JPS62148191A - Working limit protective mechanism of industrial robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention provides an articulated work robot in which, when the rotation axis rotates at an operating angle of 360 degrees or more, the rotation axis rotates at a predetermined operating angle or more. [Background of the Invention] Conventionally, articulated industrial robots have a rotation axis that has an operating angle of less than 360 degrees. Therefore, in order to expand the functions as robots become more widespread, it is required that the rotation axis has an operating angle of 360 degrees or more.

Therefore, when an operating angle of 360 degrees or more is provided, in order to ensure the safety of workers and objects around the robot, care should be taken to prevent the rotation axis from running out of control. need to be limited to.

Therefore, it is easy to consider providing a detector capable of detecting the angle of the rotation axis, for example, at the origin position and the maximum angle position of the rotation axis. However, simply installing a detector will not
Since there is a region where the operating angles overlap, the overlapping region cannot be processed. Therefore, even if the rotating shaft has an operating angle of 360 degrees or more, it is not safe to prevent the rotating shaft from rotating beyond the predetermined operating angle, so the function of the rotating shaft can be simplified. There is a problem that is difficult to expand.

[Purpose of the invention]

In view of the above circumstances, an object of the present invention is to reliably limit the range of the operating angle even if the rotating shaft has an operating angle of 360 degrees or more, and to effectively utilize the space of the rotating shaft to increase the operating angle. To provide an operating limit protection mechanism for an industrial robot that prevents the robot from becoming distorted and has a simple structure.

[Summary of the invention]

The present invention provides a space between the rotating case of the rotating shaft and the fixed base.
A winding transmission member is wrapped around the winding case to convert a working angle of 360 degrees or more into a rotation angle of less than 360 degrees.

The present invention is characterized in that the operating member of the operating angle limiter is provided on the wrapped transmission member, and the operated member of the operating angle limiter is installed at the moving path position of the operating member, and with this configuration, the above object is achieved. I was able to do that.

[Embodiments of the invention]

An example of the implementation of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 is an overall view showing a welding robot to which the present invention is applied, FIG. 2 is an enlarged sectional view showing the turning shaft, and FIG. 3 is an enlarged plan view showing the main parts of the turning shaft.

As shown in FIG. 1, the welding robot of the embodiment has a rotating shaft 2 installed on a support 1 to be fixed to the floor.
One end of an upper arm 5 is connected via a first arm shaft 4 to the tip of an arm section 3 provided at an upper lateral position, and a forearm 7 is connected to the other end of the upper arm 5 via a second arm shaft 6. one end is connected,
A wrist 9 is connected to the other end of the forearm 7 via a third arm shaft 8.

A welding torch 10 is held on the wrist 9.
A welding wire 12 is fed by a wire feeding device 11 installed on the welding shaft 2. Further, between the wire supply device 11 and the welding 1--chi 10, the welding wire 12 and wiring cords (not shown) are covered with a conduit cable 13, and this conduit cable 13 is placed on a stand 14 so as not to prevent the movement of the robot. and is suspended by a spring 15.

In this welding robot, the upper arm 5 rotates in the direction of arrow A with respect to the arm portion 3 by driving the first arm shaft 4, and the forearm 7 rotates in the direction of arrow B with respect to the upper arm 5 by driving the second arm shaft 6. The wrist 9 rotates in the direction of the arrow C with respect to the forearm 7 by the drive of the third arm shaft 8, and the wrist 9 rotates in the direction of the arrow C by the drive source installed therein. There is.

Further, the turning shaft 2 is configured such that the turning case 21 is rotated at an operating angle of 360 degrees or more in the direction E around the axis with respect to the fixed base 22 by driving a motor 23 installed on the turning shaft 2.

