Film thickness measurement method for metalworking agent and film thickness measurement system for metalworking agent

Abstract

The present invention is a method for measuring the film thickness of a visible metalworking agent that is adhered to a mold. According to the present invention, a film thickness measurement method for a metalworking agent includes an image data acquisition step for acquiring image data obtained by capturing an image of the appearance of the surface of a mold to which a metalworking agent is adhered and a plurality of markers that have different measured L* values, a correspondence relationship derivation step for using the measured L* values and captured L* values for the plurality of markers from among captured L* values from the image data to derive the correspondence relationship between the measured L* values and the captured L* values, a film thickness derivation step for using the correspondence relationship and the correlation between the measured L* values and film thickness values to derive a film thickness for the metalworking agent from a captured L* value for a measurement site in the image data, and an outputting step for outputting the film thickness derived for the metalworking agent.

Description

Method for measuring the film thickness of a metalworking agent and system for measuring the film thickness of a metalworking agent

[0001] The present invention relates to a method for measuring the film thickness of a metalworking agent and a system for measuring the film thickness of a metalworking agent. This application claims priority under Japanese application No. 2024-159952, filed on 17 September 2024, and incorporates all the provisions of the said Japanese application.

[0002] Techniques for measuring the adhesion state, such as the amount of release agent applied, have been disclosed (see, for example, Patent Documents 1 and 2).

[0003] Japanese Patent Publication No. WO2024 / 070261, JP 2022-94564

[0004] In metalworking technologies such as die casting and plastic deformation, there is a need to be able to accurately and easily measure the film thickness of metalworking agents such as mold release agents and lubricants adhering to molds in order to ensure good productivity and improve the quality of molded products. In particular, it is desirable to be able to accurately measure the film thickness at various points on the surface of the mold while improving convenience.

[0005] One of the objectives of the present invention is to provide a method and system for measuring the film thickness of a metalworking agent that can accurately and easily measure the film thickness of a metalworking agent adhering to a mold while improving convenience.

[0006] The present invention relates to a method for measuring the film thickness of a metalworking agent that is visible when applied to a mold. The method for measuring the film thickness of a metalworking agent involves measuring the surface appearance of the mold to which the metalworking agent is applied. ＊ Image data acquisition process to acquire image data captured with multiple markers, each with a different value, and image data imaging L ＊ Image acquisition of multiple markers among the values ​​L ＊ Value and measurement L ＊ Using the value to image L ＊ Value and measurement L ＊ A correspondence derivation process to derive the correspondence with the value, and imaging L of the measurement location in the image data. ＊ From the values, the correspondence and measurement L ＊A film thickness derivation step of deriving the film thickness of a metalworking fluid using the correlation between the imaging L value and the film thickness value, and an output step of outputting the derived film thickness of the metalworking fluid are provided.

[0007] According to the above film thickness measurement method, it is possible to accurately and simply measure the film thickness of the metalworking fluid adhering to the mold while improving convenience.

[0008] FIG. 1 is a schematic cross-sectional view showing a part of a die-casting apparatus used in the method for measuring the film thickness of a mold release agent in Embodiment 1 of the present invention. FIG. 2 is a block diagram showing the configuration of a film thickness measurement system for a mold release agent according to the present invention. FIG. 3 is a flowchart showing typical steps in the method for measuring the film thickness of a mold release agent according to Embodiment 1. FIG. 4 is a diagram showing an example of image data of a photographed image in which four markers are attached to the surface of a mold. FIG. 5 is a diagram showing the photographed image shown in FIG. 4 in a line diagram. FIG. 6 is an imaging L of a marker ＊ value and a measurement L ＊ value. FIG. 7 is a diagram showing the correlation between the measurement L ＊ value and the film thickness.

[0009] [Outline of Embodiment] The method for measuring the film thickness of a metalworking fluid according to the present invention is a method for measuring the film thickness of a metalworking fluid having visibility attached to a mold. The method for measuring the film thickness of a metalworking fluid includes an image data acquisition step of acquiring image data in which the appearance of the surface of a mold to which the metalworking fluid is attached is photographed together with a plurality of markers having different imaging L ＊ values, and an imaging L of the image data ＊ Among the values, the imaging L of a plurality of markers ＊ values and the measurement L ＊ values are used to derive the correspondence between the imaging L ＊ value and the measurement L ＊ value in a correspondence derivation step, and from the imaging L ＊ value of the measurement location in the image data, a film thickness derivation step of deriving the film thickness of the metalworking fluid using the correspondence and the correlation between the measurement L ＊ value and the film thickness value, and an output step of outputting the derived film thickness of the metalworking fluid are provided.

[0010] Metalworking agents used by adhering them to molds require even and uniform adhesion to the mold surface. This will be explained using die-casting release agents as an example. In die-casting, a type of mold processing, molten metal is poured into a cavity formed by combining molds heated to a predetermined temperature. After molding, the product is removed from the combined molds to produce a casting. To prevent sticking between the molten metal and the mold, to manufacture castings with high precision, and to smoothly remove the casting from the mold, a release agent is applied to the mold surface by methods such as coating, spraying, or dispensing. If too much release agent is applied, discoloration may occur on the surface of the casting, or quality may deteriorate due to vaporization of the release agent components. Conversely, if too little release agent is applied, or if the amount of release agent applied is uneven on the mold surface, it may hinder the manufacture of high-precision castings or make it difficult to remove the casting from the mold. Therefore, it is necessary to uniformly apply an appropriate amount of release agent to the mold surface. Similarly, uniform adhesion is required for other metalworking agents, such as lubricants for plastic deformation.

