JPH05324035A - Cutting path generating method - Google Patents

Abstract

PURPOSE:To automatically adjust the depth of cut of a down cutting path and to generate a cutting path which is free from chattering in cutting by varying a normal depth of cut at the time of the down path according to an input item for the down cutting path and automatically generating the cutting path. CONSTITUTION:A down cutting parameter storage part 5 stores a down cutting parameter SCD from an input part 1. For example, a cutting division value at the time of down cutting or the depth of cut and down part cutting length of a cutting path part are specified as item of down cutting parameters which are inputted. A down part cutting line setting part 11 re-sets the cutting line of the down part according to a machining path RDw in a work generated by a work shape internal path generation part 10 and a value specified in the down cutting parameter SCD. A setting part 11 determines a cutting line LD' by a down path generation part 12 and generates and sends machining path data RDw' in the work shape to a storage part 13. Consequently, the winding of chips and chattering are prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of creating numerical control information input to a numerical control machine tool, and more particularly to a method of creating a cutting path in an NC lathe.

[0002]

2. Description of the Related Art Automatic programs and NCs for numerically controlled lathes
In the automatic program function built into the NC device as a (numerical control) function, by specifying the cutting conditions such as the work shape, the material shape, the tool used and the cutting amount,
The machining path automatic generation function that automatically generates the machining path from the material to the machining of the specified work shape is widely used, and it is not necessary to specify the machining path in the middle, which greatly contributes to the load reduction of the programmer. FIG. 5 is a block diagram showing an example of a system that realizes a conventional cutting path generation method, and the processing path generation method will be described with reference to FIG. The work shape data WD, the material shape data MD and the cutting condition data CD, which are input from the keyboard or the like by the guidance of the CRT, are respectively input via the input unit 1 to the work shape storage unit 2, the material shape storage unit 3 and the cutting condition storage unit. Sent to 4.

The cutting line setting unit 6 sets the cutting line LD of the work based on the work shape data WD, the material shape data MD and the cutting condition data CD.
It is sent to the cutting line range check unit 7. The cutting line range check unit 7 performs a range check on the inside and outside of the work for the cutting line LD, and the machining range internal path generation unit 9 and the work shape internal path generation unit 10 generate a machining path based on the result of the range check. The return route generation unit 8 generates a return route, that is, a non-process route. Machining route data RDp, RDw and non-machining route data RDb, which are the generation results.
Are sent to and stored in the storage unit 13. FIG. 6 is a side view showing an example of a general work.
Is the work shape, and ae is the material shape. FIG. 7 is a diagram showing an example of a machining path automatically generated by the conventional cutting path generation method. The numbers in the figure represent the order of the cutting operation by the tool 20, the solid line represents the cutting path, and the broken line represents the rapid feed path. It represents.

[0004]

In the above-described conventional cutting path generation method, for example, the path 2 → 3 in FIG. 7 can be processed favorably, but the down path 6 → 7, 11 → 12, etc. In the processing of, workpieces and tools 2 without cutting chips
Since it may be wound around 0 or the tool 20 may bite into the work, it not only adversely affects the processing accuracy and tool life, but also causes chattering. Therefore, the operator has been forced to perform inefficient machining such as reducing the cutting conditions of the entire machining depending on the cutting situation. The present invention has been made under the circumstances described above, and an object of the present invention is to automatically adjust a cutting amount of a downward cutting path portion to generate a cutting path in which chatter and the like at the time of cutting do not occur. It is to provide a route generation method.

[0005]

The present invention relates to a cutting path generation method in an NC lathe which automatically generates a cutting path based on input data including at least a work shape and cutting conditions such as a cutting amount. The above object of the present invention is achieved by automatically generating a cutting path by changing the normal cutting amount in the down cutting path part based on the cutting amount or the cut division value for the down cutting path part that is input. To be done.

[0006]

In the cutting path generation method of the present invention, a cutting path with a small cutting depth is automatically generated in the down path, so that chattering occurs during cutting of the down part of the workpiece during machining. And the cutting chips will not be wrapped around the work or tool or the tool will not bite into the work.

[0007]

FIG. 2 is a block diagram showing an example of a system for realizing the cutting path generating method of the present invention in correspondence with FIG. 5, and the same components are designated by the same reference numerals and the description thereof will be omitted.
A down cutting parameter storage unit 5, a down cutting line setting unit 11 and a down route generation unit 12 are added to the conventional block diagram. Downhill cutting parameter storage unit 5
Stores the downward cutting parameter SCD input from the keyboard or the like via the input unit 1. The items of the down-cutting parameter to be input include, for example, a cutting division value (a value indicating how many cuts are cut in the down path) or a cutting amount and a down-cutting length of the down cutting path during down cutting. Is specified. The descending section cutting line setting unit 11 sets the descending section cutting line based on the machining path data RDw in the workpiece shape generated by the in-workpiece shape path generating unit 10 and the value specified for the descending cutting parameter SCD. Then, the descending path generator 12 determines the cutting line LD 'to generate the machining path data RDw' in the work shape,
It is sent to the storage unit 13.

