JP6642392B2 - Surface roughness measuring method and surface roughness measuring device - Google Patents

Description

  The present invention relates to a surface roughness measuring method and a surface roughness measuring device.

  In the case of measuring the surface roughness of a processing surface such as cutting or grinding, for example, Patent Document 1 discloses a method using a laser sensor. Alternatively, there is a method of measuring with an optical interferometer or the like. For example, it is also known to use a measuring instrument such as a scale or a vernier caliper for a surface having relatively large irregularities of a millimeter size, and to measure a microscopic photograph or the like for minute irregularities of a nanometer size. Have been.

  Also, a method of measuring the surface roughness with a line profile, such as a stylus type step meter, is known.

JP 201410001

  Since these measurement methods are performed by human judgment, camera image processing, and distance measurement using a laser, the only way to measure surface roughness over a wide range is to move the device or sample, which requires time. Was.

Therefore, when inspecting the surface roughness of the machined surface on the production line, the total number cannot be measured, but only by sampling.
The present invention has been made in view of the above problems, and provides a surface roughness measuring method and a surface roughness measuring device that can be measured in a short time.

In a first embodiment of the present invention,
A method for measuring surface roughness,
A heating step of heating the device under test (17);
A heat flux sensor (11) having a front surface (21, 43) and a back surface (22, 44) and generating an electromotive force due to the Seebeck effect due to a temperature difference between the front surface and the back surface. An output measurement step of contacting the back surface of the heat flux sensor on the object to be measured and measuring the output of the heat flux sensor corresponding to the temperature difference between the front surface and the back surface;
Determining a surface roughness from a response of the output voltage of the heat flux sensor to determine whether the surface roughness is within a standard value.
According to this measuring method, it is possible to easily determine in a short time whether or not the surface roughness of the object to be measured is within the standard value, so that it is possible to measure all the products.

A second embodiment of the present invention provides:
An apparatus (10) for measuring surface roughness, comprising: a heating element (12); and a temperature controller (13) for controlling the temperature of the heating element to a predetermined temperature.
A heat flux sensor (11) having a front surface (21) and a back surface (22) and generating an electromotive force due to a Seebeck effect due to a temperature difference between the front surface and the back surface; An output line (143, 145) for outputting an output of the heat flux sensor corresponding to the temperature difference;
A voltmeter (24) for measuring the output of the heat flux sensor.
Further, a contact plate (42) installed on the back surface of the heat flux sensor and having a surface roughness of a surface facing the object to be measured smaller than the surface roughness of the object to be measured, and an air plate installed on the surface of the heat flux sensor and And a radiator plate (41) installed between the radiator and the radiator.
With this device, it is possible to easily determine in a short time whether or not the surface roughness of the object to be measured is within the standard value, so that it is possible to measure all the products.

1 is an overall view of a surface roughness measuring device using a heat flux sensor. It is II-II sectional drawing in FIG. 3 of a heat flux sensor. FIG. 3 is a view taken in the direction of the arrow III in FIG. FIG. 3 is an explanatory diagram when the heat flow sensor shown in FIG. 2 contacts a workpiece as shown in FIG. 1. FIG. 5 is an explanatory diagram showing a case where the heat flux sensor has another configuration in the configuration diagram of the cross section shown in FIG. 4. It is a flowchart of a surface roughness measurement and a determination method. FIG. 6 is another explanatory diagram in FIG. 5 when a heating element is close to a work. It is a characteristic diagram of the output voltage of a heat flux sensor and time. 1 is an overall view of a surface roughness continuous determination device. It is a specific example of the result of having measured the surface roughness continuously by the surface roughness continuation determination device. It is a figure of other embodiments of a surface roughness measuring device using a heat flux sensor.

