Patent Grant
10113812
This application is a U.S. National Phase Application under 35 U.S.C. 371 of International Application No. PCT/JP2014/000745 filed on Feb. 14, 2014 and published in Japanese as WO 2014/125825 A1 on Aug. 21, 2014. This application is based on and claims the benefit of priority from Japanese Patent Applications No. 2013-029153 filed on Feb. 18, 2013, and No. 2013-029152 filed on Feb. 18, 2013. The entire disclosures of all of the above applications are incorporated herein by reference.
The present disclosure relates to a heat exchanger including tubes and a heat-exchange promotion fin and to a manufacturing method of the heat exchanger.
An existing heat exchanger includes multiple tubes for a first fluid to flow and fins which promote heat exchange between the first fluid and a second fluid that flows around the tubes along one direction. Such a heat exchanger is disclosed, for example, in Patent Document 1. In the heat exchanger of Patent Document 1, each fin includes a plate-like planar portion along the one direction and multiple louvers which are parallel to one another and twisted up so as to incline with respect to the planar portion.
The second fluid flows a clearance between every pair of the adjacent louvers. A louver interval between some of the louvers is made wider than a louver interval between the other louvers. Hence, when viewed in the one direction, a louver height from the planar portion is not equal in all of the louvers. The louver height becomes higher as the louver interval becomes wider in one of a pair the louvers between which the louver interval is formed.
In the heat exchanger of Patent Document 1, the fin includes multiple louvers which are parallel to one another and twisted up so as to incline with respect to the one direction. The second fluid flows a clearance between every pair of the adjacent louvers and an interval between some of the louvers is made wider than an interval between the other louvers.
Typically, the louver height is equal in all of the louvers provided to the fins of the heat exchanger. However, it is considered from a study conducted by the inventor of the present disclosure that the louver height cannot be set equal in all of the louvers in some cases as disclosed in Patent Document 1 when heat exchange performance of the heat exchanger is to be enhanced.
When a fin provided with the louvers not all of which have an equal louver height is processed by a typical fin shaping method, for example, roller shaping, it is anticipated that the fin undergoes unnecessary shape deformation due to a difference of the louver heights among the louvers. The shape deformation has an influence on fin performance and an air current and may possibly become a cause of deterioration in heat exchange performance of the heat exchanger. Further, a faulty fin may possibly be shaped.
The heat exchanger of Patent Document 1 is improved by making an interval between some of the louvers wider than an interval between the other louvers, so that the second fluid flowing a clearance between the louvers at the wider interval hardly stagnates. However, a study conducted by the inventor of the present disclosure reveals that Patent Document 1 fails to explicitly describe a relation of a width of the fin in the one direction and shapes of the respective louvers provided to the fin.
As the width of the fin becomes narrower, in particular, the louvers become finer and hence a clearance between the louvers becomes smaller. Accordingly, the second fluid more readily stagnates in a clearance between the louvers as the width of the fin becomes narrower. Hence, as the width of the fin becomes narrower, it is considered more critical to clearly describe a relation of the width of the fin and shapes of the respective louvers provided to the fin in obtaining satisfactory heat exchange performance.
In view of the foregoing, it is an objective of the present disclosure is to provide a heat exchanger capable of obtaining a satisfactory heat exchange performance by including a fin in which unnecessary shape deformation is limited in shaping of the fin, and a manufacturing method of the heating exchanger.
It is another objective of the present disclosure to provide a heat exchanger capable of obtaining a satisfactory heat exchange performance while reducing a fin width.
According to a first aspect of the present disclosure, a heat exchanger includes tubes through which a first fluid flows, and a fin bonded to the tubes to promote heat exchange between the first fluid and a second fluid that flows along one direction through spaces among the tubes. The fin includes a planar portion having a plate-like shape along the one direction, and louvers aligned in the one direction on the planar portion and inclined with respect to the planar portion. The louvers include a higher louver and a lower louver that is lower than the higher louver in a louver height from the planar portion to a tip end of the louver. The higher louver is shorter than the lower louver in a length at the tip end along the planar portion, and each of the louvers has tip end corners, at which the tip end intersects with a side end, on both sides of each of the louvers. The tip end corners located on a same side of the louvers are positioned on a same flat plane parallel to the one direction.
