JPH0463132B2 - - Google Patents

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 usually 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. A top plate 5 having a smooth pressure-receiving surface 4 facing the strip plate 3 is attached to a box-shaped main body 2 whose interior is a chamber 1 for fluid such as air. Between the front and back ends of the upper plate 5 in the strip plate 3 passing direction and the main body 2, pressurized fluid is supplied from the chamber 1 communicating with a fluid supply source (not shown) via piping 6 to the center side of the pressure receiving surface 4. A slit-shaped fluid spout 7 that spouts obliquely toward
are formed respectively, and the strip plate 3 is supported on the supporting floater in a non-contact state by the static pressure of the pressurized fluid generated between the pressure receiving surface 4 and the strip plate 3.

<Problems to be Solved by the Invention> In the conventional support floater, the pressurized fluid ejected from the fluid jet port 7 flows from the gap between the pressure receiving surface 4 and the strip plate 3 in the plate width direction of the strip plate 3 (in FIG. 7). , perpendicular to the plane of the paper), but 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 and sufficient static pressure cannot be secured. There is. Further, as shown by the x marks 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 toward the outside in the width direction of the strip plate 3. For this reason, with conventional support floaters, the support force is only about 30 to 40% of the theoretical value, so the flow rate of the pressurized fluid from the fluid jet port 7 has to be considerably increased from the theoretical value, which causes a large A volume fluid source is required.

As a support floater that eliminates the above-mentioned drawbacks, the following support floater was previously proposed (Japanese Patent Application No. 49419/1982). As shown in FIG. 5, this supporting floater has a buttful plate 8 extending in the threading direction of the strip 3 and extending in the width direction of the strip 3, which follows the deformation of the strip 3 due to its own weight. A plurality of pressure receiving surfaces 4 are provided so as to protrude from each other so as to be arranged along the same line.

With such a full plate 8, the strip plate 3
Since the flow of fluid in the width direction is prevented, the static pressure between the pressure receiving surface 4 and the strip plate 3 is maintained high.
When installing such a full plate 8,
It is more economical to increase the pitch of the buffful plates (the interval between the buffful plates) and lower the height h, since the number of steps is reduced. However, if the pitch of the buffle plates is increased and the height h is decreased, the above-mentioned effect of increasing static pressure by the buffle plates may be impaired.

Therefore, the present invention aims to increase the pitch of the buffer plate as much as possible without impairing its effectiveness.
It is an object of the present invention to provide a support floater for a strip plate having an economically excellent buff-full plate by keeping the height as low as possible.

<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 along the width direction of the strip plate at both front and rear ends of the pressure-receiving surface along with the pressure-receiving surface, and spouting fluid obliquely upward toward the center of the pressure-receiving surface, so that the strip plate and the pressure-receiving surface In the support floater for a strip plate, the floater is provided with a pair of fluid ejection ports for generating static pressure of the fluid between the strip plates, and a buff-full plate extending in the threading direction of the strip plate is attached along the width direction of the strip plate. When a plurality of buff-full plates are provided protruding from the pressure-receiving surface in an array, the pitch (interval between buff-full plates) P of the buff-full plates in the strip width direction and/or the height H of the buff-full plates is determined by the following formula. It is characterized by being arranged as follows.

Pitch P: 2P≦Wmin Height H: [h/3, 2δ] min≦H≦[5h, 7δ]
max Here, Wmin is the minimum width of the strip to be handled, h is the floating height of the strip from the buttful plate, and δ is the width of the body jet opening (nozzle gap).

Hereinafter, the configuration of the present invention will be explained in more detail along with experimental examples.

An example of a support floater according to the present invention is shown in FIGS. 1a and 1b. By variously changing the pitch Pl of the buttful plate and the height Hl of the buttful plate shown in the same figure,
Experiments were conducted by varying the width W and floating height h of the floating strip, and the appropriate values for the buffer plate pitch P and height H were determined as described above.

FIG. 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 buttful plates are provided (indicated by O mark).
In addition, for comparison, the values when no buff-full plate is provided are marked with an x. As shown in the figure, efficient static pressure can be obtained by providing the buttful plate, and the center of the band in the width direction from the end of the band to the third buttful plate. Almost the same pressure was obtained.

Figure 3 shows the height of the full plate as 15, 20,
25mm, the width of the strip is 1m, and the nozzle pitch is 500mm.
In the experiment, the height of the full plate was 20
The relationship between the ratio of the strip width to the buffer plate pitch and the theoretical pressure ratio in the case of mm is shown. A similar tendency is observed when the height of the full plate is 15 and 25 mm.

