1
The present invention relates to one first part comprising of one first part
which extends along an axis X, the first part being laterally bordered by a
lateral surface and presenting a proximal portion, which is extended by an
intermediate portion which is extended by a distal tip, the extremity of which
is one first surface, this first surface is meant to be welded/soldered by friction
on one second surface of a second portion of a second part.
The welding/soldering by friction is a procedure of welding which consists
of assembling two parts by putting these two parts in movement in relation to
one another and by supporting them against each other in such a way that one
surface of the first part rubs on the surface of the second part. The rubbing of
these surfaces against each other thus generates sufficient heat to heat the
area of each part which is adjacent to the surfaces in contact which brings
them to a malleable state.
These areas are thus are capable to get deformed and solder
together. After stopping the movement of one part relative to another, and
the cooling of the two parts, these are thus soldered together.
During this welding, the regions adjacent to the contacting surfaces,
which are in the malleable state, are deformed by discharging of the material
at the extremities of the contact zone. This expelled material forms beads.
This is illustrated in Figures 4A and 4B, which represent the prior art.
A first part 1100 comprises of one first part 1120 which is an excrescence
of the first part 1100 and extending along an axis X. This first portion 1120 is
bordered laterally by one lateral surface 1130 and presenting one a proximal
portion 1122, which extends through intermediate portion 1124 that extends
2
Plough a distal portion 1126. The extremity of this distal portion 1126 is one
first surface 11136.
A second part 1200 includes one second part 1220 which is an
excrescence of the second part 1200 and which extends along an axis Y. This
second portion 1220 is bordered laterally by one lateral surface 1230 and
presents one proximal portion 1222, which extends through intermediate
portion 1224 that extends through a distal portion 1226. The extremity of this
distal portion 1226 is one second surface 1236 .
In the welding procedure according to the prior art, one places in the first
part 1100 in motion in relation to the second part 1200, and one approaches
the first surface 1136 until they are in contact.
In the case illustrated in Figures 4A and 4B, the first portion 1100 is a tube
axis of symmetry of which is the X axis, and the second portion 1120 is a tube
of which the axis of symmetry is the Y axis, these two tubes are identical with
the possible exception of their lengths according to the axis X and axis Y.
Considering the symmetry with respect to axes X and Y, only one half of
parts is shown in longitudinal section.
The lateral surface 1130 of the first portion 1120 is thus comprised of a
interior surface 1131 (which is a cylindrical surface of diameter equal to the
interior diameter Di) and an external surface 1132 (which is a cylindrical
surface of diameter equal to the diameter from the exterior De).
The lateral surface 1130 of the first part 1220 is thus comprised of an
interior surface 1231 (which is a cylindrical surface of diameter equal to the
interior diameter Di) and an external surface 1232 (which is a cylindrical
surface of diameter equal to the exterior diameter De ).
The first lateral surface 1136 and the second part 1236 are thus each an
annular band with the inner diameter Di and the same exterior diameter De
3
IP The first member 1100 is put into rotation around the X axis by means of
a drive system (not shown). Once an angular speed of rotation is attained, the
first part 1100 is separated from the drive system (the first piece 1100 is thus
in free rotation), then the first surface 1136 is put in contact and pressed
against the second surface 1236 with a determined force, in such a way that
these two surfaces overlap. The X axis and Y axis are merged. Likewise, the
inner surface 1131 of the first part 1120 on the inner surface 1231 of the
second part 1220 are aligned and form part of the same inner surface of a
circular tube with a diameter Di. Similarly, the outer surface 1132 of first part
1120 and the outer surface 1232 of the second part are aligned and 1220 are
part of the same surface of a circular tube diameter De
The heat generated by the rubbing of the first surface 1136 and of the
second surface 1236 makes the distal portion 1126 of the first member 1100
and the distal portion 1226 of the second member 1200 malleable which
welds/solders by discharging the material at the extremities of their contact
surface. This expelled material forms an interior bead 1310 on inner surface
1131 of first part 1120 and inner surface 1231 of the second part 1220, and an
external 1320 on the outer surface 1132 of first part 1120 and the inner
surface 1232 of the second part 1220.
4A shows the two parts (1100,1200) just prior to contact.
4B shows the two parts (1100,1200) after welding.
