JPS6159866B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying control device, and more particularly, to a copying control device that is capable of calculating and setting the lifting amount of a tracer head in a surface unidirectional copying mode to a predetermined value according to the surface shape of a copying model. Regarding.

First, a copying control device applied to the present invention will be explained with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram of an example of a copying control device to which the present invention is applied, and FIGS. 2A, B, and C are side views and cross-sectional views of the tracer head portion at different positions, respectively.

In FIG. 1, a copying control device 1 controls copying processing of a machine tool 1a such as a machining center or a milling machine. The tracer head 2 traces the model surface of a copy model 4 made of wood, plaster, etc., and detects the displacement of the stylus 11 at that time. As shown in FIG. 2, this tracer head 2 is supported from all sides by a head support 11a connected to a stylus 11 so as to be suspended in the air by an elastic body 15 such as a spring, so that the stylus 11 comes into contact with the copying model 4. Displacement ε _x , ε with respect to the three axes of the
_y and ε _z are detected. The X-axis differential transformer 12, the Y-axis differential transformer 13, and the Z-axis differential transformer 14 are attached to the column 11a in a three-dimensional array for detecting the three-axis linear displacement, and each subscript corresponds to the displacement. ε
Detect _x , ε _y , and ε _z .

The control device 10 has a three-dimensional vector displacement √ _x ²
Displacement ε _x , so that +ε _y ² +ε _z ² becomes a constant value ε _p
ε _y , ε _z and feed rate F are calculated, and the X-axis motor 7,
The Y-axis motor 8 and Z-axis motor 9 are controlled to drive the main shaft cutter 3 and table 6. As a result, the copying control device 1 cuts the workpiece 5 into the same shape as the copying model 4.

Next, an example of the control mode of the copying control device 1 will be explained in the third example.
The explanation will be made with reference to FIGS. 6 to 6. Figure 3 is a perspective view of an example of a two-dimensional imitation model, and Figure 4 is an X-Z diagram of Figure 3.
A sectional view, FIG. 5 is a perspective view of an example of an X-Y contour full-circumference model, and FIG. 6 is an X-Y sectional view of FIG.

In Fig. 3, point A- on the model surface of copying model 4a
The area between B and point C and D is a two-dimensional copying mode on the copying plane XZ, and the area between points B and C is a two-dimensional copying mode on the copying plane YZ. That is, this example is an example of a two-dimensional reciprocating copying mode. In addition, in Fig. 5, on the model surface of the copying model 4b, between points A-B-C-D and between points E-F-G-H are the two-dimensional copying mode of the copying plane X-Y, that is, the entire circumference of the contour. The copying mode between DE and E is a two-dimensional copying mode of the copying plane YZ. The range of copying modes shown in FIGS. 3 to 6 is regulated by a limit switch or a counter attached to the apparatus.

Here, the control algorithm for two-dimensional copying is generally expressed by the following equation, as already clarified in "MELDAS2200 type continuous two- and three-dimensional copying control device" (Mitsubishi Electric Technical Report VOL.40, NO11, 1966). It can be done.

However, F is the feed rate of copying, and Fα and Fβ are the feed rates of the copy control axis. Δε is a triaxial displacement vector value √ _x ² + _y ² + _z ² , and its sign differs depending on the feeding direction. εα and εβ are detected displacements of the copying control axis, and for example _, in the case of copying between points A-B- _CD in FIG.

In addition, cos (△ε−ε _p ) and sin (△ε
-ε _p ) is complicated to calculate, so it is often approximated by the straight line shown in FIG.

FIG. 8 shows a perspective view of an example of a surface unidirectional copying model. In Fig. 8, 4c is a surface unidirectional copying model,
Its surface is wavy and has peaks and valleys. Now, when the tracer head 2 moves along the surface of the copy model 4c from the copy start point A to the copy end B, the end point detection limit switch 41 is activated.
Point C where limit switch 42 operates from end point B
High-speed pulling is performed in the Z-axis direction until point A.
- Tracer head 2 by the same distance as the amount of copying movement between B.
moves between points C and D at high speed. Next, the tracer head 2 is pulled down at high speed to the approach start point E where the limit switch 43 is activated, performs an approach operation between points E and A, and comes into contact with the copying model 4c. Next, the tracer head 2 is pick-fed between points A and F, which is a direction rotated 90 degrees with respect to the direction of copying movement, and the same copying operation is repeated again.

By repeating this series of copying operations, the surface of the copying model 4c is copied in one direction, and highly accurate cutting is performed. Here, each operation of high-speed lifting between points B and C, high-speed movement between points C and D, and high-speed lowering between points D and E is performed while the tracer head 2 is separated from the surface of the copying model 4c in the air. This is an action that Therefore, it is desirable to perform the operations necessary for such aerial movement in as short a time as possible, which is particularly important for improving time efficiency when continuous one-way scanning is performed.

However, in the conventional copying control device, point B
The amount of pull-up during high-speed pull-up between points C and D is as follows: The amount of pull-up during high-speed pull-up between points C and D is
The range was determined so as not to cause collisions with the mountains. Furthermore, for example, when using a surface unidirectional imitation model 4d in which a portion of the model surface is locally raised to form a protrusion as shown in FIG. 9, solid lines in the figure that are unrelated to the protrusion may The amount of pull at the location indicated by and the amount of pull at the location indicated by the dashed line in the figure where the protrusion is located were all set to the same amount by the limit switch 42. For this reason,
The operation required for aerial movement at a location unrelated to the protrusion is wasted, and the time efficiency of the copying operation is correspondingly poor.

