JP2021133454A - Work surface roughness predicting method by rotary cutting tool processing and surface roughness predicting device - Google Patents

Abstract

To predict a surface roughness of a work surface to be processed by an abrasive surface of a rotary grinding wheel.SOLUTION: A work surface roughness predicting method includes the steps of: installing a camera 23 for imaging the whole circumference of an abrasive surface 14a of a rotary grinding wheel 14 in a grinder while the rotary grinding wheel 14 rotates; storing captured image data in a storage part of a control device; compressing the stored image data in a work feeding direction in accordance with a relationship between a length of the abrasive surface 14a in a circumferential direction and a feed rate of a work 100; and predicting a surface roughness of a surface to be processed of the work 100 on the basis of the compressed image data.SELECTED DRAWING: Figure 1

Description

The present invention relates to a surface roughness prediction method and a surface roughness prediction device for predicting the surface roughness of a workpiece to be machined by the cutting surface of a rotary cutting tool such as a rotary grindstone after machining. ..

Patent Document 1, Patent Document 2 and Patent Document 3 disclose a technique for photographing the abrasive surface of a rotary grindstone in order to confirm the state of the abrasive surface.

Japanese Unexamined Patent Publication No. 2004-42158 Japanese Unexamined Patent Publication No. 2004-45078 Japanese Unexamined Patent Publication No. 2013-2810

For example, on the grindstone surface of a rotary grindstone, changes such as wear and drop of abrasive grains and adhesion / accumulation of foreign matter (chips, etc.) appear on the grindstone surface as the work is processed. When such a change appears, the surface roughness of the work surface to be processed after processing is lowered. For this purpose, a method of inspecting the state of the abrasive surface by photographing the abrasive surface can be considered. However, in the above-mentioned Patent Document 1, Patent Document 2 and Patent Document 3, the surface roughness of the surface to be processed after processing is determined. It is difficult to predict.

An object of the present invention is to provide a surface roughness prediction method and a sharpness prediction device capable of predicting the surface roughness of the work surface to be machined after processing prior to the work processing.

In order to achieve the above object, in the surface roughness prediction method of the present invention, the entire circumference of the cutting surface of the rotary cutting tool is photographed during the rotation of the rotary cutting tool, and the image data is taken as the cutting surface of the image data. It is characterized in that the surface roughness of the work surface of the work is predicted by compressing in the work feed direction according to the relationship between the length in the circumferential direction and the feed amount of the work.

Further, in the surface roughness predicting device of the present invention, a photographing means for photographing the entire circumference of the cutting surface of the rotating cutting tool while the rotating cutting tool is rotating, a storage means for storing the photographed image data, and a storage method. A compression means that compresses the generated image data in the work feed direction according to the relationship between the length of the image data in the circumferential direction of the cutting surface and the work feed amount, and the surface roughness of the work surface of the work based on the compressed image data. It is characterized by having a prediction means for predicting the degree.

Therefore, in the present invention, for example, the entire circumference of the cutting surface of the rotary cutting tool is photographed during the rotation of the rotary cutting tool. Then, the captured image data is compressed in the work feed direction according to the relationship between the length in the circumferential direction of the cutting surface and the feed amount of the work, and based on the compressed image data, the surface roughness of the work surface of the work is roughened. The degree is predicted. Therefore, since the surface roughness of the work is predicted before the work is machined, it becomes unnecessary to perform test machining before machining the work, measurement after the test machining, or measurement after machining the actual work. Work can be executed efficiently.

According to the present invention, since the surface roughness of the surface to be machined of the work can be predicted prior to the work machining, the test machining before the work machining becomes unnecessary, and the machining work can be efficiently executed. ..

The front view which shows the cutting part by a rotary grindstone. Sectional drawing which shows the photographing apparatus. The simplified figure which shows the allocation pitch of the grindstone of a rotary grindstone. A block diagram showing an electrical configuration of an inspection device. A flowchart showing the operation of surface roughness measurement of a machined workpiece. The flowchart which shows the operation of the surface roughness prediction of a work by processing of a rotary grindstone. The schematic diagram which shows the relationship between the image data and the feed amount of a work.

(Embodiment)
Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. This embodiment is embodied in a cutting machine in which a rotary cutting tool is a rotary grindstone.

