JPH03249516A - Flatness measuring instrument - Google Patents

Abstract

PURPOSE:To accurately measure flatness regardless of the parallelism of a swiveling arm by measuring variation data at measurement points on a straight line passing through the center of rotation of a measurement surface by a displacement sensor while confirming the measurement points with a position detecting means, and calculating the flatness from the difference between the maximum displacement and minimum displacement in the entire area. CONSTITUTION:The back surface 2 of a hypoid gear 1 to be measured is regarded as the measurement surface and the gear is installed on the top surface of a turntable 11 while aligning shaft centers. The swiveling arm 21 is disposed on the back surface 2 which faces up and swiveled by a moving means 20 and the displacement sensor 23 is fitted to the arm 21 and moved reciprocally from one end to the other end of the back surface 2. Thus, the position detecting means detects the movement quantities of the table 11 and means 20 and a movement quantity signal from the means 32 is stored in the storage part of an arithmetic means 25 in a state corresponding to measurement data on gap size G by the displacement sensor 23. Thereafter, this data is used to determine the flatness of the measurement surface 2.

Description

Detailed Description of the Invention [Object of the Invention] The flatness side (industrial application field) characterized by In particular, the present invention relates to a flatness measuring device that can accurately measure flatness regardless of the installation state of the measuring device.

(Prior art) For example, hypoid gears used in automobile power transmission devices are used under high loads, so it is necessary to process them with sufficient finishing accuracy. , since it is used with other parts assembled on its back surface, it is especially necessary to ensure the flatness of the back surface in order to improve reliability.

To measure the flatness of a workpiece that requires such high precision flatness, first select the three most convex positions on the surface to be measured, and then measure the heights of these three positions on the same plane. The method used is to measure the dimensions of the recess after installing the recess. The difference between the highest value of the convex portion and the lowest value of the concave portion is defined as flatness (μm).

19 to 21 are configuration diagrams showing an example of a conventional flatness measuring method and measuring device, and will be explained using a hypoid gear as an object to be measured.

First, as shown in FIG. 19, after applying Komyotan to the back surface 2 of the warp gear 1, the back surface 2 of the warp gear 1 and the surface plate 3 are slid together, and the most protruding three parts of the back surface 2 are Select the points visually. Here, hypoid gear 1
As a result of sliding the back surface 2 and the surface plate 3 together, the three most protruding points on the back surface 2 are in direct contact between the metals and the metal surface 4 is exposed, as shown in FIG. , the measurer can sensually select the three protrusions 5 (marked with X in the figure).

Next, as shown in FIG. 21, a jack 6 is placed on the surface plate 3.
The hypoid gear 1 is installed on the auxiliary surface plate 7-1- installed through the Adjust 6. And in this state,
The entire surface of the back surface is scanned with a dial gauge 8, the depth of the four lowest parts is measured, and the difference between the height of the convex part 5 and the height of these four parts is determined by calculation, and this is determined as the flatness of the back surface 2. Was.

(Problem to be solved by the invention) However, in conventional flatness measurement, flatness is determined by selecting three convex portions 5, but the exact positions of these three positions are determined by the individual of the measurer. There is an element of uncertainty to prevent errors from occurring due to differences, and it is not suitable for flatness measurements that require accuracy of several tens of micrometers.

Another disadvantage is that it takes a lot of time for preliminary work such as sliding alignment of hypoid gears and flatness measurement.

The present invention has been made in view of the problems of the prior art, and provides a hypoid gear plane measuring device that can accurately and reliably determine the flatness of the back surface of a hypoid gear. The purpose is to

[Structure of the Invention (Means for Solving the Problems) To achieve the above object, the present invention includes 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; a displacement sensor that faces the measurement surface of the object mounted on the turntable and detects the gap between the measurement surface; calculating an average value of two gap dimensions at the same position using a moving means for moving from one end to the other on a straight line, and detection signals from the displacement sensor and the position detecting means; Based on the average value data, a virtual reference plane is determined and a flatness calculation process is performed so that the displacements of the most protruding positions in the trisected areas in the circumferential direction on the measurement surface are equal to each other. This is a flatness measuring device characterized by comprising: means.

(Function) In the present invention configured as described above, displacement data at 4 (4) fixed points on a straight line passing through the center of rotation of the measurement surface is determined by the displacement sensor while confirming the measurement point by the position detection means. Then, this data is stored in the calculation means.

Next, calculate the average value of the two gap size data at the same measurement point, use this as corrected gap size data, and use this value to calculate the most protruding position in the third area in the circumferential direction of the measurement surface. In order to equalize the displacements, arithmetic processing is performed to rotate the displacement data by homogeneous transformation and determine a virtual reference plane.

