JPH0253161B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grooving control method for automatically performing grooving in a numerically controlled lathe.

Recently, in numerically controlled lathes, multiple machining patterns classified by machining shape are registered in advance, and the operator can control the lathe by simply inputting machining information based on the final machining shape shown in the production drawing. On the other hand, control methods for automatically creating and executing machining programs, that is, automatically performing machining, are being developed.

However, grooving using a grooving tool has not yet been automated due to its complicated control, and has traditionally relied on the creation of machining programs by programmers, but this work requires specialized knowledge. This requires a high degree of skill, and the machining program is also long, which has the disadvantage that program errors are more likely to occur. On the other hand, some numerically controlled lathes are equipped with canned cycles for grooving, but these canned cycles can only form U-shaped, so-called straight, grooves; they can only form V-shaped or straight grooves. It was not possible to form trapezoidal grooves.

In other words, a normal cutting tool is used parallel to the shape to be cut.For example, when machining the outer circumference of a workpiece into a cylindrical shape, the final machining shape is parallel to the Z-axis, so the cutting tool is used parallel to the Z-axis. Grooving tools move in different directions to form the outer shape, whereas grooving tools
Machining is performed by moving the workpiece in a direction perpendicular to the shape to be cut, as if cutting through it. Therefore, U-shaped grooves can be easily cut, but when machining V-shaped grooves or groove slopes with chamfering or rounding of the front and rear corners, it is necessary to hold the tool parallel to the cutting shape. Because there are elements that must be moved, the tool interferes with the unmachined part of the workpiece adjacent to the tool, making machining impossible. Therefore, in order to process the groove slope part,
After machining a U-shaped groove using a grooving tool, it is necessary to further process the corresponding part using a normal cutting tool, making the creation of a machining program extremely complicated. In order to eliminate the above-mentioned drawbacks, the present invention provides a method for grooving in a numerically controlled lathe that can machine grooves of various shapes with a single grooving tool, and therefore allows easy creation of machining programs. It relates to a processing control method.

That is, in the present invention, a grooving tool having a predetermined tool width and having noses R formed on both sides of the tool tip is moved in a direction perpendicular to the bottom of the groove to be formed, and the groove is formed by this movement. In the lathe grooving process to cut and form the outer circumference of a workpiece, a machining line having a bottom machining area and a slope machining area is set on the workpiece, and the groove to be machined is horizontally moved in the first and second steps. The processing of the first step is performed by positioning the tool in the direction of the spindle axis based on the nose R on the first step side, and moving the positioned tool in the direction perpendicular to the spindle axis. , a tool trajectory in which the tool is moved toward the spindle axis until the tip of the tool reaches the machining line in the bottom machining area, and then retracted in the opposite direction, once or
Machining the bottom machining area is repeated two or more times while shifting the tool by a predetermined amount in the direction of the spindle axis, and then positioning the tool in the direction of the spindle axis with reference to the nose R on the first process side. moving the positioned tool from a direction perpendicular to the spindle axis toward the spindle axis until the nose R reaches the machining line of the slope machining area;
Furthermore, after moving the tool along the machining line to the second process side, the tool trajectory to be retracted in a direction perpendicular to the spindle axis is changed once or twice while shifting the tool by a predetermined amount in the direction of the spindle axis. The machining of the second step is carried out by repeatedly machining the slope machining area more than once, and the tool is positioned in the spindle axis direction with reference to the nose R on the second step side. The tool is moved from a direction perpendicular to the spindle axis toward the spindle axis until the tip of the tool reaches the machining line in the bottom machining area, and then is retracted in the opposite direction. times or
The bottom machining area is machined twice or more while shifting the tool by a predetermined amount in the direction of the spindle axis, and then, if the second process includes a slope machining area, the nose on the second process side is The tool is positioned in the direction of the spindle axis using R as a reference, and the positioned tool is moved along the spindle from a direction perpendicular to the spindle axis until the nose R reaches the machining line of the slope machining area. Move it toward the axis,
Furthermore, after moving the tool along the machining line to the first process side, the tool locus for retreating in a direction perpendicular to the spindle axis is changed once or twice while shifting the tool by a predetermined amount in the direction of the spindle axis. By repeating the machining of the slope machining area more than once, and by controlling the first and second steps,
A groove having a sloped portion on at least one side is formed by cutting on the outer circumference of the workpiece using the same grooving tool.

