U.S. patent application number 13/026589 was filed with the patent office on 2011-08-18 for in-pipe work device.
This patent application is currently assigned to KABUSHIKI KAISHA TOSHIBA. Invention is credited to Taiji Kobayashi, Satoshi Okada, Masataka Tamura, Masaki Yoda.
Application Number | 20110198075 13/026589 |
Document ID | / |
Family ID | 44059024 |
Filed Date | 2011-08-18 |
United States Patent
Application |
20110198075 |
Kind Code |
A1 |
Okada; Satoshi ; et
al. |
August 18, 2011 |
IN-PIPE WORK DEVICE
Abstract
According to an embodiment, an in-pipe work device is inserted
into a pipe and remotely controlled by a control device to perform
an operation for an inner surface of the pipe. The in-pipe work
device has: a main unit; a main-unit support unit; a rotation arm;
a process head; a first distance sensor; and a process head
position adjustment mechanism that changes a distance from a
rotation center of the rotation arm to the process head. The
control device makes the process head position adjustment mechanism
expand and contract based upon a result of measurement by the first
distance sensor and operation condition information that is input
in advance.
Inventors: |
Okada; Satoshi; (Tokyo,
JP) ; Tamura; Masataka; (Kanagawa, JP) ;
Kobayashi; Taiji; (Kanagawa, JP) ; Yoda; Masaki;
(Kanagawa, JP) |
Assignee: |
KABUSHIKI KAISHA TOSHIBA
|
Family ID: |
44059024 |
Appl. No.: |
13/026589 |
Filed: |
February 14, 2011 |
Current U.S.
Class: |
166/170 |
Current CPC
Class: |
Y02E 30/30 20130101;
F16L 55/28 20130101; G21C 17/017 20130101 |
Class at
Publication: |
166/170 |
International
Class: |
E21B 37/00 20060101
E21B037/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 15, 2010 |
JP |
2010-30553 |
Claims
1. An in-pipe work device that is inserted into a pipe and remotely
controlled by a control device to perform an operation for an inner
surface of the pipe, the in-pipe work device comprising: a main
unit; a main-unit support unit that comes in contact with the pipe
to position and fix the main unit in the pipe; a rotation arm that
rotates around a rotation axis that is parallel with a long axis of
the pipe; a process head that is attached to the rotation arm to
perform processes for the inner surface of the pipe; a first
distance sensor that is placed ahead of the process head in a
rotation direction of the rotation arm to measure a distance to the
inner surface of the pipe; and a process head position adjustment
mechanism that changes a distance from a rotation center of the
rotation arm to the process head, wherein the control device makes
the process head position adjustment mechanism expand and contract
based upon a result of measurement by the first distance sensor and
operation condition information that is input in advance.
2. The in-pipe work device according to claim 1, wherein: the
main-unit support unit includes a plurality of support legs that
come in contact with the pipe and expand and contract in response
to a control signal from the control device; and the control device
includes a function of calculating a positional difference between
the rotation axis of the rotation arm and the long axis of the pipe
and correcting position of the rotation axis of the rotation arm by
making the support legs expand and contract based upon the
calculated positional difference.
3. The in-pipe work device according to claim 1, comprising a
second distance sensor that is attached to the rotation arm and
measures a distance to the inner surface of the pipe, wherein the
control device includes a function of using the second distance
sensor to collect data concerning a distance between the rotation
axis of the rotation arm and the inner surface of the pipe,
calculating a difference in position between the rotation axis of
the rotation arm and the long axis of the pipe based upon the
collected distance data, and making corrections so that the
rotation axis of the rotation arm is positioned at the center of
the pipe.
4. The in-pipe work device according to claim 3, wherein the
control device calculates the difference in position between the
rotation axis of the rotation arm and the long axis of the pipe
based upon a relationship between a rotation angle of the rotation
arm and the distance data.
5. The in-pipe work device according to claim 1, wherein the first
distance censor is a magnetic distance sensor.
6. The in-pipe work device according to claim 1, wherein: the first
distance sensor is a laser scanner; and the control device includes
an output unit and displays three-dimensional graphics on the
output unit based upon a result of scanning by the laser scanner to
show the shape of the inner surface of the pipe.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2010-030553, filed on
Feb. 15, 2010, the entire content of which is incorporated herein
by reference.
FIELD
[0002] Embodiments described herein relate to an in-pipe work
device that is disposed in a pipe and conducts inspection,
repairing and other works for an inner surface of the pipe.
BACKGROUND
[0003] When inspection, process and other works are conducted for
an inner surface of a lateral or horizontal pipe in an environment
that people have difficulty getting into, an in-pipe work device is
sent by remote control into the pipe where the in-pipe work device
conducts operations for the inner surface of the pipe. In
particular, for example, when high-precision operations are
required in an environment such as a nuclear reactor pressure
vessel whose interior is complicated and confined, skilled workers
and enormous man-hours are necessary. For example, a conventional
operation of installing an in-pipe work device in a lateral pipe
involves lifting the in-pipe work device down using a large crane
or hoist to transfer the in-pipe work device to an inlet of the
pipe before disposing the in-pipe work device in the pipe using a
mechanism that sends the in-pipe work device in a horizontal
direction. Therefore, large equipment is needed to transfer the
in-pipe work device to the inlet of the pipe as well as to send the
in-pipe work device into the pipe.
[0004] As for such an in-pipe work device, there is a device that
rotates a processing head inside the lateral pipe to conduct
inspection and processes in a circumferential direction of the
inner surface of the pipe. For example, what is disclosed in Jpn.
Pat. Appln. Laid-open Publication No. 11-304985, the entire content
of which is incorporated herein by reference, is a device that
rotates a laser emission unit along an internal circumference of
the pipe using a rotation motor to irradiate the entire
circumference of a welded part of the pipe with the laser beam and
performs surface solution heat treatment. The device also includes
three support arms, each of which has a roller on a tip of the arm.
The support arms are expanded by the same distance and pushed
against the inner surface of the pipe so that the device is
supported at the center of the axis of the pipe.
[0005] As described above, when inspection and processes are
carried out for the inner surface of the lateral pipe in a
complicated and confined environment, skilled workers and enormous
man-hours have been needed for the device to be installed by remote
control.
