JPH08100800A - Vacuum exhaust structure - Google Patents

Abstract

PURPOSE: To provide a vacuum exhaust device in which an oil diffuse pump for generating no back flow of oil at the time of power failure is used. CONSTITUTION: A vacuum exhaust device is provided with a cooling fan 3 for cooling the low temperature casing part 2b of an oil diffuse pump 2, a relay 11 for monitoring electrification condition of commercial power supply 4, and a battery 10 which is connected to the cooling fan 3 through a contact point 12, and the cooling fan 3 is driven by the battery 10 when the commercial power supply 4 is cut off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum exhaust device using an oil diffusion pump.

[0002]

2. Description of the Related Art Oil diffusion pumps are used in various fields as a vacuum exhaust device for medium and high vacuum.

FIG. 2 shows a conventional vacuum exhaust device using an oil diffusion pump. In the figure, reference numeral 1 is a vacuum container for forming a vacuum inside a vacuum chamber of an analyzer, and 2 is an oil diffusion pump attached to the vacuum container 1. The oil diffusion pump 2 ejects the boiler portion 2a which turns the oil contained in the case into an oil vapor by heating it with a heater H, and the oil vapor generated above the boiler portion 2a. It is composed of a low temperature casing portion 2b which produces a vacuum exhaust action. A cooling fan 3 is attached in the vicinity of the case of the low temperature casing portion 2b so as to face it, and the low temperature casing portion 2b is cooled by air cooling.

Reference numeral 4 denotes a power source for supplying electric power to the heater and the cooling fan 3 of the boiler section 2a of the oil diffusion pump, and a commercial power source is generally used. A switch indicated by 5 is provided in the power supply line to the heater of the boiler section 2a,
A timer switch 6 is provided in the power supply line of the cooling fan 3. When this switch 5 is turned on, the timer switch 6 is turned on in conjunction with it. In addition, the timer switch 6 is kept in the ON state for a certain period of time (for example, about 15 minutes) after the switch 5 is turned OFF, and then the timer switch 6 is delayed in OF.
It is set to be F.

When performing vacuum exhaust with the vacuum exhaust device using the oil diffusion pump as described above, the switch 5 is activated to heat the boiler section 2a and drive the cooling fan 3 to cool the low temperature casing section 2b. This prevents the oil vapor from flowing back into the vacuum container 1. When the boiler portion 2a is heated to a sufficiently high temperature to generate oil vapor, the inside of the vacuum container 1 is evacuated. However, it is a matter of course that an auxiliary pump such as an oil rotary pump (not shown) is provided on the exhaust port side of the oil diffusion pump to perform auxiliary exhaust, or the vacuum container is preliminarily exhausted to a low vacuum region. To do.

During evacuation, the cooling fan 3 is energized at the same time as the heater H of the boiler portion 2a, and the outer case of the low temperature casing portion 2b is air-cooled.
When the oil vapor inside b is cooled, the oil vapor that has completed the vacuum evacuation action is condensed again into a liquid state and is returned to the boiler portion 2a.

When the vacuum exhaust is finished, the switch 5 of the oil diffusion pump 2 is turned off to stop the heating of the heater H. Even if the heater H is stopped, the boiler part 2a is still at a high temperature for a while, so that the cooling fan 3 needs to be continuously driven for a while after that because oil vapor continues to be generated. Therefore, at the same time when the switch 5 is turned off, the timer switch 6 starts timing, maintains the energization state of the cooling fan 3 for a predetermined time and continues air cooling, cools it to near room temperature, and cools it until the oil temperature drops and oil vapor is no longer generated. The timer switch 6 is turned off later.

Even when the end work is manually performed without using the timer switch, the heater is stopped in the same manner as described above, and then the cooling fan is driven for a while to stop the cooling fan after oil vapor is no longer generated. To do so.

FIG. 3 is a diagram of a vacuum exhaust device using another conventional oil diffusion pump. In this oil diffusion pump, the low temperature casing portion 2b is cooled by a water cooling system,
The water cooling pipe 2c is wound around the outer case of the low temperature casing portion 2b and fixed with solder, and the cooling water passage 7
Cooling water is supplied from the cooling water circulation device 7 to the water cooling pipe 2c via a and 7b to cool the low temperature casing portion 2b. Even in the case of this example, even after the heater H of the boiler part 2a is turned off, the cooling water circulation device is kept in the ON state for a while and the cooling water is kept flowing, and the cooling water circulation device is sufficiently cooled after the boiler part 2a is cooled. 7 is stopped.

[0010]

In such a conventional vacuum exhaust device, when a power failure occurs (when a power source other than the commercial power source is used and the power source fails or the power supply is stopped). In addition, the cooling fan or the cooling water circulation device is stopped at the same time as the heater of the boiler part of the oil diffusion pump is stopped. Even if the heating of the heater is stopped by stopping the power supply,
Since the temperature of the boiler is high for a while, oil vapor continues to be generated. However, since the cooling fan or the cooling water circulation device is stopped, the low temperature casing portion is not cooled, so that the temperature of the low temperature casing portion rises and the oil vapor is not condensed. Therefore, the oil vapor flows back from the oil diffusion vacuum pump to the upper vacuum container, and the vacuum container is contaminated with oil.