In addition, the present invention moves a grooving tool having a predetermined tool width and noses R formed on both sides of the tool tip in a direction perpendicular to the bottom of the groove to be formed, and by this movement, the groove is formed. In the lathe grooving process that cuts and forms the outer circumference of the workpiece, a machining line having a bottom machining area and a slope machining area is set on the workpiece, and the groove to be machined is placed in the first and second processes in the left and right direction. The first process is performed by positioning the tool in the direction of the spindle axis based on the nose R on the first process side, and moving the positioned tool in the direction perpendicular to the spindle axis. , a tool trajectory in which the tip of the tool is moved toward the spindle axis until it reaches the machining line in the bottom machining area, and then retracted in the opposite direction, once or
The bottom machining area is machined twice or more while shifting the tool by a predetermined amount in the direction of the spindle axis, and then, if the first process includes the slope machining area, the nose on the first process side is The tool is positioned in the direction of the spindle axis based on R, and the positioned tool is moved along the spindle axis from a direction perpendicular to the spindle axis until the nose R reaches the machining line of the slope machining area. The tool is moved toward the center, further moved along the machining line to the second process side, and then retracted in a direction perpendicular to the spindle axis once, or the tool is moved in the direction of the spindle axis. The machining of the slope machining area is carried out twice or more while shifting by a predetermined amount, and the machining of the second process is performed in the direction of the main axis of the tool with reference to the nose R on the second process side. After performing positioning, the positioned tool is moved from a direction perpendicular to the spindle axis toward the spindle axis until the tip of the tool reaches the machining line in the bottom machining area, and then in the opposite direction. Machining the bottom machining area is performed by repeating the retracting tool trajectory once or twice or more while shifting the tool by a predetermined amount in the direction of the spindle axis, and then using the nose R on the second process side as a reference. to position the tool in the spindle axis direction, and move the positioned tool toward the spindle axis from a direction perpendicular to the spindle axis until the nose R reaches the machining line in the slope machining area. After moving the tool and moving it further along the machining line to the first process side, the tool locus is retracted in a direction perpendicular to the spindle axis, either once or by shifting the tool by a predetermined amount in the direction of the spindle axis. by repeatedly machining the slope machining area two or more times while controlling the first and second steps,
A groove having a sloped portion on at least one side is formed by cutting on the outer circumference of the workpiece using the same grooving tool.

The present invention will be specifically described below based on embodiments shown in the drawings.

Fig. 1 is a block diagram showing an example of a control part of a numerically controlled lathe to which the present invention is applied, Fig. 2 is a diagram showing a groove to be machined, Fig. 3 is a partially enlarged view showing a machining area, and Fig. 4 and FIG. 5 are diagrams showing tool trajectories.

As shown in FIG. 1, the numerically controlled lathe 1 has a main control section 2, which includes a data memory 3, a keyboard 5, a processing control section 6, a display 7, a program memory 9, and a processing section. Deployment control unit 1
0, the cutting condition determination control section 15, etc. are connected.
The machining control unit 6 is connected to an X-axis feed drive motor 11 for tool feeding, a Z-axis feed drive motor 12, and a spindle drive motor 13, and the machining development control unit 10
A machining pattern memory 19 is connected to.

