JP2022143957A - Measurement jig, three-dimensional measurement system, and three-dimensional measurement method - Google Patents

Abstract

To three-dimensionally measure a protrusion such as a seal fin that linearly extends easily with good accuracy.SOLUTION: A measurement jig 30 pertaining to an embodiment of the present invention is attachable to a probe 21 which can be used when bringing a convex contact face 22a of a probe 21 into contact with a contact point at the tip of a protrusion 17 of a measurement object that extends linearly and measuring the three-dimensional position of the contact point at the tip of the protrusion 17. The measurement jig 30 comprises: a guide part 31 that can be arranged sandwiching both sides of the protrusion 17 while the measurement jig 30 is attached to the probe 21; and a holding part 32 that holds the measurement jig 30 to the probe 21 integrally with the guide part 31 while the measurement jig 30 is attached to the probe 21. The contact point at the tip of the protrusion 17 can be brought into contact with the convex contact face 22a of the probe 21 while the measurement jig 30 is attached to the probe 21.SELECTED DRAWING: Figure 6

Description

TECHNICAL FIELD Embodiments of the present invention relate to a measuring jig, a three-dimensional measuring system, and a three-dimensional measuring method.

A rotating device of an axial flow turbine such as a steam turbine includes a rotor (rotor shaft) and a casing provided around the rotor. Moving blades are provided on the outer peripheral surface of the rotor, and form a rotating body together with the rotor. A stationary blade is provided on the inner peripheral surface of the casing, and constitutes a stationary body together with the casing.

A gap is provided in the radial direction between the stationary body and the rotating body. A sealing device is provided in this gap. The seal device has an annular seal fin provided on the inner surface of the stationary body and having a sharp tooth tip shape protruding toward the outer peripheral surface of the rotating body. A minute gap is provided between the tip of the seal fin and the rotating body to prevent contact and reduce the flow rate of the working fluid passing therethrough.

The dimension of the minute gap (gap dimension) between the tip of the tooth tip of this seal fin and the rotating body is the contact between the rotating body and the stationary body during operation of the rotating equipment, the adhesion of scale to the rotating body, and the It can change over time due to changes in the state of the rotating/stationary body. Therefore, when inspecting the turbine (rotating equipment), the gap size is measured to confirm whether or not the gap size is within a specified range.

This gap size can be estimated using a measurement of an inside dimension such as the inside diameter of the opposing seal fins of the stationary body. Conventionally, an inside micrometer is used to measure inner dimensions such as the opposing inner diameters of the seal fins for estimating the gap dimensions.

The inside micrometer has a cylindrical rod, and probes at both ends of the rod have hemispherical ends. For example, when measuring the inner diameter of the seal fin, one end of the inside micrometer is brought into contact with the seal fin, and the other probe is brought into contact with the opposing seal fin tip to measure the inner dimension of the seal fin tip. In addition, when measuring the inner diameter in the vertical direction, a metal straight edge is placed on the horizontal surface of the stationary body with the upper half / lower half separate structure, and the metal straight edge is vertically lowered from the lower surface of the metal straight edge across the horizontal surface. A method of measuring the radial distance to the tip of the lowermost seal fin is used.

However, in the conventional measurement method, when measuring the inner diameter with an inside micrometer, due to the structure of the measuring instrument, when measuring a stationary object with a large inner diameter, the inside micrometer becomes long and requires two people to measure the inner diameter. become. In addition, there are severe restrictions on the measurement work, such as the use of a large metal straight rule accompanying the measurement and the accompanying crane work.

Therefore, as an alternative measurement method to solve the above-mentioned restrictions on measurement, the coordinates of the tip of the seal fin to be measured by a coordinate measurement device using laser or 3D scanning are proposed. A method of measuring and determining the inner diameter between the tips of the opposing seal fins from the measured coordinates is being studied.

Japanese Patent Application Laid-Open No. 2020-101370

A measurement probe for a generally used three-dimensional measurement device has a spherical tip so that coordinate measurement can be performed by point contact with a surface to be measured. Therefore, when measuring the tip of the seal fin, the center of the spherical measurement probe and the center line of the tip of the seal fin may deviate from each other, resulting in a measurement error.

In addition, regarding the measurement method for measuring the spherical surface and the tip of the tooth tip, a technique is known in which a special jig with a slit structure is fitted in the inside micrometer and the jig has a shape that prevents deviation from the tip of the seal fin. there is However, this technique is a jig that utilizes the conventional structure of the inside micrometer, and cannot be applied to the measuring probe of the three-dimensional measuring device having a spherical shape.

