JP2020106465A - Test tank device - Google Patents

Abstract

To provide a test tank that increases a wind velocity in a space inside an inner diaphragm where a workpiece is arranged without increasing a size of a fan.SOLUTION: A test tank, which has a space surrounded by a heat insulation diaphragm 11, further has a space (space 14 inside an inner diaphragm) surrounded by an inner diaphragm 13 in the space surrounded by the heat insulation diaphragm, in which a gas circulation flow path 20 where gas flows exists between the heat insulation diaphragm and the inner diaphragm, and in the space inside the inner diaphragm, work cases 17 for setting up a plurality of workpieces are arranged, and an indentation fan 15 is arranged on a windward side of the work case, and a suction fan 16 is arranged on a leeward side thereof so as to face the indentation fan. The indentation fan uses an acceleration rectification mechanism using a venturi effect at an exit of the indentation fan, in which the acceleration rectification mechanism includes: a mechanism that accelerates a wind velocity of a reflux by making a cross-sectional area smaller in a reflux flow pass of the gas; and a fan unit that uses a concave type fan casing for storing the indentation fan.SELECTED DRAWING: Figure 1

Description

The present invention is for testing temperature characteristics, heat resistance, low temperature resistance, durability, etc. of products and internal parts by changing the environment such as temperature and humidity of products such as electronic devices and their internal parts. The present invention relates to a test tank device.

Various thermostats are used according to the purpose in the performance test, durability test, or reliability test of individual parts such as resistors and capacitors used in electronic circuits, integrated circuits (ICs), or various embedded boards. To be done. As an example of a constant temperature bath, a device that keeps the temperature of the device mounting substrate constant by blowing air from the air blower to the device mounting substrate set on a shelf placed in the constant temperature chamber is used. ing. For example, by using a function that can automatically change the wind speed by detecting the output of a temperature sensor installed on a shelf, a circulating fan placed downstream of the test piece, and an outside air introduction fan for the outside air. There has been proposed a thermostatic chamber in which the airflow in the thermostatic chamber is circulated by sending it to the sample. (Patent Documents 1 and 2)

Japanese Patent Laid-Open No. 7-275718 Actual Kaisho 61-184972

A large number of works (test parts and products) are lined up in a thermostatic chamber, gas is applied to the works to observe the change in surface temperature, and in the performance test to evaluate the performance of the work, the gas flow velocity (so-called wind speed) is changed. Therefore, it is necessary to measure the relationship between wind speed and temperature change. In the conventional test tank, it is necessary to use a fan with a large air volume in order to obtain a high wind speed. However, in order to use a fan with a large air volume, it is necessary to support the fan with a robust frame, so the test tank as a whole must be upsized. As a result, not only the price (equipment cost) of the test tank itself increases, but also the facility for installing the test tank becomes large, and facility installation costs and incidental costs such as maintenance costs also increase. Further, from the viewpoint of corporate economy, space saving of the test tank is required to increase the production amount (footprint) of the test tank per unit area.

The present invention relates to a test tank that generates a large wind speed as compared with the wind speed of a conventional fan without using a large fan, and has the following features.
(1) The present invention is a test tank having a space surrounded by a heat insulating partition, wherein the test tank is a space further surrounded by an internal partition in a space surrounded by the heat insulating partition (internal partition inner space). There is a gas circulation flow path through which the gas flows between the heat insulating partition wall and the inner partition wall, and a work case for setting a plurality of works is arranged in the inner partition inner space, A pushing fan is disposed on the windward side of the work case, and a suction fan is disposed on the leeward side of the work case so as to face the pushing fan.
(2) In the present invention, in addition to (1), the internal partition on the gas inlet side of the pushing fan is open to the gas circulation flow path, and the internal partition on the gas outlet side of the suction fan is the gas. The gas that has opened to the circulation flow path and that has come out of the suction fan enters the gas circulation flow path, passes through the gas circulation flow path, and is opened from the opening of the internal partition wall on the gas inlet side of the pushing fan. Entering the gas inlet of the pushing fan, exiting from the gas outlet of the pushing fan to the inner partition inner space, further passing through the work case and entering the gas inlet of the suction fan, and the gas outlet of the suction fan to the gas. It is characterized in that it enters a circulation channel and circulates.