[0011] Here, understanding the adhesion state of the release agent, that is, whether an appropriate amount of release agent is uniformly adhered to the surface of the mold, is important from the viewpoint of good productivity and improvement of the quality of castings. Furthermore, to ensure uniform adhesion of the release agent, accurate measurement of the film thickness at various points on the surface of the mold is required. The inventors diligently studied methods for accurately measuring the film thickness of the release agent adhered to the surface of the mold, and have come up with the present invention. The method for measuring the film thickness of a metalworking agent according to the present invention first prepares a visible metalworking agent, and the appearance of the surface of the mold to which the visible release agent has been adhered is measured using different known measurement methods L ＊ Image data is acquired along with multiple markers that have values. Then, the image data is captured L ＊ Image acquisition of multiple markers among the values ​​L ＊ Value and measurement L ＊ Using the value, take the photograph L ＊ Value and measurement L ＊ The correspondence with the value is derived. Then, the measurement location in the image data is captured L. ＊ From the value, shooting L ＊ Value and measurement L＊ Correspondence with values ​​and measurement L ＊ The film thickness of the metalworking agent is derived using the correlation between the value and the film thickness value. Finally, the derived film thickness of the metalworking agent is output. With this method, first, when measuring the film thickness, a colorimeter is not necessarily used for measurement. ＊ The need to measure values ​​is eliminated. Colorimeters require pressing a probe against a flat surface for measurement. However, with this method, only image data of the coating surface needs to be acquired, improving convenience and facilitating the measurement of film thickness in fine details and on surfaces with large irregularities. Furthermore, this method allows for film thickness measurement even when the metalworking agent is directly applied to the mold without applying any chemicals (such as a developer), thus enabling film thickness measurement without being affected by the aforementioned chemicals. Additionally, marker imaging L ＊ Value and known measurement L ＊ The correspondence between the values ​​is derived, and this correspondence is used to photograph the measurement location L. ＊ Measure the value L ＊ Convert to a value and measure L ＊ Since the film thickness is derived based on the correlation between the value and the film thickness, the L during imaging ＊ This method suppresses the decrease in measurement accuracy due to variations in values. This reduces the influence of shooting conditions such as light intensity and the degree of shading during shooting, as well as the performance of the shooting equipment, enabling high-precision measurement of the film thickness of the metalworking agent. Therefore, expensive and complex shooting equipment is unnecessary, and the film thickness can be measured accurately even using image data captured with a general-purpose digital camera or a camera on a smartphone. Thus, the metalworking agent film thickness measurement method described above allows for accurate and simple measurement of the film thickness of a metalworking agent applied to a mold while improving convenience. The metalworking agent is a release agent or lubricant used by applying it to a mold, particularly when performing processing using a mold, and includes, for example, die-casting release agents and lubricants for plastic deformation. Furthermore, in this invention, L ＊ L represents brightness, and the method for measuring the film thickness of the metalworking agent of the present invention is L ＊ a ＊ b ＊ Color space, L ＊ C＊ Values ​​obtained under any measurement conditions, including the h color space, are applicable. ＊ The value is between 0 and 100, L ＊ If the value is high, the color will be closer to white, L ＊ A lower value results in a color closer to black.

[0012] In the above method for measuring the film thickness of the metalworking agent, the above correspondence is as follows: ＊ Value and measurement L ＊ A function obtained from the values ​​through regression analysis, such as a function obtained by the least squares method, may be represented as a calibration curve. By using this correspondence, the shooting L, which is affected by the shooting environment and conditions, can be represented. ＊ Measure the value L ＊ The data can be converted into a numerical value, and the film thickness of the metalworking agent can be derived. By doing so, by deriving a correspondence such as a calibration curve from the acquired image data, it becomes possible to accurately derive the film thickness of the metalworking agent. Therefore, the film thickness of the metalworking agent can be measured more simply.

[0013] In the above method for measuring the film thickness of a metalworking agent, there is no limit to the number of markers; for example, there may be two to six markers. For example, in the above method for measuring the film thickness of a metalworking agent, image data may be acquired by placing multiple markers in areas close to the four corners of the shooting range. That is, the image data acquisition step may involve acquiring image data by placing four markers in areas close to each of the four corners of the shooting range. By doing so, the influence of variations in light intensity and shading within the shooting range can be reduced, and the overall image data can be improved. ＊ Value and measurement L ＊ This improves the correlation between the values ​​and the measurement. Therefore, it is possible to more accurately measure the film thickness of the metalworking agent across the entire image data. When there are two or three markers, it is preferable that each be placed in an area close to the four corners of the imaging range, although there may be corners where no markers are placed. When there are five or more markers, the positions of the markers can be determined arbitrarily. Typically, they are placed at the edges so as not to overlap with the film thickness measurement points.