Since the numerically controlled lathe 1 has the above-described configuration, when performing grooving to cut and form trapezoidal grooves 16a as shown in FIG. 2 on the workpiece 16, the operator must: Operate the keyboard 5 to enter the coordinates of the start point SP and end point FP, groove width W1, and front corner 16.
The presence or absence of chamfering and rounding of the rear corner 16c and the shape thereof, the width of the grooving tool 17 to be used, the nose radius at both ends, etc. are input as processing information INF. The processing information INF is stored in the data memory 3, and the information
When the input of the INF is completed, the main control section 2 drives the machining development control section 10 to determine the final machining shape of the groove 16a from the machining information INF in the data memory 3 as shown in FIG. Prescribed finishing allowance FT
The rough machining line RCL is set as shown in Fig. 3, taking this into account. Rough machining line RCL is groove 16a
a bottom machining area BCA corresponding to the bottom 16d, a rear corner machining area RCA corresponding to the rear corner 16c,
Front corner machining area corresponding to front corner 16b
Slope machining area compatible with FCA and groove slope 16e
SCA is divided into SCA, and boundary points P _A , P _B , ... P _D , P _E , ... P _H are set at the boundaries of each area as shown in Fig. 2 (Fig. 2 In the case shown, groove 1
The shape of 6a is set symmetrically with respect to the center line CL in FIG. ) As shown in FIGS. 4 and 5, the control unit 10 divides the groove 16a into left and right parts in the figure with the boundary point P _D as a boundary, and processes the first part on the left side in the figure.
The process is separated into a rough finishing process and a second rough finishing process for machining the right side in the figure, and the tool movement pattern PAT in each machining area is read out from the machining pattern memory 19, and a specific tool trajectory is determined. That is, in the bottom machining area BCA, the movement pattern PAT positions the Z coordinate position of the nose R on either side of the tool 17 at a predetermined start position with reference to the nose R on either side of the tool 17. from -X direction, therefore the bottom machining area
The tool 17 is moved while pecking in a direction perpendicular to BCA, that is, toward the spindle center which is the Z axis, and when the tool tip 17b reaches the rough machining line RCL, a straight line is drawn between the boundary points P _D and P _H. This is a pattern PAT in which the tool is retracted in the +X direction after interpolation or immediately without any interpolation, and the pattern is repeated once or twice or more with the tool 17 shifted by a predetermined amount in the direction of the spindle axis. Processing is performed by Front and rear corner machining area FCA,
In RCA, with reference to the nose R on either side of the tool 17, the Z coordinate position of the nose R is positioned at a predetermined start position, and the workpiece is moved from the start position to the rough machining line RCL. Move the tool 17 while pecking in the direction, that is, the spindle axis (Z-axis), so that the nose R on the corner side of the tool 17 is on the rough machining line RCL.
When the boundary points P _A and P _B are reached, and between P _E and P _F ,
Linear or circular interpolation is performed between P _C and P _D and between P _G and P _H according to the chamfering and R chamfering based on the machining information INF, and when that is completed, the tool 17 is moved to +
This is a pattern for retreating in the direction. Note that chamfering and rounding using the nose R are performed by performing the same correction as the known nose R correction in normal turning processing. That is, the pattern is such that the nose R portion of the grooving tool is regarded as part of a perfect circle, and the tool is moved so that one point on the perfect circle is always in contact with the rough machining line RCL. Furthermore, in the slope machining area SCA, with reference to the nose R on either side of the tool 17, the Z coordinate position of the nose R is positioned at a predetermined start position, and the nose R on the slope side is moved from the start position. The tool 17 is moved while pecking in the direction of the workpiece until it reaches the rough machining line RCL, then linear interpolation is performed between the boundary points P _B and P _C and between P _F and P _G , and then the tool 17 is moved in the +X direction. This is a movement pattern PAT for retracting the tool, and the pattern is 1
