JP2011206661A - Thermostat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermostat capable of saving energy consumption, while uniformly controlling the internal temperature distribution of the thermostat.SOLUTION: This thermostat 1 can keep the temperature of a sample arrangement part 2 on which a heating sample piece W is arranged, at a level near the preset value, and comprises an air blower 12, a heating means 13 and a damper part 21. Inside the thermostat 1, upstream side temperature sensors 16 and 17 are arranged on the upstream side of the air flow direction, while downstream side temperature sensors 18 and 20 are arranged on the downstream side. When the temperature of the sample arrangement part 2 is controlled so as to retain a preset value, the blast level of the air blower 12 can be increased or decreased so that the temperature difference representing the specified range from not less than the lower limit temperature difference to not more than the upper limit temperature difference may exist between the upstream side temperature A detected by the upstream side temperature sensors 16 and 17 and the downstream side temperature B dctected by the downstream side temperature sensors 18 and 20.

Description

  The present invention relates to a thermostatic device that can be adjusted to a target temperature in a predetermined chamber or room, and is particularly suitable as a burn-in test device or an environmental test device, and the temperature distribution in the chamber or room is practically sufficient. The present invention relates to a thermostatic device that can be made uniform and save energy.

  Electronic devices such as semiconductor devices are subjected to a burn-in test in the final process of manufacturing to remove defective products. Here, the burn-in test is an inspection in which an electronic device such as a semiconductor device is exposed to a temperature higher than a normal temperature environment, and a defective product is identified by applying a voltage higher than a normal use voltage. Patent Document 1 discloses a temperature control apparatus for performing such a burn-in test. In the burn-in test, since power is supplied to the semiconductor device, the semiconductor device generates heat.

  By the way, in the burn-in test, a plurality of semiconductor devices of the same type are mounted on the same thermostat (burn-in test apparatus), so that each semiconductor device can be tested in almost the same environment. It is desirable to execute control to maintain the power supplied to the temperature etc. and the temperature distribution inside the thermostatic device substantially uniformly. By controlling in this way, high test accuracy can be ensured in the burn-in test.

However, because the semiconductor device, etc., generates heat when energized in the thermostat, the temperature difference between the air circulating inside and outside the semiconductor device may increase and the overall temperature distribution may become uneven. It was.
Therefore, in this type of thermostatic device, a strong air blower is used to vigorously stir the interior of the thermostatic device to form a high-speed air flow inside, thereby reducing the temperature difference and making the temperature distribution uniform. ing.
Specifically, a strong blower is selected that can ensure a preset constant blown air volume based on the set temperature inside the thermostatic apparatus and the maximum heat generation amount that can be predicted by a semiconductor device or the like. . Further, in the prior art, during the burn-in test, the blower is rotated at a constant rotational speed so as to have a constant air volume.
In many cases, the blower is rotated at full speed during the burn-in test.

JP 2000-214933 A

  In recent years, with the increase in functionality and performance of semiconductor devices, their individual capacities have increased. As a result, the amount of current supplied to the semiconductor devices has increased, and the amount of heat generated has been increasing year by year. On the other hand, there is no change in required performance for a thermostatic apparatus for performing a burn-in test. Therefore, recently, in order to maintain the uniformity of the temperature distribution inside the thermostat, the capacity of the motor of the blower employed in the thermostat has been increased. That is, the amount of stirring in the thermostatic device is increased to make the temperature distribution uniform.

Although the conventional thermostatic apparatus having such a configuration can perform a burn-in test on a semiconductor device having a high calorific value, the control of the blower assumes that conditions such as the type and mounting amount of the semiconductor device as a sample body have changed. However, since the air flow is controlled to be constant as described above, the temperature distribution may be made more uniform than necessary depending on the test.
Moreover, since the work amount which stirs air is greatly increased in the blower with the increased capacity of the motor, the temperature in the thermostatic device is raised by the heat of stirring. This amount of heat needs to be absorbed by the cooling device.
In the conventional thermostatic device, such a blower is operated with a constant air flow rate from the initial operation of the thermostatic device to the end of the test, so the air flow rate may be excessive depending on the temperature condition inside the thermostatic device. In other words, wasteful power consumption was generated by the work of air agitation and cooling.

That is, in the conventional thermostat, the air flow rate of the blower is almost constant from the start to the stop of the thermostat without depending on the test conditions, the temperature inside the thermostat, the difference in the calorific value of the sample body, etc. Therefore, when a blower equipped with a large-capacity motor is adopted, the power consumption becomes unnecessarily large and it is difficult to save energy.
In addition, the energy that the blower agitates the air becomes excessive, the temperature inside the thermostatic device rises, and there is a waste that the refrigerator must be operated to suppress the temperature rise of the thermostatic device. It was difficult to save energy.

  In view of the above-described problems of the prior art, an object of the present invention is to provide a thermostatic device capable of saving energy while appropriately controlling the temperature distribution in the thermostatic device.

  In order to solve the above-described problems, the invention described in claim 1 includes a sample placement section in which a heat generating sample body that generates heat is disposed, a blower that can flow air in a certain direction in the sample placement section, and a sample placement This is a constant temperature apparatus that has a heating means that can raise the temperature of the section and a temperature lowering means that can lower the temperature of the sample placement section, and can maintain the temperature in the sample placement section at a set value. In the constant temperature apparatus, an upstream temperature detecting means for detecting the temperature upstream of the sample arrangement portion in the air flow direction and a downstream for detecting the temperature downstream of the sample arrangement portion in the air flow direction. When the temperature of the sample placement portion is controlled to a set value, the temperature between the upstream temperature detected by the upstream temperature detector and the downstream temperature detected by the downstream temperature detector So that a certain appropriate temperature difference exists in A thermostatic apparatus characterized by increasing or decreasing the air volume of air blower.

Here, the appropriate temperature difference may be a specific temperature difference such as 4 degrees Celsius or 6 degrees Celsius, or may be a temperature difference having a width of 4 degrees Celsius to 6 degrees Celsius.
In practice, proportional control and on / off control by an inverter is performed with a specific temperature difference of 4 degrees Celsius or 6 degrees Celsius as a target, but even in that case, the temperature difference must be accurately matched to the control. If this is difficult, control is performed so as to maintain a certain temperature difference range.

  The thermostat of the present invention is provided with temperature detection means on the upstream side and the downstream side in the air flow direction with respect to the sample placement unit, respectively, and when controlling the temperature of the sample placement unit to the set value, Control is performed to increase or decrease the air flow rate of the blower so that the temperature difference with the downstream temperature becomes an appropriate temperature difference.

  For example, when the temperature difference between the two is greater than the appropriate temperature difference under the temperature condition where the downstream temperature is higher than the upstream temperature, control is performed to increase the air flow rate of the blower. As a result, the flow rate of the air flowing through the sample placement portion increases, so the time during which the flowing air can be heated by the exothermic sample body (residence time) is shortened, and the temperature difference approaches the appropriate temperature difference.

