JPH03121751A - Preciseness measuring device for machine motion - Google Patents

Abstract

PURPOSE:To measure the preciseness of the circular motion due to relative biaxial motion of a spindle with table accurately in a short time without machining a work actually, by allowing a displacement measuring means to measure the periphery of a master gauge always from the radial direction when the spindle is making circular motion in the area to the table. CONSTITUTION:A displacement sensing means 6 rotates round a master gauge 9 and senses the displacement in the radial direction always. The master gauge 9 is mounted on the housing 2 for a rotary shaft 2a, i.e., at the fixation part. Therefore, no error due to rotation will be generated to ensure measuring the displacement of circular motion due to relative biaxial motion of the spindle 1 with table precisely.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a motion that measures the accuracy of circular motion by relative two-axis movement between the main axis and table of a machine such as a machine tool or a three-dimensional measuring machine. Use precision measuring equipment.

[Conventional technology]

When measuring circular motion accuracy due to relative two-axis movement between the tool spindle and worktable of a machine tool, conventionally the workpiece was actually cut, the workpiece was moved to another location, and the true Circularity was actually measured using a roundness measuring device for measuring object shapes. In this way, the accuracy of the circular motion of machine tools was evaluated and the circular motion programs used to operate the machine tools were corrected.

Also, as stated on pages 148 to 154 of the June 1985 issue of the magazine "Precision Machinery" published by the Japan Society of Precision Machinery,
As a device that directly measures the relative circular motion accuracy between the spindle and table in machine tools, coordinate measuring machines, etc.
A spherical seat is provided on the main shaft and table, and a measuring bar with balls at both ends is attracted to both spherical seats using a magnet to perform relative circular motion.The measuring bar is restrained by a strain gauge built into the measuring bar. There is a system that measures the momentary displacement between the main shaft and the table from the strain that occurs when the table moves in a circular motion.

[Problem to be solved by the invention]

In this conventional method, first of all, in the former case, two steps are required to measure the -degree: cutting the workpiece and actually measuring the roundness, and it takes a lot of man-hours to measure the roundness by changing the conditions many times. Requires.

■Since the cutter radius is not zero, the motion locus of the tool spindle itself is not transferred to the cutting surface, and in particular,
- It is not possible to accurately evaluate the relationship between the stick motion that occurs when switching quadrants on the Y-axis and the behavior of the tool spindle.

There were other problems.

Furthermore, the latter conventional technology requires (1) a spherical seat with a magnetic attraction means and a special measuring bar with balls at both ends and a built-in strain gauge, making it difficult and expensive to manufacture;

■Since both ends of the measuring bar are restrained by spherical seats, the measuring bar usually tilts, and the displacement cannot be determined unless the cosine error is corrected.

There were other problems.

The purpose of the present invention is to quickly and highly improve the accuracy of circular motion by relative two-axis movement between the main axis of the machine and the table without actually cutting the workpiece, and with an inexpensive and easy-to-handle device. An object of the present invention is to provide a motion accuracy measuring device that can measure accurately.

[Means to solve the problem]

