JPS60118308A - Guide shoe of skew rolling mill - Google Patents

Abstract

PURPOSE:To reduce the wear of shoe and to prevent a product from flaws generating in its outer surface by deviating the position of shoe-bottom at the contacting surface contacting a shell from the center line of a cross section of shoe so as to enlarge a wearing surface in conformity with the deforming state of shell. CONSTITUTION:In guide shoes 12 oppositely incorporated between rolling rolls 10 for the purpose of preventing the deflection of a shell during rolling and also adjusting the outer diameter of shell at the outlet side; a position D of the bottom of shoe at the contacting surface contacting the shell 21 is deviated from the center line E of the cross section of shoe so as to enlarge a wearing surface in conformity with the deforming state of shell 21. At that time, the deviation quantities (a), (b), and (c) of a gorging part A, a wall-thickness deciding position B, and the position D at the outlet side C with respect to the center line E, and also the radii R1a, R2a, R1b, R2b, R1c, R2c of the shoe 12 are set to optimum values. In this way, the wear of guide shoe is reduced, and a product is prevented from flaws generating in its outer surface.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a guide shoe for an inclined roll rolling mill, particularly for an inclined roll type elongation rolling mill such as an elongate mill or a Leela mill, or a Mannesmann perforator, a Stifel perforator, or a conical perforator. Suitable for use in an inclined roll type perforation rolling machine such as a rolling machine, the inclined roll rolling machine is installed oppositely between rolling rolls to prevent shell vibration during rolling and to adjust the outer diameter of the exit shell. Regarding improvement of guide shoes.

In recent years, various rolling mills have been employed in the manufacturing process of seamless steel pipes, and among them, inclined roll rolling mills such as Mannesmann perforators have become important rolling mills. This inclined roll rolling mill, e.g. elongate mill,
As shown in the drawings and FIG. 2, a pair of barrel-shaped rolls 10 are arranged at the same angle, for example, 6 to 14 degrees with respect to the pass line, and a pair of barrel-shaped rolls 10 are installed opposite to each other between the rolls 10. a guide shoe 12, and a plug 18 disposed at the tip of a plugper 16, which is disposed between the roll 10 and the guide shoe 12. A thin-walled hollow tube 22 is obtained by stretching the tube 20 to reduce its thickness.

As mentioned above, the guide shoe 12 plays the role of preventing the shell 21 from wobbling during rolling and adjusting the outer diameter of the exit shell, but the contact state between the guide shoe 12 and the shell 21 is completely soaked friction. Because of this, the shoe material is high strength,
Heat resistance is required, there is a lot of wear, and the guide shoe 1
The shell 21 has problems such as seizure and gouging, and spiral external scratches on the shell 21.

In order to solve this problem, the cross-sectional shape of the contact surface of the guide shoe 12 with the shell 21 has traditionally been designed as shown in FIG. As shown in FIG. 4, the entrance angle α1 and the exit angle α2 in the longitudinal section of the guide shoe 12 are set to optimal values, or as shown in FIG. Rotation direction entrance radius R
1 and the exit radius R2 are set to optimal values. However, in the past, the position of the shoe bottom on the contact surface with the shell 21 was set on the center line E of the cross section of the shoe as shown in FIG. The guide shoe 12 did not match the deformed shape, and the worn part of the guide shoe 12 was curved, as shown by the hatched part F in FIG. 5, and local gouges and seizures occurred in the G part.

The present invention has been made in order to solve the above-mentioned conventional problems, and provides a guide shoe for an inclined roll rolling mill that can reduce the wear of the guide shoe and prevent scratches on the external surface of the product caused by the guide shoe. The purpose is to provide.

The present invention provides a guide shoe for an inclined roll rolling mill installed oppositely between rolling rolls in order to prevent shell runout during rolling and to adjust the outer diameter of the exit shell. The above object is achieved by deviating the position of the shoe sole from the center line of the shoe cross section so that the wear surface becomes wider in accordance with the deformation state of the shell.

