JP6646957B2 - Environmental test equipment - Google Patents

Description

  The present invention relates to an environmental test device.

  As the background art of this technical field, the abstract of Patent Document 1 below states, "Inverter control at the time of low-temperature test reads the amount of undershoot caused by rapid cooling and temperature recovery time, and the rotation of the compressor is determined by the temperature and time. Correct the speed. "

JP-A-6-288985

Patent Document 1 describes a thermal shock test apparatus that corrects the rotational speed of a compressor based on a predetermined amount of undershoot of a low-temperature bath temperature and a temperature recovery time. However, in the thermal shock test apparatus described in Patent Document 1, when combined with a test condition in which undershoot does not occur or a control method capable of minimizing the occurrence of undershoot, the rotational speed of the compressor is reduced. There was a problem that the refrigeration capacity of the refrigerator could not be adjusted by correction.
The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an environmental test device that enables determination of excess or deficiency of refrigeration capacity even under conditions where undershoot does not occur, and that can obtain optimal refrigeration capacity. is there.

In order to solve the above-mentioned problems, an environmental test apparatus according to the present invention includes a test tank in which a test object is arranged, a low-temperature tank communicating with the test tank, and a refrigerator that cools gas in the low-temperature tank to a pre-cooled state. A low-temperature tank-side heater for heating gas in the low-temperature tank; a high-temperature tank communicating with the test tank; a high-temperature tank-side heater for heating the gas in the high-temperature tank to a preheated state; A control unit for controlling the operating conditions of the low temperature tank side heater, the control unit monitors the utilization rate of the low temperature tank side heater, the utilization rate of the low temperature tank side heater exceeds a preset threshold value If the refrigeration capacity has not been increased due to the operating conditions during the low-temperature test period, it is determined that there is a margin of the current refrigeration capacity, and control for reducing the refrigeration capacity is performed .
Further, in order to solve the above problems, the environmental test apparatus of the present invention includes a test tank in which a test object is arranged, a low-temperature tank communicating with the test tank, and a gas in the low-temperature tank cooled to a pre-cooled state. A refrigerator, a low-temperature tank-side heater that heats gas in the low-temperature tank, a high-temperature tank that communicates with the test tank, a high-temperature tank-side heater that heats gas in the high-temperature tank to a preheated state, A control unit for controlling the driving of the refrigerator, wherein the control unit compares the measured test layer temperature with a set test tank temperature, and the measured test layer temperature is a predetermined value with respect to the set test tank temperature. If the temperature is higher than the temperature, control is performed to increase the refrigeration capacity, the refrigeration capacity increase completed flag is turned on, and when the low temperature test is completed, it is determined whether or not the utilization rate of the low temperature tank side heater has exceeded a threshold value. And when the utilization rate exceeds the threshold, When the refrigeration capacity increase flag is ON, the refrigeration capacity increase flag is turned OFF. On the other hand, when the refrigeration capacity increase flag is not set to ON, control is performed to decrease the refrigeration capacity. .

ADVANTAGE OF THE INVENTION According to the environmental test apparatus of this invention, even if the undershoot does not generate | occur | produce, the excess / deficiency of refrigerating capacity can be determined and the optimal refrigerating capacity can be obtained.
Problems, configurations, and effects other than those described above will be clarified by the following embodiments.

FIG. 1 is a schematic view of an environmental test device according to a first embodiment of the present invention. FIG. 2 is a block diagram of the environmental test apparatus according to the first embodiment. 3 is a flowchart of the environmental test apparatus according to the first embodiment. 3 is a time chart of the environmental test device of the first embodiment. 3 is a time chart of a test having a plurality of cycles in the environmental test device of the first embodiment. 3 is a time chart of a test having a plurality of cycles in the environmental test device of the first embodiment.

First embodiment

(overall structure)
Hereinafter, the configuration of the environmental test apparatus 1 according to the first embodiment of the present invention will be described with reference to the schematic diagram of the configuration shown in FIG. 1 and the block diagram shown in FIG.
In FIG. 1, an environmental test apparatus 1 is provided in a test tank 10 in which a device under test 70 is arranged, a low-temperature tank 20 communicating with the test tank 10 through ventilation ports 28 and 29, and the low-temperature tank 20. A high-temperature tank 30 communicating with the test tank 10 through ventilation holes 38 and 39; a high-temperature tank-side heater 36 provided in the high-temperature tank 30; And a tank blowing unit 37.

Further, as shown in FIG. 2, the control unit 40 includes the refrigerator 24, the low-temperature tank blowing unit 27, the high-temperature tank side heater 36, the high-temperature tank blowing unit 37, and the test tank temperature sensor 12, the low-temperature tank temperature sensor 22, and the high-temperature tank Each is connected to the temperature sensor 32.