Conversely, when the temperature difference between the downstream temperature and the upstream temperature is less than the appropriate temperature difference, control is performed to reduce the air flow rate of the blower.
As a result, the flow rate of the air flowing through the sample placement portion is reduced, so the time during which the flowing air can be heated by the exothermic sample body (residence time) is increased, and the temperature difference approaches the appropriate temperature difference.

  Therefore, according to the present invention, it is possible to suppress the power consumption of the blower while keeping the temperature distribution of the sample placement portion constant.

  That is, according to the thermostatic apparatus of the present invention, the temperature detection means provided on the upstream side and the downstream side of the sample placement unit allows the temperature distribution from the upstream side to the downstream side in the sample placement unit to be within a predetermined upper and lower limit range. Since the blower amount of the blower can be controlled depending on whether or not there is, the temperature control can be performed while reducing the power consumption while keeping the temperature environment of all the exothermic sample bodies placed on the sample placement unit within an appropriate range. Thereby, even if it is a case where the air blower provided with the large capacity motor is employ | adopted, since excessive power consumption is suppressed, compared with the conventional thermostat, the energy-saving thermostat can be provided.

As a measure for increasing or decreasing the amount of air blown from the blower, a configuration in which the rotational speed of the blower is changed is recommended.
According to such a configuration, the amount of air blown from the blower is increased or decreased depending on the number of rotations, so that it is easy to control the air flow to the target. For example, as this means, when a DC motor is adopted as the motor of the blower, there is a measure for controlling the voltage of the DC motor. Moreover, when an AC motor is employed as the motor of the blower, measures such as inverter control of the AC motor can be cited.

  When the temperature difference between the upstream temperature and the downstream temperature is less than the appropriate temperature difference, the invention described in claim 2 reduces the air volume of the blower, and the temperature difference exceeds the appropriate temperature difference. Increases the amount of air blown by the blower.

According to such a configuration, the air flow rate of the blower is increased or decreased so that the temperature difference between the downstream temperature and the upstream temperature becomes a predetermined appropriate temperature difference, so the temperature difference of the sample placement portion does not adversely affect the test. The range can be stabilized within a range where energy saving is possible.
That is, in the present invention, when the temperature difference between the downstream temperature and the upstream temperature is less than the appropriate temperature difference, the air flow rate of the blower is reduced compared to the case where the temperature difference is within the predetermined range, and the temperature difference is the appropriate temperature difference. In the case where the temperature exceeds the value, the air flow rate of the blower is increased as compared with the case where the temperature difference is appropriate. Therefore, the temperature difference does not extend to a range that adversely affects the test, and the temperature difference does not disappear to an excessive extent. Therefore, according to this invention, the power consumption of a fan can be reduced more.

  The invention described in claim 3 is the thermostatic device according to claim 1 or 2, wherein a plurality of at least one of the upstream temperature detecting means and the downstream temperature detecting means is provided.

  According to such a configuration, since there are a plurality of upstream temperature detection means or downstream temperature detection means, erroneous detection can be eliminated, and control is performed with higher performance than when only one temperature detection means is provided. Can do. Further, even if any one of a plurality of temperature detecting means fails, another temperature detecting means can cope with it, so that the problem that the control cannot be executed does not occur in the present invention.

In the sample placement unit on which the exothermic sample body is placed, the thermostat is operated and the energizing sample body is energized. Therefore, the downstream temperature becomes higher than the upstream temperature due to heat generation of the exothermic sample body after a certain period of time. Conversely, when there is no heat generation, the upstream temperature is higher than the downstream temperature. Further, the upstream temperature also varies depending on the position depending on the air flow. Similarly, the downstream temperature also varies depending on the position.
Accordingly, the invention according to claim 4 is the detection temperature detected by the downstream temperature detection means, wherein the plurality of temperature detection means among the upstream temperature detection means and the downstream temperature detection means are arranged at separate positions. The flow rate of the blower is controlled based on a temperature difference between the highest temperature or the lowest temperature in the temperature and the lowest temperature or the highest temperature among the detected temperatures detected by the upstream temperature detection means. 3.

According to this configuration, when there are a plurality of upstream temperature detection means, the upstream temperature detection means are arranged at intervals, and when there are a plurality of downstream temperature detection means, the downstream temperature detection means are spaced apart from each other. Therefore, temperature unevenness in the temperature detection region can be detected. That is, the thermostat of the present invention controls the entire air volume of the sample placement unit by controlling the air flow rate of the blower based on the temperature difference between the maximum temperature or minimum temperature of the downstream side temperature and the minimum temperature or maximum temperature of the upstream side temperature. It can be surely brought close to the set temperature.
The combination of the downstream temperature and the upstream temperature is arbitrary, and the policy that adopts the maximum temperature of the downstream side temperature and the minimum temperature of the upstream side, the policy that adopts the maximum temperature of the downstream side temperature and the maximum temperature of the upstream side It is possible to adopt a measure that adopts the lowest temperature of the downstream temperature and the lowest temperature of the upstream temperature, and a measure that adopts the lowest temperature of the downstream temperature and the highest temperature of the upstream temperature. However, from the viewpoint of more accurately controlling the temperature difference between the downstream side temperature and the upstream side temperature, it is recommended to adopt a measure that employs the maximum temperature of the downstream side temperature and the minimum temperature of the upstream side temperature.

  In the invention according to claim 5, among the upstream temperature detection means and the downstream temperature detection means, a plurality of temperature detection means are arranged at positions separated from each other, and a plurality of upstream temperature detection means are provided. In this case, the average value of the detected temperatures detected by the plurality of upstream temperature detecting means is set as the upstream temperature, and when the number of the upstream temperature detecting means is singular, the detected temperature detected by the one upstream temperature detecting means is When there are a plurality of downstream temperature detection means provided as the upstream temperature, the average value of the detection temperatures detected by the plurality of downstream temperature detection means is the downstream temperature, and the number of the downstream temperature detection means is singular. In this case, the detected temperature detected by the one downstream temperature detecting means is set as the downstream temperature, and the air flow rate of the blower is increased or decreased so that a predetermined appropriate temperature difference exists between the upstream temperature and the downstream temperature. It is characterized by A thermostatic device according to claim 3.

  According to this configuration, when there are a plurality of upstream temperature detection means, the upstream temperature detection means are arranged at intervals, and when there are a plurality of downstream temperature detection means, the downstream temperature detection means are spaced apart from each other. Therefore, temperature unevenness in the temperature detection region can be detected. Then, by controlling the air flow rate of the blower based on the temperature difference calculated using the average temperature of a plurality of upstream and downstream sides, an abnormal value is detected in the detected temperature due to a malfunction of the temperature detecting means or the like. Even in such a case, since the abnormal value is reduced by calculating the average value, it is possible to suppress the malfunction of the control due to the abnormal value.

