JPH07334223A - Tool spindle attitude control system - Google Patents

Abstract

PURPOSE:To easily command the attitude of a tool spindle with respect to the tool spindle attitude control system for a numerical control machine tool to work a work while inclining the tool spindle on a three-dimensional space. CONSTITUTION:A preprocessing means 102 reads out a working program 101 and decodes a tool spindle attitude control mode and a tool spindle attitude vector command. While using tool spindle attitude vector commands (I, J and K) transmitted from the preprocessing means 102 in the tool spindle attitude control mode, a spindle rotating angle arithmetic means 103 calculates the respective rotating angles of rotary spindles to decide the attitude of a tool spindle. This arithmetic is performed according to a prescribed operation expression decided by a parameter Pa set for each machine constitution pattern of the numerical control machine tool. An interpolating means 104 reads the rotating angle of two rotary spindles, performs interpolation for operating two rotary spindles just at that rotating angle and interpolates X, Y and Z axes. A programmer can easily perform programming for three-dimensional working only by commanding the tool spindle attitude vector commands (I, J and K).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool axis attitude control system for a numerically controlled machine tool, and more particularly to a tool axis attitude control system for machining a workpiece by inclining the tool axis in a three-dimensional space.

[0002]

2. Description of the Related Art In a numerically controlled machine tool, when machining a complicated die or the like, an inclined surface is machined by inclining a tool in an arbitrary direction with respect to a work. For such three-dimensional processing, a five-sided machine having three basic axes and two rotary axes orthogonal to each other is usually used.

In this five-face processing machine, in order to perform cutting with the tool axis having a certain inclination with respect to the work,
At the stage of creating a machining program, the posture (direction) of the tool axis is determined, and each rotation angle of the two rotation axes required to take that posture is calculated, and the rotation angle is commanded by the machining program. There is a need.

[0004]

However, such a command is complicated in calculation and requires time and labor. Further, this command needs to be calculated every time the posture of the tool axis changes, and needs to be calculated by an automatic programming device or the like.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tool axis attitude control system capable of easily instructing the attitude of the tool axis.

[0006]

According to the present invention, in order to solve the above problems, a tool axis for controlling the attitude of the tool axis in a numerically controlled machine tool for machining a workpiece by inclining the tool axis in a three-dimensional space. In the attitude control method, preprocessing means for reading and decoding a tool axis attitude control mode command and a tool axis attitude vector command from a machining program, and a tool axis attitude from the tool axis attitude vector command when the tool axis attitude control mode command is issued. A shaft rotation angle calculating means for calculating each rotation angle of the rotation axis, an interpolation for moving the tool to a movement target position, and an interpolation means for interpolating the rotation angle of the rotation axis. A tool axis attitude control method is provided.

[0007]

The preprocessing means reads the tool axis attitude control mode command and the tool axis attitude vector command from the machining program,
Decipher. The axis rotation angle calculation means calculates each rotation angle of the rotation axis that determines the attitude of the tool axis from the tool axis attitude vector command when the tool axis attitude control mode command is issued. The interpolation means performs interpolation for moving the tool to the movement target position, and the rotation axis 2
Interpolate the rotation angle of the axis.

Thus, the programmer can simply command the attitude of the tool axis by only commanding the tool axis attitude vector command (I, J, K).

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a tool axis attitude control system of the present invention. Each means 102, 103, 1 in the figure
04 and 105 are functions executed by a processor of a numerical control device (CNC) described later according to software. Here, in the target numerically controlled machine tool, the coordinate system for determining the position of the tool is the three basic axes X, Y, and Z orthogonal to each other. The axes that control the attitude of the tool shaft are two of the rotation axes A, B, and C.

The preprocessing means 102 is a machining program 101.
From the tool movement target position data X, Y, Z, tool axis attitude control mode, and tool axis attitude vector command (I, J,
Read K).

The rotation axis angle calculation means 103 determines the attitude of the tool axis from the tool axis attitude vector command sent from the preprocessing means 102 in the tool axis attitude control mode. The two rotation axes (A, B, C axes). Of each of the two rotation angles). This calculation is performed according to a predetermined calculation formula set for each machine configuration pattern of the numerically controlled machine tool described later. The machine configuration pattern Pa is stored in the nonvolatile memory 14 in advance.
It is stored in.