In the present invention, the attitude control axis is interposed between the rotation axis on the spindle side and the rotation axis on the table side, and when a relative circular movement is performed between the spindle and the table, the displacement measuring means is always in the radial direction. This makes it possible to measure displacement in circular motion from any direction. Specifically, the first invention provides a motion accuracy measurement device that measures the motion accuracy of circular motion by relative two-axis movement between a spindle and a table, including a rotation axis provided on the spindle side, a rotating shaft provided on the table side substantially parallel to the axis; and one rotating shaft is fixed to the other rotating shaft so that the same point always faces the other rotating shaft and performs the circular motion relative to the other rotating shaft, An attitude control axis that is movably engaged with the other rotation axis only in the radial direction, a rotation axis to which the attitude control axis is fixed, or a displacement measuring means provided on the attitude control axis, and the attitude control axis a circular mask gauge fixed coaxially to the rotary shaft housing movably engaged with the rotary shaft; and when the main shaft performs the circular movement with the table, the displacement is measured. A motion accuracy measuring device characterized in that the means always measures the outer circumference of the master gauge from the radial direction, or a motion accuracy measuring device that measures the motion precision of circular motion by relative two-axis movement between the main axis and the table. , a rotating shaft provided on the main shaft side, a rotating shaft provided on the table side substantially parallel to the rotating shaft, and one rotating shaft is always facing the same point around the other rotating shaft, and the rotating shaft is relatively aligned with the above-mentioned circle. an attitude control shaft that is fixed to one rotating shaft so as to perform a motion and is movably engaged with the other rotating shaft only in the radial direction; and a rotating shaft that is movably engaged with the other rotating shaft; a circular master gauge fixed coaxially to a housing of a rotating shaft to which the attitude control shaft is fixed; When the movement is performed, the displacement measuring means always measures the outer circumference of the master gauge from the radial direction. Furthermore, a second invention is a motion accuracy measuring device for measuring the motion precision of circular motion due to relative two-axis movement between a main shaft and a table,
A rotating shaft provided on the main shaft side, a rotating shaft provided on the table side substantially parallel to the rotating shaft, and one rotating shaft is always facing the same point around the other rotating shaft, and the circular movement is performed relative to the other rotating shaft. an attitude control shaft that is fixed to one rotating shaft and is movably engaged with the other rotating shaft only in the radial direction; and a reference block provided on a rotating shaft to which the attitude control axis is fixed or a reference block provided on the attitude control axis and having a reference surface on which the displacement measurement means measures the displacement, When performing the circular movement with the table, the displacement measuring means always faces the reference block in the same posture and performs the measurement, or the relative displacement between the main shaft and the table is In a motion accuracy measurement device that measures the motion precision of circular motion by two-axis movement,
A rotating shaft provided on the main shaft side, and a rotating shaft provided on the table side substantially parallel to the rotating shaft, so that one rotating shaft always faces the same point around the other rotating shaft to perform the circular motion. an attitude control shaft that is fixed to one rotating shaft and movably engaged with the other rotating shaft only in the radial direction, and a rotating shaft to which the attitude control shaft is fixed or a displacement provided on the attitude control shaft and a reference block provided on a rotating shaft movably engaged with the attitude control shaft and having a reference surface on which the displacement measuring means measures displacement, the main shaft being connected to the table. When performing the circular motion between the two, the displacement measuring means always faces the reference block in the same posture and measures the displacement.

[For production]

In the first invention, the displacement detecting means rotates around the mask gauge and can always detect displacement in the radial direction. Since the master gauge is attached to the housing of the rotating shaft, that is, the fixed part, the displacement of circular motion can be measured with high accuracy without errors caused by rotation.

Furthermore, in the second aspect of the invention, the displacement detecting means can always face the reference block in the same posture and measure displacement, and there is no need to particularly manufacture a master gauge.

〔Example〕

FIG. 1 is a diagram showing the main part of an embodiment of the first invention. 1st
In the figure, 1 is a tool spindle of a machine tool, 1a is a chuck attached to the tool spindle 1 via a taber shank, 2 is a housing gripped by the chuck 1d and contains a rotating shaft 2a, and 2b is a housing for connecting the rotating shaft 2a to a housing 2. 2C is a seal, and 3 is a bearing 2 at the bottom of the rotating shaft 2a.
A posture control shaft is inserted horizontally into the crotch portion 4 and fixed with a screw so that it can be slid in the axial direction according to the radius of circular motion. 6 is a fixed block screwed to the bottom of the posture control shaft 3. 5 is a wireless micrometer attached and can be moved forward and backward in the attitude control axis direction by means of a fine adjustment screw 3a; 7 is a measuring tip at the tip of the wireless micrometer 6;
8 is a transmitting antenna of the wireless micrometer 6; 10 is a housing having a master gauge 9 formed on its outer periphery as a reference for circular motion whose roundness is guaranteed in advance; 10a is rotatably supported by the housing 10 by a bearing 10b; A rotation axis on the table side provided parallel to the rotation axis 2a on the main shaft side,
10c is a seal, 10d is a shaft groove at the tip of the rotary shaft 10a which allows the attitude control shaft 3 to be slidably received only in the axial direction of the attitude control shaft 3, and 11 is a shaft groove for placing the housing 10 on the table T of the machine. Base to be fixed, 12 is phase detection plate 12
This is a phase detection proximity switch that detects the rotational phase of the rotary shaft 10a via a.

