JPS60221201A - Cutting method of roll face - Google Patents

Abstract

PURPOSE:To modify the rolls of a three roll type rolling mill for manufacturing a seamless pipe by simultaneously cutting them in the state that they are left incorporated in a roll stand. CONSTITUTION:In the modification of the surfaces of rolls 10 incorporated in a roll stand 30, the roll stand 30 is placed on the top of a roll modify stand 44 and fixed in the state that the center of the roll stand 30 aligns with the central axis of cutter shaft 20. Then, each roll 10 is rotated at a high speed and a cutter 22 is fed into a roll surface from its end. And then, the cutter 22 is rotated in the way from the end to the center of the roll 10 at a low speed to cut the roll surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for surface cutting of rolls, and in particular to a method for cutting the face of a roll, and in particular, a method for cutting the rolls of a 30-inch rolling mill used to manufacture seamless steel pipes. Roll surface cutting is suitable for simultaneous cutting of multiple rolls arranged on a roll stand so that the roll axes are in the same plane and at equal angles to each other while still installed in the roll stand. Concerning improvements in processing methods.

In general, when manufacturing seamless steel pipes, a so-called 30-roll type continuous system is used, in which a plurality of roll stands each having three rolls arranged so that their roll axes are at equal angles to each other in the same plane are arranged in series. A rolling mill is used. In this continuous rolling mill, the O-
The roll surface of the caliber bottom 1211 is formed by an ellipse with a major axis a1 and a minor axis b1, as shown by the solid line in FIG.
The portion corresponding to the semi-major axis ai is the caliber edge 141
It becomes. On the other hand, the roll 10t-+ of the i-1st roll stand, whose roll surface is formed by an ellipse with a major axis a i-1 and a minor axis b +-1, is
Similarly, as shown by the broken line in Figure 1, the caliber bottom 1
2 +-+ are arranged on the caliber edge 141 of the roll 10i, and the raw pipe is rolled while these roll stands are alternately replaced one after another.

In such a 30-rule continuous rolling mill, it is necessary to adjust the ellipticity al/old in order to eliminate scratches caused by roll edges and uneven thickness in the circumferential direction. In other words, in order to prevent scratches, it is advantageous to increase the ellipticity a1,/b I to allow the roll edge side to escape, but on the other hand, in order to keep the wall thickness constant, it is advantageous to In order to equalize the contact length within the roll plane, the ellipticity ai/
It is desirable that bi be approximately 1. Therefore, in order to create a caliber that satisfies these conflicting demands,
For example, in the center of the roll, an arc with a small ellipticity that is close to a perfect circle is formed, while at the ends, an arc with a large ellipticity is formed, and the ellipticity can be changed continuously within the same roll surface. It was necessary to perform cutting.

As a conventional technique that meets such requirements, in Japanese Patent Publication No. 58-27041, a plurality of rolls are arranged so that their roll axes are at equal angles to each other in the same plane, and the rolls are placed on the circumference of the cutter shaft. The same number of cutters as the rolls are arranged at equal angles, the center of the space surrounded by each roll is aligned with the center of the cutter axis, and each roll is rotated at high speed. First, the roll surface before processing is The cutter is pressed against the end of the roll, and then the cutter is moved toward or away from the roll axis while being rotated at a low speed from the end of the roll toward the center. Select rotation speed and movement speed arbitrarily,
A roll face cutting method has been proposed which is characterized in that a continuous work roll surface with a different surface ratio is cut simultaneously on each roll using a single cutter for each roll.

3- However, in the surface cutting method proposed in this Japanese Patent Publication No. 58-27041, although the rotating speed and moving speed of the cutter, that is, the amount of advance and retreat in the cutter axis direction, is controlled, each cutter is not aligned with the cutter axis. It is fixed;
Since it was a two-axis control in which the cutter could not be moved in and out in the radial direction of the cutter shaft, the amount of advance and retreat of the cutter in the axial direction of the cutter, that is, the amount of offset, and the effective cutting radius of the cutter, that is, the radius of the blade, interfered with each other. Therefore, there was a problem in that it was not possible to have a sufficient degree of freedom in processing the caliber, and different roll diameters or different elliptical arc shapes could not be obtained.

The present invention has been made in order to solve the above-mentioned conventional problems, and has a high degree of freedom in caliber processing. Therefore, the face cutting process of the roll can form different roll diameters and different elliptical arc shapes. The purpose is to provide a method.

The present invention provides a method for simultaneously cutting a plurality of rolls arranged in a roll stand so that the roll axes are in the same plane and at equal angles to each other in a 4-state state while the rolls are still installed in the roll stand. In the surface cutting method, a tool is placed on the circumference of the blade shaft, which is rotatable and can move forward and backward.
Using a blade means in which the same number of blades as the rolls are disposed at equal angles so as to be movable in and out in the radial direction, the center of the blade axis of the blade means is aligned with the center of the roll stand, and each roll is rotated at high speed. In this state, the cutter is first cut from the end of the roll surface before cutting, and then the cutter is rotated at a low speed from the end of the roll toward the center while cutting the roll surface. The above object is achieved by simultaneously controlling the rotation angle of the shaft, the amount of advance and retreat, and the amount of entry and exit of each cutter so that continuous roll surfaces with different surface ratios can be cut at the same time.

