JP3716573B2 - Non-contact temperature distribution measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a non-contact temperature distribution measuring apparatus that measures a two-dimensional temperature distribution of a cutting tool during cutting in a non-contact state.
[0002]
[Prior art]
As a device that measures the surface temperature of an object in a non-contact manner, a far-infrared image forming device (thermograph) that captures a far-infrared image radiated from the object surface is generally known.
[0003]
[Problems to be solved by the invention]
However, this far-infrared image forming apparatus measures the temperature distribution on the surface of the measurement object. For this reason, there is a problem that the cutting tool is hidden by the chips generated from the work material during the cutting process, and the two-dimensional temperature distribution of the cutting edge of the cutting tool, the cutting edge rake face, etc. cannot be measured.
[0004]
In addition, a temperature measurement method called a one-byte method in which a thermocouple is embedded in a cutting tool and the temperature of the cutting tool is measured by this thermocouple is known. A wide range of two-dimensional temperature distribution cannot be measured. In addition, this method has a problem that the mechanical strength of the cutting tool is lowered because it is necessary to form a hole, a groove or the like for embedding a thermocouple in the cutting tool. In addition, there is a problem that a complicated pretreatment for forming such holes and grooves is necessary.
[0005]
The present invention has been made in view of the problems of the prior art, and can measure the two-dimensional temperature distribution of a cutting tool during cutting more easily and with high accuracy in a non-contact state. An object of the present invention is to provide a non-contact temperature distribution measuring device that can be used.
[0006]
[Means for Solving the Problems]
The present invention relates to a non-contact temperature distribution measuring apparatus for measuring a two-dimensional temperature distribution of a cutting tool during cutting, and a substantial cutting period by bringing the cutting tool into contact with a work material during the cutting. Cutting state setting means for setting a substantial non-cutting period by separating the cutting tool and the work material, and imaging means for imaging the cutting tool a plurality of times for each predetermined delay time; A plurality of pieces of image information obtained by a plurality of times of imaging by the imaging unit are associated with the exposure elapsed time from the switching time for each piece of information corresponding to the same part of the cutting tool, and the image with respect to the exposure elapsed time A change characteristic calculating means for obtaining a change tendency of information, and a temperature for calculating a two-dimensional temperature distribution of the cutting tool at the time of switching based on the change tendency obtained by the change characteristic calculating means And configured to include a fabric arithmetic means.
[0007]
[Action]
A plurality of exposure image information of the cutting tool can be obtained by imaging the cutting tool a plurality of times at a plurality of different delay times with reference to the switching time detected by the sensor means. By associating the plurality of pieces of image information with the exposure elapsed time from the time of switching for each piece of information corresponding to the same part of the cutting tool, the tendency of the temperature change of the exposed cutting tool can be obtained. Based on this change tendency, by calculating the temperature of the cutting tool at the time of switching, the two-dimensional temperature distribution of the cutting tool is obtained when the cutting tool is in contact with the work material, that is, during the cutting process. .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described below with reference to FIGS. In these drawings, the same or equivalent components are denoted by the same reference numerals.
[0009]
FIG. 1 is a block diagram illustrating a configuration of a non-contact temperature distribution measuring apparatus according to an embodiment, and FIG. 2 is a diagram illustrating an example of an installation mode of the apparatus on a measurement target.
[0010]
In FIG. 1, this apparatus includes an imaging unit for imaging a measurement object, and an image signal S output from the imaging unit. _AW And an analysis unit for obtaining a two-dimensional temperature distribution of the measurement object.
[0011]
As shown in FIG. 2, the imaging unit includes a camera mechanism 2 that captures an image with a two-dimensional imaging device, and an optical sensor 4 that includes a phototransistor or the like.
[0012]
The camera mechanism 2 and the optical sensor 4 are disposed at appropriate positions with respect to the measurement object. For example, as shown in the figure, the cutting edge 8 and the cutting edge rake face of the cutting tool 8 for cutting the peripheral side wall of the work material 6 rotating in the circumferential direction θ when performing cutting using various lathe devices. When the two-dimensional temperature distribution is measured, the camera mechanism 2 is arranged so that the cutting tool 8 to be measured falls within the imageable range (the visual field range indicated by the alternate long and short dash line AW), and the optical sensor 4 Is arranged toward the peripheral side wall of the work material 6.
