Patent Application
20120118543
This application is based on and incorporates herein by reference Japanese Patent Application No. 2010-257181 filed on Nov. 17, 2010.
1. Field of the Invention
The present invention relates to a heat exchanger.
2. Description of Related Art
For example, Japanese Unexamined Patent Publication JP 2007-120827A teaches a heat exchanger (more specifically, a radiator of a vehicle). This heat exchanger includes a core, in which tubes are stacked one after another in a stacking direction such that a fin is interposed between each adjacent two of the tubes. Two core plates are provided on two opposed longitudinal end sides, respectively, of the tubes. Each core plate includes tube holes and a groove. The tube holes are formed in a tube joint surface of the core plate, and the groove is formed to surround the tube joint surface in the core plate. Longitudinal end portions of the tubes are joined to the tube holes, respectively, of the core plate, and an opening end of a tank main body is inserted into the groove of the core plate.
Furthermore, a holding claw is formed in an outer wall surface (a core plate end portion) of each longitudinal end portion of the core plate and is bent by 180 degrees from the tank main body side toward the longitudinal center side of the tubes. Two reinforcing side plates (inserts) are placed on two sides, respectively, of the core, which are opposed to each other in the stacking direction of the tubes. A corresponding longitudinal end portion of the corresponding side plate is inserted into a gap between the outer wall surface and the holding claw. In the side plate, a shallow recess (a stepped part) is formed in a widthwise center part of the longitudinal end portion of the side plate, which is centered in the longitudinal end portion in an air flow direction of cooling air applied to the core of the heat exchanger. This recess is placed at a corresponding location where an end of the holding claw, which is bent by 180 degrees, is positioned relative to and engages the shallow recess. The tubes, the fins and the core plates are securely brazed together in a brazing process with a brazing material, which is previously applied to each brazing location (contact location) of the tubes, the fins and the core plates.
At the time of assembling the core of the above heat exchanger, the tubes and the fins are alternately stacked one after another in the stacking direction, and the two side plates are placed at the two outermost sides, respectively, of the stack of the tubes and the fins, which are opposed to each other in the stacking direction. In this way, a stacked assembly of the tubes, the fins and the side plates is formed. Thereafter, the longitudinal end portions of the tubes of the stacked assembly are inserted into the tube holes of the core plates, and the longitudinal end portions of the side plates are inserted into the gaps, respectively, each of which is formed between the corresponding outer wall surface and the corresponding holding claw. Thereby, the assembling of the core is completed.
The shallow recess (stepped part) of the longitudinal end portion of each side plate is made shallow and is positioned relative to the corresponding holding claw. Therefore, when an external force is applied in the air flow direction after the completion of the assembling of the core, each side plate may possibly be inadvertently released from the corresponding gap between the corresponding outer wall surface and the corresponding holding claw to possibly cause disassembling, i.e., collapse of the temporarily assembled core before the brazing process.
The present invention addresses the above disadvantage. According to the present invention, there is provided a heat exchanger, which includes a plurality of tubes, a side plate, a core plate and a tank. The tubes extend in a first direction and are stacked one after another in a second direction that is perpendicular to the first direction. The side plate is adapted to reinforce the plurality of tubes. The side plate is located on an outer side of the plurality of tubes in the second direction and extends in the first direction. The core plate extends in the second direction. A longitudinal end portion of each of the plurality of tubes is joined to the core plate. The tank is fixed to the core plate. A holding claw is formed in the core plate and is bent into a U-shape from a tank side end of an outer wall surface of a longitudinal end portion of the core plate to extend in the first direction on an outer side of the outer wall surface toward a side where the plurality of tubes is located. The side plate includes a side plate end portion, which is an end portion of the side plate in the first direction and is inserted into a gap that is defined between the outer wall surface and the holding claw. A through-hole extends through a bent portion of the holding claw, which is bent into the U-shape. A projection is formed in the side plate end portion to project in the first direction. The projection is inserted through the through-hole of the holding claw.
The invention, together with additional objectives, features and advantages thereof, will be best understood from the following description, the appended claims and the accompanying drawings in which:
Various embodiments of the present invention will be described with reference to the accompanying drawings. In the following embodiments, similar components are indicated by the same reference numerals and will not be redundantly described to simplify the description. In each of the following embodiments, if only a part of a structure is described, the remaining part of the structure is the same as that of the previously described embodiment(s). Any one or more components of any one of the following embodiments may be combined with the components of the other one of the following embodiments without departing a scope and spirit of the present invention.
