JPH04244355A - Tracer control method - Google Patents

Abstract

PURPOSE:To adequately select a tracing region of a model by preventing useless movement of a tool relating to a workpiece, in the case of a profile control method for performing profile control based on each displacement amount epsilonx, epsilony and epsilonz in X, Y and Z-axis directions of a stylus brought into contact with a model surface. CONSTITUTION:A stylus 3 is judged for whether it is detached or not from a model 1 in accordance with a position on a surface of a model 1 of a tracer head 2. When the stylus 3 is judged detached from the model 1, an additional moving amount Vm is input and added to a moving amount Vz in a Z-axis direction by an arithmetic device 7. As a result, a command data different from a shape of the model 1 is created.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a profiling control method in a profiling control device having a manual profiling function, and more particularly to a profiling control method that allows manual control of axial movement following a model.

0002

[Prior Art] Conventionally, the two axes of the tracer head have been controlled by NC.
A tracing control method is used in which movement is performed by command and tracing control is performed using the remaining one axis. For example, the X and Y axes are given NC commands, and the Z axis is followed and controlled. In other words, the X and Y axes are
Control is performed using the C command, and the Z axis is controlled based on the following formula. Vz=(ε-ε0)×G Here, Vz is the Z-axis tracing speed, ε is the combined displacement amount of the X-axis, Y-axis, and Z-axis, and ε0 is the reference displacement amount.

In a tracing control device having such a tracing function, manual tracing is generally possible by jog-feeding or handle-feeding the tracer head in the X and Y axis directions. Manual feeding allows tracing arbitrary locations and paths on the XY plane, which is convenient when partially tracing complex shapes.

0004

[Problems to be Solved by the Invention] However, in conventional manual tracing, the only axes that can be manually moved are two of the three axes, excluding the Z-axis, which moves the stylus to follow the model surface. The tracer head inside could not be manually operated on all three axes. Therefore, even when it is necessary to separate the stylus from the model surface or bring it into contact with the model surface again during the tracing operation, the stylus cannot be easily moved up and down by manual operation of the tracer head.

In particular, during rough machining, it is not possible to manually move the stylus on all three axes and repeatedly bring the stylus into contact with and separate from the model, making it extremely inconvenient to carry out the profiling operation. The present invention has been made in view of these points, and it is an object of the present invention to provide a tracing control method that allows free manual operation of a tracer head in all three axes.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides an X-axis of a stylus that contacts a model surface,
In a tracing control method in which a workpiece is machined by following a model shape using a tracer head that is contour-controlled based on displacement amounts εx, εy, and εz in the Y-axis and Z-axis directions, speed data in the X-axis and Y-axis directions is The movement of the tracer head is controlled based on the position command data and the 3-axis composite displacement amount of the stylus at this time is calculated, and the amount of movement of the tracer head in the Z-axis direction is calculated.
Create command data different from the model shape by adding an additional travel amount in the direction in which the stylus leaves the model surface to the travel amount in the axial direction, and control the movement of the tracer head in the Z-axis direction using the created command data. A tracing control method is characterized in that the workpiece is machined by
provided.

[0007]

[Effect] Z of the tracer head following the model shape
In the axial direction, the stylus is moved into and out of contact with the model surface by adding an additional amount of movement proportional to the rotational speed of the manual handle, for example.

[0008]

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 of a profile control device for implementing the profile control method of the present invention. In the profiling machine tool, a tracer head 3 that detects displacement in three axes of a stylus 2 that contacts the surface of a model 1 instructs the movement of a tool that processes a workpiece. In other words, regarding the X axis,
The X-axis command circuit 11 outputs the X-axis position command to the error register 13 via the adder 12, and the X-axis speed command Vx is input from the error register 13 to the speed control circuit 14, and the
The shaft servo motor 15 is driven. The speed signal of the X-axis servo motor 15 is fed back from the pulse coder 16 to the adder 12, where the position deviation is calculated and stored in the error register 13. Regarding the Y-axis, the Y-axis command circuit 21 similarly outputs a Y-axis position command to the error register 23 via the adder 22, and the error register 23
The Y-axis speed command Vy is input to the speed control circuit 24 from
It drives the Y-axis servo motor 15. The speed signal of the Y-axis servo motor 25 is sent from the pulse coder 26 to the adder 22.
The position deviation is calculated here.
It is stored in the error register 23.

The tracer head 3 has an
Displacement amounts εx, εy, and εz in the Y-axis and Z-axis directions are detected and input to the synthesis circuit 4. In the synthesis circuit 4, the composite displacement amount ε(=(εx2 +
εy2 +εz2 ) 1/2 ) is obtained, and this composite displacement amount ε is input to the calculator 5. The calculator 5 calculates the difference Δε (Δε=ε
-ε0) and input it to the movement amount calculation circuit 6. The movement amount calculation circuit 6 generates a movement amount Vz in the Z-axis direction in proportion to the difference Δε, and outputs it to the calculation unit 7. For example, a speed signal Vm proportional to the rotational speed of the handle of the manual pulse generator is input to the calculator 7 as an additional amount of movement in the Z-axis direction.

