JP2016176791A - Temperature measuring device and dimension measuring device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature measuring device capable of measuring temperature distribution of an object to be measured precisely although the measurement uses a non-contact-type temperature sensor having a problem of measurement precision individually.SOLUTION: The temperature measuring device measures temperature distribution of an object to be measured by a non-contact-type temperature sensor 3. The temperature measuring device includes: emissivity masters Mw, Ma including emissivity equal to emissivity of the object to be measured; contact-type temperature sensors 5, 7 provided in the emissivity masters; an emissivity setting part for setting an emissivity setting value in that a temperature of the emissivity masters Mw, Ma measured by the non-contact-type temperature sensor 3 becomes equal to a measurement temperature by the contact-type temperature sensors 5, 7; and a temperature correction part for correcting information on actual temperature distribution measured by the non-contact-type temperature sensor 3 set to the emissivity setting value by using the temperature measurement value by the contact-type temperature sensors 5, 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a temperature measuring device and a dimension measuring device using the same.

  In general, a dimension measuring device such as a three-dimensional measuring device for measuring the length of an object to be measured in three axial directions is known. Since the reference temperature at the time of dimension measurement is set to 20 ° C. based on an international standard, it has been necessary to perform accurate dimension measurement in a temperature-controlled room controlled to 20 ° C. However, in recent years, with the improvement of production efficiency, the demand for measurement at a place close to the machining manufacturing site has increased, and the number of cases in which the dimension measuring device is installed around the machining manufacturing site has increased.

  However, it is rare that the ambient temperature at the processing and manufacturing site is kept constant at 20 ° C. When the dimension measuring apparatus is used in such an environment, an error due to thermal deformation of the dimension measuring apparatus and the object to be measured is generated, so that highly accurate measurement becomes difficult. Further, even when measuring in a temperature-controlled room controlled at 20 ° C., it is necessary to adjust the temperature of the dimension measuring device main body and the object to be measured to 20 ° C. for a long time in the temperature-controlled room. Therefore, there is a problem that it takes time to measure the dimensions.

  As a prior art for solving the above problem, a technique described in Patent Document 1 is known. In this technology, the temperature of each axis of the dimension measuring device (three axes in the case of the three-dimensional measuring device) and the temperature of the object to be measured are measured by the temperature detecting means, and the dimension measurement value is corrected based on the detected temperature. Yes.

  In a dimension measuring apparatus that requires high accuracy, temperature correction is generally essential. Therefore, it is necessary to accurately grasp the temperature of the dimension measuring apparatus main body and the object to be measured. Conventionally, a contact temperature sensor with high measurement accuracy has been mainly used as a temperature measurement means in such a case. However, the contact-type temperature sensor has problems such as cable routing and is difficult to attach to the movable part of the dimension measuring device. In addition, when replacing the object to be measured, it is necessary to attach and detach a sensor to the object to be measured every measurement, which is not suitable for automation.

  Moreover, the measured object rarely has a uniform temperature distribution in each part, and often has a slight temperature difference for each part. Therefore, in order to perform temperature correction with high accuracy, it is necessary to accurately grasp the entire temperature distribution of the object to be measured. However, the contact temperature sensor measures only one point with the sensor attached, and cannot grasp the temperature distribution of the entire object to be measured. If the number of contact temperature sensors is increased and multipoint measurement is performed, the overall temperature distribution can be roughly grasped. In this case, however, problems such as an increase in the number of cables occur, which is not preferable.

  On the other hand, a non-contact temperature measurement method using a radiation thermometer is also known. However, since the radiation thermometer outputs different results depending on the emissivity of the object to be measured, highly accurate temperature measurement is difficult.

JP-A-11-190617

  The present invention has been made in view of the above-mentioned matters, and its purpose is to measure the temperature distribution of the object to be measured with high accuracy while measuring by itself using a non-contact temperature sensor that has a measurement accuracy problem. It is an object of the present invention to provide a temperature measuring device capable of measuring, and a dimension measuring device using the same.

