JPH07287613A - Axial speed deciding system - Google Patents

Abstract

PURPOSE:To execute a linear interpolation and a circular arc interpolation holding the speed of a specified control axis constant by a simple programming, with respect to an axial speed deciding system deciding the speed of the control axis in a numerial controller. CONSTITUTION:A designated axis speed setting means 3 makes the speed of the designated control axis of control axes or an X-axis, for instance, constant speed FXO and sets the speed vector FXO* of the X-axis. A direction vector deciding means 2 decides a direction vector V* based on the location command of a read working program 14a. An other axis speed deciding means 4 decides the speed vector of other control axis except the designated axis or a Z-axis, for instance, based on the speed vector FXO* of the designated axis (X-axis) and the direction vector V*. As a result, a grinder 92 or a work 91 advances along the direction vector V* to be decided based on a location command, the designated axis (X-axis) rotates at the set constant speed at the time and a table 90 is advanced at constant speed FXO.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft speed determination system for determining the speed of a control shaft in a numerical controller.

[0002]

2. Description of the Related Art In linear interpolation and circular interpolation in a numerical control device, the command speed is a tangential speed F between two points.
The velocity components Fx, Fy, Fz of each control axis are calculated and distributed from the velocity F in the tangential direction. Therefore, even if the moving speed of the tool or the work is controlled to be constant, the speed of each control axis is not necessarily constant.

On the other hand, there are cases where it is desired to feed the control axis at a constant speed all the time. For example, there is a case where a table in which a work having an upper surface of a gentle curved surface is fixed to a surface grinder is fed at a constant speed in the X-axis direction to perform stable processing. In such a case, in order to keep the velocity component of the axis constant, a programming operation of re-instructing the tangential velocity F for each command block is required.

In circular interpolation, if the velocity component of a specific control axis is to be kept constant, it is necessary to divide the circular arc into minute sections and re-command the tangential velocity F for each section. .

[0005]

However, such programming work is complicated and time-consuming. In particular, in the case of circular interpolation, it is virtually impossible to recommand the speed F for each minute section, and it is not possible to issue a command to keep the speed of a specific control axis constant. It was

The present invention has been made in view of the above circumstances, and it is possible to execute linear interpolation and circular interpolation for maintaining the speed of a specific control axis constant with simple programming. The purpose is to provide a decision method.

[0007]

According to the present invention, in order to solve the above problems, in a shaft speed determination method for determining the speed of a control shaft in a numerical controller, one of the control shafts is designated according to the shaft designation information. The speed of the control axis is made constant, the specified axis speed setting means for setting the speed vector of the specified axis, the direction vector determination means for determining the direction vector based on the position information of the read machining program, and the specified axis The other axis speed determining means for determining the speed vector of the control axis other than the designated axis based on the speed vector and the direction vector is provided.

[0008]

Function: The designated axis speed setting means, according to the axis designation information,
The speed of the designated control axis among the control axes is made constant, and the velocity vector of the designated axis is set. The direction vector determining means determines the direction vector based on the position command of the read machining program. Then, the other axis speed determining means determines the speed vector of the control axis other than the specified axis based on the speed vector and the direction vector of the specified axis.

The tool or the work advances along a direction vector determined based on the position command, and at that time, the designated axis rotates at a set constant speed, and the table or the like advances in the axial direction at the constant speed. .

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the shaft speed determination method of the present invention. In the figure, the pre-processing means 1 of the numerical controller reads the machining program 14a, and among the read information, the position information is supplied to the interpolating means 5 and the direction vector determining means 2, and the axis specifying information is supplied to the axis specifying means 3. send. Here, the axis designation information is composed of control axis designation information and speed information of the designated control axis (designated axis).

Based on the received axis designation information, the designated axis speed setting means 3 designates one of the X-axis, Y-axis, and Z-axis control axes, here, for example, the X-axis. The velocity Fx of the designated X-axis is the constant velocity Fx
Fixed to ₀ and the resulting X-axis velocity vector Fx
₀ ^* is output to the other axis speed determining means 4.

The direction vector determining means 2 receives the received information.
Direction vector obtained by connecting two points based on the placement information
V^*Is output to the other axis speed determining means 4. This direction vector
Le V ^*Details of will be described later.

The other-axis speed determining means 4 is based on the X-axis speed vector Fx ₀ ^* and the direction vector V ^*, and is the Y-axis speed vector Fy ^* which is the speed vector of the other axis than the X-axis ^.
Alternatively, the velocity vector Fz ^* of the Z axis is determined, and the velocity information Fx ₀ , Fy, Fz obtained as a result is output to the interpolating means 5. The other axis is an axis corresponding to the position information, and the position information is composed of X-axis position information and Y-axis position information.
When the axis is the designated axis, the other axis is the Y axis, and the position information is composed of the X axis position information and the Z axis position information. When the X axis is the designated axis, the other axis is the Z axis. The method for determining the velocity vector of the other axis will be described in detail later.

