JPH04171161A - Reference hole position measuring method by touch sensor - Google Patents

Abstract

PURPOSE:To measure the position of a reference hole with high accuracy by rotating a touch sensor in such a way that a measuring element abuts against a definite position with respect to the measured position in the inner circumferential surface of the reference hole formed in a work as the moving direction of a spindle is changed. CONSTITUTION:The tip end 1c of the measuring element 1b of a touch sensor 1 provided for a spindle 2 is inserted into a reference hole wa by operating, the spindle 2. And they are relatively moved in the directions of X and Y, furthermore, the spindle 2 is rotated in such a way that the same position of the tip end 1c of the measuring element 1b abuts against the inner circumferential surface wc of the reference hole wa at all times, the position of the tip end 1c of the measuring element 1b which abuts against the inner circumferential surface wc, that is, the measured position is detected, so that the detected signal is thereby transmitted from an electric wave transmitting device 1e to a control device. And the center position of the reference hole w is thereby operated by the aforesaid control device based on the detected signal transmitted from the electric wave transmitting device 1e.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a reference hole using a touch sensor, which is mounted on the main spindle of a numerically controlled machine tool, etc., and used for detecting the reference position lf of the machining position of a workpiece, etc. Relating to a position measurement method.

(Prior art) For example, when changing the target work in a numerically controlled machine tool, or restarting machining after interrupting operation due to an emergency stop, etc., or forming a shape on the work W as shown in Fig. 7. When drilling new holes A and B using the reference hole Wa as a dimensional reference, an accurate center P of the reference hole is required. For this reason, for example, in a turret device,
As disclosed in Japanese Patent Application No. 202 and shown in FIGS. 5 and 6, the shaft head body provided with the touch sensor a is moved, and the probe a' of the touch sensor a is aligned with the reference hole Wa of the workpiece W. Insert the workpiece W to the reference hole number center Q in Figure 6.
As shown in the relative movement of the contact point a' with respect to Find it and position it at its center. As a result, the true center P of the reference hole Wa is positioned, a correction value for the temporary center Q is calculated, and the origin is corrected.

It has been proposed that each hole is machined based on the corrected origin.

(Problem M to be Solved by the Invention) According to the above-mentioned prior art, the probe of the touch sensor is brought into contact with the inner periphery of the reference hole at two points in the X-axis direction and two points in the Y-axis direction, and The center of the reference hole can be easily determined. However, when attaching a touch sensor to the spindle of a machine tool, especially if the contact tip is long, the tip of the touch sensor may be misaligned with the center axis of the spindle. For some reason, it may be bent, resulting in misalignment between the tip of the probe and the center axis of the main shaft. These misalignments cause variations in measurement accuracy, causing problems such as variations in the measurement accuracy of the center position of the reference hole.

Therefore, an object of the present invention is to maintain the center position of the reference hole at a high level even if misalignment occurs between the center axis of the main shaft and the tip of the probe due to attachment of the touch sensor to the main shaft or bending of the probe. The purpose of this paper is to propose a method for measuring the position of semi-holes using a touch sensor that can measure accurately.

(Means for Solving the Problems) In order to achieve the above object, a reference hole position measuring method using a touch sensor according to the present invention is provided by attaching the touch sensor to the main spindle of a machine tool, moving the headstock as appropriate, and measuring the position of the reference hole by moving the headstock appropriately. In the method of measuring the reference hole position using a touch sensor that detects when the tip of the probe has contacted the workpiece, the contact point of the tip of the probe remains constant with respect to the measured location on the inner peripheral surface of the reference hole formed in the workpiece. The touch sensor body is rotated as the direction of movement of the main axis is changed, and when the probe comes into contact with the measurement target, a detection signal is emitted from a radio wave transmitter disposed within the sensor body.

(Example) An example of the reference hole position measuring method using a touch sensor according to the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a touch sensor 1 used in this embodiment, and FIG. 2 is an overall explanatory diagram of a machine tool also used in this embodiment.

The touch sensor 1 includes a touch sensor main body 1a, a rod-shaped measuring tip 1b protruding from the touch sensor main body 1a, and a shank portion 1d.The shank 1d is inserted into a taper hole 2a formed in the main shaft 2 of a numerically controlled machine tool, for example, as a tool. The main shaft 2 is moved in the appropriate direction to attach the sensor body 1.
This is to electrically detect that the tip IC of the probe 1b protruding from the contact point a has come into contact with the workpiece W. The probe 1b of the touch sensor 1 is an automatic centripetal device (not shown).
The tip IC of the probe 1b is biased to align with the center axis of the sensor body 1a, that is, the center axis of the main shaft 2, and is mounted on the sensor body 1a.
Even if the sensor is tilted by 0 degrees in any direction, a tilt detection switch (not shown) provided in the sensor main body la is activated to detect the tilt. When the tilting of the probe 1b is electrically detected by the tilting detection switch,
Based on the detection, a detection signal is emitted from the radio wave transmitter 11E1e disposed within the sensor main body la to the control panel 3 of the machine tool shown in FIG. Note that 1f is a power source that operates the radio wave transmitting bag @1e.

