Note: Descriptions are shown in the official language in which they were submitted.
CA 03187787 2022-12-16
DIGITAL ASSEMBLY AND MANUFACTURING METHOD FOR FLAME
EXHAUST PIPE OF SERVO MECHANISM
TECHNICAL FIELD
[01] The present disclosure is mainly applied to the technical field of
aerospace
assembly and manufacturing, and particularly relates to a digital assembly and
manufacturing method for a flame exhaust pipe of a servo mechanism.
BACKGROUND ART
[02] A flame exhaust pipe of a servo mechanism is an important component of
an
aircraft pipeline system. Its working environment is mainly influenced by high
temperature, high pressure, vibration and other comprehensive environmental
factors.
Connection strength reduction, sealing performance weakening, structural
characteristic
change, etc. of pipelines will directly influence normal operation of the
whole pipeline
system and the servo mechanism.
[03] At present, this kind of flame exhaust pipes are still assembled and
manufactured
in a manufacturing mode of serial production and field sampling. The method
has
common problems of a low degree of digitization and poor adaptability to
assembly
boundary conditions. The problems mainly includes the following aspects:
[04] 0 During pipeline manufacturing, parallel production cannot be achieved.
In an
existing mode, flame exhaust pipes must be sampled in a final assembly site of
a
workshop, and the sampling must be conducted after assembly and butt-joint of
an
engine and a tail section, which greatly increases waiting time for final
assembly of
products.
[05] 0 During pipeline assembly, boundary conditions are highly dependent on
actual
products. Every time, 2-3 people need to work together and transport welding
machines,
tools, instruments and other materials from a manufacturing workshop to the
final
assembly site, and complete repair, spot welding, trial assembly and other
processes on
the basis of the actual products on the site, resulting in conflict and waste
of a certain
amount of time, manpower and resources.
[06] 0 An artificial experience requirement is high and repair time is long.
The flame
exhaust pipes have no compensation functions, which greatly increases the
difficulty of
on-site repair. Minor repair of a coordination section may lead to a large
inclination
angle at an end of a pipeline. At present, filing is completely dependent on
artificial
experience, which is labor intensive, requires high experience and takes a
long time. It
takes at least 2 hours for an experienced technician to file a product.
SUMMARY
[07] In order to overcome the above defects in the prior art, the present
disclosure
provides a digital assembly and manufacturing method for a flame exhaust pipe
of a
servo mechanism. Digital measurement and assembly coordination technologies
are
used to simulate actual assembly spaces of boundaries of two ends of the flame
exhaust
pipe, a digital coordination model based on pipeline assembly is established,
selection
and assembly of a pipeline coordination section in a digital virtual space are
proposed,
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pipeline laser cutting is conducted with digital coordination parameters as
the basis of
manufacturing in a whole process, and finally digital manufacturing of the
flame
exhaust pipe is achieved, such that assembly and production efficiency is
greatly
improved, and assembly waiting time is shortened.
[08] The present disclosure solves the technical problems through the
technical
solution as follows: a digital assembly and manufacturing method for a flame
exhaust
pipe of a servo mechanism includes the following steps:
[09] step one, using a laser tracker to create a measurement coordinate
system
V1XYZ for a butt-joint face between a horizontally-placed engine and a tail
section, and
then measuring an outer circle of a servo mechanism pipe mouth, the outer
circle being
represented by a proxy model circle Q1 in a vector form;
[10] step two, using the laser tracker to create a measurement coordinate
system
V2XYZ for a butt-joint face between a vertically-placed tail section and an
engine, and
then measuring a tail section flame exhaust pipe mouth inner side face and
arc, the inner
side face and arc being represented by a proxy model circle Q2 in a vector
form;
[11] step three, converting measurement data of step one and step two to
three-dimensional models separately, conducting digital virtual assembly, and
aligning
the measurement coordinate system V1XYZ with the measurement coordinate system
V2XYZ, so as to obtain boundary conditions of two ends of the flame exhaust
pipe;
[12] step four, assembling a flame exhaust pipe joint and a transition pipe
on the
proxy model circle Q 1, so as to obtain a proxy model circle Q3 of a tail end
of the
transition pipe;
[13] step five, importing a pipe to be repaired into a digital assembly
coordination
model, assembling a long end of the pipe at a tail section flame exhaust pipe
mouth, and
ensuring that a central axis passes a center of the proxy model circle Q2, and
that a
central axis of a short end of the other side of the pipe passes a center of
the proxy
model circle Q3 of the tail end of the transition pipe;
[14] step six, adjusting the pipe to an appropriate position in the digital
assembly
coordination model, and ensuring that the short end overlaps the transition
pipe
moderately, the long end may extend out of a wall face of the tail section,
and a required
clearance value is reached;
[15] step seven, coordinating the pipe and the transition pipe in the
digital
assembly coordination model, so as to obtain a pipe after virtual cutting and
size
parameters of the pipe; and
[16] step eight, importing the size parameters of the pipe after virtual
cutting into a
three-dimensional laser machine, conducting laser cutting on an actual pipe,
and finally
welding the actual pipe after laser cutting to an actual pipe joint and an
actual transition
pipe, so as to complete digital assembly and manufacturing of the flame
exhaust pipe.
