Environment formation device

Abstract

To minutely control the temperature distribution in an internal space of an environment formation room in which an object is accommodated.SOLUTION: An environment formation device comprises: first air conditioning means that adjusts the temperature of air flowing into an air-conditioned room from a side of a first wall surface of an environment formation room in which an object is accommodated to generate conditioned air; a plurality of blower fans that is arranged on a side of a second wall surface of the environment formation room opposite to the first wall surface and sends the conditioned air from the air-conditioned room in a direction directed from the second wall surface to the first wall surface; control means that individually controls the rotation speeds of the plurality of blower fans; and a plurality of first temperature detection means that is arranged at a plurality of portions on the side of the first wall surface. The control means controls the first air conditioning means until detected temperature detected by the plurality of first temperature detection means reaches a target control temperature, and when the detected temperature detected by specific first temperature detection means, of the plurality of first temperature detection means, does not reach a target setting temperature, increases the rotation speed of a specific blower fan, of the plurality of blower fans, which corresponds to the specific first temperature detection means.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to an environment creating device, and more particularly to an environment creating device capable of precisely controlling the temperature distribution in the internal space of an environment creating chamber in which an object is housed. [Background technology]

[0002] Environmental testing is known as a test for evaluating the performance of a test object such as an electronic component. In the environmental testing, the performance of the test object is evaluated by applying environmental stress such as temperature to the test object housed in a test chamber. In addition, an environmental testing device is known as a device for carrying out the environmental testing. The environmental testing device according to the background art is configured to include a test chamber surrounded by a heat-insulating housing, an air-conditioning chamber communicating with the test chamber, an air-conditioning device such as a heater and a cooler arranged in the air-conditioning chamber, and a blower that sends conditioned air generated by the air-conditioning device from an air passage in the air-conditioning chamber to the test chamber. As the blower, one blower fan is arranged so as to be located on one side wall side of the test chamber.

[0003] In addition, the following Patent Document 1 discloses an environmental test device including an air conditioner arranged in a temperature adjustment section above a test chamber, two centrifugal fans arranged side by side in the left-right direction in the temperature adjustment section, and a plurality of temperature sensors for detecting the temperature distribution in the test chamber. A first partition wall separating the test chamber from the air supply path extending downward from the temperature adjustment section has a number of ventilation openings arranged in the up-down and left-right directions. Similarly, a second partition wall separating the test chamber from the exhaust path extending downward from the temperature adjustment section, facing the first partition wall, has a number of ventilation openings arranged in the up-down and left-right directions. The conditioned air sent out from the centrifugal fan is guided downward from the temperature adjustment section through the air supply path and sent out from the ventilation opening of the first partition wall into the test chamber. The sent out conditioned air passes through the test chamber, is exhausted from the ventilation opening of the second partition wall, and is guided through the exhaust path to the temperature adjustment section above. In this environmental testing device, based on the detection results of the temperature sensor, the airflow rate of each of the two centrifugal fans is individually adjusted to ensure a uniform temperature distribution in the test room by focusing on blowing conditioned air to areas of the internal space of the test room with large temperature variations. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5969968 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the environmental test device of the background art, since one blower fan is disposed at approximately the center of the side wall, the amount of air blown to the periphery of the internal space of the test chamber is relatively smaller than the amount of air blown to the center. Therefore, a temperature difference may occur between the periphery and the center in the internal space of the test chamber. In addition, when a plurality of test objects are arranged in the test chamber, the conditioned air blown from the blower may be blocked by the upstream test object and may not reach the downstream test object, causing a temperature difference in the internal space of the test chamber between the upstream side and the downstream side of the air blowing path. Thus, according to the environmental test device of the background art, various factors may cause unintended variations in the temperature distribution of the internal space of the test chamber.

[0006] According to the environmental test device disclosed in the above-mentioned Patent Document 1, the air volume can be made different between the left and right half regions in the test room by individually controlling the air volume of each of the two centrifugal fans arranged in the left-right direction. However, for each of the left and right half regions, for example, if the air volume of the left centrifugal fan is increased, the air volume in the left half region increases overall, and if the air volume of the right centrifugal fan is decreased, the air volume in the right half region decreases overall. In other words, it is impossible to control the air volume by increasing or decreasing only a part of the air volume in each of the left and right half regions. Therefore, according to the environmental test device disclosed in the above-mentioned Patent Document 1, the control of the temperature distribution in the internal space of the test room may not be precise enough.

[0007] In addition, in the environmental testing device disclosed in the above Patent Document 1, the control goal is to make the temperature distribution in the internal space of the test chamber uniform. However, a uniform temperature distribution is not necessarily optimal depending on the contents of the test steps of the environmental test, so it is desirable to realize a means for forming a desired temperature distribution, including a non-uniform temperature distribution, in the test chamber depending on the contents of the test steps.

[0008] The present invention has been made in consideration of the above circumstances, and has an object to provide an environment creating device capable of precisely controlling the temperature distribution in the internal space of an environment creating chamber in which an object is housed. [Means for solving the problem]

[0009] An environmental forming device according to one embodiment of the present invention is characterized in that it comprises an environmental forming chamber in which an object is housed, an air conditioning chamber connected to the environmental forming chamber, a first air conditioning means for generating conditioned air by adjusting the temperature of air flowing into the air conditioning chamber from a first wall side of the environmental forming chamber, a plurality of blower fans arranged in a row along a plurality of directions on a second wall side of the environmental forming chamber opposite the first wall, and for blowing conditioned air from the air conditioning chamber to the environmental forming chamber in a direction from the second wall toward the first wall, and a control means for individually controlling the rotational speed of each of the plurality of blower fans.

[0010] According to the environment forming device of this aspect, a plurality of blower fans are arranged in a line along a plurality of directions on the second wall side of the environment forming chamber, and the control means controls the rotation speed of each of the plurality of blower fans individually. In this way, by individually controlling the rotation speed of each of the plurality of blower fans arranged in a line along a plurality of directions, the flow of conditioned air in each area in the environment forming chamber can be controlled arbitrarily. As a result, it is possible to precisely control the temperature distribution in the internal space of the environment forming chamber, including uniform and non-uniform temperature distribution.

[0011] For example, by creating a uniform temperature distribution within the environment creating chamber, even if multiple objects are stored in multiple locations within the environment creating chamber, it is possible to apply the same temperature stress to each object regardless of where they are stored within the environment creating chamber.

