JPH07266210A - Brazed part grinding robot - Google Patents

Abstract

PURPOSE:To stabilize the grinding quantity so as to obtain the constant height of a brazed bead part by computing a predetermined height of a brazed bead part on the basis of the data from displacement sensors, and correcting a movement route of a hand unit. CONSTITUTION:Two displacement sensors 5, 6 are fitted to a robot hand unit 4. These displacement sensors 5, 6 respectively measure the distance to a work 1 and the distance to a brazed bead 1a. A robot control device 7 is provided with a computing circuit for computing the height of the brazed bead 1a from the work surface on the basis of the data output from the displacement sensors 5, 6, and corrects the moving speed of the robot hand unit 4 for control in response to the height so that the moving speed of the robot hand unit 4 is reduced, as the height of the brazed bead 1a is higher. Pushing force of a finish tool 3 to the brazed bead part 1a is thereby maintained constant, and the grinding is stabilized. Namely, grinding quantity can be stabilized in response to the pile of the brazed bead.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brazing robot for brazing. More specifically, the modification is made so that the moving path or the moving speed is changed in accordance with the position and the unevenness of the brazing bead.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, as a robot 04 for grinding a brazing bead 01a of a work (body) 01, a spring 02 is interposed between a tip of a wrist and a finishing tool 03. Is used.

The spring 02 freely expands and contracts in response to the unevenness of the brazing bead 01a and the variation of the position of the work, and the variation is absorbed without adjustment. Although the spring 02 is used in the above-described example, air (compressed air) may be used instead of the spring 02.

As another example, as shown in FIG. 3, a grinding means 06 is attached to a numerically controlled robot 05, and a surface position for detecting the surface position of a MIG welded portion on the surface of the workpiece with respect to the robot 05. Detection means 07,
A tool wear amount detecting means 08 for detecting the wear amount of the tool provided in the grinding means 06 is provided, and a surface position error is obtained from the detection value of the surface position detecting means 07 and predetermined surface position data. A control device 09 is provided for performing surface position correction corresponding to the surface position of the tool trajectory based on the detected value of the tool wear amount detection means 08. It is known (Japanese Patent Laid-Open No. 2-205472).

[0005]

In the above-mentioned prior art shown in FIG. 2, the force for pressing the finishing tool 03 changes depending on the position shift of the work 01 and the shape of the brazing bead 01a, and the cutting becomes unstable. . In addition, trial and error are required to select an appropriate spring (spring constant, pressing force), and there is a problem that selection takes a long time.

Further, even if the position accuracy of the work is the same for different vehicle types depending on variations, it is necessary to separately prepare a robot program even if the movements seem to be the same. The present invention has been made in view of the above-mentioned prior art, and automatically corrects the movement in accordance with the position of the work and how the brazing bead is built up to keep the height of the brazing bead constant. It is an object of the present invention to provide a brazing part grinding robot capable of stabilizing the amount of shaving.

[0007]

A structure relating to a brazing part grinding robot of the present invention which achieves such an object is a brazing process for cutting a brazing bead part of a work in which a plurality of members are joined by brazing. In the partial grinding robot, a hand unit that moves along a pre-teached path along the brazing bead, and a grinding tool that is provided on the hand unit and is rotationally driven to grind the brazing bead unit,
A first sensor provided in the hand part and located in front of the grinding tool in the moving direction of the hand part, for measuring the distance between the work surface near the brazing bead part and the hand part, and provided in the hand part. A second sensor located in the vicinity of the first sensor for measuring the position of the brazing bead portion formed on the work surface, and based on data output from both sensors connected to the first sensor and the second sensor And a robot control device for calculating an optimum movement path of the hand unit and correcting the movement path of the hand unit.

Further, the control circuit is connected to the first sensor and the second sensor and calculates the height of the brazing bead portion from the work surface based on the data output from both sensors, and the brazing is performed. The moving speed of the hand part may be corrected according to the height of the bead, and further, the optimum hand part is connected based on the data output from both sensors connected to the first sensor and the second sensor. Calculate the movement path and correct the movement path of the hand part, and also calculate the height from the work surface of the brazing bead part and correct the movement speed of the hand part according to the height of the brazing bead. Is also good. Further, the robot control device may control the moving speed of the hand part to be slower as the height of the brazing beat part becomes higher.

[0009]

The first sensor measures the distance to the work and the second sensor measures the distance to the brazing beat formed on the work, and the robot controller obtains the difference between the output values of the first and second sensors. And the height of the brazed bead is required.

