JPS6321557Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a ceramic roll for conveyance installed in a hot treatment line for metal strips.

[Prior art]

Conventionally, rolls for conveying metal strips installed in heat treatment furnaces and the like are made of heat-resistant cast steel, and therefore residual rolling oil, iron powder, etc. on the surface of the strip tend to adhere to the roll surface and cause pick-ups. This pick-up has the problem of causing serious quality defects such as scratches, seizures, and dents on the surface of the metal strip, reducing productivity.

On the other hand, recently, as described in Japanese Patent Application Laid-Open No. 58-81916, heat-resistant
There is a method that uses a ceramic roll to which a ceramic sleeve with excellent wear resistance is attached to prevent the occurrence of pick-ups.

However, the amount of thermal expansion of the metal core is several times larger than that of the ceramic sleeve due to its characteristics, so an annular clearance is formed between the metal core and the ceramic sleeve to absorb the difference in thermal expansion in the radial direction. It is necessary to do so. Therefore, if the temperature is not high enough to eliminate this clearance, the fit between the two will be loose and looseness will occur. For example, when used in cold conditions, there is a risk that the ceramic sleeve will crack, so it is difficult to use it in actual equipment. There were aspects of it that were inappropriate for use.

[Purpose of invention]

An object of the present invention is to provide a ceramic roll in which the roll body is made of ceramic and the shaft part is made of metal, so that the ceramic member and the metal member can be connected without any looseness to enable good operation.

[Structure of the idea]

The present invention has a ceramic cylindrical body constituting the roll body, and metal rings fitted to the inner and outer peripheries of both ends of the body cylindrical body, forming a passage for cooling water to circulate within the ring. A water conduit is provided for circulating cooling water from the outer ring toward the inner ring.

[Effect of invention]

With the above configuration, the high-temperature cooling water that passes through the outer ring expands the inner ring in the radial direction, so both ends of the ceramic cylinder are supported by the inner and outer rings under narrow pressure and are connected without play. be able to.

〔Example〕

The present invention will be explained below based on embodiments shown in the drawings.

FIG. 1 is a sectional view of a ceramic roll according to the present invention, and FIG. 2 is an enlarged sectional view showing a water conduit portion.

In the figure, 1 is a ceramic cylindrical body with openings at both ends, 2 is a metal inner ring that is fitted into the inner periphery of both ends of the cylindrical body 1, and 3 is a metal inner ring that is fitted to the outside of both ends of the ceramic cylindrical body 1 together with the inner ring 2. It is a metal outer ring that is placed to sandwich the entire circumference at both ends. The inner ring 2 and the outer ring 3 form a cavity around the entire circumference, and are provided with cooling water passages 4 and 5, respectively.

The inner ring 2 has a disc-shaped hub 7 between it and the shaft 6, and is connected to the same shaft 6. When the shaft 6 rotates, the ceramic cylindrical body 1 functions as a roll cylinder and conveys the strip 8. be able to.

Reference numerals 9a and 9b are outgoing holes for cooling water formed in the shaft 6 and communicating with a cooling water source outside the system, and 10 are return holes for discharging the cooling water. The return passage hole 10 and the return passage hole 10 are each communicated with the inner ring 2 by a return passage pipe 12.

Furthermore, 13 is a water conduit arranged between the inner ring 2 and the outer ring 3, which in this example is a bent short pipe as shown in FIG. The position of this water conduit 13 is such that the outgoing pipe 11 and the returning pipe 12 are in the inner ring, the outer ring 2 is
As shown in FIG. 3, the cooling water flowing into the outer ring 3 from the outgoing pipe 11 is divided into two streams in the cooling water passage 5 and flows into the same outer ring 3. It flows down the entire circumference, flows into the cooling water passage 4 of the inner ring 2 from the water conduit 13, and can circulate in the direction of the return pipe 12 in a flow state opposite to the flow inside the outer ring 3.

When the ceramic roll having the above configuration is operated in a high-temperature furnace while circulating cooling water, the temperature of the cooling water increases due to heat transfer from inside the furnace as it flows inside the outer ring 3, and the temperature rises to a high temperature inside the inner ring 2. flows into.
Therefore, a temperature gradient is generated in the cooling fluid passing through the cooling water passages 4 and 5 of the inner ring 2 and the outer ring 3, and the temperature on the inner ring 2 side becomes higher than that on the outer ring 3 side.

Due to this temperature difference, the inner ring 2 increases its thermal expansion in the radial direction and expands in diameter, while the outer ring 2 is not exposed to the low-temperature cooling water even in the high-temperature atmosphere inside the furnace. The amount of thermal expansion is small because it is cooled. Therefore, if the flow rate and velocity of the cooling water are appropriately selected for the furnace atmosphere temperature, the inner ring 2
By expanding the diameter of the ceramic cylindrical body 1, the outer ring 3
A clamping force that presses against the inner surface can be applied. Thereby, the ceramic cylindrical body 1 can be made into a stable structure without causing any play between the inner ring 2 and the outer ring 3.

As described above, the ceramic cylindrical body 1 is reliably supported at both ends, so it will not crack during rotational operation, and by using ceramic it is possible to prevent pick-ups and improve productivity.

〔effect〕

The ceramic roll according to the present invention has the following effects depending on its structure.

The ceramic cylindrical body constituting the roll cylinder can be stably fixed to the inner ring and the outer ring, and the cylindrical body can be prevented from cracking during operation.

Since the roll cylinder is made of ceramic material, pick-up in the heat treatment line can be prevented and productivity can be improved.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the ceramic roll according to the present invention, Fig. 2 is an enlarged cross-sectional view of the water conduit portion, and Fig. 3 is a view taken along the - arrow in Fig. 1, showing the flow of cooling water in the inner and outer rings. FIG. 1...Ceramic cylindrical body, 2...Inner ring, 3
...Outer ring, 4, 5...Cooling water passage, 6...
Shaft, 7...Hub, 8...Strip, 9...Outgoing hole, 10...Returning hole, 11...Outgoing pipe, 12...
Return pipe, 13... headrace.

Claims (1)

[Scope of utility model registration request] Metal rings having cooling water passages are fitted to the inner and outer peripheries of both ends of the ceramic cylindrical body, respectively, and a conduit is provided between both rings to guide the cooling water from the outer ring to the inner ring. Features Ceramic Roll.