JPH0429509B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a copying machine used for machining molds and the like.

Prior Art In a copying machine, before starting copying operation, the model on the copying table and the workpiece on the table are aligned with each other. During this alignment, a scribing needle-like stylus as shown in Figure 3 is attached to the tracer head and the processing spindle, and the scribing lines on the model and workpiece are aligned on the X and Y axes as shown in Figure 1. After alignment and centering with the stylus at , the stylus of the tracer head is replaced with a stylus having various ball radii that fit the model curved surface.
Also, copying operation is performed by replacing the stylus on the main shaft with a cutter. The same can be said of digitizers.

Problems to be Solved by the Invention There is no problem if the stylus is not replaced at all, but when replacing the stylus and adhering it to the tracer head, the tightening of the set bolt may cause problems such as those shown in Figure 4.
As shown in FIG. 5, when the central axis of the stylus is installed at an angle, a deflection of ΔS may occur at the contact position. Furthermore, due to processing accuracy, bending, etc. of the stylus, if tracing control is performed in this state, the ΔS shape will deviate from the model shape, resulting in a problem of poor accuracy.

Measures to solve the problem A stylus centering station for correcting the machine origin when changing the stylus is installed at a position on the model table where the stylus of the tracer head can be positioned using NC. An inverted truncated cone-shaped concave portion having a cone angle larger than the apex angle or an inverted truncated pyramid shape having a surface parallel to the X-axis direction and a surface parallel to the Y-axis direction and a cone angle larger than the stylus apex angle is formed; The recess is provided with a reference horizontal bottom surface in the Z-axis direction, and is adapted to cope with misalignment of various types of styli.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings, taking a copying machine as an example.

In a large processing machine with 6-axis control, a table 2 movably placed on a guide surface on a bed 1 is operated by a feed screw 4 rotated by a drive motor 3 controlled by an MC or copying command. The position is controlled in the X-axis direction. Columns 5, 5 installed on both sides of the bed 1 are formed into a gate shape by a top beam 6, and furthermore, a cross rail 7 is provided on the front surface of the column 5 so that the height can be adjusted. A spindle head 8 movably mounted on the front horizontal guide surface of the black frame 7 is position-controlled in the Y-axis direction by a feed screw 10 rotated by a drive motor 9 controlled by an NC or copying command.
A spindle quill 12, which rotatably supports a spindle 11, is movably supported in the axial direction (Z-axis direction) on the spindle head 8, and a feed screw (not shown) is rotated by a drive motor 13 controlled by an NC or copying command. The position is controlled in the Z-axis direction by. On the other hand, on the copying side, a copying table 22 is slidably placed on the guide surface of the bed 21.
is the drive motor 2 controlled by NC or copying commands.
The position in the X-axis direction is controlled by a feed screw 24 rotated at 3. A stylus centering station 35 is provided at a corner of the copying table 22. In this station, the stylus 31 is provided within the positioning range of the X and Y axes, and a truncated pyramid-shaped recess 37 that has opposing sides parallel to the X and Y axes, is narrow at the bottom, and is a horizontal plane with a flat bottom. is formed, and its center position and reference horizontal bottom b position are NC
is stored in The inclination angle θ of this pyramidal surface is made to be an angle that can be measured for any shape of the stylus used. That is, the pyramidal angle is made larger than the stylus apex angle, so that the tip of the needle-like stylus can come into contact with the inclined surface. Note that depending on the stylus, it is also possible to use a square cylinder or a cone instead of the pyramid. Column 2 on both sides of bed 21
5, 25 are established and formed into a gate shape by a top beam 26, and a spindle head 27, which is slidably mounted on a horizontal guide surface in front of the top beam 26, is rotated by a drive motor 28 controlled by an NC or copying command. The position is controlled in the Y-axis direction by a feed screw 29.

