JP2661405B2 - Air tank type thermal shock test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air tank type thermal shock test apparatus, and more particularly to the above-described air tank type thermal shock test apparatus which realizes low-temperature exposure control at low temperature.

[0002]

2. Description of the Related Art An air-bath type thermal shock test apparatus is an apparatus for testing the characteristics of electric and electronic parts against thermal shock.
The test is configured with a high-temperature chamber that generates high-temperature air and a low-temperature chamber that generates low-temperature air.The test is performed by exposing high-temperature air while circulating high-temperature air from the high-temperature chamber to the test chamber, and removing low-temperature air from the low-temperature chamber. This is performed by alternately repeating the low-temperature exposure performed while circulating in the test chamber.

At this time, the temperature of the high temperature exposure is, for example, 10
0 ° C., and the low-temperature exposure temperature is, for example, −50 ° C. By the way, when repeatedly exposing the high-temperature exposure and the low-temperature exposure at extremely different temperatures in this way, in order to improve the efficiency of the test, for example, when switching from the high-temperature exposure to the low-temperature exposure,
In the initial stage, it is necessary to send a large amount of cooling heat to the test chamber at a stretch, and rapidly cool the test chamber that was previously hot.

Therefore, as means for that purpose, conventionally, a regenerator is provided together with a cooler in a low-temperature chamber, and during the high-temperature exposure, the cooling heat of the cooler is stored in the regenerator. Heat was delivered to the test chamber along with the cooling heat generated by the cooler.

[0005] However, in this case, the regenerator has a limited regenerative capacity. Even if the regenerator cools the heat at first and contributes to the cooling of the test chamber, the test chamber is kept at the required set low-temperature exposure temperature. By then, all of the regenerative cooling heat is generally exhausted, and thereafter, the load becomes a reverse load to the cooling of the test chamber, which in turn causes a delay in cooling the test chamber to the set temperature. Therefore, the applicant has
After examining the above-mentioned problems, as a result, when the regenerator has finished radiating the regenerative cooling heat, or just before the end of the heat radiation, a means for avoiding the regenerator from the low-temperature airflow circulating between the test chamber and the low-temperature chamber is provided. And found that it was effective to provide it in a low-temperature room, and proposed it earlier. (Japanese Patent Application No. 2
As a specific example of this avoiding means, a regenerator damper for opening and closing the air inflow of the regenerator is mainly applied, and when the regenerator damper operates to close the regenerator inflow side, the test chamber is closed. The low-temperature air returned to the low-temperature room,
The airflow that flows from the cooler through the cooler to the cooler is switched to the airflow that returns to the cooler by bypassing the cooler. As a result, the reverse load as described above until the conventional low-temperature exposure set temperature is reached is eliminated, and when switching from the high-temperature exposure, the low-temperature exposure set temperature can be reached in a very short time. Efficiency was achieved.

[0006] However, with respect to low-temperature exposure, another problem arises as to how to maintain and control the temperature in the test chamber which has reached the set temperature.
Even in the thermal shock test apparatus proposed earlier by the applicant, even if the test chamber is efficiently cooled to the set temperature in a short time by using the avoiding means, if the test chamber is left as it is, then the test chamber is While the temperature is reduced by the action of the cooler, it leads to a situation where a normal low temperature exposure test cannot be performed. By the way, conventionally, various means have been proposed for the low-temperature exposure setting temperature holding control means, for example, by means of a reverse load heater, by controlling the capacity of a refrigerator attached to a cooler, or by Japanese Patent Application Laid-Open No. Sho 62-1987. 125
As described in Japanese Patent Publication No. 233, there is a method in which the evaporating temperature of a cooler is controlled by a hot gas bypass of a refrigerator to maintain a set temperature. Therefore, even in the thermal shock test apparatus proposed by the present applicant, in order to solve the above-mentioned problem, it is necessary to provide one of these temperature holding control means.

[0007]

However, each of the set temperature holding means mentioned above, for example, by means of a capacity control of a reverse load heater or a refrigerator, is preferable because it is simple and has an energy saving effect. If there is an inconvenience that cannot be controlled depending on the set temperature, or particularly in the case of capacity control, there is a limit to raising the temperature of the cooling heat generated by the cooler even if the operating frequency of the refrigerator is reduced, and the set temperature is -30. When the temperature is relatively high, such as ℃, there is a drawback that control is difficult.

