JP7207349B2 - Grinding device and method - Google Patents

Description

The present invention relates to a grinding apparatus and method for grinding a material to be ground such as steel using a grinding wheel.

Grinding is performed to smoothen the surface of a steel plate or the like. In this grinding process, in principle, the grinding wheel wears away fine projections on the surface of the material to be ground. Conventionally, the grinding of a steel plate or the like has been performed by a worker manually pressing a small grinding device or putting his or her weight on it. Since the grinding wheel wears out as the grinding work progresses, the adjustment of the grinding depth relies on the experience and intuition of the operator, and is a heavy-duty task. In addition, since it is not possible to measure the grinding depth during grinding, it is possible to measure the grinding depth of the ground surface with a displacement gauge after grinding, or to measure the thickness of the steel material using an ultrasonic thickness gauge. It was

On the other hand, there has been proposed a grinder that automatically performs a grinding operation while measuring the grinding depth (see, for example, Patent Document 1). In Patent Document 1, grinding sparks are detected by a camera during grinding, the grinding amount (grinding depth) is estimated from the amount of grinding sparks generated, and the grinding belt is adjusted so that the amount of grinding sparks generated is within a set range. A method for controlling the amount of pressing of the is disclosed.

JP-A-7-164318

However, when grinding is controlled based on grinding sparks as in Patent Document 1, the amount of grinding sparks generated varies depending on the type of abrasive grains, the type of material to be ground, the grinding conditions, etc., so the grinding situation can be accurately determined. It is not possible to grasp and control the precise grinding operation.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a grinding apparatus and method capable of performing precise grinding of a material to be ground.

[1] A grinding unit comprising a grinding wheel for grinding a material to be ground, a rotation driving section for rotating the grinding wheel, and a pressing amount adjusting section for holding the grinding wheel and pressing the grinding wheel against the material to be ground. ,
an imaging device that captures an image of the grinding wheel grinding the steel material to obtain a grinding image;
an image processing device that detects the wear amount of the grinding wheel from the grinding image acquired by the imaging device;
an operation control device that controls the operation of the grinding unit based on the detected amount of wear of the grinding wheel;
Grinding device with
[2] In [1], the operation control device controls the pressing amount adjusting section of the grinding unit based on the amount of wear of the grinding wheel, and adjusts the pressing amount of the grinding wheel against the material to be ground. Grinding equipment as described.
[3] The imaging device acquires the grinding image of the entire grinding wheel being ground,
The image processing device has information on the reference diameter of the grinding wheel before grinding, extracts the periphery of the grinding wheel during grinding from the grinding image, and extracts the grinding wheel from the extracted periphery of the grinding wheel. is detected, and the wear amount is detected using the difference between the detected diameter of the grinding wheel and the reference diameter.
[4] The imaging device acquires the grinding image by imaging a part of the periphery of the grinding wheel being ground,
The image processing device has a reference grinding image of the grinding wheel before grinding, extracts a part of the periphery of the grinding wheel during grinding from the grinding image, and extracts the periphery of the grinding wheel and the The grinding device according to [1] or [2], wherein the wear amount is detected using a difference from the reference grinding image.
[5] A grinding wheel that grinds a material to be ground, a rotation drive part that rotates the grinding wheel, and a pressing amount adjusting part that holds the grinding wheel and presses the grinding wheel against the material to be ground. A grinding method for grinding a material to be ground using a grinding unit,
an acquisition step of acquiring a grinding image by imaging the grinding wheel grinding the material to be ground with an imaging device;
a detection step of detecting the wear amount of the grinding wheel from the acquired grinding image;
and a control step of controlling the operation of the grinding unit based on the detected wear amount of the grinding wheel.
[6] The control step according to [5], wherein the control step controls the pressing amount adjusting section of the grinding unit based on the amount of wear of the grinding wheel, and adjusts the pressing amount of the grinding wheel against the material to be ground. grinding method.
[7] The grinding image is acquired by imaging the entire grinding wheel during grinding,
When detecting the amount of wear, the periphery of the grinding wheel during grinding is extracted from the grinding image, the diameter of the grinding wheel is detected from the extracted periphery of the grinding wheel, and the detected diameter of the grinding wheel and the diameter before grinding are measured. The grinding method according to [5] or [6], wherein the amount of wear is detected using the difference between the reference diameter of the grinding wheel and the grinding wheel.
[8] The grinding image is acquired by imaging a part of the periphery of the grinding wheel being ground,
When detecting the wear amount, a part of the periphery of the grinding wheel being ground is extracted from the grinding image, and a difference between the extracted part of the periphery of the grinding wheel and a reference grinding image of the grinding wheel before grinding. The grinding method according to [5] or [6], wherein the amount of wear is detected using