[0012] Furthermore, when performing an environment creation step for which a certain non-uniform temperature distribution is optimal, by forming that non-uniform temperature distribution within the environment creation chamber, it becomes possible to perform the environment creation step with the optimal temperature distribution.

[0013] In the environment forming device according to the above aspect, it is preferable that the device further comprises a plurality of first temperature detection means arranged at a plurality of positions on the first wall surface side.

[0014] According to the environment forming device of this aspect, a plurality of first temperature detection means are arranged at a plurality of locations on the first wall side, which is the most downstream side of the flow of conditioned air in the environment forming chamber. Therefore, the control means can determine whether or not a desired temperature distribution is correctly formed in the environment forming chamber based on the detection results of the plurality of first temperature detection means. Then, the control means can appropriately form a desired temperature distribution in the environment forming chamber by individually feedback-controlling each of the plurality of blower fans based on the determination result.

[0015] In the environment creating device according to the above aspect, it is preferable that the plurality of first temperature detecting means and the plurality of blower fans are the same in number and arranged in the same layout.

[0016] In the environment creating device according to this aspect, the first temperature detecting means and the blower fans are arranged in the same number and in the same layout. Therefore, since the first temperature detecting means and the blower fans correspond one-to-one, the control means can easily feedback control the blower fans corresponding to each first temperature detecting means based on the detection result of the first temperature detecting means.

[0017] In the environmental forming device of the above-mentioned aspect, it is desirable to further provide a plurality of second air conditioning means arranged corresponding to the plurality of blower fans and adjusting the temperature of the conditioned air sent to the environmental forming room by each of the plurality of blower fans, and the control means further individually control the conditioned temperature of each of the plurality of second air conditioning means.

[0018] According to the environment creating device of this aspect, a plurality of second air conditioning means are arranged corresponding to a plurality of blower fans, and the control means controls the air conditioning temperature of each of the plurality of second air conditioning means individually, thereby adjusting the temperature of the conditioned air sent to the environment creating chamber by each of the plurality of blower fans. Therefore, since not only the flow of the conditioned air but also its temperature can be controlled in each of the plurality of blower fans, it becomes possible to more precisely control the temperature distribution in the internal space of the environment creating chamber.

[0019] In the environmental forming device of the above-mentioned aspect, it is desirable that the control means, when the temperature detected by a specific first temperature detection means among the multiple first temperature detection means does not reach the target set temperature, increases the rotation speed of a specific blower fan among the multiple blower fans corresponding to the specific first temperature detection means, and when the temperature detected by the specific first temperature detection means still does not reach the target set temperature, drives a specific second air conditioning means among the multiple second air conditioning means corresponding to the specific first temperature detection means.

[0020] According to the environment forming device of this aspect, the control means increases the rotation speed of the specific blower fan corresponding to the specific first temperature detection means when the temperature detected by the specific first temperature detection means has not reached the target set temperature, and drives the specific second air conditioning means corresponding to the specific first temperature detection means when the temperature detected by the specific first temperature detection means still does not reach the target set temperature. Therefore, when the temperature detected by the specific first temperature detection means reaches the target set temperature when the rotation speed of the specific blower fan is increased, there is no need to drive the specific second air conditioning means, and it is possible to reduce the possibility of overheating or overcooling occurring due to driving the specific second air conditioning means.

[0021] In the environment forming device according to the above aspect, it is preferable that the device further comprises a plurality of second temperature detection means arranged at a plurality of positions on the second wall surface side.

[0022] According to the environment forming device of this aspect, a plurality of second temperature detection means are arranged at a plurality of locations on the second wall side, which is the most upstream of the flow of the conditioned air in the environment forming room. Therefore, when the temperature of the conditioned air is overheated above the allowable upper limit or overcooled below the allowable lower limit by the first air conditioning means and the second air conditioning means, the control means can identify the location of the overheating or overcooling based on the detection results of the plurality of second temperature detection means. Then, the control means can suppress the temperature of the conditioned air sent to the environment forming room by the plurality of blower fans to below the allowable upper limit or above the allowable lower limit by individually feedback controlling each of the plurality of second air conditioning means based on the identification result. As a result, it is possible to prevent the failure of the object caused by exposure to the overheated or overcooled conditioned air in advance.

[0023] In the environment creating device according to the above aspect, it is preferable that the plurality of second temperature detecting means and the plurality of blower fans are arranged in the same number and in the same layout.

[0024] In the environment creating device according to this aspect, the second temperature detecting means and the blower fans are arranged in the same number and in the same layout. Therefore, the second temperature detecting means and the second air conditioning means correspond one-to-one to each other, so that the control means can easily feedback control the second air conditioning means corresponding to each second temperature detecting means based on the detection result of the second temperature detecting means.

[0025] In the environment creating device according to the above aspect, it is preferable that each of the plurality of blower fans is driven by a DC motor.

[0026] In the environment creating device according to this aspect, each of the blower fans is driven by a DC motor, and therefore, compared to a case where the blower fans are driven by an AC motor, the control means can control the blower fans with good responsiveness and can control the rotation speed of the blower fans over a wide adjustment range from low speed to high speed.

[0027] An environmental forming device according to one embodiment of the present invention comprises an environmental forming chamber in which an object is housed, an air conditioning chamber connected to the environmental forming chamber, an air conditioning means for generating conditioned air by adjusting the temperature of air flowing into the air conditioning chamber from a first wall side of the environmental forming chamber, a plurality of blower fans arranged on a second wall side of the environmental forming chamber opposite the first wall and for blowing conditioned air from the air conditioning chamber to the environmental forming chamber in a direction from the second wall side toward the first wall side, and a control means, wherein the control means individually controls the rotation speed of each of the plurality of blower fans, thereby forming a non-uniform temperature distribution within the environmental forming chamber in synchronization with changes in the environmental forming step that forms a predetermined environment within the environmental forming chamber.

[0028] According to the environment creating device of this aspect, a plurality of blower fans are arranged on the second wall side of the environment creating chamber, and the control means individually controls the rotation speed of each of the plurality of blower fans to form a non-uniform temperature distribution in the environment creating chamber in synchronization with the change of the environment creating step. Therefore, when performing an environment creating step for which a specific non-uniform temperature distribution is optimal, the control means individually controls the rotation speed of each of the plurality of blower fans to form the non-uniform temperature distribution in the environment creating chamber, thereby making it possible to perform the environment creating step with the optimal temperature distribution.