It is noted in Figure 4B at the end of the welding process the flanges
(1310, 1320) exceeds and are raised relative to the lateral surface 1130 of the
first part 1100 and at the lateral surface 1230 of the second part 1200.
Ifi practice, these (1310, 1320) should be further smoothened by
machining.
4
W One observes, for a lot of parts f described here-above and theoretically
identical, which are welded by friction according to the method described
above, a significant dispersion in the volume of the beads (the dispersion is
defined as the difference between the maximum value and the minimum
value). This dispersion is due to the geometric tolerances of parts, tolerances in
the properties of the materials constituting the parts, tolerances in the
operating conditions of the welding process in general.
As a result, it is impossible to accurately predict the volume of the beads
and it is therefore necessary to provide for each part a larger distal portion
(1126, 1226), since the beads (1310, 1320) are formed by the deformation of
the distal portions.
It results in an utilisation of a material in the development of parts
(amount of material consumed during welding, called "material consumption")
more than necessary, which is expensive and undesirable. In addition, the
superfluous material (thickness superfluous of certain parts) must later be
removed, resulting in additional costs.
The present invention seeks to overcome these drawbacks.
The invention aims at providing one first part, meant to be welded by
friction with a second part, which is such that the dispersion in the volume of
formed is minimized.
This object is achieved by the fact that the distal portion is brought in the
malleable state during the welding by friction, in that the intermediate part
flares from the distal part towards and till the proximal part so that the
material resulting from the deformation of said distal portion during the said
welding rubs against the lateral surface of the intermediate portion.
With these provisions, the excess metal, during it's formation at the
time of welding, rubs against the lateral surface of the intermediate portion of
5
I p e first part, which was not the case for the first part of the prior art. This
friction causes a significant slowing down of the rotation of the first part
(compared to the prior art). This slowdown results in a decrease in the
dispersion of the material consumption. In addition, the amount of material
consumed, which forms the bead is generally much less..
Advantageously, the proximal portion of the first part presents a crosssection
more or less constant, so that this intermediate portion of the first part
forms a depression with respect to the proximal portion of the first part.
Thus, the majority of the excess metal or its totality, comes, during it's
formation, housed in the depression (or cavity) formed by the intermediate
portion. The excess metal thus does not exceed, or practically not above the
lateral surface of the proximal portion of the first part. As a result, the
machining necessary to remove material that exceeds the lateral surface is
minimized.
The invention also relates to an assembly comprising on the one hand
consisting of a first part with a first portion which is a tube which extends along
an axis X, the first part being bordered laterally by a lateral surface and having
a proximal portion , which is extended by an intermediate portion which is
extended by a distal portion the extremity of which is one first surface, and on
the other hand, of one second part with one second part comprising of one
second surface, the first surface and the second surface being adapted to be
welded by friction.
According to the invention, the distal portion carried in a malleable state
during the welding by friction, and the intermediate portion flares from the
distal portion to the proximal part so that the excess metal material resulting
from the deformation of the distal portion during welding rubs against the
lateral surface of the intermediate portion during welding, the first surface
6
^Pbing an annular band, and a second portion extending along an axis Y, this
second part being bordered laterally s by one lateral surface and presents a
proximal portion, which extends by an intermediate portion which is extended
by a distal portion the extremity of which is the second surface, which is an
annular band, the distal portion of the second part is brought to a malleable
state during the welding by friction, in that the intermediate portion of the
second portion flares from said distal portion towards and till the s proximal
part of the second part such that the bead of material resulting from
deformation of the distal portion of the second part during the welding rubs
against the lateral surface of the intermediate portion of the second part
during the welding.
The invention also relates to a procedure of frictibn welding between
one first part and the second part.
According to the invention, the method comprises the following steps :
(a) One provides the first part comprising one first portion which is a tube
which extends along an axis X, this first part being bordered laterally by a
lateral surface and presenting a proximal portion, which is extended by an
intermediate portion which is extended by a the distal portion the
extremity of which is one first surface, the intermediate portion flaring
from the distal portion towards and till the proximal portion, the first
surface being an annular band,
(b) One provides one second part comprising one second part which
prevents one second surface, the second part is extending along an Y
axis, this said second part being laterally bordered by a lateral surface
and presenting a proximal portion, which is extended by an intermediate
portion which is extended by a distal portion the extremity of which is
the second surface, which is an annular band, the intermediate portion of
7
4P the second portion flares from said distal portion of the second part
towards and till the proximal part of the second part.
