JPH10138190A - Pressurized protected motor-driven robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressurized protected motor-driven robot preventing a cable between adjacent pressure chambers from receiving sudden bending and torsion at the same time, taking no time to scavenge all pressure chambers and allowing a pressure chamber with gas leak to be immediately specified in case of gas leak. SOLUTION: A pressurized protected motor-driven robot has a base 16 with a first pressure chamber 101, a turning base 12 with a second pressure chamber 102, an internal arm 20 with a third pressure chamber 103, and an external arm with a fourth pressure chamber. Each pressure chamber is independently formed in an airtight state without being communicated with each other and can accommodate electric motors 861, 862, and the like and cables 82. Pressure air is supplied to each pressure chamber individually through each partition wall 302 and the like of each pressure chamber. Explosion-proof wiring is extended from a robot control device to the first pressure chamber 102, and other explosion-proof wiring 821, 824, or the like are extended from the first pressure chamber 101 to the second, third and fourth chambers so as to supply power to the electric motors 861, 862, and the like accommodated in the respective pressure chambers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating robot, and more particularly to an internal pressure explosion-proof electric robot which can be used in a coating booth in an area having an explosive atmosphere, and in which a motor, a flammable cable and electric equipment are accommodated in a pressurizing chamber. .

[0002]

2. Description of the Related Art A conventional explosion-proof electric robot for painting is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-168492, in which a plurality of pressurizing chambers communicate with each other and a motor and a non-explosion-proof cable are housed in the pressurizing chamber. There is disclosed an internal pressure explosion-proof electric robot in which a non-explosion-proof cable built in a coated steel pipe and supplied with pressurized air supplies electric power to a motor. USP 5,212,432
Uses a hollow motor, accommodates the motor in multiple independently provided pressure vessels, provides separate inlets and exhaust outlets for each pressure vessel, and connects a pressurized air hose to each inlet separately A vent hose connected to each exhaust outlet is disclosed. A plan to incorporate these hoses has also been proposed.

[0003]

However, in the former case, the cable may be damaged at the same time by sudden bending and torsion in a short portion due to relative movement between the inner arm and the adjacent pressurizing chamber, and the cable may be damaged. In addition, it takes time to scavenge the entire pressurizing chamber, and when the gas leaks, the leaked pressurizing chamber cannot be identified immediately, and when the air supply pressure from the air tunite drops, it takes too much time to scavenge. In addition, the latter uses a hollow motor, which increases the cost, and the pressurized air hose connected to each inlet and the vent hose connected to each exhaust outlet are exposed outside the robot body. In addition, there is a possibility that damage may occur between the pressurized air hose and the vent hose and the operating robot arm and the coating device. In the case of incorporating these hoses, the hoses may be damaged. An object of the present invention is to prevent a cable between adjacent pressurizing chambers from being subjected to sudden bending and twisting at the same time to prevent damage to the cable, and to reduce the time required to scavenge the entire pressurizing chamber. To provide a robot. Another object of the present invention is to provide an internal-pressure explosion-proof electric robot that can immediately identify a leaked pressurized chamber when gas leaks, and detect and take measures when the air supply pressure from the air tunite drops. Another object of the present invention is that the air pipe and the cable are less exposed outside the robot body,
It is an object of the present invention to provide an internal-pressure explosion-proof electric robot which does not require an installation space, and does not cause damage between a pressurized air hose and a vent hose and an operating robot arm and a coating device.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a base having a first pressurizing chamber, a turning base provided on the base so as to be turnable about a vertical axis and having a second pressurizing chamber, and a turning base having a first pressurizing chamber. An outer arm having a third pressure chamber rotatably provided about a vertical axis and an outer arm having a fourth pressure chamber rotatably provided at an end of the inner arm about a second vertical axis. Arm, and each of the pressurizing chambers is independently and airtightly formed without communicating with each other, and can accommodate an electric motor and a cable, and the first pressurizing chamber has pressurized air in the first pressurizing chamber. The air is supplied through an air pipe communicating with a manifold arranged in one pressurizing chamber, one outlet port of the manifold is communicated with the first pressurizing chamber, and three separate air pipes from the manifold are connected to the first pressurizing chamber. 1 Explosion penetrating through the wall of the pressure chamber It extends into each of the pressurizing chambers through each partition of each of the pressurizing chambers to enter pressurized air into the second, third, and fourth pressurizing chambers from there, respectively. However, each of the air pipes does not have a built-in cable, and the pressure and exhaust flow rate of each of the pressurizing chambers can be individually detected, and a cable coated with a steel pipe is built in to fill the steel pipe to prevent air from entering. Explosion-proof wiring, into which material is injected and no pressurized air is supplied, extends from the controller of the robot to the first pressurizing chamber, and other explosion-proof wiring from the first pressurizing chamber to the second, third, and third wirings. 4. An internal pressure explosion-proof construction, wherein power is supplied to electric motors housed in the second, third, and fourth pressurizing chambers by extending through the partition wall between the four pressurizing chambers. Solving the above-mentioned problems of the prior art by providing an electric robot .

