JP2003019688A - Safety device of robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety device of a robot capable of widely detecting even if the detecting width of an area sensor is reduced, and achieving space saving and reduction of price. SOLUTION: This safety device of a robot is provided with an area sensor ES for a detection width D, formed by a projector 11 and a photo detector 13 disposed in the outer periphery of a movable area K of a robot arm, and a curtain 15 disposed outside the air sensor. When a worker tends to enter the movable area K in an operating welding robot in error, the curtain 15 is pressed to the movable area K, thereby intercepting a light ray of the area sensors, so the robot is suddently stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device when a worker enters a movable area of a welding robot or a work transfer robot of a machine tool, or when the robot jumps out of the movable area.

[0002]

2. Description of the Related Art Conventionally, there has been provided a safety device in the case where a worker attempts to enter a movable area of a robot in a welding robot or a work transfer robot of a machine tool, or when the robot jumps out of the movable area. As a typical embodiment thereof, (1) a safety device in which the outer circumference of the robot is surrounded by a safety fence so that an operator cannot enter the robot's range of motion during operation of the robot (2) a moving table is arranged on the robot, A device that allows the product to be handed over to the robot at a place where the worker's safety is secured by moving the table to the robot side after the worker puts and sets the product on this table ( 3) A safety device that lays a safety mat around the robot and stops the operation of the robot when the worker enters the movable area of the robot and steps on the safety mat. (4) Area sensor capable of wide area detection around the robot Is provided, and a safety device or the like that suddenly stops the robot when an intrusion of a worker into the movable area of the robot is detected when the robot is operating is provided.

As shown in FIG. 14, the safety device in which an area sensor is arranged on the outer periphery of the robot has a large number of pairs of projectors 11 on the left and right sides of the front face which is one side on the outer periphery of the robot R.
And a safety device 10 in which a vertically long area sensor ES including a light receiver 13 is arranged. As a result, there is a high degree of certainty in detection by an operator invading the robot during operation, and the operator can freely move in and out during inspection and maintenance of the robot.

However, as shown in FIG. 14, an area sensor ES having a wide detection width D capable of detecting the knee M1 to the head M2 of the worker M is required. The detection width needs to be, for example, a 1-meter type (56 optical axes), a large space is required for installing the area sensor ES, and the purchase price for equipment is expensive. There is.

[0005]

SUMMARY OF THE INVENTION The present invention has been made based on such a point. An object of the present invention is to enable wide area detection while narrowing the detection width of the area sensor, thus saving space in the area sensor. It is to provide a safety device for a robot that can be made more efficient and cost can be reduced.

[0006]

In order to achieve the above object, the robot safety device according to claim 1 of the present invention comprises a plurality of pairs of light emitters and light receivers arranged on the outer periphery of the movable region of the robot arm. An area sensor having a narrow detection width and a curtain arranged outside the area sensor are provided.

The robot safety device according to a second aspect is the robot safety device according to the first aspect, characterized in that a curtain is arranged inside the area sensor.

According to a third aspect of the present invention, in the robot safety device according to the first or second aspect, the area sensor is a beam sensor including a pair of a light emitter and a light receiver. It is a feature.

[0009]

According to claim 1 of the present invention, an area sensor having a narrow detection width, which is composed of a plurality of pairs of light emitters and light receivers, is arranged on the outer periphery of the movable area of the robot arm, and the areas facing each other are arranged. A curtain is arranged outside the sensor. As a result, if a worker accidentally tries to enter the movable area of a welding robot or the like that is operating,
The curtain is pushed into the movable area to block the light rays of the area sensor. Then, even with an area sensor having a narrow detection width, the robot can be stopped suddenly if any part of the curtain is pushed into the movable area.

As described above, the area sensor need only have a narrow detection width in combination with the curtain, so that the area sensor can be downsized and the cost of the area sensor can be reduced.
As a result, a space-saving and inexpensive safety device can be provided.