[0014] In the above method for measuring the film thickness of a metalworking agent, the measurement L of multiple markers ＊ The values ​​should preferably be set without bias between 0 and 100. In this way, the measurement L of multiple markers ＊ By setting a wide range of values ​​for intensity, the film thickness of metalworking agents can be measured more accurately.

[0015] In the above method for measuring the film thickness of the metalworking agent, in the image data acquisition step, image data including areas of the mold surface where the metalworking agent is not attached may be acquired. In the film thickness derivation step, imaging L of the area where the metalworking agent is not attached is performed based on the correspondence. ＊ Measured L converted from value ＊ The value, measured L ＊ The correlation is derived by using a blank value as the lower limit of the value, and the imaging L of the measurement location in the image data. ＊ The film thickness of the metalworking agent may be derived from the values ​​using correspondence and correlation relationships. This allows for changes in the image L for each image. ＊ The influence of the values ​​can be reduced. As a result, the correlation of the above relationship becomes stronger, and the film thickness of the release agent can be measured more accurately.

[0016] In the above method for measuring the film thickness of the metalworking agent, the correlation is between the film thickness of the metalworking agent when sufficiently thickly applied and the measured L ＊ The value may also be derived as a hypothetical saturation value. By doing so, the film thickness of the release agent can be measured more accurately.

[0017] In the above-described method for measuring the film thickness of a metalworking agent, the output step may output the film thickness distribution in different colors. This makes the film thickness distribution on the surface of the mold easier to see visually, thereby improving convenience.

[0018] In the above-mentioned method for measuring the film thickness of a metalworking agent, measurement L ＊ Get the value L ＊ A value measurement process may be further included. ＊The value measurement process is usually performed before the image data acquisition process. This allows the correspondence derivation process, film thickness derivation process, and output process to be carried out immediately after image data acquisition. Therefore, the measurement results of the metalworking agent film thickness can be obtained more quickly. Marker measurement L ＊ The value is measured using a colorimeter. Because the marker is flat, the measuring part of the colorimeter can be brought into contact with the marker, and measurement can be performed without being affected by the surrounding environment. ＊ It is possible to measure the value.

[0019] Measurement L ＊ The correlation between the value and the film thickness value is determined in advance by comparing the film thickness value and the measured L. ＊ The value is measured in correspondence with the measurement, and the result is derived from this measurement. Measurement L ＊ The value changes depending on the film thickness, but as the film thickness increases, the measurement L gradually decreases. ＊ The rate of change in the value becomes smaller. In other words, as the film thickness of the metalworking agent is increased, the measured L ＊ The change in value becomes small, and the measurement L ＊ The value saturates. Therefore, measurement L ＊ When the correlation equation is plotted with the value on the vertical axis and the film thickness on the horizontal axis, and expressed as a logarithmic function with a base greater than 1, the coefficient of determination (r) is obtained. ２ ) is preferable as it becomes higher. As a logarithmic function with a base greater than 1, for example, the natural logarithm may be used. Therefore, the film thickness value and measurement L are set in advance. ＊ In addition to the data measured by correlating the values, the film thickness of the metalworking agent film with a sufficiently thick film thickness and the measured L ＊ The values ​​(extremely thick film data) may be obtained and used to derive the correlation. Specifically, the measurement L of a region (film thickness 50 μm) on the surface of an arbitrary substrate in which a metalworking agent is sufficiently thickly attached. ＊ If the value is 95, these values ​​can be measured using a measuring device L ＊ The correlation is derived by setting the upper limit (virtual saturation value) of the value and film thickness value. This allows for accurate film thickness measurement. A sufficiently thick film thickness is defined as a film thickness that can be measured even when the film thickness is increased. ＊ This refers to the film thickness at which the rate of change of the value becomes small, for example, the measured L relative to the film thickness (μm). ＊This refers to the film thickness at which the rate of change of the value is 0.5 or less. Generally, metalworking agents are used with a film thickness of 20 μm or less, so a sufficiently thick film (for example, 40 μm or more) is prepared, and the film thickness and measurement L are used. ＊ You just need to measure the value.

[0020] In the above method for measuring the film thickness of a metalworking agent, the metalworking agent may be a release agent containing an organic acid salt. Such a release agent has high visibility and L ＊ There is a high correlation between the value and the film thickness. Therefore, such a release agent is suitably used in the above-mentioned method for measuring the film thickness of metalworking agents. In particular, it is suitable when the release agent is for die casting because the presence of organic acid salts in the release agent enhances the visibility of the coating. Efforts are being made to reduce the amount of die casting release agents used in order to be environmentally conscious. According to the above-mentioned method for measuring the film thickness of metalworking agents, even when a small amount of die casting release agent is applied to the mold, the adhesion state, such as unevenness, and the distribution of film thickness can be easily grasped.

[0021] The metalworking agent film thickness measurement system according to the present invention is a system for measuring the film thickness of a visible metalworking agent applied to a mold. The metalworking agent film thickness measurement system measures the appearance of the surface of the mold to which the metalworking agent is applied, L ＊ Image data acquisition unit acquires image data captured with multiple markers, each with a different value, and image data imaging L ＊ Image acquisition of multiple markers among the values ​​L ＊ Value and measurement L ＊ Using the value to image L ＊ Value and measurement L ＊ A correspondence derivation unit that derives the correspondence with the value, and an imaging L of the measurement location in the image data. ＊ From the values, the correspondence and measurement L ＊ The system includes a film thickness deriving unit that derives the film thickness of the metalworking agent using the correlation between a value and a film thickness value, and an output unit that outputs the derived film thickness of the metalworking agent. With such a metalworking agent film thickness measurement system, it is possible to accurately and easily measure the film thickness of the metalworking agent applied to a mold while improving convenience.