[0029] In the environment forming device of the above-mentioned aspect, the environment forming step includes a temperature change step of changing the temperature inside the environment forming chamber and a temperature maintenance step of maintaining the temperature inside the environment forming chamber, and in the temperature change step, the control means relatively increases the rotational speed of the blower fan among the multiple blower fans that blows air-conditioned air toward the center of the internal space of the environment forming chamber and relatively decreases the rotational speed of the blower fan that blows air-conditioned air toward the peripheral part of the internal space of the environment forming chamber, and in the temperature maintenance step, relatively decreases the rotational speed of the blower fan among the multiple blower fans that blows air-conditioned air toward the center of the internal space of the environment forming chamber and relatively increases the rotational speed of the blower fan that blows air-conditioned air toward the peripheral part of the internal space of the environment forming chamber.

[0030] According to the environment forming device of this aspect, in the temperature changing step, the control means relatively increases the rotation speed of the blower fan that blows the conditioned air toward the center of the internal space of the environment forming chamber among the multiple blower fans. The object is often accommodated in the central part of the internal space of the environment forming chamber. Therefore, by relatively increasing the rotation speed of the blower fan that blows the conditioned air toward the central part, more conditioned air can be blown toward the object, so that temperature stress can be efficiently applied to the object. As a result, when multiple objects are accommodated in the central part, it is possible to promote the temperature transition of the object during the temperature changing step and reduce the temperature variation. In addition, in the temperature maintaining step, the control means relatively increases the rotation speed of the blower fan that blows the conditioned air toward the peripheral part of the internal space of the environment forming chamber among the multiple blower fans. This allows more conditioned air to be blown toward the peripheral parts, that is, the wall surface, ceiling surface, and floor surface of the environment forming chamber. As a result, the effect of the outside air temperature inside the environment creating chamber on the temperature in the internal space of the environment creating chamber can be mitigated, making it possible to maintain a stable temperature inside the environment creating chamber. Effect of the Invention

[0031] According to the present invention, it is possible to precisely control the temperature distribution in the internal space of the environment creating chamber in which the object is housed. [Brief description of the drawings]

[0032] [Figure 1] 1 is a diagram showing a schematic configuration of an environment forming device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a diagram illustrating a schematic layout of a plurality of blower fans. [Diagram 3] FIG. 4 is a diagram illustrating a schematic layout of a plurality of sub-heaters. [Figure 4] FIG. 2 is a diagram illustrating a schematic layout of a plurality of DC motors. [Diagram 5] FIG. 2 is a diagram illustrating a schematic layout of a plurality of temperature sensors. [Figure 6] FIG. 2 is a diagram illustrating a schematic layout of a plurality of temperature sensors. [Figure 7] FIG. 2 is a diagram showing a control unit included in the environmental test device. [Figure 8] 5 is a flowchart showing a method for controlling the environmental testing device by the control unit. [Figure 9] FIG. 1 is a diagram partially illustrating an example of a temperature cycle performed by an environmental test device. [Figure 10] 10A and 10B are diagrams each showing a schematic diagram of a modified example of the layout of a plurality of blower fans. [Figure 11] 10A and 10B are diagrams each showing a schematic diagram of a modified example of the layout of a plurality of blower fans. [Figure 12] FIG. 13 is a diagram illustrating a configuration of an environment forming device according to a modified example. [Figure 13] FIG. 13 is a diagram illustrating a configuration of an environment forming device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that elements with the same reference numerals in different drawings indicate the same or corresponding elements.

[0034] <Configuration of Environmental Testing Device 1> FIG. 1 is a diagram showing a schematic configuration of an environment forming device according to an embodiment of the present invention. In the example of this embodiment, the environment forming device is configured as an environment testing device 1 for evaluating the performance of a test object 6 by applying a predetermined temperature stress to the test object 6. However, the environment testing device 1 may be configured as a constant temperature and humidity chamber for applying a predetermined temperature stress and humidity stress to the test object 6 by additionally mounting a humidifier. In addition, the environment testing device 1 may be configured as a burn-in testing device for screening initial defects by applying a predetermined temperature stress and voltage stress to the test object 6. The test object 6 is, for example, an electronic component such as a circuit board. In the following description, directions are defined by an orthogonal coordinate system having an X-axis extending along the horizontal direction, a Y-axis extending along the vertical direction, and a Z-axis perpendicular to both the X-axis and the Y-axis, as shown in FIG. 1. The orthogonal coordinate system shown in FIG. 1 shows a W-axis extending in a direction opposite to the direction of extension of the X-axis.

[0035] The environmental test device 1 includes a test chamber 3 (environment forming chamber) and an air-conditioning chamber 4 surrounded by a heat-insulating housing 2. The test chamber 3 has a first wall surface 7 and a second wall surface 9 that face each other. The air-conditioning chamber 4 has a first space portion 41 defined by the first wall surface 7 and the inner surface 2A of the housing 2, a second space portion 42 defined by the second wall surface 9 and the inner surface 2B of the housing 2, and a connection space portion 43 that connects the first space portion 41 and the second space portion 42. A plurality of ventilation holes 8 are formed in the first wall surface 7, and a plurality of ventilation holes 10 are formed in the second wall surface 9. The test chamber 3 and the air-conditioning chamber 4 communicate with each other through the plurality of ventilation holes 8, 10. The first wall surface 7 on which the plurality of ventilation holes 8 are formed may be omitted, in which case the inner surface 2A of the housing 2 becomes the first wall surface of the test chamber 3. Furthermore, the first wall surface 7 or the inner surface 2A may be the inner surface of a door for accessing the testing chamber 3 from the outside, in which case the inner surface of the door becomes the first wall surface of the testing chamber 3.

[0036] Shelves 5 are installed in the test chamber 3. The shelves 5 have a lattice-like external shape in which a number of rod-shaped members are arranged crosswise. The test objects 6 are placed on the shelves 5. In the example shown in FIG. 1, the shelves 5 are installed in a number of tiers in the test chamber 3, and a number of test objects 6 are placed side by side on each shelf 5, thereby accommodating a number of test objects 6 in the center of the internal space of the test chamber 3. However, the number of tiers of shelves 5 installed in the test chamber 3 may be one or more, and the number of test objects 6 placed on each shelf 5 may be one or more.