The present invention has the following configuration.
(1) A temperature measuring device for measuring a temperature distribution of the object to be measured by detecting infrared radiation from the object to be measured by a non-contact temperature sensor,
An emissivity master having an emissivity equal to that of the object to be measured;
A contact temperature sensor provided in the emissivity master;
The temperature distribution of the region including the object to be measured and the emissivity master is measured by the non-contact temperature sensor to obtain adjustment temperature distribution information, and the position of the emissivity master obtained from the adjustment temperature distribution information An emissivity setting unit for setting an emissivity set value of the non-contact type temperature sensor so that the temperature of
The actual temperature distribution information is obtained by measuring the temperature distribution of the object to be measured by the non-contact temperature sensor in which the emissivity setting value is set, and the actual temperature distribution information is measured by the contact temperature sensor. A temperature correction unit for correcting using values,
A temperature measuring device comprising:
(2) A plurality of the emissivity masters are provided for each of a plurality of parts having different emissivities of the device under test.
The emissivity setting unit sequentially sets the non-contact temperature sensor to the emissivity setting value for each part,
The temperature measuring device according to (1), wherein the temperature correction unit corrects the actual temperature distribution information measured for each of the emissivity setting values by the non-contact temperature sensor.
(3) The temperature measuring device according to (1) or (2), wherein the non-contact temperature sensor is a radiation thermometer that measures a two-dimensional temperature distribution.
(4) The temperature measuring device according to any one of (1) to (3);
A dimension measuring unit for measuring the dimension of the object to be measured;
A dimension correction unit that corrects a dimension measurement value obtained by the dimension measurement unit based on a difference between a corrected temperature obtained by the temperature measurement device and a predetermined reference temperature;
A dimension measuring apparatus comprising:

  According to the present invention, it is possible to measure the temperature distribution of an object to be measured with high accuracy while using a non-contact temperature sensor that has a measurement accuracy problem alone, thereby enabling highly accurate dimension measurement. It becomes.

It is a figure for demonstrating embodiment of this invention, and is a perspective view which shows the whole structure of a dimension measuring apparatus. It is an external appearance perspective view which shows the principal part structure of a dimension measurement part. It is a partial block diagram which shows the structure of the X-axis direction linear motion mechanism which moves a measuring element. It is a control block diagram of a dimension measuring device. It is a flowchart which shows the procedure of temperature correction. It is explanatory drawing which shows the measurement point by a radiation thermometer. It is a flowchart which shows the procedure of temperature correction.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view showing an overall configuration of a dimension measuring apparatus, for explaining an embodiment of the present invention.

  The dimension measuring apparatus 100 includes a dimension measuring unit 200 that measures the dimension of an object to be measured (hereinafter referred to as a workpiece W), and a part necessary for compensating for thermal deformation due to temperature changes in the workpiece W and the dimension measuring unit 200. A temperature measuring device that measures temperature, and a dimension correcting unit that corrects a dimension measurement value based on a difference between a temperature measured by the temperature measuring device and a predetermined reference temperature (20 ° C.).

  The temperature measuring device includes a radiation thermometer 3 that is a non-contact temperature sensor that detects a temperature distribution of an object to be measured by detecting infrared radiation from the object to be measured, and contact temperature sensors 5 and 7. The radiation thermometer 3 measures the temperature distribution of the workpiece W and the dimension measuring unit 200, and the contact temperature sensors 5 and 7 measure the temperature of a specific part of the dimension measuring unit 200.

  The dimension correction unit calculates the dimension measurement value of the workpiece W by the dimension measurement unit 200 based on the temperature distribution measured by the radiation thermometer 3 and the temperature measurement value of the specific part measured by the contact temperature sensors 5 and 7. to correct.

  The temperature measuring device and the dimension correcting unit include a control unit 1 that performs overall control of the dimension measuring device 100. The control unit 1 includes a PC (personal computer), a PLC (programmable logic controller), and the like. Details of the temperature measuring device and the dimension correcting unit will be described later.

