JPH0957583A - Automatic measurement method and device for tool abrasion quantity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quantitatively measure abrasion loss of respective tools at high speed by a direct measuring method by accurately finding tip positions of the tools without any necessity of a complicated image processing, even if the types and sizes of tools to be measured in abrasion loss are varies. SOLUTION: The whole or almost whole of a tool after cutting work is photographed by an infrared camera 29, a tip position of a tool is recognized by the temperature distribution of the tool surface which is distinguished by image pick-up data by the infrared camera 29, a television camera 31 of high image pick-up magnification is moved to a position right opposed to the tool tip based on the information of this tip position, the image of the tool tip is picked up by the television camera 31, and abrasion loss of the tool tip is measured from the image pick-up data by the television camera 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool wear amount automatic measuring method and a tool wear amount automatic measuring device, and more particularly to a method and a device for directly measuring the tool blade edge wear amount directly by imaging a tool.

[0002]

2. Description of the Related Art Indirect measurement methods and direct measurement methods have been conventionally known as methods for measuring the amount of wear of a cutting edge of a tool.

The indirect measuring method focuses on the fact that the cutting resistance increases due to the wear of the cutting edge, and the tool wear is estimated by measuring the spindle motor power, vibration, noise, AE (acoustic emission), etc. during cutting. This method is applicable to the magazines, machines and tools, published by Industrial Research Institute, 198.
No. 5, pp. 30 to 38, "Detection and prediction of deterioration of cutting function".

The direct measurement method is a method of directly observing the wear surface of the tool by using a tool microscope, an ITV camera or the like. This method is the above-mentioned "detection of cutting function deterioration and prediction",
Japan Society for Precision Engineering Vol. 55, No. 8,
1989, pp. 73-78 "Development of non-contact tool damage monitoring device by optical measurement incorporating autofocus mechanism".

[0005]

However, in the indirect measurement method, the levels of measured values of the spindle motor power, vibration, noise, AE, etc. during cutting vary depending on the type of tool, the material of the work material, the cutting conditions, etc. In addition, since noise is easily mixed in the measurement signal, the estimation accuracy of tool wear is poor, the reliability of measurement results is poor, and even if tool wear reaches the limit or damage is detected, tool wear is detected. It is difficult to measure quantity accurately and quantitatively.

The method of directly observing the worn surface of the tool by a tool microscope can measure the tool wear reliably and strictly, but this method is intended exclusively for tool inspection, and the inspection is automated. However, there remains a problem to be solved in digitizing and quantifying the inspection result and transmitting it online to the machine control device to take countermeasures.

A method of imaging a tool with an ITV camera is described in I
Although it is possible to quantitatively measure the amount of wear of the tool by image data of the tool obtained by imaging the tool with a TV camera, it is possible to measure the amount of wear of the tool with the currently proposed method. There are limited types of tools, and this technology is used to detect various types of tools such as machine tools, especially machining centers, to detect tool replacement timing and tool position correction using an automatic tool changer. There are still some problems to be solved for application to machine tools to be installed.

This problem is that in order to detect the tool replacement time and correct the tool position, the blade edge of the tool is found, the blade edge portion is locally imaged with a high imaging magnification, and detailed imaging data of the blade edge portion is obtained. Whereas you need to get
If there are various types and sizes of tools (used tools) whose wear is to be measured, such as in machining centers, IT
This means that it takes time and effort to find the blade edge position of each tool from the imaged data of the entire tool by the V camera.

The present invention has been made by paying attention to the above-mentioned problems, and in a machine tool with an automatic tool changer or the like, even if the type and size of the tool whose wear amount is to be measured are various. The tool edge position is accurately found without the need for complicated image processing, the wear amount of each tool is quantitatively measured at high speed by the direct measurement method, and the inspection result is transmitted to the machine control device online. It is an object of the present invention to provide a tool wear amount automatic measuring method and apparatus that enables to take countermeasures by taking appropriate measures and accurately determine the tool replacement timing.

[0010]

In order to achieve the above-mentioned object, the method for automatically measuring the amount of tool wear according to claim 1 of the present invention uses an infrared camera to image the entire or almost the entire tool after cutting. Recognizing the position of the blade edge of the tool from the temperature distribution on the tool surface that can be identified from the image data captured by the infrared camera, and moving the TV camera with a high imaging magnification to the position directly facing the blade edge of the tool based on this blade edge position information,
The feature is that the tool blade edge is imaged by the TV camera, and the wear amount of the tool is measured from the image data of the tool blade edge captured by the TV camera.

