JPH0411030Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electric industrial robot that has an internal pressure explosion-proof structure and can be used, for example, as a painting robot.

[Prior art]

In general, an electric industrial robot includes a base, a swivel base that is rotatably mounted on the base, and a swivel base on which a robot body driven by an electric motor is mounted on the upper side, and one end that is attached to the base. The cable is supported, the other end side is connected to the robot body via the swivel base, and a cable side extension/contraction part is formed in a portion located between the base and the swivel base. has been done. As a cable having a cable-side telescopic portion, a cable using a curl cord is known from Japanese Patent Laid-Open No. 60-25671.

[Problem that the invention attempts to solve]

By the way, in the electric industrial robot according to the above-mentioned conventional technology, since the cable has an extendable cable side part located between the base and the swivel table, the slewing table can be easily rotated. At times, the cable-side telescopic portion can be extended to follow the swivel base. However, when the cable-side telescoping part extends when the swivel base rotates, the cable-side telescoping part comes into contact with the surface of the equipment accommodating part provided on the base to accommodate the turning equipment for driving the swivel base. However, there is a problem that the cable may break.

On the other hand, when an electric industrial robot is used as an electric painting robot, an explosion-proof structure is required because it is used in an atmosphere containing flammable gases caused by solvents such as thinner. For this reason, in the above-mentioned conventional technology, special cables such as captire cables and coaxial cables that have been specially insulated and subjected to explosion-proof treatment are used. However, these special cables have a problem in that the swivel table cannot turn smoothly because they have poor followability when the swivel table turns.

In addition, an airtight chamber is formed between the swivel table and the base,
The airtight chamber was filled with a protective gas such as an inert gas to create an internal pressure explosion-proof structure, which was developed in 1983.
It is known from the publication No.-160193. but,
In this case, the volume of the airtight chamber increases, so
There is a problem in that the capacity of the protective gas filled in the airtight chamber also increases, making it impossible to efficiently provide explosion protection.

The present invention was developed in view of the problems of the prior art described above, and provides an electric industrial robot that can make the cable follow the rotation of the swivel table and efficiently form the cable into an internal pressure explosion-proof structure. The purpose is to provide.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention adopts a configuration that includes a base, a swivel base that is rotatably provided on the base, and a robot body driven by an electric motor is mounted on the upper side. , one end side is supported by the base, the other end side is connected to the robot main body via the swivel base, and a portion located between the base and the swivel base has an extensible cable-side extension part. In the electric industrial robot, a container-side telescopic part is disposed between the base and the swivel table, accommodates the cable-side telescopic part, and expands and contracts in accordance with the cable-side telescopic part. A cable container is formed, and a ventilation path is formed between the cable container and the cable, and the inside thereof is filled with a protective gas.

[Effect]

When the swivel base rotates together with the robot body, the cable-side telescopic portion of the cable extends in accordance with the rotation of the swivel base, and the container-side telescoping portion of the cable container also extends in accordance with the cable-side telescopic portion. Since the ventilation path is filled with protective gas, the cable can be surrounded with protective gas to form an internal pressure explosion-proof structure.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

First, FIGS. 1 to 4 show a first embodiment of the present invention.

In the figure, 1 is an electric robot, 2 is a cylindrical base constituting the electric robot 1, and the base 2 has a small diameter cylindrical part 3B in the center of its upper surface 3A.
A base 3 with a protruding structure and a motor chamber 4 inside.
, a cylindrical support portion 5 erected and fixed on the upper side of the small diameter cylindrical portion 3B, and a circumferential body portion 6 integrally provided around the upper surface portion 3A of the base 3. A plurality of cable insertion holes 7, 7, . . . are formed in the upper surface portion 3A of the base 3.

Reference numeral 8 denotes a covered cylindrical swivel base which is rotatably provided on the circumferential body 6 of the base 2 via a bearing 9, and a pair of support brackets 8B, 8B are opposed to the upper surface 8A of the swivel base 8. A plurality of cable insertion holes 10, 10, . . . are formed in the upper surface portion 8A between the support brackets 8B.