[0013]
In order to prevent problems such as contamination of the imaging surface of the camera mechanism 2 due to scattering of chips generated from the work material 6 during the cutting process, the imaging optical system in the camera mechanism 2 includes: The optical characteristics are designed so that the focal length is 50 mm or more and the resolving power is 30 μm or less. Here, the resolving power means a limit value of detail reproducibility. For example, when black-and-white stripe patterns with equal intervals are imaged, the black minimum at the limit point where they can be separated and imaged. It is defined as the stripe interval. More preferably, it is desirable to set the focal length to 100 mm or more and the resolving power to be finer than 25 μm (resolving power ≦ 25 μm).
[0014]
Further, a substantial cutting period due to the contact between the work material 6 and the cutting tool 8 and a substantial non-cutting time due to the separation between the work material 6 and the cutting tool 8 are set during the cutting process. As a cutting state setting means for this purpose, a work material 6 having a notch 12 inside the work surface 10 to be cut by the cutting tool 8 is used. Therefore, when the work material 6 rotates in the circumferential direction θ, the cutting tool 8 is separated from the work material 6 when passing through the notch 12, so that no cutting work is temporarily performed. The rake face is exposed.
[0015]
As shown in FIG. 3, the camera mechanism 2 is arranged so that the horizontal line direction j of the built-in two-dimensional imaging device and the rotation direction (circumferential direction) θ of the work material 6 are substantially orthogonal to each other. . As a result, the work material 6 moves from the first (i = 1) horizontal line side in the imageable range AW along the vertical line direction i.
[0016]
Further, the shape and size of the notch 12 may be arbitrary. In short, any shape may be used as long as the cutting tool 8 is separated from the work material 6 during the cutting process so that the cutting process is not substantially performed.
[0017]
In FIG. 1, the analysis unit has a control unit 14 having an arithmetic control function and a microprocessor (MPU) that controls the operation of the entire analysis unit, and an imaging control unit 16 that controls the imaging operation of the camera mechanism 2. And the image signal S output from the camera mechanism 2 _AW And an input / output port 20 for connecting an external device such as an external display device, an external storage device, and a keyboard. Each component 14-20 is connected via what is called a bus line BUS.
[0018]
The imaging control unit 16 includes a synchronization detection unit 22, a measurement condition setting unit 24, a measurement condition storage memory 26, and a drive unit 28.
[0019]
The synchronization detection unit 22 detects the light detection signal S output from the optical sensor 4 while the work material 6 is rotating. _PD At the time of switching from the surface to be cut 10 to the notch 12 (hereinafter referred to as the first synchronization time) t _F And a time point (hereinafter referred to as a second synchronization time point) t when the cutout portion 12 is switched to the surface 10 to be cut. _E Is detected.
[0020]
FIG. 4 shows the first synchronization time t by the synchronization detector 22. _F And the second synchronization time t _E It is a timing chart which shows this detection operation. In the same figure, the light detection signal S output from the optical sensor 4. _PD The amplitude of is changed between when the cut surface 10 is received and when the notch 12 is received. This light detection signal S _PD Is subjected to differential processing to obtain a pulse-shaped differential waveform signal ΔS. _PD Is generated. Further, the differential waveform signal ΔS _PD The first synchronization signal Sout that becomes logic “H” when the minus-side pulse waveform exceeds a predetermined threshold THD2, and the logic “H” when the plus-side pulse waveform exceeds a predetermined threshold THD1. A second synchronization signal Sin is formed. The time point at which the first synchronization signal Sout becomes logic “H” is defined as the first synchronization time point t. _F , The time when the second synchronization signal Sin becomes logic “H” is the second synchronization time t _E Is determined.
[0021]
The measurement condition setting unit 24 includes first and second synchronization points t set by the first and second synchronization signals Sout and Sin. _F , T _E The time T required for the work material 6 to make one rotation based on ₀ And the rotational speed V of the work material 6 and the passing time T required for the notch 12 to pass in front of the optical sensor 4. _W And the passing time T required for the cut surface 10 to pass in front of the optical sensor 4 _S Then, the width W of the cutout portion 12 in the circumferential direction θ is obtained.
[0022]
Furthermore, the period required for the cutting tool 8 to pass through the notch 12 (ie, T _W ) The number of frames to be imaged N within this period T _W Is divided into a reference delay time Δ (= T _W / N). The number of frames N can be arbitrarily set by the operator.