In this automatic tool wear amount measuring method, attention is paid to the fact that the cutting edge of the tool after cutting has a higher temperature than other parts due to the heat generated by the cutting resistance, and the tool surface of the tool which can be identified from the image data taken by the infrared camera is identified. Accurately recognize the tool tip position from the temperature distribution. Based on this information on the blade edge position, the TV camera with a high imaging magnification is moved to a position directly facing the tool blade edge, the tool blade edge is imaged by the TV camera, and the wear amount of the tool is measured from the image data of the tool blade edge captured by the TV camera. .

A method for automatically measuring the amount of tool wear according to claim 2 is the method for automatically measuring the amount of tool wear according to claim 1, wherein the blade portion of the tool is recognized from the temperature distribution on the tool surface that can be identified from the image data obtained by the infrared camera. , Tool diameter for each tool obtained from this blade information and tool information database,
The feature is that the blade edge position is specified by the blade edge information such as the number of blades and the rotation direction.

In this automatic tool wear amount measuring method, the position of the cutting edge is specified by the image data of the infrared camera and the cutting edge information obtained from the tool information database.

A tool wear amount automatic measuring method according to a third aspect is the tool wear amount automatic measuring method according to the first or second aspect, wherein a front image and a side image of the tool are respectively imaged by an infrared camera, and these images are taken. The feature is that the position of the cutting edge of the tool is recognized from the temperature distribution on the tool surface that can be identified from the data.

In this method for automatically measuring the amount of tool wear, the position of the cutting edge of the tool is recognized from the temperature distribution on the surface of the tool which can be identified from the image data of the front and side images of the tool obtained by the infrared camera.

A method for automatically measuring the amount of tool wear according to claim 4 is the method for automatically measuring the amount of tool wear according to any one of claims 1 to 3, wherein the imaging position of the tool by the infrared camera is the type and size of the tool. It is a pre-defined image pickup position for picking up the image of the entire tool or almost the entire tool, regardless of the type and size of the tool.

In this automatic tool wear amount measuring method, the coordinate origin position of the image data picked up by the infrared camera is the type of tool,
It is always constant regardless of size.

According to a fifth aspect of the present invention, there is provided an automatic tool wear amount measuring device, which comprises an infrared camera for picking up an image of the entire tool after cutting, a television camera for picking up a cutting edge with a high image pickup magnification, and image pickup data by the infrared camera. From the temperature distribution of the tool surface that can be identified from the cutting edge position recognition means for recognizing the cutting edge position of the tool, and based on the information of the cutting edge position identified by the cutting edge position recognition means, the television camera is moved to a position directly facing the cutting edge of the tool. And a tool wear amount measuring means for measuring the wear amount of the tool from the image data of the tool blade edge by the television camera.

In this automatic tool wear amount measuring device, an infrared camera images the whole or almost the entire tool after machining, and the cutting edge position recognizing means uses the infrared camera image data to detect the temperature distribution of the tool surface. The position of the cutting edge is recognized, and based on the information on the position of the cutting edge, the TV camera imaging position control means moves the TV camera with a high imaging magnification to a position directly facing the tool cutting edge, and the TV camera images the tool cutting edge to determine the amount of tool wear. The amount of wear of the tool is measured by the measuring means from the image data of the tool blade edge by the TV camera.

The tool wear amount automatic measuring device according to claim 5 is the tool wear amount automatic measuring device according to claim 4, wherein the infrared camera and the television camera are provided on the same camera stand, and the camera stand is It is characterized in that it can be moved individually in the vertical direction and the horizontal direction, and can be individually turned around a horizontal axis and a vertical axis.

In this tool wear amount automatic measuring device, the infrared camera is processed by moving the camera stand individually in the vertical direction and the horizontal direction and individually turning around the horizontal axis and the vertical axis. It is located at a position where an image of the entire rear tool or almost the entire tool is captured, and the television camera is located at a position directly facing the tool blade edge.

[0022]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a machine tool to which an automatic tool wear amount measuring device according to the present invention is applied. The machine tool includes a machine tool main body 3 having a spindle 1, a tool magasin 7 for storing a plurality of tools 5 in a retractable manner, and a tool magasin 7
And a tool exchanging arm 9 for exchanging the tool 5 stored in the main shaft 1 of the machine tool body 3 in an exchangeable manner.

As shown in FIGS. 2 and 3, a tool imaging device 11 is installed in front of the tool magasin 7 so as to face one tool holding position of the tool magasin 7. From this point onward, the tool magasin 7 corresponding to the tool imaging device 11
The tool holding position of is sometimes called a tool wear amount measuring station.

The tool imaging device 11 is guided by the guide rail 13 in the front-back direction (Z-axis direction), that is, the tool magasin 7
The movable base member 15 provided to be movable in the central axis direction of the tool 5 stored in and the vertical bar 17 erected on the movable base member 15 are vertically movable, that is, movable in the Y-axis direction. A vertical moving block 19 provided on the vertical bar 21, a horizontal bar 21 having one end attached to the vertical moving block 19 and extending horizontally in the left-right direction (X-axis direction), and a horizontal bar 21.
And a rotary base 25 provided around the horizontal axis (θZ rotation axis) in the Z-axis direction on the platform main body 23, and the θZ axis on the rotary base 25. It has a horizontal swivel base (camera base) 27 provided around an axis line (θY rotation axis line) orthogonal to the infrared swivel base 27, and an infrared camera 29 and a close-up IT as a TV camera with a high imaging magnification.
The V camera 31 is attached in parallel with each other.

Although not shown, an illuminator of a coaxial incident type or a illuminator of a small ring light is attached to the horizontal swivel base 27, and these illuminators illuminate an object.

The movable base member 15 is positioned in the Z-axis direction by a Z-axis stepping motor 35 that rotationally drives the feed screw 33, and the vertical movement block 19 is fed by the feed screw 37.
Positioning in the Y-axis direction is performed by the Y-axis stepping motor 39 that rotates the pan.
The X-axis stepping motor 43 that rotationally drives the X-axis is positioned in the X-axis direction, the rotary base 25 is positioned by the θZ stepping motor 45 around the θZ rotation axis, and the swivel base 27 is rotated by the θY stepping motor 47.
Positioning around the Y rotation axis is performed.

FIG. 4 shows a control system of the automatic tool wear amount measuring device according to the present invention. Stepping motor 3 for each axis
5, 39, 43, 45, 47 are controlled by the imaging position control section 49, and the imaging position control section 49 is controlled by the stepping motors 35, 39, 43, 45, 47 to measure the tool wear amount measuring station of the tool magasin 7. Positioning control for positioning the infrared camera 29 at a position for imaging the entire or almost the entire tool 5 located at the position, and the tool 5 located at the tool wear amount measuring station of the tool magasin 7.
Position control is performed to position the close-up ITV camera 31 at a position where the image of the specific portion, in this case, the blade edge portion is imaged.

At a position where the infrared camera 29 takes an image of the entire or almost the entire tool 5 located at the tool wear amount measuring station of the tool magasin 7, an image pickup position of a front image (opposite axis direction) and an image of a side image are taken. There is a position, and each imaging position is defined in advance as one imaging position for imaging the entire or almost the entire tool 5 regardless of the type and size of the tool to be imaged. This allows the infrared camera 29
The image pickup position of the tool by is always constant, and the coordinate origin position of the image pickup data is always constant regardless of the type and size of the tool.

The infrared camera 29 has the entire front surface of the tool 5 immediately after being cut and stored in the tool magasin 7 with the front image capturing position and the side image capturing position defined in advance as described above. Alternatively, almost the entire image is captured. Since the image data captured by the infrared camera 29 shows the surface temperature distribution of the object to be imaged, the temperature distribution on the tool surface can be recognized from the image data.

Image data picked up by the infrared camera 29 is input to the blade edge position identifying section 51. The blade tip position identification part 51
The edge position of the tool is recognized based on the temperature distribution on the tool surface from the overall image pickup data of the tool after cutting by the infrared camera 29. Since the cutting edge after cutting has a higher temperature than other parts due to the heat generated by cutting resistance, the cutting edge position of the tool can be accurately recognized by this temperature difference.
As a result, the position of the cutting edge of the tool can be accurately found without requiring complicated image processing.

In this case, the infrared camera 29 captures a front image and a side image of the tool, and the cutting edge position identifying section 51 obtains a temperature distribution on the tool surface from the image data of the front image and the side image of the tool obtained by the infrared camera 29. Since the position of the cutting edge of the tool is recognized, the position of the cutting edge of the tool can be recognized regardless of whether the cutting edge is attached to the front surface of the tool or the cutting edge is attached to the side surface of the tool.

FIG. 5 shows a detailed configuration example of the blade edge position identifying section 51. The blade tip position identification section 51 has a tool information database 59 and a blade tip position coordinate detection section 61. The tool information database 59 has a tool diameter for each tool,
Stores information unique to each tool, such as the number of blades and tool rotation direction. The blade tip position coordinate detection unit 61 extracts a high temperature region from the image data captured by the infrared camera 29, and calculates the coordinate data of this high temperature region and the tool diameter, rotation direction, and number of blades of the corresponding tool stored in the tool information database 59. Based on this, the coordinate value of the cutting edge of each blade is calculated.

