Heat exchanger

Abstract: A heat exchanger has a tank (6) formed from at least first and second tank members (11, 12, 17) connected to each other and at least one partition (10) disposed in the tank (6) for dividing the interior of the tank (6) into at least two chambers (6a, 6b). A pair of protrusions (13a, 13b) extending in a circumferential direction of the inner surface of the tank (6) and arranged in an axial direction of the tank (6) are provided on the inner surface of the first tank member (11) to hold an edge portion (10a) of the partition (10) therebetween. The protrusions (13a, 13b) can be provided without forming a thinner and weaker portion on the tank (6). The partition (10) can be disposed easily and precisely at a predetermined position in the tank (6) by the function of the pair of protrusions (13a, 13b). Further, a good brazing condition can be realized easily and naturally.

Description: The present invention relates to a heat exchanger used for, for example, air conditioners for vehicles, and more particularly to a heat exchanger having a tank and a partition disposed in the tank. A tank structure for a heat exchanger having a partition for dividing an interior of a tank into at least two chambers is well known. For example, JP-A-HEI 7-103683 discloses a structure as shown in FIG. 4. In this structure, tank 30 comprises at least two tank members 31 and 32, and the tank members 31 and 32 forms the tank 30 by being connected to each other by, for example, brazing. Partition 33 is provided in tank 30 for dividing the interior of the tank 30 into separate chambers. This partition 33 has a projection 34 for positioning. Projection 34 is inserted into a hole 35 defined on the wall of tank member 32, thereby positioning partition 33 in tank 30. Further, a flux guide hole 36 is provided on tank member 31 for introducing a flux for brazing into the interior of tank 30. In such a tank structure for a heat exchanger, partition 33 is disposed in and fixed to tank 30 as follows. After projection 34 of partition 33 is inserted into hole 35 of tank member 32, the tank member 32 and tank member 31 are assembled. Then, the respective assembled members are connected to each other by, for example, brazing in a furnace at a time. In the brazing, a flux F is injected from hole 36 of tank member 31 into the interior of tank 30. The injected flux is provided between the inner surface of tank 30 and the edge of partition 33, thereby improving the brazing condition. Further, Japanese Utility Model Laid-Open HEI 2-54078 on which the preamble of claim 1 is based discloses another tank structure as shown in FIG. 5. A slot 38 is defined on the wall of tank 37 for inserting partition 40 into the interior of the tank 37 through the slot 38. An arclike groove 39 is defined on the inner surface of tank 37 at a position facing slot 38 for fixing partition 40 by engaging the edge of the partition 40 with the groove 39. In the above-described tank structure disclosed in JP-A-HEI 7-103683, however, projection 34 of partition 33 must be inserted into hole 35 of tank member 32 prior to connection of tank members 31 and 32 for forming tank 30, and thereafter the tank members 31 and 32 must be assembled. Therefore, the operation for assembly is troublesome and the freedom for the assembly is low. Further, in the brazing, although flux F is injected into the interior of tank 30 through hole 36, because the cross section of tank 30 is circular, it is extremely difficult to deliver the flux F uniformly all over the portion between the inner surface of tank 30 and the edge of partition 33. As a result, it would be difficult to achieve a good brazing condition. On the other hand, in the above-described tank structure disclosed in Japanese Utility Model Laid-Open HEI 2-54078, in a case where a flux is provided on the inner surface of tank 37, the flux must be applied before inserting partition 40 into the tank 37. Further, because groove 39 is defined on the inner surface of tank 37, the thickness of the tank wall becomes fairly small at the portion defined with the groove 39 and a stress is likely to be concentrated at the portion, thereby causing decrease of the strength at the tank portion. Furthermore, EP 0 514 248 A discloses a heat exchanger having a tank, at least one partition disposed in the tank for deviding an interior of the tank into at least two chambers. A pair of protrusions extending in a circumferencial direction of an inner surface of the tank and arranged in an axial direction of the tank are provided on an inner surface of the tank to hold an edge portion of the partition