(c) One puts the first part and the second part in relative movement one in
relation to the other,
(d) One applies the first part against the second part with one given force F
in such a way that the first surface rubs against the second surface till it
stops, the force F being sufficient for carrying the distal portion of the first
part and the distal portion of the second part in a malleable state during
this welding by friction, the beads of resulting material from the
deformation of the distal portion of the first part during the welding
rubbing against the said lateral surface of the intermediate portion during
the welding/soldering, and the beads of resulting material by the
deformation of the portion of the distal portion of the second part during
the soldering/welding rubbing against the lateral surface of the
intermediate portion of the second part during the soldering/welding.
The invention will be better understood and its advantages will become
more apparent from reading the following detailed description which follows
given by way of non-limiting example. The description refers to the annexed
drawings in which:
- The figure 1A shows an assembly of two parts according to the
invention which are welded by friction, before welding,
- IB is an assembly of two parts according to the invention which
are welded by friction at the end of welding,
- 2A shows one part according to the invention,
- 2B shows another mode of realisation of a part according to the
invention,
8
I P - Figure 2C shows yet another mode of realisation according to the
invention,
- Figure 2D shows another mode of realisation of a part according to
the invention,
i
- 3A shows a part of the invention which is friction welded to a ring,
before welding,
- 3B represents one part according to the invention which is welded
by friction on a ring after it's welding,
- 4A shows two parts according to the prior art which are/ friction
welded, before welding,
- 4B shows the two parts according to prior art which are friction
welded at the end of welding.
1A and IB is a longitudinal section view of a set of two pieces of the
invention.
In the description below, the first portion 120 is an excrescence of the
first part 100. The invention also applies to cases where the first part 120 is any
part of the first part 100.
One first part 100 includes a first part 120 which is an excrescence of the
first part 100 and which extends along an axis X. This first part 120 is laterally
bordered by a lateral surface 130 and has a proximal portion 122 (located
closest to the junction between the first portion 120 and the rest of the first
part 100), which is extended by an intermediate portion 124 which is
extended by a distal portion 126. The extremity of the distal portion 126 is one
first surface 136.
According to the invention, the intermediate portion 124 flares from the
distal portion 126 towards and till the proximal portion 122.
9
Jpl Thus, the area of the cross section (in a plan perpendicular to the axis X)
of the proximal portion 122 adjacent the intermediate portion 124 is greater
than the area of the cross section of the distal portion 126.
One second part 200 comprises of a second portion 220 which is an
excrescence of the second part 200 and which extends along an axis Y. This
second portion 220 is bordered laterally by one lateral surface 230 and
presents a proximal portion 222, which extends by one intermediate portion
224 which is extended by a distal portion 226. The extremity of this distal
portion 226 is one second surface 236.
According to the invention, the intermediate portion 224 flares from the
distal portion 226 towards and till the proximal portion 222
Thus, the area of the cross section (in a perpendicular plan to the axis Y)
of the proximal portion 222 adjacent the intermediate portion 224 is greater
than the area of the cross section of the distal portion 226.
In the case illustrated in Figures 1A and IB, the first part 100 is a tube the
axis of symmetry of which is the is the X axis, and the second part 120 is a
tube the axis of symmetry of which is the Y axis, these two tubes are identical
with the possible exception of their length along the axis X and axis Y.
Taking into consideration the symmetry with respect to axes X and Y, only
one half of parts is shown in longitudinal section.
The side surface 130 of the first part 120 comprises a inner surface 131
(which is a cylindrical surface of diameter equal to the inner diameter Di) and
an outer surface 132 (which is a cylindrical surface of diameter equal to the
outer diameter of the distal portion 126, and a toric surface on the concave
intermediate portion 124 and a cylindrical surface of diameter Df strictly
greater than the external diameter De of the proximal portion 122).
10
4p The geometry of the first portion 120 is also shown in Figure 2A, which
represents a first part 100 of the invention.
In the case illustrated in Figures 1A and IB, the second portion 220 of the
second part 200 has the same geometry as that of the first portion 120.