[0006] The use of the device designed to rotate an operation head
that the in-pipe work device includes and perform inspections and
operations in the circumferential direction of the pipe involves
the following: before the operation head is positioned, the in-pipe
work device is moved to the location where the operation head
reaches an operation site. However, in many cases, the shape and
inner surface of the pipe, on which operations are conducted, are
significantly different from what has been designed. Particularly
in a pipe where a welded part exists, there are rugged portions on
the inner surface of the pipe due to weld beads. When operations
are conducted with the rotating operation head in the
circumferential direction of the pipe, it is necessary to keep a
constant distance between the operation head and the inner surface
of the pipe for precise positioning.
[0007] If there are rugged portions on the inner surface of the
pipe, it is necessary to make corrections appropriately in order to
keep a distance between a process-applied surface and the operation
head within a tolerance of an operation condition when the
operation head is rotating.
[0008] However, as the in-pipe work device becomes larger and more
complicated, it is more difficult to install the in-pipe work
device and monitor how operations go on, requiring more skilled
workers and man-hours.
[0009] Moreover, when operations are conducted for the inner
surface of a pipe that has been installed in an actual plant and is
in operation, there are restrictions, including a distance between
a control area for remote operation and a work site, a work
atmosphere (underwater, a gas-filled area or the like), effects on
peripheral devices, and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The above and other features and advantages of the present
invention will become apparent from the discussion hereinbelow of
specific, illustrative embodiments thereof presented in conjunction
with the accompanying drawings, in which:
[0011] FIG. 1A is a front view of a processing device 3 according
to the first embodiment of the present invention when viewed in an
axial direction of a nozzle stub 2, and FIG. 1B is an arrow
cross-sectional view taken along line A-A shown in FIG. 1A;
[0012] FIG. 2 is a flowchart showing a process ranging from the
installation of the processing device 3 in a processing location to
a laser welding process by the processing device 3;
[0013] FIG. 3 is a perspective view outlining a lifting device 22
and a device insertion jig 23 in the first embodiment;
[0014] FIG. 4 is a perspective view illustrating an operation of
installing the processing device 3 using the lifting device 22;
[0015] FIG. 5A is a lateral view showing a situation before the
processing device 3 is held by the lifting device 22, and FIG. 5B
is a lateral view showing a situation where the processing device 3
is held by the lifting device 22;
[0016] FIG. 6 is a lateral view showing the processing device 3
that is inserted into the nozzle stub 2 by the lifting device
22;
[0017] FIG. 7A is a front view of a support leg 4 when viewed in an
axial direction of the nozzle stub 2, and FIG. 7B is a front view
of the support leg 4 when viewed in a direction perpendicular to
the axial direction of the nozzle stub 2;
[0018] FIG. 8A is a front view illustrating a motion mode of the
processing device 3, and FIG. 8B is a front view illustrating a
fixed mode of the processing device 3;
[0019] FIG. 9 is a conceptual diagram showing, in a simplified way,
a situation where a rotation axis of a rotation arm 9 is positioned
away from the center of the nozzle stub 2;
[0020] FIG. 10 is a graph showing a relationship between a distance
from a distance sensor 8 to the inner surface of the nozzle stub 2
and a rotation angle of the rotation arm;
[0021] FIG. 11 is a conceptual diagram showing support-leg axes
54a, 54b and 54c before and after corrections are made to a
rotation axis 52;
[0022] FIG. 12A is an enlarged view of essential portions around a
processing head 7 when viewed in the axial direction of the nozzle
stub 2, and FIG. 12B is an enlarged view of essential portions when
viewed in a direction perpendicular to the axial direction of the
nozzle stub 2;
[0023] FIG. 13 is an enlarged view of essential portions in the
vicinity of the processing head 7 in the second embodiment when
viewed in the axial direction of the nozzle stub 2;
[0024] FIG. 14 is a flowchart showing a process of adjusting the
distance between the processing head 7 and the inner surface of the
nozzle stub 2 using distance data detected by a magnetic distance
sensor 81;
[0025] FIG. 15 is an enlarged view of essential portions in the
vicinity of the processing head 7 when viewed in the axial
direction of the nozzle stub 2 in the third embodiment; and
[0026] FIG. 16 is a diagram showing an example of what a state
display controller 17 displays in the third embodiment.
DETAILED DESCRIPTION
[0027] A problem to be solved by the present invention is to
provide an in-pipe work device that accurately adjusts a distance
between the inner surface of the pipe and a rotation axis of the
operation head with a simple configuration to improve the accuracy
of operations.
[0028] According to one embodiment, an in-pipe work device that is
inserted into a pipe and remotely controlled by a control device to
perform an operation for an inner surface of the pipe is provided.
The in-pipe work device comprises: a main unit; a main-unit support
unit that comes in contact with the pipe to position and fix the
main unit in the pipe; a rotation arm that rotates around a
rotation axis that is parallel with a long axis of the pipe; an
operation head that is attached to the rotation arm to perform
processes for the inner surface of the pipe; a first distance
sensor that is placed ahead of the operation head in a rotation
direction of the rotation arm to measure a distance to the inner
surface of the pipe; and an operation head position adjustment
mechanism that changes a distance from a rotation center of the
rotation arm to the operation head. The control device makes the
operation head position adjustment mechanism expand and contract
based upon a result of measurement by the first distance sensor and
operation condition information that is input in advance.
[0029] The following describes embodiments of the present invention
with reference to the accompanying drawings.
First Embodiment
[0030] The following describes the first embodiment of the present
invention with reference to the drawings. FIGS. 1A and 1B are
diagrams showing the configuration of a processing device 3 that
conducts repairing and processes on an inner surface of a nozzle
stub 2 that is installed in a nuclear reactor pressure vessel 1 as
an example of a lateral pipe; the diagrams show the situation where
the processing device 3 is put in the nozzle stub 3. FIG. 1A is a
front view of the processing device 3 when viewed in an axial
direction of the nozzle stub 2. FIG. 1B is an arrow cross-sectional
view of the processing device 3 taken along line A-A shown in FIG.
1A; the diagram also shows a control device 15 and the like, which
are connected to the processing device 3
[0031] In the present embodiment, the processing device 3 is
described as a device that performs processes of laser welding to
the inner surface of the nozzle stub 2, for example.
[0032] With reference to FIGS. 1A and 1B, the following describes
the configuration of the processing device 3 as well as a remote
control system of the processing device 3.