  The invention according to claim 6 has a plurality of upstream temperature detection means and a plurality of downstream temperature detection means, and the air flow passing through the sample placement portion is roughly divided into a plurality of layers, and the plurality of layers The upstream temperature detecting means is upstream of the layer, and the downstream temperature detecting means corresponding to the upstream temperature detecting means is installed downstream of the layer, and the upstream temperature detecting means detects the upstream temperature detected by the upstream temperature detecting means. The maximum temperature difference among the downstream temperature differences detected by the downstream temperature detection means corresponding to the reference temperature difference is set as a reference temperature difference, and the air flow rate of the blower is increased or decreased so that the reference temperature difference becomes an appropriate temperature difference. The constant temperature device according to claim 3.

A shelf or the like is often provided in the sample placement portion of the thermostatic device, and an air flow path is substantially formed by the shelf in many cases. That is, the shelf of the sample placement section does not strictly block air flow, but the air flow passing through the sample placement section is roughly divided into a plurality of layers due to the presence of the shelf. In addition, since the arrangement of samples is performed in units of shelves, it is no exaggeration to say that the presence or absence of samples is determined for each shelf.
In the present invention, the upstream temperature detection means is provided upstream of the plurality of layers, and the downstream temperature detection means corresponding to the upstream temperature detection means is provided downstream of the layers. Therefore, the upstream temperature detecting means and the corresponding downstream temperature detecting means are paired to measure the temperature difference of the air flowing through the layer, and the temperature differences of the plurality of layers are individually detected.
In the present invention, the temperature difference between the plurality of layers is based on the largest temperature difference, and the air flow rate of the blower is increased or decreased based on this temperature difference.
Further, this may be further developed, and a partition or the like may be provided for dividing the air flow passing through the sample placement portion into a plurality of layers.

  It is desirable that the temperature lowering unit lowers the temperature in the sample placement unit by replacing the air in the sample placement unit with outside air.

  According to this configuration, the temperature lowering unit lowers the temperature by substituting the air in the sample placement unit, and therefore consumes less power than when the temperature is decreased using a refrigerator or the like. As an embodiment, for example, the temperature lowering means includes an exhaust part that exhausts part or all of the air that has passed through the sample placement part, an air supply part that supplies external air, and the exhaust part. A damper device configured with opening / closing means capable of adjusting the amount of air passing through the air portion is conceivable.

  Further, when the temperature on the downstream side is lower than the temperature on the upstream side, it is recommended that the blower amount of the blower be controlled based on the upstream temperature.

  According to such a configuration, when the downstream temperature is lower than the upstream temperature, the air flow rate of the blower is controlled based on the upstream temperature, so that the temperature of the sample placement unit can be increased efficiently. is there. Here, when the amount of air blown by the blower is increased, the amount of work for stirring the air by the blower is increased, so that the temperature raising efficiency is increased. In other words, in situations where a sudden temperature increase is required, such as when the downstream temperature is lower than the upstream temperature, the sample can be placed in a short period of time by increasing the air flow rate based on the upstream temperature on the high temperature side. The temperature of the part can be raised.

In addition, although the temperature in the sample placement unit itself is maintained at a set value, the thermostat of the present invention is based on the premise that there is a temperature difference between the upstream side and the downstream side of the sample placement unit. The overall temperature changes depending on whether it is set as a reference.
As a reference temperature for maintaining the temperature in the sample placement portion at a set value, an upstream temperature, a downstream temperature, or an average of these can be used.

  That is, the invention according to claim 7 is characterized in that the temperature in the sample placement portion is maintained at a set value based on the temperature detected by the upstream temperature detecting means. It is a thermostatic device.

  According to an eighth aspect of the present invention, the temperature in the sample placement section is maintained at a set value based on the detected temperature of the downstream temperature detecting means. The constant temperature according to any one of the first to sixth aspects Device.

  The invention according to claim 9 is characterized in that the temperature in the sample placement section is maintained at a set value based on the average of the detected temperature of the upstream temperature detecting means and the detected temperature of the downstream temperature detecting means. Item 7. The thermostat according to any one of Items 1 to 6.

  The thermostat of the present invention is provided with temperature detection means on the upstream side and the downstream side in the air flow direction in the sample placement part in which the exothermic sample body is placed, and when the temperature of the sample placement part is controlled to a set value. The air flow rate of the blower can be increased or decreased so that the temperature difference between the upstream side and the downstream side of the sample placement unit is within a certain range. Thereby, even if it is a case where the temperature distribution of a sample arrangement | positioning part is maintained in a predetermined test environment with the air blower provided with the large capacity motor, the constant temperature apparatus with which control aiming at energy saving is performed can be provided.

It is sectional drawing which shows notionally the thermostat which concerns on embodiment of this invention. It is a block diagram which shows the relationship between the control part of the thermostat of FIG. 1, and another apparatus. It is a graph for explaining a comparative example and simply showing a general relationship between the upstream temperature A, the downstream temperature B, and time in the sample placement portion of the thermostatic apparatus. It is a graph for explaining a comparative example, and is a graph simply showing the relationship between the upstream temperature A, the downstream temperature B, and the time in the sample placement portion of the thermostat, and shows a case where the blower volume of the blower is small. It is a graph for explaining a comparative example, and is a graph simply showing the relationship between the upstream temperature A, the downstream temperature B, and the time in the sample placement portion of the thermostatic device, and shows a case where the blower has a large blast volume. FIG. 3 is a graph for explaining the embodiment of the present invention, and simply shows the relationship between the upstream temperature A and the downstream temperature B in the sample placement portion of the thermostatic device in FIG. is there. The upper row is a graph simply showing the relationship between the temperature difference C (downstream temperature B-upstream temperature A) and time in the sample placement portion of the thermostat of FIG. 1, and the lower row shows the state of the blower air flow rate. It is a graph to show. It is a graph which shows simply the relationship between the upstream temperature A in the sample arrangement | positioning part of the thermostat of FIG. 1, the downstream temperature B, and time in the thermostat of another embodiment. 8 is a graph simply showing the relationship between the temperature difference C (downstream temperature B-upstream temperature A) in the sample placement portion of the thermostatic apparatus and time, and the lower part is a blower. It is a graph which shows the state of the blast volume.

Hereinafter, the thermostat 1 according to the embodiment of the present invention will be described.
The thermostat 1 of the present embodiment is a burn-in test apparatus for performing a burn-in test on a semiconductor device (heat generating sample body W), and is based on the background that the amount of heat generated by the heat generating sample body W is increasing year by year. The exothermic sample W is configured to be inspected. Specifically, the total calorific value of the exothermic sample body W is about 7 to 8 kwh.

