JP4085616B2 - Inner surface shape measuring method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inner surface shape measuring method and apparatus for measuring an inner surface shape of a measuring object by providing a measuring means inside a hollow measuring object.
[0002]
[Prior art]
Japanese Patent Application Laid-Open No. 63-58130 and Japanese Patent Application Laid-Open No. 7-43103 disclose methods for measuring the shape of the inner surface of a hollow measurement object such as a cylinder having a circular cross section.
[0003]
In these prior arts, the measuring means is installed at the axial center position of the object to be measured, the distance from the axial center to the hollow inner surface is sequentially measured in the circumferential direction, and the measuring means is further moved in the axial direction to hollow the hollow from the axial core. By repeatedly measuring the distance to the inner surface in the circumferential direction and processing the measurement distance information, the three-dimensionalization is achieved, and the shape of the inner surface such as unevenness can be measured from the deviation of the measurement distance.
[0004]
[Problems to be solved by the invention]
In the above prior art, when installing the measuring means at the axial center position of the measuring object, there is a fixing jig extending radially from the center position of the measuring means toward the hollow inner surface of the measuring object, such as a radial part. The distances of the leg portions extending to the same are made equal so that the center of the measuring means coincides with the axial center position. Measurement is performed by measuring the distance from the center position of the measuring means toward the hollow inner surface of the measurement object.
[0005]
Therefore, when repeatedly measuring the distance from the axial center to the hollow inner surface while sequentially moving the measuring means, that is, the fixing jig in the axial direction of the measuring object, if the measuring object is straight, The locus of the center position of the fixing jig obtained by sequentially moving the fixing jig in the axial direction is straight and there is no problem.
[0006]
However, when the measurement object is bent, the locus of the center position in the measurement means is moved along the curve of the measurement object.
[0007]
However, since the distance from the measured axis to the hollow inner surface is a scalar amount, the movement of the center position of the measuring means cannot be grasped, and even if the inner surface shape such as irregularities can be measured relatively, It was difficult to measure the absolute inner surface shape including bending.
[0008]
Therefore, an object of the present invention is to provide an inner surface shape measuring method and apparatus capable of faithfully measuring the inner surface shape of a measurement object.
[0009]
[Means for Solving the Problems]
A feature of the present invention that achieves the above object is as follows. In an inner surface shape measuring method for measuring a hollow measurement object having a stepped cylindrical portion on the inner surface and having both ends open using a measuring means having a shaft disposed through the inside of the measurement object. The shaft is held by the measurement object and is rotatable, and the first measurement unit (6B) capable of measuring the axial distance from the reference point to the shaft and the distance from the shaft center can be measured. A second measurement unit (6C) is attached, the shaft is rotated, the center position of the shaft is shifted based on the measurement value of the first measurement unit, and the shaft of the shaft is measured based on the measurement value of the second measurement unit. After obtaining the parallel displacement and changing the shaft position so that these deviations are within the predetermined tolerance, the deflection of the shaft is eliminated and the shaft can be moved in the axial direction. Measuring the inner shape of the measurement object by using the third measurement units There is.
[0010]
Further features of the present invention that achieve the above object are as follows: In an inner surface shape measuring apparatus having a stepped cylindrical portion on the inner surface and measuring a hollow measurement object having both end surfaces opened, and having a shaft disposed through the measurement object. The first measuring unit (6B) capable of measuring the axial distance from the reference point and the distance from the shaft center are measured at both ends of the shaft with support means for rotatably supporting the shaft. A possible second measurement unit (6C) is attached to the shaft, and the shaft center position deviation based on the measurement value of the first measurement unit obtained simultaneously by rotating the shaft and the measurement value of the second measurement unit And calculating means for determining the parallel displacement of the shaft based on the shaft, and means for detecting the deflection of the shaft is provided on the shaft There is.
[0011]
According to the present invention, even if the measuring means is sequentially moved in the axial direction of the measurement object, the fixed position of the measurement means moves along the shaft and does not move along the center of the measurement object. Since the center is determined by the quantity, the inner shape of the measurement object can be measured faithfully.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The method and apparatus of the present invention will be described below with reference to the drawings.
[0013]
FIG. 1 shows a situation in which the inner surface of a cylindrical stepped casing 100, which is a measurement object, is measured by the measuring apparatus 1 according to the present invention.
