JP2020099991A - Fiber-reinforced composite material for arm member, arm member, and method of manufacturing arm member - Google Patents

Abstract

To provide a highly economical arm member for a multijoint robot, which establishes compatibility between torsional rigidity and flexural rigidity.SOLUTION: An arm member for a multijoint robot has an articulated part at least on one side. On at least one flat side surface of a metal beam member having the at least one flat side surface, a reinforcement layer made of a fiber-reinforced composite material is arranged along a lengthwise direction of the metal beam member from the articulated part.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a fiber-reinforced composite material for an arm member for an articulated robot, an arm member, and a method for manufacturing the arm member, which has a joint portion on at least one side. The present invention relates to an arm member having a reinforcing layer and excellent in bending rigidity and torsional rigidity.

For example, in a multi-joint robot that performs welding, work handling, etc., sufficient bending rigidity and torsional rigidity are required for an arm member having a joint portion on at least one side. On the other hand, since the base end portion of the robot is further loaded with its own weight on the tip end side, the moment of inertia becomes large, which is one of the factors that hinder the speedup and downsizing of the robot. That is, for the frame for the arm, a material that has high bending rigidity and torsional rigidity and is lighter is required.

In general, the frame of a robot is a molded product made of a metal material such as iron, stainless steel, or aluminum, but in recent years, the frame on the tip side has been improved in order to reduce cost and further increase speed and accuracy. Is required to be significantly smaller and lighter, and there has been proposed a technique of applying a fiber reinforced plastic (FRP), which is relatively inexpensive, has high strength, high rigidity and low specific gravity, as a material for a frame (for example, a patent. Reference 1).

By the way, fiber-reinforced plastic has a directionality (fiber direction) according to the orientation of the reinforcing fiber, and has great strength against forces perpendicular to the fiber direction such as bending stress, but it is generated by torsional load. It is characterized by low strength against forces parallel to the fiber direction, such as shearing forces.

When applying this fiber reinforced plastic to the frame of the robot, in order to obtain sufficient strength against bending stress in various directions and stress in the torsion direction, the fiber direction of the fiber reinforced plastic used for the frame must be at least the frame direction. A technology of manufacturing by laminating while alternately orienting in two directions of 0° (axial direction) and 90° (direction orthogonal to the axis) (three directions such as 0°, 45°, 90° in some cases). Has been proposed (for example, see Patent Document 2). According to this technology, sufficient strength and rigidity can be secured against bending stress and torsional stress in various directions, but the material cost is higher than that of metal material, the molding process is complicated, and the productivity is reduced. From the economical point of view, the number of practical applications was limited.

JP, 2006-55936, A JP 2002-292591 A

An object of the present invention is to provide an economically-efficient arm member for an articulated robot that achieves both torsional rigidity and bending rigidity.