[0022] [Specific Examples of Embodiments] Next, an example of a specific embodiment of the method for measuring the film thickness of a metalworking fluid and the film thickness measurement system for a metalworking fluid according to the present invention will be described while referring to the drawings. Here, as the metalworking fluid, a mold release agent used for die casting will be specifically described as an example. In the following drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions will not be repeated.

[0023] (Embodiment 1) An outline of the die casting apparatus used in the method for measuring the film thickness of the mold release agent and the film thickness measurement system for the mold release agent according to Embodiment 1 of the present invention will be briefly described. FIG. 1 is a schematic cross-sectional view showing a part of the die casting apparatus used in the method for measuring the film thickness of the mold release agent in Embodiment 1 of the present invention. FIG. 1 shows a state in which the mold described later is opened. FIG. 2 is a block diagram showing the configuration of the film thickness measurement system for the metalworking fluid (mold release agent) according to the present invention. Note that the above system may be integrated as one apparatus, or may be configured by combining a plurality of apparatuses. Also, the film thickness measurement system 51 and the die casting apparatus 11 may be integrated.

[0024] The film thickness measurement system 51 for the metalworking fluid (mold release agent) in Embodiment 1 shown in FIG. 2 is used together with the die casting apparatus 11 shown in FIG. 1, and includes an image data acquisition unit 52, a correspondence relationship derivation unit 53, a film thickness derivation unit 54, and an output unit 55. The image data acquisition unit 52 acquires image data in which the appearance of the surface of the mold to which the mold release agent is attached is photographed together with a plurality of markers having different measurement L ＊ values. The correspondence relationship derivation unit 53 derives the correspondence relationship between the imaging L ＊ 0 value and the measurement L ＊ value using the imaging L ＊ values and the measurement L ＊ values of a plurality of markers among the imaging L ＊ values. The film thickness derivation unit 54 derives the film thickness of the mold release agent from the imaging L ＊ value of the measurement location in the image data using the correspondence relationship and the correlation between the measurement L ＊ value and the film thickness value. The output unit 55 outputs the derived film thickness of the mold release agent. These configurations will be described later.

[0025] The die-casting apparatus 11 includes a fixed mold 13, a movable mold 14, an injection sleeve 15, and an injection piston 16. The fixed mold 13 is fixed in place. On the other hand, the movable mold 14 is configured to move relative to the fixed mold 13. When the fixed mold 13 and the movable mold 14 are brought into contact, a cavity 17 is formed. One open end of the injection sleeve 15 is connected to the cavity 17. The injection sleeve 15 is provided with an injection port 18 for injecting molten metal into the injection sleeve 15. Molten metal, i.e., molten aluminum or other metal, is injected into the injection sleeve 15 through the injection port 18.

[0026] The injection piston 16 injects the molten metal contained in the injection sleeve 15 into the cavity 17 formed by contacting the mold, specifically the fixed mold 13 and the movable mold 14. The injection piston 16 includes a plunger tip 21 and an injection rod 22. The plunger tip 21 pushes the molten metal injected into the injection sleeve 15 into the cavity 17.

[0027] Next, the process for manufacturing a casting using the die-casting apparatus 11 will be briefly explained. First, the fixed mold 13 and the movable mold 14 are heated to a predetermined temperature, and then the fixed mold 13 and the movable mold 14 are opened as shown in Figure 1. Then, the release agent is discharged from the release agent application member 27 and applied to the entire surface 25 of the fixed mold 13 and the entire surface 26 of the movable mold 14.

[0028] Next, the movable mold 14 is moved to form the cavity 17. Then, the injection rod 22 is moved, and the molten metal inside the injection sleeve 15 is pushed out and filled into the cavity 17. This state is maintained for a predetermined time to allow the molten metal to solidify. After that, the movable mold 14 is opened, and the casting attached to the movable mold 14 is removed. Since a release agent is attached to surfaces 25 and 26, it can be easily removed.

[0029] Here, the release agent used will be described. As an example, the release agent contains a solvent and an organic acid salt. In the present embodiment, the solvent is water, and the release agent is an aqueous release agent. The organic acid salt may be produced by mixing an organic acid and a basic compound. In the present embodiment, the release agent contains a salt of at least one carboxylic acid compound selected from succinic acid, adipic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, and trimellitic acid, and water. Since the film of such a release agent has high visibility, it is suitable for film thickness measurement.

[0030] Next, the method for measuring the film thickness of the release agent will be described. FIG. 3 is a flowchart showing typical steps in the method for measuring the film thickness of the release agent according to Embodiment 1. In the method for measuring the film thickness of the release agent in Embodiment 1, as step (S10), as preparation for film thickness measurement, the measurement L ＊ value of a plurality of markers described later is measured. ＊ The L ＊ value measurement step is performed. In this step (S10), the L ＊ values of the plurality of, specifically four, prepared markers are each measured by a colorimeter. Note that the L

[0031] value measurement step (S10) may be performed at any time as long as it is before the image data acquisition step (S20) described later, and the two steps do not have to be continuously performed without a gap between them.