More specifically, as shown in FIG. 2, the rotation case 21 has a cylindrical shape, and a peripheral wall 21a formed at the lower part of the rotating case 21 is connected to the cylindrical portion 21 of the fixed base 22 via a cross roller bearing 24. is rotatably supported. A motor 23 is installed on a mounting base 51 extending upward and laterally in the outer position of the rotating case 21, and a first pulley 25 fixed to the shaft of the motor 23 and the first pulley 25 are placed on the axis of the rotating case 21 in the inner position. A belt 27 is wound around a second pulley 26 installed in has been done.

The fixed base 22 has a cylindrical portion 2 on its upper outer periphery that supports the lower peripheral wall 21a of the rotating case 21 via the bearing 24.
9, a fixing plate 30 disposed above the cylindrical part 29 and inward of the winding case 21, and
A cover 31 is provided on the outer periphery of the cover 31.

Further, on the fixed plate 30 of the fixed base 22 and the input shaft part 21b side of the rotation case 21, a support part 32 that supports the second pulley 26 and the reducer 28 is provided with a bearing 33 and a bearing 34.
is held through.

When the motor 23 is driven, the rotation shaft 2 is connected to the first pulley 25. The rotational force is transmitted to the second pulley 26 via the belt 27, and the rotational force of the second pulley 26 is reduced in speed by the reducer 28 and transmitted to the input shaft portion 21b of the rotation case 21. 21 rotates around the axis relative to the fixed base 22, and at that time, the rotating case 21 rotates 360 degrees.
It is designed to operate at an operating angle of 367 degrees or more (in the example, 367 degrees).

Therefore, the rotation angle of the motor 23 is set so that the rotation case 21 can operate within a desired operating angle range.

Therefore, in the operating limit protection mechanism of the present invention, in order to prevent the swing case 21 from operating beyond the operating angle due to some abnormality, the operating angle of the swing case 21 is set at a predetermined operating angle of 36 mm.
A wrap-around transmission member 40 that converts an operating angle of 0 degrees or more into a rotation angle of less than 360 degrees is connected to the rotating case 21 and the fixed base 22.
wrapped in between.

As clearly shown in FIGS. 2 and 3, the wrapped transmission member 40 includes a first sprocket 41 coaxially fixed to the input shaft portion 21b of the swing case 21, and a fixed plate of the fixed base 22. The chain is rotatably mounted on the sprocket 30 via a support mechanism 43 and is wound between the first sprocket 41 and a plurality of second sprockets 42 arranged on the same horizontal line. And turning case 2
1 operates, the operating force is transmitted to the winding transmission member 40 via the first sprocket 41, and the winding transmission member 40
is the first. The rotation angle between the second sprockets 41 and 42 is changed to less than one rotation, that is, less than 360 degrees, and the rotation angle is changed to operate.

Further, as shown in FIGS. 2 and 3, the wrap-around transmission member 40 is provided with an operating member 44 of the operating angle limiter, and at a movement path position 50 of the operating member 44, an operated member 45 of the operating angle limiter is provided. is installed.

The operating member 44 is attached to the wrap-around transmission member 40 so as to hang down therefrom, and is disposed above the fixed plate 30 so as to operate together with the wrap-around transmission member 40 .

The actuated member 45 includes two limit switches 46, 47 installed at movement path positions 50 of the actuating member 44 on the fixed plate 30). The two limit switches 46 and 47 are of the proximity type, and when the swing case 21 is operated at an angle exceeding the operating angle range, the operating member 44 that operated together with the wrapped transmission member 40
The approach of the motor 23 is detected and the power supply to the motor 23 is cut off. For example, when the swing case 21 operates in the direction of arrow F at an angle exceeding the maximum angle, one limit switch 46 detects the approach of the operating member 44 and the motor 2
3 and the rotating case 21 operates in the direction opposite to the arrow F to an angle exceeding the home position, the other limit switch 47 detects the approach of the operating member 44,
The power supply to the motor 23 is cut off.

Therefore, the two limit switches 46 and 47 are arranged at positions corresponding to angles slightly exceeding the operating angle range of the swing case 21 in the movement path position 50 of the operating member 44.

