JPH05340355A - Vacuum pump - Google Patents

Abstract

PURPOSE:To provide a vacuum pump capable of being surely restarted only by slightly improving an atmospheric side second valve provided adjacent to a port communicating to an atmospheric chamber. CONSTITUTION:A second valve 18 on the atmospheric side in a vacuum pump for making a vacuum apparatus 24 exhausted by the reciprocation of a gas sucking means 12 is slightly bent to be opened by its own force in the stoppage of the gas sucking means 12, when pressure of a communicating port 17 is lower than predetermined one, and the second valve 18 on the atmospheric side is formed of a stainless steel plate. When the reciprocation of the gas sucking means 12 is once stopped, the second valve 18 on the atmospheric side is returned to the original state by its own force to open the communication port 17 and open a pump head chamber 11 to the atmosphere since the second valve 18 is bent originally to the opening side. Thus, the restart can be smoothly carried out without conventionally operating an unloader valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relatively small vacuum pump for vacuuming equipment to be evacuated by reciprocating movement of gas intake means such as a piston and a diaphragm.

[0002]

2. Description of the Related Art Generally, a vacuum pump of this type has a pump head chamber 11 of a vacuum pump body 10 as shown in FIG.
When the gas suction means 12 moves downward inside, the air in the equipment 24 to be evacuated passes through the pipe 23, the check valve 22, and further from the vacuum chamber 15 through the first valve 20 on the vacuum side of the communication port 19 to the above. When the gas is sucked into the pump head chamber 11 and the gas suction means 12 moves upward, the first valve 20 on the vacuum side is closed and the inside of the equipment 24 to be evacuated is kept vacuum, and the second valve on the atmosphere side is kept. 18 opens slightly and pump head chamber 11
Is discharged into the atmosphere through the communication port 17 and the atmosphere chamber 14, and this is repeated to make the vacuumed device 24 a vacuum.

In such a vacuum pump, when the gas suction means 12 is completely stopped and then restarted,
Due to the residual negative pressure existing in the pump head chamber 11, if the vacuum start (atmospheric pressure-vacuum) is larger than the start torque, a start failure occurs. Therefore, conventionally, as shown in FIG. 5, a method of opening the unloader valve 25 to introduce the atmosphere into the pump head chamber 11 to remove the residual negative pressure and then driving the valve has been adopted.

[0004]

In the conventional method using the unloader valve 25, since the unloader valve 25 is composed of a solenoid valve or the like, the shape of the pump itself becomes large and the cost becomes high. Moreover, there is a problem that a control circuit for the solenoid valve is required.

The present invention can be surely restarted without the unloader valve 25 by making a slight modification to the second valve 18 on the atmosphere side provided facing the communication port 17 of the atmosphere chamber 14. The purpose is to obtain.

[0006]

According to the present invention, the gas suction means 12 reciprocates the pump head chamber 11 of the vacuum pump body 10 to move the first valve 20 on the vacuum side of the communication port 19 from the vacuum chamber 15. Suction into the pump head chamber 11 through the pump head chamber 11 and discharge from the pump head chamber 11 to the atmosphere through the second valve 18 on the atmosphere side of the communication port 17 are repeated to make the vacuumed device 24 a vacuum. In the vacuum pump, the atmosphere-side second valve 18 is opened slightly by itself when the gas suction means 12 is stopped, that is, the atmosphere-side second valve 18 is made of a stainless steel plate and has a communication port. 1
7 is a vacuum pump characterized by being slightly bent so as to open by itself when the pressure is below a predetermined pressure.

[0007]

When the gas suction means 12 moves downward, the second valve 18 on the atmosphere side is sucked and the communication port 17 is closed tightly. Further, when the gas suction means 12 moves downward, the communication port 19 is opened and the check valve 22 is opened, so that the air inside the vacuumed device 24 is sucked into the pump head chamber 11.
When the gas suction means 12 moves upward, the first valve 20 on the vacuum side is closed and the vacuum state of the vacuum chamber 15 and the vacuumed device 24 is maintained. The second valve 18 on the atmosphere side is opened in place of the first valve 20 on the vacuum side, and the pump head chamber 11 is replaced by the atmosphere chamber 1.
4 communicates with the atmosphere. By repeating the above operation, the vacuumed device 24 can obtain a predetermined degree of vacuum. Here, once the vacuum work by the gas suction means 12 is temporarily stopped, the second valve 18 on the atmosphere side is originally bent toward the opening side, so it returns to the original state by itself and opens the communication port 17 to open the pump. The head chamber 11 is opened to the atmosphere. Therefore, the restart can be smoothly performed without operating the unloader valve 25 as in the conventional case.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 10 denotes a vacuum pump body such as a cylindrical body or each cylinder body. The vacuum pump body 10 is provided with a gas suction means 12 such as a piston, and at the end of the vacuum pump body 10. Is an air chamber 1 separated from each other
4 and a vacuum chamber 15 are provided. Of these, atmosphere room 1
4, an atmosphere port 16 communicating with the atmosphere is opened, and a communication port 17 communicating with the pump head chamber 11 is bored. In addition, the vacuum chamber 15 includes an intake port 21 and a pipe 2.
The device to be vacuumed 24 is connected via 3 and a communication port 19 communicating with the pump head chamber 11 is formed.

