[0001] Heat exchangers are used in vehicles to cool engine coolant, to cool charge air and
to heat and/or cool refrigerant in a vehicle air conditioning system. Such heat exchangers
typically comprise upper and lower header tanks or manifolds having a plurality of
fluid passages extending therebetween, air gaps, typically provided with strengthening
ribs, are provided between the refrigerant passages to allow heat transfer between
a flow of air passing through the air gaps and a flow of a fluid passing through the
fluid passages.
[0002] Connection means are typically provided at ends of one or both of the header tanks
for connecting to delivery and discharge conduits supplying fluid to be cooled/heated
to and from the heat exchanger.
[0003] Typically such connection means are formed by brazing a pipe connection onto a connection
block joined to an end region of a header tank. Such pipe connections are difficult
to form in situe in the vehicle, particularly in the case of a heat exchanger (typically
an evaporator) provided within a HVAC module of a vehicle air conditioning system,
leading to packaging constraints due to the need for extended header tank end regions
and fixed pipe routing. Such pipe connections can also lead to leakage problems, particularly
where carbon dioxide is used as a refrigerant. When carbon dioxide is used as refrigerant,
very high pressures in the range of up to more than 80 bar exist within the refrigerant
circuit of the air conditioning system. The pressure loading on individual components
of an air conditioning system therefore rises significantly.
[0004] What is needed is a more compact and reliable pipe connecting structure that provides
more versatile pipe routing while better withstanding high refrigerant pressures while
at the same time simplifying header construction.
[0005] According to the present invention there is provided a pipe connecting structure
for a heat exchanger comprising:-
a header portion or manifold defined by a plurality of parallel elongate header tubes;
a connector block having a side face adapted to abut against a side region of an outer
one of said header tubes and connection means configured to connect a pipe thereto;
and joining means comprising at least one elongate tubular member having a first end
adapted to be inserted through a hole formed in a first side wall of at least said
outer one of said header tubes, and a second end extending through a corresponding
hole in said side face of the connector block, whereby said second end communicates
with said connection means.
[0006] Preferably said at least one tubular member extends substantially perpendicular to
said plurality of header tubes.
[0007] In one embodiment said first end of said at least one elongate tubular member is
adapted to extend through a corresponding hole in a second side wall of said outer
one of said header tubes diametrically opposite said first side wall and through an
aperture in a side wall of the one of said plurality of header tubes furthest from
said outer one of said header tubes, whereby said first end communicates with an interior
of said furthest one of said header tubes, whereby the at least one tubular member
of the joining means extends between, and perpendicular to, said plurality of elongate
header tubes to connect the plurality of elongate pipes to one another and to the
connector block.
[0008] Preferably said at least one tubular member of the joining means includes a radially
extending flange located between said first and second ends and adapted to be positioned
between sides faces of said furthest one of said header tubes and an adjacent header
tube.
[0009] In one embodiment said header portion comprises two parallel elongate header tubes,
a first tube corresponding to said outer one of said header tubes and a second tube
corresponding to said furthest one of said header tubes, said radially extending flange
being positioned between said first and second tubes.
[0010] Preferably the joining means comprises a plurality of parallel tubular members arranged
in a plane containing the longitudinal axis of each of the plurality of header tubes
of the header portion.
[0011] The connection means of the connector block may be adapted to receive said pipe with
said pipe arranged parallel to said plurality of header tubes. Alternatively, the
connection means of the connector block may be adapted to receive said pipe with the
pipe arranged perpendicular to said plurality of header tubes.
[0012] In one embodiment the connection means of the connector block comprises a flange
or stub to be received within an end of the pipe. In an alternative embodiment the
connection means comprises an aperture for receiving an end of the pipe.
[0013] Preferred embodiments of the present invention will now be described, by way of example,
with reference to the accompanying drawings, in which:-
Fig. 1 is a perspective view of a known pipe connecting structure for a heat exchanger;
Fig. 2 is a perspective view of a pipe connecting structure according to a first embodiment
of the present invention;
Fig. 3 is an exploded view of the pipe connecting structure of Fig. 2;
Fig. 4 is a perspective view of a pipe connecting structure according to a second
embodiment of the present invention;
Fig. 5 is an exploded view of the pipe connecting structure of Fig. 4;
Fig. 6 is a sectional view of the pipe connecting structure of Fig. 4 taken along
line A-A;
Fig. 7 is a perspective view of a pipe connecting structure according to a third embodiment
of the present invention;
Fig. 8 is a further perspective view of the pipe connecting structure of Fig. 7;
Fig. 9 is an exploded view of the pipe connecting structure of Fig. 6;
Figs. 10 and 11 are exploded perspective views of a pipe connecting structure according
to a fourth embodiment of the present invention;
Fig. 12 is a sectional view of the pipe connecting structure of Fig. 10 taken along
line B-B and;
Fig. 13 is a detailed perspective view of the pipe connecting structure of Fig. 10
with the conduit omitted.
