JPS647250Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Use The present invention relates to a high vacuum evacuation device that has a dust countermeasure mesh at the exhaust port in a vacuum chamber and that makes it possible to improve the evacuation speed.

Configuration of the conventional example and its problems In the conventional vacuum apparatus, the exhaust port in the sample chamber is covered with a metal mesh in order to prevent the inside of the pump from being contaminated by dust and the like. On the other hand, the above mesh is
When the sample chamber is evacuated, it acts as an evacuation resistance and has the disadvantage of prolonging the time required to reach the required degree of vacuum. For example, if the diameter of the thin wire constituting the mesh is equal to the width of the gap, the effective exhaust port area will be 1/4 of that without the mesh.
When pumping a sample chamber to high vacuum, if the pumping speed is regulated by the conductance of the exhaust port, if the effective exhaust port area is reduced to 1/4, the pumping time to reach the required high degree of vacuum will be approximately quadrupled. Become.

Purpose of the invention This invention was made to eliminate the above-mentioned drawbacks.The sample chamber is roughly evacuated, the pressure is reduced, and the dust in the sample chamber is sucked into the pump from the exhaust port by the airflow during exhaust. To provide a high vacuum evacuation device capable of shortening evacuation time by moving the mesh upward to increase the conductance of an evacuation port when there is no longer a possibility that the mesh will be evacuated.

Composition of the invention The composition of the present invention is a high vacuum evacuation device equipped with a mechanism that allows the mesh covering the indoor vacuum exhaust port to be detachably moved to the sample chamber during evacuation. During the process of evacuation of the vacuum chamber from atmospheric pressure, a mesh to prevent dust is placed at the exhaust port during the initial evacuation, increasing the degree of vacuum.
By removing the mesh from the exhaust port section when it is no longer necessary to take measures against dust by airflow, the exhaust time can be shortened.

Description of examples The present invention will be explained using examples thereof.

The figure shows a high vacuum evacuation device equipped with a movable mesh according to the present invention. 1 is the sample chamber to be evacuated to high vacuum, 2 is the mesh, 2a is the mesh position during rough evacuation, 2b is the mesh position during high vacuum evacuation,
3 is an exhaust port of the sample chamber, 4 is a rough evacuation valve, and 5 is a high vacuum evacuation valve.

First, rough drawing from atmospheric pressure is done using mesh 2 as before.
Perform this at position 2a. This is to prevent internal contamination of the exhaust system, which is the original purpose of the mesh.

When the rough pulling is completed, the mesh is lifted to position 2b and the main pulling begins. When the degree of vacuum reaches the level at which rough evacuation has been completed, the airflow within the sample chamber 1 is gentle, and there is not enough flow to suck into the exhaust system foreign matter such as dust newly generated by moving the mesh. That is, if the mesh 2 is moved from the position 2a to the position 2b, which is raised by about 1/2 of the exhaust port system, a gap will be created between the mesh 2 and the exhaust port 3, so the effective exhaust capacity due to the presence of the mesh 2 will be reduced. There is no problem. Further, even if there is a falling foreign object in the sample chamber 1, since the sample chamber 1 is already maintained at a high degree of vacuum, it will fall vertically, and on the exhaust port 3, it will fall onto the mesh 2. Therefore, by lifting the mesh, the effective exhaust area can be expanded while preventing foreign matter from entering the exhaust port.

Effects of the invention As explained above, according to the invention, internal contamination of the exhaust system is prevented by the mesh placed at the exhaust port, and the mesh is removed from the exhaust port during high vacuum evacuation, thereby increasing the effective exhaust area. It can be expanded and the exhaust time can be shortened.

[Brief explanation of the drawing]

The figure shows the high vacuum evacuation device of the present invention. 1...Sample chamber, 2...Mesh, 2a...Mesh (position) during rough evacuation, 2b...Mesh (position) during high vacuum evacuation, 3...Exhaust port of sample chamber, 4
... Valve for rough evacuation, 5... Valve for high vacuum exhaust.

Claims (1)

[Scope of utility model registration request] a sample chamber to be evacuated to a high vacuum; an exhaust port connected to the sample chamber and having a rough evacuation passage and a high vacuum exhaust passage; A movable mesh installed on the side of the sample chamber, and the movable mesh is placed in a position covering the connection opening during evacuation using the rough evacuation path, and the movable mesh is placed in a position covering the connection opening when evacuation is performed using the high vacuum evacuation path. 1. A high vacuum evacuation device characterized by comprising a moving mechanism set at a position spaced from the .