JPH07318301A - Method and device for measuring uneven wall thickness of cylindrical body - Google Patents

Abstract

PURPOSE:To provide a method for measuring uneven wall thickness of a cylindrical body and a device therefor by which the cylindrical body with uneven wall thickness can be measured easily and accurately. CONSTITUTION:A device 2 for measuring uneven wall thickness of a cylindrical body is provided with a first contact 3 that is brought into contact with the outer circumferential surface of a cylindrical body 1, a second contact 4 that is brought into contact with the inner circumferential surface of the body 1, a first potentiometer 5 for the contact 1, and a second potentiometer 6 for the contact 4. Further, the device 2 is equipped with a calculator that calculates the uneven wall thickness of the body 1 based on coordinate positions (b), (c), (e), etc., that are detected by the contacts 3 and 4, etc. As the result, a cylindrical body that is accurately controlled in dimension can be produced easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder produced by a deviation between a center point of an inner diameter and a center point of an outer diameter of a cylindrical body in manufacturing a cylindrical body such as a perforated round billet manufactured on the premises of an iron mill. The present invention relates to a method and an apparatus for measuring uneven thickness of a cylindrical body for measuring the state of uneven thickness.

[0002]

2. Description of the Related Art As a method for measuring such an uneven thickness state of a cylindrical body, an operator uses calipers to measure arbitrary four places regarding the wall pressure of the cylindrical body, and measure the four measured values. Some have the maximum value as the maximum uneven thickness.

[0003]

However, in the above-described conventional method for measuring the uneven thickness of the cylindrical body, a large amount of time is required to search for an appropriate measurement point due to occurrence of measurement error or deviation of the measurement value due to manual work of the operator. However, there is a problem that the reliability of the measurement accuracy is not high due to the fatigue of the worker and the restriction of the measurement time, and that the long and simple work is a heavy labor followed by the middle waist labor.

Therefore, an object of the present invention is to provide a method and apparatus for measuring the thickness deviation of a cylindrical body, which can easily and accurately measure the thickness deviation state of the cylinder.

[0005]

A method for measuring the uneven thickness of a cylindrical body according to the present invention is a method for measuring the uneven thickness of a cylindrical body whose outer diameter and inner diameter are known in advance. Assuming a first straight line passing through the virtual center point, the coordinates of the four points at which the first straight line intersects the outer circumference circle and the inner circumference circle of the cylindrical body are measured by the position detecting means, and the four points Based on the coordinates and the outer diameter dimension and the inner diameter dimension, the amount of deviation between the center point of the outer diameter and the center point of the inner diameter, the maximum wall thickness dimension, the minimum wall thickness dimension, the maximum wall thickness dimension and the minimum wall thickness. It is characterized in that the maximum uneven thickness, which is the difference from the thickness dimension, is calculated by a computing unit.

Further, the thickness deviation measuring device for a cylindrical body has a structure in which an outer diameter dimension and an inner diameter dimension are known in advance, and the cylindrical body has an arbitrary point on the outer circumference circle and an imaginary center point of the outer diameter. 1
Assuming that the first straight line intersects with the outer circumference circle and the inner circumference circle of the cylindrical body, it has position measuring means for measuring the coordinates of four points, and the coordinates of the four points and the outer diameter Based on the dimensions and the inner diameter dimension, the deviation amount between the center point of the outer diameter and the center point of the inner diameter, the maximum wall thickness dimension, the minimum wall thickness dimension, and the difference between the maximum wall thickness dimension and the minimum wall thickness dimension. It is characterized by having an arithmetic unit for calculating a certain maximum uneven thickness.

Further, the method for measuring the uneven thickness of the cylindrical body of the present invention is as follows:
For a cylindrical body whose outer diameter and inner diameter are known in advance, a first straight line passing through an arbitrary point on the outer circumference circle and a virtual center point of the outer diameter is assumed, and this first straight line is The coordinates of four points that intersect the outer circumference circle and the inner circumference circle of the cylindrical body are measured by the position detecting means, and further, a second straight line orthogonal to the first straight line at an imaginary center point is assumed. The position detecting means measures the coordinates of four points at which the second straight line intersects the outer circumference circle and the inner circumference circle of the cylindrical body, and based on the coordinates of the eight points, the outer diameter dimension, and the inner diameter dimension. Difference between the center point of the outer diameter and the center point of the inner diameter, the maximum wall thickness dimension, the minimum wall thickness dimension, the maximum uneven thickness that is the difference between the maximum wall thickness dimension and the minimum wall thickness dimension, and the inner diameter The coordinates of the center point and the distribution of wall thickness,
It is preferable to calculate the position of the maximum wall thickness and the position of the minimum wall thickness with a computing unit.