According to the second aspect, since the curtain is arranged inside and outside the area sensor, when the robot runs away and this arm pushes some part of the inside curtain to the outside of the movable area, the area sensor moves. Block the rays.
Also, when the outside worker pushes somewhere on the outside curtain into the movable area, the light beam of the area sensor is blocked. Then, even with an area sensor having a narrow detection width composed of a light projector and a light receiver, some part of the curtain is pushed into the movable area, the light beam of the area sensor is blocked, and the robot is suddenly stopped. As described above, the area sensor need only have a narrow detection width in combination with the curtain, so that the area sensor can be downsized and the cost of the area sensor can be reduced. As a result, a space-saving and inexpensive safety device can be provided.

According to claim 3, the area sensor comprises:
Since the beam sensor is composed of the pair of the light projector and the light receiver, it is possible to further reduce the size and cost. As a result, further space saving can be achieved and a cheaper safety device can be provided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a robot safety device according to the present invention will be described below with reference to FIGS. FIG. 1 is a front view of a welding robot provided with a safety device, FIG. 2 is a plan view showing a relationship between an area sensor and a light-shielding curtain, and FIG. 3 is a perspective view thereof.

The vertical articulated robot R (or any other type of robot may be used) is a welding robot 10 for attaching a welding torch 3 to the tip of its robot arm 1 and performing a welding operation on a work W on a workbench 5. It is used. An area sensor ES having a narrow detection width D, which includes a plurality of pairs of light emitters 11 and light receivers 13 on one side H on the front side of the movable area K of the robot arm 1 in the welding robot 10.
Are arranged. Projector 11 of the area sensor ES
Incorporates a light emitting diode (semiconductor laser) and emits a light ray L on the optical axis converged by a condenser lens. Further, the light receiver 13 has a built-in light receiving diode, and converges the light beam L with a condenser lens to receive the light beam. The light projector 11 and the light receiver 13
As shown in FIG. 3, eight area sensors ES forming a pair with and are arranged at intervals of about 20 mm in the vertical direction and have a detection width D.
Has an optical axis of 140 mm. This is "1/7" shorter than the conventional method. This is
The price of the area sensor ES is low.

A light-shielding curtain 15 is arranged outside the light projector 11 and the light receiver 13 of the area sensor ES which face each other. The pair of the light projector 11 and the light receiver 13 are arranged at a substantially middle position of the light shielding curtain 15. The light-shielding curtain 15 has a function of preventing spatter scattering of welding and shielding a powerful arc light. The light-shielding curtain 15 may be any other curtain as long as it is a curtain. The shading curtain 15 has two poles 17, 19
It is hung from a horizontal support bar 20 that is passed between the tops of the. Then, when the worker M touches the light-shielding curtain 15 and pushes the light-shielding curtain 15 toward the movable region K0 of the welding robot arm 10, the light beam L on the optical axis between the projector 11 and the light receiver 13 is blocked, and the light receiver is received. It is configured to react 13 to detect that the worker has entered the movable area K0 side of the welding robot arm 10. Although the light-shielding curtain 15 is hung, it may be erected vertically upward, or other attachment forms may be freely adopted.

Further, the robot safety device 100 is
As shown in FIG. 5, the robot arm 1 in the welding robot 10 may be arranged on one side H2 on the front side and one side H2 on the back side of the movable area K of the robot arm 1. Then, the welding robot arm 10 may be arranged on four surfaces which are the entire circumference of the movable area K.

The robot safety device 100 according to the first embodiment of the present invention is configured as described above, and operates as follows.

In the movable area K of the robot arm 1, an area sensor ES having a narrow detection width D composed of a plurality of pairs of light projectors 11 and light receivers 13 is arranged. Then, the light-shielding curtain 15 is arranged outside the facing area sensors. As a result, the detection is performed according to the detection flowchart shown in FIG. First, the safety device 100
Did the light-shielding curtain block the light ray L by the "start of detection" 101? ] 102 is determined. If it is not cut off, the "normal operation" 103 is maintained with "NO" without a detection signal. Then, the work of the robot is “finished” 104. on the other hand,
If the worker M mistakenly tries to enter the movable area K of the welding robot or the like in operation, the light shielding curtain 15 is pushed into the movable area K to block the light beam L of the area sensor ES, and the detection signal “YES” is given. It is output and becomes “a sudden stop of the robot” 105, and an “alarm” 106 is issued to warn. After the avoidance action, the safety device 100 is “reset” 107 to be “start detection” 101. Even if the area sensor ES has a narrow detection width D, the light-shielding curtain 1
When any part of 5 is pushed into the movable area K0, the robot is suddenly stopped.