As a result of intensive studies to solve the above problems, the present inventors have found an arm member having the following configuration and a method for manufacturing the arm member, and completed the present invention. That is, the present invention has the following configurations.
(1) An arm member for an articulated robot having a joint portion on at least one side, wherein a reinforcing layer made of a fiber-reinforced composite material is formed on the side surface of a metal beam member having at least one flat surface from the joint portion. An arm member arranged along the length direction of a metal beam member.
(2) The arm member according to (1), which has joints on both sides.
(3) The arm member according to (1) or (2), wherein the metal beam member has a polygonal cross section.
(4) The arm member according to (3), wherein the metal beam member has a rectangular cross section.
(5) The arm member according to any one of (1) to (4), wherein the metal beam member has a hollow cross section.
(6) The arm member according to any one of (1) to (5), wherein the reinforcing layer is arranged so as to avoid a corner of a metal beam cross section.
(7) The polygonal cross section is a hollow polygonal cross section, and the length ai of the inner side i of the polygonal hollow cross section and the length bi of the reinforcing layer joined to the outer side facing the inner side i. Is the arm member according to (5) or (6), which has a relationship of 0.5ai≦bi≦ai.
(8) The arm member according to any one of (1) to (7), wherein the reinforcing layer is arranged on at least two side surfaces.
(9) The arm member according to any one of (1) to (8), in which the reinforcing layer has a tapered portion whose thickness gradually decreases toward an end portion in the width direction.
(10) The arm member according to any one of (1) to (9), wherein the reinforcing fibers of the fiber-reinforced composite material are carbon fibers, and the orientation of the carbon fibers is aligned in the longitudinal direction of the metal beam member. ..
(11) The arm member according to any one of (1) to (10), wherein the metal beam member is a composite beam member in which at least two metal beam components are combined.
(12) A method for manufacturing an arm member for an articulated robot according to any one of (1) to (11), wherein a composite body in which a prepreg cut to a predetermined size is laminated on a beam member is used as a curing atmosphere for the prepreg. A method for manufacturing an arm member, which comprises simultaneously performing the step of exposing and curing the prepreg to form a reinforcing layer and the step of adhering the metal beam member and the fiber reinforced composite material.
(13) The method for manufacturing an arm member for an articulated robot according to any one of (1) to (11), wherein a reinforcing layer made of a pre-cured prepreg is bonded and integrated with a metal beam member. And a method for manufacturing an arm member.
(14) The method for manufacturing an arm member for an articulated robot according to any one of (1) to (11), wherein the thermoplastic UD tape serving as a reinforcing layer is melted in a matrix of the thermoplastic UD tape. A method for manufacturing an arm member, which comprises heating to a certain temperature and then welding the metal beam member.
(15) A fiber-reinforced composite material for arm member used for the arm member according to any one of (1) to (11).
(16) The fiber-reinforced composite material for arm members according to (15), wherein the fiber-reinforced composite material for arm members is a prepreg.
(17) The fiber-reinforced composite material for arm members according to (15), wherein the fiber-reinforced composite material for arm members is a thermoplastic UD tape.

The present invention provides an arm member for an articulated robot that has both torsional rigidity and bending rigidity and is highly economical.

FIG. 1 is a perspective view (a) and a sectional view (b) showing an example of an arm member according to the present invention. FIG. 2 is a sectional view showing an example of the arm member according to the present invention. FIG. 3 is a sectional view showing an example of an arm member according to the present invention. FIG. 4 is a sectional view showing an example of an arm member according to the present invention. FIG. 5 is a sectional view showing an example of an arm member according to the present invention. FIG. 6 is a sectional view showing an example of an arm member according to the present invention.

Hereinafter, the modes for carrying out the arm member and the method for manufacturing the arm member of the present invention will be described in more detail.

The present invention is an arm member for an articulated robot having a joint portion on at least one side, wherein a reinforcing layer made of a fiber-reinforced composite material is formed on the side surface of a metal beam member having at least one flat surface. From the metal beam member is arranged along the length direction of the metal beam member.

FIG. 1 is a perspective view (a) and a sectional view (b) showing an example of the arm member of the present invention. As shown in FIG. 1, an arm member 1 according to an example of the present invention includes a metal beam member 2 having a rectangular hollow structure, a reinforcing layer 3, and a joint portion 4. The articulation part 4 has a joint structure with other members, and may include an electric motor for driving.

According to the knowledge of the present inventors, those satisfying all such ranges satisfy both bending rigidity and torsional rigidity required for an arm member for an articulated robot, and are lighter than an arm member manufactured from a metal material. Yes, it is cheaper than an arm member manufactured from a single fiber-reinforced composite material. Further, by disposing the reinforcing layer on the flat side surface of the metal beam member, not only the lamination process of the fiber-reinforced composite material is simplified, but also wrinkles are prevented and the appearance is excellent.

INDUSTRIAL APPLICABILITY The present invention can be used for both an arm having articulated parts on both sides of an articulated robot and an arm having articulated parts on only one side, but both sides having higher required bending rigidity and torsional rigidity. It is preferably used for an arm having an articulated part.

Each component of the fiber-reinforced composite material for arm members used in the present invention will be described.

For a fiber-reinforced composite material arm member used in the present invention include, for example, a prepreg or thermoplastic UD (U ni D irectional) tape. The prepreg is preferable from the viewpoint of bending rigidity of the arm member.

The prepreg is not particularly limited, and the reinforcing fiber or the cloth made of the reinforcing fiber is arranged in the flat plate mold by arranging the fiber bundle or laying the fiber cloth, and then impregnated with the thermosetting resin. By pressing, a prepreg can be easily created.