In addition, the uneven thickness measuring device for a cylindrical body has a structure in which an outer diameter dimension and an inner diameter dimension are known in advance, and the cylindrical body has an arbitrary point on the outer circumference circle and a virtual center point of the outer diameter. 1
Assuming that the first straight line is, the first straight line has position measuring means for measuring the coordinates of four points which are points intersecting the outer circumference circle and the inner circumference circle of the cylindrical body. Assuming a second straight line that is orthogonal to the straight line at the virtual center point, the coordinates of four points, which are the points where the second straight line intersects with the outer circumference circle and the inner circumference circle of the cylindrical body, are also measured, Based on the coordinates of 8 points, the outer diameter dimension, and the inner diameter dimension, the deviation amount between the outer diameter center point and the inner diameter center point, the maximum wall thickness dimension, the minimum wall thickness dimension, and the maximum wall thickness dimension A calculator for calculating the maximum uneven thickness that is the difference from the minimum wall thickness, the coordinates of the center point of the inner diameter, the distribution state of the wall thickness, the position of the maximum wall thickness, and the position of the minimum wall thickness Is preferred.

Further, in the uneven thickness measuring device for a cylindrical body, the position detecting means is moved so as to come into contact with the outer peripheral surface of the cylindrical body.
A contact, a second contact that comes into contact with the inner peripheral surface of the cylindrical body by moving, a first potentiometer that provides an electric resistance according to the moving position of the first contact, and the second contact A second potentiometer having an electric resistance according to the moving position of the child, and the arithmetic unit can perform arithmetic processing based on the electric signals from the first potentiometer and the second potentiometer. preferable.

Further, in the uneven thickness measuring device for a cylindrical body, the position detecting means moves to contact the outer peripheral surface of the cylindrical body.
A contactor, a second contactor that moves to contact the inner peripheral surface of the cylindrical body, a third contactor that moves to contact the outer peripheral surface of the cylindrical body 1, and a movable contactor to the cylindrical body 1 A fourth contactor that comes into contact with the inner peripheral surface of the first contactor, a first potentiometer that has an electric resistance corresponding to the moving position of the first contactor, and a second potentiometer that has an electric resistance corresponding to the moving position of the second contactor. A potentiometer, a third potentiometer having an electric resistance corresponding to the moving position of the third contactor, and a fourth potentiometer having an electric resistance corresponding to the moving position of the fourth contactor, The computing unit calculates the coordinates of four points, which are the points where the first straight line intersects the outer circumference circle and the inner circumference circle of the cylindrical body, based on the electric signals from the first potentiometer and the second potentiometer. Furthermore, the arithmetic unit is a third potentiometer and a fourth potentiometer. It is preferable that the second straight line based on the electric signal from the Nmeta calculates the coordinates of a point which intersects the outer circumference and the inner circumference of four points of the cylindrical body.

[0011]

In the method and apparatus for measuring the uneven thickness of the cylindrical body of the present invention, the position detecting means is provided for the cylindrical body whose outer diameter and inner diameter are known in advance, at an arbitrary point on the outer circumference circle and the outer diameter. Assuming a first straight line passing through the virtual center point of, the coordinates of four points, which are points where the first straight line intersects with the outer circumference circle and the inner circumference circle of the cylindrical body, are measured. The coordinates of these four points include data that can determine two dimensions, a wall thickness dimension of a predetermined portion of the cylinder and a wall thickness dimension at a position substantially symmetrical with respect to the predetermined portion about the axis of the cylinder. I'm out. Then, based on these data and the known outer diameter dimension and inner diameter dimension, the arithmetic unit determines the deviation amount between the outer diameter center point and the inner diameter center point, the maximum wall thickness dimension, and the minimum wall thickness dimension. And the maximum thickness deviation, which is the difference between the maximum thickness dimension and the minimum thickness dimension, is calculated to easily and accurately measure the uneven thickness state of the cylinder.