Machining is performed by repeating the process twice or more, or by shifting the tool 17 by a predetermined amount in the direction of the spindle axis (Z-axis direction). The control unit 10 determines a specific tool trajectory in the first rough finishing process by combining the movement patterns PAT of the tool 17 in each machining area. That is, the tool 17 is first moved to the preparation position A in such a way that the Z coordinate of the left end 17a, which is the nose R on the first rough finishing process side, and the Z coordinate of the boundary point P _D match.
1, and then, as shown in Fig. 4, the tool 17 is moved in the Z-axis direction, which is the spindle axis direction, on the trajectories PR1, PR2, ... PR13, PR14 according to the movement pattern PAT of each machining area. The rough machining line moves by shifting by a predetermined amount.
The tool path PR is to cut approximately the left half of the groove 16a in the figure in accordance with the RCL (Figure 4 shows the movement path of the nose R, which is the reference for machining in the first rough finishing step, that is, the left end of the tool 17a). ing.). Once the tool trajectory PR in the first rough finishing step is determined, the control unit 10 determines the tool trajectory QR in the second rough finishing step. That is, tool 17
is in the preparation position A2 connected to the part machined in the first rough finishing process of the bottom processing area BCA,
The Z-axis, that is, the spindle axis direction, is positioned, and then, as shown in FIG. 5, according to the movement pattern PAT of each processing area, the trajectories QR1, QR2, ......
The tool 17 is moved over QP14 and QR15 by shifting it by a predetermined amount in the Z-axis direction, which is the direction of the spindle axis, and cuts the groove 16a in a shape that follows the rough machining line RCL.
This is the tool path QR for cutting the approximate right half of the figure (in FIG. 5, the tool path QR is the tool path QR, which is the reference point for machining in the second rough finishing process, that is, the tool right end 17c).
The trajectory of the movement is shown. ). In addition, at this time, the trajectory
There are cases where PR and QR move on the rough machining line RCL over two or more machining areas, but in that case, each area has its own movement pattern.
PAT applies. That is, regarding the trajectory PR5, the trajectory PR5 moves within the slope machining area SCA and the back corner machining area RCA, but within the area SCA, it moves between the boundary points P _B and P _C by linear interpolation,
Within the area RCA, the movement is performed by circular interpolation between the points P _C and P _D. In this way, when the tool trajectories PR and QR for the first and second rough finishing processes are determined, the deployment control unit 10 determines the tool trajectory SR for the finishing process, but the tool movement pattern in this case is
As shown in Figure 2, PAT first processes the rough-machined part in the first rough-finishing process in the front corner machining area.
FCA, slope machining area SCA, back corner machining RCA,
Move the tool left end 17a in order to remove the finishing allowance FT in the order of the bottom machining area BCA, and
Machining is performed based on 7a, and then the right end of the tool 17
c is a pattern PAT in which the rough-machined part in the second rough-finishing step is similarly moved and machining is performed based on the tool right end 17c, and the tool path SR is determined based on the pattern PAT as shown in FIG. It is determined as shown in . In this way, when the tool trajectories PR, QR, and SR for both the rough finishing and finishing processes are determined, they are processed by the cutting condition determination control section 15.
is stored in the program memory 9 as a machining program PRO along with the cutting conditions such as feed rate and spindle rotation speed for each process determined. In the actual machining, the machining control unit 6 controls the X-axis and Z-axis feed drive motors 11 and 12 and the spindle drive motor 13 according to the machining program PRO in the program memory 9.
The workpiece 16 is rotationally driven, and the tool 17 is moved along the tool trajectories PR, QR, and SR, and the groove 16a is moved from the preparation position A1 to the fourth position.
The machining area on the left side of the figure is machined based on the nose R of the tool 17 on the left side of the figure, that is, the left end 17a of the tool, and the machining area on the right side of FIG. Nose R of 17, that is, tool right end 1
Processing is performed based on 7c, and a single tool 17
Then, the groove 16a is machined.