[0014]
The stepped casing 100 is a casing for a rotary machine having a maximum inner diameter of about φ900 (mm) and a length of about 1800 (mm). The measuring device 1 is used by using the casing stud bolts 101 and 102 on both end faces of the casing 100. It is installed.
[0015]
The measuring device 1 is provided with three shaft support arms 2a and 2b radially at 120 degree intervals on both end sides of the casing 100. The ring portion at each end of the shaft support arms 2a and 2b is connected to a casing stud bolt 101, The other end side of the three shaft support arms 2a, 2b is connected to the shaft receiving blocks 3a, 3b and supports both ends of the shaft 4. Although not shown, the shaft support arms 2a and 2b have a mechanism capable of adjusting the length of a turnbuckle or the like in the middle.
[0016]
In the axial direction of the casing 100 (left-right direction in FIG. 1), the shaft 4 is divided into two at the center into left and right pieces 4a and 4b shown in FIG. The support 5 is supported while correcting the deflection caused by its own weight.
[0017]
The shaft 4 is provided with measuring units 6A to 6E which are measuring means. The measuring unit 6A is fixed to the casing bolt 101 together with the shaft support arm 2a, and the measuring units 6B to 6E are movably provided on the shaft 4.
[0018]
Measuring unit 6A is the axial direction of shaft 4 Opposite The position is measured, and the measurement units 6B to 6E measure the positions of the inner surface and end surface of the casing 100 in the circumferential direction and the axial direction. The shaft 4 can be rotated in the circumferential direction, that is, clockwise or counterclockwise by the operation of a handle (not shown), and the rotation amount is connected to the shaft 4 by a flexible joint (not shown). Measurement is performed by the rotary encoder 7. While the shaft 4 is rotating, there may be a positional deviation in the axial direction. The amount of movement is measured by the measuring unit 6A, and the inner surface measurement result in the circumferential direction in the measurement position and the casing 100 or the measurement in the axial direction. Corresponding to the result, it is used in the calculation process of the inner surface shape later.
[0019]
With reference to FIG. 2, the measurement method of the measurement units 6A to 6E will be described with the measurement unit 6D as a representative.
[0020]
A support block 6a is movably fixed to the outer periphery of the shaft 4.
[0021]
That is, the support block 6a is provided with a single cut in the radial direction, and the support block 6a is tightly fixed to the shaft 4 by narrowing the interval between the cuts by screw tightening.
[0022]
The support block 6a supports the slide rail 6b, and the slide rail 6b holds the fine movement stage 6c. As shown in FIG. 3, the fine movement stage 6c is mounted with optical distance sensors 6d and 6e for measuring the radial and axial distances to the surface of the casing 100 so as to allow fine movement. However, the measurement units 6A and 6B are only axial distance sensors, and the measurement unit 6C is only a radial distance sensor. As described above, the measurement unit 6A is directly fixed to the casing 100, and has a mounting structure without a slide rail. The measurement units 6B and 6C have a right end portion (a portion in FIG. 1) of the casing 100, the measurement unit 6D has an inner surface (a portion in FIG. 1), and the measurement unit 6E has a left end portion (a portion in FIG. 1). ). Although the non-contact type sensor is used as each distance sensor, the work for incorporating the shape measuring apparatus is simplified, but a contact type sensor may be used.
[0023]
Returning to FIG. 1, the installation of the measuring device 1 on the casing 100 will be described.
[0024]
As shown in FIG. 4, the measuring device 1 has a laser projector 1a at the left end, a spot plate 1b having a lens or pinhole for focusing the laser beam, a spot plate 1c at the center, and a right end. Is provided with a light receiver 1d. As the type of laser light, a normal He—Ne laser or a semiconductor laser is used. As described above, there is a support 5 that supports the shaft 4 while correcting the deflection, outside the center of the shaft 4. The support 5 includes a drive device 5a such as a servo motor and a support member 5b of the shaft 4, and the drive device 5a corrects the deflection due to the weight of the shaft 4.
[0025]
As shown in FIG. 1, when the measuring device 1 is installed in the casing 100, the shaft 4 is in a straight state with no bending.