[0032] Next, as step (S20), an image data acquisition step is performed. In this step (S20), the mold surfaces 25 and 26 are photographed with a digital camera (not shown) as a photographing device. In this case, the four prepared markers are placed at the four corners of the shooting range and attached to the surface of the mold, and then the surface of the mold is photographed to acquire image data including the markers. The image data acquisition unit 52 receives the image data captured by the digital camera to acquire the image data. In this embodiment, a digital camera is used as the photographing equipment, but it is not limited to this, and a camera built into a smartphone or a CCD camera may also be used as the photographing equipment.

[0033] Figure 4 shows an example of image data of a photograph taken with four markers attached to the surface of a mold. Figure 5 shows a line diagram of the photograph shown in Figure 4. Referring to Figures 4 and 5 together, the marker 31a is a rectangular sheet member of uniform thickness. The marker 31a includes an attachment area 32a used when attaching it to an object, and a measurement area 33a that serves as a color sample measured by a colorimeter. The marker 31a is attached to an object, for example, the surface of a mold, by magnetic force using a magnet (not shown) attached to the back of the attachment area 32a. The measurement area 33a has a flat surface and is configured so that there is no unevenness in brightness throughout the entire measurement area 33a. Before being attached to the mold, the L of the measurement area 33a of the marker 31a is measured by a colorimeter. ＊ The value is measured. Measurement L ＊ The values ​​are stored in the correspondence derivation unit 53 in association with each marker. In this embodiment, when measuring the film thickness of the release agent, L ＊ Four markers with different values, 31a, 31b, 31c, and 31d, are prepared.

[0034] The image data 29 includes a black and white image 30 based on the release agent attached to the surface 26 of the mold 14, and images of the four markers 31a to 31d. In the image data acquisition process, the image data 29 is acquired by positioning the four markers 31a to 31d so that they are located in areas close to the four corners. That is, the four markers 31a to 31d are attached to the surface 26 of the mold 14 so that they are located at the four corners when photographed with a digital camera. Note that measurement L ＊ The values ​​decrease in the order of markers 31a, 31b, 31c, and 31d. In this embodiment, the measurement L of the measurement areas 33a, 33b, 33c, and 33d of markers 31a to 31d, which have been measured in advance. ＊ The values ​​are 90, 70, 50, and 30, respectively.

[0035] Subsequently, as step (S30), a correspondence relationship derivation step is performed. In this step (S30), the acquired image data is used to determine the imaging L of the measurement areas 33a to 33d of the markers 31a to 31d. ＊ Extract the values. Figure 6 shows the imaging L of markers 31a to 31d. ＊ Value and measurement L of markers 31a to 31d ＊ This figure shows the correspondence with the values. In Figure 6, the vertical axis is the imaging L. ＊ The horizontal axis shows the measurement L. ＊ The values ​​are shown. Refer to Figure 6 as well, imaging L ＊ Value and measurement L ＊ The calibration curve 34, which is a linear straight line obtained from the values ​​using the least squares method, is located at the imaging L ＊ Value and measurement L ＊ This shows the correspondence with the values. Plots 35a, 35b, 35c, and 35d correspond to markers 31a, 31b, 31c, and 31d, respectively. By using this correspondence, the imaging L of each part of the image data can be determined. ＊ The value, measured L ＊ It can be converted to a value. Typically, imaging L ＊ The value changes each time a photograph is taken due to ambient light, camera, etc., so the colorimeter L ＊ The values ​​do not match. In the correspondence relationship derivation process, measurement L ＊ Imaging of a marker with a known value L ＊Using the value to image L ＊ Value and measurement L ＊ The correspondence relationship with the value is derived. Note that the correspondence relationship derivation process is performed by obtaining the color digit information from the image data. ＊ If it is not a value, the image data's color digitization information is L ＊ The process may further include a step to convert it into a value.

[0036] Next, as step (S40), the film thickness extraction step is performed. In this step (S40), imaging L ＊ Value and measurement L ＊ Correspondence between values ​​and measurement L ＊ Using the correlation between the value and the film thickness value, the imaging L of any measurement location in the image data ＊ The film thickness of the release agent is derived from the value. In detail, first, the image data is captured L ＊ The value is measured using the correspondence L ＊ It is converted to a value. This results in the imaging L ＊ It can correct for variations in values. Furthermore, imaging L ＊ The measurement L derived by converting the value ＊ Value and measurement L ＊ The film thickness of the release agent is derived using the correlation between the value and the film thickness value. Figure 7 shows the measurement L ＊ This graph shows the correlation between the value and film thickness. In Figure 7, the vertical axis represents the measured L. ＊ The values ​​are shown, and the horizontal axis represents the film thickness (μm).

