JPH02242306A - Controller for multi-axis numerical controlled machine tool - Google Patents

Abstract

PURPOSE:To automatically avoid the interference of an object to be worked and a cutter by operating the interval quantity of the cutter and the object to be worked from data of a shape of the object to be worked, a shape of the cutter and a cutting position of the object to be worked. CONSTITUTION:A cutter offset point Pi being a center point of a cutter 11 for cutting a blade face 9 and a cutter vector are derived in advance from a host computer, and these point and vector and blade face design data are inputted to an NC device through a storage medium. In the NC device, a comparing operation with a mesh-like data group for expressing a blade face shape is executed at every one point of the inputted cutter offset point Pi and cutter vector Vi, and whether an interference exists or not is discriminated. In the case when the interference exists, the cutter vector Vi is rotated by a designated angle DELTAtheta in the direction separated from the interference face, and by repeating it until the interference comes not to exist, a new cutter vector Vi is derived.

Description

[Detailed description of the invention] (Object of the invention) (Industrial application field) The present invention relates to a numerical value M11<NC)I machine tool control device,
In particular, the present invention relates to a multi-axis numerically controlled machine tool system for machining three-dimensional free-form surfaces such as water turbine launches.

(Prior art) Conventionally, cutting of objects with three-dimensional free-form surfaces such as the blade surfaces of water turbine runners has been carried out using profiling methods or special machining methods using multi-axis NC machine tools with four or five axes or more. It is done by method.

Copy machining has limitations depending on the shape of the workpiece, and it is difficult to cut while avoiding narrow spaces between blades. In multi-axis NC machine tools, narrow N
In addition to the need to insert the cutter between the surfaces, constant care must be taken to ensure that the cutter does not interfere with adjacent blade surfaces. In practice, cutting experiments are conducted using model blocks and the like to check whether interference occurs between the cutter and the blade surface.

If interference between the adjacent blade surface and the cutter is discovered during cutting, the motion trajectory of each axis of the NC machine tool is determined again.

(Problem to be Solved by the Invention) When cutting a free-form surface such as the rough surface of a water turbine runner using a multi-axis NC machine tool, it is necessary to conduct cutting experiments using a model block, etc., as described above, to ensure that no interference occurs. After confirming the above, actual processing is carried out. Therefore, the actual operating time of the NC machine tool is shortened, which is unfavorable in terms of work efficiency.

Also, when detecting interference between the workpiece and cutter,
In three-axis control, interference can be detected relatively easily using numerical values or drawings. However, when machining a workpiece with a complicated shape, such as a four-sided water turbine launch, it is necessary to perform the machining using multi-axis control. In polyphase control, it is difficult to check for interference from the motion trajectory of each axis, and if interference occurs, it becomes necessary to recalculate the motion trajectory of each axis several times. Therefore, in multi-axis NC machine tools, it has been difficult to accurately grasp interference in advance.

The present invention has been made in consideration of the above circumstances, and can automatically avoid interference between the workpiece and the cutter by calculating the distance υ between the workpiece and the cutter. The purpose of this paper is to improve the work efficiency and reform of numerical control programming (to promote a multi-axis numerical control machine tool control device that can greatly improve the operating efficiency of direct control machine tools).

[Structure of the invention]

(Means for Solving the Problems) The present invention provides an input section into which the external shape of the workpiece, the shape of the cutter, the cutter-off point indicating the cutting position of the workpiece, and the direction of the cutter axis are entered as data. , a storage section that stores those data, and a cutter offset point and a cutter offset point that calculates the distance between the workpiece and the cutter from the stored data, and avoids interference when the cutter interferes with the workpiece. A calculation unit that calculates the cutter axis direction and converts it into the movement amount of each axis of the numerically controlled machine tool, and outputs the movement amount of each axis calculated by the calculation to the machine tool and detects the movement position of each axis. The controller is equipped with a control unit that controls the

(Operation) The external shape of the workpiece, the cutter shape, the cutter offset point indicating the cutting position of the workpiece, and the cutter axis direction are inputted as data from the input part and stored in the storage part.

