JPH02232142A - Tilt spindle control method and device thereof - Google Patents

Abstract

PURPOSE:To perform work in a wide range with a work program facilitated in its preparation by generating a work command in rectangular coordinates by a function on the rectangular coordinates, converting a command position on the rectangular coordinates one after another into a command position on oblique coordinates and performing a position control of the oblique coordinates for a tilt spindle. CONSTITUTION:By a command SA from a control panel 1, a work program control part 2 edits and transfers a work program SB stored in a work program memory part 3. A work program analytic part 5 analyzes this work program SC transferring information SD of kind or the like of interpolation function to a rectangular coordinate system interpolation control part 6. The control part 6, synchronizing with a signal SE generated by a timing signal generating part 7, executes functional interpolation in accordance with the information SD, calculating a rectangular coordinate system interpolation position SF. A converter part 8 converts the rectangular coordinate system interpolation position SF into an oblique coordinate system interpolation position SG. A spindle drive control device 9, synchronizing with the timing signal SE, controls driving motors 10, 11 of grindstone spindle and main spindle in accordance with the interpolation position SG.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is characterized in that a tool is movable in two independent axes relative to a workpiece, and that the two axes intersect at an angle other than 90 degrees. The present invention relates to a control method and device for a numerically controlled machine tool having an inclined shaft system installed in such a manner that the machine tool is tilted.

(Prior art) As an example of a numerically controlled machine tool with an inclined axis system,
There has been an angle slide type grinding machine that can be equipped with a large-diameter grindstone in order to efficiently grind the circumferential surface and edges of the workpiece and to save the trouble of replacing the grindstone. It is shown in Figure 3. As is clear from FIG. 3, the work table 23 on which the workpiece 24 is attached is movable in the main axis (Z. axis) direction with respect to the bed 2G, and
The whetstone stand 22 to which l is attached is movable in the whetstone axis (x.) direction with respect to the bed 20, and the whetstone axis (2. axis axis) and the whetstone axis glaze j! (X.axis axes) intersect at an angle other than 90 degrees. In other words, the z1-axis and the x1-axis form an oblique coordinate system. By the way, it is extremely difficult to create a machining program for a machine with this kind of structure. This is because although all information such as dimensions on the machining drawings are values in the orthogonal coordinate system, the machining program needs to be created in the oblique coordinate system.

The coordinate system in Figure 4 is the orthogonal coordinate system of the processing drawing
The oblique coordinate system of the angle slide type grinding machine is indicated by X. axis and z. , and the xa axis is
It is inclined at an angle θ with respect to the glaze.

Here, consider a case where the grinding wheel 2l is moved from point P to point P relative to the workpiece 24. As shown in Figure 5 (A), the position of point P1 in the orthogonal coordinate system is (X, +.Zp
+), the position of point P2 is (xp2, zpz), the position of point P1 in the oblique coordinate system is (x-p+.z-p+) as shown in the same figure (B), and the position of point P2 is (Xa
pz, Zapz) +! = do. Figures 5 (8) and (B
), in most cases, the data on the machining drawing cannot be used as is to create the machining program. As a means to solve these problems, a machining program created using an orthogonal coordinate system,
There is a method of automatically converting machining commands on an oblique coordinate system within a numerical control device. The method will be explained below.

FIG. 6 shows an example of a device that implements the method, and its operation will be explained with reference to the flowcharts in FIGS. 7(^) to (C).

The machining program conversion unit 3o in the numerical control device 33 converts the machining program SJ created in the orthogonal coordinate system into a seventh
The process shown in the flowchart in FIG. The interpolation control unit 3l performs a process as shown in FIG.
The process shown in the flowchart B) is executed to perform interpolation control (step 526), and the interpolation position Sl at each predetermined time is determined (steps S27 and 528). Axis drive control section 34
Similarly, in synchronization with the timing signal SE from the timing signal generator 32, drive control of the drive motors 10 and 11 of the xIidl and Z-axes is performed according to the interpolated position Sl.
Step S29》. The important point here is the processing in the machining program converter 30, and the processing will be explained according to the flowchart of FIG. 7(A). First, one block of the orthogonal coordinate system machining program SJ is read (step 520).
, the conversion shown in the following equations (3) to (6) is executed to convert into a machining command 511 for oblique rectangular drift (step 521).