[0012]

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

FIG. 1 is a schematic view of an uneven thickness measuring device for a cylindrical body according to an embodiment of the present invention. The thickness deviation measuring device 2 for a cylindrical body according to the present embodiment moves the first contactor 3 that comes into contact with the outer peripheral surface of the cylindrical body 1 and the second contactor that comes into contact with the inner peripheral surface of the cylindrical body 1 with the second contactor 3. The contactor 4, the first potentiometer 5 having an electric resistance corresponding to the moving position of the first contactor 3, and the second
The second potentiometer 6 has an electric resistance corresponding to the moving position of the contactor 4.

Furthermore, the thickness deviation measuring device 2 for a cylindrical body of this embodiment
Is the outer circumference of the cylindrical body 1 with respect to the reference position a of the first contactor 3 and the reference position d of the second contactor 4 based on the electric resistance values of the first potentiometer 5 and the second potentiometer 6. It has a calculator 7 for calculating the position b of the surface, the position c of the inner peripheral surface of the cylindrical body 1, and the position e of the inner peripheral surface of the cylindrical body 1. Further, the calculator 7 calculates the uneven thickness state of the cylindrical body 1 based on the above-mentioned position (b), position (c) and position (e).

FIG. 2 is a schematic side view of FIG. Here, the cylindrical body 1 is placed on the cylindrical body supporting roller 23 in order to fix its position. Further, the center point of the outer circumference circle of the cylindrical body 1 is set to the position O, and the center point of the inner circumference circle thereof is set to the position O ′.

Next, the operation of the thickness deviation measuring device for a cylindrical body according to the present embodiment will be described focusing on the arithmetic processing in the arithmetic unit 7. The surfaces of the outer circumference and the inner circumference of the cylindrical body 1 are processed with high accuracy compared with the uneven thickness amount, and the outer circumference circle and the inner circumference circle are ideal circles without distortion or the like. And Further, the outer diameter dimension value and the inner diameter dimension value of the cylindrical body 1 are manufactured according to the set values, and those values are
This is known as the outer diameter dimension value R and the inner diameter dimension value r.

A first method for calculating the uneven thickness state.

FIG. 3 is a side view of the cylindrical body 1 and is an explanatory view for explaining the calculation processing of the uneven thickness state in the arithmetic unit 7. In FIG. 3, points A, A'and B, B'where a straight line passing through an arbitrary point on the outer circumference circle and a virtual center point O of its outer diameter intersects with the outer circumference circle and the inner circumference circle, respectively, and T
= AA 'and T' = BB 'are defined as wall thickness dimensions, respectively.

Two measured values of the wall thickness dimensions T and T'and a predetermined outer diameter dimension value R, that is, the outer radius R
And the inner diameter dimension value r, that is, the inner diameter radius r, The amount of deviation between the center point of the outer diameter and the center point of the inner diameter Δ b. Maximum wall thickness and minimum wall thickness and c. Determine the maximum thickness deviation (= maximum wall thickness-minimum wall thickness).

First, a method of calculating the deviation amount Δ between the center point of the outer diameter and the center point of the inner diameter will be described. Here, the deviation amount Δ between the center point of the outer diameter and the center point of the inner diameter in FIG. 3 can be expressed by the following formula 1.

[0021]

[Equation 1]

However, the coordinates O and O'of the center point of the outer diameter and the center point of the inner diameter are the coordinates O = (0,0) and the coordinates O '= (-
a, b), a ≧ 0, and b ≧ 0.

The radius R of the outer diameter and the radius r of the inner diameter can be expressed by the following equations 2 and 3, respectively.

[0024]

[Equation 2]

[0025]

[Equation 3]

Coordinates A = (0, R) and coordinates A ′ =
(0, RT), coordinate B = (0, -R), coordinate B '=
By substituting the respective conditions of (0, T'-R) into the equations 2 and 3, the following equations 4 and 5 can be derived.

