Physical property evaluation method, physical property evaluation apparatus, and physical property evaluation program

Abstract

This invention provides a physical property evaluation method, a physical property evaluation apparatus, and a physical property evaluation program that can measure the consistency of even small amounts of samples. [Solution] The physical property evaluation method, physical property evaluation apparatus, and physical property evaluation program use a controller connected to an input unit into which physical property data showing the thermal behavior of the grease to be evaluated is input. Based on the physical property data, the controller obtains the melting peak area of ​​the grease and calculates the consistency corresponding to the grease based on a model that relates the melting peak area to the consistency of the grease. The model is generated by regression analysis based on measurement data consisting of measured consistency and measured melting peak area for a reference grease.

Description

Technical Field

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[0001] The present disclosure relates to a physical property evaluation method, a physical property evaluation apparatus, and a physical property evaluation program.

Background Art

[0002] Non-Patent Document 1 discloses a test method for consistency, which is a measure of the hardness of grease. According to this method, the pointed end of a specified cone is placed on the surface of the grease sample from above, and the consistency is measured based on the depth to which the cone penetrates into the sample during a predetermined time.

Prior Art Documents

Non-Patent Documents

[0007] The measurement data may include multiple data obtained for each thermal degradation condition relative to the reference grease.

[0008] The conditions may include at least one of the following: heating temperature and heating time, which are related to thermal degradation.

[0009] The conditions include the heating temperature related to thermal degradation, and the heating temperature may be equal to or higher than the melting start temperature of the standard grease.

[0010] The standard grease may contain at least one of the following: Ca soap-based grease, Li soap-based grease, or urea-based grease.

[0011] The input unit may be connected to at least one of the following: a thermogravimetric differential thermal analyzer, a differential scanning calorimeter, and a thermal analyzer. [Effects of the Invention]

[0012] According to this disclosure, a physical property evaluation method, a physical property evaluation apparatus, and a physical property evaluation program can be provided that can measure the consistency of even small amounts of samples. [Brief explanation of the drawing]

[0013] [Figure 1] This is a block diagram showing the configuration of a physical property evaluation apparatus according to an embodiment of the present disclosure. [Figure 2]This flowchart shows the processing procedure (during model generation) for the physical property evaluation device. [Figure 3] This flowchart shows the processing procedure of the physical property evaluation device (during physical property evaluation). [Figure 4] This figure shows an example of physical property data illustrating the thermal behavior of grease. [Figure 5] This figure shows an example of a model obtained through regression analysis. [Modes for carrying out the invention]

[0014] Several exemplary embodiments will be described below with reference to the drawings. Common parts in each drawing are denoted by the same reference numerals, and redundant explanations will be omitted.

[0015] [Configuration of the physical property evaluation device] Figure 1 is a block diagram showing the configuration of a physical property evaluation apparatus according to an embodiment of the present disclosure. As shown in Figure 1, the physical property evaluation apparatus 20 comprises an input unit 21 and a controller 25. The physical property evaluation apparatus 20 may also comprise an output unit 23 and an operation unit 27. The controller 25 is connected to the input unit 21, the output unit 23, and the operation unit 27 so as to be able to communicate with them.

[0016] In addition, the input unit 21, output unit 23, and operation unit 27 may be provided within the physical property evaluation device 20 itself, or they may be installed outside the physical property evaluation device 20 and connected to the physical property evaluation device 20.

[0017] The input unit 21 receives physical property data indicating the thermal behavior of the grease being evaluated. For example, the input unit 21 may be connected to a measuring device 10 and acquire physical property data from the measuring device 10. Alternatively, the input unit 21 may read physical property data from a recording medium.

[0018] Here, the measuring device 10 may be at least one of a thermogravimetric differential thermal analyzer, a differential scanning calorimeter, and a thermal analyzer.

[0019] A thermogravimetric differential thermal analyzer is a device that can perform thermogravimetric analysis and differential thermal analysis simultaneously. In thermogravimetric analysis, the weight of a target sample (grease) is measured while changing the temperature of the sample. In differential thermal analysis, the temperature difference between the sample and a reference material is measured while changing the temperatures of the sample and the reference material. By measuring the temperature difference, endothermic and exothermic peaks associated with reactions and the like can be confirmed.

[0020] A differential scanning calorimeter is a device that measures the temperatures of a reference material and a sample while applying a certain amount of heat, captures the thermal properties of the sample as a temperature difference, and measures endothermic and exothermic reactions due to changes in the state of the sample.

[0021] A thermal analyzer is a device that measures the physical properties of a sample as a function of temperature while changing the temperature of the sample according to a certain program.

