JPH0891652A - Fluid supporting roll and fluid supporting device for strip - Google Patents

Abstract

PURPOSE: To provide the fluid supporting roll and the fluid supporting device, which has a function for easily selecting the appropriate space between nozzles in relation to the plate width and for easily selecting the fluid floating carrying and the roll carrying and which can restrict the generation of thermal clown at the time of carrying a roll. CONSTITUTION: A roll 10, which is wrapped with a strip so as to carry and support it, is formed of a central roll 1 and end rolls 2, which are provided in both ends of the roll and which can be slid in the roll shaft direction, and a pair of fluid jetting nozzles 4 having a variable opening width, which can be changed by sliding the end rolls in the roll shaft direction, on the roll surface between the central roll and the end rolls over the whole circumference of the roll are formed into the step shape with a pitch at 90 degree or 120 degree in the roll circumferential direction. A pyrogenetic conductive metal member is desirably assembled near the surface of the roll. The fluid supporting roll, a back surface pad, and the fluid nozzles are arranged so as to form a fluid supporting device for strip.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll for floatingly supporting a running strip by means of a fluid force over the entire strip processing line. More specifically, the present invention relates to a continuous annealing line for steel strips, a continuous plating line, a roll and a device for floating and supporting the strips by a fluid force in the continuous coating line.

Since the present invention can be applied to the production and transportation of other metals, paper, plastics, etc.,
In the following description, it is simply referred to as "strip".

[0003]

2. Description of the Related Art As a method of floating and supporting a strip in a non-contact manner, a method of arranging a large number of fluid bearings and a method of applying the principle of hovercraft are generally known.

In the case of utilizing a fluid bearing, a large number of nozzle holes are arranged on a drum-shaped outer peripheral surface around which a strip is wound, high-pressure fluid is ejected from these nozzles, and the strip wound around the nozzle is not in contact. It is a method of floating, supporting and transporting in a state.

According to this method, when the strip is floated by air, if the tension of the strip is increased, a very large air pressure is required, and the swing of the strip is said to be large.

Therefore, it is used for transporting light-weight strips such as photographic film, photographic paper, and magnetic tape which do not require a large fluid jetting force, as disclosed in JP-A-62-167162. . However, since this method levitates the strip with the ejection energy from a large number of air bearings, when applied to the levitation-supported transport of metal strips, there are too many nozzle holes and a large fluid ejection pressure is required. It is uneconomical.

On the other hand, the one to which the principle of the hovercraft is applied utilizes the cushion pressure generated in the region surrounded by the curtain of the fluid by ejecting the fluid from the slit nozzle toward the inside of the strip to be floated and conveyed. This method also basically converts the kinetic energy of the fluid into static pressure or dynamic pressure to support the strip in a floating manner.

For example, as disclosed in Japanese Unexamined Patent Publication No. 62-139832, it is generally constructed as a fixed strip floating device. However, when the strip is conveyed by this method, power is required to continuously supply the fluid, and in order to reduce the running cost, when conveying the strip that does not require floating conveyance, it should be conveyed by rolls. However, since it is a fixed type, it is not possible to use different transportation methods. Furthermore, even in the plate threading work at the tip of the strip, a problem arises only with the levitation transport device.

On the other hand, the inventors of the present invention disclosed in Japanese Patent Laid-Open No. 4-1
A fluid support device disclosed in Japanese Patent No. 57121 has been proposed, in which an auxiliary roll is installed to avoid complication of switching between levitation transfer and roll transfer and to easily switch the transfer.

However, the fluid support device also has the following improvements.

When a fluid is supplied from a plurality of nozzles extending in the circumferential direction of the roll in the plate width direction to form a fluid cushion, the nozzle intervals are set to be wider than the plate width so that the nozzle positions can be arranged inside the plate width. Need to be small. Moreover, if the nozzle spacing is too small relative to the plate width, the cushion becomes unstable, so there is an allowable nozzle spacing for a certain plate width. However, since the plate width to be manufactured is not constant in a normal thin plate processing line, it is necessary to arrange nozzles extending in multiple circumferential directions and select the nozzle to be used according to the plate width. However, when many nozzles are arranged,
The number of movable parts of the roll increases, and a mechanism for selecting the facing nozzle interval according to the plate width is also required, which complicates the structure.

