JPS643639Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a grinding device that automatically deburrs, for example, a casting.

<Conventional technology> When producing cast iron products, it is necessary to remove the thin fin-like cast burrs that are formed when hot water flows into the joints of the castings, as well as the bulges that are inevitably formed due to gas venting in the mold. is necessary. When mass producing the same type of cast iron products, such deburring work has conventionally been carried out by automatic grinding using a robot in order to improve work efficiency. In other words, the grinding tool is installed on a robot arm of the so-called teaching playback type, which automatically repeats the procedure once operated by the operator, and the grinding tool is moved to follow the burr of the casting product by the operation of the robot arm. Remove this burr by grinding. However, due to the nature of casting, there is a limit to product accuracy, and dimensional errors occur between cast products, so no matter how high-precision positioning equipment is used to position and hold the workpiece, casting products,
Errors in burr position occur between individual products. For this reason, when grinding using the teaching playback method described above, errors may occur between the movement path of the grinding tool based on teaching and the actual burr position, resulting in reduced work efficiency due to product defects and rework. had occurred.

Therefore, in order to deal with the above-mentioned problems, measures as shown in FIGS. 4 to 6 have conventionally been taken. This means irradiates a burr 2 protruding from a cast product 1 with light from a light source 3 diagonally above,
It uses the principle that the boundary between the dark area caused by the shadow on one side of the burr 2 and the bright area on the other side of the burr 2, that is, the position of the burr 2, is detected by the upper image sensor 4, and the light source 3 and the image sensor 4 grinding tool 5
It is also installed on a teaching playback type robot arm (not shown), and before grinding, the robot arm is operated based on the taught data, and the actual position of the burr 2 detected by the image sensor 4 and the robot arm are displayed. After correcting the deviation from the teaching data,
Based on this correction data, the robot arm is operated again and the burr 2 is ground away by the grinding tool 5.

<Problems to be solved by the invention> While the above countermeasures can improve the positional accuracy of grinding, it is necessary to use a robot arm to correct data for each workpiece before grinding. Because it has to be activated,
There was a problem in that the working time was increased by this amount, resulting in a significant drop in working efficiency. Also,
Because the image sensor measures the front side of the grinding point in the direction of travel, two-dimensional position correction is required, and the image sensor gets in the way, making it impossible to grind in some places.

The present invention was devised to effectively solve the above-mentioned problems, and an object of the present invention is to provide an automatic grinding device that realizes highly accurate and efficient grinding work.

<Means/effects for solving the problem> In the present invention, the grinding tool is made movable along the part to be ground and also movable in a direction intersecting the part to be ground, and At the bottom, an image sensor is installed integrally with the grinding tool in the grinding tool support section, and within the field of view of the image sensor, the boundary position between light and dark caused by sparks during grinding by the grinding tool is detected, and this boundary position is detected by the grinding tool. The position of the grinding tool is controlled so that it matches the boundary position between light and dark that should occur in the field of view when grinding is performed by following the center line of the grinding part, and the direction of movement of the grinding tool is taught in advance. The grinding work is performed while correcting the data that has been provided, so that the part to be ground can be ground with high precision and efficiency.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. Figure 1 is a side view of the automatic grinding device of this embodiment, Figures 2a and b are front and side views of the tip of the robot arm, respectively, and Figure 3 is a view of the grinding tool seen from the rear in the direction of movement. It is an action explanatory diagram.

As shown in the figure, the automatic grinding device is constructed by providing a grinding tool 11 and an image sensor 12 at the tip of a teaching playback type multi-joint robot arm 10, and the grinding tool 11 and the image sensor 12 are connected to lead wires, respectively. It is connected to the control device 10a of the robot arm 10 via 13 and 14.