[0027]

[Equation 4]

[0028]

[Equation 5]

Since a ≧ 0, only the positive term is adopted for the right side of the equation (5). From these, the deviation amount Δ between the center point of the outer diameter and the center point of the inner diameter can be expressed by the following mathematical expression 6.

[0030]

[Equation 6]

Next, a method for calculating the maximum wall thickness dimension, the minimum wall thickness dimension, and the maximum uneven thickness (maximum wall thickness dimension-minimum wall thickness dimension) will be described.

In FIG. 4, the minimum wall thickness dimension TMIN is a straight line passing through the point 0 from the above definition of the wall thickness and assuming that the point on the inner circumference circle that is farthest from the point 0 is point D. It is above. Here, the minimum wall thickness dimension TMIN can be expressed by the following Equation 7.

[0033]

[Equation 7]

If the intersection of the straight line passing through the points O and O'and the inner circumference circle is point C (α, β), the dimension OC can be expressed by the following equation 8.

[0035]

[Equation 8]

The dimension OO 'can be expressed by the following equation 9.

[0037]

[Equation 9]

Therefore, the dimension OD can be expressed by the following mathematical expression 10.

[0039]

[Equation 10]

In Equation 8, the dimension OC becomes maximum when a ² + b ² + r ² ≧ 0, so cos θ = −
It becomes 1. Therefore, θ = 180 degrees.

Since the point C in FIG. 4 is the most different point from the point O, the minimum wall thickness dimension TMIN can be expressed by the following formula 11.

[0042]

[Equation 11]

Further, in FIG. 4, the maximum wall thickness dimension TMAX
Is on the straight line passing through the point O from the above definition of the wall thickness and on the inner circumference circle, and letting the point closest to the point O be the point OE. Therefore, the maximum wall thickness TMAX is
It can be expressed by the following formula 12.

[0044]

[Equation 12]

From these, the maximum uneven thickness ΔTMAX can be expressed by the following expression 13.

[0046]

[Equation 13]

Next, the second method for calculating the uneven thickness state will be described.

In FIG. 5, points A, A'and B, B'where a straight line passing through an arbitrary point on the outer circumference circle and a virtual center point O of its outer diameter intersects with the outer circumference circle and the inner circumference circle, respectively,
T = AA 'and T' = BB 'are respectively defined as wall thickness dimensions. Further, a straight line that is orthogonal to the above straight line at the virtual center point O is hypothesized, and points intersecting the outer circumference circle and the inner circumference circle are defined as L, L'and M, M ', and W = LL' and W '= MM 'is defined as the wall thickness dimension.

An example of an uneven thickness measuring device for automatically executing the second method will be described below. This uneven thickness measuring device is similar to the uneven thickness measuring device 2 shown in FIG. 1 described above, and the first contactor that comes into contact with the outer peripheral surface of the cylindrical body 1 by moving, and the cylindrical body 1 by moving. A second contactor that comes into contact with the inner peripheral surface, a first potentiometer that provides an electrical resistance according to the moving position of the first contactor, and a second potion that provides an electrical resistance according to the moving position of the second contactor. It is equipped with a tension meter. Furthermore, the thickness deviation measuring device includes a third contactor that moves to contact the outer peripheral surface of the cylindrical body 1, a fourth contactor that moves to contact the inner peripheral surface of the cylindrical body 1, and a third contactor. The third potentiometer has an electric resistance corresponding to the moving position of the contactor, and the fourth potentiometer having an electric resistance corresponding to the moving position of the fourth contactor.

If the first contactor and the second contactor are respectively moved on the virtual straight line AB in FIG. 5, the third contactor and the fourth contactor are the virtual straight line ML in FIG. Let's move up respectively. That is,
The respective moving directions of the first contactor 3 and the second contactor 4 are deviated by an angle of 90 degrees with respect to the moving directions of the third contactor and the fourth contactor.

Furthermore, the present thickness deviation measuring device detects the position of the point A based on the electric resistance value of the first potentiometer 5 in FIG. 5, and based on the electric resistance value of the second potentiometer 6. Position of each of the points A'and B ',
Each position of the point M is detected based on the electric resistance value of the potentiometer, and each position of the points M ′ and L ′ is detected based on the electric resistance value of the fourth potentiometer. After that, the calculator 7 incorporated in the thickness deviation measuring device calculates the respective values of the points B and L based on the above detection positions and the like, and also calculates the thickness deviation state described below. .