When viewed in the one direction, the length at the tip end of the louver becomes shorter with increase of the louver height. Therefore, assuming that the fin is shaped, for example, by roller shaping which is a typical fin shaping method, the cutting blades to shape the respective louvers come into contact with a raw material of the fin, and a lag in contact starting time of the cutting blades becomes smaller. For example, multiple louver-shaping cutting blades start to cut in the raw material of the fin substantially at the same time. The heat exchanger thus includes a fin in which unnecessary shape deformation is limited in shaping, and therefore a satisfactory heat exchange performance can be obtained.
According to a second aspect of the present disclosure, a method for manufacturing a heat exchanger is disclosed. The heat exchanger includes tubes through which a first fluid flows, and a fin bonded to the tubes to promote heat exchange between the first fluid and a second fluid that flows along one direction through spaces among the tubes. The fin includes a planar portion having a plate-like shape along the one direction, and louvers aligned in the one direction on the planar portion and inclined with respect to the planar portion. The manufacturing method includes a step of manufacturing the fin by a roller shaping method. The step includes a fin shaping step of making a fin material into a corrugated shape and shaping the louvers by letting the fin material be bitten by a pair of gear-like shaping rollers. The fin shaping step includes using the shaping rollers including louver-shaping cutting blades aligned in a row in an axial direction of the shaping rollers. The louver-shaping cutting blades includes a high cutting blade and a low cutting blade that is lower than the high cutting blade in a cutting blade height from a tooth flank to a cutting blade tip end. The high cutting blade is shorter than the low cutting blade in a length at the cutting blade tip end. The fin shaping step includes shaping the louvers by making the louver-shaping cutting blades start to cut in the fin material at same timing with one another.
According to the discourse as above, the shaping rollers including multiple louver-shaping cutting blades having different cutting blade heights are used in the fin shaping step. Hence, multiple louvers having different louver heights can be shaped. The shaping rollers include the multiple louver-shaping cutting blades in which the high cutting blade having a high cutting blade height has a short length at the cutting blade tip end in comparison with the low cutting blade having a low cutting blade height. Since the multiple louver-shaping cutting blades start to cut in the fin material at the same timing with one another, the louver-shaping cutting blades mutually cancel out pulling-in of the fin material that occurs when the louver-shaping cutting blades cut in the fin material. Hence, the present disclosure has an advantage that the fin material hardly undergoes deformation in a direction in which the louver-shaping cutting blades are aligned, namely, an axial direction of the shaping rollers.
The shaping rollers used in the fin shaping step include the high cutting blade and the low cutting blade and the length at the cutting blade tip end is shorter in the high cutting blade than in the low cutting blade. Consequently, the multiple louvers are shaped in such a manner that the multiple louvers include louvers having different louver heights and the higher louver having a high louver height among the multiple louvers has a short length at the tip end of the louver in comparison with the lower louver having a low louver height.
According to the third aspect of the present disclosure, a heat exchanger includes tubes through which a first fluid flows, and a fin bonded to the tubes to promote heat exchange between the first fluid and a second fluid that flows along one direction through spaces among the tubes. The fin includes a first flat portion, a second flat portion and a third flat portion disposed sequentially from upstream in a flow of the second fluid in the one direction. The fin includes first louvers aligned in the one direction between the first flat portion and the second flat portion and inclined with respect to the one direction, and second louvers aligned in the one direction between the second flat portion and the third flat portion at a louver pitch equal to a louver pitch of the first louvers and inclined with respect to the one direction in an opposite orientation to the first louvers. A length of the fin in the one direction is shorter than or equal to 14 mm. The first louvers include an upstream-end first louver connected to the first flat portion. The second louvers include an upstream-end second louver connected to the second flat portion. A louver length in the one direction of each of the upstream-end first louver and the upstream-end second louver is longer than or equal to ⅝×LP, where LP is the louver pitch.
