JPH08106311A - Numerical controller - Google Patents

Abstract

PURPOSE: To perform continuous machining outside the movable range of a machine by controlling synchronism with a rotary coordinate system when a movement quantity of each axis exceeds the movable range of the axis without modifying a program on an orthogonal coordinate system. CONSTITUTION: This numerical controller is equipped with an analyzing means which analyzes the machining program 1 on the orthogonal coordinate system, a movement quantity calculating means 3 which finds the movement quantities of the respective axes according to the program, a movable range storage means 4 which stores the movable range determined by the machine in use, a signal generating means 5 which generates a synchronous machining mode signal when the movable range is exceeded, and a synchronism control means 6 which controls the position relation between a work and a tool by bringing one axis or two axes of the orthogonal coordinate system and a C axis as the axis of rotation of a turntable under synchronous control in synchronous machining mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerical value having a function of realizing movement of two linear axes or three linear axes in a machine tool such as a machining center having a turntable by one linear axis or two linear axes and one rotary axis. The present invention relates to a control device. The present invention also relates to a numerical control device for controlling a machine tool arranged so that two linear axes intersect at an angle other than 90 degrees.

[0002]

2. Description of the Related Art FIG. 13 is a view showing a relationship between a processing head, a turntable and a work in a general machine,
(A) is a side view thereof, (b) is a plan view showing a workpiece in an initial state in which the C axis, which is the rotation axis of the turntable, is not rotated, and (c) is a plane showing the workpiece in which the C axis is rotated 180 degrees. It is a figure. In the figure, 7 is a turntable,
8 is a work, 9 is a tool, 12 is a spindle, 13 is a first tool path, 14 is a second tool path, and P1 to P6 are processing points. As shown in FIG. 13A, a machine generally has a limited movable range due to its structure. FIG. 14 is a flowchart showing a machining procedure by a machining program when machining the first tool path 13 and the second tool path 14 in such a machine.

In FIG. 14, the tool 9 is selected in step 1, and the spindle 12 is rotated in step 2. Step 3
The coordinate system for machining the first tool path 13 is set with, the tool 9 is moved to P1 on the XY coordinate system in step 4, and step 5 is executed.
The tool 9 is cut in the Z-axis direction with. In step 6, the work 8 is machined from P1 to P2, P3, P4 on the XY coordinate system, and in step 7, a Z-axis direction command is issued to separate the tool 9 from the work 8 once.

If the turntable 7 is provided, the turntable 7 is rotated 180 degrees in step 8, the coordinate system for machining the second tool path 14 is set in step 9, and P4 on the XY coordinate system is set in step 10. And the tool 9 is cut in the Z-axis direction in step 11. Step 1
In step 2, the work 8 is machined from P4 to P5, P6, P1 on the XY coordinate system, and in step 13, a command in the Z-axis direction is issued to separate the tool 9 from the work 8. Finally, in step 14, the spindle 12 is stopped.

If the turntable 7 is not provided, the work 8 is reattached and P4 to P5, P6, P
The work 8 was processed up to 1.

[0006]

According to the above-mentioned prior art, there is a drawback that machining outside the movable range of the machine cannot be continuously performed. Therefore, JP-A-53-11
As disclosed in Japanese Patent No. 3978, there is proposed a technique capable of approximately performing linear cutting that does not pass through the center of rotation of a rotary shaft, but with this technique, machining outside the movable range of the machine is continuously performed. In order to do so, you can set the coordinate system many times, divide the program, specify the angle of the line segment (only a straight line is possible), etc. It had the drawback of having to create another program. In addition, Japanese Patent Publication 5-980
As seen in Japanese Patent Publication No. 3, a technique has been proposed in which a table on which a work is placed and a tool rest that holds a tool are moved relative to each other so as to efficiently achieve contour cutting of the work. If this machine is used to continuously perform machining outside the movable range of the machine, the precision near the center will drop when cutting through the center of the rotary axis, making it particularly difficult to apply to machining centers. was there.