As shown in
The core 110 includes the tubes 111, the fins 112, the side plates 113 and the core plates 114. These components 111-114 are made of aluminum or an aluminum alloy, which has a high strength and is highly corrosion resistant.
Each tube 111 is a tubular member, in which the coolant flows. Furthermore, the tube 111 is formed by, for example, bending an elongated rectangular plate material and is configured as a flat tube, which has a generally flat cross section in a plane that extends in a direction perpendicular to a longitudinal direction of the tube 111. The longitudinal direction of the tube 111 will be also referred to as a first direction. Furthermore, each fin 112 is a heat radiation member that enlarges a heat transfer surface area (i.e., a heat radiating surface area). In the present embodiment, the fin 112 is a corrugate fin, which is formed by bending an elongated thin rectangular plate material into a wavy form through a roll forming process.
Each side plate 113 is a reinforcing member, which is adapted to reinforce the structure of the core 110 (thereby reinforcing the tubes 111) and is elongated in the longitudinal direction of the tube 111. A length of the side plate 113 is set to be substantially the same as a length of the tube 111 in the longitudinal direction of the tube 111. An intermediate portion (also referred to as a general portion) 113a, which is located in a longitudinal intermediate region of the side plate 113, is configured to have a U-shaped cross section that opens toward an outer side in a stacking direction (a left-to-right direction in
A distal end part 113c is formed in a distal end part (an upper part in
The core plate 114 is a narrow elongated plate member, which is elongated in the stacking direction of the tubes 111. A groove 114b is formed by press working in an outer peripheral portion of the core plate 114 to extend all around the core plate 114. A wall surface of the groove 114b, which is located at an outer side (the left side in
The two pawls 114c are formed in the outer wall surface 114a such that the two pawls 114c are symmetrically placed about a center location of the outer wall surface 114a, which is centered in the air flow direction. An extent of a space between the two pawls 114c is set to be larger than the width of the side plate end portion 113b, which is measured in the air flow direction. The holding claw 114d is formed between the two pawls 114c (a center location of the outer wall surface 114e. which is centered in the air flow direction). An upper tank 120 side end portion (a claw portion) of the outer wall surface 114a, which projects toward the upper tank 120, is bent by 180 degrees toward the tubes 111 to form the holding claw 114d. That is, the holding claw 114d includes a U-turned portion (bent portion) and a claw main body. The U-turned portion is formed by bending the upper tank 120 side end portion of the outer wall surface 114a toward the tubes 111 in a U-shape form. The claw main body extends from the U-turned portion toward the tubes 111. A gap is formed between the outer wall surface 114a and the claw main body of the holding claw 114d, and the side plate end portion 113b is insertable into this gap.
A width of the holding claw 114d, which is measured in the air flow direction, is set to be generally the same as the width of the side plate end portion 113b, which is measured in the air flow direction. A projecting length of the claw main body of the holding claw 114d, which projects toward the tubes 111, is set such that the claw main body covers at least a portion of the side plate end portion 113b to limit outward movement of the side plate end portion 113b in the stacking direction of the tubes 111. Furthermore, the distal end part 113c of the side end portion 113b is placed in the inner side of the U-turned portion of the holding claw 114d, and thereby the longitudinal movement of the side plate end portion 113b in the longitudinal direction of the side plate 113 is limited.
A through-hole 114e is formed to extend through the wall of the U-turned portion of the holding claw 114d in a thickness direction thereof, and the projection 113d of the side plate 113 is insertable through the through-hole 114e in the longitudinal direction of the side plate 113. The through-hole 114e is elongated in the air flow direction. A width of the through-hole 114e, which is measured in the air flow direction, is set to be larger than a width of the distal end of the projection 113d, which is measured in the air flow direction. Furthermore, the width of the through-hole 114e, which is measured in the air flow direction, is set to be slightly larger than or generally equal to a width of the base end of the projection 113d, which is measured in the air flow direction. Thereby, when the projection 113d is completely inserted through the through hole 114e to place the base end of the projection 113d into the through-hole 114e, the movement of the projection 113d and thereby of the side plate 113 in the air flow direction is limited.