(3) In the present invention, in addition to (1) or (2), the pressing fan is a centrifugal fan, and the acceleration using Bernoulli's theorem and the Venturi effect is applied to the air outlet arranged on the outer peripheral portion of the pressing fan. A rectifying mechanism (meaning a mechanism involving acceleration and rectifying action) is provided, and the gas discharged from the pressing fan enters the gas inlet of the acceleration rectifying mechanism and exits from the gas outlet of the accelerating rectifying mechanism to the inner partition inner space, The acceleration rectifying mechanism using the Venturi effect is a cone-shaped gas passage having a wide gas inlet toward the gas outlet and a gradually decreasing flow passage cross-sectional area. A plurality of through holes for sucking gas in the inner space of the inner partition wall are provided in the side wall of the gas passage, and a part of the gas circulation passage has a small gas passage cross-sectional area. The feature is that the wind velocity of the gas flowing through the passage can be accelerated.
(4) In the present invention, in addition to (1) to (3), the pressing fan includes a fan unit arranged in a concave fan casing, and the concave fan casing in which the pressing fan is arranged has an outlet portion. The narrowed (throttled) cross section has a substantially inverted trapezoidal shape, and part or all of the gas blown from the pressing fan hits the substantially inverted trapezoidal inner side surface of the concave fan casing, and from the outlet of the concave fan casing. It is characterized in that it is pushed out and enters the acceleration rectification mechanism.
(5) In addition to (1) to (4), the present invention is a method in which the suction fan is a centrifugal fan, sucks gas from the front part, and discharges gas from the outer peripheral side surface of the suction fan. The suction fan is arranged in a concave fan casing, and a part or all of the side surface of the concave fan casing facing the outlet of the centrifugal fan is opened, and gas is flown from the opening to the gas circulation flow path. Further, a dispersion mechanism (a dispersion plate having a plurality of through holes, a rectifying plate, or a rectifying grid) is arranged between the work case and the pressing fan, and the work case is provided in the work case. It is characterized in that the air volume of the gas hits the set works in a substantially equal amount.

A feature of the present invention is that the push-pull type test tank is provided with a pushing fan and a suction fan facing each other, and an acceleration rectifying mechanism (a mechanism involving acceleration and rectifying action) that utilizes the Venturi effect at the outlet of the pushing fan. A fan that uses a concave fan casing that stores a forced-in fan, and that has a mechanism for accelerating the flow velocity of the reflux with a reduced flow passage cross-sectional area in the gas return (circulation) flow passage. Since the unit is provided, it is possible to increase the wind speed in the internal partition inner space in which the work is arranged without increasing the size of the fan. If the fan is enlarged, the size of the main body of the test tank is also increased and the price of the test tank is also increased. However, by adopting the present invention, it is not necessary to increase the size of the fan. Therefore, the footprint (production per unit area) It is possible to reduce the total cost including test tank equipment cost, facility cost, operation cost, and test cost.

FIG. 1 is an explanatory view conceptually showing the cross-sectional structure of a thermostatic oven device (test bath) of the test apparatus. FIG. 2 is an enlarged (cross-sectional) view of the pushing fan 15-1 in FIG. 1 and a side view thereof. FIG. 3 is a view showing a side surface of the internal partition wall viewed from the outside of the concave fan casing that houses the suction fan 16.

