JP2002302234A - Drum-shaped conveyance roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drum-shaped conveyance roller whose service life can be prolonged by cooling a roller body uniformly and suppressing the generating of local thermal stress. SOLUTION: This drum-shaped conveyance roller 1 includes a hollow roller body 1A, the diameter of the conveyance width center of which is smaller than those of both ends in its external shape, and the shape of the internal face of which is nearly similar to the external shape, and a support shaft 3, which is inserted into the roller body 1A. In the drum-shaped conveyance roller 1, the cooling medium flow passages formed in the internal face of the roller body 1A and the external periphery of the support shaft 3 are formed into a spiral shape in the conveyance width direction of the roller body 1A by the revolving blade 2 provided in the external periphery positioned in the internal face of the roller body 1A of the support shaft 3 to let cooling medium flow from one end of the roller body 1A in the width direction to the spiral flow passage and discharge the cooling medium from the other end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating furnace for steel pipe or billet or steel bar for steel pipe material, and a drum-shaped transfer roll provided in a steel pipe heat treatment furnace.

[0002]

2. Description of the Related Art Heating furnaces for steel pipes or billets or steel bars for steel pipe materials and transport rolls provided in steel pipe heat treatment furnaces are:
A cantilever type that supports one end of the transport width of the roll body from the viewpoint of the narrow width of the transport material and the installation space, etc. Are commonly used.

When the tube is transported, for example, due to its shape, the drum-shaped transport roll makes two-point contact, so that the temperature difference in the width direction increases, and deposits from the transported material are removed from the roll body. There is a problem in that the quality of the transport material is degraded due to deposition on the surface to scratch the surface of the transport material, or burning of the roll body surface by the transport material.

In order to solve the above-mentioned problem, a drum-shaped transport roll having a structure in which the roll body is cooled by a cooling medium is employed. For example, a cantilevered drum-shaped transporting roll shown in FIG. 2 has a double-walled shaft portion penetrating from one end outside to the other end of a solid roll main body 51, and a cooling medium supply pipe 52 serving as an inner pipe. The open end is located at the other end of the roll main body 51 in the cooling medium discharge pipe 53 serving as an outer pipe, and the cooling water supplied from the cooling medium supply pipe 52 turns the other end of the roll main body 51 to form the roll main body 51. While being cooled, the roll body 51 is discharged from one end of the conveying width of the roll body 51 through the cooling medium discharge pipe 53.

However, since the drum-shaped transport roll shown in FIG. 2 has a structure in which the shaft is cooled to cool the solid roll body, the roll body cannot be directly cooled, and the roll body is cooled. As a result, there is a problem that high thermal stress is generated at both ends of the conveying width of the roll main body in contact with the material, and the roll is broken in a short period of about three months.

Therefore, as shown in FIG. 3, a shaft portion 54 inserted from one end outside to the other end of a hollow roll body 51 having an inner surface shape conforming to the outer shape is formed as a double tube to form an inner tube. The open end of the cooling medium supply pipe 54A is positioned at the other end of the roll body 51 in the cooling medium discharge pipe 54B serving as the outer pipe, and the roll body 51 in the cooling medium discharge pipe 54B is positioned.
The inflow port 54Ba is provided at the other end and the outflow port 54B is provided at one end.
b, and a drum-shaped transport roll in which the inflow port 54Ba and the outflow port 54Bb are partitioned by a partition wall provided in the cooling medium discharge pipe 54B has been proposed.

In the drum-shaped transport roll shown in FIG. 3, a cooling medium supplied from a cooling medium supply pipe 54A flows out of a hollow body of a roll body 51 through an outlet 54Ba of a cooling medium discharge pipe 54B. The cooling medium flows from the other end of the conveying width of the roll body 51 to one end in the flow path formed by the hollow inside of the roll body and the outer periphery of the shaft portion 54, and the cooling medium discharge pipe 54B
The cooling medium returns from the outlet 54Bb into the cooling medium discharge pipe 54B and is discharged from the roll main body 51. Therefore, compared with the drum-shaped transport roll having the structure shown in FIG.
Is cooled directly by the cooling medium, so that the cooling capacity is improved.