The thermosetting resin that constitutes the prepreg is not particularly limited as long as it is a resin that undergoes a crosslinking reaction by heat to at least partially form a three-dimensional crosslinked structure. Examples of such thermosetting resins include epoxy resins, unsaturated polyester resins, vinyl ester resins, benzoxazine resins, phenol resins, urea resins, melamine resins and thermosetting polyimide resins, and the like, and modified products thereof and A resin obtained by blending two or more kinds may also be used. Further, these thermosetting resins may be self-curable by heating, or may be ones in which a curing agent, a curing accelerator and the like are blended.

Among these thermosetting resins, epoxy resins are preferable from the viewpoint of excellent balance of mechanical properties and small curing shrinkage.

The thermoplastic UD tape is not particularly limited, but a thermoplastic UD tape can be easily prepared in the same manner as the above prepreg except that a thermoplastic resin is used instead of the thermosetting resin. it can.

Examples of the thermoplastic resin forming the thermoplastic UD tape include polyolefin resins such as polyethylene (PE) resin and polypropylene (PP) resin, polyethylene terephthalate (PET) resin, polyamide (PA) resin, and polyphenylene sulfide (PPS). ) Resins and the like, copolymer resins and modified resins thereof, alloys and the like. Among them, polypropylene resin is preferable from the viewpoint of lightness of the obtained molded product, and polyamide resin is preferable from the viewpoint of mechanical properties and moldability. From the viewpoint of heat resistance, polyphenylene sulfide resin is preferably used.

Next, each component of the reinforcing layer according to the present invention will be described.

The reinforcing layer according to the present invention can be obtained by laminating and molding fiber-reinforced composite materials for arm members.

Examples of the laminated structure of the reinforcing layer according to the present invention include unidirectional lamination in which reinforcing fibers are laminated in one direction, pseudo isotropic lamination including 0°, ±45°, and 90° evenly, and fabric lamination. Among them, unidirectional lamination in which the orientation of the reinforcing fibers is aligned in the length direction of the metal beam is preferable from the viewpoint of bending rigidity, and combined with the high torsional rigidity of the metal beam member, both bending rigidity and torsional rigidity are It is preferable because an excellent arm member can be obtained.

The reinforcing layer according to the present invention is preferably arranged by avoiding the corners of the metal beam member, so that the reinforcing layer can be cut and prepared from a flat-plate forming plate to simplify the working process.

As a dimension of the reinforcing layer according to the present invention, the polygonal cross section is a polygonal hollow cross section which is a hollow cross section, and a length ai (mm) of an inner side i of the polygonal hollow cross section and an outer side facing the inner side i. It is preferable that the length bi (mm) of the reinforcing layer joined to the side has a relationship of 0.5ai≦bi≦ai. By setting the bi (mm) of the reinforcing layer to be equal to or less than the ai (mm) of the inner side i, stiffening around the corners of the metal beam member which is originally excellent in rigidity is omitted, and it is excellent in lightness, which is preferable. Further, it is preferable from the viewpoint of bending rigidity and torsional rigidity that bi (mm) of the reinforcing layer is 0.5×ai (mm) or more, which is half the length of ai (mm) of the inner side i.

The relationship between ai (mm) of the preferable inner side i and bi (mm) of the reinforcing layer will be described with reference to FIG. 2 which is a sectional view showing an example of the arm member of the present invention. As shown in FIG. 2, an arm member 5 according to an example of the present invention has a length ai (subscript i=1, 2, 3, 3) of an inner side i (i=1, 2, 3, 4) of a rectangular hollow section. 4) is the length bi of the reinforcing layer facing the inner side (subscript i=1, 2, 3, 4) and 0.5ai≦bi≦ai (subscript i=1, 2, 3, 4), respectively. ) To satisfy the relationship.

The reinforcing layer according to the present invention is preferably arranged on at least two side surfaces of the metal beam member. For example, it is preferable to dispose the rectangular cross section only on the upper side surface and the lower side surface because the bending rigidity of the cross section in the vertical direction can be dramatically increased. Further, it is more preferable to arrange the reinforcing layers on the four side surfaces of the rectangular cross section, that is, in the vertical and horizontal directions in addition to the vertical direction of the cross section.