A plurality of tube holes 114f is formed in the core plate 114 at an inner area of the core plate 114 (a main surface of the core plate 114), which is located on an inner side (a right side in
The tubes 111 and the fins 112 are stacked such that the tubes 111 and the fins 112 are alternately arranged one after another in the stacking direction (the left-to-right direction in
As shown in
The tubes 111, the fins 112, the side plates 113 and the core plates 114 are brazed together with a brazing material applied to the surfaces of the tubes 111, the side plates 13 and the core plates 114 to form the core 110.
Each of the upper tank (tank) 120 and the lower tank (tank) 130 extends along the length of the corresponding core plate 114 in the stacking direction of the tubes 111. Each of the upper and lower tanks 120, 130 is configured into a half-container body that has a U-shaped cross section in a plane, which is taken in a direction perpendicular to the longitudinal direction of the tank 120, 130. An opening end of each tank 120, 130, which is directed toward the core 110, is inserted into the groove 114b of the adjacent core plate 114 and is securely held by the pawls 114c through a sealing packing (not shown) upon swaging the pawls 114c against the tank 120, 130. Therefore, each of the tanks 120, 130 is mechanically fixed to the corresponding core plate 114. The tubes 111 (more specifically, the interior of each tube 111) is communicated with the interior space of each tank 120, 130.
The upper tank 120 is a tank that distributes the coolant from the engine to each tube 111. The upper tank 120 is made of a resin material (e.g., polyamide also referred to as a PA material). The upper tank 120 includes a tank main body 121, which is formed as the half-container body. The tank main body 121 has an inlet pipe 121a, a plurality (four in this instance) of fan shroud attachment portions 121b and a plurality (two in this instance) of vehicle body attachment portions 121c, which are formed integrally in the tank main body 121. The inlet pipe 121a receives the coolant from the engine. Upper connections of a fan shroud of the electric fan (not shown) are installed to the shroud attachment portions 121b, respectively. The vehicle body attachment portions 121c are installed to a body of the vehicle.
The lower tank 130 is a tank that collects the coolant from the respective tubes 111. The lower tank 130 is made of a resin material (e.g., polyamide also referred to as the PA material). Similar to the upper tank 120, the lower tank 130 includes a tank main body 131, which is formed as the half-container body. The tank main body 131 has an outlet pipe 131a, a plurality (two in this instance) of fan shroud attachment portions 131b, a plurality (two in this instance) of vehicle body attachment portions 131c and a drainer 131d, which are formed integrally in the tank main body 131. The outlet pipe 131a outputs the coolant from the interior of the tank main body 131. Lower connections of the fan shroud are installed to the fan shroud attachment portions 131b, respectively. The vehicle body attachment portions 131c are installed to the body of the vehicle. The drainer 131d is provided to drain the coolant at the time of maintenance. In addition, an oil cooler 140 is installed in the lower tank 130 to cool automatic transmission fluid (ATF) of an automatic transmission of the vehicle.
The radiator 100, which is formed as described above, is placed in a front portion of an engine compartment (a behind of a grille) of the vehicle. The vehicle body attachment portions 121c, 131c are installed to a frame of the body of the vehicle. An inlet hose extending from the engine is installed to the inlet pipe 121a. In addition, an outlet hose returning to the engine is installed to the outlet pipe 131a.
The coolant, which is supplied from the engine into the upper tank 120 through the inlet hose and the inlet pipe 121a, is distributed into the tubes 111 and flows downward through the tubes 111. At this time, the coolant, which flows downward through each tube 111, is cooled through heat exchange with the cooling air applied to the core 110. This heat exchange is promoted by the fins 112 joined to the tubes 111. Then, the coolant is collected into the lower tank 130 after flowing through the tubes 111 and is returned to the engine trough the outlet pipe 131a and the outlet hose.
At the time of assembling the core 110 of the radiator 100, each of the two side plate end portions 113b of each side plate 113 is inserted into the gap between the outer wall surface 114a of the corresponding core plate 114 and the corresponding holding claw 114d, so that the side plate 113 is secured to the core plate 114 by the holding claw 114d. In this way, the tubes 111 and the fins 112 are held between the side plates 113. Furthermore, the projection 113d of each side plate end portion 113b of each side plate 113 is inserted into the through-hole 114e of the corresponding holding claw 114d.
