JPH0763925B2 - Chip adhesion monitoring device for cutting machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a chip adhesion monitoring device for a cutting machine such as a planing machine that monitors chips (also referred to as chips) attached to a cutting tool. is there.

[Prior Art] FIG. 5 is a front view showing a conventional cutting machine such as a planing machine. In the figure, 1 is a cutting machine, 2 is a pair of cutting tools provided on the cutting machine 1 so as to be vertically movable, 3 is a bed movably provided on the cutting machine 1, and 4 is an object to be cut placed on the bed 3.

Next, the operation will be described. First, with the bed 3 moved to a position where the cutting tool 2 does not contact the work 4,
The cutting tool 2 is lowered according to the cutting amount. Next, when the bed 3 is moved toward the cutting tool 2, the work 4 is cut by the cutting tool 2.
And the bed 3 continues to move as it is, so that the surface of the workpiece 4 is cut at a depth determined by the cutting tool 2. When the cutting stroke of a predetermined length is completed, the cutting tool 2 is lifted and the bed 3 enters the return stroke, and moves in the opposite direction to return to the original position.
Next, after the bite 2 is lowered again and positioning is performed,
The cutting stroke is entered again and cutting is performed.

[Problems to be Solved by the Invention]

Since the conventional cutting machine is configured as described above, cutting chips may adhere to the cutting tool or become entangled during the cutting stroke. May damage the machined surface of the work to be cut, which requires the operator to constantly monitor the cutting tool to remove chips, which may cause the operator to leave the cutting machine during machining. there were.

The present invention has been made to solve the above problems, and a chip adhesion monitoring device for a cutting machine capable of automatically monitoring the adhesion of chips and stopping the cutting machine in the case of the adhesion of chips. The purpose is to get.

[Means for Solving the Problems]

A chip adhesion monitoring device of a cutting machine according to the present invention has a camera for detecting chips adhering to a cutting tool, and an image processing circuit judges adhering of chips based on a video signal of the cutting tool. Data indicating whether or not to shift to a stroke is output to the control circuit, and the control circuit controls the next cutting operation of the cutting machine.

[Action]

In the chip adhesion monitoring device of the cutting machine according to the present invention, the next cutting operation is stopped by the control circuit when the adhesion of the chips is determined by the image processing circuit.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings. First
In the figure, the same parts as those in FIG. 5 is a camera including a solid-state image sensor for detecting chips adhering to the cutting tool 2, 6 is an image processing circuit for processing a video signal obtained from the camera 5, and 7 is chip adhering determination data from the image processing circuit 6. Is a control circuit for receiving the control signal and controlling the cutting machine 1 accordingly.

Next, the operation will be described. In FIG. 2, the cutting stroke indicates a period during which the bed 3 is moving in the cutting direction for the cutting tool 2 to cut the workpiece 4. The return stroke indicates a period in which the bed 3 moves in the opposite direction after the cutting stroke is completed. The bite rise is a period for lifting the bite 2 and dodging the workpiece 4 immediately before entering the return stroke. Just before the cutting stroke enters the cutting stroke,
This is a period in which the cutting tool 2 is lowered by the cutting amount. Chip detection starts from the time when the cutting tool 2 is set to the cutting position.
It is necessary to perform the operation in a period in which the stop time of the bed 3 (the time required to change the direction from the return stroke to the cutting stroke) is subtracted from the time until the contact with the workpiece 4. When the image processing circuit 6 receives the data indicating that the cutting tool 2 is in the cutting position from the control circuit 7, the image signal from the camera 5 is changed to 0.5.
After processing within seconds, the control circuit 7 is transmitted with data indicating the result of determination as to whether or not chips have adhered to the cutting tool 2 during the previous cutting stroke. The control circuit 7 stops the next cutting operation of the cutting machine 1 and issues an alarm when the determination result shows that the chips are attached.

Next, an image processing method in the image processing circuit 6 will be described. First, as shown in FIG. 3, a difference image is obtained by the difference between a normal reference image with no chips attached and an abnormal image with the chips 8 obtained from the camera 5. In this difference image, only the chips 8 appear as shown in the figure.

Next, as shown in FIG. 4, a density distribution histogram for the entire difference image is created. The example of FIG. 4 shows the case of 256 gradations, and the peaks that concentrate on zero and the peaks that concentrate on the density T _{1 of the} cutting chips 8 appear with the density of Ts as a boundary. When the cutting chips 8 are not attached to the cutting tool 2, the image from the camera 5 is a normal image, so that the density distribution histogram of the difference image concentrates only on zero.

Next, each pixel data forming the difference image is binarized using the value of Ts as a threshold value, and then the number of pixels exceeding the threshold value Ts is counted. If this count value exceeds a predetermined set value, it is determined whether chips are attached.

Since the back light of the bite 2 for a day changes, an error occurs in the detection by the camera 5. Therefore, it is advisable to obtain a difference image from the image obtained by the camera 5 using the normal image one stroke before as the reference image. If so, the above error can be reduced.

〔The invention's effect〕

As described above, according to the present invention, the adhesion of chips is determined based on the density distribution histogram in the difference image due to the difference between the image of the current cutting operation and the image of the previous normal cutting operation, and the determination result is determined. Since it is configured to control the next cutting operation by the bite accordingly, if chips are attached, that is, if there are chips in the difference image, it is possible to easily determine because there are non-zero peaks in the density distribution histogram,
Further, since it is determined from the difference image of the previous time and the difference image of this time, it is not affected by the change in the back light, and further, it is possible to unmanned the adherence monitoring of the chips and it is possible to eliminate the damage of the object to be cut by the chips.

[Brief description of drawings]

FIG. 1 is a front view showing a chip adhesion monitoring device of a cutting machine according to an embodiment of the present invention, FIG. 2 is a timing chart of chip adhesion monitoring operation, and FIG. 3 is an image for explaining image processing of the device. Is a front view of FIG. 4, FIG. 4 is a density distribution histogram for explaining the image processing of the apparatus, and FIG. 5 is a front view of a conventional cutting machine. 1 is a cutting machine, 2 is a cutting tool, 4 is an object to be cut, 5 is a camera, 6 is an image processing circuit, and 7 is a control circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A camera for photographing a bite for cutting an object to be cut after completion of a cutting operation, and a difference image due to a difference between an image of a current cutting operation obtained from the camera and an image of a previous normal cutting operation. A cutting machine provided with an image processing circuit for judging the adhesion of chips to the cutting tool based on the density distribution histogram in FIG. 9 and a control circuit for controlling the next cutting operation by the cutting tool according to the judgment result of the image processing circuit. Adhesion monitoring device for chips.