According to the present invention, the wear amount of the grinding wheel is accurately detected from the grinding image acquired by the imaging device, and the operation of the grinding unit is controlled based on the wear amount, so that the material to be ground is precisely ground. be able to.

It is a schematic diagram showing a preferred embodiment of the grinding apparatus of the present invention. FIG. 2 is a schematic diagram showing an example of a grinding unit in FIG. 1; It is a schematic diagram which shows an example of the grinding image imaged by the imaging device. 8 is a schematic diagram showing another example of the grinding image P; FIG.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a preferred embodiment of the grinding apparatus of the present invention. The grinding apparatus 1 of FIG. 1 grinds a thick steel material as the material S to be ground, and acquires a grinding image P by imaging a grinding unit 10 for grinding the material S to be ground and a grinding state during grinding. An imaging device 20, an image processing device 30 for detecting the wear amount from the grinding image P, and an operation control device 40 for controlling the grinding unit 10 based on the wear amount ΔDW are provided. The material S to be ground is placed on a table (not shown) so as to be movable in the horizontal direction (arrow X direction and arrow Y direction) with respect to the grinding unit 10 . The material S to be ground and the grinding unit 10 may move relatively, and the grinding unit 10 may move horizontally with respect to the material S to be ground.

FIG. 2 is a schematic diagram showing an example of the grinding unit 10 in FIG. The grinding unit 10 shown in FIGS. 1 and 2 includes a grinding wheel 11 for grinding a material S to be ground, a rotation drive unit 13 for rotating the grinding wheel 11, and a pressing amount Hd of the grinding wheel 11 against the material S to be ground. A pressing amount adjusting unit 14 is provided. The grinding wheel 11 is, for example, disc-shaped and has a shaft 12 fixed at its center. As for the shape of the grinding wheel 11, a well-known technology such as a cup shape can be applied in addition to the disk shape. The shaft 12 is connected to a rotation drive unit 13 such as a motor, and the rotation drive unit 13 rotates the grinding wheel 11 via the shaft 12 . Then, the outer peripheral side surface of the grinding wheel 11 is pressed against the material S to be ground while rotating, whereby the material S to be ground is ground. The operation of the rotation driving section 13 is controlled by an operation control device 40 .

The pressing amount adjustment unit 14 is composed of, for example, a direct-acting cylinder, and holds the grinding wheel 11 and the rotation driving unit 13 so as to be movable in the vertical direction (direction of arrow Z). By adjusting the stroke amount of the pressing amount adjusting unit 14, the pressing amount Hd of the grinding wheel 11 against the material S to be ground is adjusted. That is, since the pressing amount Hd becomes the grinding depth, the grinding depth is adjusted by adjusting the pressing amount. The operation of the pressing amount adjustment unit 14 is controlled by the operation control device 40 . Note that the pressing amount adjustment unit 14 is not limited to a direct-acting cylinder as long as it can adjust the distance between the grinding wheel 11 and the material S to be ground, and a known technique can be applied. 1 and 2 exemplify the case where the pressing amount adjusting unit 14 moves the grinding wheel 11 side, but it is also possible to move the material S side to be ground.

