Mounting bracket for heat exchanger

Abstract: A mounting bracket (1) for a heat exchanger is connected to a heat exchanger body (2) by brazing. The bracket (1) has a first surface (13) connected to the heat exchanger body (2), a second surface (14) connected to an external member (6) and a pin (12) projecting from the second surface (14) for positioning the bracket (1) relative to the external member (6). A hole (16) is formed in the first surface (13) of the bracket (1) and this hole (16) is in communication with a bracket portion securing the pin (12) to enable a brazing material to flow from the first surface (13) to the pin securing bracket portion through the hole (16). The separation (a) between the first and second surfaces (13, 14) is reduced, and the overall size of the bracket (1) is reduced. By the reduction of the size of the bracket (1), a space for installation of the heat exchanger may be reduced, or the area of the core portion of the heat exchanger body (2) may be increased even in a limited space.

Description: The present invention relates to a heat exchanger including a mounting bracket for mounting the heat exchanger on an external member, and more particularly, to an improved mounting bracket for a heat exchanger suitable for a situation in which space for mounting is limited, for example, for a heat exchanger used in automobiles. An example of a known bracket structure 100 for mounting a heat exchanger on an external member 107 comprising the features of the preamble of claim 1 is shown in Fig. 8. In Fig. 8, a heat exchanger body 101 has a header pipe 102, and a bracket 103 is connected to header pipe 102 by brazing. Bracket 103 comprises a bracket body 103a and a pin 103b projected from bracket body 103a for positioning bracket body 103a relative to an external member, for example, a frame or a member of an automobile or a rubber cushion 107. Pin 103b is fixed to bracket body 103a by welding or brazing. Bracket body 103a is formed, for example, by the pressing of a plate or the extrusion. In bracket structure 100, pin 103b is fixed to bracket body 103a after pin 103b is inserted into a hole 104 provided in bracket body 103a. Because space for inserting pin 103b into hole 104 and working space for welding or brazing inserted pin 103b are required for bracket structure 100, a separation "a" must be maintained between a surface 105 of bracket body 103a connected to header pipe 102 and a surface 106 of bracket body 103a connected to an external member 107. Moreover, when bracket body 103a is formed by the pressing of a plate, the plate must be bent in a curved form along the surface of header pipe 102. Because a sufficient working space must be present for this pressing, it is also necessary that the dimension "a" is maintained at a sufficient large value. Thus, the permissible reduction in dimension "a" is limited in known bracket structure 100. In a situation in which space for installation of a heat exchanger is limited, for example, in the situation of heat exchanger installation in automobiles, it is desirable to ensure that the area of the core portion of the heat exchanger is as large as possible, thereby increasing the heat exchange performance of the heat exchanger as much as possible. However, when a reduction of separation "a" between surfaces 105 and 106 is limited, as described above, the increase of the heat exchange performance is also limited. It would be desirable to provide an improved bracket structure for mounting a heat exchanger which may reduce the separation between the surface connected to a heat exchanger body and the surface connected to an external member, thereby enlarging the area of a core portion of a heat exchanger despite limitation of the space for installation of the heat exchanger. Further, it would be desirable to provide an improved bracket structure for mounting a heat exchanger which may improve the reliability of brazing for fixing a pin used for positioning a mounting bracket relative to an external member. According to the present invention there is provided a heat exchanger comprising a mounting bracket, the bracket comprising a first surface connected to a body of the heat exchanger, a second surface connected to an external member, and a pin projecting from the second surface for positioning the bracket relative to the external member, characterised in that a hole is formed in the first surface of the bracket and is in communication with the bracket portion securing the pin to enable a brazing material to flow from the first surface to the pin securing bracket portion through the hole. In the bracket structure, it is preferred that a brazing condition