Xan = Xn/cos&・・・・・・(3) Zan − Zn-1/2・(Xn-tanθ)
---... (4)...(6) Here, Xo,)! n. F and t are the X-axis movement amount and Z!, respectively, according to commands in the machining program of the orthogonal coordinate system. IIl
b is the movement amount, feed speed, and time required for execution, and the fifth
In the case of figure (Δ), it is.

Also, X...Z... determined by equations (31 to (6))
．． Fa is the amount of X-axis displacement in the oblique coordinate system. Z@travel amount. In the case of FIG. 5(B), it is the feed rate. Furthermore, the X axis. The x, axis is the diameter command value, usually indicated by the diameter of the workpiece. The above conversion is executed until the function interpolation is completed and the target position is reached (step S24), and is further repeated until the entire machining program SJ is completed (step S24).
25).

FIG. 8(A) is an example of a machining program SJ created using an orthogonal coordinate system.
Since it is automatically converted into the machining command Sl[in the orthogonal coordinate system as shown in FIG.

(Problems to be Solved by the Invention) Generally, numerical control devices have interpolation functions for multiple types of functions, such as linear interpolation, circular interpolation, and parabolic interpolation.

The problem here is that the method described above can only be used in cases where the transformation from the orthogonal coordinate system to the oblique coordinate system results in a rainbow, a function of the same type. For example, a straight line can be expressed as ax + by + c - Q in either orthogonal or oblique coordinates.
= (9) (a, b, c
; constant) can be expressed as the same function, and the method described above can be used. On the other hand, a circular arc on Cartesian coordinates is (x-a) '+ (y-b) '-c2-・- ・・
(to), but in the oblique coordinate system the above (l
O) The function expressed by the formula is not an arc. Therefore, if you want to perform contour control, you can only give commands using linear approximation, making it virtually impossible to create a machining program. The drawback was that it was almost impossible to use.

In summary, in an angle slide type cylindrical grinding machine equipped with a large outer diameter angle grinding wheel, the workpiece movement east - (Z@)
and the movement axis (X-axis) of the grindstone form an oblique coordinate system that intersects at an angle other than 90 degrees. Since the numerical values written in the work drawing are in the orthogonal coordinate system, in order to create a machining command (machining program) in the oblique coordinate system based on them,
It takes a lot of time and effort. In order to solve this problem, the machining command created in the orthogonal coordinate system is moved along the X axisff
l. Z-axis 15 vJ; ft. Performs feed rate correction conversion, and calculates X@travel amount and Z@travel amount corresponding to the oblique coordinate system.
Send. There was a method to determine and control the speed. This has the advantage that it can be converted at the numerical control program level without changing the function generation method within the control device.
Basically, only linear interpolation, where the type of function does not change even when converting from orthogonal coordinates to oblique coordinates, was supported.

The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to utilize all the function interpolation functions realized in a Cartesian coordinate system in controlling a numerically controlled machine tool having an inclined axis system. The purpose of this invention is to provide a tilt axis control method and device that makes it possible. (Means for Solving the Problems) The present invention relates to a tilt axis control system, and the above object of the present invention is to enable a tool to move in two independent axes relative to a workpiece, and to In an inclined axis control method for a numerically controlled machine tool having an inclined axis system installed so that the two intersect at an angle other than 90 degrees, a machining command in an orthogonal coordinate system is generated as a function on the orthogonal coordinate, and the orthogonal coordinate Convert the sequential command position above to the sequential command position on the oblique coordinates,
This is achieved by controlling the position of the oblique coordinates with respect to the tilt axis. The tilt axis control device also includes a machining program analysis means that analyzes a machining program command created in a Cartesian coordinate system and determines the type of interpolation function and other information necessary for interpolation of the function; An orthogonal coordinate system function interpolation means interpolates the function determined by and calculates the interpolated position of each axis at each predetermined time interval. The control device of the numerically controlled machine tool is provided with a converting means for converting the orthogonal coordinate system into an oblique keyaki system interpolation position corresponding to the orthogonal coordinate system, and the machining program analysis means, This is achieved by driving and controlling each axis according to the oblique coordinate system interpolation position obtained by the orthogonal coordinate system function interpolation means and the conversion means.

