JP5488329B2 - Material testing machine - Google Patents

Description

The present invention relates to a material testing machine for performing a material test by applying a test force to the test piece.

  In a material testing machine, for example, when a tensile test or the like is performed on a test piece such as a resin, the ambient temperature during the material test may be measured. In addition, the material test may be performed while controlling the temperature of the test piece during the material test. Patent Document 1 discloses a material testing machine including an atmosphere furnace that controls the temperature around a test piece.

JP 2001-183275 A

  FIG. 3 is a block diagram showing a configuration for displaying the temperature measured by the temperature sensor 91 on the display unit 94 in a conventional material testing machine.

  When the temperature measured by the temperature sensor 91 is taken from the analog voltage input port of the material testing machine main body 93, the temperature sensor 91 is used on the temperature sensor 91 side, and the analog voltage output of the temperature sensor 91 is zero volts. In addition to performing voltage adjustment and full-scale voltage adjustment, it is necessary to set both the temperature at the time of zero volt output and the slope of the voltage per unit temperature as a coefficient for converting the temperature into the voltage. On the material testing machine main body 93 side, the zero volt voltage adjustment and the full scale voltage adjustment at the analog voltage input port are performed, and the coefficient at the time of converting the temperature into the voltage is the temperature at the time of zero volt input and the voltage per unit temperature. It is necessary to set both the slope and the slope.

  Also, on the material tester main body 93 side, when setting the temperature at the time of zero volt input and the slope of the voltage per unit temperature for the coefficient for converting the temperature into the voltage, a reference voltage power source as a reference is prepared. There is a need to. For this reason, these operations must be extremely complicated.

  For this reason, for example, it is conceivable to adopt a method of taking temperature information into a computer by digital communication using RS232C or USB, but in this case, software in which a dedicated protocol is installed is required.

The present invention has been made to solve the above-described problems, and provides a material testing machine capable of displaying the temperature at the time of material testing without preparing a reference voltage power source or making complicated adjustments. With the goal.

The invention according to claim 1 is the same as the resistance value of the resistance temperature detector when the resistance temperature detector measures zero degree Celsius in the material testing machine having a temperature measurement mechanism. A first resistor having a resistance value, a second resistor having a resistance value equal to the resistance value of the resistance temperature detector when the resistance temperature detector measures the maximum measured temperature, an amplifier circuit, Displacement measurement for measuring the displacement of the test piece , a changeover switch for selectively connecting the first resistor, the second resistor, and the resistance temperature detector to the amplifier circuit And a temperature measured by the resistance temperature detector based on a signal from the amplification circuit is displayed on the display unit, and a displacement amount of the test piece at the time of a material test measured by the displacement measuring means is and a control unit for displaying on the display unit, wherein the control unit When the first resistor and the amplifier circuit are connected by the changeover switch, the display unit displays zero degrees Celsius, and the changeover switch connects the second resistor and the amplifier circuit. Sometimes the temperature display control is performed so that the maximum measured temperature is displayed as a full scale on the display unit, and the displacement amount display control is performed so that the maximum measured displacement measured by the displacement amount measuring unit is displayed as a full scale. It is characterized by performing .

  According to the first aspect of the present invention, the temperature measured by the resistance temperature detector can be easily displayed on the display unit without preparing a reference voltage power source or performing complicated adjustment work. Become.

Further , the temperature can be displayed on the display unit for displaying the displacement amount of the test piece during the material test. For this reason, for example, even when a temperature measurement function is added to an existing apparatus, it is not necessary to newly add a display unit.

It is a schematic diagram of the material testing machine to which this invention is applied. It is a block diagram which shows the main electrical structures of the material testing machine which concerns on this invention. In the conventional material testing machine, it is a block diagram which shows the structure for displaying the temperature measured with the temperature sensor 91 on the display part 94. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a material testing machine to which the present invention is applied.

  This material testing machine is movable along a table 16, a pair of screw rods 11, 12 that are erected on the table 16 so as to be vertically oriented, and these screw rods 11, 12. A crosshead 13 and a load mechanism 30 for moving the crosshead 13 to apply a test force to the test piece 10 are provided.