The interpolation means 104 reads the rotation angles (two of a, b, and c) of the two rotation axes obtained by the above calculation, and interpolates and interpolates the two rotation axes by the rotation angle. Interpolation for moving the tool to the movement target position X, Y, Z is performed and an interpolation pulse is output.

The interpolation distribution pulse is generated by the acceleration / deceleration control means 105.
Is accelerated and decelerated by and sent to the position control circuit (axis control circuit) 41. The position control circuit 41 converts the interpolation pulse into a speed control signal and sends it to the servo amplifier 51. Servo amplifier 51
Drives the servo motor 61 by amplifying the speed control signal. The tool moves to the movement target position according to the drive of the servomotor 61, and takes the posture instructed by the tool axis posture vector command (I, J, K) at the movement target position. The servo motor 61 has a built-in pulse coder for position detection, and feeds back a position feedback pulse to the position control circuit 41.

In FIG. 1, the position control circuit 41, the servo amplifier 51, and the servo motor 61 are shown for only one axis, but actually five axes are provided as shown in FIG. FIG. 2 is a block diagram of hardware of a CNC to which the present invention is applied. In the figure, 10 is a CNC. The processor 11 is a central processor for controlling the entire CNC 10, reads out a system program stored in the ROM 12 via the bus 21, and executes control of the entire CNC 10 according to the system program. RAM13
Stores temporary calculation data, display data, and the like.
SRAM is used for the RAM 13. The non-volatile memory 14 is composed of CMOS and stores various parameters such as the machine configuration parameter Pa according to the present invention and a machining program. The nonvolatile memory 14 is backed up by a battery (not shown), and even if the power of the CNC 10 is turned off, those data are retained as they are.

The interface 15 is an interface for an external device, and is connected to an external device 91 such as a paper tape reader, a paper tape puncher, or a paper tape reader / puncher. The processing program is read from the paper tape reader, and the processing program edited in the CNC 10 can be output to the paper tape puncher.

A PMC (Programmable Machine Controller) 16 is built in the CNC 10 and controls a machine tool by a sequence program created in a ladder format. That is, the M function instructed by the machining program,
According to the S function and the T function, these are converted into necessary signals on the machine side by the sequence program and output from the I / O unit 17 to the machine side. This output signal drives a magnet or the like on the machine side to operate a hydraulic valve, a pneumatic valve, an electric actuator, or the like. Further, it receives a signal from a limit switch on the machine side, a switch on the machine operation panel, etc., performs necessary processing, and passes it to the processor 11.

Data such as the current position of each axis and the amount of movement is sent to the CRT / MDI unit 25 and displayed. Further, a data input signal from the keyboard in the CRT / MDI unit 25 is sent to the interface 19, and the bus 2
1 is passed to the processor 11.

The interface 20 is a manual pulse generator 3
2 and receives the pulse from the manual pulse generator 32. The manual pulse generator 32 is mounted on the machine operation panel,
Used to precisely position machine working parts manually.

The axis control circuits 41 to 45 receive the movement commands of the respective axes from the processor 11 and output the commands of the respective axes to the servo amplifiers 51 to 55. The servo amplifiers 51 to 55 receive the movement command and drive the servo motors 61 to 65 of the respective axes. The servo motors 61 to 65 have a built-in pulse coder for position detection, and the position signal is fed back from this pulse coder as a pulse train. In some cases, a linear scale is used as the position detector. Further, a speed signal can be generated by F / V (frequency / speed) conversion of this pulse train.
In the figure, the feedback line and velocity feedback of these position signals are omitted.

The spindle control circuit 71 receives a spindle rotation command and a spindle orientation command, and outputs a spindle speed signal to the spindle amplifier 72. The spindle amplifier 72 receives the spindle speed signal and rotates the spindle motor 73 at the commanded rotation speed. In addition, the spindle is positioned at a predetermined position according to the orientation command.