The test tank 10 includes a test tank temperature sensor 12 that detects a temperature of a gas in the test tank 10. The test tank temperature sensor 12 detects temperature data of gas (atmosphere) in the test tank 10 and outputs the data to the control unit 40.
The low-temperature tank 20 includes a low-temperature tank temperature sensor 22. The low-temperature tank temperature sensor 22 detects the temperature of the gas in the low-temperature tank 20 and outputs temperature data of the detected gas to the control unit 40.

In the low-temperature bath 20, a low-temperature bath-side heater 26 as an overheat source is provided together with the refrigerator 24. The refrigerator 24 is started up together with the low-temperature tank side heater 26 or independently, and is alternately switched so as to be in an operating state and a stopped state. The refrigerator 24 is started up together with the low-temperature tank side heater 26 or independently, and is alternately switched so as to be in an operation state and a stop state.

The low-temperature tank-side heater 26 corrects the refrigerating capacity of the refrigerator 24 and adjusts the temperature of the gas in the low-temperature tank 20 so that the measured temperature inside the test tank 10 is the low-temperature test temperature (BL). ) Is configured to be adjusted together with the refrigerator 24 so as to coincide with ()).
The refrigerator 24 of the first embodiment is started up together with the low-temperature tank side heater 26 or independently, and is alternately switched to an operating state and a stopped state. And the control part 40 switches the said operation mode among several operation modes based on the utilization rate of the said low temperature tank side heater.

The refrigerator 24 of the first embodiment has three operation modes. For example, the reference refrigeration capacity is different for each of the high load mode, the normal mode, and the energy saving (low load) mode. The operation mode can be set in advance using the input unit 41 of the control unit 40.
That is, the drive of the refrigerator 24 is controlled by the control unit 40 to cool the gas in the low-temperature tank 20 in the operating state to a pre-cooling temperature TL which is a temperature necessary for pre-cooling, and a low-temperature test is performed. In this state, the test chamber temperature (A) is kept at the low temperature test chamber temperature (BL).

The low-temperature tank blower 27 includes a low-temperature tank-side blower 52, a low-temperature side opening / closing damper 50 that can open and close the ventilation ports 28 and 29, and a low-temperature side suction opening / closing damper 51. The low-temperature side opening / closing damper 50 and low-temperature side suction opening / closing damper 51 of this embodiment have actuators 54 and 55 that are operated by compressed air or an electric motor. The actuators 54 and 55 open / close the low-temperature side opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 in response to a control signal from the control unit 40.

The control unit 40 opens the low-temperature side opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 while driving the low-temperature tank side blower 52, and arranges them in the test tank 10 through the ventilation ports 28 and 29. The gas in the pre-cooled low-temperature tank 20 is sent around the tested object 70.
Further, the control unit 40 circulates the gas in the low-temperature tank 20 in the pre-cooled state by closing the low-temperature-side blowout opening / closing damper 50 and the low-temperature-side suction opening / closing damper 51 while driving the low-temperature side fan 52. be able to.

Further, the low-temperature side opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 may be opened and closed in synchronization with the drive control of the low-temperature tank side blower 52. For example, the low-temperature side blower opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 are opened by driving the low-temperature side fan 52, and the driving of the low-temperature side blower 52 is stopped, so that the low-temperature side opening / closing damper 50, low-temperature side The suction opening / closing damper 51 may be closed to shut off the gas flow between the test tank 10 and the low-temperature tank 20.
In this case, the actuators 54 and 55 of the low-temperature side opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 may be further simplified or omitted in both mechanism and operation.

The high-temperature-bath-side heater 36 provided in the high-temperature tub 30 is controlled by the control unit 40 to alternately switch between an operating state and a stopped state. In the operation state, the gas in the high-temperature tank 30 can be heated to be in a preheating state.

The high-temperature-chamber blowing unit 37 includes a high-temperature-chamber-side blower 62, a high-temperature-side blowout opening / closing damper 60 and a high-temperature-side suction opening / closing damper 61 that can open and close the ventilation ports 38 and 39, and an actuator operated by compressed air or an electric motor. 64, 65.

Further, the control unit 40 opens the high-temperature side blowout opening / closing damper 60 and the high-temperature side suction opening / closing damper 61 while driving the high-temperature chamber side blower 62, and enters the test chamber 10 through the ventilation holes 38 and 39. The gas in the preheated high-temperature chamber 30 is sent around the placed test object 70.

Further, the control section 40 circulates the gas in the high-temperature tank 30 in the preheated state by closing the high-temperature side opening / closing damper 60 and the high-temperature suction opening / closing damper 61 while the high-temperature tank side blower 62 is being driven. be able to.

Then, the high-temperature side opening / closing damper 60 and the high-temperature side suction opening / closing damper 61 may be opened and closed in synchronization with the drive control of the high-temperature tank side blower 62. For example, the high-temperature side blower opening / closing damper 60 and the high-temperature side suction opening / closing damper 61 are opened by driving the high-temperature side fan 62, and the driving of the high-temperature side blower 62 is stopped. The suction opening / closing damper 61 may be closed to shut off the gas flow between the test tank 10 and the high-temperature tank 30.
In this case, the actuators 64 and 65 of the high-temperature side blowing opening / closing damper 60 and the high-temperature side suction opening / closing damper 61 may be further simplified or omitted in both mechanism and operation.