An example of the cutting path generation method of the present invention will be described in detail below with reference to the flowchart of FIG. 1 with reference to FIGS. 3, 4, and 6. However, the present invention relates to a method of generating a machining path, and the approach to the tool turning position and the like and the escape path are the same as those of the conventional method. Therefore, a description will be given from the time when the tool approaches the machining start point (point P in FIG. 3) To do. First, the operator first determines the work shape and the material shape (abcd in FIG. 6).
(shapes indicated by e and ae) are input from the keyboard or the like by the guidance of the CRT (step S1), and then the cutting conditions such as the depth of cut and the feed amount and the downward cutting parameters such as the cutting division value during the downward cutting are input. Yes (step S2). Now, as an example, it is assumed that the normal cutting amount is 6 mm, the cutting division value at the time of down cutting is 3, and the down cutting length is 10 mm in the down cutting parameter. The cutting line setting unit 6 checks whether there is a cutting residue (step S3), and if there is a cutting residue, the cutting amount from the machining start point P in FIG. 3 (6 in the example).
The cut line L0 shifted by (mm) is set (step S4).

The cut line range check unit 7 is located outside the material (the line in FIG. 3) at the set cut line L0.
B), the machining range between the material and the work shape (loha in the same figure) and the range inside the work (Hani in the same figure) are checked (step S5),
A route of the machining range is generated based on the result of the range check (step S6). That is, unnecessary lines such as lines outside the material are deleted from the cut line L0 of FIG. 3, and a clearance is provided at the position of B of FIG.
2 is generated. Next, the work shape internal path generation unit 10 generates a path (path 2 → 3 in FIG. 4) along the work shape (step S7). The cutting path is generated by repeating the above processing, but the processing up to this point is the same as the conventional one.

Next, it is checked whether or not there is a down route (step S8). Since there is no down route on the cut line L0, the process returns to step S3. Next, in step S4, the cutting line is further shifted by the cutting amount to set the cutting line L1, and steps S5, S6, and S7 are processed as in the conventional case, and →→→
→ Generate a route. As a result of checking the presence or absence of the down route of the cut line L1 in step S8, since-is the down route, the process proceeds to step S9. The down cut line setting unit 11 resets the down cut line based on the specified value of the down cutting parameter. That is, the cutting lines (l ₁ , l _{2 in} FIG. 3) shifted by the cutting amount of the downward cutting path or (normal cutting amount / cutting division value during downward cutting) are set (step S9).

In this example, the cutting amount (shift amount) of the downward cutting path portion = 6 mm / 3 = 2 mm, which is a shift of 2 mm. The descending path generating unit 12 sets a vertical line M, which is moved by the descending cutting length l ₀ (10 mm in the example) from the final cutting line L1 in this cutting, and defines the cutting lines l ₁ and l ₂ . The intersection points 2 and 4 of the line M are obtained, and one cutting amount (→→→) is divided into cutting dividing values for down-cutting (three times in this example), and the respective cutting paths are determined and generated ( Step S10). The routes determined as a result are → 1 → 2, 1 → 3
→ 4,3 →→→, and route 4 → 5 in Fig. 4
→ 6, routes 7 → 8 → 9, routes 10 → 11 → 12 → 13 are generated.

Next, returning to step S3, step S4
3 is generated in the process of to S7 and there is a down route, the process proceeds to step S9 and cut lines l ₁ and l ₂ (not shown) are set, and step S1
Similarly, when 0 is set, the route is determined and generated, but at this time, the final shape is obtained at the second time, and therefore the first time (route 1
4 → 15 → 16) and the route of the final line (route 17 → 18)
→ 19 → 20) is generated. Then, the process proceeds to step S3, and since there is no cutting residue, all processing is ended.

[0013]

As described above, according to the cutting path generation method of the present invention, a cutting path having a small cutting amount is automatically generated in the down path, so that the cutting section with a smaller cutting depth is used in the down part of the work. As a result of cutting, cutting chips are prevented from winding and chattering is prevented, and it is possible to prevent adverse effects on processing accuracy, tool life, etc., and to perform effective processing.

[Brief description of drawings]

FIG. 1 is a flowchart illustrating a cutting path generation method of the present invention.

FIG. 2 is a block diagram showing an example of a system for implementing the method of the present invention.

FIG. 3 is a diagram illustrating a method of setting a route of the work of FIG. 6 according to the method of the present invention.

FIG. 4 is a diagram showing an example of a cutting path generation result of the work of FIG. 6 by the method of the present invention.

FIG. 5 is a block diagram showing an example of a system that realizes a conventional cutting path generation method.

FIG. 6 is a side view showing an example of a general work.

7 is a diagram showing an example of a cutting path generation result of the workpiece of FIG. 6 by a conventional method.

[Explanation of symbols]

 5 Downstream cutting parameter storage unit 11 Downstream cutting line setting unit 12 Downstream route generation unit

Claims (1)

[Claims] 1. A cutting path is automatically generated based on input data including at least a work shape and cutting conditions such as a cutting amount.
In the cutting path generation method for a C-lathe, a cutting amount or a cutting division value for a down cutting path portion is input, and a normal cutting amount in the down cutting path portion is input based on the input item for the down cutting path portion. A method for generating a cutting path, which is modified to automatically generate a cutting path.