  As shown in FIG. 1, the thermostatic device 1 has an outer frame formed of a heat insulating wall 3 so as not to be affected by an external temperature change, and the inside is sealed by closing a door (not shown). Can do. Moreover, the semiconductor device etc. which are the exothermic sample bodies W can be taken in and out by opening the said door. In the constant temperature apparatus 1, the structure is divided into a sample placement portion 2 for placing the heat generation sample body W and a passage portion 5 through which air flows. In the burn-in test, as described above, a voltage higher than the normal working voltage is applied to the exothermic sample body W that generates heat when energized, while being exposed to a temperature higher than the normal temperature environment. This is an inspection to identify defective products.

As shown in FIG. 1, the sample placement unit 2 is positioned substantially at the center of the thermostatic device 1, and the passage unit 5 is adjacent to the upstream side and the downstream side in the air flow direction. The sample placement section 2 includes a plurality of sample placement shelves 6 called burn-in boards arranged in the vertical direction, and each sample placement shelf 6 is provided with a terminal (not shown) for energizing the heat generating sample body W. Is configured. That is, the air passing through the sample placement unit 2 flows along the sample placement shelf 6 substantially in parallel. That is, the air passing through the sample placement unit 2 is roughly divided into five layers by the sample placement shelf 6 and flows in parallel. More specifically, as shown in FIG. 1, the flow is divided into a layer and e layer.
And the air which passes through the sample arrangement | positioning part 2 is heat-exchanged with the exothermic sample body W which generate | occur | produced the electricity and was heated.

  As shown in FIG. 1, the passage portion 5 is located so as to surround the sample placement portion 2. Specifically, the passage portion 5 is between the heat insulating wall 3 and the sample placement portion 2, and the air passage 10 adjacent to the upstream side (right side) in the air flow direction in the sample placement portion 2 and the sample placement portion 2. And an exhaust passage 11 adjacent to the downstream side (left side) in the air flow direction, and a circulation passage 15 sandwiched between the blower passage 10 and the exhaust passage 11 and provided with a blower 12 and a heater (heating means) 13. Yes. Note that there is no partition between the sample placement unit 2 and the air passage 10 and the exhaust passage 11, and a partition plate 29 is provided only between the sample placement unit 2 and the circulation passage 15.

  Further, the passage portion 5 includes an exhaust portion 22 that exhausts part or all of the air that has passed through the exhaust passage 11 to the outside, an air supply portion 23 that supplies air to the circulation passage 15 from the outside, and an exhaust portion. 22 and an opening / closing plate 24 capable of adjusting the flow rate of air passing through the air supply unit 23 are provided, and a damper unit 21 is formed. Specifically, the exhaust part 22 is located downstream of the exhaust passage 11 in the air flow direction, and the air supply part 23 is located upstream of the circulation passage 15 in the air flow direction. The exhaust unit 22 and the air supply unit 23 are connected to the exhaust duct 34 or the air supply duct 35, respectively.

  The damper portion 21 has an opening / closing plate (opening / closing means) 24 whose opening is adjusted by a motor (not shown), and the opening / closing plate 24 can simultaneously adjust the flow rate of air passing through the exhaust portion 22 and the air supply portion 23. . More specifically, the opening / closing plate 24 is a single metal plate having a size that can cover the exhaust unit 22 and the air supply unit 23 at the same time. A hinge 25 is disposed on the opening / closing plate 24. That is, the opening / closing plate 24 can be adjusted with respect to the opening degree of the exhaust unit 22 and the air supply unit 23 simultaneously by rotating with respect to the hinge 25. That is, the opening degree adjustment of the damper unit 21 is performed by driving the motor and rotating the opening / closing plate 24 with respect to the hinge 25 based on a signal generated from the control unit 30 described later. Therefore, the damper part 21 can supply the external low-temperature air while exhausting the heated air inside the constant temperature apparatus 1 by adjusting the opening degree of the exhaust part 22 and the air supply part 23, so that the sample The temperature of the arrangement part 2 can be lowered (temperature drop means). That is, the damper portion 21 can replace the air inside the thermostatic device 1 with the outside air. The opening / closing plate 24 is a so-called butterfly type, but may be a gate type.

  Furthermore, the damper portion 21 employed in the present embodiment has a configuration in which the opening / closing speed of the opening / closing plate 24 can be controlled. Thereby, the temperature adjustment of the sample placement unit 2 can be performed more smoothly. Note that the opening / closing speed control of the opening / closing plate 24 is not directly related to the present invention and will be described briefly. That is, the opening speed of the opening / closing plate 24 is increased when the temperature of the sample placement section 2 is desired to be rapidly lowered, and the closing speed of the opening / closing plate 24 is increased when the temperature of the sample placement section 2 is desired to be raised rapidly.

The air passage 10 is a passage extending in the vertical direction, and two temperature sensors (upstream temperature detecting means) 16 and 17 are arranged. Specifically, an upstream upper temperature sensor (upstream temperature detection means) 16 is disposed on the upper side in the vertical direction of the passage, and an upstream lower temperature sensor (upstream temperature detection means) 17 is provided on the lower side in the vertical direction of the passage. It is arranged.
As described above, the air passing through the sample placement unit 2 flows separately from the a layer to the e layer, so the upstream upper temperature sensor 16 measures the temperature of the air introduced into the a layer, The upstream side lower temperature sensor 17 measures the temperature of the air introduced into the e layer.
Thereby, even if there is temperature unevenness in the vertical direction in the air passage 10, the control performance can be enhanced by using the average temperature, the minimum, and the maximum temperature of the temperature sensors 16, 17 as a reference. In addition, by providing a plurality of temperature sensors, the temperature control of the sample placement unit 2 can be reliably executed even when any one of the temperature sensors fails.
In the present embodiment, the control is performed with the average value of the detected temperatures of the two temperature sensors (upstream temperature detecting means) 16 and 17 as the upstream temperature A.

  Further, four regulating plates 36 that can smoothly flow air in a certain direction are arranged in the air passage 10 in a vertical direction.

The exhaust passage 11 has the same extending direction as that of the air passage 10, and two temperature sensors (downstream temperature detecting means) 18 and 20 are arranged. Specifically, a downstream lower temperature sensor (downstream temperature detection means) 18 is disposed on the lower side in the vertical direction of the passage, and a downstream upper temperature sensor (downstream temperature detection means) 20 is provided on the upper side in the vertical direction of the passage. It is arranged. As described above, the air passing through the sample placement unit 2 flows separately from the a layer to the e layer, so the downstream upper temperature sensor 20 measures the temperature of the air discharged from the a layer, The downstream side lower temperature sensor 18 measures the temperature of the air discharged from the e layer.
Thereby, even if there is temperature unevenness in the vertical direction in the exhaust passage 11, the control performance can be enhanced by using the average temperature of the temperature sensors 18, 20 and the minimum and maximum temperatures as a reference. Further, as described above, even if any of the temperature sensors fails, the temperature control of the sample placement unit 2 can be executed.
In the present embodiment, the control is performed with the average value of the detected temperatures of the two temperature sensors (downstream temperature detecting means) 18 and 20 as the downstream temperature B.
The exhaust passage 11 is also provided with one restriction plate 36 similar to the above.