The control unit 40 alternately switches the operation state and the stop state of the low-temperature tank-side blower 52 and the high-temperature tank-side blower 62. Thus, based on the data detected by the test tank temperature sensor 12, the low-temperature tank temperature sensor 22, and the high-temperature tank temperature sensor 32, the refrigerator 24, the low-temperature tank side heater 26, and the low-temperature tank blower 27 are mainly used. The low-temperature test using the pre-cooled state and the high-temperature test mainly using the pre-heated state mainly using the high-temperature tank side heater 36 and the high-temperature tank air blower 37 can be performed alternately.

(Configuration of the control unit 40)
The control unit 40 according to the first embodiment illustrated in FIG. 2 includes an input unit 41, a calculation unit 42, a timer unit 44, a storage unit 46, and an output unit 48, and includes an application developed on the RAM. FIG. 2 is a block diagram showing functions realized by the program.

The input unit 41 receives temperature data detected by the test tank temperature sensor 12, the low temperature tank temperature sensor 22, and the high temperature tank temperature sensor 32. In addition to this, the input unit 41 is connected to an external input device such as a keyboard or a communication device (not shown), for example, data on test status and test results, the number of repetitions of high and low temperature tests, or the two-zone or three-zone test. The configuration may be such that data of test conditions such as switching and high and low temperature setting test temperatures are input.

The calculation unit 42 includes hardware as a general computer such as a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and an HDD (Hard Disk Drive). , An OS (Operating System), application programs, various data, and the like. The OS and the application programs are loaded on the RAM, executed by the CPU, and perform arithmetic processing according to the data input to the input unit 41 together with the timer unit 44 and the storage unit 46.

The calculation unit 42 of this embodiment performs a process of comparing the set test tank temperature and the measured test tank temperature to increase or decrease the refrigerating capacity. When the control unit 42 performs control to increase the refrigerating capacity of the refrigerator 24, it sets the refrigerating capacity increased flag to “ON”, and when not performing control to increase the refrigerating capacity of the refrigerator 24, A process of turning off the capacity increase flag is performed. Thus, the arithmetic unit 42 is configured to prioritize the condition for increasing the refrigeration capacity and reflect the adjustment of the refrigeration capacity in the test of the current cycle in the test of the next cycle.

The timer unit 44 measures the control time based on the test condition data, or measures an elapsed time from when a desired temperature is reached. The timer unit 44 of this embodiment is configured to count the remaining time of the low temperature test.

  The storage unit 46 stores the test condition data or temporarily stores the temperature data detected by the test tank temperature sensor 12, the low-temperature tank temperature sensor 22, and the high-temperature tank temperature sensor 32, and reads and writes by the arithmetic unit 42. Memory or buffer (both not shown).

In the storage section 46 of the first embodiment, a threshold value A (for example, A = about 30%) of the utilization rate R of the low-temperature tank side heater 26 is stored. Further, the storage 46 stores in advance a set test tank temperature to be compared with the measured test tank temperature.

The output unit 48 outputs the result of the arithmetic processing as a control signal to the refrigerator 24, the low-temperature tank-side heater 26, the low-temperature tank-side blower 52, the high-temperature tank-side heater 36, and the high-temperature tank-side blower 62 connected to the control unit 40. I do. The refrigerator 24, the low-temperature tank-side heater 26, the low-temperature tank-side blower 52, the high-temperature tank-side heater 36, and the high-temperature tank-side blower 62 are each configured to be driven or stopped in accordance with a control signal. .

As described above, the control unit 40 outputs the control signal to thereby control the gas in the low-temperature tank 20 pre-cooled by the low-temperature tank blowing unit 27 and the high-temperature tank blowing unit 37 or the high-temperature tank 30 in the pre-heated state. Is sent around the DUT 70 placed in the test tank 10 and rapidly cooled or heated. The control unit 40 can continuously repeat one temperature cycle in which the high temperature test and the low temperature test are alternately repeated as one temperature cycle.

In the first embodiment, the low-temperature side opening and closing is controlled by controlling the driving of the actuators 54, 55, 64, and 65 in accordance with the control signal output from the output unit 48 of the control unit 40 shown in FIG. The damper 50, the high-temperature side opening / closing damper 60, the low-temperature side suction opening / closing damper 51, and the high-temperature side suction opening / closing damper 61 are opened and closed. However, for example, the gas in the low-temperature tank 20 that has been pre-cooled by the low-temperature tank blowing section 27 and the high-temperature tank blowing section 37 or the gas in the high-temperature tank 30 that has been preheated has been disposed in the test tank 10. What is necessary is to send around the DUT 70 and repeat the high-temperature test and the low-temperature test as one temperature cycle as one temperature cycle. The opening / closing using the actuators 54, 55, 64, and 65 as in the configuration of the low-temperature tank blowing section 27 and the high-temperature tank blowing section 37 in one embodiment is not necessary.