[0014] Fig. 1 illustrates a typical cross flow heat exchanger 1 having a first and second
spaced manifolds or header tanks 2,3 with a plurality of coolant or refrigerant tubes
4 extending therebetween, said refrigerant tubes 4 being separated by fins to enhance
refrigerant to air heat transfer. Refrigerant flows between the manifolds 2,3 via
the tubes 4.
[0015] Each manifold 2,3 is formed from two parallel header tubes 10,11, each header tube
10,11 of the first manifold 2 communicating with a respective header tube 12,13 of
the second manifold 3 via a respective number of said refrigerant tubes 4. One of
the two header tubes 10 of the first manifold 2 comprises a refrigerant delivery conduit
and the other header tube 11 of the first manifold 2 comprises a discharge conduit.
The second manifold 3 is provided with bridging passageways between its two constituent
header tubes 12,13 to provide cross flow.
[0016] A refrigerant delivery line 14 is connected to the first header tube 10 of the first
manifold 2 and a refrigerant discharge line 15 is connected to the second header tube
11 of the first manifold 2. Such connections are made by a connector block 16 joined
to the ends the header tubes 10,11 beyond the block of refrigerant tubes 4, apertures
being formed in such connection block into which are fixed, typically by brazing,
the ends of the delivery and discharge lines 14,15.
[0017] The connector block 16 also has to serve as a support and spacer for the ends of
the header tubes 10,11, the header tubes 10,11 requiring further support, spacing
and joining means adjacent the ends of the header tubes remote from the connector
block 16, this requiring further brazing and/or assembly steps.
[0018] As illustrated in Figs 2 and 3, in a first embodiment of the present invention, an
improved pipe connecting structure comprises a connector block 110 having a side face
112 configured to abut against a side region 124 of a first header tube 100 and having
an elongated aperture or row of holes formed in said face 112 for receiving the ends
of joining members 130a,130b,130c as will be described below.
[0019] Each joining member 130a,130b,130c comprises a tubular body having a first portion
131a,131b,131c, adapted to be inserted into a corresponding hole 103a,103b,103c formed
in a side wall of a second header tube 102, and a second portion 132a,132b,132c, adapted
to be inserted through diametrically opposed holes 101a,101b,101c, formed in opposite
side walls of the first header tube 100, whereby said second portion 132a,132b,132c
of the joining member 130a,130b,130c extends through said first header tube 100 and
into the connector block 110, thus providing fluid communication between the second
header tube 102 and the connector block 110.
[0020] A radially extending flange 134a,134b,134c is formed on each joining member 130a,130b,130c
between said first and second portions thereof to be positioned, in use, between the
first and second header tubes.
[0021] An outer face 114 of the connector block 110 is provided with an aperture 116 for
receiving a flattened end 142 of a delivery or discharge conduit 140.
[0022] During assembly, the connector block 110 can be secured to the header tubes by inserting
a tool through the aperture 116 into at least one of the joining members whereby regions
of the joining member on either side of the respective apertures in the header tubes
and be expanded or clinched to lock the components together. The joining members 130a,130b,130c,
connector block 110 and the conduit 140 can then be sealed in their respective receiving
apertures by brazing or by suitable adhesive.
[0023] Thus, a compact connecting structure is provided that serves to provide fluid connection
between a delivery or discharge conduit and a header pipe of the manifold while at
the same time supporting and correctly spacing the ends of the header tubes.
[0024] In a second embodiment, illustrated in Figs 4 to 6, the connector block 210 has a
side face 212 configured to abut against a side region 224 of a first header tube
200 and having an elongated aperture or row of holes 211a,211b,211c formed in said
face 212 for receiving the ends of joining members 230a,230b,230c.
