U.S. patent application number 11/252237 was filed with the patent office on 2006-05-25 for joint structure of header tank and connector in heat exchanger, and method of joining thereof.
This patent application is currently assigned to CALSONIC KANSEI CORPORATION. Invention is credited to Takumi Funatsu, Koichi Iwasaka, Toru Takai, Hiroyuki Tamura, Minoru Tsuchiya.
Application Number | 20060108096 11/252237 |
Document ID | / |
Family ID | 35811627 |
Filed Date | 2006-05-25 |
United States Patent
Application |
20060108096 |
Kind Code |
A1 |
Tsuchiya; Minoru ; et
al. |
May 25, 2006 |
Joint structure of header tank and connector in heat exchanger, and
method of joining thereof
Abstract
A joint structure of a header tank and a connector in a heat
exchanger includes a header tank (1) including a plate wall (1c)
formed with a first communication hole (1a). The joint structure
includes a block-shaped connector (2) having a second communication
hole (2b) positioned to the first communication hole (1a) and
joined to the header tank (1). The first communication hole (1a) is
smaller than the second communication hole (2b). The first
communication hole (1a) has therearound a periphery (1b) caulked
and fixed on an inner peripheral surface of the second
communication hole (2a) by burring formation.
Inventors: |
Tsuchiya; Minoru; (Gunma,
JP) ; Takai; Toru; (Tochigi, JP) ; Iwasaka;
Koichi; (Gunma, JP) ; Tamura; Hiroyuki;
(Tochigi, JP) ; Funatsu; Takumi; (Gunma,
JP) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
CALSONIC KANSEI CORPORATION
|
Family ID: |
35811627 |
Appl. No.: |
11/252237 |
Filed: |
October 18, 2005 |
Current U.S.
Class: |
165/76 |
Current CPC
Class: |
F28F 9/185 20130101;
F28F 9/0246 20130101 |
Class at
Publication: |
165/076 |
International
Class: |
F28F 7/00 20060101
F28F007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 18, 2004 |
JP |
P2004-303250 |
Claims
1. A joint structure of a header tank and a connector in a heat
exchanger comprising: a header tank including a plate wall formed
with a first communication hole; and a block-shaped connector
having a second communication hole positioned to the first
communication hole and joined to the header tank, wherein the first
communication hole is smaller than the second communication hole,
wherein the first communication hole has therearound a periphery
caulked and fixed on an inner peripheral surface of the second
communication hole by burring formation.
2. The joint structure according to claim 1, wherein the header
tank and the connector caulked and fixed on each other by burring
formation are brazed to each other.
3. The joint structure according to claim 1, wherein the connector
comprises a first portion diverged in a concave form, wherein the
joint structure further comprises a header-tank backup member
mating with the connector and having a second portion converged in
a convex form, wherein the diverged first portion and the converged
second portion hold the plate wall therebetween.
4. A method of joining a header tank and a connector in a heat
exchanger, comprising: forming, on a plate wall of a header tank of
a heat exchanger, a first communication hole smaller than a second
communication hole of a block-shaped connector; positioning the
first and second communication holes to each other; inserting a
punch into the header tank to burring form a periphery around the
first communication hole, with the first and second communication
holes positioned to each other; caulking and fixing the periphery
around the first communication hole on an inner peripheral surface
of the second communication hole by the punch; and brazing the
header tank and the connector caulked and fixed.
5. The method according to claim 4, further comprising: applying a
brazing material on an outer surface of the plate wall of a header
tank before the step of caulking and fixing by burring formation;
and brazing the header tank and the connector to each other with
the brazing material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2004-303250 filed on
Oct. 18, 2004; the entire contents of which are incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a joint structure of a header tank
and a connector in a heat exchanger, and a method of joining
thereof.
[0003] Ordinary heat exchangers have a plurality of tubes in which
fluid flows, fins arranged between the tubes, and header tanks for
distribution and confluence joined at both ends of the tubes. The
header tank is joined with a block-shaped connector for external
pipe connection. Joining of the header tank and the connector is
generally performed by brazing simultaneously when the tubes, fins,
and the header tanks are brazed together.