Reference numeral 11 denotes a robot body mounted on the swivel base 8, and the robot body 11 has a support column 11A that is swingably supported at the base end by support brackets 8B, 8B.
, an arm 11B that is supported laterally and protrudes from the upper end of the support column 11A and is swingable in the vertical direction, and a wrist 11C that has three degrees of freedom and is provided at the tip of the arm 11B. .

Reference numeral 12 denotes an electric motor for swinging the column, which is fixed to the support bracket 8B on one side in order to swing the column 11A, and 13 is fixed to the support bracket 8B on the other side in order to swing the arm 11B. An electric motor for swinging the arm, and a link 1 is connected between the output shaft of the electric motor 13 and the rear end of the arm 11B.
A swing mechanism 14 consisting of 4A and 14B is provided. Further, 15, 16, 17 are the wrists 11C.
This is an electric motor for driving the wrist, which is fixed to the rear end of the arm 11B in order to drive the arm 11B in each of three degrees of freedom. Here, each electric motor 12, 13,
15, 16, and 17 are configured to have an internal pressure explosion-proof structure in which an airtight container is filled with nonflammable gas or fresh air, and is designed to prevent explosions of flammable gas within the painting workshop.

On the other hand, reference numeral 18 denotes a turning electric motor provided in the motor chamber 4 of the base 2 in order to turn the turning table 8, and a drive shaft 18A of the electric motor 18 protrudes into the cylindrical support part 5. There is. Reference numeral 19 denotes a harmonic drive as a deceleration mechanism provided in the cylindrical support portion 5 to reduce the rotation speed of the electric motor 18 and rotate the swivel table 8. The harmonic drive 19 is connected to the drive shaft 18A. A wave generator 19A consists of an elliptical cam fixed to the cam and a ball bearing fitted on the outer periphery of the wave generator 19A, the inner peripheral surface is in sliding contact with the wave generator 19A, and external teeth are provided around the outer periphery. It is composed of a cup-shaped flexspline 19B and a circular spline 19C that is fitted into the cylindrical support portion 5 and has internal teeth on its inner periphery that mesh with the external teeth of the different flexspline 19B. There is.

Reference numeral 20 denotes a pivot shaft rotatably supported by the cylindrical support portion 5 via a bearing 21, and the upper end of the pivot shaft 20 is fixed to the upper surface portion 8A of the swivel base 8 via set screws 22, 22. Its lower end is fixed to the flex spline 19B of the harmonic drive 19 via set screws 23, 23.

Next, 24, 24 is supported by the base 2 at one end, and connected to the robot main body 11 via the swivel base 8 at the other end.
Each electric motor 12, 13, 15, 16 and 17
A plurality of power transmission cables 24 are shown connected to each other, and each cable 24 is formed from a so-called curl cord. A portion of each cable 24 between the base 2 and the swivel table 8 becomes an extensible portion 24A formed in a spiral shape, and both ends thereof are connected to a power source (not shown) and each motor. 12, 13, . . . is connected to the connecting portion 24B.

Reference numeral 25 designates a tube as a cable container, which has an inner diameter slightly larger than the outer diameter of the cable 24, and has an air passage 27, which will be described later, formed between it and the cable 24. The tube 25 is also shown in FIG. As shown, it is inserted into the outside of each cable 24 from one end to the other end. The tube 25 also has a spiral-shaped container that is disposed between the base 2 and the swivel table 8, accommodates the cable-side telescoping portion 24A of the cable 24, and expands and contracts in accordance with the cable-side telescoping portion 24A. A side expandable portion 25A is formed. and,
One end of the tube 25 is inserted into the tube insertion hole 7 of the base 2 and supported, leading to a nonflammable gas source (not shown), and the other end of the tube 25 is inserted into the tube insertion hole 10 of the swivel base 8. Insert each electric motor 1
2, 13, 15, 16 and 17.

26, 26, . . . are elastic holding members made of rubber or the like that are inserted into the respective tube insertion holes 7, 10 to hold the tubes 25 inserted therein.