Hereinafter, a surface roughness measuring method and a surface roughness measuring device of the present invention will be described with reference to the drawings. In the following plurality of embodiments, the same components will be denoted by the same reference numerals, and description thereof will be omitted.
(First embodiment)
FIG. 1 shows an overall view of a surface roughness measuring device 10 using a heat flow sensor. The surface roughness measuring device 10 includes a heat flux sensor 11, a heating element 12, a temperature control device 13 for controlling the heating element at a constant temperature, a heating element driving unit 18 for driving the heating element up and down, and a heating element drive. Drive control unit 14 for controlling the unit, a measuring amplifier 15 for amplifying the output voltage from the heat flux sensor, a voltmeter 24 for measuring the output voltage, and measuring the surface roughness to determine whether the value is within a standard value. And a controller 16. Here, the controller 16 may operate in conjunction with the temperature control device 13 and the drive control device 14.

  In the present embodiment, the measurement location of the workpiece 17 which is the workpiece is a flat portion processed by cutting or grinding.

  As shown in FIG. 2, the heat flux sensor 11 includes an insulating base material 51, a back surface protection member 52, a surface protection member 53, a first interlayer connection member 54, and a second interlayer connection member 55. In FIG. 2, in order to make the configuration of the heat flux sensor 11 easy to understand, the direction from the back surface protection member 52 to the front surface protection member 53 is enlarged as compared with the actual shape. The surface of the surface protection member 53 facing the direction opposite to the direction of gravity is referred to as the front surface 21, and the surface of the back surface protection member 52 facing the direction of gravity is referred to as the back surface 22.

  The insulating base material 51 is formed from a film made of a thermoplastic resin. The insulating base material 51 has a plurality of via holes 111 penetrating in the thickness direction. In the via hole 111, a first interlayer connection member 54 or a second interlayer connection member 55 is provided. A via hole 111 in which the second interlayer connection member 55 is provided is provided next to the via hole 111 in which the first interlayer connection member 54 is provided. That is, the first interlayer connection member 54 and the second interlayer connection member 55 are arranged on the insulating base material 51 so as to be separated from each other and alternate with each other.

  The back surface protection member 52 is formed of a film made of a thermoplastic resin whose size is the same as the size of the insulating base material 51. The back surface protection member 52 is provided on the back surface 112 of the insulating base material 51. Between the back surface 112 of the insulating base material 51 and the surface 121 of the back surface protecting member 52 on the insulating base material 51 side, there are provided a plurality of back surface patterns 114 as a “first conductive pattern” in which copper foil or the like is patterned. ing. The back surface pattern 114 electrically connects the first interlayer connection member 54 and the second interlayer connection member 55.

  The surface protection member 53 is formed of a film made of a thermoplastic resin whose size is the same as the size of the insulating base material 51. The surface protection member 53 is provided on the surface 113 of the insulating base material 51. A plurality of surface patterns 115 as “second conductive patterns” in which copper foil or the like is patterned are formed between the surface 113 of the insulating base material 51 and the surface 131 of the surface protection member 53 on the insulating base material 51 side. ing. The surface pattern 115 electrically connects the first interlayer connection member 54 and the second interlayer connection member 55.

  The plurality of first interlayer connection members 54 and the plurality of second interlayer connection members 55 are made of different metals so as to exhibit the Seebeck effect. For example, the first interlayer connection member 54 is made of a metal compound obtained by solid-phase sintering such that the powder of the Bi-Sb-Te alloy constituting the P-type maintains the crystal structure of a plurality of metal atoms before sintering. Is formed. The second interlayer connection member 55 is formed from a metal compound obtained by solid-phase sintering such that the Bi-Te alloy powder constituting the N-type maintains a predetermined crystal structure of a plurality of metal atoms before sintering. Have been. The first interlayer connection members 54 and the second interlayer connection members 55 are alternately arranged in series by a back surface pattern 114 and a front surface pattern 115.