<Configuration of dimension measuring unit>
First, the configuration of the dimension measuring unit 200 will be described.
The dimension measuring apparatus 100 includes a gantry 11, a mounting table 13 provided on the gantry 11 on which a workpiece W is placed, a pair of measuring elements 15A and 15B, a pair of measuring elements 17A and 17B, and each measuring element. An X linear motion mechanism 21 that drives in the X axis direction, a Z linear motion mechanism 25 that drives in the Z axis direction, and a Y linear motion mechanism 27 that drives in the Y axis direction are provided.

  The X linear motion mechanism 21 is provided on the mounting plate 19, the Z linear motion mechanism 25 is provided on the frame 23, and the Y linear motion mechanism 27 is provided on the gantry 11.

  The mounting table 13 is directly connected to a rotating shaft (not shown) installed in the gantry 11 and supports the workpiece W in a rotatable manner. For example, if the workpiece W is cylindrical, the workpiece W supported on the mounting table 13 can be rotated at an arbitrary rotation angle with the cylindrical center of the workpiece W as the rotation center.

  The pair of measuring elements 15A and 15B and the pair of measuring elements 17A and 17B have an equivalent structure. The base ends of the measuring elements 15A, 15B, 15C, and 15D are connected to the X linear motion mechanism 21, respectively, and the measuring elements 15A, 15B, 15C, and 15D are independently supported to be movable in the X-axis direction. The

FIG. 2 is an external perspective view showing the main configuration of the dimension measuring unit.
The X linear motion mechanism 21 includes a ball screw mechanism 31 and a linear guide portion 33. The ball screw mechanism 31 includes a ball screw 35 disposed on the mounting plate 19 along the X-axis direction, a servo motor 37 that rotationally drives the ball screw 35, and nut portions 39A and 39B.

  The nut part 39A supports the measuring element 15A, and the nut part 39B supports the measuring element 17A. The nut portions 39A and 39B are moved in the X-axis direction by the rotation of the ball screw 35 while being screwed together with the ball screw 35.

  The linear guide portion 33 includes a guide rail 41 and sliders 43A, 43B, 45A, and 45B that move in the X-axis direction along the guide rail 41. A probe 15A is fixed to the slider 43A, and a probe 15B is fixed to the slider 43B. Further, the measuring element 17A is fixed to the slider 45A, and the measuring element 17B is fixed to the slider 45B.

  Since the pair of measuring elements 15A and 15B and the pair of measuring elements 17A and 17B have the same configuration, the pair of measuring elements 15A and 15B will be described below as an example.

FIG. 3 is a partial configuration diagram showing the configuration of the X-axis direction linear motion mechanism that moves the probe.
When the workpiece W of the object to be measured has a cylindrical shape, the measuring element 15A functions as a measuring element for measuring the outer diameter, and the measuring element 15B functions as a measuring element for measuring the inner diameter.

  Each measuring element 15A, 15B has long arm portions 47A, 47B extending downward from the X linear motion mechanism 21 side toward the workpiece W. Electric micrometers 49A and 49B serving as displacement detection units for measuring the distance from the workpiece W are disposed at the distal ends of the arms 47A and 47B on the workpiece W side.

  The electric micrometers 49A and 49B are comparative length measuring devices that measure by converting a minute displacement of the contact type touch element 51 into an electrical quantity. The contact 51 is provided so as to protrude from the main body of the electric micrometers 49A and 49B along the distance detection direction, and is elastically biased and supported in the protruding direction. The electric micrometers 49A and 49B output the position of the contact 51 within a predetermined length of detectable stroke as distance information. In the case of this configuration, the contacts 51, 51 of the electric micrometers 49A, 49B are arranged on the contact side of the arm portions 47A, 47B facing each other and the workpiece W.

  One end of an electric actuator 53 connected to the base end of the probe 15B is connected between the nut portion 39A of the probe 15A and the slider 43A. The electric actuator 53 is provided on the measuring element 15B, and moves the measuring element 15B closer to or away from the measuring element 15A along the X-axis direction.

