Temperature history estimation device, temperature history estimation method, and temperature history estimation program

Abstract

The temperature history of the rubber composition is estimated by a simple method. A temperature history estimation device (1) estimates a temperature history of an object to be measured, which is a rubber composition. A temperature history estimation device (1) is provided with: a measured value reception unit (101) that receives a measured value of the carbonization rate of a polymer contained in an object to be measured; a storage unit (20) that stores data (202) indicating the relationship between the carbonization rate and the temperature of the polymer contained in the sample of the rubber composition; and a temperature history estimation unit (102) that estimates the temperature history of the object to be measured on the basis of the measured value of the carbonization rate and the data (202).

Description

Technical Field

[0001] The present invention relates to a temperature history estimation device, a temperature history estimation method, and a temperature history estimation program. Background Art

[0002] Conventionally, for a rubber composition, the degree of deterioration has been estimated by measuring structural changes using FT-IR or by measuring changes in rubber hardness (for example, refer to Non-Patent Document 1).

[0003] Prior Art Documents

[0004] Non-Patent Documents

[0005] Non-Patent Document 1: Tetsuya Kawashima, Toshio Ogawa, "Failure Caused by Thermal Deterioration of NBR", "Journal of the Rubber Society of Japan, Vol. 75, No. 6, 2002", Japan Rubber Association, p257 - 262 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] However, since these changes are difficult to quantify and the error is large, it is difficult to accurately estimate the temperature history of a sample of the rubber composition.

[0008] The present invention has been made in view of the above problems, and an object thereof is to provide a technique for estimating the temperature history of a rubber composition by a simple method.

[0009] Means for Solving the Problems

[0010] In order to achieve the above object, a temperature history estimation device according to the present invention is a device for estimating the temperature history of a measurement object that is a rubber composition, and includes: a measurement value receiving unit that receives a measurement value of the carbonization rate of a polymer contained in the measurement object; a storage unit that stores data representing the relationship between the carbonization rate of a polymer contained in a sample of the rubber composition and temperature; and a temperature history estimation unit that estimates the temperature history of the measurement object based on the measurement value of the carbonization rate and the data.

[0011] In the temperature history estimation device according to one aspect of the present invention, the temperature history estimation unit correlates the measurement value of the carbonization rate with the carbonization rate of the polymer contained in the sample in the data, and estimates the temperature history of the measurement object.

[0012] In the temperature history estimation device according to one aspect of the present invention, the measurement value of the carbonization rate is measured using a thermogravimetric differential thermal analysis device.

[0013] In order to achieve the above object, the temperature history estimation method according to the present invention is a method for estimating the temperature history of an object to be measured as a rubber composition, and the following steps are performed: a step of receiving a measured value of the carbonization rate of a polymer contained in the object to be measured; and a step of estimating the temperature history of the object to be measured based on the measured value of the carbonization rate and data representing the relationship between the carbonization rate and temperature of the polymer contained in a sample of the rubber composition.

[0014] In order to achieve the above object, the temperature history estimation program according to the present invention is a program for a computer to execute a process of estimating the temperature history of an object to be measured as a rubber composition, and causes the computer to execute the following steps: a step of receiving a measured value of the carbonization rate of a polymer contained in the object to be measured; and a step of estimating the temperature history of the object to be measured based on the measured value of the carbonization rate and data representing the relationship between the carbonization rate and temperature of the polymer contained in a sample of the rubber composition.

[0015] In the temperature history estimation method and temperature history estimation program according to one embodiment of the present invention, in the step of estimating the temperature history of the object to be measured, the measured value of the carbonization rate is made to correspond to the carbonization rate of the polymer contained in the sample in the data, and the temperature history of the object to be measured is estimated.

[0016] In the temperature history estimation method and temperature history estimation program according to one embodiment of the present invention, the measured value of the carbonization rate is measured using a thermogravimetric differential thermal analyzer.

