JPH10137878A - Forming method of integrated internal baffle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming an integrated internal baffle with high bursting strength without any leak in an end part and a fin type heat exchanger. SOLUTION: In this method, a manifold is immovably (permanently) pressed and collapsed in a prescribed position so that a manifold wall top part 50 and a manifold wall bottom part 52 form about a U shape recessed part 58, and a slit is formed in the U shape recessed part. A brazing filler metal is applied to the manifold, and the manifold is treated so that the brazing filler metal is made to flow through the slit and between the manifold wall top part 50 and the manifold wall bottom part 52 at the time of brazing and whereby the manifold wall top part 50 and the manifold wall bottom part 52 are mutually fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to heat exchangers such as condensers, evaporators and oil coolers used in automotive air conditioners. In particular, the invention relates to a method of forming an integral internal baffle in a heat exchanger.

[0002]

2. Description of the Prior Art Fin and tube heat exchangers are commonly used for heating and cooling applications in in-vehicle, industrial and residential environments. Typically, such heat exchangers use a plurality of tubes through which the fluid to be heated or cooled is flowed. The number of tubes used depends on the heat capacity required of the fin and tube type heat exchanger. To connect the tubes together so that fluid can flow through the tubes, a manifold having a series of apertures associated with the ends of the tubes is used.
The manifold has an inlet port and an outlet port to circulate the fluid through the heat exchanger and then return the fluid to a remote location for the next recirculation.

In a multi-pass heat exchanger, the heat exchange fluid is passed through the heat exchanger multiple times to increase efficiency. Such multiple passes are achieved by interrupting fluid flow at key points and forcing the fluid to traverse the heat exchanger. Typically, this obstacle is a baffle located inside the manifold. Several methods are well known for placing a baffle inside a manifold.
In one method, a circular disc material is placed within a predetermined opening of the manifold and welded. In another method, such as that disclosed in U.S. Pat. No. 5,090,477, a baffle is formed mechanically by crushing a manifold such that a portion of the manifold wall contacts its opposing portion. No. 5,090,477 teaches that in order to plastically deform the manifold wall, a leak-free seal is formed and no brazing is needed to secure the baffle inside the manifold. However, if the manifold is used in a heat exchanger where a very high internal pressure is required, the baffle will leak. Therefore, it is advantageous to provide the manifold with an internally formed baffle that can withstand high pressures.

[0004]

It is a feature of the present invention that the baffles formed therein can withstand high operating pressures without leaking.

[0005]

SUMMARY OF THE INVENTION The present invention comprises a step of permanently (permanently) crushing a manifold at a baffle position such that the top of the manifold wall and the bottom of the manifold wall form a substantially U-shaped depression in the manifold. Forming a slit in the U-shaped recess, which solves the difficulties and deficiencies of the prior art by providing a method of forming an internally integrated baffle at a baffle location of a heat exchanger manifold. The method includes applying brazing material to the manifold, flowing the brazing material through slits and between the manifold wall top and the manifold wall bottom, and pre-determining to secure the manifold wall top and the manifold wall bottom together. Treating the manifold under the set conditions.

[0006] In this method, the bonding strength of the baffle is large,
This offers the advantage of increasing the burst strength of the manifold.

[0007] These and other objects, features and advantages of the present invention will become apparent from the brief description of the drawings, the detailed description, and the claims.

[0008]

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, FIGS. 1 and 2 show two different types of tube and fin heat exchangers 10. FIG. Each exchanger includes a plurality of tubes 12, with heat dissipation fins 14 interposed between each of the tubes 12. In FIG. 1, the heat exchanger includes U-shaped tubes 12 whose free ends are matedly engaged with a manifold 16 located only at one end of the heat exchanger 10. As shown in FIG. 1, the manifold 16 is a two-chamber manifold having a first fluid conduit 18 and a second fluid conduit 20. FIG. 2 shows a heat exchanger of the "parallel flow" type, in which a plurality of substantially straight tubes 12 'are interposed between a pair of fluid manifolds 16'. Each heat exchanger includes an inlet port 22 for receiving fluid and an outlet port 24 for discharging fluid. As described further below, manifolds 16 and 16 'of either type of heat exchanger
Also includes a plurality of crushed baffles 26 formed therein to direct the fluid to flow according to a predetermined passage. The baffle 26 of the present invention
Is essentially the same for both heat exchangers, so the description of baffle 26 will be described with reference to the heat exchanger of FIG. However, it should be recognized that the description of the baffle 26 and the method for forming the baffle is provided for the parallel flow heat exchanger of FIG. 2 as well.

According to well known principles of heat exchangers, the fluid to be cooled (or heated) flows into the manifold 16 through the inlet port 22 and is passed through a plurality of U-shaped tubes while the fluid is flowing through the fins 14. Cooled by a second fluid such as air flowing over it. Baffle 26 and manifold 16 allow fluid to flow through the U-shaped tube, and the fluid is ultimately discharged from outlet port 24. One skilled in the art will appreciate that while the heat exchanger of FIG. 1 uses a manifold having a pair of longitudinal fluid conduits, the present invention can also be used in connection with a manifold having a single fluid conduit. You have to be aware. As shown in FIG. 1, the heat exchanger is a condenser, but the principles of the present invention can be used with other types of heat exchangers as well.