The control unit 40 also controls the refrigerator 24, the low-temperature tank-side heater 26, the low-temperature tank-side blower 52 based on the temperature data detected by the test tank temperature sensor 12, the low-temperature tank temperature sensor 22, and the high-temperature tank temperature sensor 32. If the control unit outputs the control signal from the output unit 48 to the high temperature tank side heater 36 and the high temperature tank side blower 62, these controls can be realized by dedicated hardware (such as an electronic circuit). It can also be realized by software.

The control unit 40 closes the low-temperature side opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 when the current high-temperature test starts after the previous low-temperature test ends. As a result, when performing the high-temperature test in the same temperature cycle as the current low-temperature test, the ventilation ports 28 and 29 between the low-temperature tank 20 and the test tank 10 are closed and shut off. Therefore, the gas in the low-temperature tank 20 can be efficiently precooled by starting the refrigerator 24.

When the low-temperature test is being performed, the control unit 40 controls the temperature of the refrigerator 24 and the low-temperature tank side heater so that the inside of the test tank 10 is maintained at a constant set low-temperature test temperature (BL). 26 (see FIG. 4).
However, when the capacity of the refrigerator 24 is excessive with respect to the test state, the temperature falls below the set low temperature test temperature (BL) so that the test chamber temperature (A) does not undershoot (AL) as shown by a virtual line. In addition, the control unit 40 performs control to increase the output (hereinafter, also referred to as a utilization rate) of the low-temperature-bath-side heater 26. For this reason, the power consumption increases as the utilization rate R of the low-temperature tank side heater 26 increases.
If the capacity of the refrigerator 24 is insufficient for the test state, the temperature of the test tank 10 cannot be lowered to the set low-temperature test temperature (BL). For this reason, it takes time until a stable low-temperature test temperature (BL) is obtained (time b to time c1), and there is a possibility that the test accuracy may decrease.

If the control unit 40 determines that the capacity of the refrigerator 24 is excessively large with respect to the test state, the control unit 40 lowers the refrigerating capacity of the refrigerator 24 so that the utilization rate R of the low-temperature tank side heater 26 does not increase. There is a need. Further, when it is determined that the capacity of the refrigerator 24 is insufficient for the test state, it is preferable to increase the refrigerating capacity promptly to reach the set low temperature test temperature (BL).

Therefore, the environmental test apparatus 1 according to the first embodiment monitors the utilization rate R of the low-temperature tank-side heater 26 during the test, thereby grasping the current margin of the refrigerating capacity. When the tolerance is large, control is performed so that the refrigeration capacity is reduced. Conversely, when there is no tolerance or the test accuracy is deteriorated, control is performed to change to the operating condition where the refrigeration capacity is increased. This is to obtain the optimum refrigeration capacity and drive of the low-temperature tank side heater 26.

For this reason, the control unit 40 of the environmental test apparatus 1 of the first embodiment changes the operating conditions to increase or decrease the refrigerating capacity of the refrigerator 24, thereby selecting the optimal operating conditions according to the refrigerating capacity margin. it can. Therefore, it is possible to maintain both the test accuracy and reduce the power consumption without being affected by the test object and surrounding conditions.

The flowchart shown in FIG. 3 mainly shows the processing order of the low-temperature test among the temperature cycle tests in which the low-temperature test and the high-temperature test are alternately performed as one cycle.
When the low-temperature test is started, in step S1, the control unit 40 determines whether there is a low-temperature test remaining time. If there is a low-temperature test remaining time (YES in step S1), the process proceeds to the next step S2 to monitor whether the refrigerating capacity of the refrigerator 24 is insufficient.
Here, the stable state indicates a state in which the temperature of the test tank is within a predetermined temperature a above and below the set test tank temperature.

In step S2, the control unit 40 determines whether or not the test tank temperature is in a stable state.
If it is determined in step S2 that the test tank temperature is in a stable state (YES in step S2), the process proceeds to the next step S3, and if it is determined that the temperature is not in a stable state (NO in step S2), the process proceeds to step S3. Returning to S1, the process is repeated.

In step S3, the measured test tank temperature measured by the test tank temperature sensor 12 is compared with a preset test tank temperature. If the measurement test tank temperature is higher than the set test tank temperature by a predetermined temperature a (here, + 2 ° C.) or more, the measurement test tank temperature is higher than the target value, and the refrigeration capacity of the refrigerator 24 is insufficient. A determination is made (YES in step S3), and the process proceeds to step S4. If it is determined in step S3 that the current measured test tank temperature is less than the predetermined temperature a with respect to the preset fixed test tank temperature, the process returns to step S1 and repeats the processing until the low temperature test is completed.

In step S4, the control unit 40 increases the refrigerating capacity of the refrigerator 24. Then, in step S5, the control unit 40 sets the refrigeration capacity increased flag to ON. By setting the refrigerating capacity increased flag to ON, if the increasing condition for increasing the refrigerating capacity and the decreasing condition for decreasing the refrigerating capacity are simultaneously satisfied, the control unit 40 can prioritize the increasing condition.

