JPS61241001A - Forming process of optimum cutting path for shape of flute in numerical control lathe - Google Patents

Abstract

PURPOSE:To remove useless portion of path cutting by dividing cut portion into those of the center-bottom, right-hand side and left-hand side, and making lathe carry out a cutting cycle including a preset shift motion depending on the shape raw material of a work and the shape of a flute. CONSTITUTION:Data such as the shape of a flute, that of raw material are input to an input controller 3 through a key board 2 following a guidance shown on a display 1. These data are discriminated in the controller 3, sent to memories 4-6, and the data read out from them are input to a controller 7. Cutting path data CP, obtained through collaboration among path forming units 8-10 and the output from the controller, are sent to a cutting path memory 11 and the data MD is read out when the numerical control lathe operates for cutting work, thereby, the flute cutting is carried out through the optimum cutting path formed by the controller 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a method for generating an optimal cutting path for a workpiece in groove machining using a numerically controlled lathe.

(Technical background of the invention and its problems) In automatic programs and interactive manual data for numerically controlled lathes, cutting paths for groove machining have conventionally been automatically generated internally. However, there are restrictions on the shape of the groove and the material shape of the groove, and for arbitrary groove shapes and material shapes, unnecessary movement corrections and fine division of the machining range are forced, which places a great burden on operators. The reality is that

(Object of the invention) This invention was made under the above circumstances,
An object of the present invention is to provide a method for generating an optimal groove shape cutting path for a numerically controlled lathe, which automatically generates an optimal cutting path without waste by inputting the shape of an arbitrary groove shape or material shape. There is a particular thing.

(Summary of the Invention) The present invention relates to a method for generating an optimal groove-shaped cutting path in a numerically controlled lathe. , divided into right side and left side, X axis or
A groove cutting cycle that is parallel to the axis and includes a constant shift operation is performed to remove the empty cutting path portion.

(Embodiment of the invention) This invention inputs an arbitrary material shape and groove shape, and also inputs part data such as clearance data.
A virtual cycle start point for central bottom cutting is determined from the material shape, groove shape, and clearance data, a first cutting line passing through this virtual cycle start point is set, and this first cutting line and the material shape are and the workpiece shape, and find a third point moved by the clearance data from the first intersection point as the actual cycle start point, and determine the actual cycle start point (third point). → Set the second intersection as the first cutting path, then set a second cutting line shifted from the center to the left side by the input shift amount S for left side cutting, and
Find the fourth and fifth intersections between the cutting line and the material shape and workpiece shape, find a sixth point moved by the clearance data from the fourth intersection, and connect the sixth point and the virtual cycle. A seventh point of intersection is determined from the line passing through the starting point, the second point of intersection -> the seventh point of intersection - the sixth point is set as the rapid feed path, and the point of sixth intersection -> the fifth point of intersection is set as the second cutting path. The fifth intersection point→the second intersection point is set as the third cutting path. Below, the 3rd shift is shifted by the above shift amount S. By sequentially setting the fourth cutting line and then sequentially setting the cutting path for the right side, the above! R1, the second and third cutting paths are set as the optimum cutting paths.

The apparatus for realizing the method of this invention has a configuration as shown in FIG. 1, and an input control unit 3 is provided with information from a keyboard 2 such as the shape of the groove in the cutting part, the shape of the material in the cutting part, the width of the cutting tool, and the amount of shift.

Part data such as step amount 1M or stop time, clearance, etc. are input, and these input data are stored in the groove shape memory section 4. The data are stored in the material shape memory section 5 and the part data memory section 6, respectively. A display 1 such as a CRT is connected to the input control unit 3, and a guide display for interactive input and a confirmation display of input data are performed on the display 1. In other words, the operator inputs data from the keyboard 2 according to the dialogue guidance on the display l, and this input data is determined by the input control unit 1 3 and the corresponding storage unit 4 to
6 is stored. Further, the data read from the storage units 4 to 6 is input to a route generation main control unit 7 that controls the entire route generation, including a center bottom route generation unit 8, a left side route generation unit 9, and a right side route generation group 10. Cutting path data CP generated by a method described later is provided to the cutting path storage section 11 in cooperation with the cutting path storage section 11. The cutting path data No. stored in the storage section 11 is read out during cutting by the numerically controlled lathe, and groove machining is performed using the optimum cutting path generated by the path generation main control section 7.

Next, how the path generation main control section 7 generates a cutting path according to the present invention will be explained with reference to the flowcharts of FIGS. 2 and 3 and FIGS. 4 to 7.

FIG. 2 shows a flowchart of an embodiment of the present invention. First, the central bottom of the groove shape of the workpiece (the minimum diameter part of the groove) is set (step S1), and this cutting path is set (step 52). This shows that the shape of the left side of the 0th-order groove is set (Step S3), the cutting path is set (Step 54), and the shape and path of the right side of the 0th-order groove are set (Step S5.SS). Third
The figure shows the details of the cutting path setting described above in a flowchart, and will be explained below along with the operation.