Further, the position of the shoe bottom is biased toward the exit side in the shell rotational direction at the gorge portion and the exit side, and biased toward the entrance side in the shell rotational direction at the wall thickness determination position d-, so that the optimal shoe bottom position can be easily determined. It was designed so that it could be obtained.

The present invention was made by focusing on the fact that in the conventional example where the shoe bottom position [D is on the center line E of the shoe cross section, the worn part has a shape like the shaded part F shown in FIG. 5 mentioned above. With something that
The position of the bottom of the shoe on the contact surface with the shell is shifted from the center line of the cross section of the shoe so that the wear surface becomes wider according to the deformation state of the shell, thereby making the wear surface wider. This is designed to reduce wear on the product and prevent scratches on the product's external surface caused by the guide shoe.

That is, in general, in the gorge part, as shown in FIG. 6 (A>), the thick part of the shell 21 hits the guide shoe 12 in the direction of shell rotation from the center line E of the cross section of the shoe. In this gorge part, the shoe bottom position @D is shifted toward the exit side in the shell rotation direction from the center line E of the shoe cross section.On the other hand, at the thickness determination position, as shown in Fig. 6-4-(B), , the thin part of the shell 21 is located on the inlet side of the guide shoe 1 in the direction of shell rotation from the center line E of the shoe cross section.
It's hitting 2. Therefore, at this thickness determination position, the shoe bottom HD is biased toward the entrance side in the shell rotation direction from the center line E of the shoe cross section. Furthermore, on the exit side, as shown in FIG.
I'm running into 2. Therefore, on this exit side, the position of the shoe bottom is shifted toward the exit side in the shell rotation direction from the center line E of the shoe cross section. Note that the method of biasing the position of the shoe bottom from the center line E of the shoe cross section in accordance with the deformation state of the shell is not limited to this, and other biasing methods may be used in accordance with the actual wear state of the guide shoe. It is also possible.

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIGS. 7 to 10, the first embodiment of the present invention is a guide shoe 12 for rolling a 7B pipe with a wall thickness of 8 to 100 ions, and the bottom position of the shoe in the gorge (FIG. 8) The amount of deviation a toward the exit side in the direction of shell rotation from the center line E of the shoe cross section is 8 degrees, the amount of deviation a toward the input side in the direction of shell rotation at the wall thickness determination position (Fig. 9) is 14 degrees, and the amount a is 14 degrees on the exit side (
The amount of deviation c toward the exit side in the shell rotation direction in FIG. 10) is 8 ml.

In addition, in this guide shoe 12, the gorge part (the eighth
In Figure), the inlet radius R+8 in the shell rotation direction is 130 mm, the outlet radius R2a in the shell rotation direction is 300 mm, and the thick wall orientation I
The entry side radius in the shell rotation direction of N (Fig. 9) is the radius R from the entry side until the specified angle θ-10.5° is reached from the bottom of the shoe.
The radius R+2b from when 11b reaches the predetermined angle θ to when it reaches the bottom of the shoe is 150 mm, and the exit radius R2b in the shell rotation direction at the wall thickness determination position is 300 mm.
The input radius R+0 in the direction of shell rotation on the exit side is 180mm.
, the exit radius R2C in the shell rotation direction is 400 n.

When we investigated the wear condition of this first example, we found that the wear surface of the guide shoe was wider, as shown by the shaded area H in Fig. 11, and the amount of wear of the guide shoe was reduced by about 20%. It could be confirmed.

In addition, when the guide shoe of the first embodiment and the corresponding conventional shape guide shoe were used, the incidence of external surface scratches due to the guide shoe during rolling was investigated. While the ratio was 0.7%, it was 0.05% in the first example, and it was confirmed that the ratio was significantly reduced.