  The cross head 13 is connected to the pair of screw rods 11 and 12 via nuts (not shown). Worm speed reducers 32 and 33 in the load mechanism 30 are connected to lower ends of the screw rods 11 and 12. The worm speed reducers 32 and 33 are connected to a servo motor 31 that is a drive source of the load mechanism 30, and the rotation of the servo motor 31 is transferred to the pair of screw rods 11 and 12 via the worm speed reducers 32 and 33. It is configured to be transmitted. As the pair of screw rods 11 and 12 rotate in synchronization with the rotation of the servo motor 31, the crosshead 13 moves up and down along these screw rods 11 and 12.

  The crosshead 13 is provided with an upper gripping tool 21 for gripping the upper end portion of the test piece 10. On the other hand, the table 16 is provided with a lower gripping tool 22 for gripping the lower end portion of the test piece 10. When performing a tensile test, the test force (tensile load) is applied to the test piece 10 by raising the cross head 13 in a state where both ends of the test piece 10 are held by the upper gripping tool 21 and the lower gripping tool 22. ).

  At this time, the test force acting on the test piece 10 is detected by the load cell 14 and input to the control unit 23. Further, the displacement amount of the distance between the gauge points in the test piece 10 is measured by the displacement meter 15 and input to the control unit 23. The ambient temperature in the vicinity of the test piece 10 is measured using the temperature measurement unit 25, amplified by the amplifier circuit 24, and then input to the control unit 23.

  The control unit 23 is configured by a computer, a sequencer, and peripheral devices thereof, and takes in test force data and displacement amount data from the load cell 14 and the displacement meter 15 and executes data processing. The servo motor 31 is feedback controlled by the control unit 23. The control unit 23 processes a signal input from the temperature measurement unit 25 via the amplifier circuit 24. Moreover, this control part 23 is connected with the display part 41 for displaying the displacement amount of the test piece 10 at the time of a material test.

  FIG. 2 is a block diagram showing the main electrical configuration of the material testing machine according to the present invention.

  This material testing machine includes a temperature measurement unit 25 including an NTC thermistor 51 as a resistance temperature detector, a fixed resistor 52 corresponding to 0 degrees Celsius, and a fixed resistor 53 corresponding to 50 degrees Celsius. This temperature measurement unit 25 is connected to the control unit 23 in the main body of the material testing machine via the changeover switch 54 and the amplifier circuit 24. The signal from the temperature measurement unit 25 is amplified by the amplifier circuit 24 and output to the analog voltage input port in the control unit 23 as an analog voltage output.

  Here, the changeover switch 54 has a function of selectively connecting the NTC thermistor 51, the fixed resistor 52 equivalent to 0 degrees Celsius, and the fixed resistor 53 equivalent to 50 degrees Celsius to the amplifier circuit 24. As the change-over switch 54, a switch that manually executes a change-over operation may be used, or a switch that can be automatically switched based on an electrical signal or the like may be used.

  The NTC thermistor 51 in the temperature measurement unit 25 is a thermistor whose resistance value decreases with increasing temperature. The NTC thermistor 51 is widely used for temperature detection because the temperature and the resistance value have a substantially proportional relationship.

  The fixed resistor 52 corresponding to 0 degrees Celsius in the temperature measurement unit 25 has a resistance value equal to the resistance value when the NTC thermistor 51 measures zero degrees Celsius. That is, the relationship between the temperature and the resistance value in the NTC thermistor 51 is announced by the manufacturer of the NTC thermistor 51. For this reason, the resistance value of the fixed resistor 52 corresponding to 0 degrees Celsius is set to be the resistance value when the NTC thermistor 51 measures zero degrees Celsius.

  Similarly, the fixed resistor 53 corresponding to 50 degrees Celsius in the temperature measurement unit 25 has a resistance value equal to the resistance value when the NTC thermistor 51 measures 50 degrees Celsius. That is, the resistance value of the fixed resistor 53 corresponding to 50 degrees Celsius is set to be the resistance value when the NTC thermistor 51 measures 50 degrees Celsius, like the fixed resistor 52 corresponding to 0 degrees Celsius.