  A linear scale 55 is arranged on the side of the ball screw 35 of the guide rail 41 on the mounting plate 19. A detection head 59 is arranged at a position facing the linear scale 55 of the probe 15A. The detection head 59 detects the position of the arm portion 47A in the X-axis direction from the linear scale 55 facing the detection head 59. Further, a detection head 63 is disposed at a position facing the linear scale 55 of the probe 15B. The detection head 63 detects the position of the arm portion 47B in the X-axis direction from the linear scale 55.

  The dimension measuring unit 200 having the above configuration detects the position of the workpiece W in the X-axis direction while the tip ends of the measuring elements 15A and 15B sandwich the outer peripheral surface 73 and the inner peripheral surface 75 of the workpiece W and are in contact with the workpiece W. .

  The dimension measuring unit 200 includes an emissivity master Mw having an emissivity equal to the emissivity of the object to be measured, and an emissivity master Ma having an emissivity equal to the emissivity of the measuring elements 15A, 15B, 15C, and 15D. Prepare. In the case of this configuration, the emissivity master Mw is formed of the same material as the workpiece W, and the emissivity master Ma is formed of the same material as the arm portions 47A and 47B.

<Configuration of temperature measuring device>
The temperature measuring device includes a radiation thermometer 3 that is a non-contact temperature sensor that detects the infrared radiation from the object to be measured and measures the temperature distribution of the object to be measured, and a contact temperature sensor that is attached to the emissivity master Mw. 5 and a contact-type temperature sensor 7 attached to the emissivity master Ma.

  As the radiation thermometer 3, for example, a thermography capable of measuring a two-dimensional temperature distribution is used. As the contact temperature sensors 5 and 7, for example, a platinum temperature sensor, a thermocouple, or the like is used.

  In this configuration example, two types of emissivity masters are prepared, but one type of emissivity master is provided for each of a plurality of parts (each material) having different emissivities of the object to be measured as necessary. What is necessary is just to provide above.

<Dimension measurement procedure using dimension measurement device>
Next, the dimension measurement procedure by the dimension measuring apparatus 100 will be described. FIG. 4 is a control block diagram of the dimension measuring apparatus 100. The operation using the measuring elements 15A and 15B will be described here as well.

  In response to the measurement start signal input to the input unit 77, the control unit 1 outputs a drive signal to each of the X linear motion mechanism 21, the Z linear motion mechanism 25, and the Y linear motion mechanism 27, and the measuring element 15A, 15B is moved to a desired position in the space.

  The controller 1 keeps the contact 51 in contact with a workpiece such as the workpiece W, takes in the distance detection signal output from the electric micrometer 49A of the measuring element 15A, and also uses the electric micrometer 49B of the measuring element 15B. Captures the distance detection signal output by.

  The control unit 1 obtains a dimension measurement value of the object to be measured based on the captured distance detection signal. Information on the obtained dimension measurement values is stored in the storage unit 81.

  The dimension measurement by the dimension measuring unit 200 of this configuration is to obtain a relative dimension difference between the master body (the master work Wm described above) and the work W, that is, the dimensions of the master work Wm and the dimensions of the work W. And measure the difference between the two.

  The master work is guaranteed to have a prescribed size, and has the same shape as or a shape close to the work W that is the object to be measured. Here, as shown in FIG. 1, a master work Wm constituted by a block gauge is used as an example. The dimension information of the master work is registered in advance in the storage unit 81 or separately registered before the dimension measurement so that the control unit 1 can refer to it.

  When measuring the dimensions, the control unit 1 drives the X linear movement mechanism 21, the Z linear movement mechanism 25, and the Y linear movement mechanism 27 to move the measuring elements 15A and 15B to positions where the master work Wm is set in advance from the standby position. Move to.

  And the control part 1 drives the X linear motion mechanism 21, the Z linear motion mechanism 25, and the Y linear motion mechanism 27 according to the shape of the master work Wm based on a manual operation or a pre-registered algorithm, The measuring elements 15A and 15B are moved to positions where the electric micrometers 49A and 49B of the measuring elements 15A and 15B come into contact with the master work Wm.