The louver lengths of the upstream-end first louver and the upstream-end second louver are set to ⅝×LP or longer. Hence, wide clearances are secured between the upstream-end first louver and adjacent first louver and between the upstream-end second louver and adjacent second louver according to the louver lengths. The second fluid thus hardly stagnates in these clearances in which the second fluid readily stagnates otherwise when the fin width is 14 mm or shorter. Hence, a satisfactory heat exchange performance of the heat exchanger can be obtained while the heat exchanger is made more compact by reducing the width of the fin of the heat exchanger to 14 mm or shorter.
The phrase, “the first louvers and the second louvers have an equal louver pitch”, referred to in the disclosure above does not means that the louver pitches are equal in mathematical term but means that the louver pitches are substantially equal by taking a manufacturing variation into consideration.
According to a fourth aspect of the present disclosure, a heat exchanger includes tubes through which a first fluid flows, and a fin bonded to the tubes to promote heat exchange between the first fluid and a second fluid that flows along one direction through spaces among the tubes. The fin includes a first flat portion, a second flat portion and a third flat portion disposed sequentially from upstream in a flow of the second fluid in the one direction. The fin includes first louvers aligned in the one direction between the first flat portion and the second flat portion and inclined with respect to the one direction, and second louvers aligned in the one direction between the second flat portion and the third flat portion at a louver pitch equal to a louver pitch of the first louvers and inclined with respect to the one direction in an opposite orientation to the first louvers. The first louvers include an upstream-end first louver connected to the first flat portion, a downstream-end first louver connected to the second flat portion, and an intermediate first louver located between the upstream-end first louver and the downstream-end first louver. The second louvers include an upstream-end second louver connected to the second flat portion, a downstream-end second louver connected to the third flat portion, and an intermediate second louver located between the upstream-end second louver and the downstream-end second louver. The upstream-end first louver, the downstream-end first louver, the upstream-end second louver and the downstream-end second louver are larger in an inclination angle with respect to the one direction than the intermediate first louver and the intermediate second louver.
The upstream-end first louver, the downstream-end first louver, the upstream-end second louver, and the downstream-end second louver are provided so as to have a large inclination angle in comparison with the intermediate first louver and the intermediate second louver. Hence, inter-louver passages tangent to the upstream-end first louver, the downstream-end first louver, the upstream-end second louver, and the downstream-end second louver become wider. Consequently, air can be made to hardly stagnate where air generally stagnates easily, and a heat exchange performance of the heat exchanger can be enhanced.
According to a fifth aspect of the present disclosure, a heat exchanger includes tubes through which a first fluid flows, and a fin bonded to the tubes to promote heat exchange between the first fluid and a second fluid that flows along one direction through spaces among the tubes. The fin includes a first flat portion, a second flat portion and a third flat portion, each of which has a plate-like shape, disposed sequentially from upstream in a flow of the second fluid in the one direction. The fin includes first louvers aligned in the one direction between the first flat portion and the second flat portion and inclined with respect to the one direction, second louvers aligned in the one direction between the second flat portion and the third flat portion at a louver pitch equal to a louver pitch of the first louvers and inclined with respect to the one direction in an opposite orientation to the first louvers, and a connection portion having plate-like shape and extending in the one direction, the connection portion integrally connecting the first flat portion, the first louvers, the second flat portion, the second louvers and the third flat portion. Each of the first flat portion, the second flat portion and the third flat portion is disposed so as to be displaced from the connection portion in a thickness direction of the connection portion. The first louvers define first inter-louver passages between the first louvers such that passages of the first inter-louver passages which are positioned on an uppermost stream side and a lowermost stream side in an air flow are wider than other passages of the first inter-louver passages. The second louvers define second inter-louver passages between the second louvers such that passages of the second inter-louver passages, which are positioned on an uppermost stream side and a lowermost stream side in the air flow, are wider than other passages of the second inter-louver passages.
As has been described, the passages of the first inter-louver passages on the uppermost stream side and the lowermost stream side in the air current are wider than the other first inter-louver passages. The passages of the second inter-louver passages on the uppermost stream side and the lowermost stream side in the air current are wider than the other second inter-louver passages. Consequently, air can be made to hardly stagnate where air generally stagnates easily, and a heat exchange performance of the heat exchanger can be enhanced.
Hereinafter, multiple embodiments for implementing the present invention will be described referring to drawings. In the respective embodiments, a part that corresponds to a matter described in a preceding embodiment may be assigned the same reference numeral, and redundant explanation for the part may be omitted. When only a part of a configuration is described in an embodiment, another preceding embodiment may be applied to the other parts of the configuration. The parts may be combined even if it is not explicitly described that the parts can be combined. The embodiments may be partially combined even if it is not explicitly described that the embodiments can be combined, provided there is no harm in the combination.
Hereinafter, embodiments of the present disclosure will be described according to the drawings. Among the respective embodiments below, same or equivalent portions are labeled with same reference numerals in the drawings.
As is shown in
Fins 14 as a heat-transfer member formed in a corrugated shape are bonded to flat surfaces of the tube 12 on both sides. The fins 14 increase a heat-transfer area for air flowing around the tubes 12 along the airflow direction X1. The fins 14 thus promote heat exchange between the coolant and air. Hereinafter, a heat exchange portion of substantially a rectangular shape made up of the tubes 12 and the fins 14 is referred to as a core portion 16.
Header tanks 18 are provided to the tubes 12 at ends on the both sides in a longitudinal direction X2 of the tubes 12, namely, a tube longitudinal direction X2. In short, two header tanks 18 are provided. The header tanks 18 are provided so as to extend in a direction X3 in which the multiple tubes 12 are laminated, namely, a tube lamination direction X3. The header tanks 18 communicate with the multiple tubes 12. The tube longitudinal direction X2 and the tube lamination direction X3 shown in
Each header tank 18 is formed of a core plate 18a into which the tubes 12 are inserted and bonded and a tank main body portion 18b that defines a tank inner space together with the core plate 18a. In the present embodiment, the core plate 18a is made of metal, for example, aluminum alloy, and the tank main body portion 18b is made of resin. Inserts 20 that extend substantially parallel to the tube longitudinal direction X2 to reinforce the core portion 16 are provided at both ends of the core portion 16.
Of the two header tanks 18, an inlet-side tank 181 disposed on an upper side and distributing the coolant to the tubes 12 is provided with an inlet pipe 18c in the tank main body portion 18b to let the coolant, which has cooled, for example, the engine, flow into the tank main body portion 18b. Also, of the two header tanks 18, an outlet-side tank 182 disposed on a lower side and collecting the coolant flowing out from the tubes 12 is provided with an outlet pipe 18d in the tank main body portion 18b to let the coolant, which has been cooled through heat exchange with air, flow out from the radiator 10.
When the radiator 10 is mounted to the vehicle, for example, an air-current upstream side in the airflow direction X1 is a vehicle front side and the tube longitudinal direction X2 is a vehicle up-down direction.
The ridge portions 142 are bonded to the flat surfaces of the tubes 12 by, for example, brazing. The fin 14 is thus bonded to the tubes 12 and becomes capable of transferring heat. The ridge portions 142 are curved portions each having an arc-like cross section when viewed in the airflow direction X1. The ridge portions 142 are therefore occasionally referred to also as curved portions 142 in the description below.
The fin 14 having the corrugated shape is shaped by applying a roller shaping method to a thin-sheet of metal material made, for example, of aluminum alloy.
More specifically, as is shown in
As is shown in
All of the first louvers 24 are provided to be parallel to one another and all of the second louvers 26 are also provided to be parallel to one another. The twist angle θtw of the first louvers 24 is as large as the twist angle θtw of the second louvers 26 and a twist direction is opposite to a twist direction of the second louvers 26. The term, “being parallel”, referred to herein for the first louvers 24 and the second louvers 26 does not mean to be parallel in a mathematical term and means to be substantially parallel by taking a manufacturing variation into consideration.
As are shown in
In other words, the fin 14 includes the upstream flat portion 34 (first flat portion), the center flat portion 36 (second flat portion), and the downstream flat portion 38 (third flat portion), and the upstream flat portion 34, the center flat portion 36, and the downstream flat portion 38 are disposed sequentially from the upstream side in the air current in the airflow direction X1. The first louvers 24 are disposed between the upstream flat portion 34 and the center flat portion 36 and aligned in the airflow direction X1 at a predetermined louver pitch LP. The second louvers 26 are disposed between the center flat portion 36 and the downstream flat portion 38 and aligned in the airflow direction X1 at the same louver pitch LP as the first louvers 24.