  The circulation passage 15 is a passage that is located on the upper side of the sample placement section 2 and extends in a direction substantially orthogonal to the air passage 10 and the exhaust passage 11. That is, in the circulation passage 15, the exhaust passage 11 is adjacent to the upstream side in the air flow direction, and the blower passage 10 is adjacent to the downstream side in the air flow direction. That is, in the circulation passage 15, a part of the air that has passed through the exhaust passage 11 and the external air that has been supplied from the air supply unit 23 pass, or all the air that has passed through the exhaust passage 11 passes. In addition, a blower 12 and a heater 13 are arranged in the circulation passage 15, and the blower 12 is located downstream of the heater 13 in the air flow direction. That is, the air heated by the heater 13 is sent out to the blower passage 10 by the blower 12.

  In the present embodiment, six heaters 13 are provided, one of which is a constant heater 13a that always operates, and the other five that operate when it is necessary to perform a rapid temperature increase in a short time. Temporary heaters 13b to 13f. In addition, all the heaters 13a-13f can adjust the emitted-heat amount by changing an input.

  The blower 12 is a centrifugal fan provided with an inverter, and the number of rotations of a motor (not shown) can be increased or decreased steplessly by changing the frequency by the inverter. Moreover, in the thermostat 1 of this embodiment, the thing whose capacity | capacitance of a motor is larger than the air blower 12 used for the conventional thermostat is employ | adopted. This is in order to cope with the recent exothermic sample body W which has increased in heat. Specifically, the capacity of the motor of the blower 12 employed in the present embodiment is about 9 kw (two motors of about 4.5 kw).

  Next, the relationship between the control unit and other devices in the thermostatic device 1 will be described with reference to the drawings.

  In the thermostatic device 1 of the present embodiment, the control of the blower 12 based on the temperature detected by the temperature sensors 16, 17, 18, and 20 is executed so that the temperature variation in the sample placement unit 2 becomes a predetermined appropriate temperature difference. The That is, as shown in FIG. 2, the temperature sensors 16, 17, 18, 20 and the control unit 30 are connected by a signal line 31, and the blower 12 and the control unit 30 are connected by a signal line 32.

  Further, the control unit 30 can control each device of the damper unit 21 and the heater 13 based on the temperature detected by the temperature sensor 16. That is, as shown in FIG. 2, the control unit 30 is connected to each device of the damper unit 21 and the heater 13 by signal lines 33 and 34.

  In the thermostat 1 of this embodiment, specifically, the inputs of the heaters 13a to 13f are controlled so that the temperature in the sample placement unit 2 becomes a set value. The temperature in the sample placement unit 2 is usually based on the temperature of the blowing part of the blower 12, and in this embodiment, the upstream side upper temperature sensor 16 is closest to the blowing part of the blower 12. Therefore, in this embodiment, the temperature of the sample placement unit 2 is determined by the detected temperature of the upstream upper temperature sensor temperature sensor 16, and the inputs of the heaters 13a to 13f are PID controlled based on the detected temperature of the upstream upper temperature sensor 16. Is done.

Further, the control unit 30 includes a calculation unit (not shown), and the calculation unit calculates a temperature difference C between the upstream temperature A and the downstream temperature B in the sample placement unit 2 (downstream temperature B-upstream). The side temperature A) is calculated.
In the present embodiment, as described above, the average temperature of the two upstream temperature sensors 16 and 17 is the upstream temperature A, and the average temperature of the two downstream temperature sensors 18 and 20 is the downstream temperature B. . The upstream temperature A itself and the downstream temperature B itself are also calculated by the calculation unit. That is, in this embodiment, the average temperature on the upstream side and the average temperature on the downstream side are calculated, and the temperature difference C between the upstream temperature A and the downstream temperature B (downstream temperature B−upstream temperature A) is calculated. The

Next, the function of the thermostat 1 of this embodiment is demonstrated.
In the thermostatic device 1 of the present embodiment, the heat generating sample body W is placed on the sample mounting shelf 6 of the sample placing section 2, the sample placing section 2 is heated with hot air, and the heat generating sample body W is energized to generate heat. Test W. The set temperature (set value) of the sample placement unit 2 is a high temperature such as 125 degrees Celsius.
As described above, the thermostatic device 1 of the present embodiment uses the temperature of the blowing portion of the blower 12 as the temperature of the sample placement portion 2, and the temperature of the sample placement portion 2 is based on the temperature detected by the upstream temperature sensor 16 as a heater 13a. ˜13f input is adjusted by PID control.

The damper unit 21 is opened and closed based on the actual temperature of the sample placement unit 2. Specifically, when the temperature detected by the upstream upper temperature sensor 16 is low (a temperature of about 80 to 90% of the set temperature, or about 100 to 110 degrees Celsius if the set temperature is 125 degrees), the damper The heater 13 is operated while the opening of the section 21 is closed. On the other hand, when the temperature detected by the upstream side upper temperature sensor 16 is high (temperature exceeding 90% of the set temperature), the opening degree of the damper portion 21 is opened.
In this embodiment, the temperature distribution of the sample placement unit 2 is uniformly controlled, and a predetermined temperature is detected between the upstream temperature detected by the upstream temperature detection means and the downstream temperature detected by the downstream temperature detection means. The air flow rate of the blower 12 is PID controlled so that an appropriate temperature difference exists.
In addition, in the following description, it demonstrates as a structure which can increase / decrease the ventilation volume in the thermostat 1 continuously.

In the thermostat 1 of the present embodiment, as described above, there is a predetermined appropriate temperature difference between the upstream temperature detected by the upstream temperature detection means and the downstream temperature detected by the downstream temperature detection means. However, in order to explain the operation of this function, the behavior when the air flow rate of the air blower 12 is initially constant (the state where PID control is not performed) is described. This will be described as a comparative example.
That is, as a comparison with the present embodiment, the temperature distribution of the sample placement unit 2 when a burn-in test is performed with the sample placement unit 2 of the thermostatic device 1 fully loaded with the exothermic sample body W and the blast volume of the blower 12 kept constant. Will be described.

When the burn-in test is performed in a state where the exothermic sample body W is fully loaded, the temperature on the upstream side and the downstream side of the sample placement unit 2 generally changes as shown in the graph of FIG. 3 (a) or FIG. 3 (b). . That is, the exothermic sample body W is installed in the sample placement unit 2, the heater 13 is operated to raise the temperature of the sample placement unit 2, the blower 12 is started, and the rotational speed of the blower 12 is kept constant to air. When flowing in parallel along the sample mounting shelf 6, the temperatures on the upstream side and the downstream side of the sample placement unit 2 change as shown in the graph of FIG. 3 (a) or FIG. 3 (b).
That is, during the initial operation of the thermostat 1, the heat generation amount of the exothermic sample body W is low, and the heat of the air passing through the sample placement unit 2 is taken away by the sample mounting shelf 6 and other internal materials and the exothermic sample body W itself. Therefore, when the upstream temperature A and the downstream temperature B are compared, the downstream temperature B is in a lower state.
Thereafter, the sample mounting shelf 6 and other internal materials are heated by the heat generated by the exothermic sample body W and the temperature rises, and the temperature difference between the upstream temperature A and the downstream temperature B decreases with time.