Further, in a numerical control device for controlling a machine tool arranged so that two linear axes intersect at an angle other than 90 degrees, a virtual straight line orthogonal to one of the two linear axes described above. When controlling the movement command and the speed command on the axis, the movement amount and the feed speed are calculated using the trigonometric function based on the intersection angle between the two linear axes and the command on the virtual linear axis. Due to the calculation error, the error of the calculated movement amount and feed rate increases as the command on the virtual linear axis increases, and the physical movement of each axis is possible due to the intersection angle of the two linear axes. Although the range changes, there is a drawback that there is no means for automatically calculating this movable range.

According to the present invention, when the moving amount of each axis exceeds the movable range of each axis without changing the machining program on the rectangular coordinate system, the movable range of the machine is controlled by synchronizing with the rotating coordinate system. An object of the present invention is to provide a numerical control device capable of continuously performing external machining.

Further, according to the present invention, in a numerical controller for controlling a machine tool arranged such that two linear axes intersect at an angle other than 90 degrees, a virtual axis orthogonal to one of the two linear axes. When controlling the movement command and the speed command on the linear axis, the ratio of the lengths of the sides of the right triangle formed by the virtual axis and the two linear axes is used to reduce the error at the time of conversion. An object is to provide a numerical control device.

A further object of the present invention is to provide a numerical controller capable of automatically checking the movable range on the two linear axes which changes according to the intersection angle of the two linear axes. .

[0011]

A numerical controller according to the present invention is a numerical controller for controlling a machine tool having a turntable for mounting a work and rotating the work, and a tool for machining the work. Analyzing means for obtaining the target position, feed rate, etc. from the machining program on the Cartesian coordinate system, and the moving amount of each axis per unit time is calculated based on the data obtained by the analyzing means, and the moving amount is further accumulated. A movement amount calculation means for storing the current position, a movement range storage means for storing the movement range of each axis determined by the machine tool used, and synchronization when the movement amount of each axis exceeds the movement range of each axis Based on the signal generating means for generating the processing mode signal and the synchronous processing mode signal output from the signal generating means, the portion beyond the movable range is set to 1 in the orthogonal coordinate system.
A synchronous control means for synchronously controlling the two or more axes and the C axis, which is the rotary axis of the turntable, to control the positional relationship between the work and the tool is provided.

Further, the numerical control device according to the present invention is a numerical control device for controlling a machine tool arranged so that the two linear axes intersect at an angle other than 90 degrees, and among the two linear axes. It is provided with a movement amount conversion means for proportionally converting a movement command on an orthogonal coordinate system formed by one axis and an imaginary linear axis orthogonal thereto to the amount of movement of the two linear axes.

Further, the numerical control device according to the present invention is a numerical control device for controlling a machine tool arranged so that two linear axes intersect at an angle other than 90 degrees. It is provided with speed conversion means for proportionally converting a feed speed command on an orthogonal coordinate system made up of one axis and an imaginary linear axis orthogonal thereto to the above-mentioned feed rates of the two linear axes.

Further, the numerical controller according to the present invention is provided with a stroke check means for checking a movable range on the two linear axes which changes according to an intersection angle of the two linear axes.

[0015]

According to the numerical controller of the present invention, during the execution of the machining program on the Cartesian coordinate system, the movement amount of each axis per unit time is added to the cumulative value of the movement amount, and that value is moved. When the range is exceeded, by synchronously controlling the rotary shaft, machining outside the movable range of the machine can be continuously performed.

Further, according to the numerical controller of the present invention, the ratio of the lengths of the sides of the right triangle formed by the virtual linear axis and the two linear axes intersecting at an angle other than 90 degrees is used as a parameter. It is possible to set and set the movement command and the speed command given on the virtual linear axis to the two linear axes by the above parameters to obtain the movement amount and the feed rate.

Further, according to the numerical controller of the present invention,
It is possible to check whether or not the obtained movement amount is within the movable range of movement on the two linear axes that changes according to the intersection angle of the two linear axes.