In such a configuration, the tool spindle 1 and the mask gauge 9
A circular motion is performed by relative two-axis movement between the mask gauge and the table T on which it is attached, and the accuracy of the circular motion at that time is checked by simultaneously contacting the measuring tip 7 of the micrometer 6 that rotates with the outer periphery of the mask gauge 9. The displacement is measured and transmitted from the transmitting antenna 8 of the wireless micrometer. In this way, by using a wireless method instead of a wired method, it is possible to continuously measure circular motion data for many rotations.

The attitude control shaft 3 freely slides in the radial direction within the shaft groove 10d of the housing 10, and is mounted so as not to put a load on the gauge head 7, so that displacement in the radial direction can always be measured. . Therefore, the displacement direction of the probe 7 of the micrometer 6 always points toward the center of the master gauge 9, and by changing the fixed position of the posture control shaft 3, the rotation radius of the circular motion of the tool spindle 1 can be adjusted. can be easily changed. Although it is possible to measure even if the micrometer 6 is attached directly to the rotation axis 2a, it is better to attach it to the attitude control axis 3 when changing the rotation radius. It is convenient because the radius can be adjusted all in one piece.

Further, the phase detection proximity switch 12 detects the rotational position of the quadrant switching of the circular motion of the tool spindle 1 in the X-Y plane ( The rotation angle θ) is detected.

Here, the master gauge 9 may be provided in the housing 2 on the main shaft side, the micrometer 6 may be provided on the rotating shaft 10a on the table side, and one end of the attitude control shaft 3 may be fixed to the rotating shaft 10a. , the other end is 2 at the lower end of the rotating shaft 2a.
It may be slidably engaged with the crotch groove.

FIG. 2 is a diagram showing the main parts of an embodiment of the second invention. Here, the same reference numerals are given to the same components as in FIG. 1. In the second section, 13 is a reference block for a surface to be measured that is adjustable and fixed at a predetermined position on the attitude control shaft 3, and 14 is an upper part of the rotating shaft 10a facing the reference block 13 for a surface to be measured at a predetermined interval. 15 is displacement meter 1
This is a rotary connector that receives the signal line No. 4, and allows connection regardless of the rotational position of the displacement meter 14.

In such a configuration, when a circular motion is performed by relative two-axis movement between the tool spindle 1 and the table T, the displacement of this circular motion is measured by the reference block 13 for the surface to be measured and the displacement meter 1.
4, and the output of the displacement meter 14 is outputted via the rotary connector 15. In this case, by using the rotary connector 15, circular motion data for many rotations can be continuously measured.

As mentioned above, only the displacement in the radial direction can always be measured using the attitude control axis 3, and the position where the attitude control axis 3 is fixed to the lower part 4 of the rotating shaft 2a can be adjusted without attaching the reference block 13 for the surface to be measured. The radius of rotation of the circular motion of the main shaft 1 can be easily changed.

Here, the reference block 13 may be provided on the rotating shaft 10a, and the displacement meter 14 may be provided on the attitude control shaft 3 on the rotating shaft 2a side. Alternatively, one end of the attitude control shaft 3 may be fixed to the rotating shaft 10a, and the other end may be slidably engaged in a bifurcated groove at the lower end of the rotating shaft 2a.

FIG. 3 is a schematic system configuration diagram of the motion accuracy measuring device of the device shown in FIG. A loop antenna 16 that receives the signal from the transmitting antenna 8 is installed near the transmitting antenna 8 and at an appropriate location so as not to interfere with the rotational movement of the micrometer 6 on the outer periphery of the mask gauge 9.
7, the waveform is observed using, for example, an oscilloscope 18. Furthermore, the computer 19 calculates the circular motion quadrant switching position signal from the proximity switch 12, records the roundness display on the pen recorder 20, and records the circularity display on the pen recorder 20.
9 can be displayed on the screen.