FIG. 1 is an explanatory view conceptually showing the cross-sectional structure of a constant temperature oven device (also called a test bath device) of the present invention. The shape of the test tank is the same as that of a general thermostatic tank having a substantially cubic shape or a substantially rectangular parallelepiped shape, but is not limited to that shape. The test tank 10 has a space 12 (referred to as a test tank inner space) surrounded by a heat insulating partition wall 11 containing a heat insulating material. In FIG. 1, the space shape in the test tank is shown as a hollow shape which is the same as the shape of a general constant temperature tank, but the shape is not limited and may be an arbitrary shape such as a spherical shape or an elliptical shape. A space (interior partition inner space) surrounded by an internal partition wall 13 in which a work (test sample) or the like can be put into the test tank space 12 and various evaluation tests such as various environmental tests and reliability tests can be performed. ) 14 is disposed inside the partition (housing). The shape of this internal partition wall (housing) may be any shape as long as it can be stored in the space inside the test tank, but it is usually a substantially cubic shape or a substantially rectangular parallelepiped shape. The inner partition wall must have sufficient strength to support the various devices and parts arranged in the inner partition inner space, which will be described later, because there is no inflow or outflow of gas other than the necessary parts with respect to its outer space, thermal deformation, etc. at the test temperature. Since it is sufficient, the material forming the internal partition does not need to be a heat insulating material except for special applications, and can be made of, for example, heat-resistant plastic, stainless steel, or aluminum-based material. Two types of fans 15 (pushing fans) and 16 (suction fans) are arranged facing each other on both sides of the inner partition inner space 14. As described above, the test tank of the present invention employs the push-pull method in which the gas is blown by the pushing fan and the gas is sucked by the suction fan. A work case 17 is arranged in a space near the suction fan 16 in the internal partition inner space 14. The work case is to set the work, and its shape and size are not particularly limited. For example, the work case 17 has a shelf shape (for example, a frame), and a plurality of works 18 are arranged on the shelf. A space 19 (referred to as a wind velocity increasing space) having a certain distance exists between the pressing fan 15 and the work case 17. In some cases, there is no work case and the work is directly set in the inner partition inner space 14.

There is a space (gas circulation flow path) 20 through which the gas passes between the heat insulating partition wall 11 and the internal partition wall 13, and the gas can flow through the gas circulation flow path 20. Here, the gas is air, oxygen, nitrogen, or an inert gas (rare gas such as argon) or the like, and these are supplied from the outside of the test tank 10 through through holes, small windows, doors, etc. provided in the heat insulating partition wall 11. Can be introduced. For example, nitrogen or an inert gas can be used when it is desired not to oxidize (rust) the test piece during the test. The pushing fan 15 is a centrifugal fan (for example, a sirocco fan or a turbo fan), and sucks gas from the front part of the pushing fan 15 (cylindrical type) and blows out gas from the outer (circumferential) side surface. The pushing fan 15 is arranged in a concave space (referred to as a concave fan casing) 22. The concave fan casing 22 on the inlet (suction port) side of the pushing fan 15 for introducing gas is open, and the pushing fan 15 is further pushed. The internal partition wall 13 on the inlet side of the fan 15 has an opening (opening 21), and the inlet (gas inlet) of the pressing fan 15 is connected to the gas circulation flow path 20 through the opening 21. As described above, the test tank of the present invention includes the fan unit including the concave fan casing in which the pushing fan is housed. (Note that the opening includes a support frame that supports the opening, and a partition that is partitioned by a lattice-shaped or mesh-shaped frame.) Here, the inner side surface 23 of the concave fan casing 22 is formed so that the outlet side (cross section) is narrow. It has an inverted trapezoidal shape, and a part of the gas blown out from the pushing fan 15 hits the inner side surface 23 and is efficiently pushed out to the outlet side. Even if the cross section is a substantially rectangular shape that is not a substantially inverted trapezoidal shape or a substantially regular trapezoidal shape, gas is extruded toward the outlet if it is closed except at the outlet of the concave casing.