The calculation unit calculates the distance between the workpiece and the cutter from the stored data, calculates the cutter offset point and cutter axis direction to avoid interference when the cutter interferes with the workpiece, and performs numerical control machining. Convert to motion ω of each axis of the machine.

The control unit outputs the operation amount of each axis determined by the calculation to the numerically controlled machine tool to slow down the operation, and detects the operation position of each axis.

(Embodiment) An embodiment of the multi-axis numerical control machine tool control system δ according to the present invention will be described with reference to the accompanying drawings.

The multi-axis NG machine tool control device 1 receives data such as the external shape of the workpiece, cutter shape, etc. from a storage medium 2 such as a floppy disk.
an input unit 3 for inputting a cutter offset point and a cutter axis direction (cutter vector) indicating the cutting position of the workpiece;
A storage unit 4 stores the input data, a graphic display device 5 visually expresses the input workpiece shape, cutter offset point, etc., and displays the workpiece and cutter P1 from the data stored in the storage unit 4. Calculate the interval m, use the results of this calculation to determine the cutter offset point and cutter vector to avoid interference if the cutter interferes with the workpiece, and calculate the amount of movement of each axis from these data. section 6, and a control section 8 that outputs the operating amount of each axis to the NC machine tool 7 and detects the operating position of each axis.

The NC machine tool 7 has orthogonal coordinate axes (x, y, z) and rotation axes (table, cutter head), inputs control signals from the control unit 8 to operate each axis, and operates the cutter to cut the workpiece. It is designed to process workpieces.

Note that the storage unit 4 includes a first storage unit that stores the external shape of the workpiece.
It consists of a storage section 4a, a second storage section 4b that stores cutter shapes, and a third storage section 4C that stores cutter offset points and cutter vectors.

Next, the multi-axis NC machine tool control device 1 will be roughly described in detail along FIG. 2 and with reference to FIGS. 3 to 6.

When using the NC machine tool 7 to cut a model Francis runner 10 having ten or more blade surfaces 9 as shown in FIG. Cutter offset point P1 which is the center point
and cutter vector v1.

Then, the cutter offset point P1, cutter vector Via, and the wing surface design data Q of the model Francis runner 10 (Figs. 4 and 5 ) are stored in the storage medium 2, and the input section 3 of the multi-axis NC machine tool control device 1 inputs these data from the storage medium 2, and stores them in the storage section 4 (step 1).

Next, the input cutter offset point P1 and all the cutter vector points 1iJ are compared with the mesh-like data group Q expressing the shape of the model Francis runner blade surface. The processing procedure is to perform coordinate transformation for one blade on either the front side or compliment side of Francis runner N side 9 (1)
This is done using the formula.

Then, cutter offset point P1 and cutter vector v1
Calculate the interference between For example, if cutter offset 1-point Pi1 cutter vector Vi, blade surface design data Qi, cutter neck diameter OR, and cutter inclination angle α are (2) 2 to (8
), the distance ΔD between the cutter 11 and the model Francis runner blade surface 8 is determined. Such arithmetic processing is performed for all points on the blade surface on the outer shape side from the cutoff fret point Pi (step 2). The interval amount Δ found here
If D is larger than a pre-designated margin, it is determined that no interference occurs, and if D is smaller than that, it is determined that interference is occurring.