[0037] Measurement L ＊ The correlation between the value and film thickness was determined by preparing multiple samples and measuring L ＊ The value and film thickness are obtained in advance by measuring them. Here, as shown in Figure 7, even if the film thickness of the release agent is increased, the measurement L ＊ The value will saturate. Therefore, measure L in advance. ＊ In addition to the data measured by correlating the value with the film thickness, saturation measurement L ＊ By understanding the value and the corresponding film thickness (extremely thick film data), measurement L ＊ The correlation between the value and the film thickness can be obtained. For example, if a metalworking agent is applied thickly and the film thickness is 50 μm, the measurement L ＊ If the value is 95, these values ​​are measured L ＊By setting virtual saturation values ​​for the value (vertical axis) and film thickness (horizontal axis), a logarithmic equation with a base greater than 1 is created, and its correlation is derived. This correlation shows good reproducibility of the rate of change. In addition, measurement L of a mold without metalworking agent attached is performed. ＊ By setting the value as a blank value, the correlation is improved, and the film thickness can be measured with greater accuracy. This will be explained below. Pre-measured L ＊ Even if a logarithmic equation is set as the equation representing the correlation between the value and the film thickness (correlation equation), the correlation equation changes depending on the blank value, as shown in the calibration curves 36a to 36f in Figure 7. Therefore, when actually measuring the film thickness, the image L of the mold where the film thickness is 0 ＊ Obtain the value and use the correspondence to measure L ＊ Convert to a value. Measure this L ＊ The correlation formula is derived using the blank values. The above ultra-thick film data and measurement L ＊ The correlation formula may be derived using blank values, or a correlation formula may be provisionally set in advance using the extremely thick film data mentioned above, and then the final correlation formula may be derived using the blank values ​​of the measurements.

[0038] In the image data acquisition process (S20), imaging L of the mold with a film thickness of 0 ＊ Measure the value using the correspondence L ＊ Convert to a value, and this measurement L ＊ By using the value as a blank value, measurement L ＊ The correlation between the value and the film thickness can be set with high precision. Furthermore, by acquiring blank values, the color and properties of the mold surface can be captured in the image. ＊ The impact on the value can also be reduced. Note that the measurement L of the blank ＊ The value is obtained when, in the image data acquisition step (S20), an area is provided on the mold surface where a release agent is not applied along with the marker, and then image data is acquired, and the image L of the area where the release agent is not applied is obtained. ＊ Measure the value L ＊ It can be obtained by converting it to a value. In Figure 7, the blank measurement L is at line 36a. ＊ This shows the case where the value is 25, and the blank measurement L is at line 36b. ＊ This shows the case where the value is 30, and the blank measurement L is at line 36c.＊ This shows the case where the value is 35, and the blank measurement L is at line 36d. ＊ This shows the case where the value is 40, and the blank measurement L is at line 36e. ＊ This shows the case where the value is 45, and the blank measurement L is at line 36f. ＊ This shows the case where the value is 50.

[0039] Next, as step (S50), an output step is performed. In this step (S50), for example, the image captured in the image data acquisition step may be displayed, and when a predetermined location on the mold is selected, the film thickness at that location may be displayed numerically and output. Alternatively, for example, the distribution of film thickness on the surface of the mold may be output with color coding (including mapping display).

[0040] Table 1 shows the film thickness of the release agent calculated according to Embodiment 1, and the image L without performing the above correspondence derivation step. ＊ Measure the value directly L ＊ The film thickness of the release agent calculated using the value, and the L value measured with a colorimeter. ＊ The film thickness of the release agent, calculated by measuring the values, is shown. (Colorimeter reading: L) ＊ The film thickness of the release agent calculated by measuring the values ​​shows the value closest to the true film thickness. The film thickness of the release agent calculated by Embodiment 1 is closer to the colorimeter value than the film thickness obtained without performing the correspondence derivation process, indicating that a more accurate film thickness can be measured. Furthermore, the method of Embodiment 1 allows for the calculation of the film thickness without having to measure the release agent adhering to the mold each time using a colorimeter, thus enabling a simpler measurement of the film thickness. The measurement locations R1, R2, and R3 are shown in Figure 4, respectively.

[0041]

[0042] According to the above method for measuring the film thickness of the release agent, the appearance of the surface 26 of the mold 14 to which a visible release agent has been applied is measured L ＊ Image data 29 is acquired along with multiple markers 31a to 31d, each with different values. Then, the image L of the image data 29 is acquired. ＊ Image L of multiple markers 31a to 31d among the values ＊ Measure the value L ＊The correspondence between the values ​​is derived. Then, imaging L ＊ Value and measurement L ＊ Correspondence between values ​​and measurement L ＊ Using the correlation between the value and the film thickness value, the imaging L of the measurement location in the image data 29 ＊ Measure the value L ＊ Convert to a value and measure L ＊ The release agent film thickness is derived from the correlation between the value and the film thickness value. Finally, the derived release agent film thickness is output. With this method, L is not necessarily the case when measuring film thickness. ＊ Since a colorimeter is not required to measure the value, a colorimeter is unnecessary when deriving the film thickness. This improves convenience and makes it easier to measure the film thickness of fine details and shapes with large irregularities. In addition, the image L derived using markers 31a to 31d ＊ Value and measurement L ＊ Correspondence with values ​​and measurement L ＊ Since the film thickness at the measurement location is derived using the correlation between the value and the film thickness, imaging L ＊ This method suppresses the decrease in measurement accuracy due to fluctuations and variations in values. This reduces the influence of shooting conditions such as the amount of light and the degree of shading during shooting, as well as the performance of the shooting equipment, allowing for highly accurate measurement of the release agent film thickness. Therefore, the above-described method for measuring the film thickness of a release agent allows for accurate and simple measurement of the film thickness of a release agent attached to a mold while improving convenience.

