WO1997004284A1

WO1997004284A1 - Measuring system and method of measuring a wall contour

Info

Publication number: WO1997004284A1
Application number: PCT/DE1996/001133
Authority: WO
Inventors: Georg Gebald; Erich Kohlert; Egon Neubauer
Original assignee: Siemens Aktiengesellschaft
Priority date: 1995-07-17
Filing date: 1996-06-26
Publication date: 1997-02-06
Also published as: DE19525975C1

Abstract

When connection pieces inserted in a container or a pipe (4) are replaced, it is necessary to know exactly, both for installation and production of the new connection piece, the actual inner contour of the container (4) in the region to be penetrated by the new connection piece. The invention concerns a measuring system for measuring this contour, the system comprising an arrangement (14) which can be secured in its position relative to the wall and accommodates a rotatably mounted shaft (18) which can be moved axially therein. A measuring probe (22) with a measuring tip (28) is pivotably disposed at the free end of the shaft (18). The measuring system further comprises a device (36) for measuring an axial displacement (F) of the shaft and a device (50) for detecting and displaying contact between the measuring tip (28) and the wall.

Description

description

Measuring device and method for measuring a contour of a wall

Depending on the complexity of the system, containers or pipelines are provided with a large number of openings into which other pipelines open. This mouth region or nozzle, with its weld seams, is a particularly stressed point in normal operation, which has to be checked regularly, especially in nuclear plants. In the event of a finding, it is necessary to remove the nozzle and replace it with a new nozzle.

Both for the expansion of the old nozzle and for the

Installation and manufacture of the new nozzle, it is necessary to know exactly the inner contour of the wall of the container or the pipeline in the penetration area. Because of the sometimes complicated geometries in the area of pipe bends and a lack of documentation of the "as-built" dimensions of the components, it is necessary to measure the inner contour exactly in the new penetration area of the new nozzle.

A device for determining the contour of a tubular body is known from German patent application 38 18 400, in which an angled arm is arranged at the free end of a rotatably mounted shaft that can be displaced in the axial direction, in which a scanning device, for example a Pen that is guided telescopically. With this scanning device, the contour on the inner surface of the tubular body can be eaten and checked for out-of-roundness.

From German Offenlegungsschrift 44 14 747 is one

Measuring device for measuring the contour of a surface of a body is known, in which a probe at the free end of a is rotatably arranged in two mutually orthogonal directions movable arm.

From German laid-open specification 39 40 645 a device for checking the quality of conical contact surfaces is known, in which a measuring probe with a measuring tip pivotably arranged in it is axially displaceably mounted on a hollow body which is stationary around the cone ¬ shaped contact surface shaft is rotatably mounted.

The invention is based on the object of specifying a device for measuring the contour of a wall, which is particularly suitable for use in the mouth region of a pipe in a container. The invention is also based on the object of specifying a method for measuring the contour of a wall.

The first-mentioned object is achieved with the features of patent claim 1.

The second object is achieved with the features of claim 9.

Further advantageous embodiments of the invention are given in the subclaims.

To further explain the invention reference is made to the embodiment of the drawing, in the

1 shows a plant part with a large number of nozzles. 2 shows a socket inserted into the opening of a container before the weld seam is closed. In Figure 3, a device according to the invention is schematically illustrated in a side view. FIG. 1 shows a partial view of a boiling water reactor 2 with one of its motive water loops as an example of a plant part. Each driving water loop comprises a large number of tubes 4, which are provided in their straight tube or bend areas with connectors 6 for connecting further pipelines. In the event of a finding, these nozzles 6 must be eroded out of the tubes 4 and replaced by a new nozzle 6.

According to FIG. 2, a new connection piece 6 is inserted into the cutout 7 in the wall of a pipe 4 which was created by the removal of the old connection piece. The inner surfaces of the tube 4 and the nozzle 6 are provided with an austenitic cladding 8. The seam surfaces of the tube 4 and the nozzle 6 are chamfered to form a V-shaped weld joint 9. In order to ensure proper welding of the connector 6 in the tube 4, the dimensional deviation a between the inner edge 10 of the connector 6 and the inner edge 11 of the tube 4, d. H. at the root of the weld joint 9 should not be larger than 1mm. This requires precise knowledge of the contour of the tube 4 along its inner edge 11 in order to enable the nozzle 6 to be produced with a precise fit.

In FIG. 3, the wall of a container or pipe 4 with an opening 70 is shown in simplified form, into which a nozzle 6 to be exchanged opens. A measuring device for measuring the contour of the wall on the inside of the tube 4 comprises a clamping device 14 which is at least retracted with its clamping jaws 16 into the tubular connecting piece 6 and braced and centered in it.

The tensioning device 14 also serves as a guide for a shaft 18 which is axially displaceable and rotatable therein.

A holder 20 for a measuring probe 22 is fixed to a free end of shaft 18 that can be inserted into opening 70. The probe 22 is slidable in a receiving sleeve 24 mounted, which is arranged pivotable about an axis 26 perpendicular to the shaft 18 in the bracket 20. The measuring probe 22 comprises a measuring tip 28 which, in the working position shown in the figure, touches the wall on the inside of the tube 4.

