JP2007245312A - Pipe half-splitting cutting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe half-splitting cutting device which half-splits a pipe contaminated with radioactive materials by applying a shearing force thereto so as to prevent cutting powder or chips contaminated with radioactive materials from scattering, with a reduced manufacturing cost therefor. <P>SOLUTION: This pipe half-splitting cutting device for half-splitting a pipe 2 along the longitudinal direction includes: a pair of rotating shear blades 3 arranged facing each other in the direction orthogonal to a feeding direction of the pipe 2 sandwiched therebetween; a bar-shaped receiving blade 4 having an approximately circular cross-section, arranged coaxially to the pipe and facing an end opening face of the pipe 2, and is fitted thereinto; and a supporting member 5 for supporting the receiving blade 4 from the cutting device body. In a pipe half-splitting cutting device 1, by using a unilateral angle formed at a circumferential rim portion of the rotating shear blade 3 and a circumferential angle formed with steps arranged in the radial direction of an outer circumferential surface of the receiving blade 4, the pipe 2 is moved in the feeding direction and then is fitted into the receiving blade 4. Thus, the pipe 2 is continuously cut in an approximate radial direction thereof by applying shearing force thereto. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pipe half-cutting device that continuously halves a relatively small-diameter metal pipe (hereinafter referred to as piping) in its longitudinal direction.

  Conventionally, when removing old equipment at a nuclear power plant with equipment renewal, it is necessary to process a large amount of radioactive waste. These radioactive wastes are measured and monitored (surveyed) for contamination by a measuring device such as a Geiger counter, and processed as necessary according to the results. In such treatment, waste with a high contamination level is finely divided and then put into a special tank called a cask and stored in a stable storage of the formation (called formation treatment). Therefore, the processing cost is very high.

  On the other hand, the waste with a low contamination level is subjected to a cleaning process such as decontamination, and is treated as a general waste at a low cost. A heat exchanger (condenser, feed water heater, etc.) in a nuclear power plant is generally a structure in which a large number of pipes are arranged in a container, and each pipe has a quantity of several tens of tons.

  When removing the heat exchanger, first, the container and the pipe which is a small-diameter metal pipe are separated, and the contamination level is measured. In this case, since the pipe is a long pipe having a small diameter, a measuring device such as a Geiger counter cannot check the internal contamination state. Therefore, regardless of the presence or absence of contamination levels, all of the piping is packed in a cask that is a dedicated tank and is subjected to geological treatment. For this reason, the cost of processing the piping increases.

Therefore, in order to make it possible to easily measure the contamination level by halving the pipe, there is a method of heat-cutting the pipe (conventional example 1). Also proposed are a device that cuts the pipe into a predetermined length in advance and divides it into halves (conventional example 2), a cutting device that can divide the pipe continuously into half pieces (conventional example 3), etc. It is known (see Patent Document 1). This consists of a pair of cutting discs consisting of a pair of left and right disk-shaped tip saws having a large number of incisors in the circumferential direction, and a cutting guide rod arranged concentrically with a cutting symmetrical pipe, and the pipe is continuously formed. It cuts in half.
Japanese Patent Laid-Open No. 2005-7483

  However, in the conventional pipe half-cutting device, for example, in the above-described conventional example 1, dust that is activated by metal or radioactive material that has been activated at the time of interruption is scattered in the air, and the operator sucks it and is exposed to exposure. In addition, the radioactive material dissolves in the pipe, and the decontamination work becomes difficult. Moreover, in the apparatus which cuts a pipe into a predetermined length and then divides the pipe in half as in the conventional example 2, it is necessary to prepare a pretreatment for cutting the pipe into a predetermined length. Cutting process increases. Furthermore, since the conventional example 3 uses a disc-shaped tip saw having cutting teeth, it is necessary to collect chips generated during the cutting using a vacuum cleaner, and the structure of the entire cutting device is complicated. This increases the manufacturing cost. The pipe half-cutting device according to the present invention has been proposed in order to solve such a problem.