[0043] In this embodiment, the film thickness extraction process is performed at imaging L ＊ Value and measurement L ＊ The process may include a step of deriving the film thickness of the release agent by using a linear straight line obtained from the values ​​using the least squares method as a calibration curve. Therefore, the film thickness of the release agent can be easily derived using the obtained calibration curve. Consequently, the film thickness of the release agent can be measured more simply.

[0044] In this embodiment, the plurality of markers 31a to 31d include at least four. The image data acquisition step acquires image data captured so that the four markers 31a to 31d are each located in areas close to the four corners. Therefore, the influence of variations in light intensity and shading within the plane of the image data can be reduced, and the overall image data is captured L ＊ Value and measurement L ＊ This improves the correlation between the values ​​and the measured thickness. Therefore, the film thickness of the release agent can be measured more accurately.

[0045] In this embodiment, the measurement L of multiple markers ＊ By setting a wide range of values ​​for intensity, the film thickness of the release agent can be measured more accurately. Measurement L at multiple markers ＊ The difference between the maximum and minimum values ​​is preferably 20 or more.

[0046] In this embodiment, the image data acquisition step acquires image data of the area on the surface 26 of the mold 14 where no release agent is applied. The film thickness calculation step involves imaging L of the area where no release agent is applied. ＊ Measure the value L ＊ The values ​​are converted based on their correspondence, and the converted measurement L ＊ The value, measured L ＊ This value is used as a blank value. Therefore, the region where the release agent film thickness is zero is measured L. ＊ By using this as a blank value that serves as the lower limit of the value, the accuracy of measuring the film thickness of the release agent can be improved.

[0047] In this embodiment, the method for measuring the film thickness of the release agent is measurement L ＊ L to measure the value ＊ Includes a value measurement process. L ＊ The value measurement process is performed before the image data acquisition process. Therefore, the correspondence derivation process, film thickness derivation process, and output process can be performed immediately after image data acquisition. Consequently, the measurement results of the release agent film thickness can be obtained at an earlier stage.

[0048] In this embodiment, the metalworking agent is a release agent containing an organic acid salt. Such a release agent has high visibility and exhibits a high correlation between brightness and film thickness. Therefore, such a release agent is suitably used in the method for measuring the film thickness of the metalworking agent described above.

[0049] The metalworking agent film thickness measurement system 51 according to the present invention is a system for measuring the film thickness of a visible metalworking agent applied to a mold 14. The metalworking agent film thickness measurement system 51 measures the appearance of the surface 26 of the mold 14 to which the metalworking agent is applied. ＊ Image data acquisition unit 52 acquires image data 29 captured together with multiple markers 31a to 31d, each with different values, and imaging L of the image data 29 ＊ Image L of multiple markers 31a to 31d among the values ＊ Value and measurement L ＊ Using the value to image L ＊ Value and measurement L ＊ A correspondence relationship derivation unit 53 derives the correspondence relationship with the value, and imaging L of the measurement location in the image data 29. ＊ From the values, the correspondence and measurement L ＊ The system includes a film thickness deriving unit 54 that derives the film thickness of the release agent using the correlation between a value and the film thickness value, and an output unit 55 that outputs the derived film thickness of the release agent. With such a metalworking agent film thickness measurement system 51, it is possible to accurately and easily measure the film thickness of the metalworking agent attached to the mold while improving convenience.

[0050] (Other Embodiments) In the above embodiment, the output step in the method for measuring the film thickness of the metalworking agent may output the film thickness distribution in different colors (including mapping display). By doing so, the film thickness distribution on the surface of the mold can be made visually easier to see, improving convenience. In addition, if any part of the mold in the captured image is selected, the film thickness value of that part may be displayed on the screen or printed and output.

[0051] Furthermore, although the metalworking agent described in the above embodiment was a release agent containing an organic acid salt, it is not limited to this, and any metalworking agent that is visible can be used, and a release agent that does not contain an organic acid salt may also be used.

[0052] In the above embodiment, L is performed before the image data acquisition process. ＊ We decided to carry out the value measurement process, but this is not limited to this; after the image data acquisition process, L ＊ A value measurement process may be performed. L ＊ The value measurement process (S10) and the image data acquisition process (S20) may be performed in any order, and the two processes do not have to be performed consecutively without any gaps between them.

[0053] Furthermore, in the film thickness derivation process, a blank value is acquired each time image data is acquired and measured L ＊ The correlation between the value and the film thickness value (e.g., a calibration curve) may be adjusted and then derived. Alternatively, specific calibration curves may be prepared in advance for each metalworking agent and mold, and the film thickness may be measured by selecting and using the corresponding calibration curve according to the metalworking agent and mold.

