JPH0419305B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a roll seal structure used when continuously guiding a strip material such as a steel plate or film to a vacuum processing chamber.

[Conventional technology] Conventionally, when a strip material is continuously introduced into a vacuum processing chamber,
A differential pumping device consisting of a large number of vacuum chambers is provided on the entrance side of the vacuum processing chamber, and the strip material is fed while successively reducing the pressure. The seal between each vacuum chamber 2 is
As shown in FIG. 3, roll covers 4 are provided above and below the roll 3 on which the strip material 1 is wound, with a narrow gap between them, and sealing is achieved by making it difficult for leakage fluid to flow. At the entrance of the first-stage vacuum chamber 2 that is in contact with the atmosphere, a cover 5 that forms a constriction part 6 with the roll 3 is provided on a part of the roll cover 4 to form an ejector, as shown in FIG. However, by blowing out high-pressure gas through this constriction part 6, sealing performance is improved.

[Problems to be solved by the invention] However, the nozzle portion of the above ejector is
Since the nozzle is formed along the circumferential surface of the nozzle, the cross-sectional shape of the nozzle becomes asymmetrical. As a result, the flow at the nozzle becomes unstable. Furthermore, this type of ejector has a limited suction performance, and can only obtain a vacuum of up to 0.4 times atmospheric pressure, or 300 Torr.

The object of the present invention is to provide a seal structure that allows stable flow and provides a high degree of vacuum.

[Means and effects for solving the problem] In a roll-type seal structure for a strip material, a roll and a roll provided opposite to the roll to form a second throat portion between the roll and the roll are provided. consisting of an arc-shaped hardware having the same curvature surface, and a nozzle hardware having a triangular cross-section and having a first throat portion in the center facing the second throat portion and provided between the roll and the arc-shaped hardware; The tip of the secondary flow channel formed symmetrically between the upper and lower surfaces of this nozzle hardware and the roll and arc-shaped hardware is connected to the intermediate enlarged part formed between the first throat part and the second throat part. Let me come.

In this way, with respect to the surface including the first throat portion,
The secondary flow channels are formed symmetrically, resulting in a stable flow. Moreover, since it has a double throat structure, suction performance can be increased.

[Example] An example of the present invention will be described with reference to FIG. In the figure, reference numeral 11 denotes a hardware having an arcuate cross section and the same curvature surface as the roll 3. Its center line is located on the center line of the roll 3, and the second throat portion S ₂ is connected between the roll 3 and the roll 3.
is formed. 12 is the first throat part in the center
A nozzle metal fitting having a triangular cross section and having a cross section S ₁ is provided between the arc-shaped metal fitting 11 and the roll 3 with its tip facing the second throat portion S ₂ . In this way, the upper and lower surfaces of the nozzle hardware 12 and the arc-shaped hardware 11
and the outer peripheral surface of the roll 3, there is a secondary flow channel 1 between the
3 and 13 are formed. And these channels 1
The tip portions of 3 and 13 are connected to the extended surface of the flared end of the exit side of the first throat portion _S1 , the arcuate hardware 11, and the roll 3.
It is directed toward the intermediate enlarged part S _B defined by the intersection with the outer circumferential surface of. Further, the rear ends of the secondary flow passages 13, 13 are connected to the vacuum chamber 2 via the roll cover 4 or the piping 14, and are adjusted by a throttle or the like so that the passage resistance therebetween is equal.

In this way, the secondary flow channels 13, 13 are formed symmetrically with respect to the plane containing the first throat section _S1 , and there is also an intermediate enlarged section between the first throat section _S1 and the second throat section _S2 . A double throat structure with S _B is formed.

An enlarged view of the nozzle portion is shown in Figure 2b. Such a nozzle can be modeled as shown in Figure 2a.
For example, the radius of the roll 3 is 150 mm, the second throat part S ₂ ,
When the distances between the first throat part and the intermediate enlarged part S _B are 5 mm, 1 mm, and 6 mm, respectively, the pressure gradient along the axis of the nozzle is as shown in FIG. 2c.
0.017 Po is obtained in the intermediate expansion part S _B , and Po is 3.4 atm
In this case, the vacuum will be 58 Torr, which is much higher than the conventional 300 Torr. In this way, the suction performance of the secondary flow channel can be enhanced and stable suction can be performed.

[Effects of the Invention] This invention is as described above, and by making the nozzle part symmetrical, stable suction performance can be obtained, and by using a double throat type ejector nozzle, the suction performance is improved compared to the conventional one. It can be increased further. In this way, sealing performance can be improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the present invention, and FIGS. 2 a, b, and c are model diagrams of the nozzle part, respectively.
An enlarged view of the nozzle portion and a pressure gradient diagram within the nozzle, and FIGS. 3 and 4 are an explanatory view of a conventional seal structure and an enlarged explanatory view of the nozzle portion. DESCRIPTION OF SYMBOLS 1...Band-shaped material, 3...Roll, 1...Circular hardware, 12...Nozzle hardware, 13...Secondary flow channel, _S1 ...First throat part, _S2 ...Second throat part , S _B ... intermediate enlarged section.

Claims (1)

[Claims] 1 Roll-type seal structure of strip material, with roll and
an arcuate metal piece having the same curvature surface as the roll, which is provided opposite to the roll to form a second throat part with the roll; and an arcuate metal piece with the roll facing the second throat part. and a nozzle metal fitting having a triangular cross section and having a first throat part at the center provided between the nozzle metal fitting and a secondary nozzle metal fitting formed symmetrically between the upper and lower surfaces of this nozzle fitting and the roll and arc-shaped metal fitting. A seal structure characterized in that the tip of the flow passage faces an intermediate enlarged portion formed between the first throat portion and the second throat portion.