In addition, although the above-mentioned embodiment described the case of forming the trapezoidal groove 16a, the V-shaped groove reduces the bottom processing area BCA, and the U-shaped groove eliminates the slope processing area SCA. This makes it possible to do this easily. For example, starting point
Keyboard 5 with the Z coordinates of SP and end point FP equal
If input from , the slope machining area SCA is not set and a U-shaped groove is formed. Furthermore, it is naturally possible to form the slope machining area SCA only on one side of the groove 16a in FIG. 2.

In addition, in the above embodiment, the rough machining line RCL is
We have described the case where it is divided into bottom machining area BCA, back corner machining area RCA, front corner machining area FCA, and slope machining area SCA, but rough machining line RCL
As for the setting mode, if the bottom machining area BCA and slope machining area SCA are set, groove machining with a grooving tool is possible even without the rear corner machining area RCA and front corner machining area FCA, so corner machining is not necessarily required. There is no need to provide an area.

As explained above, the grooving tool 17, which has a predetermined tool width and has noses R such as the tool left end 17a and the right end 17c on both sides of the tool tip, is placed at right angles to the bottom of the groove 16a to be formed. In lathe grooving processing in which a groove is cut and formed on the outer periphery of a workpiece by moving the workpiece in a direction, a processing line such as a rough processing line RCA having a bottom processing area BCA and a slope processing area SCA on the workpiece is used. is set, and the groove to be machined is divided into a first process and a second process in the left-right direction, and the machining of the first process is performed in the direction of the main axis of the tool with reference to the nose R on the first process side. After performing positioning, the positioned tool is moved from a direction perpendicular to the spindle axis toward the spindle axis until the tip of the tool reaches the machining line in the bottom machining area, and then moved in the opposite direction. The tool path to be retracted is changed once or
Machining the bottom machining area is repeated two or more times while shifting the tool by a predetermined amount in the direction of the spindle axis, and then positioning the tool in the direction of the spindle axis with reference to the nose R on the first process side. moving the positioned tool from a direction perpendicular to the spindle axis toward the spindle axis until the nose R reaches the machining line of the slope machining area;
Furthermore, after moving the tool along the machining line to the second process side, the tool trajectory to be retracted in a direction perpendicular to the spindle axis is changed once or twice while shifting the tool by a predetermined amount in the direction of the spindle axis. The machining of the second step is performed by repeatedly machining the sloped machining area more than once, and the tool is positioned in the spindle axis direction with reference to the nose R on the second step side, and the A tool trajectory in which the tool is moved from a direction perpendicular to the spindle axis toward the spindle axis until the tip of the tool reaches the machining line in the bottom machining area, and then retracted in the opposite direction. times or
The bottom machining area is machined twice or more while shifting the tool by a predetermined amount in the direction of the spindle axis, and then, if the second process includes a slope machining area, the nose on the second process side is The tool is positioned in the direction of the spindle axis using R as a reference, and the positioned tool is moved along the spindle from a direction perpendicular to the spindle axis until the nose R reaches the machining line of the slope machining area. Move it toward the axis,
Furthermore, after moving the tool along the machining line to the first process side, the tool locus for retreating in a direction perpendicular to the spindle axis is changed once or twice while shifting the tool by a predetermined amount in the direction of the spindle axis. By repeating the machining of the slope machining area more than once, and by controlling the first and second steps,
Grooves with slopes on at least one side are formed by cutting on the outer periphery of the workpiece using the same grooving tool, so grooves with various shapes can be machined with a single grooving tool. This can be easily done with the tool 17, and as in the past, in order to process the sloped part of the groove, after machining the U-shaped groove with a grooving tool, the corresponding part is further machined using a normal cutting tool. This eliminates the need for such complicated processes, making it extremely easy to create machining programs. In particular, when machining a groove with a narrow sloped area, in the conventional method, when machining the sloped area, the tool tip is positioned in the groove and moved parallel to the spindle axis direction. Because I have to let
The workpiece and the tool cutting edge interfered, making machining impossible, and the only option was to use a full-form cutting tool whose cutting edge was formed in the groove shape that was to be formed in advance.However, according to the present invention, a general-purpose tool By using a grooving tool with a narrow blade width, it is possible to easily process a groove having a narrow sloped portion.