[0017] Effect of the Invention

[0018] According to the temperature history estimation device, temperature history estimation method, and temperature history estimation program of the present invention, the temperature history of a rubber composition can be estimated by a simple method. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a functional block diagram of a temperature history estimation device according to an embodiment of the present invention.

[0020] Figure 2 is a sectional perspective view of a gear shock absorber having an example of a rubber composition in which the temperature history is estimated by the temperature history estimation device according to the present embodiment.

[0021] Figure 3 is a schematic view showing an example of a screen in which an input of a measured value of the carbonization rate is received by a measured value receiving unit in the temperature history estimation device according to the present embodiment and is displayed on a notification unit.

[0022] Figure 4It is a graph showing the TG-DTA curve of a rubber composition for which temperature history is estimated by the temperature history estimation device according to this embodiment.

[0023] Figure 5 It is a schematic diagram for explaining the deterioration principle of the rubber composition.

[0024] Figure 6 It is a graph showing the relationship between the carbonization rate of the polymer in the rubber composition for which temperature history is estimated by the temperature history estimation device according to this embodiment and the temperature history.

[0025] Figure 7 It is a graph showing the relationship between the change in rubber hardness in the rubber composition and the temperature history.

[0026] Figure 8 It is a graph showing the relationship between the FT-IR of the rubber composition and the temperature history.

[0027] Figure 9 It is a schematic diagram showing an example of a screen that displays the estimation result of the temperature history calculated by the temperature history estimation unit in the temperature history estimation device according to this embodiment on the notification unit.

[0028] Figure 10 It is a flowchart for explaining the temperature history estimation method executed by the temperature history estimation device according to this embodiment.

[0029] Symbol Explanation

[0030] 1 Temperature history estimation device

[0031] 2 Gear shock absorber

[0032] 3 Rubber ring

[0033] 10 Data processing control unit

[0034] 20 Storage unit

[0035] 30 Operation unit

[0036] 40 Notification unit

[0037] 50 Interface unit

[0038] 101 Measurement value reception unit

[0039] 102 Temperature history estimation unit

[0040] 201 Temperature history estimation program

[0041] 202 Temperature sample data

[0042] 203 Temperature history estimation result

[0043] 210 and 211 TG-DTA curves

[0044] 300 Measured value receiving screen

[0045] 301 Measured value input section

[0046] 310 Temperature history estimation result display screen

[0047] 311 Estimation result display section Detailed implementation mode

[0048] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0049] Figure 1 It is a functional block diagram of the temperature history estimation device 1 according to the embodiment of the present invention.

[0050] As Figure 1 shown, the temperature history estimation device 1 according to the embodiment of the present invention is an information processing device having a data processing control unit 10 and a storage unit 20, such as a PC (personal computer), a smart phone, a tablet terminal, etc.

[0051] The data processing control unit 10 is composed of an information processing device capable of executing a computer program, such as an MCU (Micro Controller Unit) including a processor such as a CPU (Central Processing Unit) and a storage device. The storage device included in the data processing control unit 10 is realized by a known storage device (storage medium) such as a ROM, a RAM, a flash memory, etc.

[0052] The data processing control unit 10 is a functional unit that comprehensively controls each functional unit in the temperature history estimation device 1. As described above, the data processing control unit 10 is composed of a processor such as a CPU, for example. The data processing control unit 10 controls each functional unit in the temperature history estimation device 1 by executing various operations according to the program stored in the storage unit 20, for example.

[0053] The storage unit 20 is a non-volatile storage device that stores various information described later, and is, for example, a magnetic storage device such as a hard disk drive, or an electrical storage device such as a solid state drive.

[0054] In the storage unit 20, various programs for enabling the information processing apparatus to implement the functions of the temperature history estimation apparatus 1 are stored. Among the various programs stored in the storage unit 20, there is a temperature history estimation program 201 related to the present invention. In addition, data representing the relationship between the carbonization rate of the polymer contained in the sample of the rubber composition and the temperature (hereinafter referred to as "carbonization rate-temperature sample data 202") is stored in the storage unit 20, and the rubber composition has a composition corresponding to the measurement object used in the calculation for estimating the temperature history of the measurement object. Furthermore, the storage unit 20 is a functional unit for storing various data such as the temperature history estimation result 203.