[0033] The processing device 3 is supported by a plurality of
support legs 4 that extend in radial directions of the nozzle stub
2. The support legs 4 are disposed partly within grooves that are
formed in a main-unit module 5. Each of the support legs 4 is
provided with an expansion mechanism unit 6 that expands and
contracts the support leg 4. A processing head 7 and a distance
sensor (a second distance sensor) 8 are attached to the processing
device 3 via a rotation arm 9, a rotation driving mechanism unit 10
and a back-and-forth driving mechanism unit 11. The processing head
7 and the distance sensor 8 are set so as to face the inner surface
of the nozzle stub 2 and to face mutually opposite directions. The
processing head 7 and the distance sensor 8 are attached to the
rotation arm 9, which is rotated by the rotation driving mechanism
unit 10. A pivot axis of the rotation arm 9 is in the same
direction as the axial direction of the nozzle stub 2. The
back-and-forth driving mechanism unit 11 is attached to the
rotation driving mechanism unit 10 and moves the rotation driving
mechanism unit 10 back and forth with respect to the main unit of
the processing device 3. What is installed between the processing
head 7 and the rotation arm 9 is a push driving mechanism unit 12
that expands and contracts (or shortens) in the radial direction of
the nozzle stub 2 to move the processing head 7. A head unit
monitoring camera is attached to the processing head 7 to monitor a
portion on which processes are conducted. Welded parts 13 are
convex portions formed on the inner surface of the nozzle stub
2.
[0034] The processing device 3 is signally connected to the control
device 15 placed on an operation floor via a cable 14. The control
device 15 is connected to a driving controller 16 and a state
display controller 17. The control device 15, the driving
controller 16 and the state display controller 17 communicate with
each other. The driving controller 16 generates driving control
data using a processing request input by an operator and state data
of the processing device 3 collected through the control device 15,
and inputs a driving control request of the processing device 3
into the control device 15. The state data of the processing device
3 represents, for example, an attitude, a rotation angle of the
rotation arm 9, expansion or contraction state of the support legs
4 or of the back-and-forth driving mechanism unit 11, and the like.
The state display controller 17 outputs the state data of the
processing device 3, which is collected through the control device
15, and a captured image of a head unit monitoring camera 18. As
for the state data, information-processing conversion is performed
on the state data that is to be displayed so that it is easy for an
operator to know the state of the processing device 3. The control
device 15, the driving controller 16 and the state display
controller 17 make up a remote control system of the processing
device 3.
[0035] FIG. 2 is a flowchart showing a process of operation by the
processing device 3, from the installation of the processing device
3 in a processing location to a laser welding process by the
processing device 3.
[0036] First, the processing device 3 is put into the nozzle stub
2. That is the processing device 3 is lifted down from outside the
nuclear reactor pressure vessel (RPV) 1 (Step S1); the processing
device 3 is moved closer to the nozzle stub 2 (Step S2); and the
processing device 3 is inserted into the nozzle stub 2 from the
nozzle stub 2 (Step S3).
[0037] Then, a process of positioning the processing device 3 in
the processing location in the nozzle stub 2 is performed. That is
the processing device 3 is made move in the nozzle stub 2 to the
processing location (Step S4); and the position of the processing
device 3 is fixed so that the processing device 3 is positioned at
the processing location (Step S5).
[0038] Finally, a rotation axis of the rotation arm 9 is positioned
on the center of the nozzle stub 2 and a laser welding process is
performed. First, the distance sensor 8 attached to the rotation
arm 9 detects a difference in position between the center of the
nozzle stub 2 and the rotation axis of the rotation arm 9 (Step
S6). Based on the detected positional difference, the lengths of
the support legs 4 are adjusted so that the rotation axis of the
rotation arm 9 comes to the center of the nozzle stub 2 (Step S7).
After the positioning of the rotation arm 9 is completed, a laser
welding process is carried out by the processing head 7 (Step
S8).
[0039] Each of the above steps shown in FIG. 2 will be described in
detail with reference to each of the drawings.
[0040] First, the configuration of devices that put the device 3
into the nozzle stub 2 will be described with reference to FIG. 3.
FIG. 3 is a perspective view outlining a lifting device 22 and a
device insertion jig 23 that are used to put the processing device
3 into the nozzle stub 2.
[0041] The lifting device 22 is a kind of crane and is attached to
a rotation mechanism 25 placed on the operation floor. The lifting
device 22 includes: a rotation mechanism installed on the operation
floor 93; an expansion arm 26 which is attached to and rotated by
the rotation mechanism 25; a wire reel 27 which hangs from a tip of
the expansion arm 26; and a lifting wire 28 which is paid out from
the wire reel 27. The device insertion jig 23 includes: a device
holding jig 29 which holds the processing device 3; a jig-side
lifting wire 30 which is to be connected to the lifting wire 28; a
jig monitoring camera 31 which monitors how the processing device 3
is inserted into the nozzle stub 2; and a guide cable 32 which is
used both for signal communication of the jig monitoring camera 31
and for a direction-adjustment guide of the device insertion jig
23. There are a pair of wire connectors 24, one of which is
attached to a tip of the lifting wire 28 and the other to a tip of
the jig-side lifting wire 30. After the wire connectors 24 are
connected together, the device insertion jig 23 hangs from the
lifting device 22. The cable 14 is not shown in this diagram.
[0042] The following describes the installation of the processing
device 3 with the use of the lifting device 22 and the device
insertion jig 23 with reference to FIGS. 4, 5 and 6 (Steps S1 to S3
in FIG. 2). FIG. 4 is a perspective view illustrating an operation
of installing the processing device 3.
[0043] As shown in FIG. 4, an operation truck 20 and the lifting
device 22 are placed on an operation floor 93. The lifting device
22 lifts the device insertion jig 23 holding the processing device
3 down into the nuclear reactor pressure vessel 1. On the operation
truck 20, there is a cable supply device 21 that leads cables
extending into the nuclear reactor pressure vessel 1. The cable 14
of the processing device 3 and the guide cable 32 of the device
insertion jig are led by the cable supply device 21.
[0044] A process of installing the processing device 3 will be
described in detail with reference to FIGS. 5 and 6. FIGS. 5A, 5B
and 6 are lateral views illustrating a process of installing the
processing device 3, where the longitudinal section of the
processing device 3 is shown as in the case of FIG. 1B. Some
portions of the structure, such as the support legs of the
processing device 3, are not shown in these diagrams.