[0018]

【Example】

Example 1. Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall configuration diagram of the numerical control device. 1 is a machining program on a Cartesian coordinate system created by a programmer, 2 is an analysis unit that analyzes the machining program 1, 3 is a movement amount calculation unit that obtains a movement amount based on the data analyzed by the analysis unit 2, and 17 is machining. An automatic input unit for inputting the movable range of each axis on the Cartesian coordinate system from the program 1, 4 is a movable range storing unit for storing the movable range, and 5 is a movable range storing the moving amount calculated by the moving amount calculating unit 3. A signal generating section for generating a synchronous machining mode signal when the movable range stored in the section 4 is exceeded, and 6 is a turntable having one linear axis or two linear axes and a work 8 attached when a signal is generated by the signal generating section 5. 7 is a synchronization control unit that controls the synchronization with 7.

Next, the operation of the above configuration will be described with reference to FIG. The processing program 1 is read by the analysis unit 2 in step 101. The analysis unit 2 stores subsequent data in a predetermined memory according to addresses such as X and Y forming the program block of the machining program 1, and prepares a command (G command) indicating processing contents such as straight line and circular arc.
Analyze the above data according to.

The automatic input unit 17 obtains the movable range data of each axis on the rectangular coordinate system output from the analysis unit 2 in step 103.
Then, the necessary number of axes is input to the movable range storage unit 4.

In step 104, the movement amount calculation unit 3 calculates the movement amount per unit time of each movement axis from the data such as the target position and feed rate output from the analysis unit 2. Further, the movement amount is accumulated and the current position is stored.

In step 105, the signal generator 5 executes the movement amount output from the movement amount calculation unit 3 to determine whether or not the movement range stored in the movement range storage unit 4 is exceeded.
In addition, whether or not the target position output from the analysis unit 2 exceeds the movable range is arbitrarily selected and checked.

In step 106, the check result is Yes.
If it is determined (over), the process proceeds to step 107 to generate a synchronous machining mode signal and output it to the synchronous control unit 6. The synchronous control unit 6 converts the moving amount of one of the linear axes into a rotation angle based on the synchronous machining mode signal and the moving amount input from the signal generating unit 5, and synchronously controls the linear axis and the rotating axis. The movement data is output to a servo mechanism (not shown) to drive a motor attached to the machine to rotate the turntable 7.

No in step 106 (does not exceed)
When it is determined that the synchronous machining mode signal is not output from the signal generator 5 in the synchronous controller 6, the synchronous controller 6 outputs the movement data between the linear axes to a servo mechanism (not shown). , Drives the motor attached to the machine to move the turntable 7.

Here, each axis on the Cartesian coordinate system (X axis, Y
Axis, Z-axis) exceeds the movable range, turntable 7
A synchronous control unit (hereinafter, referred to as table rotation processing) 6 that performs the same movement control as the movement obtained by the movement amount calculation unit 3 by rotating the will be described in detail with reference to FIG. Here, the horizontal axis of the figure is the X axis, the vertical axis is the Y axis, and the line segment given by the coordinate value on the X axis and the coordinate value on the Y axis is the coordinate value on the Y axis and the rotation angle of the turntable 7. It shall be converted into and processed.

As shown in FIG. 3, the movement amount per unit time obtained by the movement amount calculation unit 3 is a line segment AB, the rotation center of the turntable 7 is D, and the coordinate values of points A and B are (Ax). , Ay), (Bx, By), and the length of the line segment BD is L. To move the point A to the point B without moving the X axis, the turntable 7 may be rotated by θ and the Y axis may be moved from the point A to the point C. The movement amount Ymove of the Y axis from the point A to the point C is obtained by the equation 1.

Ymove = ((L × L−Ax × Ax) ^1/2 ) −Ay (Equation 1) If the coordinates of the point C obtained above are (Cx, Cy), θ is an equation Required from 2.

