JPS62277202A - Surface machining method for roll - Google Patents

Abstract

PURPOSE:To enable the formation of small corvature for the center of the external surface of rolls and large curvature for both ends thereof by applying a cutter axis to the disposition center of a plurality of rolls disposed at equal angles and changing the offset of the cutter axis for a roll axis in an axial direction. CONSTITUTION:A plurality of rolls 2 are so arranged that axes 2A will have an equal angle in the same plane, the same number of cutters 14 are arranged at equal angles on the periphery of a cutter rotary axis center 13A as the disposition center line 2B of the rolls 2, the rolls 2 are rotated at high speed and the cutters 14 are rotated at low speed, thereby forming the external surface of the rolls 2. In this case, the offset Xi of the cutters 14 for the axes 2A in a rotary axis center direction, the curvature radius R of the external roll surface and an angle theta from the center of the rolls 2 to the edge thereof give relations as illustrated herein. Therefore, even when the offset Xi is numerically controlled for changes from the point A to the point C via the point B, thereby changing the curvature radius R and the point C via the point B, thereby changing the curvature radius R and machining the external surface of the rolls 2 to an arc nearly equal to that of a circle with offset points A to B, chamfering with large radius can be done at points B to C.

Description

[Detailed description of the invention] 3. Detailed description of the invention [Industrial application field] The present invention relates to a roll surface cutting method.

[Prior Art] In a seamless steel pipe manufacturing line, a reducing pressure Ll& (stretch reducer) is used as a finishing rolling mill. The reducing mill determines the pipe dimensions such as the outer diameter, wall thickness, and length of the pipe, and controlling the pipe dimensions in the reducing mill is an important element in quality control of seamless steel pipes. This reducing rolling machine is
As shown in FIG. 5, a plurality of roll stands 1 are arranged continuously, and three rolls 2 are arranged at angular intervals of 120 degrees in a plane perpendicular to the rolling pass line of each roll stand l. ing. 3 is a raw pipe.

The rolls arranged in each roll stand of the above-mentioned reducing rolling mill roll the raw tube into a perfect circle, and in order to eliminate scratches caused by roll edges and uneven wall thickness in the diurnal direction, the roll surface at the center of the roll is The shape is an arc with a small ellipticity close to a perfect circle, and the shape of the roll surface at the roll edge part is an arc with a large ellipticity.

Conventionally, a method described in Japanese Patent Publication No. 58-27041 has been proposed as a surface cutting method for a roll as described above. This previously proposed method involves arranging a plurality of rolls such that their roll axes are at equal angles to each other in the rotating plane, and placing the same number of cutters as the rolls on the tool axis. The groove center axis of each roll is aligned with the center axis of the tool shaft, and each cutter is pressed against the workpiece surface of the corresponding roll while each roll is rotated at high speed. This is a method of forming a roll surface on each roll while rotating the tool at a low speed around the tool axis.

The relationship between parameters will be explained. The relationships among various parameters are illustrated in FIGS. 6 and 7. From Figures 6 and 7, the relationship of formula f holds between the various values. Figure 4 illustrates this relational expression, so the roll diameter D w = 300 mm, the tool radius R w = 50 mm, How R changes when the offset amount X i is changed is 0=0 degrees, 20 degrees, 40 degrees, 60 degrees.
This diagram illustrates the case of degrees.

In this cutting method, as shown in Fig. 4), 2.) When the cutter is pressed against the hole forming part (0 is in the range of 0 degrees to 45 degrees, for example) excluding the edge part of the roll, A-B As shown in (), the cutter's off-sera amount ( When pressed against an edge portion (for example, 0 is 60 degrees), as shown in B to C, the offset amount Xi is driven in a smaller direction, and the edge portion is chamfered with a relatively large ellipticity. is possible.

In Fig. 4, θ indicates the angular position from the center of the roll to the edge of the roll around the center axis of the roll hole (center axis of the tool shaft), and R indicates the radius of curvature of the roll surface. There is.

In addition, the roll surface in FIG. 4 has an elliptical minor radius rl located at the center of the roll (0=0), and a roll edge CO=6.
The semi-major axis r2 of the ellipse is located at 0 degrees).