The height of the brazing bead varies irregularly depending on how the bead is piled up, so that it varies irregularly. In the present invention, since the robot controller corrects the moving speed of the hand portion according to the height of the brazed bead detected, the force for pressing the grinding tool becomes constant and the cutting is stabilized.

Further, the first sensor measures the distance to the work and the second sensor measures the distance to the brazing beat formed on the work, and the robot controller determines the distances from the output values of the first and second sensors. To find the optimum travel route. Since the robot hand unit is controlled to move along the optimum movement path, it is possible to properly grind the brazed bead unit even if the work is displaced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 shows an embodiment of the present invention. As shown in the figure, the finishing tool 3 is attached to the robot hand portion 4, and two displacement (distance) sensors 5 and 6 are attached to the robot hand portion 4. The robot hand unit 4 is
The path is taught in advance so as to move along the brazing bead portion 1a formed on the surface of the work 1.

A plurality of members are joined to the work 1 by brazing, and a brazing bead 1a is formed on the surface thereof. The height of the brazing bead 1a varies irregularly due to unevenness of the bead, and is not constant. The finishing tool 3 has its moving speed adjusted by the robot hand unit 4, advances in the direction of the arrow in the drawing, and rotationally drives the brazing bead 1a formed on the surface of the work 1 for grinding.

The displacement sensors 5 and 6 are attached to the front of the finishing tool 3 in the traveling direction and measure the distances to the work 1 and the brazing bead 1a, respectively. That is, the displacement sensor 5 measures the position of the brazing bead portion formed on the work surface as indicated by the arrow in the figure, whereas the displacement sensor 6 measures the position of the brazing bead as indicated by the arrow in the figure. The distance between the work surface near the bead portion 1a and the robot hand portion 4 is measured. As the displacement sensors 5 and 6,
For example, a comparison sensor such as a laser sensor or a CCD sensor can be used. The displacement sensors 5 and 6 are connected to the robot controller 7 as shown in FIG. 4, and the output values thereof are input to the robot controller 7.

The robot control device 7 moves the robot hand portion 4 along the path taught in advance as described above, and grinds the brazing bead portion 1a with the finishing tool 3 attached to the robot hand portion 4. Is. The robot controller 7 is provided with an arithmetic circuit 8 which calculates the height of the brazing bead 1a from the work surface based on the data output from the displacement sensors 5 and 6.

Therefore, according to the height of the brazing bead 1a obtained by the arithmetic circuit 8, the robot controller 7 lowers the moving speed of the robot hand unit 4 as the height of the brazing bead 1a increases. Correct and control so that. In this way, when the moving speed of the robot hand unit 4 is corrected according to the height of the brazing bead 1a, the finishing tool 3 for the brazing beat 1a that changes irregularly
The pressing force of is constant and the shaving becomes stable. That is, in this embodiment, the movement can be automatically corrected and the amount of scraping can be stabilized in accordance with how the brazing beads are piled up.

As described above, in this embodiment, the two displacement sensors 5 and 6 are provided, the height of the brazing bead 1a is obtained, and the moving speed of the robot is corrected accordingly. The advantages are that the shaving is stabilized and the number of rework steps by the worker in the post process is reduced. Furthermore, if it is applied when finishing the same place of the same vehicle type, it will automatically determine the variation of the work between variations and respond accordingly, so there is no need to create a robot program for each variation as in the past, and teaching time It has the advantage of being short.

Although the robot controller 7 corrects the moving speed of the robot hand portion 4 according to the height of the brazing bead 1a in the above embodiment, the present invention is not limited to this. As shown in another embodiment shown in FIG. 5, the movement path of the robot hand unit 4 may be corrected. That is, as shown in FIG. 5, the robot control device 7 is provided with an arithmetic circuit 9 that calculates the optimum movement path of the robot hand unit 4 based on the data output from the displacement sensors 5 and 6.

The arithmetic circuit 9 compares the path data previously taught to the robot hand section 4 with the data of the position of the brazing bead 1a to obtain the position deviation of the work 1 and responds to this. Then, the optimum movement path that allows the robot hand unit 4 to appropriately follow is obtained. The robot control device 7 corrects the movement path according to the optimum movement path thus obtained, and controls the robot hand unit 4 to move.
Therefore, since the robot hand unit 4 moves along the optimum moving path, it is possible to accurately grind the brazing bead unit 1a even if the work 1 is displaced.

