JP6087578B2 - Ultrasonic measurement method and ultrasonic measurement apparatus - Google Patents

Description

  The present invention, for example, in an electrode production line used in a battery, exceeds the basis weight (thickness) of a workpiece or substrate coated with a coating material on one side or both sides of a belt-like substrate traveling in the longitudinal direction. The present invention relates to an ultrasonic measurement method and an ultrasonic measurement apparatus that perform in-line measurement using sound waves.

  2. Description of the Related Art Conventionally, in an electrode production line used for a battery, an electrode is produced by applying an electrode paste on a strip-shaped metal foil that runs in the longitudinal direction. The quality of this electrode greatly affects the performance of the battery product. Therefore, for quality control of the electrode, it is important to perform a quality inspection on the basis weight (thickness) and basis weight profile of the electrode paste applied to the metal foil after application of the electrode paste. As such a quality inspection, there is a case where it is widely and uniformly performed on a moving workpiece on an in-line of an electrode manufacturing line.

  Therefore, the applicant examined, for example, the total amount inspection of the basis weight of the electrode paste and the basis weight on the in-line of the electrode production line using an ultrasonic measuring device as disclosed in Patent Document 1 below. FIG. 17 is an explanatory diagram showing the ultrasonic measurement device disclosed in Patent Document 1. As shown in FIG. 17, in this apparatus, a pair of ultrasonic transmission means 101 and ultrasonic reception means 102 are arranged above the measurement object 103, and the ultrasonic waves transmitted from the ultrasonic transmission means 101 are measured. The ultrasonic wave receiving means 102 receives the reflected wave from the measurement object 103 by being applied to the object 103.

  In this apparatus, the propagation time measuring unit 104 measures the propagation time of the ultrasonic wave propagating through the measurement object 103 based on the ultrasonic wave transmitted from the ultrasonic wave transmitting unit 101 and the reflected wave received by the ultrasonic wave receiving unit 102. To do. Further, the two temperature measuring means 105 and 106 measure the temperatures of the solid phase 103b and the liquid phase 103a constituting the measurement object 103, respectively. The speed calibration means 107 calibrates the propagation speed of the propagating ultrasonic wave based on the measured temperatures of the solid phase 103b and the liquid phase 103a measured by the temperature measurement means 105 and 106. The propagation path length measurement unit 108 determines the basis weight (thickness) of the measurement object 103 based on the propagation time of the ultrasonic wave obtained by the propagation time measurement unit 104 and the calibration value of the propagation velocity by the velocity calibration unit 107. In addition, the position of the phase change of the measurement object 103 in which the solid phase 103b and the liquid phase 103a are stacked is measured.

  Here, in order to correct the deviation of the measured value for each measuring instrument based on the reference value, calibration (calibration: In general, the case where the measuring instrument is not adjusted is called “calibration”. Is distinguished from “calibration” in the accompanying case). Nothing is described in Patent Document 1 regarding this calibration. However, even in the ultrasonic measurement apparatus of Patent Document 1, it is considered that the ultrasonic sensors used as the ultrasonic transmission unit 101 and the ultrasonic reception unit 102 are calibrated. The calibration is performed, for example, by measuring the thickness of a reference material having a known thickness using a calibration ultrasonic sensor. Specifically, based on the calibration measurement value, the actual measurement value of the workpiece measured by the actual measurement ultrasonic sensor can be corrected. In order to reduce the measurement error of the ultrasonic sensor, the calibration is usually performed before or after measuring the thickness or distance of the measurement object with the ultrasonic sensor, or when the measurement is interrupted. This is done when measurement is not being performed.

JP 2008-102160 A

  However, in the ultrasonic measurement apparatus described in Patent Document 1, the following has been considered. That is, in this apparatus, the ultrasonic wave transmitted from the ultrasonic wave transmission means 101 toward the measurement object 103 or the ultrasonic wave reflected by the measurement object 103 and received by the ultrasonic wave reception means 102 is measured. It propagates through the air layer, which is a medium other than For this reason, if the temperature of the air layer is not managed, the resistance value (acoustic impedance) regarding sound changes due to the temperature change of the air layer. When the acoustic impedance changes due to the air layer, the wavelength of the ultrasonic wave propagating through the air layer changes, and if the velocity of the ultrasonic wave is simply calibrated by the speed calibration means 107, the thickness of the measurement object 103 is consequently reduced. There is a risk that accurate measurement cannot be performed.

  Further, if calibration of the ultrasonic sensor is not performed in real time at the time of actual measurement using ultrasonic waves, the ambient temperature around the ultrasonic sensor may greatly differ between the time of performing calibration and the actual measurement using ultrasonic waves. In this case, for example, the reception signal intensity of the reception-side ultrasonic sensor that receives ultrasonic waves may change due to the difference in ambient temperature.

  As an example, FIG. 18 is a graph showing the relationship between the received signal intensity and the ambient temperature for the receiving-side ultrasonic sensor. In this measurement, the reception side ultrasonic sensor in the same frequency band is set to 2 samples, and in FIG. As shown in FIG. 18, for both sensors A and B, for example, when the ambient temperature is around 20 (° C.), the received signal intensity is about 825 (mV), but the ambient temperature exceeds 23 (° C.). It can be seen that the received signal strength falls below 780 (mV), and the received signal strength actually decreases by 5 (%) or more with a temperature rise change of 3 (° C.).

  Also, the ultrasonic sensor self-heats with the passage of time when transmitting or receiving ultrasonic waves due to the characteristics of the sensor. FIG. 19 is a graph showing the relationship between self-heating and received signal intensity as an example of the receiving-side ultrasonic sensor. As shown in FIG. 19, in the reception-side ultrasonic sensor, at the start of operation (t = 0 (min)), for example, the sensor temperature was about 28.5 (° C.) after the start of operation. When a predetermined time elapses (t = 120 (min)), the temperature rose to about 30.7 (° C.) due to heat generation of the sensor itself. On the other hand, it can be seen that the received signal strength decreases from about 76200 (mV) to about 72300 (mV) by about 5 (%) while 2 hours have elapsed after the start of operation.

  In this way, for the same receiving-side ultrasonic sensor, the ambient temperature differs between when calibration is performed and when actual measurement is performed using ultrasonic waves, and the received signal intensity of ultrasonic waves also changes due to self-heating of the ultrasonic sensor. As a result, the magnitude of the wavelength of the ultrasonic wave received by the reception-side ultrasonic sensor changes. Here, the measurement by the ultrasonic wave is processed based on the magnitude of the wavelength of the ultrasonic wave received by the reception-side ultrasonic sensor. Therefore, even if the calibration is performed properly, if the calibration is not performed in real time in accordance with the actual measurement using ultrasonic waves, even if the same ultrasonic sensor is used, it may be caused by the difference in ambient temperature or self-heating. Accordingly, the wavelength of the received ultrasonic wave is different, and there is a possibility that ultrasonic measurement cannot be performed with high accuracy.

  On the other hand, even if the receiver-side ultrasonic sensor is calibrated in consideration of the difference in ambient temperature and self-heating, the temperature of the reference material used for calibration and the temperature of the workpiece for measurement may be different. . Also, the workpiece temperature and the workpiece ambient temperature may be different. In such a case, the magnitude of the wavelength of the ultrasonic wave received by the reception-side ultrasonic sensor via the reference material and the magnitude of the wavelength of the ultrasonic wave received by the reception-side ultrasonic sensor via the workpiece are Unlikely, the actual measurement value of the workpiece cannot be accurately calibrated by the calibration measurement value obtained by measuring the reference material, and there is a possibility that the ultrasonic measurement of the workpiece cannot be performed with high accuracy.

  In particular, in the electrode production line, the electrode paste may be dried by heating immediately after the electrode paste is applied to the metal foil. When ultrasonically measuring the weight (thickness) of the workpiece immediately after drying, the temperature of the reference material for calibration and the temperature of the workpiece may be different, or the temperature of the workpiece and the ambient temperature of the workpiece may be different.

  FIG. 20 is a graph showing the relationship between the coating length and the measured amount of basis weight (thickness) when the workpiece is applied at a constant temperature of 25 (° C.). FIG. 21 is a graph showing the relationship between the coating length and the measured value of the basis weight (thickness) when the workpiece is coated with the temperature increased from 25 (° C.) to 32 (° C.). When the temperature of the workpiece is constant, as shown in FIG. 20, it can be seen that the measured value of the basis weight (thickness) is maintained in a substantially constant range between the upper limit value and the lower limit value. On the other hand, when the temperature of the workpiece increases, as shown in FIG. 21, it can be seen that the measured value of the basis weight (thickness) gradually increases between the standard upper limit value and the standard lower limit value. Thus, the measured value of the workpiece weight (thickness) varies with the temperature change of the workpiece. According to the experiments so far, it was confirmed that the measured value of the basis weight (thickness) fluctuated by about 5 (%) at the maximum with the temperature change of the workpiece.

  The present invention has been made in view of the above circumstances, and the purpose of the invention is to particularly reduce the thickness of a workpiece coated with a coating material on one side or both sides of a belt-like substrate traveling in the longitudinal direction in a production line. An object of the present invention is to provide an ultrasonic measurement method and an ultrasonic measurement apparatus capable of ultrasonically measuring the thickness of a workpiece immediately after being heated and dried on a line with high accuracy.

In order to achieve the above-mentioned object, the invention described in claim 1 includes an ultrasonic sensor set including a first ultrasonic sensor and a second ultrasonic sensor, and is provided on one side of a belt-like substrate that runs in the longitudinal direction or A first ultrasonic sensor on one side and a second ultrasonic sensor on the other side of the workpiece coated with coating material on both sides in the thickness direction are arranged facing each other through an air layer, An ultrasonic measurement method for measuring the thickness of a workpiece by propagating ultrasonic waves between a first ultrasonic sensor and a second ultrasonic sensor, and for measuring the thickness of the workpiece as an ultrasonic sensor group. The ultrasonic sensor group for actual measurement and the ultrasonic sensor group for actual measurement are provided separately, and are disposed in the vicinity of the workpiece, an ultrasonic sensor group for calibration for calibrating the actual measurement value by the ultrasonic sensor group for actual measurement, Thickness by calibration ultrasonic sensor set In the ultrasonic measuring method and a predetermined reference material to be measured, while aligning the temperature of the reference material temperature of the workpiece, for calibration of the reference material thickness of the reference material and the workpiece thickness by calibration ultrasonic sensor set each The measured value of the workpiece and the measured value for calibration of the workpiece are measured, and the thickness of the workpiece is measured as the measured value of the workpiece by the measured ultrasonic sensor set at the same time or immediately after the measurement by the calibration ultrasonic sensor set, and the workpiece is calibrated. The workpiece calibration thickness is obtained based on the measured value for calibration, the measurement value for calibration of the reference material, and the known thickness of the reference material, and the actual workpiece measurement value is calculated from the measured value for workpiece calibration and the workpiece calibration. The purpose is to obtain the final thickness of the workpiece by performing correction based on the calibration thickness .

  According to the configuration of the invention, the measurement value for calibration can be obtained by measuring the thickness of the predetermined reference material arranged in the vicinity of the workpiece for calibration by the calibration ultrasonic sensor group. Since the measurement value for calibration is arranged in the vicinity of the reference material and the workpiece, environmental conditions such as ambient temperature around the calibration ultrasonic sensor group and the measurement ultrasonic sensor group are common. . Simultaneously with or immediately after the measurement by the calibration ultrasonic sensor set, the thickness of the workpiece is measured by the measurement ultrasonic sensor set. Then, the final thickness of the workpiece is obtained by correcting the actual measurement value obtained by the actual measurement ultrasonic sensor group using the calibration measurement value obtained by the calibration ultrasonic sensor group. Thus, for example, if the thickness of the reference material is known, the thickness of the workpiece is obtained by multiplying the ratio of the measured value for calibration of the reference material and the actual measurement value of the workpiece by the known thickness of the reference material. Can do. In this case, since the measurement of the thickness of the reference material and the actual measurement of the thickness of the workpiece are performed while adjusting the temperature of the reference material to the temperature of the workpiece, the temperature conditions of these measurement objects are made uniform.

  In order to achieve the above object, the invention according to claim 2 is the invention according to claim 1, wherein when measuring the thickness of the reference material and measuring the thickness of the workpiece, The purpose is to bring the ambient temperature around the calibration ultrasonic sensor set close to the workpiece temperature.

  According to the configuration of the above invention, in addition to the operation of the invention according to claim 1, the ambient temperature around the ultrasonic sensor group for actual measurement and the ultrasonic sensor group for calibration is brought close to the temperature of the workpiece. The ambient temperature of the set and the temperature of the workpiece are made uniform.

In order to achieve the above object, the invention described in claim 3 is provided with an ultrasonic sensor set including a first ultrasonic sensor and a second ultrasonic sensor, and is provided on one side of a belt-like base material that runs in the longitudinal direction. A first ultrasonic sensor on one side and a second ultrasonic sensor on the other side of the workpiece coated with coating material on both sides in the thickness direction are arranged facing each other through an air layer, In an ultrasonic measuring apparatus that measures the thickness of a workpiece by propagating ultrasonic waves between the first ultrasonic sensor and the second ultrasonic sensor, the ultrasonic sensor is provided as an ultrasonic sensor group and measures the thickness of the workpiece. In addition, at least one set of the ultrasonic sensor group for actual measurement composed of the first ultrasonic sensor and the second ultrasonic sensor, and the ultrasonic sensor group for actual measurement are provided separately from the actual ultrasonic sensor group as the ultrasonic sensor group. Calibration of actual measured values For this purpose, a calibration ultrasonic sensor set including a first ultrasonic sensor and a second ultrasonic sensor, a predetermined reference material which is disposed in the vicinity of the workpiece and whose thickness is measured by the calibration ultrasonic sensor set, Reference material heating means for heating the reference material, reference material temperature detection means for detecting the temperature of the reference material, workpiece temperature detection means for detecting the temperature of the workpiece, and temperature of the detected reference material While the reference material is heated by the reference material heating means so that the temperature of the workpiece is detected, the thickness of the reference material and the thickness of the workpiece are respectively measured by the calibration ultrasonic sensor set and the measurement value for calibrating the reference material and the workpiece. The measured thickness of the workpiece is measured as the measured value of the workpiece by the measured ultrasonic sensor set at the same time or immediately after the measurement by the calibration ultrasonic sensor set, and the measured value for the calibration of the workpiece , Group The measured value for the calibration of the timber, determined the thickness of the calibration work on the basis of the known thickness of the reference material, the measured value of the workpiece, based on the thickness of the calibration measurement values and the work for calibration of the workpiece It is intended to include measurement control means for calculating the final thickness of the workpiece by correcting.

  According to the configuration of the invention, the calibration ultrasonic sensor group, the actual measurement ultrasonic sensor group, the reference material heating means, the reference material temperature detection means, the workpiece temperature detection means, and the measurement control means are used. The ultrasonic measurement method can be implemented.

  In order to achieve the above object, the invention according to claim 4 is the atmosphere heating for heating the atmosphere around the ultrasonic sensor group for actual measurement and the ultrasonic sensor group for calibration in the invention according to claim 3. And an ambient temperature detecting means for detecting the ambient temperature around the ultrasonic sensor group for actual measurement and the ultrasonic sensor group for calibration, and the measurement control means measures the thickness of the reference material, The purpose is to heat the atmosphere by the atmosphere heating means so that the detected ambient temperature becomes the detected workpiece temperature when the thickness is actually measured.

  According to the configuration of the invention, the ultrasonic measurement method according to claim 2 can be carried out by further adding an atmosphere heating means and an atmosphere temperature detection means.

  According to the first aspect of the present invention, in the production line, the thickness of the workpiece coated with the coating material on one side or both sides of the belt-like base material running in the longitudinal direction, particularly the thickness of the workpiece immediately after heating and drying. Can be ultrasonically measured in-line with high accuracy.

  According to the invention described in claim 2, in contrast to the effect of the invention described in claim 1, the thickness of the work immediately after being heated and dried can be ultrasonically measured on the in-line with higher accuracy.

  According to the invention described in claim 3, in the production line, the thickness of the workpiece coated with the coating material on one side or both sides of the belt-like base material running in the longitudinal direction, particularly the thickness of the workpiece immediately after being heated and dried. Can be ultrasonically measured in-line with high accuracy.

  According to the invention described in claim 4, in contrast to the effect of the invention described in claim 3, the thickness of the workpiece immediately after being heated and dried can be ultrasonically measured on the in-line with higher accuracy.

The schematic block diagram which concerns on one Embodiment and shows an electrode manufacturing line. The top view showing the schematic structure of the latter stage thickness measurement part concerning one embodiment. The side view which concerns on one Embodiment and shows schematic structure of a back | latter stage thickness measurement part. Sectional drawing which concerns on one Embodiment and cut | disconnects and shows the electrode manufactured by the electrode manufacturing line in the width direction. The schematic block diagram which concerns on one Embodiment and shows arrangement | positioning of the 1st and 2nd ultrasonic sensor group for a measurement in the width direction of a workpiece | work. The schematic block diagram which shows arrangement | positioning of the ultrasonic sensor group for a calibration in the width direction of a workpiece | work concerning one Embodiment. The schematic block diagram which concerns on one Embodiment and shows a discontinuation thickness measurement part and a back | latter stage thickness measurement part. An exploded perspective view showing a relation between a reference material and a reference material heater according to one embodiment. The block diagram which shows the electric constitution of 2nd and 3rd ultrasonic measuring device concerning one Embodiment. The flowchart which shows the content of the measurement control program which concerns on one Embodiment and is performed using the ultrasonic sensor group for a calibration. The flowchart which shows the content of the measurement control program which concerns on one Embodiment and is performed using the 1st and 2nd ultrasonic sensor group for a measurement. FIGS. 4A to 4C are plan views illustrating a change in position of a calibration ultrasonic sensor group in a subsequent thickness measurement unit according to an embodiment. The flowchart which shows the content of the temperature control program which is related with one Embodiment by the 2nd and 3rd ultrasonic measuring device in a middle stage thickness measurement part and a back | latter stage thickness measurement part. The flowchart which shows the content of the calculation program which concerns on one Embodiment and calculates the thickness of each electrode paste applied to the A surface and B surface of metal foil. 1 is a plan view showing a schematic configuration of a conventional ultrasonic measurement apparatus according to an embodiment. The top view which shows only the motion of the one part mechanism of the apparatus shown in FIG. 15 concerning one Embodiment. An explanatory view showing an ultrasonic measuring device concerning a conventional example. The graph which shows the relationship between the received signal intensity | strength and ambient temperature about a receiving side ultrasonic sensor concerning a prior art example. The graph which shows the relationship between a self-heating and a received signal intensity | strength about a conventional example about a receiving side ultrasonic sensor. The graph which shows the relationship between the coating length at the time of coating a workpiece | work at 25 (degreeC) constant, and the measured value of a fabric weight (thickness) concerning a prior art example. The graph which shows the relationship between the coating length at the time of raising a workpiece | work from 25 (degreeC) to 32 (degreeC), and the measured value of a fabric weight (thickness) concerning a prior art example.

  Hereinafter, an ultrasonic measurement method and an ultrasonic measurement apparatus according to the present invention will be described in detail with reference to the drawings with respect to an embodiment in which ultrasonic measurement in an electrode production line used for a battery is embodied.

