JPH02180580A - Origin adjusting device for industrial robot - Google Patents

Abstract

PURPOSE:To easily set the original position of a robot operation part, by fixing an origin adjusting device transmitting an origin detection signal from a switch means according to the sliding and projecting actions of a slide lever corresponding to the relative rotation of 1st and 2nd two members freely attachably to the origin corresponding position of the 2nd member. CONSTITUTION:A paragraph 16 is formed at the origin corresponding position of the peripheral face of a 1st member 12 in relative two members and an origin adjusting device 20 is fixed freely attachably to the origin corresponding position of the 2nd member 14 as well. A switch means 22 for transmitting an origin detection signal is held on the switch holder 24 of this origin adjusting device 20. The other end of a slide lever 26 whose one end is engageable with the ON and OFF needle of this switch means is provided freely slidably and projectably toward the paragraph 12 inside by the direct moving type bearing 28 of the switch holder 24. The origin detection signal is transmitted from the switch means according to the sliding and projecting actions of the slide lever corresponding to the relative rotations of the 1st, 2nd two members. The original position is set based on the rotation detection signal of a rotation driving motor and this origin detection signal.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an origin adjustment device that adjusts and sets the origin position of each joint in an industrial articulated robot. The present invention relates to an origin adjustment device for an industrial robot that can adjust and set the origin between two relatively rotatable members at each joint.

[Conventional technology]

An industrial robot consists of a robot body that has moving parts such as a robot rotating body, a robot arm, and a robot wrist, as well as motors that serve as a drive source for these moving parts, and a robot control system that controls the movements of each moving part of the robot body. It consists of a device,
An end effector attached to the tip of the robot's wrist performs robot operations such as gripping a workpiece and transporting it between individual positions, or performing a certain task on the workpiece, such as assembly work. Therefore, in order for each operating section of the robot body to perform highly accurate robot operations, a certain matching relationship must be established between the robot control device and each operating section of the robot body. For this purpose, an origin position device is provided in the robot operating section, and when each operating section is located at the origin position, the origin position is set on the robot controller side, and the desired position is set according to the commands of the robot controller. The motion part of the robot body performs robot motions with high precision. In order to achieve consistency between the robot body side and the robot control device side, the reference position setting work, which involves adjusting and setting the origin of each moving part of the robot body, is generally specified during the shipping process at the final stage of the robot manufacturing process. It is well known that the process is carried out using a jig, for example, as disclosed in the patent application filed in 1983-12 filed by the present applicant.
No. 7734, US Pat. No. 4,702,665.

However, the origin position adjustment, setting, or reference position setting using the above-mentioned specific jig cannot be carried out after the robot has entered the practical stage at each use site, for example, if any drive motor of each operating part of the robot It is not always possible to use it easily when it is replaced due to a failure. In other words, if the site where the industrial robot is used is extremely small, or if the operating range of each robot's operating parts is restricted to avoid interference with surrounding equipment or machinery, etc. It becomes difficult to make the operating parts of the aircraft assume an attitude for setting the reference position, and therefore, setting the reference position becomes impossible.

On the other hand, instead of the method of setting the reference position of a robot using such a specific jig, as shown in FIG. A dial gauge 8 is attached to the member 2 using the fixing fitting 6, and a V-groove-shaped recess 4a perpendicular to the rotational direction is formed at a position corresponding to the origin in a corresponding adjacent portion of the other member 4, and both members 2. 4, the tip of the plunger rod 8a of the dial gauge 8 falls into the recess 4a, and the position where the scale reading of the dial gauge 8 indicates the peak value is the origin position, and the origin is adjusted and set. A simple origin adjustment mechanism for performing calibration is also provided. In addition, there is a method in which a mark indicating the origin position is written on each of the relatively rotatable members 2.4 in advance and wiped, and the origin is adjusted and set by matching the marks, or a gauge with an edge is provided on both members 2.4. Make the block attachable, and when adjusting and setting the origin position,
There is also a well-known method in which the gauge block is mounted, a relative rotational position where the edges of the gauge block match is found, and the origin is adjusted and set.