[0023]
And these measurement condition data T calculated | required in the measurement condition setting part 24 ₀ , V, T _W , T _S , W, N, and Δ are stored in the measurement condition storage memory 26 and used when the image processing unit 18 described later calculates a two-dimensional temperature distribution.
[0024]
The drive unit 28 is a time point (first synchronization time point) t when the first synchronization signal Sout output from the synchronization detection unit 22 becomes logic “H”. _F Time T _S To a delay time τm (= T _S + MΔ)), the shutter signal S is sent to the camera mechanism 2. _T Supply. Time T _S Is the time t _E Is an offset period from when the cutting tool 8 is detected until the cutting tool 8 enters the notch 12. That is, time T _S Is obtained by dividing the offset interval between the optical sensor 4 and the cutting tool 8 by the rotational speed V of the work material 6.
[0025]
The delay time τm is the time T _S When + N × Δ is reached, the delay time τm is reset again, and the process of setting the shutter timing for the camera mechanism 2 is repeated while sequentially increasing from the reference delay time Δ.
[0026]
Thus, by causing the camera mechanism 2 to perform an imaging operation while variably controlling the delay time τm, the relative positional relationship between the work material 6 and the cutting tool 8 shown in FIGS. Corresponding images (a ′) to (e ′) are obtained.
[0027]
In FIG. 1, the image processing unit 18 includes an A / D converter 30, a temperature compensation unit 32, a measurement range extraction unit 34, an exposure elapsed time determination unit 36, a temperature change characteristic calculation unit 38, a temperature distribution calculation unit 40, an image. A synthesis unit 42, a captured image memory 44, a temperature change characteristic memory 46, and a synthesized image memory 48 are provided.
[0028]
The A / D converter 30 outputs an image signal S output by the camera mechanism 2 for each delay time τm. _AW Digital image data D _AW And stored in the captured image memory 44 as a frame image file associated with each delay time τm.
[0029]
The temperature compensation unit 32 is a digital image data D representing a luminance component stored in the captured image memory 44. _AW Is digital image data (hereinafter referred to as temperature image data) TD representing a temperature component. _AW Convert to Then, it is stored again in the captured image memory 44 as a frame image file associated with each delay time τm. Here, the digital image data D _AW Each pixel data P constituting _{i, j} (Where 1 ≦ i ≦ I, 1 ≦ j ≦ J), the temperature image data TD of the temperature component is obtained by applying the Stefan Boltzmann equation of the following equation (1): _AW Ask for.
[0030]
ω = εσT ^Four … (1)
Where ω is infrared energy (each pixel data P _{i, j} T) is the absolute temperature of the object (each temperature pixel data TP) _{i, j} ) Is an emissivity (ε ≦ 1), and σ is a Stefan Boltzmann constant.
[0031]
The measurement range extraction unit 34 includes temperature image data TD for a plurality of frame images stored in the captured image memory 44. _AW To, the temperature image data TR corresponding to a period when the cutting tool 8 is not substantially cut. _B Is extracted and stored in the composite image memory 48. That is, temperature image data TD _AW Among them, data of an image in which the cutting edge of the cutting tool 8 and the rake face of the cutting tool are hidden by the chips generated during the cutting process is not extracted, and the cutting tool 8 substantially passes through the notch 12 of the work material 6. Temperature image data TR obtained when no cutting was performed _B To extract. By this processing, temperature image data TR representing an image of the cutting tool 8 exposed without being disturbed by the chips. _B Is extracted.
[0032]
FIG. 6 shows temperature image data TR _B It is a figure which shows the extraction principle of. Temperature image data TR of each frame image file _AW Is a pixel group (for example, Q in the figure) along the vertical line direction i of the two-dimensional imaging device. ₁ -Q ₁ A group of pixels on the line, and Q ₂ -Q ₂ The temperature change distribution of the temperature pixel data obtained from the pixel group on the line) is examined. Q ₁ -Q ₁ From the change in the temperature image data of the pixel group on the line, the range W of the notch 12 _B This range W _B If temperature image data corresponding to the cutting tool 8 exists in the temperature image data TR _AW Pixel temperature data TR representing the cutting tool 8 that is not hidden by the chips by extracting _B Get.
[0033]
As described above, the range W of the notch 12 _B This range W _B Temperature image data data TR existing in _AW Only the temperature image data corresponding to the non-cutting surface 10 or the like of the workpiece 6 is removed, and the pixel temperature data TR representing the cutting tool 8 that is not hidden by the chips. _B May be obtained.