In step S4, although the test tank temperature is in a stable state, there is no allowance. If the refrigeration capacity increased flag is set to ON, the process returns to step S1, and the control unit 40 returns to step S1 until the low temperature test ends. , And repeat the process.

As described above, when the tolerance of the refrigeration capacity during the test is large, the control unit 40 controls the refrigerator 24 so that the refrigeration capacity decreases. In the environmental test apparatus 1 according to the first embodiment, the refrigeration capacity is reduced only at the time when the low-temperature test in one temperature cycle ends (step S1). When the low-temperature test remaining time runs out (NO in step S1) and determines that the low-temperature test has been completed, control unit 40 proceeds to step S6.

In step S6, it is determined whether or not the utilization rate R of the low-temperature tank side heater 26 has exceeded a predetermined threshold value A (here, about 30%). Here, the utilization rate R is set to a value having a sufficient margin so that the required refrigerating capacity can be secured even when the refrigerating capacity of the refrigerator 24 is reduced. Other values may be used as long as they have a sufficient margin. For example, a different value may be adopted for each of the operation modes such as energy saving, two zones, and three zones. If the optimum value differs depending on the refrigerating capacity of the refrigerator 24 or the device configuration, it may be appropriately selected.

Steps S6 to S10 show processing for changing the refrigerating capacity according to the refrigerating capacity of the refrigerator 24. At this time, by determining whether or not the utilization rate R of the low-temperature tank-side heater exceeds the threshold value A, the refrigerator 24 and the low-temperature tank-side heater 26 are simultaneously driven, so-called co-heating occurs. It is monitored whether power consumption is wasted.

If the utilization rate R of the low-temperature-bath-side heater 26 exceeds the preset threshold value A in step S6 (YES in step S6), the control unit 40 proceeds to step S7 and proceeds to step S7. In the cycle, it is determined whether to change the refrigeration capacity.
In step S7, if the refrigeration capacity increase flag is set to ON, the control unit 40 proceeds to step S8, and turns off the refrigeration capacity increase flag in step S8.

As described above, when the refrigeration capacity increase flag is not set to ON in step S7, or when the utilization rate R of the low-temperature tank side heater 26 is less than the preset threshold A in step S6. (NO in Step S6), the refrigeration capacity increase completed flag is turned off in Step S8. At this time, the refrigerating capacity is not immediately changed.

The control unit 40 of the first embodiment monitors the usage rate R of the low-temperature tank side heater 26 and increases the power consumption (the usage rate R is high) even under the test condition in which the undershoot does not occur. Determines that the refrigerating capacity is excessive and grasps the current margin of the refrigerating capacity. If the allowance is large, control is performed so that the refrigeration capacity is reduced (step S9). Conversely, if there is no allowance or the test accuracy is deteriorated, control is performed to change to an operating condition where the refrigeration capacity is increased. (Step S4).

In step S7, when it is determined that the refrigerating capacity increased flag is set to ON (YES in step S7), control unit 40 proceeds to step S8, and proceeds to step S8. Then, the refrigerating capacity increased flag is turned OFF to end the low temperature test.

If it is determined in step S7 that the refrigerating capacity increased flag has not been set to ON (NO in step S7), the control unit 40 determines that the utilization rate R of the low-temperature tank side heater 26 immediately before the end of the low-temperature test. It is determined that there is sufficient margin, and the process proceeds to step S9.
In step S9, the control unit 40 lowers the refrigerating capacity of the refrigerator 24, terminates the low-temperature test, and performs the high-temperature test of the current temperature cycle. After the end of the high-temperature test, the low-temperature test of the next temperature cycle is started. In the low-temperature test of the next temperature cycle, the refrigerating capacity of the refrigerator 24 has been adjusted by this low-temperature test. Therefore, it is possible to carry out the test so that the test chamber temperature (A) approaches the target low temperature test temperature (BL) as early as possible so as not to undershoot the test chamber temperature under more appropriate operating conditions and stabilizes. is there.

As described above, the environmental test apparatus 1 of this embodiment monitors the utilization rate R of the low-temperature tank-side heater 26 during the low-temperature test, thereby grasping the current refrigerating capacity of the refrigerator 24. I have. Then, the control unit 40 lowers the refrigerating capacity of the refrigerator 24 on the assumption that the state of the large margin is a state where the utilization rate R (power consumption increases) of the low-temperature tank side heater 26 is high. Change operating conditions. Conversely, even when there is no margin or the test accuracy is deteriorated, the control unit 40 gives priority to the condition for increasing the refrigerating capacity in step S4 and increases the refrigerating capacity in step S5. Change to operating conditions.

In addition, the low-temperature test and the high-temperature test in which the operation performances of the refrigerator 24 are different are alternately performed. A high temperature test may be performed.