[0037] A cooler 11 as a cooling device and a main heater 12 as a heating device are arranged in the connection space 43 of the air-conditioning room 4. The cooler 11 and the main heater 12 function as a first air-conditioning means, and generate conditioned air adjusted to a desired temperature by cooling or heating air that has flowed into the air-conditioning room 4 from the test room 3 through the ventilation opening 8 of the first wall surface 7. The conditioned temperatures of the cooler 11 and the main heater 12 are controlled by the control unit 30 described later.

[0038] Further, within the test chamber 3, a plurality of temperature sensors 17 and 18, which will be described later, are disposed.

[0039] A plurality of blower fans 13 are arranged on the second wall surface 9 side of the test chamber 3. The blower fans 13 are configured as axial fans having a DC motor 14 and a plurality of blades fixed to the tip of a rotating shaft 15 of the DC motor 14. The DC motor 14 is arranged outside the housing 2. The rotating shaft 15 penetrates the outer wall of the housing 2 and extends along the W direction in the air-conditioning chamber 4 toward the test chamber 3. The tip of the rotating shaft 15 is arranged concentrically with the center of the ventilation port 10 of the second wall surface 9. The blades of the blower fans 13 are arranged in the same plane as the ventilation port 10. When the DC motor 14 is driven and the blower fans 13 rotate, conditioned air is sent from the air-conditioning chamber 4 through the ventilation port 10 into the test chamber 3. Because the blades of blower fan 13 rotate within the YZ plane, the conditioned air sent into test chamber 3 by blower fan 13 travels generally in the W direction as indicated by the thick straight arrow in Figure 1, passes through test chamber 3, and is then exhausted into air-conditioned room 4 through ventilation opening 8 in first wall 7.

[0040] 2 is a diagram showing a schematic layout of the multiple blower fans 13, and corresponds to a plan view of a position along line II-II shown in FIG. 1 as viewed in the X direction. In this embodiment, the environmental test device 1 is provided with a total of nine blower fans 131-139, in which three blower fans 13 are arranged at a distance from each other along each of the Y direction and the Z direction, and are arranged in a matrix of three rows and three columns. The blower fans 131-139 are distributed and arranged across the entire area including the central part and the peripheral part of the second wall surface 9. The rotation speed of each of the blower fans 131-139 is individually controlled by the control unit 30 described later.

[0041] Further, the second wall surface 9 is formed with a plurality of ventilation openings 10 in the same number and with the same layout as the plurality of blower fans 13. In this embodiment, a total of nine circular ventilation openings 101-109 are formed in a matrix of 3 rows and 3 columns. Each of the ventilation openings 101-109 is formed at a position where the center of the circle is concentric with the rotation axis 15 of each of the blower fans 131-139.

[0042] As shown in Fig. 1, sub-heaters 16 are disposed in the second space 42 of the air-conditioning room 4 corresponding to each blower fan 13. The sub-heaters 16 are disposed in a position between the blades of the blower fan 13 and the DC motor 14, close to the blades. The sub-heaters 16 are disposed in a position and shape that does not interfere with the rotational operation of the rotary shaft 15 of the blower fan 13. The sub-heaters 16 function as a second air-conditioning means, and further heat the conditioned air generated by the main heater 12, thereby finely adjusting the temperature of the conditioned air sent into the test chamber 3 by each blower fan 13.

[0043] 3 is a diagram showing a schematic layout of the sub-heaters 16, and corresponds to a plan view of a position along line III-III shown in FIG. 1 as viewed in the X direction. The sub-heaters 16 are arranged in the same number as the blower fans 13 and in the same layout. In this embodiment, a total of nine sub-heaters 161-169 are arranged in a matrix of 3 rows and 3 columns. The air conditioning temperature of each of the sub-heaters 161-169 is individually controlled by the control unit 30 described later.

[0044] Fig. 4 is a diagram showing a schematic layout of a plurality of DC motors 14, and corresponds to a plan view of a position along line IV-IV shown in Fig. 1 as viewed in the X direction. In this embodiment, a total of nine DC motors 141 to 149 are arranged in a matrix of 3 rows and 3 columns.

[0045] 1, a plurality of temperature sensors 17 serving as first temperature detection means are disposed close to a first wall surface 7 of the test chamber 3. Since the first wall surface 7 is located at the most downstream position of the air path of the conditioned air blown by the blower fan 13, the temperature sensors 17 detect the temperature of the air in the test chamber 3 at the most downstream position.

[0046] FIG. 5 is a diagram showing a schematic layout of the temperature sensors 17, and corresponds to a plan view of a position along the line VV shown in FIG. 1 viewed in the W direction. The temperature sensors 17 are arranged in the same number as the blower fans 13 and in the same layout. In this embodiment, a total of nine temperature sensors 171-179 are arranged in a matrix of three rows and three columns. The temperatures detected by the temperature sensors 171-179 are input to the control unit 30, which will be described later. The temperature sensors 171-179 are arranged at the intersections of a lattice-shaped frame 20 in which a plurality of rod-shaped members are arranged in a cross-arrangement. The frame 20 is fixed to the inner wall of the test chamber 3 in the vicinity of the first wall surface 7. As shown in FIG. 1, each temperature sensor 171-179 is arranged on an extension line of the rotation axis 15 of the corresponding blower fan 131-139.

[0047] 1, a plurality of temperature sensors 18 serving as second temperature detection means are disposed adjacent to a second wall surface 9 of the test chamber 3. The temperature sensors 18 are disposed adjacent to the blower fan 13. Since the second wall surface 9 is located at the most upstream position of the blowing path of the conditioned air by the blower fan 13, the temperature sensors 18 detect the temperature of the air in the test chamber 3 at the most upstream position.

[0048] FIG. 6 is a diagram showing a schematic layout of the temperature sensors 18, and corresponds to a plan view of a position along the line VI-VI shown in FIG. 1 viewed in the X direction. The temperature sensors 18 are arranged in the same number as the blower fans 13 and in the same layout. In this embodiment, a total of nine temperature sensors 181-189 are arranged in a matrix of three rows and three columns. The temperatures detected by the temperature sensors 181-189 are input to the control unit 30, which will be described later. The temperature sensors 181-189 are arranged at the intersections of a lattice-shaped frame 21 in which a plurality of rod-shaped members are arranged crosswise. The frame 21 is fixed to the inner wall of the test chamber 3 in the vicinity of the second wall surface 9. As shown in FIG. 1, each of the temperature sensors 181-189 is arranged on an extension line of the rotation axis 15 of the corresponding blower fans 131-139.

[0049] FIG. 7 is a diagram showing a control unit 30 provided in the environmental test apparatus 1. A processor such as a CPU that functions as the control unit 30 is disposed outside the housing 2. Temperature detection signals S11 to S19 are respectively input to the control unit 30 from temperature sensors 171 to 179. Further, temperature detection signals S21 to S29 are respectively input to the control unit 30 from temperature sensors 181 to 189. The control unit 30 controls the driving of the cooler 11 by a driving signal S3. The control unit 30 controls the driving of the main heater 12 by a driving signal S4. The control unit 30 individually controls the outputs of the DC motors 141 to 149 by driving signals S51 to S59, thereby individually controlling the rotational speeds of the blower fans 131 to 139 within a range of 0 or more and a maximum value Vmax or less. The control unit 30 individually drives the sub-heaters 161 to 169 by driving signals S61 to S69, thereby individually controlling the temperature of the conditioned air that has passed through the main heater 12 by additional heating by the sub-heaters 161 to 169. Thereby, the temperature of the conditioned air sent to the test chamber 3 by each of the blower fans 131 to 139 is individually adjusted by the sub-heaters 161 to 169.

[0050] <Operation of the environmental test apparatus 1> FIG. 8 is a flowchart showing a control method of the environmental test apparatus 1 by the control unit 30. Here, the operation in the case of forming a uniform temperature distribution of a predetermined high temperature (for example, 150° C.) less than the allowable upper limit temperature Tmax as the target set temperature TP in the test chamber 3 will be described. In the initial state, the cooler 11, the main heater 12, the sub-heaters 161 to 169, and the blower fans 131 to 139 are all stopped from driving.

[0051] When an execution start command for the environmental test is input after the object under test 6 is placed on the shelf board 5, first, in step SP101, the control unit 30 starts driving all the blower fans 131 to 139 at a rotational speed of an initial value V0 (<Vmax) by driving the DC motors 141 to 149 by driving signals S51 to S59.

[0052] Next, in step SP102, the control unit 30 inputs the temperature detection signals S11-S19, S21-S29 from the temperature sensors 171-179, 181-189. The control unit 30 then identifies the maximum value among the detected temperatures T171-T179, T181-T189 represented by the temperature detection signals S11-S19, S21-S29, and determines whether or not the maximum value is less than the target set temperature TP. At this point in time, the main heater 12 has not yet been driven, and the temperature of the internal space of the test chamber 3 is at room temperature, so the maximum value is less than the target set temperature TP.

[0053] If the maximum value of the detected temperatures T171-T179, T181-T189 is less than the target set temperature TP (step SP102: YES), the process proceeds to step SP103, where the control unit 30 controls the main heater 12 with the drive signal S4 to increase the output of the main heater 12 by a predetermined amount. This causes the main heater 12 to start heating the air. The control unit 30 then executes the determination of step SP102 again. Since the temperature of the internal space of the test chamber 3 has not risen significantly immediately after the main heater 12 starts to be driven, the processes of steps SP102 and SP103 are repeatedly executed for a while.

[0054] When the temperature in the internal space of the test chamber 3 rises and the maximum value of the detected temperatures T171-T179, T181-T189 becomes equal to or higher than the target set temperature TP (step SP102: NO), the control unit 30 executes the following process for each of the blower fans 13N (N is 1-9 in this embodiment). The process for the blower fan 131 will be representatively described below, but similar processes are also executed for the other blower fans 132-139.

[0055] First, in step SP104, the control unit 30 determines whether or not the currently set rotation speed V1 of the blower fan 131 is equal to or greater than the maximum value Vmax. At this point in time, the rotation speed V1 of the blower fan 131 is set to the initial value V0, so the rotation speed V1 is less than the maximum value Vmax.

[0056] If the rotation speed V1 is less than the maximum value Vmax (step SP104: NO), the process proceeds to step SP105, and the control unit 30 determines whether the detected temperature T171 of the temperature sensor 171 corresponding to the blower fan 131 is less than the target set temperature TP based on the temperature detection signal S11 input from the temperature sensor 171.

[0057] If the detected temperature T171 is equal to or higher than the target set temperature TP (step SP105: NO), it can be said that the air temperature has risen to the target set temperature TP at the most downstream point of the air flow path of the blower fan 131, and the temperature rise is considered to have been completed in all areas upstream of that point in the air flow path. In this case, the process proceeds to step SP110, where the control unit 30 determines whether or not a command to end the environmental test has been input.

[0058] If the detected temperature T171 is lower than the target set temperature TP (step SP105: YES), the air temperature has not risen to the target set temperature TP at the most downstream of the air flow path of the blower fan 131, and therefore it is considered that the conditioned air sent out by the blower fan 131 to the test room 3 has not sufficiently reached the most downstream of the air flow path. In this case, the process proceeds to step SP106, and the control unit 30 increases the rotation speed V1 of the blower fan 131 by a predetermined amount by controlling the DC motor 141 corresponding to the blower fan 131 by the drive signal S51. This increases the volume of the conditioned air sent out by the blower fan 131 to the test room 3. Next, the control unit 30 executes the determination of step SP104 again.

[0059] If the detected temperature T171 does not rise above the target set temperature TP even when the rotation speed V1 is increased, the processes of steps SP104 to SP106 are repeatedly executed until the rotation speed V1 reaches its maximum value Vmax. This feedback control gradually increases the rotation speed V1 of the blower fan 131, and as a result, the volume of the conditioned air blown into the test room 3 by the blower fan 131 gradually increases.

[0060] When the rotation speed V1 becomes equal to or greater than the maximum value Vmax (step SP104: YES), the rotation speed V1 cannot be increased any further, and so the control unit 30 proceeds to a process of increasing the temperature of the conditioned air blown out by the blower fan 131. First, in step SP107, the control unit 30 determines, based on the temperature detection signal S21 input from the temperature sensor 181 corresponding to the blower fan 131, whether or not the detected temperature T181 of the temperature sensor 181 is less than the allowable upper limit temperature Tmax.