[0008]

However, in the drum-shaped transport roll shown in FIG. 3, since the area of the flow path of the cooling medium at the central portion P0 of the roll body 51 and at both ends P1 and P1 thereof is different, the transport material is different. The central portion P of the transport width of the roll body 51 where the roller body 51 is unlikely to be heated to a high temperature without much contact.
In the case of 0, the flow rate of the cooling water is high and it is easy to cool. On the other hand, at the both ends P1 and P1 of the transport width of the roll body 51 where the transport material comes into contact and the temperature is high, there is a phenomenon that the flow rate is low and the cooling is difficult.

As a result, a non-uniform temperature distribution occurs at the central portion P0 of the transport width of the roll body 51 and at both ends P1 and P1, and the cooling water boils at both ends P1 and P1 to reduce the cooling efficiency. As a result, locally high heat stress is generated, and the durability is longer than that of the drum-shaped transport roll shown in FIG. 2, but there is a problem that the roll is broken in a short period of about four months.

Note that, for example, Japanese Patent Application Laid-Open No. Sho 59-153844
Japanese Patent Application Laid-Open No. 59-140334 discloses a transport roll in which the center and both ends in the transport width direction have the same diameter in order to transport a strip or the like, and a flat roll body is supported at both ends by a support shaft. A cooling technique is described.

According to these publications, in order to improve the cooling effect, a spiral cooling medium flow path is formed on the inner surface of a hollow roll body supported at both ends, and a spiral flow path is formed from one end of the conveying width of the roll body. The cooling medium is supplied to the flow path, and the cooling medium passing through the spiral flow path is discharged from the other end of the transport width of the roll body.

However, Japanese Patent Application Laid-Open No. Sho 59-153844
The roll disclosed in Japanese Patent Application Laid-Open No. 59-140334 discloses that a flat material such as a strip is placed on a flat transport surface having a center portion and both ends having the same diameter. Heat is evenly transmitted to the transport surface of the roll body on which it is placed, and it is not possible to cope with the same concept as the above-described drum-shaped transport roll.

In addition, the double-sided support roll described in JP-A-59-153844 and JP-A-59-140334 cools a roll body having a hollow flat shape from one end of a transfer width of the roll body. Since the medium flows in and is discharged from the other end, the cooling medium easily stays at the end on the inflow side of the cooling medium, the inflow side is not cooled as compared with the discharge side of the cooling medium, and the entire width of the conveyance width is reduced. Cannot be cooled uniformly.

The present invention has been made to solve the above problems, and has an inner surface of a hollow roll body having an inner surface shape substantially similar to an outer shape of a drum, and an outer periphery of a support shaft inserted through the roll body. Supply the cooling medium to the annular space formed by
An object of the present invention is to provide a drum-shaped transport roll capable of uniformly cooling a roll main body, suppressing the generation of local thermal stress, and extending the life.

[0015]

In order to achieve the above object, a drum-shaped transport roll according to the present invention has an outer shape in which a diameter at a center portion of a transport width is smaller than both ends thereof, and an inner surface of the outer shape is substantially equal to the outer shape. A swirl vane is provided on the outer periphery of a support shaft inserted into a hollow roll body having a similar shape, and a flow path formed by the outer periphery of the support shaft and the inner surface of the roll body by the swirl blade in the transport width direction. The structure is such that the cooling medium flows in from one end of the conveying width of the roll body and is discharged from the other end.

In this manner, the cooling medium can be spread over the entire width and the entire circumference of the hollow portion of the roll body by the revolving blades. Therefore, the cooling medium can be uniformly distributed over the entire width and the entire circumference of the roll body. , And the generation of local thermal stress can be suppressed, and the life can be prolonged.

