JP2001194103A - Spherical surface measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spherical surface measuring method whereby dimensional adjustments and the operation of sorting a number of workpieces according to size during a workpiece machining process can be efficiently carried out without requiring use of an expensive exclusive measuring instrument. SOLUTION: The spherical surface measuring method for the workpiece having a spherical surface 3 and a workpiece reference surface 2 is provided. A plurality of measuring jigs 11 having recessed spherical surfaces 12 with different radii of curvature R have their respective recessed spherical surfaces 12 made to abut the spherical surface 3 of a workpiece body 1, and the distance between the center of the recessed spherical surface 12 and the workpiece reference surface 2 is measured whereby the radius r and the center of curvature of the spherical surface 3 of the workpiece body 1 are measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a spherical surface such as a toroidal surface of a power roller of a toroidal type continuously variable transmission.

[0002]

2. Description of the Related Art Conventionally, as a method of measuring the radius of curvature of a spherical surface of a work having a spherical surface, there has been known a method of obtaining the shape and dimensions of a curved surface as coordinate values using a general-purpose measuring device such as a three-dimensional measuring device. Further, as shown in JP-B-59-44561, a micrometer having a stylus is provided on a rotary spindle, and a stylus is brought into contact with a curved surface of a work having a curved surface to separate from a predetermined circle or arc. A device for detecting a displacement amount is known.

As disclosed in Japanese Patent Application Laid-Open No. 8-285506, there is known a curved surface measuring method for measuring a center of curvature and a radius of curvature of a concave surface using a plurality of reference spheres having different diameters and a restraining member.

[0004]

However, the curved surface measuring method disclosed in Japanese Patent Application Laid-Open No. 8-285506 measures a radius of curvature and a center of curvature of a concave curved surface. For example, a power roller of a toroidal type continuously variable transmission is used. It cannot be applied to the measurement of a spherical surface such as a toroidal surface. In addition, Japanese Patent Publication No. 59-
No. 44561 discloses a high-precision rotatable spindle,
It is a device having a complicated mechanism including a position control mechanism for making the center of the reference rotation guide surface coincide with the center of the curve to be measured, and a simple measuring method has been required.

In a toroidal-type continuously variable transmission used as an automobile transmission, a power roller for transmitting power by friction between an input disk and an output disk coaxially arranged on a power transmission shaft is tiltable. The transferred variator is the main component.

[0006] As shown in FIG.
The workpiece body 1 as a roller body is substantially hemispherical, is separated from the axis S of the workpiece body 1 by a distance X, and
Has a spherical surface 3 having a radius of curvature r with two centers of curvature O separated by a distance Y from the reference surface 2. Then, the spherical surface 3 of the work body 1 is rotatably rolled on the input disk and the output disk.

Therefore, the power roller slips between the input / output disk and the power roller even with a slight dimensional error.
There is a possibility that power cannot be transmitted, and in the manufacture of the power roller, it is necessary to finish the radius of curvature and the center of curvature of the spherical surface 3 with high precision. There is no known method for measuring spherical surface.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a spherical surface measurement capable of easily measuring the radius of curvature and the center of curvature of a spherical surface such as a toroidal surface of a power roller. It is to provide a method.

[0009]

In order to achieve the above object, the present invention provides a method for measuring a spherical surface of a work having a spherical surface and a work reference surface. The method is characterized in that a spherical surface is brought into contact with a spherical surface of the workpiece, and a distance between the center of the concave spherical surface and the workpiece reference plane is measured.

According to a second aspect of the present invention, in the method for measuring a spherical surface of a workpiece having a spherical surface and a workpiece reference surface, the concave spherical surfaces of a plurality of measuring jigs having concave spherical surfaces having different radii of curvature are brought into contact with the spherical surface of the workpiece. The distance between the center of the concave spherical surface and the work reference plane is measured to measure the radius of curvature and the center of curvature of the spherical surface of the work.

According to a third aspect of the present invention, there is provided a method for measuring a spherical surface of a workpiece having a spherical surface and a workpiece reference surface, wherein a plurality of measuring jigs having concave spherical surfaces having different radii of curvature are used, and the spherical surface of the workpiece is known. The method is characterized in that the concave spherical surface of the measuring jig is abutted to determine the center of curvature of the spherical surface of the work.