[17] Compared with the prior art, the present disclosure has the beneficial
effects:
[18] (1) The present disclosure uses a manufacturing mode of parallel
production and
may shorten manufacturing time of the flame exhaust pipe, and pipeline
assembly may
be conduced after final assembly and butt-joint, such that waiting time of
final assembly
is obviously shortened.
[19] (2) The present disclosure uses measurement devices, such as the laser
tracker, to
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measure a size of a product, which has high measuring accuracy, such that
product
feature information may be quickly and accurately reflected, and digital
manufacturing
accuracy of the product is improved.
[20] (3) The present disclosure omits a process of on-site repair, spot
welding and trial
assembly by an operator, thus avoiding conflict and waste of a certain time,
manpower
and resources.
[21] (4) According to the present disclosure, production is conducted with the
measurement data as the basis of a manufacturing process, such that long time
consumption and high labor intensity caused by over-reliance on artificial
experience
during production are prevented, and in addition, a digital manufacturing
degree of
products is improved, and production efficiency of products is increased.
[22] The present disclosure solves a problem that pipeline assembly in the
aerospace
field is highly dependent on on-site filing, and has characteristics of
accurate
measurement, data control, strong operability, high efficiency and economy,
etc. The
method has higher popularization and practical value compared with similar
methods,
may generate high economic value after extensive popularization and
application, and
has a good reference function in the field of sectional pipeline connection
and assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[23] The present disclosure will be explained in examples and with
reference to the
accompanying drawings. In the drawings:
[24] FIG. 1 is a schematic diagram of mounting positions of an engine and a
servo
mechanism of the present disclosure;
[25] FIG. 2 is a schematic diagram of positions of a tail section and a
flame exhaust
pipe mouth of the present disclosure;
[26] FIG. 3 is a schematic diagram of boundary conditions of two ends of a
flame
exhaust pipe of a three-dimensional model of the present disclosure;
[27] FIG. 4 is a schematic diagram of a digital assembly model of the
present
disclosure;
[28] FIG. 5 is a schematic diagram of a digital assembly model of the
present
disclosure after coordination;
[29] FIG. 6 is a schematic diagram of laser cutting and clamping of a pipe
of the
present disclosure; and
[30] FIG. 7 is a schematic diagram of actual assembly of a flame exhaust
pipe of a
servo mechanism of the present disclosure.
[31] In the drawings, the reference numerals include: engine 1, butt-joint
face
between engine and tail section 2, servo mechanism pipe mouth 3, tail section
4,
butt-joint face between tail section and engine 5, tail section flame exhaust
pipe mouth
inner side face 6, tail section flame exhaust pipe mouth inner side face arc
7, pipe joint 8,
transition pipe 9, pipe to be repaired before coordination 10, pipe after
coordination 11,
laser cutting positioning tool 12, pressing block 13, and flame exhaust pipe
of servo
mechanism 14.
DETAILED DESCRIPTION OF THE EMBODIMENTS
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[32] Specific implementations of the present disclosure are further
described in
detail below with reference to accompanying drawings.:
[33] Before an engine 1 and a tail section 4 are horizontally butted, sizes
of
connectors of two ends of a flame exhaust pipe of a servo mechanism to be
assembled
are measured separately: as shown in FIG. 1, when the engine 1 is placed
horizontally, a
coordinate system based on a butt-joint face 2 is created to describe a vector
position of
a servo mechanism pipe mouth 3. A method for creating a measurement coordinate
system V1XYZ includes the steps that at least 8 points on the butt-joint face
of the
engine 1 are measured to create the YOZ butt-joint face 2, a projection point
of a center
created by butt-joint holes of four quadrants on the butt-joint face 2 is used
as an origin
ol of the coordinate system, and a normal of the butt-joint face 2 is used as
an X1 axis
direction, where a part pointing to a tail (rear portion) is positive; and a
connecting line
of projections of the origin ol and hole points in quadrant III on the butt-
joint face 2 is
used as a Y1 axis direction, where a part pointing to the quadrant III is
positive, and a
Z1 axis is determined according to a right-hand rule. At least 6 points on a
circumference of an outer circle of the servo mechanism pipe mouth 3 are
measured to
create a proxy model circle Ql, where a center position is expressed as
(642.827,
251.997, 602.581), and a direction vector is (134.6554, 66.4247, 336.6763).