The imaging device 20 in FIG. 1 is composed of, for example, a high-speed camera capable of imaging at 1000 frames/second, and images the grinding wheel 11 during grinding on-line to acquire grinding images P sequentially. Here, the imaging device 20 images the grinding wheel 11 so that the grinding image P includes the periphery of the grinding wheel 11 during grinding. FIG. 3 is a schematic diagram showing an example of the grinding image P captured by the imaging device 20. As shown in FIG. The grinding image P in FIG. 3 is obtained when the imaging device 20 is installed, for example, right beside the grinding wheel 11 and captures an image of the entire grinding wheel 11 .

The image processing device 30 in FIG. 1 is composed of, for example, a computer, and detects the wear amount ΔDW of the grinding wheel 11 by image processing based on the grinding image P. As shown in FIG. The image processing device 30 stores the reference diameter DW0 of the grinding wheel 11 before grinding (dotted line portion in FIG. 3). Then, when the grinding image P is acquired during grinding, the image processing device 30 extracts the edge of the grinding wheel 11 from the grinding image P, and uses the extracted peripheral edge portion to determine the diameter DW of the grinding wheel 11. To detect. After that, the image processing device 30 detects the wear amount ΔDW (=(DW0−DW)/2) based on the difference between the reference diameter DW0 and the diameter DW. Further, the image processing device 30 detects the diameter DW each time the grinding image P is acquired by the imaging device 20 .

Although the image processing device 30 detects the wear amount ΔDW after detecting the diameter DW, any method can be used as long as the wear amount ΔDW can be detected. FIG. 4 is a schematic diagram showing another example of the grinding image P. As shown in FIG. A grinding image P in FIG. 4 is an image of part of the peripheral edge of the grinding wheel 11 . The image processing device 30 stores a reference grinding image obtained by imaging a part of the periphery of the grinding wheel 11 before grinding (dotted line portion in FIG. 4), and the difference between the reference grinding image and the grinding image P during grinding. The amount of wear ΔDW may be directly detected based on.

The operation control device 40 of FIG. 1 controls the operation of the grinding unit 10 based on the wear amount ΔDW detected by the image processing device 30 . The image processing device 30 and the operation control device 40 may be configured by separate computers, or may be configured by the same computer. In particular, the motion control device 40 has a function of controlling the pressing amount Hd of the grinding wheel 11 against the material S to be ground based on the wear amount ΔDW detected by the image processing device 30 .

The motion control device 40 stores in advance a reference pressing amount Hd0 that is set with reference to the unworn grinding wheel 11 before grinding. The setting of the reference pressing amount Hd0 can be changed according to the grinding depth of the material S to be ground, the size of the grinding wheel 11, or the like. The motion control device 40 determines the pressing amount Hd during grinding using the wear amount ΔDW as shown in the following equation (1). Then, the operation control device 40 controls the operation of the pressing amount adjusting section 14 so that the grinding wheel 11 is pressed against the material S to be ground by the determined target pressing amount Hd.

Hd=Hd0+ΔDW (1)

Next, a preferred embodiment of the grinding method of the present invention will be described with reference to FIGS. 1 to 4. FIG. First, the reference pressing amount Hd0 is set in the operation control device 40, and the reference diameter DW0 before grinding or the reference grinding image is stored in the image processing device 30. FIG. Then, the rotation driving section 13 and the pressing amount adjusting section 14 are operated under the control of the operation control device 40, and the grinding of the material S to be ground is started. While the material S to be ground is being ground, the grinding wheel 11 is imaged by the imaging device 20, and the grinding image P is acquired at, for example, 1000 frames/second (acquisition step, see FIGS. 3 and 4).

In the image processing device 30, the wear amount ΔDW of the grinding wheel 11 is detected from the grinding images P that are sequentially acquired (detection step). After that, the target pressing amount Hd is calculated by the operation control device 40 based on the above equation (1), and the operation of the pressing amount adjusting section 14 is controlled based on the calculated target pressing amount Hd (control step). The control of the target pressing amount Hd described above is performed in real time each time the grinding image P is acquired during grinding.