(Function) In general, the interpolation control unit 3l moves a specified movement path at a specified feed rate by moving the specified movement path at a specified feed rate based on the type of function commanded by the machining program SJ and other information necessary for generation of the function.
The position of each axis at each predetermined time when at, is calculated as the interpolated position. That is, the function is approximated by successive interpolation positions. This is the same for any type of function; in other words, only the interpolated position of each axis is output from the interpolation control unit 3l regardless of the type of function. The present invention focuses on this point, and since the tilted glaze control method of the present invention executes function interpolation in an orthogonal coordinate system,
In principle, it can be used for all kinds of functions realized in orthogonal coordinate systems, and it is only necessary to transform the interpolated position of each axis after function interpolation, and the information to be transformed is minimal. , each axis forming the oblique coordinate system can be driven and controlled by a machining program created in the orthogonal coordinate system. In the conventional technology, the machining program commands are parsed block by block and coordinate conversion processing is performed. In other words, processing is performed in which a machining command in an orthogonal coordinate system is converted into a machining command in an oblique coordinate system, and a position on the oblique coordinate is controlled by generating a function in an oblique coordinate system.

Here, in the present invention, we focus on the fact that the sequential command position obtained after the generation of a function is a value at fixed time intervals and does not include information such as feed rate information or function type, and convert the machining command in the orthogonal coordinate system into orthogonal coordinates. The position is generated by the above function, and the sequentially commanded position on the orthogonal coordinates is converted into the sequentially commanded position on the oblique position, thereby performing position control on the oblique coordinates. CPU! Although the A filling time is longer, it is not a big problem due to recent advances in hardware such as faster CPUs. The object of conversion is only the command position of each axis, and it can correspond to all functions on orthogonal coordinates.Furthermore, as long as the coordinate conversion formula is given, the method of the present invention can be applied to machines forming any coordinate system. is also applicable.

(Example) FIG. 1 is a block diagram showing an example of a control device that implements the tilted glaze control method of the present invention. This control device 4 edits the machining program S8 stored in the machining program storage section 3 in response to a command S^ from the operation panel 1 equipped with a display device (CIIT). Analyzes the machining program control unit 2 to be transferred and the machining program SC transferred from the machining program control unit 2, and obtains the type of interpolation function instructed to the machining program SC and other information SO required for interpolation of the function. The machining program analysis section 5 transfers to the orthogonal coordinate system interpolation control section 6 and the timing signal generation section 7 generates signals SE every predetermined time. An orthogonal coordinate system interpolation control section 6 executes function interpolation according to other information SD and calculates an orthogonal coordinate system interpolated position SF synchronized with a signal SE at predetermined time intervals, and an orthogonal coordinate system interpolation control section 6 that calculates an orthogonal coordinate system interpolated position SF by oblique coordinate system interpolation. The shaft drive control device 9 drives the grindstone shaft (X-axis) in synchronization with the timing signal SE from the control device 4 in accordance with the oblique seat keyaki system interpolation position SG. The motor 1O and the main shaft (Z-axis) drive motor 11 are driven and controlled.

In such a configuration, its operation is shown in Figures 2 (A) to (C).
) will be explained with reference to the flowchart. Here, the second
Figure (8) shows the operation of the machining program control unit 2 and the machining program analysis unit 5, Figure 2 (6) shows the operation of the orthogonal coordinate system interpolation control unit 6 and the conversion unit 8, and Figure 2 (C) is I
This figure shows the operation of the IIll drive control device 9.
Each of the operations B) and (C) is executed only once every predetermined time in synchronization with the timing signal SE.

First, the operation shown in Figure 2 (8) will be explained. The machining program control section 2 reads one block of machining program from the program storage section 3 (step S1), and the machining program analysis section 5 determines the type of function instructed by the machining program (step S2). ), and other information necessary for interpolation of the function is also determined (step S3). For example, in the case of the machining program shown in Figure 8 (A), the function type is a straight line, and the other information necessary for function generation is
Glaze target position Xp2. Z-axis target position ZP2 + feed speed f
There is. After determining the information necessary for the interpolation of the function, the interpolation of the function is completed and the target positions itxp2, Zp
Wait until the number reaches 2 (step S4). When the interpolation is completed, it is determined whether the machining program is finished or not in step S5.
), if there is a next block, the process returns to step Sl, and the above operation is repeated until the end of the machining program.