  That is, as shown in FIG. 3, the control unit 1 moves the measuring element 15 </ b> A to the outside of the outer surface (the surface corresponding to the outer peripheral surface 73 of the workpiece W) in the dimension measurement portion of the master workpiece Wm. At this time, the probe 15B is moved to the inside of the inner side surface (the surface corresponding to the inner peripheral surface 75 of the workpiece W) in the dimension measurement portion of the master workpiece Wm.

  Then, the control unit 1 drives the ball screw mechanism 31 to move the measuring element 15A in the X-axis direction until the contact 51 of the electric micrometer 49A comes into contact with the master work Wm. Further, the control unit 1 drives the electric actuator 53 to move the probe 15B toward the probe 15A until the contact 51 of the electric micrometer 49B comes into contact with the master work Wm.

  As a result, the outer peripheral surface and the inner peripheral surface of the master work Wm are sandwiched between the electric micrometers 49A and 49B. The controller 1 detects the distance from the master work Wm (the amount by which the toucher 51 is pushed) by the electric micrometers 49A and 49B with the master work Wm sandwiched therebetween. Further, the absolute position of the linear scale 55 in the X-axis direction is read by the detection heads 59 and 63.

  Then, the control unit 1 causes the storage unit 81 to store the detected output values from the electric micrometers 49A and 49B and the output values from the detection heads 59 and 63 as reference values. Each output value at this time becomes an output value corresponding to a reference point (origin) when the workpiece W is measured.

  When the setting of the reference value is completed, the control unit 1 drives the X linear motion mechanism 21, the Z linear motion mechanism 25, and the Y linear motion mechanism 27 to temporarily retract the measuring elements 15 </ b> A and 15 </ b> B, and then the mounting table 13. The workpiece W is moved to the set position of the workpiece W, and the dimension measurement of the workpiece W is started.

  The controller 1 drives the X linear motion mechanism 21, the Z linear motion mechanism 25, and the Y linear motion mechanism 27 in the same manner as the measurement of the master work Wm, and moves the measuring elements 15A and 15B to desired measurement positions. . And the control part 1 detects the distance (the amount by which the touch element 51 was pushed in) with the electric micrometer 49A, 49B in the state which the measurement elements 15A and 15B have completed the movement to the measurement position. Further, the absolute position of the linear scale 55 in the X-axis direction is read by the detection heads 59 and 63.

  The control unit 1 causes the storage unit 81 to store the detected output values from the electric micrometers 49A and 49B and the output values from the detection heads 59 and 63.

  Next, the control unit 1 calculates a dimension measurement value of the workpiece W using various output values stored in the storage unit 81. That is, the difference between the first distance obtained by measuring the master workpiece Wm having a known dimension and the second distance obtained by measuring the workpiece W is obtained, and these differences are added to the known dimensions of the master workpiece. By doing so, the dimension measurement value of the workpiece W is obtained.

  When calculating this dimensional measurement value, the control unit 1 compensates for the amount of thermal deformation generated according to the temperature difference between the workpiece W and the arm portions 47A and 47B from the reference temperature (20 ° C.). Correct the measured value.

<Thermal deformation amount correction processing procedure>
Next, a procedure for performing temperature compensation of the dimension measurement value measured by the control unit 1 will be described with reference to the flowcharts of FIGS. Each procedure shown below is centrally controlled by the control unit 1.