SUMMARY OF THE INVENTION Accordingly, an object of an embodiment of the present invention is to accurately and easily perform three-dimensional measurement of linearly extending protrusions such as seal fins.

A measuring jig according to an embodiment of the present invention is configured to bring a convex contact surface of a probe into contact with a contact point at the tip of a projection extending linearly on an object to be measured, thereby to move three contact points at the tip of the projection. A measurement jig attachable to and detachable from the probe that can be used to measure a dimensional position, and can be placed on both sides of the protrusion while the measurement jig is attached to the probe. and a holding part that is integrated with the guide part and holds the measurement jig to the probe in a state where the measurement jig is attached to the probe, and the measurement jig is It is characterized in that the contact point at the tip of the protrusion and the convex curved contact surface of the probe are configured to be in contact with each other when attached to the probe.

In addition, the three-dimensional measurement system according to one embodiment of the present invention includes a convex curved contact surface, and the convex curved contact surface can be brought into contact with a contact point at the tip of the linearly extending protrusion of the measurement object. A three-dimensional measurement system having a probe and a measurement jig detachable from the probe and capable of measuring the three-dimensional position of the contact point, wherein the measurement jig is the A guide part that can be arranged on both sides of the protrusion when attached to the probe, and a measuring jig integrated with the guide part when the measuring jig is attached to the probe. to the probe, and a contact point at the tip of the protrusion and a convex curved surface contact surface of the probe can be in contact with each other when the measurement jig is attached to the probe. characterized by:

A three-dimensional measurement method according to an embodiment of the present invention uses a probe having a convex curved contact surface capable of contacting a contact point at the tip of a projection extending linearly on an object to be measured. A measuring jig attaching step of detachably attaching a measuring jig having a guide portion that can be arranged on both sides of the protrusion to the probe; and after the measuring jig attaching step, the A probe contacting step of contacting a contact point on the tip of the protrusion with a convex curved contact surface of the probe; and a measuring step of measuring the three-dimensional position of the contacting point after the contacting step. Characterized by

According to the embodiment of the present invention, three-dimensional measurement of linearly extending protrusions such as seal fins can be performed accurately and easily.

FIG. 2 is a partial vertical cross-sectional view showing the upper half of one stage of an axial flow turbine to which a measurement system according to an embodiment of the present invention is applied; FIG. 2 is a partial vertical cross-sectional view showing the inner diameter dimension of a seal fin in one stage of the axial flow turbine of FIG. 1; FIG. 3 is an exploded perspective view of the lower half of a seal fin in one stage of the axial flow turbine of FIGS. 1 and 2, showing the inner diameter dimension of the seal fin; FIG. 4 is a perspective view schematically showing how the lower half of the seal fin in one stage of the axial flow turbine of FIG. 3 is three-dimensionally measured during disassembly. In the measuring system according to the embodiment of the present invention, when the measuring jig is not attached to the probe, it is a partial cross-sectional view for explaining the situation when the tip of the probe is brought into contact with the tip of the seal fin, (a) shows a state of a correct measurement position, and (b) shows a case where the measurement position is deviated. 8A and 8B are partial cross-sectional views showing a state in which the measurement jig is attached to the probe and the tip of the probe is brought close to the tip of the seal fin in the measurement system according to the first embodiment of the present invention; VI-VI arrow cross-sectional view of. VII-VII arrow top view of FIG. VIII-VIII arrow bottom view of FIG. FIG. 2 is a flowchart showing procedures of a measurement method using the measurement system according to the first embodiment of the present invention; FIG. 5 is a partial cross-sectional view showing a state in which a measurement jig is attached to a probe and the tip of the measurement jig is brought close to a flat measurement surface in a measurement system according to a second embodiment of the present invention; FIG. 11 is a partial cross-sectional view showing a state in which a measurement jig is attached to a probe and the tip of the probe is brought into contact with the tip of a seal fin in a measurement system according to a third embodiment of the present invention; FIG. 11 is a partial cross-sectional view showing a state in which a measurement jig is attached to a probe and the tip of the probe is brought into contact with the tip of a seal fin in a measurement system according to a fourth embodiment of the present invention; FIG. 13 is a partial cross-sectional view showing a state in which the measurement jig is lifted after the state in FIG. 12 in the measurement system according to the fourth embodiment of the present invention; FIG. 11 is a flowchart showing the procedure of a measurement method using the measurement system according to the fourth embodiment of the present invention; FIG. 11 is a partial cross-sectional view showing a state in which a measurement jig is attached to a probe and the tip of the probe is brought into contact with the tip of a seal fin in a measurement system according to a fifth embodiment of the present invention; FIG. 16 is a partial cross-sectional view showing a state in which the guide portion of the measurement jig is pulled down after the state of FIG. 15 in the measurement system according to the fifth embodiment of the present invention; FIG. 11 is a partial cross-sectional view showing a state in which a measurement jig is attached to a probe and the tip of the probe is brought close to the tip of a seal fin in a measurement system according to a sixth embodiment of the present invention; A bottom view of FIG. 17 viewed from XVIII-XVIII. FIG. 19 is a partial cross-sectional view showing a state in which the measurement jig shown in FIGS. 17 and 18 is attached to the probe and the tip of the probe is brought into contact with the tip of the seal fin in the measurement system according to the sixth embodiment of the present invention;