In the case of the wired system shown in FIG. 2, the signal is received by the receiver 17 via a signal line from the rotary connector 15, and post-processing is performed in the same way. There is also a method of detecting the quadrant switching position signal of the circular motion without using the proximity switch 12 from the switching timing of the positive and negative signs of the X and Y axis command values issued by the NC device (not shown).

FIG. 4 is a flowchart showing the procedure for measuring roundness. This figure shows the case of the invention shown in FIG. First, base 11
is fixed on the machine table T using a clamp jig (step 1). In this case, in order to specify the position of the proximity switch attached to the base 11, a flat portion is provided on a portion of the outer periphery of the base 11, and this flat portion is made parallel to the X axis. Next, the loop antenna 16 is placed at a predetermined position and connected to the receiver 17 (2). Next, in order to align the center of the master gauge 9 with the center of the tool spindle 1, centering is performed by adjusting the feed amounts of the X and Y axes (3). Next, the housing 2 is set on the chuck 1a attached to the tool spindle 1, and the tool spindle 1 is clamped so that it does not rotate (4). Next, the radius R of the circular motion of the tool spindle 1 from the center of the master gauge 9
Move the tool spindle 1 in the X-axis direction or Y-axis direction while watching the feed axis counter of the NC device (not shown).
5〉. Next, a circular motion program for the tool spindle 1 is programmed (6).

Next, the Z-axis is sent to engage the attitude control shaft 3 in the shaft groove 10d of the rotating shaft 10a, and the micrometer 6 is further inserted into its measuring tip 7.
The attitude control shaft 3 is moved until just before it contacts the outer periphery of the master gauge 9 and is fixed to the bifurcated portion 4 of the rotating shaft 2a (7).

Next, while looking at the receiver 17, touch the probe 7 to the outer periphery of the mask gauge 9, adjust with the fine adjustment screw 3a so that the needle of the receiver 17 is located in the center, and then place the micrometer 6 on the fixed block 5. Fix it (8).

Next, start the circular motion program (9).

The displacement of the probe 7 due to the circular motion of the tool spindle 1 is received by the loop antenna 16, and the waveform is observed by the oscilloscope 18 via the receiver 8!17 (10).

FIG. 5 is an example of a waveform displayed by an oscilloscope. The vertical axis is the actual displacement detected by the probe 7. ΔR is
This is the amount of decrease in the radius of circular motion caused by servo delays on the X and Y axes. The circular motion starts from +X and moves from 10X → −Y
→ -X → +Y → +X, and the circular motion completes one rotation clockwise. The whisker shapes seen in -Y, -X, and +Y are stick motions that occur when switching quadrants, and can be reflected in the circular motion program to minimize the amount of stick motion.

In the first embodiment, since the master gauge 9 is provided in the housing 10 fixed to the table T, the rotating shaft 10
Highly accurate measurement is possible without being affected by the rotation error of a. The second embodiment is a mask gauge 9 with guaranteed roundness.
It is not necessary to prepare a simple reference block 13, resulting in a cheaper configuration. In addition, in both embodiments,
Since the measurement signal can be taken out via a wireless or rotary connector, it is possible to perform multiple rotations and measure the motion accuracy in a steady state where the circular motion speed is stable.

The device of the present invention can also be used to measure circular motion accuracy by relative two-axis movement between the spindle and table of machine tools and coordinate measuring machines whose spindles do not rotate, and can also be used to measure circular motion accuracy by relative two-axis movement between the spindle and table of machine tools or coordinate measuring machines in which the spindle does not rotate. It can be similarly used in machines with horizontal spindles.

〔Effect of the invention〕

As explained above, according to the present invention, the accuracy of circular motion due to relative two-axis movement between the main axis of the machine and the table can be improved.
Measurements can be made quickly and accurately without actually cutting the workpiece. In addition, since the structure is configured to always measure displacement from the radial direction of circular motion using a commercially available displacement measuring device without using a special measuring device, an inexpensive and easy-to-handle motion accuracy measuring device can be obtained. .