The interpolating means 5 includes position information from the preprocessing means 1 and each axis speed information F from the other axis speed determining means 4.
Based on x ₀ , Fy, and Fz, distribution pulses Xp, Yp, and Zp distributed to the X axis, Y axis, and Z axis are determined, and the distribution pulses Xp, Yp, and Zp are determined by the X axis control means 6.
a, Y-axis control means 6b, Z-axis control means 6c.
The respective motors 61, 62, 63 on the machine tool side are drive-controlled by the distribution pulses Xp, Yp, Zp, and as a result, the grindstone 92 is movement-controlled in the Z direction at the speed Fz, and the work 91 on the table 90 is The movement is controlled in the X direction at a constant speed Fx ₀ .

FIG. 2 is a block diagram of hardware showing an overall configuration of a numerical controller (CNC) to which the present invention is applied. In the figure, a processor 11 is a central processor for controlling the entire numerical controller (CNC) 10, reads a system program stored in a ROM 12 via a bus 21, and controls the entire CNC 10 according to the system program. Run. The preprocessing means 1, the direction vector determination means 2, the designated axis speed setting means 3, the other axis speed determination means 4, and the interpolation means 5 are functions of software executed by the processor 11 according to the system program in the ROM 12.

The ROM 12 is EPROM or EEP.
ROM is used. DRAM is used as the RAM 13, and various data is stored therein. Since the non-volatile memory 14 stores the processing program 14a, parameters, etc., and the battery-backed CMOS is used,
The contents are retained even after the power of the numerical control device is turned off.

The interface 15 is an interface for an external device, and is connected to an external device 31 such as a paper tape reader or a paper tape 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 the machine side with a sequence program created in a ladder format. That is, the M function, the S function, which are instructed by the machining program,
According to the T function, these are converted into a signal necessary for 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 machine-side limit switch, a machine operation panel switch, or the like, performs necessary processing, and passes it to the processor 11.

Data such as the current position and movement amount of each axis 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 the machine working part by hand.

The axis control circuits 41 to 43 receive the position command of each axis from the processor 11 and receive servo motors 61 to 63.
Speed command signals for controlling the servo amplifiers 51 to 5
Output to 3. The servo amplifiers 51 to 53 amplify this speed command signal and drive the servo motors 61 to 63.
The X-axis control means 6a to 6c described above use the axis control circuit 41.
To 43 and servo amplifiers 51 to 53. A pulse coder (not shown) for position detection is fed back to the servo motors 61 to 63 as a pulse train. In some cases, a linear scale is used for position detection. In addition, this pulse train is F / V (frequency / speed)
By converting, a velocity signal can be generated. In the figure, the feedback line and velocity feedback of these position signals are omitted.

The spindle control circuit 71 outputs a spindle speed signal to a spindle amplifier 72 in response to a spindle rotation command and a spindle orientation command. The spindle amplifier 72 receives the spindle speed signal and rotates the spindle motor 73 at the commanded rotation speed. The rotation causes the grindstone 92 (FIGS. 1 and 3) to rotate, and grinding is performed. Further, the spindle motor 73 is positioned at a predetermined position according to the orientation command. A position coder 82 is coupled to the spindle motor 73 by a gear or the like, and a feedback pulse from the position coder 82 is read by the processor 11 via the interface 81.
This feedback pulse is used to synchronize the other axis with the spindle motor 73.

Next, the shaft speed determination according to the present invention will be described with reference to FIGS. Here, as shown in FIG. 3, the case where the workpiece 91 is ground by the grindstone 92 will be described. In FIG. 3, the work 91 is fixed to the table 90, and the table 90 is moved by the servo motor 61 to X-axis.
In the Y direction, which is perpendicular to the paper surface, by the servomotor 62. Further, the grindstone 92 is the servomotor 6
Move in the Z direction by 3. The rotation drive of the grindstone 92 is
This is performed by a spindle motor 73 not shown here.

FIG. 4 is a diagram showing the outer dimensions of the finished work. The work 91 has linear inclined surfaces 911 and 912 at both ends of its upper surface, and R100 mm at the center.
Arc surfaces 912 are formed. Here, a processing program for grinding the workpiece 91 having such a shape using the grindstone 92 will be described.

First, the following machining program of program number 1 is executed. O0001; G200 F1000; M98 P1000; M98 P2000; M99; The code "G200" is the code according to the present invention.
The speed of the shaft is kept constant. The speed in the X-axis direction is
It is set to 1000 mm / min by "F1000". Program number 10 by following "M98"
00 and program number 2000 are executed,
The program ends with "M99". Next, program number 1000 is shown below. O1000; G01 G91 X10. Z5. G02 X50. R100. G01 X10. Z-5; M99; This program number 1000 is a program for grinding from the left side to the right side in FIG. "G01" in the previous stage
By the linear interpolation, the inclined surface 911 is ground. Next, "G02" is used to perform circular arc interpolation to grind the circular arc surface 912. Linear interpolation is performed by "G01" in the latter stage, and the inclined surface 913 is ground. Note that "G91" and "G92" described later are commands for processing coordinate values as incremental dimensions. In this grinding process, the speed in the X-axis direction is
As mentioned above, by "G200 F1000",
It is maintained at a constant speed of 1000 mm / min.

