JP2001337707A - Method for automatic generation of turning nc data and the preprocess - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic generation method to obtain easily turning NC data with straight tools and side tools, and the preprocess method. SOLUTION: In this method for preprocess and generation, relation between the finishing profile of a turning workpiece and the slope angle of the straight tool to be used is examined first, and depending on the result, the semi-finishing profile is obtained through the operation. Then the rough machining area is gained according to the blank profile and the semi-finishing profile in order to generate automatically the turning data for the rough machining area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically generating turning NC data and a pre-processing method suitable for a case where a required turning amount is large in turning of a material such as a forged product.

[0002]

2. Description of the Related Art An NC lathe for automatically turning a material such as a forged product is used as a cutting tool.
The cutting tool 2 shown in FIG. Single-edged tool 1 is material 3
Can be turned at right angles, but the strength of the insert is weak,
On the other hand, although the bevel tool 2 has a high chip strength, the blank 3 cannot be turned at right angles. In other words, as shown in FIG. 2, the bevel cutting tool 2 cannot turn a slope having an angle equal to or greater than the glue gradient θ defined by the tip shape.

[0003] Therefore, in turning with an NC lathe, generally, first, after roughing a material using a beveled tool 2, finishing is performed using a single-edged tool 1. As is well known, the movement of the NC lathe is controlled on the basis of numerical data. Therefore, to perform turning of a material separately into roughing and finishing, numerical data for these roughing and finishing are That is, it is necessary to prepare turning NC data in advance.

[0004]

In recent years, various automatic creation programs for automatically creating turning NC data have been developed. To use this automatic creation program, the shape of a material before and after turning is defined in advance. There is a need to. For this reason, in order to perform the turning process separately into the roughing process and the finishing process, it is necessary to prepare a working drawing for creating the turning NC data for the roughing separately from the design drawing of the turned product.

[0005] Even a skilled technician takes time and effort to optimally create such a working drawing.
Skilled techniques are required to create a machining drawing that is efficient for rough machining, and it is not easy to create turning NC data. The present invention has been made based on the above-described circumstances, and the object thereof is only from a design drawing of a turned product.
An object of the present invention is to provide a pre-processing method capable of obtaining a machining area for creating optimum turning NC data for rough machining, and a method of automatically generating turning NC data using the pre-processing method.

[0006]

According to a first aspect of the present invention, there is provided a pre-processing method according to the first aspect of the present invention, wherein an oblique sword is provided on the basis of input information of shape elements which respectively define a material shape and a finished shape of a turned product. The method is characterized by calculating the intermediate finish shape that can be obtained by turning using a cutting tool and that is closest to the finish shape, and then calculates the rough machining area between the material shape and the intermediate finish shape. And

[0007] According to the above pre-processing method, an optimum intermediate finish shape for rough machining by a beveled tool is calculated only from input information obtained from a design drawing and a material shape of a turned product. Based on finish shape and material shape,
A rough machining area for automatic creation of turning NC data is defined. More specifically, the calculation of the intermediate finish shape is performed by determining the presence / absence of a non-linear element in the finish shape element, replacing the non-linear element with one or more linear elements, and obtaining a finish shape including only linear elements. The process of correction and the presence / absence of a part in the straight line element of the finished shape after the correction, in which turning with a beveled tool is not possible in the turning direction, are determined, and the part is sequentially changed to a straight line element having the same inclination angle as the nori gradient. Replacement process (claim 2).

[0008] In the intermediate finish shape obtained in this way, the shape element is composed of only a linear element, and a portion that cannot be turned with a bevel tool is replaced with a linear element having the same inclination angle as the glue gradient. Therefore, for turning with a beveled tool, it is the one that most closely resembles the finished shape. Therefore, if the turning NC data is created based on the rough machining area obtained from the intermediate finish shape and the material shape, and if the material is turned according to the turning NC data,
The turning can be performed optimally, and the turning speed can be increased.