[0010] The manifold 16 is SAE3003, 310
2 or made from an extruded aluminum alloy, such as 6062, or any other type of well-known deformable material. The manifold 16 can be formed by any of a number of well-known methods. For example, one such method is disclosed in U.S. Pat.
No. 101 is taught. The disclosure of that patent is incorporated herein by reference. Manifold 16
Must include fluid conduits 18, 20 (FIG. 3), as well as fluid conduit passages engaged in combination with the tube ends, so that fluid can flow through the plurality of tubes. One type of fluid conduit passage is formed as a plurality of openings or raised fluid pipes. These passages are in fluid communication with the fluid conduits 18, 20 of the manifold 16.

After the fluid conduits and passages have been formed, each fluid conduit 18, 20 is mechanically crushed according to predetermined locations to obtain the desired fluid circulation, and the baffle 2
6 are formed. The crushing operation can be performed by any of a number of well-known machining operations, one of which is shown in FIGS. Fluid conduits 18,20 form curved top and bottom walls 50,52. Manifold type 54
Placed inside and fixedly held. A vertically reciprocating punch 56 having a slit forming member 60 on the distal end surface
Is pressed against the top wall 50 of the conduit, which press
The top wall 50 is attached to the bottom wall 52 so that
It is continued until it is plastically deformed toward. As shown in FIG. 8, the recess 58 is generally U-shaped and the slit 5
9 is included. Either method produces an integrally formed baffle.

After the baffle has been formed, the end of the manifold is crushed and the manifold assembly is washed in a deoiled solution. The inlet port 22 and outlet port 24 are then formed and assembled into a manifold according to known manufacturing processes. The manifold is typically coated with a material that will include a fluxing agent. This brazing material can be in the form of a paste or wire and can be made of a manifold 48.
Along the length and in the recess 58. The manifold assembly is then placed in a brazing furnace and a weld line or braze bond between each of the fluid conduits 18 and 20 along the longitudinal length of the manifold as shown at 48 in FIG. To form a part. As shown in FIGS. 4 and 5, the flux / brazing material 66 melted during this process flows through the slit 59 due to the flow phenomenon of the capillary, and the top wall 50 of the manifold is connected to the bottom wall 5.
2 This positive connection between the top and bottom walls allows a stronger baffle to be formed without binding. This increases the rupture strength of the manifold over mechanical crush alone and reduces leakage at the baffle. The lateral end of the fluid conduit is also sealed at this point in the process. The ends also include slits for purposes similar to those described above.

After the manifold has been manufactured according to the process described above, a U-shaped tube is connected to the manifold 16. The free end of the U-shaped tube of the heat exchanger is matedly engaged with the fluid passage opening of the manifold. Fins 14 and end plate 62 complete the assembly. Solder joints are formed in each of the fluid passages to ensure a leak-free and suitable connection of the manifold to the U-shaped tube end. The manifold can be coupled to the heat exchanger by any of a number of well-known processes, such as, for example, vacuum brazing, brazing at a controlled atmospheric pressure, or welding the manifold to the heat exchanger.

In view of the above, it is without doubt that modifications and adaptations of the present invention will occur to those skilled in the art. For example, a method of making a manifold from a single extruded piece of aluminum can also be practiced with a single manifold as well as a dual manifold. Various other materials may also be selected to make the manifold, and the invention is not meant to be limited to only the particular examples described above. The claims encompass all equivalents that define the scope of the invention.

[Brief description of the drawings]

FIG. 1 is a perspective view of a tube and fin heat exchanger including a baffle structure in accordance with the principles of the present invention.

FIG. 2 is a front view of another tube and fin heat exchanger including a baffle structure in accordance with the principles of the present invention.

FIG. 3 is an enlarged perspective view of a portion of FIG. 1 showing the baffle of the present invention.

FIG. 4 is a cross-sectional view of the baffle of FIG. 3 taken along line 4-4.

FIG. 5 is a cross-sectional view taken along line 5-5 in FIG.

FIG. 6 is a perspective view of a tool used to make a baffle according to the principles of the present invention.

FIG. 7 is a perspective view of a tool used to make a baffle according to the principles of the present invention.

FIG. 8 is a cross-sectional view during crushing along line 8-8 in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Heat exchanger 12, 12 'tube 14 Fin 16, 16' manifold 18, 20 Fluid conduit 22 Inlet port 24 Outlet port 50 Top wall 52 Bottom wall 54 Type 56 Punch 59 Slit 60 Slit forming member

Claims (2)

[Claims] 1. A method of forming an integral internal baffle at a baffle location inside a manifold used in a heat exchanger, wherein a top of the manifold wall and a bottom of the manifold wall form a substantially U-shaped recess in the manifold. Fixedly (permanently) crushing the manifold at the baffle position; forming a slit in the U-shaped depression; applying brazing material to the manifold; slits and the top of the manifold wall and the bottom of the manifold wall. Flowing the brazing material between the two, and treating the manifold under predetermined conditions to fix the manifold wall top and the manifold wall bottom to each other. Method of forming internal baffle. 2. The method of claim 1, wherein the step of crushing is performed by contacting a punch with a top of the manifold wall and exerting a force on the punch. Formation method.