Further, when detecting a temperature higher than the target temperature in the low-temperature test state, the control unit 40 changes the capacity of the refrigerator 24 to increase the refrigeration capacity. For this reason, it can be implemented under more appropriate operating conditions. When detecting a temperature higher than the target temperature by a predetermined value or more in the low-temperature test state, the control unit 40 switches the operation mode to a direction in which the operation capacity of the refrigerator 24 increases. For this reason, it can be implemented under more appropriate operating conditions.

Then, in the same test cycle in which the temperature is higher than the target temperature by a predetermined value or more in the low-temperature test state, the control unit 40 determines that the utilization rate R of the low-temperature tank side heater 26 satisfies the condition for changing the capacity of the refrigerator 24. Also, the operation capacity of the refrigerator 24 is not changed. Thus, by giving priority to the condition for increasing the refrigeration capacity, the adjustment of the refrigeration capacity in the test of the current cycle can be reflected in the test of the next cycle. Therefore, a more optimal operating condition can be selected according to the margin of the refrigeration capacity without being affected by the test object and the surrounding conditions, and both the maintenance of the test accuracy and the reduction of the power consumption can be achieved.

FIG. 4 is a time chart for explaining the operation in the case where there is no margin and the refrigeration capacity is insufficient, for example.
At time a, when the low-temperature test starts (the high-temperature test ends), the pre-cooled low-temperature tank temperature (B) rises by communicating with the test tank 10 in which the high-temperature test has been performed. And the test chamber temperature (A) starts to decrease.

At time b, when the test chamber temperature (A) reaches the set low temperature test temperature (BL), the temperature of the refrigerator 24 does not follow the low temperature chamber temperature (B) and is in a lower temperature state. There is a possibility that the temperature falls below the test temperature (BL) and undershoots like the test chamber temperature (AL) indicated by a virtual line.

For this reason, the control unit 40 increases the utilization rate R of the low-temperature tank side heater 26 in addition to the driving of the refrigerator 24 from the time b, and sets the test tank temperature (A) to a constant set low-temperature test temperature (BL). , And the low-temperature tank side heater 26 is braked to lower the control so as not to undershoot (AL).
If the refrigerating capacity of the refrigerator 24 is excessive with respect to the test conditions, a large output of the low-temperature tank side heater 26 used for temperature adjustment is also required, but the use of the low-temperature tank side heater 26 in the next temperature cycle is required. In order not to increase the rate R, the refrigerating capacity of the refrigerator 24 is reduced.

On the other hand, when the refrigerating capacity of the refrigerator 24 is insufficient, the temperature rises and falls again as shown in the chart of the test tank temperature (A) in the section (b-c1) in FIG. The adjustment time (c1-b) is required until the stable state is reached. As the proportion of the adjustment time (c1-b) in the low-temperature operation period (d1-b) shown in FIG. 4 increases, the test chamber temperature (A) is stabilized at a constant set low-temperature test temperature (BL). Since the time (d1-c1) is relatively reduced, the test accuracy is reduced.

The environmental test apparatus 1 according to the present embodiment solves the conflicting problem of suppressing the increase in power consumption while increasing the utilization rate R of the low-temperature tank side heater 26 so as to adapt to the refrigerating capacity of the refrigerator 24. The present invention provides an environmental test apparatus capable of obtaining an optimum refrigeration capacity by enabling determination of excess or deficiency of the refrigeration capacity even under conditions in which an undershoot does not occur.

FIG. 5 is a time chart for explaining the timing of increasing the refrigerating capacity in the environmental test apparatus of the first embodiment.
For this reason, when the low-temperature test of the nth cycle starts at time a, the test chamber temperature (A) starts to decrease, and the low-temperature chamber side heater 26 is driven together with the driving of the refrigerator 24. . From time b when the test tank temperature (A) reaches the set low-temperature test temperature (BL), the utilization rate R of the low-temperature tank side heater 26 becomes maximum so that the test tank temperature (A) does not undershoot.

At this time, since the refrigerating capacity of the refrigerator 24 is kept constant, the test tank temperature (A) starts to rise with the passage of time and starts to rise, and separates from the set low temperature test temperature (BL). There are cases.
For example, in the first embodiment, during the current temperature cycle (n-th cycle in FIG. 5), at the time point cc when the test chamber temperature (A) becomes higher than the set low-temperature test temperature (BL) by a predetermined temperature a or more, It is determined that the test tank temperature (A) is higher than the target test tank temperature value and the refrigerating capacity of the refrigerator 24 is insufficient, and the driving force of the compressor of the refrigerator 24 is increased to increase the refrigerating capacity. The increased refrigerating capacity of the refrigerator 24 is continuously increased (MAX) even during the low-temperature test performed after the next temperature cycle (n + 1th cycle).

For this reason, in the low temperature test of the next temperature cycle, the undershoot and the test chamber temperature (A) at time b2 when the test chamber temperature (A) reaches the set low temperature test temperature (BL) are higher than the set test chamber temperature (BL). Is suppressed.

