JPH0343577B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a low-pressure environmental test chamber in which various tests are performed while maintaining the chamber at a low pressure. The present invention relates to a low-pressure environmental test chamber that can be carried out safely for people.

[Prior Art] Performance tests of automobiles and the like that are intended to be driven at high altitudes are carried out by housing the automobile and the like in a low-pressure test chamber that maintains the interior at a low pressure below atmospheric pressure. This low-pressure test chamber has an anteroom that serves as a reserve room so that workers can safely enter and exit the test chamber without being exposed to extreme pressure fluctuations. ing. This front room is also provided to allow workers to quickly leave the test room for safety in the event of a sudden drop in the atmospheric pressure in the test room or a fire outbreak.

In such an anteroom, a solenoid valve for restoring pressure is installed in the middle of the vent pipe, with one end open to atmospheric pressure and the other end open into the anteroom, and one end open to the low-pressure test chamber and the other end opened into the anteroom. A solenoid valve for pressure reduction is provided in the middle of the ventilation pipe whose end is open into the front chamber.

For example, when a worker enters a low-pressure test chamber, he or she opens the pressure reducing solenoid valve and temporarily stays in the front chamber, which is pressure equalized with the low-pressure test chamber, to acclimatize before entering the test chamber. I try to do that.

When leaving the low-pressure test chamber, the pressure return solenoid valve is opened to reduce the pressure in the front chamber to atmospheric pressure, and the worker exits the chamber through the regulated front chamber.

[Problems to be Solved by the Invention] Conventionally, the pressure inside the front chamber is regulated by simply opening the solenoid valve for pressure reduction or the solenoid valve for restoring the pressure. There was a problem that occurred. FIG. 3 shows the change in atmospheric pressure over time when, for example, a pressure reducing electromagnetic valve is opened to reduce the voltage in the prepressure.
As shown in the graph of FIG. 3, the atmospheric pressure drops rapidly in a short time after the solenoid valve is opened.

Such a sudden change in atmospheric pressure will have an adverse effect on the human body, such as making workers in the vestibule feel unwell.

Therefore, the present invention was proposed to solve these conventional problems, and aims to provide a low-pressure environmental test chamber in which the pressure inside the front chamber can be controlled without adversely affecting the human body. purpose.

[Means for Solving the Problems] In order to achieve this objective, the low pressure environmental test chamber of the present invention has a low pressure chamber in which various tests are performed while maintaining the chamber at a low pressure, and an anteroom for entering and exiting the low pressure chamber. a first vent pipe having one end open to the atmospheric pressure side and the other end open to the above-mentioned interior in a low-pressure environmental test chamber;
A first solenoid valve provided in the middle of this first ventilation pipe, a second ventilation pipe whose one end opens to the low pressure chamber and the other end opens into the front chamber, and a middle part of this second ventilation pipe. A second electromagnetic valve provided in the front chamber, a sensor that detects the air pressure inside the front chamber, and a control device that controls the inside of the front chamber by repeatedly controlling the first or second solenoid valve on and off based on the detection output of this sensor. The invention is characterized in that it has a control section that presses the button.

[Function] Therefore, in the present invention, the control section controls the first
Alternatively, since the second electromagnetic valve can be repeatedly controlled on and off, the pressure within the prepressure can be adjusted (reduced or restored) in a stepwise manner without causing a sudden change in atmospheric pressure.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a configuration diagram of a low-pressure environmental test chamber of the present invention.

In FIG. 1, the low-pressure environmental test chamber includes a low-pressure chamber 1 in which various tests are conducted while keeping the chamber at a low pressure;
A small front chamber 2 used for entering and exiting the low pressure chamber 1 is provided. This front room 2 includes a door 3 for entering and exiting the front room 1 and a door 4 for entering and exiting the low pressure room 1.
is provided.

Further, a vent pipe 5 is provided with one end open to the atmospheric pressure side and the other end open into the front chamber 2, and a solenoid valve 6 for pressure recovery is provided in the middle of the vent pipe 5. Also, one end opens to the low pressure chamber 1 and the other end opens to the front chamber 2.
A vent pipe 7 that is open inside is provided, and a solenoid valve 8 for pressure reduction is provided in the middle of the vent pipe 7.

By opening the electromagnetic valve 6, the pressure inside the front chamber 2 is restored and the pressure is equalized with the atmospheric pressure. Further, by opening the solenoid valve 8, the pressure inside the front chamber 2 is reduced and the pressure is equalized with the inside of the low pressure chamber 1.

Further, a sensor 9 for detecting the atmospheric pressure in the front chamber 2 is provided in the front chamber 2, and a detection signal from this sensor 9 is sent to a detection section 10. The output of this detection unit 10 is transmitted to a control unit 1 that controls opening and closing of the solenoid valves 6 and 8.
1. This control unit 11 includes a detection unit 1
A program setting device is provided that repeatedly controls opening and closing of the solenoid valve 6 or 8 based on the output of zero.

Further, an indicator light 12 connected to the control section 11 is provided in the front chamber 2, and the indicator light 12 is turned on when pressure restoration or depressurization in the front chamber 2 is completed.

In the low-pressure environmental test chamber configured as described above, when the front chamber 2 is depressurized, for example, the solenoid valve 8 is repeatedly turned on and off by the control section 11 having a built-in program setting device. Pressure 2
The pressure inside the tank is not rapidly reduced in a short period of time as in the conventional case, but the pressure is reduced in a nearly straight line as shown in FIG.

The same is true when restoring the pressure inside the front chamber 2. Since the solenoid valve 6 for restoring pressure is repeatedly controlled on and off by the control section 11, and opening and closing are repeated, a near-linear restoring characteristic can be obtained. become.

[Effects of the Invention] As explained above, the present invention uses a solenoid valve or a low-pressure test chamber that equalizes the pressure inside the front chamber with atmospheric pressure when regulating (reducing or restoring) the pressure inside the front chamber. Since the pressure is regulated by repeatedly turning on and off the solenoid valve that equalizes the pressure, the pressure in the front chamber can be gradually regulated, reducing the impact on the human body of workers inside the front chamber. .

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a low-pressure environmental test chamber according to an embodiment of the present invention, Fig. 2 is a characteristic diagram showing the depressurization characteristics in the front chamber of the low-pressure environmental test chamber, and Fig. 3 is a characteristic diagram showing the conventional depressurization characteristics. It is a diagram. In the figure, 1...Low pressure chamber, 2...Ante chamber, 3, 4...
Door, 5, 7... Ventilation pipe, 6, 8... Solenoid valve, 9...
...Sensor, 10...Detection section, 11...Control section, 1
2... Indicator light.

Claims (1)

[Claims] 1. In a low-pressure environmental test chamber equipped with a low-pressure chamber in which various tests are performed while keeping the room at low pressure, and an anteroom for entering and exiting this low-pressure chamber, one end is open to atmospheric pressure and the other end is inside the anteroom. an open first ventilation pipe; a first solenoid valve provided in the middle of the first ventilation pipe;
A second ventilation pipe with one end open to the low pressure chamber and the other end opened into the anteroom, a second electromagnetic valve provided in the middle of the second ventilation pipe, and a pressure inside the anteroom detected. A low-pressure environmental test chamber comprising: a sensor; and a control section that controls the first or second solenoid valve repeatedly on and off based on the detection output of the sensor to regulate the pressure in the front chamber.