epoxy resin (A).
1 to 60 parts by weight of a linear polymer (II) having a molecular weight of 5,000 or more and 100,000 or less compatible with the composition (I) compounded in a ratio of 7 to 1.2 equivalents for lamination The arm member for a machine tool according to claim 1, which is an epoxy resin composition. 6. The work according to claim 1, wherein the pipe-shaped composite material molded body composed of reinforcing fibers and epoxy resin is manufactured by a sheet winding method using a prepreg made of a woven fabric of reinforcing fibers. Machine arm member. 7. The arm member for a machine tool according to claim 1, wherein the internal reinforcing fibers of the pipe-shaped composite material molded body are mainly carbon fibers, and the surface layer reinforcing fibers are glass fibers. 8. The arm member for a machine tool according to claim 1, wherein the internal reinforcing fibers of the pipe-shaped composite material molded body are mainly aramid fibers, and the surface layer reinforcing fibers are glass fibers. 9. A wire electric discharge machine, wherein the machine tool arm member according to claim 1 is used as a wire guide holding arm of a wire electric discharge machine.