The lateral surface 230 of the first part 220 comprises a inner surface 231
(which is one cylindrical surface of diameter equal to the inner diameter Di)
and an outer surface 232 (which is a cylindrical surface of diameter equal to
the outer diameter of the distal portion 226, and a toric surface on the concave
intermediate portion 224 and a cylindrical surface of diameter Df strictly
greater than the external diameter De of the proximal portion 222).
The first surface 136 and second surface 236 are each an annular band
with the inner diameter Di and the same outside diameter De
In the welding method according to the invention, the first part 100 is
rotated around the X axis by means of a drive system (not shown). Once an
angular speed of rotation is attained, the first part 100 is separated from the
drive system (the first part 100 is free to rotate) and the first surface 136 is
brought into contact and pressed against the second surface 236 with a
predetermined force (force F), such that these two surfaces overlap. The X axis
and Y axis are then merged. Thus, the inside surface 131 of first portion 120
and the inner surface 231 of the second portion 220 are aligned and are part of
the same surface of a circular cylinder with a diameter Di.
The heat generated by the friction of these two surfaces makes the distal
portion 126 of the first part 100 and the distal portion 226 of the second part
200 malleable which are welded by discharging the material at the extremities
of their contact surface. A material is said be in the state " malleable "When
heated to a temperature high enough to irreversibly deform upon application
of a stress.
11
£ This expelled material forms an inner bead 310 on the inside surface 131
of first portion 120 and the inner surface 231 of second portion 220, and forms
an external bead 320 on the outer surface 132 of the first portion 120 and on
the surface 232 of the second interior portion 220.
1A shows the two parts (100, 200) just prior to contact.
IB shows the two parts (100, 200) after welding.
According to the invention, the intermediate portion 124 of the first
portion 120 and the intermediate portion 224 of the second portion 220 form
a toric depression in which the the exterior beads comes to lodge during it's
formation .
Accordingly, the external protrusion 320 rubs against the surface of the
intermediate portion 124 of the first portion 120 and intermediate portion 224
of the second portion 220 during welding, and besides half of the exterior
beads 320 of the beads arriving from the deformation of the distal portion
126 of the first part 100 rub against the half of the exterior beads 320 coming
from the deformation of the distal portion 226 of the second part 200.. These
friction result in slower movement of the first part 100 relative to the second
part 100 compared with the second part 200 faster than in the case where the
intermediate portions (124, 224) are in the straight extension of the distal
portions (126, 226) and part 200 proximal portions (122, 222) (prior art,
Figures 4A and 4B).
The amount of material required to obtain a welding of the two parts,
that is to say the volume of the distal portions (126, 226) is thus minimized.
The tests performed by the inventor on parts as illustrated in Figures 2A
and 2C show that this slowdown saves the dispersion of the material in the
order of 80% consumption (see Table 1 below).
12
^ In particular, this slowdown is more pronounced at the end of welding
(just before stopping the movement of the first part 100) as the surface of the
bead that rubs against the surfaces of the intermediate portions (124, 224) is
much more that at the beginning of welding than start welding.
This dispersion has a standard deviation of 0.1 compared to a standard
deviation of 0.4 to 0.8 according to the prior art in which the intermediate
portions are in the linear extension of the distal portions (see Table 1 below).
Table 1
Type of room Dispersion Standard
deviation
Prior art (FIG. 4A), diameter ~ 50 2.17 0.82
mm
Prior art (FIG. 4A), = 180 mm
1.37 0.39
diameter
(Average (Average
Prior art (FIG. 4A), = 380 mm
value) value)
diameter
Invention (FIG. 2A), diameter = 50
0.27 0.1
mm
i (Average (Average
Invention (FIG. 2C), diameter = 50
value) value)
mm
In addition, the machining of the outer flange 320 so that its surface is in
the linear extension of the proximal surfaces (122, 222) is minimized. This
results in an increase in cost and manufacturing time.
After the welding process exceeds the inner bead 310, which is raised
relative to the inner surface 131 of the first part 100 and the inner surface 231
13
^ the second part 200 (FIG. IB).Indeed, the interior surfaces do not show
intermediate portion in which the inner bead 310 can be accommodated.