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 configuration diagram showing the entire flatness measuring device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. ) is a sectional view showing a modified example of the adapter, FIGS. 4 to 12 are sectional views illustrating the procedure for correcting the parallelism of the rotating arm, FIG. The figure is a conceptual diagram explaining the calculation principle of the same embodiment, and FIG. 18 is a plan view showing another example of application of the present invention.

Although this embodiment will be explained using a hypoid gear that requires high-precision flatness as the object to be measured, the flatness measuring device of the present invention is not limited to this hypoid gear, and can be applied to various objects to be measured. It can be used about.

First, as shown in FIGS. 1 and 2, the flatness measuring device 10 of the present embodiment measures the back surface of a hypoid gear 1, which is an object to be measured.
It has a turntable 11 that rotates the wave mll constant object 1 at a predetermined speed, with ff1ll being a constant surface.

This hypoid gear 1 has a convex portion 11a formed protrudingly on two sides of the turntable 11, and a through hole 14a of the adapter 14.
By fitting the adapter 14 into the concave portion 1a of the hypoid gear 1, the adapter 14 is installed on the upper surface of the turntable, whereby the axial center of the hypoid gear 1 and the axial center of the turntable 11 are aligned.

Here, if there are multiple shapes of the hypoid 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 the through hole shape of each of these adapters 14 is formed to a shape corresponding to the shape of the convex part of the turntable 11. It is desirable to form.

As a result, even if there are multiple types of hypoid gears 1 to be measured, it is possible to measure these multiple types of hypoid gears 1 with one turntable 11 by simply preparing dedicated adapters for each type. For example, in Figure 3 (A
) The two hypoid gears 1 shown in (B) have different shapes of the recessed portions 1a, but the stepped portion 1 of the adapter
4b is formed to correspond to the shape of each of the four parts 1a, and the through hole 14a of the adapter 14 corresponds to the shape of the convex part 11a of the turntable 11. If you want to measure the other hypoid gear after completing the
4, the hypoid gear 1 can be measured using the same measuring device 10.

The moving means 20 has a pivot arm 21 that pivots around a support shaft 24 and a horizontal arm 22 that is perpendicular to the pivot arm 21 and moves linearly along the pivot arm 21. A displacement sensor 23 is fixed to.

This rotating arm 21 rotates the object 1 to be measured on the turntable 1.
1, the displacement sensor 23 is turned to the retracted position to prevent interference between the displacement sensor 23 and the object to be measured 1. On the other hand, when the displacement sensor 23 is installed on the measuring surface 2, the displacement sensor 23 is turned to the retracted position (
It is designed to swivel until it is fixed (on a straight line passing through the center of the back).

The horizontal arm 22 of this embodiment is capable of reciprocating movement on the swing arm 21 via a ball screw 31 or the like by a servo motor 30 or the like from one end of the object to be measured to the other end. That is, on a straight line passing through the center of the hypoid gear 1 shown in FIG. 1, the gap in the area from the left end to the right end = J method G
scan. I can do it. Further, during measurement, a command is sent 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.

The respective movement amounts of the turntable 11 and the moving means 20 are configured to be detected by the position detecting means 32, thereby grasping the current position of the displacement sensor 23 with respect to the /11 plane 2 of the hypoid gear 1. be able to. Then, this detection signal is stored in the storage section of the calculation means 25 in a state corresponding to m11 constant data of the gap size G obtained by the displacement sensor 23.

As described above, the displacement sensor 23 that detects the gap G between the hypoid gear 1 and the measurement surface 2 with high accuracy is installed opposite the measurement surface 2 while being attached to the swing arm 21 of the moving means 20. However, this displacement sensor 23
For example, a magnetic sensor can be used,
The gap size G is detected by using the magnetic amount of the magnet circuit, which changes depending on the gap size G between the displacement sensor 23 and the measuring surface 2 of the hypoid gear 1. This displacement sensor 2
After the magnetic quantity detected in step 3 is converted into an electrical quantity, it is stored in the storage section of the calculation means 25 as described above. The data of the gap size G 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 one in which a certain standard value is manually set in advance, and a display of pass or fail is displayed depending on whether the measurement result satisfies this standard value. The configuration may be such that measurement data is displayed separately. In this case, the value of the measurement data is displayed in various ranges, for example, when the measured value with respect to the reference plane is 0 to 10 μm, it is “red”, when it is 10 to 20 μm, it is “orange”,
When it is 0 to 30 μm, it is "yellow", as in...
Color display on the RT display is also possible.

Next, the /11 setting procedure and arithmetic processing method of the flatness measuring apparatus of this embodiment configured as described above will be explained with reference to FIG. 1 and FIGS. 4 to 17.

Measurement procedure First, after installing the hypoid gear 1 to be measured on the turntable 117 via the attack 14, the moving means 2
0 swing arm 21 to the measurement position, and fix the swing arm 21 so that it is located at one end (the left end in FIG. 1) of a straight line passing through the center of the displacement sensor 23 or the measurement surface 2 of the hypoid gear 1. do.