Furthermore, the gorge part deviation amount a is 1211, the wall thickness determination position deviation amount is 14 inches, and the exit side deviation amount C is 12 mm, which are suitable for use when rolling a 9.5/8B pipe with a wall thickness of 9 to 12 u.
When we investigated the incidence of guide shoe damage when using the guide shoe of the second embodiment of the present invention and the corresponding guide shoe of the conventional shape, it was found that the rate of occurrence of guide shoe scratches was 0.3 in the conventional example.
%, but in the second example it became 0.04%,
It was confirmed that the reduction was still significant.

In addition, the gorge part deflection amount a-/- is 20u, the wall thickness normal position 111i is 181111, which is suitable for use when rolling a 12 3/4B pipe with a wall thickness of 10 to 13 mm.
When we investigated the incidence of guide shoe scratches when using the guide shoe of the third embodiment of the present invention with an exit-side biased weight of 20 mm and the corresponding guide shoe of the conventional shape, we found that in the conventional example, the incidence of guide shoe damage was 0. Although it was 6%, it became 0.06% in the third example, and it was confirmed that it was also significantly reduced. - In each of the above embodiments, not only is the position of the shoe bottom offset from the center line of the cross section of the shoe, but also the cross-sectional shape on the entrance side in the direction of shell rotation at the wall thickness determination position is set to radius R+ +I). Since it is a compound curve of R12b, it is particularly effective in preventing seizure and gouging on the entrance side in the direction of shell rotation at the wall thickness determination position.

Furthermore, even if the cross-sectional shape of the shoe on the inlet side in the direction of shell rotation at the wall thickness determination position is made into a single curve as in the past,
The effects of the present invention can be improved.

Although the above description has been made using an elongate mill as an example, the scope of application of the present invention is not limited thereto, and may be applied to other elongated rolling mills with 8 inclined rolls such as Leela mill, Mannesmann perforator, stapler mill, etc. It is obvious that the present invention can be similarly applied to other inclined roll type perforation rolling machines such as perforators and conical perforators.

As explained above, according to the present invention, the wear surface of the guide shoe can be widened, and therefore, the wear of the guide shoe can be reduced, and the occurrence of scratches on the external surface of the product caused by the guide shoe can be prevented. Has excellent effects.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing the structure of the elongate mill to which the present invention is applied, FIG. 2 is a cross-sectional view taken along the line ■-m in FIG. 1, and FIG. A vertical cross-sectional view showing the vertical cross-sectional shape of a conventional ID shoe used in
FIG. 4 similarly shows the cross-sectional shape of the rV-
FIG. 5 is a cross-sectional view taken along the rV line, FIG. 5 is a front view showing worn parts and areas where seizures and gouges occur frequently, and FIG. Fig. 7 is a front view showing the shape of the first embodiment of the guide shoe of the inclined roll rolling mill according to the present invention; Figure 8 is a cross-sectional view taken along the line ■-■ in Figure 7;
Figure 9 is a cross-sectional view taken along line IX-■ in Figure 7;
The figure is a cross-sectional view taken along the line X-X in Figure 7, and Figure 11 is
The wear condition of the first practical example described in ^b is shown (front view). 10... Roll, 12... Guide shoe, 21...
...Shell, D...Shoe bottom position, F...Shoe cross-section center line. Agent Takaya Ron (and 1 other person) Figure 1-11- Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) The side shoe of the inclined roll rolling mill, which is installed opposite to each other between the rolling rolls, is used to prevent the shell from coming off during rolling and to adjust the outer diameter of the exit shell. A guide shoe for an inclined roll rolling mill, characterized in that the position is offset from the center line of the cross section of the shoe so that the wear surface becomes wider in accordance with the deformed state of the shell. (2) The position of the shoe bottom is biased toward the exit side in the shell rotational direction at the gorge portion and the exit side, and biased toward the entry side in the shell rotational direction at the wall thickness determination position. Guide shoe for the inclined roll rolling machine described.