Bx × Cx + By × Cy = L × L × cos θ (Equation 2)

Thus, the line segment given by the coordinate value on the X axis and the coordinate value on the Y axis is converted into the coordinate value on the Y axis (or X
This can be realized by moving the turntable 7 and the coordinate value on the axis). Also, in the case of the circular arc 10 in FIG. 4, since the movement amount per unit time is given by a group of minute straight lines 11, it can be realized by the same formula.

Next, the programming procedure according to the present invention will be described with reference to FIG. An example of machining the first tool path 13 and the second tool path 14 of FIG. 13 will be given. First step 11
The tool 9 is selected at 0, and the spindle 12 is rotated at step 111. Set the coordinate system in step 112, then step 1
The XY axis is moved to P1 at 13, the Z axis is cut at P1 at step 114, and P1-P2-P3- at step 115.
Process P4-P5-P6-P1. And step 1
The Z axis is separated from the work 8 at 16, and the spindle 12 is stopped at step 117. Here, as shown in FIG.
6A, P1-P2-P3-P4 is processed along the XY axes, and P4-P5-P6 is processed as shown in FIG. 6B.
-P1 is processed while rotating the turntable 7.

Embodiment 2 FIG. Next, a second embodiment will be described with reference to FIGS. 1 and 7. In FIG. 1, 15 is a display / operation board, 16 is manual input means for manually inputting the movable range of each axis on the Cartesian coordinate system, 18 is a movable range setting check unit for checking whether the movable range is set, 19 Is a warning signal generator that generates a warning signal when the movable range is not set. This will be described below with reference to FIG. However, the same parts as in FIG. 2 are omitted. The movable range setting check unit 18 reads the stored contents of the movable range storage unit 4 in step 205 and checks whether or not the movable range is set / stored.

If the above check result is judged in step 206 and "No", that is, if the movable range is not stored or set, the process proceeds to step 207, where the warning signal generator 19 outputs a warning stop signal, The signal is input to the display / operation board 15, the output of the movement amount is stopped, and the machine is stopped.

The display / operation board 15 displays a warning stop state by the warning stop signal input from the warning signal generator 19 and waits for the operator's operation.

When the operator recognizes that the warning is stopped and operates the display / operation board 15 to input the movable range (step 208), the movable range is stored in the movable range storage section 4 by the manual input section 16. It is written in a predetermined memory.

The warning stop state is canceled by the operator inputting the movable range, and in step 206, "Yes
It is determined to be “s” (setting exists), and the process proceeds to step 209. After step 209, the same processing as that of FIG. 2 in the first embodiment is performed, and if the movable range is exceeded, processing is performed only by the linear axis, and if the movable range is exceeded, processing is performed by the linear axis and the rotary axis. .

Example 3. Next, a third embodiment will be described. FIG. 8 is a diagram for explaining the principle of operation of the invention relating to a numerical control device for a machine tool having two linear axes intersecting at an angle other than 90 degrees, and in this figure, a linear axis intersecting at an angle other than 90 degrees. The two axes are the X axis and the Y axis, respectively.
An imaginary axis orthogonal to the axis is the Y ′ axis, and the angle between the X axis and the Y axis is θ. In this figure, if the movement command on the virtual axis Y'axis is Y'a, the movement amount of the X axis becomes Xa as shown in the figure, and at this time, it moves by Ya in the Y axis direction. FIG. 9 is a diagram showing the length of each side of a right triangle formed by the X axis, the Y axis, and the Y ′ axis. The length of the side parallel to the X axis is the side parallel to the Xp and Y axis. The length of Yp,
The length of the side parallel to the Y'axis is Y'p. In addition, Xp, Y
Since Xa and Ya in FIG. 8 are obtained from the ratio of p and Y′p, as long as Xp, Yp, and Y′p can be set, a larger value tends to reduce the error.