[0008] On the other hand, the hot gas bypass
It is possible to control the holding at any set temperature, but it is necessary to provide a pipe for hot gas bypass for the cooler, and to install a solenoid valve that allows hot gas to flow appropriately to the pipe. Not
Since the solenoid valve is expensive, there is a problem that the cost of the entire apparatus increases.

In view of the above situation, the present invention has found that the damper of the regenerator can be opened and closed, and the set temperature of low-temperature exposure in the air tank type thermal shock test apparatus having the airflow avoiding means can be reduced. In addition, it is an object of the present invention to easily and easily hold and control any set temperature.

[0010]

That is, a feature of the present invention that meets the above-mentioned object is that a low-temperature room, a high-temperature room, and a test room are provided, and a cooler is arranged in the low-temperature room, and the cooler is provided with the cooler. On the other hand, a regenerator is arranged on the upstream side of the airflow flowing through the low-temperature chamber, and cold storage can be performed when the high-temperature exposure is performed. Detecting means for detecting and outputting the end of or near the end of heat radiation of the cooling heat stored in the regenerator; and, when exposing at a low temperature, operating the avoiding means by an output from the detecting means to cause an air flow flowing through the low-temperature chamber. And a controller for switching to an airflow that bypasses the regenerator,
Means for controlling the cooler by inverter control, and arranging a temperature sensor in the test chamber, a means for comparing a measured value of the temperature sensor with a set temperature value of low temperature exposure, and a result of the comparison by the comparing means Means for operating the avoidance means when the measured value is lower than the set temperature value, then reducing the operating frequency of the cooler, and reducing the operating frequency of the cooler to the lowest frequency by the reducing means. However, the controller is provided with means for stopping the operation of the avoiding means when the measured value is still lower than the set temperature value.

[0011]

According to the present invention, the temperature of the test chamber that has reached the set temperature is maintained at a constant temperature as described below. That is, the controller always compares the temperature of the test chamber sent from the temperature sensor with the set temperature, and as a result, when the actual temperature is higher than the set temperature, the controller activates the avoiding means. The operation of the cooler is continued as it is, and the temperature in the test chamber is reduced.

On the other hand, as a result of the comparison, if the actual temperature of the test chamber is equal to or lower than the set temperature, the controller instructs the refrigerator that operates the cooler to decrease the operating frequency, thereby causing the cooling device to operate. Reduce the amount of cooling heat generated in the vessel and raise the temperature in the test chamber. However, even when the operating frequency is lowered to the lowest frequency, the temperature of the test chamber may still be lower than the set value. At this time, the controller stops the operation of the avoiding means and positions the regenerator in the airflow circulating between the low-temperature chamber and the test chamber. Then, since the regenerator becomes a reverse load when cooling the test chamber, the temperature of the test chamber rises again. In the present invention, the set temperature holding control at the time of low temperature exposure is performed by appropriately operating the cooler and the avoiding means as described above.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of a gas tank type thermal shock test apparatus according to the present invention. The interior surrounded by a housing (HG) has a high temperature chamber (2), a test chamber (1) and a low temperature chamber from the top. It is divided into three rooms (3). Each of the chambers (1), (2), and (3) is partitioned by a heat insulating partition (W), (W).
Supply port (10) provided with opening and closing dampers (4) and (5),
(11) and outlets (12) and (13) provided with opening / closing dampers (6) and (7) and partition dampers (8) and (9), respectively, and these dampers (4) to Appropriate opening / closing control of (9) allows air to flow between the high temperature chamber (2) and the test chamber (1) or between the low temperature chamber (3) and the test chamber (1) (FIG. 5, FIG. 5). (See FIG. 4).

The high-temperature chamber (2) is provided with a heater (14) and a heating fan (15) therein, and generates heated air of, for example, about 100 ° C., and discharges the heated air to the outlet. It can be circulated and supplied to the test chamber (1) via (12) and the supply port (10). (M ₁ ) located outside the high-temperature chamber (2) is a drive motor for rotating the heating fan (15).