[Problems to be solved by the invention] However, the conventional roll surface cutting method described in L.
As is clear from FIG. 4, for a roll for a working stand of a reducing mill that has a relatively large arc of ellipticity even at the center of the roll and a large variation range of R with respect to a variation of 0, the offset i However, for rolls for sizing stands where the roll surface is close to a perfect circle and the range of change in R with respect to changes in θ is small, %Xi should be set large. Therefore, the edge portion cannot be chamfered as described above.

The present invention provides a surface cutting method for a roll that is capable of f+7 chamfering of a large ellipticity on the roll edge even in a roll where substantially the entire roll surface is composed of an arc of a perfect circle to a small ellipticity. The purpose is to

[Means for solving the problem] The present invention arranges a plurality of rolls so that their roll axes are at equal angles to each other in the same plane, and the same number of rolls as h foot rolls are placed on the circumference of the tool axis. The cutters are arranged at equal angles, the center axis of the hole shape of each roll is aligned with the center axis of the tool shaft, and each cutter is pressed against the workpiece surface of the corresponding roll while each roll is rotated at high speed. In a roll surface cutting method in which a roll surface is formed on each roll while rotating the cutter at a low speed around a tool axis, when the cutter is pressed against the hole forming part of the roll except for the edge part. ,
The offset i of the cutter in the tool axis direction with respect to the roll axis is changed so that the curvature of the roll surface is from a perfect circle to a small ellipticity, and when the cutter is pressed against the edge of the roll, the above offset amount is changed to The curvature of the surface is set so that it has a large ellipticity.

[Function] According to the present invention, as shown in FIG. 1, which shows the relationship between cutting finish conditions under the same conditions as in FIG. When the cutter is pressed against the roll axis (in the range of 0 degrees to 45 degrees), the offset amount Xi of the cutter in the tool axis direction with respect to the roll axis is greatly changed so that R changes from constant to small as shown by A-B. Forming a roll surface with a perfect circle to small ellipticity in the hole forming part,
・ri) The cutter is at the edge of the roll (0 is, for example, 60 degrees)
When pressed, the offset amount Xi is set to vary from constant to small so that R changes greatly, as shown by B-C, and the edge portion is chamfered with a large ellipticity. becomes possible. In addition, in Fig. 1, A'~
Cl indicates a roll hole type processing line in which the entire range of the roll surface is completely circular.

That is, according to the present invention, the position of the cutter relative to the roll is controlled by, for example, a number of 1 (NC control) while the roll is still installed in the stand, and the relationship between the offset amount Xi and the pressure contact angle position of the cutter is 0. By adjusting iA as described above, it is possible to chamfer T with a large ellipticity on the roll edge even in a roll where almost the entire roll surface consists of an arc with a perfect circle to a small ellipticity. Become.

[Example] 2IA is a schematic diagram showing an example of a cutting device used for implementing the present invention, and FIG. 3 is a view taken along the line ■-■ in FIG. 2.

In FIGS. 2 and 3, l is a roll stand, 2 is a roll, 10 is a cutting device, 11 is a bed of the cutting device Hto,
12 is a tool rest, 13 is a tool shaft, and 14 is a cutter.

In this embodiment, three rolls 2 are assembled and arranged in a roll stand 1 so that their roll axes 2A are spaced apart from each other by 120 degrees within the same plane of deformation. In addition, the Nogeso atIO has three cutters 14, the same number as the recording rolls 2, arranged at equal angles on the circumference of the tool shaft 13. ,! ! )L, the hole type central axis 2B of each roll 2 and the central axis 13 of the tool shaft 13
Matches A. The roll surface 20 of each roll 2 is
Each roll 2 is simultaneously rotated at high speed by a drive mechanism (not shown), the cutter 14 of the cutting device to is pressed against the cut surface of the corresponding roll 2, and the cutter 14 is rotated around the tool shaft 13 (pressing angle position θ). It is formed by cutting while rotating at low speed. Here, in this embodiment, (1) when the cutter 14 is pressed against the perfect circular hole forming portions 20A to 20B (θ is, for example, 0 degrees to 45 degrees) excluding the edge portion 21 of the roll 2, the roll axis The offset acid Xi of the cutter 14 in the tool axis direction with respect to 2A is changed so that the curvature of the roll surface 20 becomes a perfect circle (~small ellipticity). On the other hand, (2
) The cutter 14 is connected to the edge portion 21 of the roll 2 (θ is, for example, 6
0 degree), the offset roller 1jtXi is set so that the curvature of the roll surface 20 has a large ellipticity.

Therefore, according to the above embodiment, while the roll 2 is still installed in the roll stand 1, the position of the cutter 14 relative to the roll 2 is controlled numerically, for example, and the off-sera amount
By adjusting the relationship between i and the pressure contact angle position θ of the cutter as shown below, it is possible to create a large ellipse at the roll edge z1 even in the roll 2 where almost the entire roll surface 20 is an arc with a perfect circle to small ellipticity. It becomes possible to perform a chamfering process of a certain ratio.

[Effects of the Invention] As described above, in the present invention, the rolls on multiple sides are arranged so that their roll axes are at equal angles to each other in the same plane, and the same number of rolls as the rolls are arranged on the circumference -H of the tool axis. The cutters are arranged at equal angles, the center axis of the hole shape of each roll is aligned with the center axis of the tool shaft, and each cutter is pressed against the workpiece surface of the corresponding roll while each roll is rotated at high speed. In a roll surface cutting method in which a roll surface is formed on each roll while rotating the cutter at a low speed around a tool axis, when the cutter is pressed against the hole forming part of the roll except for the edge part. , the amount of offset of the cutter in the tool axis direction with respect to the roll axis is changed so that the curvature of the roll surface is from a perfect circle to a small ellipticity, and when the cutter is pressed against the edge of the roll, the offset amount is changed as follows: The curvature of the roll surface is set to have a large ellipticity.

Therefore, even in a roll in which substantially the entire roll surface is formed from a perfect circle to a hexagonal shape with a small ellipticity, the roll edge portion can be chamfered with a large ellipticity.

[Brief explanation of drawings]

Figure 1 is a diagram showing an example of the cutting method of the present invention, Figure 2 is a diagram showing an example of the cutting method of the present invention.
The figure is a schematic diagram showing an example of cutting and placing used in the implementation of the present invention, Figure 3 is a view taken along the line ■-■ in Figure 2, and Figure 4 is a diagram showing the conventional cutting method. , FIG. 5 is a perspective view showing a general reducing rolling mill, FIG. 6 is a sectional view showing the roll shape, and FIG. 7 is a sectional view showing the T section and the ■ section in FIG. 6. It is. 1... Roll stand, 2... Roll, 2A...
Roll axis, 2B... Hole type center axis, 10... Cutting device, 13... Tool axis, 13A... Center axis, 14...
- Cutter, 20... Roll surface, 21... Edge portion. Agent Patent Attorney Shuji Shiokawa 1st Figure Offset 2 x i (mm) 2nd ■= 3rd Figure 4 Key Offset = xi,) 5th 6th Circle II Dw: p-le radius RW: Tool radius XL: Offset IR: Roll surface length θ: From the center of the roll to [Fig.

Claims (1)

[Claims] (1) Arrange multiple rolls so that their roll axes are at equal angles to each other in the same plane, and arrange the same number of cutters as the rolls at equal angles around the tool axis. The center axis of the hole mold and the center axis of the tool shaft are aligned, each roll is rotated at high speed, each cutter is pressed against the work surface of the corresponding roll, and the cutter is rotated around the tool shaft at low speed. In a roll surface cutting method that forms a roll surface on each roll while rotating, when the cutter is pressed against the hole forming part of the roll except for the edge part, the cutter is offset in the tool axis direction with respect to the roll axis. The amount of offset is changed so that the curvature of the roll surface becomes a perfect circle to a small ellipticity, and when the cutter is pressed against the edge of the roll, the offset amount is changed so that the curvature of the roll surface becomes a large ellipticity. A roll surface cutting method characterized by setting.