[0025] As in the first embodiment, each joining member 230a,230b, 230c comprises a tubular
body having a first portion 231 a,231 b,231 c, adapted to be inserted into a corresponding
hole 203a,203b,203c formed in a side wall of a second header tube 202, and a second
portion 232a,232b,232c, adapted to be inserted through diametrically opposed holes
201 a,201 b,201 c, formed in opposite side walls of the first header tube 200, whereby
said second portion 232a,232b,232c of the joining member 230a,230b,230c extends through
said first header tube 200 and into the connector block 210, thus providing fluid
communication between the second header tube 202 and the connector block 210.
[0026] Again, a radially extending flange 234a,234b,234c is formed on each joining member
230a,230b,230c between said first and second portions thereof to be positioned, in
use, between the first and second header tubes.
[0027] In the second embodiment the connector block 210 comprises a substantially tubular
body having an aperture 216 in one end face for receiving end 242 of a delivery or
discharge conduit 240 such that said end of the conduit 240 is arranged parallel to
the header tubes 200,202. An axial slot 244 is provided in the end of the conduit
240 for receiving the ends of the second portions 232a,232b,232c of the joining member
230a,230b,230c. The conduit 240 is formed with a bend spaced from said end 242. Such
arrangement provides a degree of flexibility in the angle of the conduit extending
from the manifold to provide more flexibility in installation of the heat exchanger
by selecting the circumferential position of the slot 244 in the end of the conduit
240.
[0028] An aperture 205 is provided in an outer side of the connector block through which
a tool can be inserted to deform or clinch the central joining member 230b to lock
the connector block 210 to the header tubes 200,202, the connecting structure being
subsequently sealed by means of brazing or adhesive.
[0029] As shown in Fig. 6, the ends of the header tubes 200,202 are sealed by means of a
plug 250.
[0030] In a third embodiment, illustrated in Figs 7 to 9, the connector 310 is again joined
to the header tubes 300,302 by means of joining members 330a,330b, 330c, each comprises
a tubular body having a first portion 331a,331b,331c, adapted to be inserted into
a corresponding hole 303a,303b,303c formed in a side wall of a second header tube
302, and a second portion 332a,332b,332c, adapted to be inserted through diametrically
opposed holes 301a,301b,301c, formed in opposite side walls of the first header tube
300, whereby said second portion 332a,332b,332c of the joining member 330a,330b,330c
extends through said first header tube 300 and into the connector block 310, thus
providing fluid communication between the second header tube 302 and the connector
block 310.
[0031] Again, a radially extending flange 334a,334b,334c is formed on each joining member
330a,330b,330c between said first and second portions thereof to be positioned, in
use, between the first and second header tubes 300,302.
[0032] In the third embodiment , the connector block 310 is adapted to slidingly receive
an end 342 of a delivery or discharge conduit 340 over a portion of the connector
block 310. An axial slot 344 is provided in the end 342 of the conduit 340 to enable
the conduit 340 to be slid over a substantially tubular portion 346 of the connector
block 310, the tubular portion 315 having an opening 316 end to enable fluid communication
between the conduit 340 and the joining members 330a,330b,330c and hence the second
header tube 302.
[0033] An aperture 305 is provided in an outer side of the connector block through which
a tool can be inserted to deform or clinch the central joining member 330b to lock
the connector block 310 to the header tubes 300,302, the connecting structure being
subsequently sealed by means of brazing or adhesive. A plug 350 is inserted into the
ends of the header tubes 300,302 to close the tubes.
[0034] A fourth embodiment of the present invention is illustrated in Figs 10 to 13. In
the fourth embodiment, the connector block 410 is adapted to provide fluid communication
with the header tube 400 to which it is abutted.
[0035] The connector block 410 has a side face 412 configured to abut against a side region
424 of a first header tube 400 and having an elongated row of holes formed in said
face 412 for receiving the ends of joining members 430a,430b,430c as will be described
below.
[0036] Each joining member 430a,430b,430c comprises a tubular body having a first portion
431 a,431 b,431 c, adapted to be inserted into a corresponding hole 401 a,401 b,401
c formed in the side region 424 of the first header tube 400, and a second portion
432a,432b,432c, adapted to be inserted into the corresponding hole in the connector
block 410, thus providing fluid communication between the second header tube 102 and
the connector block 110. The first portion 431a,431b,431c of each joining member has
a smaller diameter than the second portion 432a,432b,432c to limit the insertion of
each joining member into its corresponding aperture in the header tube 400.