As shown in FIGS. 2 and 3, one first interlayer connection member 140 of the plurality of first interlayer connection members 54 is electrically connected to the terminal 141. One of the second interlayer connection members 150 among the plurality of second interlayer connection members 55 is electrically connected to the terminal 151. As shown in FIG. 4, the terminals 141 and 151 are connected such that the back surface pattern 114, the first interlayer connection member 54, the front surface pattern 115, and the second interlayer connection member 55 meander in one heat flux sensor 11. (See two-dot chain line L4 in FIG. 3). The terminals 141 and 151 are exposed to the outside via the opening 132 of the surface protection member 53.
The terminal 141 is electrically connected to the output line 143 via the connection bump 142. The terminal 151 is electrically connected to the output line 153 via the connection bump 152.

  In the heat flux sensor 11, when the magnitude of the amount of heat flowing in the thickness direction of the heat flux sensor 11 (the direction from the back surface protection member 52 to the front surface protection member 53 in FIG. 3) changes, the first layers alternately connected in series are changed. The electromotive voltage generated in the inter-connecting member 54 and the second inter-layer connecting member 55 changes. The heat flux sensor 11 outputs this voltage to the outside via the output lines 143 and 153 as a detection signal. The magnitude of the heat flux passing through the heat flux sensor 11 is calculated based on the output voltage. Hereinafter, the internal configuration is not illustrated when the cross-sectional configuration of the heat flux sensor is represented. The surface facing the direction of gravity is defined as the back surface, and the surface on the opposite side is defined as the front surface.

Assuming that the heat flow in the solid is Q, the heat flux can be obtained as the following equation (1) by Fourier's law.
Q∝ (T2−T1) = (C / d) × (T2−T1) (1)
C: thermal conductivity, d: distance between front and back surfaces, T1: surface temperature (K), T2: back surface temperature (K)
The unit of the heat flux Q is W / m ^2, which is represented by the amount of heat crossing a unit area per unit time.
As described above, by using the heat flux sensor, the heat flux can be obtained based on the output proportional to the difference between the temperature T1 (K) of the front surface 21 and the temperature T2 (K) of the back surface 22.

Here, the heat in the solid flows from the higher surface temperature to the lower surface temperature. Since the heat flux sensor detects this flow, it measures the temperature difference (T2-T1) between the front surface temperature T1 (K) and the back surface temperature T2 (K), and measures the absolute temperature. Not something. Therefore, the surface roughness measurement according to the present embodiment can be performed without controlling the outside air temperature.

  FIG. 4 is a diagram illustrating a cross-sectional configuration when the heat flux sensor 11 is placed on the work 17. It is assumed that the work 17 is on the back surface 22 of the heat flux sensor 11 and the air layer is on the front surface 21. The size of the heat flux is represented by the size of a white arrow. When the temperature of the air is T1 (K), the temperature of the work is T2 (K), and T2> T1, the heat flux flows from the work to the air via the heat flux sensor 11. When the temperature T2 of the work is high (a), the heat flux indicated by the white arrow becomes large. When T2 is low (b), the heat flux indicated by the white arrow becomes small.

  The heat flux sensor outputs the magnitude of the heat flux to the controller 16 via the voltmeter 24 as output voltage data. The voltmeter 24 may include the measurement amplifier 15. When the voltage is very small, the detection ability is improved by amplifying the voltage by the measuring amplifier 15. If the output voltage has a sufficient voltage, the measuring amplifier 15 may be omitted.

FIG. 5 is a diagram illustrating a cross-sectional configuration of another configuration of the heat flux sensor 11.
As shown in FIG. 5A, the surface of the heat flux sensor 11 that does not contact the work 17 is referred to as a front surface 21, and the opposite surface is referred to as a back surface 22. At this time, if the surface 21 is in contact with air, heat dissipation does not proceed, and the temperature of the surface 21 may increase during repeated measurements. The heat flux sensor 11 outputs a temperature difference between the front surface 21 and the back surface 22. Therefore, if the temperature of the heat flux sensor rises significantly, the temperature difference between the front surface 21 and the back surface 22 will be small, making it difficult to detect a change in the output voltage.