[0055] The operation unit 30 is an input interface for the user to operate the temperature history estimation apparatus 1. Examples of the operation unit 30 include various buttons, a keyboard, a pointing device, a touch panel, etc. For example, by the user operating the operation unit 30, various conditions for estimating the temperature history of the measurement object can be set in the temperature history estimation apparatus 1, and the execution and stop of the temperature history estimation process can be instructed to the temperature history estimation apparatus 1. In addition, the operation unit 30 is not limited to the above-mentioned buttons or touch panel, as long as it has a function capable of receiving the input from the user for operating the temperature history estimation apparatus 1. The operation unit 30 can also receive operations, for example, through voice-based command input.

[0056] The notification unit 40 is a functional unit for outputting various information such as the determination of the measurement object in the temperature history estimation apparatus 1, the name of the carbonization rate-temperature sample data 202 used in the temperature history estimation process, the confirmation of the stored data, the estimation conditions, the estimation result, etc., and notifying the user of the information. The notification unit 40 is, for example, a display device equipped with an LCD (Liquid Crystal Display) or an organic EL. In addition, the notification unit 40 can also be a device such as a speaker or headphones that outputs sound data to notify the user of the information. In addition, the notification unit 40 can also be a display device equipped with a touch panel that implements a part of the functions of the operation unit 30.

[0057] The interface unit 50 is composed of various interfaces capable of inputting and outputting data between the temperature history estimation device 1 and an external device (not shown). The interface unit 50 can be, for example, various communication interfaces such as LAN, USB, and RS-232C. Through the interface unit 50, the temperature history estimation device 1 can perform input and output of data via the above-mentioned external device. The interface unit 50 may also include a communication circuit or the like that outputs various data used in the estimation of the temperature history to the outside by wire or wirelessly. Through these various communication interfaces, the temperature history estimation device 1 can communicate with, for example, a wide area network (WAN: Wide Area Network) represented by the Internet or a local area network (LAN: Local Area Network).

[0058] The temperature history estimation device 1 has the above hardware configuration, and the data processing control unit 10 executes the temperature history estimation program stored in the storage unit 20, and the hardware and software cooperate to perform the process of estimating the temperature history of the object to be measured, which is a rubber composition. As functional blocks implemented by the temperature history estimation program, the temperature history estimation device 1 includes a measurement value receiving unit 101, the above-mentioned storage unit 20, and a temperature history estimation unit 102.

[0059] Figure 2 FIG. is a sectional perspective view of a gear shock absorber 2 having an example of a rubber composition for which the temperature history is estimated by the temperature history estimation device 1 according to the present embodiment. In the present embodiment, the temperature history estimation device 1 estimates, for example, the temperature value, that is, the temperature history, of the heat received by the rubber composition by measuring the carbonization rate of the polymer contained in a rubber composition such as a rubber ring 3 provided on the gear shock absorber 2, for example, hydrogenated nitrile rubber (HNBR).

[0060] In addition, the rubber composition as the object to be measured for performing the temperature history estimation process based on the temperature history estimation device 1 is not limited to the rubber composition used in vibration-proof rubber products such as the Figure 2 shown gear shock absorber or torsion shock absorber, and can be used in various rubber products.

[0061] The measurement value receiving unit 101 receives the measurement value of the carbonization rate of the polymer contained in the object to be measured (hereinafter referred to as "measurement value"). The measurement value is measured using a thermogravimetry-differential thermal analysis device (TG-DTA: Thermogravimetry-Differential Thermal Analysis), which is a device that simultaneously measures thermogravimetric analysis and differential thermal analysis. Specifically, based on the weight reduction amount of the rubber in the combustion region (in air, about 450 to 550 °C), the amount of carbonization of the rubber due to structural changes caused by the temperature history is measured.