Further, if there is a temperature difference between the strip and the roll, heat is transferred from one to the other, so that a thermal crown is generated in the roll. For example, if the temperature of the strip is higher than the ambient temperature where the roll is installed,
At the strip passing position, heat transfer from the strip raises the roll surface temperature. This temperature difference is conducted by heat conduction in the axial direction and the radial direction of the roll to generate a heat gradient in the roll. That is, thermal expansion differs depending on the axial position of the roll due to this temperature difference, and appears as a convex crown. On the contrary, when the plate temperature is relatively low, a concave crown occurs. The change in the crown shape of the roll induces the meandering of the strip during traveling and impairs stable traveling.

On the other hand, Japanese Patent Application Laid-Open No. 63-258354 discloses a method of rotating a roll in order to prevent deformation of the apparatus due to unbalanced heat during floating transportation of the strip. No technique has been shown that can cope with the suppression of the thermal crown during transportation.

[0014]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a fluid-supporting roll and a fluid having a simple mechanism capable of selecting an appropriate nozzle interval with respect to a plate width and easily selecting fluid levitation transfer and roll transfer. A support device is provided. Another object of the present invention is to provide a fluid-supporting roll and a fluid-supporting device that suppress a thermal crown generated due to a temperature difference between the roll and the strip when the roll is conveyed.

[0015]

The present inventors have completed the present invention by obtaining the following findings as a result of examining the above problems.

When the strip is turned at an angle of 90 degrees, a fluid cushion can be formed on the roll surface if there is a circumferential nozzle on the surface corresponding to an angle of at least 90 degrees with respect to the entire circumference of the roll surface. There is no need to provide a spanning circumferential nozzle.

A device having a simple roll structure is possible by dividing the circumferential length of the nozzle into a minimum required angle or more and changing the pair of nozzle intervals corresponding to the width of the strip to be conveyed on the entire circumference of the roll. .

By simplifying the pair of left and right circumferential nozzles, it is possible to simplify the opening and closing mechanism for the circumferential nozzles for selecting the fluid floating conveyance and the roll conveyance.

In order to prevent the thermal crown due to the temperature difference between the strip and the roll, it is important to mitigate the thermal gradient, and by incorporating an auxiliary medium for promoting heat transfer in the axial direction into the roll, the crown is prevented. It can be suppressed.

The present invention is a roll for winding and supporting a strip wound around a roll, which comprises a central roll and end rolls provided at both ends and slidable in the roll axial direction. By sliding the partial rolls, a pair of fluid ejection nozzles with variable opening widths over the entire circumference of the rolls on the roll surface between the central roll and the end rolls are formed in a stepwise pattern of 90 ° pitch or 120 ° pitch in the roll circumferential direction. 3 is a fluid bearing roll of a strip of formed structure. Further, it is desirable to incorporate a high thermal conductive metal member near the surface of the roll so that the central roll and the end roll are connected in the axial direction of the roll when the rolls are fitted together.

In another embodiment, the roll described above,
It is a fluid support device for a strip in which a back surface pad is provided so as to face the roll surface opposite to the strip winding surface of the roll, and a fluid nozzle is arranged side by side in the vicinity of the roll winding start line of the strip.

[0022]

The present invention will be described in detail with reference to the drawings.

FIG. 1 is a front view of the fluid support roll of the present invention in which the fluid ejection nozzle at the time of floating conveyance is opened.

FIG. 2 is a front view of the fluid support roll in which the fluid ejection nozzle is closed when it is used as a normal roll of the present invention.