In the present invention, the same number of cutters as the number of rolls are arranged at equal angles on the circumference of a rotatable and movable cutter shaft, and the number of cutters is freely put in and taken out in the radial direction, and the cutters are moved from the end of the roll toward the center. When cutting the roll surface while rotating at a low speed, we simultaneously controlled not only the rotation angle and the amount of advance and retreat of the blade axis, but also the amount of movement in and out of each blade, so the parameters that determine the caliber shape The rotation angle θ of the cutter (see FIG. 2), the amount of axial movement (hereinafter referred to as offset amount) e of the cutter shaft 20 with respect to the center line A of the roll 1o (see FIG. 3), and each cutter 22 It is now possible to perform so-called 3-axis control in which the three amounts of the in and out movement, that is, the blade radius Rw (see Figures 2 and 3), can be arbitrarily selected during cutting without interfering with each other, allowing for greater freedom in caliber machining. As the degree of rotation increases, it becomes possible to form different roll diameters and different elliptical arc shapes.

Once the major axis a1 and minor radius b1 of the target caliber are determined, the offset Me and the blade radius Rw can be determined from the geometrical relationship between the cutting surface of each roll 10 and the blade 22, for example using the following formula: can be determined.

Rw -bi/ 2-b12/4 R1d-at/4+
al' / 4 RId+ 0,375 al' /
(bl-b12/ 2 RId-ai/ 2 +ai'
/ 2 Rld)...(1) e-1 [-old) 2(Rid-RW) 2...
(2) Here, Rld is the virtual roll radius (see FIGS. 2 and 3).

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a roll modification apparatus to which the present invention is applied will be described in detail with reference to the drawings.

In this embodiment, as shown in FIG. 4, on the circumference of the knife shaft 20,
The same number of blades (three in the example) as the roll 1o are arranged at equal angles (
A blade object 4o arranged to be freely removable and removable in the radial direction at an angle of 120 degrees in the embodiment, a crosshead 42 for rotating the blade object 40 about the center line of the blade shafts 2 and 0,
The cutter body 40 is connected to the cutter shaft 2 via the crosshead 42.
The stand 44 includes a slide mechanism 44A for advancing and retracting in the axial direction (up and down direction in the figure) of 0.

As shown in FIGS. 5 and 6, the inside of the knife shaft 20 is hollow, and within the cavity is a generally rice ball-shaped cam 46 disposed so as to be in contact with the rear end of the knife 22. , and a cam shaft 48 for remotely controlling the relative rotation angle of the cam 46 with respect to the cutter shaft 2°7 from inside the crosshead 42. Therefore, by controlling the relative rotation angle of the cam shaft 48, that is, the cam 46, with respect to the cutter shaft 2o from inside the crosshead 42, the amount of insertion and removal of the cutter 22, that is, the cutter radius Rw
is said to be controllable. The ridge line connecting the top and bottom points of the cam 46 is appropriately selected depending on the shape of the roll caliber to be ground.

The effects of the embodiment will be explained below.

When modifying the roll surface of the roll 1o incorporated in the roll stand 30, as shown in FIG. 30 center and knife axis 2o
Fix it so that the centers of the two are aligned. Next, while each roll 1o is being rotated at high speed, the blade 22 is first cut from the end of the roll surface before cutting, and then the blade 22 is
While rotating at low speed from the end of the roll 10 toward the center, the roll surface is cut 9-8-. At this time, in the present invention, for example, the rotation angle θ of the cutter 22 is detected, and the target major axis for each stand is stored in advance in a control device (not shown) for the rotation angle θ. The offset amount e and the blade radius RW are calculated from ai (θ) and the short radius bi (θ) using the relationships in equations (1) and (2) above. Based on the calculated value, the control device uses a servo motor (not shown) or the like to automatically position the axial movement amount of the knife shaft 20 so that the offset amount e becomes the calculated value. . Further, the control device rotates the camshaft 48 by an appropriate angle in accordance with the rotation angle θ, and moves the cutter 22 in and out, so that the cutter radius RW becomes the calculated value. In this way, any caliber shape can be modified.

In the above embodiments, the present invention was applied to a 30-type roll stand, but the scope of application of the present invention is not limited to this, and can be applied to other types such as a 20-type roll stand and a 40-type roll stand. It is clear that the same applies to a roll stand having a roll number of 10-.

As described above, the present invention has the excellent effect that the degree of freedom in caliber processing is increased and it becomes possible to form different roll diameters or different elliptical arc shapes.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the schematic configuration of a 30-inch rolling mill;
FIG. 2 is a front view of a roll for detailed explanation of the present invention, FIG. 3 is a side view thereof, and FIG. 4 is a schematic configuration of an embodiment of a roll modifying device in which the present invention is adopted. FIG. 5 is a longitudinal cross-sectional view showing the configuration of the blade object used in the above embodiment, and FIG. 6 is a cross-sectional view taken along the line ■-■ in FIG. 5. 10.10 r, 10+-+... roll, 20...
・Cutter axis, 22...Cutter, θ...Rotation angle, e
...Offset amount, RW...Cutter radius, 30...
- Roll stand, 40...Blade object, 42...Cross head, 44...Stand, 44A...Slide mechanism, 46...Cam, 48...Cam shaft. Agent Takaya Ron (and 1 other person) Figure 5 42 Figure 6

Claims (1)

[Claims] (1) Surface cutting of the rolls to simultaneously cut multiple rolls arranged on the roll stand so that the roll axes are in the same plane and at equal angles to each other while still installed in the roll stand. In the method, using a cutter means in which the same number of cutlers as the rolls are disposed on the same side of a rotatable and movable cutter shaft so as to be movable in and out in the radial direction at equal angles, the center of the cutter shaft of the cutter means and With the centers of the roll stands aligned and each roll rotating at high speed, first cut with a knife from the end of the roll surface before cutting.
Next, when cutting the roll surface while rotating the cutter at a low speed from the end of the roll toward the center, the rotation angle of the cutter shaft, the amount of advance/retraction, and the time between entry and exit of each cutter are simultaneously controlled. A roll surface cutting method characterized by simultaneously cutting continuous roll surfaces with different surface ratios.