Next, the turntable 11 is rotated, and the displacement sensor 2
3 and the position detection means 32 detect the gap size G at each position for one rotation of the hypoid gear 1, and input the detection signal to the calculation means 25 manually. To complete this measurement for one revolution, the moving means 20 is then driven to move the displacement sensor 2.
3 inward in the radial direction by a predetermined pitch and rotate the turntable 11 again to determine the gap size G for the next round.
is measured, and this mllll-ta is input to the calculation means 25. By repeating such operations, the calculation means 25 is manually inputted with the method G of the gap over the entire area from the outermost circumference to the innermost circumference of the measurement surface 2 of the hypoid gear 1.

Furthermore, after completing the measurement of the gap dimension G over the entire area from the outermost periphery to the innermost layer in this way, from this innermost periphery to the outermost periphery which is the other end of the hypoid gear 1 (the right end in FIG. 1) The gap size is determined according to the above-mentioned procedure and input manually to the calculation means.

In this embodiment, the gap size of the entire area from one end of the hypoid gear to the other end is measured because if the movement trajectory of the displacement sensor 23 is not parallel to the rotating surface of the turntable 11, For example, as shown in FIG. 4, if the swing arm 21 is tilted by an angle α with respect to the turntable 11,
This is because the flatness is stored in the calculation means 25 as a general plane of a fixed surface or an incorrect plane shape in the measurement data, and the flatness is calculated based on this, and this is a simple method without adjusting it using a master. This is what we are trying to correct. This point will be described further below, but in short, it can be said that the feature of the present invention is that it can be measured without making any adjustment by the master and regardless of the parallelism of the swing arm 21.

Computation processing method First, the movement trajectory of the displacement sensor 23 and the turntable 11
Correct the parallelism with the plane of rotation.

This is based on the principle described below. That is, as shown in FIG. 4, if the rotating arm 21 or the turntable 11 is tilted by an angle θ with respect to the rotating surface, the displacement sensor 23 starts measurement from the outermost circumferential position X of the back surface 2, and When the inner peripheral position Y is reached, the 711 constant data at this time is measured as a hapoid cap 1 whose central portion is concave at an angle θ, as shown in FIG. On the contrary,
When the displacement sensor 23 moves further from the innermost circumferential position Y and reaches the other end, the outermost circumferential position Z, the measurement data at this time shows that the central part is convex at an angle θ, as shown in FIG. This means that it was measured as hypoid gear 1. Therefore, even if the measurement surface 2 is originally approximately flat as shown in FIG. 4, it may not be possible to obtain an accurate measurement surface 2 depending on the inclination of the rotating arm 21 or the scanning range of the displacement sensor 23. , as in this embodiment, if the configuration is such that it passes from the outermost circumferential position The same point is determined once on the left and right sides of the plane, and by averaging the data measured twice, accurate data for the measurement surface 2 can be obtained.

Further, as shown in FIG. 7, the central part of the back surface 2 of the hypoid gear 1 is originally convex, and
is inclined at an angle θ with respect to the rotating surface of the turntable 11, when the displacement sensor 23 starts the hori positioning from the outermost circumferential position X of the back surface 2 and reaches the innermost circumferential position Y, at this time As shown in FIG. 8, the mllll-ta was measured as a hapoid cap 1 whose central portion was convex by an angle θ from the original surface. On the other hand, when the displacement sensor 23 moves further from the innermost circumferential position Y and reaches the other end, the outermost circumferential position Z, the measurement data at this time shows that the central part is the original position as shown in FIG. This means that M is defined as a hypoid gear 1 that is recessed by an angle θ from the surface.

Similarly, as shown in FIG. 10, when the central part of the back surface 2 of the hypoid gear 1 is originally concave and the swing arm 21 is inclined by an angle θ with respect to the rotational surface of the turntable 11, When the displacement sensor 23 starts the millimeter determination from the outermost circumferential position X of the rear surface 2 and reaches the innermost circumferential position Y, the measurement data at this time is as shown in FIG. Hapoid Gya 1 concave by angle θ
This means that it was measured as . On the other hand, when the displacement sensor 23 further moves from the innermost circumferential position Y and reaches the other end, the outermost circumferential position Z, the measurement data at this time is
As shown in the figure, the measurement was performed as a hypoid gear 1 in which the central portion was convex by an angle θ from the original surface.

In this way, in this embodiment, the gap data G determined by the displacement sensor 23 is stored separately in the calculation means 25 in the ranges of X-Y and Y-Z, and the position data at the same point is is searched, and these two gap size data G are averaged, and this is used as the corrected gap size data G.