As shown in FIG. 1, the cutting machine of the embodiment includes a table 12 movably supported on the bed 11 in the X-axis direction (left-right direction) indicated by the arrow P. The movement of the table 12 in the X-axis direction is driven by a table movement motor (not shown). The work 100 is installed on the upper surface of the table 12. Therefore, the work 100 is machined and fed in the arrow P direction, which is the X-axis direction.

A grindstone shaft 13 is supported on the bed 11 so as to be able to move up and down (Y-axis direction) on a column (not shown) that is moved in the front-rear direction (Z-axis direction). The grindstone shaft 13 is driven up and down by a grindstone feed motor (not shown). A rotary grindstone 14 as a rotary cutting tool is supported on the grindstone shaft 13, and the rotary grindstone 14 is rotationally driven in one direction by the grindstone rotary motor 15 shown in FIG. The rotation speed of the rotary grindstone 14 is, for example, 1800 rotations or 3600 rotations per minute, and the rotation speed is arbitrarily set.

The outer peripheral surface of the rotary grindstone 14 is the grindstone surface 14a as a cutting surface. When the rotary grindstone 14 is rotated, the upper surface of the work 100 is cut by the grindstone surface 14a. The surface to be cut is defined as the surface to be machined.

As shown in FIGS. 1 and 2, a photographing device 21 as an imaging means is installed at a lateral position of the rotary grindstone 14. The photographing device 21 is moved up and down (movement in the Y-axis direction) and back-and-forth movement (movement in the Z-axis direction) integrally with the rotary grindstone 14. The imaging device 21 has a light path 22, which path 22 has a first path 22a and a second path 22b that intersects the first path 22a. A camera 23 having a CCD (solid-state image sensor) is provided at the end of the second path 22b.

At the lateral position of the rotary grindstone 14, a measuring device 50 is arranged as a measuring means for measuring the surface roughness of the surface to be machined, which is the cut surface of the work 100, and outputting the measurement data. The measuring device 50 is moved in the Z-axis direction and the Y-axis direction together with the rotary grindstone 14.

A reflective light transmitting member 24 having a light reflecting function such as a prism and a light transmitting function is arranged between the first path 22a and the second path 22b. A first lamp 25 is provided at the end of the first path 22a. The first lamp 25 irradiates light having a wavelength in a specific region, and in the present embodiment, the first lamp 25 irradiates light having a wavelength that makes the abrasive grains 14b on the abrasive surface 14a stand out.

An illumination dome 26 is arranged at a position between the reflective light transmitting member 24 and the abrasive surface 14a on the second path 22b. The illumination dome 26 is formed with an opening 27 for the second path 22b. A plurality of second lamps 28 for surface-illuminating the front of the illumination dome 26 are provided on the inner surface of the illumination dome 26. The second lamp 28 is designed to irradiate light having a wavelength in a specific region, and in the present embodiment, it irradiates light having a wavelength that makes the abrasive surface 14a stand out.

Then, the beam-shaped light from the first lamp 25 is reflected by the reflective light transmitting member 24, passes through the opening 27, and is irradiated to the abrasive surface 14a. When the reflected image of the irradiated light passes through the reflected light transmitting member 24 and reaches the camera 23, an image of the abrasive grains 14b on the abrasive surface 14a is acquired. Further, the light from the plurality of second lamps 28 is applied to a wide area range of the grindstone surface 14a of the rotary grindstone 14. The reflected image by the light also passes through the reflected light transmitting member 24 and reaches the camera 23, so that the image of the abrasive surface 14a is acquired.

The captured image data is stored in the storage unit 33 of the control device 31, which will be described later.
FIG. 2 shows the electrical configuration of this embodiment. The control device 31 includes a central processing unit 32 as a predictive means and a storage unit 33 as a storage means. Then, the cutting machine of the present embodiment is operated by executing the program stored in the storage unit 33 under the control of the central processing unit 32. The motor 15 and the camera 23 are connected to the control device 31. An encoder 34 is connected to the control device 31. As shown in FIG. 3, the encoder 34 generates allocation pulses at each rotation angle of a predetermined equal pitch (allocation pitch δ) of the rotary grindstone 14 when the rotary grindstone 14 is rotated. Then, in response to the pulse, the camera 23 releases the shutter at predetermined intervals to execute shooting. The allocation pulse is, for example, 1000 per rotation of the rotary grindstone 14, but the number of the allocation pulses is not limited and can be arbitrarily set according to the encoder used.