An embodiment of a measurement system according to the present invention will be described below with reference to the drawings. Here, parts common to each other are denoted by common reference numerals, and redundant explanations are omitted.

First, application targets of the measurement system according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG.

FIG. 1 is a partial vertical cross-sectional view showing the upper half of one stage of an axial flow turbine to which a measurement system according to an embodiment of the present invention is applied. 2 is a partial vertical cross-sectional view showing the inner diameter dimension of one stage of the seal fin of the axial flow turbine of FIG. 1. FIG. FIG. 3 is an exploded perspective view of the lower half of a seal fin in one stage of the axial flow turbine of FIGS. 1 and 2, showing the inner diameter dimension of the seal fin. Here, the axial direction of the axial turbine is the X direction, the radially outer side is the Y direction, and the circumferential direction is the Z direction.

An axial flow turbine (for example, a steam turbine), which is a rotating device, has a rotating body and a stationary body. The stationary bodies include a casing 12, a plurality of nozzle diaphragms 13 attached to the casing 12 and extending along a plane (YZ plane) perpendicular to the axial direction, and a plurality of nozzle diaphragms 13 attached to each nozzle diaphragm 13 and spaced from each other in the circumferential direction. and a plurality of stator vanes 14 arranged in a row.

The rotating body has a rotor (rotor shaft) 15 extending along the rotation axis and a plurality of rotor blades 16 attached to the rotor 15 . The rotor blades 16 are circumferentially spaced apart from each other to form a rotor blade cascade, and a plurality of rotor blade cascades are arranged at intervals in the axial direction. A row of stationary blades 14 attached to one nozzle diaphragm 13 and one rotor blade row axially adjacent to the row of stationary blades 14 constitute one stage. The working fluid (eg, steam) flows axially through successive rows of stator vanes 14 and rotor blades 16 into the next stage.

Here, since the leakage flow of the working fluid flowing through portions other than the stationary blade 14 and the moving blade 16 does not contribute to power generation, the nozzle diaphragm 13 is provided with seal fins 17, 18, and 19 in order to suppress this leakage flow. It is The seal fins 17, 18, and 19 are annularly protruding inward, and are arranged such that their annular tips face the outer peripheral surface of the rotating body. Annular tips of the seal fins 17, 18 and 19 have sharp tooth tips.

A minute gap is provided between the annular tips of the seal fins 17, 18 and 19 and the outer peripheral surface of the rotating body to prevent contact and suppress leakage flow.

In order to keep the dimension of this minute gap within an appropriate range, in this embodiment, when inspecting the rotating equipment, the inside diameters D1, D2 of the annular tips of the seal fins 17, 18, 19 are adjusted while the rotating body is removed. , D3.

FIG. 4 is a perspective view schematically showing how the lower half of the seal fin of one stage of the axial flow turbine of FIG. 3 is three-dimensionally measured during disassembly. The measurement probe 21 has a spherical portion 22 and a rod portion 23 connected to the spherical portion 22 . The probe 21 is irradiated with a laser beam emitted from the three-dimensional measuring device 20 while the convex contact surface 22 a at the tip of the spherical portion 22 is in contact with the contact points at the tips of the seal fins 17 , 18 , and 19 . By measuring the reflected laser light from the probe 21, the three-dimensional coordinates of the tips of the seal fins 17, 18 and 19 can be obtained. Furthermore, by determining the coordinates of the positions on the opposite sides in the radial direction of each of the seal fins 17, 18, 19, the inner diameter can be calculated as the distance between the two points.