The present invention has been made in view of the above-mentioned conventional circumstances, and is configured to calculate and set the lifting amount of the end point of copying to a predetermined value according to the shape of the copying model, thereby performing copying operations with high time efficiency. It is an object of the present invention to provide a copying control device.

An embodiment of the present invention will be described below with reference to FIGS. 10 and 11. FIG. 10 is a block system diagram of one embodiment of the control device of the copying control device of the present invention;
The figure shows a longitudinal sectional view of an example of a one-surface copying model applied to the copying control device of the present invention.

In the control device 10 shown in FIG.
are excited by a sinusoidal voltage supplied from the excitation oscillator 17 via an amplifier, and when the tip of the stylus 11 contacts the copying model 4, the displacement ε
Generate _x , ε _y , and ε _z . The microcomputer 19 is supplied with the displacements ε _x , ε _y , ε _z detected by the tracer head 2 via the AD comparator 18, and calculates the profile feed speed F set by a speed setting device (not shown). The following control algorithm is calculated using equations (1) and (2). In addition, the output of the microcomputer 19 is sent to sample and hold circuits 31, 32 for each axis via a DA converter 30.
33, and based on this memory value, the amplifier 3
The speeds of the drive motors 7, 8, 9 for the X, Y, and Z axes are controlled via the drive motors 4, 35, and 36. The speeds of the respective drive motors 7, 8, 9 are detected by speed detectors 37, 38, 39 each comprising a tacho generator or the like and fed back.

A pulse generator 40 is directly connected to the Z-axis drive motor 9 and generates pulses in accordance with the rotation of the motor 9. 41 is an up-down counter which counts up when the Z-axis moves in the positive direction and counts down when it moves in the opposite direction. The microcomputer 19 updates the counter 4 at regular intervals.
The counter value of 1 is sampled and stored, and the highest point during the copying operation is determined from the counter value.

For example, the surface unidirectional copying model 4 shown in Fig. 11
When using e, from copying start point A (ZA) to copying end point B
By comparing the counter values at each point up to (ZB), the highest point H (ZH) of the traced portion is detected. The microcomputer 19 is at this highest point H.
(ZH) and the height of the end point B (ZB), ZH≧ZB
If so, set the value slightly larger than ZH − ZB to the end point B
Set as the amount of lift in . Also, ZH<
At the time of ZB, the amount of pulling at the end point B is set to zero.

In this way, when the required lifting amount during one copying operation is set, when the count amount of the counter 41 matches the set lifting amount during the pulling operation,
Z-axis drive motor 9 is stopped.

In this way, the control device 10 is configured to perform control so that the minimum lifting amount is always required depending on the shape of the copying model 4e when repeating one-way surface copying. Even when using a copying model 4d that has a protrusion on a part of its surface, the tracer head 2 can be returned from the copying end point B to the copying start point A in the shortest distance at any location, making it always time efficient. Copying operation can be performed.

Furthermore, since the control device 10 is configured to set the pull-up point C during the copying operation, a limit switch 42 for mechanically positioning the pull-up point C is provided.
can be made unnecessary.

As explained above, according to the copying control device of the present invention, in the surface unidirectional copying mode in which the tracer head copies the surface of the copying model in one direction, when the tracer head is pulled up from the copying model surface at the copying end point. Since the lifting amount is calculated and set to a predetermined value according to the surface shape of the copying model, for example, there is a part of the surface of the copying model where the height of the copying curve connecting the copying start point and the copying end point is higher than other parts. Even in such a case, by setting a different lifting amount for that specific location, unlike conventional equipment, even areas that are not needed can be set to the same lifting amount as that of the specific location, improving the time efficiency of copying. It is possible to eliminate the inconvenience caused by lowering the value, and this has the effect that efficient copying control is always possible regardless of the shape of the copying model.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an example of a copying control device to which the present invention is applied, Fig. 2 A, B, and C are side views and cross-sectional views of the tracer head portion at different positions, respectively, and Fig. 3 is a two-dimensional A perspective view of an example of a copying model, FIG. 4 is a cross-sectional view taken along the X-Z line in FIG. 3, and FIG.
-A perspective view of an example of a Y contour full-circumference copying model, Figure 6 is an X-Y sectional view of Figure 5, and Figure 7 is a cos(△ε-ε
_p ), −sin (△ε−ε _p ), a graph of the straight line used for linear approximation, Figure 8 is a perspective view of an example of a surface unidirectional copying model, and Figure 9 is an example of another surface unidirectional copying model. 10 is a block system diagram of an embodiment of the control device of the copying control device of the present invention, and FIG. 11 is a vertical sectional view of an example of a surface one-way copying model applied to the copying control device of the present invention. . 1... Copying control device, 2... Tracer head,
4, 4c, 4d, 4e... surface unidirectional copying model,
9... Z-axis drive motor, 10... Control device, 40
...Pulse generator, 41...Up-down counter.

Claims (1)

[Claims] 1 In a copying control device in which a built-in microcomputer calculates and controls the copying direction and copying speed based on the displacement of a tracer head that traces the surface of a copying model, the tracer head traces the surface of the copying model in one direction. In the copying mode, a means for detecting the height of the highest point of the traced portion according to the surface shape of the copying model, a means for storing the detected height, and a means for detecting the height of the highest point of the traced portion according to the surface shape of the copying model; 1. A copying control device comprising means for calculating and setting a lifting amount when lifting from a model surface by adding a certain set value to the stored height amount.