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to FIGS. FIG. 1A is a plan view of an internal-pressure explosion-proof electric robot showing a configuration of an embodiment of the present invention,
FIG. 1 (b) shows a right side view of the robot of FIG. 1 (a). FIG.
(a) is an enlarged front view of the robot of FIG. 1 (a), and FIG. 2 (b) is a right side view of the robot. FIG.
7A are respectively iii-ii of FIGS. 2A and 2B.
Partial cross-sectional view along line i, iv-iv, vv, vi-vi, vii-vii, and Fig. 7 (b) is an enlarged view of the explosion-proof wiring at the top of Fig. 7 (a). It is. The internal pressure explosion-proof electric robot 1 is arranged in a coating booth which is an explosive atmosphere area having an explosive atmosphere defined by a protective wall 26, and the control device 28 and the air unit 118 are arranged in a non-explosive atmosphere area. An explosion-proof wiring 30 extends from the control device 28 through the protection wall 26 to the robot 1. Air pipe without cable inside
44 is the robot 1 from the air unit 118 through the protection wall 26
And pressurized air is supplied to the robot 1. The robot 1 is controlled by the control device 28 via the explosion-proof wiring 30.

[0006] The first base 16 of the internal pressure explosion-proof electric robot 1
A pressurizing chamber 101 is provided, and a second pressurizing chamber 102 is provided on the swivel base 12 rotatably supported on a vertical axis 501 (FIG. 5) on the base 16. As can be clearly seen in FIG. 5, the first pressurizing chamber 101 is formed by the inner wall of the base 16 and the lower outer wall of the revolving base 12, the shield cover 301 and the annular oil seal 111, and the second pressurizing chamber 102 has its own. Sealed at the wall. An annular oil seal 111 is provided to prevent communication between the first pressurizing chamber 101 and outside air or an explosive atmosphere.
The first pressure chamber 101 and the second pressure chamber 102 are prevented from communicating with each other by a fixed wall. Space 120 is explosion-proof wiring
Explosive atmosphere area with explosive atmosphere where 821 and air pipe 400 are exposed.
Only the cover 122 is provided to prevent the 00 from being damaged. The fixed seal wall 301, which is made detachable for maintenance via a bolt and a packing 110 (not shown), is a fixed seal wall, and supports the explosion-proof wiring 821 via a sealed joint attached thereto.

The swivel base 12 rotatably supported on the base 16 is driven by an electric motor 861 disposed in its own second pressurizing chamber 102. The reduction gear 166 of the motor 861 is
The first pressurizing chamber 101 is disposed. The arm assembly includes an inner arm 20 whose lower part is rotatably supported around a first horizontal axis 502 (FIG. 5) on the revolving base 12, and a lower part mounted on the inner arm 20 with a second horizontal axis 503 (FIG. a) having an outer arm 22 rotatably supported around). Inner arm
20 is an electric motor in the second pressurizing chamber 102 in the turning base 12
The outer arm 22 is driven by the electric motor 863 in the third pressurizing chamber 103 formed in the inner arm 20 (FIG. 7A).
Driven by The third pressure chamber 103 is hermetically sealed by its own wall, rotating seal walls 302 and 303 and oil seals 112 and 113, and the fourth pressure chamber 104 is formed by its own wall and a fixed seal wall.
304 and sealed. First horizontal axis 502 and second horizontal axis
Rotating seal walls 302 and 303 rotatably supported around a horizontal axis 503 (FIG. 7A) are supported on the inner arm inner wall by bearings 332 and 333 and oil seals 112 and 113, respectively. Each rotating seal wall 302,303 is connected to the air pipe 444 and the explosion-proof wiring 824,8 via a sealing joint attached to itself.
Support 26 (Fig. 7 (a)). 2nd pressurization room 102, 3rd pressurization room
The space 103 and the fourth pressurizing chamber 104 are separated from each other by spaces 120 and 121 which are outside air or explosive atmosphere regions, so that they do not communicate with each other. The wrist 24 is rotatably mounted on the free end of the outer arm 22 and has a fourth
It is driven by an electric motor 864 in the pressurizing chamber 104 and supports a coating gun (not shown).