The intake port 21 is provided with a check valve 22, the communication port 19 is provided with a first valve 20 on the vacuum side, and the communication port 17 is provided with a second valve 18 on the atmosphere side. Is provided. The atmosphere-side second valve 18 and the vacuum-side first valve 2
0 means that the stainless steel plate is provided with a pin or the like so as to open and close the communication port 17 and the communication port 19, respectively, and the first valve 20 on the vacuum side is normally in close contact with the communication port 19 side. Or, it is provided in a slightly opened state. The second valve 18 on the atmosphere side is according to the present invention. As shown in FIG. 2, in a normal state, a part of the communication port 17 is slightly opened, for example, about 1 to 2 mm, and the gap 2 is formed.
6 is formed. That is, the second valve 18 on the atmosphere side
Normally opens and closes when reciprocating by the gas suction means 12, but once the gas suction means 12 is stopped, the second valve 18 on the atmosphere side is opened by itself to form the gap 26 and communicate with the atmosphere. It is like this.

In the above structure, when the gas suction means 12 is moved downward by the piston rod 13, as shown in FIG. 3, air is sucked from the slight gap 26 of the second valve 18 on the atmosphere side. The second valve 18 on the atmosphere side is also sucked to close the communication port 17 in close contact. Further, when the gas suction means 12 moves downward, the communication port 19 is opened and the check valve 22 is opened, so that the air in the vacuumed device 24 passes through the pipe 23, the vacuum chamber 15, and the communication port 19. It is sucked into the pump head chamber 11. Next, when the gas suction means 12 is moved upward by the piston rod 13, the first valve 20 on the vacuum side is closed and the vacuum state of the vacuum chamber 15 and the equipment to be vacuumed 24 is maintained. At this time, the check valve 22 is closed so that the vacuum degree of the vacuumed device 24 is not impaired. at the same time,
The atmosphere-side second valve 18 is opened instead of the vacuum-side first valve 20, and the pump head chamber 11 communicates with the atmosphere through the atmosphere chamber 14. By repeating the above operation, the vacuumed device 24
A predetermined degree of vacuum is obtained.

Here, once the reciprocating movement of the gas suction means 12 is temporarily stopped, a residual negative pressure remains in the pump head chamber 11. However, since the second valve 18 on the atmosphere side is originally bent toward the opening side, as shown in FIG. 1, the second valve 18 returns to the original state by itself and opens the communication port 17 to open the pump head chamber 11 to the atmosphere chamber 14 , To the atmosphere through the atmosphere port 16. Therefore, the restart can be smoothly performed without operating the unloader valve 25 as in the conventional case.

In the above embodiment, the case where the gas suction means 12 is composed of a piston is taken as an example, but as shown in FIG.
It can also be configured by a diaphragm.

[0013]

Since the present invention is constructed as described above,
It is not necessary to use the unloader valve 25 as in the past. Therefore, a solenoid valve or the like that constitutes the unloader valve 25 is not required, the shape of the pump itself can be reduced, the cost is reduced, and a control circuit for the solenoid valve is not required.
Further, it is possible to reliably restart without the unloader valve 25.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a vacuum pump according to the present invention at a stop time.

FIG. 2 is an enlarged view of a second valve 18 on the atmosphere side in FIG.

FIG. 3 is a sectional view of FIG. 1 in operation.

FIG. 4 is a sectional view showing a second embodiment of the vacuum pump according to the present invention.

FIG. 5 is a sectional view of a conventional vacuum pump.

[Explanation of symbols]

10 ... Vacuum pump main body, 11 ... Pump head chamber, 12 ...
Gas suction means, 13 ... Piston rod, 14 ... Atmosphere chamber,
15 ... Vacuum chamber, 16 ... Atmosphere port, 17 ... Communication port, 18 ... Atmosphere side second valve, 19 ... Communication port, 20 ... Vacuum side first valve,
21 ... Intake port, 22 ... Check valve, 23 ... Pipe, 24 ... Vacuum equipment, 25 ... Unloader valve, 26 ... Gap.

Claims (3)

[Claims] 1. A pump head chamber 1 of a vacuum pump body 10.
1 by the reciprocating movement of the gas suction means 12, suction from the vacuum chamber 15 to the pump head chamber 11 via the first valve 20 on the vacuum side, and the second valve on the atmosphere side from the pump head chamber 11 In the vacuum pump that vacuums the vacuumed device 24 by repeating the discharge to the atmosphere via 18, the second valve 18 on the atmosphere side is slightly opened by itself when the gas suction means 12 is stopped. A vacuum pump characterized by being formed into. 2. The second valve 18 on the atmosphere side is made of a stainless steel plate, and the communication port 17 opened and closed by the second valve 18 is slightly bent so as to open by itself when the pressure is below a predetermined pressure. 1. The vacuum pump according to 1. 3. The vacuum pump according to claim 1, wherein the gas suction means 12 comprises a piston or a diaphragm.