Further, the operated member 45 has stoppers 48 and 49 installed at positions slightly beyond the range between the two limit switches 46 and 47 on the moving path of the fixed plate 30. These stops 48, 49 prevent the operating member 44 if the limit switch 46, 47 fails when the swivel case 21 is operated at an angle exceeding the operating angle.
The operation of the operating member 44 is stopped when the two members collide with each other.

In the welding robot, when the rotating shaft 2 is driven, the rotating case 21 of the rotating shaft 2 normally operates only within the operating angle range. In this case, the wrapped transmission member 40 wound between the rotating case 21 and the fixed base 22 and the operating member 41 provided thereon operate only at an operating angle of less than 360 degrees.

However, if the swing case 21 operates at an angle exceeding the operating angle due to some abnormality, the wrapped transmission member 40 and the operating member 41 operate beyond the normal operating angle, and the operating member 4
4 is detected by the limit switches 46 and 47 of the operated member 45 and cuts off the power to the motor 23, so the swing case 21 is immediately stopped.

At this time, if the limit switches 46 and 47 are out of order, the operating member 44
The rotating case 21 is also stopped as it passes through and stops against the stoppers 48 and 49.

In this way, even if the rotating case 21 has an operating angle of 360 degrees or more, the wrapped transmission member 40 converts the rotation angle to less than 360 degrees, and both the operating member 44 and the operated member 45 Since the swing case 21 can be stopped only when the swing case 21 is operated at an angle exceeding the operating angle, the overlapping range of the swing case 21 can be easily distinguished.
It is possible to reliably prevent the swing case 21 from running out of control, thereby increasing safety for workers.

Also, a power transmission member 40 is wound around the inside of the rotation shaft 2. Operating member 4
4. Since all the components of the operated member 45 are provided, the space of the rotating shaft can be used effectively, there is no risk of increasing the size, and the structure is similar to a speed reduction mechanism using the wrapped transmission member 40. From this, a simple structure can be obtained.

Further, the operated member 45 is a limit switch 46°47
and stoppers 48 and 49, and has a double safety structure in which the stopper stops the rolling case 21 if the limit switch breaks down, so safety can be improved.

Furthermore, when the rotation shaft 2 is rotated, the rotation case 21
Gawani upper arm 5. The forearm 72 wrist 9 etc. are provided, and the range of rotation is quite large, but if this mechanism is used for the rotation axis 2,
Safety can be extremely effective.

〔Effect of the invention〕

As described above, the present invention provides a winding transmission member that converts an operating angle of 360 degrees or more of the winding case into a rotation angle of less than 360 degrees between the winding case of the winding shaft and the fixed base. However, since the operating member of the operating angle limiter is provided on the wrapped transmission member, and the operated member of the operating angle limiter is installed on the moving path of the operating member, the rotation case can be reduced to 360°.
Even if the operating angle exceeds 50°, the operating angle can be reliably limited by distinguishing the overlapping areas of the turning case, thereby reliably preventing the turning shaft from running out of control and increasing safety.
In addition, since the space of the rotating shaft is effectively used to arrange the components, there is no risk of increasing the size, and there is an advantage that the structure can be simplified.

[Brief explanation of drawings]

FIG. 1 is an overall view showing a welding robot to which the present invention is applied;
FIG. 2 is an enlarged sectional view showing the turning shaft, and FIG. 3 is an enlarged plan view showing the main parts of the turning shaft. 2... Rotating shaft, 21... Rotating case, 22... Fixed base. 40... Wrap transmission member, 44... Operating member of operating angle limiter, 45... Operated member of operating angle limiter, 5
0: Movement path position of the operating member.

Claims (1)

[Claims] A winding transmission member that converts a working angle of 360 degrees or more of the winding case to a rotation angle of less than 360 degrees is wound between the winding case and the fixed base of the winding shaft, and the winding transmission member has a working angle. An operating limit protection mechanism for an industrial robot, characterized in that an operating member of a limiter is provided, and an operated member of an operating angle limiter is installed at a moving path position of the operating member.