[0022] The measuring device 10 can use various methods for measuring the heat quantity of a sample and is not limited to the examples given here. The input unit 21 acquires physical property data regarding the sample obtained by the above-described measuring device 10.

[0023] In addition, the input unit 21 may acquire data used for generating a model described later. Examples of data used for generating a model include, for example, the measured consistency of a reference grease, the measured melting peak area, and the like. The input unit 21 may acquire physical property data indicating the thermal behavior of the reference grease instead of the measured melting peak area.

[0024] The output unit 23 outputs data indicating the consistency corresponding to the grease obtained by the controller 25 described later. The output unit 23 may output information determined based on the data indicating the consistency together with or instead of the data indicating the consistency.

[0025] For example, the output unit 23 may output a grease grade that corresponds to data indicating consistency. Examples of grease consistency grades include the NLGI consistency classification established by the National Lubricants and Greases Institute (NLGI). The grease grade output by the output unit 23 is not limited to this.

[0026] The operation unit 27 is an input device that allows the user of the physical property evaluation device 20 to perform operations. For example, the operation unit 27 may be a keyboard, mouse, trackball, touch panel, etc. The operation unit 27 is not limited to the examples given herein. User operations entered via the operation unit 27 are transmitted to the controller 25.

[0027] For example, the operation unit 27 may acquire information to identify the grease based on user operations. Alternatively, the operation unit 27 may acquire a range of physical property data to be used for analysis based on user operations.

[0028] The controller 25 is a general-purpose computer equipped with a CPU (Central Processing Unit), memory, and input / output units. The controller 25 has a computer program (physical property evaluation program) installed on it that allows it to function as the physical property evaluation device 20. By executing the computer program, the controller 25 functions as one of the multiple information processing circuits (251, 253, 255) provided by the physical property evaluation device 20.

[0029] This disclosure provides an example of implementing multiple information processing circuits (251, 253, 255) using software. However, it is also possible to configure the information processing circuits (251, 253, 255) by preparing dedicated hardware for each of the information processing operations described below. Alternatively, the multiple information processing circuits (251, 253, 255) may be configured using separate hardware.

[0030] As shown in Figure 1, the controller 25 includes a plurality of information processing circuits (251, 253, 255), namely a melting peak acquisition unit 251, a consistency calculation unit 253, and a model setting unit 255.

[0031] The melting peak acquisition unit 251 acquires the melting peak area of ​​the grease based on the physical property data. For example, the "melting peak area" is calculated based on the thermal behavior of the grease within the range from the melting start temperature to the melting end temperature, as shown in the physical property data.

[0032] Figure 4 shows an example of physical property data illustrating the thermal behavior of grease. As shown in Figure 4, the physical property data is plotted with the thermal behavior of the grease on the vertical axis and the temperature of the grease on the horizontal axis. In Figure 4, as an example, the temperature difference between the sample and the reference sample is shown on the vertical axis as the thermal behavior of the grease. When plotting the physical property data, the weight difference may also be used on the vertical axis. In addition, the fluctuation of index values ​​indicating the physical properties of the grease may also be used on the vertical axis.

[0033] In Figure 4, the value on the horizontal axis at point P1 represents the melting start temperature of the grease. The value on the horizontal axis at point P3 represents the melting end temperature of the grease. The value on the horizontal axis at point P2 represents the melting peak temperature.

[0034] Among the plotted physical property data, point P1, which represents the thermal behavior at the melting initiation temperature of the grease, and point P3, which represents the thermal behavior at the melting termination temperature of the grease, are connected to form the baseline. The amount obtained by subtracting the baseline value from the thermal behavior curve value is integrated from the melting initiation temperature to the melting termination temperature of the grease and defined as the "melting peak area". If the thermal behavior curve is below the baseline, the "melting peak area" is defined as a negative value.

[0035] The consistency calculation unit 253 calculates the consistency corresponding to the grease based on a model that relates the melting peak area to the consistency of the grease.

[0036] Figure 5 shows an example of a model obtained by regression analysis. As shown in Figure 5, the set model shows the relationship between the melting peak area and the consistency of the grease. Therefore, if the melting peak area is obtained based on the grease to be evaluated, the consistency of the grease corresponding to that melting peak area can be determined based on the model. The consistency calculation unit 253 calculates the consistency value of the grease given by the model as the consistency of the grease to be evaluated.

[0037] The model setting unit 255 sets up a model that relates the melting peak area to the consistency of the grease. Here, the set model is generated by regression analysis based on measurement data consisting of measured consistency and measured melting peak area for a reference grease.

[0038] More specifically, the model setting unit 255 performs regression analysis based on multiple measurement data obtained for each thermal degradation condition of the reference grease and generates a model. For example, the thermal degradation conditions may include multiple conditions such as the heating temperature and heating time of the reference grease. The conditions include at least one of the heating temperature and heating time.