[0061] If the detected temperature T181 is equal to or higher than the allowable upper limit temperature Tmax (step SP107: NO), the temperature of the conditioned air sent to the test room 3 by the blower fan 131 cannot be increased any further. In this case, the control unit 30 executes step SP110.

[0062] If the detected temperature T181 is less than the allowable upper limit temperature Tmax (step SP107: YES), the process proceeds to step SP108, where the control unit 30 determines whether or not the detected temperature T171 of the temperature sensor 171 is less than the target set temperature TP, based on the temperature detection signal S11 input from the temperature sensor 171 corresponding to the blower fan 131. Immediately after the transition from step SP104 to step SP107, the sub-heater 161 has not yet been driven, so that the detected temperature T171 is likely to be less than the target set temperature TP.

[0063] If the detected temperature T171 is lower than the target set temperature TP (step SP108: YES), the process proceeds to step SP109, where the control unit 30 controls the sub-heater 161 corresponding to the blower fan 131 using a drive signal S61 to increase the output of the sub-heater 161 by a predetermined amount. This starts driving the sub-heater 161, and the temperature of the conditioned air sent to the test room 3 by the blower fan 131 increases. Then, the control unit 30 executes the determination of step SP107 again.

[0064] If the detected temperature T171 does not rise to or exceed the target set temperature TP even when the output of the sub-heater 161 is increased, the processes of steps SP107 to SP109 are repeatedly executed as long as the detected temperature T181 is below the allowable upper limit temperature Tmax. By this feedback control, the temperature of the conditioned air sent to the test room 3 by the blower fan 131 gradually rises due to the additional heating by the sub-heater 161.

[0065] When the detected temperature T171 becomes equal to or higher than the target set temperature TP (step SP108: NO), it is considered that the temperature rise is completed in all areas upstream of the air blowing path, since the air temperature has risen to the target set temperature TP at the most downstream of the air blowing path by the blower fan 131. In this case, the control unit 30 next executes step SP110.

[0066] In step SP110, the control unit 30 determines whether or not an end command for the environmental test has been input. If an end command for the environmental test has not been input (step SP110: NO), the control unit 30 repeats the processes from step SP102 onwards. On the other hand, if an end command for the environmental test has been input (step SP110: YES), the control unit 30 stops the operation of the environmental test apparatus 1.

[0067] In the above description, an example has been described in which sub-heaters 161-169 are provided corresponding to the blower fans 131-139, and in the heating process, the conditioned air heated by the main heater 12 is additionally heated by the sub-heaters 161-169 individually. The present invention is not limited to this example, and a configuration in which sub-coolers are provided corresponding to the blower fans 131-139, and in the cooling process, the conditioned air cooled by the main cooler (cooler 11) is additionally cooled by the sub-coolers individually may be adopted. Also, the main heater 12, the cooler 11, the sub-heaters 161-169, and the sub-cooler may start to be driven before the blower fans 131-139 are driven.

[0068] <Effects of the Environmental Testing Device 1> According to the environmental testing device 1 of this embodiment, a plurality of ventilation fans 131-139 are arranged in a line along a plurality of directions (Y direction and Z direction in the above example) on the second wall surface 9 side of the test chamber 3, and the control unit 30 controls the rotation speeds V1-V9 of the plurality of ventilation fans 131-139 individually. In this manner, by individually controlling the rotation speeds V1-V9 of the plurality of ventilation fans 131-139 arranged in a line along a plurality of directions, the flow of conditioned air in each region in the test chamber 3 can be arbitrarily controlled. As a result, it becomes possible to precisely control the temperature distribution in the internal space of the test chamber 3, including uniform and non-uniform temperature distribution.

[0069] Furthermore, according to the environmental testing device 1 of this embodiment, a plurality of temperature sensors 171-179 serving as first temperature detection means are disposed at a plurality of locations on the first wall surface 7 side, which is the most downstream side of the flow of conditioned air in the test chamber 3. Therefore, the control unit 30 can determine whether or not a desired temperature distribution is properly formed in the test chamber 3 based on the detection results of the temperature sensors 171-179. Then, the control unit 30 can appropriately form a desired temperature distribution in the test chamber 3 by individually feedback-controlling the blower fans 131-139 based on the determination result.

[0070] Furthermore, according to the environmental testing apparatus 1 of this embodiment, the temperature sensors 171-179 and the ventilation fans 131-139 are arranged in the same number and in the same layout as each other. Since the temperature sensors 171-179 and the ventilation fans 131-139 correspond one-to-one in this manner, the control unit 30 can easily perform feedback control of the ventilation fans 131-139 corresponding to each of the temperature sensors 171-179 based on the detection results of the temperature sensors 171-179.

[0071] Moreover, according to the environmental testing apparatus 1 of this embodiment, a plurality of sub-heaters 161-169 serving as second air conditioning means are arranged corresponding to a plurality of blower fans 131-139. Then, the control unit 30 individually controls the conditioned temperature of each of the sub-heaters 161-169, thereby adjusting the temperature of the conditioned air sent to the test chamber 3 by each of the blower fans 131-139. Therefore, in each of the blower fans 131-139, not only the flow of the conditioned air but also its temperature can be controlled, so that the temperature distribution in the internal space of the test chamber 3 can be controlled more precisely.

[0072] Furthermore, according to the environmental test apparatus 1 of this embodiment, when the temperature T17N detected by the temperature sensor 17N has not reached the target temperature TP, the control unit 30 increases the rotation speed VN of the blower fan 13N corresponding to the temperature sensor 17N, and when the detected temperature T17N still has not reached the target temperature TP, drives the sub-heater 16N corresponding to the temperature sensor 17N. Therefore, when the detected temperature T17N reaches the target temperature TP by increasing the rotation speed VN of the blower fan 13N, there is no need to drive the sub-heater 16N, and it is possible to reduce the possibility of overheating occurring due to driving the sub-heater 16N.

[0073] Moreover, according to the environmental test device 1 of this embodiment, a plurality of temperature sensors 181-189 are arranged as second temperature detection means at a plurality of locations on the second wall surface 9 side, which is the most upstream of the flow of the conditioned air in the test chamber 3. Therefore, when the temperature of the conditioned air is overheated by the main heater 12 and the sub-heaters 161-169 to a temperature higher than the allowable upper limit temperature Tmax, the control unit 30 can identify the location of the overheating based on the detection results of the temperature sensors 181-189. Then, the control unit 30 can suppress the temperature of the conditioned air sent to the test chamber 3 by each of the blower fans 131-139 to be equal to or lower than the allowable upper limit temperature Tmax by individually performing feedback control on each of the sub-heaters 161-169 based on the identification results. As a result, it is possible to prevent the test object 6 from being damaged by being exposed to the overheated conditioned air.