[0004] When the header tank and the connector are brazed, they must
be placed in a brazing furnace in such a state that they have been
positioned and temporarily fixed in advance. In the related art,
such a method is adopted that positioning and temporary fixing are
performed utilizing a positioning unit provided, or positioning and
temporary fixing is conducted by welding (for example, see Japanese
Patent Applications Laid-open Nos. H6-229696 and H10-238987).
SUMMARY OF THE INVENTION
[0005] The positioning and temporary fixing method according to the
related art, however, requires a complicated structure or takes
man-hours, or it is difficult to conduct reliable positioning and
temporary fixing, which may cause variations of the positioning and
temporary fixing and further increases in cost.
[0006] The invention is directed to provide a joint structure of a
header tank and a connector in a heat exchanger and a joining
method thereof, which allows reliable positioning and temporary
fixing with a simple constitution and allows constant-quality
brazing at a low cost.
[0007] The first aspect of the invention provides a joint structure
of a header tank and a connector in a heat exchanger. The joint
structure includes a header tank (1) including a plate wall (1c)
formed with a first communication hole (1a). The joint structure
includes a block-shaped connector (2) having a second communication
hole (2b) positioned to the first communication hole (1a) and
joined to the header tank (1). The first communication hole (1a) is
smaller than the second communication hole (2b). The first
communication hole (1a) has therearound a periphery (1b) caulked
and fixed on an inner peripheral surface of the second
communication hole (2a) by burring formation.
[0008] The header tank (1) and the connector (2) caulked and fixed
on each other by burring formation may be brazed to each other.
[0009] The connector (2) includes a first portion (2d) diverged in
a concave form. The joint structure further includes a header-tank
backup member (12) mating with the connector and having a second
portion (12a) converged in a convex form. The diverged first
portion and the converged second portion hold the plate wall (1c)
therebetween.
[0010] The second aspect of the invention provides a method of
joining a header tank and a connector in a heat exchanger. The
method includes the step of forming, on a plate wall (1c) of a
header tank (1) of a heat exchanger, a first communication hole
(1a) smaller than a second communication hole (2b) of a
block-shaped connector (2). The method includes the step of
positioning the first and second communication holes (1a; 2b) to
each other. The method includes the step of inserting a punch (13a)
into the header tank (1) to burring form a periphery (1b) around
the first communication hole (1a), with the first and second
communication holes positioned to each other. The method includes
the step of caulking and fixing the periphery (1b) around the first
communication hole (1a) on an inner peripheral surface of the
second communication hole (2b) by the punch (13a). The method
includes the step of brazing the header tank (1) and the connector
(2) caulked and fixed.
[0011] The method may include the step of applying a brazing
material on an outer surface of the plate wall (1c) of a header
tank (1) before the step of caulking and fixing by burring
formation. The method may include the step of brazing the header
tank (1) and the connector (2) to each other with the brazing
material.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0012] FIGS. 1A to 1C are step diagrams illustrating a caulking
process based upon a burring formation for obtaining a joint
structure according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] Embodiments of the invention will be described below with
reference to the drawings.
[0014] FIGS. 1A to 1C are step diagrams illustrating a caulking
process based upon a burring formation. In FIGS. 1A to 1C, a header
tank 1, a connector 2, a connector backup member 11, a header tank
backup member 12, a punch rod 13, and a punch 13a are
illustrated.
[0015] The header tank 1 is of a two-separate type. Only a tank
main unit in which a heat exchange fluid passage is formed is
illustrated. The tank main unit is assembled with a header plate
(not illustrated) joined to another tube, constituting an actual
header tank.
[0016] The header tank 1 has a tubular base 1d extending straight.
The header tank 1 has a semi-cylindrical plate wall 1c, and a
central portion thereof in a transverse direction has a
communication hole 1a communicating with a flow holes 2a and 2b.
The semi-cylindrical plate wall 1c has, at the end, an oblique
peripheral surface relative to the base 1d. The plate wall 1c
extends from the base 1d to be converged. The flow holes 2a and 2b
of the connector 2 constitute a stepped hole. The flow holes 2a and
2b have an enlarged diameter portion 2a connected to an external
pipe and a reduced diameter portion 2b connected to the
communication hole 1a of the header tank 1.
