JP6122266B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a so-called multi-plate heat exchanger in which a plurality of flat tubes serving as flow paths for the first fluid are stacked and a gap serving as a flow path for the second fluid is secured between the flat tubes. Regarding improvement.

  As a so-called multi-plate heat exchanger, as described in Patent Document 1, for example, an oil flow path is formed inside by joining an oval first plate and a second plate to each other at the periphery thereof. There has been known an oil cooler that includes a formed flat tube and is formed by stacking a plurality of flat tubes in a plurality of stages such that a gap serving as a cooling water flow path is formed between the flat tubes. This type of oil cooler is used, for example, in a form housed in a case provided in a cylinder block of a large engine, and the engine coolant is forcibly circulated in the case, while oil is contained in the oil cooler. The oil is cooled and oil is cooled by heat exchange between the two.

  The first plate and the second plate are made of a so-called clad material, for example, and are joined to each other with the fin plate sandwiched therebetween by brazing by heating in a furnace. That is, the peripheral edge of the first plate and the peripheral edge of the second plate are abutted and brazed to each other, and the first plate and the second plate are disposed on both upper and lower surfaces of the fin plate inside the oil passage. Each of the two plates is brazed.

  Then, between the flat tubes of each stage, the peripheral edge of the opening serving as the oil inlet and oil outlet of each plate is formed one step higher in a boss shape on one plate, and this is sequentially connected to form a stack. An oil inlet passage and an oil outlet passage that are continuous in the direction are formed, whereby the oil passages in the respective flat tubes communicate with each other. The oil inlet passage and the oil outlet passage are respectively connected to an oil inlet and an oil outlet provided in a mounting flange of the oil cooler.

JP 2001-90518 A

  In the conventional heat exchanger as described above, each flat tube has a certain width, whereas there is one opening provided at the end of the flat tube. As a fluid flow distribution, there is a tendency that only the central portion of the flat tube flows linearly from the opening at one end serving as the inlet of each flat tube to the opening at the other end serving as the outlet. Therefore, the entire width of the flat tube cannot be effectively used for heat exchange, and there is room for improvement in terms of heat exchange efficiency.

  Also, if a fin plate with a large flow resistance is used in order to spread the flow widely in the width direction in the flat tube, the passage resistance as a heat exchanger becomes large. For example, in an oil cooler, the pressure loss of the hydraulic system is large. It is not preferable.

The present invention is a heat exchanger in which a flat tube whose inside is a flow path for a first fluid is stacked in a plurality of stages via a gap which is a flow path for a second fluid, , An opening formed of a first plate and a second plate that are joined to each other at the periphery, and two adjacent flat tubes are provided at respective ends in the longitudinal direction of the second plate of one flat tube And the openings provided at the respective ends in the longitudinal direction of the first plate of the other flat tube are connected to each other to communicate with each other, and the length of each flat tube is communicated with each other through these openings. In the heat exchanger in which the first fluid flows in the direction,
At each end in the longitudinal direction of the first plate in the lowermost flat tube, a single opening serving as a fluid inlet or a fluid outlet of the heat exchanger is formed as the opening.
At each end in the longitudinal direction of the second plate combined with the first plate, as the opening, a plurality of openings are arranged extending in the width direction of the flat tube,
The flat tubes after the second stage are characterized by having a plurality of openings at each end corresponding to the second plate of the flat tube at the lowermost stage.

  That is, in the heat exchanger according to the present invention, the first fluid flows through a single opening in the lowermost flat tube on the equipment side through which the first fluid such as oil flows. Part of the inflowing first fluid flows in the longitudinal direction in the lowermost flat tube and flows out from the single opening at the other end to the device side. The other part of the first fluid that has flowed in flows into the second-stage flat tube through the opening of the second plate. At this time, in the second plate and the corresponding second-stage flat tube, there are a plurality of openings arranged in the width direction of the flat tube, and the other end also has a plurality of outlets. Since the opening is present, the first fluid flows in the flat tube while widening in the width direction. Therefore, heat exchange is performed more efficiently in the entire width direction of the flat tube.

  In one specific aspect of the present invention, a mounting flange is attached to the lower surface of the first plate of the lowermost flat tube, and a fluid inlet and a fluid outlet provided on the mounting flange are provided on the first plate. Connected to a single opening at each end of the plate. Therefore, it can be easily attached to a single fluid outlet and fluid inlet on the device side.