  The gist for solving the above-mentioned problems of the pipe half-cutting device according to the present invention is to achieve a purpose in a cutting device that divides a pipe in half along its longitudinal direction, in a direction orthogonal to the delivery direction of the pipe. A pair of rotary shear blades are arranged opposite to each other with the pipe interposed therebetween, facing the end opening surface of the pipe sent out, arranged coaxially with the pipe, and fitted into the pipe in a substantially circular shape And a support member for supporting the receiving blade from the cutting device main body, and a stepped portion in the radial direction from the one-side corner of the peripheral edge of the rotary shearing blade and the outer peripheral surface of the receiving blade. And the peripheral corner portion formed by providing a cut in the feed direction and continuously fitting the pipe fitted to the receiving blade in a substantially radial direction with a shearing force.

The thickness of the peripheral edge of the rotary shearing blade is made thinner with a step than the thickness of the main body;
The circumferential edge of the rotary shearing blade is formed with unevenness extending in the radial direction along the entire width of the rotary blade;
Furthermore, two pairs of the rotary shearing blades are disposed at an appropriate interval along the pipe delivery direction;
A connecting portion between the receiving blade and the support member is provided with a diameter-expanding portion that expands and guides the pipe that has been divided in half along the pipe feeding direction;
Is included.

According to the pipe half-cutting device of the present invention, the long pipe is continuously cut by a shearing force, so that it is divided into half, so there is no generation of chips and there is no risk of scattering, so the conventional example Such a device for sucking chips is not necessary in the cutting device of the present invention. Therefore, the manufacturing cost of the cutting device does not increase.
Further, since the rotary shearing blade cuts the pipe by a shearing force, it is not necessary to form a plurality of cutting blades at the peripheral portion, and it is sufficient if there are orthogonal corners having a rectangular cross section. Therefore, the manufacturing cost of the rotary shearing blade is also reduced.

  The thickness of the peripheral edge of the rotary shearing blade is less than the thickness of the main body by providing a step portion radially outward from the central portion, so that the outer peripheral edge becomes thin and the pipe is easily sheared. be able to. Furthermore, since the load due to the cutting is applied to the central portion of the rotary shear blade, it is possible to reduce the warp and escape of the rotary shear blade. Furthermore, since the thickness of the main body of the rotary shearing blade can be reduced, the yield of the material can be improved.

  Further, by providing irregularities on the peripheral edge of the rotary shearing blade and making it a saw blade, the pipe is bitten into the pipe, and the pipe is pulled in the feed direction and pushed out by the rotation of the pair of rotary shearing blades. It comes to be. In this way, the rotational driving force of the rotary shear blade is used for the pipe feed, so that the pipe feed becomes light and easy and the cutting speed is improved.

  By providing two pairs of the rotary shearing blades, rotation around the shaft center due to twisting of the pipe that is sent out along the longitudinal direction while being halved by the shearing force is prevented, and the halves are almost linearly divided. The load on each stage is reduced, and the cutting speed of the piping is improved.

  The connecting portion of the receiving blade and the support member is provided with a diameter-expanding portion that guides the pipe that has been enlarged and halved along the pipe feed direction, so that the half-divided pipe is left and right. Guided to spread and distribute.

  As shown in FIG. 1, a pipe half-cutting device 1 according to the present invention continuously divides a pipe 2 having a relatively small diameter, which is a radioactive waste of a heat exchanger in a nuclear power plant, along its longitudinal direction. It is a cutting device to split.

  The schematic configuration is such that, for example, a pair of rotatable steel rotating shearing blades 3 and 3 are arranged opposite to each other across the pipe 2 in a direction orthogonal to the delivery direction a of the pipe 2, and the pipe sent out. A bar-shaped receiving blade 4 having a substantially circular cross section and disposed in the pipe 2 is disposed opposite to the end opening surface of the pipe 2 so as to be coaxial with the pipe 2. And it is comprised with the supporting member 5 which supports the said receiving blade 4 from the cutting device main body 1a.