recognizing portion is provided on the pin securing bracket portion, so that the status of the brazing may be observed from the bracket's exterior. The pin may be temporarily secured prior to brazing. The temporary securing of the pin may be performed by caulking or spot welding. The pin may be inserted into an attachment hole provided in the bracket. In order to set an insertion depth of the pin into the attachment hole or a projection length of the pin from the second surface to a desired length, the pin may have an engaging portion for regulating an insertion depth of the pin into the attachment hole, or the attachment hole may have an engaging portion for regulating an insertion depth of the pin into the attachment hole. Although materials for forming the heat exchanger body and the bracket are not particularly restricted, at least a portion of the heat exchanger body connected to the first surface of the bracket may be composed of a material coated with a brazing material. Further, the position of attachment of the bracket on the heat exchanger body is not particularly restricted. For example, when the heat exchanger has a header pipe, the first surface of the bracket may be connected to a surface of the header pipe. In addition, the type of the heat exchanger is not limited. For example, the present invention is suitable for use in a multi-flow type heat exchanger comprising a pair of header pipes and a plurality of heat transfer tubes interconnecting the pair of header pipes. In such a multi-flow type heat exchanger, the bracket may be connected to each of the pair of header pipes. In the bracket structure according to the present invention, a brazing material easily flows from the first surface (for example, from the header pipe of the heat exchanger) into the pin securing bracket portion through the hole formed in the first surface during brazing of the heat exchanger body. Therefore, the brazing of the heat exchanger body and the brazing of the pin may be performed substantially simultaneously. In particular, when the portion of the heat exchanger body connected to the first surface is composed of a brazing material-coated material, the brazing material may flow naturally into the pin securing bracket portion. As a result, because a working space for securing a pin by welding or brazing in advance is not necessary, the separation between the first and second surfaces of the bracket may be decreased. The overall size of the bracket may be reduced, and ultimately, the area of the core portion of the heat exchanger may be enlarged even if the space for installation of the heat exchanger is limited. Moreover, because it is not necessary that the pin is fixed to the bracket by welding or brazing prior to the attachment to the heat exchanger body and because the pin may be brazed to the bracket substantially simultaneously with the brazing of the assembly of the heat exchanger body in a furnace, the manufacturing cost for the heat exchanger assembly including the bracket may be reduced. Further, when a brazing condition recognizing portion is provided, the brazing condition of the pin may be readily observed from the exterior of the bracket, thereby increasing the reliability of the brazing. Further objects and advantages of the present invention will be understood from the following detailed description of the preferred embodiments of the present invention with reference to the accompanying figures. Embodiments of the invention are now described with reference to the accompanying figures, which are given by way of example only, and are not intended to limit the present invention. Fig. 1 is a partial, perspective view of a heat exchanger connected with a mounting bracket according to a first embodiment of the present invention. Fig. 2 is an overhead view of the heat exchanger depicted in Fig. 1. Fig. 3 is a perspective view of the bracket depicted in Fig. 1. Fig. 4 is a side view of the bracket depicted in Fig. 3 as viewed in the direction of arrow A of Fig. 3. Fig. 5 is a side view of the bracket depicted in Fig. 3 as viewed in the direction of arrow B of Fig. 3. Fig. 6A is a perspective view of a pin with an engaging portion, and Fig. 6B is a perspective view of another embodiment of the pin with an engaging portion according to a second embodiment of the present invention. Fig. 7 is an elevational view of a bracket having a pin attachment hole with an engaging portion according to a third embodiment of the present invention. Fig. 8 is an overhead view of a known bracket structure for a heat exchanger. Referring to Figs. 1 to 5, a mounting bracket 1 for a heat exchanger is provided according to a first embodiment. Heat