A fluid support roll 10 is formed by a central roll 1 for winding and carrying the strip and end rolls 2 provided at both ends of the roll, and the central roll 1 and the end rolls 2 are separated from each other in the axial direction of the roll. As a result, a fluid ejection nozzle 4 (hereinafter, referred to as a "nozzle") that serves as a nozzle is formed on the roll surface. The nozzles 4 are arranged in a step shape over the entire circumference of the roll, with a pitch of 90 degrees or 12
It is preferable that one pair is provided at a predetermined interval of 0 degree pitch, and the positions thereof are symmetrical with respect to the center of the strip passing position.

The nozzle 4 can change the nozzle opening width t by sliding the end roll 2 on the roll shaft 3, and can function as a normal roll by closing the nozzle as shown in FIG. Is possible.

The meshing portion of the center roll 1 and the end roll 2 forming the nozzle 4 is divided into four steps of 90 degrees as shown by a, b, c and d in FIG.

FIG. 3 is a sectional view of the roll with the nozzle corresponding to FIG. 1 in the open state, and FIG. 4 is a sectional view of the roll with the nozzle corresponding to FIG. 2 in the closed state. The roll shaft 3 is hollow so that a fluid can flow inside, and the central roll 1
A plurality of fluid holes 6 are formed in the roll shaft portion 3 so that the fluid can be fed into the space 5 formed between the end roll 2 and the end roll 2.

FIG. 5 and FIG. 6 are sectional views of another roll of the invention in which the nozzle is open and the nozzle is closed.

A metal material 7 having high thermal conductivity is incorporated near the surface inside the roll. When the roll 10 is closed as shown in FIG. The high thermal conductive metal member 7 incorporated in the end roll 2 is connected. Therefore, for example, it is possible to suppress the generation of the thermal crown of the roll by efficiently moving the heat generated at the central portion to the low heat portion at the end portion.

The material of the roll main body and the high thermal conductive metal member is not particularly limited, but the roll is required to have strength as a structure in order to support the tension of the strip. Therefore, it is preferable to use a roll made of steel or stainless steel for the outer cylinder and use copper, aluminum, silver, or the like as the high thermal conductive metal member. Further, when an austenitic stainless steel material is used for the roll and a copper material is used for the heat transfer member, there is an advantage that the difference in linear expansion coefficient is small, and a combination thereof is suitable.

(1) When the strip is floated and conveyed FIG. 7 shows an example of the floated conveyance of the strip. In the fluid support device 20 of the present invention, a fluid nozzle 11 is arranged in the vicinity of the roll winding start line of the fluid support roll 10 and the strips before and after the fluid support roll 10 so as to face the roll surface opposite to the strip winding surface of the roll. The back pad 15 is provided.

FIG. 8 is a view showing a fluid nozzle, (a)
Shows a perspective view thereof, and (b) shows a sectional view thereof. Fluid nozzle 1
1 is provided with a fluid supply pipe 12 and a slit 13 for ejecting a fluid toward a strip.

For floating transportation of the strip, the fluid is individually supplied to the fluid support roll 10 and the fluid nozzle 11. First, the right and left fluids individually supplied from the roll shaft 3 travel through the cavities in the roll shaft into the inside of the roll, pass through the fluid holes 6, and then are formed between the central roll 1 and the end rolls 2. It is ejected from the nozzle 4 through the open space 5. At this time, the ejection of the fluid from the lower surface is suppressed by the back pad 15.

On the other hand, the fluid is supplied from the supply pipe 12 to the fluid nozzles 11 arranged on the inlet side and the outlet side of the roll, and is discharged from the slit 13. The ejection angle θ of the fluid from the slit 13 shown in the sectional view of FIG.
45 degrees is desirable.

As described above, by ejecting the fluid from the fluid support roll 10 and the fluid nozzle 11, a stable cushion layer of the fluid is formed on the winding surface of the strip, and the strip floats without contacting the roll. Supported.