In this specification, various temperature measurement values are defined as follows.
Tw ₀ : Measurement value of the emissivity master Mw with respect to the workpiece W by the contact type temperature sensor 5 Ta ₀ : Measurement by the contact type temperature sensor 7 of the emissivity master Ma with respect to the arm part (hereinafter referred to as the arm part 47A as an example) Value tw ₀ : Measurement value of the emissivity master Mw for the workpiece W by the radiation thermometer 3 ta ₀ : Measurement value of the emissivity master Ma for the arm portion 47A by the radiation thermometer 3 tw: Measurement value of the workpiece W by the radiation thermometer 3 ta: Value measured by the radiation thermometer 3 of the arm portion 47A

FIG. 6 shows a two-dimensional temperature distribution image IMG including areas of the work W, the arm portion 47A, and the emissivity masters Mw and Ma by the radiation thermometer 3, and each measurement point. As preparation for temperature measurement by the radiation thermometer 3, first, the following coordinate values of each part in the temperature distribution image are obtained and stored in the storage unit 81 (see FIG. 4).
The position of the emissivity master Ma with respect to the arm portion 47A (X1, Y1)
-Position of arm 47A (X2, Y2)
-Position of the emissivity master Mw of the object to be measured (X3, Y3)
・ Measurement position (X4, Y4)

From the temperature distribution image IMG, temperature measurement values tw ₀ , ta ₀ , tw, ta are obtained as follows.
- determine the temperature measurements of the measurement points P1 emissivity master Ma (X1, Y1), which is referred to as ta _0.
A temperature measurement value at the measurement point P2 (X2, Y2) of the arm portion 47A is obtained, and this is defined as ta.
- determine the temperature measurement value of the measurement point P3 emissivity master Mw (X3, Y3), which is referred to as tw _0.
-The temperature measurement value of the measurement point P4 (X4, Y4) of the workpiece W is obtained and is defined as tw.

After the above preparation process, the control unit 1 measures the temperature Tw ₀ of the emissivity master Mw using the contact temperature sensor 5 of the emissivity master Mw. Further, the temperature Ta ₀ of the emissivity master Ma is measured by the contact-type temperature sensor 7 of the emissivity master Ma (S11 in FIG. 6).

  Next, emissivities εw and εa of the radiation thermometer 3 at which the temperature measured values by the contact temperature sensors 5 and 7 and the radiation thermometer 3 are equal are obtained (S12). Details of this processing are shown in the flowchart of FIG.

First, the emissivity εw for the workpiece W is obtained. First, an initial value εw ₀ of a predetermined emissivity setting value is set as an emissivity setting value of the radiation thermometer 3 (S21). Then, a two-dimensional temperature distribution image (first adjustment temperature distribution information) is acquired by the radiation thermometer 3 in which the emissivity setting value is set to the initial value εw ₀ (S22).

From the acquired temperature distribution image, reference is made to the coordinate value (measurement point) in the image of the workpiece W, and the temperature measurement value tw ₀ of each part is obtained (S23).

Then, compared with tw ₀ determined by a radiation thermometer, and Tw ₀ obtained by the contact-type temperature sensor 5 (S24). When both values are different, the emissivity set value is changed (S25), the measurement with the radiation thermometer 3 is performed again, and the processing from S22 is repeated. At this time, Tw ₀ may be measured again by the contact temperature sensor 5. By measuring Tw ₀ each time the processing from S22 is repeated, the measurement accuracy by the radiation thermometer 3 can be further improved.

When the measured values of tw ₀ and Tw ₀ are equal, the emissivity setting value of the radiation thermometer 3 at that time is determined as the emissivity εw (S26).

Next, in the same manner as described above, the emissivity εa for the arm portion 47A is set to the emissivity set value of the radiation thermometer 3 until ta ₀ obtained by the radiation thermometer is equal to Ta ₀ obtained by the contact temperature sensor 5. Change the value gradually and measure repeatedly.

That is, the predetermined initial value εa ₀ of the emissivity εa is set as the emissivity setting value of the radiation thermometer 3 (S21). Then, a two-dimensional temperature distribution image (second adjustment temperature distribution information) is acquired by the radiation thermometer 3 in which the emissivity setting value is set to the initial value εa ₀ (S22).

From the acquired temperature distribution image, reference is made to a coordinate value (measurement point) in a predetermined image to obtain a temperature measurement value ta ₀ of each part (S23).