Advantageously, the inner surface 131 of the first portion 120 and the
inner surface 231 of the second portion 220 are similar to that of the outer
surfaces (132, 232) geometry, as shown in FIG 2B to the first portion 120. Thus,
the inner surface 131 is a cylindrical surface of diameter equal to the inner
diameter Di of the distal portion 126, and a toric surface on the concave
intermediate portion 124 and a cylindrical surface of diameter Dh strictly
smaller than the inside diameter Di of the portion 122 proximally. The interior
surface 231 of the second portion 220 has a shape identical to that of the
inside surface 131 of first portion 120 geometry.
Thus, the intermediate portion 124 of the first part and the intermediate
portion 224 of the second part 200 forms a depression in which is housed the
inner bead 310 during its formation.
As a result, the inner bead 310 also rubs against the surface of the
intermediate portion 124 of the first portion 120 and the intermediate portion
224 of the second portion 220 during welding. This has the advantage that the
slow movement of the first member 100 relative to the second member 200 is
even faster, and that the interior bead 310 little or no relief with respect to
the inner surface of the first portion via 124 and the second intermediate
portion 224.
The invention relates to an assembly consisting of one first part 100 and
second part 200 as described above.
In the mode of realisation described above, the intermediate portion 124
of the first portion 120 (and optionally the intermediate portion 224 of the
second portion 220) has a toric surface, that is to say semi-circular, concave
and . 2A illustrates, for the first portion 120, where only the outer surface 132
14
4Qf the intermediate portion 124 is a toric concave surface. The inner surface
131 is cylindrical with a diameter Di. 2B illustrates, for the first portion 120,
where the outer surface 132 and inner surface 131 of the intermediate portion
124 are each a concave toric surface.
Alternatively, the intermediate portion 124 of the first portion 120 (and
optionally the intermediate portion 224 of the second portion 220) is a conical
surface, the generators of which are for example an angle of 45 ° with the axis
X. 2C illustrates, for the first portion 120, where only the outer surface 132 of
the intermediate portion 124 is flared surface. The inner surface 131 is
cylindrical with a diameter Di. Figure 2D shows, for the first part 120, if the
outer surface 132 and the inner surface 131 of the intermediate portion 124 is
a conical surface.
More generally, the intermediate portion 124 has a parabolic, or any
profile (concave, convex, plane, or a combination thereof), and generally flares
from the distal portion 126 towards and till the proximal portion 122. This also
applies if required for the intermediate portion 224 of the second portion 220.
The geometry of the intermediate portion 124 of the first portion 120 and
the geometry of the intermediate portion 224 of the second portion 220 may
be identical.
Alternatively, these may be different geometries, in order to optimize the
friction pad (310, 320) and 131 132 on the outer surfaces of the inner
intermediate portion 124 and 231 232 on the inner and outer surfaces of the
intermediate portion 224.
This can be especially true if the material of the first part 100 is different
from the material of the second part 200.
In the mode of realisation above, the inner surfaces (131, 231) and outer
surfaces (132, 232) of the proximal portions (122, 222) are tubes of circular
15
Infection. The proximal portion 122 of the first portion 120 and proximal portion
| 222 of the second portion 220 thus each have a cross section (perpendicular to
the axes X and Y) substantially constant. More generally, the proximal portions
can be of varying thickness, and / or may not be the tubes.
In general, the proximal portion 122 of the first portion 120 has a
substantially constant cross-section, so that the intermediate portion 124 of
the first portion 120 forms a depression in relation to the proximal portion 122
of the first part 120.
Similarly, the proximal portion 222 of second portion 220 has a
substantially constant cross-section, such that the intermediate portion 224 of
the second portion 220 forms a depression with respect to the proximal
portion 222 of the second portion 220.
This or these depressions thus form a groove or cavity.
In general, the invention also relates to an assembly comprising a first
component 100 as described above, and a second part 200 as described above,
but with dimensions (one or more diameter Df, L, D, Dh) are different from the
dimensions of the first part 100.
The invention also relates to a first part 100 as described above, and an
assembly consisting of a first part 100 as described above and a second piece
200 having no intermediate portion of the invention.
Thus for example, according to another mode of realisation of the
invention, the first component 100 is a part that extends along an X axis, and
the second part 200 has a second surface 236 that is perpendicular to the X
axis and extends beyond the first surface 136 when the X axis is placed at the
geometric center of the second surface 236.