27 is located within the tube 25 and
5 and the cable 24, and the ventilation path 27 is filled with a nonflammable gas as a protective gas. One end side of the ventilation passage 27 is connected to the nonflammable gas source, and the ventilation passage 27 is connected to the nonflammable gas source.
The other end side of 7 is each electric motor 12, 13, 15, 1
It communicates with the airtight containers 6 and 17.

The electric industrial robot according to this embodiment is constructed as described above, and when the arm 11B of the robot body 11 is to be turned in the left and right directions, the turning electric motor 18 provided in the base 2 is driven. , harmonic drive 19, and rotation shaft 20 in order to rotate the swivel base 8. In addition, each cable 24
By transmitting power to each electric motor 12, 13, 15, 16, and 17 via
The arm 11B, wrist 11C, etc. can be freely driven to perform painting work, etc.

Thus, according to this embodiment, the tube 25 is inserted into the outside of the cable 24, and the tube 25 has the base 2 on the fixed side and the swivel base 8 on the movable side.
and accommodates the cable side elastic part 24A of the cable 24, and the cable side elastic part 24A
Since the spiral container-side telescopic portion 25A is formed to expand and contract according to the rotation of the rotating electric motor 18, each of the telescopic portions 24A and 25A can extend following the swivel base 8, and the swivel base 8 is cable 2
4. It is possible to turn smoothly with a large turning angle of, for example, about 120° to 300° without being restricted by the tube 25. Further, since the outer circumferential side of the cable 24 is covered with the tube 25, the cable 24 is reliably prevented from coming into direct sliding contact with the cylindrical support portion 5 etc. when the swivel base 8 is turned.
4 can be prevented from being damaged or disconnected, thereby improving the lifespan and reliability.

Furthermore, a passageway 27 is formed between the cable 24 and the tube 25, and since the passageway 27 is filled with nonflammable gas to provide an internal pressure explosion-proof structure, combustible material may be prevented due to cable breakage during painting work, etc. Gas explosion accidents can be prevented. In addition, since the tube 25 is inserted uniformly over the entire length of the cable 24, the volume of the ventilation path 27 can be reduced and the amount of nonflammable gas filled inside can be reduced. A pressure drop in the air passage 27 can be quickly detected by the pressure switch.

Next, FIGS. 5 and 6 show a second embodiment of the present invention, and the feature of this embodiment is that the container-side extension and contraction part of the cable container is formed into a bellows shape. In addition,
In this embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the explanation thereof will be omitted.

In the figure, 31 indicates a cable container according to this embodiment provided outside the cable 24, and the cable container 31 includes a bellows 32 and a tube joint 3, which will be described later.
5. It consists of a tube 36.

Reference numeral 32 denotes a bellows as a container side elastic part located between the upper surface part 3A of the base 2 and the upper surface part 8A of the swivel table 8, and provided so as to integrally cover the cable side elastic part 24A of the cable 24. The bellows 32 is made of a flexible material such as rubber. Furthermore, an internal bellows air passage 37A, which will be described later, is formed within the bellows 32.

Reference numerals 33 and 33 denote mounting plates fixed to each end of the bellows 32 in the expansion/contraction direction to the base 2 and the swivel base 8, respectively. It is fixed to each upper surface part 3A, 8A of the swivel base 8.

34, 34 are joint insertion holes formed in the mounting plates 33, 33, respectively, and are formed of female threads; 35;
35 indicates a tube joint screwed into each joint insertion hole 34 through each tube insertion hole 7, 10;
Both end side connection parts 24B of the cable 24 are inserted into each tube joint 35, and the base 2 and the swivel base 8 are connected to each other.
Extending outward, the power supply and each electric motor 12,1
3, 15, 16 and 17. Further, 36, 36 are each connection portion 2 of the cable 24.
4B shows a tube inserted outside to form an intra-tube air passage 37B, which will be described later.The end of each tube 36 is attached tightly to each tube joint 35, and the tube inner air passage 37B is connected to the inside of the bellows. It communicates with road 37A.

