JPH10220854A - Environmental testing device with inner pressure adjustment mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an inner pressure adjustment function. SOLUTION: There is provided a pipe 11 opened at a position P of a low pressure section of an air conditioned room 3. Each of a main valve 12 and a sub-valve 13 in the main valve 12 is rotatably installed at an outer side end 1b as indicated in an arrow A-A' and an arrow C, respectively. During a normal operation, the position P shows a negative pressure, the main valve 12 is contacted with an inclined opening 11c of the pipe under a state in which the sub-valve 13 is closed so as to prevent surrounding atmosphere from entering the device. As the negative pressure at the position P is increased when the operation is transferred to a low temperature operation, the sub-valve 13 is further inclined toward an inside part of the pipe from the aforesaid state, a clearance in respect to the main valve 12 is further widened to introduce surrounding atmosphere and then an abnormal low pressure within the inner region is prevented from being produced. As the position P shows a positive pressure during a high temperature operation or when the door is opened, the main valve 12 is moved away from the inclined opening under a state in which the sub-valve 13 is closed, inner air is released to prevent an excessive inner pressure from being attained. With such an arrangement as above, an inner pressure adjustment can be positively adjusted by a simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an environmental test apparatus in which the inside is conditioned by circulating air, and more particularly to an internal pressure adjusting mechanism.

[0002]

2. Description of the Related Art In an environmental test apparatus such as a constant temperature and humidity chamber, a test chamber and an air-conditioning chamber are provided in the chamber, and air whose temperature and humidity are adjusted in a heat-insulated and airtight state is circulated and supplied into the test chamber, and the internal pressure is adjusted. A mechanism is provided to adjust for internal pressure fluctuations caused by changes in operating conditions and the like.

As shown in FIG. 5 (a), a conventional internal pressure adjusting mechanism uses a drain pipe 9 for draining overflow water or the like of a humidifying dish 4, and an internal pressure adjusting pipe 20 branched from the drain pipe. Met. A drain filter 9a is provided at the opening of the drain pipe 9 into the tank, and the internal pressure adjusting pipe 2 is provided.
As shown in FIG. 2B, a resin ball 21 was placed on the top of the zero and a small hole 22 was provided.

In such a conventional apparatus, when the internal pressure increases, the internal air passes through the internal pressure adjusting pipe 20, lifts the ball 21 and is discharged to the outside, and when the internal pressure decreases, the internal pressure increases from the small hole 22. Outside air is sucked into the tank via the adjustment pipe 20. However, in such a device, when the small hole 22 is large, the amount of outside air sucked is large.
A problem that water accumulated on the surface of the drain filter 9a at the time of draining or draining of the drain in the tank forms a frost column together with the inhalation of outside air during low-temperature operation has occurred. On the other hand, when the small hole is small, the internal pressure adjustment function is insufficient, the pressure in the tank drops significantly, and water gushes from the wick pan arm and hits the sample inside, or water overflows from the humidifying dish and the inside of the tank A problem such as flooding the bottom surface occurred.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art and to provide an environmental test apparatus having an improved internal pressure adjusting function.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an environmental test apparatus in which the inside is air-conditioned by circulating air. A tube opened to a part remote from the outside and the other end guided to the outside, and provided at the other end to allow air to pass from the outside to the inside at a low pressure when the internal pressure is lower than a predetermined pressure. And an air discharge mechanism that opens so as to allow air to pass from the inside to the outside when the internal pressure is higher than the predetermined pressure.

According to a second aspect of the present invention, in addition to the above, the air intake mechanism and the air discharge mechanism are configured such that the first valve is formed so as to open at the time of either the high pressure or the low pressure. It is characterized by being integrally formed by a body and a second valve body formed to open at a time opposite to the time when the first valve body opens at any one of the times. The invention according to claim 3 is characterized in that, in addition to the above, the other end side has an inclined opening projecting upward and retracting downward, and the first valve body rotates upward with a size at least covering the inclined opening. The second valve body is partly supported by the first valve body and is rotatably supported by the first valve body.

[0008]

FIG. 1 shows a schematic structure of a thermo-hygrostat as an example of an environmental test apparatus to which the present invention is applied. The constant temperature and humidity chamber includes a test room 2 and an air conditioning room 3 inside a heat insulating wall 1, and is conditioned by a humidifier 4, a cooler 5, a heater 6, a blower 7, and the like provided in the air conditioning room 3. The circulated air is circulated in the direction of the arrow. The humidifier 4 is provided with a heater (not shown), and the cooler 5 is supplied with a refrigerant from a refrigerating device (not shown), and the inside of the test chamber 2 is adjusted to a target temperature and humidity by the heater 6 and the like. . A pit 8 adjacent to the humidifier 4 to fill the overflow water
, And a drain pipe 9 for draining overflow water through a drain filter 9a is provided. An internal pressure adjusting mechanism 10 is provided in addition to the general components of the constant temperature and humidity chamber as described above. Therefore, the drain pipe 9
Is not provided with an internal pressure adjusting mechanism.