  FIG. 4 is a cross-sectional view of the electrode 1 manufactured by the electrode manufacturing line in this embodiment, cut in the width direction Y (the left-right direction in FIG. 4). As shown in FIG. 4, this electrode 1 is applied to each of a metal foil 2 as a strip-shaped substrate and one surface (A surface) 2a and the other surface (B surface) 2b of the metal foil 2. Electrode pastes 3A and 3B as applied coating materials. The electrode 1 is manufactured by applying electrode pastes 3A and 3B to the A surface 2a and the B surface 2b of the metal foil 2 and drying them, as will be described later. The ultrasonic measurement method and ultrasonic measurement apparatus of this embodiment are used for quality inspection of electrode products in an electrode production line. That is, the ultrasonic measurement method and the ultrasonic measurement apparatus are configured so that, in the manufacturing process of the electrode 1, the electrode paste is applied to the metal foil 2 before the electrode pastes 3A and 3B are applied and to one side (A surface) 2a of the metal foil 2. Weight of each of the intermediate product (work) coated with 3A and the final product (work) coated with the electrode pastes 3A and 3B on both surfaces (A surface and B surface) 2a and 2b of the metal foil 2 Used to measure (thickness).

  The electrode 1 of this embodiment is used for, for example, a secondary battery serving as a power source for an electric vehicle or a hybrid vehicle. Here, as a material of the metal foil 2, for example, Al, Cu or the like is used. The thickness of the metal foil 2 is, for example, about “20 (μm)”. As shown in FIG. 4, the thicknesses TpA and TpB of the electrode pastes 3A and 3B applied to the metal foil 2 are, for example, about “40 to 50 (μm)”. The electrode 1 includes uncoated portions 4 on both side edges in the width direction Y where the electrode pastes 3A and 3B are not coated.

  FIG. 1 shows a schematic configuration diagram of an electrode production line. As shown in FIG. 1, the electrode manufacturing line includes a plurality of process parts 11, 12, 13, 14, 15, 16, 17, 18, 19, 20. Each process part 11-20 is each covered and comprised by heat resistant (maximum 100 (degreeC)) boxes 21A, 21B, 21C, 21D, 21E, 21F, 21G, 21H, 21I, and 21J. Each box 21 </ b> A to 21 </ b> J is configured so that the metal foil 2 and the work 6 can pass through continuously until the electrode 1 is manufactured from the strip-shaped metal foil 2. The electrode production line is arranged in order from the upstream part to the downstream part, the metal foil feeding part 11, the former stage thickness measuring part 12, the A side coating part 13, the A side drying part 14, the middle stage thickness measuring part 15, the workpiece reversal Part 16, B-side coating part 17, B-side drying part 18, rear-stage thickness measuring part 19, and electrode winding part 20.

  The metal foil feeding unit 11 includes a metal foil roll 22 in which a band-shaped metal foil 2 is wound and stored, and the band-shaped metal foil 2 is drawn out from the metal foil roll 22 in one direction.

  The former thickness measurement unit 12 includes a first ultrasonic measurement device 23, and the first ultrasonic measurement device 23 measures the thickness of the metal foil 2 fed from the metal foil feed unit 11.

  The A-side coating unit 13 includes a first nozzle 24 that sprays the electrode paste 3A, and the electrode paste 3A is continuously applied from the first nozzle 24 onto the A-side 2a of the metal foil 2 that has passed through the previous thickness measurement unit 12. It is designed to be sprayed onto the coating.

  The A-side drying unit 14 includes a first work heater 25 made of an electric heater, and the electrode paste 3A applied by the A-side coating unit 13 is continuously heated and dried by the first work heater 25. It has become.

  The middle thickness measurement unit 15 includes a second ultrasonic measurement device 26, and the second ultrasonic measurement of the thickness of the workpiece 6 (the thickness of the metal foil 2 and the electrode paste 3A) dried by the A-surface drying unit 14 is performed. Measurement is performed by the device 26.

  The work reversing unit 16 includes a pair of reversing rollers 27 and 28. The reversing rollers 27 and 28 reverse the top surface of the metal surface 2 of the metal foil 2 so that the B surface 2b faces upward. It has become.

  The B-side coating unit 17 includes a second nozzle 29 that sprays the electrode paste 3B, and the electrode paste 3B from the second nozzle 29 on the B-side 2b of the metal foil 2 of the workpiece 6 fed out from the workpiece reversing unit 16. It is designed to be sprayed continuously.

  The B surface drying unit 18 includes a second work heater 30 made of an electric heater, and the electrode paste 3B applied by the B surface coating unit 17 is continuously heated and dried by the second work heater 30. It has become.

  The latter-stage thickness measurement unit 19 includes a third ultrasonic measurement device 31, and determines the thickness of the workpiece 6 (the thickness of the metal foil 2 and the electrode pastes 3A and 3B) dried by the B-side drying unit 18 to the third superthickness. Measurement is performed by the sound wave measuring device 31.

  The electrode winding unit 20 includes an electrode roll 32, and the workpiece 6 that has passed through the post-measurement unit 19 is wound around the electrode roll 32 as the electrode 1 that is a product.

  As described above, in the electrode production line of this embodiment, the electrode pastes 3A and 3B are applied and dried on the A surface 2a and the B surface 2b of the metal foil 2 from the upstream portion to the downstream portion, The thickness of the metal foil 2, the thickness of the metal foil 2 and the electrode paste 3A applied to the A surface 2a thereof, the electrode paste 3A and 3B applied to the metal foil 2, the A surface 2a and the B surface 2b thereof, and Are measured sequentially by the former thickness measuring unit 12, the middle thickness measuring unit 15, and the latter thickness measuring unit 19, respectively.

  Next, each thickness measurement part 12,15,19 is demonstrated. Here, since each thickness measurement part 12,15,19 is each fundamentally provided with the same structure, the back | latter stage thickness measurement part 19 is demonstrated typically below. FIG. 2 is a plan view showing a schematic configuration of the rear thickness measuring unit 19. FIG. 3 is a side view showing a schematic configuration of the rear thickness measuring unit 19.

  As shown in FIGS. 2 and 3, the box 21 </ b> I of the rear thickness measuring unit 19 is divided into a first chamber 35 and a second chamber 36. A plurality of feed rollers 37, 38, 39, and 40 are provided for feeding the workpiece 6 in one direction while applying tension to the workpiece 6 before and after the box 21 </ b> I and in each of the chambers 35 and 36. On the front wall 21a, the rear wall 21b, and the partition wall 21c of the box 21I, through holes 21d, 21e, and 21f that allow the strip-shaped workpiece 6 to pass are formed.

  In the first chamber 35 of the box 21I, as the ultrasonic sensor set including the first ultrasonic sensors 41A and 42A and the second ultrasonic sensors 41B and 42B, the first actual ultrasonic sensor group 41 and the second actual measurement sensor 41 are used. An ultrasonic sensor set 42 is provided. These measurement ultrasonic sensor sets 41 and 42 are fixed at fixed positions in order to measure the thickness of the workpiece 6 in which the electrode pastes 3A and 3B are applied to the A surface 2a and the B surface 2b of the metal foil 2, respectively. The In this embodiment, the first ultrasonic sensors 41A and 42A of each of the actual measurement ultrasonic sensor groups 41 and 42 are configured as sensors that receive ultrasonic waves, and include an amplifier 44 for amplifying a received signal. On the other hand, the second ultrasonic sensors 41B and 42B are configured as sensors that transmit ultrasonic waves.

  FIG. 5 is a schematic configuration diagram showing the arrangement of the first and second actual measurement ultrasonic sensor groups 41 and 42 in the width direction Y of the workpiece 6. As shown in FIGS. 2, 3, and 5, each of the actual measurement ultrasonic sensor sets 41 and 42 is aligned along the width direction Y of the workpiece 6 and is separated from the center of the workpiece 6 and each side edge by the same distance. Be placed. That is, when the workpiece 6 is cut into two at the center in the width direction Y, the respective ultrasonic sensor sets 41 and 42 for actual measurement are arranged so as to correspond to the center of the divided workpiece. The first ultrasonic sensors 41A and 42A and the second ultrasonic sensors 41B and 42B constituting each of the actually measured ultrasonic sensor groups 41 and 42 are first on one side of the work 6 in the thickness direction Z. The ultrasonic sensors 41A and 42A are arranged on the other side with the second ultrasonic sensors 41B and 42B facing each other through an air layer. And the fabric weight (thickness) of the workpiece 6 is measured by propagating the ultrasonic wave between the first ultrasonic sensors 41A and 42A and the second ultrasonic sensors 41B and 42B with the workpiece 6 interposed therebetween. It is like that. The two first ultrasonic sensors 41A and 42A are fixed to the upper support frame 45A fixed to the box 21I, and the two second ultrasonic sensors 41B and 42B are similarly fixed to the lower support frame 45A. It is fixed to the support frame 45B.

  In the traveling direction X of the workpiece 6, in the second chamber 36 located on the upstream side of the first chamber 35, the first ultrasonic sensor 43 </ b> A and the second ultrasonic sensor are separated from the actual measurement ultrasonic sensor sets 41 and 42. A calibration ultrasonic sensor set 43 including a sound wave sensor 43B is provided. The calibration ultrasonic sensor group 43 is provided to calibrate the actual measurement values of the actual measurement ultrasonic sensor groups 41 and 42.