[0017] Prior to brazing, as illustrated in FIG. 1A, the diameter of
the communication hole 1a of the header tank 1 is formed smaller
than a diameter of the flow hole 2b of the connector 2 in advance.
The connector 2 and the header tank 1 are supported by the backup
members 11 and 12, respectively. The connector 2 and the plate wall
1c of the header tank 1 are caused to abut against each other, so
that the communication hole 1a and the flow hole 2b are positioned
to each other.
[0018] At this time, the plate wall 1c of the header tank 1 is
supported from inside thereof by the semicircular column portion
12a of the backup member 12 on the side of the header tank 1. The
semicircular column portion 12a as a second portion has, at the
end, a periphery converged to conform to the inner surface's shape
of the semi-cylindrical plate wall 1c. The end face of the
connector 2 is supported by the flat portion of the backup member
11 on the side of the connector 2. The abutting portion 2d of the
connector 2 is caused to abut against the outer face of the plate
wall 1c of the header tank 1. The abutting portion 2d as a first
portion is shaped to conform to the oblique outer surface of the
distal end of the plate wall 1c. The abutting portion 2d is
diverged to conform to the converged outer surface of the plate
wall 1c.
[0019] In this state, as illustrated in FIG. 1B, the punch rod 13
is elevated from inside of the header tank 1, while being guided by
a slide hole 12b of the backup member 12. The punch 13a at the
distal end of the punch rod 13 burring-forms the periphery 1b
around the communication hole 1a formed in the plate wall 1c of the
header tank 1. The punch 13a caulks and fixes the periphery 1b
(burring portion) of the communication hole 1a on the inner
peripheral portion of the flow hole 2b. When caulking is conducted
in this manner, the friction between the burring formation portion
and the flow hole 2b of the connector 2 establishes fixing
force.
[0020] The "burring formation" means that the punch 13a stretches
and flanges the periphery 1b around the communication hole 1a. The
punch 13a presses the periphery 1b burred against the inner
peripheral surface of the flow hole 1b.
[0021] After caulking and fixing, as illustrated in FIG. 1C, the
punch 13a moves down, the backup members 11 and 12 are removed, and
the header tank 1 with the connector 2 temporarily fixed is
transferred to a brazing step. The header tank 1 and the connector
2 are brazed to each other and the both are finally joined to each
other, so that the joint structure is completed. During the
formation, brazing material may be applied on the outer face of the
plate wall 1c of the header tank 1 in advance. After caulking and
fixing are performed in this state by the burring formation, the
header tank 1 and the connector 2 are brazed to each other by the
brazing material. This method establishes brazing with stable
quality without supplying brazing material later.
[0022] According to the joint structure produced by the above
method, brazing is performed in a state that the header tank 1 and
the connector 2 have been positioned and temporarily fixed to each
other reliably and firmly, so that products with stable quality are
provided. Furthermore, the burring formation is conducted simply
without taking man-hours, and the automation may be performed.
[0023] Although the invention has been described above by reference
to certain embodiments of the invention, the invention is not
limited to the embodiments described above. Modifications and
variations of the embodiments described above will occur to those
skilled in the art, in light of the above teachings. The scope of
the invention is defined with reference to the following
claims.
[0024] According to the invention, the first communication hole is
smaller than the second communication hole, and the periphery
around the first communication hole is burring formed. This method
allows the periphery around the first communication hole to be
caulking fixed on the inner peripheral surface, thus securely and
firmly positioning and temporarily fixing the header tank and the
connector to each other. Further, the burring formation allows for
secure positioning and temporary fixing with a simple structure
without taking man-hours, thus achieving brazing with a constant
quality at a lower production cost.
[0025] With the header tank and the connector caulked and fixed by
burring formation, the header tank and the connector are brazed to
each other, thus securely joining the header tank and the connector
to each other.
[0026] A brazing material is applied on the outer surface of the
plate wall before the step of caulking and fixing by burring
formation, and the header tank and the connector are brazed to each
other. This method achieves brazing with a stable quality without
feeding a brazing material later.
* * * * *