According to a fourth aspect of the present invention, the spherical surface of the workpiece according to any one of the first to third aspects is a toroidal surface of a power roller of the toroidal-type continuously variable transmission.

According to the above construction, a plurality of measuring jigs having concave spheres having different radii of curvature are used, and the concave sphere of the measuring jig is brought into contact with the spherical surface of the work, and the center of the concave spherical surface and the reference surface of the work. The radius of curvature and the center of curvature of the spherical surface of the work can be obtained simply by measuring the distance to the work, and the work of adjusting the size in the work process of the work and the work of selecting the size of a large number of works can be performed efficiently.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment, and FIG. 1 shows a state in which the curvature of a spherical surface serving as a toroidal surface of a work as a power roller of a toroidal type continuously variable transmission is measured by a measuring jig.

The measuring jig 11 is a rectangular metal block.
On the lower surface, a concave spherical surface 12 large enough to fit to the work body 1 is provided.
Is provided. In this embodiment, the radius of curvature R
₁ , R ₂ , R ₃ are composed of _three different measuring jigs 11,
Distance a between reference surface 2 of work body 1 and center of concave spherical surface 12
_1, to measure _a 2, _{a 3.}

As shown in FIG. 3, the work body 1 is substantially hemispherical and has a radius X from the axis S of the work body 1 and a distance Y from the reference surface 2 of the work body 1. Has a spherical surface 3 having a curvature radius r with a curvature center O.

Next, a method for measuring the radius of curvature r and the center of curvature O of the work body 1 will be described. When the manufactured work main body 1 is placed on a measuring table or the like and the concave spherical surface 12 of the measuring jig 11 is fitted to the work main body 1, a part of the concave spherical surface 12 comes into contact with the spherical surface 3 of the work main body 1. This contact 13
The angle θ between the contact point 13 and the axis S of the work body 1 changes depending on the position of the contact point 13, and the three measurement jigs 11 having different radii of curvature R ₁ , R ₂ , and R ₃ respectively move the contact point 13 and the work piece Assuming that the angles of the body 1 with the axis S are θ ₁ , θ ₂ , and θ ₃ , (R ₁ −r) sin θ ₁ = X (1) (R ₁ −r) cos θ ₁ = A ₁ -Y (2) (R ₂ -r) sin θ ₂ = X (3) (R ₂ -r) cos θ ₂ = a ₂ -Y (4) (R ₃ -r) sin θ ₃ = X (5) (R ₃ -r) cos θ ₃ = a ₃ -Y (6) Here, R ₁ , R ₂ , and R ₃ are the radii of curvature of the concave spherical surface 12 in the three measurement jigs 11, which have been measured in advance, and _three of a ₁ , a ₂ , and a ₃ are measured here. This is the distance between the reference surface 2 of the work body 1 and the center of the concave spherical surface 12.

The unknowns are r, X, Y, θ ₁ , θ ₂ , θ ₃
Where θ ₁ , θ ₂ , and θ ₃ are intermediate parameters, and the originally desired values are r, X, and Y.

Therefore, the simultaneous equations are solved. First, θ
₁ , θ ₂ and θ ₃ are deleted.

X ² / (R ₁ -r) ² + (a ₁ -Y) ² / (R ₁ -r) ² = 1 ... (7) X ² / (R ₂ -r) ² + (a _2- ) _{^{Y) 2 / (R 2 -r}} ) 2 = 1 ... (8) X 2 / (R 3 -r) 2 + (a 3 -Y) 2 / (R 3 -r) 2 = 1 ... (9) next Then, when X is deleted, (R ₁ -r) ^2- (R ₂ -r) ² = (a ₁ -Y) ² / (a ₂ -Y) ² (10) (R ₂ -r) ^{2- _{(R 3 -r) 2 = (}} a 2 -Y) 2 / (a 3 -Y) 2 ... (11) (R 3 -r) 2 - (R 1 -r) 2 = (a 3 -Y) 2 / (A ₁ −Y) ² (12) Further, regarding Y,

[0022]

(Equation 1)

Here, the radius of curvature r of the spherical surface 3 of the work body 1 was obtained. By substituting the radius of curvature r into the intermediate equation, X and Y can also be obtained.

