JPH03138510A - Flatness measuring instrument for plane - Google Patents

Abstract

PURPOSE:To measure the flatness of the plane by measuring displacement data at a specific measurement point on the measured surface by a displacement sensor while the measurement point is confirmed by a position detecting means, and operating the flatness from the difference between maximum displacement and minimum displacement in the entire area. CONSTITUTION:A body 1 to be measured is mounted on a turntable 11 through an adapter 14 and then the swivel arm 21 of a moving means 20 is turned and so fixed that the displacement sensor 23 faces the measured surface 2 of the object body 1. Then while the turntable 11 is rotated, the sensor 23 and a position detecting means 32 detect each position gap size of one circumference of the object 1 to be measured and input a detection signal to an arithmetic means 25. Then the means 20 is driven after one-circumference measurement to move the sensor 23 in a radius direction by a specific pitch, the table 11 is rotated, and the gap size of next one circumference is measured to input its data to the means 25. This operation is repeated to input gap sizes in the entire area from the outermost periphery of the innermost periphery of the measured surface 2 to the means 25, thereby calculating the flatness of the object to be measured.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to a measuring device that can accurately and reliably measure the \11 surface degree of a flat surface of an object to be measured.

(Prior Art) For example, hypoid gears used in automobile power transmission systems and the like are used under high loads, so it is necessary to process them accurately with sufficient finishing precision. Further, since this /% void gear is used in a state where it is assembled with other parts on its back surface, it is especially necessary to ensure the flatness of the back surface in order to improve reliability.

To measure this flatness, after machining the hypoid gear, select three positions where the contact surface on the back surface exhibits a convex part, then install the three positions on the same plane, and then Measure the dimensions of. The difference between the highest value of the convex portion and the lowest value of the concave portion is defined as the flatness (μm).

FIGS. 11 to 13 are configuration diagrams showing an example of a conventional method and apparatus for measuring the 14-sidedness of the back surface of a hypoid gear.

First, as shown in FIG. 11, after applying Komeitan to the back surface 2 of the hypoid gear 1, the back surface 2 of the hypoid gear 1 and the surface plate 3 are slid together, and the three most protruding points on the back surface 2 are selected. Here, the back side 2 of the hypoid gear 1 and the surface plate 3
As a result, as shown in FIG. 12, the three most protruding points on the back surface 2 are in direct contact between the metals and the metal surface 4 is exposed. Part 5
can be selected.

Next, as shown in FIG. 13, the hypoid gear 1 is placed on an auxiliary surface plate 7'' installed on the surface plate via jacks, and the protrusion 5 is measured using the dial gauge 8 attached to the hide gauge 9. 3 so that the heights at the 3 positions are the same
Adjust the two jacks 6. In this state, the back surface is scanned with a dial gauge to measure the depth of the four lowest parts, and the flatness of the back surface 2 is determined by calculation.

(Problem to be Solved by the Invention) However, in conventional flatness measurement, flatness is determined by selecting three convex portions;
The exact position has uncertainties such as errors caused by individual differences among the measurers, which is not preferable in flatness measurement which requires an accuracy of several tens of μm.

Further, a lot of measurement time is required for preliminary work such as sliding alignment of hypoid gears and flatness measurement.

An object of the present invention is to solve the various drawbacks and problems associated with the above-mentioned conventional techniques and to provide a +i-plane measuring device that can accurately and reliably measure the τββ variation of a plane. It's about doing.

[Structure of the Invention (Means for Solving the Problems)] To achieve the second object, the present invention provides a turntable for mounting and rotating an object to be measured having a substantially circular measurement surface; a position detection means for detecting the rotational position of the table; a displacement sensor that faces the measurement surface of the object mounted on the turntable and detects the gap between the measurement surface; a moving means for moving the flatness of the measurement surface; and a calculation means for calculating the flatness of the measurement surface; This flatness measuring device is characterized in that a virtual reference plane is determined and flatness calculation processing is performed so that the displacements of the most protruding positions in three equal regions in a direction are equal to each other.