[0026]
For such installation, as shown in FIG. 4 (b), the support 5 is checked in advance with a level not shown so that the two ends of the shaft 4 and the center of the shaft 4 are horizontal. The center of the shaft 4 is raised by the driving device 5a, and the amount of movement of the driving device 5a is stored when the level is obtained. Alternatively, the shaft 4 is installed on a surface plate having a precise horizontal surface such as a stone, and light reception position information in the light receiver 1d in that state is stored. In this case, if the light receiver 1d is a CCD element, light reception position data is stored.
[0027]
When the measuring device is installed in the casing 100, the installation length e with respect to the casing 100 shown in FIG. 4A varies, and the deflection amount w when the shaft 4 is not supported at the center also changes. The distance d between the spot plates 1b and 1c is unique to the measuring device.
[0028]
Therefore, when the measuring device 1 is installed in the casing 100, the light receiving position deviation δ can be confirmed by the light receiver 1d, and the installation length e can be measured.
[0029]
The actual deflection amount w is given by the following equation.
[0030]
δ≈ (e / d) × w (1)
Accordingly, the position data of the photoreceiver 1d stored and corrected is determined by determining the operation amount of the driving device 5a from the light receiving position deviation δ obtained by the photoreceiver 1d so that the flexure amount w becomes zero after installation. Confirm that the straightening process is correct, and set the shaft 4 straight.
[0031]
As the light receiver 1d, an image sensor of a CCD element is used. However, a PSD for resistance detection method, a light amount sensor that takes a method for searching for the maximum point of light amount, or a photoelectric sensor that performs a method for searching for the center of the incident light ON range. Etc. may be adopted.
[0032]
The linearity of the shaft 4 is further improved by arranging the light beams formed by the projector 1a, the spot plates 1b and 1c, and the light receiver 1d vertically or horizontally.
[0033]
FIG. 5 shows the electrical system of the measuring device 1.
[0034]
In FIG. 5, reference numeral 5c denotes a driver of the driving device 5a. 8 is an analog input interface for inputting the measurement results of the distance sensors of the light receiver 1d and the measurement units 6A to 6E, 9 is a parallel input interface for inputting the measurement results of the encoder 7, 10 is a central controller (calculation means), 11 Is a pulse generator, 12 is an external storage device, 13 is a monitor, and 14 is a printer.
[0035]
The central controller 10 is composed of a ROM containing a measurement software program to be described later, a RAM for temporarily storing inputs from the interfaces 8 and 9, and an MPU having a CPU for performing various processes based on the measurement software program in the ROM. Has been.
[0036]
The operation amount of the driving device 5a is calculated by the central controller 10 and output as a pulse amount. The pulse generator 11 receives this and outputs a necessary pulse to the driver 5c, and the driving device 5a straightens the shaft 4. The monitor 13 displays the processing status in the central controller 10 and provides it to the operator's convenience. Information such as measurement targets and measurement conditions, processing results, and the like are stored in the external storage device 12 and output as a hard copy by the printer 14.
[0037]
FIG. 6 is an example of a screen displayed on the monitor 13.
[0038]
On the screen of the monitor 13, the measurement location, the measurement result, and the figure obtained by data processing of the measurement result are displayed, but the measurement procedure described below is also displayed so as to prevent work mistakes in advance. ing.
[0039]
Next, the inner surface shape measurement of the casing 100 will be described with reference to FIGS.
[0040]
First, installation of the measuring device 1 will be described with reference to FIG.
[0041]
In step (hereinafter abbreviated as S) 1 in FIG. 7, the right end surface of the casing 100 in FIG. 1 is used as a reference surface, and the right end side of the shaft 4 is composed of three shaft support arms 2 a and casing stud bolts 101. Temporarily fix to.
[0042]
Next, in S2, the left end side of the shaft 4 is temporarily fixed to the other end (left end in FIG. 1) side of the casing 100 with the three shaft support arms 2b and the casing stud bolt 102.
[0043]
Since the shaft 4 is rotatable in the circumferential direction, the shaft 4 is rotated in S3 by slowly turning a handle (not shown).
[0044]
During the rotation of the shaft 4, the measuring unit 6 shown in FIG. B The distance to the right end of the shaft 4 is measured by the distance sensor, and the measurement data is stored in the RAM of the central controller 10 shown in FIG. 5 in association with the rotation amount measurement result by the rotary encoder 7. Further, the distance to the right inner surface of the casing 100 by the distance sensor of the measurement unit 6C. Detuning Measurements are also performed at the same time, and those measurement data are also stored in the RAM of the central controller 10.