there between. It would be desirable to provide a heat exchanger having a tank structure which can incooperate a partition into a tank for dividing an interior of the tank into separate chambers without causing decrease of the strength of the tank, and which can increase the freedom of assembly of the tank, improve the working ability for the assembly and improve the connection property of the respective members, particularly, the breathing condition. This bbject is solved by a heat exchanger as set forth in claim 1. Preferred developments of the invention are given in the subclaims. In the heat exchanger, the pair of protrusions provided on the inner surface of the first tank member so as to extend in the circumferential direction and to be arranged in the axial direction can hold at least one edge portion of the partition between the pair of protrusions. The held partition can be disposed at a desired predetermined position in the tank at a high accuracy. This positioning can be easily achieved merely by inserting the edge portion of the partition between the pair of protrusions. At a condition where the partition is thus positioned in the tank, the respective members including the partition are brazed. Therefore, the partition can be fixed precisely at a predetermined position in the tank. A necessary amount of flux required for achieving a good brazing can be easily retained between the pair of protrusions merely by applying flux at a portion between the pair of protrusions before brazing. At the time of brazing, a molten brazing material flows into the portion between the pair of protrusions naturally, and a sufficiently great amount of the brazing material can be retained at this portion. As a result, the partition and the inner surface of the tank can be brazed at a great strength. Moreover, since the edge portion of the partition is held between the pair of protrusions, even if there is a small dimensional error in the positions or shapes of the protrusions or the partition, a gap caused by the dimensional error can be absorbed by the above-described sufficiently great amount of the brazing material. Further, when the pair of protrusions are formed by the wall itself of the first tank member by processing, for example, drawing, bending, or pressing, the wall so as to protrude a part of the wall into the interior of the tank, the pair of protrusions having a function for positioning the partition can be provided in the tank without creating a portion small in thickness of wall, as in a conventional structure where a groove is defined on the inner surface of a tank such as one shown in FIG. 6. Therefore, decrease of the strength of the tank does not occur. Furthermore, when a slot is defined on the second tank member, the partition can be easily inserted into the interior of the tank through the slot in spite of a condition before or after assembly of the tank. Therefore, the working ability can be improved as well as the working freedom in the process for assembly can be increased. The application of flux also can be performed in spite of before or after assembly of the tank. For example, flux can be easily provided through the slot defined on the second tank member at a stage of temporary assembly of the tank. Further, when the partition and/or the first and second tank members are constructed from a material having a structure clad with a brazing material, both parts can be brazed to each other extremely easily. Some embodiments of the invention will now be described with reference to the appropriate figures, which are given by way of example only, and are not intended to limit the present invention. FIG. 1 is a perspective view of a heat exchanger according to a first embodiment of the present invention. FIG. 2 is an enlarged, exploded partial perspective view of a tank of the heat exchanger depicted in FIG. 1. FIG. 3 is a partial, vertical sectional view of the tank depicted in FIG. 2. FIG. 4 is a cross-sectional view of a tank of a conventional heat exchanger. FIG. 5 is a partial side view of a tank of another conventional heat exchanger. Referring to FIGS. 1 to 3, a heat exchanger 1 is provided according to the invention. Heat exchanger 1 is constructed as a heater for vehicles heated by water supplied after cooling an engine. Heat exchanger 1 includes a pair of headers construacted as a first tank 6 and a second tank 7. A plurality of flat heat transfer tubes 2 (for example, water tubes or refrigerant tubes) are fluidly interconnected between first and second tanks 6 and 7. In this embodiment, flat heat transfer tube 2 is formed as a flat