With respect to the movement command Ya 'on the virtual axis Y'axis,
The movement amount Xa of the X axis is expressed by the following equation. Xa = Y'a * Xp / Y'p (1) Similarly, the Y-axis movement amount Ya is expressed by the following equation. Ya = Y'a * Yp / Y'p (2) Further, with respect to the speed command Y'f on the virtual axis Y'axis, the X axis,
The Y-axis feed rate is expressed by the following equation. Xf = Y'f * Xp / Y'p (3) Yf = Y'f * Yp / Y'p (4) Based on the above formula, the virtual axis Y ' The upper movement command is X
It is converted proportionally to the movement amount on the Y axis.

Embodiment 4 FIG. Next, a fourth embodiment will be described. FIG. 10 is a diagram showing a movable range of a machine tool having two linear axes intersecting at an angle other than 90 degrees. In this figure, the two linear axes intersecting at an angle θ are the X axis, The Y axis is defined as a Y axis, the virtual axis orthogonal to the X axis is defined as a Y ′ axis, and the movable range of the physical axis when the X axis and the Y axis are orthogonal is defined as a rectangular range surrounded by ABCD. When the angle between the axis and the Y axis is θ, the movable range of the physical axis is set within the range of the rhombus surrounded by A′BFC′DE. X
When the axis is orthogonal to the Y-axis, generally the movable range is checked by inputting each machine coordinate of ABCD and judging whether the tool position is inside the rectangle formed by four points. However, when the X-axis intersects the Y-axis at an angle other than 90 degrees, the movable range is checked by the above method, and the physically unmovable right triangles F and DD'E also move. It is determined to be possible, and the risk of interference increases. Therefore, by adding the following equation to the conventional movable range determination condition, right triangles BB'F and D
D'E is excluded from the movable range.

Assuming that the machine coordinates of the cutting edge of the tool are (Xm, Ym), the movable condition when the X axis is in the plus region is shown in the following equation. XA- (Xm + Xa)> 0 (5) The movable range when the X axis is in the minus region is shown by the following formula. XA- (Xm + Xa) <0 (6)

FIG. 11 is a block diagram of a main part of a control device for carrying out the present invention, in which 21 is a microprocessor (hereinafter referred to as CP).
U), 22 is a ROM storing a control program,
23 is an RA for temporarily storing a machining program and data
M and 24 are data input devices with a CRT display device (hereinafter C) for inputting various set values and various commands and displaying various data.
RT), 25 and 26 are servo interfaces for the first axis and the second axis, 27 and 28 are servo circuits for the first axis and the second axis, and 29 and 30 are servo circuits for the first axis and the second axis, respectively. It is a motor. In addition, 11 shows a bus.

Next, FIG. 12 is an operation flow chart of the embodiment. When a control command for an intersecting axis is inputted by the CRT 24, the CPU 21 reads one block from the machining program in the orthogonal coordinate system stored in the RAM 23 (step 301). From the read movement command amount of the virtual axis Y'axis,
The calculation shown in the equations (1) and (2) is performed to obtain the movement amount of the two linear axes intersecting at an angle other than 90 degrees (step 302). Further, from the read feed rate command Y'p, the calculation shown in the equations (3) and (4) is performed to obtain the feed rate of each axis (step 303). Next, the movement amount obtained in step 302 is determined by the equations (5) and (6) to check whether the commanded movement amount is within the movable range (step 304). Step 304
When it is determined that the movement is possible in step 302, the movement amount and the feed speed obtained in step 302 and step 303 are pulse-distributed,
Servo interfaces 25, 26, servo circuits 27, 2
The servomotors 29 and 30 are driven via 8 (step 305). Then, the processing from step 1 onward is repeated again until the program end code is read from the machining program.

[0042]

According to the present invention, the programmer can create and process a machining program without being aware of the movable range of the machine. Therefore, the program creation time and the machining time can be significantly reduced. Further, since the movable range of the machine can be reduced, the machine can be downsized and the cost can be reduced.