[0045] First, as shown in FIG. 5A, the device insertion jig 23
holds the processing device 3. The processing device 3 is held in
the following manner: projecting portions 29a of the device holding
jig 29 are inserted into a concave portion provided in the
main-unit module 5, and the projecting portions 29a are widened
outward and pushed against the inner wall of the concave portion of
the main-unit module 5. Then, as shown in FIG. 5B, the lifting
device 22 lifts down the device holding jig 29 holding the
processing device 3 (Step S1 in FIG. 2).
[0046] Alternatively, if the attitude of the processing device 3
can be kept horizontal, a different method may be used to hold the
processing device 3. For example, the following methods may
available: a method of attaching male and female members to the
device holding jig 29 and the processing device 3 so that the
device holding jig 29 and the processing device 3 engage with each
other, and a method of pushing convex portions of the processing
device 3 from outside to hold. As for the attitude of the
processing device 3, all that is required is for the attitude of
the processing device 3 to be kept horizontal just before the
processing device 3 is inserted into the nozzle stub 2. For
example, the following is possible: the attitude of the processing
device 3 is kept vertical while the processing device 3 is being
lifted down; after the processing device 3 comes closer to the
nozzle stub 2, the attitude of the processing device 3 is then
turned to become horizontal. This method is effective when the
vertical attitude of the processing device 3 is advantageous in
moving the processing device 3 inside the nuclear reactor pressure
vessel 1 which is a complicated and confined space.
[0047] The following describes how to insert the processing device
3 into the nozzle stub 2 with reference to FIG. 6. The processing
device 3 hanging from the lifting device 22 moves closer to the
nozzle stub 2 as the lifting device 22 rotates, the expansion arm
26 expands or contracts and the wire reel 27 pays out the lifting
wire 28 (Step S2 in FIG. 2).
[0048] Watching an image of the jig monitoring camera 31, an
operator accurately positions the processing device 3 in front of
the entrance of the nozzle stub 2. After the positioning of the
processing device 3 is completed, the expansion arm 26 is further
contracted, thereby inserting the processing device 3 into the
nozzle stub 2 (Step S3 in FIG. 2). If a location where the
processing device 3 is installed is far away from the nozzle stub
2, the projecting portions 29a of the device holding jig 29 can be
replaced with expansion arms or with other structures so that it is
easy to insert the processing device 3 deep into the nozzle stub
2.
[0049] The following explains how to position the processing device
3, which is inserted into the nozzle stub 2, at the processing
location, with reference to FIGS. 7 and 8 (Steps S4 and S5 in FIG.
2).
[0050] First, the detailed configuration of the support legs 4 of
the processing device 3 will be described with reference to FIGS.
7A and 7B. FIGS. 7A and 7B are enlarged views of essential
portions, showing the configuration of each of the support legs 4.
FIG. 7A is a front view, viewed in the axial direction of the
nozzle stub 2. FIG. 7B is a lateral view, viewed in a direction
perpendicular to the axial direction of the nozzle stub 2.
[0051] As described above, the support legs 4 are provided with the
expansion mechanism units 6. The expansion mechanism units 6 make
the support legs 4 expand or contract in length. The following are
provided at the tips of the support legs 4: fixing jigs 40 which
come in contact with the internal surface of the nozzle stub 2, and
mobile wheels 41. The fixing jigs 40 are provided at the tips of
the support legs 4 via pushing mechanisms 42. The pushing
mechanisms 42 expand or contract in the same directions as the axes
of the support legs 4 to push the fixing jigs 40 against the inner
surface of the nozzle stub 2. The expanding and contracting of the
pushing mechanisms 42 are independent of the mobile wheels 41. The
mobile wheels 41 are provided at the tips of the support legs 4 via
springs which are not shown. The mobile wheels 41 are driven by
wheel driving mechanisms. Each of the wheel driving mechanism may
include a built-in motor which is positioned around the tip of the
support leg 4, and a timing belt which transfers the power of the
motor to the mobile wheel 41.
[0052] With the pushing mechanisms 42 and the wheel driving
mechanisms mentioned above, the processing device 3 shifts between
a motion mode and a fixed mode; the processing device 3 moves to
the processing location where the processing device 3 is positioned
and fixed. The following provides a detailed description thereof
with reference to FIGS. 8A and 8B. FIG. 8A is a front view
illustrating the motion mode of the processing device 3. FIG. 8B is
a front view illustrating the fixed mode of the processing device
3.
[0053] In the motion mode shown in FIG. 8A, the pushing mechanisms
42 do not push the fixing jigs 40 against the inner surface of the
nozzle stub 2. In addition, the expansion mechanism units 6 remain
contracted. Of the support legs 4a, 4b and 4c extending in three
directions, only the mobile wheels 41b and 41c of the support legs
4b and 4c come in contact with the inner surface of the nozzle stub
2. If the wheel driving mechanisms are driven under the
circumstances mentioned above, the processing device 3 moves in the
nozzle stub 2. It is possible for the operator to move the
processing device 3 to the processing location by watching the
image of the head unit monitoring camera 18 and by controlling the
driving of the wheel driving mechanisms (Step S4 in FIG. 2).
Alternatively, the processing device 3 may be driven using three
mobile wheels with the mobile wheel 41a of the support leg 4a being
pushed against the inner surface of the nozzle stub 2 by the
expansion mechanism unit 6.
[0054] In the fixed mode shown in FIG. 8B, the fixing jigs 40 are
pushed against the inner surface of the nozzle stub 2 by the
pushing mechanisms 42. As the fixing jigs 40 are pushed against the
inner surface of the nozzle stub 2, the mobile wheels 41 move away
from the inner surface of the nozzle stub 2. As a result, the
position of the processing device 3 is fixed in the nozzle stub
2.
[0055] In that manner, the driving of the expansion mechanism units
6, the pushing mechanisms 42 and the wheel driving mechanisms,
which are provided on the support legs 4, is controlled, and the
processing device 3 therefore shifts between the motion mode and
the fixed mode. Thus, it is possible to move the processing device
3 to the processing location for positioning (Step S5 in FIG.
2).
[0056] The following describes a process of positioning the
rotation axis of the rotation arm 9 at the center of the nozzle
stub 2 with reference to FIGS. 9, 10 and 11 (Steps S6 and S7 in
FIG. 2).
[0057] First, a process of detecting a difference in position
between the center of the nozzle stub 2 and the rotation axis of
the rotation arm 9 will be described with reference to FIG. 9 (Step
S6 in FIG. 2). FIG. 9 is a conceptual diagram showing, in a
simplified way, the situation where the rotation axis of the
rotation arm 9 is positioned away from the center of the nozzle
stub 2.
