SK392992A3 - Device and process for cutting off a pipe from the inside - Google Patents

Abstract

When replacing parts in a piping system, it is sometimes necessary to cut off a pipe (2) from the inside by mechanical cutting, using a device inserted into the pipe (2). The invention calls for a device with a manipulator (6) which can be inserted into the pipe (2) and displaced inside the pipe (2), the manipulator having amilling head (15) which can be adjusted at right angles to the pipe axis (4) and can be rotated about the pipe axis (4). The use of a milling head as the cutting tool for removal of the pipe (2) ensures that it is virtually impossible for the cutting tool to get jammed.

Description

Technical field

BACKGROUND OF THE INVENTION The present invention relates to an apparatus and method for dividing a pipe on an inner circumference.

BACKGROUND OF THE INVENTION

During repair work on the feed water pipes inside the steam generator, it may be necessary to completely dismantle parts of the pipe system, for example, the feed water pipes. For this purpose, the neck of the supply water pipe needs to be separated from the distribution pipes by means of mechanical cutting, for example by means of a saw. Due to the confined space conditions inside the steam generator, this separation must be carried out by means of a device which can be introduced into the inside of the branch pipes, for example T-shaped, from the neck. However, cutting the pipes with the saw blade still poses the risk that the saw blade will clog and the entire device can then be removed from the inside of the pipe with considerable effort only.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an apparatus and method for lengthening a pipe on an inner circumference, by means of which the above-mentioned drawbacks are eliminated, and which are particularly suitable for use in pipes of low nominal size.

The essence of the invention

This object is achieved by a device for lengthening a pipe on an inner circumference, according to the invention, which is based on:

(a) the device comprises a manipulator, insertable into the pipe and movable inside the pipe and attachable to the inside of the wall pipe;

b) the manipulator is equipped with a milling head with a milling tool, adjustable perpendicular to the axis of the tube and rotatable around the axis of the tube,

(c) Flexible shafts are provided for transmitting the driving torques required for the rotary movement and for the advancing movement of the milling head.

By using a manipulator so formed in which a milling tool is used as the cutting tool, the cutting tool can practically no longer become jammed, which would make it difficult to rescue the manipulator. The milling tool, in particular the shank cutter, can be easily pulled out even under unfavorable circumstances, for example after clamping inside the tube wall, by reversing its movement. Thus, the manipulator can still be easily released.

Since flexible shafts are provided to transmit the drive torques required for the in-feed or approach motion and for the rotary movement of the milling head, this results in an extremely compact manipulator design which allows working in pipes of small nominal diameters. In addition, trouble-free operation is ensured even under water.

A hydraulic motor is preferably used as a drive for the rapid rotation of the milling tool.

A shank cutter is particularly suitable as a milling tool.

According to a preferred embodiment of the invention, the manipulator for clamping inside the pipe is provided with a clamping cylinder with several hydraulically operated clamping jaws which can extend in the direction of the inner wall of the pipe. A particularly advantageous compact design is achieved in that annular ducts, which are arranged in the form of an annular groove, are arranged on a bearing housing surrounded by a clamping cylinder for supplying the pressure medium to the clamping jaws operated by a single piston.

The above object furthermore fulfills the method of dividing a pipe on an inner circumference according to the invention, which is based on the principle that:

a) a manipulator movable inside the pipe is inserted into the pipe and fixed to the inner wall of the pipe;

(b) with a milling tool, milling heads arranged arranged on a manipulator, adjustable perpendicular to the axis of the tube and rotatable about the axis of the tube, the tube is milled on the inner circumference, wherein:

(c) the drive torques required for rotary motion and for the milling head to be delivered to the manipulator by the flexible shafts.

A milling cutter is preferably used as a milling tool.

Overview of the figures in the drawings

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to the accompanying drawings, in which: FIG. 1 shows a schematic view of a device according to the invention; FIGS. 2 and 3 show preferred embodiments of the device.

DETAILED DESCRIPTION OF THE INVENTION

As can be seen from FIG. 1, a manipulator 6 is introduced into a pipe 2, for example a distribution pipe branching off the neck 5 of the steam generator feed water pipe. The manipulator 6 can be moved inside the pipe 2 and has a milling head 10.

The milling head 10 is provided with a milling tool on the inner circumference for cutting the tube 2, not shown in FIG. 1, embedded in the dot-dash axis 2. The milling head 10 is provided with an adjusting device 12 by means of which it is displaceable in the Z axis direction perpendicular to the tube axis 4. 2 and perpendicular to the plane of FIG. This Z axis intersects the plane of the figure outside the axis 4, with which it is therefore extraordinary.

The manipulator 6 is movable in the direction of the axis 4 of the pipe 2 on the balls 8. In order to prevent the manipulator 6 from tilting when moving inside the pipe 2, an additional support ring 9 can also be provided. a roller 14, provided with a plurality of, for example, six radially extending clamping jaws 16.

In addition, the milling head 10 can be rotated about the axis 4 of the tube 2 together with the attachment device 12 inside the fixed clamping cylinder 14, so that the milling tool 11 can move along the inner circumference of the tube 2.