The spindle head 27 has a replaceable stylus 3 at its tip.
1 or 38 or 39 and outputs signals at displacements ε _X and ε _Y in the X-axis and Y-axis directions, and outputs signals at displacement ε _Z in the Z-axis direction A feed screw 3 is provided with a quill 30 that is slidably supported in the axial direction, and is rotated by a drive motor 33 that is controlled by an NC or copying command.
4, the position is controlled in the Z-axis direction. Next, regarding a 3-axis controlled small processing machine, as shown in Figure 2,
A saddle 42 is placed on the upper surface of the saddle 42 so as to be slidable in the Y-axis direction, and its Y-axis position is controlled by a feed screw rotated by a motor (not shown) that is controlled by an NC or copying command. A table 43 is placed on the upper surface of the saddle 42 so as to be slidable in the X-axis direction, and its position in the X-axis direction is controlled by a feed screw rotated by a motor (not shown) that is controlled by an NC or copying command. A column 44 is installed at the rear end of the bed 41, and a spindle head 45 is attached to the column 44 so as to be able to slide up and down by a vertical guide surface on the front surface of the column, and the feed screw is rotated by a motor that is rotated by an NC or copying command. The position in the Z-axis direction is controlled by . The spindle head 45 has a spindle 46 on which a tool is attached rotatably supported vertically, and a tracer head 47 on which a replaceable stylus 53 is attached is provided on an arm 46 extending laterally. The position of this tracer head 47 in the X-axis direction is corrected by a screw rotated by an X-axis correction handle 48, the position in the Y-axis direction is corrected by a screw rotated by a Y-axis correction handle 49, and the position in the Y-axis direction is corrected by a screw rotated by a Y-axis correction handle 49. It is vertically mounted on a tracer stand 51 which is adjustable in height so that it can be corrected by a gear rotated at 50. Each of the handles can also be connected to a servo motor for automatic correction. A workpiece is placed and fixed on the same surface of the table 43 directly below the spindle 46, and a model is placed and fixed directly below the tracer head 47. A centering station 52 is provided at the end on the model side. , the X-axis, and the Y-axis, respectively, and are formed with a truncated pyramid-shaped recess that is narrowed at the bottom, and is positioned under the tracer head 47 during centering.