Since this invention involves groove machining, it goes without saying that the tip surface of the cutting tool used for cutting is parallel to the center bottom of the groove (in Fig. 5, the tip G of the cutting tool is
H is parallel to the center bottom of the groove.) First, from the screen of the display l as shown in Figure 4,
, B, C, D, E, Fc7) 7-1 Shape and A, A, Mouth,
The minimum value point C in the X-axis direction at the center bottom of the workpiece (minimum diameter part of the groove) based on the material shape of C, 2, E, H, F,
Find the maximum point PO in the X-axis direction through C. Then, as shown in FIG. 5, a virtual cycle start point PS is determined by moving in the X-axis direction by 1 after the clearance of the input data input using the keyboard 2 from the maximum point PO (step 5IO). Next, Passing through the virtual cycle starting point PS,
Set the perpendicular line in the axial direction, that is, the cutting line LO (step 912), and the intersection points P1 and P2 with the material shape and the groove shape.
is determined (step 513), and a point P3 is set, which is moved by a clearance of 2 from the intersection point Pi with the material shape. This point P3 is then set as the actual cycle start point. Therefore, the rapid feed path is PJ4P3, and the cutting path is P3→P2.
(Step!914), and the intersection PI is P3→
Since it is on the path of P2, it is omitted as output data.

In this cutting path P3→P2, as shown in FIG. 6, the tool is cut along the cutting line LO from point P3 by the input clearance value 2 and step ID, and the cutting tool is cut by the input return amount t. Then, cutting is performed by the sum of the return amount t and the step amount d, and the process is repeated in the same manner.

Next, as shown in Fig. 5, assuming a perpendicular line Ll shifted by the input shift amount S to the left side of the groove of the workpiece, find the intersections P4 and P5 of the line Ll with the material shape and the groove shape, and Clearance 13 from the intersection P4
A point P8 moved in the axial direction is determined. A parallel line LH1 is assumed in the X-axis direction from this point P8, and an intersection point P7 with the perpendicular line LO is determined. As a result, after cutting the bottom part, the tool returns to the intersection point P7, and after fast forwarding from the intersection point P2 to the intersection point P7 to the point P8 (step 515), the cutting line L1 is set with point P8 as the actual starting point of the cutting path on the left side. The cutting is performed while repeating the operation along the input step amount d while taking into account the return amount t as described above. Therefore, the rapid traverse path is P2→
P7→P8. The cutting path becomes P64P5.

Note that since the intersection P4 is on the path →P8→P5, it is omitted as output data. Further, from the intersection P5, P5→P2 is set along the groove shape, and a cutting path is generated (step 51B).

Similarly, the line L2 shifted by the input shift amount S
．． L3. . . are set in sequence, and the same route generation process as described above is performed (step 517).

It goes without saying that the above-mentioned cutting path process is based on the left end G of the cutting tool, and the same path generation process as described above is performed on the right side of the groove of the workpiece using the right end H of the cutting tool as a reference.

The cutting path data CP generated in this manner is temporarily stored in the cutting path storage section 11, and is sent to the processing section of the numerically controlled lathe during processing to be subjected to cutting.

In the above-mentioned path generation process, if the rapid feed portion is shown by a broken line and the cutting feed portion is shown by a thick solid line, cutting path data as shown in FIG. 7 will be obtained.

(Modified example of the invention) In this invention, the groove shape has one center bottom, and as shown in the second example, the processing example is shown in which the center bottom of the groove shape → the left side → the right side, but the center of the groove shape This method can also be applied to the machining procedure from the bottom to the right side to the left side by simply changing the reference point of the cutting tool blade.

Further, as described above, although the groove shape has one central bottom, it is not limited to one groove shape, but is naturally applicable to groove shapes having a plurality of bottoms.

(Effects of the Invention) As described above, according to the groove-shaped cutting path generation method of the present invention, it is possible to deal with any material shape and groove shape by inputting the material shape and groove shape, which reduces the burden on the operator and This has the advantage of greatly reducing the man-hours required to create a program.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an apparatus for realizing the method of this invention, FIG. 2 is a flowchart showing an example of the procedure of this invention, and FIG. 3 is a flowchart showing the procedure of route generation of this invention. FIG. 4, FIG. 5, and FIG. 6 are diagrams for explaining the state of path generation according to the present invention, and FIG. 7 is a diagram showing path data when idle feeding and cutting are distinguished. l...display, 2...keyboard, 3...
Input control section, 4... Workpiece shape memory section, 5... Material shape memory section, 6... Part data storage section, 7... Route generation main control section, 8... Center bottom route generation section , 9...
・Left path generation unit, lO...Right path generation unit, 11・
...Cutting path memory section. Applicant's agent Yu Yasugata Sanraku 2zu LI Lθ

Claims (1)

[Claims] In the generation method of the groove-shaped cutting path in a numerically controlled lathe, the cutting part is divided into the center bottom, right side, and left side based on the material shape of the workpiece such as a forged or cast product and the groove shape. Alternatively, a method for generating an optimum groove-shaped cutting path in a numerically controlled lathe, characterized in that a groove cutting cycle is performed that is parallel to the Z-axis and includes a constant shift operation, and an empty cutting path portion is removed.