JP3775364B2 - Thermal fatigue testing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermal fatigue testing machine that performs a thermal fatigue test on a test piece by applying a tensile compression cycle and a temperature raising / lowering cycle to the test piece in a superimposed manner.
[0002]
[Prior art]
In general, a thermal fatigue testing machine is equipped with a load mechanism that can apply tensile and compressive test forces to the test piece, and a heating / cooling means that raises and lowers the temperature of the test piece. Investigate the thermal fatigue characteristics of the test piece by measuring the strain of the test piece while loading the test piece with a preset tension and compression cycle and heating / cooling cycle. .
[0003]
The strain of the test piece during the test is measured by, for example, a displacement gauge between gauge points, and the measured value includes elongation due to thermal expansion of the test piece, so-called thermal elongation. Therefore, in this type of test, after the test piece is mounted on the testing machine prior to the test, the heating temperature of the test piece is increased at a constant rate, usually under the control of zero test force, The temperature is held for a predetermined time, and then the test piece is cooled to lower the temperature at a constant rate, and the strain of the test piece at a plurality of temperatures in the meantime is measured to prepare a thermal strain table. Then, the measured strain value during the test is corrected using the thermal strain table.
[0004]
Conventionally, the thermal strain table is created by recording a list of strains at a plurality of temperatures in the temperature raising process and the temperature lowering process, and manually inputting the list.
[0005]
[Problems to be solved by the invention]
By the way, manual creation of the thermal strain table is not only cumbersome and time-consuming, but it is particularly troublesome to read the point where the slope changes from the temperature and strain list, and many points are listed. If you manually read and input from, you may make an input error, and there is a possibility that an accurate thermal distortion table cannot be created.
[0006]
An object of the present invention is to provide a thermal fatigue testing machine that greatly facilitates the work of creating a thermal strain table prior to a thermal fatigue test as compared to the conventional technique and that does not cause a table creation error.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a thermal fatigue testing machine of the present invention includes a load mechanism capable of applying a tensile and compression test force to a test piece, a heating / cooling means for raising and lowering the temperature of the test piece, and a test piece. In a thermal fatigue testing machine that includes strain detection means for detecting the strain of the specimen and measures the strain every moment while applying a tensile compression cycle and heating / cooling cycle superimposed on the test piece, the test force prior to the thermal fatigue test Storage means for storing time-temperature data and time-strain data when the specimen is heated and lowered under zero control, and time-temperature data and time-strain stored in the storage means by giving a command Display data on the same graph on the display and display control means for displaying a cursor movable along the time axis on the graph, and a point on the graph specified by using the cursor It kicking characterized by that it comprises a table creation means for creating a thermal expansion tables automatically reads the temperature data and strain data.
[0008]
In the thermal fatigue testing machine of the present invention, the time-temperature data and time-strain data collected and stored under the control of zero test force are displayed on the same graph on the display by giving a command. When the operator designates an arbitrary point on the graph with a cursor, temperature data and strain (thermal elongation) data corresponding to the point are read, and a thermal elongation table is automatically created.
[0009]
The operator designates the point to be registered in the thermal elongation table on the temperature and strain graph, so that the point where the inclination changes can be easily understood, and the data of the designated point is automatically read and the thermal elongation table is read. Therefore, mistakes and complications due to manual input can be eliminated.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram of an embodiment of the present invention, and is a diagram illustrating a schematic diagram showing a mechanical configuration and a block diagram showing an electrical configuration.
[0011]
The testing machine main body 1 has a structure in which two columns 12a and 12b are arranged on a table 11 and both ends of the cross yoke 13 are supported by the columns 12a and 12b. A pair of gripping tools 14a and 14b facing each other are mounted. The upper gripping tool 14 a is attached to the cross yoke 13 via the load cell 15, and the lower gripping tool 14 b is configured to move up and down by driving the hydraulic actuator 16. The test piece W is used for the test in a state where both ends thereof are gripped by the gripping tools 14a and 14b.
[0012]
The hydraulic actuator 16 is driven and controlled by the hydraulic pressure supplied from the hydraulic pressure source 16b via the servo valve 16a whose valve opening is operated by an operation signal from the test machine controller 17. The test machine controller 17 takes in the detection signal of the test force from the load cell 15 and controls the hydraulic actuator 16 so that a tension / compression cycle in which the test force acting on the test piece W is set in advance is loaded.
[0013]
The test piece W gripped by the gripping tools 14a and 14b is heated by the high-frequency induction heating type heating coil 21 and can be cooled by the cooling gas from the cooling gas injection nozzle 22. A high-frequency heating device 21 a that drives the heating coil 21 and a cooling device 22 a that supplies cooling gas to the cooling gas injection nozzle 22 are placed under the control of the tester controller 17. The test machine controller 17 captures a temperature detection signal from a temperature sensor (not shown) arranged in the vicinity of the test piece W, and performs high-frequency heating so that a preset heating / cooling cycle is loaded on the test piece W. The drive of the apparatus 21a and the cooling device 22a is controlled.
[0014]