According to the above embodiment, the wear amount ΔDW is directly detected from the grinding image P acquired by the imaging device 20, and the operation control device 40 controls the operation of the grinding unit 10 based on the wear amount ΔDW. As a result, the wear amount ΔDW can be accurately detected, and the search conditions can be adjusted in real time according to changes in the wear amount ΔDW during grinding. Material S can be ground. In particular, by controlling the target pressing amount Hd of the grinding wheel 11 based on the wear amount ΔDW of the grinding wheel 11 detected by the image processing device 30, the grinding depth can be precisely controlled.

That is, in the conventional technology, the grinding depth is measured by measuring the ground surface with some kind of displacement gauge after grinding, or by measuring the steel material itself using an ultrasonic thickness gauge. cannot be measured. Therefore, even when grinding is performed automatically, the pressing amount of the grinding wheel 11 is set to a predetermined fixed value without considering the amount of wear. However, since the diameter of the grinding wheel 11 decreases due to wear during grinding, if the grinding wheel diameter is fixed, the set grinding depth may not be obtained (uncut portion). In addition, when the grinding depth is detected from the amount of spark generation, the grinding state cannot be accurately grasped, and precise control of the grinding work cannot be performed. On the other hand, according to the grinding apparatus 1 of FIGS. 1 and 2, the wear amount ΔDW can be directly and accurately detected from the grinding image P acquired by the imaging device 20, so that precise control of the grinding operation can be performed. can.

A grinding wheel 11 having a diameter of 200 mm and a width of 75 mm was used, and a 60 kg steel was ground as a material S to be ground to a target grinding depth of 150 μm. Further, the grinding image P was acquired at 1000 frames per second by the imaging device 20 . Further, the wear amount ΔDW was detected after the diameter DW of the grinding wheel 11 was calculated by the process of extracting the edge of the outer periphery of the grinding wheel 11 in the image processing device 30 .

First, when grinding is performed with a fixed value without adjusting the target pressing amount Hd based on the wear amount ΔDW as in the conventional art, the target grinding depth is 150 μm, whereas the actual grinding depth is 150 μm. The average was 140 μm. This is because the amount of pressing of the grinding wheel 11 was set at 150 μm from the surface of the material S to be ground and was fixed (unchanged). This is because it was not possible to perform a minute cutting, resulting in an uncut portion.

On the other hand, grinding was performed while performing control to change the target pressing amount Hd based on the wear amount ΔDW detected using the grinding image P using the grinding apparatus 1 of FIG. 1 . As a result, the average grinding depth was 150 μm, which is the target grinding depth. The maximum pressing amount of the grinding wheel 11 was 160 μm. In this way, since the wear amount ΔDW detected from the grinding image P can be accurately detected, the grinding work can be precisely controlled.

Embodiments of the present invention are not limited to the above embodiments, and various modifications can be made. For example, in the above-described embodiment, the case where the material S to be ground is a thick steel material is exemplified. good too. In addition, FIG. 1 illustrates the case of performing so-called surface grinding, but it can also be applied to known grinding processes such as cylindrical grinding, inner surface grinding, thread grinding, and gear grinding.

Furthermore, in the above-described embodiment, as an example of the operation control of the grinding unit 10 based on the wear amount ΔDW, the case of controlling the target pressing amount Hd of the grinding wheel 11 is illustrated, but the present invention is not limited to this. Any device that controls the operation of the grinding unit 10 may be used. For example, the grinding wheel 11 may be unevenly worn during grinding. Therefore, the image processing device 30 detects the roundness of the grinding wheel 11 based on the grinding image P, and stops the grinding unit 10 when the detected roundness exceeds the set allowable range. and output a warning to the effect that truing is necessary.