[Problem to be solved by the invention]

The devices and jigs used to carry out the well-known origin adjustment and setting method described above mainly rely on mechanical detection of the origin position by reading the indication scale of the dial gauge 8, and their accuracy is too high for visual inspection. There is an inconvenience in not being able to meet the expectations □.

Moreover, since the plunger rod 8a of the dial gauge is originally made to be suitable for detecting a displacement component in a plane perpendicular to its displacement direction, It is not suitable for detecting 4a and plunger 8 is not suitable for detection.
The influence of play in a will have a negative effect on the adjustment and setting of the origin.
That is, there is a problem that the accuracy of origin adjustment and setting is lowered.

In addition, the V-groove recess 4a has the disadvantage that in the process of driving the relative rotation of two relatively rotatable members with a motor, errors may occur if the rotation direction is arbitrarily performed in both forward and reverse directions due to backlash within the drive system. be.

On the other hand, with the method of applying marks in advance, when the robot body gradually becomes dirty at the site of use, etc., the marks may also become dirty or peel off, making it impossible to carry out the origin adjustment and setting work. easy. Therefore, an object of the present invention is to improve origin adjustment and setting accuracy and to improve robot The origin position of each robot movement part can be automatically set on the control device side, and the degree of freedom of movement is reduced because the site where the industrial robot is used is small or there are various devices nearby. The present invention aims to provide an origin adjustment device for an industrial robot that can be used even in a restricted environment.

[Means of solution and action]

According to the present invention, in view of the above-mentioned object of the invention, there is provided an origin adjustment device for an industrial robot that adjusts and sets an origin between two relatively rotating members in a joint of an industrial robot. A paragraph is formed at a position corresponding to the origin on the circumferential surface of the first member, and an origin adjustment device is removably fixed to a position corresponding to the origin of the second member in the two relative members, and the origin adjustment device is A switch holder fixed to a position corresponding to the origin of the second member, a switch means for transmitting an origin detection signal held by the switch holder, and one end capable of engaging with an on/off movable element of the switch means. and a sliding rod whose other end can slide and protrude into a paragraph formed at a position corresponding to the origin of the 181st member by the guidance of a direct-acting bearing fixed to the switch holder. Provided is an origin adjustment device for an industrial robot, which is configured to transmit an origin detection signal from a switch means in accordance with the sliding and protruding action of the sliding rod in accordance with the relative rotation of the eleventh and second two members. The robot control device receives the origin detection signal together with the rotation detection signal of the joint drive motor and automatically sets the origin position.Moreover, the above-mentioned direct-acting bearing allows the robot to slide freely and precisely. Since the origin position is detected only when rotation in a certain direction is always applied between two relative members due to the interaction between the sliding rod supported without any play and the paragraph formed at the position corresponding to the origin, the origin position is detected. There is no risk that backlash in the drive system caused by the drive motor will affect the adjustment or setting of the origin.

Hereinafter, the present invention will be described in more detail based on embodiments shown in the accompanying drawings.

〔Example〕

FIG. 1 is a sectional view showing a state in which the origin adjustment device for an industrial robot according to the present invention is attached to one joint of the robot.

In FIG. 1, one joint 10 of an industrial articulated robot has two members 12, 14 that rotate relative to each other. These 21 members 12 and 14 are normally configured such that one member 12 rotates with respect to the other member 14. Therefore, in the following, the member 12 is assumed to be a fixed member and the member 14 is a rotating member.
explain.

According to the present invention, the rotating member 14 of the joint 10 is located at a position corresponding to the origin on the relative rotating peripheral surface 14a facing the fixed member 12, that is, the fixed member 12 and the rotating member 14 are in a predetermined relative reference posture. Sometimes, a rectangular notch 16 is provided at one arbitrarily selected position.