Next, the program number 2000 is shown below. O2000; G01 G91 X-10. Z5. G03 X-50. R100. G01 X-10. Z-5; M99; This program number 2000 is a program for grinding from the right side to the left side in FIG. "G01" in the previous stage
By the linear interpolation, the inclined surface 913 is ground. Next, "G02" is used to perform circular arc interpolation to grind the circular arc surface 912. The linear interpolation is performed by "G01" in the latter stage, and the inclined surface 911 is ground. As in the case of the grinding by the program number 1000, the speed in the X-axis direction in this grinding is
"G200 F1000" gives a constant speed of 1000
It is held at mm / min. However, that direction is negative.

FIG. 5 is an explanatory view of the procedure for determining the shaft speed according to the present invention. First, in step 1, "G *** F1000" in the machining program is read. "G *
"**" is a code that specifies the control axis, and in "G200" in the above example, the X axis is specified. And "F1
"000" sets the speed of the designated axis to a constant value.

Next, in step 2, the direction vector V ^* is obtained. That is, the current position P1 and step 1
The directional vector V ^* is obtained by connecting the target position P2 read in.

Then, in step 3, step 1
Velocity vectors Fx ^* of the designated axis is obtained from the information (here, the X-axis), and the direction vector V ^* described above,
The velocity vector Fz ^* of the Z axis which is another control axis is determined.

The linear interpolation or the circular interpolation is performed based on the X-axis speed Fx and the Z-axis speed Fz obtained in the above procedure. The distributed pulse signal obtained by such interpolation passes through the axis control circuits 41 to 43 and the servo amplifiers 51 to 53 as described above, and the servo motor 61 for driving each axis shown in FIG. 62, 63. As a result, the speed of the table 90 in the X-axis direction is constant speed Fx.
The velocity in the other Z-axis direction is held at _0, and is controlled to the velocity Fz obtained by the above procedure.

As described above, in this embodiment, the control axis is designated and the speed of the designated axis is set by the command of "G *** F ..." in the machining program, and the speed vector of the designated axis is set. Since the velocity vector of the other axis is calculated from the direction vector and the linear or circular interpolation is performed based on the velocity information of each axis obtained as a result, the velocity of a specific control axis is held constant. Such linear interpolation or circular interpolation can be executed by simple programming. Therefore, stable machining such as feeding the table 90 in the X-axis direction at a constant speed can be easily executed.

Further, conventionally, circular interpolation for keeping a certain specific axis speed constant was practically impossible, but according to the present embodiment, such circular interpolation can be easily executed by a simple program. Can be made.

[0033]

As described above, according to the present invention, the control axis is specified and the speed of the specified axis is set by a simple program command, and linear interpolation or linear interpolation is performed based on the speed information of each axis obtained as a result. Since I tried to do circular interpolation,
Linear or circular interpolation that keeps the speed of a specific control axis constant can be executed with simple programming. For example, stable machining is also easy, such as feeding the table at a constant speed in the X-axis direction. Can be executed.

Conventionally, it has been practically impossible to perform circular interpolation for keeping a certain specific axis velocity constant, but such circular interpolation can be easily executed by a simple program.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a shaft speed determination system of the present invention.

FIG. 2 is a hardware block diagram showing an overall configuration of a numerical controller (CNC) to which the present invention is applied.

FIG. 3 is an explanatory diagram when the present invention is applied to grinding.

FIG. 4 is a diagram showing external dimensions of a finished work.

FIG. 5 is an explanatory diagram of a procedure for determining a shaft speed according to the present invention.

[Explanation of Codes] 1 Pre-processing means 2 Direction vector determination means 3 Designated axis speed setting means 4 Other axis speed determination means 5 Interpolation means 6a to 6c Each axis control means 10 Numerical controller (CNC) 11 Processor 12 ROM 13 RAM 14 CMOS 41-43 Axis control circuit 51-53 Servo amplifier 61-63 Servo motor 90 Table 91 Work piece 92 Grinding stone

Claims (2)

[Claims] 1. A shaft speed determining method for determining a speed of a control axis in a numerical controller, wherein a speed of a designated control axis among the control axes is made constant according to axis designation information, and a velocity vector of the designated axis is set. A specified axis speed setting means for setting a direction vector determining means for determining a direction vector based on the position information of the read machining program; and a speed vector of the specified axis and the direction vector other than the specified axis. An axis speed determination method comprising: another axis speed determination means for determining a speed vector of another control axis. 2. The axis speed determining system according to claim 1, wherein the axis specifying means specifies the control axis and sets a speed vector by a G code.