[0058] The rotation axis 52 of the rotation arm 9 is positioned
away from the center 51 of the nozzle stub 2. The processing device
3 is in the fixed mode, which is illustrated in FIG. 8B. The
support legs 4 are in contact with the inner surface of the nozzle
stub 2. In FIG. 9, the lines connecting the contact points of the
support legs 4 with the inner surface of the nozzle stub 2 to the
rotation axis 52 are represented in the diagram as support-leg axes
54a, 54b and 54c. The support-leg axes 54a, 54b and 54c correspond
to the support legs 4a, 4b and 4c, respectively. The support-leg
axes 54a, 54b and 54c are La, Lb and Lc in length, respectively.
The distance between the rotation axis 52 and the distance sensor 8
is represented by Ld, and the distance between the distance sensor
8 and the inner surface of the nozzle stub 2 by Lmi. Therefore, the
distance between the inner surface of the nozzle stub 2 and the
rotation axis 52 is Ld+Lmi. The angle between the support-leg axes
54a and 54b is represented by .theta.ab, the angle between the
support-leg axes 54b and 54c by .theta.bc, and the angle between
the support-leg axes 54a and 54c by .theta.ac. The support legs 4a,
4b and 4c are placed at regular intervals. In the case of FIG. 9,
.theta.ab, .theta.bc and .theta.ac are all 120 degrees.
Alternatively, the support legs may not be placed at regular
intervals, and the support legs may be placed arbitrarily.
[0059] As for the difference in position between the center of the
nozzle stub 2 and the rotation axis of the rotation arm 9, (Ld+Lmi)
is measured by the distance sensor 8 while the rotation arm 9 is
rotated one revolution. Therefore, it is possible to detect the
direction and distance of the positional difference. The following
provides a detailed description thereof with reference to FIG. 10.
FIG. 10 is a graph outlining the results of measurement by the
distance sensor 8 when the rotation arm 9 makes one revolution. The
x-axis represents the rotation angle .phi.s of the rotation arm 9,
with the initial position .phi..sub.0=0 degree. The y-axis
represents the distance, Ld+Lmi, between the rotation axis 52 and
the inner surface of the nozzle stub 2. The radius r of the nozzle
stub 2 is indicated by a dotted line.
[0060] FIG. 10 shows the results of measurement for the rotation
arm 9 that is rotated one revolution clockwise, with the position
of the distance sensor 8, shown in FIG. 9, set at .phi..sub.0.
Incidentally, the angle of the rotation arm shown in FIG. 9 is
opposite to the direction of the support-leg axis 54a, so that the
angles are different by 180 degrees. Since the rotation axis 52 is
closer to the inner surface of the nozzle stub 2 than the center 51
is in the .phi..sub.0 direction, Ld+Lmi is smaller than radius r.
As .phi.s increases, Ld+Lmi also increases, peaking at .phi.m. At
.phi.m, the rotation arm 9 overlaps on the center 51. As .phi.s
increases further, Ld+Lmi decreases. Finally, at .phi.s=360
degrees, Ld+Lmi becomes the same value as at .phi.s=0 degree, and
the measurement ends. The difference between Ld+Lmi and radius r at
.phi.m is represented by .DELTA.d.
[0061] The direction of the positional difference of the center 51
relative to the rotation axis 52 is .phi.m, which is obtained by
the measurement described above. The magnitude of the positional
difference between the center 51 and the rotation axis 52 is
.DELTA.d. Angles such as .phi.m are based on the initial position
of the rotation arm 9.
[0062] The following describes an example of how to correct the
position of the rotation axis 52 with reference to FIG. 11. The
position of the rotation axis 52 can be changed by expanding and
contracting the support legs 4a, 4b and 4c, with the contact points
of the support legs 4a, 4b and 4c with the inner surface of the
nozzle stub 2 being unmoved. The following explains in detail how
to calculate the length of each of the support legs 4a, 4b and 4c
after corrections are made to the rotation axis 52.
[0063] FIG. 11 is a conceptual diagram showing the support-leg axes
54a, 54b and 54c before and after corrections are made to the
rotation axis 52. The dotted lines represent the support-leg axes
54a, 54b and 54c before corrections are made. The solid lines
represent the support-leg axes after the corrections are made.
Hereinafter, after the corrections are made, the support-leg axes
are referred to as "corrected support-leg axes 64a, 64b and 64c." A
line connecting the center 51 and the rotation axis 52, before the
corrections are made, is represented by a single-dot chain line as
a difference direction 55. Suppose that the corrected support-leg
axes 64a, 64b and 64c are La+.DELTA.a, Lb+.DELTA.b and Lc+.DELTA.c
in length, respectively.
[0064] The length of the support legs 4a, 4b and 4c, after the
rotation axis 52 is corrected, is determined by calculating the
length of the corrected support-leg axes 64a, 64b and 64c, i.e.
La+.DELTA.a, Lb+.DELTA.b and Lc+.DELTA.c. The following provides a
detailed description of how to calculate Lc+.DELTA.c, the length of
the corrected support-leg axis 64c, among the corrected support-leg
axes 64a, 64b and 64c.
[0065] Suppose that in FIG. 11 the contact point of the support leg
4c with the inner surface of the nozzle stub 2 is point A, the
location of the uncorrected rotation axis 52 point B, and the
center 51 of the nozzle stub 2 point O. In this case, it is
possible to calculate the length of the corrected support-leg axis
64c, Lc+.DELTA.c, by focusing on a triangle made by three points A,
B and O. Segment AO is Lc+.DELTA.c in length. Segment AB is Lc in
length. Segment BO is .DELTA.d in length. Angle OBA is .phi.ic,
which is shown in FIG. 11 and is the angle between the difference
direction 55 and the support-leg axis 54c. .phi.ic is calculated by
the following equation (1).
.phi.ic=.phi.a+120 (1)
[0066] where .phi.a is the angle between the support leg 4a and the
difference direction 55 as shown in FIG. 11. It is possible to
calculate .phi.a from the initial position of the distance sensor
8, the position of the uncorrected support leg 4a, and the measured
.phi.m.
[0067] Based on the information described above, the square of
(Lc+.DELTA.c), i.e. the square of the length of segment AO, is
calculated by the following equation (2) because of the second law
of cosines.