  Therefore, a material having good thermal conductivity can be brought into contact with the surface 21 to form the heat radiating plate 41. Thereby, the front surface 21 of the heat flux sensor 11 can be efficiently cooled by heat radiation, the temperature of the front surface 21 can be easily set to the same temperature as the surrounding air, and the temperature difference between the front surface 21 and the back surface 22 can be maintained. . Therefore, the heat flux also increases, and it becomes easy to detect a change in the output voltage. It is conceivable that the radiator plate 41 is formed of, for example, a metal block such as aluminum or copper. In addition, as shown in FIG. 5B, the surface of the heat radiating plate 41 may be configured to have more irregularities in order to further increase the contact area of the heat radiating plate with the air and increase the heat radiation efficiency.

  The heat flux sensor 11 and the heat radiating plate 41 are fixed with, for example, a heat conductive tape or an adhesive material having a high heat conductivity such as epoxy or silicone adhesive, silicone grease, silver paste, or InGa alloy.

  The heat flux sensor 11 may further include a contact plate 42 on the back surface 22 that contacts the work 17. For example, when the surface roughness of the heat flux sensor 11 is larger than the surface roughness of the work, the size of the heat flux to be measured depends on the surface roughness of the heat flux sensor. Therefore, it is difficult to measure the surface roughness of the work.

Therefore, the contact plate 42 whose surface roughness is smaller than the surface roughness of the work 17 is fixed to the back surface 22 of the heat flux sensor 11. Thereby, it is possible to avoid that the magnitude of the heat flux depends on the surface roughness of the heat flux sensor 11.
Examples of the contact plate 42 include a metal thin plate made of aluminum or the like and a Si wafer thin plate whose surface roughness is smaller than the surface roughness of the work by polishing or the like.

  The heat flux sensor 11 and the contact plate 42 are fixed with, for example, a heat conductive tape or an adhesive material having a high heat conductivity such as epoxy or silicone adhesive, silicone grease, silver paste, or InGa alloy.

  As described above, when the heat flux sensor 11 includes the heat radiating plate 41 and the contact plate 42 on the front surface 21 and the back surface 22, the heat flux sensor 11 has a new front surface 43 and a new back surface 44.

The surface roughness determination method will be described with reference to the flowchart of FIG.
In step S <b> 1, the heating element 12 is set to a predetermined heating value by the temperature control device 13. In the present embodiment, the heating element 12 uses a so-called block heater in which a heater is embedded in a metal body. The surface roughness of the surface of the heating element 12 close to the work is preferably smaller than the surface roughness of the work 17 or the like, but is not particularly limited to this. Further, since it is sufficient that a certain amount of heat is stably applied to a certain part of the work 17, the method is not limited to the block heater. For example, heating with a laser or a spot heater or high-frequency heating may be used.

In step S <b> 2, under the control of the drive control device 14, the heating element 12 that moves up and down by the heating element drive unit 18 approaches the work 17 from above. In the present embodiment, the heating element 12 approaches the work 17 from above, but may approach from the lateral direction, or may approach from below and heat the back surface of the work 17. Further, the heating element 12 may contact the work 17. When the heating element 12 contacts the work 17, sufficient heat is applied to the work 17 more quickly than when the heating element 12 approaches the work 17. Therefore, the measurement time can be shortened, and the change in the output voltage can be easily detected.
At this time, it is assumed that the heat flux sensor 11 is in contact with the workpiece 17 by a human hand or a mechanical drive. It is preferable that the heat flux sensor contacts the work 17 before the heating element 12 approaches the work 17. However, even if the heat flux sensor 11 contacts the work 17 after the heating element 12 approaches the work 17. , Surface roughness measurement is possible.