[0074] Furthermore, according to the environmental testing apparatus 1 of this embodiment, the temperature sensors 181-189 and the blower fans 131-139 are arranged in the same number and in the same layout. Since the temperature sensors 181-189 and the sub-heaters 161-169 correspond one-to-one in this manner, the control unit 30 can easily perform feedback control of the sub-heaters 161-169 corresponding to each of the temperature sensors 181-189 based on the detection results of the temperature sensors 181-189.

[0075] Moreover, according to the environmental testing apparatus 1 of this embodiment, the blower fans 131-139 are driven by DC motors 141-149. Therefore, compared to driving the blower fans by AC motors, the control unit 30 can control the blower fans 131-139 with better responsiveness, and can control the rotation speeds V1-V9 of the blower fans 131-139 over a wide adjustment range from low speed to high speed.

[0076] Furthermore, in the environmental testing apparatus 1 according to this embodiment, the control unit 30 individually controls the rotation speeds V1-V9 of the blower fans 131-139 to form a uniform temperature distribution in the test chamber 3. Therefore, even if a plurality of test objects 6 are housed in a plurality of locations within the test chamber 3, it is possible to apply the same temperature stress to each test object 6 regardless of the location within the test chamber 3.

[0077] <First Modification> In the above embodiment, the control unit 30 formed a uniform temperature distribution of the target set temperature TP within the test chamber 3, but it may also form a non-uniform temperature distribution that is optimal for each test step by synchronizing with the test steps of the environmental test performed on the test object 6.

[0078] FIG. 9 is a diagram partially illustrating an example of a temperature cycle by the environmental test device 1. It starts from a room temperature state at time T0, and at time T1, heating control from the room temperature state to a high temperature state is started by driving the main heater 12, and the transition to the high temperature state is completed at time T2. The temperature in the test chamber 3 in the high temperature state is, for example, 150° C. From time T2 to time T3, the high temperature state is maintained by driving the main heater 12, and this period is the high temperature exposure period. The high temperature exposure period is, for example, 30 minutes. At time T3, cooling control from the high temperature state to a low temperature state is started by driving the cooler 11, and the transition to the low temperature state is completed at time T4. The temperature in the test chamber 3 in the low temperature state is, for example, −40° C. From time T4 to time T5, the low temperature state is maintained by driving the cooler 11, and this period is the low temperature exposure period. The low temperature exposure period is, for example, 30 minutes. At time T5, heating control from a low temperature state to a high temperature state by driving the main heater 12 is started, and the transition to the high temperature state is completed at time T6.

[0079] A series of cycles from time T2 to time T6 constitutes a unit cycle of the temperature cycle, and this unit cycle is repeated a desired number of times (for example, 1000 cycles). In this manner, the unit cycle of the environmental test performed on the test object 6 by the environmental test device 1 has a temperature change step (times T3 to T4, T5 to T6) for changing the temperature in the test chamber 3, and a temperature maintenance step (times T2 to T3, T4 to T5) for maintaining the temperature in the test chamber 3.

[0080] In the temperature change step, the control unit 30 controls the driving of the DC motors 141-149 using drive signals S51-S59 to relatively increase the rotational speed V5 of the blower fan 135 that blows conditioned air toward the center of the internal space of the test chamber 3, and relatively decrease the rotational speeds V1-V4, V6-V9 of the blower fans 131-134, 136-139 that blow conditioned air toward the periphery of the internal space of the test chamber 3.

[0081] As a result, in the temperature change step when the temperature is increased, a non-uniform temperature distribution is formed in the test chamber 3 with the temperature being relatively high at the center and relatively low at the periphery in the cross section (YZ plane) of the blowing path of the conditioned air by the blower fan 13. Note that in the temperature change step when the temperature is increased, the control unit 30 may drive the sub-heater 165 corresponding to the blower fan 135 to additionally heat the conditioned air sent toward the center of the internal space of the test chamber 3.

[0082] In the temperature change step when the temperature is decreased, a non-uniform temperature distribution is formed in the test chamber 3 in the cross section (YZ plane) of the blowing path of the conditioned air by the blower fan 13, with the temperature in the central portion being relatively low and the temperature in the peripheral portion being relatively high. Note that in the temperature change step when the temperature is decreased, the control unit 30 may additionally cool the conditioned air sent toward the central portion of the internal space of the test chamber 3 by driving the above-mentioned sub-cooler corresponding to the blower fan 135.

[0083] As shown in FIG. 1, the test subject 6 is accommodated in the center of the internal space of the test chamber 3. Therefore, by performing air volume control (centralized control) in this manner, which concentrates the driving force of the blower fans 131-139 on the central blower fan 135, a larger amount of conditioned air can be sent toward the test subject 6.

[0084] On the other hand, in the temperature maintenance step, the control unit 30 controls the driving of the DC motors 141-149 using drive signals S51-S59 to relatively reduce the rotational speed V5 of the blower fan 135 that blows conditioned air toward the center of the internal space of the test chamber 3, and relatively increase the rotational speeds V1-V4, V6-V9 of the blower fans 131-134, 136-139 that blow conditioned air toward the periphery of the internal space of the test chamber 3.

[0085] As a result, in the temperature maintaining step when maintaining the temperature at a high temperature, a non-uniform temperature distribution is formed in the test chamber 3 with the temperature being relatively low at the center and relatively high at the periphery in the cross section (YZ plane) of the blowing path of the conditioned air by the blower fan 13. Note that in the temperature maintaining step when maintaining the temperature at a high temperature, the control unit 30 may additionally heat the conditioned air sent out toward the periphery of the internal space of the test chamber 3 by driving the sub-heaters 161-164, 166-169 corresponding to the blower fans 131-134, 136-139.

[0086] In the temperature maintaining step when maintaining the temperature at a low temperature, a non-uniform temperature distribution is formed in the test chamber 3 with the temperature being relatively high at the center and relatively low at the periphery in the cross section (YZ plane) of the blowing path of the conditioned air by the blower fan 13. In the temperature maintaining step when maintaining the temperature at a low temperature, the control unit 30 may additionally cool the conditioned air blown toward the periphery of the internal space of the test chamber 3 by driving the above-mentioned sub-coolers corresponding to the blower fans 131-134, 136-139.