(Lc+.DELTA.c).sup.2=Lc.sup.2+.DELTA.d.sup.2-2Lc.times..DELTA.d.times.|co-
s(.phi.ic)| (2)
[0068] Each parameter in the right side of equation (2) is already
known as described above. Therefore, it is possible to calculate
the length of the corrected support-leg axis 64c based upon
equation (2). It is also possible to calculate La+.DELTA.a and
Lb+.DELTA.b from the angles and length that are already known in a
similar way.
[0069] As described above, the length of the support legs 4a, 4b
and 4c is adjusted based on the calculated length of the corrected
support-leg axes 64a, 64b and 64c. In this manner, corrections are
made so that the rotation axis 52 comes to the position of the
center 51 (Step S7 in FIG. 2).
[0070] The following describes the laser welding process by the
processing head 7 for the inner surface of the nozzle stub 2 with
reference to FIGS. 12A and 12B (Step S8 in FIG. 2).
[0071] FIGS. 12A and 12B are enlarged views of essential portions
around the processing head 7. FIG. 12A is a diagram showing the
front side of the processing device 3, i.e. the side viewed in the
axial direction of the nozzle stub 2. FIG. 12B is a diagram when
viewed in a direction perpendicular to the axis of the nozzle stub
2. The following provides a detailed description of the
configuration of the processing head 7.
[0072] The processing head 7 is attached to the tip of the rotation
arm 9 through the push driving mechanism unit 12. The processing
head 7 includes: a roller holding unit 76 which holds scanning
guide rollers 71; a cover 78 which is attached to the tip side
through an elastic body 77; a welding nozzle 72 which is attached
to the inner side of the cover; a filler supply nozzle 73; and a
cover gas nozzle 74. An optical fiber (not shown) is connected to
the welding nozzle 72 to transfer a laser beam. A hose (not shown)
is connected to the cover gas nozzle 74 to supply gas. A filler
drum 75 is attached to the rotation arm 9 and supplies filler (not
shown) to the filler supply nozzle 73. In both the cases of FIGS.
12A and 12B, the traveling direction of the processing head 7
during a process of operation is from left to right on the paper. A
process of operation is performed as the processing head 7 draws a
spiral trajectory on the inner surface of the nozzle stub 2.
[0073] The following describes the process of operation performed
by the processing head 7. After the position of the rotation axis
52 is corrected, the rotation arm 9 is rotated so that the rotation
arm 9 comes to a process start position. Then, the processing head
7 is moved in the axial direction of the nozzle stub 2 by the
back-and-forth driving mechanism unit 11 illustrated in FIG. 1 in
such a way that the processing head 7 is positioned. After the
positioning of the processing head 7 is completed, the laser
welding process starts. A cover gas atmosphere is created as a
cover gas is supplied from a cover gas nozzle into the space within
the cover 77: welding is carried out as a laser beam is emitted
from the welding nozzle 72. The processing head 7 moves
counterclockwise in FIG. 12A, with the help of the rotation arm.
The processing head 7 then moves rightward in FIG. 12B, with the
help of the back-and-forth driving mechanism unit 11 so as to draw
a spiral trajectory. As the process of operation goes on, the
processing head 7 moves rightward in FIG. 12B, and then runs onto
the welded part 13.
[0074] As described above, according to the processing device 3 of
the present embodiment, even if the shape of the inner surface of
the nozzle stub 2 is different from what has been designed, it is
possible to highly accurately perform the laser welding process to
the inner surface of the nozzle stub 2 by measuring the inner
surface of the nozzle stub 2 and correcting the difference between
the rotation axis 52 and the center 51 after the processing device
3 is installed in the nozzle stub 2, on which the process of
operation is conducted.
[0075] In the present embodiment described above, the laser welding
process is performed by the processing head 7. However, for any
operation in which the distance between the processing head 7 and
the inner surface of the nozzle stub 2 affects the accuracy of
processes, the present invention helps to improve the accuracy. For
example, instead of the processing head 7, an operation head for
laser peening, ultrasonic flaw detection, surface polishing or the
like may be used.
[0076] As for the process of correcting the difference in position
of the rotation axis 52, the calculation method described in the
present embodiment is one example. Alternatively, it may be also
possible to use a calculation method depending on the configuration
of the processing device 3 or the way the distance sensor 8
measures the positional difference. For example, in the present
embodiment, the contact points of the support legs 4a, 4b and 4c
with the inner surface of the nozzle stub 2 are held unmoved and
corrections are made only by expanding and contracting the support
legs 4a, 4b and 4c as described above. However, alternatively, the
following structures may be also possible: a structure in which
mechanisms that move in the circumferential direction of the nozzle
stub 2 is provided on the tips of the support legs 4a, 4b and 4c
and corrections are made while the angles between the support legs
4a, 4b and 4c are kept unchanged; a structure in which sensors are
mounted to measure the angles between the support legs 4a, 4b and
4c and the angles between the support legs 4a, 4b and 4c can be
adjusted. Then, a correction process or calculation method suitable
for each of the structures described above may be adopted. For
example, for the structure in which corrections are made while the
angles between the support legs 4a, 4b and 4c are kept unchanged,
the following processes may be possible: after the center 51 is
calculated, the entire processing device 3 is rotated so that one
of the support legs 4a, 4b and 4c is on the difference direction
55; if the support leg 4a is put on the difference direction 55,
the support leg 4a is expanded while the support legs 4b and 4c are
contracted by the same amount; and corrections are made so that the
rotation axis 52 moves along the difference direction 55 to the
center 51. For example, such a process is possible when the support
legs 4a, 4b and 4c have the flexibility to move slightly in the
circumferential direction because the support legs 4a, 4b and 4c
are fixed on the processing device 3 through elastic bodies such as
spring or rubber.
[0077] In the present embodiment, the processing head 7 is
continuously rotated while the processing device 3 moves axially,
and the process of operation is conducted while the processing head
7 draws a spiral trajectory as described above. However, the
process of operation can alternatively be performed by repeating
the following operation: an operation in which the rotation arm 9
is rotated one revolution while the processing device 3 remains
unmoved axially and then the processing device 3 moves axially
after the processing head 7 is rotated one revolution.
[0078] When the process of operation is performed with the
processing head 7 drawing a spiral trajectory, a slip ring is
adopted for the rotation driving mechanism unit 10 in order to
prevent kinks in cables such as that of the distance sensor 8 as
the rotation arm 9 is continuously rotated in the same direction.
Therefore, it is possible to continuously perform the process of
operation using the processing head 7 and therefore reduce the time
required for the process of operation.