The outlet side peripheral edge (outer peripheral portion) of the concave fan casing or the outer peripheral portion of the pushing fan (circumferential (end) portion when the outer peripheral (end) portion of the concave fan casing or the pushing fan is circular) is shown in FIG. 2(a) (opening at the peripheral edge of the outlet of the concave fan casing) and has a cone-shaped cross section for increasing the wind speed (also called an acceleration rectification mechanism or a jet cone. Here, the acceleration rectification mechanism is a gas. It is connected to an inlet 26 of a flow accelerating action (accelerating a gas flow (gas flow) velocity) and a rectifying action (referring to a mechanism that aligns a gas flow (gas flow) in a certain direction). The concave fan casing outlet peripheral opening 24 opens up to a region including the peripheral edge of the pressing fan 15, and the gas blown out from the pressing fan 15 includes the gas hitting the inner side surface 23 of the concave fan casing. It is introduced into the inside of the jet cone 25 from the inlet 26 of the jet cone 25. That is, the concave fan casing changes the gas exhausted from the pushing fan 15 in the vertical (vertical) direction into a horizontal (horizontal) flow, and introduces the gas flow into the jet cone 25. The jet cone 25 has a cone shape whose cross section becomes narrower as it goes from the inlet 26 to the outlet 27, and the flow passage area of the gas becomes smaller as it goes in the downstream direction of the gas (for example, the inlet portion 26. Since the size of the outlet part is 1/2 to 1/5 with respect to the size of, the velocity of the gas entering from the inlet 26 is gradually increased (accelerated), and the wind velocity increasing space 19 from the outlet 27 is faster than the inlet velocity. To go out. That is, the wind speed in the wind speed increasing space 19 can be increased. It is also possible to align the direction of the gas flow with the direction of the outlet 27 of the jet cone 25. If a through hole (intake hole) 28 penetrating to the wind velocity increasing space 19 as shown in FIG. 1 or FIG. 2(a) is opened on the side surface of the jet cone 25, the inside of the jet cone 25 becomes closer to the outlet 27 side. Since the air pressure is higher than that in the wind speed increasing space 19, the gas in the wind speed increasing space 19 is sucked in and exits from the outlet 27. These can also be called an acceleration rectification mechanism utilizing the Venturi effect by Bernoulli's law (fluid). That is, the gas blown from the pushing fan 15 enters the gas inlet 26 of the acceleration rectifying mechanism 25, and exits from the gas outlet 27 of the acceleration rectifying mechanism 25 to the internal partition inner space 14 (wind velocity increasing space 19). Further, the gas blown from the pushing fan 21 also enters the gap 30 between the inner diameter partition plate 29 of the inlet 26 of the jet cone 25 and the side surface of the pushing fan 21, but the inner diameter partition plate 29 penetrates into the wind velocity increasing space 19. By providing a plurality of appropriate through holes 31, the gas flows out into the wind velocity increasing space 19 also from the through holes 31, so that the wind velocity in the wind velocity increasing space 19 can be increased.

In the wind velocity increasing space 19, the dispersion plate 32 is arranged in a part or the whole of the space between the work case 17 and the jet cone 25 (or between the work case 17 and the pushing fan). A large number of through holes 33 are appropriately formed in the dispersion plate 32, and the gas emitted from the outlet 27 of the jet cone 25 flows out from the through holes 33 of these dispersion plates 32 into the space on the work case 17 side. The dispersion plate 32 is, for example, a punching plate, and the material thereof is, for example, a stainless plate, an aluminum plate, or a hard plastic plate. Alternatively, a rectifying plate (for example, a VH register) configured by a flat plate whose angle can be adjusted in the vertical direction and the horizontal direction, or a rectifying grid (for example, a grid-shaped component in which the depth is optimized with respect to the length) may be used. .. (Hereinafter, this is represented by a dispersion plate.) Note that these mechanisms are called a dispersion mechanism. The amount of gas (air amount) emitted from the through hole 33 of the dispersion plate 32 becomes a parallel flow which is a flow in the horizontal direction in a substantially horizontal direction, so that the work 18 set (installed) in the work case 17 is equally divided. The hole size of the through hole 33 is adjusted. The work case 17 is a mounting table on which a work is set (placed), and is arranged on the suction fan 16 side in the internal partition inner space 14, but is, for example, a rack-shaped rack and has a horizontal (horizontal) direction. It has such a structure that the flow of gas flowing therethrough is not obstructed. The work case 17 is made of, for example, stainless steel, aluminum or hard plastic.