The electric motors 861, 862, 863, 864 form drives for the pivot base 12, the inner arm 20, the outer arm 22, and the wrist 24, respectively, and have three pressurizing chambers 102, 103, 104, respectively.
Is located within. The first pressurizing chamber 101 in the base 16 is provided with a reduction gear 166, but is not provided with an electric motor which is a driving device of the turning base 12. Swivel base
In the second pressurizing chamber 102 inside the rotating base 12, the vertical axis 501 is attached.
Not only the electric motor 861 which is the first driving device for rotating around (FIG. 5), but also the second driving for driving the inner arm 20 in the front-rear direction about the horizontal axis 502 (FIG. 5) with respect to the turning base 12. An electric motor 862 as a device is also provided. The third arm 103 inside the inner arm 20 has an inner arm 20.
The electric motor 8 is a third driving device for driving the outer arm 22 in a vertical direction around a horizontal axis 503 (FIG. 7A).
63 are provided. Fourth pressurizing chamber 104 in outer arm 22
Is provided with an electric motor 864 which is a fourth driving device for rotating the wrist 24 around three axes (not shown) with respect to the outer arm 22. Each of the explosion-proof wirings 30,821,824,826 incorporates a cable 82 and is covered with a steel pipe. Further, fillers 822, 825, 827 are injected between each steel pipe and the cable 82 to prevent air from entering, and no pressurized air is supplied. An explosion-proof wiring 30 extends from the robot controller 28 through a wall 26 between the non-explosive atmosphere area and the explosive atmosphere area, and extends from this wall 26 to a first pressurizing chamber 101 in the base 16.
The cable 82 is connected to a terminal block 161 in the first pressurizing chamber 101. Explosion-proof wiring 821, 824, 826 each in the first pressurized chamber 1
01 through the fixed seal wall 301 to the lower wall of the second pressurizing chamber 102, from the upper wall of the second pressurizing chamber 102 to the rotating seal wall 302 of the third pressurizing chamber 103, and to the third pressurizing chamber. It extends from the rotary seal wall 303 of 103 to the seal wall 304 of the fourth pressurizing chamber 104. The cable 82 is electrically connected to the terminal block 162 of the second pressurizing chamber 102, and is connected to the motors 861, 862, 863, and 864 via motor terminal blocks (not shown).