Guide rails 30 for a carriage 32 are fastened to the clamping device 14 and comprise an inductive displacement transducer 36 designed as a sleeve, through which the shaft 18 is guided. With this inductive displacement sensor 36, the axial displacement F of the shaft 18 can be measured relative to the measuring sleeve 36 and, with the clamping device 14 fixed and the slide 32 held in place, relative to the wall of the tube 4.

The inductive displacement sensor 36 is connected to a measuring and display device 50, on which there is a digital display 52 for the actual position of the shaft 18.

At its end opposite the holder 20, the shaft 18 is provided with a perforated disk 40 which is provided with holes 42 at uniform angular intervals of, for example, 5 ° and can be locked in these angular positions by a pin 44.

The angle of the receiving sleeve 24 and the axial position of the

Probe 22 within this receiving sleeve 24 define the diameter D of a measuring circuit, which results from rotation of the shaft 18 with the axial position held. The projection of this measuring circuit onto the inner wall of the tube 4 defines a contour along which the connection piece 6 is then separated out by an electro-eroding process. This contour is also a simple circle for a flat wall. In the case of curved walls, the contour is also a three-dimensional curve which is mathematically determined by the angle of rotation of the shaft 18 and the distance from a plane parallel to this measuring circuit. To measure this contour of the wall of the tube 4, the shaft 18 is axially displaced in a first fixed angular position until the measuring tip 28 touches the wall. Probe 28 and wall are parts of a circuit, not shown, which is closed when contact between probe 28 and wall. This contact can be optically indicated, for example, by a control lamp 54 on the measuring device 50. The measured value F resulting in this first angular position upon contact is used as a reference or zero value, on which all subsequent measurements relate.

In a subsequent work step, the shaft 18 is lifted inwards, rotated by a predetermined angle, for example 5 °, secured against rotation in this new angular position and moved back until the measuring tip 28 touches the wall again. The measured value resulting from this contact for the longitudinal displacement F of the shaft 16 is shown on the display 52. The measuring device 50 is connected via a data line 56 to a computer in which the measured values are stored and, if necessary, further processed.

A guide plate 60 for a grain 62 is also fixed on the clamping device 14, with which a marking can be made on the outer wall of the tube 4 in order to achieve reproducible measuring and processing conditions.

The measured values obtained with the aid of the measuring device are used for the computer-controlled removal of the connecting piece 6, for example by an eroding process, so that the inner edge of the cut-out 7 shown in dashed lines when the connecting piece 6 is removed corresponds automatically with the measured contour. With the help of the same measured values, a new connection piece can then be produced which can be inserted into this cutout 7 with a precise fit.

Claims

claims

1. Measuring device for measuring a contour of a wall of a container or pipe (4), with the following features:

a) a device (14) which can be fixed in position relative to the wall, for receiving a shaft (18) which is axially displaceable and rotatable therein,

b) a measuring probe (22) pivotably arranged on a free end of the shaft (18) with a measuring tip (28),

c) a device for measuring an axial displacement (F) of the shaft, and

d) a device (50) for detecting and displaying a contact of the measuring tip (28) with the wall.

2. Measuring device according to claim 1, in which a clamping device (14) is provided as a fixable device, which with its clamping jaws (16) in a container or into the pipe (4) opening nozzle (6) is clamped iεt.

3. Measuring device according to claim 2, that on the tensioning device (14) a marking device (60, 62) for marking the

Position of the clamping device (14) is arranged.

4. Measuring device according to one of claims 1 to 3, with an inductive displacement transducer (36) for detecting the axial displacement (F) of the shaft (18).

5. Measuring device according to one of the preceding claims, in which the measuring tip (28) forms an electrical switch with the wall through which an electric current flows when touched.

6. Measuring device according to one of the preceding claims, it a device (40, 42, 44) for rotating the shaft (18) in predetermined angular steps.

7. Measuring device according to claim 6, with one on the shaft

(18) arranged perforated disc (40), which contains holes (42) at the same angular distance from each other, through which a pin (44) for locking the shaft (18) can be inserted.

8. Measuring device according to claim 2 and one of the preceding claims, which has such a displacement transducer (36) or in which the displacement transducer (36) is designed such that it surrounds the shaft (18) and relative to the clamping device (14) is slidably arranged.

9. Method for measuring a contour of a wall of a container or tube (4), with the following work steps:

a) A device (14) for receiving an axially displaceable and rotatable shaft (18) mounted in it is relative to the

Wall fixed,

b) a measuring probe (22) arranged at a free end of the shaft (18) is pivoted into a measuring position,

c) the shaft is axially displaced until the measuring probe (22) touches the wall with its measuring tip (28),

d) the axial position of the shaft (18) is measured and stored as a reference value of a reference position,

e) the measuring tip (28) is lifted off by an axial displacement of the shaft (18),

f) the shaft (18) is rotated by a predetermined angle and again axially displaced until the measuring tip (28) touches the wall, g) the path length of the axial displacement necessary for the new contact relative to the reference position is measured.

10. The method according to claim 9, in which a marking is attached to the wall, with which the measuring device can be fixed reproducibly relative to the wall during a subsequent measurement.