FIG. 5 is a partial cross-sectional view for explaining the state when the tip of the probe is brought into contact with the tip of the seal fin when no measurement jig is attached to the probe in the measurement system according to the embodiment of the present invention. 3A shows a state of a correct measurement position, and FIG. 3B shows a case where the measurement position is deviated.

As shown in FIG. 5A, by aligning the center position of the spherical portion 22 at the tip of the probe 21 with the tip position of the seal fin 17 (18, 19) in the X direction, the three-dimensional measuring device 20 measures the seal fin 17 ( 18, 19) can be obtained correctly. However, as shown in FIG. 5B, if there is an eccentricity e in the X direction between the center position of the spherical portion 22 of the probe 21 and the tip position of the seal fins 17 (18, 19), the position of the probe 21 produces a deviation ε in the Y direction. As a result, an error occurs in the inner diameter of the seal fin 17 (18, 19) obtained from this measurement result.

Therefore, in the measurement system according to the embodiment of the present invention, a detachable measurement jig is attached to the probe 21 to reduce the measurement error described above.

[First embodiment]
FIG. 6 is a partial cross-sectional view showing a state in which the measurement jig is attached to the probe and the tip of the probe is brought close to the tip of the seal fin in the measurement system according to the first embodiment of the present invention; 9 is a cross-sectional view taken along line VI-VI of FIGS. 7 and 8. FIG. 7 is a top view taken along line VII-VII in FIG. 6, and FIG. 8 is a bottom view taken along line VIII-VIII in FIG.

In this first embodiment, a detachable measuring jig 30 is attached so as to surround the spherical portion 22 of the probe 21 . The measurement jig 30 has a guide portion 31 , a holding portion 32 , and a coupling member 33 that couples the guide portion 31 and the holding portion 32 in a separable manner.

The guide part 31 is arranged so as to surround the circumference and the lower part of the spherical part 22, and a projecting part 35 tapered downward is formed in the center thereof, and a slit 36 is formed at the tip of the projecting part 35. . The upper end of the guide portion 31 is open, and after the spherical portion 22 of the probe 21 is inserted from above the guide portion 31 , the holding portion 32 is placed over the spherical portion 22 , and the coupling member 33 connects the guide portion 31 and the holding portion 32 to each other. are connected to each other, and a measuring jig 30 is attached to the probe 21 .

The coupling member 33 is, for example, two bolts. By inserting these bolts from above into through-holes formed in the holding portion 32 and screwing them into screw holes formed in the upper portion of the guide portion 31, the holding portion 32 and the guide portion 31 can be coupled. . A depression 32a is formed in the lower surface of the holding portion 32, and by fitting the upper end of the guide portion 31 into the depression 32a, positioning and coupling of the holding portion 32 and the guide portion 31 can be easily performed.

An opening 37 through which the rod-like portion 23 of the probe 21 passes is formed in the center of the holding portion 32 . Since the size of the opening 37 is large enough for the thickness of the rod-shaped portion 23, the orientation of the measuring jig 30 is adjusted according to the shape of the seal fins 17, 18, and 19 to be measured. can be adjusted.

With the measurement jig 30 attached to the probe 21, the spherical portion 22 can be brought close to and brought into contact with the tip of the seal fin 17 (18, 19). At this time, the tip of the seal fin 17 (18, 19) passes through the slit 36 at the tip of the projecting portion 35 of the guide portion 31 . In addition, the projecting portion 35 of the guide portion 31 does not interfere with other adjacent seal fins 17 (18, 19). The direction in which the slit 36 extends is aligned with the direction (Z direction) in which the seal fins 17 (18, 19) extend. Due to the presence of the projecting portion 35 of the guide portion 31, the eccentric state shown in FIG. can be brought into proper proximity and contact.

In this first embodiment, the gap width (width in the X direction) of the slit 36 is constant both in the Y direction and in the Z direction.

Next, the procedure of the measuring method using the measuring system according to the first embodiment of the present invention will be described with reference to FIG. FIG. 9 is a flowchart showing procedures of a measurement method using the measurement system according to the first embodiment of the present invention.

First, the measurement jig 30 is attached to the probe 21 (measurement jig attachment step S1).

Next, three-dimensional measurement preparation is performed (three-dimensional measurement preparation step S2). That is, the position of the spherical portion 22 of the measurement probe 21 is set at an arbitrary reference origin, and the reference origin and the three-dimensional coordinate space are defined by the three-dimensional measuring device 20 .