On the other hand, a cooler (1) is provided inside the low temperature chamber (3).
6), a cooling fan (17) and a regenerator (18). In this case as well, it is located outside the low temperature chamber (3) (M
₂ ) is a drive motor for rotating the cooling fan (17). The cooler (16) is connected to a capacity-controllable refrigerator (not shown) installed outdoors. For example, the refrigerator is controlled by an inverter in a range of 30 Hz to 100 Hz by inverter control. The output temperature can be changed, for example, to about −40 ° C. to −60 ° C. The regenerator (18) is fixed in the low-temperature chamber (3) in a state where it is suspended obliquely from the upper end of the side wall of the low-temperature chamber (3), and the side facing the cooler (16) is air. Inflow side (18
A), the opposite side is the air outflow side (18B). In the regenerator (18), an upper end portion of the air inflow side (18A) is further closed by a closing plate (19), and a lower portion of the regenerator (18) pivots around the lower end of the air inflow side (18A). Upside down regenerator damper (20)
It is opened and closed by.

By the way, the regenerator damper (20) constitutes the avoiding means in the above-mentioned invention, and the upper part (20A) of the damper (20) bent in the inverted shape is formed by the regenerator (18). When closing the air inlet side (18A) of (2), the lowermost end of the lower part (20B) comes into contact with the floor of the low-temperature chamber (3). From chamber (1) to supply port (1
With respect to the low-temperature airflow returning to the low-temperature chamber (3) via 1), the flow is a flow that bypasses the regenerator (18) (see FIG. 3). When the upper part (20A) of the regenerator (20) is separated from the regenerator (18) and opens the air inlet side (18A) of the regenerator (18), the upper part (20A) upper end Is a cooler (16)
The upper portion is in contact with the lower portion (20B) and the lower portion (20B) is in contact with the lower surface of the regenerator (18) (see FIGS. 4 and 5).
Through the regenerator (18) from the air inlet side (18A) to the air outlet side (18B). , The flow returning to the cooler (16),
8) Conventional use is possible.

In this case, the regenerator damper (2)
The state when the test chamber (1) was exposed to a low temperature and cooled to the set temperature using the above (0) was as follows. First, FIG.
Fig. 1 shows an air-bath type thermal shock test apparatus during cold storage while performing high-temperature exposure. On the high-temperature chamber (2) side, the opening / closing dampers (4) and (6) and the partition damper (8) are all open, and high-temperature air is sent to the test chamber (1) and placed in the test chamber (1). The electrical and electronic components (not shown) have been tested for high heat while the open / close dampers (5) and (7) and the partition damper (9) are all closed on the low temperature room (3) side. In this state, the cooler (16) and the cooling fan (17) are driven, and the cooling heat generated by the cooler (16) circulates in the low-temperature chamber (3), and the regenerator in the circulating airflow. (18) is located with the regenerator damper (20) open, and the cooling heat generated by the regenerator (16) is
8) It is stored cold.

Next, as shown in FIG. 4, when the cold storage operation is completed with the end of the high-temperature exposure, the dampers (5), (7) and (9) on the low-temperature chamber (3) side are opened. 1
The cooling heat of 6) and the cold storage of the regenerator (18) are supplied to the test chamber (1) together with the operation of the cooling fan (17), and thereby the test chamber (1) which has been heated up to now.
Is cooled to a set temperature at which low temperature exposure is to be performed.
At this time, the regenerator (1
When all or almost all of the heat of the cool storage heat of 8) is exhausted, the cool storage damper (20) turns to the cool storage (18) side and the air inlet side (18A) of the cool storage (18). Is closed and the low-temperature airflow circulating between the low-temperature chamber (3) and the test chamber (1) is switched to a flow bypassing the regenerator (18) (see FIG. 3), whereby the regenerator (1) is turned on.
8) The test chamber (1) is efficiently cooled to the set temperature by preventing reverse load from occurring. The regenerator damper (2)
1), the regenerator temperature sensor (21) for detecting the presence or absence of regenerative cooling heat of the regenerator (18) is provided near the regenerator (18) as shown in FIG. cold accumulation device (18) a temperature sensor (21) and a drive motor (M ₃₎ of the regenerator damper (20) connected to each controller (22), the regenerator temperature sensor to said drive motor (M ₃₎ ( It is performed by appropriately driving based on the detection value of 21).