The reinforcing layer according to the present invention preferably has a tapered portion in which the thickness gradually decreases toward the end in the width direction, and the reinforcing layer does not peel off even after long-term use, which is preferable.

For the purpose of modifying the fiber-reinforced composite material for arm member according to the present invention, a thermosetting resin other than the above-mentioned resins, elastomer, filler, rubber particles, thermoplastic resin particles, inorganic particles and other additives are blended. You can also

The fiber-reinforced composite material for arm members according to the present invention is preferably mixed with a conductive filler for the purpose of improving conductivity. Such conductive fillers include carbon black, carbon nanotubes, vapor grown carbon fibers (VGCF), fullerenes, metal nanoparticles, carbon particles, metal-plated thermoplastic resin particles exemplified above, and metal-plated. Examples thereof include the thermosetting resin particles exemplified above, which may be used alone or in combination. Among them, inexpensive and highly effective carbon black, carbon particles are preferably used, and as such carbon black, for example, furnace black, acetylene black, thermal black, channel black, Ketjen black, etc. can be used. Carbon black in which two or more kinds are blended is also preferably used. Further, as such carbon particles, "Belle Pearl (registered trademark)" C-600, C-800, C-2000 (manufactured by Kanebo Co., Ltd.), "NICABEADS (registered trademark)" ICB, PC, MC (Nippon Carbon Co., Ltd.) Manufactured) and the like. Specific examples of the metal-plated thermosetting resin particles include particles "Micropearl (registered trademark)" AU215 in which divinylbenzene polymer particles are plated with nickel and gold is further plated thereon.

Next, the reinforcing fiber used in the present invention will be described.

Examples of the reinforcing fiber used in the present invention include organic fiber, aramid fiber, glass fiber, metal fiber and carbon fiber. Among them, glass fiber is preferable from the viewpoint of economy, and carbon fiber is preferable from the viewpoint of strength and elastic modulus.

In addition, examples of the carbon fibers include polyacrylonitrile (PAN)-based, rayon-based, and pitch-based carbon fibers. Among them, PAN-based carbon fibers having an excellent balance between strength and elastic modulus are preferably used.

The metal beam member that constitutes the arm member of the present invention will be described.

It is important that the metal beam member according to the invention has at least one flat side surface for arranging the reinforcing layer. With the curved shape, there is a problem in that the laminating and forming operations of the fiber-reinforced composite material for arm members are complicated and the economy is poor.

Examples of the cross-sectional shape of the metal beam member include polygonal cross-sections such as triangles and rectangles, open cross-sections such as angles, channels, I-shapes and T-shapes, and cross-sections having curved lines such as semicircles and fans. A polygonal cross section is preferable from the viewpoint of bending rigidity and torsional rigidity, an open cross section is preferable from the viewpoint of wiring arrangement, and a cross section having a curve is preferable from the viewpoint of designability.

As a desirable polygonal cross section of the metal beam member, for example, a rectangular cross section is preferable from the viewpoint of economic efficiency, and an octagonal cross section is preferable from the viewpoint of further increasing bending rigidity and torsional rigidity, and economic and mechanical characteristics are improved. From the viewpoint of balancing, a hexagonal cross section is preferable.

The metal beam member according to the present invention has, for example, a hollow cross section and a solid cross section, but the hollow cross section is preferable from the viewpoint of lightweight.

The arm member of the present invention may use a metal beam member composed of a composite beam member in which two or more metal beam components are combined. For example, there is a case where two metal beam constituent members of angles or channels are combined to form a rectangular cross section, which is preferable from the viewpoint that the reinforcing layer can be relatively easily arranged on the inner side of the cross section. FIG. 3 shows an example of a cross-sectional view of the arm member 6 using a metal beam member made of a composite beam member in which angled metal beam constituent members 7 are combined. Further, the metal beam constituent material may be used alone as a metal beam member.

The arm member of the present invention may be a composite arm member in which a plurality of arm constituent members each having a reinforcing layer arranged on a metal beam constituent member are combined.

Examples of the metal material forming the metal beam member include aluminum alloy, steel, stainless steel, copper alloy, titanium and magnesium alloy. Among them, an aluminum alloy is preferably used from the viewpoint of lightness. Moreover, when combining two or more metal beam components, it is preferable to combine the same kind of metal.