  In FIG. 1, reference numeral 1 b indicates a base that supports the apparatus main body 1 a, reference numeral 6 indicates a motor that rotationally drives the rotary shear blade 3, and reference numeral 7 indicates an attachment and fixing of the rotary shear blade 3. The fixing member is shown. As shown in FIG. 2, the motor 6 rotates the upper rotary shear blade 3 counterclockwise and rotates the lower rotary shear blade 3 clockwise to move the pipe 2 in the feed direction. .

  As shown in FIG. 2, the cutting method of the pipe half-cutting device 1 includes the one-side corner 3b at the peripheral edge of the rotary shearing blade 3 and the receiving blade 4 shown in FIGS. 3 (A) and 3 (B). As shown in FIG. 4, the pipe 2 that is moved in the feed-out direction a and fitted to the receiving blade 4 by a peripheral corner portion 4 c formed by providing a step portion 4 a in the radial direction from the outer peripheral surface is shown in FIG. 4. In addition, it is continuously cut by a shearing force toward the substantially radial direction.

  The one-side corner 3b of the peripheral edge of the rotary shear blade 3 is a rectangular corner that is orthogonal, but when the cutting action is performed, the thinner one is easier to cut, so FIG. 5 (A) As shown, it has a stepped portion 3a and is thinner than the thickness of the main body.

  On the other hand, as shown in FIGS. 3A and 3B, the receiving blade 4 is provided with a peripheral corner portion 4c formed by the step portion 4a so as to have a desired length along the feeding direction a. ing. And the connection part of the receiving blade 4 and the supporting member 5 is provided with the enlarged diameter part 4b which expands the diameter along the feed direction a of the piping 2, and expands and guides the piping 2 divided by half. By this enlarged diameter portion 4b, the divided pipes 2 are distributed to the left and right.

  As shown in FIGS. 5B and 6, the positional relationship between the rotary shear blades 3 and 3 and the receiving blade 4 is set so that the positions of the outer peripheral end faces of the pair of rotary shear blades 3 and 3 are to be cut. As if the radial wall surface of the stepped portion 3a of the rotary shearing blade 3 is almost in contact with the radial wall surface of the stepped portion 4a of the receiving blade 4 by offsetting back and forth according to the central axis of the pipe 2. Place them close together.

  As shown in FIG. 5 (B), the rotary shearing blades 3 and 3 are arranged symmetrically with respect to the central axis of the receiving blade 4 and as shown in FIG. 5 (C). May be placed. The pipe half-cutting device 1 is provided with adjusting mechanisms 8 and 9 using screw pairs so that the rotary shear blades 3 and 3 can be adjusted in the vertical positional relationship.

  If the pipe half-cutting device 1 configured as described above is used, as shown in FIG. 1, the long pipe 2 removed from the heat exchanger is directly used as the receiving blade 4 of the pipe half-cutting device 1. The pipe 2 is fitted from the tip opening side and pushed in the feeding direction a.

  The pipe 2 is drawn in contact with the one-side corner 3b of the peripheral edge of the rotary shearing blade 3 rotated by the motor 6. 4 to 5A and 5B, the one-side corner 3b enters the radial direction of the receiving blade 4 as it goes in the feeding direction, and the peripheral corner of the receiving blade 4 A shearing force is exerted by 4c, and the pipe 2 is continuously cut.

  Further, the divided pipe 2 is distributed to the left and right by the enlarged diameter portion 4b of the receiving blade 4 and collected in a collection box. Thereafter, the half-divided pipe 2 is subjected to a cleaning process, for example, by washing the radioactive contaminant adhering to the inner surface of the pipe with water, and is discarded or recycled as general waste. Therefore, there is no need for geological treatment, and the disposal cost is significantly reduced.