[0009] Air pipes having no cables built into the four pressurizing chambers 101, 102, 103 and 104, respectively.
44, 442, 443, 444 are communicated with each other, and four flow switches 54, pressure switches 48,
Four air systems including the discharge valve 49 are formed. The air pipe 44, which has no built-in cable inside, passes from the air unit 118 in the non-hazardous area through the wall 26 to the first pressurizing chamber.
It enters into the 101 and is connected to the manifold 6 arranged in the first pressurizing chamber 101, and one of the outlet ports of the manifold 6 communicates with the first pressurizing chamber 101, and from the manifold 6 to three separate insides. Air pipe without cable 44
2,443,444 penetrate the fixed seal wall 301 of the first pressurizing chamber 101, pass through the wall, and once in the atmosphere, which is an explosive atmosphere region.
Go out to 120 and from there the second, third and fourth pressurized chambers
In order to individually supply pressurized air into the pressure chambers 102, 103, 104, the pressure chambers 102, 103, 104 pass through the walls 302, 303, 304 of the pressure chambers.
Extend to the inside. Vent air pipe (only part is shown,
No cables are built in).
Air pipes 400, 442, 443, 444 are arranged outside the first pressurizing chamber 101 from 1,102, 103, 104 to the vent manifold 66.
And connected to the respective flow switches 54 attached to the vent manifold 66. One relief valve 60 is disposed outside the first pressurizing chamber 101 and communicates with the manifold 6. Each flow switch 54 is the first
Each of the pressurizing chambers 101, 102, 103, 104 arranged outside the pressurizing chamber 101
Are connected to the four pressure switches 48 for detecting the pressures. Each pressure switch 48 is connected to the first pressure chamber 1
It communicates with four discharge valves 49 arranged outside 01, from which it is exhausted to the atmosphere. The discharge valve 49 is an air operated type and is opened and closed by a predetermined pressure or an electric signal. Explosion-proof wiring 821,824,826, air pipes 442,443,444 and fittings to keep the airtightness of each pressurizing chamber are provided for each partition 301,302,303,304.
It is provided in.

Next, the operation will be described.
Before starting the operation, pressurized air is supplied from the air unit 118 to each of the pressurizing chambers 101, 102, 103, 104 via the air pipe 44, the manifold 6, and the air pipes 400, 442, 443, 444. Return air from each pressurizing chamber is discharged to the atmosphere via a vent air pipe, a vent manifold 66, four flow switches 54, a pressure switch 48, and a discharge valve 49.
When all of the four pressure switches 48 reach a predetermined pressure, the four discharge valves 49 can be opened, and during the exhaust from each discharge valve, each flow switch 54 is moved from each pressurizing chamber. When the scavenging of a predetermined volume of each pressurized chamber is performed, each exhaust valve 49 is closed, and then the robot 1
In a safe and bootable state. During the exhaust, the air supply pressure from the air nit 118 decreases, and when the flow rate of any one of the pressurizing chambers is smaller than the exhaust flow rate set by each flow switch 54, this is detected, and the flow switch detects the exhaust. Since the energization of the subsequent robot is disabled, raising the air supply pressure can prevent the delay of scavenging, and speed up the time until the robot is safely and startable. be able to. After the evacuation has been completed normally, after that, during operation of the robot 1, each pressurizing chamber is maintained at a pressure equal to or higher than the air pressure set by each pressure switch 48, and the air pressure of one of the pressurizing chambers is reduced by the pressure switch 48.
When the pressure falls below the set air pressure, the pressure switch 48 is actuated to stop energizing the robot 1.

According to this configuration, each explosion-proof wiring 821,82
4,826 is supported via joints by the partition walls 301,302,303,304 of each pressurizing chamber, so that the cable 82 passing between the pressurizing chambers is not simultaneously subjected to sudden bending and torsion, so there is no danger of cable damage. Was. In addition, since there are four pressurizing chambers and an independent air circulation path, it does not take much time to scavenge the entire pressurizing chamber, and it takes time to make the robot safe and startable. Faster, each pressurizing chamber is kept above the air pressure set by each pressure switch 48, and when gas leaks, it can immediately identify the leaking pressurizing chamber, and the air supply pressure from the air tunite 118 during scavenging dropped When the flow switch 54 drops below the set scavenging flow rate, the flow switch detects this and raises the air supply pressure to take measures to prevent a delay in scavenging. In addition, air piping between pressurizing chambers 400,442,443,444 and explosion-proof wiring 821,824,8
In the case of 26, only a slightly short portion was exposed to the outside of the robot main body, and was not substantially exposed to the outside of the robot main body. In addition, rotating seal walls 302 and 303 rotatably supported around vertical shafts 502 and 503 are provided on the walls of the inner arm 20 via annular sliding seals 112 and 113 and bearings 332 and 333, respectively, and the rotating seal walls 302 and 303 penetrate therethrough. The air pipes 443, 444 and the explosion-proof wiring 824, 826 are supported via sealed joints to prevent sudden bending and twisting of the air pipes and the explosion-proof wiring due to relative movement between the pressurizing chambers. Was.