[0045]
When one rotation of the shaft 4 is completed, graphic processing is performed using the distances of three arbitrary points among the results measured by the measurement unit 6C. That is, the circumscribed circle is assumed to be located on one circumference of the inner surface of the casing 100, and the center position is calculated from the center of gravity of the three points.
[0046]
Since the center position of the virtual circumscribed circle represents the center position of the shaft 4 and the center position of the casing 100 is known by design, the difference between the center position of the shaft 4 and the center position of the casing 100, that is, the right end of the casing 100. The center position deviation amount when both center positions are viewed from the side is calculated.
[0047]
Further, the normal vector in the virtual circumscribed circle is virtualized. This normal vector represents the central axis of the shaft 4, and the virtual circumscribed circle is perpendicular to the normal vector. On the other hand, assuming that the center axis known in the design of the casing 100 is perpendicular to the right end surface of the casing 100, the right end surface of the casing 100 and the virtual circumscribing are determined from the virtual normal vector and the deviation angle between the center axis known in the design of the casing 100. The inclination state of the surface of the circle is calculated as the amount of plane parallel deviation. Simply speaking, the amount of plane parallel deviation is obtained as a measure representing whether the shaft 4 is installed such that the central axis of the shaft 4 does not intersect the central axis known in the design of the casing 100.
[0048]
Thereafter, in S4, it is determined whether the center position deviation amount is within the allowable value. If it is out of the allowable value, in S5, the operator manually rotates the turnbuckle (not shown) in the shaft support arm 2a as appropriate. Centering is performed so that the center of 4 approaches the center of the casing 100.
[0049]
When it is considered that the center of the casing 100 has been approached, the process returns to S3, and the shaft 4 is rotated again for measurement, and the center position deviation amount and the plane parallel deviation amount are calculated.
[0050]
If the center position deviation amount is within the allowable value, the process proceeds from S4 to S6, and it is determined whether the surface parallel deviation amount is within the allowable value. Since the center axis of the shaft 4 is not parallel to the designed center axis of the casing 100, the outside of the allowable value means that in S7, the operator manually turns the buckle on the shaft support arm 2b (not shown). Is appropriately rotated so that the center axis of the shaft 4 is parallel to the center axis of the casing 100. When it is considered that they coincide with each other, the process returns to S3, and the shaft 4 is rotated again for measurement, and the center position deviation amount and the plane parallel deviation amount are calculated.
[0051]
Since the center position deviation amount on the right end side is within the allowable value, the process proceeds from S4 to S6, and it is determined again whether the plane parallel deviation amount is within the allowable value.
[0052]
When the amount of plane parallel deviation falls within the allowable value, the temporary fixing of the shaft support arms 2 a and 2 b and the casing bolts 101 and 102 is changed to the main fixing, and the measuring device 1 is fixed at both ends of the casing 100.
[0053]
Thereafter, the amount of deflection of the shaft 4 is detected in S8.
[0054]
In this process, the deflection amount w of the shaft 4 is obtained from the aforementioned equation (1) from the light receiving position deviation δ of the laser beam received by the light receiver 1d in FIG.
[0055]
If the deflection amount w is outside the allowable value, the process proceeds to S10, the operation amount by the driving device 5a is calculated by the central controller 10 in FIG. When the deflection amount w falls within the allowable value, the shaft 4 is installed straight.
[0056]
In installing the measuring device 1, the difference in the inner diameter of the casing 100 is adjusted by positioning the distance sensor with the slide rail 6b and the fine movement stage 6c of the measuring units 6B to 6E, and the difference in the axial direction of the casing 100 is detected. Corresponds to the adjustment of the mounting position of the measurement units 6B to 6E on the shaft 4.
[0057]
In actual work, the measuring device 1 is roughly positioned in advance within a possible range outside the casing 100, and then incorporated into the casing 100 to perform centering work.
[0058]
Next, measurement of the inner surface shape will be described.