Then, compared with ta ₀ determined by a radiation thermometer, and a Ta ₀ obtained by the contact-type temperature sensor 7 (S24). If both values are different, the emissivity set value is changed (S25), and the measurement by the radiation thermometer 3 is repeated until both values are equal. At this time, Ta ₀ may be measured again by the contact temperature sensor 7.

As described above, the emissivity εw at which Tw ₀ and tw ₀ are equal and the emissivity εa at which Ta ₀ and ta ₀ are equal are obtained by measuring the temperature distribution image for each emissivity set value.

  Note that the initial value of the emissivity setting value may be a value registered in advance in the storage unit 81 (see FIG. 4), or may be a value input from the input unit 77.

Next, the emissivity set value of the radiation thermometer 3 is set to the obtained emissivity εw, and a temperature distribution image (first actual temperature distribution information) is acquired by the radiation thermometer 3 (S13 in FIG. 5). . Further, the temperature measurement value Tw ₀ at the position of the emissivity master Mw is obtained by the contact-type temperature sensor 5 attached to the emissivity master Mw (S14).

Then, from the temperature distribution image acquired by the radiation thermometer 3, the temperature measurement value tw _{0 at} the position of the emissivity master Mw [measurement point P3 (X3, Y3)] and the actual position of the workpiece W [measurement point P4 (X4 , Y4)] is obtained (S15).

Next, the emissivity set value of the radiation thermometer 3 is set to the obtained emissivity εa, and a temperature distribution image (second actual temperature distribution information) is acquired by the radiation thermometer 3 (S16). Also, the contact temperature sensor 7 mounted on the emissivity master Ma, obtaining temperature measurements Ta ₀ at the position of the emissivity master Ma (S17).

Then, from the temperature distribution image acquired by the radiation thermometer 3, the temperature measurement value ta _{0 at} the position [measurement point P1 (X1, Y1)] of the emissivity master Ma and the actual arm position [measurement point P2 (X2 , Y2)] is obtained (S18).

  Note that the procedures for obtaining and processing the temperature distribution images of the emissivity set values εw and εa are arbitrary and are not limited to the above order.

Next, the temperature tw of the workpiece W is corrected by the following equation (1) to obtain the corrected temperature twc of the measured object.
twc = Tw ₀ + (tw−tw ₀ ) (1)
Further, the arm portion temperature ta is corrected by the following equation (2) to obtain the corrected arm portion temperature tac (S19).
tac = Ta ₀ + (ta−ta ₀ ) (2)

  Then, the amount of thermal deformation of the workpiece W and the arm portion is calculated from the difference between the corrected temperature twc of the workpiece W, the temperature tac of the arm portion, and the reference temperature (20 ° C.). The calculated amount of thermal deformation is reflected in various dimension values (S20).

  For example, when the corrected temperature twc of the workpiece W is higher than the reference temperature (20 ° C.), the thermal expansion amount of the workpiece W is calculated, and the expansion amount is subtracted from the measured dimension value of the inner and outer diameters. When the temperature is low, the amount of heat shrinkage of the workpiece W is calculated, and the amount of heat shrinkage is added to the measured value of the inner and outer diameters.

  When the corrected temperature tac of the arm part is higher or lower than the reference temperature (20 ° C.), the amount of rotation of the arm part due to thermal expansion of the arm part is calculated, and the measured value of the measured inner and outer diameters Addition / subtraction of the dimensional change according to the amount of rotation.

  By correcting the dimensional measurement values of the inner and outer diameters described above, accurate dimensional measurement values can be obtained regardless of the temperature change of each part of the apparatus. The control unit 1 performs an emissivity setting unit that sets an emissivity setting value of the radiation thermometer 3, a temperature correction unit that corrects a measurement result by the radiation thermometer 3, and a correction process of the measured dimension measurement value. It functions as a dimension correction unit to perform, and controls the entire dimension measuring apparatus 100 in an integrated manner.