A position coder 82 is connected to the spindle motor 73 by a gear or a belt. Therefore, the position coder 82 rotates in synchronization with the spindle motor 73 and outputs a feedback pulse, which is read by the processor 11 via the interface 81. This feedback pulse moves the other shaft in synchronization with the spindle motor 73, enabling precise tapping processing and the like.

Next, a method of calculating the rotation angles of the two rotation axes from the tool axis posture vector command (I, J, K) according to the present invention will be described. Since this calculation differs depending on the machine configuration of the numerically controlled machine tool as described above, it will be described separately for each machine configuration.

The machine structure is divided into the following five patterns depending on the type of the two rotary shafts and the tool axis direction. (1) Basic 3 axes = X, Y, Z axes, 2 rotation axes = A, C
Axis, tool axis = Z axis (2) Basic 3 axes = X, Y, Z axes, rotating axis 2 axes = B, C
Axis, tool axis = Z axis (3) Basic 3 axes = X, Y, Z axes, 2 rotation axes = A, B
Axis, Tool axis = X axis (4) Basic 3 axes = X, Y, Z axes, Rotation axis 2 axes = A, B axes (B axis is the master axis), Tool axis = Z axis (5) Basic 3 Axis = X, Y, Z axes, 2 rotation axes = A, B axes (A axis is the master axis), tool axis = Z axis Next, the case of the machine configuration pattern (1) will be described.

FIG. 3 is a schematic diagram of a mechanical configuration in the case of mechanical configuration pattern (1). In the drawing, the tool 3 has a coordinate system composed of three basic X, Y, and Z axes that are orthogonal to each other, and an A axis and a C axis of rotation that control the attitude of the tool axis. The tool 3 is attached to the lower end of the tool attachment portion 1 such that the point O is the center of rotation. Here, work 2 with tool 3
The inclined surface 2a is processed. In the machining program, tool axis posture vector commands (I, J, K) are commanded. Generally, the tool axis posture vector command is perpendicular to the inclined surface 2a.

When the tool axis posture vector command is given,
Substituting this tool axis posture vector command (I, J, K) into a predetermined arithmetic expression described later in detail, the rotation angles a and C of the A axis
The rotation angle c of the shaft is obtained.

In the coordinate system having the point O as the origin, when the C-axis rotates by the angle c and the A-axis further rotates by the angle a from that state, the tool axis direction of the tool 3 becomes the direction shown by the chain line. . At this time, the tool axis is the inclined surface 2 of the work 2.
Take a posture perpendicular to a. In the actual machining program, the following commands are given.

G41 Xp Yp Zp I J K D Xp: X-axis movement amount Yp: Y-axis movement amount Zp: Z-axis movement amount D: Tool number I, J, K: Tool axis attitude vector command The tool 3 is Xp, Yp by this G code command. , Z
Moving to the coordinate position of p, the axis of the tool 3a faces the direction determined by the tool axis posture vector command (I, J, K).

FIG. 4 is a diagram showing how to obtain the rotation angles a and c in the case of the mechanical structure pattern (1). In the machine configuration pattern (1), the two rotation axes are the A and C axes and the tool axis is the Z axis. In this case, when the tool axis attitude vector command (I, J, K) is commanded, the rotation angle a of the A axis and the rotation angle c of the C axis are as follows: a = arctan [(I ² + J ² ) ^1/2 / K] c = arctan (I / -J).

As described above, the rotation angles a and c of the rotation axes A and C are automatically obtained only by instructing the tool axis posture vector commands (I, J, K) in the machining program, and the tool 3 is the work. It is possible to take a posture perpendicular to the second inclined surface 2a. Therefore, the programmer does not need to perform complicated rotation angle calculation of the rotation axis, and programming work for three-dimensional machining can be completed easily and in a short time. Further, since the tool axis posture vector command (I, J, K) is generally shown in the drawing by the inclination or the like, these values can be used.

FIG. 5 is a diagram showing how to obtain the rotation angles b and c of the rotation axes B and C in the case of the machine configuration pattern (2). In this machine configuration pattern (2), the rotation axes A and C of the machine configuration pattern (1) shown in FIGS. 3 and 4 are the rotation axes B and C, respectively. Therefore, the rotation angle b of the B axis and the rotation angle c of the C axis can be obtained by the following equations.