  In the material testing machine according to this embodiment, the maximum measurement temperature in the temperature measurement unit 25 is set to 50 degrees Celsius. Moreover, in this material testing machine, the maximum measured displacement of the displacement meter 15 is 50 mm. That is, in this material testing machine, the temperature full scale value is 50 degrees Celsius, and the displacement full scale value is 50 mm.

  In the material testing machine having the above-described configuration, the analog voltage input port of the control unit 23 in the material testing machine body is adjusted when the temperature measurement unit 25 is installed. In this case, first, the changeover switch 54 is switched to connect the fixed resistor 52 corresponding to 0 degrees Celsius and the amplifier circuit 24. In this state, zero of the analog voltage input port of the control unit 23 is adjusted. That is, in this state, the control unit 23 performs adjustment so that the display on the display unit 41 is 0 degree.

  Next, the changeover switch 54 is switched to connect the fixed resistor 53 corresponding to 50 degrees Celsius and the amplifier circuit 24. In this state, the full scale of the analog voltage input port of the control unit 23 is adjusted. That is, in this state, the control unit 23 performs adjustment so that the display on the display unit 41 is full scale, that is, 50 degrees.

  Thereafter, the changeover switch 54 is switched to connect the NTC thermistor 51 and the amplifier circuit 24. Further, the control unit 23 performs adjustment so that the display unit 41 displays the displacement measured by the displacement meter 15 at full scale, that is, the maximum measured displacement is 50 mm.

  A material test is performed after performing the above adjustment process. At the time of this material test, a temperature measurement process using the NTC thermistor 51 in the temperature measurement unit 25 is executed. At this time, since the zero and full scale adjustments are performed in the control unit 23, the temperature measured by the NTC thermistor 51 can be accurately displayed on the display unit 41. Further, the display unit 41 displays the amount of displacement of the test piece 10.

  As described above, in the material testing machine according to the present invention, it is possible to display the temperature at the time of material testing without preparing a reference voltage power source or making complicated adjustments. For this reason, even when a temperature detection function is added to an operating material testing machine, the operation becomes easy. Further, since the temperature detected by the NTC thermistor 51 can be displayed on the display unit 41 for displaying the amount of displacement of the test piece 10, the material in operation without adding a display unit for temperature display. It becomes possible to add a temperature detection function to the testing machine.

  In the above-described embodiment, the NTC thermistor is used as the resistance temperature detector. However, other thermistors may be used, or a resistance temperature detector other than the thermistor may be used.

DESCRIPTION OF SYMBOLS 10 Test piece 11 Screw rod 12 Screw rod 13 Crosshead 14 Load cell 15 Displacement meter 16 Table 21 Upper gripper 22 Lower gripper 23 Control part 24 Amplifier circuit 25 Temperature measurement unit 30 Load mechanism 31 Servo motor 41 Display part 51 NTC thermistor Fixed resistor equivalent to 0 degrees Celsius 53 Fixed resistor equivalent to 50 degrees Celsius 54 Changeover switch

Claims (1)

In a material testing machine equipped with a temperature measurement mechanism,
A resistance temperature detector,
A first resistor having a resistance value equal to the resistance value of the resistance temperature detector when the resistance temperature detector measures zero degrees Celsius;
A second resistor having a resistance value equal to the resistance value of the resistance temperature detector when the resistance temperature detector measures the maximum measurement temperature;
An amplifier circuit;
A selector switch that selectively connects the first resistor, the second resistor, and the resistance temperature detector to the amplifier circuit;
A display unit;
A displacement amount measuring means for measuring a displacement amount of the test piece;
Based on the signal from the amplifier circuit, the temperature measured by the resistance temperature detector is displayed on the display unit, and the displacement amount of the test piece during the material test measured by the displacement measuring means is displayed on the display unit. A control unit to be displayed ;
Equipped with a,
The control unit displays zero degrees Celsius on the display unit when the first resistor and the amplifier circuit are connected by the changeover switch, and the second resistor and the amplifier circuit are displayed by the changeover switch. Is controlled so that the maximum measured temperature is displayed as a full scale on the display unit, and the maximum measured displacement measured by the displacement measuring means is displayed as a full scale. A material testing machine characterized by performing displacement amount display control .

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