[Brief explanation of drawings]

FIG. 1 is a block diagram of the main parts of the embodiment of the first invention, FIG. 2 is a block diagram of the main parts of the embodiment of the second invention, FIG. 3 is a system block diagram of the apparatus of FIG. 1, and FIG. This figure is a flowchart showing the procedure for measuring roundness using the apparatus shown in FIG. 1, and FIG. 5 is an example of the output waveform of the present invention. (Explanation of symbols) 1... Tool spindle, 2... Housing, 2a.
...Rotation axis, 3.Attitude control axis, 6.Wireless micrometer, 7.Measure head, 8.Transmission antenna, 9.
...Master gauge, 10...Housing, 10a.
... Rotating axis, 11... Base 12... Proximity switch, 13... Reference block for measurement, 14... Displacement meter, 15... Rotary connector. 2nd illustration

Claims (1)

[Claims] 1. A motion accuracy measurement device that measures the motion precision of circular motion due to relative two-axis movement between a main shaft and a table,
A rotating shaft provided on the main shaft side, a rotating shaft provided on the table side substantially parallel to the rotating shaft, and one rotating shaft is always facing the same point around the other rotating shaft, and the circular movement is performed relative to the other rotating shaft. an attitude control shaft that is fixed to one rotating shaft and movably engaged with the other rotating shaft only in the radial direction; and a circular master gauge fixed coaxially to a housing of a rotating shaft to which the attitude control shaft is movably engaged, the main shaft being between the main shaft and the table. When the circular motion is performed, the displacement measuring means always measures the outer circumference of the master gauge from the radial direction. 2. In a motion accuracy measurement device that measures the motion precision of circular motion due to relative two-axis movement between the main axis and the table,
A rotation axis provided on the main shaft side, a rotation axis provided on the table side approximately parallel to the rotation axis, and one rotation axis is always facing the same point around the other rotation axis, and the rotation axis is relatively connected to the circle. an attitude control shaft that is fixed to one rotating shaft so as to perform a motion and is movably engaged with the other rotating shaft only in the radial direction; and a rotating shaft that is movably engaged with the other rotating shaft; a circular master gauge fixed coaxially to a housing of a rotating shaft to which the attitude control shaft is fixed; A motion accuracy measuring device for a machine, wherein the displacement measuring means always measures the outer circumference of the master gauge from the radial direction when the machine moves. 3. In a motion accuracy measurement device that measures the motion precision of circular motion due to relative two-axis movement between the main axis and the table,
A rotating shaft provided on the main shaft side, a rotating shaft provided on the table side substantially parallel to the rotating shaft, and one rotating shaft is always facing the same point around the other rotating shaft, and the circular movement is performed relative to the other rotating shaft. an attitude control shaft that is fixed to one rotating shaft and is movably engaged with the other rotating shaft only in the radial direction; and a reference block provided on a rotating shaft to which the attitude control axis is fixed or a reference block provided on the attitude control axis and having a reference surface on which the displacement measurement means measures the displacement, An apparatus for measuring motion accuracy of a machine, characterized in that when performing the circular motion with a table, the displacement measuring means always faces the reference block in the same posture for measurement. 4. In a motion accuracy measurement device that measures the motion precision of circular motion due to relative two-axis movement between the main axis and the table,
A rotating shaft provided on the main shaft side, and a rotating shaft provided on the table side substantially parallel to the rotating shaft, so that one rotating shaft always faces the same point around the other rotating shaft to perform the circular motion. an attitude control shaft that is fixed to one rotating shaft and movably engaged with the other rotating shaft only in the radial direction, and a rotating shaft to which the attitude control shaft is fixed or a displacement provided on the attitude control shaft and a reference block provided on a rotating shaft movably engaged with the attitude control shaft and having a reference surface on which the displacement measuring means measures displacement, the main shaft being connected to the table. An apparatus for measuring motion accuracy of a machine, characterized in that when performing the circular motion between the two, the displacement measuring means always faces the reference block in the same posture for measurement.