B = arctan [(I ² + J ² ) ^1/2 / K] c = arctan (J / I) FIG. 6 is a schematic diagram of the machine configuration in the case of the machine configuration pattern (3). In the figure, the tool 31 is provided with a coordinate system consisting of three basic X, Y, and Z axes indicated by broken lines orthogonal to each other, and rotation axes of the A axis and the B axis. The tool 31 is attached to the tip of the tool attachment portion 1a such that the point O1 is the center of rotation. In the case of such a machine configuration pattern (3), the A-axis rotates by the angle a, and from that state B
When the axis rotates by the angle b, the tool axis 31a of the tool 31 takes a direction determined by the tool axis attitude vector command (I, J, K). And, the tool shaft 31a is the inclined surface 2b of the work 2b.
It is perpendicular to a.

FIG. 7 is a diagram showing how to obtain the rotation angles a and b in the case of the machine structure pattern (3). In the case of the machine configuration pattern (3), the two rotation axes are the A and B axes and the tool axis is the X axis. In this case, when the tool axis posture vector command (I, J, K) is commanded, the rotation angle a of the A axis and the rotation angle b of the B axis are obtained by the following formulas.

A = arctan (J / -K) b = arctan [(J ² + K ² ) ^1/2 / I] FIG. 8 is a schematic configuration diagram of the machine configuration in the case of the machine configuration pattern (4). In the figure, the tool 32 is provided with a coordinate system consisting of three basic axes of X, Y, and Z, which are shown by broken lines orthogonal to each other, and rotation axes of A axis and B axis. Tool 3
2 is attached to the rotary head 33 such that the O2 point is the center of rotation and the Z-axis direction is the tool axis direction. Further, the B axis is attached so as to be the master axis.

When the A axis rotates by the angle a and the B axis further rotates by the angle b from that state, the tool axis 3 of the tool 32
2a takes a direction determined by the tool axis posture vector command (I, J, K). Then, the tool shaft 32a becomes perpendicular to the inclined surface 2ca of the work 2c.

FIG. 9 is a diagram showing how to obtain the rotation angles a and b in the case of the machine structure pattern (4). In the case of the machine configuration pattern (4), the two rotation axes are the A and B axes and the tool axis is the Z axis. The master axis is the B axis. In this case, when the tool axis posture vector command (I, J, K) is commanded, the rotation angle a of the A axis and the rotation angle b of the B axis can be obtained by the following formulas.

A = arctan [-J / (I ² + K ² ) ^1/2 ] b = arctan (I / K) FIG. 10 is a schematic configuration diagram of the machine configuration in the case of the machine configuration pattern (5). In the figure, the tool 34 has a coordinate system consisting of three basic X, Y, and Z axes orthogonal to each other, and A
The rotation axes of the axis and the B axis are set. The tool 34 is attached to the rotary head 35 such that the point O3 is the center of rotation, and the Z axis direction is the tool axis direction. Further, the A axis is attached so as to be the master axis.

When the B-axis rotates by the angle b and the A-axis further rotates by the angle a from that state, the tool axis 3 of the tool 34
4a has a posture determined by the tool axis posture vector command (I, J, K). Then, the tool shaft 31a is perpendicular to the inclined surface 2da of the work 2d.

FIG. 11 is a diagram showing how to obtain the rotation angles a and b in the case of the machine structure pattern (5). In the case of the machine configuration pattern (5), the two rotation axes are the A and B axes,
The tool axis is the Z axis. The master axis is the A axis. In this case, when the tool axis posture vector command (I, J, K) is commanded, the rotation angle a of the A axis and the rotation angle b of the B axis can be obtained by the following formulas.

[0039] is a flowchart for a = arctan (-J / K) b = arctan ^{[I / (J 2 + K 2} ) 1/2 ] 12 to perform the tool axis attitude control method of the present invention. The numbers following S in the figure represent step numbers. [S1] It is determined whether the tool axis posture control mode is set. If it is the tool axis attitude control mode, the process proceeds to the next step S2,
Otherwise, the process ends. The tool axis attitude control mode is determined by the commands of G41 and I, J, K being issued to the same block. [S2] Machine configuration pattern is set to machine configuration parameter Pa
Recognize by. [S3] The rotation angles of the two rotation axes are calculated and obtained. [S4] The rotation angle is interpolated and an operation command (interpolation pulse) is output to the tool.

