JPS6296621A - Supporting floater for strip - Google Patents

Abstract

PURPOSE:To develop noncontacting floater having a high performance, by providing plural baffle plates in width direction of a steel strip and prescribing the space and height to specified values in floater for supporting steel strip in noncontacting state due to static pressure of fluid. CONSTITUTION:At running the steel strip in continuous casting line and continuous galvanizing line, it is run and transferred in noncontacting state differing from contact transferring by guide roll, etc., by using supporting floater while utilizing static pressure between the steel strip 3 and a pressure receiving surface 4 due to injecting of fluid such as air. As supporting floater, plural baffle plates 8 along deformation of the strip 3 due to its dead weight are protrudedly provided on the surface 4 so that it extends in steel strip passing direction and arranged along width direction. In this case, by prescribing a pitch P in width direction of the strip 3 and a height H of the plate 8 to the values exhibited by a formula (1), supporting float for steel strip superior economically and having good efficiency is developed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a support floater that supports a traveling band plate in a non-contact manner using the static pressure of a fluid.

<Prior art> In continuous annealing lines and continuous plating lines for strips such as steel plates, or continuous electrolytic degreasing lines and continuous pickling lines that precede these lines, a guide device is required to guide the running of the strips. A guide roll is used. However, when performing surface treatment on the strip, a non-contact supporting floater is used that applies the principle of hydrostatic bearings, as shown in Figure 6, which shows its appearance, and Figure 7, which shows its cross-sectional structure. As shown, the box-shaped main body 2 whose interior is a chamber l for fluid such as air has an upper plate 5 forming a smooth pressure receiving surface 4 facing the strip plate 3.
is installed. Pressurized fluid from a chamber 1 communicating with a fluid supply source (not shown) is supplied to the center side of the pressure receiving surface 4 between the front and rear ends of the upper plate 5 in the strip plate 3 passing direction and the main body 2. A slit-shaped fluid ejection lower is formed to eject obliquely toward the support floater, and the static pressure of the pressurized fluid generated between the pressure receiving surface 4 and the strip plate 3 causes the strip plate 3 to touch the support floater without contacting it. It is now supported by the state.

<Problems to be Solved by the Invention> In the conventional support floater, the pressurized fluid ejected from the fluid ejection lower flows from the gap between the pressure receiving surface 4 and the strip plate 3 in the width direction of the strip plate 3 (in FIG. 7, However, because the gap between the center of the pressure-receiving surface 4 and the strip plate 3 is large, the leakage flow rate is extremely large, making it impossible to ensure sufficient static pressure. be. Further, as shown by the X mark in FIG. 2 showing the pressure distribution on the pressure receiving surface, the static pressure between the pressure receiving surface 4 and the strip plate 3 decreases at the outer side in the width direction of the strip plate 3. For this reason, in the conventional supporting floater, the supporting force is 30% of the theoretical value.
Since only about 40% can be obtained, the flow rate of the pressurized fluid from the fluid jet port 7 must be considerably increased from the theoretical value, and a large-capacity fluid supply source is required.

As a support floater that eliminates the above-mentioned drawbacks, we previously proposed the following support floater (Japanese Patent Application Sho EiO-
No. 43419), this support floater has a similar appearance to the fifth
As shown in the figure, a baffle plate 8 that follows the deformation of the strip 3 due to its own weight extends in the threading direction of the strip 3 and
A plurality of pressure-receiving surfaces 4 are protruded from each other so as to be arranged along the width direction of the pressure-receiving surface 4.

Since such a baffle plate 8 prevents the flow of fluid in the width direction of the strip plate 3, the static pressure between the pressure receiving surface 4 and the strip plate 3 is maintained high.

When such a baffle plate 8 is installed, it is more economical to increase the pitch of the baffle plates (the interval between the baffle plates) and decrease the height h because the number of steps is reduced. However, if the pitch of the baffle plates is increased and the height h is decreased, the above-described effect of increasing static pressure by the baffle plates may be impaired.

Therefore, the present invention provides a support floater for a strip plate having a bar and a full plate that is economically excellent by increasing the pitch as much as possible and keeping the height as low as possible without impairing the effect of the baffle plate. The purpose is to

<Means for Solving the Problems> The structure of the present invention that achieves the above object includes a main body in which a smooth pressure-receiving surface facing the strip plate is formed directly below the strip plate, and a smooth pressure-receiving surface facing the strip plate, and Openings are made along the width direction of the band plate at both front and rear ends of the pressure receiving surface along the line, and fluid is ejected diagonally in the −E direction toward the center of the pressure receiving surface to connect the band plate and the pressure receiving surface. In the strip support floater, which is provided with a set of fluid jet ports for generating static pressure of the fluid between the strip plate and the strip plate, a baffle plate extending in the threading direction of the strip plate is arranged along the width direction of the strip plate. When a plurality of baffle plates are arranged protruding from the pressure receiving surface, the pitch of the baffle plate in the strip width direction (the interval between eight full plates) P and/or
Alternatively, the height H of the baffle plate is determined by the following formula and arranged.

Pitch P: 2P≦Wmin Height H: [h/3, 2δ1ain≦H≦[5h, 7
δ1□Work Here, WIlin is the minimum width of the strip to be handled, and h is,
The floating height of the strip above the baffle plate, δ, is the width of the fluid jet (nozzle gap).

Hereinafter, the structure of the present invention will be explained in more detail with reference to an actual example.

FIGS. 1(a) and 1(b) show an example of a support floater according to the present invention, and the width of the floated strip is varied by varying the buckle plate pitch PI and the baffle plate height H2 shown in the figures. Experiments were conducted by varying W and flying height h, and appropriate values for baffle plate pitch P and height H were determined as described above.