  In a preferred aspect of the present invention, a fin plate is disposed between the first plate and the second plate of each flat tube, and the fin plate in the flat tube at the lowest stage among the plurality of flat tubes. The resistance to the flow along the longitudinal direction of the flat tube is higher than the resistance of the fin plate in the other flat tubes.

  If the resistance of the fin plate is set in this way, the lowermost flat tube restricts the flow that goes straight from the single opening at one end to the single opening at the other end. The flow extending through the plurality of openings to the flat tubes after the eyes increases. On the other hand, in the second and subsequent flat tubes, the resistance of the fin plate is relatively low with respect to the flow in the longitudinal direction. Accordingly, the heat exchange efficiency can be increased without excessively increasing the passage resistance as the entire heat exchanger.

  The number of openings in the second plate of the lowermost flat tube and the second and subsequent flat tubes corresponding thereto is arbitrary.

  In one embodiment, the second plate of the lowermost flat tube and the second and subsequent flat tubes are symmetrical at each end with a single opening in the first plate of the lowermost flat tube sandwiched between them. Has an even number of openings.

  In another embodiment, the second plate of the lowermost flat tube and the second and subsequent flat tubes are provided at each end with a single opening in the first plate of the lowermost flat tube. It has an odd number of openings including a central opening having the same center position.

  For example, a configuration in which the number of openings is different between the second-stage flat tube and the third-stage flat tube is possible, but generally the same number of openings is sufficient.

Furthermore, the present application includes the second invention. The second aspect of the present invention is a heat exchanger in which a flat tube whose inside becomes a flow path of a first fluid is stacked in a plurality of stages through a gap which becomes a flow path of a second fluid, The flat tube is composed of a first plate and a second plate joined to each other at the periphery, and two adjacent flat tubes are respectively provided at respective longitudinal ends of the second plate of one flat tube. And the openings provided at the respective ends of the first plate of the other flat tube in the longitudinal direction are connected to each other so as to communicate with each other through the openings. In the heat exchanger in which the first fluid flows in the longitudinal direction of the tube,
At each end in the longitudinal direction of the first plate and the second plate, as the opening, a plurality of openings are arranged extending in the width direction of the flat tube,
A plate-like mounting flange is laminated on the lower surface of the first plate in the lowermost flat tube,
A plurality of communication ports corresponding to the plurality of openings of the flat tube are opened on the surface of the mounting flange on the first plate side, and a fluid inlet or a fluid outlet is formed on the opposite mounting surface. The plurality of communication openings and the single opening are in communication with each other inside the mounting flange.

  In a specific embodiment, the plurality of communication ports and the single opening are formed as recesses having a depth that does not penetrate the mounting flange, and these recesses partially overlap each other. By being arranged in this way, they communicate with each other.

  In other words, in the second invention, the flow of fluid spreads in the width direction of the flat tube to the plurality of communication ports corresponding to the plurality of openings of the flat tube inside the plate-like mounting flange.

  According to this invention, the first fluid can be allowed to flow in a form that is widened in the width direction of the flat tube, and the heat exchange efficiency can be improved without an unnecessary increase in passage resistance. In addition, since the flow is expanded in the width direction inside the flat tube at the bottom or inside the mounting flange, the connection structure between the equipment and the heat exchanger is complicated, and the size of each part including the heat exchanger is increased. Will not be invited.

The perspective view of the oil cooler concerning this invention. The exploded perspective view of the oil cooler. Sectional drawing along the AA line of FIG. The perspective view of a part of fin plate. Sectional drawing which shows the state which accommodated this oil cooler in the case by the side of an engine. The front view of an oil cooler. The side view of the edge part of an oil cooler. Sectional drawing which shows the modification which changed direction of the fin plate in the flat tube of the lowest step. Sectional drawing along the BB line of FIG. The perspective view of the oil cooler of a 2nd Example. The exploded perspective view of the oil cooler. Sectional drawing along CC line of FIG. Sectional drawing along the DD line | wire of FIG. The disassembled perspective view which shows the modification which made the center opening part the small diameter. Sectional drawing of this modification. Sectional drawing similar to FIG. 3 of the oil cooler of a 3rd Example. The top view of the attachment flange in this 3rd Example.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  1 to 7 show a water-cooled oil cooler 1 as an embodiment of a heat exchanger according to the present invention. The oil cooler 1 is used for cooling lubricating oil of a large engine, and a plurality of flat tubes 2 each having an oil flow path 11 (see FIG. 3) are stacked, and a gap between the flat tubes 2 is provided. It becomes the cooling water flow path 12 (refer FIG. 7). In addition, it is possible to increase / decrease the heat exchange capacity | capacitance as the oil cooler 1 by changing the step number of the flat tube 2 laminated | stacked, and the step number of the flat tube 2 is set according to required heat exchange capacity | capacitance. Accordingly, in each of FIGS. 1 to 7, the number of stages of the oil cooler 1 is not necessarily matched. For example, in FIGS. 1, 6, and 7, the flat tube 2 of seven stages is included. In FIG. 5, it is drawn as having a four-stage flat tube 2, and in FIG. 2, only the two-stage flat tube 2 is shown.