Further, after the calculation of the rough processing area, it is preferable to further calculate and obtain a finishing processing area between the intermediate finishing shape and the finished shape of the turned product. In this case, after or simultaneously with the generation of the turning NC data for the rough machining area, the turning NC data for the finishing machining area is also automatically created. Regarding automatic creation of turning NC data for a rough machining area or a finishing machining area, it is determined whether or not there is a data portion indicating an invalid movement of a byte in the created turning NC data, and the turning is performed based on the determination result. It is preferable to modify the NC data (claim 4). The turning NC data obtained by the correction in this manner gives an efficient turning operation to the cutting tool, thereby increasing the efficiency of the turning process.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 schematically shows an automatic creation system for automatically creating turning NC data when turning a material such as a forged product with an NC lathe. The automatic creation system consists of a computer system and includes a control board with a central processing unit (CPU) 10. The CPU 10 is connected to an input / output interface (input / output I / F) 14 via a bus line 12. The input / output interface 14 has a display device 16 such as a CRT, an input device 18 such as a keyboard, and an external storage device such as an FDD device. The device 20 and the printer 22 are connected. Further, the bus line 12 is connected to a communication interface (communication I /
F) 24.

Further, the CPU 10 is also connected to an internal storage device via a bus line 12, and the internal storage device includes memories M1 and M5 formed of ROM and memories M2 to M4 and M6 formed of RAM. Memory M1, M5
Stores a pre-processing program for executing pre-processing when creating turning NC data, and a creating program for creating turning NC data in response to an execution result of the pre-processing program.

Various data are stored in the memories M2 to M4 and M6. Specifically, the input information and the result of the process from the input device 18 and the external storage device 20 are stored in the memory M2, the execution result of the preprocessing program is stored in the memory M3,
Turning conditions are stored in the memory M4, and execution results of the creation program are stored in the memory M6. The preprocessing program is shown in the routine of FIGS. 4 to 7, and this routine will be described below.

Preprocessing First, the CPU 10 reads the finished shape of a turned product from the external storage device 20 or the input device 18 and stores it in the memory M2 (step S1). Here, since the finished shape of the turned product is represented as a continuum of various finished shape elements from the design drawing, the coordinates specifying each of the finished shape elements are read in step S1.

To simplify the explanation, the finished shape is shown in FIG.
Assuming that only the linear element and the circular arc element are shown as shown by the solid line AK in the middle, in this case, the finish shape is a linear element of AB, BC, CD, DE, a concave circular arc element of EF, FG linear element, GH convex arc element, HI
, A concave arc element of IJ, and a linear element of JK, and when viewed in the turning direction of the cutting tool, each linear element is specified by coordinates of a start point and an end point, and each arc element is defined by a start point and a start point. In addition to the coordinates of the end point, the coordinates of the center are specified.

In FIG. 8, the turning direction is indicated by the Z axis.
The X axis indicates the cutting direction of the cutting tool. In this embodiment, the turning direction by the cutting tool is set to the minus direction of the Z axis. Next, the CPU 10 similarly sets the coordinates of each shape element constituting the shape of the material in the external storage device 2.
0 or read from the input device 18 and store it in the memory M2 (step S2). The material dimensions are prepared in advance by actual measurement. For example, the material shape is indicated by a broken line K-
Indicated by N.

Thereafter, the CPU 10 extracts a concave or convex arc element from the read finished shape element in accordance with the preprocessing program, and replaces the arc element with a straight line element. Are stored in the memory M2 (step S3). As specifically shown in FIG. 9, the concave arc element EF, IJ is replaced by a linear element EF, IJ connecting its start and end points, and the convex arc element GH is parallel to the X axis. It is replaced by a straight line element GG ′ that extends and tangent at its start point and a straight line element G′H that extends parallel to the Z axis and tangent at its end point. Therefore,
After the execution of step S, all of the finished shape elements are composed of only linear elements.