FIG. 6 schematically shows the temperature distribution obtained by imaging the milling tool after cutting with the infrared camera 29. In FIG. 6, the higher temperature part is represented in white. In FIG. 6, in the milling tool after the cutting process, each blade portion c is whitest, and each blade portion c is extracted as a high temperature region.

In the calculation of the cutting edge coordinate value of this milling tool, the tool radius R, the rotation direction and the number of blades are acquired from the tool information stored in the tool information database 59, and for example, the rotation direction is the counterclockwise direction. If there is, as shown in FIG. 7, for each blade portion c that can be known from the number of blades, the counterclockwise rotation angle θ ₁ of the blade front surface t from the reference angle position,
theta ₂ ... a determined from imaging data of the infrared camera 29, the rotation angle theta _1, identifies with a theta ₂ ... and polar value coordinate values of the cutting edge p by the tool diameter R. The polar coordinate value can be converted into a rectangular coordinate value by general polar coordinate / rectangular coordinate conversion.

The coordinate position information of the cutting edge p (cutting edge position information) is input to the imaging position control section 49. The imaging position control unit 49 performs positioning control for moving the close-up ITV camera 31 to a position directly facing the blade edge based on the blade edge position information from the blade edge position identifying unit 51.

The coordinate system of the ITV camera 31 for close-up photography is
Since the coordinate origin position of the image data of the infrared camera 29 is always constant, it is given by a common coordinate system for any tool, and the positioning control of the ITV camera 31 for close-up photography described above is performed for any tool. Reasonably done in one coordinate system.

When the close-up ITV camera 31 is located at a position directly facing the cutting edge, an illuminating device (not shown) is turned on,
The close-up ITV camera 31 images the tool edge at a high imaging magnification.

When there are a plurality of cutting edges as in a milling tool, the ITV camera 31 for close-up photography is directly faced to each of the cutting edges to image each cutting edge.

Image data of the cutting edge of the ITV camera 31 for close-up photography is input to the tool wear amount measuring unit 53. The tool wear amount measuring unit 53 quantitatively measures the wear amount of the tool from the image data of the cutting edge of the ITV camera 31 for close-up photography. This wear amount measurement is performed by comparing the initial image data of the cutting edge set in advance for each tool with the latest imaging data, or comparing the previous imaging data with the latest imaging data, and comparing the worn part and the non-weared part. The width of the discolored portion may be obtained from the image data by utilizing the difference in color and gloss.

The measured value of the amount of tool wear is input to the tool monitor 55. The tool monitoring unit 55 determines whether or not the measured value of the tool wear amount from the tool wear amount measurement unit 53 is within the maximum allowable value. If the tool wear amount measured value is not within the maximum allowable value, the tool The alarm of replacement is output and the process of prohibiting the use of the tool is performed.

At this time, it is determined whether or not the alternative tool is present in the tool magasin 7, and if the alternative tool is present, the instruction to use the alternative tool and the tool wear amount measured value are within the maximum allowable value. In this case, when the tool 5 is used next time, a command for reducing the tool rotation speed and the feed speed according to the tool wear amount is output to the machine controller 57 of the machine tool.

In the above, the present invention has been described in detail with respect to a specific embodiment, but the present invention is not limited to this, and various embodiments within the scope of the claims of the present invention. It will be apparent to those skilled in the art that

[0044]

As can be understood from the above description, according to the automatic tool wear amount measuring method and the tool wear amount automatic measuring device according to claims 1 and 5 of the present invention, the tool surface which can be identified from the image data obtained by the infrared camera. The edge position of the tool is recognized from the temperature distribution of the tool, and based on the information of the edge position, a TV camera with a high imaging magnification is made to face the tool edge to image the tool edge, and the wear amount of the tool is measured from the image data. Therefore, even if there are various types and sizes of tools whose wear amount is to be measured, the position of the cutting edge of the tool can be accurately and quickly recognized without complicated image processing, and the wear of the cutting edge of each tool The quantity can be quantitatively measured at high speed by the direct measurement method. As a result, it becomes possible to transmit the inspection result online to the machine control device, take a countermeasure, and determine the tool replacement time with high accuracy.

In the automatic tool wear amount measuring method according to the second aspect, the blade tip position is specified by the image data obtained by the infrared camera and the blade tip information obtained from the tool information database. Therefore, the blade tip position can be specified efficiently and reliably. Done.