  As shown in FIGS. 1 and 2, the oil cooler 1 has a plurality of flat tubes 2, a pair of mounting flanges 3 that respectively constitute oil inlets and outlets, and a plurality of flat tubes 2. A pair of reinforcing plates 4 disposed to face the flange 3. In the following description, in order to facilitate understanding, the terms “upper” and “lower” are used on the basis of the vertical postures shown in FIG. 2 and FIG. That is, the side where the mounting flange 3 is located is called the lower part of the oil cooler 1, and the direction where the reinforcing plate 4 is located is called the upper part of the oil cooler 1, but the mounting posture of the oil cooler 1 in an actual vehicle is arbitrary. Yes, it is not limited to the posture as shown in FIG. According to the above “upper” and “lower” standards, FIG.

  The flat tube 2 has an elongated strip shape as a whole so that oil flows in the longitudinal direction, and has a substantially arc shape in which both ends are gently curved. The mounting flange 3 disposed at each end of the flat tube 2 in the longitudinal direction has a relatively thick plate shape such as a rhombus or an ellipse, and has a circular opening 6 serving as an oil inlet or outlet from the engine side. It has in the center and has a pair of mounting holes 7 at both ends. The reinforcing plate 4 has an edge shape corresponding to the arc shape of the end portion of the flat tube 2 and has a relatively thick plate shape.

  As shown in FIGS. 2 and 3, one flat tube 2 includes a lower plate 21 serving as a first plate, an upper plate 22 serving as a second plate, and a fin plate 23 disposed therebetween. , Consisting of three. Each of these plates 21, 22, 23 and the mounting flange 3 and the reinforcing plate 4 are made of a metal plate such as stainless steel or iron, and are temporarily assembled in a predetermined state, and then heated in a furnace to integrate each part. It is brazed. A so-called clad material obtained by coating the surface of the base material with a brazing material can also be used.

  The lower plate 21 of each stage of the flat tube 2 has the same configuration except for the lower plate 21A of the lowermost flat tube 2 and basically has a flat and thin plate shape at both ends in the longitudinal direction. A pair of circular openings 25 are formed as openings. The pair of openings 25 are arranged side by side in the width direction of the lower plate 21. Further, at the curved end portions, the peripheral edge rises slightly for positioning the upper plate 22, but at the pair of side edges that are straight portions along the longitudinal direction, the connecting pieces 24 rise almost vertically. ing. The connecting piece 24 has a protruding length slightly smaller than the interval between the steps so that the upper end of the connecting piece 24 in the flat tube 2 of a certain step overlaps the lower end portion of the connecting piece 24 in the flat tube 2 of the adjacent step. And has a taper shape slightly extending outward so as to overlap each other in a cup shape.

  In the lower plate 21A of the lowermost flat tube 2, one circular opening 25A is formed at each end in the longitudinal direction. Other basic configurations are the same as those of the lower plate 21 of other stages. The opening 25A in the lowermost flat tube 2 has the center of the circle positioned at the center between the pair of openings 25 and has an opening area larger than the individual opening area of the pair of openings 25. . The single opening 25A at each end corresponds to the circular opening 6 of the mounting flange 3, and as shown in FIGS. 2 and 3, the periphery of the opening 25A is bent downward. Thus, a short cylindrical tubular portion 26 is formed. The mounting flange 3 is brazed to the lower surface of the lower plate 21 </ b> A of the lowermost flat tube 2, and the cylindrical portion 26 is fitted to the inner periphery of the circular opening 6 of the mounting flange 3. .