By providing a reference position on the work and detecting the position with a displacement sensor, it is possible to know in which direction and to what extent the work is deviated. Therefore, the movement of the robot is adjusted accordingly. By making a correction, it is possible to deal with the positional deviation of the work.

Further, as the robot control circuit 7, the optimum of the operation circuit 8 and the robot hand section 4 for calculating the height of the brazing bead 1a from the work surface based on the data output from the displacement sensors 5 and 6. It is also possible to provide an arithmetic circuit 9 for calculating the movement path so as to correct the movement speed of the hand portion in accordance with the height of the brazing bead 1a and the movement path of the robot hand portion 4. . ,

[0022]

As described above in detail with reference to the embodiments, the two displacement sensors are provided, the height of the brazing bead is obtained, and the tool is determined according to the height of the brazing bead. Since the moving speed of the robot is corrected so that the pressing force is constant, there is an advantage that the shaving is stabilized and the number of man-hours for rework in the post process is reduced. Further, since the optimum movement path is obtained based on the output values of the two displacement sensors, it is possible to grasp in which direction and to what extent the work is deviated, and correct the movement path of the robot accordingly, so that the brazing bead part Has the advantage that it can be stably cut to a constant height.

[Brief description of drawings]

FIG. 1 is a schematic view of a brazing part grinding robot according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a conventional technique.

FIG. 3 is an explanatory diagram showing another example of the conventional technique.

FIG. 4 is an explanatory diagram showing an example of a robot controller.

FIG. 5 is an explanatory diagram showing another example of the robot control circuit.

[Explanation of symbols]

 1 Work 1a Brazing bead 3 Finishing tool 4 Robot 5,6 Displacement (distance) sensor 7 Robot controller 8 Bead height calculation circuit 9 Optimal movement path calculation circuit

Claims (4)

[Claims] 1. A brazing part grinding robot for cutting a brazing bead part of a work, in which a plurality of members are joined by brazing, in a hand part that moves along a previously taught path along the brazing bead. A grinding tool which is provided in the hand portion and is driven to rotate to grind the brazing bead portion; and a grinding tool which is provided in the hand portion and is located in front of the grinding tool in the moving direction of the hand portion. A first sensor for measuring the distance between the work surface and the hand portion in the vicinity thereof, and a second sensor provided for the hand portion and positioned near the first sensor for measuring the position of the brazing bead portion formed on the work surface The brazing bead portion is ground to a predetermined height based on a sensor and data output from both the first sensor and the second sensor which are connected to each other. Braze grinding robot, characterized in that that was equipped with a correction allowed to robot controller the optimum travel route calculating the movement path of the hand portion of the hand portion. 2. A brazing part grinding robot for cutting a brazing bead part of a work, in which a plurality of members are joined by brazing, in a hand part which moves along a previously taught path along the brazing bead. A grinding tool which is provided in the hand portion and is driven to rotate to grind the brazing bead portion; and a grinding tool which is provided in the hand portion and is located in front of the grinding tool in the moving direction of the hand portion. A first sensor for measuring the distance between the work surface and the hand part in the vicinity, and a distance between the hand part and a brazing bead part formed on the work surface, which is provided in the hand part and located near the first sensor. Of the brazing bead portion based on the data output from both the second sensor that is connected to the first sensor and the second sensor. Braze grinding robot, characterized by comprising a robot controller allowed to correct the speed of movement of the hand unit in accordance with the height from over click surface to the height of the operation described above brazing bead. 3. A brazing part grinding robot for cutting a brazing bead part of a work, in which a plurality of members are joined by brazing, in a brazing part grinding robot, a hand part moving along a pre-taught path along the brazing bead. A grinding tool which is provided in the hand portion and is driven to rotate to grind the brazing bead portion; and a grinding tool which is provided in the hand portion and is located in front of the grinding tool in the moving direction of the hand portion. A first sensor for measuring the distance between the work surface and the hand portion in the vicinity thereof, and a second sensor provided for the hand portion and positioned near the first sensor for measuring the position of the brazing bead portion formed on the work surface The brazing bead portion is ground to a predetermined height based on a sensor and data output from both the first sensor and the second sensor which are connected to each other. The optimum movement path of the hand part is calculated to correct the movement path of the hand part, and the height of the brazing bead from the work surface is calculated to calculate the height of the hand part according to the height of the brazing bead. A brazing part grinding robot, comprising: a robot controller for correcting a moving speed. 4. The robot for grinding a brazed portion according to claim 2, wherein the robot controller lowers the moving speed of the hand portion as the height of the brazing beat portion increases.