[0012]

According to the structure of the present invention, since the partition walls of the pressurizing chamber support the explosion-proof wiring, the cables passing between the pressurizing chambers are not simultaneously subjected to sudden bending and torsion. The cable can no longer be damaged. In addition, since there are four pressurizing chambers and an independent air circulation path, it does not take much time to scavenge the entire pressurizing chamber, and it takes time to make the robot safe and startable. Faster, each pressurizing chamber is maintained above the air pressure set by each pressure switch, and when gas leaks, it can immediately identify the leaking pressurizing chamber, and the air supply pressure from the air nitite during scavenging is set by the flow switch The flow switch detects this when the scavenging flow rate falls below and raises the air supply pressure to prevent delays in scavenging, so that the robot can be safely and started up quickly. Can be. The air pipes and explosion-proof wiring between the pressurizing chambers are exposed only slightly short outside the robot main body, and are not substantially exposed outside the robot main body. There is no longer any risk of damage to the arm, painting line, etc. during operation.

[Brief description of the drawings]

FIG. 1 is a plan view of an internal pressure explosion-proof electric robot showing a configuration of an embodiment of the present invention, and FIG. 1 (b) is a right side view of the robot of FIG. 1 (a).

FIG. 2 is an enlarged front view of the robot shown in FIG. 1 (a), and FIG. 2 (b) is a right side view thereof.

FIG. 3 is a partial cross-sectional view taken along the line iii-iii of FIG. 2 (a).

FIG. 4 is a partial cross-sectional view taken along line iv-iv of FIG. 2 (b).

FIG. 5 is a partial cross-sectional view taken along line vv of FIG. 2 (b).

FIG. 6 is a partial cross-sectional view taken along line vi-vi of FIG. 2 (b).

7 (a) is a partial cross-sectional view taken along the line vii-vii in FIG. 2 (b), and FIG. 7 (b) is an enlarged view of an explosion-proof wiring portion in the upper part of FIG. 7 (a). .

[Explanation of symbols]

1. . Robot 6. . Manifold 12． . Swivel base 16. . Base 20. . Inner arm 22. . Outer arm 24. . Wrist 30,821,824,826. . Explosion-proof wiring 44,442,443,444. . Air piping 48. . Pressure switch 30
1,304. . Fixed seal wall 302,303. . Rotating seal wall 861,862,863,864. . Electric motor

Claims (2)

[Claims] 1. A base having a first pressure chamber, a pivot base provided on the base so as to be pivotable about a vertical axis, and a pivot base having a second pressure chamber, and a pivot about the first vertical axis on the pivot base. And an outer arm having a fourth pressure chamber rotatably provided around the second vertical axis at an end of the inner arm. The pressurizing chambers are independently formed airtight without communicating with each other, and can accommodate an electric motor and a cable,
Pressurized air is supplied to the first pressurized chamber via an air pipe communicating with a manifold disposed in the first pressurized chamber, and one outlet port of the manifold is connected to the first pressurized chamber. From the manifold, three separate air pipes penetrate the wall of the first pressurized chamber and enter the explosive atmosphere area, from which pressurized to the second, third and fourth pressurized chambers respectively. In order to supply air, it extends to each of the pressurizing chambers through each partition of each of the pressurizing chambers, and each of the air pipes has no built-in cable, and the pressure and exhaust flow rate of each of the pressurizing chambers are individually The explosion-proof wiring, in which a filler is injected into the steel pipe and pressurized air is not supplied to prevent the intrusion of air, is built in from the control device of the robot, to prevent the air from entering. Extending to the pressurizing chamber,
Another explosion-proof wiring extends from the first pressurizing chamber through the partition between the second, third, and fourth pressurizing chambers, and extends into the second, third, and fourth pressurizing chambers. An internal-pressure explosion-proof electric robot characterized by supplying electric power to a housed electric motor. 2. The partition of a third pressurizing chamber of the inner arm is supported on the wall of the inner arm via a bearing and an annular sliding seal, respectively, and is about a first and second vertical axis. Formed of a rotatable rotating seal wall,
2. The internal pressure explosion-proof electric robot according to claim 1, wherein each of the rotary seal walls supports the explosion-proof wiring and the air pipe via a sealing joint attached thereto.