  The upper plate 22 of the flat tube 2 at each stage has the same configuration except for the upper plate 22A of the uppermost flat tube 2, and as shown in FIG. The resulting joint flange portion 27 is formed continuously over the entire circumference. In addition, a pair of circular openings 28 are formed at each end in the longitudinal direction of the upper plate 22 corresponding to each pair of openings 25 at both ends of the lower plate 21. The periphery of the opening 28 is bent so as to be raised one step upward, thereby forming a boss portion 29 surrounding each opening 28 in an annular shape. In other words, the circular boss portion 29 is formed so as to protrude upward, and the opening 28 is formed at the center thereof. Moreover, in order to secure a gap serving as a cooling water flow path, a frustoconical embossed portion 30 having the same height as the boss portion 29 is formed at appropriate locations on the upper plate 22.

  The upper plate 22A of the uppermost flat tube 2 has a flat structure that does not include the opening 28, the boss 29, and the emboss 30 as is apparent from FIG. Other basic configurations including the joint flange portion 27 are the same as those of the upper plate 22 of other stages.

  As shown in FIG. 2, the fin plate 23 has a rectangular outer shape, and is provided in a range that does not overlap the openings 25, 25 </ b> A, 28 at both ends. As shown in an enlarged view of a part of the fin plate 23 in FIG. 4, a single base material is provided with a number of slits to form a number of strips having a constant width, and the strips are formed at a constant pitch. It consists of corrugated fins that are bent in a rectangular or U-shape, and in particular, it consists of offset corrugated fins in which the positions of the corrugations of adjacent strips are shifted from each other by a half pitch. For convenience of explanation, if two directions orthogonal to each other in the plane of the fin plate 23 are defined as an X direction and a Y direction, respectively, as shown in FIG. Corrugation is performed by bending the sheet to the opposite side at every fixed pitch at the shifted position. Therefore, the fin plate 23 has anisotropy that has a low resistance to the flow in the X direction and a high resistance to the flow in the Y direction.

  In this embodiment, as shown in FIG. 3, the fin plate 23 is arranged in the flat tube 2 so that the X direction that provides low resistance is along the longitudinal direction of the flat tube 2.

  The lower plate 21 (21A) and the upper plate 22 (22A) configured as described above are joined together by brazing with the fin plate 23 sandwiched therebetween. That is, the joining flange portion 27 at the periphery of the upper plate 22 is superimposed on the upper surface of the periphery of the lower plate 21, and the joining surfaces are brazed together. Further, the fin plate 23 is bent as a corrugated fin and has a space in the vertical direction, but its lower surface is brazed to the lower plate 21 and its upper surface is brazed to the upper plate 22. Thereby, it becomes the oil flow path 11 with which the inside of the flat tube 2 was sealed.

  As described above, the plurality of flat tubes 2 are laminated and brazed together. At this time, the boss 29 around the opening 28 of the upper plate 22 in the flat tube 2 at a certain stage is brazed and joined to the periphery of the opening 25 of the lower plate 21 in the flat tube 2 adjacent thereto. The As a result, a gap corresponding to the height of the boss portion 29 is ensured as the cooling water flow path 12 between the upper plate 22 of a certain step and the lower plate 21 of the upper step, while the former opening 28. And the latter opening 25 are connected to each other. Therefore, in a state where the flat tubes 2 are stacked in a plurality of stages, a plurality of boss portions 29 are configured to be continuous in the stacking direction so that the oil flow paths 11 in each flat tube 2 communicate with each other.

  Further, the embossed portion 30 of each upper plate 22 is brazed to the lower surface of the lower plate 21 at the top of which is adjacent. The embossed portion 30 contributes to securing the cooling water flow path 12 between the adjacent flat tubes 2 together with the boss portion 29 described above.

  Furthermore, as shown in FIG. 3, the connecting piece 24 provided on the lower plate 21 (21A) of each level of the flat tube 2 is the inner side of the connecting piece 24 of the lower level flat tube 2 which is relatively lower. In addition, the lower ends of the connecting pieces 24 of the adjacent upper flat tubes 2 are sequentially fitted, and a large number of connecting pieces 24 are sequentially overlapped in the stacking direction. These overlapping connecting pieces 24 are also joined to each other by brazing. Therefore, as shown in FIGS. 1, 6, and 7, a large side wall integrated in the stacking direction is constituted by the plurality of connecting pieces 24, and a plurality of flat tubes 2 are interposed via the pair of side walls. Are firmly connected in the stacking direction.