The image sensor 12 is located at the lower part of the rear side in the traveling direction of the grinding wheel 11a provided in the grinding tool 11, and when grinding the burr 16 of the cast product 15 with the tip of the grinding wheel 11a, The scattered sparks 17 are in the field of view 12a of the image sensor 12.
It's starting to go inward. The field of view 12a is a collection of many pixels, and the image sensor 1
2 shows the generation state of the spark 17 in the field of view 1 due to the spark 17.
It is detected as the boundary position between light and dark within 2a. The control device 1 connected to the image sensor 12
The state of spark generation when grinding is performed with the tip of the grindstone 11a positioned on the center line of the burr 16 is input in advance to 0a, and the state of spark generation is actually detected by the image sensor 12. The operation of the robot arm 10 based on the teaching is corrected so that the spark generation conditions are the same. For example, if the state in which ideal grinding is performed as described above is set in advance as a state in which the boundary between brightness and darkness caused by the sparks 17 is in the center of the field of view 12a, the actual sparks 17 detected by the image sensor 12
The robot arm 10 is controlled to correct the grinding position by the grindstone 11a of the grinding tool 11 so that the boundary between bright and dark is located at the center of the field of view 12a.

Therefore, the robot arm 10 operates based on the data taught in advance and grinds the grinding tool 1.
When grinding and removing the burr 16 while following it with the grinding wheel 11a of the robot arm 1, according to the above configuration, the robot arm 1
The operation of the grinding wheel 1 of the grinding tool 11 is corrected and controlled.
Since the burr 1a is held in a state where it accurately captures the center of the burr 16 and grinds it, even if there is an error between the actual position of the burr 16 and the teaching to the robot arm 10, the grinding tool 11 is always The grindstone 11a follows the center of the burr 16 to automatically perform efficient grinding work.

In the above embodiment, the present invention was applied to deburring a cast product, but the present invention is of course not limited to this and can be applied to grinding work of various parts to be ground. Further, an image sensor capable of two-dimensional detection may be used, and in this way, the contact state between the grindstone and the burr can also be controlled by the component of the spark in the direction in which the burr projects.

<Effect of invention> According to the present invention, the following effects are achieved.

When teaching the grinding path, even if there is a slight error, the image sensor measures the error and automatically corrects it using the control device, which simplifies the teaching work and also automatically corrects dimensional errors between workpieces. Grinding work can be performed with high precision without performing teaching data correction work that reduces grinding work efficiency, such as redoing teaching for each workpiece.

Even if there is an error in the positioning accuracy of the workpiece, the grinding tool always follows the part to be ground, so the workpiece positioning device can be made simple and inexpensive.

Compared to conventional correction means using shadows (see Figures 4 to 6), a light source is not required and the image sensor is located on the rear side in the direction of movement, so the tip of the robot arm can be made smaller and the device can be placed more easily on the workpiece. It is possible to reduce the dead space that interferes with parts other than the grinding part and makes grinding impossible.

[Brief explanation of the drawing]

1 to 3 relate to an embodiment of the present invention, in which FIG. 1 is a side view of an automatic grinding device, FIGS. 2a and 2b are a front view and a side view of the tip of a robot arm, respectively.
Fig. 3 is an explanatory diagram of the operation of the grinding tool viewed from the lower rear side in the direction of movement, Figs. 4 to 6 relate to conventional correction means, Fig. 4 is a principle diagram of the means, and Fig. 5 is A conceptual diagram showing the shadow caused by the burr, and FIGS. 6a and 6b are a front view and a side view, respectively, of the tip of the robot arm. In the drawing, 10 is a robot arm, 10a is a control device, 11 is a grinding tool, 12 is an image sensor,
12a is a field of view, 15 is a cast product, 16 is a burr, 1
7 is a spark.

Claims (1)

[Scope of utility model registration request] The grinding tool is movable along the part to be ground of the workpiece, and is also movable in a direction intersecting the part to be ground, and the part to be ground is viewed during grinding, and the boundary position of light and darkness that occurs in the field of view due to sparks during grinding. An image sensor is provided integrally with the support part of the grinding tool on the rear side of the grinding tool to detect the bright and dark boundary that should occur in the field of view when the grinding tool is grinding on the center line of the part to be ground. An automatic grinding device characterized in that it is equipped with a control device whose position is inputted in advance and which controls the position of the grinding tool so that the boundary position detected by the image sensor coincides with the boundary position.