Then, the CPU 10 determines whether or not the linear elements obtained by the replacement are arranged on the same straight line as the same finished shape element as the modified finished shape element before and after the replacement (step S4). If the determination result is true (Yes), the finished shape elements are combined, and the coordinates of the combined finished shape elements are stored in the memory M2 (step S5). Specifically, two linear elements FG and GG ′ are one linear element F
G ′, and the two linear elements G′H and HI are also combined into one linear element G′I.

On the other hand, the determination result of step S4 is false (No)
In this case, step S5 is not executed, and thereafter, the number n of the finished shape elements is counted (step S6). Thereafter, the CPU 10 shifts its execution steps from the flow of FIG. 4 to the flow of FIG. 5, and stores the last n-th finished shape element viewed in the turning direction, that is, the end point coordinates of the finished shape element n in the memory M2 (step S7), the element flag is set to “up” (step S8).

Then, the CPU 10 generates a line segment T having the same inclination angle as the glue gradient θ of the bevel cutting tool from the end point of the finished shape element n (step S9), and sets the start point of the finished shape element n to the line segment T. It is determined whether or not it is above (step S
10). If the determination result is false, the element flag is reset to "down" (step S11), and after the element number n is decremented by 1 (step S1).
2), the determination in step S10 is repeated.

Here, as apparent from FIG. 10, the finish shape elements, that is, the starting point J of the element JK and the starting point I of the next element IJ are both below the line segment T. , IJ are both false in step S10, whereas the result of step S10 for the next element G′I is true. in this case,
The CPU 10 determines whether or not the element flag is “up” (step S13), but the determination result here is false. Therefore, the CPU 10 calculates the current finished shape element n, that is, the intersection of the element G′I and the line segment T (step S14), and stores the coordinates of the calculated intersection as the starting point in the memory M.
2 (step S15). Specifically, the intersection in this case is indicated by I ′ in FIG.

Thereafter, the CPU 10 stores the starting point (in this case, G ') of the finished shape element n in the memory M2 (step S16), and sets the element flag to "up" (step S17). Then, the CPU 10 determines the element number n
Is decremented by 1 (step S18), and it is determined whether or not the element number n has reached 0 (step S19).
If the determination result is false, the steps after step S7 are repeated in the same manner, and the intersection and the starting point of the current element are sequentially stored.

When the target finish shape element (element number n = 1) reaches the first element AB at this time, the determination result of step S10 becomes true without executing step S11. , And the next step S
Since the determination result of 13 is also true, the CPU 10 stores the coordinates of the starting point of the finished shape element n in the memory M2 (step S20 in FIG. 6). The starting point coordinates here are the coordinates of A in FIG.

As a result, coordinate data of I ', G', F ', E, D, C', B, and A are stored in the memory M2 starting from K by executing the flow of FIG. After this, step S
When step 18 is executed, the result of the determination in step S19 becomes true, so that the CPU 10 shifts its execution step to the flow of FIG. Here, first, based on the coordinate data stored in the memory M2 by executing the above-described steps S1 and S2, the CPU 10 finishes the finished shape R _f (A → K) and the material shape _Ro (A → N → M) of the turned product. → L → K) (step S21), and the coordinate data which is the execution result of the flow of FIG. 5 described above, that is, K, I ′, G ′, F ′, E, stored in the memory M2. An intermediate finish shape _Ri is calculated based on the coordinate data of D, C ', B, and A (step S2).
2).

Here, as is clear from FIGS. 10 and 11, all the intermediate finish shapes R _i are defined only by linear elements.
Moreover, since the straight line element that does not match the straight line element of the finished shape _{Rf is} a straight line element having the same inclination angle as the glue inclination of the beveled tool, the shape that maximizes the turning range by the beveled tool, that is, the finished shape The shape most approximates to _Rf .