[0039] The model setting unit 255 may also perform regression analysis based on multiple measurement data obtained by heating the reference grease to a temperature above the melting point of the reference grease.

[0040] Furthermore, the reference grease may contain at least one of the following: Ca soap-based grease, Li soap-based grease, or urea-based grease. In reference greases containing these greases, a good correlation is observed between the measured consistency and the measured melting peak area. Therefore, the inventors have found that by generating a model that relates the melting peak area and the consistency of the grease based on a reference grease containing these greases, the consistency of the grease to be evaluated can be estimated with high accuracy.

[0041] For example, as shown in Figure 5, the smaller the melting peak area, the lower the consistency of the grease tends to be. This is thought to be partly due to the fact that the melting peak area is composed of the melting energy of the thickener crystals contained in the grease and the formation energy of the higher-order structure.

[0042] When grease is exposed to a temperature environment above its melting point, the higher-order structure of the thickener changes, and the formation energy of the higher-order structure decreases. As a result, the proportion of the melting energy of the crystals increases, and it is thought that the value of the melting peak area decreases. The situation in which the formation energy of the higher-order structure decreases corresponds to a situation in which the consistency of the grease is low. Therefore, it is thought that the smaller the value of the melting peak area, the lower the consistency of the grease tends to be.

[0043] [Processing procedure for the physical property evaluation device (during model generation)] Figure 2 is a flowchart showing the processing procedure (during model generation) of the physical property evaluation device.

[0044] In step S101, the model setting unit 255 obtains the consistency (measured consistency) of the reference grease via the input unit 21. The consistency of the reference grease is measured by applying a method other than the evaluation method disclosed herein to the reference grease.

[0045] In step S103, the model setting unit 255 obtains the melting peak area (measured melting peak area) for the reference grease via the input unit 21. For example, the measured melting peak area of ​​the reference grease is obtained based on the physical property data of the reference grease.

[0046] In step S105, the model setting unit 255 generates a model through regression analysis.

[0047] In step S107, the model setting unit 255 records the generated model in a database or the like (not shown). The model setting unit 255 may also record the model in the memory of the controller 25.

[0048] [Processing procedure for the physical property evaluation device (during physical property evaluation)] Figure 3 is a flowchart showing the processing procedure of the physical property evaluation device (during physical property evaluation).

[0049] In step S201, the melting peak acquisition unit 251 acquires physical property data of the grease to be evaluated via the input unit 21.

[0050] In step S203, the melting peak acquisition unit 251 acquires the melting peak area for the grease under evaluation based on the physical property data.

[0051] In step S205, the consistency calculation unit 253 calculates the consistency of the grease to be evaluated based on the melting peak area. At that time, the consistency calculation unit 253 calculates the consistency of the grease corresponding to the melting peak area using the model set by the model setting unit 255. Alternatively, the consistency calculation unit 253 may determine the grade of the grease based on the calculated consistency of the grease.

[0052] In step S207, the consistency calculation unit 253 outputs the calculated consistency of the grease via the output unit 23. The consistency calculation unit 253 may also output the determined grade of the grease.

[0053] [Effects of the Embodiment] As described in detail above, the physical property evaluation method, physical property evaluation apparatus, and physical property evaluation program related to this disclosure use a controller connected to an input unit into which physical property data indicating the thermal behavior of the grease to be evaluated is input. Based on the physical property data, the controller obtains the melting peak area of ​​the grease and calculates the consistency corresponding to the grease based on a model that relates the melting peak area to the consistency of the grease. The model is generated by regression analysis based on measurement data consisting of measured consistency and measured melting peak area for a reference grease.

[0054] This allows for the measurement of consistency even in small samples. For example, physical property data indicating the thermal behavior of the grease being evaluated can be obtained even from small samples. Therefore, by calculating the consistency corresponding to the grease based on the physical property data, the consistency of a small amount of grease can be evaluated.

[0055] Furthermore, even when only a small amount of sample can be collected, such as grease used in rolling bearings, the consistency can be evaluated. This makes it easier to operate and maintain equipment that uses grease lubrication.

[0056] The measurement data may include multiple data obtained for each thermal degradation condition relative to a reference grease. This allows for the evaluation of grease consistency within a range of thermal degradation conditions. For example, by setting the range of thermal degradation conditions to include the temperature range of the temperature environment to which the grease is exposed, the consistency of grease after use for purposes such as grease lubrication can be evaluated. Furthermore, the accuracy of the model can be improved when generating a model that relates the melting peak area to the consistency of the grease.