The method of installing the reinforcing layer according to the present invention is not particularly limited, for example, in the uncured state of the prepreg, pasted on the metal beam member, the comolding method for simultaneously curing and bonding the prepreg, prepreg or heat. A co-bonding method in which a plastic UD tape is laminated and molded in advance and then adhered onto a metal beam member with an adhesive, or a welding method in which a thermoplastic UD tape is welded onto a metal beam member while heating or vibrating However, the cobond method is preferable because it can suppress the generation of wrinkles.

FIG. 4 illustrates a cross-sectional view of the arm member 8 having a C-shaped cross section manufactured by the welding method. The reinforcing layer 10 of the thermoplastic UD tape is welded to the metal beam member 9 having a C-shaped cross section, but since the reinforcing layer is located on the outer circumference of the arm member, it has a feature of excellent bending rigidity.

FIG. 5 illustrates a cross-sectional view of a C-shaped cross-section arm member 11 that is manufactured by the welding method and has two layers of thermoplastic UD tapes laminated as the reinforcing layer 12. By welding two layers of thermoplastic UD tape to one outer surface of the metal beam member 9 having a C-shaped cross section, there is a feature that it is excellent in bending rigidity and torsional rigidity.

FIG. 6 illustrates a cross-sectional view of the arm member 13 having a rectangular cross section in which two arm components having a C-shaped cross section are combined with each other through the joint surface 16. A feature is that a core material and the like can be easily inserted inside before combining the individually formed C-shaped cross-section arm constituent materials. The arm member 13 having a rectangular cross section shown in FIG. 6 is a combination of the C-shaped cross-section arm members 8 shown in FIG. 4, but the present invention is not limited to this mode and is made of metal having two C-shaped cross sections. It is also possible to weld a thermoplastic UD tape as the reinforcing layer 10 after forming a composite beam member in which beam constituent materials are combined in advance.

Next, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

<Evaluation/Measurement method>
(1) Evaluation of Bending Stiffness Test pieces cut out to a length of 400 mm were prepared from the arm members obtained in Examples or Comparative Examples, bending tests were performed, and bending stiffness EI was calculated from Equation (1). .. The number of measurements was n=2, and the average value was used.

"Instron (registered trademark) universal testing machine 5980 type (manufactured by Instron Co., Ltd.)" is used as a testing machine, and a support span is measured by using a three-point bending test jig (indenter diameter 10 mm, fulcrum diameter 10 mm). The bending rigidity was measured by setting the test speed to 4 times and the test speed to 1% strain/mm. The test was conducted under the conditions that the water content of the test piece was 0.1% by mass or less, the ambient temperature was 23° C., and the humidity was 50% by mass.
EI=L ³ /48·ΔP/Δδ (1)
・EI: Bending rigidity of arm member (N·m ² ).
・L: Indicated span (m)
.DELTA.P/.DELTA..delta.: load-gradient of the straight line portion of the deflection curve (deflection range 0.05%-0.25%) (N/m)

(2) Evaluation of Torsional Rigidity Test pieces cut out to a length of 400 mm were prepared from the arm members obtained in Examples or Comparative Examples, respectively, and subjected to a torsion test, and the torsional rigidity GIp was calculated from the equation (2). ..

"Instron" (registered trademark) torsion tester MT-10 (manufactured by Instron) is used as a tester, and a deflection angle range is obtained by applying a heavy load under the conditions of a frequency of 0.2 Hz, a twisting angle amplitude of 20°, and both swings. The torsional rigidity GIp at 1 degree to 10 degrees was continuously measured 10 times, and the average value was obtained. The test was conducted under the conditions that the water content of the test piece was 0.1% by mass or less, the ambient temperature was 23° C., and the humidity was 50% by mass.
GIp=L·ΔT/Δφ (2)
・GIp: torsional rigidity of the arm member (N·m ² ).
・L: Between chucks (m)
・ΔT/Δφ: Torsion-Slope of straight line part of twist angle curve (deflection angle range 1°-10°) (Nm)

<Materials used>
The materials and components used in each example and each comparative example are as follows.