Next, with the measuring jig 30 attached to the probe 21, the convex curved contact surface 22a of the spherical portion 22 of the probe 21 is brought close to the tip of the seal fin 17 (18, 19) and brought into contact therewith (probe contact step S3). .

Next, the coordinates of the position of the spherical portion 22 of the probe 21 are measured using the three-dimensional measuring device 20 (measurement step S4).

Next, it is determined whether measurement of another position is necessary (movement determination step S5), and if measurement of another position is necessary (if YES in the movement determination step S5), the probe 21 is moved ( Probe moving step S6).

After the probe moving step S6, the process returns to the probe contacting step S3.

If it is not necessary to measure other positions in the movement determination step S5 (NO in the movement determination step S5), the distance between the two locations is calculated based on the coordinate position data of the two locations obtained in the measurement step S4. Calculate (distance calculation step S7).

For example, when obtaining three types of inner diameters D1, D2, and D3 as shown in FIG. .

Furthermore, for example, when measuring the vertical radius perpendicular to the horizontal inner diameter D1 of the semi-annular seal fin 17 to obtain the roundness, the coordinates of the midpoint of the inner diameter D1 of the semi-annular seal fin 17 are and the distance between the midpoint and the position of the inner end (upper end) of the seal fin 17 just below the midpoint.

As described above, according to this embodiment, the inner diameter of the seal fin can be measured easily and accurately.

[Second embodiment]
FIG. 10 is a partial cross-sectional view showing a state in which the measurement jig is attached to the probe and the tip of the measurement jig is brought close to the flat measurement surface in the measurement system according to the second embodiment of the present invention.

This second embodiment is a modification of the first embodiment. A flat machined surface 40 with a guaranteed geometrical tolerance is formed at the tip (lower end) of the projecting portion 35 of the guide portion 31 . Other configurations are the same as those of the first embodiment.

In the second embodiment, as shown in FIG. 10, the machined surface 40 at the tip of the projecting portion 35 of the guide portion 31 can be brought into surface contact with the flat measurement surface 41 by facing it.

In this second embodiment, the center height H0 obtained from the coordinates C0 measured by bringing the spherical portion 22 of the probe 21 into contact with the measurement surface 41 in a state in which the measurement jig 30 is not attached to the probe 21 in advance. Ask for Further, the center height H obtained from the coordinates C measured on the same measurement surface 41 is obtained in the spherical portion 22 with the measurement jig 30 attached to the probe 21 .

From the obtained center heights H0 and H, the offset amount Os is calculated from the following relational expression (1).

H−H0=Os (1)
As a result, even when an arbitrary measurement surface 41 is measured with the measurement jig 30 attached to the probe 21, the spherical portion 22 can be corrected by correcting the calculated offset Os with respect to an arbitrary measured coordinate. A result similar to that obtained by directly contacting the measurement surface 41 and measuring is obtained.

According to the second embodiment, similarly to the first embodiment, the inner diameters of the seal fins 17, 18, and 19 can be easily and accurately measured with the measuring jig 30 attached to the probe 21. In addition, an arbitrary measurement plane 41 can be measured without removing the measurement jig 30 from the probe 21 .

[Third embodiment]
FIG. 11 is a partial cross-sectional view showing a state in which the measurement jig is attached to the probe and the tip of the probe is brought into contact with the tip of the seal fin in the measurement system according to the third embodiment of the present invention.

This third embodiment is a modification of the first or second embodiment. In the third embodiment, a projecting portion 35 tapered downward is formed on the guide portion 31 and a slit 45 is formed at the tip of the projecting portion 35 . The shape of this slit 45 is different from the shape of the slit 36 (see FIG. 6, etc.) in the first or second embodiment. That is, in the third embodiment, the opening angle θ2 of the slit 45 is formed so as to match the tip angle θ1 of the seal fins 17 (18, 19). It is desirable that the opening angle θ2 of the slit 45 is slightly larger than the tip angle θ1 of the seal fins 17 (18, 19). Other configurations are the same as those of the measurement system according to the first or second embodiment.

With this configuration, the deviation (eccentricity e in FIG. 5B) between the center line of the seal fins 17 (18, 19) and the center of the spherical portion 22 can be minimized. The measurement error .epsilon. Further, since the opening angle θ2 of the slit 45 is slightly larger than the tip angle θ1 of the seal fins 17 (18, 19), the contact of the probe 21 can be facilitated.