Thus, in the present invention, the regenerator damper (20) is used thereafter in order to maintain and control the temperature of the low temperature exposure that has reached the set temperature at a constant temperature. Here, in FIG. 1, (23) located in the test room (1) indicates a temperature sensor for measuring the temperature in the test room (1). The measured value of the temperature sensor (23) is input to the controller (22). Further, a low-temperature exposure set temperature is also input to the controller (22). And the controller (22)
According to the flowchart shown in FIG. 2, the set temperature at the time of low temperature exposure can be maintained and controlled. In FIG. 2, initially, at the time of start (A), the regenerator damper (20) is closed toward the regenerator (18) air inflow side (18A), and in the controller (22), the time measurement by the time measuring means is performed. This timing is started (b), in order to advance the control cycle described below, for example, with each count of -10 seconds as one count.

Next, a comparison is made between the low temperature exposure set value (SP) and the measured temperature value (MT) in the test chamber (1) sent from the temperature sensor (23) in the test chamber (1). (C). At this time, if the set value (SP) is lower than the measured value (MT), the cooler (16) is operated as it is. This naturally cools the test chamber (1),
Eventually, the measured value (MT) becomes less than or equal to the set value (SP).

On the other hand, in the comparison in (c), the set value (S
When P) is equal to or greater than the measured value (MT), it is first confirmed that the regenerator damper (20) is closed. Of course, in this case,
From the beginning, the regenerator damper (20) is closed, and therefore may be closed as it is. However, if it is open in the process of repeating the processing, it is closed here (d). The state in which the regenerator damper (20) is closed is shown in FIG. 3, and the cooling heat generated in the cooler (16) passes through the outlet (13) by the cooling fan (17) and passes through the test chamber ( 1)
Flows from the supply port (11) to the cooler (16) without passing through the cool storage (18). In this state, it is checked whether or not the refrigerator for operating the cooler (16) is operated at the lowest frequency (e). If the refrigerator is not at the lowest frequency, the frequency is reduced by, for example, 10 Hz. (F) To reduce the amount of cooling heat generated by the cooler (16),
After raising the temperature of the test chamber (1), it was confirmed that the time counting by the time counting means had advanced by one count (g).
After the first control cycle, return to the original state.

Since such a control cycle is repeated during the low-temperature exposure, as long as the measured value (MT) of the test chamber (1) is equal to or less than the set value (SP), the frequency is reduced for each count and the test is performed. Although the temperature of the chamber (1) gradually increases, even if the frequency is lowered to the lowest frequency (for example, 30 Hz) at which the refrigerator can be operated, the set value (S
When P) is equal to or greater than the measured value (MT), the controller (22) operates the regenerator damper (2) which has been closed so far.
An open command is issued for 0) (h). The state where the regenerator damper (20) is opened is as shown in FIG. 4, in which the cooling heat generated by the cooler (18) rides on the airflow generated by the cooling fan (17) and is tested from the outlet (13). Room (1)
After cooling the test chamber (1), supply port (1)
When returning to the low-temperature chamber (3) via 1), the circulation that passes through the regenerator (18) from the air inlet side (18A) to the outlet side (18B) and returns to the cooler (16) is repeated. And as a result,
Here, the regenerator (18), which has already released the heat storage amount, becomes a reverse load on the cooler (16), and raises the cooling temperature of the test chamber (1) accordingly. The above is the description of the flowchart illustrated in FIG. During the low-temperature exposure, the temperature in the test chamber (1) is maintained at the desired set temperature by repeating the control cycle along the above-mentioned float chart.

In the above embodiment, the regenerator damper (20), which is an avoiding means, is particularly equipped with the regenerator (1).
8) is fixed so as to hang obliquely from the upper part of the side wall of the low-temperature chamber (3) as described above, so that the upper part (20A) and the lower part (20B) are separated as described above. The regenerator damper (20) is applied to the regenerator damper (20). It is important that the airflow flowing through the low-temperature chamber (3) can be switched to the airflow that bypasses the regenerator (18). The applicant filed the above-mentioned Japanese Patent Application No. 2-504.
As described in JP-A-18, the shape of the regenerator damper (20) and its operation mode are appropriately changed according to the shape and the installation position of the regenerator (18) in the low-temperature chamber (3). . As described in the above-mentioned publication, the regenerator (18) itself can be moved out of the airflow flowing through the low-temperature chamber (3) without providing the regenerator damper (20) in some cases, The present invention may be configured to avoid this.