[0034]
The elapsed exposure time determination unit 36 has elapsed from the time (instant) when each part of the cutting tool 8 hidden by the chips passes through the notch 12 to be imaged by the camera mechanism 2. Time τ (hereinafter referred to as elapsed exposure time) τ is the respective temperature image data TR _B Calculate based on
[0035]
Based on FIGS. 3 and 7, the calculation principle of the exposure elapsed time τ will be described. As described with reference to FIG. 3, the image of the work material 6 moves along the vertical line direction i of the two-dimensional imaging device built in the camera mechanism 2. Therefore, the cutting tool 8 moves relative to the work material 6 in the opposite direction. From this relationship, as shown in FIG. 7, the exposure elapsed time τ becomes longer as the position is farther from the front edge portion E of the notch 12. For example, the elapsed exposure time τ at the same specific part x shown in FIG. 7 gradually becomes longer as it moves from (a) to (c).
[0036]
Therefore, as shown in FIG. 7, the temperature pixel data TP of the specific part x. _{i, j} A plurality of temperature image data TR having _B (1)-TR _B (N) is read from the composite image memory 48, and the temperature image data TR _B (1)-TR _B The horizontal line I which hits the front edge part E of the notch 12 in (N) _E (1) to I _E (N) and temperature pixel data TP corresponding to the specific part x _{i, j} Horizontal line I _F (1) to I _F (N) is detected. In addition, each horizontal line I _E (1) to I _E (N) and I _F (1) to I _F Number of horizontal lines existing between (N) _F (1) -I _E (1), ~, I _F (N) -I _E (N) is calculated. Then, the time δ required for the notch 12 to pass through one horizontal line period of the two-dimensional imaging device is expressed as the number of horizontal lines I _F (1) -I _E (1), ~, I _F (N) -I _E By multiplying (N), exposure elapsed times τ (1) to τ (N) of the specific part x are obtained.
[0037]
That is, the temperature image data TR shown in FIG. _B Temperature pixel data TP in (1) _{i, j} Exposure elapsed time τ (1) of τ (1) = (I _F (1) -I _E (1)) xδ and temperature image data TR _B (2) Temperature pixel data TP in _{i, j} Exposure elapsed time τ (2) of τ (2) = (I _F (2) -I _E (2)) × δ, and similarly, temperature image data TR _B Temperature pixel data TP in (N) _{i, j} Exposure elapsed time τ (N) of τ (N) = (I _F (N) -I _E (N)) × δ. Further, the exposure elapsed time τ of the remaining temperature pixel data is obtained in the same manner.
[0038]
The time δ is the rotational speed V of the work material 8 and the length L in the circumferential direction θ of the imageable range AW. _AW And the total number of horizontal lines I of the two-dimensional imaging device, δ = L _AW / (I × V).
[0039]
The temperature change characteristic calculation unit 38 includes a plurality of files of temperature image data TR stored in the composite image memory 48. _B Pixel data TP corresponding to the same part of the cutting tool 8 _{i, j} Are arranged along the exposure elapsed time τ (1) to τ (N), and the temperature characteristic curve CP representing the tendency of the temperature change after the portion is exposed _{i, j} Is estimated.
[0040]
FIG. 8 shows temperature pixel data TP corresponding to a specific part of the cutting tool 8. _{i, j} Temperature characteristic curve CP for _{i, j} The calculation principle is shown as a representative. In the figure, temperature image data TR _B (1)-TR _B From (N), temperature pixel data TP _{i, j} (1)-TP _{i, j} (N) is read and these temperature pixel data TP _{i, j} (1)-TP _{i, j} (N) is arranged along each exposure elapsed time τ (1) to τ (N). Temperature pixel data TP using statistical processing such as curve fitting method and least square method, neural network method, etc. _{i, j} (1)-TP _{i, j} Temperature characteristic curve CP showing change tendency of (N) _{i, j} Is estimated. Further, the same estimation calculation is performed for the remaining part of the cutting tool 8 so that the temperature characteristic curve CP of all parts is obtained. _{i, j} And the data is stored in the temperature change characteristic memory 46.