Therefore, the gas flowing out from the through hole 33 of the dispersion plate 32 does not obstruct the flow, enters the work case 17, and hits the plurality of works 18 set in the work case 17. Since the work 18 set in the work case 17 is uniformly hit with the gas of the same air volume, the performance (electrical characteristics, etc.) of the work 18 can be evaluated with high accuracy and little variation. For example, if a sensor for measuring the surface temperature of the work 18 is provided, it is possible to measure the temperature accurately while applying a current or voltage to the work 18. The amount of air that hits the work 18 can be adjusted by adjusting the voltage or the current to change the blowout amount and the suction amount of the pushing fan 15 and/or the suction fan 16. Further, since the (high-speed) gas flow accelerated by the acceleration rectifying mechanism of the present invention hits the work, the heat of the work can be quickly removed.

The work case 17 is arranged near the side surface of the internal partition on the side where the suction fan 16 is arranged. The side surface portion 34 of the internal partition wall on the suction port side of the suction fan 16 is open (called an internal partition wall suction fan suction port side opening portion), and the side surface parts other than the internal partition wall suction fan suction port side opening portion are not open. Therefore, almost all the gas discharged from the work case 17 is sucked into the suction fan 16 from the suction port of the suction fan 16. In this way, the work case for installing a plurality of works (test pieces) is arranged in the inner partition inner space, the pushing fan is arranged on the windward side of the work case, and the pushing fan is arranged on the leeward side of the work case. The suction fan is arranged so as to face with. Here, the work is a general term for a test body that is tested by using a test tank (constant temperature tank), and is an individual component such as an IC, a resistor, or a capacitor, one in which these individual components are mounted on a mounting board, or various products. The shape and size are not limited as long as they can enter the space inside the inner partition wall of the test tank (constant temperature tank). INDUSTRIAL APPLICABILITY The present invention is a test tank that employs the push-pull method in which the pushing fan 15 and the suction fan 16 are arranged to face each other as described above, and the acceleration rectifying mechanism utilizing the Venturi effect, and thus is parallel to the high-speed gas flow. The gas flow can be realized, and the gas flow hits the work, so that the work can be accurately evaluated, and it is not necessary to increase the size of the entire fan.

The suction fan 16 is also a centrifugal fan and sucks gas from the front part (cylindrical) and blows out (discharges) gas from the outer peripheral (circumferential) side surface. The suction fan 16 is also arranged inside the concave fan casing 36. The shape of the concave fan casing 36 is a substantially cylindrical shape or a substantially prismatic shape (substantially rectangular parallelepiped, substantially cubical, etc.), and the surface of the concave fan casing 36 facing the work case 17 side is open, and the suction fan is in this opening surface. Since the suction port of 16 faces, the gas flowing in the work case 17 gathers toward this opening surface and is sucked into the suction fan 16 by the suction port of the suction fan 16. There is an air outlet 37 above or below the concave fan casing 36 (in FIG. 2, the two-stage suction fans 16 (16-1, 16-2) are arranged, and the suction fan 16-1 arranged on the upper side is The concave fan casing 36 to be arranged has an air outlet 37 on the upper side, and the concave fan casing 36 to arrange the suction fan 16-2 arranged on the lower side has an air outlet 37 on the lower side (see also FIG. 3)). The outlets 37 are connected to the gas circulation flow path 20 (the gas circulation flow paths are present on the top surface side and the bottom surface side). When the portion of the gas circulation flow passage 20 connected to the blowout port 37 is 20A, the gas discharged from the suction fan 16 exits from the blowout port 37 and flows into the gas circulation flow passage 20A.

A portion of the gas circulation passage 20 to which the opening 21 of the pushing fan 15 is connected is designated as 20B, and a portion of the gas circulation passage 20 on the top surface side or the bottom surface side that connects the gas circulation passage 20A and the gas circulation passage 20B ( It is also called a wind tunnel part) and is set to 20C. That is, the wind tunnel portion 20C (top surface side) of the gas circulation flow path 20 is the gas circulation flow path 20 between the heat insulating partition wall 11 and the internal partition wall 13 on the top surface side as can be seen from FIG. The wind tunnel portion 20C (bottom surface side) of the passage 20 is the gas circulation flow passage 20 between the heat insulating partition wall 11 and the internal partition wall 13 on the bottom surface side. The gas discharged from the suction fan 16 and flowing from the outlet 37 to the gas circulation passage 20A enters the gas circulation passage 20B through the gas circulation passage 20C on the ceiling (surface) side or the bottom surface side, and then the pushing fan 15 Through the suction side opening 21 of the above, enters the suction port of the pushing fan 15, is blown out from the pushing fan 15, passes through the acceleration rectifying mechanism 25 and goes out to the inner partition inner space 14, and further enters the suction fan 16. The air flows out of the suction fan 16 and flows from the outlet 37 of the concave fan casing 36 of the suction fan 16 into the gas circulation flow path 20A. In this way, the gas circulates in the test tank such that the suction fan 16→the gas circulation flow path 20→the pushing fan 15→the inner partition inner space 14→the suction fan 16 circulates in the inner partition inner space 14 in the circulation path. It hits the arranged work 18 and carries away heat of the work, cools the work, or warms the work, for example.

Here, the wind velocity of the recirculating gas is accelerated by reducing the flow passage cross-sectional area of all or part of the wind tunnel portion 20C of the gas circulation flow passage 20 to be smaller than other portions (for example, 1/2 to 1/4). Therefore, the gas entering the gas circulation channel 20B can be circulated without reducing the wind speed. That is, the wind velocity is increased by a structural device that reduces the flow passage cross-sectional area of all or part of the wind tunnel portion 20C of the gas circulation flow passage 20 without providing a new blower fan in the gas circulation flow passage 20. Can be realized. This is called a reflux gas wind speed acceleration mechanism. A cooling mechanism or a heater can be placed at a place in the gas circulation flow path 20 (for example, 20 A) to cool or warm the flowing gas. A blower can be installed if the wind speed is higher than that shown above. If a filter is arranged in the gas circulation channel 20 and the gas is circulated through the filter, a clean gas can be flowed. Further, if the gas is introduced from the outside through the through hole formed in the heat insulating partition, the atmospheric pressure of the test tank can be increased. Normally, a door or window for loading and unloading workpieces and jigs is provided on part of the side of the heat insulation partition, but when opening them, gas is introduced from outside so that air etc. does not enter from the opening of the door from the outside. By doing so, the inside of the test tank can be made to have a positive pressure.

In FIG. 1, the pushing fan 15 and the suction fan 16 are arranged in two stages (15-1, 15-2) (16-1, 16-2) vertically in the inner partition inner space 14 (approximately). ing. Even if they are arranged in two stages (they can be arranged in two rows in the depth direction as well), the respective mechanisms (the push-pull system in which the pushing fan and the suction fan face each other, the acceleration rectification mechanism utilizing the Venturi effect) Etc.) are symmetrically arranged in the inner partition inner space 14, so that they have the same effect on the work. Of course, the effect is the same even if the number is further increased in the vertical direction and the depth direction. FIG. 2 is an enlarged view (FIG. 2A) and a side view (FIG. 2B) of the pushing fan 16-1 in FIG. As shown in FIG. 2B, the pushing fan 16 (outer system (shape) thereof) is circular (coarse broken line 52), and the inlet portion of the jet cone 25 is also circular (inner diameter (shape) is solid line 51, The outer diameter (shape) is a solid line 55). The inner diameter (shape) portion 51 of the inlet portion of the jet cone 25 is inside the outer diameter (shape) of the pushing fan 16 so that the gas discharged from the pushing fan 16 enters the jet cone 25 as much as possible. .. The outside (outlet) diameter (shape) of the outlet of the concave fan casing 22 is also circular (narrow broken line 53), and the space between the narrow broken line 53 and the solid line 51 is the concave fan casing outlet peripheral opening (or the pushing fan outer periphery (end). ) Part) 24. The outlet portion of the jet cone 25 is also circular (outer diameter (shape) is solid line 55, inner diameter (shape) is solid line 54). Since the outer diameter (shape) of the jet cone 25 is horizontal, the outer diameter (shape) of the inlet portion and the outer diameter (shape) of the outlet portion of the jet cone 25 are coincident with each other by the solid line 55. It is also possible to make the outer diameter (shape) of the inlet portion of 25 larger so as to be closer to the cone shape. In this way, the jet cone 25 has a structure in which the entire peripheral portion of the pushing fan is surrounded in a circular shape. Therefore, the velocity of the gas flow in the inner partition inner space 14 can be accelerated and the flow of the gas flow can be rectified. Since it suffices to surround the entire peripheral portion of the pushing fan, the outer diameter (shape) and inner diameter (shape) of the jet cone 25, and the shape of the concave fan casing may be substantially square (square or the like).