[0062] Figure 3 is a schematic diagram showing an example of a measurement value reception screen 300 for receiving a measurement value of a carbonization rate by a measurement value reception unit 101 in the temperature history estimation device 1 according to the present embodiment, which is displayed on a notification unit 40. The measurement value reception screen 300 is displayed, for example, on a display device constituting the notification unit 40 (see Figure 1 ). A user can input a measurement value to a measurement value input unit 301 on the measurement value reception screen 300 via an operation unit 30 or an interface unit 50, for example. The measurement value input to the measurement value input unit 301 is received by the measurement value reception unit 101. Note that the method of inputting the measurement value is not limited to the above example.

[0063] A temperature history estimation unit 102 estimates a temperature history of a measurement object based on the measurement value received by the measurement value reception unit 101 and carbonization rate-temperature sample data 202 stored in a storage unit 20. Specifically, the temperature history estimation unit 102 correlates the measurement value of the carbonization rate received by the measurement value reception unit 101 with the carbonization rate of the polymer contained in the samples in the carbonization rate-temperature sample data 202, and estimates the temperature history of the measurement object.

[0064] Figure 4 is a chart showing a TG-DTA curve of a rubber composition for which a temperature history is estimated by the temperature history estimation device 1 according to the present embodiment. In Figure 4 , the left vertical axis represents a weight reduction rate (wt%), the right vertical axis represents temperature (°C), and the horizontal axis represents time (minutes). In Figure 4 , a TG-DTA curve 210 of a new rubber composition (not placed in a high-temperature environment) and a TG-DTA curve 211 of a rubber composition that has been heated at a specified temperature (e.g., 150 °C) are shown. In the present embodiment, the rubber composition used in a high-temperature environment is the rubber composition that is the object of estimating the temperature history, i.e., the measurement object.

[0065] Figure 5 is a schematic diagram for explaining the deterioration principle of the rubber composition. As can be seen from the TG-DTA curve 210 of the new rubber composition shown in Figure 4 and the TG-DTA curve 211 of the rubber composition that has been heated at a specified temperature, the weight percentage of carbide (carbon precursor) in the rubber composition increases by using it in a high-temperature environment. Then, as shown in Figure 5 , it is estimated that polymers in rubber compositions such as HNBR cyclize and deteriorate into carbides (carbon precursors) in a high-temperature environment. Therefore, in the temperature history estimation device 1, the temperature history of the measurement object is estimated based on the carbonization rate of the polymer contained in the measurement object of the rubber composition.

[0066] Figure 6is a graph showing the relationship between the carbonization rate of the polymer in the rubber composition for which the temperature history is estimated by the temperature history estimation device 1 according to the present embodiment and the temperature history. In Figure 6 the vertical axis represents the carbonization rate (%) of the polymer, and the horizontal axis represents the temperature history (°C) of the rubber composition. As Figure 6 shown, it can be seen that in the rubber composition for which the temperature history is estimated by the temperature history estimation device 1, the following relationship exists: as the carbonization rate of the polymer increases, the temperature indicated by the temperature history to which the rubber composition containing the polymer is subjected also increases. That is, it can be seen that in the rubber composition, if the carbonization rate of the polymer can be measured, the temperature history to which the rubber composition is subjected can be estimated. In such a graph showing the relationship between the carbonization rate of the polymer and the temperature history, the line L1 represents the specified temperature and the carbonization rate as a reference for judging the deterioration of the rubber composition. It can be seen that among any number of points depicted in the graph, for example, Figure 5 the point P4 exceeding the line L1 among the points P1 to P4 in

[0067] Figure 7 is a temperature history exceeding the above specified temperature. Figure 8 is a graph showing the relationship between the change in rubber hardness in the rubber composition and the temperature history. In addition,

[0068] In the evaluation using the Figure 7 shown change in rubber hardness and the evaluation using the Figure 8 shown FT-IR (Fourier Transform-Infrared Spectroscopy), the deviation between each value measured from the rubber composition and the temperature history to which the rubber composition is subjected is large. Therefore, it is difficult to estimate the temperature history of the rubber composition using the change in rubber hardness and FT-IR. In addition, in the case of estimating the temperature history based on the structural change of FT-IR, the structural change at high temperature cannot be captured from the measured value, and it is difficult to normalize.