In order to measure the position of the reference hole Wa of the tool W set on the jig 4 as shown in FIG. 2 using the touch sensor 1, the main shaft 2 is moved and the touch Insert the tip 1c of the probe 1b of the sensor 1 into the reference Wa, move it relative to the The main shaft 2 is rotated so that the inner circumferential surface WC and the tip IC of the probe 1b come into contact with each other, that is, the location to be measured is detected, and each detection signal is transmitted from the radio wave transmitter t1e to the control device 3. , the radio wave transmitting device 1e is controlled by the control device f3.
This is done by calculating the center position of the reference hole W based on the detection signal transmitted from the reference hole W.

Specifically, the relative movement of the touch sensor 1 with respect to the workpiece W for which the reference hole Wa is measured using the touch sensor 1 is described in the third example.
This will be explained using figures.

The main shaft 2 is advanced so that the tip 1c of the measuring element 1b of the touch sensor 1 attached to the main shaft 2 is located within the reference hole Wa formed in the workpiece W, and the center axis l of the main shaft 2 and the reference hole Wa are moved forward.
Let the intersection point be the tentative center Q of the reference hole Wa. The tip of the probe 1b of the touch sensor 1! 1! For example, 1 in Figure 1
Assume that there is a misalignment of the center axis of the main shaft 2 by a dimension of 0, as shown by 0, and that the tip 1c of the measuring tip 1b is located at a point a, which is displaced by a dimension of 0 from the temporary center Q, for example. . In this state, the tip 1c of the measuring stylus 1b is brought into contact with the inner peripheral surface WC of the reference hole Wa by relatively moving in the X-axis direction, and the measuring point X, which is the abutting position, is moved.

to be detected. The measurement point X detected by the touch sensor 1 is transmitted as a detection signal to the control device 3 by the radio wave transmitter [1e] and inputted thereto.

Next, return the main shaft 2 so that the central axis l of the main shaft 2 coincides with the temporary center Q, rotate the main shaft 2, and therefore the touch sensor 1, 180 degrees, and position the tip IC of the contact stylus 1b at point b. . Next, the tip IC of the probe 1b is moved along the X axis.
is moved in the opposite direction to the measured point XI, and is brought into contact with the inner peripheral surface we to detect the measured point X2, and the radio wave transmitting device 1
A detection signal is issued to the control device 3 by e. Control device 3
, the center of XI and X2 in the X-axis direction from the measured point X,, X2! ff1Q, wo performance > E formula (X, -X,
) Ask for /2 Niyo.

At this time, the displacement dimension l between the center axis l of the main shaft 2 and the tip IC
l is the measurement point L- formed on the workpiece W by rotating the main shaft 2 and therefore the touch sensor 1 by 180 degrees.
Since the contact point of the tip 1c of the measuring element 1b with respect to Xn is fixed, it is corrected, and the measured point XI, X! with respect to the accurate temporary center Q is corrected. The positions of X and X are measured.
The center position IEQ of 2 can be accurately determined. Next, move the main shaft 2 so that the center axis J of the main shaft 2 coincides with the center position QI.
, and further rotate the main shaft 2 by 90 degrees to position the tip IC of the probe 1b at the 0 point. Subsequently, the tip IC of the probe 1b is moved along the Y-axis and brought into contact with the inner circumferential surface WC to detect the measurement point YI, which is transmitted by the radio wave transmitter 1e to the control device W3 for input.

Next, move the main shaft 2 so that the center axis 1 of the main shaft 2 coincides with the center position 1fQ of the X-axis, and move the main shaft 2 to 18
Rotate 0 degrees and position the tip IC of the probe 1b at point d. Next, the main shaft 2 is moved along the Y-axis in the opposite direction to the point to be measured Y, and the tip IC of the probe 1b is brought into contact with the inner circumferential surface we to detect the point to be measured YII, and the radio wave transmitter 1
e is sent to the control device 3 as a detection signal. The control device 3 determines the measurement point Y*=Y from Ya, and Ys.
The center position of t is determined by the calculation formula (Ya - Ya)/2, and the true center P of the reference hole Wa is determined. At this time, since the main shaft 2 is rotated and the touch sensor 1 is rotated 180 degrees, the displacement dimension between the central axis l of the main shaft 2 and the contact point IC is determined by the contact of the tip 1c with respect to the measurement points Y and Y2. The contact point becomes constant and the displacement dimension l.

is corrected, the position of the measured point Yl-Y2 with respect to the accurate center position 1fQ on the X axis is accurately obtained, and the center positions of the measured points Y and Y2 are accurately determined. Next, a correction value for the tentative center Q is calculated using the true center P, and each hole is machined based on the corrected origin.