As is shown in
The first louvers 24 belonging to the first louver group 30 are classified more in detail as shown in
The upstream-end first louver 241 is connected to the upstream flat portion 34 at one end 44 in the airflow direction X1, namely, one base 44. The downstream-end first louver 243 is connected to the center flat portion 36 at the other end 44 in the airflow direction X1, namely, the other base 44.
The second louvers 26 belonging to the second louver group 32 are also classified more in detail as shown in
The upstream-end second louver 261 is connected to the center flat portion 36 at one end 44 in the airflow direction X1, namely, one base 44. The downstream-end second louver 263 is connected to the downstream flat portion 38 at the other end 44 in the airflow direction X1, namely, the other base 44.
As is shown in
As is shown in
Louver tip end widths WDtp, which are the widths in the direction indicated by the arrow AR5 at the tip ends 46, are equal to one another in all of the first louvers 24 on either side in the thickness direction of the upstream flat portion 34. The louver tip end widths WDtp correspond to a tip end width of the louvers of the present disclosure.
The louver side-end angle θsd is also referred to as a cut-over angle θsd of the louvers 24 and 26. The louver tip end width WDtp is also referred to as an effective cut length WDtp of the louvers 24 and 26. The louver base width WDfd is also referred to as a full cut length WDfd of the louvers 24 and 26.
The multiple intermediate first louvers 242 are provided so that a louver height LH shown in
Louver lengths LLN (see
For example, given that all of the airflow-end louver lengths LLN are expressed as [LLN=½×LP]. Then, the louver heights LH of the upstream-end first louver 241, the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263 are equal to the louver heights LH of the intermediate first louvers 242 and the intermediate second louvers 262. In the present embodiment, however, the airflow-end louver lengths LLN at all of the four points are set to be longer than [½×LP]. Hence, the louver heights LH of the upstream-end first louver 241, the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263 (higher louvers) are higher than the louver heights LH of the rest of the louvers 24 and 26, namely the intermediate first louvers 242 and the intermediate second louvers 262 (lower louvers). In short, some of the multiple louvers 24 and 26 have different louver heights LH. For example,
As is shown in
As is shown in
A manufacturing method of the fin 14, namely, roller shaping will now be described briefly.
A fin shaping device 86 makes the fin material 82 into a corrugated shape by folding the fin material 82 to which the predetermined tension has been conferred by the tension device 84 and thereby providing a large number of the curved portions 142 (see
The fin shaping device 86 includes a pair of gear-like shaping rollers 861 and 862. The shaping rollers 861 and 862 include multiple external teeth 861a and 862a, respectively, which are aligned in a circumferential direction. As is shown in
The fin shaping device 86 as above lets the fin material 82 be bitten by a pair of the shaping rollers 861 and 862. While the fin material 82 passes by a space between a pair of the shaping rollers 861 and 862, the fin shaping device 86 makes the fin material 82 into a corrugated shape by folding the fin material 82 so as to conform to the external teeth 861a and 862a of the shaping rollers 861 and 862, respectively, and also shapes the louvers 24 and 26 using the louver-shaping cutting blades 861b and 862b. In other words, a set of the first louver group 30 and the second louver group 32 aligned in a row as shown in
A cutting device 88 shown in
The correction device 92 is a correction device that corrects irregularities of the curved portions 142 by pressing the curved portions 142 in a direction substantially at right angle to a ridge direction of the curved portions 142.
A brake device 94 is a brake device having brake surfaces 94a and 94b that generate a frictional force to a direction opposite to a travel direction of the fin material 82 by coming into contact with the multiple curved portions 142. The brake device 94 uses a feed force generated by the feed device 90 and the frictional force generated by the brake surfaces 94a and 94b to compress the fin material 82 in such a manner that the curved portions 142 adjacent to each other in the feed direction of the fin material 82 are in contact with each other.
An operation of the roller shaping device 78 described above will be now be described in order of steps performed in the roller shaping device 78.