[0069] Therefore, the temperature history estimation device 1 stores, in the storage unit 20, a combination of the temperature history value preliminarily measured from a sample of the rubber composition having the same composition as the measurement object and the carbonization rate of the polymer in the temperature history as the carbonization rate-temperature sample data 202. The carbonization rate-temperature sample data 202 is stored in the storage unit 20, for example, according to the category of the rubber composition. In the carbonization rate-temperature sample data 202, the temperature history corresponding to the carbonization rate may be stored in the storage unit 20, for example, at intervals (step sizes) of every 20°C of the temperature history or every 5% of the carbonization rate or any other value.

[0070] Then, the temperature history estimation device 1 determines the value of the temperature history corresponding to the measured value of the carbonization rate received from the measured value receiving unit 101 based on the carbonization rate-temperature sample data 202 stored in the storage unit 20. Thereby, the temperature history estimation device 1 can estimate the temperature history of the rubber composition by measuring the carbonization rate of the polymer of the rubber composition.

[0071] Figure 9 FIG. is a schematic diagram showing an example of a temperature history estimation result display screen 310 that displays the estimation result of the temperature history calculated based on the measured value by the temperature history estimation unit 102 in the temperature history estimation device 1 according to the present embodiment on the notification unit 40. The temperature history estimation result display screen 310 is displayed, for example, on the display device constituting the notification unit 40. The user can identify the estimation result of the temperature history, for example, by confirming the value displayed on the estimation result display unit 311 in the temperature history estimation result display screen 310. In addition, the display method and output method of the estimation result of the temperature history are not limited to the above examples.

[0072] Figure 10 FIG. is a flowchart for explaining the temperature history estimation method executed by the temperature history estimation device 1 according to the present embodiment.

[0073] First, in the temperature history estimation device 1, the measured value receiving unit 101 receives an input of the measured value of the carbonization rate of the polymer of the measurement object from the operation unit 30 or the interface unit 50 (step S101).

[0074] The temperature history estimation unit 102 retrieves in the storage unit 20 the carbonization rate-temperature sample data 202 of the rubber composition having the same composition as the measured value received by the measured value receiving unit 101 corresponding to the measured value of the measurement object (step S102).

[0075] The temperature history estimation unit 102 determines whether there is carbonization rate-temperature sample data 202 corresponding to the measured value of the measurement object in the storage unit 20 (step S103). If there is no carbonization rate-temperature sample data 202 corresponding to the storage unit 20 (S103: No), the temperature history estimation unit 102 notifies the user via the notification unit 40 to request saving the corresponding carbonization rate-temperature sample data 202 (step S104). After S104, the temperature history estimation unit 102 returns to the process of S102.

[0076] If there is carbonization rate-temperature sample data 202 corresponding to the storage unit 20 (S103: Yes), the temperature history estimation unit 102 estimates the temperature history of the measurement object based on the measured value of the measurement object and the carbonization rate-temperature sample data 202 (step S105).

[0077] The temperature history estimation unit 102 determines whether the estimation process of the temperature history of the object to be measured is completed by correlating the measured value of the object to be measured with the carbonization rate value in the carbonization rate-temperature sample data 202 (step S106). When the estimation process of the temperature history of the object to be measured is not completed (S106: No), the temperature history estimation unit 102 notifies an error message indicating that the temperature history estimation process is not completed from the notification unit 40 (step S107), and returns to the process of S101.

[0078] When the estimation process of the temperature history of the object to be measured is completed (S106: Yes), the temperature history estimation unit 102 outputs the estimated value of the temperature history of the object to be measured from the notification unit 40 (step S108). After the process of S108, the temperature history estimation device 1 ends the process.