[0054] Furthermore, image data of the area on the mold surface where a sufficient thickness of release agent is applied is acquired, and measurement L ＊ A correlation between the value and the film thickness value (e.g., a calibration curve) may be derived. Imaging L of the region where the release agent is applied thickly. ＊ Measure the value L ＊ This can also be used as an upper limit (virtual saturation value). By doing so, the film thickness of the release agent can be measured more accurately.

[0055] In the above embodiment, the marker was rectangular with an attachment area, but the shape is not particularly limited and may be circular, and the attachment area and the measurement area may be integrated by coating the magnet surface, etc. Also, measurement L ＊ The method for obtaining the value is L ＊ The method of obtaining the value is not particularly limited and may be acquired by a device other than a colorimeter. Furthermore, the number of markers should be two or more, preferably three or more, and more preferably four or more. If there are two or more markers, the image L ＊Value and measurement L ＊ The correspondence between values ​​can be derived and converted. If there are four or more markers, the influence of ambient light can be reduced, and the film thickness can be measured with high accuracy.

[0056] The embodiments disclosed herein should be understood to be illustrative in all respects and not restrictive in any way. The scope of the invention is defined by the claims and all modifications within the meaning and scope of the claims are intended to be equivalent.

[0057] 11 Die casting apparatus, 13 Fixed mold, 14 Movable mold (mold), 15 Injection sleeve, 16 Injection piston, 17 Cavity, 18 Injection port, 19 Inner wall surface, 21 Plunger tip, 22 Injection rod, 24 Outer diameter surface, 25, 26 Surface, 27 Release agent dispensing member, 29 Image data, 30 Image, 31a, 31b, 31c, 31d Marker, 32a Application area, 33a, 33b, 33c, 33d Measurement area, 34, 36a, 36b, 36c, 36d, 36e, 36f Calibration curve, 35a, 35b, 35c, 35d Plot, 51 Film thickness measurement system, 52 Image data acquisition unit, 53 Correspondence relationship derivation unit, 54 Film thickness derivation unit, 55 Output unit.

Claims

1. A method for measuring the film thickness of a visible metalworking agent applied to a mold, wherein the appearance of the surface of the mold to which the metalworking agent is applied is measured L ＊ Image data acquisition step: acquires image data captured with multiple markers, each with a different value, and imaging L of the image data. ＊ The imaging L of the plurality of markers among the values ＊ Value and the measurement L ＊ Using the value, the imaging L ＊ Value and the measurement L ＊ A correspondence derivation step for deriving the correspondence with the value, and the imaging L of the measurement location in the image data. ＊ From the values, the correspondence and the measurement L ＊ A method for measuring the film thickness of a metalworking agent, comprising: a film thickness derivation step of deriving the film thickness of the metalworking agent using the correlation between a value and a film thickness value; and an output step of outputting the derived film thickness of the metalworking agent.

2. The method for measuring the film thickness of a metalworking agent according to claim 1, wherein the image data acquisition step involves arranging the plurality of markers in areas close to the four corners of the shooting range and acquiring the captured image data.

3. In the image data acquisition step, image data including an area where the metalworking fluid is not adhered to the surface of the mold is acquired, and in the film thickness derivation step, the imaging L of the area where the metalworking fluid is not adhered is determined based on the correspondence relationship. ＊ The measured L value converted from the value is used as a blank value that is the lower limit value of the measured L value to derive the correlation, and the film thickness of the metalworking fluid is derived from the imaging L value at the measurement location in the image data using the correspondence relationship and the correlation. The method for measuring the film thickness of a metalworking fluid according to claim 1 or claim 2. ＊ value, ＊ and the correlation is derived using the measured L value as a blank value that is the lower limit value of the measured L value. From the imaging L value at the measurement location in the image data, the film thickness of the metalworking fluid is derived using the correspondence relationship and the correlation. ＊ value to derive the film thickness of the metalworking fluid using the correspondence relationship and the correlation relationship. The method for measuring the film thickness of a metalworking fluid according to claim 1 or claim 2.

4. The correlation is between the thickness of the metalworking agent when sufficiently thickly applied and the measured L ＊ A method for measuring the film thickness of a metalworking agent according to claim 1 or claim 2, wherein the value is derived as a virtual saturation value.

5. The method for measuring the film thickness of a metalworking agent according to claim 1 or claim 2, wherein the output step outputs the distribution of the film thickness in different colors.

6. The method for measuring the film thickness of a metalworking agent according to claim 1 or claim 2, wherein the metalworking agent is a release agent containing an organic acid salt.

7. A system for measuring the film thickness of a visible metalworking agent applied to a mold, wherein the appearance of the surface of the mold to which the metalworking agent is applied is measured L ＊ Image data acquisition unit that acquires image data captured with multiple markers, each with a different value, and imaging L of the image data ＊ The imaging L of the plurality of markers among the values ＊ Value and the measurement L ＊ Using the value, the imaging L ＊ Value and the measurement L ＊ A correspondence relationship derivation unit that derives the correspondence relationship with the value, and the imaging L of the measurement location in the image data. ＊ From the values, the correspondence and the measurement L ＊ A metalworking agent film thickness measurement system comprising: a film thickness deriving unit that derives the film thickness of the metalworking agent using the correlation between a value and a film thickness value; and an output unit that outputs the derived film thickness of the metalworking agent.

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