JPH0523571A - Vacuum chamber - Google Patents

Abstract

(57) [Abstract] [Purpose] The atmosphere used to release the vacuum in the vacuum chamber varies in the subsequent vacuuming time due to variations in the humidity. In order to solve this problem, dry air, which has low humidity and is stable, is used to reduce the vacuuming time and improve reproducibility. [Structure] The dry air source shown in FIG. 1, an air tank supply pipe, an air tank, a vacuum chamber supply pipe, and an air shower pipe. [Effect] Shorten and stabilize the evacuation time of the vacuum chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to equipment having a chamber for performing a vacuuming operation and equipment for supplying a specified amount of gas.

[0002]

2. Description of the Related Art In an electron beam welding machine, conventionally, the vacuum of a welding chamber is released by taking in air.

However, since the humidity of the atmosphere (the degree of moisture contained) varies daily depending on the weather and the like, there is a problem that the evacuation time after taking in varies and it takes a long time to contain moisture. .

The present invention has been made to solve this problem.

That is, since the moisture in the air causes the evacuation time to be long, the dry chamber (dry air) containing the moisture as little as possible is used, and a vacuum chamber is provided through a tank capable of always storing a fixed amount of dry air. By constructing a system to supply to, the vacuuming time was shortened and stabilized.

This system has already been applied to the right auxiliary chamber of a three-chamber type (composed of a right auxiliary chamber, a welding chamber, and a left auxiliary chamber) of an electron beam welding machine. It can be shortened for comparison, which greatly contributes to the reduction of welding man-hours.

As a related publicly known document, an easy-to-understand vacuum technique, Japan Vacuum Association, Kansai Chapter, ed. (P60
(A) Measures against water vapor, baking of P109 and P113).

[0008]

[Problems to be Solved by the Invention]

Problem 1: In the vacuum chamber, since the vacuum is released by taking in the atmosphere, the time required for the subsequent evacuation also varies due to variations in atmospheric humidity. Further, if the humidity is high, it takes a long time to vacuum. Therefore, the first object of the present invention is to shorten and stabilize the evacuation time.

Problem 2: When supplying gas to the vacuum chamber, the amount of gas must be adjusted to match the volume of the chamber.

When a gas in an amount exceeding the volume of the chamber is supplied, the inside of the chamber exceeds atmospheric pressure and the work intake / removal work door is damaged. In this regard,
A second object of the present invention is to always be able to send a constant amount of gas into the chamber.

Problem 3: Even if dry air is supplied into the chamber in order to shorten the evacuation time, if the atmosphere around the chamber is mixed into the chamber when the work is taken in and taken out, the original purpose is achieved. Is not enough for. In consideration of this point, a third object of the present invention is to prevent atmospheric air from entering the chamber when the work door is opened.

[0012]

[Means for Solving the Problems]

1. Shortening and stabilizing means for evacuation time The vacuum in the vacuum chamber was released by supplying dry air. By using constant air with a humidity of 25%, it was possible to reduce the vacuuming time, which conventionally took nearly 1 minute, to 30 seconds or less.

FIG. 4 shows the relationship between humidity and evacuation time.

2. Means for stabilizing supply gas amount In the present invention, a tank and a solenoid valve were provided between the dry air source and the vacuum chamber, and piping was installed.

As a result, by supplying the dry air once stored in the tank to the vacuum chamber by controlling the solenoid valve, a constant amount of dry air can be supplied.

3. Preventing air from entering the vacuum chamber when the work door is opened Piping was provided on the front of the work door so that a dry air shower could be formed. Furthermore, the system was designed such that dry air was continuously supplied to the chamber while the work door was open.

As a result, it was possible to prevent atmospheric mixture when the work door was opened.

[0018]

[Function] The dry air sent from the dry air source is
First, it is stored in an air tank, and from there, a fixed amount of dry air is supplied into the vacuum chamber by controlling a solenoid valve. The air used here is constantly controlled at a humidity of 25%.