[0079] As described above, in the temperature history estimation device 1 according to the present embodiment, by executing the temperature history estimation program, it is possible to execute a temperature history estimation method for estimating the temperature history of the rubber composition based on the carbonization rate measurement value of the polymer contained in the rubber of the object to be measured.

[0080] Specifically, in the temperature history estimation method executed by the temperature history estimation device 1 according to the present embodiment, attention is paid to the fact that when rubber (NBR) deteriorates and the structure of the rubber changes, it passes through a carbon precursor. Moreover, in the temperature history estimation method, TG-DTA is used to measure the amount of the carbon precursor, that is, the carbonization rate of the polymer, and based on the relationship between the carbonization rate and the temperature history, the temperature history of the object to be measured is estimated. Here, the temperature history of the rubber composition can be used as an index of the degree of deterioration. Compared with FT-IR or rubber hardness change, the error in the relationship between each value and the temperature history is smaller for TG-DTA. In addition, compared with FT-IR or rubber hardness change, TG-DTA can also be easily quantified.

[0081] Therefore, according to the temperature history estimation method executed by the temperature history estimation device 1, the temperature history of the rubber composition can be estimated by a simple method.

[0082] The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments of the present invention, and includes all modes included in the concept of the present invention and the claims. In addition, the respective structures can be appropriately and selectively combined to achieve at least a part of the above effects. For example, the shape, material, arrangement, size, etc. of each component in the above embodiments can be appropriately changed according to the specific usage mode of the present invention.

Claims

1. A temperature history estimation device, which is a device for estimating the temperature history of an object to be measured as a rubber composition, and includes: A measured value receiving unit that receives the measured value of the carbonization rate of the polymer contained in the object to be measured; A storage unit that stores data representing the relationship between the carbonization rate of the polymer contained in the sample of the rubber composition and the temperature; and A temperature history estimation unit that estimates the temperature history of the object to be measured based on the measured value of the carbonization rate and the data.

2. The temperature history estimation device according to claim 1, wherein The temperature history estimation unit establishes a correspondence between the measured value of the carbonization rate and the carbonization rate of the polymer contained in the sample in the data, and estimates the temperature history of the object to be measured.

3. The temperature history estimation device according to claim 1 or 2, wherein The measured value of the carbonization rate is measured using a thermogravimetric differential thermal analyzer.

4. A temperature history estimation method, which is a method for estimating the temperature history of an object to be measured as a rubber composition, and performs the following steps: A step of receiving the measured value of the carbonization rate of the polymer contained in the object to be measured; and A step of estimating the temperature history of the object to be measured based on the measured value of the carbonization rate and the data representing the relationship between the carbonization rate of the polymer contained in the sample of the rubber composition and the temperature.

5. The temperature history estimation method according to claim 4, wherein In the step of estimating the temperature history of the object to be measured, a correspondence is established between the measured value of the carbonization rate and the carbonization rate of the polymer contained in the sample in the data, and the temperature history of the object to be measured is estimated.

6. The temperature history estimation method according to claim 4 or 5, wherein The measured value of the carbonization rate is measured using a thermogravimetric differential thermal analyzer.

7. A temperature history estimation program, which is a program for a computer to execute a process of estimating the temperature history of an object to be measured as a rubber composition, and causes the computer to execute the following steps: A step of receiving the measured value of the carbonization rate of the polymer contained in the object to be measured; and A step of estimating the temperature history of the object to be measured based on the measured value of the carbonization rate and the data representing the relationship between the carbonization rate of the polymer contained in the sample of the rubber composition and the temperature.

8. The temperature history estimation program according to claim 7, wherein In the step of estimating the temperature history of the object to be measured, a correspondence is established between the measured value of the carbonization rate and the carbonization rate of the polymer contained in the sample in the data, and the temperature history of the object to be measured is estimated.

9. The temperature history estimation program according to claim 7 or 8, wherein The measured value of the carbonization rate is measured using a thermogravimetric differential thermal analyzer.

Images