  In step S <b> 3, when the work 17 is heated, the heat passes through the work 17 and reaches the heat flux sensor 11. The voltmeter 24 measures the voltage corresponding to the heat flux output from the heat flux sensor 11, and the measured data is transmitted to the controller 16. The controller 16 may take various forms such as a personal computer, a workstation, or a sequencer, but may be any information processing terminal having a measurement processing capability.

Here, FIG. 7 is a diagram illustrating a cross-sectional configuration in the case where the heat flux sensor 11 contacts the work 17 and the heating element 12 approaches the work 17 from the direction of the arrow indicated by the solid line. It is assumed that the heat flux sensor 11 has a heat radiating plate 41 and a contact plate 42.
Due to the proximity of the heating element 12 to the work 17, a portion of the surface of the work 17 near the heating element 12 has a heating portion 61 where the temperature is increased by heating.
When the surface roughness of the work 17 is small, as shown in FIG. 7A, the back surface 44 of the heat flux sensor 11 and the surface of the work 17 are in close contact with each other, and the air layer is small. On the other hand, when the surface roughness of the work 17 is large as shown in FIG. 7B, an air layer 60 is included between the back surface 44 of the heat flux sensor 11 and the surface of the work 17.

  The thermal conductivity of air is 0.024 W / (m · K), the thermal conductivity of iron is 84 W / (m · K), the thermal conductivity of glass is 1 W / (m · K), and the thermal conductivity of epoxy resin is The conductivity is 0.20 W / (m · K). Thus, the thermal conductivity of air is generally lower than that of solid. Therefore, if air is included, the temperature of the back surface 44 of the heat flux sensor 11 is unlikely to rise, and the temperature T2 (K) of the back surface in Expression (1) is low. Therefore, the magnitude of the heat flux indicated by a white arrow flowing from the heated portion 61 on the surface of the workpiece 17 to the air from the front surface 43 through the back surface 44 of the heat flux sensor 11 is smaller than the case where the air layer 60 is not included. Therefore, the characteristic curve of the output voltage and time of the heat flux sensor 11 depends on how much the air layer 60 is included between the work surface and the back surface 44 of the heat flux sensor 11, in other words, the surface roughness of the work. Change.

  In step S4, the controller 16 measures the surface roughness from the output curve of the heat flux sensor 11, and determines whether or not the surface roughness is within a standard value. FIG. 9 shows a characteristic curve between the output voltage of the heat flux sensor 11 and time. Here, an example in which it is determined whether the surface roughness of the work 17 is within a specified value will be described.

8A shows the output voltage data of the heat flux sensor 11, and FIG. 8B shows the position of the heating element 12.
At time t1, when the heating element 12 approaches the surface of the work 17, the heat flux is detected by the heat flux sensor 11, and the output voltage rises.
At time t2, the output voltage of the work 17 whose surface roughness is within the standard value and the work 17 whose surface roughness is larger than the standard value are in the process of rising.
At time t3, the rising of the output voltage of the work 17 whose surface roughness is within the standard value ends. The output voltage of the work 17 whose surface roughness is larger than the standard value is still in the process of rising.
At time t4, the rising of the output voltage of the work 17 having the surface roughness larger than the standard value also ends.

The method of determining whether or not the surface roughness is within the standard value is, for example, in FIG. 8A, the slope of the output voltage from time t1 to time t2 is equal to or greater than a certain reference value. You can judge whether or not. When the surface roughness is large, the inclination becomes small.
Alternatively, the time till the end of the rising, for example, the work 17 whose surface roughness is within the standard value is time t2, and the work 17 whose surface roughness is larger than the standard value is time t3. If the elapsed time from t1 is within a certain range, it is determined that the surface roughness is within the standard value.

  Here, even if the temperature of the outside air slightly changes and the temperatures of the front surface 43 and the back surface 44 of the heat flux sensor 11 in FIG. 7 change, the slope of the heat flux output curve itself does not greatly change. Therefore, the measurement according to the present embodiment can be performed without particularly controlling the outside air temperature.