(Function) In the present invention configured as described above, displacement data at a predetermined measurement point on the measurement surface is measured by the displacement sensor while confirming the measurement point by the position detection means, and this data is stored in the calculation means. Then, in order to equalize the displacement of the most protruding position in three equal areas in the circumferential direction of the measurement surface, arithmetic processing is performed to determine a virtual reference plane by rotationally moving the displacement data by homogeneous transformation. . Then, flatness is calculated from the difference between the highest displacement and the lowest displacement in the entire area.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a block diagram showing the entire structure of a surface roughness measuring device according to an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line Flowchart showing the operating procedure of the example, Figures 4 to 7 are conceptual diagrams explaining the calculation principle of the example, Figures 8 (A) and (B) are cross-sectional views showing modifications of the adapter, Figures 9 and FIG. 10 is a plan view and a sectional view showing another example of application of the present invention.

As shown in FIGS. 1 and 2, the flatness measuring device 1 of this embodiment
0 indicates a turntable 11 that rotates the object to be measured 1 at a predetermined speed, with the back surface 2 of the hypoid gear 1 being the object to be measured as the measurement surface. This hypoid gear 1 has a convex portion 1 formed protrudingly on the upper surface of the turntable 11.
1a into the through hole 14a of the adapter 14, and further fit the adapter 4 into the recess 1a of the hypoid gear 1, so that the hypoid gear 1 and the turntable 11 are installed on the surface of the turntable so that they form concentric circles. . Here, if there are multiple shapes of the ipoid gear 1 to be measured, especially the shapes of the four parts 1a,
) As shown in (B), the shape of the adapter 14 is formed to correspond to the shape of each hypoid gear 1, and on the other hand, the shape of the through hole of each of these adapters]4 is formed to a shape corresponding to the shape of the convex part of the turntable 11. By forming it in the following manner, it becomes possible to measure various /S void gears with one turntable by simply providing an adapter.

The two 71 wart gears 1 shown in FIGS. 8(A) and 8(B) each have different shapes of the four parts 1a, but the shapes of the step parts 14b of the adapter 14 are formed to correspond to the shapes of these four parts 1a. In addition, since the through hole 14a of the adapter 14 corresponds to the shape of the protrusion 11a of the turntable 1], when measuring the other hypoid gear after completing the measurement of the - hypoid gear, The hypoid gear can be measured simply by replacing the adapter 14.

A displacement sensor 23 that detects the gap G between the hypoid gear 1 and the measurement surface 2 with high precision is provided opposite to the measurement surface 2 while being attached to the arm of the moving means 20 . The moving means 20 includes a pivot arm 21 that pivots around a support shaft 24 and a horizontal arm 2 that is orthogonal to the pivot arm 21 and moves linearly along the pivot arm 21.
2 is shown in white, and the displacement sensor 23 is attached to the end of the horizontal arm 22.
is fixed. The rotating arm 21 rotates when the object 1 to be measured is placed on the turntable 111-, so that the displacement sensor 23 and the treasure 1 to be measured do not interfere with each other. It is moved to a position facing the measurement surface 2 and fixed.

The horizontal arm 22 reciprocates around the swing arm 21'' by a servo motor 30 or the like via a ball screw 31 or the like.
During measurement, a command signal -J is transmitted from a control means (not shown) to move the turntable 11 by a predetermined pitch in relation to the rotational state of the turntable 11. In addition, in order to grasp the current position of the displacement sensor 23 with respect to the measurement surface 2 of the hypoid gear 1, the amount of movement of the turntable 11 and the moving means 20 is detected by a position detecting means 32. The belief is stored in the storage section of the calculating means 25 in a state corresponding to the measurement data of the gap angle method by the displacement sensor 23.

As the displacement sensor 23, a magnetic sensor or the like can be used, for example, and the gap size G can be detected by using the magnetic amount of the magnet circuit that changes depending on the gap size G between the displacement sensor 23 and the measurement surface 2 of the hypoid gear 1. It is done. The magnetic quantity detected by the displacement sensor 23 is converted into an electrical quantity and then stored in the storage section of the calculating means 25 as described above. The gap size data stored in the storage section is further subjected to arithmetic processing, which will be described later, to determine the flatness of the measurement surface 2 of the hypoid gear 1.

Further, the calculation means 25 is connected to a display means 26 for displaying the measurement results calculated by the calculation means. This display means 26 may be of a type in which a certain reference value is inputted as γ, and a display of pass or fail is displayed depending on whether the measurement result satisfies this reference value. The measurement data may be displayed for each part. In this case, the value of the measurement data can be varied in various ranges, e.g.
When it is m, it is "red", when it is 10 to 20 lt m, it is "orange", and when it is 20 to 3011 m, it is [yellow J,
It is also possible to display the image in color on a CRT display, such as -.

Next, the measurement procedure and arithmetic processing method of the flatness measuring apparatus of this embodiment configured as described above will be explained with reference to FIGS. 3 to 7.

First, after installing the object 1 to be measured on the turntable 117 via the adapter 14, the rotating arm 21 of the moving means 20 is rotated so that the displacement sensor 23 faces the measurement surface 2 of the object 1. The pivot arm 21 is fixed so that the rotation arm 21 is fixed. Then, while rotating the turntable 11, the displacement sensor 23 and the position detection means 32 measure the gap at each position of the void gear 1 for one revolution.
is detected, and the detection signal is manually input to the calculation means 25. 1
After completing the measurement for the circumference, the moving means 20 is driven to move the displacement sensor 23 in the radial direction by a predetermined pitch, and the turntable 11 is rotated again to measure the gap size G for the next circumference. , this measurement data is manually input to the calculation means 25. By repeating such operations, the gap size G over the entire area from the outermost circumference to the innermost circumference of the measurement surface 2 of the hypoid gear 1 is inputted into the calculation means.

Next, the flatness of the object to be measured 1 is calculated from the measured gap size data, and this calculation process is performed according to the flowchart shown in FIG. 3 and the procedure described below.

Note that conventionally, Komyotan was applied to the object to be measured and the object was rubbed against a surface plate, and the three points of contact were determined by the measurer's judgment, but in this example, these three points were determined by the measurer's judgment. The purpose is to determine the points using the following calculation procedure, and at the same time calculate the flatness measurement results.

Steps 1 to 3 First, as shown in FIG.
In the straight line in the radial direction 1 that forms a 20° angle (divides the circumference into 3 equal parts), the points with the largest gap size G are extracted from the storage section of the calculating means 25, and these three points α
, β, and γ are rotated together with all displacement data so that the displacements in the Z-axis direction are equal.

Note that the X-axis, Y-axis, and Z-axis are the turntable 11.
is the orthogonal coordinate at .

This rotational movement begins with three points α and β as shown in Figure 5.
, γ is found, and the coordinates of the three points α, β, and γ with respect to the origin are α(Xa, Ya, Za), β(X, , Y, , Zlj), respectively. If expressed as γ (X2, Ya, Za), the normal vector V = (V,, F, Vri is, ■ Vx = VX V, = Vy Vt = Vz
VI IVI IVVx = (
yβ-yα) (Zγ-2α) (Zβ-Za) (Yγ-Y
a) vy = (zβ-Za) (Xγ-Xa) (Xβ-Xa
)(Zγ-Za) 2 Vz = (Xβ-Xa) (Y7-Ya)-(yβ
-Ya) (Xγ-Xa) Vl - (Vz2 +Vy2 VZ2) 2.