As shown in the figure, when the width of the strip plate/the pitch of the full plate is less than 2, the blowing power efficiency is low as the theoretical pressure ratio is 40%. Furthermore, if the width of the strip/bumpful plate pitch is less than 1.5, the strip will vibrate due to leakage from the edges of the strip and disturbances such as slight tension on one side, making it impossible to obtain stable levitation. Further, when the width of the strip plate/buffle plate pitch exceeds 7, the pressure almost reaches the theoretical pressure. This is because when the width of the strip is as wide as 1 m, several buff-full plates from the edge of the strip contribute to maintaining internal static pressure.

Furthermore, if the width of the strip is narrower to about 100 mm in 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, it is necessary to reduce the pitch of the baffle plates, and the pitch of the buffle plates must be less than 1/2 of the minimum width of the strips to be handled.

Regarding the height of the buffle plate, it is sufficient to form a kind of labyrinth with the band plate and the buffle plate. FIG. 4 shows the relationship between the height H of the buffle plate, the nozzle gap δ, and the flying height h. In the figure, the O mark indicates a case where the levitation is good, and the X mark indicates a case where the levitation is unstable. As is clear from the figure, in order for the strip to float without coming into contact with the floater even in areas with poor strip shape, the height H of the buttful plate must be at least twice the nozzle gap δ→2δ or 1/3 of the set flying height h→h/3 is required. In addition, the velocity of the jet jet blown out from the nozzle seems to start to attenuate after jetting a distance of about 7 times the nozzle gap δ, so it becomes less than 7δ.
Furthermore, if the buttful plate is arranged in such a shape that the strip bends downward due to gravity and the weight of the strip between the floaters, the effect will be lost if the height of the buttful plate is too high, as shown in Figure 4. As is clear from the above, it must be less than 5 times the set flying height h. In other words, a good flying condition can be obtained by setting the height H of the buffful plate within the range of the following equation.

[h/3, 2δ]min≦H≦[5h,7δ]max <Example> Example 1 Floater nozzle gear nozzle pitch floater width 5, 10, 20, 30mm 500, 600mm 1.7m Band in each floater above When the board width is 1 to 1.5 m (minimum 0.2 m) and the floating height is 5 to 50 mm, the height is 20
mm full plate with a pitch of 100mm
When installed, very good levitation was possible.

Example 2 Floater nozzle gear nozzle pitch floater width 5 mm 130 mm 500 mm In the above floater, when the strip width is 100 to 500 mm and the flying height is 5 to 15 mm, the height of the 5 mm buttful plate is 10, 20. , 50mm, very good levitation was possible.

<Effects of the Invention> As described above in detail with the embodiments, according to the present invention, when providing a strip support floater with a buttful plate, it can be manufactured economically without sacrificing its effects, and can be manufactured at high cost. A high-performance support floater for a strip can be provided.

[Brief explanation of the drawing]

Figures 1a 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 a graph showing the width of the strip plate/bumpful plate pitch and the pressure receiving surface. 4 is a graph showing the relationship between the height H of the buffful plate, the nozzle gap δ and the flying height h,
FIG. 5 is a perspective view showing a support floater for a strip with a buff-full plate, and FIGS. 6 and 7 are explanatory diagrams of a conventional support floater for a strip. In the drawing, 2 is the main body, 3 is a strip plate, 4 is a pressure receiving surface, and 7
is the fluid jet nozzle, 8 is the buttful plate, Pl is the buttful plate pitch, Hl is the height of the buttful plate,
δ is the nozzle gap, and l is the nozzle pitch.

Claims (1)

[Scope of Claims] 1. A main body in which a smooth pressure-receiving surface facing the strip plate is formed directly below the strip plate, and the strip plate is provided at both front and rear ends of the pressure-receiving surface along the threading direction of the strip plate. a pair of strips each having openings along the width direction thereof and ejecting fluid diagonally 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 equipped with a fluid jet port, when a plurality of buttful 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 band plate, characterized in that the pitch (interval between the buttful plates) P of the buff full plate in the band width direction and/or the height H of the buff full plate is determined from the following formula and arranged. . Pitch P: 2P≦Wmin Height H: [h/3, 2δ] min≦H≦[5h, 7δ]
max where Wmin is the minimum width of the strip to be handled, h is the flying height of the strip from the buttful plate, and δ is the width of the fluid jet port.