FIG. 3 is a (conceptual) view showing a side surface of the internal partition wall as seen from the outside of the concave fan casing 36 that houses the suction fan 16. Since the suction fan 16 is housed in the concave fan casing 36, it is indicated by a broken line. The suction fan 16 is substantially circular from this direction (three-dimensionally substantially cylindrical), and the suction fan 16 has two stages vertically and two rows horizontally (horizontal (horizontal) direction), four in total ( 16-1, 2, 3, 4) are arranged. The four suction fans 16 and the four concave fan casings 36 (36-1, 2, 3, 4) that store them are arranged in a space surrounded by the internal partition wall 13 (internal partition inner space). There is. Further, the internal partition wall (housing) 13 is arranged in a space (a space inside the test tank or an inner space inside the internal partition wall) 12 surrounded by the heat insulating partition wall 11. The concave fan casings 36 (36-1, 2, 3, 4) also have a substantially circular shape according to the shape of the suction fan 16, and each have an outlet 37. The blow-out port 37 of the concave fan casing 36-1 storing the suction fan 16-1 and the blow-out port 37 of the concave fan casing 36-3 storing the suction fan 16-3 are symmetrical and face upward. The resulting gas enters the gas circulation channel 20A (on the top side). The outlet 37 of the concave fan casing 36-2 that houses the suction fan 16-2 and the outlet 37 of the concave fan casing 36-4 that houses the suction fan 16-4 are symmetrical and point downward. The gas enters the gas circulation channel 20A (on the bottom side). Since the pushing fan 15 is arranged so as to face the suction fan 16, the pushing fan 15 also has a layout similar to that of FIG.

INDUSTRIAL APPLICABILITY As described in detail above, the present invention is a test tank (apparatus) that employs a push-pull method in which a pushing fan and a suction fan are arranged to face each other, and an acceleration rectification mechanism that utilizes the Venturi effect at the outlet of the pushing fan. A test tank equipped with a fan unit that uses a concave fan casing that houses a forced-in fan and that has a mechanism that accelerates the flow velocity of the reflux with a reduced flow passage cross-sectional area in the gas return passage. Is. As a result, it is possible to realize an excellent effect that the wind speed in the space inside the internal partition where the work is arranged can be increased without increasing the size of the fan. In addition, in the present specification, it is needless to say that the content can be applied to other portions as well, even if the content described and described in a certain portion of the specification is not described, which is applicable to other portions. Further, it goes without saying that the above embodiment is an example, and various modifications can be made without departing from the scope of the invention, and the scope of rights of the present invention is not limited to the above embodiment.

INDUSTRIAL APPLICABILITY The present invention can be applied to a device that uses a fan and that increases the wind speed without increasing the size of the blower.