Next, CPU 10 is necessary, by adding the machining allowance amount ΔR an intermediate finish shape R _i, to calculate the intermediate finishing shape R _'i (step S23). Specifically, the allowance ΔR
Is obtained by adding p and q to the coordinates of I ′, G ′, F ′, E, D, C ′, and B in the Z-axis direction and the X-axis direction, respectively.
Then, p is added to the coordinates of K only in the Z-axis direction, and q is added to the coordinates of A only in the X-axis direction. Therefore,
Intermediate finish shape R _'i is in FIG. 11, K', I ", G", F ",
The coordinates are indicated by E ', D', C ", B ', and A'.

[0026] Thereafter, CPU 10 is based on the following equation, the _{S wi = R o -R 'i} S wf = R' i -R f swash rough to be turned using a sword-byte working area S _wi and single-edged bytes The finish machining areas S _wf to be turned using are calculated and stored in the memory M3 (step S24), and the pre-processing routine for turning NC data creation is completed.

[0027] Here, in rough machining area S _wi is 11, it is represented by the hatched region surrounded by between material form R _o and intermediate finishing shape R _'i, then finish machining area S _wf is Figure 1
In 2, it is represented by the hatched region surrounded by between intermediate finish shape R _'i and finish shape R _f. When the rough processing area _Swi and the finish processing area _Swf are obtained as described above,
Next, the CPU 10 automatically creates turning NC data for each of these machining areas based on the creating program in the memory M5, and stores the created result in the memory M6.

Here, the intermediate finish shape R ′ _i that defines the rough machining area _Swi is based on the preprocessing routine as described above.
Because it is determined by independently calculating the material shape R _o, a portion of the intermediate finishing shape R _'i, as shown in FIG. 13, that is, even it is hatched portion as protruded to the outside of the material shape R _o Conceivable. In this case, based on the rough machining area _Swi ,
According to the turning NC data obtained by a known creation program, the turning direction of the bevel tool in the hatched portion is reversed,
It gives a meaningless turning operation to the bevel tool.

In order to avoid such inconveniences, in the present invention, a program for creating turning NC data is improved, and the improved creating program is shown in the routine of FIG. Creation Routine The CPU 10 follows the creation program, and first, the memory M3
The rough machining area _Swi is read from the memory M4 (step S25), and the turning conditions suitable for the rough machining area _Swi , that is, the cutting amount, the feed speed, the cutting direction, and the like of the bevel bit are read from the memory M4 (step S25). S26).

Thereafter, the CPU 10 creates raw turning NC data for the rough machining area _Swi based on the read data and stores it in the memory M6 (step S27).
Then, the CPU 10 executes the debugging process of the raw turning NC data (step S27), and detects the ineffective portion where the cutting amount of the bevel byte becomes negative or the turning direction is reversed in the raw turning NC data. Determine (Step S2
9). If the determination result is true, the invalid portion in the raw turning NC data is corrected (step S30), and this debugging process is repeated until the determination result in step S31 becomes true. The correction of the invalid portion in the raw turning NC data is performed by stopping the cutting at the position of the cut amount.

As described above, according to the pre-processing routine of the present invention, the intermediate finish shape R ′ _i ,
That is, the rough machining area _Swi and the finish machining area _Swf can be easily obtained, and the turning NC data can be automatically created based on these machining areas.

Since the intermediate finish shape R ′ _i is defined only by the linear elements and is most similar to the finish shape R _f ,
Not only is turning with a beveled tool easier,
The rough machining area _Swi can be expanded to the maximum allowable. As a result, the time required for turning the rough machining area _Swi can be significantly reduced, and the turning speed can be increased.

Further, turning NC for the rough machining area _Swi
Since the data does not give an invalid turning operation to the oblique cutting tool, the turning can be effectively performed in the roughing area _Swi , and the turning speed is also increased from this point. The present invention is not limited to the above embodiments, and various modifications are possible.

For example, even if the finished shape of the turning includes a curved element such as an ellipse in addition to the circular arc, the preprocessing method of the present invention can be applied. In this case, the curved element is converted into a plurality of linear elements. Then, the intermediate finish shape is calculated in the same manner. In addition, when the turning NC data of the finishing area is created, the above-described debugging may be performed on the turning NC data.