tube. Corrugated fins 3 are disposed on both surfaces of each heat transfer tube 2. Side members 4 and 5 are provided on the upper surface of the uppermost fin 3 and on the lower surface of the lowermost fin 3, respectively. Each of tanks 6 and 7 is sealed at both open ends by caps 21 and 22, respectively. A partition 10 is provided in first tank 6 for dividing the interior of the first tank 6 into two chambers 6a and 6b. An inlet pipe 8 for introducing a heat transfer medium, for example, refrigerant or water, into the interior of first tank 6 is connected to chamber 6a. An outlet pipe 9 for discharging the heat transfer medium from the interior of first tank 6 is connected to chamber 6b. Second tank 7 does not have a partition therein. Although only one partition 10 is provided in first tank 6 in this embodiment, a plurality of partitions may be provided therein and the interior of a tank may be divided into three or more chambers, as needed. Further, second tank 7 may have a partition, as needed. First tank 6 comprises at least two members connected to each other. In this embodiment, as shown in FIG. 2, first tank 6 comprises a first tank member 11 and a second tank member 12 connected to each other. First tank member 11 is constructed as a member having a U-shaped cross section with an opening at its upper end. Second tank member 12 is constructed as a plate-like member having connecting portions 12a and 12b formed by bending or pressing at both end portions in the width direction. The upper edge portions 11a and 11b of first tank member 11 are inserted into the respective connecting portions 12a and 12b of second tank member 12 and connected thereto to form first tank 6. A pair of protrusions 13a and 13b are provided on the inner surface of first tank member 11. Pair of protrusions 13a and 13b extend in the circumferential direction of the inner surface of first tank 6 and they are arranged in the axial direction of first tank 6 at a predetermined position. Pair of protrusions 13a and 13b hold an edge portion 10a (lower edge portion and side edge portions) of partition 10 in a concave portion 16 formed between the pair of protrusions 13a and 13b as shown in FIG. 3. Although pair of protrusions 13a and 13b are formed by drawing a part of the wall itself of first tank member 11 in this embodiment, they may be formed by preparing other members and connecting the members onto the inner surface of the first tank member 11. A slot 15 is defined on second tank member 12 at a central position in the longitudinal direction of the second tank member 12, and the slot 15 extends in the width direction of the second tank member 12. Partition 10 is inserted into the interior of first tank 6 through slot 15 down to a position where the lower end of the partition 10 comes into contact with the inner surface of first tank member 11. The position provided with slot 15 is determined such that the slot 15 is located at a position just above concave portion 16 formed between pair of protrusions 13a and 13b when first and second tank members 11 and 12 are assembled. A plurality of other slots 14 are defined on second tank member 12. One opening end portion of each tube 2 is inserted into each slot 14 and connected to second tank member 12 for communicating the fluid path of each tube 2 with the interior of first tank 6. In this embodiment, partition 10 and/or first and second tank members 11 and 12 are constructed from a material having a structure clad with a brazing material, for example, an aluminum alloy material clad with a brazing material. Partition 10 is brazed to first and second tank members 11 and 12 at positions of the side surfaces of pair of protrusions 13a and 13b, a portion between the pair of protrusions 13a and 13b and the inner edge portion of slot 15. In the heat exchanger a heat transfer medium (for example, water or refrigerant) introduced through inlet pipe 8 flows into chamber 6a of first tank 6, and is distributed into the respective tubes 2 disposed upper side in FIG. 1. After the heat transfer medium flows in the respective tubes 2, the respective flows of heat transfer medium join in second tank 7. The joined heat transfer medium flows in the second tank 7 in the axial direction, and then the heat transfer medium is distributed into the respective tubes 2 disposed lower side in FIG. 1. After the heat transfer medium flows in the respective tubes 2, the respective flows of heat transfer medium join in chamber 6b of first tank 6, and the heat transfer medium is then discharged through outlet pipe 9. Pair of protrusions 13a and 13b are formed on the inner surface