JPH01250702A - Apparatus for measuring straightness - Google Patents

Abstract

PURPOSE:To measure the straightness of the surface of an object to be measured in an X-axis direction with high accuracy, by bringing a stylus into contract with the surface of the object to be measured to scan an air slide table in the X-axis direction. CONSTITUTION:The reference surface 22 of an object 21 to be measured is horizontally set by an inclined table 10 and a displacement sensor 13 and the height of a detection part 16 is properly set by an up-and-down column 14. Next, an air slide table 3 is moved on the object 21 to be measured in an X-axis direction to perform scanning. Then, the height of a surface 20 to be measured and that of the reference surface on a left side and the height of the reference surface 22 and that of the surface 20 to be measured on a right side are respectively detected by a stylus 16 and, by operating the difference in level between a reference line and the surface 20 to be measured on the basis of the signal from the detection part 16, the straightness of the surface 20 to be measured can be measured with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a straightness measuring device for measuring the straightness of a surface of an object to be measured.

(Prior art and problems to be solved) Conventionally, the flatness of the upper surface of the object to be measured as shown in the PIIJS diagram and FIG.
I was comparing it with U-nt. However, this method has the disadvantage that it is not possible to obtain a flatness measurement result as a concrete numerical value with high precision (submicron order).

In view of the above-mentioned α, the present invention makes it possible to measure the straightness of the object to be measured, as well as its shape such as flatness, cylindricity, coaxiality, etc. with high precision, and to easily process the measurement results on a computer, etc. It is an object of the present invention to provide a straightness measuring device that can obtain an electrical signal.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides an air slide table placed on a vibration isolating table and slidable in the X-axis direction, and an air slide table placed on the air slide table. A front and rear table movable in the Y-axis direction, a tilting table disposed on the front and rear table, a chuck disposed on the tilting table to hold a workpiece, and a chuck for holding a workpiece. an inclination/measuring unit that measures the parallelism with the X-axis of the object, and a detection unit that is attached to upper and lower columns erected on the vibration isolation table and measures the straightness of the object to be measured. It is said that

(Function) In the straightness measuring device of the present invention, by bringing the stylus serving as the detection unit into contact with the surface of the object to be measured and scanning the air slide table in the X-axis direction, the straightness of the surface of the object to be measured in the measure degree. The stylus outputs an electrical signal corresponding to the height (position in the Z-axis direction) of the top surface of the object to be measured, which is A/D converted and processed by the combination processor. Furthermore, the front and rear tables are moved in the X-axis direction, and the stylus is scanned in the X-axis direction to different positions in the X-axis direction.
By comparing the measured values of two or more X-axis positions in the X-axis direction, the straightness in the X-axis direction can also be measured.

By measuring these in the X-axis direction and the X-axis direction, it is possible to measure the shape of the object to be measured, such as flatness, cylindricity, coaxiality, etc., with high precision.

(Example) Hereinafter, an example of the straightness measuring device according to the present invention will be described with reference to the drawings.

FIG. 1 shows the mechanical configuration of the straightness measuring device, and FIG. 2 shows the control and signal processing system of the straightness measuring device.

In Figure 1, an air slide guide 2 is placed on the vibration isolation table 1.
is fixed upright, and an air slide table 3 is provided to be slidable in the X-axis direction with respect to the air slide guide 2. The position of the air slide table 3 in the X-axis direction is detected by a linear scale 4 placed on the vibration isolating table 1.

The air slide table 3 has, for example, vertical straightness (single unit) of about 0.1 μm 7100 am or less.

A motor 6 is arranged and fixed on a base 5 different from the vibration isolation table 1, and a pulley 7A fixed to the rotating shaft of the motor 6;
A wire 8 is stretched between pulleys 7 B, 7 C, 7 D, and 7 E arranged above and below both ends of the air slide guide 2, and both ends of the wire 8 are connected to the air slide table 3. Therefore, the rotation of the motor 6 drives the air slide table 3 in the X-axis direction.

A front and rear table 9 slidable in the X-axis direction is mounted and fixed on the air slide table 3, and a tilting table 10 is mounted and fixed on the table surface of the front and rear table 9. The table surface of the tilting table 10 can be tilted within a range of ±2°, for example.

A vacuum chuck 11 is fixed on the table surface of the tilting table 10. The vacuum chuck 11 is for suctioning and holding an object to be measured 21 having a surface to be measured 20 and a reference surface 22 on its upper surface as shown in FIGS. fjIJ3 and FIG. The reference surface 22 has been polished flat in advance.

A sensor stand 12 is erected and fixed on the vibration isolation table 1, and two displacement sensors 13 are attached to the sensor stand 12. The two displacement sensors 13 are connected to the object to be measured 21
The displacement sensors 13 are arranged to face the reference surfaces 22 at two locations, and measure the distance between each displacement sensor 13 and the reference surfaces 22 at the two locations. Then, two reference planes 2
The inclination of the tilting table 10 is adjusted so that the respective intervals corresponding to
below). This is because the measurement magnification in the Z-axis direction is large (X500
0 to X20000), to avoid overrange.

Further, an upper and lower column 14 is erected and fixed on the vibration isolating table 1, and a detection unit 16 for measuring the straightness of the upper surface of the object to be measured 21 is mounted on an elevating block 15 that moves up and down in the Z-axis direction of the upper and lower columns 14. is installed. The detection unit 16 is composed of a stylus for measuring roughness, and performs measurement by bringing the tip of the stylus into contact with the upper surface of the object to be measured 21 with a measurement load of about 0.4 g. Stylus resolution is 0.0
It is about 1 μm.