  FIG. 6 is a schematic configuration diagram showing the arrangement of the calibration ultrasonic sensor group 43 in the width direction Y of the workpiece 6. As shown in FIGS. 2, 3, and 6, a predetermined sheet-like reference material 7 is disposed on one side of the workpiece 6 in the width direction Y on the same plane as the workpiece 6. The first ultrasonic sensor 43A and the second ultrasonic sensor 43B constituting the calibration ultrasonic sensor group 43 are the first ultrasonic sensor on one side of the reference material 7 and the workpiece 6 in the thickness direction Z. 43A is arranged on the other side with the second ultrasonic sensors 43B facing each other through an air layer. In order to move the calibration ultrasonic sensor set 43 between the reference material 7 and the workpiece 6 in the width direction Y of the workpiece 6, a moving mechanism 46 as a moving means is provided. The moving mechanism 46 includes a pair of guide rails 46A and 46B fixed to one side and the other side of the workpiece 6 in the thickness direction Z. The first ultrasonic sensor 43A and the second ultrasonic sensor 43B constituting the calibration ultrasonic sensor group 43 are supported by the guide rails 46A and 46B via brackets 47, respectively. Each bracket 47 is configured to be movable along the guide rails 46A and 46B by a drive source (not shown). The calibration ultrasonic sensor set 43 has an initial position P0 facing with the reference material 7 as shown by a solid line in FIG. 6, and facing with the work 6 as shown by a two-dot chain line in FIG. The first measurement position P1 and the second measurement position P2 can be sequentially moved.

  In this embodiment, the reference material 7 is supported by a fixed frame 48 fixed to the box 21I. The fixed frame 48 includes upper and lower sandwich plates 48A and 48B, and the reference material 7 is sandwiched between the sandwich plates 48A and 48B and supported horizontally. In the center of the sandwiching plates 48A and 48B, a through hole 48a is formed to expose the reference material 7 in order to apply ultrasonic waves to the reference material 7. The reference material 7 is, for example, a PET film (polyethylene terephthalate film) or other polymer film that has a thickness and density similar to that of the workpiece 6 due to a material that does not oxidize over time and does not change in weight. Formed with. The thickness of the reference material 7 is known in advance by directly measuring it using a scale or the like.

  In this embodiment, as the first ultrasonic sensors 41A, 42A, 43A and the second ultrasonic sensors 41B, 42B, 43B constituting the ultrasonic sensor groups 41 to 43, for example, an obstacle sensor such as a vehicle back sonar Highly versatile ultrasonic sensors used in In these sensors, for example, an ultrasonic wave of about “40 kHz” is used.

  As described above, the first and second actual measurement ultrasonic sensor sets 41 and 42, the calibration ultrasonic sensor set 43, and the moving mechanism 46 constitute the third ultrasonic measurement device 31 in the rear-stage thickness measurement unit 19. .

  In this embodiment, the middle thickness measurement unit 15 is provided immediately after the A-side drying unit 14, and the rear-stage thickness measurement unit 19 is provided immediately after the B-side drying unit 18. Therefore, the middle thickness measurement unit 15 and the rear thickness measurement unit 19 measure the workpiece 6 that is in a high temperature state immediately after drying by the second ultrasonic measurement device 26 and the third ultrasonic measurement device 31, respectively. In this case, the temperature of the reference material 7 may be different from the temperature of the workpiece 6 in each step thickness measurement unit 15, 19, and the measurement of the reference material 7 and the measurement of the workpiece 6 by the calibration ultrasonic sensor set 43 are mutually performed. It may not be possible under the same temperature conditions. Moreover, in each step thickness measurement part 15 and 19, the temperature of the workpiece | work 6 located in the boxes 21E and 21I (equivalent to the measurement area of this invention) differs from the temperature in the boxes 21E and 21I. As a result, air convection may occur in the boxes 21E and 21I, and the thickness of the reference material 7 and the workpiece 6 may not be accurately measured by the calibration ultrasonic sensor set 43. Therefore, in the middle stage thickness measurement unit 15 and the rear stage thickness measurement unit 19, the ultrasonic measurement devices 26 and 31 are provided with the following devices for temperature adjustment.

  In FIG. 7, the middle stage thickness measurement part 15 and the back | latter stage thickness measurement part 19 are shown with a schematic block diagram. As shown in FIG. 7, in the box 21I (21E), the reference material 7 includes a reference material heater 61 made of an electric heater for heating the reference material 7 (corresponding to the reference material heating means of the present invention). .) Is provided. Further, the reference material 7 is provided with a reference material temperature sensor 66 (corresponding to the reference material temperature detection means of the present invention) made of a thermocouple for detecting the temperature of the reference material 7. The box 21I (21E) is provided with a workpiece temperature sensor 67 (corresponding to the workpiece temperature detecting means of the present invention) for detecting the temperature of the workpiece 6. The workpiece temperature sensor 67 is calibrated by a radiation thermometer that can detect the temperature of the workpiece 6 without contact. Further, in the box 21I (21E), the ultrasonic sensor sets 41 and 42 for actual measurement and the ultrasonic sensor set 43 for calibration are arranged at the bottom of the box 21I (21E). An atmosphere heater 62 (corresponding to the atmosphere heating means of the present invention) made of an electric heater is provided for heating the atmosphere around .about.43. Further, in the box 21I (21E), to detect the temperature in the box 21I (21E), that is, to detect the ambient temperature around the measurement ultrasonic sensor sets 41 and 42 and the calibration ultrasonic sensor set 43. An ambient temperature sensor 68 (corresponding to the ambient temperature detection means of the present invention) is provided. Each of the heaters 61 and 62 and each of the temperature sensors 66 to 68 are electrically connected to the controller 51.

   FIG. 8 is an exploded perspective view showing the relationship between the reference material 7 and the reference material heater 61. The reference material heater 61 is provided on the fixed frame 48 of the reference material 7. That is, as shown in FIG. 8, the reference material heater 61 is sandwiched and fixed between the two sandwich plates 48 </ b> A and 48 </ b> B constituting the fixed frame 48 in a state of being superimposed on the reference material 7. The reference material heater 61 has a substantially C shape and is disposed in a buried groove (not shown) formed so as to surround the through hole 48a on the surface of the sandwiching plate 48B. The outer diameter of the reference material heater 61 is formed to be about 10 (mm) larger than the outer diameter of the through hole 48a. Thus, the reference material heater 61 is not exposed from the through hole 48a.

  FIG. 9 is a block diagram showing the electrical configuration of the second and third ultrasonic measuring devices 26 and 31. As shown in FIG. As shown in FIG. 9, the second and third ultrasonic measuring devices 26 and 31 include a controller 51 and first ultrasonic sensors 41A, 42A, and 43A that constitute the ultrasonic sensor sets 41, 42, and 43, respectively. And the second ultrasonic sensors 41B, 42B, 43B, and the first oscillator 52, the second oscillator 53, the third oscillator 54, which transmit ultrasonic waves to the ultrasonic sensors 41A, 42A, 43A, 41B, 42B, 43B, A fourth oscillator 55, a fifth oscillator 56 and a sixth oscillator 57, a reference material heater 61, an atmosphere heater 62, a reference material temperature sensor 66, a workpiece temperature sensor 67, and an atmosphere temperature sensor 68 are provided. Each oscillator 52 to 57 is connected to the controller 51. In addition, a movement mechanism 46, a keyboard 58, and a monitor 59 are connected to the controller 51. The controller 51 includes a central processing unit (CPU), various memories, input / output ports, and the like. The controller 51 controls the oscillators 52 to 57 and the moving mechanism 46 based on a predetermined control program in order to measure the thickness of the reference material 7 and the workpiece 6. Further, in the third ultrasonic measurement device 31, the controller 51 is applied to the metal foil 2 and the A surface 2a and the B surface 2b of the metal foil 2 based on the measurement values of the ultrasonic sensor groups 41 to 43. The thickness of both electrode pastes 3A and 3B is actually measured, and correction calculation is performed. On the other hand, in the other first ultrasonic measurement device 23, the thickness of the metal foil 2 is measured and corrected. In the second ultrasonic measurement device 26, the thicknesses of the metal foil 2 and the electrode paste 3A applied to the A surface 2a of the metal foil 2 are measured and corrected. Further, the controller 51 of the third ultrasonic measurement device 31 is based on the various thicknesses corrected and calculated by the first to third ultrasonic measurement devices 23, 26, 31 as described above, and the A surface of the metal foil 2 The thickness of the electrode paste 3A applied to 2a and the thickness of the electrode paste 3B applied to the B surface 2b of the metal foil 2 are calculated. The first ultrasonic measurement device 23 is not provided with the reference material heater 61, the atmosphere heater 62, the reference material temperature sensor 66, the workpiece temperature sensor 67, and the atmosphere temperature sensor 68.

  Each of the oscillators 52 to 57 includes an oscillation circuit that ultrasonically vibrates each of the ultrasonic sensors 41A, 42A, 43A, 41B, 42B, and 43B by applying a voltage, and the sensors 41A, 42A, 43A, 41B, 42B, and 43B. And a conversion circuit for converting the ultrasonic vibration received in step S1 into a voltage signal. The controller 51 controls transmission / reception of ultrasonic waves to the ultrasonic sensors 41A, 42A, 43A, 41B, 42B, and 43B via the oscillators 52 to 57.

  In this embodiment, the controller 51 measures the measured value of the reference material 7 measured by the calibration ultrasonic sensor set 43, and the workpiece measured at the first measurement position P1 and the second measurement position P2 by the calibration ultrasonic sensor set 43. Based on the measurement value of 6, the thickness for calibration of the workpiece 6 at a certain location (first extraction location and second extraction location) is calculated. Further, the controller 51 corrects the thickness of the workpiece 6 measured at the first extraction location and the second extraction location by the first and second measurement ultrasonic sensor sets 41 and 42 based on the calibration thickness. By doing so, the final thickness of the workpiece 6 at the first extraction location and the second extraction location is calculated.

  Here, certain locations (first extraction location and second extraction location) where the thickness of the workpiece 6 is measured are arbitrarily set according to the traveling speed of the workpiece 6. In this embodiment, a certain location first measured for the metal foil 2 by the former thickness measuring unit 12 is then measured for the workpiece 6 by the middle thickness measuring unit 15 and the latter thickness measuring unit 19 in the same manner. It has become. If the traveling speed of the workpiece 6 is determined, the arrival time at each stage (the first extraction location and the second extraction location) at the respective thickness measuring units 12, 15, 19 is determined, and each ultrasonic wave is adjusted accordingly. This is because the measurement device 23, 26, 31 can specify and measure the same location (first extraction location and second extraction location). Accordingly, as the workpiece 6 travels, a plurality of locations (first extraction location and second extraction location) are measured by the ultrasonic measurement devices 23, 26, and 31.