Next, if we find the homogeneous transformation formula T so that the normal vector V becomes parallel to the Z axis as shown in Figure 7, then the homogeneous transformation formula %) () ) Thus, the total displacement Regarding the data, rotational movement processing is performed so that the displacement data at the three points α, β, and γ become the same in the Z-axis direction by calculating the product with the homogeneous transformation formula.

Steps 4 to 5 Next, as shown in FIG. 6, after completing this rotational movement, scan and extract the most protruding position in each area 4 arbitrarily divided into three in the circumferential direction,
The rotational movement process of the displacement data is repeated until the displacement data at these three new points α1, β1, and γ1 become approximately equal. Displacement data α when the displacement data at these three new points α, β, and γ become equal. ,β. , γ.

The 14 planes with this in mind serve as virtual reference planes, and with this virtual reference plane as a reference, the flatness of the measurement plane is calculated based on the difference between the highest displacement and the lowest displacement of the displacement data.

As described above, according to this embodiment, when selecting the reference position,
Since the determination can be made without including subjective factors of the measurer, accurate and reliable measurement can be achieved.

Moreover, no special pre-work is required when measuring flatness, and the measurement time can be significantly shortened.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made.

For example, as shown in FIG. 9, it is also possible to divide the measurement surface into several regions and measure the flatness in each region. In this case, the measuring surface 2 of the hypoid gear 51 is divided into three concentric regions 27, 28, and 29, the highest displacement and the lowest displacement are measured, and the flatness is calculated based on the difference between the two regions. 27.28.29
The flatness at is obtained. Therefore, the flatness of each sectioned area can be obtained in more detail and accurately instead of for the entire measurement surface 2.

Furthermore, the present invention can also be applied to a measurement surface 2 having a predetermined taper. For example, as shown in Figure 10,
If there is a difference in displacement between the outer circumferential portion 2a and the inner circumferential portion 2b of the measurement surface 2, the average value of the displacement of the outer circumferential portion 2a and the inner circumferential portion 2b is determined from the measured values, and the difference is used as the “taper amount t”. ” and can be displayed by the display means 26.

Furthermore, if a bolt hole is provided on the measurement surface of the hypoid gear, it is also possible to exclude the displacement data near the bolt hole and perform the above-mentioned calculation process to calculate the flatness.

(Effects of the Invention) As described above, according to the present invention, the reference position can be determined without including subjective factors of the measurer, so that accurate and reliable measurement can be achieved. Can be done. Moreover, no special pre-work is required when measuring flatness, and the measurement time can be significantly shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the entire configuration of a surface roughness measuring device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line XX in FIG. 1, and FIG. Flowchart showing the operating procedure of the embodiment, FIGS. 4 to 7 are conceptual diagrams explaining the calculation principle of the embodiment, FIGS. 8A and 8B are sectional views showing modifications of the adapter, and FIG. 9 and FIG. 10 are plan and cross-sectional views showing another application example of the present invention, and FIGS. 11 to 13 are explanatory views showing a conventional flatness measuring device. 32...Position detection means. DESCRIPTION OF SYMBOLS 1... Object to be measured, 2... mlJ constant surface, 10... Flatness measuring device, 11... Turntable, 20...
Moving means, 23...Displacement sensor, 25...Calculating means, 26...Displaying means, ]7 8 4th factor 2nd axis diagram (A) 4a

Claims (1)

[Claims] A turntable on which a measured object having a substantially circular measurement surface is mounted and rotated, a position detection means for detecting the rotational position of the turntable, and a measured object mounted on the turntable. a displacement sensor facing the measurement surface and detecting a gap size between the measurement surface and the measurement surface; a moving means for moving the displacement sensor in a radial direction of the measurement surface; and a calculation means for calculating the flatness of the measurement surface. The calculation means uses detection signals from the displacement sensor and the position detection means to determine a virtual reference so that the displacements of the most protruding positions in three equal regions in the circumferential direction on the measurement surface are equal to each other. A flatness measuring device for a plane, characterized in that it determines a surface and performs flatness calculation processing.