[0017]

DETAILED DESCRIPTION OF THE INVENTION A drum-shaped transport roll according to the present invention comprises a hollow roll body having an outer shape having a diameter at a center portion of a transport width smaller than both ends and an inner surface having a shape substantially similar to the outer shape. Having a support shaft inserted through the roll body,
In a drum-shaped transport roll capable of supplying a cooling medium for cooling the roll body to an annular space formed by the inner surface of the roll body and the outer circumference of the support shaft, the rotating blades are provided on the outer circumference located on the inner surface of the roll body of the support shaft. The spiral blade in the conveying width direction is formed in the flow path of the cooling medium formed between the outer periphery of the support shaft and the inner surface of the roll main body by the swirling blade, and the spiral cooling passage is formed from one end of the conveying width of the roll main body. The structure is such that the medium flows in and the cooling medium is discharged from the other end.

With the above configuration, the flow path of the cooling medium flowing from one end to the other end of the transport width of the roll body is spiraled by the swirling vanes, and the cooling medium is passed in the circumferential direction inside the hollow inside of the roll body. As a result, the cooling is prevented from becoming non-uniform, and the roll can be cooled uniformly over the entire width and the entire circumference, and the durability can be improved.

Further, in the drum-shaped transport roll of the present invention, in the above configuration, the interval between the swirling blades at the central portion in the transport width direction of the roll main body is wider than both ends of the transport width. The difference in the flow rate of the cooling medium based on the difference between the diameters at both ends and the center in the width direction of the roll body can be adjusted by adjusting the interval between the swirling blades, so that the durability is further improved as compared with the above. Can be improved.

In the drum-shaped transporting roll according to the present invention, the roll main body is cantilevered by a support shaft, and the cooling medium flows out to one end side of the roll main body in the flow path through the support shaft. An outflow path and a discharge path through which the cooling medium flows in from the other end side and is discharged outside the support shaft are formed. As described above, by supporting the roll body in a cantilever manner, the cooling medium does not stay around the outflow path, and the cooling capacity is increased.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a drum-shaped transport roll according to the present invention will be described below with reference to FIG. As shown in FIG. 1, the drum-shaped transport roll 1 of the present invention is configured such that the inside of a roll body 1 </ b> A in which the diameter of the transport width central portion is smaller than both ends is made hollow substantially similar to the outer shape, And roll body 1
The conveying width of A is provided on the outer periphery of a portion of the support shaft 3 that is inserted from one end outside to the other end inner surface and located inside the roll body 1A.

In the present embodiment, the swirl blade 2 is configured such that the interval between the transport rolls in the transport width direction is widened at the central portion in the transport width direction so that the flow velocity at both ends and the central portion of the roll body 1A in the transport width direction is reduced. I try to keep it constant.

The support shaft 3 is, for example, a double tube of an outer tube 3A and an inner tube 3B. The outer tube 3A has an outlet 3Aa at the other end of the roll body 1A and an inlet 3Ab at one end.
Are provided respectively. On the other hand, the inner tube 3B is
The open end of the roll body 1A is located at the other end of the roll body 1A. The outer tube 3A is provided with a partition wall 3Ac that divides the outlet 3Aa and the inlet 3Ab inside the outer tube 3A.

The drum-shaped transport roll 1 having the above-described configuration includes an inner tube 3
Cooling water as a cooling medium supplied through B is sent from the outside of one end of the roll body 1A to the inside of the other end, and flows out of the inner tube 3B.

The cooling water flowing out of the inner tube 3B is separated from the inner surface of the other end of the roll body 1A, the inner peripheral surface of the outer tube 3A, and the partition wall 3Ac.
Outlet 3Aa of outer tube 3A through the space defined by
Flows into the hollow of the roll main body 1A, moves toward one end of the roll main body 1A along a spiral flow path formed by the swirling blades 2, and is discharged from the inlet 3Ab of the outer tube 3A.

As described above, in the drum-shaped transport roll 1, the cooling water supplied from the outside of one end of the roll main body 1A flows out into the hollow of the roll main body 1A at the other end, so that the cooling water is surely supplied to the hollow of the roll main body 1A. It can extend over the entire width and the entire circumference.

