JPH08290385A - Steel tubular arm of industrial robot - Google Patents

Abstract

PURPOSE: To simplify the working process, and to reduce the cost by providing an arm with a main arm part where a plurality of cold rolled steel tubes are welded to each other and a flange part for connection or for fitting equipment through the partial removal on each end of the main arm part. CONSTITUTION: At one end part of a main arm part 30 where a plurality of cold rolled steel tubes 12 are welded to each other, a circular dome part of two cold rolled steel tubes 12 which are already welded is cut in an approximately symmetrical shape. A flat steel plate part is exposed from the inside, and a telescopic hole 18a and bolt insertion holes 18b are drilled in the exposed flat part 16a to form a connection flange part 20 to provide an arm parts of a robot. Because in the exposed flat part 16a, the steel plate in the stock stage of the cold rolled steel tubes 12 is already flat and smooth in surface, the flat part can be made use of as a correctly flat part without any machining.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arm of an industrial robot, and in particular, it is formed from a cold-rolled steel pipe as a raw material, and has mechanically high strength and high rigidity, yet is light in weight and low in cost. The present invention relates to a steel pipe arm of an industrial robot having a structure capable of

[0002]

2. Description of the Related Art An arm of an industrial robot is provided as a movable part of a robot body, and conveys a work or the like through a wrist, a hand, etc. provided at the tip of the arm, positions the work at a predetermined position, or holds the hand. Instead of forming a functional element for carrying out a required robot work by gripping a predetermined tool, a mechanical structural element for supporting a load weight such as the work or hand is formed. In particular, based on the above-mentioned functional elements, an electric cable, a signal line, a hose for piping a working fluid such as pressurized air, a laser light conduit, etc. are internally wired between the arm proximal end and the distal end. Generally, a structure is used in which the inside is formed as a hollow passage for piping, and both ends of the arm have various shapes as a connecting part with other arms and a mounting part for mounting devices such as motors and speed reducers. Is provided with a flange structure.

FIG. 5 is a perspective view showing the overall structure of the body of an industrial robot. The top end 1a of the robot base portion 1 is shown in FIG.
Has a structure in which the arm 2 and the arm 3 are sequentially coupled to each other,
It has a structure in which a robot wrist 4 is provided at the tip of the arm 3 on the front side, and receives the command input sent from an external robot control device (not shown) according to a predetermined program, and carries and positions as described above. , Perform various robot tasks, etc.

In order to satisfy the two conditions of the functional element and the mechanical structural element of the robot as described above, the arms 2, 3 etc. are, for example, shown in FIGS.
As shown in FIG.
b, 5c and a hollow tube structure having coupling flange portions 6a, 7a, 6b, 7b, 6c, 7c and the like provided at both ends of the arm main portions 5a to 5c.

However, in the arms 2 and 3 of the conventional industrial robot, most of the arm main parts 5a to 5c are formed as metal casting pipes using a casting die, and both ends of such casting pipes are formed. Separately, it has a structure in which connecting flange portions 6a to 7c formed by shaving and machining are fixed and connected by welding.

[0006]

Therefore, the arm main part of the robot arm has a variation in wall thickness which is inevitable from the viewpoint of casting, and the thickness is generally small in order to avoid insufficient strength and rigidity due to thin wall thickness. Exceeding the required dimensions adds weight. Also, when fixing the coupling flanges formed by machining to both ends of the arm main part by welding etc., it is necessary to perform machining on the ends of the arm main part, resulting in an increase in the number of arm processing steps. Cause high cost.

In addition, when the arm main part is formed as a metal casting pipe body, it is necessary to manufacture and use a mold inevitably, and the mold manufacturing cost is reflected in the manufacturing cost of each arm. There is a disadvantage that it becomes expensive. In view of the above-mentioned various disadvantages, an object of the present invention is to process a partially circular shape such as a semicircle and a quadrant, which is processed by cold roll forming which is commercially available as a material for manufacturing an arm of a robot body. And rectangular rectangular hollow, lightweight steel pipe members are effectively used, and the steel pipe members are processed by gas cutting, plasma cutting, laser cutting, etc. It is to provide a steel pipe arm for a robot that simplifies the process and reduces the cost.

[0008]

DISCLOSURE OF THE INVENTION In view of the above-mentioned object of the present invention, the present invention is achieved by welding steel pipe members having a circular cross section or a rectangular shape in cross section, which are processed and formed by cold roll forming, to each other. An arm main part having a required length is formed, and at both ends of the arm main part, a part of the steel pipe member is cut off by a gas fusing method, a plasma fusing method, or a laser fusing method to form a coupling flange. A completed bolt of one robot arm is obtained as an arm part of a robot body by punching a connecting bolt hole and an attaching spigot hole in the connecting flange portion.