[0024]

As described above, according to the present invention, when the regenerator radiates the regenerative cooling heat at or near the end, the low-temperature airflow circulating between the low-temperature chamber and the test chamber passes through the regenerator. What is claimed is: 1. An air-bath type thermal shock test apparatus having an avoiding means capable of switching from a flow to a flow bypassing a regenerator, wherein the avoiding means is used as a temperature holding control means while the exposure to a low temperature is continued. Means for comparing the measured temperature value in the test chamber with the set temperature value of the low-temperature exposure to the controller for operating the avoiding means, and as a result of the comparison by the comparing means, when the measured value is lower than the set temperature value, Means for reducing the operating frequency of the cooler after operating the avoiding means, and the measured value is still set to the set value even if the operating frequency of the cooler is reduced to the lowest frequency by the reducing means. Means for stopping the operation of the avoiding means when the temperature is lower than the temperature value, so that the low temperature exposure set temperature is maintained by controlling the capacity of the refrigerator and the regenerator by the avoiding means. The control can be performed by a coupling action with the application of a reverse load to cooling, and control in a temperature range where control by capacity control alone is not possible is also possible. In this case, the reverse load heater and the hot gas solenoid valve, which were conventionally used as the set temperature holding control means, are of course unnecessary, and the cost of the entire apparatus can be reduced, and at any set temperature. On the other hand, it becomes easy to hold and control the temperature.

As described above, the present invention makes it possible to effectively use the avoiding means as a low-temperature exposure set temperature holding control means. Since the low temperature exposure set temperature in the thermal shock test apparatus of the type is quickly reached, in the air tank type thermal shock test apparatus of the present invention, after the high temperature exposure is switched to the low temperature exposure, the next low temperature exposure is performed. Until the time of switching to the high-temperature exposure, the avoidance means can be consistently used as the temperature control means for the low-temperature exposure, so that the temperature control can be efficiently performed throughout the low-temperature exposure test in the air tank type thermal shock test apparatus. It can be performed at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a gas tank type thermal shock test apparatus according to the present invention.

FIG. 2 is a process flow chart for maintaining and controlling a set temperature at the time of low-temperature exposure in the gas tank type thermal shock test apparatus according to the present invention.

FIG. 3 is a partial cross-sectional view illustrating a test mode using the above-described air-bath type thermal shock test apparatus.

FIG. 4 is a partial cross-sectional view illustrating a test mode using the above-described air-bath type thermal shock test apparatus.

FIG. 5 is a partial cross-sectional view illustrating a test mode using the above-described air-bath type thermal shock test apparatus.

[Explanation of symbols]

 (1) Test room (2) High temperature room (3) Low temperature room (16) Cooler (18) Regenerator (20) Regenerator damper (21) Regenerator temperature sensor (detection means) (22) Controller (23) Temperature sensor

Claims (1)

(57) [Claims] 1. A low-temperature chamber (3), a high-temperature chamber (2), and a test chamber (1), and a cooler (1) is provided in the low-temperature chamber (3).
6), and a regenerator (18) is arranged on the upstream side of the airflow flowing through the low-temperature chamber (3) with respect to the cooler (16), so that the regenerator can be stored when exposed to high temperature. (18) is provided with an avoiding means (20) for avoiding the airflow flowing through the low-temperature chamber (3) at the time of low-temperature exposure, and detecting the end of or near the end of heat radiation of the cooling heat stored in the regenerator (18). Detecting means (21) for outputting the data;
At the time of low temperature exposure, the controller (22) that operates the avoiding means (18) based on the output from the detecting means (21) and switches the airflow flowing through the low temperature chamber (3) to the airflow bypassing the regenerator (18). ), Wherein the cooler (16) is provided.
Means that can be controlled by an inverter, and a temperature sensor (23) is arranged in the test chamber (1), and a measured value of the temperature sensor (23) is compared with a set temperature value of low temperature exposure; Means for operating the avoiding means (20) when the measured value is lower than the set temperature value as a result of the comparison by the comparing means, and thereafter reducing the operating frequency of the cooler (16); Means for stopping the operation of the avoiding means (20) when the measured value is still lower than the set temperature value even if the operating frequency of the cooler (16) is reduced to the lowest frequency by the controller (22). An air tank type thermal shock test device characterized by being provided with: