JPS62251007A - Machining method for roll and device therefor - Google Patents

Abstract

PURPOSE:To machine the optional contour of a roll surface, by inputting coordinate data on a roll profile curve, calculating the cutter coordinate data, and according to these data, controlling a rotary driver of a cutter holder and a forward-backward driver. CONSTITUTION:At an arithmetic unit, a roll profile function is found out of coordinate data of plural points on a roll profile curve to be inputted from an input unit, and a numerical control program for cutting a roll 10 is automati cally composed, transmitting these data to a numerical control system by a telecommunication line. In conformity with the program transmitted, the NC system controls each drive of a tool rotating servomotor 36 for driving a cutter holder 30, a tool feeding servomotor 40 for making a tool head 34 forward or backward and a spindle motor or the like rotating and driving the spindle 18 connected to a roll 10. With this constitution, this roll 10 is machined by the cutter clamped to the cutter holder 30, thus a roll form having the targeted roll profile is secured.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a roll cutting method and apparatus, and in particular, the roll axes are in the same plane and are at equal angles to each other, suitable for use in a roll lathe that simultaneously cuts a plurality of rolls having the same shape. A plurality of rolls to be cut arranged as shown in FIG. The present invention relates to improvements in a roll cutting method and apparatus in which the center of a space surrounded by each roll is aligned with the center of the cutter holder and the roll is cut with the cutter while rotating each roll. [Prior Art 1] Generally, when manufacturing seamless steel pipes and the like, a 30-inch continuous rolling mill with a plurality of stands incorporating, for example, three rolls is used. Conventionally, when cutting a roll 10 having a profile such as cbaa=b-c- with different curvatures at each point as shown in FIG. The method of surface cutting of a roll in Publication No. 58-27041 is proposed as follows. That is, first, the roll 10 is rotated at high speed, and the roll 10 is rotated at high speed.
A cutter (not shown) applied to the roll is rotated at a low speed from a point C4 in the figure toward the bottom of the roll, and at the same time, a cutter holder (not shown) to which the cutter is attached is separated from the plane containing the roll axis 12 of each roll 10. Cutting is performed while moving the cutter a predetermined distance ΔZ in the Z-axis direction, and at the same time as the cutter reaches point a, the movement of the cutter in the Z-axis direction is stopped. Then, the cutter is rotated at low speed around the central axis (numeral 52 in the figure) of the space surrounded by each roll 10 to cut the portion aa in the figure, and at the same time when the cutter reaches one point a, While moving the cutter a predetermined distance ΔZ in the direction approaching the roll shaft 12, a-b-c
By cutting -, continuous roll surfaces with different surface ratios can be processed simultaneously. Therefore, in the technique proposed in Japanese Patent Publication No. 58-27041, the cutter holder is moved by a predetermined distance during cutting, thereby making it possible to cut a roll having a plurality of different curvature surfaces.

[Problems to be solved by the invention]

However, the conventional technology related to the cutting of the roll surface proposed as described above has the following two problems. One of them is that the conventional technology has The problem is that there is no specific means for adjusting the amount of movement for moving the cutter holder a predetermined distance, and there is no specific method for determining the amount of movement.Therefore, cutting rolls with complex shapes has not been put to practical use. That is, as disclosed in Japanese Patent Publication No. 58-27041, only a partial improvement effect such as making the slope of the edge of the roll 10 gentler and forming a relief at the edge can be obtained, and the roll It was not possible to obtain an arbitrary shape over the entire surface.Another problem is that in the prior art, there was a problem with continuity at any point on the cut roll profile curve. , - Even the seemingly continuous roll profile curve is the first derivative (slope) of the curve.
, there is no guarantee that the second derivative (curvature) is continuous at any point on the curve. For example, in the method proposed in the aforementioned Japanese Patent Publication No. 58-27041, the 11th
The roll profile shown in the figure cbaa′b −c′
To cut the profile aa= and profile a
It is difficult to say that the slope and curvature are continuous at point a', which is the contact point of =b-c-, and similarly, the continuity is maintained at any point on the profile aa=. There is no guarantee. Generally, the surface shape of a rolling roll is required to have continuity in slope and curvature. This is to prevent rolling defects from occurring in the rolled material during rolling, and to prevent uneven wear from occurring on the rolls during rolling. However, despite the roll user's request for the surface shape of the roll, as mentioned above, in the prior art, continuity of slope and curvature at any point on the roll surface is maintained. However, there was a problem in that it was not possible to perform accurate cutting.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a roll cutting method and apparatus that can obtain an arbitrary shape of the roll surface.

[Means to solve the problem]

The present invention provides a plurality of rolls to be cut arranged such that roll axes are arranged at equal angles to each other in the same plane, a cutter holder that holds the same number of cutters as the rolls at equal angles, and a rotational drive device for the rolls. and a rotation and forward/backward driving device for the cutter holder, and aligning the center of the space surrounded by each roll with the center of the cutter holder, and cutting the roll with the cutter while rotating each roll. In the processing method, based on a pre-given roll profile curve to be cut in which an arbitrary flat surface including the roll axis and the roll surface intersect, the center of the space is A data input procedure for inputting coordinate data (', θ) of arbitrary plural points on the roll profile curve, with the distance to the roll profile curve forming an angle of θ with the axis; A roll profile function having a continuous curvature is derived from a plurality of coordinate data, and the derived roll profile function is divided into minute sections and converted into a rotation angle B of the cutter holder and a distance Z from the roll axis to the cutter. By including a calculation procedure for calculating cutter coordinate data (B, Z), and a control procedure for controlling a rotary drive device and a forward and backward drive device of the cutter holder based on the calculated cutter coordinate data, , the above object has been achieved.Furthermore, an embodiment of the present invention performs spline interpolation calculation processing on the roll profile function for a plurality of coordinate data input in the data input procedure, and The cutter coordinate data (BlZ) is derived by interpolating between points with a cubic function curve and reconstructing.Furthermore, in another embodiment of the present invention, the cutter coordinate data (BlZ) The distance to the axis 52 is one day, and the distance between the roll axis and the center axis is P.
It is calculated using the following formula 8 (%). Further, the present invention provides a plurality of rolls to be cut arranged such that the roll axes are arranged at equal angles to each other in the same plane, a cutter holder that holds the same number of cutters as the rolls at equal angles,
It has a rotation drive device for the rolls, and a rotation and forward/backward drive device for the cutter boulder, and the center of the space surrounded by each roll is aligned with the center of the cutter holder, and the cutter is rotated while each roll is rotated. In a roll cutting device configured to cut a roll by cutting the roll, based on a pre-given roll profile curve to be cut,
From the central axis of the space surrounded by the roll to be cut to the central axis and θ
data input means for inputting coordinate data (r, θ) of a plurality of arbitrary points on the roll profile curve, where the distance to the roll profile curve is r, and the plurality of input coordinates; By deriving a roll profile function with continuous curvature from the data, dividing the derived roll profile function into minute sections, and converting it into the rotation angle B of the cutter holder and the distance Z from the cutter's zero axis. , a calculation means for calculating cutter coordinate data (B, Z'), and a calculation transmission means for converting the calculated cutter coordinate data into predetermined numerical control data and transmitting the data.
The above objective is also achieved by comprising means for storing the transmitted numerical control data, and a control means for simultaneously numerically controlling the rotary drive device and the forward and backward drive device of the cutter holder based on the stored numerical control data. has been achieved.

[Effect]

In the present invention, when cutting a plurality of rolls to be cut, based on a roll profile curve given in advance to be cut, the central axis is θ Input coordinate data (r, θ) of arbitrary points on the roll profile curve, where r is the distance to the profile curve at an angle of
A roll profile function with continuous curvature is derived from a plurality of input coordinate data, and the derived roll profile function is divided into minute sections to calculate the rotation angle B of the cutter holder and the distance Z from the roll axis to the cutter. By converting, cutter coordinate data (B, Z) is calculated, and the rotary drive device and the forward and backward drive device of the cutter holder are controlled based on the calculated cutter coordinate data. Therefore, since the roll surface can be cut as desired, 0-
Cutting can be performed in such a way that continuity of slope and curvature is maintained at any point on the surface. Further, for example, it is possible to accurately cut a roll having a laterally asymmetric roll hole shape. Note that the roll profile function is derived by performing spline interpolation calculation processing on a plurality of coordinate data input in the data input procedure, and reconstructing by interpolating between mutually adjacent points with a cubic function curve. Then, the continuous curvature of the roll profile function can be made smooth at each point on the function, and the control of the entire system becomes smooth. Further, the cutter coordinate data (B, Z) is expressed as the following 12 sets (1) and (2), where r9 is the distance from the cutting edge of the cutter to the central axis, and P is the distance between the roll axis and the central axis. ), the cutter coordinate data can be calculated using a relatively simple calculation procedure because the only multipliers to be determined are the distance r9 and the distance p. 3=sin −' ((r/rEl) sinθ
) ・・・・・・(1)z=”−rcosθ)
2- (P-r day CO8B) 2・・・・・・・・・・
・(2)

[Example 1] Hereinafter, an example of the roll cutting method according to the present invention will be described in detail. This embodiment is a roll lathe having a control device as shown in FIG. 1 and whose overall configuration is shown in FIG. 2. This roll lathe has the following features as shown in detail in Figure 3:
The bearings for assembling the three hole-shaped rolls 10 to be cut and their roll shafts 12 so as to make an angle of 120' with each other in the same plane are assembled into a presser case 14, and the bearings are assembled with the presser case 14. Roll stand 1 for loading and fixing
6, a spindle 18 connected to each of the rolls 10 so that its axial center coincides with the roll axis 12, and a coupling 20 for transmitting a driving force to the spindle to rotate it. , is provided. Moreover, the roll stand 16 is incorporated into the roll lathe, as shown in FIG. 2. The roll lathe includes a lock device 22 for fixing the roll stand 16, a lock plate 24 for fixing the lock device 22, a housing 26 for maintaining the rigidity of the roll lathe, and the roll lathe. A cutter holder 30 to which the cutter 28 for cutting 10 is fixed as shown in FIG. 4, a tailstock 32 for preventing the cutter holder 30 from shifting during cutting, and a tool head 34 for supporting the cutter 30 and changing the position of the cutter 28; and a tool rotation servo motor 3 installed on the tool head 34 for driving the cutter holder 30.
6, a pulse coder 38 for detecting the rotation angle of the tool rotation servo motor 36, and the tool head 34.
A tool feed servo motor 40 for moving the tool back and forth, a valve coder 42 for detecting the rotation angle of the tool feed servo motor, and a rotational force of the tool rotation servo motor 36 to move the tool head 34 to the slide bed 44. A ball screw 46 is provided for moving the robot back and forth at the top. The spindle 18 extending from each roll axis is
Power is transmitted from a spindle motor (not shown) through a coupling 20 to drive the rotation. Normally, one spindle motor is installed.
Power is distributed by a bevel gear mechanism (not shown), and the mechanism drives each of the three rolls 10 simultaneously at the same rotational speed. At that time, the spindle motor is controlled by a numerical control device (Numerical Co., Ltd.) shown in FIG.
The rotational speed is controlled to a target rotation speed by a control device (hereinafter referred to as an NC device) 50. The center axis of the cutter holder 30 is made to coincide with the center axis (reference numeral 52) of the space surrounded by each roll 10 shown in FIG. 3 and the above-mentioned FIG. 11. Cutter holder 30
As shown in FIG. 4, the cutters 28 are attached in a number equal to the number of rolls 10 to be cut (three in the embodiment) so as to be equiangular to each other within the same plane. The tool head 34 to which the cutter holder 30 is fixed is provided with a rotation mechanism for rotating the cutter holder 30 using the tool rotation servo motor 36. As shown in FIG. 5, this rotation mechanism includes a worm wheel 54 for rotating the cutter holder 30, a worm gear 56 for rotating the worm wheel 54, and a worm gear 56 for rotating the tool. A gear 58 for transmitting the driving force of the servo motor 36 to the worm gear 56 is provided. Further, in order to move the tool head 34 forward and backward, a drive force of the tool feeding servo motor 40 is decelerated between the ball screw 46 and the tool feeding servo motor 40, as shown in FIG. A tool feed reduction 1M160 is installed to convey the information. In addition, a movement mechanism for the tool head 34 is constituted by the ball screw 46 including the reducer 60, and the tool feeding servo motor 40. As described above, since the tool head 34 is equipped with the rotation mechanism of the cutter holder 30 and the movement mechanism of the tool head 34, the cutter 28 is moved directly to the cutter roll 10 as shown in FIG.
It is possible to rotate around the central axis (reference numeral 52) of the space surrounded by and to move parallel to the central axis. In this case, the rotation angle around the central axis will be represented by the symbol B in FIG. 5, and the movement position parallel to the central axis will be represented by the symbol Z as shown in FIG. Further, the angle B takes the upward direction in the vertical direction to be zero, and positively defines the counterclockwise direction from the tool holder 30 side toward the roll 10 to be cut. The distance Z is defined as the distance from the plane including the three roll axes to the cutter edge. Note that the angle B is adjusted by the tool rotating servo motor 36, and the distance Z is adjusted by the tool feeding servo motor 40. By the way, the control device for controlling the roll lathe shown in FIG. 2 includes, as shown in FIG. 1, a valve coder 61 for detecting the rotation of the spindle motor for driving the spindle 18, A spindle motor control unit 62 for controlling the rotational speed of the spindle motor based on the output of the valve hooder 61, a target rotational speed set in the spindle motor control unit 62, a tool rotation servomotor 36, and a tool feeding servomotor. A program for a numerical control device used to control the NC device 50 is automatically created from the roll profile curve input from the NC device 50 and the input device 64. a computing device 66 for transmitting data to the computing device 66;
and a data storage device 68 for storing programs and data created by the computer. Note that the tool rotation servo motor 36 is rotationally controlled by the NC device 50 based on the feedback signal of the pulse coder 38 attached to this rotating shaft, and the tool feeding servo motor 40 is similarly attached to the rotating shaft. Valscorder 4
Based on the feed comparison back signal of 2, NC1!1l
The rotation is controlled by 150. The effects of the embodiment will be explained below.゛While the roll lathe shown in FIG. 2 is driving, the arithmetic unit @66 of the control device shown in FIG. A roll profile function having a continuous curvature is determined from the coordinate data, a program for the numerical control device is automatically created to cut the roll 10 into a roll profile having the function, and the data is transmitted to the NC device 50 via a communication line. The NC device 50 controls the driving of the tool rotation servo motor 36, the tool feed servo motor 40, and the spindle motor according to the transmitted program. At this time, the data storage device 68 is
6 is stored and held as data. Here, when automatically creating a program for the NC device 50 using a desired roll profile curve given in advance as described above, select any plurality of points on the roll profile curve, and Coordinate data is input to the calculation device 66 via the data input device 64, the smoothest curve passing through these points is determined by the calculation device 66, and the roll profile curve is calculated by the calculation device 66. First, a method for reconstructing the data as numerical data inside the 66 will be explained. The smoothest curve is defined as a curve whose slope and curvature are continuous at any point on the curve. The slope is the first derivative of the function that describes the curve.