Then, when the time further elapses, the levels of the upstream temperature A and the downstream temperature B are reversed as shown in FIG. That is, the temperature of the air passing through the sample placement portion 2 is increased by the heat generation of the heat generation sample body W, and the downstream temperature B becomes higher than the upstream temperature A. The time when the downstream temperature B becomes higher than the upstream temperature A is a function of the sample mounting shelf 6 and other heat capacities and the heat generation amount of the heat generating sample body W. When the heat capacity is large and the calorific value of the exothermic sample body W is small, it is after the temperature of the sample placement portion 2 becomes close to the set temperature as shown in FIG.
Conversely, when the heat capacity of the sample mounting shelf 6 or the like is small and the calorific value of the exothermic sample body W is large, before the temperature of the sample placement unit 2 reaches the set temperature as shown in FIG. B is higher than upstream temperature A.

  In addition, the temperature of the sample placement unit 2 is maintained at a set temperature that is allowed by opening / closing the damper unit 21 and controlling the heater 13. The calorific value of the exothermic sample body W is constant, the heat generated by the exothermic sample body W, the heat discharged to the outside via the damper portion 21, the heat added by the heater 13 in a corrective manner, and the blower As shown in FIGS. 3A and 3B, the upstream temperature A is stabilized in the vicinity of the set temperature if the heat of stirring by 12 is balanced and the amount of air blown from the blower 12 is constant.

On the other hand, the downstream temperature B is maintained in a state higher than the upstream temperature A by a substantially constant temperature and is in an equilibrium state and stabilized in the same manner as the upstream temperature A.
When the blower 12 has a small amount of blown air, as shown in FIG. 4, the temperature difference C between the upstream temperature A and the downstream temperature B becomes large, and when the blower 12 has a large blown amount, FIG. As shown, the temperature difference C between the upstream temperature A and the downstream temperature B becomes small.
The above is a comparative example for explaining the effect of the present embodiment, and describes the temperature distribution of the sample placement unit 2 when the burn-in test is performed with the air flow rate of the blower 12 being constant. In the present embodiment, as described above, the blower 12 has a predetermined appropriate temperature difference between the upstream temperature detected by the upstream temperature detection means and the downstream temperature detected by the downstream temperature detection means. The air flow is PID controlled.

  Hereinafter, as in this embodiment, the fan 12 is fed so that a predetermined appropriate temperature difference exists between the upstream temperature detected by the upstream temperature detecting means and the downstream temperature detected by the downstream temperature detecting means. The temperature distribution of the sample placement unit 2 when the air volume is PID controlled will be described.

That is, in this embodiment, the air flow rate of the blower 12 is increased or decreased so that the temperature difference C between the upstream temperature A and the downstream temperature B becomes an appropriate temperature difference.
Also, during the test, the heat generation amount of the heat generation sample body W (total heat generation amount of all the heat generation sample bodies W) changes due to a change in test conditions or a failure of the heat generation sample body W itself, When the balance between the heat discharged outside via the damper 21 and the heat added by the heater 13 and the stirring heat by the blower 12 is lost and the upstream temperature A deviates from the set temperature, the amount of heat generated by the heater 13 is adjusted. Thus, the upstream temperature A is returned to the vicinity of the set temperature.

FIG. 6 illustrates an embodiment of the present invention, and is a graph simply showing the relationship between the upstream temperature A, the downstream temperature B, and the time in the sample placement portion of the thermostatic device of FIG.
FIG. 7 is a graph showing the temperature difference C between the upstream temperature A and the downstream temperature B.
That is, during the initial operation of the constant temperature apparatus 1, as shown in FIG. 7, the temperature difference C between the upstream temperature A and the downstream temperature B once increases (minus side), but the heat generation of the heat generating sample body W occurs. As a result, the temperature difference C changes over time. Then, the downstream temperature B becomes higher than the upstream temperature A when the temperature difference C between the upstream temperature A and the downstream temperature B becomes 0 degrees. That is, when the temperature difference C becomes 0 degree, the surface temperature of the exothermic sample body W becomes higher than the temperature of the air sent out by the blower 12, and the air passing through the sample placement unit 2 becomes the exothermic sample body W. Heated by. In the present embodiment, an operation until a certain time has elapsed after the thermostat 1 is activated and the temperature in the thermostat 1 reaches a set temperature (set value) is referred to as an initial operation. In this embodiment, since the temperature in the constant temperature apparatus 1 is in the process of rising until the temperature in the constant temperature apparatus 1 reaches the set temperature (set value) (initial operation period), the blower 12 is rotated at full power. .

When the initial operation period ends, the temperature of the sample mounting shelf 6 and other internal materials rises, the temperature of the exothermic sample body W becomes higher, and the downstream temperature B becomes higher than the upstream temperature A. When the initial operation period is exceeded, the temperature in the thermostatic device 1 becomes a set temperature (set value), but the air flowing through the sample placement unit 2 is further heated by the heat of the exothermic sample body W, so that FIGS. As shown, the temperature difference C between the downstream temperature B and the upstream temperature A gradually increases.
However, in the present embodiment, when the initial operation period ends, a predetermined appropriate temperature difference exists between the upstream temperature detected by the upstream temperature detection means and the downstream temperature detected by the downstream temperature detection means. The air flow rate of the blower 12 is PID controlled. Therefore, since the air flow rate of the blower 12 is increased or decreased, the air flow rate of the blower 12 tends to decrease as between a and b in FIG. As a result, the temperature difference C between the downstream temperature B and the upstream temperature A converges to an appropriate temperature difference and stabilizes as shown in FIGS.

That is, in the present embodiment, after the initial operation period is over, based on the detected temperatures detected by the upstream temperature sensors 16 and 17 and the downstream temperature sensors 18 and 20 in view of the change in the temperature distribution of the sample placement unit 2. It is set as the structure which carries out PID control of the ventilation volume of the air blower 12, and keeps the temperature distribution of the sample arrangement | positioning part 2 in the predetermined | prescribed range which can accept | permit. Specifically, during the initial operation, the temperature of the sample placement unit 2 is low, and the temperature of the sample placement unit 2 is in the rising process, so the blower 12 is rotated at full power. When the initial operation period ends, the high temperature side reverses due to heating of the exothermic sample W and the downstream temperature B becomes excessively high, but between the high temperature downstream temperature B and the low temperature upstream temperature A. The air flow rate of the blower is controlled so that an appropriate temperature difference is maintained and the temperature distribution falls within a predetermined range. That is, the air flow rate of the blower is set so that the temperature difference C between the downstream temperature B on the high temperature side and the upstream temperature A on the low temperature side is equal to or higher than a lower limit temperature difference and a predetermined range of temperature difference below the upper limit temperature difference. Adjust strength.
Thereby, in the thermostat 1 of this embodiment, in the burn-in test, it is possible to efficiently bring the temperature environment of the sample placement unit 2 close to the set temperature and to achieve energy saving by making the temperature distribution within an allowable range. Become.