Next, the flatness of the back surface 2 of the hypoid gear 1 is calculated from the gap dimension data G corrected in this way, and this calculation process is performed according to the flowchart shown in FIG. 13 and the procedure described below.

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, the determination of these three points was The calculation is performed using the following calculation procedure, and the flatness measurement results are also calculated at the same time.

Steps 1 to 3 First, as shown in Fig. 14, on the measurement surface 2, on the straight lines in the radial direction that make 120 degrees to each other (dividing the circumference into three equal parts), the point where the gap is the largest [J method G] is extracted from the memorized part of the calculation means 25, and the Z of these two points α, β, γ is
Rotate and move along with all displacement data so that the axial displacements 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, as shown in FIG.
The normal hector V perpendicular to the plane containing β and γ is determined, and the coordinates of the three points α, β, and γ with respect to the origin are α(Xa, Y., 2.), β(L, Y, , Z), respectively. ), γ(X7, Y7, Za) is expressed as Normal vector V=(v,, Y, vl) is v,=:+
vX v, -Vy V--VzVl,
Vl IV Vx = (yβ-yα) (zγ-Zα) (Zβ-Zα
)(Yγ−Yα) Vy = (Zβ−Zα)(Xγ−Xa)(Xβ−Xa
)(Zγ−Zα) Vz = (Xβ−Xα) (Yγ−Yα)−(Y
β−Yα) (Xγ−Xα) Vl −(VX2+Vy2 VZ2 )2.

Next, either the normal vector V or Z as shown in FIG.
By finding the homogeneous transformation formula T that is parallel to the axis, we can obtain the homogeneous transformation formula %) () ) In this way, for all displacement data, by finding the product with the homogeneous transformation formula, we can calculate the 3 points α , β, and γ are the same in the Z-axis direction.

Steps 4 to 5 Next, as shown in Fig. 16, after completing this rotational movement, scan and extract the most protruding positions in each of the areas arbitrarily divided into thirds in the circumferential direction. The rotational movement process of the displacement data is repeated until the displacement data at the three points α1, β□, and γ1 become approximately equal. and,
Displacement data at these two new points α, β, and γ, or displacement data α when they become equal. ,β. , γ. am+;,
surface or a virtual reference plane, and with this virtual reference plane as a reference,
The flatness of the measurement surface is calculated based on the difference between the highest displacement and the lowest displacement of the displacement data.

In this way, according to the present embodiment, regardless of the parallelism of the swing arm, and without adjusting it using a master,
Accurate flatness can be determined with simple operations. In addition, since the reference position can be determined without including the subjective factors of the measurer, it is possible to accurately and reliably set the standard position as high as <4. Measurement time can be significantly shortened without requiring any special preliminary work.

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. 18, 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 1 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. The flatness at 28.29 is obtained.

Therefore, the flatness of each divided 1; n area can be obtained in more detail and accurately instead of the entire measurement surface 2.

Furthermore, if a hole is provided on the measurement surface of the hypoid gear, it is possible to calculate the flatness by excluding the displacement data in the vicinity of the hole and performing the above calculation process.

(Effects of the Invention) As stated below, according to the present invention, accurate flatness can be measured with a simple operation, regardless of the parallelism of the rotating arm, and without adjusting it using a master. I can do it.

In addition, when selecting the reference position, it is possible to determine whether the reference position is accurate and reliable or not, since it can be determined without including the subjective element of fixation.

Furthermore, no special pre-mortem work is required to measure the severity of the disease, and the measurement time can therefore be significantly shortened by one order of magnitude.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the entire flatness measuring device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line nn in FIG. 1, and FIG. 3 (A) (13) is 4 to 12 are sectional views illustrating a modification of the attack; FIGS. 4 to 12 are sectional views illustrating the procedure for correcting the parallelism of the rotating arm; and FIG. Fig. 17 is a conceptual diagram explaining the calculation principle of the same embodiment, Fig. 18 is a plan view showing another application example of the present invention, and Figs. . DESCRIPTION OF SYMBOLS 1... Object to be measured, 2... Measurement surface, 10... Higashi gravity measuring device, 11... Turntable, 20... Moving means, 23... Displacement sensor, 25...
... calculation means, 26 ... display means, 32 ... fη position detection a'J means. Patent Ganjin [] San Jidosha Co., Ltd.

Claims (1)

[Scope of 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 the gap size between the measurement surface and the measurement surface; a moving means for moving the displacement sensor from one end to the other end on a straight line passing through the rotation center of the measurement surface; calculating an average value of two gap dimensions at the same position based on detection signals from the displacement sensor and the position detection means;
Based on this average value data, a virtual reference plane is determined and flatness calculation processing is performed so that the displacements of the most protruding positions in the trisected areas in the circumferential direction on the measurement surface are equal to each other. 1. A flatness measuring device comprising: calculation means.