exchanger body 2 is mounted to an external member 6 (Fig. 2) via bracket 1. Heat exchanger body 2 includes a pair of header pipes 3 (in the figure, only one header pipe 3 is depicted.). A plurality of heat transfer tubes 4 (for example, flat-type refrigerant tubes) fluidly interconnect the pair of header pipes 3. Corrugated fin 5 is interposed between heat transfer tubes 4. Thus, the heat exchanger is constructed as a multi-flow type heat exchanger. Bracket 1 is connected to header pipe 3 of heat exchanger body 2 by brazing. Header pipe 3 is composed of a material coated with a brazing material, for example, an aluminum alloy coated with a brazing material. Utilizing this brazing material, bracket 1 is brazed to header pipe 3 as described below. Bracket 1 comprises a bracket body 11 and a pin 12 for positioning bracket body 11 of heat exchanger body 2 relative to an external member, for example, rubber cushion 6, or a frame or a member of an automobile. Bracket body 11 has a curved first surface 13 connected to header pipe 3 of heat exchanger body 2 and a second surface 14 connected to external member 6. Bracket body 11 is formed integrally with a header pipe side portion 11a forming first surface 13 and an external member side portion 11b forming second surface 14. Bracket body 11 includes a pin attachment hole 15. Pin 12 is inserted into pin attachment hole 15 to a predetermined depth, and the remaining portion of pin 12 projects from second surface 14 toward the exterior of bracket body 11 to permit connection to external member 6 and to position bracket body 11 at a predetermined position in relation to external member 6. Bracket body 11 and pin 12 are constructed, for example, from aluminum or an aluminum alloy, and they may be formed by extrusion. A hole 16 enabling a brazing material to flow from first surface 13 (header pipe side) to the pin securing bracket portion in pin attachment hole 15 is formed in first surface 13 to place hole 16 in communication with the pin securing bracket portion. This hole 16 may be readily formed, for example, by merely pressing a tip of a tool for hole processing by pressing, drilling, or end milling against first surface 13 and penetrating first surface 13 to produce hole 16 therein, at the time of processing of pin attachment hole 15 from the side of second surface 14. In this embodiment, pin attachment hole 15 is partially opened toward the exterior of bracket body 11 at an intermediate portion in the axial direction, i.e. , at a central portion of bracket body 11 between header pipe side portion 11a and external member side portion 11b. This partially opened portion forms a brazing condition recognizing portion 17 exposed to the exterior of bracket body 11 for recognizing the brazing condition of pin 12. Figs. 4 and 5 depict side views of bracket 1 of Fig. 3 as viewed in the respective directions of arrows A and B of Fig. 3. In this embodiment, although the insertion depth of pin 12 into pin attachment hole 15 is regulated by bringing the tip of pin 12 into contact with the outer surface of header pipe 3, pin 12 may be temporarily secured in pin attachment hole 15 prior to the brazing of heat exchanger body 2. For example, pin 12 may be temporarily secured at appropriate positions 18 in brazing condition recognizing portion 17 by caulking or spot welding, as depicted in Pig. 4. In such a temporary securing, the insertion depth of pin 12 into pin attachment hole 15 may be set substantially freely. In the first embodiment thus constituted, hole 16 is formed in first surface 13 of bracket body 11 that is connected to header pipe 3, and this hole 16 is in communication with pin attachment hole 15. When heat exchanger body 2 and bracket 1 are assembled and the assembly is brazed in a furnace, the brazing material flows naturally from the surface of header pipe 3 into pin attachment hole 15 through hole 16. The brazing material flows into the pin securing bracket portion in pin attachment hole 15 to braze and fix pin 12 to bracket body 11. Therefore, it is not necessary to braze or weld pin 12 to bracket body 11 in advance, thereby simplifying the manufacturing process and reducing the manufacturing cost. Because a working space for connecting pin 12 to bracket body 11 in advance is not necessary, separation "a" (Fig. 2) between first surface 13 and second surface 14 may be significantly reduced, and the entire size of bracket body 11 may be reduced. This reduction of separation "a" and the entire size of bracket body 11 may result in an enlargement of the area of the core portion of heat exchanger body 2, even if a space for installation of the heat exchanger is limited. Moreover, because