  In this embodiment, the controller 51 moves the calibration ultrasonic sensor set 43 in parallel from the initial position P0 to the first measurement position P1 and the second measurement position P2 by the moving mechanism 46, and the thickness of the reference material 7 and the workpiece The thicknesses of the first extraction location 6 and the second extraction location 6 are periodically and sequentially measured for calibration by the calibration ultrasonic sensor set 43. Thereafter, as the workpiece 6 travels, the controller 51 calculates the thicknesses of the first extraction location and the second extraction location of the workpiece 6 measured immediately before by the calibration ultrasonic sensor set 43, for each measurement ultrasonic sensor set 41, The actual measurement is performed according to 42. Then, the controller 51 corrects the actual measurement values of the actual measurement ultrasonic sensor groups 41 and 42 using the measurement values for calibration that have been sequentially measured by the calibration ultrasonic sensor group 43 immediately before, thereby correcting the workpiece 6. The final thickness at the first extraction location and the second extraction location is calculated.

  In this embodiment, the controller 51 uses the reference material heater 61 so that the temperature of the reference material 7 detected by the reference material temperature sensor 66 becomes the temperature of the workpiece 6 detected by the workpiece temperature sensor 67. While heating 7, the thickness of the reference material 7 is measured for calibration by the calibration ultrasonic sensor set 43. At the same time, the controller 51 actually measures the thickness of the workpiece 6 or the metal foil 2 by each of the ultrasonic sensor sets 41 and 42 for actual measurement. Then, the controller 51 corrects the actual measurement values obtained by the actual ultrasonic sensor groups 41 and 42 using the calibration measurement values obtained by the calibration ultrasonic sensor group 43, thereby finalizing the workpiece 6 or the metal foil 2. The thickness is calculated. In this embodiment, the controller 51 corresponds to a measurement control unit of the present invention.

  Next, a control program related to ultrasonic measurement executed by the controller 51 will be described. FIG. 10 is a flowchart showing the contents of a measurement control program executed using the calibration ultrasonic sensor set 43.

  When the process proceeds to this routine, the controller 51 measures the thickness (reference thickness) of the reference material 7 by the calibration ultrasonic sensor group 43 at the initial position P0 in step 100. After measuring the reference thickness, the controller 51 stores the measured value Sk in the memory.

  Next, in step 110, the controller 51 moves the calibration ultrasonic sensor group 43 to the first measurement position P <b> 1 by the moving mechanism 46.

  Next, in step 120, the controller 51 measures the thickness (first calibration thickness) at the first extraction location of the workpiece 6 by the calibration ultrasonic sensor set 43 at the first measurement position P1. When the controller 51 measures the first calibration thickness, the controller 51 stores the measured value Sx1 in the memory.

Next, in step 130, the controller 51 calculates the unknown first calibration thickness Mx1 of the workpiece 6 by the following (Equation 1) based on the measurement value Sk of the reference thickness and the measurement value Sx1 of the first calibration thickness. . The controller 51 stores the first calibration thickness Mx1 in the memory after the calculation.
Mx1 = Mk * Sx1 / Sk (Formula 1)
Here, “Mk” means a known (weight per unit area) thickness of the reference material 7.

  Next, in Step 140, the controller 51 moves the calibration ultrasonic sensor group 43 to the second measurement position P2 by the moving mechanism 46.

  Next, in step 150, the controller 51 measures the thickness (second calibration thickness) at the second extraction location of the workpiece 6 by the calibration ultrasonic sensor set 43 at the second measurement position P2. When the controller 51 measures the second calibration thickness, the controller 51 stores the measured value Sx2 in the memory.

Next, in step 160, the controller 51 calculates the unknown second calibration thickness Mx2 of the workpiece 6 based on the measurement value Sk of the reference thickness and the measurement value Sx2 of the second calibration thickness of the workpiece 6 as follows (Formula 2): Calculate by The controller 51 stores the second calibration thickness Mx2 in the memory after the calculation.
Mx2 = Mk * Sx2 / Sk (Formula 2)

  Thereafter, in step 170, the controller 51 moves the calibration ultrasonic sensor group 43 to the initial position P 0 corresponding to the reference material 7 by the moving mechanism 46, and then returns the process to step 100.

  As described above, the controller 51 repeats the processing from step 100 to step 170 in accordance with the traveling speed of the workpiece 6. That is, if the traveling speed of the workpiece 6 is increased, the processing speed of step 100 to step 170 is increased accordingly.

  FIG. 11 is a flowchart showing the contents of a measurement control program executed using the first and second actual measurement ultrasonic sensor sets 41 and 42.

  When the process proceeds to this routine, the controller 51 waits for the first extraction point to arrive at step 200. That is, it is determined whether or not the first extraction location measured by the calibration ultrasonic sensor set 43 immediately before has reached a position corresponding to the first actual measurement ultrasonic sensor set 41. This determination can be made by monitoring the traveling speed of the workpiece 6 and the reference position.

  When the first extraction point arrives, in step 210, the controller 51 measures the thickness (first actually measured thickness) of the workpiece 6 at the first extraction point by the first actually measured ultrasonic sensor set 41. The controller 51 stores the measured value SRx1 of the first measured thickness in the memory after the measurement.

Next, in step 220, the controller 51 calculates the first measured thickness SRx1 based on the first calibration thickness measured value Sx1 and the calculated first calibration thickness Mx1 according to the following (Equation 3). The final first measured thickness MRx1 is calculated after correction. The controller 51 stores the first measured thickness MRx1 in the memory after the calculation.
MRx1 = Mx1 * SRx1 / Sx1 (Formula 3)

  Next, in step 230, the controller 51 waits for the second extraction point to arrive. That is, it is determined whether or not the second extraction point measured by the calibration ultrasonic sensor set 43 just before has reached a position corresponding to the second actual measurement ultrasonic sensor set 42.

  When the second extraction location arrives, in step 240, the controller 51 measures the thickness of the workpiece 6 (second measured thickness) at the second extraction location by the second actual measurement ultrasonic sensor set 42. The controller 51 stores the measured value SRx2 of the second measured thickness in the memory after the measurement.

In step 250, the controller 51 corrects the measured SRx2 of the second measured thickness based on the measured value Sx2 of the second calibration thickness and the calculated second calibration thickness Mx2 according to (Equation 4) below. The final second actually measured thickness MRx2 is calculated. The controller 51 stores the second actually measured thickness MRx2 in the memory after the calculation. Thereafter, the controller 51 returns the process to step 200.
MRx2 = Mx2 * SRx2 / Sx2 (Formula 4)

  As described above, the controller 51 repeats the processing from step 200 to step 250 according to the traveling speed of the workpiece.

  In this embodiment, the following ultrasonic measurement method can be implemented by executing each measurement control program. That is, the calibration ultrasonic sensor set 43 is moved, and the thickness of the predetermined reference material 7 arranged in the vicinity of the workpiece 6 or the metal foil 2 and the location where the workpiece 6 or the metal foil 2 is located (the first extraction location and the first extraction location). The thickness of the two extraction points) is periodically or alternately measured for calibration by the calibration ultrasonic sensor group 43. Thereafter, as the workpiece 6 or the metal foil 2 travels, the thicknesses of the locations (first extraction location and second extraction location) where the workpiece 6 or the metal foil 2 is measured immediately before by the calibration ultrasonic sensor set 43 are set. Actual measurement is performed by the ultrasonic sensor sets 41 and 42 for measurement. Then, by correcting the actual measurement values obtained by the ultrasonic sensor groups 41 and 42 for actual measurement using the measurement values for calibration measured alternately or sequentially, a location on the workpiece 6 or the metal foil 2 (first extraction location) And the final thickness at the second extraction location).

  FIGS. 12A to 12C are plan views showing changes in the position of the calibration ultrasonic sensor set 43 in the rear-stage thickness measurement unit 19. In order to measure the thickness of a part of the workpiece 6 (first extraction part and second extraction part), first, as shown in FIG. 12A, the calibration ultrasonic sensor set 43 is arranged at the initial position P0. Perform calibration. That is, the thickness of the reference material 7 is measured by the calibration ultrasonic sensor group 43.

  Next, as shown in FIG. 12B, the calibration ultrasonic sensor set 43 is moved to the first measurement position P1 by the moving mechanism 46, and the workpiece is moved by the calibration ultrasonic sensor set 43 at the measurement position P1. The thickness of the first extraction location of 6 is measured. The first extraction location reaches the position of the first actual measurement ultrasonic sensor set 41 by the workpiece 6 subsequently traveling. At this time, the first actual measurement ultrasonic sensor set 41 again measures (actually measures) the thickness of the first extraction portion.

  Next, as shown in FIG. 12C, the calibration ultrasonic sensor set 43 is further moved to the second measurement position P2 by the moving mechanism 46, and the calibration ultrasonic sensor set 43 is moved to the measurement position P2. The thickness of the 2nd extraction location of the workpiece | work 6 is measured. The second extraction location reaches the position of the second actually measured ultrasonic sensor set 42 by the workpiece 6 subsequently traveling. At this time, the second actual measurement ultrasonic sensor group 42 measures (actually measures) the thickness of the second extraction portion again.

  Thereafter, the calibration ultrasonic sensor set 43 is returned from the second measurement position P2 shown in FIG. 12C to the initial position P0 shown in FIG. Then, the measurement at the initial position P0 shown in FIG. 12A, the measurement at the first measurement position P1 shown in FIG. 12B, and the measurement at the second measurement position P2 shown in FIG. Repeat that cycle. In addition, in accordance with the measurement for one cycle, the thicknesses of the first extraction portion and the second extraction portion of the workpiece 6 are actually measured by the first and second ultrasonic sensor sets 41 and 42 for actual measurement.