[0041]
The temperature distribution calculation unit 40 includes a temperature characteristic curve CP stored in the temperature change characteristic memory 46. _{i, j} The moment t when each part of the cutting tool 8 is exposed based on the data of _r Temperature distribution at TP _{i, j} (t _r ) Is estimated and the result data is re-stored in the composite image memory 48. The moment t when each part of the cutting tool 8 is exposed. _r Is a horizontal line I corresponding to the front edge portion E of the notch 12 shown in FIG. _E (1) to I _E It is obtained from the position information of (N).
[0042]
The image composition unit 42 is configured to store the temperature distribution TP stored in the composite image memory 48. _{i, j} (t _r ) Data is interpolated by statistical processing to form two-dimensional temperature distribution data TSB representing the two-dimensional temperature distribution of the entire surface of the cutting tool 8 and store it in the composite image memory 48. The two-dimensional temperature distribution data TSB is also stored in an external storage device via the input / output port 20, reproduced and displayed on an external monitor device, and printed on a hard copy.
[0043]
Next, a series of operations of this non-contact temperature distribution measuring apparatus will be described based on the flowchart shown in FIG.
[0044]
When the apparatus is activated, in step S100, the imaging control unit 16 is activated, and the work detection unit 6 and the measurement condition setting unit 24 detect the light detection signal S of the optical sensor 4 while the work material 6 rotates 5 to 10 times. _PD Based on the above, various measurement conditions such as the reference delay time Δ and the rotation speed V of the work material 6 are obtained. During this process, the process for obtaining the two-dimensional temperature distribution by the image processing unit 18 is not performed, and the image signal S _AW Is transferred to the external display device or the like via the A / D converter 30 and the input / output port 20.
[0045]
When the various measurement conditions are obtained, the process proceeds to step S110, and the image processing unit 18 is activated. First, in step S120, the image signal S output from the camera mechanism 2 in synchronization with the delay time τm set by the drive unit 28. _AW A / D converter 30 converts digital image data D _AW And stored in the captured image memory 44. Here, the digital image data D for a frame image sufficient to obtain the two-dimensional temperature distribution on the surface of the cutting tool 8 _AW The imaging process is performed until the image is collected.
[0046]
Enough digital image data D _AW In step S130, the temperature compensator 32 performs luminance component digital image data D in step S130. _AW Temperature image data TD of the temperature component _AW Convert to Next, in step S140, the temperature range data TD is obtained by the measurement range extraction unit 34. _AW Temperature image data TR related to the exposed surface of the cutting tool 8 _B To extract. Next, in step S150, the exposure elapsed time determination unit 36 performs temperature image data TR. _B The exposure elapsed time τ of each part of the exposed surface is obtained based on Next, in step S160, the temperature change characteristic calculation unit 38 performs the temperature characteristic curve CP at each part of the exposed surface. _{i, j} Ask for.
[0047]
In step S170, the temperature distribution calculation unit 40 determines that the temperature characteristic curve CP. _{i, j} The exposed moment t of the cutting tool 8 based on _r The two-dimensional temperature distribution data TBS at is calculated. In step S180, the image synthesis unit 42 interpolates the missing data of the two-dimensional temperature distribution data TBS to obtain two-dimensional temperature distribution data TSB representing the entire two-dimensional temperature distribution of the cutting tool 8, and a series of the data. The process ends.
[0048]
Thus, according to this embodiment, the temperature distribution when the cutting tool 8 passes through the notch 12 is measured, and the cutting tool 8 cuts the surface 10 to be cut based on the data of the temperature distribution. The two-dimensional temperature distribution of the cutting tool 8 can be measured with high accuracy even if the cutting tool 8 is hidden by chips during the cutting process. .
[0049]
In the above description, the measurement condition setting unit 24 is provided in the imaging control unit 16, and the measurement condition is automatically obtained by the measurement condition setting unit 24. However, the present invention is limited to this configuration. Is not to be done. For example, when the measurement conditions such as the rotational speed V and the delay reference time Δ are known, the data of these measurement conditions may be stored in advance in the measurement condition storage memory 26 via the input / output port 20. Good. In this case, the measurement condition setting unit 24 can be omitted.
[0050]
Further, when the material of the work material 6 and the cutting tool 8 and the temperature change characteristic when the cutting tool 8 is exposed are known in advance, the temperature characteristic curve CP. _{i, j} These data may be stored in the temperature change characteristic storage memory 46 via the input / output port 20. In this case, the exposure elapsed time determination unit 36 and the temperature change characteristic calculation unit 38 can be omitted. The temperature characteristic curve CP _{i, j} Is stored in the temperature change characteristic storage memory 46, the digital image data D corresponding to one frame image when the cutting tool 8 is exposed. _AW This temperature characteristic curve CP _{i, j} The moment t at which each part of the cutting tool 8 is exposed only by applying to the data of _r Temperature distribution at TP _{i, j} (t _r ) Can be calculated. For this reason, the digital image data D _AW The processing time (time required for imaging) for sampling can be shortened, and the two-dimensional temperature distribution can be measured at a higher speed.
[0051]
Furthermore, when the reference delay time Δ is made equal to a so-called frame period preset in the camera mechanism 2, the imaging control unit 16 may be omitted. That is, the synchronization detection unit 22, the measurement condition setting unit 24, the measurement condition storage memory 26, and the drive unit 28 in the imaging control unit 16 illustrated in FIG. 1 are omitted, and the image processing unit 18 uses this frame period as the reference delay time Δ. By performing the image processing described above, a two-dimensional temperature distribution can be obtained. In this case, the optical sensor 4 can also be omitted.
[0052]
Furthermore, although the configuration in which the surface sequential imaging is performed by the camera mechanism 2 including the two-dimensional imaging device has been described, a configuration in which line sequential imaging or point sequential imaging is performed may be employed.
[0053]
FIG. 10 shows a configuration example of a camera mechanism that performs line-sequential imaging. In the figure, the rotary mirror 50 is disposed opposite to the work material 6 and is rotated at a predetermined angular velocity Δi in the same direction θi as the rotation direction θ of the work material 6, and is reflected by the rotary mirror 50. A line sensor 52 for receiving an optical image is provided, and an image signal S output from the line sensor 52 is provided. _AW Is supplied to the A / D converter 30 in FIG. And the image signal S _AW Digital image data D in frame image units _AW To the captured image memory 44, and this digital image data D _AW The two-dimensional temperature distribution can be obtained by performing the image processing in the image processing unit 18.
[0054]
FIG. 11 shows a configuration example of a camera mechanism that performs point sequential imaging. In the figure, a rotating mirror 54 that is disposed opposite to the work material 6 and rotates at a predetermined angular velocity Δi in the same direction θi as the rotation direction θ of the work material 6, and the rotation direction θi of the rotation mirror 54. A polygon mirror 56 that rotates at a predetermined angular velocity Δj in a direction θj perpendicular to the angle θ, and a light receiving element 58 such as a phototransistor that receives reflected light from the polygon mirror 56 are provided, and an image output from the light receiving element 58 Signal S _AW Is supplied to the A / D converter 30 in FIG. And the image signal S _AW Digital image data D in frame image units _AW To the captured image memory 44, and this digital image data D _AW The two-dimensional temperature distribution can be obtained by performing the image processing in the image processing unit 18.
[0055]
As described above, when the configuration is such that line-sequential or point-sequential imaging scanning is performed, the camera mechanism 2 can be realized at a lower cost than the configuration where plane-sequential imaging is performed.
[0056]
Moreover, although the above description demonstrated the usage aspect which cuts the outer peripheral surface of the workpiece 6 with the cutting tool 8, this apparatus is applicable also to another usage aspect.
[0057]
FIG. 12 shows a case where the inner wall of the cylindrical workpiece 60 rotating in the circumferential direction θ is cut with the cutting tool 8 using various lathe devices.
[0058]
In this case, a notch 62 made of a slit-like recess or through hole is formed in advance on a part of the inner wall of the work material 60, and when the cutting tool 8 passes the notch 62 temporarily. To be exposed. Then, the two-dimensional temperature distribution during the cutting process of the cutting tool 8 can be measured by capturing an image of the cutting tool 8 in the exposed state with the camera mechanism 2 and performing image processing with the image processing unit 18.
[0059]
Further, as shown in the figure, a thin optical fiber 64 is extended to the camera mechanism 2, and an image of the cutting tool 8 is introduced from the distal end portion (light incident end) of the optical fiber 64 and is captured by an imaging device. You may do it. When the optical fiber 64 is provided in this way, it is possible to measure a two-dimensional temperature distribution of a cutting tool when a fine part is cut or a complicated part of the structure is cut.
[0060]
【The invention's effect】
As described above, according to the present invention, a substantial non-cutting period is set during the cutting process, image information of the cutting tool that is exposed during the non-cutting period is obtained, and based on this image information. The temperature change characteristics of each part of the cutting tool are obtained, and the temperature at the moment when the cutting tool is exposed is estimated and calculated based on the temperature change characteristic. Since the two-dimensional temperature distribution is formed, even if chips are generated, the influence can be removed and the two-dimensional temperature distribution of the cutting tool can be measured.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a non-contact temperature distribution measuring apparatus according to an embodiment.
FIG. 2 is an explanatory diagram showing an example of an installation mode of a non-contact temperature distribution measuring device.
FIG. 3 is an explanatory diagram illustrating the principle of imaging scanning.
FIG. 4 is a timing chart for explaining the principle for synchronizing a measurement object and an imaging scan.
FIG. 5 is an explanatory diagram illustrating an image obtained by imaging scanning in synchronization with a delay time.
FIG. 6 is an explanatory diagram illustrating a principle for extracting image data of an exposed surface.
FIG. 7 is an explanatory diagram for explaining the principle for obtaining the elapsed exposure time.
FIG. 8 is an explanatory diagram for explaining the principle for obtaining a temperature change curve;
FIG. 9 is a flowchart illustrating a series of operations until a two-dimensional temperature distribution is obtained by a non-contact temperature distribution measuring apparatus.
FIG. 10 is a configuration explanatory diagram illustrating a modified example of the imaging unit.
FIG. 11 is a configuration explanatory diagram illustrating another modification of the imaging unit.
FIG. 12 is an explanatory diagram for explaining another application example of the non-contact temperature distribution measuring apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 2 ... Camera mechanism, 4 ... Optical sensor 6, 60 ... Work material, 10 ... Surface to be cut, 12, 62 ... Notch part, 14 ... Control part, 16 ... Imaging control part, 18 ... Image processing part, 20 ... Input / output port, 22 ... synchronization detection unit, 24 ... measurement condition setting unit, 26 ... measurement condition storage memory, 28 ... drive unit, 30 ... A / D converter, 32 ... temperature compensation unit, 34 ... measurement range extraction unit, 36: Exposure elapsed time determination unit, 38 ... Temperature change characteristic calculation unit, 40 ... Temperature distribution calculation unit, 42 ... Image composition unit, 44 ... Captured image memory, 46 ... Temperature change characteristic storage memory, 48 ... Composite image memory, 64 ... optical fiber.

Claims (5)

In a non-contact temperature distribution measuring device that measures the two-dimensional temperature distribution of a cutting tool during cutting,
Cutting that sets a substantial cutting period by bringing the cutting tool and the work material into contact with each other and a substantial non-cutting period by separating the cutting tool and the work material during the cutting process. State setting means;
Imaging means for imaging the cutting tool a plurality of times for each predetermined delay time;
A plurality of pieces of image information obtained by a plurality of times of image pickup by the image pickup means are associated with the exposure elapsed time from the switching time for each piece of information corresponding to the same part of the cutting tool, and the image with respect to the exposure elapsed time A change characteristic calculating means for obtaining a change tendency of information;
Temperature distribution calculating means for calculating a two-dimensional temperature distribution of the cutting tool at the time of switching based on the change tendency obtained by the change characteristic calculating means;
A non-contact temperature distribution measuring device comprising: The imaging means includes sensor means for detecting a time point when the cutting period is switched to the non-cutting period, and the cutting tool is provided at each predetermined delay time with reference to the switching time point detected by the sensor means. The non-contact temperature distribution measuring apparatus according to claim 1, wherein imaging is performed a plurality of times. Image information obtained by imaging the cutting tool during the non-cutting period is extracted from a plurality of image information obtained by a plurality of times of imaging by the imaging means, and the extracted image information is extracted from the plurality of image information. The non-contact temperature distribution measuring device according to claim 1, further comprising a measurement range extracting unit that causes the change characteristic calculating unit to process a plurality of pieces of image information obtained by one imaging. The non-contact temperature distribution measuring apparatus according to claim 1, wherein the imaging unit includes an optical fiber that guides and images at least an image of the cutting tool. 2. The non-contact temperature distribution measuring apparatus according to claim 1, wherein the imaging unit includes an imaging optical system that is set to perform fine imaging with a focal length of 50 mm or more and a resolving power higher than 30 μm.

Images