FIG. 1 (b) shows an internal pressure adjusting mechanism 10 of this embodiment.
As shown in (c), the pipe 11, the main valve 1 as the first valve body
2. It is composed of a sub-valve 13 which is a second valve body. Tube 1
One end 11a is a low-pressure portion having a relatively low pressure in the test room 2 or the air-conditioning room 3 and opens at a position P which is a portion distant from the bottom, and the other end 11b penetrates the heat insulating wall 1. And is guided to the outside 100. The opening position of the one end 11a may be near the position Q in the test chamber 2 as another low-pressure part.

The other end 11b has an inclined opening 11c which projects upward and retracts downward as shown in the figure. Main valve 1
2 is slightly larger than this so as to cover this opening, and is indicated by an arrow AA by a pipe 11 at the upper end position.
It is rotatably supported in the 'direction. The sub-valve 13 constitutes a part of the main valve 12, and is rotatably supported at an upper end B position as shown by an arrow C. However, the rotation in the direction of arrow A 'is restricted so as not to deviate from the main valve 12. The sub-valve 13 may be made of the same material as the main valve 12, but is desirably a material having a higher specific gravity.

FIG. 2 shows the operation of such an internal pressure adjusting mechanism 10. The dimensions and the like of the main valve 12 and the sub-valve 13 are height H, h, width B, thickness t, and specific gravity γ, respectively, and the inclination angle when the main valve 12 hits the inclined opening as shown by a dashed line is α, At this time, the pressure at the internal position P (FIG. 1) is p, the angle at which the sub-valve 13 is further opened is β, the pressure at the position P at this time is p ′, and the external atmospheric pressure as indicated by the two-dot chain line. the When p _0, the valve 12, 13, respectively, the force due to the pressure difference _{F = (p 0 -p) BH} , f = (p 0 -p
') Bh, its own weight W = BHtγ, w = Bhtγ act. From the balance of the moments generated by these, as shown by the chain line, in order for the main valve 12 to close the inclined opening, Need to be

From this equation, p ≦ p ₀ −tγsin α − (− 1) (1)

Since the position P is a low-pressure portion having a relatively low pressure inside, for example, when the average pressure in the tank is the atmospheric pressure p ₀ as a predetermined pressure, the pressure p at the position P becomes p.
_Lower than ₀ . Therefore, by appropriately selecting the values of t, γ, and α, the above equation is established, the main valve 12 is pressed against the inclined opening, and the negative pressure p at the position P is maintained during the steady operation while the outside air is maintained. Cooler 5 consisting of an evaporator
It is possible to prevent frosting on the surface.

Assuming that the pressure at the position P is lower than p and becomes p ', the position of the main valve 12 is regulated by the inclined opening of the pipe 11, so that the main valve 12 does not rotate any more.
3 rotates and opens as shown by the two-dot chain line. At this time, since air flows in from the outside, a dynamic pressure is generated or the static pressure in the pipe 11 changes, and the pressure (total pressure) on both sides of the sub-valve 13 does not always become p ₀ and p ′. Assuming that such a pressure is applied, (p ₀ −p ′) Bh × (H / 2) = Bhtγ × (H /
2) It becomes sin (α + β). Therefore, p ′ = p ₀ −tγsin (α + β) −−−− (2)

From the above equation, when the pressure at the position P decreases from p to p ', the sub-valve 13 opens by the angle β, and the outside air can be sucked. As a result, for example, when the set temperature is lowered from the steady operation state, the temperature in the tank decreases, and when the pressure in the tank decreases due to shrinkage of the air, the outside air is sucked,
Extremely low internal pressure can be prevented. Then, the occurrence of water spouting from the wick pan arm and other various problems are prevented. Further, since the outside air is sucked into the position P away from the bottom, no frost column is formed when the outside air is sucked.

In equations (1) and (2), the main and sub-valves 1
Although t and γ of 2, 13 are the same,
And / or γ may be made somewhat larger than those of the main valve 12. If these are the same, assuming that the pressure at the P position becomes p and the main valve 12 closes, then if the pressure drops, the sub-valve 13 subsequently opens and the intake of outside air starts. If t and γ are changed as described above, equations (1) and (2) become discontinuous, and even if the pressure further decreases after the main valve 12 is closed, the pressure drops until a predetermined value or more. The sub-valve 13 will not open. As a result, even if there is some pressure fluctuation during steady operation with the main valve 12 closed,
Both the main valve 12 and the sub-valve 13 maintain the closed state, and it is possible to reliably prevent unnecessary suction of air.