Since curvature is the second derivative of the function that describes the curve, the smoothest curve is one in which the first and second derivatives of the function that describes the curve are continuous at any point on the curve. It can be said. Therefore, when reconstructing the numerical data, arbitrary points on the roll profile curve input from the outside via the data input device 64 are used as nodes, and curve sections connecting these nodes are used. A roll profile curve is considered as a collection of segments), and this roll profile curve is considered as one in which the first-order differential and the second-order differential are continuous at each node. A spline function is mathematically known as a means for connecting the contacts. Various documents are known about the details of this spline function, but for example, it is introduced in detail in Chapter 4 of [Yamaguchi Fuji University, Shape Processing Engineering (■)] (published by Nikkan Kogyo Shimbun). The curve segment can be easily determined as a spline function by referring to these documents. In this way we obtain a mathematical representation of the roll profile curve (
Once a shape model (hereinafter referred to as a shape model) is obtained, the roll profile curve is divided into extremely short length microsegments, and the coordinates of the division nodes between the divided microsegments are calculated by calculating the shape model. You can ask for it. The above calculation process will be explained as follows based on the curve shown in FIG. 7, for example. A plurality of arbitrary points on the selected roll profile curve inputted from the data input device 64 are
Let them be B, C, and D. Let us consider the roll profile curve ABCD as a collection of curve segments AB, BC, and CD connected with AlB, C, and D as nodes, and the curve ABCD has a first-order differential (slope) at any point on the curve. Assume that the second derivative (curvature) of and is continuous. Therefore, such a curve ABCD can be a spline function expressed by a separate cubic function equation in each curve segment. Once such a spline function is obtained for each curve segment, each curve segment is further divided into minute interval curve segments AA+, AT A, as shown in the figure.
2. Divide into CnD. Nodes A1, A2.../l, B1, B2...8m1C+ of the divided minute section
, C2...0, the coordinates (r. θ) based on the central axis 52 of the plane surrounded by each roll axis 12 can be calculated by calculating the spline function obtained as described above. . The calculation results are stored and held in the data storage device 68. The number of dividing points for obtaining the minute sections may be determined so that the length of the minute sections is from several tens of micrometers to several hundred micrometers. Next, the coordinates (r, θ) of the many dividing nodes stored in the data storage device 68 are calculated based on the rotation angle B of the cutter holder 30 shown in FIG. 5 and the cutter 28 and three rolls shown in FIG. A method of calculating the cutter coordinate data (B, Z) by converting it into a distance IIZ from a plane including the axis 12 will be described below. FIG. 8 shows the central axis 12 of one roll 10 and each roll 10.
The distance P to the central axis 52 of the space surrounded by and the central axis 52
The point (r. θ) on the roll 10 is shown for . In order to apply the cutting edge of the cutter 28 to the position on the roll 10 corresponding to the point (r, θ) (the position on the ring indicated by the symbol CL in the figure), cutter coordinate data (B, Z)
is calculated using equations (1) and (2) above. Note that when the roll 10 is viewed parallel to the center @52, the distance is 1
The relationship between 111r Sr e and the angles θ and B is as shown in FIG. When viewed from 12 directions, the relationship between each distance Z1P and the distances of the h1 equations p-rcosθ and p-rBcos3 is as shown in FIG. As described above, several hundred to several thousand pieces of cutter coordinate data (
B, Z) are required. Then, by rotating the spindle motor while controlling the B-axis and Z-axis of the cutter 28 so that the cutting edge of the cutter 28 passes through the obtained cutter coordinate data (B, Z), the desired roll profile can be obtained. It is possible to cut the roll 10 so that it becomes. By the way, the NO device 50 has another name (:, output
erN umerical Control (CN
Although it is also referred to as C), in order to numerically control the roll lathe according to this embodiment, a dedicated data input is required. The dedicated data to be input is written in a G code or the like that specifies a mode of control operation, and the correspondence between the G code and the control function is determined by the ISOR1056 standard. Therefore, the tool rotation servo motor 36 and the tool feed servo motor 4 are operated so that the cutting edge of the cutter 28 passes through the plurality of cutter coordinate data (B, Z) obtained as described above.
In order to control 0, it is necessary to input data corresponding to this into the NG device 50. In order to perform this input, the calculation device 66 performs automatic programming based on the plurality of cutter coordinate data (B, Z), and the calculation device 66 communicates numerical control data obtained as a result of the automatic programming to the NC device 50. Transmit directly via line, etc. Note that the specific method of automatic plumbing performed by the arithmetic unit 66 is not particularly limited, but the cutter 28 may be moved between the cutter coordinate data (B. A method such as moving it may be used. Also, as mentioned earlier, the distance between adjacent nodes of the minute division nodes (r, θ) on the roll profile curve is
Since the distance is from several 10 μm to several 100 μ−, the tip of the cutter 28 should move linearly between the cutter coordinate data (B, Z) obtained by converting the coordinates of these points using equations (1) and (2) above. Even with servo control, the resulting roll shape has no problem in terms of dimensional accuracy. Here, the method of directly transmitting the numerical control data obtained by the automatic programming from the arithmetic device 66 to the NC device 50 via a communication line is generally a DNC (Dir
This is a method called ect Nug+erical control) or direct numerical control. This method is a control method that directly transmits numerical control data to the machine tool for processing without using media such as paper tape or floppy disks, so it has the advantage of being able to transmit large amounts of numerical control data without human intervention. There is. In the above embodiment, a method called DNC was adopted to transmit the numerical control data from the arithmetic unit 66 to the NC device 50, but the method of transmitting the numerical control data is not limited to this. As a matter of course, a paper tape making machine or the like is attached to the arithmetic unit 66 to punch out the numerical control data onto a paper tape, and then the paper tape is read out from the paper tape reading machine attached to the NC unit 50.
A method such as inputting data into the C device 50 may be used, and the method is not limited to the method using the DNC. Furthermore, in the above embodiment, the case where three hole-shaped rolls as shown in FIGS. 2 and 3 are cut with the roll lathe shown in FIG. 2 was exemplified. The number of rolls is not limited to three, and the number of rolls may be two, four, or any other number, and the type of rolls is not limited to hole-shaped rolls, and other types of rolls can also be used for cutting according to the present invention. It is possible to process it. Furthermore, in the embodiment described above, a case was exemplified in which a roll lathe as shown in FIG. 2 was controlled by a control device having a configuration as shown in FIG. The control device and roll lathe to be used are not limited to these, and it is clear that the present invention can be applied to other control devices and roll processing devices. Effects of the Invention As explained above, according to the present invention, it is possible to perform zero-roll cutting to obtain a desired roll shape while maintaining continuity at any point on the roll surface. Therefore, if the coordinate data of an arbitrary point on the target roll profile curve is input in advance into the calculation device shown in FIG. The roll to be cut can be cut into a roll shape having the desired roll profile. Therefore, it is not only possible to automate the operation of, for example, a roll lathe for cutting rolls, but also it is possible to cut rolls having complicated roll profiles that could not be cut conventionally. This makes it possible to cut rolls that have the optimal roll shape for rolling mill rolls, so if the rolled material is rolled using the cut rolls, it will have a significant effect on improving the quality of the rolled material. it is obvious. Specifically, if roll cutting is performed using the present invention, it has excellent effects such as being able to cut rolls having a laterally asymmetrical roll hole shape, for example.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a control device for implementing the roll cutting method according to the present invention, and FIG. 2 is a perspective view showing the overall configuration of a roll lathe controlled by the control device. FIG. 3 is a perspective view showing the shape of a hole-shaped roll cut by the roll lathe, and FIG. 4 is a perspective view showing a cutter and a cutter holder for cutting the hole-type roll. FIG. 5 is a cross-sectional view showing the configuration of the rotation mechanism in the tool head of the roll lathe, FIG. The figure is a diagram showing the roll profile curve divided into minute segments for detailed explanation of the present invention. Similarly, FIG. 8 shows the center of the space surrounded by the rolls and the cutter blade edge. 9 is a front view of the same, and FIG. 10 is a perspective view showing the positional relationship of
Transverse cross-sectional view along the ring indicated by the symbol CL in Fig. 8, No. 11
The figure is a front view showing an example of a machined surface of a roll cut by a conventional cutting method. 10... Roll to be cut, 12... Roll axis, 1
6... Roll stand, 18... Spindle, 2
8...Cutter, 30...Cutter holder, 34...Tool head, 36...Tool rotation servo motor, 38.42.6
DESCRIPTION OF SYMBOLS 1... Valse coder, 40... Servo motor for tool feeding, 46... Ball screw, 50... Numerical control device (NC device), 52... Center axis, 54... Worm wheel, 56. ... Worm gear, 60... Tool feed reducer, 62... Spindle motor control unit, 64...
Input device, 66... Arithmetic device, 68... Data storage device.

Claims (4)

[Claims] (1) A plurality of rolls to be cut arranged such that the roll axes are arranged at equal angles to each other in the same plane, a cutter holder that holds the same number of cutters as the rolls at equal angles, and a rotational drive device for the rolls. , a roll cutting process in which the center of the space surrounded by each roll matches the center of the cutter holder using a rotation and forward/backward driving device for the cutter holder, and the roll is cut by the cutter while rotating each roll. In the method, based on a roll profile curve to be cut given in advance, a distance from a central axis of a space surrounded by the roll to be cut to the roll profile curve at an angle θ with the central axis is defined as r. a data input procedure of inputting coordinate data (r, θ) of arbitrary plural points on the roll profile curve; deriving a roll profile function having a continuous curvature from the input plural coordinate data; a calculation procedure for calculating cutter coordinate data (B, Z) by dividing the derived roll profile function into minute sections and converting it into a rotation angle B of the cutter holder and a distance Z from the roll axis to the cutter; A method for cutting a roll, comprising: a control procedure for controlling a rotary drive device and a forward and backward drive device of the cutter holder based on calculated cutter coordinate data. (2) The roll profile function is reconstructed by performing spline interpolation calculation processing on the plurality of coordinate data input in the data input procedure and interpolating between mutually adjacent points with a cubic function curve. A method for cutting a roll according to claim 1. (3) The cutter coordinate data (B, Z) is expressed as follows, where r_B is the distance from the cutting edge of the cutter to the center axis, and P is the distance between the roll axis and the center axis, as follows: B=sin^-^
1 {(r/r_B) sin θ}Z=√[(P−rcos
θ)^2-(P-r_BcosB)^2]. (4) A plurality of rolls to be cut arranged such that the roll axes are arranged at equal angles to each other in the same plane, a cutter holder that holds the same number of cutters as the rolls at equal angles, and a rotational drive device for the rolls. , a rotation and forward/backward driving device for the cutter holder, and the cutter cuts the roll while rotating each roll by aligning the center of the space surrounded by each roll with the center of the cutter holder. In the roll cutting apparatus, the roll profile curve is cut from the central axis of the space surrounded by the roll to be cut at an angle θ with the central axis, based on a roll profile curve to be cut given in advance. a data input means for inputting coordinate data (r, θ) of arbitrary plural points on the roll profile curve, with the distance to r being the distance to the roll profile curve; a calculation means that calculates cutter coordinate data (B, Z) by dividing the function into minute sections and converting it into the rotation angle B of the cutter holder and the distance Z from the roll axis of the cutter; and the calculated cutter coordinate data a calculation transmission means for converting and transmitting the data into predetermined numerical control data; a means for storing the transmitted numerical control data; A roll cutting device characterized by comprising: a control means for simultaneous numerical control;