Firstly, the roller shaping device 78 performs a roll-out step of rolling out the fin material 82 from the material roll 80 and performs next a tension generation step of conferring predetermined tension to the rolled-out fin material 82 in the travel direction of the fin material 82 using the tension device 84. The roller shaping device 78 next performs a fin shaping step of shaping the curved portions 142 and the louvers 24 and 26 in the fin material 82 using the fin shaping device 86. Subsequently, in the roller shaping device 78, the roller shaping device 78 performs a fin separation step of separating the fin material 82 from the shaping rollers 861 and 862 at the center flat portion 36 in which no louvers 24 and 26 are provided and performs a cutting step of cutting the fin material 82 in the predetermined length using the cutting device 88.
Subsequently, the roller shaping device 78 performs a feeding step of feeding the fin material 82 cut in the predetermined length to the correction device 92 using the feed device 90. The roller shaping device 78 next performs a correcting step of correcting irregularities by pressing the curved portions 142 using the correction device 92 and performs a compression step of compressing the fin material 82 for the adjacent curved portions 142 to be in contact with each other using the brake device 94. The fin material 82 after the compression step stretches with an own elastic force and eventually has a predetermined fin pitch.
In the fin shaping step as above, the louvers 24 and 26 aligned in a row in the airflow direction X1 are shaped in such a manner that the louvers 24 and 26 are shaped row by row. Hence, in order to avoid unnecessary material deformation, it is preferable that the multiple louver-shaping cutting blades 861b and 862b start to cut in the fin material 82 at the same time for the louvers 24 and 26 in a row.
Accordingly, the louvers 24 and 26 of the present embodiment are shaped as shown in
To be more specific, as is shown in
Further, as is shown in
More specifically, as is shown in
In other words, some of the multiple louver-shaping cutting blades 861b and 862b have different cutting blade heights (Hctr). For example, the cutting blade height Hctr of one of the mutually opposing louver-shaping cutting blades 861b and 862b used to cut and raise the upstream-end first louver 241 (see
The cutting blade heights Hctr of the louver-shaping cutting blades 861b and 862b used to cut and raise the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263 (see
When the louver-shaping cutting blades 861b and 862b are distinguished according to the cutting blade heights Hctr in the description of
As is shown in
Cutting blade side ends 873 of the louver-shaping cutting blades 871 and 872 used to shape the side ends 42 of the louvers 24 and 26 (see
As is shown in
Hence, in
In other words, because the louvers 24 and 26 have the outer shapes shown in
As is shown in
As has been described, according to the present embodiment, when the louvers 24 and 26 are viewed in the airflow direction X1, the louver tip end width WDtp becomes shorter as the louver height LH (see
For example, assume that the louver side-end angle θsd of
When the meshing start times are different as shown in
Also, for example, assume that the tip end corner 48 of the downstream-end first louver 243 shown in
According to the present embodiment, in the fin shaping step by the fin shaping device 86 of
According to the present embodiment, some of the multiple louver-shaping cutting blades 861b and 862b of the shaping rollers 861 and 862, respectively, used in the fin shaping step have different cutting blade heights Hctr, and the width WDctp at the cutting blade tip end 875 is short in either the multiple louver-shaping cutting blade 861b or 862b whichever has the higher cutting blade height Hctr in comparison with the other having the lower cutting blade height Hctr. Hence, the fin 14 including the louvers 24 and 26 which have different louver heights LH can be shaped. Also, as is shown in
An appropriate length of the airflow-end louver length LLN will now be described using
In the test shown in
As is shown in
When the fin width WDfn is 12 mm, an increase of the radiation amount Wo by making the airflow-end louver length LLN longer is further noticeable in comparison with the case when the fin width WDfn is 14 mm. The radiation amount Wo continues to peak when the airflow-end louver length LLN is in a range of “¾×LP” to “⅞×LP”.