  The oil cooler 1 integrally assembled by brazing as described above is used in a state of being accommodated in a case 31 through which cooling water flows, as shown in FIG. The case 31 includes, for example, a base portion 33 that is a part of a cylinder block of an engine and a cover 32 that is attached to the base portion 33, and the oil cooler 1 is accommodated in a water jacket 34 that is formed therebetween. The The water jacket 34 is provided with a cooling water inlet (not shown) at one end in the longitudinal direction thereof and a cooling water outlet (not shown) at the other end, respectively, and the cooling water is a water pump (not shown) on the engine side. Is forced to circulate. The oil cooler 1 is fixed to the cover 32 by a bolt 35 passing through the mounting hole 7 of the mounting flange 3, and high-pressure oil (engine lubricating oil) is introduced into the inside through an oil passage 36 of the cover 32. The oil flows from one end to the other end in the longitudinal direction of the oil cooler 1, and the cooling water in the water jacket 34 is also in the forward or reverse direction with respect to the oil flow. Flows along the longitudinal direction. Therefore, the connecting piece 24 at the side edge formed along the longitudinal direction does not particularly disturb the flow of the cooling water. Since the plurality of flat tubes 2 are bound to each other by the connecting piece 24, the pressure resistance of the oil cooler 1 against the oil pressure of the internal oil is increased.

  Here, in the configuration of the above-described embodiment, as shown in FIG. 3, the opening 25 </ b> A in the lower plate 21 </ b> A of the lowermost flat tube 2 serving as the oil inlet of the oil cooler 1 is the center in the width direction of the flat tube 2. Is a single one located in On the other hand, in the second and subsequent flat tubes 2, a pair of openings 25 and 28 serving as oil inlets to the flat tubes 2 are symmetrical in the width direction of the flat tube 2 with the opening 25 </ b> A interposed therebetween. Is provided. Accordingly, the oil that has flowed into the lowermost flat tube 2 from the single opening 25A flows partly along the longitudinal direction of the flat tube 2, but the other part has a width from the opening 25A. It spreads in the direction and flows into the second-stage flat tube 2 through the pair of openings 25 and 28, and flows in the flat tube 2 from the pair of openings 25 and 28 in the longitudinal direction. And in the other end part used as the oil outlet of each flat tube 2, since the pair of opening parts 25 and 28 exist in the flat tube 2 after the 2nd step | paragraph, it spreads widely in the width direction of the flat tube 2. The flow is distributed, and heat exchange is performed by effectively utilizing the entire width of the flat tube 2. In the end portion on the outlet side, the oil flow finally merges into the single opening portion 25A in the lowermost flat tube 2 and is led out from the opening portion 25A to the case 31 side.

  Thus, in the above-described embodiment, the flat tubes are provided between the pair of oil inlets (openings 25, 28) and the pair of oil outlets (openings 25, 28) in each of the flat tubes 2 in the second and subsequent stages. Since the oil flows in the width direction of 2, the heat exchange efficiency is high. On the other hand, since the oil inlet and the oil outlet (that is, the central opening 6) in the mounting flange 3 are a single opening, for example, the connection structure on the case 31 side is complicated, or the mounting flange 3 is enlarged. There is no. It can be easily handled as a replacement part of an existing oil cooler.

  Next, FIGS. 8 and 9 show an embodiment in which the fin plate 23 in the lowermost flat tube 2 has a higher resistance than the fin plates 23 in the other flat tubes 2.

  Specifically, in the lowermost flat tube 2, the above-described fin plate 23 in FIG. 4 is accommodated such that the high resistance Y direction (see FIG. 4) is along the longitudinal direction of the flat tube 2. It is. In the other flat tube 2, the low resistance X direction is along the longitudinal direction of the flat tube 2 as described above. Therefore, the lowermost flat tube 2 has a relatively higher flow resistance than the other flat tubes 2 with respect to the flow of oil flowing from one end to the other end in the longitudinal direction of the flat tube 2. It has become.

  In such a configuration, in the flat tube 2 at the lowermost stage, it flows linearly from a single oil inlet (opening 25A) at one end to a single oil outlet (opening 25A) at the other end. The narrow flow is suppressed, the flow is more widely diffused in the lowermost flat tube 2, and the oil is more actively guided to the second and subsequent flat tubes 2. Accordingly, the heat exchange efficiency is further improved. Further, since only the lowermost flat tube 2 has a high resistance, an increase in passage resistance or pressure loss as the entire oil cooler 1 is minimized.