[Metal beam member (A)]
-A-1: Metal beam member of rectangular hollow section After heating aluminum alloy "A5052" to a processing temperature, it is loaded into a container of an extruder and extruded from a die for rectangular hollow section to have a width of 50 mm, A metal beam member (A-1) having a rectangular hollow cross section with a height of 50 mm, a thickness of 1 mm and a length of 500 mm was obtained.

-A-2: Metal beam member having a hexagonal hollow cross section After heating aluminum alloy "A5052" to a processing temperature, it is loaded into a container of an extruder and extruded from a die for a regular hexagonal hollow cross section to form one side. A metal beam member (A-2) having a regular hexagonal hollow cross section having a length of 32 mm, a thickness of 1 mm and a length of 500 mm was obtained.

-A-3: Metal beam member having a C cross section An aluminum alloy "A5052" is heated to a processing temperature, then loaded into a container of an extruder and extruded from a die for a rectangular hollow cross section to have a width of 25 mm and a high height. A metal component (A-3) having a C-shaped cross section having a length of 50 mm, a thickness of 1 mm and a length of 500 mm was obtained.

[Carbon fiber reinforced composite material (B)]
B-1: "Torayca (registered trademark)" prepreg P3252S-12 manufactured by Toray Industries, Inc.
B-2: Thermoplastic UD tape A carbon fiber bundle ("Torayca (registered trademark)" yarn T700S-12K manufactured by Toray Industries, Inc.) was prepared, and the carbon fiber bundle was continuously fed through the yarn guide. 6 Nylon resin ("Amylan (registered trademark)" CM1017 manufactured by Toray Industries, Inc.) was supplied from the filled feeder in a fixed amount to the carbon fiber bundles that were continuously fed out and impregnated. Subsequently, the carbon fiber bundle impregnated with 6 nylon resin was continuously drawn out from the nozzle of the impregnation die using a take-up roll, passed through a cooling roll, the 6 nylon resin was cooled and solidified, and wound as a thermoplastic UD tape. It was wound up by the opportunity. The thickness of the obtained thermoplastic UD tape was 0.5 mm, and the carbon fiber directions were arranged in one direction. The carbon fiber content in the thermoplastic UD tape was 50 vol%.

[Adhesive (C)]
C-1: Cemedine Co., Ltd., epoxy adhesive "EP-171"

[Release agent (D)]
-D-1: Daikin Co., Ltd. release agent "Diefree GW-251"

(Example 1)
The carbon fiber reinforced composite material (B-1) cut to a predetermined size was laminated in a 0° direction to a thickness of 2 mm, and the cured plate exposed to a curing atmosphere was set to 500 mm in the carbon fiber orientation direction and in a perpendicular direction. It was cut to a size of 50 mm. Then, the adhesive surface of the cured plate is sandblasted to prepare it, apply adhesive (C-1), put the adhesive surface upward in a desiccator, reduce the pressure to 3 mmHg with a vacuum pump and leave for 1 minute, and then air. It was put in and returned to normal pressure. The operation of reducing the pressure and returning to the normal pressure was repeated three times in total, and taken out from the desiccator to prepare a cured adhesive coated plate.

Next, all four side surfaces of the metal beam member (A-1) having a rectangular hollow section are sandblasted to be prepared, and the adhesive agent (C-1) is applied, and the adhesive surface is placed in a desiccator, and a vacuum pump is used. The pressure was reduced to 3 mmHg, and the mixture was allowed to stand for 1 minute, and then air was added to return to normal pressure. The operation of depressurizing and returning to normal pressure was repeated a total of 3 times, taken out from the desiccator, and an adhesive-coated metal beam was prepared.

A metal beam with adhesive-coated cured plates attached to each of four sides is covered with a bagging film, and the bagging film is heated to 30°C for 30 minutes in a warm air machine set to 80°C while the vacuum level is reduced to 3 mmHg. Then, an arm member in which a reinforcing layer was adhered to the metal beam was obtained, and bending rigidity and torsional rigidity were evaluated. The results are shown in Table 1.

(Example 2)
The cured plate prepared in Example 1 was cut into a dimension of 500 mm in the carbon fiber orientation direction and a dimension of 48 mm in the direction perpendicular to the orientation direction, and the width was set on each of the four side surfaces of the metal beam member (A-1) having a rectangular hollow section. An arm member was obtained and evaluation of bending rigidity and evaluation of torsional rigidity were performed in the same manner as in Example 1 except that a gap having an end of 1 mm was opened and bonded. The results are shown in Table 1.

