JPS5827041B2 - Roll face cutting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface cutting method for a roll.

Conventionally, a three-roll continuous rolling mill having a plurality of stands incorporating three rolls has been used to manufacture seamless steel pipes.

As shown in FIG. 1, the roll surface of the n-th roll is formed by an elliptical arc curve consisting of a major axis Rn' and a minor axis rn, and three rolls are installed at an angle of 1200, respectively. The space surrounded by them is shaped like a rice ball, and in the roll 1 of the n-th stand represented by the dotted line, the center Bn is the end of the roll of the n+1-th stand. An+1, and the end An becomes the center B n +1, and the rolling of the main tube progresses while being alternated in turn.

However, in these devices, in order to prevent the unevenness of the tube surface and wall thickness caused by the rolling of the main tube,
At the center of the roll, it was necessary to form an arc with a small ellipticity α-n, which is close to a perfect circle, and at the ends, it was necessary to form an arc with a large ellipticity.

In view of the above points, the present invention is capable of simultaneously cutting successive processing roll surfaces at different rates on three rolls incorporated in each stand, and can be processed with one cutter for each roll. The present invention attempts to provide a surface cutting method.

An embodiment of the present invention will be described below with reference to the drawings. In the present invention, three rolls 1 are arranged so that their roll axes 2 are at equal angles to each other within the same plane, and a cutter shaft 3 is The same number of cutters 4 as the rolls 1 are arranged at equal angles on the circumference, the center 6 of the space 5 surrounded by the rolls 1 and the center of the cutter shaft 3 are aligned, and each roll 1 is rotated at high speed. As shown in FIG. 2, the cutter 4 is first pressed against the end of the roll surface before processing, and then the cutter 4 is rotated at a low speed around the shaft 3 from the end of the roll 1 toward the center. While moving the cutter 4 toward or away from the roll axis 2, that is, in the direction of the axis 3, the rotational speed and movement speed of the cutter 4 are arbitrarily selected, and the processing rolls are continuously processed at different rates. The surface of each roll is cut at the same time.

Here, the processing device 7 used for surface cutting of a roll according to the present invention will be explained. As shown in FIG. A cutter shaft 3 that is movable in the direction of the shaft 3, a cutter body 14 externally fitted and fixed to the shaft 3, three cutters 4 arranged at equal angles on the circumference of the body, and a cutter body 14 that is movable in the direction of the shaft 3. , a stand 10 for mounting the roll 1 so that the roll shaft 2 is arranged at equal angles in the same plane, and a stand 10 for mounting the stand 10. a workbench 11, a bevel gear 12 attached to the end of each roll shaft 2 and meshed with each other in order to simultaneously rotate the roll shafts 2 at the same rotation speed at high speed, and a drive shaft for rotating the roll shafts 2. It has 13.

Three of the cutters 4 are provided as shown in FIG.
a cutter shank 15 removably fixed to the cutter shaft 3;
It consists of a circular tip 16 fixed to the front surface of the tip.

In FIGS. 5 and 6, 17 is a cover disposed on the front surface of the shank 15, 18 is a push bolt that is screwed through the cover 17 and presses the shank toward the cutter body 14, and 19 is a cover 17. This is a ring nut that is externally screwed onto the cutter shaft 3 in order to press the cutter shaft 3 into contact with the body 14.

Further, the cutter body 14, the cutter 4, etc. have enough rigidity to cope with changes in load during cutting of the roll surface due to movement in the axial direction of the cutter.

In order to perform face cutting of the rolls 1 with this device 7, a stand 10 incorporating three rolls 1 is interposed between the cutter shaft 3 and the Shinshindai 9, and a space 5 surrounded by each roll 1 is inserted. After aligning the center 6 of the cutter shaft 3 with the center of the cutter shaft 3 and supporting the stand 10 on the workbench 11, the roll shaft 2 is connected to the drive shaft 13, and the drive shaft 13 is rotated at high speed.
rotate at the same time.

Furthermore, the processing method according to the present invention will be explained in detail based on FIGS. 1 and 2. With the roll 1 rotating at high speed, the position indicated by the solid line in FIG. 2, that is, the plane formed by the three roll shafts 3, When the cutter 4 is stopped in the direction of the axis 3 at a position further forward than the cutter 4 and rotated around the axis 3 for cutting, the center of the roll surface of the roll 1 draws a circular locus shown by the solid line in Figure 2, and the roll surface has a An elliptical arc curve indicated by d a a'd' in FIG. 1 is formed.

The space 5 surrounded by the three rolls 1 has a substantially rice ball shape.

Therefore, in order to cut the processing roll surfaces cba and abc shown in FIG. 1, the cutter 4 is held stationary in the direction of the axis 3 and rotated around the axis 3, and the cutter 4 is pressed against the point a. While gradually rotating the cutter 4 around the shaft 3 at low speed from point a to point C on the roll surface, the cutter 4 gradually moves in the axial direction, that is, in the direction in which the cutter 4 approaches the plane formed by the three roll shafts 2. move it.

At this time, if the moving speed and rotating speed of the cutter 4 are controlled to move the cutter 4 by the moving distance ΔX shown in FIG.
As shown in the figure, a continuous circular arc curve with a different rate is formed on the roll surface abc.

The rake angle of the cutter 4 changes as it moves in the direction of the cutter axis 3, and the load applied to the cutter 4 also changes, but the cutter 4, cutter body 14, etc. have enough rigidity to withstand this load. , arc curves with different ratios can be formed smoothly.

Moreover, since the cutting edge of the cutter 4 uses a round tip 16, the contact with the roll surface is a surface contact, and the cutter shaft 3
The machining speed in the direction perpendicular to the curve can be increased rapidly, and smooth curves can be formed even at the joints of curves with different ratios.

Also, if you change the distance Y from the center of axis 3 to the cutter,
An arcuate curve with a different curvature from that described above is formed.

In other words, the rotation angle θ of the cutter that is displaced as the cutter moves in the axis 3 direction, the distance from the axis center to the cutter ￥1, and the amount of movement ΔX in the axis 3 direction as the center of axis 3 in Fig. 1 are affected. As a result, the shape of the ellipse formed on the roll surface differs.

In addition, in order to simultaneously cut continuous roll surfaces of different ratios, cutting may be performed from the ends of the roll 1 toward the center.

That is, cutting is performed by rotating the cutter 4 from C in Fig. 1 and moving it by △X in the direction away from the roll axis 2, and at the same time as it reaches point a, the movement of the cutter in the three axis directions is stopped, and the above process is performed. Similarly, cutter 4 is rotated at low speed around axis 3 to cut portion a a', and at the same time when cutter 4 reaches a', move cutter 4 in the direction close to the roll axis to cut a'b'c ′ is cut.

In addition, in the present invention, the same effect can be obtained by using a pointed tip instead of using a round tip as the cutting edge of the cutter as in the above embodiment.

In this case, the change in the rake angle caused by the movement of the cutter in the three axial directions can be solved by increasing the rigidity of the cutter body, etc., as in the above embodiment.

Furthermore, the rotation speed around the cutter axis must be slower than when using a round chip because the chip and the roll surface come into point contact.

As is clear from the above explanation, according to the present invention, it is possible to simultaneously cut the surface of a continuous working roll of an unusual rate with a plurality of rolls installed, and it is possible to cut only one roll for each roll at the same time. Since it can be processed with a cutter, there is no need to change the cutter for each surface with a different curvature, which greatly improves work efficiency and can be expected to have excellent economical effects.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention,
Fig. 1 is an explanatory diagram showing the roll portion of a three-roll continuous rolling mill, Fig. 2 is a schematic side view, Fig. 3 is a perspective view showing the cutting device, and Fig. 4 is a cutter on the roll surface. 5 is a longitudinal sectional side view of the cutter, and FIG. 6 is a front view of the cutter. 1...Roll, 2...Roll axis, 3.
...Cutter shaft, 4...Cutter 5.
...space, 6...center.

Claims (1)

[Claims] 1. A plurality of rolls 1 are arranged so that their roll axes 2 are at equal angles to each other in the same plane, and the same number of cutters 4 as the rolls are arranged at equal angles on the circumference of a cutter shaft 3,
With the center 6 of the space 5 surrounded by each roll 1 aligned with the center of the cutter shaft 3, and each roll 1 being rotated at high speed, first place the cutter 4 at the end of the roll surface before processing. Then, while rotating the cutter 4 at a low speed from the end of the roll 1 toward the center, the cutter 4
are moved toward or away from the roll axis 2, and at this time, the rotation speed and movement speed of these cutters are arbitrarily selected to simultaneously cut successive processing roll surfaces at different rates on each roll 1. A roll surface cutting method characterized by: