JPH0238281B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in conical rolls used in planetary inclined roll mills.

A planetary inclined roll mill has at least three conical rolls disposed equiangularly around a material to be rolled, and the material to be rolled is drawn and rolled by rotation and revolution of the rolls.

The conical roll used here has a conventional configuration in which a rolling zone that mainly performs rolling on the roll surface and a straightening zone that primarily smoothes the surface of the material after rolling are continuously formed in the shape of a truncated cone with different inclination angles. are in practical use.

In the case of this type of conical roll, which is a so-called straight roll in which the generatrix of the straightening area is in the form of a straight line, a fairly deep spiral mark is formed on the surface of the material after rolling, which is formed by the point where the conical roll leaves. The cross-section of this mark has a fairly sharp edge shape, which not only reduces the product value, but also causes surface defects due to rolling, and furthermore, when deep ultrasonic waves cause noise, it can cause deep damage. .

To solve this problem, a so-called curved roll in which the straightening area of the conical roll has a concave cross section has been proposed, as disclosed in Japanese Patent Application Laid-Open No. 53-132454.

However, since this rolling using curved rolls ignores the effect of rolling on the actual material surface in the straightening zone, it is not possible to completely remove spiral marks from the material surface after rolling in actual rolling. Proven. Furthermore, as stated in the above publication, there is no close correlation between the rolling speed and surface texture of the rolled material, and the actual material feed length varies considerably depending on the rolling steel type and rolling temperature.
It is also known that the mark pitch varies considerably even in the case of rolled materials such as books, and it is necessary to allow considerable leeway when setting the length of the straightening zone of the rolls.

By the way, there are four types of spiral marks produced on the surface of a rolled material by rolling with the conical rolls of a planetary inclined roll mill.

(a) The boundary between the rolling zone and the straightening zone is transferred to the material surface (b) The shape change that remains because the shape of the straightening zone does not match the exit diameter (c) The material that occurs when the material is pulled out from the straightening zone Raised surface (d) Caused by the tip of the straightening area biting into the material surface Now, by using a straight roll, the mark in (a) above can be erased in the straightening area, but (b) and (c) above The mark remains clearly, and depending on the design of the correction area, the above
Mark (d) may also appear together. Furthermore, in the design of a curved roll as shown in Japanese Patent Application Laid-Open No. 53-132454, the above-mentioned revised marks (a), (c), and (d) are not taken into account.

Based on the above considerations, the present invention provides the above (a), (b), (c), and (d).
We designed the roll shape taking into account all the marks,
The object of the present invention is to provide a conical roll that can make the surface of the material to be rolled completely smooth.

Embodiments of the present invention will be described below with reference to the drawings. In the figure, 1 indicates a rolled material and 2 indicates a conical roll. Around the rolled material 1 there are at least 3
conical rolls 2 are equiangularly arranged, and the rolls 2
The diameter of the material 1 to be rolled is reduced by the revolution and rotation of the material 1, and the material 1 is rolled into a cylindrical shape.

The roll surface of the conical roll 2 has a rolling zone 3 mainly for rolling and a straightening zone 4 mainly for smoothing.
are continuously formed in the shape of a truncated cone with different inclination angles, and the joint 5 between the rolling zone 3 and the straightening zone 4 has a smooth curved surface configuration, and in the straightening zone 4, the truncated cone contacts the cylindrical surface of the material to be rolled. It is formed into a concave cross-sectional shape with a radius of curvature larger than the radius of curvature of the concave cross-section determined geometrically. Incidentally, at the tip of the correction area 4 having a concave cross section, a straight truncated conical correction area 6 whose inclination angle is slightly larger than that of the concave cross section correction area 4 is continuously formed, and the joint part 7 of both correction areas has a smooth curved surface structure. Sometimes it is.

Conventionally, discussions have been made on the premise that rolling work is not performed in the straightening area of the conical roll in this type of rolling mill, but in reality, the volume shown in the range A shown in Figure 1 is based on the assumption that rolling is not performed in the straightening area of the conical roll. It will be done. Therefore, in the present invention, as shown in FIG. If the value is not greater than the value determined assuming that the . Therefore, the radius of curvature of the correction area 4 is set by correcting it by an appropriate amount (for example, 1.5 times the theoretical value). As a result, the rolling in the straightening zone 4 becomes very light, and the marks in (b), (c), and (d) above can be eliminated.

However, this alone leaves the mark in (a) above on the material surface. In order to solve this problem, the joint between the rolling zone 3 and the straightening zone 4 is formed into a curved surface. Since the radius _r1 of this roundness remains on the surface of the material to be rolled, it is required that the curved surface has the largest allowable radius. However, in actual design, it can be arbitrarily selected within the range of about 30 to 80 mm, and almost the same effect can be obtained. Incidentally, when the exit diameter of the material to be rolled is small, it goes without saying that the roundness should be made smaller accordingly.

As explained above, in rolling using the conical roll of the present invention, the depth of marks left on the rolled material is maximum.
It is less than 0.1 mm, which is practically negligible compared to the minimum of about 0.4 mm during rolling with conventional rolls. In addition, the shape of the mark does not form sharp edges; it is smooth and undulating, and does not pose any hindrance to ultrasonic flaw detection.Furthermore, the surface quality is good, increasing product value and making it suitable for external sales. to enable rolling;
It has the following effects.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a side view of a material to be rolled and a conical roll, FIG. 2 is a front view of the same, and FIGS. 3A and 3B are explanatory diagrams of the roll design of the present invention. . 1... Raw material to be rolled, 2... Conical roll, 3...
Rolling area, 4... Straightening area, 5... Joining area, 6... Straightening area, 7... Joining area.

Claims (1)

[Claims] 1. A conical roll used in a rolling mill in which at least three conical rolls are equiangularly arranged around a material to be rolled, and the material to be rolled is drawn and rolled by rotation and revolution of the rolls. In this process, a rolling zone mainly for rolling and a straightening zone mainly for smoothing are continuously formed in the shape of a truncated cone with different inclination angles on the roll surface, and the joint between the rolling zone and the straightening zone is formed into a smooth curved surface. A planetary planet having a configuration in which the correction area is formed in a concave cross-sectional shape with a radius of curvature larger than the radius of curvature of the concave cross-section geometrically determined assuming that the truncated cone contacts the surface of the cylindrical rolled material. Conical roll for type inclined roll rolling mill. 2 The radius of curvature of the straightening area of the conical roll is at least the radius of curvature of the concave cross section, which is geometrically determined assuming that the truncated cone contacts the surface of the cylindrical rolled material.
A conical roll for a planetary inclined roll rolling mill according to claim 1, wherein the conical roll is set to 1.5 times. 3. A straight truncated conical correction area whose inclination angle is slightly larger than that of the concave cross-section correction area is continuously formed at the tip of the correction area having a concave cross section of the conical roll, and the joint part of both correction areas is formed into a smooth curved surface. A conical roll for a planetary inclined roll rolling mill according to claim 1 or 2, characterized in that: 4. The planetary planet according to any one of claims 1 to 3, wherein the inclination angle of the linear correction area of the conical roll is set approximately 5 degrees larger than the inclination angle of the concave cross-section correction area. Conical roll for type inclined roll rolling mill.