As shown in FIG. 2, the X-axis drive motor 6 and the Z-axis drive motors of the upper and lower columns 14 are controlled via drivers 31 and 32 that are sequentially controlled by a sequencer 30. The electrical signal output from the detection section 16 is amplified to a predetermined voltage by a head amplifier 33 and a range amplifier 34, and then sent to the A/D board 4 of the computer 40.
1 is input. In addition to the A/D board 41, the computer 40 has a CPU 42, an I10 board 43, a mouse 44, and a memory 45. Computer output is CRT4
6 and XY block 47. The output of the linear scale 4 is frequency-divided by a frequency dividing circuit 48 and applied to the I10 board 43. In addition, I10 board 4
3, a sampling pulse is created. The computer 40 performs A/D conversion on the X-axis value and the corresponding Z-axis value for each sampling pulse, and stores it in the memory 45 . The stored data can be displayed on a CRT 46 or an X-Y printer 47.

In the configuration of the above embodiment, the two reference planes 22 of the object to be measured 21 are set horizontally (parallel to the After setting the (position in the Z-axis direction) appropriately,
The air slide table 3 is moved in the X-axis direction to scan the object 21 having the measurement target surface 20 and the reference surface 22 in the X-axis direction as shown by line (i) in FIG. ) 16, the measurement target surface 20 on the left side, the reference surface 2 on the left side
2. Detect the heights (positions in the Z-axis direction) of the upper surfaces of the right reference plane 22 and the right measurement target surface 20, respectively.

As a result, a waveform as shown in FIG. 5, for example, is obtained as the output of the Lenz amplifier 34 which amplifies the signal of the detection section 16,
This is enlarged and displayed on the CRT 46.

Then, the heights (positions in the Z-axis direction) of the center part of the left reference plane 22 (for example, point 0) and the center part of the right reference plane 22 (for example, point d) are picked up and determined by the least square method as shown in FIG. The reference line (average line) P indicated by the dotted line is calculated by the computer 4.
Calculate with 0. Then, the open steps ZI to Z, (measurement points atb, etf
is calculated by selecting an appropriate position with the mouse 44), and it is determined whether the step is within a predetermined range, that is, whether the straightness is good or bad.

Next, move the front and rear table 9 to change the position in the Y-axis direction, and scan in the X-axis direction along the line in Figure 3 to obtain the same waveform as in Figure 5 above. . Then, the reference line is calculated in the same way, the level difference between the reference line and the surface to be measured of the object to be measured is calculated, and the straightness is evaluated in the same way. The number of measurements in the Y-axis direction and the measurement position can be selected appropriately.

Note that the shape and arrangement of the object to be measured can be changed as appropriate.
The straightness (cylindricity) of the screw head surface 50 in FIG. 6(A), the straightness (coaxiality, depth, variation) of the screw groove surface 51 in FIG. 6(B), ) can measure the straightness (parallelism, flatness, roughness), etc. of the groove bottom 52 on a flat plate. Further, the pickup point for calculating the reference line may be changed as appropriate depending on the shape of the object to be measured.

(Effects of the Invention) As explained above, according to the straightness measuring device of the present invention, an air slide table placed on a vibration isolating table and slidable in the X-axis direction, A front and rear table movable in the Y-axis direction, a tilting table disposed on the front and rear table, a chuck disposed on the tilting table to hold an object to be measured, and a chuck disposed on the tilting table to hold an object to be measured; an inclination measurement unit that measures the parallelism of the object to the X pongee;
The configuration includes a detection unit that is attached to the upper and lower columns erected on the vibration isolating table and measures the straightness of the object to be measured, so that the straightness of the object to be measured can be measured with high precision. (
(for example, submicron or smaller). Furthermore, measurement results can be obtained as electrical signals, making computer processing easy.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the straightness measuring device according to the present invention, and is a front view showing the configuration of the straightness measurement device, Fig. 2 is a block diagram showing the control and signal processing system of the embodiment, and Fig. 3 shows the straightness measuring device. FIG. 4 is a plan view showing the shape of the object to be measured, FIG. 4 is a front view of the same, FIG. 5 is a waveform diagram obtained by amplifying the output of the detection section, and FIG. 6 is an explanatory diagram showing the shape of another object to be measured. . 1... Vibration isolation table, 2... Air slide guide, 3...
・Air slide table, 4...Linear scale, 6
...Motor, 7 A, 7 B, 7 C, 7 D, 7 E
... Pulley, 8... Wire, 9... Front and rear tables, 10... Inclined table, 11... Vacuum chuck, 13... Displacement sensor, 14... Upper and lower columns, 16... Detection unit, 20...Measurement target surface, 21...
・Object to be measured, 22...Reference surface, 30...Sequencer, 40...Computer, 46...CRT, 47...
・・X-Y7”o79゜

Claims (2)

[Claims] (1) An air slide table placed on a vibration isolating table and slidable in the X-axis direction, a front and rear table placed on the air slide table and movable in the Y-axis direction, and a top of the front and rear table. a tilting table disposed on the tilting table; a chuck disposed on the tilting table for holding the object to be measured; a tilt measuring section for measuring the parallelism of the object to the X-axis; 1. A straightness measuring device comprising: a detection section that is attached to upper and lower columns erected on a table and measures the straightness of the object to be measured. (2) The straightness measuring device according to claim 1, wherein the detecting section comprises a stylus for measuring roughness.