The present invention has been made to solve such a problem. Even if the power supply is stopped due to a power failure or the like, the vacuum container is not contaminated and it is necessary to perform maintenance work after the power failure is restored. It is an object to provide a vacuum exhaust device.

[0012]

The vacuum evacuation device of the present invention made to solve the above problems is a vacuum evacuation device for evacuating a vacuum container using an oil diffusion pump. It is equipped with a cooling fan for cooling, a relay for monitoring the power supply state of the commercial power supply to the vacuum exhaust device, and a battery connected to the cooling fan via a contact.When the commercial power supply fails, the battery cools the fan. It is characterized by being driven. Hereinafter, the operation of the vacuum exhaust device of the present invention will be described.

[0013]

In the vacuum exhaust apparatus of the present invention, the electric power of the entire vacuum exhaust apparatus is supplied from the commercial power source while the electric power is supplied from the commercial power source. When an unexpected power failure occurs, a relay that monitors the energization state of the commercial power source operates to connect a contact between the cooling fan and the battery, and thereby the cooling fan is driven by the power supply from the battery. Therefore, even if a power failure occurs during operation of the oil diffusion pump,
Since the cooling of the low-temperature casing is continued, the oil vapor does not flow back into the vacuum container or scatter from the exhaust port side to the outside of the oil diffusion pump.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing an evacuation device showing an embodiment according to the present invention. In this figure, the same parts as those in the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

Similar to the conventional example shown in FIG. 2, a cooling fan 3 is attached near the case of the low temperature casing 2b so as to face it, and the low temperature casing 2 is cooled by air cooling.
b is cooled.

Reference numeral 4 is a power supply for supplying electric power to the heater of the boiler portion 2a of the oil diffusion pump and the cooling fan 3, and a commercial power supply is generally used. A switch indicated by 15 is provided in the power supply line to the heater of the boiler portion 2a, and a switch indicated by 16 and a DC power supply 13 are provided in the power supply line of the cooling fan 3. Switch 15,
And switch 16 are turned on to start the pump. Of course, these may be interlocked as in the conventional example.

Reference numeral 11 is a relay for monitoring the energization state of the commercial power source 4, and the signal from the relay 11 is sent to the contact 12. The contact 12 is connected between the cooling fan 3 and the battery 10, and the signal from the relay 11 causes the contact 12 to open when commercial power is supplied. On the contrary, the contact 12 is set to be closed by the signal of the relay 11 when the commercial power is not supplied.

Next, the operation of this vacuum exhaust device will be described. When the commercial power supply is energized, the switches 15 and 1
6 is turned on to operate the vacuum exhaust device, and when it is finished, the switch 15 is turned off first, so that the boiler unit 2a
The heater is stopped, and after a lapse of a certain time, the switch 16 is turned off and the cooling fan 3 is stopped. Next, the operation when a power failure suddenly occurs when the switches 15 and 16 are in the ON state will be described.

The power supply from the commercial power source to the heater H of the boiler 2a is stopped with the power failure, but at the same time, the cooling fan 3
The power supply to the power will also be stopped. On the other hand, simultaneously with the power failure, the relay 11 operates and closes the contact 12. As a result, electric power can be supplied from the battery 10 to the cooling fan, and only the cooling fan 3 is continuously driven. After that, the cooling fan 3 is driven until the battery becomes empty. In order to eliminate wasteful consumption of the battery, a timer may be provided in the circuit of the battery 10 and the cooling fan so that power is supplied from the battery for a certain period of time.

Although the present invention is particularly effective in the oil diffusion pump for air cooling of FIG. 2, a backup cooling mechanism including a cooling fan, a battery, a relay, and contacts is added to the water cooling type oil diffusion pump of FIG. By doing so, the same effect can be obtained.

[0021]

As described above, in the vacuum evacuation system of the present invention, the cooling of the low temperature casing can be continued by jetting the cooling gas at the time of power failure, so that the backflow of oil vapor and the scattering of oil can be prevented. Further, in the case of using the water-cooling type oil diffusion pump, it is possible to prevent the water-cooling pipe from dropping due to melting of the solder for joining the water-cooling pipe.

[Brief description of drawings]

FIG. 1 is a diagram showing a vacuum exhaust device which is an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional vacuum exhaust device.

FIG. 3 is a view showing another conventional vacuum exhaust device.

[Explanation of symbols]

 1: Vacuum container 2: Oil diffusion pump 2a: Boiler part 2b: Low temperature casing part 3: Cooling fan 4: Power supply 10: Battery 11: Relay 12: Contact 13: DC power supply

Claims (1)

[Claims] 1. A vacuum exhaust device for exhausting a vacuum container using an oil diffusion pump, comprising: a cooling fan for cooling a low temperature casing portion of the oil diffusion pump; and a relay for monitoring the energization state of a commercial power source to the vacuum exhaust device. And a battery connected to the cooling fan via a contact, and the cooling fan is driven by the battery when the commercial power supply is interrupted.