In the next temperature cycle (the (n + 1) th cycle) of the first embodiment, as shown in FIG. 5, at time b2 during the low temperature test, the shortage of the refrigerating capacity of the refrigerator 24 has been eliminated. The state where the test tank temperature (A) is not separated from the set low temperature test temperature (BL) is shown. At this time, the refrigerating capacity of the refrigerator 24 and the heating capacity of the low temperature tank side heater 26 are balanced, and no undershoot occurs. In addition, it is possible to determine whether the refrigerating capacity is excessive or insufficient even under the condition in which the undershoot does not occur, thereby obtaining the optimal refrigerating capacity.

FIG. 6 is a time chart for explaining the timing at which the refrigeration capacity is reduced.
After the precooling by the driving of the refrigerator 24, when the n-th cycle of the low-temperature test is started at the time a, the test tank temperature (A) decreases and the low-temperature tank-side heater 26 is driven. At time b3, after the test chamber temperature (A) reaches the set low-temperature test temperature (BL), if the test chamber temperature (A) does not separate from the set low-temperature test temperature (BL), the refrigerator 24 The refrigeration capacity is reduced assuming that there is a "margin" in which the refrigeration capacity is satisfied.

In the environmental test apparatus 1 of the first embodiment, the refrigeration capacity of the refrigerator 24 is reduced at the time cd when the high temperature test is started. At time cd, the control unit 40 temporarily lowers the output to the utilization rate R = 0 of the low-temperature tank side heater 26.

At time a3, when the low-temperature test of the (n + 1) th cycle (time a3 to time d3) is started, the refrigerating capacity of the refrigerator 24 is controlled by the control unit 40 in advance to decrease during the previous n cycles. I have. For this reason, even if the utilization rate R of the low-temperature tank side heater 26 does not reach the maximum value MAX at the time b3, the test tank temperature (A) can reach the set low-temperature test temperature (BL).

In addition, during the low-temperature test of the (n + 1) th cycle, particularly during the low-temperature driving from time b3 to time d3, the utilization rate R of the low-temperature-bath-side heater 26 is maintained in a state lower than the maximum value MAX.
As described above, even if the refrigerating capacity of the refrigerator 24 and the drive of the low-temperature tank side heater 26 are reduced as compared with during the previous low-temperature test in the nth cycle, the desired time (time b3 to time d3) is obtained. The test tank temperature (A) can be set to the set low-temperature test temperature (BL), and the amount of separation of the test tank temperature (A) from the set low-temperature test temperature (BL) can be reduced.

As described above, according to the environmental test apparatus 1 of the present embodiment, the refrigeration capacity is adjusted according to the margin of the refrigeration capacity of the refrigerator 24 without being affected by the test object and the surrounding conditions, and the optimum operation condition is adjusted. Can be selected. For this reason, by suppressing an increase in the utilization rate R of the low-temperature-bath-side heater 26 while preventing undershoot, it is possible to maintain both test accuracy and reduce power consumption.
Further, the environmental test apparatus 1 according to the first embodiment can be executed according to a plurality of operation modes such as a high load mode, a normal mode, and an energy saving (low load) mode.

[Modification]
The present invention is not limited to the embodiments described above, and various modifications are possible. The above-described embodiments are exemplarily illustrated for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described above. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment. Further, a part of the configuration of each embodiment can be deleted, or another configuration can be added or replaced. Possible modifications to the above embodiment are, for example, as follows.

In each of the above embodiments, in the configuration of the environmental test apparatus 1 shown in FIG. 1, the low-temperature side opening / closing damper 50 and the low-temperature side suction opening / closing damper 51 are opened and closed in synchronization with the drive control of the low-temperature tank side blower 52. However, any configuration may be used as long as the flow of the gas between the test tank 10 and the low-temperature tank 20 (or the high-temperature tank 30) is cut off and the flow of the gas is cut off with the driving of the low-temperature tank-side blower 52 and the stop of the driving. May be the blower.
Although the processing illustrated in FIG. 3 has been described as software processing using a program executed by the control unit 40 illustrated in FIG. 2 in the above-described embodiment, part or all of the processing may be performed using an ASIC (Application Specific Application). The processing may be replaced by hardware processing using an integrated circuit (IC for a specific application) or an FPGA (field-programmable gate array).

[Summary of composition and effects]
As described above, according to the environmental test apparatus 1 in the embodiment, the control unit 40 changes the operating conditions so that the refrigerating capacity of the refrigerator 24 decreases when the margin is large. On the other hand, when there is no margin or the test accuracy is deteriorated, the control unit 40 changes the operating condition so that the refrigeration capacity is increased. For this reason, the optimum operating conditions can be selected according to the refrigeration capacity without being affected by the test object and the surrounding conditions. Therefore, it is possible to maintain both test accuracy and reduce power consumption.

For example, a low-temperature test and a high-temperature test are alternately performed to perform a low-temperature test and a high-temperature test according to the utilization rate R of the low-temperature tank side heater 26 under the operating conditions of the low-temperature test among the two-mode tests that constitute one cycle. Can be.