From these measured values, a. Deviation amount Δb between the center point O of the outer diameter and the center point O ′ of the inner diameter. Maximum wall thickness and minimum wall thickness c. Maximum uneven thickness dimension d. Position of center point of inner diameter e. Thickness distribution f. Determine the location of maximum wall thickness and the location of minimum wall thickness.

First, a method of calculating the deviation amount Δ between the center point of the outer diameter and the center point of the inner diameter will be described. Here, the outer circumference circle and the inner circumference circle in FIG.
It can be expressed by Equation 3. The coordinates of each measurement point are coordinates A =
(0, R), coordinates A '= (0, RT), coordinates B =
(0, -R), coordinates B '= (0, T'-R), coordinates L =
(R, 0), coordinate L '= (RW-0), coordinate M = (-
R, 0) and coordinates M '= (-R + W', 0). By substituting each of these conditions into the equations 2 and 3, the following equations 14, 15, and 16 can be derived.

[0054]

[Equation 14]

[0055]

[Equation 15]

[0056]

[Equation 16]

Therefore, the maximum wall thickness TMAX is given by the above-mentioned formula 12, and the minimum wall thickness dimension TMIN is given by the above-mentioned formula 11,
The maximum uneven thickness ΔTMAX can be calculated by the above-mentioned formula 13.

On the other hand, the position of the minimum wall thickness shown in FIG. 6 can be expressed by the following formula 17.

[0059]

[Equation 17]

The position of the maximum wall thickness shown in FIG. 6 can be expressed by the following formula 18.

[0061]

[Equation 18]

Since the wall thickness continuously changes between the maximum wall thickness and the minimum wall thickness under the conditions defined by the above-mentioned formula 1, formula 2, and formula 3, the distribution of the wall thickness is , Can be determined based on these conditions.

In the above-described method of calculating the uneven thickness state, a virtual straight line passing between an arbitrary point on the outer circumference circle and a virtual center point O of its outer diameter is rotated by an arbitrary angle about the virtual center point O. The uneven thickness state can be calculated in the same manner as the above-described calculation method by assuming a straight line and measuring at points where the straight line intersects with the outer circumference circle and the inner circumference circle.

Next, a third method for calculating the uneven thickness state will be described.

In FIG. 7, points A, A'and B, B'are defined as points where a straight line passing through an arbitrary point on the outer circumference circle and a virtual center point O of the outer diameter intersects the outer circumference circle and the inner circumference circle, respectively. , T = AA 'and T' = BB 'are defined as wall thickness dimensions, respectively.

From these measured values, a. Deviation amount Δb between the center point O of the outer diameter and the center point O ′ of the inner diameter. Maximum wall thickness and minimum wall thickness c. Determine the maximum thickness deviation.

In FIG. 7, the measured value T = AA ',
From W = A'B ', the outer diameter R and the inner diameter r which are known in advance, another thickness dimension is T = BB'
Can be expressed as

[0068]

[Formula 19]

Therefore, in the subsequent processing, by using the above-mentioned first method, the deviation amount Δ between the center point O of the outer diameter and the center point O ′ of the inner diameter, the maximum wall thickness dimension, the minimum wall thickness dimension, and the maximum wall thickness dimension The thickness deviation can be determined respectively.

Thus, in the thickness deviation measuring device for a cylindrical body according to the present embodiment, a straight line passing through an arbitrary point on the outer circumference circle and the virtual center point O of its outer diameter intersects with the outer circumference circle and the inner circumference circle, respectively. The coordinate positions of the points A and A'and the points B and B'are measured, and the deviation amount Δ, the maximum wall thickness dimension and the minimum wall thickness between the center point of the outer diameter and the center point of the inner diameter are measured based on these measured values. Since the dimension and the maximum uneven thickness dimension can be calculated, it is possible to easily and accurately measure the uneven thickness state of the cylinder. Therefore, by using the uneven thickness measuring device for a cylindrical body of the present embodiment, it is possible to easily manufacture a cylindrical body whose dimension is controlled with high accuracy.