[0059]
As described with reference to FIG. 7, the shaft 4 is installed straight on the casing 100 on the basis of the allowable value. Therefore, the operator rotates the shaft 4 with a handle (not shown) to measure each measurement unit 6B to 6E. The distance sensor in the radial direction and the axial direction is measured with this distance sensor. In addition, although the allowable value in the installation of the shaft 4 is set from the viewpoint of the ease of installation work, as will be described later, the measurement results of the measurement units 6B to 6E have moderate accuracy. It has become.
[0060]
When measuring to every corner of the inner surface of the casing 100, the installation positions of the measurement units 6B to 6E in the axial direction with respect to the shaft 4 are moved little by little, or the slide rail 6b and the fine movement stage 6c in each measurement unit 6B to 6E. To move the position of the distance sensor in three dimensions and perform the required measurement.
[0061]
The distance in the radial direction or the axial direction is measured by the distance sensors of the measurement units 6B to 6E by one rotation of the shaft 4.
[0062]
The unevenness of the cylindrical surface of the casing 100 can be represented by the measurement result for one rotation in the radial direction by the distance sensor 6d (see FIG. 3). When measuring in the axial direction by the distance sensor 6e (see FIG. 3), the shaft 4 is changed every time the position of the distance sensor 6e in the radial direction is changed little by little using the slide rail 6b or the fine movement stage 6c. When the is rotated once, the unevenness of the flange surface can be represented by the measurement result.
[0063]
Thus, it can obtain | require by making the inner surface shape of the casing 100 into a figure etc. using a measurement result.
[0064]
Since the shaft 4 is straight even if the position of the distance sensor is shifted in the axial direction, the measurement data can be obtained as an absolute value that is not affected by the bending of the casing 100 or the like. Therefore, the bending degree of the casing 100 can be obtained from the measurement data. Even if the casing 100 is created as designed, it may be distorted when it is installed at a predetermined position, and if a rotor or the like is to be incorporated into the casing 100, it may not fit well. In such a case, it is necessary to correct the installation. According to this measurement method, the degree of bending of the casing 100 can be obtained from the measurement data, and the degree of distortion of the casing 100 can be determined. Therefore, the installation degree can be easily adjusted.
[0065]
Next, correction of measurement data and obtaining a more accurate measurement result will be described with reference to FIG.
[0066]
The allowable values in S4 and S6 of FIG. 7 are arbitrarily determined from the viewpoint of the ease of work when the measuring apparatus 1 is installed in the casing 100, and the measurement accuracy of the measuring units 6A to 6E including the distance sensor is determined. It was not decided from a viewpoint. In other words, if the installation is required to be precise, the measurement work cannot be performed. Therefore, the measurement data can be corrected with the measurement device 1 installed and measured with a certain degree of accuracy. This is based on the idea of making it easier.
[0067]
Now, in S11 of FIG. 8, using the measurement units 6B to 6E shown in FIG. 1, the right end (A part), the center (I part), and the left end (U part) of the casing 100 are in the radial direction (circumferential direction) on the entire circumference. The distance in the axial direction (plane direction) is measured (scanning), and the measurement result (data) is stored in the RAM of the central controller 10 in FIG.
[0068]
As shown in FIG. 9, the central controller 10 in FIG. 5 obtains circumscribed circles passing through the three points P1, P3, P5, R1, R3, and R5 of the section A and the section C, as shown in FIG. A straight line L1 is obtained as the center positions A0 and C0 before correction.
[0069]
In particular, since the right end side of the casing 100 is used as a reference plane, the measurement data obtained by the measurement unit 6C is used, and a number of arbitrary three points (for example, P2, P4, P6) are created. The circumscribed circle and the center position of are obtained on the coordinates. And the average position G (A1) of each center position is obtained.
[0070]
The average position G (A1) is obtained by a simple arithmetic average or a weighted average. If 60 points of measurement data are obtained by scanning, 20 sets of center positions can be obtained, and the average is taken as the average position G (A1).
[0071]
Next, in S12, errors ΔX and ΔY are obtained from the average position G (A1) and the center position A0 before correction.
[0072]
Since the measuring apparatus 1 is installed in a straight line, in the subsequent S13, the above-described error ΔX, ΔY is used to correct the center position of the section A already obtained to G (A1), and in step S14, the section C The center position C0 is also subjected to a position correction that is translated by the errors ΔX and ΔY to obtain a corrected center position C1. A line L2 connecting the corrected center positions is drawn.