In this way, upon completion of the assembling process of the core 110 through the assembling of the tubes 111, the fins 112, the side plates 113 and the core plates 114, the side plate end portions 113b can be securely held with the holding claws 114d, respectively, in both of the stacking direction of the tubes 111 and the longitudinal direction of the tubes 111. Furthermore, each projection 113d of each side plate 113 is inserted into the through-hole 114e of the corresponding holding claw 114d, so that the corresponding side plate end portion 113b can be reliably and securely held in the air flow direction. Thereby, the assembled state of the core 110 is securely maintained, so that the side plates 113 will not be come off from the core plates 114. Thereby, it is possible to limit the disassembling of the core 110.
The tapered portion 113e is formed in each projection 113d, as discussed above. Therefore, at the time of assembling the tubes 111 and the side plates 113 to the core plates 114, the insertion of the projection 113d can be started while a sufficient gap is provided between the distal end of the projection 113d and the inner surface of the through-hole 114e. Therefore, it is possible to improve and ease the insertion of the projection 113d into the through-hole 114e. When the projection 113d is completely inserted through the through-hole 114e, the base end of the projection 113d is fitted into the through-hole 114e without having a substantial gap between the base end of the projection 113d and the inner surface of the through-hole 114e. Therefore, the projection 113d can be securely held by the holding claw 114d without forming a substantial play therebetween in the air flow direction, i.e., without causing a rattling movement therebetween in the air flow direction.
Furthermore, the location of the distal end of the projection 113d of each side plate 113 is set to generally coincide with the location of the tube end 111a of each of the tubes 111 in the longitudinal direction of the tubes 111, as discussed above. Therefore, at the time of stacking, i.e., assembling the tubes 111, the fins 112 and the side plates 113 together or at the time of installing the core plates 114 to the tubes 111 and the side plates 113, a positioning member, such a simple plate, may be placed on the side where the corresponding tank 120, 130 is placed during the process of positioning the tube ends 111a of the tubes 111 and the distal ends of the projections 113d of the side plates 113. In this way, the process of the positioning can be eased while the configuration of the positioning member is simplified.
In the core 110, the tube-to-tube pitch Tp, i.e., an interval between each adjacent two of the tubes 111 is set to a predetermined value based on a thickness of each tube 111, which is measured in the stacking direction, and a height of the crests of each fin 112, which is measured in the stacking direction. In the present embodiment, a distance (hereinafter referred to as a tube-to-side plate pitch) between a center of the outermost tube 111, which is centered in the outermost tube 111 in the stacking direction, and a center of the adjacent projection 113d (the side plate end portion 113b), which is centered in the projection 113d in the stacking direction, is set to a value, which is obtained by multiplying the tube-to-tube pitch Tp with an integer number. Desirably, this integer number is two (2), so that the tube-to-side plate pitch=2 Tp in this embodiment. This setting is made for the following reason in view of a requirement of the following manufacturing process.
Specifically, the core 110 is assembled through the following procedure.
(1) The tubes 111, the fins 112 and the side plates 113 are assembled into the stacked assembly and is transferred to a next assembling process.
(2) The stacked assembly is compressed in the stacking direction to implement and maintain the preset tube-to-tube pitch Tp.
(3) The core plates 114 are pressed and fitted to the corresponding tube ends 111e. and the side plate end portions 113b of the side plates 113 are inserted into the corresponding holding claws 114d such that the projections 113d are inserted through the through-holes 114e of the corresponding holding claws 114d.
At the time of transferring, i.e., transporting the stacked assembly to the next assembling process discussed in the above section (1), a screw 210 shown in
At this time, since the tube-to-side plate pitch is set to the value, which is obtained by multiplying the tube-to-tube pitch Tp with the integer number (two in this embodiment), the projections 113d (the side plate end portions 113b) of the side plates 113 can be inserted into the corresponding segments of the valley 212 in addition to the tube ends 111a. Thereby, the stacked assembly of the tubes 111, the fins 112 and the side plates 113 can be transferred, i.e., transported with the screw 210.
Furthermore, at the time of installing the core plates 114 discussed above in the section (3), a pusher jig 220 shown in
In the state where each of the protrusions 221 of the pusher jig 220 is placed between the corresponding adjacent two of the tubes 111 after the setting of the core plate 114 to the stacked assembly of the tubes 111, the fins 112 and the side plates 113, the pusher jig 220 is pushed against the core plate 114 from the tank 120, 130 side toward the tube 111 side. Thereby, the core plate 114 is fitted to the stacked assembly of the tubes 111, the fins 112 and the side plates 113.
