Heat exchange – Side-by-side tubular structures or tube sections – With manifold type header or header plate
Reexamination Certificate
2000-06-01
2001-09-18
Flanigan, Allen (Department: 3743)
Heat exchange
Side-by-side tubular structures or tube sections
With manifold type header or header plate
C138S089000
Reexamination Certificate
active
06289979
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a heat exchanger provided with a header pipe, the two ends of which are closed off with caps.
BACKGROUND ART
In a heat exchanger disclosed in Japanese Examined Utility Model Publication No. H7-3173, one end of the header, and more specifically, the lower lid closing off the lower end of the header, is provided with a collar, a fitting portion projecting out at the upper surface of the collar and a retaining projection projecting out at the lower surface of the collar, and the heat exchanger is mounted at a vehicle body by fitting the retaining projection at a retaining hole constituted of a vibration-damping rubber provided at the lower mounting plate secured to the vehicle body.
In addition, Japanese Unexamined Utility Model publication No. H5-45482 discloses a structure achieved by forming a side projection as an integrated part of a lid closing off the opening at the lower end of the header pipe and providing an insertion pin at the lower surface of this side projection so that the insertion pin is offset from the center of the axis of the header pipe along a specific direction. By adopting this structure, the position of the insertion pin can be selected freely over a wide range.
The invention disclosed in Japanese Unexamined Patent publication No. H5-332693 achieves simplification in bracket mounting by providing a male screw that is set erect at the outer end surface of a header cap closing off the lower end of the header pipe.
The invention disclosed in Japanese Unexamined Patent Publication No. H 9-26282 is provided with a lid assuming a structure different from that of the lid having the side projection disclosed in Japanese Unexamined Utility Model Publication No. H6-45482 mentioned above. The lid disclosed in this publication has an inward projection and a side projection provided as an integrated part of the inward projection and projecting out along the direction of the width of the tubes and is formed as a block body achieving a roughly L-shape in the plan view.
As an examination of the examples quoted above reveals, since the lower end of a heat exchanger mounted at a vehicle body is set near the vehicle body side panel, a means for retention to retain the heat exchanger at the vehicle body panel is provided at the lid that closes off the lower end of the tubes of the heat exchanger. However, it is not desirable to provide a means for retention such as a pin as an integrated part of the lid, since the pin tends to become skewed during the brazing process to such an extent that, in extreme cases, it can no longer be fitted at the mounting hole at the vehicle.
In addition, reflecting the increasing need for a reduction in the engine room space in recent years, the space available for mounting the heat exchanger has become smaller, thereby necessitating reduced dimensions in the heat exchanger.
Thus, the heat exchanger itself must become more compact. The lid (cap), which is normally manufactured through cold forging or the like, must be washed after it is formed since impurities such as the mold releasing agent and the press oil adhere to the manufactured cap. If the end of the cap is formed in a flat shape in this situation, a problem arises while washing the cap in that it may not be washed thoroughly. In addition, if the lid is formed in a flat shape, it is necessary to assure a specific thickness for the lid so that it can withstand pressure applied to the lid.
Accordingly, an object of the present invention is to provide a heat exchanger achieving a reduction in the header pipe dimensions and having a cap with a sufficient degree of strength against pressure, which can be washed thoroughly when washing the lid.
SUMMARY OF THE INVENTION
In order to achieve the object described above, in the heat exchanger according to the present invention comprising, at least, a pair of header pipes having inflow/outflow pipes through which a heat exchanging fluid flows in and out, a plurality of tubes communicating between the pair of header pipes and fins provided between the individual tubes, the header pipes are each provided with a cylindrical portion having insertion holes, into which the tubes are inserted and a pair of caps that close off the openings at the two ends of the cylindrical portion. The caps are each provided with a closing portion that closes off the open ends, a circumferential wall portion formed at the circumferential edge of the closing portion to be externally fitted at the circumferential edge at the end of the cylindrical portion and a circular groove formed between the closing portion and the base end at the inner circumferential surface of the circumferential wall portion at which the end of the cylindrical portion is fitted over the entire circumference, and the closing portion has a thick portion located inside the circular groove.
Thus, by adopting the present invention having the circular groove, in which the circumferential edge at the end of the cylindrical portion is fitted over the entire circumference, formed at each cap closing off one of the two ends of the cylindrical portion constituting each of the header pipes, the cylindrical portion is fitted inside the cap to reduce the dimensions of the header pipe along the axial direction. In addition, since the thick portion is formed at the closing portion, the thickness of the closing portion can be maintained at a specific value to achieve the object described above.
Furthermore, the side surface of the thick portion located toward the cylindrical portion is formed in an indented shape. This makes it possible to form the inner side surface of the thick portion in an arch to improve the strength against internal pressure.
The cap is provided with a projected portion projecting out along the direction of the length of the cylindrical portion at the outer end surface located on the opposite side from the cylindrical portion. One such projected portion may be formed at an approximate center of the outer end surface or a plurality of such projected portions may be formed over consistent intervals near the circumferential edge of the outer end surface.
Since the presence of the projected portions at the flat outer end surface of the cap prevents the cap from becoming placed in surface contact during the washing process, the washing solution is allowed to reach the end surface of the cap with a high degree of reliability to assure thorough washing.
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Flanigan Allen
Wenderoth , Lind & Ponack, L.L.P.
Zexel Corporation
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