As a specific example, the dimensions and measured values of the measuring jig 11 and the dimensions of the toroidal surface as the spherical surface 3 are as shown in Table 1.

[0025]

[Table 1]

A representative value r of the dimension of the spherical surface 3 of the work body 1 is
If one of the three values of X and Y is known, the remaining two values can be obtained from the measurement results of the measurement jigs 11 having two different radii of curvature.

For example, when the spherical surface 3 of the work body 1 is ground with the forming grindstone, the radius of curvature r of the spherical surface 3 is determined by the dressing, so that the variation is smaller than the position of the center of curvature O determined by the cutting position. Therefore, if the radius of curvature r is measured by an automatic groove R measuring machine, Y is calculated from Expression (13) by Expression (7).
X can be obtained from (8).

As described above, the concave spherical surfaces 1 having different radii of curvature r are provided.
Using a plurality of measurement jigs 11 having
Of the spherical surface 3 of the work body 1 is determined by simply measuring the distance between the center of the concave spherical surface 12 and the reference surface 2 of the work body 1. This makes it possible to efficiently perform dimensional adjustment work and dimensional selection work of a large number of works in the work processing process.

In the above embodiment, three measuring jigs are used. However, by averaging using more measuring jigs, the radius of curvature and the center of curvature can be obtained with higher accuracy. The number of measuring jigs is not limited.

Although the bottom surface of the work body is used as the reference surface, as shown in FIG. 2, when the work body is the power roller 4 of the toroidal type continuously variable transmission, the bearing receiving groove 5 can be used as the reference surface. Good.

Further, the distance between the center of the spherical surface of the measuring jig and the reference plane of the work is measured in advance by measuring the plane 6 of the measuring jig and the center of the spherical surface, and the distance between the reference plane 2 of the work and the flat surface 6 is measured. Can also be calculated from

[0032]

As described above, according to the present invention, a plurality of measuring jigs having concave spheres having different radii of curvature are used, and the concave sphere of the measuring jig is brought into contact with the spherical surface of the work, and the concave is formed. By simply measuring the distance between the center of the spherical surface and the reference surface of the work, the radius of curvature and the center of curvature of the spherical surface of the work can be obtained, and dimensional adjustment work in the work process of the work can be performed without using an expensive dedicated measuring machine. There is an effect that the size sorting work of a large number of works can be efficiently performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view showing a first embodiment of the present invention and showing a state in which the curvature of a spherical surface of a work is being measured.

FIG. 2 is a longitudinal sectional front view showing another embodiment of the present invention and showing a state where the curvature of a toroidal surface of a power roller of a toroidal type continuously variable transmission is measured.

FIG. 3 is a vertical sectional front view showing a power roller of the toroidal type continuously variable transmission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Work body 2 ... Reference surface 3 ... Spherical surface 11 ... Measuring jig 12 ... Concave spherical surface

Claims (4)

[Claims] 1. A method for measuring a spherical surface of a work having a spherical surface and a work reference surface, wherein a concave spherical surface of a measuring jig having a concave spherical surface is brought into contact with the spherical surface of the work, and a center of the concave spherical surface and the work reference surface are formed. Measuring the distance of the sphere. 2. A method for measuring a spherical surface of a work having a spherical surface and a work reference surface, wherein the concave spherical surfaces of a plurality of measuring jigs having concave spherical surfaces having different radii of curvature are brought into contact with the spherical surface of the work, and A sphere measuring method, comprising: measuring a distance between a center and the work reference plane to measure a radius of curvature and a center of curvature of a sphere of the work. 3. A method for measuring a spherical surface of a work having a spherical surface and a work reference surface, wherein a plurality of measuring jigs having concave spherical surfaces having different radii of curvature are used, and the measuring jig is mounted on a spherical surface of a work having a known radius of curvature. A method for measuring a spherical surface, characterized in that a concave spherical surface of the workpiece is brought into contact with the spherical surface of the workpiece to determine a center of curvature of the spherical surface of the workpiece. 4. The spherical surface measuring method according to claim 1, wherein the spherical surface of the work is a toroidal surface of a power roller of a toroidal-type continuously variable transmission.