The object to be measured by the cylinder thickness deviation measuring device of the present embodiment is not limited to a cylinder such as a perforated round billet manufactured in the premises of an iron mill. Can also be applied.

FIG. 8 is an explanatory view showing another measuring mode in the uneven thickness measuring device for a cylindrical body shown in FIG. In the above-described embodiment, the virtual straight line 81 is set perpendicularly to the cylindrical body supporting roller 23, and the intersections of the virtual straight line 81 and the outer circumference circle and the inner circumference circle are measured, but the present invention is not limited to this. Instead, the virtual straight line 82 is set parallel to the cylindrical body supporting roller 23, and the intersections A and A'of the virtual straight line 82 and the outer and inner circles and the points B and B'are measured. This also makes it possible to calculate the uneven thickness state of the cylinder.

[0073]

As described above, according to the present invention, the predetermined four coordinates in the cylindrical body are measured by the position detecting means, and the arithmetic unit determines the center point of the outer diameter of the cylindrical body based on these coordinates. The amount of deviation of the center point of the inner diameter, the maximum wall thickness dimension,
Since the minimum wall thickness dimension and the maximum wall thickness deviation can be calculated, it is possible to provide a cylinder wall thickness unevenness measuring method and device capable of easily and accurately measuring the wall thickness unevenness state of the cylinder body. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an outline of an uneven thickness measuring device for a cylindrical body according to an embodiment of the present invention.

FIG. 2 is a schematic side view of FIG.

FIG. 3 is a first explanatory diagram of a method of calculating an uneven thickness state in the uneven thickness measuring device for a cylindrical body shown in FIG. 1.

FIG. 4 is a second explanatory diagram of a method of calculating an uneven thickness state in the uneven thickness measuring device for a cylindrical body shown in FIG. 1.

FIG. 5 is a third explanatory diagram of a method of calculating an uneven thickness state in the uneven thickness measuring device for a cylindrical body shown in FIG. 1.

6 is a fourth explanatory diagram of a method for calculating an uneven thickness state in the uneven thickness measuring device for a cylindrical body shown in FIG. 1. FIG.

FIG. 7 is a fifth explanatory diagram of a method of calculating an uneven thickness state in the uneven thickness measuring device for a cylindrical body shown in FIG. 1.

FIG. 8 is an explanatory diagram showing another measurement mode of the uneven thickness measuring device for a cylindrical body shown in FIG. 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical body 2 Unevenness measuring device 3 1st contactor 4 2nd contactor 5 1st potentiometer 6 2nd potentiometer O Virtual center point O'of outer diameter Virtual center point of inner diameter 23 Cylindrical body support roller

Claims (6)