As a result, the additional movement amount in the direction in which the stylus 2 leaves the model 1 is added to the movement amount Vz in the Z-axis direction calculated by the movement amount calculation circuit 6. As a result, command data different from the shape of the model 1 is input to the speed control circuit 8 as a Z-axis speed command, and the Z-axis servo motor 9 is driven. In other words, the Z-axis speed command V (mm/min
) is the amplification coefficient (1/min) of the movement amount calculation circuit 6,
From the composite displacement amount ε (mm) and the reference displacement amount ε0 (mm),
It is determined by V=K*(ε-ε0)+Vm. Here, the additional movement amount is, for example, 10
It can be determined from the amount (μm) of rotation of the manual handle in a unit time set to about msec. Alternatively, the command may be given by operating a jog button.

The X-axis command circuit 11 and the Y-axis command circuit 21 are similarly given movement commands from a manual pulse generator, or are given movement commands for the X and Y axes on the X and Y planes and feed rate commands F. Give NC command 1 including. In other words, all three axes may be moved manually, or the positions of only two axes, the X and Y axes, may be controlled, and the other axis may be moved based on the rotation speed of the manual handle. .

Next, a profile control method of the present invention using the above profile control device will be explained. FIG. 2 is a flowchart illustrating the tracing operation. In the figure, the number following S indicates the step number. [S1] A movement command is given to the X-axis command circuit 11 and the Y-axis command circuit 21, respectively, to move the tracer head in the X-axis and Y-axis directions. [S2] A composite displacement amount ε is calculated based on the displacement amounts εx, εy, and εz of the stylus 2 in the X-axis, Y-axis, and Z-axis directions. [S3] Δε=ε−ε0 is calculated and input to the movement amount calculation circuit 6, and the Z-axis movement amount is calculated.

[S4] Depending on the position of the tracer head 2 on the surface of the model 1, it is determined whether to separate the stylus 3 from the model 1. This is an important judgment to prevent unnecessary movement of the tool relative to the workpiece or to select the tracing area of model 1, and is determined by the operator in manual tracing. [S5] When it is determined in step S4 that the stylus 3 is to be released from the model 1, the input additional movement amount Vm is set to Z.
Add to the axial movement amount Vz. As a result, command data different from the shape of model 1 is created. [S6] The output V of the calculator 7 is output as a Z-axis movement command.

[0014] In the above explanation, it was assumed that manual control was performed only on the Z-axis, that the X and Y axes were under NC control, and that the Z-axis was controlled by tracing, but all three axes could be manually operated depending on the workpiece. It can also be changed to .

[0015]

[Effects of the Invention] As explained above, in the present invention, the tracer head can be freely operated manually in all three axes, so there is no need to remove the stylus from the model surface or bring it into contact again during the tracing operation. When there is a problem, the stylus can be moved up and down by simply manually operating the tracer head.

[0016] Therefore, it has become possible to easily carry out rough cutting by tracing operations.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a profile control device for implementing the profile control method of the present invention.

FIG. 2 is a flowchart illustrating the tracing operation of the present invention.

[Explanation of symbols]

1 Model 2 Stylus 3 Tracer head 4 Synthesis circuit 5,7 Arithmetic unit 6 Movement amount calculation circuit 8, 14, 24 Speed control circuit 9, 15, 25 Servo motor

Claims (3)

[Claims] [Claim 1] The workpiece is machined by following the model shape by a tracer head that is controlled based on the displacements εx, εy, and εz of the stylus in the X-axis, Y-axis, and Z-axis directions in contact with the model surface. In the tracing control method, the movement of the tracer head is controlled based on velocity data and position command data in the X-axis and Y-axis directions, and the combined three-axis displacement amount of the stylus at this time is calculated to determine the Z of the tracer head. By calculating the amount of movement in the axial direction and adding the additional amount of movement in the direction in which the stylus leaves the model surface to the calculated amount of movement in the Z-axis direction, command data different from the model shape is created. A profiling control method comprising controlling the movement of the tracer head in the Z-axis direction based on command data to process the workpiece. 2. The tracing control method according to claim 1, wherein the movement commands of the stylus in the X-axis and Y-axis directions and the additional movement amount in the Z-axis direction are given by manual operation. 3. The tracing control according to claim 1, wherein the speed data and position command data are given to the tracer head as NC commands, and the additional movement amount in the Z-axis direction is given by manual operation. Method.