10... Test tank, 11... Insulating partition wall, 12... Test tank inner space,
13... inner partition wall, 14... inner partition inner space, 15... pushing fan,
16... Suction fan, 17... Work case, 18... Work,
19... Wind velocity increasing space, 20, 20A, 20B, 20C... Gas circulation flow path,
21... Opening part, 22... Recessed fan casing,
23... Inner side surface of concave fan casing,
24... Outer peripheral edge (opening) of the concave fan casing,
25...jet cone, 26...jet cone inlet,
27... Jet cone outlet, 28... Through hole (intake hole),
29... Inner diameter partition plate at jet cone inlet, 30... Gap part,
31... Through hole, 32... Dispersion plate, 33... Through hole,
34... Suction fan suction port side inner partition wall side surface portion,
36... Recessed fan casing, 37... Air outlet,

Claims (11)

A test tank having a space surrounded by an insulating partition,
The test tank further has a space surrounded by an inner partition wall (referred to as an inner partition inner space) in a space surrounded by the heat insulation partition wall,
There is a gas circulation channel through which a gas flows between the heat insulating partition wall and the internal partition wall,
In the inner partition inner space, a work case for setting a plurality of works is arranged,
A test tank, wherein a pushing fan is arranged on the windward side of the work case, and a suction fan is arranged on the leeward side of the work case so as to face the pushing fan. The internal partition wall on the gas inlet side of the pushing fan is open to the gas circulation flow path, and the internal partition wall on the gas blowout port side of the suction fan is open to the gas circulation flow path,
The gas discharged from the suction fan enters the gas circulation passage, passes through the gas circulation passage, enters the gas inlet of the pushing fan from the opening of the internal partition on the gas inlet side of the pushing fan, The gas flows out from the gas outlet of the pushing fan into the space inside the internal partition wall, further passes through the work case to enter the gas inlet of the suction fan, enters the gas circulation passage from the gas outlet of the suction fan, and circulates. The test tank according to claim 1, wherein: The pushing fan is a centrifugal fan, the blow-out port arranged on the outer periphery of the pushing fan is provided with an acceleration rectification mechanism using the Venturi effect, and the gas discharged from the pushing fan is introduced into the gas inlet of the acceleration rectification mechanism. The test tank according to claim 1 or 2, wherein the test tank enters and exits from the gas outlet of the acceleration rectifying mechanism into the inner space of the inner partition wall. The test according to claim 3, wherein the acceleration rectifying mechanism using the Venturi effect is a cone-shaped gas passage having a wide gas inlet and a gradually decreasing flow passage cross-sectional area toward the gas outlet. Tank. The test tank according to claim 4, wherein a plurality of through holes for sucking gas in the inner partition inner space are provided in a side wall of the gas passage in the middle of the gas passage of the acceleration rectifying mechanism. A part of the gas circulation channel has a small gas channel cross-sectional area, and the wind velocity of the gas flowing through the gas circulation channel can be accelerated. Test tank described in. The test tank according to any one of claims 1 to 6, wherein the pushing fan includes a fan unit arranged in a concave fan casing. The test tank according to claim 7, wherein the concave fan casing in which the pushing fan is arranged has a substantially inverted trapezoidal cross section in which the outlet portion is narrowed. Part or all of the gas blown from the pushing fan hits the substantially inverted trapezoidal inner side surface of the concave fan casing, is pushed out from the outlet of the concave fan casing, and enters the acceleration rectification mechanism. The test tank according to claim 8. The suction fan is a centrifugal fan, and is a system that sucks gas from the front part and discharges gas from the outer peripheral side surface of the suction fan,
The suction fan is arranged in a concave fan casing,
The concave fan casing facing a discharge port of the centrifugal fan is partially or entirely opened on a side surface thereof, and gas flows out to the gas circulation flow path from the opening. The test tank according to any one of items. Between the work case and the pressing fan, a dispersion plate, a rectifying plate, or a rectifying grid having a plurality of through holes is arranged, and the plurality of works set in the work case are substantially equally divided into gas flow rates. The test tank according to any one of claims 3 to 10, characterized in that