In addition, a grooving tool having a predetermined tool width and a nose radius formed on both sides of the tool tip is moved in a direction perpendicular to the bottom of the groove to be formed, and by this movement, the groove is formed around the outer circumference of the workpiece. In the lathe grooving process for cutting and forming on the workpiece, a machining line having a bottom machining area and a slope machining area is set on the workpiece, and the groove to be machined is divided into a first process and a second process in the left and right direction, In the first process, the tool is positioned in the direction of the spindle axis based on the nose R on the first process side, and the positioned tool is moved from the direction perpendicular to the spindle axis. A tool trajectory in which the tip is moved toward the spindle axis until the tip reaches the machining line in the bottom machining area, and then retracted in the opposite direction, once or
The bottom machining area is machined twice or more while shifting the tool by a predetermined amount in the direction of the spindle axis, and then, if the first process includes the slope machining area, the nose on the first process side is The tool is positioned in the direction of the spindle axis based on R, and the positioned tool is moved along the spindle axis from a direction perpendicular to the spindle axis until the nose R reaches the machining line of the slope machining area. The tool is moved toward the center, further moved along the machining line to the second process side, and then retracted in a direction perpendicular to the spindle axis once, or the tool is moved in the direction of the spindle axis. The machining of the slope machining area is carried out twice or more while shifting by a predetermined amount, and the machining of the second process is performed in the direction of the main axis of the tool with reference to the nose R on the second process side. After performing positioning, the positioned tool is moved from a direction perpendicular to the spindle axis toward the spindle axis until the tip of the tool reaches the machining line in the bottom machining area, and then in the opposite direction. Machining the bottom machining area is performed by repeating the retracting tool trajectory once or twice or more while shifting the tool by a predetermined amount in the direction of the spindle axis, and then using the nose R on the second process side as a reference. to position the tool in the spindle axis direction, and move the positioned tool toward the spindle axis from a direction perpendicular to the spindle axis until the nose R reaches the machining line in the slope machining area. After moving the tool and moving it further along the machining line to the first process side, the tool locus is retracted in a direction perpendicular to the spindle axis, either once or by shifting the tool by a predetermined amount in the direction of the spindle axis. by repeatedly machining the slope machining area two or more times while controlling the first and second steps,
If a groove having a sloped portion on at least one side is formed by cutting it on the outer circumference of the workpiece using the same grooving tool, processing can be performed in the reverse process to the above case. .

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of a control part of a numerically controlled lathe to which the present invention is applied, Fig. 2 is a diagram showing a groove to be machined, Fig. 3 is a partially enlarged view showing a machining area, and Fig. 4 and FIG. 5 are diagrams showing tool trajectories. 1... Numerical control lathe, 16a... Groove, BCA...
...bottom machining area, RCA...rear corner machining area,
SCA...Slant machining area, FCA...Front corner machining area.

Claims (1)