That is, according to the present invention, in the hollow arm of the industrial robot which forms the movable element of the robot and has the coupling structure portions such as the flanges at both ends, the arm comprises a plurality of cold arms having a predetermined length. Steel pipe arm of an industrial robot comprising an arm main part in which intermediate roll-formed steel pipes are welded to each other, and a connecting or device mounting flange part formed by partially cutting off both ends of the arm main part Is provided.

[0010]

According to the above construction, a plurality of cold roll formed steel pipes can be commercially available as a steel pipe member having a partial circular cross section or a rectangular cross section, and such a plurality of steel pipe members are welded to each other. To form an arm main part with a circular or rectangular cross section, and then cut off a part of the steel pipe part from both ends of this arm main part by gas fusing, plasma fusing, or laser fusing. Then, since the flat steel plate surface is exposed inside the steel pipe member, a desired robot arm can be obtained only by perforating the exposed steel plate surface.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the accompanying drawings. 1 (a) and 1 (b) are partial cross-sectional views showing typical cross-sectional shape examples of a cold-roll-formed steel pipe material forming a steel pipe arm of an industrial robot according to the present invention, and FIG. FIG. 3 is a partial perspective view showing a part of a steel pipe arm formed by using the steel pipe material shown in FIG. 1, and FIG. 3 is a partial perspective view showing a part of a steel pipe arm formed by using the steel pipe material shown in FIG. 4 and 5 are partial perspective views showing a coupling flange portion provided at the tip of the arm main portion of the steel pipe arm shown in FIG. 5 is a perspective view showing the entire structure of the body of the industrial robot, and FIGS. 6A to 6C are schematic perspective views showing the structure of a conventional robot arm.

FIG. 1 shows a cold roll-formed steel pipe blank 12 having a substantially semicircular cross-sectional shape, which has a hollow structure and a circular dome-shaped portion 14 and a flat steel plate-shaped portion 16. . FIG. 2 shows a cold roll-formed steel pipe blank 22 having a substantially quadrantal cross-sectional shape, which has a hollow structure and has a quadrantal dome portion 24 and two flat steel plate shaped portions 26, 26. are doing.

These cold roll forming steel pipe members 12, 2
In No. 2, since the smooth surface of the steel plate material remains,
Since the surface is smooth and does not have a rough surface like a cast product, the arm surface can be formed by directly utilizing the rough surface of the steel plate material. Referring to FIG. 2, the arm main body 30 of the arm according to this embodiment is
Two cold roll-formed steel sheet materials 12 having a substantially semicircular cross-sectional shape shown in FIG. 1 described above are used, and both cold-rolled steel sheet materials 12 are abutted to each other at flat steel sheet shaped portions 16 and the abutting surface Applying a spot welding process or a seam welding process 32 for joining to a plurality of points around the circumference of the
It is formed by joining two cold rolled steel sheet materials 12. In the arm main portion 30 having a circular cross section formed in this way, the two-layer flat steel plate-shaped portion 16 abutted inside has a rib function to enhance mechanical strength and mechanical rigidity. At the same time, the semi-circular cavities on both sides of the two-layer flat steel plate-shaped portion 16 provide wiring and piping areas for cables and the like.

Referring to FIG. 3, the arm main portion 40 of the arm according to this embodiment has one cold roll-formed steel pipe member 12 having the semicircular cross section shown in FIG. 1 and two quadrant circular cross sections. The flat steel plate-shaped portion 16 of the former cold roll-formed steel pipe member 12 is formed by using the two cold-roll-formed steel pipe materials 22 provided.
Then, the flat steel plate shaped portions 26 of the latter two cold roll forming steel pipe blanks 22 are butted, and spot welding or seam welding 42 for joining at a plurality of points around the butting surface or over the entire circumference is performed. The arm main portion 40 having a circular cross section is formed by applying the above. At this time, the flat steel plate-shaped portion 16 or 26 forms a rib of the arm main portion 40, so that high mechanical strength and rigidity can be secured. Further, it goes without saying that the hollow area can form a wiring area for cables and hoses and a piping area.

Referring now to FIG. 4, one end of the arm main portion 30 shown in FIG. 2 has already been welded and joined by using an energy fusing type processing machine such as a laser fusing machine using laser energy. Part of the circular dome-shaped portions 14, 14 of the two cold roll-formed steel pipe members 12 are cut into a substantially symmetrical shape to expose the flat steel plate-shaped portion 16 from the inside, and the spigot hole 18a is formed in the exposed flat surface portion 16a.
And the bolt insertion hole 18b are drilled by a drilling machine or the like to form the coupling flange portion 20 and the arm parts of the robot are processed. Here, since the exposed flat surface portion 16a has already formed a flat and smooth surface in the material stage of the cold roll forming steel pipe member 12, the exposed flat surface portion 16a has an accurate flat surface without machining such as grinding. It should be noted that it is in a surface state that can be utilized as a part.

The arm component thus formed is
After that, for example, the joint flange portion 20 is used as a mounting surface for mounting an assembly of a robot arm driving motor and a speed reducer, or as a pivotal joint portion between two arms. Can be formed. Of course, it goes without saying that the coupling flange portion 20 can be similarly formed on the other end side of the arm main portion 30.

As in the case of the arm main part 30 described above, the arm main part 40 shown in FIG. 3 is also provided with coupling flange parts by using energy melting type processing machines at both ends thereof. It is possible. That is, the flat steel plate shaped portion 16 of the cold roll forming steel pipe member 12 and the flat steel plate shaped portions 26, 26 of the two cold roll formed steel pipe blanks 22.
When the exposed flat surface portion is formed by cutting in the abutting surface area, the coupling flange portion 20 can be easily formed by performing a punching process on the exposed flat surface portion.

In the above-mentioned embodiments, the embodiments in which the arm main portion having the substantially circular cross section is formed by using the cold roll forming steel pipe member having the partial circular cross section are intensively explained, but the rectangular cross section is used. It goes without saying that a robot arm having a rectangular cross section can be configured as desired by using the cold roll formed steel pipe member.

[0019]

As described above, the present invention has been described based on two embodiments. According to the present invention, a commercially available relatively low-cost cold roll forming steel pipe member is used, and a desired arm is used. After cutting to length, welding process for forming arm main part is performed to form robot arm main part of circular or rectangular cross section,
Furthermore, if a part of the steel pipe from the end of the main part of the arm is cut by a gas cutting, plasma cutting, or laser cutting processing machine, a flat steel plate surface is exposed inside the steel pipe member. A desired robot arm having a coupling flange portion can be obtained simply by perforating the exposed steel plate surface. An arm component using such a cold roll-formed steel pipe member has high mechanical strength and a structure having ribs inside, and has a predetermined strength without having an unnecessary thickness. It becomes possible to realize a secure lightweight arm. That is, from the viewpoint of robot function, the weight reduction of the arm makes it possible to improve the controllability, and since it is possible to limit the machining process with a large number of man-hours to the minimum drilling process, It is possible to bring about a cost reduction in manufacturing the arm. In addition, by using cold roll forming steel pipe members, it is possible to expect to reduce the manufacturing cost of the machine body of the robot equipment compared to the conventional technology of designing and manufacturing a dedicated mold and processing the robot arm. Becomes

Further, the cold roll forming steel pipe member can maintain the beautiful surface of the steel sheet material for roll forming as it is, and therefore the outer surface of the robot arm can be formed to be a smooth surface. Becomes

[Brief description of drawings]

1A and 1B are partial cross-sectional views showing a typical cross-sectional shape example of a cold-roll-formed steel pipe material forming a steel pipe arm of an industrial robot according to the present invention. is there.

FIG. 2 is a partial perspective view showing a part of a steel pipe arm formed by using the steel pipe material shown in FIG.

FIG. 3 is a partial perspective view showing a part of a steel pipe arm which is also formed by using the steel pipe material shown in FIG. 1.

4 is a partial perspective view showing a coupling flange portion provided at a tip of an arm main portion of the steel pipe arm shown in FIG.

FIG. 5 is a perspective view showing an overall structure of a body of an industrial robot.

6A to 6C are schematic perspective views showing the structure of a conventional robot arm.

[Explanation of symbols]

 1 ... Robot base part 2 ... Arm 3 ... Arm 4 ... Wrist 12 ... Cold roll forming steel pipe member 14 ... Circular dome shape part 16 ... Flat steel plate shape part 18a ... Inlay hole 18b ... Bolt insertion hole 20 ... Coupling flange part 22 ... Cold roll forming steel pipe material 24 ... Circular dome shape part 26 ... Flat steel plate shape part 30 ... Arm main part 32 ... Welding treatment 40 ... Arm main part

Claims (1)

[Claims] 1. A hollow arm of an industrial robot which forms a movable element of a robot and has a connecting structure such as a flange at both ends thereof, wherein the arm mutually comprises a plurality of cold roll formed steel pipes having a predetermined length. A steel pipe arm for an industrial robot, comprising: a main arm portion welded to and a flange portion for connection or equipment attachment, which is formed by partially cutting off both ends of the main arm portion.