Next, an example of relative movement of another touch sensor 1 with respect to the reference hole Wa for measuring the reference hole Wa using the touch sensor 1 will be explained with reference to FIG.

The main shaft 2 is advanced so that the tip *1c of the probe tb of the touch sensor 1 attached to the main shaft 2 is located in the reference hole Wa, and the central axis l of the main shaft 2 is set as the tentative center Q of the reference hole Wa. . At this time, it is assumed that the tip IC of the probe 1b is located at a point a displaced by a distance l from the tentative center Q. In this state, the tip IC of the probe 1b is brought into contact with the inner circumferential surface WC by relative movement in the X-axis direction to detect the point to be measured X, and send a detection signal t to the radio wave transmitter! 1 e to the control device 3. Next, the main shaft 2 is returned to the temporary center Q, and the main shaft 2 is rotated 180 degrees to position the tip of the probe 1b at point b. Next, move the tip 1c of the probe 1b in the direction opposite to the point to be measured X along the X-axis,
The measuring point X2 is detected by contacting the inner circumferential surface WC and transmitted to the control device 3. In the control device W13, the center position in the X-axis direction is calculated using the calculation formula (XI
−L)/2. At this time, the displacement between the central axis of the main shaft 2 and the tip IC is corrected by rotating the main shaft 2, and thus the touch sensor 1, by 180 degrees. Next, the main shaft 2 is returned to the temporary center Q, and the main shaft 2 is rotated by 90 degrees to position the tip 1c of the probe 1b at the 0 point, and the main shaft 2 is moved along the Y axis, and therefore the tip of the probe 1b is rotated 90 degrees. I
Move C to detect and control the measurement point Yl! ! ! 3
Sends a detection signal to Next, the main shaft 2 is returned to the temporary center Q, and the displacement dimension 2I between the center axis of the main shaft 2 and the tip IC is
In order to correct this, rotate it 180 degrees and position the tip IC at point d. Next, move the main shaft 2 along the Y-axis in the opposite direction to the point to be measured Y, and therefore move the tip IC to detect the point to be measured Y at the same point on the tip IC of the probe 1b and send it to the control device 3. Send. The control device 3 selects the measurement point Y,
and Y2, calculate the center position in the Y-axis direction using the formula (Y, -Y,
) / 2, and determine the true center P of the reference hole Wa along with the center position in the X-axis direction. As a result, a correction value for the previous provisional center Q is calculated, and each process is performed based on the corrected origin.

(Effects) According to the reference hole position measuring method using a touch sensor according to the present invention described above, the direction of movement of the main shaft is such that the contact point of the contact point with respect to the measurement point on the inner peripheral surface of the reference hole formed in the workpiece is kept constant. Since the touch sensor is rotated as the touch sensor changes, even if there is misalignment between the center axis of the spindle and the tip of the probe, the misalignment is corrected and the position of the reference hole can be measured with high precision. .

[Brief explanation of the drawing]

Fig. 1 is a side view of a touch sensor used in an embodiment of the reference hole position measuring method using a touch sensor of the present invention, Fig. 2 is an overall illustration of the machine tool, and Fig. 3 is also an illustration of the measuring method. Figure 4 is a diagram showing the relative movement of the touch sensor with respect to the workpiece. Figure 4 is a diagram showing the relative movement of the touch sensor with respect to the workpiece to explain another measurement method. Figures 5 to 7 are reference hole position measurement using a conventional touch sensor. It is an explanatory diagram of a method. , 1...Touch sensor, 1a...Sensor body,
1b--Measure head, IC...tip, 1e...Radio wave transmitting side L1f...power supply, 2...main axis, 3...control V
& Place, W... Work, w a "' Reference hole-1L-X
*, Yt-Yt... Patent attorney representing the area to be measured 1) Osamu Kuro Figure 1 I2WJ s3 Figure Y2 Figure 4 Figure 5 Figure 6 Figure 7

Claims (2)

[Claims] (1) A reference hole position measurement method using a touch sensor, which is attached to the main spindle of a machine tool and moves the headstock as appropriate to detect when the tip of a probe provided on the sensor body comes into contact with the workpiece, is formed on the workpiece. The touch sensor body is rotated as the direction of movement of the spindle is changed so that the point of contact of the tip of the probe to the point to be measured on the inner peripheral surface of the reference hole remains constant, and the contact point is brought into contact with the point to be measured. A method for measuring a reference hole position using a touch sensor, characterized in that when the sensor body detects a detection signal, a detection signal is emitted from a radio wave transmitter disposed within the sensor body. (2) The control device receives the detection signal from the radio wave transmitting device and changes the position of the main shaft when the contact point contacts the X-axis and Y-axis measurement points to the reference hole that serves as the reference for the machining position of the workpiece. 2. The reference hole position measuring method using a touch sensor according to claim 1, wherein the center is calculated.