The display device 51 made of a liquid crystal display or the like displays an image of the control result by the control device 31.
Next, the operation of the present embodiment will be described with reference to the flowcharts of FIGS. 5 and 6. In this flowchart, the program stored in the storage unit 33 of the control device 31 proceeds under the control of the central processing unit 32.

When the machining of the work 100 is completed in steps S (hereinafter, simply referred to as S) 1 and S2 of FIG. 5, the surface roughness of the work surface of the work 100 is measured by the measuring device 50 in S3, and is measured in S4. The surface roughness data is stored. Next, in S5, processing data indicating processing conditions such as the hardness of the work 100 and the count of the rotary grindstone 14 is stored. That is, here, the correlation between the surface roughness of the surface to be machined of the work 100 and the machining conditions by the grinding machine is recorded.

The work shown in FIG. 5 and FIG. 6 described later is, for example, performed as a sample before the plurality of works 100 are machined, and is not performed every time before each work 100 is machined. ..

Next, in S11 of FIG. 6, the rotary grindstone 14 is moved to the position of the dresser 16. Then, the dressing 16 executes the dressing of the grindstone surface 14a of the rotary grindstone 14 for a predetermined time set in advance. After the end of the predetermined time, the rotary grindstone 14 is separated from the position of the dresser 16 and the rotary grindstone 14 is rotated in one direction in S13 after the dressing end determination in S12 is completed.

In S14, the camera 23 executes photographing of the abrasive surface 14a according to the output timing of the allocation pulse output from the encoder 34, and stores the image in the storage unit 33. As described above, the allocation pulse is output 1000 times, for example, for each rotation of the rotary grindstone 14, and the total number of allocation pulses for each rotation is n.

In S15, it is determined whether or not the rotary grindstone 14 has rotated to the position of n + 1, that is, whether or not the rotary grindstone 14 has rotated by 1 rotation plus 1 / n, and is rotated to the position of n + 1. Then, shooting is executed in S16, and the image data is stored in the storage unit 33. In S17, it is determined whether or not n times of shooting have been completed. The positions of the grindstones 14a assigned by the encoder 34 are sequentially photographed until the number of photographs is reached n times, that is, until the rotary grindstone 14 is rotated n times. Therefore, the n image data D shown in FIG. 7 are acquired.

Then, as the n times of shooting are completed, in other words, as the entire shooting of the grindstone surface 14a of the rotary grindstone 14 is completed, after the judgment of S17, one rotation of the rotary grindstone 14 is performed in S18. The amount of feed β per hit is acquired. Next, in S19, the image data D for n numbers of images are connected so as to be continuous along the rotation direction of the rotary grindstone 14, in other words, along the feed direction of the work 100.

Next, in S20, as shown in FIG. 7, n image data Ds are compressed according to the feed amount β of the work 100 per rotation of the rotary grindstone 14. That is, the n image data D represents an image having a length α for one round of the grindstone surface 14a of the rotary grindstone 14.

Here, the work 100 is fed with a feed amount β for one rotation of the rotary grindstone 14. The relationship between the total circumference α of the grindstone surface 14a and the feed amount β of the work 100 per rotation of the rotary grindstone 14 is
α> β
Therefore, the shape of the abrasive surface 14a represented by conditions such as the density of the abrasive grains 14b on the entire circumference of the abrasive surface 14a is compressed to the length of the feed amount β of the work 100, and the feed amount β of the work 100 is compressed. It is transferred to the work surface γ having a length of minutes. Therefore, in S20, the image data of the length of one round of the rotary grindstone 14 is compressed to the length of β / α along the circumferential direction of the rotary grindstone 14 and the feed direction of the work 100.

In S21, the compressed image data and the processing data acquired in S5 of FIG. 5 are acquired. Then, the surface roughness of the work surface of the work 100 is predicted from the processed data and the compressed image data. For example, the type of count of the rotary grindstone 14, the hardness of the work 100, and the like are directly related to the level of surface roughness of the surface to be machined. Therefore, these relationships accurately predict the surface roughness of the surface to be machined.

In S21, the predicted surface roughness is displayed on the display device 51.
Therefore, in this embodiment, there are the following effects.
(1) The surface roughness of the work surface of the work 100 after processing can be predicted before the start of processing on the work 100. Therefore, it is not necessary to test-process the work 100 before processing the work 100, measure the surface roughness after the test processing, or measure the surface roughness every time the surface to be machined is cut. become. Therefore, the machining work of the work 100 can be efficiently performed.

(2) Since the surface roughness of the work surface of the work 100 after processing can be predicted only by rotating the rotary grindstone 14 once, the prediction work can be efficiently executed in a short time.
(Change example)
Each of the above embodiments can be modified and implemented as follows. Then, each embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

-The rotary cutting tool is a tool other than the rotary grindstone 14, for example, a milling cutter or a hob. In milling cutters and hobs, the cutting edge is the cutting surface.
-To predict the surface roughness of the work surface of the work by photographing the abrasive surface of the rotating grindstone with the side surface as the abrasive surface.

-In the above embodiment, in the photographing of the grindstone surface 14a, the rotary grindstone 14 is rotated and photographed by shifting by n + 1, but the photographing is performed by shifting by n-1.
-When shooting the grindstone surface 14a, shoot with a shift of 12 allocation pitch or more for each rotation of the rotary grindstone 14.

-When the rotation speed of the rotary grindstone 14 is low, in the photographing by the camera 23, the abrasive surface 14a at each allocation position is sequentially photographed as the rotary grindstone 14 rotates. Therefore, the entire grinding wheel 14a can be photographed by rotating the rotary grindstone 14 once.

-A part of the grindstone surface 14a of the rotary grindstone 14 is photographed, and the surface roughness is predicted based on the photographed data.
In the above embodiment, the image data for one round of the abrasive surface 14a is compressed so as to be the feed amount β of the work 100 per rotation of the rotary grindstone 14, but the compression ratio of the image is set to another ratio, for example. The image data D for one round of the grinding surface 14a is simply multiplied by an integral multiple such as 1/1000.

-The image of the abrasive surface 14a is continuously photographed for, for example, one round, and the surface roughness is predicted based on the image data.
(Other technical ideas)
The technical idea grasped from the above-described embodiment is as follows.

(A) The method for predicting surface roughness of a workpiece by machining a rotary cutting tool according to claim 1, wherein the rotary cutting tool is a rotary grindstone, and the cutting surface is a grindstone on the outer periphery of the rotary grindstone.
(B) Described in the above technical concept (A), wherein the grinding surface of the rotary grindstone is allocated to a plurality of grinding surfaces, the grinding surface is photographed at each allocation position, and the image data is continuous along the circumferential direction of the grinding wheel. A method for predicting the surface roughness of a workpiece by machining a rotary cutting tool.

(C) The method for predicting the surface roughness of a work by machining with a rotary cutting tool according to the above technical concept (A), wherein the abrasive surface is photographed before machining the workpiece and after dressing the abrasive surface.
(D) The method for predicting the surface roughness of a workpiece by machining a rotary cutting tool according to claim 1, wherein the photographing is performed on the entire circumference of the grindstone surface of the rotary grindstone.

14 ... Rotating grindstone 14a ... Abrasive surface 14b ... Abrasive grains 21 ... Imaging device 23 ... Camera 31 ... Control device 34 ... Encoder 100 ... Work D ... Image data α ... Length β ... Feed amount γ ... Surface to be machined

Claims (2)

The cutting surface of the rotary cutting tool is photographed during the rotation of the rotary cutting tool, and the image data is compressed in the work feed direction according to the relationship between the circumferential length of the cutting surface and the work feed amount, and the workpiece is machined. A method for predicting the surface roughness of a workpiece by machining a rotary cutting tool, which is characterized by predicting the surface roughness of the surface. A means of photographing the cutting surface of a rotary cutting tool while the rotary cutting tool is rotating, and
A storage means for storing captured image data, and a compression means for compressing the stored image data in the work feed direction according to the relationship between the length of the image data in the cutting surface circumferential direction and the work feed amount.
A surface roughness predicting device for a workpiece by machining a rotary cutting tool, which is provided with a predicting means for predicting the surface roughness of the workpiece surface of the workpiece based on compressed image data.

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