Function First, in the 6-axis control profiling machine, mark lines that serve as reference positions on the surface plate are placed at the center of each edge in the X-axis direction and Y-axis direction.For model M, Mxa,
Mxb; Mya, Myb Wxa, Wxb for workpiece W;
The model M is placed on the copying stand 22 and the workpiece W is placed on the table 2. Using an automatic tool changer or manual operation, attach and fix the stylus 31 and 36, respectively, to mark the scribe lines Mxa and Mxb of the model M and the scribe lines Wxa and Wxb of the workpiece W on the table 2. At the same time, centering in the X-axis direction is performed, and then the styli 31, 3
6 at the center of the Y-axis, move it in the X-axis direction, align the marking lines Mya and Myb of the model M, and the marking lines Wya and Wyb of the workpiece W, perform centering in the Y-axis direction, and fix them respectively. . This scribing position is stored as the machine origin X0, Y0 of the X, Y coordinates. Next, tracer head 30 is moved to copying table 2 using NC.
Move to the centering station 35 at the second end, and as shown in FIG. 6, first position the stylus 31 at the center of the pyramidal recess 37 in order to bring the stylus 31 into contact with the inclined surfaces a1 and a2 parallel to the Y axis, and adjust the height of the inclined surfaces a1 and a2. The tracer head 30 is positioned by Z-axis control using NC so that it abuts at approximately the center of the head. Move the tracer head 30 in the +X direction by controlling the X axis and move the stylus 3.
1 is brought into contact with the slope a1 and displaced by a preset amount of displacement ε, and a signal is output, the X coordinate value Xa1
Then, when the tracer head 30 is moved in the -X direction and the stylus 31 is brought into contact with the slope a2 and displaced by ε, the signal is output, the X coordinate value Xa2
The central reference position PX0 of Xa1 and Xa2 is calculated by the control device and stored. Similarly, move the tracer head 30 in the +Y direction and -Y direction and
Two planes a3 and a4 parallel to the axial direction (not shown)
Contact the stylus 31 to read the X-axis coordinates Ya3 and Ya4 at the time of signal output, and find the center reference position.
Calculate and store PY0 using the control device. When the stylus 31 is first replaced with the spherical stylus 38 for copying in order to perform copying, the X-axis coordinate values Xa'1, Read Xa′2
The center reference position PX1 of Xa'1 and Xa'2 is calculated.
Then, the difference between the stylus 31 and the reference position PX0 is determined. If the difference is zero, the stylus 38 is in the same state as the stylus 31 in the X-axis direction, so the mechanical origin X0 may be the same, but if there is an error ΔSX1, X1, which is offset by ΔSX1 from the mechanical origin X0, is set to the X-axis unique to the stylus 38. The origin of the machine. Similarly, if there is an error ΔSY1 in the Y-axis direction, the machine origin Y
Y1, which is offset by ΔSY1 from 0, is set as the mechanical origin of the Y-axis unique to the stylus 38, and copying is performed based on this. Note that since the stylus and tool are attached to the main shaft 11 accurately by taper fitting, there is no need to check with a centering gauge. When the spherical stylus is replaced with a stylus of a different diameter due to a change in the tracing surface, the reference position of the stylus 31 is first set using the same procedure as above.
Find the errors ΔSX2 and ΔSY2 from PX0 and PY0, offset the origin to the machine origin X0 and Y0, and
2. Copy processing is performed using Y2 as the unique mechanical origin of the stylus. Thereafter, each time the stylus is changed, centering is performed, correction is made, and copying is performed. Furthermore, if you want to know the Z-axis position of a predetermined position of the model M, you can find the Z-axis position when the stylus 38 is brought into contact with the reference horizontal bottom surface b of the centering gauge 35 and a signal is output when the stylus 38 is displaced by ε0. It is possible to know this by storing it as a Z-axis numerical value and moving the stylus to a predetermined position on the model M and abutting it. Furthermore, by equipping the copying machine with a tool length measuring device and combining it with the above, Z
Automatic positioning of the copying side and the machining side of the axis is also possible. In the three-axis control copying machine shown in FIG. 2, the positions of the saddle 42 and table 43 are controlled, the centering station 52 similarly checks the center of the stylus, the machine origin is corrected by the displacement, and copying is performed.

Effects As detailed above, the present invention provides a centering station on a copying table, forms a concave recess in the form of a truncated cone or a truncated pyramid with a cone angle larger than the stylus apex angle, and forms the bottom of the recess in the centering station. By using this recess as a reference horizontal plane, the amount of misalignment can be measured at the time of replacing and installing the stylus, making it possible to correct the mechanical origin unique to the stylus, allowing accurate tracing regardless of the accuracy inherent to the stylus and its installation accuracy. Processing can be achieved. In addition, the stylus is brought into contact with the reference horizontal bottom surface, its position is memorized, and the Z-axis position can be known by contacting the stylus with a predetermined position on the model.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a 6-axis control profiling machine, Figure 2
The figure is a schematic diagram of a 3-axis control copying machine, Figures 3, 4, and 5 are diagrams showing the stylus, Figure 6 is a centering diagram of the scribing needle stylus, and Figure 7 is a spherical stylus. FIG. 2...Table, 7...Cross rail, 8...
Spindle head, 11... Main spindle, 22... Copying table, 27...
...Spindle head, 30, 47...Tracer head, 3
5, 52... centering station, 31, 36,
38, 39...Stylus, M...Model, W...
...Workpiece.

Claims (1)

[Claims] 1. A stylus centering station is provided at a position on the model table where the stylus of the tracer head can be positioned using NC to correct the machine origin when replacing the stylus, and the centering station has a cone angle larger than the stylus apex angle. A recess is formed in the shape of an inverted truncated cone or an inverted truncated pyramid having a plane parallel to the X-axis direction and a plane parallel to the Y-axis direction and a pyramidal angle larger than the stylus apex angle. A copying machine with a stylus automatic centering function, which is equipped with a horizontal bottom surface and can cope with misalignment of various types of styli.