As described above, the area sensor ES in combination with the light-shielding curtain 15 may have a narrow detection width D, so that the area sensor ES can be downsized and the cost of the area sensor ES can be reduced. Become. As a result, the safety device 100 that saves space and is inexpensive can be provided.

Next, the robot safety device 200 of the second embodiment will be described with reference to FIGS. This one is
The light shielding curtain 15 is arranged outside the area sensor ES, and the light shielding curtain 16 is arranged inside the area sensor ES. In this case, in addition to detecting the intrusion of the worker M into the movable area K, the robot arm 1 of the welding robot 10 is detected.
However, when the light-shielding curtain 16 is pushed out of the movable area K and pushed out, the light ray L on the optical axis between the light projector 11 and the light receiver 13 is blocked. The light receiver 13 detects this and suddenly stops the runaway of the welding robot 10.
The other configuration is the same as that of the first embodiment, and the description is omitted.

The operation of the safety device 200 of the robot 10 according to the second embodiment will be described. This safety device 200
The light-shielding curtain 15 is provided outside the area sensor ES, and the light-shielding curtain 16 is also provided inside. As a result, as shown in FIG. 9, when the robot 10 runs out of control and the arm 1 jumps out of the movable area K, somewhere inside the light-shielding curtain 16 blocks the light beam L of the area sensor ES. When the outer worker M pushes somewhere on the outer light-shielding curtain 15 into the movable area K, the light ray L of the area sensor ES is blocked. Then, even with the area sensor ES having the narrow detection width D composed of the light projector 11 and the light receiver 13, when the light shielding curtains 15 and 16 are pushed somewhere, the light rays of the area sensor are blocked. As a result, the safety device 200 suddenly stops the robot 10. The operation status of the safety device 200 is executed according to the detection flowchart shown in FIG.

As described above, since the area sensor ES may have a narrow detection width D in combination with the light-shielding curtains 15 and 16, the area sensor ES can be downsized and the cost of the area sensor can be reduced. It will be possible. As a result, the safety device 100 that saves space and is inexpensive can be provided.

Next, the safety device 300 of the third embodiment will be described with reference to FIG. In this device, the area sensor ES is a beam sensor BS including a pair of a light projector 110 and a light receiver 130. The beam sensor BS has a pair of the light projector 13 and the light receiver 15, and has the same internal configuration and performance. Further, as shown in FIG. 11, in order to reliably detect the displacement / movement of the light-shielding curtain 15, two sets of the projectors 1
10 and the light receiver 130 may be vertically separated and arranged in parallel, or, as shown in FIG. 12, two sets of the light projector 110 and the light receiver 130 may be diagonally arranged from four corners in a diagonal direction. .

The safety device 300 according to the third embodiment also operates similarly to the two safety devices 100 and 200. Therefore, the description of the operation is omitted. According to the beam sensor BS, the area sensor ES can be further downsized and reduced in price. This makes it possible to provide an inexpensive safety device with further space saving.

The scope of application of the robot safety device of the present invention is not limited to the welding robot 10. Figure 1
As shown in FIG. 3, it may be a safety device 400 of the work transfer robot 40 that loads and unloads the workpiece W1 between the machine tool M0 and the work storage W0. This safety device 4
00 is arranged on the front side of the work transfer robot 40 and the machine tool M0. Further, as the safety device 400, any one of the safety devices 100, 200, and 300 is adopted, the operation thereof is the same, and the same effect is exhibited. The curtain is preferably a semi-transparent material or a transparent material. Even with such a curtain, the area sensor ES
The light beam L is blocked and the intruder can be detected.