[34] As shown in FIG. 2, when the tail section 4 is placed vertically,
similarly, a
coordinate system based on a butt-joint face is created to describe a vector
position of a
flame exhaust pipe mouth of a servo mechanism. A method for creating a
measurement
coordinate system V2XYZ includes the steps that at least 8 points on the butt-
joint face
of the tail section 4 are measured to create the YOZ butt-joint face 5, a
projection point
of a center created by butt-joint holes of four quadrants on the butt-joint
face 5 is used
as an origin o2 of the coordinate system, and a normal of the butt-joint face
5 is used as
an X2 axis direction, where a part pointing to a tail (lower portion) is
positive; and a
connecting line of projections of the origin o2 and hole points in quadrant
III on the
butt-joint face 5 is used as a Y2 axis direction, where a part pointing to the
quadrant III
is positive, and a Z2 axis is determined according to a right-hand rule. At
least 6 points
on a circumference of a tail section flame exhaust pipe mouth inner side face
6 and arc 7
are measured to create a proxy model circle Q2, where a center position is
expressed as
(602.614, 553.297, 877.807), and a direction vector is (45.1464, 67.3537,
22.5425).
[35] As shown in FIG. 3, the above measurement data is converted to
three-dimensional models, digital virtual assembly is conducted, and the
measurement
coordinate system V1XYZ is aligned with the measurement coordinate system
V2XYZ,
so as to obtain boundary conditions of two ends of the flame exhaust pipe
(relative
positions of the servo mechanism pipe mouth 3 and the tail section flame
exhaust pipe
mouth inner side face arc 7). The products belonging to machining parts such
as a flame
exhaust pipe joint 8 and a transition pipe 9 are assembled on the proxy model
circle Ql.
The machining parts are all rotary bodies. Actually, offset of a thickness of
a
corresponding part is made in a normal direction of the proxy model circle. A
proxy
model circle Q3 of a tail end of the transition pipe 9 is obtained. A
remaining space is a
connecting part from the transition pipe 9 to the tail section flame exhaust
pipe mouth
arc 7, which is achieved by the flame exhaust pipe.
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[36] As shown in FIG. 4, a pipe to be repaired 10 is imported into a
digital
assembly coordination model, a long end of the pipe 10 is assembled at a tail
section
flame exhaust pipe mouth, and it is ensured that a central axis passes a
center of the
proxy model circle Q2, and that a central axis of a short end of the other
side of the pipe
passes a center of the proxy model circle Q3 of the tail end of the transition
pipe 9;
and the pipe 10 is coordinated and assembled to an appropriate position, and
it is
ensured that a length of an overlapping area of the short end and the
transition pipe 9 is
controlled to be 10 mm or below, the long end may extend out of a wall face of
the tail
section, and a required clearance value with the wall face is 5 mm or above.
The pipe to
be repaired 10 is manufactured by prototype tools and has high consistency.
[37] In the digital assembly coordination model, the pipe to be repaired 10
is
coordinated, specifically, the pipe 10 is activated in an assembly environment
for editing.
With reference to the proxy model circle Q3 of the tail end of the transition
pipe 9,
stretching and cutting are conducted in a direction from a normal of the
circle to outside
of the pipe, so as to obtain a pipe after coordination 11 and size parameters
of the pipe,
as shown in FIG. 5.
[38] As shown in FIG. 6, the actual pipe 10 is clamped on a positioning
tool 12 of a
laser cutting platform by a pressing block 13, and a positioning and clamping
reference
is an end face of the long end of the pipe 10. A reference of the size
parameters of the
pipe after coordination 11 obtained in the digital assembly model is
consistent with
description of the positioning tool on the laser cutting platform, the end
face of the long
end of the pipe 11 is used as the reference, and the size parameters of the
pipe 11 are
imported into a three-dimensional laser machine for laser cutting. The actual
pipe after
virtual cutting 11 is welded to an actual flame exhaust pipe joint 8 and an
actual
transition pipe 9, so as to complete digital assembly and manufacturing of the
flame
exhaust pipe of the servo mechanism.
[39] The flame exhaust pipe 14 of the servo mechanism is delivered for
final
assembly and mounted on the servo mechanism pipe mouth 3, as shown in FIG. 7.
A
required clearance value of the pipe extending out of the wall face of the
tail section is
measured. If a circumferential clearance is 5 mm or above, a product is
considered as
qualified, and if not, the product is considered as unqualified. The pipe to
be repaired 10
is re-imported into the digital assembly coordination model, and the previous
steps are
repeated for re-manufacturing.
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