[Claims] 1. A grooving tool having a predetermined tool width and having noses R formed on both sides of the tool tip is moved in a direction perpendicular to the bottom of a groove to be formed, and the groove is formed by the movement. In the lathe grooving process that cuts and forms the outer periphery of the workpiece, a machining line having a bottom machining area and a slope machining area is set on the workpiece, and the groove to be machined is placed in the first and second steps in the left and right direction. dividing the processing into steps, positioning the tool in the spindle axis direction with reference to the nose R on the first step side, and moving the positioned tool at right angles to the spindle axis. From the direction, the tool trajectory is moved toward the spindle axis until the tip of the tool reaches the machining line in the bottom machining area, and then retracted in the opposite direction, once or,
Machining the bottom machining area is repeated two or more times while shifting the tool by a predetermined amount in the direction of the spindle axis, and then positioning the tool in the direction of the spindle axis with reference to the nose R on the first process side. moving the positioned tool from a direction perpendicular to the spindle axis toward the spindle axis until the nose R reaches the machining line of the slope machining area;
Furthermore, after moving the tool along the machining line to the second process side, the tool trajectory to be retracted in a direction perpendicular to the spindle axis is changed once or twice while shifting the tool by a predetermined amount in the direction of the spindle axis. The machining of the second step is carried out by repeatedly machining the slope machining area more than once, and the tool is positioned in the spindle axis direction with reference to the nose R on the second step side. The tool is moved from a direction perpendicular to the spindle axis toward the spindle axis until the tip of the tool reaches the machining line in the bottom machining area, and then is retracted in the opposite direction. times or
The bottom machining area is machined twice or more while shifting the tool by a predetermined amount in the direction of the spindle axis, and then, if the second process includes a slope machining area, the nose on the second process side is The tool is positioned in the direction of the spindle axis using R as a reference, and the positioned tool is moved along the spindle from a direction perpendicular to the spindle axis until the nose R reaches the machining line of the slope machining area. Move it toward the axis,
Furthermore, after moving the tool along the machining line to the first process side, the tool locus for retreating in a direction perpendicular to the spindle axis is changed once or twice while shifting the tool by a predetermined amount in the direction of the spindle axis. By repeating the machining of the slope machining area more than once, and by controlling the first and second steps,
A method for controlling grooving in a numerically controlled lathe, in which a groove having a sloped portion on at least one side is cut and formed on the outer circumference of a workpiece using the same grooving tool. 2. A grooving tool having a predetermined tool width and a nose R formed on both sides of the tool tip is moved in a direction perpendicular to the bottom of the groove to be formed, and by this movement, the groove is formed on the outer periphery of the workpiece. In the lathe grooving process, a machining line having a bottom machining area and a slope machining area is set on the workpiece, and the groove to be machined is divided into a first process and a second process in the left and right direction. In the first process, the tool is positioned in the direction of the spindle axis based on the nose R on the first process side, and the positioned tool is moved from the direction perpendicular to the spindle axis to the tip of the tool. The tool is moved toward the spindle axis until it reaches the machining line in the bottom machining area, and then retracted in the opposite direction.
The bottom machining area is machined twice or more while shifting the tool by a predetermined amount in the direction of the spindle axis, and then, if the first process includes the slope machining area, the nose on the first process side is The tool is positioned in the direction of the spindle axis based on R, and the positioned tool is moved along the spindle axis from a direction perpendicular to the spindle axis until the nose R reaches the machining line of the slope machining area. The tool is moved toward the center, further moved along the machining line to the second process side, and then retracted in a direction perpendicular to the spindle axis once, or the tool is moved in the direction of the spindle axis. The machining of the slope machining area is carried out twice or more while shifting by a predetermined amount, and the machining of the second process is performed in the direction of the main axis of the tool with reference to the nose R on the second process side. After performing positioning, the positioned tool is moved from a direction perpendicular to the spindle axis toward the spindle axis until the tip of the tool reaches the machining line in the bottom machining area, and then in the opposite direction. Machining the bottom machining area is performed by repeating the retracting tool trajectory once or twice or more while shifting the tool by a predetermined amount in the direction of the spindle axis, and then using the nose R on the second process side as a reference. to position the tool in the spindle axis direction, and move the positioned tool toward the spindle axis from a direction perpendicular to the spindle axis until the nose R reaches the machining line in the slope machining area. After moving the tool and moving it further along the machining line to the first process side, the tool locus is retracted in a direction perpendicular to the spindle axis, either once or by shifting the tool by a predetermined amount in the direction of the spindle axis. by repeatedly machining the slope machining area two or more times while controlling the first and second steps,
A method for controlling grooving in a numerically controlled lathe, in which a groove having a sloped portion on at least one side is cut and formed on the outer circumference of a workpiece using the same grooving tool.