[0026]

According to the robot safety device of claim 1,
An area sensor with a narrow detection width is placed in the movable area of the robot arm, and a curtain is placed outside of the area sensors facing each other.Therefore, an operator may accidentally enter the movable area of a welding robot or the like that is operating. Then, the curtain is pushed into the movable area, blocking the light from the area sensor,
Even with an area sensor with a narrow detection width, the curtain can be detected and the robot can be stopped suddenly. Therefore, by combining with the curtain, the area sensor can be downsized, and the cost of the area sensor can be reduced. Thereby, a space-saving and inexpensive safety device can be provided.

According to the second aspect, since the curtain is arranged inside and outside the area sensor, when the robot runs away and the arm pushes the curtain to the outside of the movable area, the light beam of the area sensor is blocked and the narrow detection width is detected. Even if the area sensor is composed of a light projector and a light receiver having the above, the robot can be stopped suddenly when the curtain is detected. By combining it with a curtain, the area sensor can be made smaller and
It is also possible to reduce the price of this area sensor. As a result, a space-saving and inexpensive safety device can be provided.

According to the third aspect of the invention, since the area sensor is replaced by a beam sensor comprising a pair of a light emitter and a light receiver, further size reduction and cost reduction can be achieved, and further space saving and inexpensive safety can be achieved. A device can be provided.

[Brief description of drawings]

FIG. 1 is a front view of a welding robot provided with a safety device according to a first embodiment of the present invention.

FIG. 2 is a plan view in which an area sensor of a safety device and a light-shielding curtain are arranged on a welding robot.

FIG. 3 is a perspective view in which an area sensor of a safety device and a light-shielding curtain are arranged in a welding robot.

FIG. 4 is a plan view of a welding robot equipped with a safety device on a front surface thereof.

FIG. 5 is a plan view of the welding robot equipped with safety devices on the front surface and the rear surface thereof.

FIG. 6 is a flowchart showing the detection function of the area sensor.

FIG. 7 is a side view showing a second embodiment of the present invention, in which light-shielding curtains are arranged outside and inside the area sensor.

FIG. 8 is a perspective view showing a second embodiment of the present invention in which an area sensor of a safety device and a light-shielding curtain are arranged in a welding robot.

FIG. 9 is a plan view showing a second embodiment of the present invention in which a safety device is provided on the front surface of the welding robot.

FIG. 10 is a perspective view showing a third embodiment of the present invention, in which the area sensor is a beam sensor for one light beam.

FIG. 11 is a front view of the safety device according to the third embodiment of the present invention and showing an example of a combination of beam sensors.

FIG. 12 is a front view of the safety device according to the third embodiment of the present invention and showing an example of a combination of beam sensors.

FIG. 13 is a plan view in which safety devices are arranged in front and rear parts of a robot of a machine tool.

FIG. 14 is a front view of a welding robot using an area sensor of a conventional safety device.

[Explanation of symbols] 1 robot arm 3 welding torch 5 Workbench 10 Welding robot 11 Floodlight 13 Light receiver 15, 16 curtains (blackout curtains) 17,19 Paul 20 Support rod 40 Work transfer robot D detection width ES area sensor K Robot arm movable area L ray M worker M1 knee M2 head M0 machine tool W work W1 processed product W0 work storage 100 safety device 200 safety device 300 safety device 400 safety device

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3C007 AS11 AS12 KV12 KX19 MS06                       MS22 MS27                 5H301 AA01 BB14 GG08 LL02 MM09

Claims (3)

[Claims] 1. An area sensor having a narrow detection width composed of a plurality of pairs of light emitters and light receivers arranged on the outer periphery of a movable area of a robot arm, and a curtain arranged outside the area sensor. Safety device for robots. 2. The safety device for a robot according to claim 1, wherein a curtain is arranged inside the area sensor. 3. The robot safety device according to claim 1, wherein the area sensor is a beam sensor including a pair of a light projector and a light receiver.