The paragraph 16 has a vertical wall surface 16a falling in a radial direction with respect to the rotation center point 0 of the joint 10, and a flat bottom surface 16b perpendicular to the vertical wall surface 16a, and the shoulder portion of the vertical wall surface 16a. 16c is formed as a shoulder portion perpendicular to the circumferential surface 14a, and cooperates with the edge of the end face of the sliding rod, which will be described later, to enable highly accurate detection of the origin.

On the other hand, the fixed member 12 has a paragraph 16 formed corresponding to the origin position of the rotating member 14 in the relative reference posture.
An origin adjustment and setting tool 20 is attached to a position for detecting. That is, the origin adjustment and setting tool 20 includes a switch means 22 for generating electric signals consisting of a limit switch, a switch holder 24 for holding the switch means 22, and one end capable of engaging with an operating rod 22a of the switch means 22. A linear-acting sliding rod 26, a linear-acting bearing 28 that slidably holds the sliding rod 26, and a switch holder 2 together with the linear-acting bearing 28.
4 to the fixing member 12 of the joint 10
0. The switch holder 24 of the origin adjustment and setting tool 20 is fixed at a pre-formed mounting position on the fixing member 12 using a set screw 30. The actuating rod 22a of the switch means 22 held in the upper part of the switch holder 24 is biased to a protruding position, either on or off, by the spring pressure from an internal spring. A through hole 24a is formed in this switch holder 24 below the operating rod 22a of the switch means 22,
The boss portion 28a of the direct acting bearing 28 is inserted into the through hole 24a and the receiving hole 12a formed in the fixing member 12 of the joint 10.
are inserted in a nearly tight fit. In other words, direct acting bearing 2
8 is attached to the fixing member 12 and the switch holder 24 without any play, and is fixed with a set screw 30. The direct-acting rod 26 is slidable by the direct-acting bearing 28, and the stage 1G of the rotating member 14 is
When facing the switch means 22, the switch means 22 is formed so as to slide and protrude linearly under the biasing force of the built-in spring of the switch means 22 and due to free fall.

In this example, paragraph 16 appears as if only by free fall.
However, in the case of a robot joint in which the axis of rotation of the joint 10 is arranged in the vertical direction, and therefore the rotation of two relatively rotatable members occurs in a horizontal plane, the lightness of the direct acting bearing 28 also applies. , and due to the linear guide function without backlash, when the stage 16 of the rotating member 14 reaches the opposing position, the translation rod 26 smoothly moves linearly into the stage 16 due to the biasing force of the internal spring pressure of the switch means 22. Works prominently. Here, the linear rod 26 is formed into a straight rod-like body, and the corner on the protruding end surface side forms an edge 26a. When the rotation is performed in the direction indicated by P and the edge 26a of the translation rod 26 is removed from the right angle shoulder 16c of the stage 1G of the rotating member 14,
At the same time, the linear motion rod 26 moves linearly and protrudes, and as a result, the linear motion rod 2
The contact and engagement between the other end of the switch 22 and the switch means 22 are released, and therefore, an origin detection signal is generated from the switch means 22, and the origin detection signal is sent to a robot control device (not shown) to calibrate the origin setting. The configuration is such that the tion is achieved.

Now, according to the origin adjustment and setting tool 20 having the above-described configuration, the vertical wall surface 16a of the rectangular recess-shaped paragraph 16 is connected to the joint 10.
Since it is formed as a surface oriented in the radial direction with respect to the rotation center of
is configured to rapidly perform direct operation and promote the origin detection action of the switch means 22, so that when the rotating member 14 rotates in the direction opposite to the arrow P shown in the figure, the linear motion rod 26 quickly slides linearly. , no protruding motion occurs. In other words, since the origin is adjusted and set only in response to rotation in a certain direction, there is no risk that backlash in the rotational drive system of the joint IO will affect or interfere with the origin position setting and cause precision deterioration. It is.

Now, in the origin adjustment and setting device of the present invention having the above-described configuration, the origin adjustment and setting tool 20 is attached to the fixed member 12 side of the joint 10, and then the robot control device is put into the origin adjustment and setting mode and the By activating the rotation drive system No. 10 and simultaneously receiving the feedback of the position detection signal from the drive motor, the above-mentioned origin adjustment and setting tool 20 can be formed in a position corresponding to the origin of the rotating member 14 from the switch means 22 of the setting tool 20. When the electric signal that detects the origin position is received through the detection in paragraph 16, the origin calibration is completed by setting that point as the origin.

This type of origin calibration can be used not only during the manufacturing process of industrial robots, but also after the robot is installed at the site where the robot is used and the robot is in use. Afterwards, it is possible to carry out a replacement for each joint axis in order to restore the broken origin position. Therefore, even after the robot is stopped for parts replacement, the origin adjustment and setting calibration can be quickly completed and the robot can be restarted in a short time.

In the illustrated embodiment, a paragraph is formed on the rotating member side,
Although the configuration has been adopted in which the origin adjustment and setting tools are attached to the fixed member side, on the other hand, if it is desirable to attach the origin adjustment and setting tools to the rotating member side and form the paragraphs on the fixed member side. Even with such a configuration, the same effect as in the above embodiment can be expected.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the origin of the operating joint of an industrial robot, particularly an industrial articulated robot, can be adjusted and set automatically and in conjunction with a robot control device. A device for adjusting and setting the origin that can be easily set for each joint axis is provided, and the origin can be easily set even in a narrow space where the robot is used or in a restricted space environment where equipment is placed nearby. This makes it possible to maintain the robot's functions in the highest possible state at all times.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing a state in which the origin adjustment device for an industrial robot according to the present invention is attached to one joint of the robot, and Fig. 2 shows an example of a conventional robot origin adjustment and setting device. Cross-sectional view. O... Joint, 12... Fixed member, 14... Rotating member, 6... Paragraph, 16a... Standing wall surface, 16b...
Flat bottom surface, 6c... Right angle shoulder, 20... Origin adjustment, setting tool, 2... Switch means, 22a... Operating rod, 2
4...Switch holder, 26...Sliding rod, 26a...
・Edge, 8... Direct acting bearing.

Claims (1)

[Scope of Claims] 1. In an origin adjustment device for an industrial robot that adjusts and sets an origin between two relatively rotating members in a joint of an industrial robot, the peripheral surface of a first member of the two relative members A paragraph is formed at the position corresponding to the origin, and the relative 2
An origin adjusting device is removably fixed to a position corresponding to the origin of the second member in the member, and the origin adjusting device is attached to a switch holder fixed to the origin corresponding to the second member, and a switch holder fixed to the origin corresponding to the second member. A held switch means for transmitting an origin detection signal, one end of which is formed so as to be engageable with an on/off movable member of the switch means, and the first a sliding rod whose other end can slide and protrude into a paragraph formed at a position corresponding to the origin of the member; An origin adjustment device for an industrial robot, characterized in that the origin adjustment device for an industrial robot is configured to transmit an origin detection signal from a switch means in accordance with the sliding and protruding action of the robot. 2. The step formed in the first member is a step-shaped recess having a vertical wall surface that falls from the right-angled shoulder in a radial direction with respect to the center of rotation, and a flat bottom surface from which the other end of the sliding rod protrudes and collides. and the sliding rod is formed of a straight rod member whose other end side is edge-shaped, and is formed so that the origin can be detected only when the two members rotate in a certain direction. The origin adjustment device for industrial robots described in . 3. The direct-acting bearing has a boss portion that is substantially tightly fitted and fixed to a receiving hole formed in the second member, as set forth in claim 1. Origin adjustment device for industrial robots.