[0073]
The center position B0 is also a position B1 that has been translated by an error ΔX, ΔY.
[0074]
The straight line L2 is based on the accurate determination of the center position G (A1) from the average of a plurality of measurement data at the right end portion A, and the central axis of the measuring device 1 is assumed to be located on this straight line L2. That is, although the measuring apparatus 1 is installed with the right end side of the casing 100 as a reference, since the casing 100 is not a perfect circle, a large number of sets of arbitrary three points on the circumference of the inner surface having irregularities are provided. Assuming a perfect circle whose center position is the average position of the center positions in the circumscribed circle, the axis center of the measuring device 1 is assumed to be located here. Therefore, when the measuring device 1 is viewed from the right end side of the casing 100, it can be considered that the position of the central axis matches the position of the designed central axis of the casing 100.
[0075]
Next, in S15, using the measurement data by the measurement unit 6B of FIG. 1, whether the shaft center of the shaft 4 in the measurement apparatus 1 is installed perpendicular to the right end reference plane of the casing 100, that is, the inclination Δθ of the shaft 4 is Perform the calculation.
[0076]
The calculation of the inclination Δθ of the shaft 4 will be described with reference to FIG.
[0077]
In FIG. 10, the straight line L2 after the center axis position correction obtained in the description of FIG. 9 is displayed as a line L3 connecting the center positions before the inclination correction.
[0078]
Also here, as shown in FIG. 10, in addition to the circumscribed circle plane D passing through arbitrary three points (for example, p1, p3, p5), a set of circumscribed circle planes of a large number of three points such as p2, p4, p6, etc. Set the normal vector for each plane. Then, an average vector of the respective normal vectors is obtained, and this is used as a line L4 connecting the corrected center positions, and an error Δθ between them is obtained. This is also based on the assumption that the right end portion A of the casing 100 is not geometrically flat but has a slight unevenness or an inclined surface.
[0079]
Therefore, it is assumed that the right end surface of the casing 100 in which the measuring device 1 is installed is a flat surface by obtaining an average value of normal vectors with respect to a plane passing through a set of a plurality of three points. Assume that the shaft is installed vertically.
[0080]
Based on the tilt error Δθ, the positional deviation on the reference plane side is corrected again in S16. In this case, the variation of the center position is slight and almost coincides (A1 = A2). In S17, the center position C1 of the left end portion (the other end side) of the casing 100 is corrected again to be a position C2. The central position B1 is a position B2.
[0081]
Finally, in S18, the measurement data obtained in S11 is corrected by assuming that the measurement units 6B to 6E are positioned on the straight line L4.
[0082]
That is, in FIG. 9, the inner surface of the casing 100 is shaped according to the distance from the corrected center positions G (A1), B1, C1 to the measurement points P1-P6, Q1-Q5, R1-R5, In FIG. 10, the shape of the inner surface of the casing 100 is accurately obtained based on the distances from the further corrected center positions A1 (A2), B2, and C2 to the measurement points p1 to p6, q1 to q5, and r1 to r5. be able to.
[0083]
The monitor screen of FIG. 6 is an example in which the state of FIG. 9 is displayed.
[0084]
In the measurement scanning by the measurement device 1, the measurement device 1 is moved along the shaft 4 and the distance to the inner surface of the casing 100 is measured, but the shaft 4 is installed straight and the center position of the measurement device 1 is moved. Since the trajectory is also straight, even if the casing 100 is bent, the substantial deformation amount can be obtained with high accuracy.
[0085]
In this embodiment, since there are a radial distance sensor and an axial distance sensor, measurement is possible even if there is a step or an inclination as shown in FIG. The inner surface shape is measured in a state where a measurement object such as a casing is installed, and if it is bent, the installation condition can be adjusted to make it easy to incorporate a rotor or the like.
[0086]
9 and 10, it is assumed that the measuring device 1 is accurately installed using the right end of the casing 100 as a reference plane. However, if it is desired to accurately measure a desired position in the axial direction inside the casing 100, If one set of measuring units is arranged at a position and the other set is using a measuring unit positioned at the right end or the left end and the measurement procedure shown in FIG. 8 is executed, the measuring apparatus 1 is attached to the right end of the casing 100. Even if the measuring device 1 is roughly installed as a reference surface, it can be virtually assumed that the measuring device 1 is accurately installed at the desired position, and the inner surface shape can be accurately obtained.