Further, according to the present invention, when the movement command on the virtual axis (orthogonal coordinate system) is proportionally converted to the movement amount of the two linear axes intersecting at an angle other than 90 degrees, the conversion command is converted. It is possible to reduce the error of and improve the processing accuracy. Further, according to the present invention, the linear axis 2 intersecting the feed speed command on the virtual axis (orthogonal coordinate system) at an angle other than 90 degrees.
By converting in proportion to the feed rate of the shaft, it is possible to reduce the error during conversion and improve the machining accuracy.

Further, according to the invention, by automatically determining the movable range of the machine tool arranged so that the two linear axes intersect at an angle other than 90 degrees, an object outside the movable range can be detected. The interference of can be prevented.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a first embodiment and a second embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a movement amount calculation method according to the first and second embodiments of the present invention.

FIG. 4 is an explanatory diagram of an arc cutting method according to the first and second embodiments of the present invention.

FIG. 5 is a flowchart showing a programming procedure of the first and second embodiments of the present invention.

FIG. 6 is an explanatory diagram of processing of Example 1 and Example 2 of the present invention.

FIG. 7 is a flowchart showing a processing procedure of the second and fourth embodiments of the present invention.

FIG. 8 is an explanatory diagram for explaining the operation principle of the third and fourth embodiments of the present invention.

FIG. 9 is a diagram showing a ratio of lengths of respective sides of a right triangle formed by two linear axes that intersect the virtual axis of the third embodiment of the present invention at an angle other than 90 degrees.

FIG. 10 is a diagram showing a movable range of a machine tool having two linear axes that intersect at an angle other than 90 degrees according to a fourth embodiment of the present invention.

FIG. 11 is a block diagram of a main part of a control device that implements Embodiments 3 and 4 of the present invention.

FIG. 12 is a diagram showing an operation flowchart of Embodiments 3 and 4 of the present invention.

FIG. 13 is an explanatory diagram of processing of a conventional example.

FIG. 14 is a flowchart showing a programming procedure of a conventional example.

[Explanation of symbols]

2 analysis means, 3 movement amount calculation means, 4 movable range storage means, 5 synchronization signal generation means, 6 synchronization control means, 10
Arc program locus, 11 arc cutting locus, 15 display, operation board, 16 manual input means, 17 automatic input means, 18 movable range checking means, 19 warning signal generating means, 21 microprocessor, 22 ROM for storing control program, 23 RAM for temporarily storing machining programs and data, data input / output device with 24 CRT display.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G05B 19/407 W

Claims (4)

[Claims] 1. A numerical controller for controlling a machine tool having a turntable for mounting a workpiece and rotating the workpiece and a tool for machining the workpiece, wherein a target position and a feed rate are set from a machining program on an orthogonal coordinate system. And the like, and an amount of movement calculation means for calculating the amount of movement per unit time of each axis based on the data obtained by the above-mentioned analyzing means, further accumulating the amount of movement, and storing the current position, Movable range storage means for storing the movable range of each axis determined by the machine tool used, signal generating means for generating a synchronous machining mode signal when the amount of movement of each axis exceeds the movable range of each axis, and said signal On the basis of the synchronous machining mode signal output from the generating means, the portion beyond the movable range is synchronously controlled with one or two axes of the orthogonal coordinate system and the C axis which is the rotation axis of the turntable. And a synchronous control means for controlling the positional relationship between the work and the tool. 2. A numerical controller for controlling a machine tool arranged so that two linear axes intersect at an angle other than 90 degrees, wherein one of the two linear axes and an imaginary straight line orthogonal thereto. The movement command on the Cartesian coordinate system created by the axis
A numerical control device comprising a movement amount conversion means for converting in proportion to the movement amounts of the two linear axes. 3. A numerical controller for controlling a machine tool arranged so that two linear axes intersect at an angle other than 90 degrees, wherein one of the two linear axes and an imaginary straight line orthogonal thereto. A numerical control device comprising a speed conversion means for proportionally converting a feed speed command on a Cartesian coordinate system created by the axes into the feed speeds of the two linear axes. 4. A numerical control device comprising a stroke check means for checking a movable range on the two linear axes which changes according to an intersection angle of the two linear axes.