In the above description, the posture of the tool 3 is set to the work 2
The tool axis posture vector command (I, J, K) was instructed so as to be perpendicular to the inclined surface 2a of the tool. However, it is not always necessary to specify it vertically, and a tool axis posture vector command (I, J, K) different from this is required. ) May be commanded.

[0041]

As described above, according to the present invention, the posture of the tool axis is instructed by the tool axis posture vector command (I, J, K), so that the programmer does not have to perform complicated calculations. You can easily create machining programs.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a tool axis attitude control system of the present invention.

FIG. 2 is a block diagram of hardware of a CNC to which the present invention is applied.

FIG. 3 is a schematic diagram of a mechanical configuration in the case of mechanical configuration pattern (1).

FIG. 4 is a diagram showing how to determine rotation angles a and c in the case of the machine configuration pattern (1).

FIG. 5 is a diagram showing how to determine rotation angles b and c in the case of the machine configuration pattern (2).

FIG. 6 is a schematic diagram of a mechanical configuration in the case of a mechanical configuration pattern (3).

FIG. 7 is a diagram showing how to determine rotation angles a and b in the case of the machine configuration pattern (3).

FIG. 8 is a schematic configuration diagram of a machine configuration in the case of a machine configuration pattern (4).

FIG. 9 is a diagram showing how to determine rotation angles a and b in the case of the machine configuration pattern (4).

FIG. 10 is a schematic configuration diagram of a machine configuration in the case of the machine configuration pattern (5).

FIG. 11 is a rotation angle a in the case of the machine configuration pattern (5).
It is a figure which shows how to obtain | require and b.

FIG. 12 is a flowchart for executing the tool axis posture control method of the present invention.

[Explanation of symbols]

1, 1a Tool mounting part 2 Work 2a Inclined surface of work 3, 31, 32, 34 Tool 10 Numerical controller (CNC) 11 Processor 12 ROM 13 RAM 14 Non-volatile memory 41, 42, 43, 44, 45 Position control circuit (Axis control circuit) 51, 52, 53, 54, 55 Servo amplifier 61, 62 63, 64, 65 Servo motor 101 Machining program 102 Pre-processing means 103 Rotation axis angle calculation means 104 Interpolation means 105 Acceleration / deceleration control means Pa Machine configuration Parameters for

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Claims (7)

[Claims] 1. A tool axis attitude control method for controlling the attitude of a tool axis in a numerically controlled machine tool for machining a workpiece by inclining a tool axis in a three-dimensional space, comprising a tool axis attitude control mode command and a tool axis attitude. Pre-processing means for reading and decoding a vector command from a machining program, and a shaft rotation angle for calculating each rotation angle of a rotary shaft that determines the attitude of the tool axis from the tool axis attitude vector command when the tool axis attitude control mode command is issued. A tool axis posture control method comprising: a computing means; an interpolation for moving a tool to a movement target position; and an interpolating means for interpolating a rotation angle of the rotation axis. 2. The rotation axis angle calculation means reads a machine configuration pattern of the numerically controlled machine tool, and calculates each rotation angle of the rotation axis according to a predetermined calculation expression set for each machine configuration pattern. The tool axis posture control method according to claim 1, wherein 3. The tool axis attitude control system according to claim 2, wherein the machine configuration pattern has a rotation axis of an A axis and a C axis. 4. The tool axis attitude control system according to claim 2, wherein the machine configuration pattern has a rotation axis of B axis and C axis. 5. The tool axis attitude control system according to claim 2, wherein the machine configuration pattern has a rotation axis as an A axis and a B axis and a tool axis as an X axis. 6. The tool axis attitude control system according to claim 2, wherein the machine configuration pattern has a rotation axis as an A axis and a B axis and the B axis as a master axis. 7. The tool axis attitude control system according to claim 2, wherein the machine configuration pattern has a rotation axis as an A axis and a B axis and an A axis as a master axis.