  Also. In FIG. 8B, the heating element 12 is located at a position close to the workpiece 17 during the measurement. For example, the heating element 12 is located close to the workpiece 17 for a short period of time from t1, and is located at a distance thereafter. The drive control device 14 may be controlled. In the present embodiment, it is sufficient that the response of the heat flux by heating the work 17 can be detected, so that the work 17 does not need to be continuously heated. This is because once the heating portion 61 of the work 17 is formed, the heat flux can be measured with the remaining heat. Such a method of heating for a short time is suitable, for example, when the work 17 is made of resin and easily deformed by heat.

  Regarding the method of determining the standard value of the standard value for the determination of the surface roughness, for example, the surface roughness is measured by another method of knowing the surface roughness with high accuracy. And the obtained output curve of the heat flux sensor 11 can be used as a reference.

The surface roughness of the work 17 is measured as described above, and the measurement result of the work 17 is recorded by the controller 16. After that, the surface roughness of the new work is measured. Since this measurement can be performed in a short time, it is easy to continuously measure the surface roughness of the work, and it is possible to perform a 100% inspection of a work that could only be conventionally inspected by sampling.
Further, in the present embodiment, the controller 16 performs the surface roughness measurement and determines whether the surface roughness is within the standard value. A person may measure the surface roughness and determine whether the surface roughness is within the standard value.

In the present embodiment, the measurement unit 31 of the heat flux sensor 11 has a rectangular plate shape. However, the present invention is not limited thereto, and heat flux sensors having various shapes can be used. Further, in the present embodiment, the work is heated at a position adjacent to the heat flux sensor. However, for example, the work may be heated from the back surface or the side surface.
The heat flux sensor 11 can easily form the measurement unit 31 into a relatively large shape of, for example, several cm square to several tens cm square. Therefore, in the present embodiment, compared to other measurement methods such as a surface roughness measurement method such as a microscope or a laser distance meter by optical measurement, or a caliper, a stylus type, measurement of the surface roughness in a wide area It can be determined in a short time whether it is within the standard value.

  In the present embodiment, when performing the surface roughness measurement, the outside air temperature is not particularly controlled, but when more stable measurement results are required, the measurement is performed in an environment controlled at a constant temperature such as a constant temperature room or a constant temperature bath. May be implemented.

(Second embodiment)
FIG. 9 shows an overall view of the surface roughness continuous measuring apparatus 100. The surface roughness continuous measurement device 100 includes a surface roughness measurement device 10, a conveyor 80, and a position measurement sensor 81.

  It is assumed that the conveyor 80 is driven by a motor 82 or the like, and moves the workpiece 17 processed by another device (not shown) from right to left when viewed from the paper surface. The processed work 17 may be placed on a conveyor by a person or loaded by a robot from a processing device. Various other forms are also conceivable. The measurement site of the work 17 is a flat portion processed by cutting or grinding.

  The position measurement sensor 81 senses that the work 17 has reached a specific position, and sends the data to the controller 16. The position measurement sensor 81 detects the position of the work, and is a laser sensor in the present embodiment. Alternatively, if the interval between the works is constant and the speed of the conveyor 80 is also constant, it is not necessary to detect the position of the work, and in that case, the sensor may not be provided.

When the work 17 reaches a certain position with respect to the heating element 12 and the heat flux sensor 11, the movement of the conveyor 80 is temporarily stopped.
Then, similarly to the first embodiment, the controller 16 performs the measurement of the surface roughness and the determination as to whether or not the surface roughness is within the standard value in accordance with steps S1 to S4 in FIG.