  Hereinafter, the operation of the thermostatic device 1 of the present embodiment when the burn-in test is performed will be specifically described.

  When the constant temperature apparatus 1 is operated and the burn-in test is started, the upstream side temperature sensor 16 detects the upstream side mainly to bring the temperature of the sample placement unit 2 close to a preset set value (125 degrees Celsius). Each device is controlled based on the side temperature. In the present embodiment, mainly the input of the heater 13 is PID-controlled and the upstream temperature detected by the upstream upper temperature sensor 16 is adjusted to be a set value (125 degrees Celsius).

More specifically, in the initial operation from when the operation starts until a certain time elapses, in order to efficiently raise the temperature of the sample placement unit 2, the damper unit 21 is fully closed, and all The heater 13 is operated at full operation. The blower 12 is rotated at full power.
Further, when the temperature detected by the upstream temperature sensor 16 reaches about 100 degrees Celsius to 110 degrees Celsius, the damper portion 21 is opened and the input of the heater 13 is reduced based on proportional control.

  At this time, since the heat generation sample body W is energized, the heat generation sample body W is generating heat, but the temperature A of the upstream side A is downstream because the temperature of the sample mounting shelf 6 and other internal materials is low. The temperature is higher than the side temperature B, and the temperature difference between the upstream temperature A and the downstream temperature B is large. Therefore, at the time of initial operation, as shown in the time chart of FIG. 7, the rotation speed of the blower 12 is controlled so that the blown air amount becomes strong. By this control, in the initial operation, the air inside the thermostatic device 1 is circulated through the sample placement unit 2 and the passage unit 5 while being largely agitated, so that the temperature rapidly rises toward the set temperature (125 degrees Celsius). .

Further, as shown in FIGS. 6 and 7, the temperature of the air heated by the exothermic sample body W that has passed through the sample placement unit 2 in the process of raising the temperature of the sample placement unit 2 toward the set value. After the (downstream temperature B) gradually approaches the upstream temperature A and the temperature difference C between the two disappears (temperature difference C is 0 degrees Celsius), the upstream temperature A reaches the set temperature (125 degrees Celsius). Up to this point, as described above, the blower 12 is operated with full power (strong).
Thereafter, as shown in FIG. 7, the rotational speed of the blower 12 is decreased so that the temperature difference C falls within a predetermined range, and the amount of blown air is small (between a and b in FIG. 6).
And since the downstream temperature B becomes high temperature by the heat_generation | fever of the exothermic sample body W and the temperature difference C is going to expand, an air flow volume increases gradually according to this (between bc of FIG. 6). That is, the air flow rate of the blower 12 is controlled in order to prevent the temperature difference C from being excessively widened and the temperature distribution from exceeding a predetermined range.

Specifically, when controlling the blower 12 based on the temperature difference C, according to the degree of the difference between the downstream temperature B and the upstream temperature A, the rotational speed of the blower 12 is controlled to control the blowing amount. Increase or decrease.
That is, in the present embodiment, when the control is executed based on the temperature difference C, the air flow rate of the blower 12 is controlled so that the temperature difference C is constant.

  On the other hand, the downstream temperature B detected by the downstream temperature sensors 18 and 20 rises due to the heat of the exothermic sample body W, the difference between the downstream temperature B and the upstream temperature A widens, and the temperature difference C is an appropriate temperature difference. If it exceeds, the rotation speed of the air blower 12 will be increased and it will return to an appropriate temperature difference.

  When the temperature difference C of the sample placement unit 2 is controlled to an appropriate temperature difference and the detected temperature of the upstream temperature sensor 16 exceeds the set value (125 degrees Celsius), the input of the heater 13 is lowered and the damper unit The opening degree is adjusted in the direction in which the open / close plate 24 of the 21 is opened. Conversely, when the temperature difference C of the sample placement unit 2 is controlled to an appropriate temperature difference but the detected temperature of the upstream temperature sensor 16 falls below the set value, the input of the heater 13 is raised and the opening / closing plate 24 of the damper unit 21 is turned on. The opening is adjusted in the closing direction.

  Therefore, in the thermostat 1 of this embodiment, it is based on the detected temperature of the upstream temperature sensor 16 or the temperature difference between the detected temperature of the downstream temperature sensors 18 and 20 and the detected temperature of the upstream temperature sensors 16 and 17. By performing the air volume control, it is possible to reduce wasteful power consumption while maintaining an appropriate temperature distribution of the sample placement unit 2.

Next, the behavior of the temperature change when a disturbance occurs during the burn-in test using the thermostatic device 1 of the present embodiment will be described.
For example, as shown in FIG. 6, if the amount of heat generated by the heat generating sample body W is reduced as a disturbance at time T1, and the temperature detected by the downstream temperature sensors 18 and 20 is decreased, the temperature difference C of the sample placement unit 2 is reduced. Is less than the appropriate temperature difference. Since the blower 12 is PID-controlled so that the temperature difference C maintains an appropriate temperature difference, after the time T1, the rotational speed of the blower 12 decreases and the blown air volume decreases. Therefore, the temperature detected by the downstream temperature sensors 18 and 20 rises, and the temperature difference C returns to the appropriate temperature difference.

However, when the rotational speed of the blower 12 is lowered, energy by stirring of the blower 12 is reduced, so that the amount of heat supplied to the sample placement unit 2 is lowered and the overall temperature is lowered. That is, a phenomenon is observed in which the temperature detected by the upstream temperature sensor 16 gradually decreases from time T2.
Here, in this embodiment, the heater 13 is PID-controlled so that the temperature detected by the upstream upper temperature sensor 16 becomes the set temperature, so that the input of the heater 13 increases and the appropriate temperature difference is maintained. As a result, the overall temperature rises. As a result, the temperature of the sample placement unit 2 is the set temperature, and the temperature difference C of the sample placement unit 2 is an appropriate temperature difference.

  In the present invention, the air flow rate of the blower 12 is controlled using the air flow rate calculated by the following equation as a target value.

V = Q · 860 / (Cp · γ · (BA) · 60) Equation 1

V: Target air flow [cubic meter par m ³ / min]
Q: Calorific value [kw] of all devices that can generate heat inside the thermostat 1
860 [kcal / kw]
Cp: Constant pressure specific heat of air [kcal / kg · K]
γ: air density [kilogram par cubic meter kg / m ³ ]
B: Downstream temperature A: Upstream temperature

In the said embodiment, although the structure which enabled the air flow volume (rotational speed of the motor) of the air blower 12 to be switched continuously was shown, this invention is not limited to this, The air flow rate of the air blower 12 is switched in steps. It does not matter if it can be.
Moreover, in the said embodiment, although PID control of the ventilation volume and the heater of the air blower 12 was carried out, you may carry out on-off control of these.
FIG. 8 and FIG. 9 show temperature changes when the air flow rate is adjusted by switching the air flow rate on and off in two stages (more precisely, the strength is switched), and the temperature rises and falls at a constant cycle.