When the main and sub-valves 12 and 13 are switched from the normal operation state in which both of them are closed to the high-temperature operation, the internal air expands to increase the pressure as a whole, and the pressure at the position P also increases to the atmospheric pressure p.
The positive pressure becomes ₀ or more. In addition, not only in the high-temperature operation but also in the low-temperature operation, when the door of the thermo-hygrostat is opened and then closed, the pressure is temporarily increased because the air is forced into the inside and the pressure at the position P is also positive. Pressure. At this time, when the sub-valve 13 is open, it closes, and the main valve 12 opens with the sub-valve closed. As a result, the internal air can be quickly and reliably released, and an increase in the internal pressure can be prevented.

In the internal pressure adjusting mechanism 10 as shown in FIG. 1B, the main valve 12 is opened so as to allow air to pass from inside to outside when the internal pressure is higher than a predetermined pressure. It is an example of a 1st valve body and an air discharge mechanism. The sub-valve 13 is an example of the second valve body and the air inflow mechanism because the sub-valve 13 opens so as to allow air to pass from inside to outside at low pressure. According to such a main valve and a sub-valve, all functions such as prevention of air suction during steady operation at a predetermined pressure, suction of air at a low pressure, and air discharge at a high pressure can be achieved by an extremely simple structure. Can be achieved.

The size of the main valve 12 and the sub-valve 13, the ratio of the size of the main valve 12 to the sub-valve 13, the positional relationship between the main valve and the sub-valve, etc. And the like, so that necessary and sufficient air can be suctioned / discharged when the internal pressure suddenly changes. Although FIG. 1 shows an example in which the main and sub-valves are square, they may be circular or other shapes. FIG. 3 shows another example of the main valve and the sub-valve. Also in these examples, as in FIG. 1, the main valve and the sub-valve are formed integrally, and open in opposite directions when the two are under low pressure or high pressure under opposite conditions. It has become. In addition, the main valve and the sub-valve in this figure also have a similar structure to that of FIG.
It is shown in a simplified manner.

1 (a), the inclination of the opening at the other end of the pipe 11 is stopped and the initial torque T _{0 in the} direction of the arrow is applied to the sub-valve 13 as shown in FIG. I have. This T ₀ is given, for example, by interposing a torsion spring at the base of the upper end of the sub-valve, or by forming the valve itself with a weak elastic plate. According to this structure, at the time of the negative pressure p at the time of the steady operation, the main valve is reliably closed to prevent the intake of the outside air, and at the time of the high pressure, the internal air can be discharged as in the case of FIG. In addition, by setting T ₀ to an appropriate value, outside air can be sucked in due to a difference in internal and external pressures at low pressure.

(C) shows the auxiliary valve 1 as in (a).
3, the initial torque T ₀ is applied in the direction of the arrow. According to this structure, at the time of negative pressure p during normal operation, the main valve 12 closes as shown in the figure due to the own weight of the valve, and when the negative pressure increases, the main valve 12 closes with the sub-valve 13 closed. When the valve opens and the pressure becomes positive, the sub-valve 13 opens outward. According to this structure,
In the case where the door is suddenly opened, the main valve is largely opened to prevent the occurrence of an instantaneous large negative pressure inside.

(D) and (e) have structures corresponding to (a) and (c), respectively, in which the openings are directed up and down, and the main valve 12 and the sub-valve 13 are arranged horizontally. ing. Such a structure has the same effect as those of (a) and (c), but has an effect of reliably preventing outside air from being sucked in a steady operation because the support state of the valve is stable. .

FIG. 4 shows another example of the internal pressure adjusting mechanism. In this embodiment, the two valves are separately provided as main valves. In the case of (a), the end of the pipe 11 is provided with branch portions 11-1 and 11-2 which are branched in the vertical direction, and the main valves 12-1 and 12-2 are mounted on the respective branches. In this structure as well, the opening and closing are adjusted using the own weight of the valve as in the other cases. That is, the main valve 12-1 does not open in the negative pressure during the steady operation and its constant small fluctuation range. When the negative pressure increases, the main valve 12-1 opens in the direction of the arrow to draw in outside air, and when a positive pressure equal to or more than a certain value is applied, The main valve 12-2 opens in the direction of the arrow to discharge the air inside. Therefore, in this example, the main valves 12-1 and 12-2 constitute an air intake mechanism and an air exhaust mechanism, respectively. A structure in which the main valves 12-1 and 12-2 are biased by a torsion spring in a direction to close the respective valves without depending on only the own weight of the main valves 12-1 and 12-2 is also possible.

(B) shows an example in which the main valves 12-1 and 12-2 of (a) are balls. Also in this example, the same operation as that of FIG. 9A is performed by the vertical movement of the ball in the direction of the arrow. This valve has a simpler structure, and has a uniform contact pressure at the contact portion, so that the valve easily comes into close contact with the opening and has good sealing properties.