In the drum-shaped transport roll 1, the interval between the swirling blades 2 at both ends in the width direction of the roll body 1A is wider than that at the center, so that the flow rate of the cooling water becomes constant.
Therefore, the entire width and the entire circumference of the drum-shaped roll body 1A can be uniformly cooled.

Next, the conventional drum-shaped transporting roll 51 shown in FIG. 3 and the above-described drum-shaped transporting roll 1 of the present invention are combined with a roll body having a thickness of 25 mm, an atmosphere temperature in a furnace of 1250 ° C.
Cooling water temperature 35 ° C, cooling water flow rate in roll hollow 1.5m /
s, under the same conditions, and the durability of both was confirmed.
Although cracks occurred at a moderate level for one month, the drum-shaped transport roll 1 of the present invention did not crack for six months or more.

[0029]

As described above, the drum-shaped transport roll of the present invention is a hollow roll having an outer shape in which the diameter at the center of the transport width is smaller than both ends and the inner surface of which is substantially similar to the outer shape. Turning blades are provided on the outer circumference of the support shaft inserted into the main body,
The cooling medium flows into the spiral flow path of the cooling medium formed by the outer periphery of the support shaft and the inner surface of the roll body by the swirling vanes from one end of the conveying width of the roll body, and discharges the cooling medium from the other end. Since the cooling medium is moved from the other end to the one end while moving in the circumferential direction inside the roll body, the cooling is prevented from being uneven,
The roll can be uniformly cooled over the entire width and circumference, and the durability can be improved.

Further, in the drum-shaped transport roll of the present invention, in the above configuration, the interval between the swirling blades at the center of the roll body in the transport width direction is wider than both ends of the transport width, so that both ends of the roll body in the transport width direction are provided. The difference in the flow rate of the cooling medium based on the difference in diameter between the rotating blades and the central portion can be adjusted to be uniform by adjusting the spacing between the swirling blades, and the allowable strength and durability can be further improved as compared with the above.

In the drum-shaped transporting roll according to the present invention, the roll main body is cantilevered by a support shaft, and the cooling medium flows through the support shaft to one end of the roll main body in the flow path. Since the outflow path and the discharge path for allowing the cooling medium to flow in from the other end side and discharging the cooling medium to the outside of the support shaft are formed, the cooling medium does not stay around the cooling medium outlet and the cooling capacity is increased. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a drum-shaped transport roll of the present invention.

FIG. 2 is a diagram showing a cooling structure of a conventional drum-shaped transport roll.

FIG. 3 is a diagram showing a cooling structure of a conventional drum-shaped transport roll.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hour-shaped conveyance roll 1A Roll main body 2 Rotating blade 3 Support shaft 3A Outer pipe 3Aa Outflow port 3Ab Inflow port 3Ac Partition wall 3B Inner pipe

Claims (3)

[Claims] 1. A hollow roll body having an outer shape whose diameter at a central portion of a conveying width is smaller than both ends and an inner surface of which is substantially similar to the outer shape, and a support shaft inserted through the roll body. And a drum-shaped transport roll capable of supplying a cooling medium for cooling the roll body to an annular space formed by the inner surface of the roll body and the outer periphery of the support shaft, wherein the inner surface of the roll body of the support shaft A swirl vane is provided on the outer periphery of the roll main body, and the swirl vane makes a flow path of the cooling medium formed by the outer periphery of the support shaft and the inner surface of the roll main body spiral in the conveying width direction. A drum-shaped transport roll having a structure in which a cooling medium flows into a spiral flow path from one end and the cooling medium is discharged from the other end. 2. The drum-shaped transfer roll according to claim 1, wherein the interval between the swirling blades at the center of the roll body in the transfer width direction is wider than both ends of the transfer width. 3. The roll main body is cantilevered by a support shaft. The support shaft has an outflow passage through which the cooling medium flows out to one end of the roll main body in the flow passage, and a cooling medium that flows in from the other end side. The drum-shaped transport roll according to claim 1 or 2, wherein a discharge path for discharging the roll outside the support shaft is formed.