A plurality of types of guide portions 31 may be prepared and the guide portions 31 may be replaced according to the shape of the seal fins 17 , 18 and 19 .

In the example shown in FIG. 11, the tips of the seal fins 17 (18, 19) and the slits 45 are substantially bilaterally symmetrical, but may be asymmetrical.

[Fourth embodiment]
FIG. 12 is a partial cross-sectional view showing a state in which the measurement jig is attached to the probe and the tip of the probe is brought into contact with the tip of the seal fin in the measurement system according to the fourth embodiment of the present invention. 13 is a partial cross-sectional view showing a state in which the measurement jig is lifted after the state of FIG. 12 in the measurement system according to the fourth embodiment.

This fourth embodiment is a modification of the third embodiment. In the fourth embodiment, the space accommodating the spherical body 22 of the guide portion 31 is long in the vertical direction. 12, a vertical clearance CL is formed between the spherical body 22 and the guide portion 31, and in the state of FIG. 13, a vertical clearance CL is formed between the spherical body 22 and the holding portion 32. . As a result, with the measurement jig 30 attached to the probe 21, the measurement jig 30 can be moved up and down relative to the probe 21 by a distance corresponding to the gap CL.

The procedure of the measurement method using the measurement system according to the fourth embodiment will be described below with reference to FIG. FIG. 14 is a flowchart showing procedures of a measurement method using the measurement system according to the fourth embodiment. Here, common step names and reference numerals are used for portions similar to the procedure of the measurement method using the measurement system according to the first embodiment shown in FIG. 9, and redundant description is omitted.

In the fourth embodiment, similarly to the first embodiment, the measurement jig attachment step S1, the three-dimensional measurement preparation step S2, and the probe contact step S3 are performed.

Next, it is inspected whether or not the measurement jig 31 can move relative to the probe 21 while the spherical portion 22 of the probe 21 is kept in contact with the tip of the seal fin 17 (18, 19) (measurement Jig movement inspection step S11).

If the measurement jig 31 cannot be moved in the measurement jig movement inspection step S11 (NO in the determination step S12), the measurement object such as the seal fins 17 (18, 19) contacts and interferes with the measurement jig 31. it seems to do. In that case, the probe contact step S3 and the measuring jig movement inspection step S11 are redone.

If the measurement jig 31 can be moved in the measurement jig movement inspection step S11 (YES in the determination step S12), the spherical portion 22 of the probe 21 is correctly in contact with the tip of the seal fin 17 (18, 19). Therefore, the process proceeds to measurement step S4.

The subsequent movement determination step S5, probe movement step S6, and distance calculation step S7 are the same as in the first embodiment (FIG. 9).

As described above, according to the fourth embodiment, measurement can be performed after confirming that the spherical portion 22 of the probe 21 is properly in contact with the seal fins 17 (18, 19).

[Fifth embodiment]
FIG. 15 is a partial cross-sectional view showing a state in which the measurement jig is attached to the probe and the tip of the probe is brought into contact with the tip of the seal fin in the measurement system according to the fifth embodiment of the present invention. FIG. 16 is a partial cross-sectional view showing a state in which the guide portion of the measurement jig is pulled down after the state of FIG. 15 in the measurement system according to the fifth embodiment.

This fifth embodiment is a modification of the fourth embodiment. In the fifth embodiment, a connecting member 33 that connects the guide portion 31 and the holding portion 32 includes a bolt 50, washers 51 and 52, and a compression spring 53. As shown in FIG. A threaded portion 50 a of the bolt 50 is screwed into a threaded hole formed in the upper portion of the guide portion 31 through a through hole 60 extending vertically through the holding portion 32 . A bolt head 50b above the threaded portion 50a is above the holding portion 32, and washers 51 and 52 are arranged above the holding portion 32 with a compression spring 53 interposed therebetween.

In the state shown in FIG. 15, the guide portion 31 is lifted upward toward the holding portion 32 by the elastic force of the compression spring 53, and the guide portion 31 and the holding portion 32 are integrated to form the spherical portion of the probe 21. In the state shown in FIG. I have 22. In this state, the spherical portion 22 is brought into contact with the tips of the seal fins 17 (18, 19).

When the guide portion 31 is manually pulled downward from the state shown in FIG. 15, the guide portion 31 can be moved downward while maintaining the positions of the probe 21 and the holding portion 32 as shown in FIG. can. Next, when the force pulling the guide portion 31 downward is released, the elastic force of the compression spring 53 causes the guide portion 31 to be pulled up, returning to the state shown in FIG.