of first tank member 11 and edge portion 10a of partition 10 is held in concave portion 16 formed between the pair of protrusions 13a and 13b when the partition 10 is assembled. Therefore, partition 10 can be disposed precisely at a predetermined position in first tank 6. At the precisely positioned condition, the partition 10 is brazed to first tank 6. Further, since partition 10 is held by pair of protrusions 13a and 13b extending in the circumferential direction on the inner surface of tank 6, the respective edge portions of the partition 10 can be surely fixed temporarily before brazing and then brazed to the inner surface of the tank 6 at a desired condition. In the brazing, a molten brazing material naturally flows into concave portion 16 between pair of protrusions 13a and 13b and a sufficiently great amount of the brazing material can be retained in the concave portion 16 for achieving a better brazing condition. For example, even if there occurs a gap between the lower edge surface of partition 10 and the bottom surface of concave portion 16 as shown in FIG. 3, the above-described sufficiently great amount of brazing material easily can fill the gap up. As a result, a good brazing condition can be ensured and a great strength of the brazed portion can be easily obtained. For the brazing, a flux may be applied on a surface to be brazed. In this embodiment, the flux can be easily applied onto concave portion 16 between pair of protrusions 13a and 13b before assembly of first and second tank members 11 and 12. Alternatively, even after assembly of first and second tank members 11 and 12, the flux can be easily provided onto concave portion 16 from upper side through slot 15 by, for example, injection. As a result, a further better condition for brazing can be-realized before actual brazing. Further, since pair of protrusions 13a and 13b are formed from the wall itself of first tank member 11 by drawing, the pair of protrusions 13a and 13b having a good function for positioning and holding partition 10 can be efficiently provided in tank 6 without forming a thinner and weaker portion, as in a conventional structure such as one shown in FIG. 6. Therefore, a sufficiently great strength of tank 6 can be ensured. Furthermore, in this embodiment, because slot 15 is defined on second tank member 12, partition 10 can be easily inserted into tank 6 through the slot 15 and easily disposed at a predetermined position in the tank 6 in spite of a condition before or after connection of first and second tank members 11 and 12. Therefore, the working efficiency for assembly can be greatly improved, and the freedom for the assembly can be increased.

Claims: A heat exchanger having a tank (6) formed from at least first and second tank members (11, 12) connected to each other, at least one partition (10) being disposed in said tank (6) for dividing an interior of said tank (6) into at least two chambers (6a, 6b), and a slot (15) being defined on said second tank member (12) for inserting said partition (10) into the interior of said tank (6) through said slot (15), characterized in that a pair of protrusions (13a, 13b) extending in a circumferential direction of an inner surface of said tank (6) and arranged in an axial direction of said tank (6) are provided on an inner surface of said first tank member (11) to hold a lower edge portion and side edge portions (10a) of said partition (10) therebetween. The heat exchanger according to claim 1, wherein said pair of protrusions (13a, 13b) are formed by protruding a part of a wall of said first tank member (11) into an interior of said tank (6). The heat exchanger according to any preceding claim, wherein said partition (10) is connected to the inner surface of said tank (6). The heat exchanger according to claim 3, wherein said partition (10) is brazed to the inner surface of said tank (6). The heat exchanger according to claim 4, wherein said partition (10) and/or said first and second tank members (11, 12, 17) are constructed from a material clad with a brazing material. The heat exchanger according to claim 4 or 5, wherein a flux is applied to the inner surface of said tank (6) before brazing at least at a position between said pair of protrusions (13a, 13b), and said partition (10) is brazed to the inner surface of said tank (6) using the flux.

Inventors: KADO HIROTAKA, WATANABE AKIMICHI, KADO, HIROTAKA, WATANABE, AKIMICHI, KADO, HIROTAKA, C/O SANDEN CORPORATION, Watanabe, Akimichi,c/o Sanden Corporation
Applicants: SANDEN CORP, SANDEN CORPORATION
Application year: 1996
Main classification: F28F9
IPC codes: F28F9, F28D1