Figure 2 shows the ratio of the pressure P at each position in the width direction of the strip to the pressure Pφ at the center of the strip when 15 baffle plates are provided (0 marks indicate de). .

For comparison, the value when no baffle plate is provided is shown with an x. As shown in the same figure, efficient static pressure is obtained by providing a baffle plate, and the From the position of the third baffle plate, substantially the same pressure as the widthwise center of the strip plate is obtained.

Figure 3 shows the height of the baffle plate at 15.20°25.
II11, the width of the strip is 1m, and the nozzle pitch is 50.
01, the height of the baffle plate was 20
The ratio between the width of the strip and the pitch of the baffle plate in the case of I1m,
The same tendency is shown when the baffle plate height is 15.25 mm, showing the relationship with the theoretical pressure ratio.

As shown in the figure, when the band width/baffle plate pitch is 2 or less, the theoretical pressure ratio is 40%, which is low blowing power efficiency, and furthermore, when the band plate width/baffle plate pitch is 1.5 or less, the Due to leakage from the edge of the plate (gravitational force), the strip plate will vibrate due to disturbances such as slight one-sided tension electric current, and stable levitation cannot be obtained.Also, if the width of the strip plate/baffle plate pitch exceeds 7. Almost reaches the theoretical pressure. This means that the width of the strip is I
This is because when the width is as wide as n, several baffle plates from the edge of the strip contribute to maintaining the internal static pressure.

Furthermore, if the width of the strip is narrower to about 100 m1 with the same floater, after the blown gas hits the strip, more of the gas will flow out in the longitudinal direction of the strip from the edges of the strip, which are wider than the collision width. Therefore, the pitch of the baffle plates must be reduced, and the pitch of the baffle plates must be less than or equal to the minimum width of the strips to be handled.

Regarding the height of the baffle plate, it is sufficient to form a kind of labyrinth with the strip plate and the baffle plate. Figure 4 shows the relationship between the height H of the baffle plate, the nozzle gap δ, and the flying height h. In the 0 diagram shown in , 0
The mark indicates when the levitation is good, and the X mark indicates when the levitation is unstable.As is clear from the figure, in order for the strip to levitate without contacting the floater, even in areas with poor strip shape. The height H of the baffle plate needs to be at least twice the nozzle gap δ→2δ or 1/3 of the set flying height h→h/3. Also, the speed of the jet jet blown out from the nozzle is
It seems that the attenuation starts when the jet is ejected at a distance of about 7 times the nozzle gap δ, so if the baffle plate is made to have a shape in which the band plate bends downward due to gravity and the weight of the band plate between the floaters, If the height of this baffle plate is too high, its effect will be lost, so as is clear from Figure 4, it must be less than 5 times the set flying height h. In other words, the height H of the baffle plate A good flying condition can be obtained by setting within the range of the following formula.

rh/3.2δ3'txin≦H≦[5h,7δ]aa
X (Example) Example 1 In each of the above floaters, the width of the strip plate is 1 to 1.5 m (minimum 0
．． 2m), when the flying height is 5 to 50mm.

Baffle plate pitch 1 with height 20cm-
When it was set at 00 mm, very good levitation was possible.

Example 2 In the above floater, the width of the band plate is 100 to 500 mm.

When the flying height is 5 to 15III11, the height is 5II1
1 baffle plate with a baffle plate pitch of 10.20.
When installed at 50a+m, very good levitation was possible.

(Effects of the Invention) As described above in detail along with the embodiments, according to the present invention, when a baffle plate is provided on a support floater for a strip, it can be manufactured economically without impairing its effects, and has high performance. It is possible to provide a supporting floater for a strip plate.

[Brief explanation of drawings]

Figures 1 (a) and (b) are explanatory diagrams of the support floater according to the present invention, Figure 2 is a graph showing the pressure distribution on the pressure receiving surface of the floater, and Figure 3 is the @/buckle plate pitch of the strip plate. Figure 4 is a graph showing the relationship between the height H of the baffle plate, the nozzle gap δ and the flying height h, and Figure 5 is a graph showing the relationship between the height H of the baffle plate and the nozzle gap δ and the flying height h. The perspective view of the floater, FIGS. 6 and 7, are explanatory diagrams of a conventional strip support floater. In the drawing, 2 is the main body, 3 is a strip plate, 4 is a pressure receiving surface, 7 is a fluid jet port, 8 is a baffle plate, P! ;L is the buckle plate pitch, Hi is the height of the baffle plate, δ is the nozzle gear 7b, and the text is the nozzle pitch.

Claims (1)

[Range of patent claim] The body in which a smooth pressure surface facing this band is formed directly below the band, and the front and rear ends of the front and rear of the front and front of the inadvertent surface according to the direction of the band. A set of fluids each opening along the width direction and ejecting fluid obliquely upward toward the center of the pressure receiving surface to generate static pressure of the fluid between the strip plate and the pressure receiving surface. In the support floater for a strip plate having a spout port, when a plurality of baffle plates extending in the threading direction of the strip plate are provided protruding from the pressure receiving surface so as to be arranged along the width direction of the strip plate, A support floater for a strip plate, characterized in that the pitch (distance between baffle plates) P of the baffle plates in the width direction of the strip plate and/or the height H of the baffle plates are determined from the following formula and arranged. Pitch P: 2P≦W_m_i_n Height H: [h/3, 2δ]_m_i_n≦H≦[5h,
7δ]_m_a_x where W_m_i_n is the minimum width of the strip to be handled, h is,
The flying height of the strip above the baffle plate, δ, is the width of the fluid jet.