When detecting a temperature higher than the target temperature in the low-temperature test state, the control unit 40 changes the capacity of the refrigerator 24 to increase the refrigeration capacity. For this reason, it can be implemented under more appropriate operating conditions.
When detecting a temperature higher than the target temperature by a predetermined value or more in the low-temperature test state, the control unit 40 switches the operation mode to a direction in which the operation capacity of the refrigerator 24 increases. For this reason, it can be implemented under more appropriate operating conditions.

Then, in the same test cycle in which the control unit 40 detects a temperature higher than the target temperature by a predetermined value or more in the low-temperature test state, the utilization rate R of the low-temperature tank side heater 26 satisfies the condition for changing the capacity of the refrigerator 24. Also, the operation capacity of the refrigerator 24 is not changed. Thus, by giving priority to the condition for increasing the refrigeration capacity, the adjustment of the refrigeration capacity in the test of the current cycle can be reflected in the test of the next cycle. Therefore, a more optimal operating condition can be selected according to the margin of the refrigeration capacity without being affected by the test object and the surrounding conditions, and both the maintenance of the test accuracy and the reduction of the power consumption can be achieved.

DESCRIPTION OF SYMBOLS 1 Environmental test apparatus 10 Test tank 12 Test tank temperature sensor 20 Low-temperature tank 22 Low-temperature tank temperature sensor 24 Refrigerator 26 Low-temperature tank side heater 27 Low-temperature tank blowing unit 28, 38 Vent 30 High-temperature tank 32 High-temperature tank temperature sensor 36 High-temperature tank side Heater 37 High-temperature tank blowing unit 40 Control unit 41 Input unit 42 Operation unit 44 Timer unit 46 Storage unit 48 Output unit 50 Low-temperature side opening / closing damper 51 Low-temperature side suction opening / closing damper 52 Low-temperature side blowing fan 54, 64 Actuator 60 High-temperature side opening / closing Damper 61 High temperature side suction opening / closing damper 62 High temperature tank side blower 70 DUT

Claims (6)

A test tank for placing a test object,
A low-temperature tank communicating with the test tank;
A refrigerator that cools the gas in the low-temperature tank to a pre-cooled state,
A low-temperature-chamber-side heater for heating gas in the low-temperature chamber ;
A high-temperature tank communicating with the test tank;
A high-temperature tank-side heater that heats the gas in the high-temperature tank to be in a preheated state;
A control unit for controlling operating conditions of the refrigerator,
The control unit includes:
The usage rate of the low-temperature tank-side heater is monitored, and the usage rate of the low-temperature tank-side heater exceeds the preset threshold value, and is frozen during the low-temperature test period according to the operating conditions. If the capacity is not increased, the environmental test apparatus determines that there is a margin of the current refrigeration capacity and performs control to decrease the refrigeration capacity . A test tank for placing a test object,
A low-temperature tank communicating with the test tank;
A refrigerator that cools the gas in the low-temperature tank to a pre-cooled state,
A low-temperature tank-side heater for heating gas in the low-temperature tank ;
A high-temperature tank communicating with the test tank;
A high-temperature-chamber-side heater that heats the gas in the high-temperature chamber to a preheated state,
A control unit for controlling the driving of the refrigerator,
The control unit includes:
The measured test layer temperature is compared with the set test tank temperature, and if the measured test layer temperature is higher than the set test tank temperature by a predetermined temperature or more, control is performed to increase the refrigerating capacity, and the refrigerating capacity is increased. When the low temperature test is completed by turning on the completed flag,
It is determined whether or not the utilization rate of the low-temperature tank-side heater has exceeded a threshold value. If the utilization rate has exceeded the threshold value and the refrigeration capacity increase flag is ON, the An environmental test apparatus that turns off a refrigeration capacity increase flag, and performs control to decrease the refrigeration capacity when the refrigeration capacity increase flag is not set to ON . 3. The environmental test apparatus according to claim 1, wherein the control unit has a plurality of operation modes in which the operation capabilities of the refrigerator are different, and switches the operation mode based on a utilization rate of the low-temperature tank-side heater. 4. . Wherein, in a low temperature test condition, if it detects a higher temperature than the target temperature, after changing the capacity of the refrigerator, based on the utilization of the heater, switching the operation mode, according to claim 3 An environmental test apparatus according to item 1. The control unit, in a low-temperature test state, when detecting a temperature higher than a target temperature by a predetermined value or more , after changing the operation mode so that the operation capability of the refrigerator becomes higher , based on the utilization rate of the heater. The environmental test apparatus according to claim 3 , wherein the operation mode is switched . In the same test cycle in which the control unit detects a temperature higher than the target temperature by a predetermined value or more in the low-temperature test state, even if the utilization rate of the low-temperature tank-side heater satisfies the condition for changing the capacity of the refrigerator, The environmental test apparatus according to claim 3, wherein the operation capacity of the refrigerator is not changed.

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