[Claims] 1. A first straight line passing through an arbitrary point on the outer circumference circle and a virtual center point of the outer diameter is assumed for a cylindrical body whose outer diameter and inner diameter are known in advance. 1 is the point where the straight line intersects with the outer and inner circles of the cylinder 4
The coordinates of the points are measured by the position detecting means, and the deviation amount between the center point of the outer diameter and the center point of the inner diameter and the maximum wall thickness dimension are calculated based on the coordinates of the four points, the outer diameter dimension, and the inner diameter dimension. A method for measuring an eccentricity of a cylindrical body, comprising: calculating a minimum wall thickness dimension and a maximum wall thickness deviation, which is a difference between the maximum wall thickness dimension and the minimum wall thickness dimension, with a calculator. 2. A first straight line passing through an arbitrary point on the outer circumference circle and a virtual center point of the outer diameter is assumed for a cylindrical body whose outer diameter and inner diameter are known in advance. 1 is the point where the straight line intersects with the outer and inner circles of the cylinder 4
Position measuring means for measuring the coordinates of points, and based on the coordinates of the four points, the outer diameter dimension, and the inner diameter dimension, the deviation amount between the outer diameter center point and the inner diameter center point, and the maximum wall thickness. An eccentricity measuring device for a cylindrical body, comprising: a calculator for calculating a dimension, a minimum wall thickness dimension, and a maximum wall thickness deviation that is a difference between the maximum wall thickness dimension and the minimum wall thickness dimension. 3. A first straight line passing through an arbitrary point on the outer circumference circle and a virtual center point of the outer diameter is assumed for a cylindrical body whose outer diameter and inner diameter are known in advance. 1 is the point where the straight line intersects with the outer and inner circles of the cylinder 4
The coordinates of the points are measured by the position detecting means, and a second straight line orthogonal to the first straight line at an imaginary center point is assumed, and the second straight line is the outer circumference circle and the inner circumference circle of the cylindrical body. The coordinates of four points, which are points intersecting with, are measured by the position detecting means, and the deviation amount between the center point of the outer diameter and the center point of the inner diameter is determined based on the coordinates of the eight points, the outer diameter dimension, and the inner diameter dimension. , The maximum wall thickness dimension, the minimum wall thickness dimension, the maximum uneven thickness that is the difference between the maximum wall thickness dimension and the minimum wall thickness dimension, the coordinates of the center point of the inner diameter, the distribution state of the wall thickness, and the maximum wall thickness. A method for measuring uneven thickness of a cylindrical body, characterized in that a position of thickness and a position of minimum wall thickness are calculated by a calculator. 4. A first straight line passing through an arbitrary point on the outer circumference circle and a virtual center point of the outer diameter is assumed for a cylindrical body whose outer diameter and inner diameter are known in advance. 1 is the point where the straight line intersects with the outer and inner circles of the cylinder 4
The position measuring means has a position measuring means for measuring the coordinates of a point, and the position measuring means assumes a second straight line orthogonal to the first straight line at a virtual center point, and the second straight line is the cylindrical body. The coordinates of four points, which are points intersecting the outer circumference circle and the inner circumference circle, are also measured, and based on the coordinates of the eight points, the outer diameter dimension, and the inner diameter dimension, the center point of the outer diameter and the center point of the inner diameter. Deviation, the maximum wall thickness dimension, the minimum wall thickness dimension, the maximum uneven thickness that is the difference between the maximum wall thickness dimension and the minimum wall thickness dimension, the coordinates of the center point of the inner diameter, and the distribution state of the wall thickness. An apparatus for measuring an eccentricity of a cylindrical body, comprising: a calculator for calculating a position of maximum wall thickness and a position of minimum wall thickness. 5. The uneven thickness measuring device for a cylindrical body according to claim 2, wherein the position detecting means moves the first contactor that comes into contact with the outer peripheral surface of the cylindrical body, and the position detecting means moves the first contactor of the cylindrical body. A second contactor that comes into contact with the inner peripheral surface, a first potentiometer that provides an electrical resistance according to the moving position of the first contactor, and an electrical resistance that provides an electrical resistance according to the moving position of the second contactor 2 potentiometer, and the arithmetic unit is the first
An uneven thickness measuring device for a cylindrical body, which performs arithmetic processing based on electric signals from a potentiometer and a second potentiometer. 6. The uneven thickness measuring device for a cylindrical body according to claim 4, wherein the position detecting means moves the first contactor which comes into contact with the outer peripheral surface of the cylindrical body, and the moving position of the cylindrical body. A second contactor that contacts the inner peripheral surface, a third contactor that contacts the outer peripheral surface of the cylindrical body 1 by moving, and a fourth contactor that contacts the inner peripheral surface of the cylindrical body 1 by moving. , A first potentiometer having an electric resistance corresponding to the moving position of the first contactor, a second potentiometer having an electric resistance corresponding to the moving position of the second contactor, and a moving position of the third contactor And a fourth potentiometer having an electric resistance corresponding to the moving position of the fourth contactor, wherein the computing unit is the first potentiometer and the fourth potentiometer. 2 Based on the electric signal from the potentiometer, the first straight line The coordinates of four points that intersect the outer and inner circles of the cylindrical body are calculated, and the computing unit further calculates a second straight line based on the electric signals from the third potentiometer and the fourth potentiometer. Is an apparatus for measuring the uneven thickness of a cylindrical body, wherein the coordinates of four points, which are points intersecting the outer circumference circle and the inner circumference circle of the cylindrical body, are calculated.