For example, according to another embodiment of the invention, the first
component 100 is a part that extends along an X axis, and the second part 200
16
^ ) circular or annular and extends along an axis Z perpendicular X-axis, the Z
axis being the axis of symmetry.
For example, the first part 100 is a blade, and the second part 200 is a ring
or disk, as shown in Figures 3A and 3B.
The foot of the blade 100 is the first part 120. The first surface 136 is the
extremity 126 of the distal portion of the foot of the blade surface. The first
surface 136 of the blade 100 may have any shape.
Positioning the blade such that the first surface 136 is opposite the outer
surface (second surface) of the ring 236. Thus, the X axis (which extends from
the head to the foot of the blade) is a radial axis of the ring, and is therefore
perpendicular to the outer surface 236.
The ring 200 is brought into rotation around it's own axis of symmetry
axis Z with a drive mechanism (not shown), and then once a given rotational
speed attained, approaching the blade 100 in such so that the first surface 136
rubs against the second surface 236 of the ring 200. Figure 3A shows the dawn
100 and ring 200 before contact.
Rubbing the first surface 136 against the outer surface 236 renders the
distal portion 126 malleable. Then the distal portion 126 forms a bead 130
which rubs against the intermediate portion 124 of which both lateral surfaces
are concave and toric, as illustrated in Figure 3A. Once the two parts are
welded, it stops rotation of the ring.
3B illustrates the dawn 100 and ring 200 after friction welding. The use of
a blade 100 of the invention minimizes machining operations in the zone
ofjunction between the blade and the ring 100 200 130 for the bead comes to
lodge itself in the cavity formed by the lateral surfaces of the intermediate
portion 124.
17
JP Advantageously one places on the circumference of a ring 200 a plurality
of blades 100 each having a 100 presenting each a foot according to the
invention, and welded by friction as described below.
The invention also applies to cases where the first portion 120 and second
portion 220 are each a solid cylinder and not a tube.
The invention also relates to a method comprising the following steps :
(A) One provides one first part 100 comprising of one first portion 120
which extends along an axis X, the first portion 120 being laterally
bordered by a lateral surface 130 and having a proximal portion 122,
which extends through intermediate portion 124 which extends by a
distal portion 126 by the extremity of which is one first surface 136, the
intermediate portion 124 flaring from the distal portion 126 towards and
til the proximal portion 122,
(B) One provides one second part 200 comprising of one second portion
220 which prevents a second surface 236,
(C) One puts the first part 100 and the second part 200 in relative motion
in relation to each other,
(D) We apply the first part 100 against the second part 200 F with a given
force so that the first surface 136 rubs against the second surface 236 till
it stops , the force F is sufficient to bring the distal portion 126 and the
second Surface 236 in the malleable state during the friction welding, the
bead material 300 (which may comprise of two beads 310, 320) resulting
from the deformation of the distal portion 126 during welding rubbing
against the lateral surface of the intermediate portion 124 during welding.
The second part 220 may have, in the above process, any form. 3A and 3B
illustrate an example of the use of such a method with a second part which is
the lateral outer layer of a ring or disc.
18
^ Advantageously, according to the invention, in step (b), the second
portion 220 extends along an axis Y, the second portion 220 is laterally
bordered by a lateral surface 230 and presenting a proximal portion 222, which
is extended by an intermediate portion 224 that extends through a portion 226
whose distal end 236 is the second surface, and in that, in step (d), the distal
portion 226 of the second portion 220 is brought to the malleable state during
the friction welding, in that the intermediate portion 224 of the second portion
220 flares from the distal portion 226 of the second portion 220 to the
proximal portion 222 of the second portion 220 so that the bead material 300
(which may comprise of two beads 310, 320) resulting from the deformation of
the distal portion 226 of the second portion 220 during welding by friction
rubbing against the lateral surface of the intermediate portion 224 of the
second portion 220 during welding .
1A and IB illustrate an example of using such a method.
The thickness of the intermediate portion 124 and proximal portion 122
of the first portion 120 of the first part 100 (2A to 2D) is obtained for example
by adding material on intermediate and proximal portions of the first part of
1120 a 1100 part in the prior art. If necessary, the procedure is similar to the
second portion 220 of the second part 200.
The realization of the first part 100 (and possibly the second part 200) is
thus simplified.