In this embodiment, the tube-to-side plate pitch is set to the value, which is obtained by multiplying the tube-to-tube pitch Tp with the integer number (two in this embodiment). Therefore, it is only required to provide the pusher jig 220, which has the length that corresponds to the maximum possible number of the tubes 111, the fins 112 and the side plates 113, which are stacked together. In this way, it is possible to avoid the abutment of the projections 113d (the side plate end portions 113b) of the side plates 113 against the protrusions 221 of the pusher jig 220 even in the case where the manufacturing line need to produce the various sizes of the cores 110, which have different numbers, respectively, of the tubes 111, the fins 112 and the side plates 113. Thereby, the core plates 114 of various sizes can be installed by using the single pusher jig 220 without a need for replacing the pusher jig 220 to another one.
Furthermore, the tube-to-side plate pitch is set to the value, which is obtained by multiplying the tube-to-tube pitch Tp with two in this embodiment, as discussed above. Therefore, the minimum size of the connection (the groove 114b) between the core plate 114 and the tank 120, 130 can be formed in the outer peripheral portion of the core plate 114, and it is possible to avoid formation of a wasteful space, which is not used in the heat exchange, at a location between each outermost tube 111 and the adjacent side plate end portion 113b. Thereby, it is possible to form the radiator 100 into the compact size (low profile).
Now, modifications of the above embodiments will be described.
In the above embodiments, the tapered portion 113e is formed in the projection 113d of each side plate 113. However, if the projection 113d can be appropriately inserted into the corresponding through-hole 114e without a difficulty, the tapered portion 113e may be eliminated. In such a case, the width of the projection 113d, which is measured in the air flow direction, may be set to be slightly smaller than the width of the corresponding through-hole 114e, which is measured in the air flow direction.
Furthermore, in the above embodiments, the location of the distal end of each projection 113d of each side plate 113 in the longitudinal direction of the tubes 111 coincides with the location of each corresponding tube end 111a in the longitudinal direction of the tubes 111. However, the present invention is not limited this. Specifically, the shape of the positioning member, which is used to position the corresponding component (the tubes 111, the fins 112 and the side plates 113) of the stacked assembly or of the assembly of the core 110, may be changed to any appropriate shape (e.g., by changing the planar member to the stepped member) to correspond with such a change in the positioning of the corresponding component (the tubes 111, the fins 112 and the side plates 113).
Furthermore, in the above embodiments, the tube-to-side plate pitch is set to the value, which is obtained by multiplying the tube-to-tube pitch Tp with the integer number (e.g., two). However, the present invention is not limited to this. Specifically, the use of the screw 210 and the pusher jig 220 discussed in the second embodiment may be eliminated from the manufacturing process. Alternatively, a transferring mechanism (a transporting mechanism) and a pusher mechanism, which correspond to the configuration of the stacked assembly or the core 110, may be used in place of the screw 210 and the pusher jig 220. In such a case, the tube-to-side plate pitch may be appropriately set depending on a need.
Furthermore, in the above embodiments, the heat exchanger is implemented as the radiator 100 for cooling the engine. However, the heat exchanger of the present invention may be implemented as any other type of heat exchanger, such as an intercooler for cooling the intake air of the engine or a condenser for a refrigeration cycle, as long as the side plate end portion 113b is inserted into the gap between the outer wall surface 114a of the core plate 114 and the holding claw 114d.
In the above embodiments, the holding claw 114d is the single holding claw in each longitudinal end portion of the core plate 114 and is centered in the longitudinal end portion of the core plate 114 in the air flow direction, and the projection 113d is the single projection in each side plate end portion 113b of the side plate 113 and is centered in the side plate end portion 113b (also in the side plate 113) in the air flow direction. However, the number of the holding claw(s) 114d, each of which has the through hole 114e, in each longitudinal end portion of the core plate 114 is not limited to one and may be increased to any desirable number. Similarly, the number of the projection(s) 113d in each side plate end portion 113b of the side plate 113 is not limited to one and may be increased to any desirable number, which corresponds to the number of the holding claws 114d.
Additional advantages and modifications will readily occur to those skilled in the art. The invention in its broader terms is therefore not limited to the specific details, representative apparatus, and illustrative examples shown and described.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2010-257181 | Nov 2010 | JP | national |