Here, if the guide portion 31 cannot be pulled down manually from the state that appears to be in the state shown in FIG. It is considered that it contacts and interferes with the tool 31 . In that case, the step of bringing the spherical portion 22 of the probe 21 to which the measuring jig 31 is attached into contact with the tip of the seal fin 17 (18, 19) is redone.

According to the fifth embodiment, as in the fourth embodiment, measurement is performed after confirming that the spherical portion 22 of the probe 21 is properly in contact with the seal fins 17 (18, 19). can be done. Besides, except when the guide portion 31 is manually pulled down, the probe 21, the guide portion 31, and the holding portion 32 are always in contact with each other due to the elastic force of the compression spring 53. Therefore, the probe 21 and the guide portion 31 are held together. The unit 32 can be moved integrally and handled, and the operability is better than that of the fourth embodiment.

[Sixth embodiment]
FIG. 17 is a partial cross-sectional view showing a state in which the measurement jig is attached to the probe and the tip of the probe is brought close to the tip of the seal fin in the measurement system according to the sixth embodiment of the present invention. 18 is a bottom view taken along line XVIII-XVIII in FIG. 17. FIG. 19 is a partial cross-sectional view showing a state in which the measurement jig shown in FIGS. 17 and 18 is attached to the probe and the tip of the probe is brought into contact with the tip of the seal fin in the measurement system according to the sixth embodiment; FIG. be.

This sixth embodiment is, for example, a modification of the first embodiment, and the guide portion 31 and the holding portion 32 that constitute the measuring jig 30 are integrally formed from the beginning. The measuring jig 30 is made of elastic resin, and can be put on the spherical portion 22 of the probe 21 by elastically deforming the measuring jig 30 . Approximately the same as in the first embodiment, the guide portion 31 is configured to surround the periphery and lower portion of the spherical portion 22, and at its center is formed a projecting portion 35 that tapers downward. A slit 36 is formed at the tip of the .

In the state of FIG. 17, the slit 36 has a uniform gap width (width in the X direction) in the direction in which the slit 36 extends (Z direction) and in the direction toward the back of the slit 36 (Y direction). However, as shown in FIG. 19, when the tips of the seal fins 17 (18, 19) are pushed into the slits 36, the measuring jig 30 is elastically deformed and the shape of the slits 36 changes to that of the seal fins 17 (18, 19). It becomes a shape that fits the outline of

The measurement jig 30 can be manufactured using, for example, a three-dimensional modeling apparatus (3D printer).

According to the sixth embodiment, the number of parts constituting the measuring jig 30 can be minimized, and the work of attaching and detaching the measuring jig 30 to the probe 21 can be easily performed in a short time. You can do it with Also, the elastic deformation of the measuring jig 30 causes the shape of the slit 36 to match the outer shape of the seal fins 17 (18, 19). The deviation from the line (eccentricity e) can be minimized, and the measurement error ε can also be minimized.

[Other embodiments]
5 to 8, 10 to 13, and 15 to 19, the directions "up" and "down" are mainly used for convenience of explanation. is not directly related to the actual direction of gravity.

In the description of the above embodiment, the spherical portion 22 of the probe 21 does not necessarily have to be spherical, as long as the contact surface that contacts the object to be measured is a convex curved surface.

In addition, in the description of the above embodiments, the object to be measured is mainly the seal fin of a rotating device, but any object to be measured that has a linearly extending projection like the seal fin can be applied.

It is also possible to combine the features of the above embodiments in various ways. For example, in the fourth and fifth embodiments, the shape of the slit in the guide portion is a shape that opens toward the tip of the seal fin with an opening angle like the slit in the third embodiment. The shape of the slit in the embodiment may be changed to a shape with a constant width like the slit in the first or second embodiment.

Although several embodiments of the invention have been described above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and spirit of the invention as well as the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 12... Casing, 13... Nozzle diaphragm, 14... Stator blade, 15... Rotor (rotor shaft), 16... Moving blade, 17, 18, 19... Seal fin (protrusion), 20... Three-dimensional measuring device, 21... Probe 22... Spherical part 22a... Convex contact surface 23... Rod-like part 30... Measuring jig 31... Guide part 32... Holding part 32a... Recess 33... Coupling member 35... Protruding part 36 Slit 37 Opening 40 Machined surface 41 Measurement surface 45 Slit 50 Bolt 50a Screw portion 50b Bolt head 51, 52 Washer 53 Compression spring 60 …through hole