  At this time, the heat flux sensor 11 is also driven up and down by the heat flux sensor drive unit 25 to contact the work 17. In the present embodiment, the heat flux sensor drive unit 25 is controlled by the drive control device 14 that drives the heating element drive unit 18. The timing at which the heat flux sensor 11 comes into contact with the workpiece 17 is preferably between steps S1 and S2 in FIG. 7, that is, before the heating element 12 approaches the workpiece 17. However, even if the heat flux sensor 11 comes into contact with the work 17 after the heating element 12 approaches the work 17, the surface roughness can be measured.

  When the measurement of the surface roughness of the work 17 and the determination of whether or not the surface roughness is within the standard value are completed, the controller 16 records the measurement of the surface roughness of the work 17 and the determination result. The drive control device 14 drives the heating element 12 and the heat flux sensor 11 that have been close to each other to a position separated from the work 17. Thereafter, the conveyor 80 is moved until the next work 17 reaches the measurement position.

The surface roughness continuous measuring device 100 continuously measures the surface roughness of the work 17 as described above. At this time, it is also possible to determine the deterioration of the processing tool from the measurement result of the surface roughness.
As the metal surface is cut by the processing blade, the processing blade deteriorates and the surface roughness increases. When the data of the surface roughness measurement can be continuously obtained as in the present embodiment, the temporal change of the surface roughness can be obtained, so that the deterioration of the cutting tool is more stably than the surface roughness measurement result by the extraction. It can be visualized and the replacement time can be determined.
By using the surface roughness continuous measurement device 100, it is possible to not only detect sudden changes such as deterioration, chipping, cracking, breakage, and the like of the cutting tool used for cutting, but also deteriorate the grinding wheel used for grinding and polishing, etc. It is also possible to visualize the deterioration of various processing tools and determine the replacement time.

FIG. 10 shows an example of the measurement results.
FIG. 10A shows a method according to the present embodiment. The horizontal axis is the number of works, and the vertical axis is the surface roughness. Here, for example, the vertical axis is not a numerical value of the surface roughness itself, but a value correlated with the surface roughness. For example, if the surface roughness is measured by the slope of the output voltage, there is a reciprocal of the slope, and the magnitude may be the heat flux. The approximate straight line obtained from these values is indicated by a one-dot chain line.
FIG. 10B shows a conventional method. The horizontal axis is the number of workpieces, and the vertical axis is the value of the surface roughness measured by a laser or a contact-type surface roughness measuring method. In FIG. 10A, only a white circle is extracted. The approximate straight line obtained from these values is indicated by a dotted line.

It can be seen from the inclination of the approximate straight line in FIG. 10A that the surface roughness tends to increase. It can also be seen from the tendency of the scattering of black circles that the dispersion of the measured values tends to increase. Therefore, before the surface roughness exceeds the standard value and the work becomes defective, the blade can be replaced and the countermeasure can be appropriately taken.
On the other hand, in FIG. 10B measured by sampling, the tendency that the surface roughness is increased cannot be read depending on the timing of the sampling, and it is not clear that the dispersion of the measured values is large. For this reason, some workpieces have a surface roughness exceeding the standard value and become defective, and the timing for replacing the cutting tool cannot be determined.

(Other embodiments)
(A) In the above embodiment, the temperature of the heating element is higher than that of the work, but may be lower than that of the work. For example, if the workpiece has a high temperature immediately after being processed, place a low-temperature or room-temperature block close to the workpiece and measure the heat flux deprived of the workpiece by the block to measure the surface roughness. It can be performed.
(B) FIG. 11A is a side view in which a heat flux sensor is brought into contact with a work having a flat plane as in the above embodiment. However, since the heat flux sensor can be formed in a flexible form, the present invention can be applied to a work having a curved surface as shown in FIG.
In the case of a work having a curved surface, it is more preferable to process the heat flux sensor into a shape that follows the shape of the work in advance. In addition, the present invention is not limited to curved surfaces, and can be applied to surface roughness measurement of works having various surface shapes.
(C) In the above embodiment, the work is a metal processed by cutting or grinding. However, the present invention is also applicable to, for example, a resin molded product manufactured by injection molding. By continuously measuring the surface roughness, for example, it is possible to estimate the maintenance time of a mold or a molding apparatus that has deteriorated due to continuous use.
(D) There are times when it is desired to lower the heating temperature as much as possible, for example, when the object to be measured is weak to heat. At this time, the temperature difference from the environmental temperature may be smaller than the heating temperature of the sample. In such a case, the measurement is preferably performed in a space such as a chamber for controlling the environmental temperature to be constant, because the output voltage decreases and the determination becomes difficult.
As described above, the present invention is not limited to the above embodiment, and can be implemented in various forms without departing from the spirit of the invention.