(Example 3)
The hardened plate prepared in Example 1 is cut into a size of 500 mm in the carbon fiber orientation direction and a size of 32 mm in the perpendicular direction, and adhered to each of the six side surfaces of the metal beam member (A-2) having a hexagonal hollow cross section. Except for this, the arm member was obtained and the bending rigidity and the torsional rigidity were evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Example 4)
The carbon fiber reinforced composite material (B-1) was added to the adhesive-coated metal beam (A-1) prepared in Example 1 according to the orientation direction of the carbon fibers and the length direction of the metal beam, An intermediate body obtained by winding the carbon fiber reinforced composite material (B-1) layer until the thickness thereof became 2 mm was obtained.

Next, the intermediate body is covered with a bagging film, and in a state where the degree of vacuum in the bagging film is reduced to 3 mmHg, the carbon fiber reinforced composite material (B-1) is exposed to a curing atmosphere to obtain an arm member, The bending rigidity and the torsional rigidity were evaluated. The results are shown in Table 1.

(Comparative Example 1)
Example 1 except that all four side surfaces of the metal beam member (A-1) having a rectangular hollow section were polished with #800 sandpaper to be a mirror surface and the release agent (D-1) was applied. An arm member was obtained in the same manner as in. After cooling this arm member in a refrigerator at −20° C., the metal beam member (A-1) having a rectangular hollow section is removed to obtain a CFRP arm member, and the bending rigidity and the torsional rigidity are evaluated. Carried out. The results are shown in Table 1.

(Comparative example 2)
The metal beam member (A-1) having a rectangular hollow cross section was used for evaluation of bending rigidity and torsional rigidity. The results are shown in Table 1.

(Example 5)
After sandblasting the metal beam member (A-3) having a C-shaped cross section to prepare the surface, thermoplastic UD tapes (B-2) are applied to the three outer surfaces using a laser welding device in the longitudinal direction. Was ultrasonically welded over the entire area of 500 mm to obtain an arm member. The thermoplastic UD tape (B-2) is a metal beam member having a C-shaped cross section and the fiber direction of the thermoplastic UD tape only on one surface of the metal beam member (A-3) having a C-shaped cross section at a time. It ultrasonically welded so that the length direction of (A-3) might correspond. At this time, of the three pasting surfaces, the upper and lower sides of the C cross section were formed of a thermoplastic UD tape (B-2) slit into 24 mm, which was narrower by 1 mm than the width of the pasting surface. The surface corresponding to the third side connecting the upper side and the lower side, which is arranged 1 mm away from the corner, is a thermoplastic UD tape (B-2) slit by 48 mm, which is narrower by 2 mm than the width of the pasting surface, in the width direction of the pasting surface. It was placed at a distance of 1 mm from each end. The obtained arm member was subjected to evaluation, and the results are shown in Table 2.

(Example 6)
For one outer surface of the metal beam member (A-3) having a C-shaped cross section, the step of laser welding one layer of the thermoplastic UD tape (B-2) is performed twice, and two layers are laminated. In the same manner as in Example 5, the arm member shown in FIG. 5 was obtained and provided for evaluation. The results are shown in Table 2.

(Comparative example 3)
The metal beam member (A-3) having a C-shaped cross section was subjected to evaluation of bending rigidity and torsional rigidity. The results are shown in Table 2.

(Example 7)
The joint surface shown in FIG. 6 of the C-shaped cross-section arm member manufactured in (Example 5) is conditioned by sandblasting, the adhesive (C-1) is applied, and the adhesive surface is placed in a desiccator with the adhesive surface up to 3 mmHg by a vacuum pump. The pressure was reduced and left for 1 minute, and then air was added to return to normal pressure. The operation of returning to normal pressure after depressurization was repeated three times in total, taken out from the desiccator, and two adhesive-coated C-shaped cross-section arm constituent materials were prepared. Two adhesive-coated C-shaped cross-section arm constituent materials were abutted as shown in FIG. 6 to obtain an arm member having a rectangular cross section in which the bonding surfaces were bonded by bonding and used for evaluation. The results are shown in Table 3.