  In the above example, the dimension measurement value is corrected using the temperature of the arm portion 47A. However, if necessary, the temperature of another part can be obtained and the dimension measurement value can be corrected in the same manner as described above. In the above example, two types of emissivity materials are used as the measurement object. However, the present invention is not limited to this, and a plurality of types of emissivity materials may be used as the measurement object. In that case, the same number of emissivities as the number of objects to be measured are obtained in the same manner as described above, the obtained emissivities are set as emissivity set values of the radiation thermometer, and actual temperature distribution images are sequentially measured. Using the obtained actual temperature distribution image, the dimension measurement value is corrected in the same manner as described above.

  In addition, when the workpiece W after measurement is replaced with the next workpiece and measurement is started again, the emissivity setting value obtained once may be used as it is, and the processes of S15 to S22 may be performed. Alternatively, the emissivity may be set every time the workpiece W is replaced. In the former case, the processing can be simplified, and in the latter case, more accurate measurement can be performed.

  As described above, according to the dimension measuring apparatus 100 of the present configuration, the object to be measured (work W or arm portion) can be obtained with high accuracy while being non-contact measurement using the radiation thermometer 3 having low measurement accuracy. ) Temperature can be measured. Then, by using the obtained temperature measurement value and correcting the measured dimension measurement value, highly accurate dimension measurement can be realized.

  Further, since there is no need to attach the contact temperature sensors 5 and 7 to the movable part such as the arm part, problems such as cable routing do not occur. Moreover, since it is not necessary to attach or detach a contact-type temperature sensor to the workpiece | work W in which replacement | exchange occurs, it becomes a structure advantageous to automation of a dimension measurement.

  It should be noted that the present invention is not limited to the above-described embodiments, and those skilled in the art can change or apply the configurations of the embodiments to each other or based on the description of the specification and well-known techniques. Is also within the scope of the present invention, which is intended to be protected.

  In the above embodiment, the case where the present invention is applied to a triaxial dimension measuring apparatus has been described. However, the present invention can also be applied to other measuring apparatuses that require temperature correction, such as a uniaxial dimension measuring apparatus.

1 Control unit (emissivity setting unit, temperature correction unit, dimension correction unit)
3 Radiation thermometer (non-contact temperature sensor)
5,7 Contact type temperature sensor 15A, 15B, 17A, 17B Measuring element 47A, 47B Arm part W Work Mw, Ma Emissivity master IMG Temperature distribution image

Claims (4)

A temperature measuring device that detects a temperature distribution of the object to be measured by detecting infrared radiation from the object to be measured by a non-contact temperature sensor,
An emissivity master having an emissivity equal to that of the object to be measured;
A contact temperature sensor provided in the emissivity master;
The temperature distribution of the region including the object to be measured and the emissivity master is measured by the non-contact temperature sensor to obtain adjustment temperature distribution information, and the position of the emissivity master obtained from the adjustment temperature distribution information An emissivity setting unit for setting an emissivity set value of the non-contact type temperature sensor so that the temperature of the non-contact type temperature sensor becomes equal to the temperature measured by the contact type temperature sensor;
The actual temperature distribution information is obtained by measuring the temperature distribution of the object to be measured by the non-contact temperature sensor in which the emissivity setting value is set, and the actual temperature distribution information is measured by the contact temperature sensor. A temperature correction unit for correcting using values,
A temperature measuring device comprising: A plurality of emissivity masters are provided for each of a plurality of parts having different emissivities of the device under test,
The emissivity setting unit sequentially sets the non-contact temperature sensor to the emissivity setting value for each part,
The temperature measuring device according to claim 1, wherein the temperature correcting unit corrects the actual temperature distribution information measured for each emissivity set value by the non-contact temperature sensor.   The temperature measuring device according to claim 1, wherein the non-contact temperature sensor is a radiation thermometer that measures a two-dimensional temperature distribution. The temperature measuring device according to any one of claims 1 to 3,
A dimension measuring unit for measuring the dimension of the object to be measured;
A dimension correction unit that corrects a dimension measurement value obtained by the dimension measurement unit based on a difference between a corrected temperature obtained by the temperature measurement device and a predetermined reference temperature;
A dimension measuring apparatus comprising:

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