For the rapid rotation of the milling tool required for milling, a hydraulic motor 21 is preferably provided, which is supplied by a flexible hydraulic line 20 with a pressure medium, for example hydraulic oil. In order to clamp and release the clamping jaws 16 of the hydraulic clamping cylinder 14, each actuated by one piston, two further hydraulic lines 22, 23 are provided. The supply of the pressure medium to the pistons is preferably carried out by means of one annular channel 36,37, an annular groove is provided on a bearing sleeve 38 surrounded by a clamping cylinder 14.

For the driving moments required for the rotational movement and the advancing or moving motion of the milling head 10, flexible shafts 24 and 26 are provided which are actuated by the outer pipes 2 or the water supply pipe 5, for example manually.

2, a bevel gear 40 is driven by the flexible shaft 26. The bevel gear 40 comprises a bevel gear coupled to the flexible shaft 26 by means of which the rotary movement of the flexible shaft 26 is converted to rotational movement of the threaded spindle 42 perpendicular to the axis of rotation. of this bevel gear. By rotating the threaded spindle 42, the milling head 10 is displaced in the Z-axis direction. That is, in the direction of the stroke movement by which the milling tool 11 is introduced onto the inner surface of the tube 2.

For rotational movement of the milling head 10 about the axis 7 of the manipulator 6, which substantially coincides with the axis 4 of the tube 2, a worm gear 54 and a worm shaft 52 are provided which are driven by the flexible shaft 24 via a bevel gear 50.

The milling tool 11, preferably a shank milling cutter, is driven by a hydraulic motor 21 and a planetary gear, which allows the high rotational speed of the milling tool 11 required for shearing the tube 2.

Referring to FIG. 3, a hydraulic fluid supply is provided for releasing and clamping the clamping jaws 16 of the clamping cylinder 14 by means of annular channels 36 and 37 which are arranged in the form of an annular V-shaped groove on the bearing sleeve 38 of the clamping cylinder 14. they are sealed with O-rings arranged in the grooves 35 of the bearing sleeve. The annular ducts 36 and 37 are each connected to a respective duct 32 or 34, which in each case is connected to a hydraulic conduit 22 or a hydraulic conduit 23 (shown in FIG. 1).

Through these annular channels 36 and 37, the hydraulic fluid is uniformly supplied to the individual clamping pistons 30 of the clamping cylinder 14. Holes always run from the cylinder of the clamping pistons 30 to the annular conduits 36 and 37 which serve to supply pressure medium for radial inward or outward movement. of the clamping pistons 30 connected to the clamping jaws 16.

For supplying the pressurizing medium of several clamping pistons 30 with hydraulic lines 22 and 23 (FIG. 1), only a supply from one single supply duct 32 or 34 to the annular ducts 36 or 37 is therefore always required. This results in a particularly compact design.

Claims (7)

PATE Claims 1. Tube lengthening device on the inner circuit, characterized c í s e by (a) equipment It contains manipulator (6), deployable to pipes (2) and inside pipes (2) mobile and attachable for inner wall pipes (2), b) the manipulator (6) is provided with a milling head (10) with a milling tool (11), adjustable perpendicular to the axis (4) of the tube (2) and rotatable about an axis (4) of the tube (2); c) flexible shafts (24, 26) are provided for transmitting the driving torques required for the rotary movement and for the advancing movement of the milling head (10). Device according to claim 1, characterized in that the manipulator (6) is provided with a hydraulic motor (21) for driving the milling tool (11). 3. A device according to one of the features (11) being a shank cutter. Device according to one of the preceding claims, characterized in that the milling tool of the preceding claims, characterized in that the clamping cylinder (14) is provided with several hydraulically operated clamping jaws (16) for the attachment of the manipulator (6). Apparatus according to claim 4, characterized in that annular channels (36, 37) are arranged on the bearing housing in the form of an annular groove for supplying the pressure medium to the clamping jaws (16j, each actuated by one piston). (38) surrounded by a clamping roller (14). 6. A method of dividing a pipe on an inner circumference, said process by: a) a manipulator (6) movable inside the pipe (2) is inserted into the pipe (2) and fixed to the inner wall of the pipe (2), b) a milling tool (11) of a milling head (10) arranged on a manipulator (6), adjustable perpendicular to the axis (4) of the tube (2) and rotatable about an axis (4) of the tube (2) circuit milling, taking c) the driving moments required for the rotary movement and for setting up the milling head (10) are transmitted to the manipulator (6) by the flexible shafts (24, 26). Method according to claim 6, characterized in that shank cutters are used as the milling tool (11). List of reference marks pipe 2 dot-dash axis 3 axis 4 tubes neck 5 manipulator 6 axis 7 ball 8 operating ring 9 milling head 10 milling tool 11 attachment device 12 clamping cylinder 14 clamping jaw 16 hydraulic pipe 20 hydraulic motor 21 hydraulic pipe 22, 23 flexible shaft 24, 26 Clamping piston 30 channel 32, 34 groove 35 annular channel 36, 37 bearing bush 38 bevel gear 40 threaded spindle 42 bevel gear 50 worm shaft 52 worm gear 54