From the test result of
As is indicated by the broken line LnR1 of
The characteristics indicated by the solid line LnR2 of
It is considered that the test results as above are obtained because the respective inter-louver passages 28 become narrower as the fin width WDfn becomes narrower and an air current readily stagnates around the louvers 24 and 26 of the fin 14. For example, as is shown in a wind velocity distribution chart of
It is considered that air flows around the louvers 24 and 26 of the fin 14 as indicated by broken arrows AR01 and AR02 due to stagnation of the air current in the part A and the part B. In other words, it is ideal for air that flows in the airflow direction X1 in
On the contrary, as can be led from the test results of
As has been described, the fin width WDfn of the fin 14 is 14 mm or shorter in the present embodiment. It is preferable to set the airflow-end louver length LLN to “⅝×LP” or longer, where LP is the louver pitch in the upstream-end first louver 241, the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263. When configured as above, it is considered that air hardly stagnates in a space between the upstream-end first louver 241 and the adjacent intermediate first louver 242, namely, the part A of
In the present embodiment, as is shown in
In the present embodiment, the multiple first louvers 24 are provided to be parallel to one another and the multiple second louvers 26 are also provided to be parallel to one another. Hence, the ventilation resistance Rair of air in the respective inter-louver passages 28 can be restricted to be low in comparison, for example, with a case where neither the louvers 24 nor the louvers 26 are parallel to one another.
A second embodiment of the present disclosure will now be described. The present embodiment will chiefly describe a difference from the first embodiment described above. Portions same as or equivalent to the counterparts of the first embodiment above are not described repetitively or described briefly.
Hence, as is shown in
In the present embodiment, too, a louver tip end width WDtp becomes shorter as the louver height LH (see
In
A third embodiment of the present disclosure will now be described. The present embodiment will chiefly describe a difference from the first embodiment described above. Portions same as or equivalent to the counterparts of the first embodiment above are not described repetitively or described briefly. The same applies to fourth and subsequent embodiments below.
To be more specific, as is shown in
In the present embodiment, too, the multiple intermediate first louvers 242 are parallel to one another and the multiple intermediate second louvers 262 are also parallel to one another as in the first embodiment above. A twist direction of the intermediate first louvers 242 is opposite to a twist direction of the intermediate second louvers 262 and the twist angle θtw of the intermediate first louvers 242 is as large as the twist angle θtw of the intermediate second louvers 262.
According to the present embodiment, the twist angles θtw of the upstream-end first louver 241, the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263 are larger than the twist angles θtw of the other louvers 242 and 262. Hence, inter-louver passages 28 tangent to the upstream-end first louver 241, the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263 become wider. Consequently, air hardly stagnates at the wider inter-louver passages 28 and radiation performance of a radiator 10 can be enhanced.
A fourth embodiment of the present disclosure will now be described. The present embodiment will chiefly describe a difference from the first embodiment described above.
Further, of the multiple first inter-louver passages 281, the one located uppermost stream in an air current is referred to as an uppermost-stream first inter-louver passage 281a and the one located lowermost stream in the air current is referred to as a lowermost-stream first inter-louver passage 281b. The first inter-louver passages 281 other than the uppermost-stream first inter-louver passage 281a and the lowermost-stream first inter-louver passage 281b are referred to as intermediate first inter-louver passages 281c.
Also, of the multiple second inter-louver passages 282, the one located uppermost stream in an air current is referred to as an uppermost-stream second inter-louver passage 282a and the one located lowermost stream in the air current is referred to as a lowermost-stream second inter-louver passage 282b. The second inter-louver passages 282 other than the uppermost-stream second inter-louver passage 282a and the lowermost-stream second inter-louver passage 282b are referred to as intermediate second inter-louver passages 282c.
As is shown in
As is shown in
As has been described, the upstream flat portion 34, the center flat portion 36, and the downstream flat portion 38 are disposed to be separately displaced with respect to the connection portions 40 in the thickness direction of the connection portions 40. Accordingly, of the multiple first inter-louver passages 281, the uppermost-stream first inter-louver passage 281a and the lowermost-stream first inter-louver passage 281b become wider than the other first inter-louver passages 281, namely, the intermediate first inter-louver passages 281c. Also, of the multiple second inter-louver passages 282, the uppermost-stream second inter-louver passage 282a and the lowermost-stream second inter-louver passage 282b become wider than the other second inter-louver passages 282, namely, the intermediate second inter-louver passages 282c.