Reference numeral 37 indicates a ventilation passage formed within the cable container 31 between the cable 24 and filled with nonflammable gas, and the ventilation passage 37 is almost the same as the ventilation passage 27 according to the first embodiment described above. One end thereof is connected to the nonflammable gas source, and the other end thereof communicates with the airtight container of each electric motor 12, 13, 15, 16, and 17. Further, as shown in FIG. 6, a portion of the ventilation path 37 located between the upper surface portion 3A of the base 2 and the upper surface portion 8A of the swivel table 8 is
The bellows internal air passage 37A is formed to have a large diameter according to the inner diameter of the bellows 32, and the portions located inside the upper and lower tubes 36 are internal tube air passages formed to have a small diameter according to the inner diameter of the tube 36. It is marked 37B.

The electric industrial robot according to this embodiment is constructed as described above, and when the swivel base 8 turns, the cable 24 is moved to the cable-side extension/contraction section 2.
4A, and the cable container 31 has a bellows 32 that can be expanded and contracted integrally with the cable expansion and contraction part 24A.
Since the above is provided, almost the same as in the first embodiment,
The swivel base 8 can smoothly swivel with a large swivel angle without being restricted by the cable 24 and the cable container 31, and the cable 31 can be protected by the bellows 32.

Furthermore, since the bellows 32, which constitutes a part of the cable container 31 and expandably accommodates the cable side stretchable part 24A of the cable 24, is formed with the bellows internal ventilation passage 37A and is filled with nonflammable gas, Almost similarly to the first embodiment, the cable 24 can be effectively made into an internal pressure explosion-proof structure without hindering the rotation of the swivel table 8 and the expansion and contraction of the cable 24, and the amount of nonflammable gas is also reduced. be able to.

Although the cable 24 in each of the above embodiments is a power transmission cable that supplies power to each of the electric motors 12, 13, and 15 to 17, it may also be a signal cable that transmits a control signal to a coating device or a robot. The present invention can also be applied to signal cables connected to rotation angle detectors provided on the arm 11B, wrist 11C, etc. of the main body 11.

[Effect of idea]

As detailed above, according to the present invention, the cable container is arranged between the base and the swivel table, houses the cable-side expandable part, and is formed with a container-side expandable part that expands and contracts in accordance with the expandable part. and a ventilation path formed between the cable container and the cable and filled with protective gas, so that when the swivel base rotates together with the robot body, the cable side extension and contraction part of the cable swivels. Extends according to the rotation of the table,
The container-side telescoping portion of the cable container also extends in accordance with the cable-side telescoping portion. As a result, the swivel table can smoothly rotate without being restricted by these cables and cable containers, and the cables can be protected by the cable containers to prevent the cables from coming into direct contact with other members. Further, by covering the cable around the cable with protective gas, an internal pressure explosion-proof structure can be effectively formed, and the volume of the ventilation passage can be formed small, so that the filling amount of protective gas can be reduced.

[Brief explanation of the drawing]

1 to 4 relate to a first embodiment of the present invention, and FIG. 1 is a front view of an electric industrial robot;
FIG. 2 is a left side view of the industrial robot shown in FIG. 5 and 6 relate to the second embodiment of the present invention, FIG. 5 is a vertical sectional view showing the internal structure of the base and the swivel table, and FIG.
The figure is an enlarged view of the main part in FIG. 2...Base, 8...Swivel base, 11...Robot main body, 12, 13, 15, 16, 17...Electric motor, 24...Cable, 24A...Cable side extension and contraction part, 25, 31... Cable container, 25A...
... Container side elastic part, 32... Bellows (container side elastic part),
27, 37... Ventilation path.

Claims (1)

[Scope of utility model registration request] a base, a swivel base which is rotatably provided on the base and has a robot main body driven by an electric motor mounted on the upper side; one end side is supported by the base and the other end side is supported by the swivel base; In the electric industrial robot, the base is connected to a robot body via a base, and a cable is formed with a cable-side extension part located between the base and the swivel base. and a cable container provided with a container-side expandable part that is disposed between the cable container and the swivel base, accommodates the cable-side expandable part, and expands and contracts in accordance with the expandable part;
An electric industrial robot characterized in that a ventilation path is formed in the cable container between the cable container and the cable, and the inside is filled with a protective gas.