Reference Signs List 10 surface roughness measuring device, 100 surface roughness continuous measuring device 11 heat flux sensor, 12 heating element, 13 temperature control device 14 drive control device, 15 measuring amplifier, 16 controller 24 voltmeter, 143, 153 output line, 41 heat radiation Plate, 42 contact plate 21, 43 heat flux sensor surface, 22, 44 heat flux sensor surface

Claims (9)

A heating step of heating the device under test (17);
A heat flux sensor (11) having a front surface (21, 43) and a back surface (22, 44) and generating an electromotive force due to a Seebeck effect due to a temperature difference between the front surface and the back surface is used. An output measurement step of contacting the back surface of the heat flux sensor on the object to be measured and measuring an output of the heat flux sensor corresponding to a temperature difference between the temperature of the front surface and the temperature of the back surface,
Surface roughness measurement step of measuring the surface roughness from the response of time and the output, to determine whether the surface roughness is within a standard value,
And a surface roughness measuring method.   The surface roughness measuring method according to claim 1, wherein in the heating step, the object to be measured is heated by bringing a heating element (12) controlled to a predetermined temperature higher than an outside air temperature close to or in contact with the heating element. .   The surface roughness measuring method according to claim 1, wherein in the heating step, the object to be measured is heated by bringing a heating element (12) controlled to a predetermined temperature lower than an outside air temperature close to or in contact with the heating element. . The heat flux sensor,
A contact plate (42) installed between the back surface (22) of the heat flux sensor and the object to be measured;
A heat sink (41) installed between the surface (21) of the heat flux sensor and air;
The surface roughness measuring method according to any one of claims 1 to 3, comprising:   The surface roughness measuring method according to claim 4, wherein in the output measuring step, the contact plate having a smaller surface roughness on a surface facing the object to be measured than a surface roughness of the object to be measured is used.   The method according to any one of claims 1 to 5, wherein, in the surface roughness determination step, measurement of surface roughness of the plurality of objects to be measured and determination of whether the surface roughness is within a standard value are performed. Surface roughness measurement method.   The surface roughness measurement according to claim 6, further comprising a replacement determination step of determining a replacement time of a processing tool used for processing the workpiece from a result of the surface roughness measurement of the plurality of workpieces. Method. The heating step and the output measuring step are performed in a space where the environmental temperature is controlled to be constant.
The method for measuring surface roughness according to claim 1. A surface roughness measuring device (10) for measuring a surface roughness of an object to be measured,
A heating element (12);
A temperature controller (13) for controlling the temperature of the heating element to a predetermined temperature;
A heat flux sensor (11) having a front surface (21) and a back surface (22), wherein an electromotive force due to a Seebeck effect is generated due to a temperature difference between the front surface temperature and the back surface temperature;
An output line (143, 145) for outputting an output corresponding to a temperature difference between the front surface and the back surface;
A voltmeter (24) for measuring the output of the heat flux sensor;
A contact plate (42) installed on the back surface of the heat flux sensor and having a surface roughness of a surface facing the object to be measured smaller than a surface roughness of the object to be measured;
A heat sink (41) installed between the surface of the heat flux sensor and air;
A surface roughness measuring device comprising:

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