[Margin below]

■ i (i, j, k) ■ i'(i', ”, k')
= i umbrella cos(Δ θ ) −j *
5in(Δθ)j' = is 5in(
Δ θ ) + j * cos(Δ θ )
Here, 〇=360/Number of blades AL=IQi-Pit...(2)
VP-(Qi-Pi)/IQi-Pi cos(θD) -V is vp
-(4)AV=AL-cos(θp)
＋＋＋＋ (5)AD=! = 7...
...(6) DD=DR+ (AV-CR)-ta
n(cr＞・・・・・・(7) ΔD=AD−DD ・・・・・・
(8) If interference occurs, cutter offset point P
Since it is known from the computational ci results whether the interference position is on the surface 4 or the surface, the cutter vector v1 is moved away from the interfered surface by a specified angle Δθ, as shown in FIGS. 6(A) and (B). This is avoided by performing rotation conversion using equation (1) (step 3). The new Katsutabek i obtained by rotation transformation
The interference check calculation between the blade surface 9 and the cutter 10 is performed again using the rule V Hr, and the calculation is repeated until there is no interference.

The above processing is performed for all the cutter vector points to obtain a cutter vector vi' without interference, and interference is automatically avoided.

Once the interference is eliminated, the NC post-processor adjusts each axis of the NC machine tool (tI orthogonal coordinate axis X.

y, z, table rotation axis, cutter head axis) into operation components (step 4).

After that, the model Francis runner 1 was created using the NC machine tool 7.
0 cutting is performed (step 5).

In addition, the operation system of the NC machine tool and the cutter offset point Pi
, Cutter Plane 1 to Vi differs depending on the configuration of the NC machine tool, so an NC post-processor corresponding to the configuration of the target NC machine tool is used.

In this way, according to the above embodiment, it is possible to automatically avoid interference with the cutter over the entire cutting area of the workpiece, so that the troublesome interference check work can be omitted, and the NC Programming becomes easier.

Furthermore, since it can be confirmed that no interference occurs, there is no need to conduct cutting experiments using model blocks, etc., and the actual operating rate of the NC machine tool is improved. Furthermore, damage to the workpiece 711 and breakage of the cutter due to interference between the cutter and the workpiece can be prevented.

〔Effect of the invention〕

The present invention includes an input section for inputting data including the outer shape of a workpiece, a cutter shape, a cutter offset point i/point indicating a cutting position of the workpiece, and a cutter axis direction, a storage section for storing these data, and a storage section for storing the data. From this data, calculate the distance m between the workpiece and the cutter, find the cutter offset point and cutter axis direction to avoid interference when the cutter interferes with the workpiece, and calculate the cutter offset point and cutter axis direction for each axis of the numerically controlled machine tool. Since the calculation part that converts the motion into the motion ω of can be avoided, the number 1IilIII
The programming work efficiency and the operating efficiency of numerically controlled machine tools can be greatly improved.

[Brief Description of the Drawings] Fig. 1 is a block diagram showing an embodiment of a multi-axis numerically controlled machine tool control device according to the present invention, and Fig. 2 is a flowchart for explaining the above embodiment)! - Fig. 3 is a configuration diagram showing the model Francis runner guide and cutter in the above embodiment, Fig. 4 is a diagram showing mesh-like design data on the model Francis runner wing surface in the above embodiment, Fig. 5 (
A), (L3) (C), Figures 6 (A) and (B) show the cutter vector and model Francis runner W in the above embodiment.
FIG. 6 is a diagram for explaining interference value calculation and interference avoidance calculation with a surface. DESCRIPTION OF SYMBOLS 1... Multi-axis numerical control machine tool control device, 2... Storage medium, 3... Input section, 4... Storage section, 5... Graphic display device, 6... Arithmetic section, 7 ... Numerical control machine tool, 8... Control section.

Claims (1)

[Claims] An input section for inputting the external shape of the workpiece, cutter shape, cutter offset point indicating the cutting position of the workpiece, and cutter axis direction as data, a storage section for storing these data, and a storage section for inputting the workpiece from the stored data. Calculate the distance between the object and the cutter, find the cutter offset point and cutter axis direction to avoid interference when the cutter interferes with the workpiece, and convert it into the amount of movement of each axis of the numerically controlled machine tool. A multi-axis numerical control machine tool control device, comprising: a calculation unit that outputs the operation amount of each axis determined by the calculation to the numerical control machine tool, and a control unit that detects the operation position of each axis. .