  The recommended appropriate temperature difference is about 4 to 6 degrees Celsius, but since the appropriate temperature difference varies depending on the test conditions, it is desirable that the appropriate temperature difference can be appropriately changed.

  In the above embodiment, a configuration in which two temperature sensors are provided in each of the air passage 10 and the exhaust passage 11 is shown. However, the present invention is not limited to this. There may be a configuration in which only one of them is provided, and only one is provided in the other, or one or three or more are provided in the air passage 10 and the exhaust passage 11.

  In the above embodiment, the control unit 30 calculates the average temperature of the two temperature sensors and adopts the average temperature as the upstream temperature A or the downstream temperature B. However, the present invention is limited to this. For example, the control unit 30 calculates the lowest temperature detected on the upstream side and adopts it as the upstream temperature A, and calculates the highest temperature detected on the downstream side and adopts it as the downstream temperature B. It does not matter.

  Furthermore, the temperature difference is calculated by setting the upstream upper temperature sensor (upstream temperature detecting means) 16 provided before and after the a layer and the downstream upper temperature sensor 20 as a set, and separately from the e layer. The upstream side lower temperature sensor (upstream side temperature detection means) 17 and the downstream side lower temperature sensor (downstream temperature detection means) 18 provided before and after are calculated as a set, and the two temperature differences are calculated. In comparison, the larger one may be used as a reference temperature difference, and the air flow rate of the blower may be increased or decreased so that the reference temperature difference becomes an appropriate temperature difference. Of course, the upstream temperature detecting means and the downstream lower temperature sensor may be provided before and after the other layers (b layer, c layer, d layer).

In the above embodiment, the upstream temperature A detected by the upstream upper temperature sensor 16 is controlled to the set value. However, the present invention is not limited to this, for example, the downstream temperature B detected by the downstream upper temperature sensor 20. It is also possible to use a configuration in which the value is controlled to the set value.
Moreover, the structure by which the average value of the detection temperature of all the temperature sensors 16, 17, 18, and 20 provided in the sample arrangement | positioning part 2 vicinity is controlled to a setting value may be sufficient.

  In the above-described embodiment, the heater 13 is PID controlled or on / off controlled. However, among the plurality of heaters, the number of heaters to be energized may be changed to adjust the total output of the heaters. Of course, PID control of each heater and control for changing the number of energized heaters may be used in combination.

DESCRIPTION OF SYMBOLS 1 Constant temperature apparatus 2 Sample arrangement | positioning part 5 Passage part 10 Blower path 11 Exhaust path 15 Circulation path 12 Fan 13 Heater (heating means)
16 Upstream upper temperature sensor (upstream temperature detection means)
17 Upstream lower temperature sensor (upstream temperature detection means)
18 Downstream lower temperature sensor (downstream temperature detection means)
20 Downstream upper temperature sensor (downstream temperature detection means)
21 Damper (Temperature drop means)
40 Airflow adjustment damper A Upstream temperature B Downstream temperature C Temperature difference W Exothermic sample body

Claims (9)

A sample placement part in which a heat generating sample body that generates heat is placed, a blower that can flow air in a certain direction in the sample placement part, a heating means that can raise the temperature of the sample placement part, and a sample placement A temperature-decreasing means capable of lowering the temperature of the part, and a thermostat capable of maintaining the temperature in the sample placement part at a set value,
Inside the thermostat, an upstream temperature detecting means for detecting the temperature upstream of the sample arrangement portion in the air flow direction, and a downstream temperature for detecting the temperature downstream of the sample arrangement portion in the air flow direction Detecting means,
When controlling the temperature of the sample placement unit to the set value, there is a predetermined appropriate temperature difference between the upstream temperature detected by the upstream temperature detection means and the downstream temperature detected by the downstream temperature detection means. Thus, the constant temperature apparatus characterized by increasing / decreasing the ventilation volume of an air blower. If the temperature difference between the upstream temperature and the downstream temperature is less than the appropriate temperature difference, reduce the blower volume of the blower,
The thermostatic device according to claim 1, wherein when the temperature difference exceeds an appropriate temperature difference, the air flow rate of the blower is increased.   The thermostat according to claim 1 or 2, wherein a plurality of at least one of the upstream temperature detecting means and the downstream temperature detecting means is provided. Among the upstream temperature detection means and the downstream temperature detection means, a plurality of temperature detection means are arranged at positions separated from each other,
Based on the temperature difference between the maximum or minimum temperature detected by the downstream temperature detection means and the minimum or maximum temperature detected by the upstream temperature detection means, the air flow rate of the blower is The thermostat according to claim 3, wherein the thermostat is controlled. Among the upstream temperature detection means and the downstream temperature detection means, a plurality of temperature detection means are arranged at positions separated from each other,
When there are a plurality of upstream temperature detection means, the average value of the detected temperatures detected by the plurality of upstream temperature detection means is the upstream temperature, and when the number of upstream temperature detection means is singular, The detection temperature detected by the upstream temperature detection means is the upstream temperature,
When there are a plurality of downstream temperature detection means, the average value of the detected temperatures detected by the plurality of downstream temperature detection means is the downstream temperature, and when the number of downstream temperature detection means is singular, The detection temperature detected by the downstream temperature detection means is the downstream temperature,
The thermostatic device according to claim 3, wherein the air flow rate of the blower is increased or decreased so that a predetermined appropriate temperature difference exists between the upstream temperature and the downstream temperature. Having a plurality of upstream temperature detection means and a plurality of downstream temperature detection means,
The flow of air passing through the sample placement area is roughly divided into multiple layers,
The upstream temperature detection means is upstream of the plurality of layers, and the downstream temperature detection means corresponding to the upstream temperature detection means is installed downstream of the layers,
The difference between the upstream temperature detected by the upstream temperature detection means and the corresponding downstream temperature detected by the downstream temperature detection means is the reference temperature difference, and this reference temperature difference is the appropriate temperature. The constant temperature apparatus according to claim 3, wherein the air flow rate of the blower is increased or decreased so as to be a difference.   The temperature control apparatus according to any one of claims 1 to 6, wherein the temperature in the sample placement section is maintained at a set value based on the temperature detected by the upstream temperature detection means.   The temperature control apparatus according to any one of claims 1 to 6, wherein the temperature in the sample placement section is maintained at a set value based on the temperature detected by the downstream temperature detection means.   The temperature in the sample placement unit is maintained at a set value based on an average of the detected temperature of the upstream temperature detecting means and the detected temperature of the downstream temperature detecting means. Constant temperature device.

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