Patent Application
20160296993
The present invention relates to a method for forming an end plate for a heat exchanger provided in a refrigerating circuit used in, for example, a vehicle air conditioning apparatus, and also relates to a heat exchanger equipped with end plates formed by this method.
Conventionally, there has been known a heat exchanger including: a pair of headers spaced from one another and extending in parallel with one another; a plurality of heat exchanger tubes spaced from each other in the header extending direction, each of the heat exchanger tubes being connected to the headers at both ends and; heat-transfer fins provided between adjacent heat exchanger tubes and also provided on the outer sides of the outer most heat exchanger tubes in the header extending direction; and end plates provided on the outer sides of the top and bottom heat-transfer fins, respectively, in the header extending direction, each of the end plates including a base part contacting the heat-transfer fin and extension parts extending from both sides in the width direction of the base part toward the outside of the header extending direction (see, for example, Patent literature 1).
This end plate for a heat exchanger is formed by press working including: inserting a plate member between a concave die and a convex die to bend the plate member, the concave die including a groove bottom surface and a pair of groove wall surfaces extending from both sides of the groove bottom surface, and the convex die including a convex top surface facing the groove bottom surface of the concave die and convex wall surfaces facing the groove wall surfaces.
The end plate formed with the concave die and the convex die includes a bent portion between the base part and each of the extension parts which has a large radius of curvature, and therefore the width of the flat surface of the end plate facing the heat-transfer fin is smaller than the width of the heat-transfer fin. In addition, the end plate formed with the concave die and the convex die is connected to the adjacent heat-transfer fin by brazing. In this case, the area of the portion contacting the heat-transfer fin is small, and therefore the strength such as vibrational proof of the entire heat exchanger might be insufficient.
It is therefore an object of the present invention to provide a method for forming an end plate for a heat exchanger that can improve the strength such as vibration proof of the heat exchanger by increasing the area of the portion of the end plate contacting the adjacent heat-transfer fin, and also provide a heat exchanger equipped with end plates formed by this method.
To achieve the above-described object, the present invention provides a method for forming an end plate for a heat exchanger, the heat exchanger including: a pair of headers spaced from one another and extending in parallel with one another; a plurality of heat exchanger tubes spaced from each other in a header extending direction, each of the heat exchanger tubes being connected to the headers at both ends; heat-transfer fins provided between adjacent heat exchanger tubes and also provided on outer sides of outermost heat exchanger tubes in the header extending direction; and end plates provided on the outer sides of the top and bottom heat-transfer fins, respectively, in the header extending direction, each of the end plates including a base part contacting a heat-transfer fin and extension parts extending from both sides in a width direction of the base part toward an outside of the header extending direction, the method comprising: preparing a concave die including a groove bottom surface and a pair of groove wall surfaces extending from both ends in the width direction of the groove bottom surface; preparing a convex die including a convex top surface facing the groove bottom surface of the concave die, convex wall surfaces facing the groove wall surfaces of the concave die, and protrusions provided along both sides in the width direction of the convex top surface; and inserting a plate member between the concave die and the convex die to form an end plate. By this means, when the plate member is bent between the concave die and the convex die, the protrusions of the convex die push both sides in the width direction of the base part of the plate member to the concave die side. Therefore, it is possible to reduce the radius of curvature of the bent portion between the base part and each of the extension parts of the end plate, and consequently increase the width of the portion of the base part contacting the heat-transfer fin.
By this means, when the plate member bent between the concave die and the first convex die is inserted between the concave die and the second convex die, the portions corresponding to the extension parts are pushed by the convex base surface of the second convex die against the concave die. Therefore, it is possible to reduce the radius of curvature of the bent portion between the base part and the extension parts of the end plate, and consequently to increase the width of the portion of the base part contacting the heat-transfer fin.
By this means, when the plate member is bent between the concave die and the convex die, the plate member is bent at the grooves formed in the plate member. Therefore, it is possible to reduce the radius of curvature of the bent portion between the base part and each of the extension parts of the end plate, and consequently to increase the width of the portion of the base part contacting the heat-transfer fin.
According to the present invention, it is possible to reduce the radius of curvature of the bent portion between the base part and each of the extension parts of the end plate, and increase the width of the portion of the base part contacting the heat-transfer fin. By this means, it is possible to increase the area of the portion of the endplate connected to the heat-transfer fin by brazing, and therefore to improve the strength, rigidity, vibration proof and so forth of the heat exchanger.
A heat exchanger equipped with an end plate according to the present invention is applicable to a refrigerating circuit used in a vehicle air conditioning apparatus. As shown in
In the refrigerant circuit 1, the outdoor heat exchanger 10 is configured to release the heat from the refrigerant, and the indoor heat exchanger 3 is configured to absorb the heat into the refrigerant, so that cooling of the vehicle interior A is performed.
As shown in
Each of the headers 11 may be a hollow cylindrical member made of metal such as aluminum. The ends of the heat exchanger tubes 12 are connected to the outer periphery of each of the headers 11. The first header 11 includes a refrigerant inlet 11a configured to flow the refrigerant discharged from the compressor 2 into the first header 11, and a refrigerant outlet 11b configured to flow the refrigerant in the first header 11 out to the indoor heat exchanger 3. Meanwhile, the second header 11 includes a refrigerant outlet 11c configured to flow the refrigerant in the second header 11 out into the liquid receiver 13, and a refrigerant inlet 11d configured to flow the refrigerant having passed through the liquid receiver 13 into the second header 11. In addition, each of the headers 11 includes a plurality of partitions 11e for dividing the inside of the header 11 in the vertical direction to determine the flow direction of the refrigerant flowing through the heat exchanger tubes 12. In
Each of the heat exchanger tubes 12 is a tubular member, which is a hollow and flat plate, formed by extruding metal such as aluminum. Each of the heat exchanger tubes 12 are arranged such that the longitudinal direction (width direction) of the cross-section of its flow path matches the flow direction of the air subjected to a heat exchange with the refrigerant. In addition, by dividing the inside of each of the heat exchanger tubes 12 in the longitudinal direction (width direction) of the cross-section of the flow path, a plurality of refrigerant flow paths, as fluid flow paths through which the refrigerant flows, are formed in the heat exchanger tube 12 in the longitudinal direction (width direction) of the cross-section of the flow path.
The liquid receiver 13 is a metallic member made of, for example, aluminum, and is formed in a cylindrical shape closed at both ends. The liquid receiver 13 is disposed such that its central axis extends in the vertical direction like the headers 11, and is connected to the second header 11 via the refrigerant outlet 11c and the refrigerant inlet 11d. A dryer and a filter are accommodated in the liquid receiver 13. The drier removes water from the refrigerant flowing into the liquid receiver 13, and the filter catches foreign materials such as dust in the refrigerant flowing into the liquid receiver 13.
Each of the heat-transfer fins 14 is formed with a corrugated plate member made of metal such as aluminum, and attached to the heat exchanger tube 12 and the end plate 15 by brazing.
Each of the end plates 15 is formed by pressing a metallic pate 15′ which is made of, for example, aluminum and has a brazing filler metal layer. As shown in
The brackets 16 are attached to the end plate 15 between the extension parts 15b by welding, riveting, swaging and so forth, and are fixed to the end plate 15 by brazing. The brackets 16 are fixed to a member, for example, in the engine room outside the vehicle interior A by fastener members such as bolts and nuts. The outdoor heat exchanger 10 is mounted in the engine room via the brackets 16.
In the refrigerant circuit 1 including the heat exchanger having the above-described configuration, when the compressor 2 is driven, the refrigerant discharged from the compressor 2 releases the heat in the outdoor heat exchanger 10, is decompressed via the expansion valve 4, absorbs the heat in the indoor heat exchanger 3, and is sucked into the compressor 2.
Now, a method for forming the end plate 15 will be described with reference to
The concave die 21 is formed as a groove and has a flat groove bottom surface 21a and groove wall surfaces 21b extending from both sides of the groove bottom surface 21a.
Meanwhile, the convex die 22 is a projection and has a convex top surface 22a facing the groove bottom surface 21a and convex wall surfaces 22b facing the groove wall surfaces 21b. Protrusions 22c are provided on the convex top surface 22a to extend along the both sides of the convex top surface 22a. Each of the protrusions 22c has a rectangular cross-section having a width W3 of 0.5 mm and a height H of 0.3 mm.
When pressed by the concave die 21 and the convex die 22, the flat metallic plate 15′ is bent to form the base part 15a and the pair of extension parts 15b, so that the end plate 15 is completed. When the metallic plate 15′ is pressed by the concave die 21 and the convex side 22, the protrusions 22c of the convex die 22 contacts the both sides of the base part 15a and pushes the contacting portions to the concave die 21 as shown in
As described above, the method for forming an endplate for a heat exchanger according to the present embodiment forms the endplate 15 by: preparing the concave die 21 including the groove bottom surface 21a and the pair of groove wall surfaces 21b extending from both sides of the groove bottom surface 21a; preparing the convex die 22 including the convex top surface 22a facing the groove bottom surface 21a of the concave die 21, the convex wall surfaces 22b facing the groove wall surfaces 21b of the concave die 21, and the protrusions 22 being provided along both sides in the width direction of the convex top surface 22a; inserting the metallic plate 15′ between the concave die 21 and the convex die 22. By this means, it is possible to reduce the radius of curvature of the bent portion between the base part 15a and each of the extension parts 15b of the end plate 15, and increase the width W2 of the flat surface of the base part 15a contacting the heat-transfer fin 14. Therefore, it is possible to increase the area of the portion of the endplate 15 connected to the heat-transfer fin 14 by brazing, and therefore to improve the strength, rigidity, vibration proof and so forth of the heat exchanger 10.
Moreover, the end plate 15 is formed with a plate member including a brazing filler metal layer. By this means, the grooves formed by the protrusions 22c of the convex die 22 during the press working can be covered with molten brazing filler metal during the brazing. Therefore, it is possible to prevent the strength of the end plate 15 from being reduced due to the grooves formed by the protrusion 22c during the press working.
With the present embodiment, protrusions 22d are provided on the convex top surface 22a of the convex die 22 to extend along the both ends in the width direction of the convex top surface 22a. Each of the protrusions 22d has a triangular cross-section having the width W3 of 0.5 mm and the height H of 0.3 mm. The vertex of the protrusion 22d lies in the same plane as or inside the convex wall surface 22b.
When the flat metallic plate 15′ is pressed with the concave die 21 and the convex die 22 configured as described above, the radius of curvature of the bent portion between the base part 15a and each of the extension parts 15b of the end plate 15 in the concave die 21 side is smaller than when the metallic plate 15′ is pressed with a die without the protrusions 22d, in the same way as Embodiment 1. In addition, the width of the flat surface of the base part 15a in the concave die 21 side is greater than when the metallic plate 15′ is pressed with a die without the protrusions 22d.
As described above, the method for forming an endplate for a heat exchanger according to the present embodiment can reduce the radius of curvature of the bent portion between the base part 15a and each of the extension parts 15b of the end plate 15, and increase the width W2 of the flat surface of the base part 15a contacting the heat-transfer fin 14, in the same way as Embodiment 1. Therefore, it is possible to increase the area of the portion of the endplate 15 connected to the heat-transfer fin 14 by brazing, and therefore to improve the strength, rigidity, vibration proof and so forth of the heat exchanger 10.
With the present embodiment, the end plate 15 is formed by: pressing the flat metallic plate 15′ between the concave die 21 and a first convex die 23; and further pressing this pressed plate member between the concave die 21 and a second convex die 24 having a shape different from the first convex die 23.
The first convex die 23 is a projection and has a convex top surface 23a facing the groove bottom surface 21a and convex wall surfaces 23b facing the groove wall surfaces 21b.
The second convex die 24 is a projection and has a convex top surface 24a facing the groove bottom surface 21a, convex wall surfaces 24b facing part of the groove wall surfaces 21b, and convex base surfaces 24c each of which extends outward in the width direction from the convex wall surface 24b at the position spaced from the convex top surface 24a by a predetermined distance and faces the groove bottom surface 21a.
When pressed with the concave die 21 and the first convex die 23, the flat metallic plate 15′ is bent on both sides in the width direction, and therefore is formed in a U-shape in cross-section as shown in
As described above, the method for forming an end plate for a heat exchanger according to the present embodiment forms the end plate 15 by: preparing the concave die 21 including the groove bottom surface 21a and the pair of groove wall surfaces 21b extending from both ends in the width direction of the groove bottom surface 21a; preparing the first convex die 23 including the convex top surface 23a facing the groove bottom surface 21a and the convex wall surfaces 23b facing the groove wall surfaces 21b; inserting the metallic plate 15′ between the concave die 21 and the first convex die 23 to bend the metallic plate 15′; and preparing the second convex die 24 including the convex top surface 24a facing the groove bottom surface 21a, the convex wall surfaces 24b facing part of the groove wall surfaces 21b, and the convex base surfaces 24c each of which extends outward in the width direction from the convex wall surface 24b at the position spaced from the convex top surface 24a by a predetermined distance and faces the groove bottom surface 21a; and inserting the metallic plate 15′ having been bent by the concave die 21 and the first convex die 23, between the concave die 21 and the second convex die 24 while the surfaces of both ends of the bent metallic plate 15′ abuts on the convex base surfaces 24c, so that the end plate 15 is completed. By this means, it is possible to reduce the radius of curvature of the bent portion between the base part 15a and each of the extension parts 15b, and increase the width W2 of the flat surface of the base part 15a contacting the heat-transfer fin 14. Therefore, it is possible to increase the area of the portion of the end plate 15 connected to the heat-transfer fin 14 by brazing, and therefore to improve the strength, rigidity, vibration proof and so forth of the heat exchanger 10.
With the present embodiment, the endplate 15 is formed by: forming a pair of grooves 15c in the width direction of the flat metallic plate 15′ by press working, cutting and so forth; and pressing the metallic plate 15′ having the grooves by using the concave die 21 and a convex die 25. Here, the pair of grooves 15c in the width direction is formed in the metallic plate 157 at or near the bent portion between the base part 15a and the respective extension parts 15b of the end plate 15.
The concave die 21 is formed as a groove and has the flat groove bottom surface 21a and the groove wall surfaces 21b extending vertically from the both ends in the width direction of the groove bottom surface 21a.
The convex die 25 is a projection, and has a convex top surface 25a facing the groove bottom surface 21a and convex wall surfaces 25b facing the groove wall surfaces 21b.
When pressed with the concave die 21 and the convex die 22, the flat metallic plate 15′ is bent to form the base part 15a and the pair of extension parts 15b, so that the end plate 15 is completed. When pressed with the concave die 21 and the convex die 22, the metallic plate 15′ is bent at the grooves 15c. Therefore, the radius of curvature of the bent portion between the base part 15a and each of the extension parts 15b of the end plate 15 in the concave die 21 side is smaller than when the metallic plate 15′ without the groves 15c is pressed. In addition, the width of the flat surface of the base part 15a in the concave die 21 side is greater than when the metallic plate 15′ without the grooves 15c is pressed.
As described above, the method for forming an endplate for a heat exchanger according to the present embodiment forms the endplate 15 by: preparing the concave die 21 including the groove bottom surface 21a and the pair of groove wall surfaces 21b extending from both ends in the width direction of the groove bottom surface 21a; preparing the convex die 25 including the convex top surface 25a facing the groove bottom surface 21a and the convex wall surfaces 25b facing the groove wall surfaces 21b of the convex die 21; and inserting the metallic plate 15′ with the pair of grooves 15c in the width direction of the metallic plate 15′ between the concave die 21 and the convex die 25. By this means, it is possible to reduce the radius of curvature of the bent portion between the base part 15a and each of the extension parts 15b of the end plate 15 and increase the width W2 of the flat surface of the base part 15a contacting the heat-transfer fin 14. Therefore, it is possible to increase the area of the portion of the end plate 15 connected to the heat-transfer fin 14 by brazing, and therefore to improve the strength, rigidity, vibration proof and so forth of the heat exchanger 10.
In addition, the endplate 15 is formed with a plate member including a brazing filler metal layer. By this means, the grooves 15c formed before the press working can be covered with the molten brazing filler metal during the brazing, and therefore it is possible to prevent the strength of the end plate 15 from being reduced due to the grooves 15c formed before the press working.
With the above described embodiments, the method for forming the end plate 15 for the outdoor heat exchanger 10 for heat release in a vehicle air conditioning apparatus has been described. However, it is by no means limiting. The present invention is applicable to any heat exchanger not for a vehicle air conditioning apparatus as long as the heat exchanger includes an end plate. Moreover, the present invention is not limited to a heat exchanger for heat release, but is applicable to a heat exchanger for heat absorption, or a heat exchanger which can switch between heat release and heat absorption.
10 outdoor heat exchanger, 11 header, 12 heat exchanger tube, 14 heat-transfer fin, 15 end plate, 15′ metallic plate, 15a base part, 15b extension part, 15c groove, 21 concave die, 21a groove bottom surface, 21b groove wall surface, 22 convex die, 22a convex top surface, 22c protrusion, 23 first convex die, 24 second convex die, 24c convex base surface
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-207621 | Oct 2013 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2014/076255 | 10/1/2014 | WO | 00 |