In the automatic tool wear amount measuring method according to claim 3, a front image and a side image of the tool are respectively imaged by an infrared camera, and a temperature distribution on the tool surface is obtained from the image data of the front image and the side image of the tool taken by the infrared camera. Since the position of the cutting edge of the tool is recognized by, the position of the cutting edge of the tool can be recognized regardless of whether the cutting edge is attached to the front surface of the tool or the cutting edge is attached to the side surface of the tool.

In the automatic tool wear amount measuring method according to the fourth aspect, the imaging position of the tool by the infrared camera is the type of the tool,
Since it does not change regardless of the size, the coordinate origin position of the image data captured by the infrared camera is always the same regardless of the type and size of the tool, and the positioning control of the TV camera by the edge position data acquired from this image data. The coordinate system is common to all tools, and can be done easily and rationally.

In the tool wear amount automatic measuring device according to the sixth aspect, the camera base is individually moved in the vertical direction and the horizontal direction, and is individually rotated about the horizontal axis and the vertical axis, whereby the tool is rotated. Despite the wide variety of types and sizes, the infrared camera is located at a position that captures the entire or almost all of the tool after processing, and the TV camera is located at a position directly facing the tool blade edge to reduce the amount of tool wear. There is no limit to the tools that can be measured.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an example of a machine tool to which an automatic tool wear amount measuring device according to the present invention is applied.

FIG. 2 is a side view showing an embodiment of a tool imaging device used in the automatic tool wear amount measuring device according to the present invention.

FIG. 3 is a front view showing an embodiment of a tool imaging device used in the automatic tool wear amount measuring device according to the present invention.

FIG. 4 is a block diagram showing an embodiment of a control system of the automatic tool wear amount measuring device according to the present invention.

FIG. 5 is a block diagram showing a specific configuration example of a blade edge position identification unit of the automatic tool wear amount measuring device according to the present invention.

FIG. 6 is an explanatory view showing an example of an image picked up by an infrared camera in the tool wear amount automatic measuring device according to the present invention.

FIG. 7 is an explanatory diagram showing the detection of the blade edge position of the milling tool.

[Explanation of symbols] 1 spindle 3 machine tool body 5 tool 7 tool magasin 9 tool change arm 11 tool imaging device 29 infrared camera 31 ITV camera for close-up photography 49 imaging position control unit 51 cutting edge position identification unit 53 tool wear amount measurement unit 55 tool Monitoring unit 57 Machine control device 59 Tool information database 61 Blade position coordinate detection unit

Claims (6)

[Claims] 1. An image of an entire tool or almost the entire tool after cutting is imaged by an infrared camera, and the edge position of the tool is recognized from the temperature distribution of the tool surface that can be identified from the image data obtained by the infrared camera. A tool characterized by moving a high imaging magnification TV camera to a position directly facing the tool edge based on this, imaging the tool edge with the TV camera, and measuring the amount of wear of the tool from the image data of the tool edge by the TV camera. Automatic wear measurement method. 2. A tool blade portion is recognized from a temperature distribution on the tool surface that can be identified from image data obtained by an infrared camera, and the tool diameter, number of blades, rotation direction, etc. for each tool obtained from this blade portion information and the tool information database. 2. The tool wear amount automatic measuring method according to claim 1, wherein the blade edge position is specified based on the blade edge information. 3. A front image and a side image of the tool are respectively imaged by an infrared camera, and the cutting edge position of the tool is recognized from the temperature distribution of the tool surface which can be identified from the imaged data. The automatic tool wear amount measuring method described in 2. 4. The image pickup position of the tool by the infrared camera is a predefined image pickup position for picking up an image of the entire tool or almost the entire tool regardless of the type and size of the tool. The tool wear amount automatic measuring method according to any one of claims 1 to 3, wherein the tool wear amount automatic measuring method is not changed. 5. An infrared camera for imaging the entire or almost the entire tool after cutting, a television camera for imaging the cutting edge with high imaging magnification, and a tool based on the temperature distribution on the tool surface that can be identified from the imaging data by the infrared camera. Blade edge position recognizing means for recognizing the blade edge position, imaging position control means for moving the television camera to a position directly facing the tool blade edge based on the information of the blade edge position identified by the blade edge position recognizing means, and the television camera A tool wear amount automatic measuring device, comprising: a tool wear amount measuring means for measuring the wear amount of the tool from the image data of the tool blade edge by. 6. The infrared camera and the television camera are provided on the same camera base, and the camera base is individually movable in a vertical direction and a horizontal direction, and is movable around a horizontal axis and a vertical axis. 5. The automatic tool wear amount measuring device according to claim 4, wherein each of them can be individually turned.