  The second embodiment of the present invention is an improvement of a rotating shear blade as shown in FIG. On the peripheral edge of the rotary shear blade 10, irregularities 11 and 12 extending in the radial direction are formed over the entire circumference along the entire width of the rotary blade. Thus, the unevenness | corrugation 11 and 12 made into saw-tooth shape increases the propulsive force which sends out the piping 2 after a cutting | disconnection by a shearing force in a feed direction. Therefore, the load when an operator pushes out the piping 2 is reduced.

  As shown in FIG. 8, the third embodiment of the present invention is a pipe half-cutting device 13 in which two pairs of rotary shear blades 3 are arranged at appropriate intervals along the delivery direction of the pipe 2. Is. The receiving blade 14 is also lengthened thereby.

  According to the pipe half-cutting device 13, first, the pair of rotary shearing blades 3, 3 in the previous stage deform the pipe 2 with respect to the feeding direction “a” of the pipe 2. It does not lead to cutting. Then, the pipe 2 is cut by the pair of rotary shearing blades 3 and 3 at the subsequent stage. In the preceding stage, the pipe 2 is advanced in the feed direction a without completely cutting the pipe 2. In the subsequent stage, the deformed pipe 2 is cut by a shearing force, so that the load is reduced.

  As a result, the pipe 2 to be halved advances substantially linearly without twisting around the longitudinal axis thereof with respect to the receiving blade 4 having a substantially circular cross section. And the cutting speed is improved.

1 is a perspective view of a pipe half cutting device 1 according to a first embodiment of the present invention. It is explanatory drawing which shows the concept cut | disconnected by a shearing force with the pipe half cutting device 1 of the same invention. They are the perspective view (A) of the receiving blade 4 of the pipe half cutting device 1, and sectional drawing (B) along the AA line. It is a front view which shows a mode that the piping 2 is cut | disconnected by the rotation shear blade 3 and a receiving blade. It is explanatory drawing (A), (B), (C) which shows the positional relationship of the rotation shear blade 3 and a receiving blade. They are the side view (A) and the front view (B) which show the mode of the cutting of the piping 2 by the pipe half cutting device 1. FIG. It is a perspective view of the rotary shear blade 10 which shows 2nd Example of this invention. It is a perspective view which shows the pipe half cutting device 13 which concerns on 3rd Example of this invention.

Explanation of symbols

1 Pipe half cutting device, 1a Cutting device body,
1b base,
2 piping,
3 rotating shear blade, 3a step,
3b One side corner,
4 receiving blade, 4a step,
4b enlarged diameter part, 4c peripheral corner part,
5 support members,
6 motor,
7 fixing member,
8,9 adjustment mechanism,
10 rotating shear blade,
11 concave,
12 Convex,
13 Pipe half cutting device.

Claims (5)

In the cutting device that divides the pipe in half along its longitudinal direction,
A pair of rotary shearing blades are arranged opposite to each other across the pipe in a direction orthogonal to the delivery direction of the pipe, and are arranged coaxially with the pipe so as to face the end opening surface of the delivered pipe. A rod-shaped receiving blade with a substantially circular cross section to be fitted to, and a support member that supports the receiving blade from the cutting device body,
The one side corner of the peripheral edge of the rotary shearing blade and the peripheral corner formed by providing a step in the radial direction from the outer peripheral surface of the receiving blade are moved in the feeding direction and fitted to the receiving blade. Continuously cutting the pipe with a shearing force in a substantially radial direction;
A pipe half-cutting device characterized by The thickness of the peripheral edge of the rotating shear blade is made thin with a step compared to the thickness of the main body,
The pipe half-cutting device according to claim 1. On the peripheral edge of the rotary shearing blade, unevenness directed in the radial direction is formed over the entire circumference along the entire blade width of the rotary blade,
The pipe half cutting device according to claim 2. Two pairs of rotary shearing blades are arranged at an appropriate interval along the delivery direction of the pipe,
The pipe half cutting device according to any one of claims 1 to 3. The connecting portion of the receiving blade and the support member is provided with an enlarged diameter portion for expanding and guiding the pipe that has been halved and divided in the pipe feeding direction.
The pipe half cutting device according to any one of claims 1 to 4.

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