The strain in the load direction of the test piece W, that is, the expansion or contraction, is detected by the inter-gage displacement meter 18 attached to the test piece W. The distortion detection result is taken into the tester controller 17 every moment. The tester controller 17 is connected to a personal computer 30 for data processing. The strain detection results, the test force detection results, and the temperature detection results, which are included in the tester controller 17, are included in the A-D. After being digitized by the converter, it is taken into the personal computer 30.
[0015]
In the thermal fatigue test, a predetermined tensile and compression cycle and a preset heating / cooling cycle are superimposed and loaded on the test piece W. Prior to the test, the thermal fatigue test is performed by thermal expansion of the test piece W. Data on elongation, so-called thermal elongation is collected, and a thermal elongation table for correcting the distortion of the test piece W detected by the inter-point displacement meter 18 in an actual thermal fatigue test is created.
[0016]
The data on the thermal elongation is collected by raising and lowering the temperature in a predetermined pattern under the control of zero test force with the test piece W mounted on the grippers 14a and 14b, and the temperature and strain at that time. This is performed by capturing the change over time in the personal computer 30. The personal computer 30 is installed with a program for automatically creating a thermal elongation table shown below. Hereinafter, a procedure for creating a thermal elongation table by the program will be described.
[0017]
When the automatic thermal expansion table creation program is activated, an image as illustrated in FIG. 2 is first displayed on the display 31 of the personal computer 30. In other words, when the extension data file creation button set in the personal computer 30 is pressed, an instruction to start the program is given, and the personal computer 30 collects the data on the display 31 under the control of zero test force. The time-dependent change of the measured temperature and the strain of the test piece W, that is, the time-temperature curve and the time-strain curve are displayed on the same graph G with the horizontal axis as a common time axis, and the heat is displayed on the same screen. A screen R for registering elongation data is also displayed. On the graph G, a vertical line cursor C is displayed so as to be movable in the horizontal direction.
[0018]
When the operator operates the mouse 32 to move the cursor C and drags an arbitrary point on the graph G displayed on the display 31, the cursor position data column P in the thermal elongation data registration screen R is displayed. The temperature and thermal elongation (%) corresponding to that point are read and displayed. Similarly, when the registration button BR in the screen R for registering thermal elongation data is clicked in that state, if the dragged point is a point at the time of temperature increase, the temperature and thermal elongation (%) are displayed in the temperature increase data column DU. In addition, if it is a point at the time of cooling, the temperature and the thermal elongation (%) are additionally displayed in the cooling temperature data column DD. If you want to actually register the additional displayed data, click the OK button BO in the thermal elongation data registration screen R to register the temperature and thermal elongation (%) data pair in the file. The If registration of the data pair is unnecessary, the cancel button BC is clicked.
[0019]
The thermal elongation table is completed by repeating the above operation and registering data at all necessary points. In the thermal fatigue test, the strain of the test piece W by the inter-point displacement meter 18 is corrected for the expansion due to the temperature using the contents of the thermal elongation table created as described above, and the true strain data. Converted to
[0020]
【The invention's effect】
As described above, according to the present invention, the temperature and test piece elongation data collected under the control of zero test force are displayed on the same graph on the screen of the display, and arbitrary data on the graph is displayed. When the operator designates a point by dragging, etc., the temperature and strain data at the designated point is automatically read and a thermal elongation table is created, so the data is manually picked up from the conventional list. Compared to input, it is very easy for the operator to determine the changing point of temperature and thermal elongation, there is no risk of manual input, and the operation is greatly simplified. It becomes.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an embodiment of the present invention, and is a diagram illustrating a schematic diagram showing a mechanical configuration and a block diagram showing an electrical configuration.
FIG. 2 is an explanatory diagram illustrating an example of a display screen on a display of a personal computer when a program for creating a thermal elongation table is started in the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Test machine main body 11 Table 12a, 12b Column 13 Cross yoke 14a, 14b Grasp 15 Load cell 16 Hydraulic actuator 16a Servo valve 16b Hydraulic source 17 Test machine controller 18 Inter-point displacement meter 21 Heating coil 21a High frequency heating device 22 Cooling gas injection Nozzle 22a Cooling device 30 Personal computer 31 Display 32 Mouse C Cursor G Graph R Screen for thermal expansion data registration W Test piece

Claims (1)

Equipped with a load mechanism that can apply a tensile and compression test force to the test piece, a heating / cooling means for raising and lowering the test piece, and a strain detection means for detecting the strain of the test piece. In a thermal fatigue testing machine that measures strain every moment while applying a load by superimposing a compression cycle and a heating / cooling cycle,
Prior to the thermal fatigue test, storage means for storing time-temperature data and time-strain data when the test piece is heated and lowered under the control of zero test force, and stored in the storage means by giving a command Display control unit that displays time-temperature data and time-strain data on the same graph on the display, and displays a cursor that can be moved along the time axis on the graph. A thermal fatigue testing machine comprising a table creation means for automatically creating a thermal elongation table by reading temperature data and strain data at points on the graph.

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