JPH0730987B2 - Frost adhesion determination device for thermal shock tester - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a frost adhesion determination device for a thermal shock tester for determining the amount of frost formed inside a cryogenic chamber in the thermal shock tester.

[Prior Art] In the conventional cooling device for the thermal shock tester, the low temperature tank is always cooled by the refrigerator, the temperature of the low temperature tank is detected by the temperature sensor, and the PID is determined based on the detected value and the set temperature.
(Proportional, integral, derivative) calculation is performed to calculate the control amount, and the temperature control heater provided in the low temperature tank is heated according to the control amount to bring the low temperature tank close to the set temperature. There is.

In such a cooling device, if frost adheres to the inside of the low temperature tank, the cooling capacity is deteriorated. Therefore, defrosting is performed when the amount of adhered frost reaches a certain level.

Conventionally, the time when this defrosting is performed is determined by the operator of the apparatus by visually observing the state of frost adhesion. In that case, it is good if the frost is visible, but if the frost is hidden and not visible, the operator should consider the operating time of the refrigerator and the ambient temperature, etc., and judge the defrosting by experience. I have to.

[Problems to be Solved by the Invention]

In the conventional thermal shock tester, it was solely the operator's judgment to decide whether or not to defrost. Therefore, the burden on the operator becomes large, further skill is required, and when the apparatus is operated without the operator, proper defrosting cannot be performed, which may hinder the operation. In addition, if defrosting is performed at regular intervals of use, the refrigerator has large individual differences and changes over time.Therefore, if the frost deposition rate is high, defrosting work will be delayed, and the cooling capacity will drop during that time. Wastes energy. Further, when the frost deposition rate is slow, the defrosting work is too fast, which wastes labor and time, and deteriorates the operating efficiency of the apparatus. Therefore, it is possible to automatically display the adhesion state of frost, but there is a problem such as not finding an appropriate method for quantifying the adhesion state of frost.

The present invention has been made to solve the above problems, and constantly monitors the temperature difference between the low temperature tank temperature and the regenerator temperature, and detects frost formation when the temperature difference exceeds a predetermined threshold value. An object of the present invention is to obtain a frost adhesion determination device for a deep impact tester that outputs a signal to notify the defrosting time.

[Means for Solving the Problems]

A frost adhesion determination device for a thermal shock tester according to the present invention has a temperature sensor for detecting a temperature in a low temperature tank, a temperature sensor for detecting a temperature of a regenerator, a temperature sensor for the low temperature tank, and a temperature sensor for a regenerator. And a calculation means for outputting a frost formation detection signal when the temperature difference between and exceeds a set value, and informs the operator of the time of defrosting.

[Action]

The calculating means in the present invention measures the temperature in the low temperature tank and the temperature of the regenerator surface by a temperature sensor and takes in the temperature, calculates the difference between the two measured temperatures, and outputs the difference when the temperature difference exceeds a predetermined set value. Output a frost detection signal.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings. First
FIG. 1 is a block diagram showing the configuration of a thermal shock tester according to the present invention. In the figure, 1 is a test tank for storing the DUT, 2 is a low temperature tank for cooling the test tank 1, a storage device 3, a refrigerator. 4 and heater 5. The storage device 3 has a function of storing cold air in the low temperature tank 2 which is cooled by the refrigerator 4. Reference numeral 6 is a high temperature tank for heating the test tank 1 and is provided with a heater 7. 8 and 9 are opened when the test tank 1 is heated,
High temperature side dampers closed during cooling, 10, 11 are low temperature side dampers opened during cooling of the test tank 1 and closed during heating, 12
Reference numerals 15 to 15 denote temperature sensors provided at respective required locations, 16 a driving operation controller for controlling the high and low temperature side dampers 8 to 11, 17 a temperature controller for temperature controlling the high temperature tank 6 and the low temperature tank 2, and 18 a temperature controller. A computing means for performing PID computation control for controlling the thermal shock tester under optimum operating conditions, 19 is an operating device, and 20 is a display device.

Next, the operation will be described. The thermal shock tester shown in FIG. 1 has a three-tank structure in which a test tank 1 is arranged in the center and a high temperature tank 6 and a low temperature tank 2 are arranged on the left and right sides, for example, high temperature exposure → normal temperature exposure → low temperature exposure. → When performing a thermal shock test temperature cycle exposed to room temperature at a preset temperature and time, the high temperature dampers 8 and 9 or the low temperature dampers 10 and 11 are output by the valve opening command or valve closing command output from the operation controller 16.
The temperature environment in the test tank 1 is exchanged in a short time together with the control commands of the temperature controller 17 and the calculation means 18 to give a thermal shock to the DUT.

In the test, the low temperature tank 2 is equipped with a regenerator 3 in addition to the refrigerator 4 in order to efficiently switch the temperature in the test tank 1 to the low temperature environment. In the case of the above-described three-tank type regenerator 3, the test tank 1 communicates with the outside air during the room temperature exposure process, but the moisture contained in the outside air at that time enters the low temperature tank 2 through the test tank 1 and thus the regenerator 3 Frost occurs on the surface. This frost has the following adverse effects on the operation of the thermal shock tester.