Claims (14)

It can be used when measuring the three-dimensional position of the contact point at the tip of the projection by bringing the convex curved surface contact surface of the probe into contact with the contact point at the tip of the projection that extends linearly on the object to be measured. A measuring jig detachable from a probe,
a guide portion that can be arranged on both sides of the projection portion in a state where the measurement jig is attached to the probe;
a holding part that is integrated with the guide part and holds the measurement jig to the probe in a state where the measurement jig is attached to the probe;
wherein the contact point at the tip of the protrusion and the convex curved contact surface of the probe are configured to be in contact with each other when the measuring jig is attached to the probe. Measuring jig. With the measurement jig attached to the probe, the tip of the guide portion is brought into contact with a contact point other than the protrusion on the object to be measured, and the three-dimensional position of the contact point other than the protrusion is determined. 2. The jig for measurement according to claim 1, which is configured to be capable of measurement. The guide section is configured to face the protrusion with an opening angle that matches the tip angle of the protrusion when the measurement jig is attached to the probe. The measuring jig according to claim 1 or 2. In a state in which the measuring jig is attached to the probe, and in a state in which the contact point at the tip of the protrusion is in contact with the convex curved contact surface of the probe, at least a part of the measuring jig is attached to the probe. 4. The measuring jig according to any one of claims 1 to 3, wherein the jig is configured to be movable relative to the probe. The measuring jig further comprises a spring that biases at least one of the guide portion and the holding portion in a predetermined relative direction with respect to the probe in a state where the measuring jig is attached to the probe. Item 4. The measuring jig according to item 4. 6. The apparatus according to any one of claims 1 to 5, further comprising a coupling member configured separately from the guide section and the holding section and coupling the guide section and the holding section in a separable manner. 1. The measuring jig according to item 1. 5. The measuring jig according to claim 1, wherein the guide portion and the holding portion are integrally molded from an elastic resin material. The guide portion is formed with a slit extending in the direction in which the projection extends in a state in which the measuring jig is attached to the probe, and the projection is inserted into the slit to move the projection. 8. The measuring jig according to any one of claims 1 to 7, wherein the contact point of the tip and the convex contact surface of the probe are configured to be in contact with each other. The object to be measured is a stationary part of a rotating device,
wherein the protrusion is an annular seal fin arranged to face the rotating body on the inner surface of the stationary portion;
The measuring jig according to any one of claims 1 to 8, characterized by: a probe having a convex curved contact surface, the convex curved contact surface being capable of coming into contact with a contact point at the tip of the linearly extending protrusion of the object to be measured;
a measuring jig detachable from the probe;
A three-dimensional measurement system capable of measuring the three-dimensional position of the contact point,
The measuring jig is
a guide portion that can be arranged on both sides of the projection portion in a state where the measurement jig is attached to the probe;
a holding part that is integrated with the guide part and holds the measurement jig to the probe in a state where the measurement jig is attached to the probe;
wherein the contact point at the tip of the protrusion and the convex curved contact surface of the probe are configured to be in contact with each other when the measuring jig is attached to the probe. 3D measurement system. A three-dimensional measurement method using a probe having a convex curved contact surface capable of contacting a contact point at the tip of a projection extending linearly on an object to be measured,
a measuring jig attaching step of detachably attaching a measuring jig having guide portions that can be arranged on both sides of the protrusion to the probe;
a probe contacting step of contacting the contact point of the tip of the protruding portion with the convex curved contact surface of the probe after the measuring jig attaching step;
a measuring step of measuring the three-dimensional position of the contact point after the contacting step;
A three-dimensional measurement method characterized by having After the probe contacting step and before the measuring step, at least a portion of the measuring jig is attached to the probe while the convex curved contact surface of the probe is in contact with the contact point at the tip of the protrusion. An inspection step of inspecting whether it can be moved relative to
The three-dimensional measurement method according to claim 11, further comprising: The object to be measured is a stationary part of a rotating device,
wherein the protrusion is an annular seal fin arranged to face the rotating body on the inner surface of the stationary portion;
The three-dimensional measurement method according to claim 12, characterized by: The probe contact step and the measurement step are performed for a plurality of the contact points at different positions,
between two of the plurality of contact points based on the three-dimensional positions of the plurality of contact points obtained in the measurement step performed for the plurality of contact points; further comprising a distance calculation step of obtaining the distance of
The three-dimensional measurement method according to any one of claims 11 to 13, characterized by:

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