[0057] The conditions may include at least one of the heating temperature and heating time related to thermal degradation. This makes it possible to generate a model that relates the melting peak area to the consistency of the grease, taking into account the heating temperature and heating time that cause changes in the consistency of the grease.

[0058] The conditions include the heating temperature related to thermal degradation, and the heating temperature may be equal to or higher than the melting onset temperature of the reference grease. This makes it possible to generate a model that relates the melting peak area to the consistency of the grease, taking into account the heating temperature and heating time that cause changes in the consistency of the grease.

[0059] For example, when grease is exposed to a temperature environment above its melting point, the higher-order structure of the thickener is thought to change, and the formation energy of the higher-order structure decreases. Therefore, a model can be generated based on measurement data in a range where the correlation between the melting peak area and the consistency of the grease is high. As a result, the accuracy of the model can be improved.

[0060] The reference grease may contain at least one of the following: Ca soap-based grease, Li soap-based grease, or urea-based grease. Using a reference grease containing these greases allows for a good correlation between the measured consistency and the measured melting peak area, thereby improving the accuracy of the model.

[0061] The input unit may be connected to at least one of the following: a thermogravimetric differential thermal analyzer, a differential scanning calorimeter, and a thermal analyzer. This allows for the acquisition of physical property data indicating the thermal behavior of the grease being evaluated, even for small amounts of grease. As a result, the consistency of the grease can be measured even for small amounts of grease.

[0062] Each of the functions described in the embodiments above may be implemented by one or more processing circuits. These processing circuits may include programmed processors, electrical circuits, and other devices such as application-specific integrated circuits (ASICs), or circuit components arranged to perform the described functions.

[0063] According to this disclosure, it will be possible to measure the consistency of even small amounts of samples, which will make it easier to operate and maintain equipment that is currently running on grease lubrication. As a result, it will be possible to contribute, for example, to Goal 9 of the United Nations Sustainable Development Goals (SDGs), "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation."

[0064] Although several embodiments have been described, it is possible to modify or transform the embodiments based on the above disclosure. All components of the above embodiments, and all features described in the claims, may be taken individually and combined, provided that they do not conflict with each other. [Explanation of Symbols]

[0065] 10 Measuring device 20. Physical property evaluation device 21 Input section 23 Output section 25 Controllers 27 Control section 251 Melting peak acquisition section 253 Consistency calculation section 255 Model Setting Section

Claims

1. A physical property evaluation method that controls a controller connected to an input unit into which physical property data showing the thermal behavior of the grease to be evaluated is input, The aforementioned controller, Based on the aforementioned physical property data, the melting peak area of ​​the grease is obtained. Based on a model relating the melting peak area and the consistency of the grease, the consistency corresponding to the grease is calculated. The aforementioned model, A method for evaluating physical properties, generated by regression analysis based on measurement data consisting of measured consistency and measured melting peak area for a reference grease.

2. The physical property evaluation method according to claim 1, wherein the measurement data includes a plurality of data obtained for each condition of thermal degradation relative to the reference grease.

3. The physical property evaluation method according to claim 2, wherein the conditions include at least one of the heating temperature and heating time related to the heat degradation.

4. The above conditions include the heating temperature related to the heat degradation, The physical property evaluation method according to claim 2, wherein the heating temperature is equal to or greater than the melting start temperature of the reference grease.

5. The physical property evaluation method according to claim 1, wherein the reference grease includes at least one of Ca soap-based grease, Li soap-based grease, and urea-based grease.

6. The physical property evaluation method according to any one of claims 1 to 5, wherein the input unit is connected to at least one of a thermogravimetric differential thermal analyzer, a differential scanning calorimeter, and a thermal analyzer.

7. An input section into which physical property data showing the thermal behavior of the grease being evaluated is input, Controller and A physical property evaluation apparatus comprising, The aforementioned controller, Based on the aforementioned physical property data, the melting peak area of ​​the grease is obtained. Based on a model relating the melting peak area and the consistency of the grease, the consistency corresponding to the grease is calculated. The aforementioned model, A physical property evaluation device that generates properties through regression analysis based on measurement data consisting of measured consistency and measured melting peak area for a reference grease.

8. A physical property evaluation program executed by a controller connected to an input unit into which physical property data showing the thermal behavior of the grease to be evaluated is input, The aforementioned controller, The steps include obtaining the melting peak area of ​​the grease based on the aforementioned physical property data, A step of calculating the consistency corresponding to the grease based on a model relating the melting peak area and the consistency of the grease, Equipped with, The aforementioned model, A physical property evaluation program generated by regression analysis based on measurement data consisting of measured consistency and measured melting peak area for a reference grease.

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