(C) has a structure similar to that of (a), except that the main valve 12-1 is inclined inward and the main valve 12-
2 shows an example in which 2 is vertically or outwardly inclined. Even with this structure, during steady operation, both valves are securely closed to prevent air from entering, and at low pressure or high pressure, the main valve 12-1 is used.
Or, 12-2 opens greatly in the direction of the arrow, and when necessary, a sufficient amount of outside air can be taken in or the inside air can be discharged.

[0026]

According to the first aspect of the present invention, the following functions and effects are produced. A pipe is introduced from the internal low pressure section to the outside, and an air suction mechanism and an air discharge mechanism that can suck in the outside air or discharge the internal air when the pressure is lower or higher than the pressure during steady operation, which is a predetermined pressure, is provided. It is possible to prevent the internal pressure of the environmental test apparatus from undesirably decreasing and increasing at high pressure or high pressure. As a result, inconveniences such as spouting of water from the wick pan arm are prevented, and the operation for opening and closing the door is facilitated. Further, since one end side of the tube is open at a portion away from the bottom, it is possible to prevent the formation of frost columns and the like at the time of air intake.

According to the invention of claim 2, in addition to the above,
A first integrally formed air intake mechanism and an air discharge mechanism are formed so as to open at opposite times at high pressure or low pressure.
Since it is constituted by the valve body and the second valve body, the structure of the internal pressure adjusting mechanism can be simplified. Such first and second valve bodies, for example, rotatably support the first valve body so as to open at high pressure, and form the second valve body as a part of the first valve body. It can be constituted by being supported by the first valve body while being urged in the opening direction of the valve body.

According to the invention of claim 3, in addition to the above,
The other end of the external pipe is an inclined opening that projects upward and retreats downward, and supports the first valve body rotatably upward.
Since the second valve body is rotatably supported by the first valve body as a part of the first valve body, the first valve body hits the inclined opening, thereby preventing the intake of outside air in a state where the low-pressure part is at a negative pressure. can do. If the negative pressure in the low pressure section increases at low pressure,
The second valve body tilted together with the first valve body rotates from the first valve body and further tilts, opens between the first valve body and sucks outside air,
It is possible to prevent the occurrence of an internal excessive negative pressure. When the internal pressure is high, the first valve element is separated from the inclined opening to discharge the internal air and prevent an excessive increase in pressure.
According to such an internal pressure adjusting mechanism, the internal pressure can be adjusted only by the weight of the valve body, so that the structure can be further simplified.

[Brief description of the drawings]

FIG. 1 shows an example of an environmental test apparatus to which the present invention is applied;
(A) is a cross-sectional view showing the entire configuration, and (b) and (c) are a cross-sectional view and a side view, respectively, of an internal pressure adjusting mechanism.

FIG. 2 is an explanatory diagram of an operation of the internal pressure adjusting mechanism.

FIGS. 3 (a) and (c) to (e) are explanatory views showing another example of the internal pressure adjusting device having an integrated main valve and sub valve.
(B) is a curve diagram of the torque of the sub-valve.

FIGS. 4A to 4C are explanatory views showing still another example of the internal pressure adjusting device.

FIGS. 5A and 5B are explanatory views showing a schematic structure of a conventional internal pressure adjusting mechanism.

[Explanation of symbols]

 2 Test room (inside) 3 Air-conditioning room (inside) 11 Pipe 11a One end side 11b Other end side 11c Inclined opening 12 Main valve (first valve body, air discharge mechanism) 12-1 Main valve (air suction mechanism) 12- 2 Main valve (air discharge mechanism) 13 Secondary valve (air suction mechanism) 100 External P, Q Low pressure section

Claims (3)

[Claims] 1. An environmental test apparatus in which the inside is air-conditioned by circulating air, wherein one end side is open to a portion of the low-pressure portion having a relatively low pressure in the inside away from the bottom, and the other end is guided to the outside. A pipe, an air suction mechanism provided on the other end side and opening to allow air to pass from the outside to the inside when the internal pressure is lower than a predetermined pressure, and the internal pressure is higher than the predetermined pressure. An environmental test apparatus comprising: an air discharge mechanism that opens so that air passes from the inside to the outside when the pressure is increased. 2. The air intake mechanism and the air discharge mechanism are provided with a first valve body which is formed to open at the time of the high pressure or at the time of the low pressure. The environmental test apparatus according to claim 1, wherein the first valve body is integrally formed with a second valve body that is formed to open at a time opposite to a time when the first valve body opens. 3. The other end includes an inclined opening projecting upward and retracting downward. The first valve body is rotatably supported upward at a size large enough to cover the inclined opening. The environmental test apparatus according to claim 2, wherein the two-valve element forms a part of the first valve element and is rotatably supported by the first valve element.