Alternatively, the image processing device 30 has a function of detecting the grinding wheel peripheral speed of the grinding wheel 11 using characters such as the type of abrasive grains attached to the side surface of the grinding wheel 11 as identifiers along with the above-described wear amount ΔDW. may Then, the operation control device 40 may control the operation of the rotation driving section 13 so that the detected grindstone peripheral speed becomes the set grindstone peripheral speed.

1 Grinding device 10 Grinding unit 11 Grinding wheel 12 Shaft 13 Rotational drive unit 14 Pressing amount adjustment unit 20 Imaging device 30 Image processing device 40 Operation control device DW Diameter DW0 Reference diameter Hd0 Reference pressing amount Hd Target pressing amount P Grinding image S Grinding object Material ΔDW Wear amount

Claims (8)

A grinding unit comprising: a grinding wheel for grinding a material to be ground; a rotation drive section for rotating the grinding wheel; and a pressing amount adjusting section for holding the grinding wheel and pressing the grinding wheel against the material to be ground;
an imaging device for capturing a grinding image by imaging the grinding wheel grinding the material to be ground;
an image processing device that detects the wear amount of the grinding wheel and the roundness of the grinding wheel from the grinding image acquired by the imaging device;
an operation control device that controls the operation of the grinding unit based on the detected wear amount and roundness of the grinding wheel;
Grinding device with 2. The grinding apparatus according to claim 1, wherein the operation control device controls the pressing amount adjusting section of the grinding unit based on the wear amount of the grinding wheel to adjust the pressing amount of the grinding wheel against the material to be ground. . The imaging device acquires the grinding image obtained by imaging the entire grinding wheel during grinding,
The image processing device has information on the reference diameter of the grinding wheel before grinding, extracts the periphery of the grinding wheel during grinding from the grinding image, and extracts the grinding wheel from the extracted periphery of the grinding wheel. 3. The grinding apparatus according to claim 1, wherein the diameter of the grinding wheel is detected, and the amount of wear is detected using the difference between the detected diameter of the grinding wheel and the reference diameter. The imaging device acquires the grinding image by imaging a part of the peripheral edge of the grinding wheel being ground,
The image processing device has a reference grinding image of the grinding wheel before grinding, extracts a part of the periphery of the grinding wheel during grinding from the grinding image, and extracts the periphery of the grinding wheel and the 3. The grinding apparatus according to claim 1, wherein the amount of wear is detected using a difference from the reference grinding image. A grinding unit comprising: a grinding wheel for grinding a material to be ground; a rotation drive section for rotating the grinding wheel; and a pressing amount adjusting section for holding the grinding wheel and for pressing the grinding wheel against the material to be ground. A grinding method for grinding a material to be ground using
an acquisition step of acquiring a grinding image by imaging the grinding wheel grinding the material to be ground with an imaging device;
a detection step of detecting the wear amount of the grinding wheel and the roundness of the grinding wheel from the acquired grinding image;
and a control step of controlling the operation of the grinding unit based on the detected wear amount and roundness of the grinding wheel. 6. The grinding method according to claim 5, wherein the control step controls the pressing amount adjusting section of the grinding unit based on the wear amount of the grinding wheel to adjust the pressing amount of the grinding wheel against the material to be ground. The grinding image is acquired by imaging the entire grinding wheel during grinding,
When detecting the amount of wear, the periphery of the grinding wheel during grinding is extracted from the grinding image, the diameter of the grinding wheel is detected from the extracted periphery of the grinding wheel, and the detected diameter of the grinding wheel and the diameter before grinding are measured. 7. The grinding method according to claim 5 or 6, wherein the amount of wear is detected by using the difference between the reference diameter of the grinding wheel and the diameter of the grinding wheel. The grinding image is acquired by imaging a part of the periphery of the grinding wheel being ground,
When detecting the wear amount, a part of the periphery of the grinding wheel being ground is extracted from the grinding image, and a difference between the extracted part of the periphery of the grinding wheel and a reference grinding image of the grinding wheel before grinding. The grinding method according to claim 5 or 6, wherein the amount of wear is detected using

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