  In this way, the thickness of the reference material 7 and the workpiece 6 is measured by the calibration ultrasonic sensor set 43, the thickness of the workpiece 6 is actually measured by the two actual measurement ultrasonic sensor sets 41 and 42, and the measured value and the measured value are used. The final thickness of the first extraction location and the second extraction location of the workpiece 6 is calculated. Such a series of measurement and calculation is periodically repeated according to the traveling speed of the workpiece 6.

  FIG. 13 is a flowchart showing the contents of the temperature control program executed by the second and third ultrasonic measurement devices 26 and 31 in the middle thickness measurement unit 15 and the rear thickness measurement unit 19.

  When the process proceeds to this routine, the controller 51 takes in the workpiece temperature Tw detected by the workpiece temperature sensor 67 in step 300.

  Next, the controller 51 takes in the reference material temperature Tb detected by the reference material temperature sensor 66 in Step 310.

  Next, the controller 51 takes in the ambient temperature Te detected by the ambient temperature sensor 68 in step 320.

  Thereafter, the controller 51 advances the processing in steps 330 to 350 and the processing in steps 360 to 380 in parallel. That is, in step 330, the controller 51 determines whether or not the workpiece temperature Tw is higher than the reference material temperature Tb. If this determination is affirmative, the controller 51 turns on the reference material heater 61 in step 340 and returns the process to step 300. As a result, the reference material 7 is heated by the reference material heater 61. On the other hand, if the determination result in step 330 is negative, the controller 51 turns off the reference material heater 61 in step 350 and returns the process to step 300. Thereby, the heating of the reference material 7 by the reference material heater 61 is stopped.

  In step 360, the controller 51 determines whether or not the difference between the reference material temperature Tb and the measurement area temperature Te is greater than “1”. If the determination result is affirmative, the controller 51 turns on the atmosphere heater 62 in step 370 and returns the process to step 300. Thereby, the inside of the box 21I (21E) is heated by the atmosphere heater 62. On the other hand, if the determination result in step 360 is negative, the controller 51 turns off the atmosphere heater 62 in step 380 and returns the process to step 300. Thereby, the heating in the box 21I (21E) by the atmospheric heater 62 is stopped.

  The controller 51 repeats the processing from step 300 to step 380 when measuring the thicknesses of the reference material 7 and the workpiece 6 by each of the actual measurement ultrasonic sensor sets 41 and 42 and the calibration ultrasonic sensor set 43, thereby immediately after drying. The temperature of the workpiece 6 in a high temperature state can be matched with the temperature in the reference material 7 and the boxes 21E and 21I.

  FIG. 14 is a flowchart showing the contents of a calculation program for calculating the thickness of each of the electrode pastes 3A and 3B applied to the A surface 2a and the B surface 2b of the metal foil 2. This calculation program is calculated by the controller 51 only by the third ultrasonic measurement device 31 of the rear-stage thickness measurement unit 19.

When the process moves to this routine, in step 400, the controller 51 calculates the thickness TpA1 of the electrode paste 3A on the A surface 2a of the metal foil 2 at the first extraction location. This thickness TpA1 is calculated from the first measured thickness MRx1 (m) of the workpiece 6 at the first extraction location, which is measured and calculated by the middle thickness measuring unit 15, as shown in the following (Equation 5). It can be obtained by subtracting the first measured thickness MRx1 (f) of the workpiece 6 (metal foil 2) at the first extraction location measured and calculated in (1).
TpA1 = MRx1 (m) -MRx1 (f) (Formula 5)

Next, in step 410, the controller 51 calculates the thickness TpB1 of the electrode paste 3B on the B surface 2b of the metal foil 2 at the first extraction location. This thickness TpB1 is calculated from the first measured thickness MRx1 (l) of the workpiece 6 at the first extraction location, which is measured and calculated by the subsequent thickness measuring unit 19, as shown in the following (Equation 6). It can be obtained by subtracting the first measured thickness MRx1 (m) of the workpiece 6 at the first extraction location measured and calculated in 15.
TpB1 = MRx1 (l) -MRx1 (m) (Formula 6)

Next, in step 420, the controller 51 calculates the thickness TpA2 of the electrode paste 3A on the A surface 2a of the metal foil 2 at the second extraction location. This thickness TpA2 is calculated from the second measured thickness MRx2 (m) of the workpiece 6 at the second extraction location, which is measured and calculated by the middle thickness measuring unit 15, as shown in the following (Expression 7). This can be obtained by subtracting the second actually measured thickness MRx2 (f) of the workpiece 6 (metal foil 2) at the second extraction location measured and calculated in 12.
TpA2 = MRx2 (m) -MRx2 (f) (Expression 7)

Next, in step 430, the controller 51 calculates the thickness TpB2 of the electrode paste 3B on the B surface 2a of the metal foil 2 at the second extraction location. This thickness TpB2 is calculated from the second measured thickness MRx2 (l) of the workpiece 6 at the second extraction location, which is measured and calculated by the subsequent thickness measuring unit 19, as shown in the following (Equation 8). It can be obtained by subtracting the second actually measured thickness MRx2 (m) of the workpiece 6 at the second extraction location measured and calculated in 15.
TpB2 = MRx2 (l) -MRx2 (m) (Equation 8)

  The controller 51 repeats the processing of step 400 to step 430 in accordance with the traveling of the workpiece 6, so that the long workpiece 6 has a plurality of first extraction locations and second extraction locations along the traveling direction X. The thicknesses of the electrode pastes 3A and 3B on the A surface 2a and the B surface 2b can be obtained. By monitoring this thickness, quality control of the electrode 1 manufactured on the electrode manufacturing line can be performed.

  According to the ultrasonic measurement method of this embodiment described above, the middle-stage thickness measurement unit 15 and the rear-stage thickness measurement unit 19 move the calibration ultrasonic sensor set 43 to a predetermined position arranged in the vicinity of the workpiece 6. The thickness of the reference material 7 and the thickness of the location where the workpiece 6 is located (first extraction location and second extraction location) are periodically and sequentially measured by the calibration ultrasonic sensor set 43 for calibration. Thereby, using the same calibration ultrasonic sensor group 43, the measurement value Sk for the calibration of the thickness of the reference material 7 (reference thickness) and the thickness of the workpiece 6 (first calibration thickness, second calibration thickness) Calibration measurement values Sx1 and Sx2 are sequentially obtained. These calibration measurement values Sk, Sx1, and Sx2 are arranged in the vicinity of the reference material 7 and the workpiece 6, and therefore environmental conditions such as atmospheric temperature and atmospheric pressure that affect measurement by the calibration ultrasonic sensor set 43. Is obtained in common. In addition, since the reference material 7 and the workpiece 6 are measured by the same calibration ultrasonic sensor set 43, the difference in the characteristics of the calibration ultrasonic sensor set 43 from the measurement values Sk, Sx1 and Sx2 for calibration. Excluded.

  Similarly, the upstream thickness measurement unit 12 moves the calibration ultrasonic sensor group 43 to place the thickness of the predetermined reference material 7 arranged in the vicinity of the metal foil 2 and the location of the metal foil 2 (first extraction location). And the thickness of the second extraction location) are periodically and sequentially measured for calibration by the calibration ultrasonic sensor set 43. Thus, using the same calibration ultrasonic sensor set 43, the measurement value Sk for calibration of the thickness (reference thickness) of the reference material 7 and the thickness of the metal foil 2 (first calibration thickness, second calibration thickness). The calibration measurement values Sx1, Sx2 are sequentially obtained. Since the reference material 7 and the metal foil 2 are disposed in the vicinity of the calibration measurement values Sk, Sx1, and Sx2, the ambient temperature, the atmospheric pressure, or the like that affects the measurement by the calibration ultrasonic sensor set 43 is used. Obtained in common conditions. Further, since the reference material 7 and the metal foil 2 are measured by the same calibration ultrasonic sensor set 43, the difference in the characteristics of the calibration ultrasonic sensor set 43 from the calibration measurement values Sk, Sx1, Sx2. Is removed.

  Therefore, in this embodiment, in the thickness measuring units 12, 15, 19 of each step, the measurement value Sk for calibration of the reference material 7 (reference thickness) and the calibration of the workpiece 6 or the metal foil 2 (first calibration thickness, By multiplying the ratio of the second calibration thickness) to the measured values Sx1 and Sx2 by the known thickness Mk of the reference material 7, the thickness for calibration of the workpiece 6 or the metal foil 2 (first calibration thickness Mx1, second Calibration thickness Mx2) can be determined.

  Thereafter, in the thickness measuring units 12, 15, and 19 of each step, the location where the workpiece 6 or the metal foil 2 is measured (the first position) measured immediately before by the calibration ultrasonic sensor set 43 as the workpiece 6 or the metal foil 2 travels. The thickness of the first extraction location and the second extraction location) is actually measured by the ultrasonic sensor sets 41 and 42 for measurement. Then, by correcting the actual measurement values SRx1 and SRx2 by the actual measurement ultrasonic sensor groups 41 and 42 using the calibration measurement values Sk, Sx1 and Sx2 sequentially measured by the calibration ultrasonic sensor group 43, the workpiece 6 or a final thickness (first measured thickness MRx1, second measured thickness MRx2) at a location (first extraction location and second extraction location) of the metal foil 2 is obtained.