The nozzle width Wn (distance between nozzles) Wn of the fluid support roll 10 shown in FIG. 1 may be appropriately set in advance with a focus on the width of the main strip to be conveyed.
The concept of the selection will be described below.

In the present invention, since the nozzle 4 extending in the roll circumferential direction is stepwise, the nozzle width in the roll axial direction is 9
When the pitch is changed in a stepwise manner at 0 ° pitch, the optimum nozzle width Wn corresponding to the width of the strip can be set by appropriately selecting the positions a to d and directing the positions toward the winding surface of the strip. Moreover, since the width of the strip to be conveyed is changed while selecting a size that is close to a certain extent, when the nozzle width needs to be changed, the fluid support roll 10 can be rotated 90 ° in either the forward or reverse direction, which is appropriate. The nozzle width can be changed instantly.

The nozzle width is selected so that the nozzle width Wn is narrower than the strip width Wn produced in a line using the fluid support roll 10, the maximum width of the nozzle: Wn (max), the maximum strip width. Large: W
When max is set, Wmax> Wn (max) Further, when the minimum width of the nozzle: Wn (min) and the minimum width of the strip: Wmin, Wmin> Wn (min) is selected.

Furthermore, the number of circumferential divisions of the nozzle is 4 (90
When the nozzle width is set in 4 steps in a stepwise manner with a pitch of ∘, dividing Wn (max) and Wn (min) into equal intervals is a simple criterion for determining the nozzle interval. That is, with reference to the maximum width Wmax and the minimum width Wmin (Wmax-Wmi
Change the nozzle width with n) / 3. In other words, the step difference in the roll axis direction of the staircase-like fluid ejection nozzle shown in FIG.
Then, H = (Wmax-Wmin) / 6 is the reference for setting the nozzle position.

The same applies to the case where the nozzle is divided into three in the circumferential direction (the nozzle width is set in three steps at 120 ° pitch). In that case, the setting criterion is H = (Wmax-Wmin) / 4. Moreover, in this case, the circumferential division of the roll surface forming the same nozzle width is 120 ° pitch, but even if the angle is more than the angle required for the direction change, there is no adverse effect on the levitation. It can also be used to change the direction by 90 degrees.

Further, the fluid support roll 10 of the present invention is
By sliding the end roll 2 on the roll shaft 3, the opening width t of the nozzle 4 can be arbitrarily set.
Since the ejection speed of the fluid changes depending on the opening width, it is possible to adjust the flying height by adjusting the opening width. The preferable opening width is 2 to 5 mm.

Further, the ejection angle of the fluid from the nozzle 4 is
A range of 30 to 90 degrees toward the central roll is preferred.

(2) In the case of carrying rolls In the fluid support roll 10 of the present invention, the openings of the nozzles 4 are closed by sliding the end rolls 2 provided at both ends of the roll on the roll shaft 3 to close the normal opening. It can function as a roll. FIG. 4 shows a state in which the end roll 2 is slid to close the nozzle 4 when the roll is conveyed. Further, as shown in FIG. 6, in the case of another invention mode,
By closing the nozzle 4, the high thermal conductive metal members 7 inside the roll adhere to each other.

A roll structure having no heat transfer member as shown in FIG. 4 of the present invention may be used at a portion where a temperature difference does not occur between the strip and the fluid support roll. However, in a line in which a temperature difference occurs between the fluid-supporting roll and the strip, for example, when a high-temperature strip is wound around the roll, the temperature at the strip passing position rises and a thermal crown is formed. However, by adopting another structure of the present invention, that is, a structure in which the high thermal conductive metal member 7 is incorporated inside the roll as shown in FIG. 6, heat transfer in the axial direction of the roll is promoted, and a metal having good thermal conductivity is also used. The temperature tends to be uniform at the place where the material is provided.

When the strip has a high temperature, a convex crown is generated on the roll, but when the low-temperature strip passes through the roll installed in a high temperature atmosphere, the roll has a concave crown shape to induce meandering. . In the case of the roll incorporating the high thermal conductive metal member of the present invention, since the mechanism for uniforming the temperature distribution in the axial direction is the same, the generation of the concave crown is suppressed and the threading is stabilized.

FIG. 9 shows another example of the present invention, in which a partition plate 8 is arranged in the space 5 between the central roll 1 and the end roll 2. The use of a heat transfer member for the partition plate 8 has the effect of increasing the heat transfer surface and contributes to temperature uniformity. In addition, when the surface is floated by the fluid, there is a rectifying effect of radially ejecting the fluid.

[0048]

【Example】

(Embodiment 1) FIG. 10 shows a transport model line used for confirming the effects of the present invention.

The coil whose temperature has been raised in the heating furnace 21 is discharged, and the strip plate is conveyed through the bridle device 22 to the fluid support device 20 of the present invention having the structure shown in FIG. 7, and the winding angle of the strip becomes 90 degrees. I did it. After that, through the tension measuring roll 23, the tension reel 24
Rolled up. Table 1 shows the specifications of the fluid support roll and the fluid nozzle of the example of the present invention.

[0050]

[Table 1]

The model line of FIG. 10 has a thickness of 0.15 mm and a width of 280 mm, 330 mm, 380 mm and 430 mm.
Compressed air is supplied to the fluid support roll and the fluid nozzle at room temperature without heating the strip using the SPCC steel strip changed to the type as the test material, and the line speed is 200 m /
The strip was floated and conveyed at min. The flying height of the strip was measured by an eddy current sensor.

FIG. 11 shows the measurement results of the flying height in the strip width direction. Air with a total flow rate of 20 Nm ³ / min including both the fluid support roll and the fluid nozzle was supplied to a tension of 50 N / mm ² . When transporting the above four types of strip width materials, 30mm from the strip width
A roll surface with a narrow nozzle width was used. The nozzle opening width of the fluid support roll was fixed at 2 mm. However, the flow rate balance of each nozzle is adjusted so that the levitation is uniform.

From FIG. 11, it was possible to carry out stable and uniform floating conveyance by the apparatus using the fluid support roll and the fluid nozzle of the present invention. Further, although the floating support was evaluated with a strip width other than the above strip width, it was possible to float a strip with a width of 270 mm to 470 mm by using a roll surface having a nozzle width narrower than the strip width.

Next, the strip was heated up to 300 ° C. in a heating furnace, and a strip roll test was conducted. The rolls used in the test were those in which the nozzles of the rolls in Table 1 were clogged, and comparison was made between a roll in which copper as a high thermal conductive metal member was incorporated in the vicinity of the roll surface and a roll in which copper was not incorporated.
In both cases, the temperature of the strip at the time it was wrapped around the roll was 270 ° C. The roll was run at 200 m / min for about 10 minutes, and after the roll was sufficiently heated, the profile of the roll was measured.

FIG. 12 is a diagram showing a thermal crown generation state in the strip width direction. The thermal crown amount was measured by sliding a contact type dial gauge in the roll axis direction. When the fluid-supporting roll shown by the solid line in which copper is not incorporated is used, the temperature of the strip passing position rises, and the difference between the crown amount at the center and the crown amount at the end in the roll width direction is 0. Although a 24 mm convex thermal crown is generated, when copper is incorporated, heat is transferred to the end side as shown by the broken line,
Although the roll surface temperature slightly rises as a whole, the thermal crown is reduced to about 1/5, which is 0.5 mm due to the difference between the central portion and the end portion.

Further, when a fluid-supporting roll incorporating copper was used, formation of a convex crown on the roll was suppressed, so that flatness of the strip did not occur. On the other hand, in the case of a roll not incorporating copper, the contact state between the strip and the roll was not uniform due to the generation of crown, and the flatness failure occurred due to the influence of uneven pulling due to the convex crown. From this, it was confirmed that when there is a difference in temperature between the strip and the roll, the effect of suppressing the thermal crown is great by incorporating the high thermal conductive metal member into the roll.

(Example 2) Air was used as the fluid, and a test was conducted using the fluid support device having the configuration of FIG. 7 as an alternative to the top roll of the hot dip coating line.

The roll has a diameter of 1800 mm and a body length of 22.
Nozzle width on roll surface is 1550m in a staircase.
The structure is selectable in four stages of m, 1210 mm, 870 mm, and 530 mm, and twelve copper partition plates are arranged in the circumferential direction of the space of the central roll and the end roll shown in FIG.
A strip having a thickness of 0.6 to 1.6 mm and a width of 800 to 1800 mm was floated and conveyed while appropriately selecting the nozzle interval. Although it was a strip after hot dipping, it was confirmed that stable flying could be performed with a flying height of about 15 mm.

Further, although the roll was conveyed, it was possible to pass the roll without causing any flaw in the nozzle portion of the roll.

[0060]

According to the present invention, it is possible to provide a simple roll structure capable of stably floating and transporting a strip and immediately setting an appropriate nozzle interval for a change in plate width. Further, it has a great effect that the roll can be conveyed and the trouble of passing the plate due to the thermal crown, which is a concern when there is a temperature difference between the roll and the strip, can be avoided.

[Brief description of drawings]

FIG. 1 is a front view of a fluid support roll in a nozzle opening state according to the present invention.

FIG. 2 is a front view of the fluid support roll of the present invention in a nozzle closed state.

FIG. 3 is a cross-sectional view of the fluid support roll in the nozzle opening state of FIG.

4 is a cross-sectional view of the fluid support roll in the nozzle closed state of FIG.

5 is a cross-sectional view of the fluid support roll when the high thermal conductive metal member is incorporated in the nozzle opening state of FIG.

FIG. 6 is a cross-sectional view of a fluid support roll when a high thermal conductive metal member is incorporated in the nozzle closed state of FIG.

FIG. 7 is a side view showing an example of the fluid support device of the present invention.

FIG. 8 is a diagram showing an example of a fluid nozzle of the present invention,
(A) is the perspective view, (b) is sectional drawing.

FIG. 9 is a perspective view of an example in which a partition plate is provided in the space of the fluid support roll of the present invention.

FIG. 10 is a side view of a model line used in an example.

FIG. 11 is a diagram showing a measurement result of flying height in the strip width direction.

FIG. 12 is a diagram showing a thermal crown amount in the strip width direction.

[Explanation of symbols]

 1: Central roll 2: End roll 3: Roll shaft 4: Fluid ejection nozzle (nozzle) 5: Space 6: Fluid hole 7: High thermal conductive metal member 8: Partition plate 10: Fluid support roll 11: Fluid nozzle 12: Fluid Supply pipe 13: Slit 15: Back pad 20: Fluid support device 21: Heating furnace 22: Bridle device 23: Tension measuring roll 24: Tension reel

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Eiji Hirooka 5-1-1109 Shimaya, Konohana-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries, Ltd. Kansai Works Steelmaking Works

Claims (3)

[Claims] 1. A roll for winding and carrying a strip around a roll, the roll comprising a central roll and end rolls provided at both ends and slidable in the roll axial direction. A pair of fluid ejection nozzles with variable opening widths are formed on the surface of the roll between the central roll and the end rolls in a step shape with a 90 ° pitch or a 120 ° pitch in the roll circumferential direction. A fluid-supporting roll of strip, characterized in that it is a structure. 2. A fluid support for a strip, characterized in that in the vicinity of the surface of the roll according to claim 1, a high heat conductive metal member is incorporated so as to connect in the axial direction of the roll when the central roll and the end roll are fitted together. roll. 3. A roll according to claim 1, a fluid nozzle provided in the vicinity of the roll winding start line of the strip and the back pad installed opposite to the roll surface opposite to the strip winding surface of the roll. A strip fluid support device characterized in that it is arranged.