FIG. 3 (a) shows changes in the temperature of each part in a normal thermal shock test, and FIGS. 3 (b) and (c) show the effect of frost formation during the temperature cycle of the two-zone test in a slightly exaggerated manner. Is. First, in FIG. 4A, when it is attempted to maintain the temperature of the test tank 1 indicated by the dotted line, the temperature inside the high temperature tank 6 and the low temperature tank 2 behaves as shown in the figure, and the influence of the followability is the test tank. It greatly changes depending on the relative relationship between the heat quantity of the DUT in 1 and the heat quantity of the high temperature and low temperature tanks themselves.

Particularly in the case of the low temperature test, the amount of heat for cooling depends on the amount of heat of the regenerator 3, so that frost formation as shown in FIG. If there is, the heat transfer efficiency of the regenerator 3 is drastically reduced, and the effect of frosting is visibly reduced.

The present invention was made in view of this point, and the temperature difference (Td) between the low temperature tank temperature (T _R ) and the regenerator temperature (T _C ) is monitored by the calculation means 18 to determine the regenerator 3 temperature. It automatically determines frost formation and outputs a frost formation detection signal.

Next, the detailed operation will be described with reference to the flowchart of FIG. First, the temperature sensor 14 detects the surface temperature (T _C ) of the regenerator 3, and the temperature sensor 15 detects the temperature inside the low temperature tank 2 (T _R ). Then, the temperature difference (Td) between them is calculated by the calculating means 18 (step ST1).
Next, it is determined whether or not the temperature difference (Td) is a preset value (threshold value), for example, 8 ° C. or higher (step ST2). If the result of the determination is YES, a frost detection signal is output to prompt the operator for the time of defrosting (step
ST3). Further, in the thermal shock test, high temperature air is suddenly sent to the low temperature tank 2 in a shock in the process of shifting from high temperature exposure or normal temperature exposure to low temperature exposure. At this time, regenerator 3
If there is frost on the surface, the temperature of the low temperature tank 2 and the regenerator 3
The difference with the temperature of will be extremely open. Therefore, the output difference between the temperature sensors of the low temperature tank 2 and the regenerator 3 becomes remarkable. Therefore, the calculation means 18 outputs the frost adhesion to the regenerator 3, that is, the frost detection signal more reliably.

〔The invention's effect〕

As described above, according to the present invention, the temperature sensor of the low temperature tank that detects the temperature in the low temperature tank, the temperature sensor of the regenerator that detects the temperature of the regenerator, and the measured values of both temperature sensors are taken in. Since the frost adhesion determination device of the thermal shock tester is configured by providing a calculation means that outputs a frost detection signal when the difference exceeds a predetermined value, the defrost timing can be accurately known, and the defrost work can be performed. There is an effect that the efficiency can be improved and the cooling efficiency of the low temperature tank can be significantly improved. Further, in the thermal shock test, high temperature air is suddenly blown to the low temperature tank 2 during the process of shifting from high temperature exposure or normal temperature exposure to low temperature exposure, so if frost is attached to the regenerator, the low temperature tank The difference between the temperature of the regenerator and the temperature of the regenerator is extremely large, so the output difference between the temperature sensors of the low temperature tank and the regenerator becomes remarkable, and it is possible to know more accurately the adhesion of frost to the regenerator. effective.

[Brief description of drawings]

FIG. 1 is a block diagram of a thermal shock test apparatus according to an embodiment of the present invention, FIG. 2 is a flow chart showing the operation sequence of the present invention, and FIGS. 3 (a) to 3 (c) are temperature cycles of a two-zone test. It is explanatory drawing which shows the temperature gradient of a regenerator by the figure and the presence or absence of frost formation. In the figure, 1 is a test tank, 2 is a low temperature tank, 3 is a regenerator, 4
Is a refrigerator, 5 is a heater, 6 is a high temperature tank, 7 is a heater, 8, 9, 1
Reference numerals 0, 11 are dampers, 12, 13, 14, 15 are temperature sensors, and 18 is a calculation means. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A test tank (1), a temperature sensor (13) for detecting the temperature of the test tank (1), a low temperature tank (2) for cooling the test tank (1), and a low temperature tank (13). 2) The low temperature tank (2) provided inside and cooled by a refrigerator (4)
A regenerator (3) for storing the cool air in the inside, a temperature sensor (14) for detecting the temperature of the regenerator (3), a temperature sensor (15) for detecting the temperature in the low temperature tank (2), and the low temperature A heater (5) provided in the tank (2) for defrosting the regenerator (3), a high temperature tank (6) for heating the test tank (1), and a heater (7) for heating the high temperature tank. ) And a temperature sensor (12) for detecting the temperature in the high temperature tank (6),
A low temperature side damper (10) (11) provided between the test tank (1) and the low temperature tank (2), which is opened when the test tank (1) is cooled and closed when heated. A high temperature side damper (8) (9) which is provided between the test tank (1) and the high temperature tank (6) and which is opened when the test tank (1) is heated and closed when cooled. And the above test tank (1)
However, in the process of repeatedly performing low temperature exposure, high temperature exposure, or normal temperature exposure, the output difference between the temperature sensors (14) and (15) of the regenerator (3) and the low temperature tank (2) is monitored, and this temperature difference is monitored. And a frost adhesion determination device for a thermal shock tester, which comprises a calculation means for outputting a frosting signal when exceeds a predetermined value.