  Therefore, in this embodiment, the measurement values Sx1, Sx2 for calibration of the workpiece 6 or the metal foil 2 and the actual measurement values SRx1, SRx2 of the workpiece 6 or the metal foil 2 are obtained by the thickness measuring units 12, 15, 19 of each step. Is multiplied by the calibration thickness of the workpiece 6 or the metal foil 2 (first calibration thickness Mx1, second calibration thickness Mx2), so that a location where the workpiece 6 or the metal foil 2 is present (the first extraction location and the first calibration location). 2 final locations (first measured thickness MRx1, second measured thickness MRx2) can be obtained. Here, even if the characteristics of the calibration ultrasonic sensor group 43 and the characteristics of the actual measurement ultrasonic sensor groups 41 and 42 are not the same, it is not necessary to match these characteristics. That is, it is not necessary to select the calibration ultrasonic sensor group 43 and the actual measurement ultrasonic sensor groups 41 and 42 having common characteristics from among many sensor products, and labor and time are required for the selection work. There is no need.

   As a result, in the production line of the electrode 1, the thickness of the workpiece 6 or the metal foil 2 coated with the electrode pastes 3A and 3B on one side or both sides of the strip-shaped metal foil 2 traveling in the longitudinal direction can be highly accurately in-line. It can be measured. Further, in the above-described electrode production line, the measurement of the thickness of the workpiece 6 or the metal foil 2 and the maintenance of the ultrasonic measuring devices 23, 26, 31 can be facilitated.

Here, as described above, the known basis weight of the reference material 7 to the ratio of the level of the ultrasonic wave transmitted through the workpiece 6 (metal foil 2) and the reference material 7 using the ultrasonic wave propagating through the air layer. By multiplying (thickness), the thickness of the workpiece 6 (metal foil 2) can be calculated. As the precondition, the characteristics (signal characteristics of reception and transmission depending on temperature) of the plurality of ultrasonic sensor groups 41 to 43 (ultrasonic sensors) are essentially the same, and the ambient temperature around the sensor at the time of measurement and the electrodes When the temperature of the reference material is substantially the same, the following condition (Equation 9) is satisfied.
Mx = Mk * Sx / Sk (Formula 9)
Here, “Mx” means a desired thickness, “Mk” means a known thickness of the reference material 7, “Sx” means a measured value of the workpiece 6 (metal foil 2), and “Sk” means a measured value of the reference material 7. .

  According to the above (Equation 9), the weight and area (weight per unit area (thickness)) “Mk” of the reference material 7 for calibration (calibration) and the ultrasonic measurement value “Sx” of the workpiece 6 (metal foil 2). Can be grasped with high accuracy, the unknown basis weight (thickness) “Mx” of the workpiece 6 (metal foil 2) can be calculated with high accuracy. Further, if the calibration and the ultrasonic measurement of the workpiece 6 (metal foil 2) are always performed at the same time, ultrasonic measurement based on the ambient temperature and atmospheric pressure around each of the ultrasonic sensor groups 41 to 43 (ultrasonic sensors). Can be eliminated.

  Here, a conventional ultrasonic measurement device and an ultrasonic measurement method performed by the applicant will be described. FIG. 15 is a plan view showing a schematic configuration of a conventional ultrasonic measurement apparatus. FIG. 16 is a plan view showing only the movement of some mechanisms of the apparatus shown in FIG. This ultrasonic measurement apparatus includes a box 81 through which the workpiece 6 passes, and feed rollers 82, 83, 84, and 85 that guide the workpiece 6 are provided in front of and behind the box 81. In the box 81, the first reference material 86 and the second reference material 87 are arranged in the same plane as the work 6 adjacent to both side edges in the width direction Y of the work 6. In the box 81, a first ultrasonic sensor set 88, a second ultrasonic sensor set 89, and a third ultrasonic sensor set 90 are provided. Each of the ultrasonic sensor sets 88 to 90 includes a first ultrasonic sensor and a second ultrasonic sensor, respectively. The first ultrasonic sensor set 88 includes a first measurement position corresponding to the workpiece 6 (see FIG. 15) and a first initial position corresponding to the first reference material 86 (see FIG. 15) by the arm-shaped first moving mechanism 91. 16)). The second ultrasonic sensor set 89 and the third ultrasonic sensor set 90 are respectively fixed to both ends of the V-shaped second moving mechanism 92, and the second ultrasonic sensor set 89 is attached to the workpiece 6 by the second moving mechanism 92. Correspondingly, the third ultrasonic sensor set 90 corresponds to the second reference material 87 and the second measurement position (see FIG. 15), the second ultrasonic sensor set 89 corresponds to the second reference material 87, The acoustic wave sensor set 90 can be switched between a second initial position (see FIG. 16) that does not correspond to the second reference material 87 or the workpiece 6.

  The thickness measurement of the workpiece 6 using the above-described ultrasonic measurement apparatus is performed as follows. First, before starting the measurement, as shown in FIG. 16, the first ultrasonic sensor set 88 is set to the first initial position, and the second ultrasonic sensor set 89 and the third ultrasonic sensor set 90 are set to the second initial position. Place each one. In this state, the first reference material 86 is measured by the first ultrasonic sensor set 88, and the second reference material 87 is measured by the second ultrasonic sensor set 89. At this time, the third ultrasonic sensor set 90 does not perform measurement. Thereby, the reference measurement value reflecting the temperature and the atmospheric pressure in the box 81 at the measurement start time can be obtained by the first and second ultrasonic sensor sets 88 and 89.

  Thereafter, at the start of measurement, as shown in FIG. 15, the first ultrasonic sensor set 88 is arranged at the first measurement position, and the second ultrasonic sensor set 89 and the third ultrasonic sensor set 90 are arranged at the second measurement position, respectively. To do. In this state, the first ultrasonic sensor set 88 measures the first one side in the width direction Y of the workpiece 6 to obtain the first thickness measurement value SFx1. The second ultrasonic sensor set 89 measures the second one side in the width direction Y of the workpiece 6 to obtain a second thickness measurement value SFx2. The third ultrasonic sensor set 90 constantly measures the second reference material 87, continuously measures the change in the basis weight (thickness) of the second reference material 87 from the start of measurement, and calculates the reference thickness measurement value SFk and its A variation value ΔSFk is obtained.

Thereby, the thickness MFx1 of the 1st one side of the workpiece | work 6 and the thickness MFx2 of the 2nd one side can be calculated | required by the following (Formula 10) and (Formula 11).
MFx1 = SFx1-ΔSFk (Equation 10)
MFx2 = SFx2-ΔSFk (Expression 11)

  However, in order for (Equation 10) and (Equation 11) to hold, all of the first to third ultrasonic sensor sets 88 to 90 need to have the same characteristics with respect to the ambient temperature and atmospheric pressure. Therefore, it is necessary to find three ultrasonic sensor sets having common characteristics from among a plurality of ultrasonic sensor sets, and time and labor are required for the work.

  On the other hand, according to the ultrasonic measurement method and the ultrasonic measurement apparatus of this embodiment, the characteristics of the ultrasonic sensor groups 41 to 43 (ultrasonic sensors) are shared by adopting the above-described configuration. Ultrasonic measurement can be performed ignoring the preconditions. Thus, in order to use the calibration ultrasonic sensor set 43 and the first and second actual measurement ultrasonic sensor sets 41 and 42, three ultrasonic sensors having a common characteristic among the plurality of ultrasonic sensor sets. There is no need to find a set, and ultrasonic sensor sets having different characteristics can be used. This shows that implementation and maintenance of ultrasonic measurement can be facilitated.

  According to the ultrasonic measurement method of this embodiment, the ratio of the measurement value for calibration of the reference material 7 and the measurement value for calibration of the workpiece 6 or the metal foil 2 is multiplied by the known thickness of the reference material 7. Thus, the thickness for calibration of the workpiece 6 or the metal foil 2 is obtained. Then, by multiplying the ratio of the measured value for calibration of the workpiece 6 or the metal foil 2 and the measured value of the workpiece 6 or the metal foil 2 by the thickness for calibration of the workpiece 6 or the metal foil 2, the workpiece 6 or the metal The final thickness of a portion of the foil 2 is obtained. Therefore, the final thickness of the part where the workpiece 6 or the metal foil 2 is located is obtained while calibrating the actual measurement values of the ultrasonic sensor groups 41 and 42 for actual measurement. As a result, in the electrode production line, the thickness of the workpiece 6 or the metal foil 2 coated with the electrode pastes 3A and 3B on one side or both sides of the strip-shaped metal foil 2 running in the longitudinal direction is measured with high accuracy in-line. In addition, the measurement of the thickness and the maintenance of the ultrasonic measuring devices 23, 26, and 31 can be facilitated.

  In this embodiment, in the process of applying the electrode pastes 3A and 3B to the metal foil 2, the final thickness of the part where the metal foil 2 is present and the final part of the part where the work 6 coated with the electrode paste 3A and 3B is provided. Specific thicknesses are determined separately. Then, by subtracting the final thickness of the metal foil 2 from the final thickness of the workpiece 6, the thicknesses of the electrode pastes 3A and 3B at a certain location of the workpiece 6 are obtained. Therefore, the thicknesses of the electrode pastes 3A and 3B at a location where the workpiece 6 is located are obtained while calibrating the actual measurement values obtained by the actual ultrasonic sensor groups 41 and 42. For this reason, the thickness of electrode paste 3A, 3B in the location with the workpiece | work 6 can be calculated | required accurately.

  The ultrasonic measurement method described above using the ultrasonic sensor sets 43 for calibration, the ultrasonic sensor sets 41 and 42 for actual measurement, the moving mechanism 46 and the controller 51 by the ultrasonic measurement devices 23, 26 and 31 of this embodiment. Can be implemented. For this reason, in the production line of the electrode 1, the thickness of the workpiece 6 or the metal foil 2 coated with the electrode pastes 3A and 3B on one side or both sides of the strip-shaped metal foil 2 running in the longitudinal direction is extended. In addition, the thickness of the electrode pastes 3A and 3B can be measured with high accuracy in-line, and the measurement can be easily performed and maintained.