19
• CLAIMS
1. Assembly consisting on one hand of one first part (100) with a first
portion (120) which is a tube which extends along an X axis, said first
portion (120) being bordered laterally by a lateral surface (130) and
having a proximal portion (122) that extends through an intermediate
portion (124) which is extended by a distal portion (126) including a first
extreme surface (136), and secondly a second part (200) with a second
portion (220) comprising a second surface (236), said first surface (136)
and said second surface (236) being adapted to be friction welded, this
assembly being characterized in that said distal portion (126) is intended
to be carried in a malleable state during said friction welding, in that
said intermediate portion (124) flares from said distal portion (126) and
up to the proximal portion (122) so that the bead of material (320)
resulting from the deformation of said distal portion (126) during said
welding rubs against the lateral surface of said intermediate portion
(124) during said welding, said first surface (136) being an annular band ,
The said second portion (220) extends along an axis Y this said second
portion (220) being bordered laterally by a lateral surface (230) and
having a proximal portion (222) that extends through an intermediate
portion (224) which is extended by a distal portion (226) including said
second extremity surface (236), which is an annular band, said distal
portion (226) of the second portion (220) is brought to the malleable
state during said friction welding, in that said intermediate portion
(224) of the second portion (220) flares from said distal portion (226) of
the second portion (220) toward and till the said proximal portion (222 )
of the second portion (220) such that the bead of material (320)
20
W resulting from the deformation of said distal portion (226) of the second
portion (220) during said welding rubs against the side surface of said
intermediate portion ( 224) of the second portion (220) during said
welding.
2. An assembly according to claim 1 characterized in that the proximal
portion (122) of the first portion (120) has a substantially constant crosssection,
such that said intermediate portion (124) of the first portion
(120) forms a depression relative to said proximal portion (122) of the
first portion (120).
3. The assembly of claim 1 or 2 characterized in that the proximal portion
(222) of the second portion (220) has a substantially constant crosssection,
such that said intermediate portion (224) of the second portion
(220) forms a depression with respect to said proximal portion (222) of
the second portion (220).
4. An assembly according to any one of claims 1 to 3, characterized in that
said second portion (220) is a tube.
5. Friction welding method between a first part (100) and a second part
(200) characterized in that it comprises the steps of :
(A) There is provided a first part (100) comprising a first portion (120)
which is a tube which extends along an X axis, said first portion (120)
being bordered laterally by a lateral surface (130) and having a proximal
portion ( 122), that extends through an intermediate portion (124) which
is extended by a distal portion (126) including a f i r s t ; lateral surface (136),
said intermediate portion (124) flaring from said distal portion (126 )
towards and till the said proximal portion (122), said first surface (136)
being an annular band,
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f^fe) One provides a second part (200) comprising of a second portion
(220) having a second surface (236), said second portion (220) extends
along an Yaxis ant, said second portion (220) being bordered laterally by
a lateral surface (230) and having a proximal portion (222) that extends
through an intermediate portion (224) which is extended by a distal
portion (226) including said second extremity surface (236) which is an
annular band , said intermediate portion (224) of the second portion (220)
flaring from said distal portion (226) of the second portion (220) towards
and till the said proximal portion (222) of the second portion (220),
(C) One puts the said first piece (100) and said second piece (200) in
relative movement with respect to each other,
(D) One applies said first part (100) against said second part (200) with a
given strength F so that said first surface (136) rubbing against the said
second surface (236) until it stops, the said force F being sufficient to
bring the said distal portion (126) of the first portion (120) and said distal
portion (226) of the second portion (220) in the malleable state during the
friction welding, the bead of material (320) resulting from the
deformation of said distal portion (126) of the first portion (120) during
said welding rubbing against said side surface of the intermediate portion
(124) during said welding, and the bead of material (320) resulting from
the deformation of said portion distal (226) of the second portion (220)
during the said friction welding rubbing against said lateral surface of the
intermediate portion (224) of the second portion (220) during said
welding.
6. Friction welding method as claimed in Claim 5, characterized in that the
one or more intermediate portions (124, 224) and proximal (122, 222)
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w are formed by addition of material on the first portion (120) and the
second portion (220).
7. Friction welding method as claimed in claim 5 or 6, characterized in that
said second portion (220) is a tube.