bracket body 11 may be made by extrusion, a space for processing of curved first surface 13, for example, by pressing, also is not necessary. From this point of view, separation "a" may be significantly reduced. Thus, the reduction of separation "a" may result in the reduction of the space required for installation of the heat exchanger or the enlargement of the area of the core portion of the heat exchanger in a limited space for installation. Therefore, the present invention is useful particularly for a heat exchanger used in automobiles. Further, in the embodiment described above, because brazing condition recognizing portion 17 is provided, the brazing condition of pin 12 may be readily observed from the exterior of bracket body 11, thereby significantly increasing the reliability of the brazing. Figs. 6A and 6B depict variations of the structure of a pin according to a second embodiment of the present invention. In Fig. 6A, a flange portion 22 protrudes radially outward on the periphery of pin 21 and functions as an engaging portion. In Fig. 6B, a stepped portion 24 is formed as an engaging portion on the periphery of pin 23. Each of these engaging portions 22 and 24 is brought into contact with second surface 14 of bracket body 11 to regulate the insertion depth of pin 21 or 23. In these structures, the projection length of pin 21 or 23 is also regulated. Fig. 7 depicts a structure of a pin attachment hole according to a third embodiment of the present invention. In Pig. 7, an engaging portion 33 formed as a stepped portion is provided in pin attachment hole 32. The tip of pin 34 is inserted into pin attachment hole 32 and engages engaging portion 33, thereby regulating the insertion depth of pin 34. Although the structure for attaching a bracket to a header pipe has been explained in the above-described first, second, and third embodiments, such a bracket may be brazed to any portion of a heat exchanger body other than a header pipe. Further, the bracket structure according to the present invention may be applied to heat exchangers other than a multi-flow type heat exchanger.

Claims: A heat exchanger comprising a body (2) and a mounting bracket (1), the bracket (1) comprising a first surface (13) connected to the body, a second surface (14) connected, in use, to an external member (6), and a pin (12) projecting from the second surface (14) for positioning the bracket (1) relative to the external member (6) in use, characterised in that a hole (16) is formed in the first surface (13) of the bracket (1) and is in communication with the bracket portion securing the pin (12) to enable a brazing material to flow from the first surface (13) to the pin securing bracket portion through the hole (16). A heat exchanger according to claim 1, wherein the mounting bracket (1) further comprises a brazing condition recognizing portion (17), for enabling the status of brazing to be observed from the exterior of the bracket (1), provided on the pin securing bracket portion. A heat exchanger according to claim 1 or 2, wherein the pin (12) is temporarily secured prior to brazing. A heat exchanger according to claim 3, wherein the pin (12) is temporarily secured by a method selected from the group consisting of caulking and spot welding. A heat exchanger according to any preceding claim, wherein the pin (12) is inserted into an attachment hole (15) provided in the bracket (1). A heat exchanger according to claim 5, wherein the pin (21, 23) has an engaging portion (22, 24) for regulating an insertion depth of the pin (21, 23) into the attachment hole (15). A heat exchanger according to claim 5, wherein the attachment hole (32) has an engaging portion (33) for regulating an insertion depth of the pin (12) into the attachment hole (15). A heat exchanger according to any preceding claim, wherein the heat exchanger has a header pipe (3), and the first surface (13) of the bracket (1) is connected to a surface of the header pipe (3). A heat exchanger according to any preceding claim, wherein at least a portion of the heat exchanger body (2) connected to the first surface (13) is composed of a material coated with the brazing material. A heat exchanger according to any preceding claim, wherein the heat exchanger is a multi-flow type heat exchanger comprising a pair of header pipes (3) and a plurality of heat transfer tubes (4) interconnecting the pair of header pipes (3). A heat exchanger of claim 10, wherein the bracket (1) is connected to each of the pair of header pipes (3).

Inventors: TANAKA HIROSHI, TANAKA, HIROSHI
Applicants: SANDEN CORP, SANDEN CORPORATION
Application year: 1998
Main classification: F28F9
IPC codes: F28F9, B60K11