[0079] When the process of operation is conducted by alternately
performing the process of rotating the rotation arm 9 and the
process of moving the processing device 3, the rotation direction
of the rotation arm 9 is controlled in such a way that the rotation
direction is reversed every time the rotation arm 9 is rotated one
revolution. In this case, a slip ring is not required. Therefore,
it is possible to make the configuration of the processing device 3
more simplified.
Second Embodiment
[0080] The following describes the second embodiment of the present
invention with reference to the drawings. The same components as
those in the first embodiment are denoted by the same reference
symbols, and repetitive explanation will be omitted.
[0081] If there is a rugged area on the inner surface of the nozzle
stub 2 due to the accuracy of manufacturing, aging degradation or
the like, the distance between the processing head 7 and the inner
surface of the nozzle stub 2 varies during the process of
operation. The device and method described in the first embodiment
are highly accurate by correcting the rotation axis 52 in such a
way that the rotation axis 52 comes to the center 51 of the nozzle
stub 2, as well as particularly effective for the case where the
tolerance of an process condition, such as the engineer works of
laser welding, is small. However, when the fluctuation range is
large because of the rugged area on the inner surface of the nozzle
stub 2, there may be impact on the quality of the processes even if
the rotation axis 52 is corrected.
[0082] The following describes the configuration of the processing
head 7 of the present embodiment with reference to FIG. 13. A
magnetic distance sensor (a first distance sensor) 81 is attached
to the rotation arm 9. The magnetic distance sensor 81 is designed
to measure the position of a core rod 82 that goes up and down,
with north-pole and south-pole magnets inserted into the core rod
82. A signal processing device included in the control device 15
transmits an excitation signal through a distance sensor cable 83
and receives a detected induced electromotive force to output
distance data. The magnetic distance sensor 81 is attached to the
side of the rotation arm 9 that faces the direction in which the
processing head 7 travels. A distance sensor roller 84 attached to
the tip of the core rod 82 is continuously in contact with the
inner surface of the nozzle stub 2. The distance data processed by
the signal processing device included in the control device 15 has
is transmitted to the driving controller 16 and the state display
controller 17. The state display controller 17 displays the
distance data detected by the magnetic distance sensor 81 as well
as the driving state of the processing device. An operator uses the
data for monitoring.
[0083] A processing head position adjustment mechanism 85 is
provided on the processing head 7. The processing head position
adjustment mechanism 85 drives the welding nozzle 72, filler supply
nozzle 73 and cover gas nozzle 74 of the processing head 7 up and
down in relation to the inner surface of the nozzle stub 2 in
response to an instruction from the driving controller 16. Based on
the distance data detected by the magnetic distance sensor 81, the
processing head position adjustment mechanism 85 is driven.
Therefore, it is possible to highly accurately keep the constant
distance between the processing head 7 and the inner surface of the
nozzle stub 2. If adjustments need to be made beyond a range in
which the processing head position adjustment mechanism 85 can make
corrections, the push driving mechanism unit 12 is also driven for
adjustments.
[0084] A procedure of the above operation will be described with
reference to FIG. 14. FIG. 14 is a flowchart showing a process of
adjusting the distance between the processing head 7 and the inner
surface of the nozzle stub 2 using the distance data detected by
the magnetic distance sensor 81.
[0085] At first, the control device 15 receives the distance data
detected by the magnetic distance sensor 81 (Step S11 in FIG. 14).
Then, the control device 15 calculates the difference in distance
between the processing head 7 and the inner surface of the nozzle
stub 2 based upon the distance data (Step S12 in FIG. 14). The
control device 15 subsequently makes a determination as to whether
the distance difference is within a correctable range based upon
the calculated distance difference and data concerning the
expanding and contracting state of the push driving mechanism unit
12 and the processing head position adjustment mechanism 85 (Step
S13 in FIG. 14). When the distance difference is outside the
correctable range, an interlock starts to work and the process of
operation is suspended (Step S14 in FIG. 14). When the distance
difference is within the correctable range, the control device 15
makes a determination as to whether the distance difference is
within a range where corrections can be made only by the processing
head position adjustment mechanism 85 at that time (Step S15 in
FIG. 14). When it is not possible to make corrections only with the
processing head position adjustment mechanism 85, the push driving
mechanism unit 12 is used in combination with the processing head
position adjustment mechanism 85 to make corrections (Step S16 in
FIG. 14). When the distance difference is within a range where
corrections can be made only by the processing head position
adjustment mechanism 85, only the processing head position
adjustment mechanism 85 is used to make corrections (Step S17 in
FIG. 14). In each case, the process of operation goes on (Step S18
in FIG. 14), and the magnetic distance sensor 81 repeatedly makes
detections.
[0086] As described above, the magnetic distance sensor 81 is
provided ahead of the scanning direction of the processing head 7.
With the use of the data concerning the distance between the
processing head 7 and the inner surface of the nozzle stub 2,
adjustments are appropriately made to the push driving mechanism
unit 12 and the processing head position adjustment mechanism 85.
Therefore, it is possible to highly accurately keep the constant
distance between the processing head unit and the inner surface of
the nozzle stub 2. Such a driving control process makes it possible
to carry out the process of operation smoothly and continuously
even if there is a rugged or distorted area on the inner surface of
the nozzle stub 2. When it is difficult to carry out the process of
operation properly because of a significantly rugged or distorted
area on the inner surface of the nozzle stub 2, an interlock works
to suspend the process of operation before the process of operation
starts. Therefore, it is possible to prevent troubles or useless
operations from happening and improve efficiency.
[0087] In the present embodiment, the adjustment of the distance
between the processing head unit and the inner surface of the
nozzle stub 2 by the processing head position adjustment mechanism
85 or the like has been described on the assumption that the
difference in position of the rotation axis of the rotation arm 9
of the first embodiment is corrected. However, it is possible to
obtain the above-described advantageous effects associated with the
structure including the processing head position adjustment
mechanism 85 without correcting the positional difference.
[0088] Alternatively, the following operation process may also be
possible: a process of storing in the control device 15 an
adjustable distance range of the processing head position
adjustment mechanism 85 as a threshold value, carrying out an
operation without correcting the positional difference of the
rotation axis of the rotation arm 9, and then suspending the
operation when a result of measurement by the magnetic distance
sensor 81 exceeds the threshold value to correct the positional
difference of the rotation axis of the rotation arm 9. Such an
operation process makes it possible to skip the process of
correcting the positional difference of the rotation axis of the
rotation arm 9 if the distance between the processing head unit and
the inner surface of the nozzle stub 2 can be adjusted only by the
processing head position adjustment mechanism 85.