  By the way, in this embodiment, immediately after applying the electrode pastes 3A and 3B to the metal foil 2 in the A side coating part 13 and the B side coating part 17 of the electrode production line, the A side drying part 14 and the B side The electrode paste 3A, 3B is dried by heating in the drying unit 18. Immediately after the drying, the thickness of the reference material 7 for calibration is measured, and the thickness of the workpiece 6 is measured. Here, in order to measure the thicknesses of the reference material 7 and the workpiece 6 with high accuracy immediately after the workpiece 6 is heated and dried, it is a precondition that the state of all the media transmitting the ultrasonic waves is always constant. However, since the workpiece 6 immediately after heating and drying is in a high temperature state, the temperature of the workpiece 6 changes, and the temperature of the calibration ultrasonic sensor group 43 and the actually measured ultrasonic sensor groups 41 and 42 and the workpiece 6 also increases. . These temperature changes do not change abruptly, but greatly change with respect to the initial state, and the above preconditions are not satisfied. That is, when ultrasonically measuring the thickness of the workpiece 6 immediately after drying, the temperature of the reference material 7 for calibration and the temperature of the workpiece 6 may be different, or the temperature of the workpiece 6 and the ambient temperature of the workpiece 6 may be different. is there.

  Therefore, in this embodiment, paying attention to the fact that the temperature change of the workpiece 6 or the like is not abrupt, the ultrasonic wave of the workpiece 6 or the like is made difficult by causing the temperature change of the reference material 7 or each of the ultrasonic sensor groups 41 to 43 and the like. I am trying to measure. That is, according to the ultrasonic measurement method of this embodiment, the measurement of the thickness of the reference material 7 and the actual measurement of the thickness of the work 6 are performed while adjusting the temperature of the reference material 7 to the temperature of the work 6. Thus, the temperature condition becomes uniform. For this reason, the difference of the transmission level of an ultrasonic wave between the reference | standard material 7 and the workpiece | work 6 can be eliminated, and the thickness of the workpiece | work 6 immediately after heat drying can be ultrasonically measured with high precision in-line.

  In this embodiment, the ambient temperature around the ultrasonic sensor groups 41 and 42 for actual measurement and the ultrasonic sensor group 43 for calibration is brought close to the temperature of the workpiece 6. The temperature of the workpiece 6 becomes uniform. For this reason, the convection of the air in the boxes 21E and 21I can be reduced to prevent the disturbance of the transmission of ultrasonic waves. In this sense as well, the thickness of the workpiece 6 immediately after heating and drying can be made highly accurate in-line. Ultrasonic measurement can be performed.

  According to the ultrasonic measurement devices 26 and 31 of this embodiment, the calibration ultrasonic sensor set 43, the actual measurement ultrasonic sensor sets 41 and 42, the reference material heater 61, the reference material temperature sensor 66, and the workpiece temperature sensor 67. The above-described ultrasonic measurement method can be implemented using the controller 51, the atmospheric heater 62, and the atmospheric temperature sensor 68. For this reason, the difference in ultrasonic transmission level between the reference material 7 and the workpiece 6 can be eliminated, and the disturbance of ultrasonic transmission is prevented by reducing the air convection in the boxes 21E and 21I. In addition, the thickness of the workpiece 6 immediately after heat drying can be ultrasonically measured on the in-line with high accuracy.

  Note that the present invention is not limited to the above-described embodiment, and a part of the calibration can be changed as appropriate without departing from the spirit of the invention.

  (1) In the embodiment described above, the ultrasonic measurement in the production line of the electrode used for the battery is embodied. What is necessary is just the case where the thickness of the workpiece | work or base material which coated the material is measured ultrasonically.

  (2) In the embodiment described above, the basis weight (thickness) of the two locations of the first extraction location and the second extraction location in the workpiece 6 is measured ultrasonically, but one location or three or more locations in the workpiece You may comprise so that the fabric weight (thickness) of this location may be measured ultrasonically.

  (3) In the above embodiment, the temperature adjustment of the atmosphere in the reference material 7 and the boxes 21E and 21I in the second and third ultrasonic measurement devices 26 and 31 shown in FIGS. This temperature adjustment can also be embodied in the ultrasonic measurement apparatus shown in FIGS.

  The present invention can be used, for example, for manufacturing an electrode used in a battery.

1 Electrode 2 Metal foil (base material)
2a A side 2b B side 3A Electrode paste (coating material)
3B Electrode paste (coating material)
6 Work 7 Reference material 23 1st ultrasonic measuring device 26 2nd ultrasonic measuring device 31 3rd ultrasonic measuring device 41 1st ultrasonic sensor set 41A 1st ultrasonic sensor 41B 2nd ultrasonic sensor 42 2nd Ultrasonic sensor set for actual measurement 42A First ultrasonic sensor 42B Second ultrasonic sensor 43 Ultrasonic sensor set for calibration 43A First ultrasonic sensor 43B Second ultrasonic sensor 51 Controller (measurement control means)
61 Reference material heater (reference material heating means)
62 Atmosphere heater (atmosphere heating means)
66 Reference material temperature sensor (reference material temperature detection means)
67 Work temperature sensor (Work temperature detection means)
68 Atmosphere temperature sensor (atmosphere temperature detection means)
Tw Work temperature Tb Reference material temperature Te Ambient temperature

Claims (4)

An ultrasonic sensor set composed of a first ultrasonic sensor and a second ultrasonic sensor is provided, and both sides in the thickness direction of a workpiece in which a coating material is applied to one side or both sides of a belt-like substrate that runs in the longitudinal direction, The first ultrasonic sensor on one side and the second ultrasonic sensor on the other side are arranged facing each other through an air layer, and the first ultrasonic sensor and the second ultrasonic sensor An ultrasonic measurement method for measuring the thickness of the workpiece by propagating ultrasonic waves between the two,
The ultrasonic sensor group is provided separately from the actual measurement ultrasonic sensor group for actually measuring the thickness of the workpiece and the actual measurement ultrasonic sensor group, and calibrates the actual measurement value by the actual measurement ultrasonic sensor group. An ultrasonic measurement method comprising: a calibration ultrasonic sensor set for measuring, and a predetermined reference material that is disposed in the vicinity of the workpiece and whose thickness is measured by the calibration ultrasonic sensor set.
While adjusting the temperature of the reference material to the temperature of the workpiece, the thickness of the reference material and the thickness of the workpiece are respectively measured by the calibration ultrasonic sensor set for calibration of the reference material and for calibration of the workpiece. measured as a measurement value,
Simultaneously or immediately after measurement by the calibration ultrasonic sensor set, the thickness of the workpiece is measured as an actual measurement value of the workpiece by the actual measurement ultrasonic sensor set,
Based on the measured value for calibration of the workpiece, the measured value for calibration of the reference material, and the known thickness of the reference material, the thickness for calibration of the workpiece is obtained,
An ultrasonic measurement method, wherein a final thickness of the workpiece is obtained by correcting an actual measurement value of the workpiece based on a measurement value for calibration of the workpiece and a thickness for calibration of the workpiece.   When measuring the thickness of the reference material and measuring the thickness of the workpiece, the ambient temperature around the ultrasonic sensor set for measurement and the ultrasonic sensor set for calibration is brought close to the temperature of the workpiece. The ultrasonic measurement method according to claim 1. An ultrasonic sensor set composed of a first ultrasonic sensor and a second ultrasonic sensor is provided, and both sides in the thickness direction of a workpiece in which a coating material is applied to one side or both sides of a belt-like substrate that runs in the longitudinal direction, The first ultrasonic sensor on one side and the second ultrasonic sensor on the other side are arranged facing each other through an air layer, and the first ultrasonic sensor and the second ultrasonic sensor In the ultrasonic measurement device that measures the thickness of the workpiece by propagating the ultrasonic wave between,
At least one set of ultrasonic sensors for measurement, which is provided as the ultrasonic sensor set and includes the first ultrasonic sensor and the second ultrasonic sensor for measuring the thickness of the workpiece;
The ultrasonic sensor group is provided separately from the actual measurement ultrasonic sensor group, and includes the first ultrasonic sensor and the second ultrasonic sensor for calibrating the actual measurement value obtained by the actual measurement ultrasonic sensor group. A calibration ultrasonic sensor set;
A predetermined reference material that is disposed in the vicinity of the workpiece and whose thickness is measured by the calibration ultrasonic sensor set; and
A reference material heating means for heating the reference material;
Reference material temperature detection means for detecting the temperature of the reference material;
A workpiece temperature detecting means for detecting the temperature of the workpiece;
While the reference material is heated by the reference material heating means so that the detected temperature of the reference material becomes the detected temperature of the workpiece, the thickness of the reference material and the thickness of the workpiece are respectively increased for the calibration. The measurement value for calibration of the reference material and the measurement value for calibration of the workpiece are measured by an acoustic wave sensor set, and the thickness of the workpiece is measured simultaneously with or immediately after the measurement by the calibration ultrasonic sensor set. The workpiece thickness is measured based on the measured value for calibration of the workpiece, the measured value for calibration of the reference material, the known thickness of the reference material, and the measured value of the workpiece. look, the measured value of the workpiece, by correcting on the basis of the thickness for the calibration of the the measured value for the calibration of the workpiece workpiece, a measurement control means for calculating a final thickness of the workpiece Ultrasonic measuring apparatus characterized by comprising. Atmosphere heating means for heating the atmosphere around the ultrasonic sensor group for actual measurement and the ultrasonic sensor group for calibration;
An atmospheric temperature detection means for detecting an ambient temperature around the ultrasonic sensor group for actual measurement and the ultrasonic sensor group for calibration;
The measurement control means measures the thickness of the reference material and measures the atmosphere by the atmosphere heating means so that the detected ambient temperature becomes the detected workpiece temperature when the thickness of the workpiece is measured. The ultrasonic measurement apparatus according to claim 3, wherein the ultrasonic measurement apparatus is heated.

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