As a result, dry air whose humidity and flow rate are always constant is supplied into the vacuum chamber, so that a stable evacuation time can be obtained.

Further, a dry air shower is provided on the front surface of the work door to prevent atmospheric air from entering the vacuum chamber when the door is opened.

At the same time, while the door was open, dry air was continuously supplied into the vacuum chamber to strengthen the prevention of atmospheric mixture and to shorten the evacuation time.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

The overall structure consists of 1 dry air source, 2 air tank supply pipes, 3 air tanks, 4 vacuum chamber supply pipes, and 5 vacuum chambers.

The dry air sent from the dry air source 1 passes through the air tank supply pipe 2 and is stored in the air tank 3. From there, it passes through the vacuum chamber supply pipe 4 and into the vacuum chamber 5. Supplied. Since the air used here has a low humidity, the adhesion of water in the vacuum chamber is extremely small, and thus the effect of shortening the evacuation time can be obtained.

Further, the dry air sent from the dry air source 1 is sent to the front surface of the working open / close door 7 through the air shower pipe 6 to form the dry air shower 12 and into the vacuum chamber 5. Prevent air pollution.

In addition, while the work opening / closing door 7 is open, the air chamber 3 is connected to the vacuum chamber supply pipe 4
After that, dry air is continuously supplied to the vacuum chamber 5, and the prevention of atmospheric mixture into the vacuum chamber 5 is strengthened.

This dry air is continuously supplied to the 56-liter vacuum chamber 5 at 1.4 liters per second.
(Until the work and jig are completely loaded and the work opening / closing door 7 is closed.) Further, the dry air shower 12 is sprayed directly above the work / jig before being sent into the vacuum chamber 5, and the vacuum is drawn. Helps reduce time.

An electron beam welding machine having a three-chamber structure is provided with a welding chamber 8
Is always evacuated, and the vacuum chamber 5 (right preliminary chamber) and the left preliminary chamber 9 are taken into the atmosphere and evacuated, thereby effectively utilizing the welding chamber.

[0029]

According to the present invention, the effect of shortening the evacuation time of the right auxiliary chamber of the three-chamber electron beam welding machine, that is, the production time is obtained.

(Vacuum evacuation time in the right auxiliary chamber) When the jig / work is not placed in the right auxiliary chamber When using the atmosphere ... 44 to 50 seconds When using dry air ... 20 to 22 seconds When the jig / work is placed in the right auxiliary chamber When it is used in the atmosphere ... 100 to 110 seconds When using dry air ... 80 to 85 seconds As a result of applying the present invention, the actual welding time of the electron beam welding machine is currently 90 seconds / one work piece It was possible to achieve the appropriate vacuum time for the right preliminary chamber.

[Brief description of drawings]

FIG. 1 is a plan view showing a state in which the present invention is applied to a three-chamber electron beam welding machine.

FIG. 2 is a right side view of FIG. 1 specifically showing an air shower.

FIG. 3 is a front view of FIG. 1 showing the function of the air shower.

FIG. 4 is a relationship diagram between humidity and evacuation time.

[Explanation of symbols]

1 ... Dry air source, 2 ... Piping for air tank supply, 3 ... Air tank, 4 ... vacuum chamber supply pipe, 5 ... vacuum chamber (right spare room), 6… Air shower piping, 7 ... Open / close door for work, 8 ... Welding room, 9 ... Left spare room, 10 ... Atmosphere intake port, 11 ... vacuum piping, 12 ... Dry air shower.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideaki Sasaki             Hitachi, Ltd. 1 Horiyamashita, Hadano City, Kanagawa Prefecture             Factory Kanagawa factory

Claims (4)

[Claims] 1. A vacuum chamber comprising a dry air supply system. 2. A dry air supply mechanism comprising a dry air source, an air tank and an air pipe. 3. A dry air shower forming mechanism,
A dry air shower forming mechanism characterized by preventing the entry of air. 4. An apparatus having a vacuum, which has a three-chamber structure and supplies dry air to the inlet side for the purpose of dehumidifying the atmosphere and the work.