Hence, according to the present embodiment, an air current hardly stagnates in the uppermost-stream first inter-louver passage 281a, the lowermost-stream first inter-louver passage 281b, the uppermost-stream second inter-louver passage 282a, and the lowermost-stream second inter-louver passage 282b. Consequently, radiation performance of a radiator 10 can be enhanced.
A fifth embodiment of the present disclosure will now be described. The present embodiment will chiefly describe a difference from the first embodiment described above.
As with the coupling portion of the downstream-end second louver 263 and the downstream flat portion 38 shown in
In the present embodiment, as is shown in
As has been described, according to the present embodiment configured as above, air introduced to each of the upstream-end first louver 241, the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263 change a flow direction smoothly in the respective coupling portions of a curved shape as described above along the curved shape. Hence, an air current hardly stagnates in the vicinity of the upstream-end first louver 241, the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263. Consequently, radiation performance of a radiator 10 can be enhanced.
(1) In the embodiments described above, the multiple louvers 24 and 26 have louver heights LH that differ in two steps: the higher side and the lower side. However, the louver heights may differ in three or more steps. Even in a case where the louver heights LH differ in three or more steps, as is shown in
(2) In the embodiments described above, the louver height LH is higher in the upstream-end first louver 241, the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263 than in the other louvers 242 and 262. However, a high louver height LH may be set in any one of the multiple louvers 24 and 26 aligned in a row in the airflow direction X1.
(3) In the embodiments described above, as is shown in
(4) In the embodiments described above, the fin width WDfn is as long as the longitudinal diameter Dtb of the tubes 12. However, the former and the latter may be different from each other.
(5) In the embodiments described above, the fin 14 is a corrugated fin. However, other types of fin may be used as long as the fin can be formed by roller shaping.
(6) In the embodiments described above, the fin 14 is bonded to the tubes 12 by, for example, brazing. However, the fin 14 may be bonded to the tubes 12 using other bonding methods.
(7) In the embodiments described above, the first fluid flowing the tubes 12 is a coolant. However, the first fluid may be a liquid other than the coolant or a gas.
(8) In the embodiments described above, the second fluid flowing around the tubes 12 is air. However, the second fluid may be a gas other than air or a liquid.
(9) In the first embodiment described above, the corner R is provided to the outer shapes of the tip end corners 48 of the upstream-end first louver 241, the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263. The corner R, however, may not be provided. When the corner R is absent, the louver side-end angle θsd shown in
(10) In the first embodiment described above, the corner R is not provided to the outer shapes of the tip end corners 48 of the intermediate first louvers 242 and the intermediate second louvers 262. However, the corner R may be provided. In such a case, it is preferable that the radius of curvature, Rcn, of the corner R provided to the tip end corners 48 of the intermediate first louvers 242 and the intermediate second louvers 262 is small in comparison with the upstream-end first louver 241, the downstream-end first louver 243, the upstream-end second louver 261, and the downstream-end second louver 263.
(11) In the second embodiment described above, the corner R as shown in
(12) In the first embodiment described above, the airflow-end louver lengths LLN (see
(13) In the embodiments described above, the fin 14 is a corrugated fin. However, the fin 14 may be a sheet-like plate fin which is not formed in a corrugated shape.
(14) In the first embodiment described above, the fin 14 having the louver pitch LP of 0.6 mm is used in the tests shown in
It should be appreciated that the present disclosure is not limited to the embodiments described above and can be modified appropriately within the scope of the present disclosure. The embodiments described above are not irrelevant to one another and can be combined appropriately unless a combination is obviously impossible. In the respective embodiments described above, it goes without saying that elements forming the embodiments are not necessarily essential unless specified as being essential or deemed as being apparently essential in principle. In a case where a reference is made to the components of the respective embodiments as to numerical values, such as the number, values, amounts, and ranges, the components are not limited to the numerical values unless specified as being essential or apparently limited to the numerical values in principle. Also, in a case where a reference is made to the components of the respective embodiments above as to materials, shapes, and positional relations, the components are not limited to the materials, the shapes, and the positional relations unless explicitly specified or limited to particular materials, shapes and positional relations in principle.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-029152 | Feb 2013 | JP | national |
| 2013-029153 | Feb 2013 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2014/000745 | 2/14/2014 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2014/125825 | 8/21/2014 | WO | A |
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