[0087]
【The invention's effect】
As described above, according to the present invention, it is possible to faithfully measure the inner shape of the measurement object.
[Brief description of the drawings]
FIG. 1 is a diagram showing a situation in which an inner surface of a stepped casing is measured by a measuring apparatus according to an embodiment of the present invention.
2 is a schematic perspective view of the measurement apparatus of the present invention shown in FIG.
FIG. 3 is a diagram showing a situation in which the distance to the surface of the stepped casing is measured by the measuring instrument in the measuring device of the present invention shown in FIG. 1;
4 is a diagram for explaining a preparation process for installing the measuring device of the present invention shown in FIG. 1 in a stepped casing. FIG.
FIG. 5 is an electrical system diagram of the measurement apparatus of the present invention shown in FIG.
6 is a diagram showing an example of a monitor screen in the measurement apparatus of the present invention shown in FIG. 4. FIG.
7 is a diagram showing a procedure for installing the measuring device of the present invention shown in FIG. 1 in a stepped casing. FIG.
8 is a diagram showing a procedure for measuring an inner surface shape of a stepped casing with the measuring device of the present invention shown in FIG. 1; FIG.
FIG. 9 is a diagram for explaining a measurement data correction method by the measurement apparatus of the present invention shown in FIG. 1;
FIG. 10 is a diagram for explaining a measurement data correction method by the measurement apparatus of the present invention shown in FIG. 1;
[Explanation of symbols]
1 ... Measuring device
1a ... Laser projector
1b, 1c ... Spot plate
1d: Receiver
2a, 2b ... Shaft support arm
3a, 3b ... Shaft receiving block
4 ... Shaft
5 ... Support
6A-6E ... Measurement unit
6a ... Support block
6b ... Slide rail
6c ... Fine movement stage
6d, 6e ... Optical distance sensor
7 ... Rotary encoder
8 ... Analog input interface
9 ... Parallel input interface
10 ... Central controller
11 ... Pulse generator
12 ... External storage device
13 ... Monitor
14 ... Printer
15 ... Displacement meter unit
100 ... casing
101, 102 ... casing stud bolt

Claims (4)

In an inner surface shape measuring method for measuring a hollow measurement object having a stepped cylindrical portion on the inner surface and having both ends open using a measuring means having a shaft disposed through the inside of the measurement object. ,
The shaft is held by a measurement object and is rotatable. The first measurement unit (6B) capable of measuring an axial distance from a reference point on the shaft and a distance from the shaft center can be measured. A second measurement unit (6C) is attached, the shaft is rotated, and the shaft center position shift based on the measurement value of the first measurement unit and the shaft based on the measurement value of the second measurement unit The parallel displacement of the shaft is obtained simultaneously, and after changing the arrangement position of the shaft so that the obtained deviation is within a predetermined allowable value, the deflection of the shaft is eliminated, and the shaft is provided to be movable in the axial direction. An inner surface shape measuring method, comprising: measuring an inner surface shape of a measurement object using the third measuring unit. The shaft is hollow and has a laser measuring device in the hollow portion, and the shaft is bent by driving a driving device provided in an intermediate portion of the shaft according to the bending of the shaft measured by the laser measuring device. The inner surface shape measuring method according to claim 1, wherein: In an inner surface shape measuring apparatus having a stepped cylindrical portion on the inner surface and measuring a hollow measurement object with both end surfaces open, and having a shaft disposed through the measurement object. ,
Supporting means for rotatably supporting the shaft is provided at both ends of the shaft, and the first measuring unit (6B) capable of measuring the axial distance from the reference point and the distance from the shaft center are measured. A possible second measurement unit (6C) is attached to the shaft, and the shaft center position shift based on the measurement value of the first measurement unit obtained simultaneously by rotating the shaft, and the second measurement unit An inner surface shape measuring apparatus comprising an arithmetic means for obtaining a parallel displacement of a shaft based on a measured value, and means for detecting a deflection of the shaft. The shaft is formed in a hollow shape, and a laser measuring device is provided in the hollow portion, and a driving device capable of correcting the deflection of the shaft measured by the laser measuring device is arranged in an intermediate portion of the shaft. The inner surface shape measuring apparatus according to claim 3.

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