[0037] An outer face 414 of the connector block 110 is provided with an aperture 416 for
receiving a flattened end 442 of a delivery or discharge conduit 440.
[0038] During assembly, the connector block 410 can be secured to the header tubes by inserting
a tool through the aperture 416 into at least the central one 430b of the joining
members to deform or clinch the end regions of the joining member to lock the components
together. The joining members 430a,430b,430c, connector block 410 and the conduit
440 can then be sealed in their respective receiving apertures by brazing or by suitable
adhesive.
[0039] The plug 450 serves to close the ends of the header tubes while at the same time
holding the two header tubes together at the correct spacing.
[0040] Thus, a compact face connecting structure is provided that can provide a pipe connection
with the header tube either the closest or furthest from the connection block by the
use of the appropriate joining members.
[0041] Various modifications and variations to the described embodiments of the inventions
will be apparent to those skilled in the art without departing from the scope of the
invention as defined in the appended claims. Although the invention has been described
in connection with specific preferred embodiments, it should be understood that the
invention as claimed should not be unduly limited to such specific embodiments.
[0042] While three parallel joining members are used in the described embodiments, it is
envisaged that one or more member could be used or a single member in the form of
a flattened pipe having a width in the axial direction of the header tubes greater
than that in the radial direction of the header tubes. However, multiple small tubes
provide greater resistance to high pressure than a single large joining member and
thus are considered particularly suitable for use with carbon dioxide refrigerant.
[0043] Where the joining members 330a,330b,330c extend though the first header tube 300
into the second header tube 302, they may be provided with radial apertures in their
second portions 332a,332b,332c if fluid communication between the connector block
310 and the first header tube 300 as well as the second header tube 302 is desired.
1. A pipe connecting structure for a heat exchanger comprising:-
a header portion or manifold defined by a plurality of parallel elongate header tubes;
a connector block having a side face adapted to abut against a side region of an outer
one of said header tubes and connection means configured to connect a pipe thereto;
and joining means comprising at least one elongate tubular member having a first end
adapted to be inserted through a hole formed in a first side wall of at least said
outer one of said header tubes, and a second end extending through a corresponding
hole in said side face of the connector block, whereby said second end communicates
with said connection means.
2. A pipe connecting structure as claimed in claim 1, wherein the at least one tubular
member of the joining means extends substantially perpendicular to said header tubes.
3. A pipe connecting structure as claimed in claim 2, wherein said first end of said
at least one elongate tubular member is adapted to extend through a corresponding
hole in a second side wall of said outer one of said header tubes diametrically opposite
said first side wall and through an aperture in a side wall of the one of said plurality
of header tubes furthest from said outer one of said header tubes, whereby said first
end communicates with an interior of said furthest one of said header tubes, whereby
the at least one tubular member of the joining means extends between, and perpendicular
to, said plurality of elongate header tubes to connect the plurality of elongate pipes
to one another and to the connector block.
4. A pipe connecting structure as claimed in claim 3, wherein said at least one tubular
member of the joining means includes a radially extending flange located between said
first and second ends and adapted to be positioned between sides faces of said furthest
one of said header tubes and an adjacent header tube.
5. A pipe connecting structure as claimed in claim 4, wherein said header portion comprises
two parallel elongate header tubes, a first tube corresponding to said outer one of
said header tubes and a second tube corresponding to said furthest one of said header
tubes, said radially extending flange being positioned between said first and second
tubes.
6. A pipe connecting structure as claimed in claim 2, wherein the diameter of said first
end of said at least one tubular member is smaller than the diameter of said second
end.
7. A pipe connecting structure as claimed in any preceding claim, wherein the joining
means comprises a plurality of parallel tubular members arranged in a plane containing
the longitudinal axis of each of the plurality of header tubes of the header portion.
8. A pipe connecting structure as claimed in any preceding claim, wherein the connection
means of the connector block is adapted to receive said pipe with said pipe arranged
parallel to said plurality of header tubes.
9. A pipe connecting structure as claimed in any of claims 1 to 7, wherein the connection
means of the connector block is adapted to receive said pipe with the pipe arranged
perpendicular to said plurality of header tubes.
10. A pipe connecting structure as claimed in any preceding claim, wherein said connection
means comprises a flange or stub to be received within an end of the pipe.
11. A pipe connecting structure as claimed in any preceding claim, wherein the connection
means comprises an aperture for receiving an end of the pipe.