[0035]

As described above, according to the preprocessing method of the present invention according to the first and second aspects of the present invention (claims 1 and 2) for the method of automatically generating turning NC data, the design drawing of a turned product is provided. Without preparing a drawing to define the rough machining area separately, the intermediate finish shape closest to the finished shape of the turned product is calculated, and based on this intermediate finish shape and its material shape, A rough machining area for the sword tool can be easily and easily obtained. Here, the intermediate finish shape is composed only of linear elements, and the rough machining area defined by this intermediate finish shape is the maximum area where turning with the beveled tool is allowed, so turning with the beveled tool is optimal. The turning speed can be increased while the turning speed can be increased.

Further, according to the pre-processing method of the present invention, in addition to the rough machining area, the finishing machining area can be simultaneously calculated and obtained from the intermediate finishing shape.
According to the turning NC data automatic creation method of the present invention according to claim 4, in the turning NC data created based on the rough machining area or the finishing machining area, the data portion that gives an invalid turning operation to the byte is corrected. Therefore, turning with a cutting tool can be performed more optimally.

[Brief description of the drawings]

FIG. 1 is a view showing a single-edged cutting tool and its turning.

FIG. 2 is a diagram showing a bevel tool and its turning.

FIG. 3 is a schematic diagram showing an automatic creation system for automatically creating turning NC data and executing preprocessing thereof.

FIG. 4 is a part of a flowchart showing a preprocessing routine.

FIG. 5 is a part of a flowchart showing a preprocessing routine.

FIG. 6 is a part of a flowchart showing a preprocessing routine.

FIG. 7 is a part of a flowchart showing a preprocessing routine.

FIG. 8 is a graph showing a material shape and a finished shape of a turned product.

FIG. 9 is a graph showing a finished shape after replacing arc elements in the finished shape with linear elements.

10 is a graph showing an intermediate finish shape in which a part of the linear elements in the finish shape of FIG. 9 is replaced with a linear element having the same inclination angle as the glue gradient of the bevel cutting tool.

FIG. 11 is a graph showing a rough machining area by a bevel cutting tool.

FIG. 12 is a graph showing a finishing area by a single-edged cutting tool.

FIG. 13 is a graph showing an example in which a part of the intermediate finish shape protrudes from the material shape.

FIG. 14 is a flowchart showing a turning NC data automatic creation routine including a debugging process for a rough machining area.

[Explanation of symbols]

 1 single-edged tool 2 beveled tool 10 CPU

Claims (4)

[Claims] 1. A method according to claim 1, wherein the shaping tool can be used for turning based on input information of a shape element that defines a material shape and a finished shape of a turned product, and is closest to the finished shape. Calculate the intermediate finish shape,
Thereafter, a rough processing area between the material shape and the intermediate finish shape is calculated, and a preprocessing method of a turning NC data automatic creation method is characterized. 2. The calculation of the intermediate finish shape includes determining the presence or absence of a non-linear element in the finish shape element, replacing the non-linear element with one or more linear elements, and forming a finish shape consisting of only linear elements. In the straight line element of the finished shape after the correction, it is determined whether there is a part that cannot be turned by the bevel tool in the turning direction, and the part is straightened at the same inclination angle as the glue gradient. 2. The pre-processing method according to claim 1, further comprising the step of sequentially replacing elements. 3. The preprocessing of a turning NC data automatic generation method, further comprising, after calculating the rough processing area, further calculating a finishing processing area between the intermediate finished shape and the finished shape of the turned product. Method. 4. Turning NC data is created based on the machining area according to claim 2 or 3, and thereafter, the created turning NC data is created.
A method for automatically generating turning NC data, comprising determining whether or not there is a data portion indicating an invalid byte movement in the data, and correcting the turning NC data based on a result of the determination.