As described above, in Examples 1 to 7, good arm members having both bending rigidity and torsional rigidity and having the reinforcing layer attached without wrinkles and having an excellent appearance were obtained. This can be achieved by arranging the reinforcing layer of the carbon fiber reinforced composite material constituting the arm member of the present invention so as to satisfy the predetermined range. However, in Example 4, the wrinkles were slightly seen around the corners of the arm member, but the wrinkles were generally at an acceptable level.

On the other hand, Comparative Example 1 was inferior in torsional rigidity in addition to wrinkles, Comparative Example 2 was inferior in bending rigidity, and Comparative Example 3 was inferior in both bending rigidity and torsional rigidity.

INDUSTRIAL APPLICABILITY The arm member of the present invention has high bending rigidity and torsional rigidity and is excellent in economic efficiency, and thus can be suitably used for an articulated robot having a joint portion on at least one side.

DESCRIPTION OF SYMBOLS 1 Arm member 2 Metal beam member 3 having a rectangular hollow structure 3 Reinforcement layer 4 Articulation part 5 Arm member 6 Arm member 7 Angled metal beam constituent material 8 Arm member having C-shaped cross section (reinforcement layer is joined by welding method)
9 Metal beam member having C-shaped cross section 10 Reinforcing layer 11 Arm member having C-shaped cross section (joining two reinforcing layers by welding method)
12 Reinforcement layer (two layers of thermoplastic UD tape are laminated)
13 A rectangular cross-section arm member that combines two C-shaped cross-section arm constituent materials 14 Metal beam constituent material 15 Reinforcement layer material 16 Bonding surface

Claims (17)

An arm member for an articulated robot having a joint on at least one side, wherein a reinforcing layer made of a fiber-reinforced composite material is formed on the side surface of the metal beam member having at least one flat surface from the joint. An arm member arranged along the length direction of the member. The arm member according to claim 1, which has articulation portions on both sides. The arm member according to claim 1, wherein the metal beam member has a polygonal cross section. The arm member according to claim 3, wherein the metal beam member has a rectangular cross section. The arm member according to claim 1, wherein the metal beam member has a hollow cross section. The arm member according to any one of claims 1 to 5, wherein the reinforcing layer is arranged so as to avoid a corner of a cross section of the metal beam. The polygonal cross section is a hollow polygonal cross section, and the length ai of the inner side i of the polygonal hollow cross section and the length bi of the reinforcing layer joined to the outer side facing the inner side i are 0. The arm member according to claim 5 or 6, which has a relationship of 5ai ≤ bi ≤ ai. The arm member according to claim 1, wherein the reinforcing layer is arranged on at least two side surfaces. The arm member according to claim 1, wherein the reinforcing layer has a taper portion whose thickness gradually decreases toward an end portion in the width direction. 10. The arm member according to claim 1, wherein the reinforcing fibers of the fiber-reinforced composite material are carbon fibers, and the orientation of the carbon fibers is aligned in the longitudinal direction of the metal beam member. The arm member according to claim 1, wherein the metal beam member is a composite beam member in which at least two metal beam components are combined. It is a manufacturing method of the arm member for articulated robots in any one of Claims 1-11, Comprising the prepreg cut on the beam member laminated on the beam member is exposed to the hardening atmosphere of a prepreg, and a prepreg is formed. A method for manufacturing an arm member, which comprises simultaneously performing a step of curing to form a reinforcing layer and a step of adhering a metal beam member and a reinforcing layer. The method for manufacturing an arm member for an articulated robot according to any one of claims 1 to 11, wherein a reinforcing layer made of a pre-cured prepreg is bonded and integrated with a metal beam member. Method of manufacturing member. It is a manufacturing method of the arm member for articulated robots in any one of Claim 1 to 11, Comprising: After heating the thermoplastic UD tape used as a reinforcement layer until the matrix of the said thermoplastic UD tape becomes a molten state. A method for manufacturing an arm member, which comprises welding on a metal beam member. A fiber-reinforced composite material for an arm member, which is used for the arm member according to claim 1. The fiber-reinforced composite material for arm members according to claim 15, wherein the fiber-reinforced composite material for arm members is a prepreg. The fiber-reinforced composite material for arm members according to claim 15, wherein the fiber-reinforced composite material for arm members is a thermoplastic UD tape.