[0089] The processing head position adjustment mechanism 85 is not
limited to the structure described above as long as it is possible
to change the distance between the rotation center of the rotation
arm 9 and the processing head 7.
Third Embodiment
[0090] The following describes the third embodiment of the present
invention with reference to the drawings. The same components as
those in the second embodiment are denoted by the same reference
symbols, and repetitive explanation will be omitted.
[0091] The following describes the configuration of the processing
head 7 of the processing device 3 of the present embodiment with
reference to FIG. 15. FIG. 15 is an enlarged view of essential
portions in the vicinity of the processing head 7 when viewed in
the axial direction of the nozzle stub 2. In the present
embodiment, instead of the magnetic distance sensor 81 of the
second embodiment, a laser distance sensor (a first distance
sensor) 91 is attached to the processing head 7. The laser distance
sensor 91 emits a laser beam in the vertically downward direction
to measure the distance to the inner surface of the nozzle stub 2.
The measurement result is transmitted to the control device 15
through the distance sensor cable 83; in a similar way to that in
the second embodiment, corrections are made to the processing head
7 in accordance with the procedure shown in FIG. 14.
[0092] A laser scanner measures the distance by irradiating a wide
range with a laser beam. Since the laser scanner is employed for
the laser distance sensor 91, it is possible to collect distance
data as to a portion that is vertically below the laser distance
sensor 91 as well as to the vicinity thereof. With the use of the
distance data information collected by laser scanning, it is
possible to display three-dimensional graphics of the inner surface
of the nozzle stub 2 on the state display controller 17. An example
of how graphics are displayed on the state display controller 17 in
this case will be described with reference to FIG. 16.
[0093] FIG. 16 shows an example of how graphics are displayed on a
display 101 of the state display controller 17. The following are
laid out: a rotation arm angle display D1, which is positioned at
the top left corner of the display 101 and shows the angle of the
rotation arm 9 on the inner surface of the nozzle stub 2; a
processing device position display D2, which is positioned at the
top right corner of the display 101 and shows the position of the
processing device 3 in the nozzle stub 2; a pipe inner surface
display D3, which is positioned below the processing device
position display D2 and shows three-dimensional graphics of the
inner surface of the nozzle stub 2 that are drawn based on the
distance data obtained by laser scanning of the laser distance
sensor 91; and an process condition history display D4, which is
positioned at the bottom of the display 101 and shows the process
condition tolerance as well as a history record of actual process
conditions.
[0094] The rotation arm angle display D1 uses segment 102 to show
the angle of the rotation arm 9 on the inner surface of the nozzle
stub 2, enabling the state of the angle of the rotation arm 9 to be
easily checked. The shape of the inner surface of the nozzle stub 2
that is based on design information is displayed with a solid line;
the shape of the inner surface of the nozzle stub 2 that is based
on the measured distance data is displayed with a dotted line.
Therefore, it is easy to know the difference in shape between the
actual nozzle stub 2 and the design thereof.
[0095] The processing device position display D2 displays the
position of the processing device 3 in the nozzle stub 2, enabling
the position of the axial direction of the processing device 3 in
the nozzle stub 2 to be easily understood. Moreover, the position
of a welding line of the nozzle stub 2 is drawn at the same time.
Therefore, it is easy to know the position of the processing device
3 relative to the welding line.
[0096] As described above, the pipe inner surface display D3 shows
three-dimensional graphics of the inner surface of the nozzle stub
2 that are based on the distance data measured by laser scanning of
the laser distance sensor 91.
[0097] The process condition history display D4 shows the process
condition tolerance of the distance between the processing head 7
and the inner surface of the nozzle stub 2 as well as a history
record concerning the distance between the processing head 7 and
the inner surface of the nozzle stub 2 in the actual process of
operation. Dotted line 104 represents a process condition. Dotted
lines 105 and 106 represent the plus- and minus-side tolerances of
the process condition, respectively. Solid line 103 represents an
actual process record. The process history 103 that is within a
process condition tolerance range, or the range between the dotted
lines 105 and 106, means that the process of operation has been
conducted under an appropriate condition. Therefore, it is easy to
know that the process of operation by the processing device 3
continues within the condition tolerance range.
[0098] As described above, according to the present embodiment,
instead of the magnetic distance sensor 81 of the second
embodiment, the laser distance sensor 91 is used. Therefore, it is
possible to obtain similar advantageous effects to those in the
second embodiment. Moreover, a laser scanner is employed for the
laser distance sensor 91. Therefore, it is possible to collect the
distance data concerning a portion vertically below the laser
distance sensor 91 as well as the vicinity thereof. Based on the
collected distance data, three-dimensional graphics are displayed
to show the inner surface of the nozzle stub 2, making it possible
for an operator to easily recognize the state of the inner surface
of the nozzle stub 2.
[0099] The embodiments of the present invention have been described
above with reference to the drawings. It is also possible to form a
structure by arbitrarily combining the features of the embodiments
described above. It is possible for those skilled in the art to
make various modifications and changes in the concrete examples
without departing from the technical idea and scope of the present
invention. For example, in the embodiments, the device is described
as having three support legs. However, the device may have four or
more support legs. The support legs may not be arranged
equiangularly.
[0100] If the process of correcting the positional difference of
the rotation axis is not performed but only the process of
adjusting the distance between the processing head unit and the
inner surface of the nozzle stub 2 is performed by the device
including the processing head position adjustment mechanism 85 of
the second embodiment, the positioning and fixing of the processing
device 3 may not be performed by the support legs 4. In such a
case, for example, a special-purpose jig or the like is also
available. The jig may be attached to the periphery of the
processing device 3 and put in place around the inlet of the nozzle
stub as the processing device 3 is inserted into the nozzle stub,
thereby positioning and fixing the processing device 3.
[0101] While certain embodiments have been described, these
embodiments have been presented by way of example only, and are not
intended to limit the scope of the inventions. Indeed, the novel
embodiments described herein may be embodied in a variety of other
forms; furthermore, various omissions, substitutions and changes in
the form of the embodiments described herein may be made without
departing from the spirit of the inventions. The accompanying
claims and their equivalents are intended to cover such forms or
modifications as would fall within the scope and spirit of the
inventions.
* * * * *