On the other hand, in the flow shown in FIG. 2 (IN), the orthogonal coordinate system interpolation control unit 6 uses the leap number type determined in steps S2 and S3 described above. Function interpolation is performed using other information necessary for function interpolation (step S6), and the orthogonal coordinate system interpolation positions X, Z, at that timing are determined. next,
In the conversion unit 8, the orthogonal coordinate system interpolated position Xi,
Z. are converted into oblique coordinate system interpolated positions Xai, Zal (step 57, S8).

Xil − X+/(L cosθ)
・−・・−(11)11=ZI−(X./2)
・tanθ ・−・−・・(12) These (
Equations (11) and (12) are equivalent to (3) and (4) explained in the prior art.
), which was conventionally used (5),
Equation (li) is unnecessary in the method of the present invention. Next, the orthogonal coordinate system interpolated positions XI, Z obtained in step S6 above are
l and the target value xP2+Zl12 to determine whether or not to terminate the function compensation (step S9). If the orthogonal coordinate system interpolation position X,,Z, has reached the target value Xe2rZp2, the The completion of the function interpolation is notified to step S4 in FIG.
Repeat step 8.

In addition, the flow of FIG. 2(C) is such that the drive control device 9 operates the X-axis and Z-axis drive motors l1 and 12 according to the oblique coordinate system interpolated positions x1 and 2.1 obtained in steps S7 and S8 above. The timing signal S
It is executed in synchronization with H (step S11).

Although the present invention has been described above using an angle slide type grinder as an example, it goes without saying that the present invention can also be applied to other numerically controlled machine tools having an inclined shaft system.

(Effects of the Invention) As described above, with the tilted axis control method of the present invention, it is possible to create a machining program for controlling an angle slide type grinder having an inclined axis system in an orthogonal coordinate system, and Since it is possible to use all the functions realized in the locus v4 system, it is easy to create a processed brochure, and it is possible to perform a wide range of processing including contour control. Furthermore, in principle, the present invention can be applied to a machine tool having any coordinate system, if a coordinate transformation formula is given, (8)
, (It may be possible to apply Equation 91 by using it as its coordinate transformation equation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a control device that realizes the tilted glaze control method of the present invention, FIG. FIG. 4 is a structural diagram for explaining an example of an angle slide type grinder, and FIG. ) is a diagram for explaining the orthogonal coordinate system, FIG. 6 is a block diagram showing an example of a conventional control device, FIG. ) to (C) are flowcharts showing examples of its operation, and FIG. Figure 1 and CB) are diagrams showing an example of the modified program 1 after conversion. ]...Operation panel, 2...Machining program control section, 3.
...Machining program storage unit, 4...Control device, 5...
- Machining program analysis section, 6... Cartesian coordinate system interpolation control section, 7... Timing {g number generation section, 8... Conversion section, 9... Axis drive control device, lO... Grinding wheel axis (X axis)
Drive motor, 11... Main shaft (Z-axis) drive motor, 20
... Bed, 2l... Grinding wheel, 22... Grinding wheel stand,
23... Work table, 24... Workpiece, 30
... machining program conversion section, 31... interpolation control section,
32... Timing No. 3 generator, 33... Numerical control device, 34... Shaft drive control device.

Claims (1)

[Claims] 1. A tool is movable in two independent axes relative to a workpiece, and an inclined axis system is installed such that the two axes intersect at an angle other than 90 degrees. In a tilt axis control method for a numerically controlled machine tool with A tilt axis control method, characterized in that the position of the oblique coordinates with respect to the axis is controlled. 2. In a numerically controlled machine tool having an inclined axis system in which the tool is movable in two independent axes relative to the workpiece, and the two axes are installed so that they intersect at an angle other than 90 degrees. In the tilt axis control device, a machining program analysis means that analyzes a machining program command created in an orthogonal coordinate system in which the two axes are perpendicular to each other, and determines a type of interpolation function and information necessary for interpolation of the function; orthogonal coordinate system function interpolation means that executes interpolation of the interpolation function determined by the program analysis means and calculates the position of each axis at each predetermined time; A converting means for converting a position in an orthogonal coordinate system to a position in an oblique coordinate system corresponding to an inclined axis system is provided in the control device of the numerically controlled machine tool, and the machining is performed in accordance with a machining program command issued in the orthogonal coordinate system. program analysis means,
A tilt axis control device characterized in that each axis is driven and controlled according to an oblique coordinate system position obtained by an orthogonal coordinate system function interpolation means and a conversion means.