[0087] In this way, by performing air volume control (peripheral concentrated control) to concentrate the driving force of the blower fans 131-139 on the peripheral blower fans 131-134, 136-139, more conditioned air can be blown toward the walls, ceiling, and floor of the test room 3.

[0088] As described above, the control unit 30 individually controls the rotation speed of each of the multiple blower fans 13 to form a non-uniform temperature distribution in the test chamber 3. In this modified example, the multiple blower fans 13 do not necessarily need to be arranged side by side along multiple directions. The control unit 30 can form a non-uniform temperature distribution in the test chamber 3 by individually controlling the rotation speed of each of the multiple blower fans 13 arranged side by side along at least one direction.

[0089] According to the environmental test apparatus 1 of this modification, the control unit 30 relatively increases the rotation speed V5 of the blower fan 135 that blows conditioned air toward the center of the internal space of the test chamber 3 in the temperature change step. The test object 6 is often accommodated in the center of the internal space of the test chamber 3. Therefore, by relatively increasing the rotation speed V5 of the blower fan 135 that blows conditioned air toward the center, a larger amount of conditioned air can be blown toward the test object 6, and temperature stress can be efficiently applied to the test object 6. When a plurality of test objects 6 are accommodated in the center, it is possible to promote the temperature transition of the test object 6 during the execution of the temperature change step and reduce the temperature variation. Moreover, the control unit 30 relatively increases the rotation speeds V1 to V4, V6 to V9 of the blower fans 131 to 134, 136 to 139 that blow conditioned air toward the periphery of the internal space of the test chamber 3 in the temperature maintenance step. This allows a larger amount of conditioned air to be sent toward the peripheral areas, i.e., the wall, ceiling, and floor of the test room 3. As a result, the effect of the outside air temperature of the test room 3 on the temperature of the internal space of the test room 3 can be mitigated, making it possible to maintain a stable temperature inside the test room 3.

[0090] <Second Modification> In the above embodiment, the environmental testing device 1 is provided with a total of nine blower fans 131 to 139 arranged in a matrix of 3 rows and 3 columns, but the layout of the multiple blower fans 13 is not limited to this example.

[0091] 10 and 11 are diagrams showing schematic diagrams of modified layouts of the plurality of blower fans 13, and correspond to plan views of a position along line II-II shown in FIG. 1 as viewed in the X direction.

[0092] In the example shown in FIG. 10, the environmental testing device 1 includes a total of 16 blower fans 13, in which four blower fans 13 are arranged at a distance from each other along each of the Y direction and the Z direction, and are arranged in a matrix of 4 rows and 4 columns. The control unit 30 individually controls the rotation speed of each of these 16 blower fans 13. It is to be noted that the environmental testing device 1 is not limited to the example shown in FIG. 10, and may include at least four blower fans 13 arranged in a matrix of at least 2 rows and at least 2 columns. In addition, the number of the blower fans 13 belonging to each row and the number of the blower fans 13 belonging to each column may be different from each other depending on the aspect ratio of the second wall surface 9.

[0093] In the example shown in FIG. 11, the environmental testing device 1 includes a large blower fan 13L arranged in the center of the second wall surface 9, and small blower fans 13S arranged at the four corners of the second wall surface 9. That is, the blower fan 13L and two blower fans 13S are arranged side by side along each of the two diagonals of the second wall surface 9. The control unit 30 controls the rotation speed of each of the blower fans 13L and 13S individually. In this way, the multiple blower fans 13 do not necessarily need to be arranged in a matrix, and the multiple blower fans 13 do not necessarily need to all be the same size.

[0094] In this modified example, the controller 30 controls the rotation speed of each of the plurality of blower fans 13 individually, thereby making it possible to obtain the same effects as those of the above embodiment.

[0095] In the above description, the environment forming device is configured as the environment testing device 1, but the present invention is not limited to this example. The environment forming device may be configured as a heat treatment device that forms a predetermined high-temperature environment to perform heat treatment on a workpiece that is an object. The environment forming device may also be configured as a cooking device that forms a predetermined high-temperature environment to heat a food that is an object.

[0096] 12 and 13 are diagrams showing the configuration of an environment forming device according to another modified example. As shown in Fig. 12, the blades of the blower fan 13 may be arranged in the X direction (on the second space 42 side) from the ventilation opening 10. Also, as shown in Fig. 13, the blades of the blower fan 13 may be arranged in the W direction (on the test chamber 3 side) from the ventilation opening 10. [Explanation of symbols]

[0097] 1 Environmental testing equipment 3. Test Room 4 Air conditioned room 7 First Wall 9 Second Wall 11 Cooler 12 Main heater 13,131~139 Blower fan 14,141~149 DC motor 16,161~169 Sub-heater 17,171~179,18,181~189 Temperature Sensor 30 Control section

Claims

1. an environment forming chamber in which an object is contained; an air conditioning room communicating with the environment creating room; a first air conditioning means for generating conditioned air by adjusting a temperature of air flowing into the air conditioning chamber from a first wall surface side of the environment creating chamber; a plurality of blower fans arranged on a second wall surface side of the environment creating chamber facing the first wall surface, the blower fans blowing conditioned air from the air conditioning chamber to the environment creating chamber in a direction from the second wall surface toward the first wall surface; A control means for individually controlling the rotation speed of each of the plurality of blower fans; a plurality of first temperature detection means arranged at a plurality of locations on the first wall surface side; The control means controls the first air conditioning means until the detected temperature detected by the multiple first temperature detection means reaches a target control temperature, and if the detected temperature by a specific first temperature detection means among the multiple first temperature detection means has not reached the target set temperature, increases the rotation speed of a specific blower fan among the multiple blower fans that corresponds to the specific first temperature detection means.

2. 2. The environment creating device according to claim 1, wherein the plurality of first temperature detecting means and the plurality of blower fans are arranged in the same number and in the same layout.

3. The environment creating device according to claim 1 or 2, further comprising a plurality of second temperature detecting means arranged at a plurality of positions on the second wall surface side.

4. The environment creating device according to claim 3 , wherein the plurality of second temperature detecting means and the plurality of blower fans are arranged in the same number and in the same layout.

Images