  Next, a second embodiment of the present invention will be described with reference to FIGS. In FIG. 11, the third and subsequent flat tubes 2 are omitted together with the reinforcing plate 4. In addition, the same reference numerals are given to the portions that are substantially the same as those of the above-described embodiment, and the duplicate description is omitted. In this embodiment, the width of the flat tube 2 is larger than that in the embodiment described above. Therefore, the flat tube 2 in the second and subsequent stages includes three openings 25 and 28 at each end of the flat tube 2.

  Specifically, circular central openings 25a and 28a are formed at positions (in other words, concentric positions) corresponding to a single circular opening 25A provided on the lower plate 21 of the lowermost flat tube 2. The pair of side openings 25b and 28b are symmetrically arranged on both sides thereof. As shown in FIG. 13, the side openings 25b and 28b have circular shapes slightly smaller in diameter than the central openings 25a and 28a, respectively, and in the longitudinal direction of the flat tube 2 than the central openings 25a and 28a. It is arranged at a position offset inward. In other words, the side openings 25b and 28b at one end are closer to the distance between the central openings 25a and 28a at one end and the central openings 25a and 28a at the other end in the longitudinal direction (that is, the flow distance). The distance in the longitudinal direction between the side openings 25b and 28b at the other end (that is, the flow distance) is shorter.

  Thereby, the circular boss 29a surrounding the central opening 28a of the upper plate 22 and the circular boss 29b surrounding the side opening 28b are offset from each other in the longitudinal direction of the flat tube 2. Therefore, in the cooling water flow path 12 between the flat tubes 2 when accommodated in the case 31, a flow path through which cooling water can flow obliquely between the central boss portion 29a and the side boss portion 29b is secured. The

  Further, in this embodiment, the fin plate 23 in the flat tube 2 at the lowermost stage is oriented in such a manner as to have a high resistance to the flow in the longitudinal direction of the flat tube 2 as in the above-described embodiments of FIGS. (See FIGS. 12 and 13). In addition, in order to diffuse the flow of the oil flowing in from the single opening 25A to the pair of side openings 25b and 28b, as shown in FIG. A rectangular extension 23a is provided to enter between the openings 25b and 28b. In other words, the end of the fin plate 23 has a shape that is cut out corresponding to the layout of the three openings 25a, 28a, 25b, and 28b.

  Further, the outer shape of the end portion of the flat tube 2 (the lower plate 21 and the upper plate 22) has a shape corresponding to the layout of the three openings 25a, 28a, 25b, and 28b, that is, the three circles are smoothly formed. It has a continuous outer shape.

  Also in the second embodiment, the oil flowing into the lowermost flat tube 2 from the single opening 25A as the oil inlet in the width direction of the flat tube 2 is the same as the above-described embodiment. Since the flow flows to the three openings 25 and 28 (the center openings 25a and 28a and the pair of side openings 25b and 28b) arranged in an expanded manner, the flat tube 2 is used in the second and subsequent flat tubes 2. The flow of oil spreading in the entire width direction is obtained, and the heat exchange efficiency is improved. In particular, the pair of side openings 25b and 28b are located on the inner side in the longitudinal direction of the central openings 25a and 28a, and the flow distance thereof is short, so that the side portions of the flat tube 2 from the side openings 25b and 28b. It becomes easier to flow through, and the flow in each part in the width direction can be made uniform.

  14 and 15 show a modification in which the diameters of the central openings 25a and 28a are smaller than those of the lowermost opening 25A in the second embodiment. In particular, the diameters of the central openings 25a and 28a are smaller than the diameters of the pair of side openings 25b and 28b. When the diameters of the central openings 25a and 28a are thus reduced, the ratio of the flow guided to the side openings 25b and 28b increases. Therefore, it is suitable when it is necessary to more actively guide the oil to the side openings 25b and 28b according to the required specifications. In the illustrated example, both the central opening 25a of the lower plate 21 and the central opening 28a of the upper plate 22 have the same diameter, but only one of them may be a small-diameter opening.

  In each of the above-described embodiments, the openings 25 and 28 are circular, but the present invention is not limited to this, and any shape such as a rectangular opening can be used. Further, the number of openings at each end of the flat tube 2 in the second and subsequent stages is not limited to two (that is, a pair) or three in the above-described embodiment, and a configuration in which a large number of openings are arranged. Good.

  Next, FIG. 16 shows a third embodiment in which the flow is expanded in the width direction of the flat tube 2 in the mounting flange 3. The oil cooler 1 of this embodiment has substantially the same appearance as the oil cooler 1 of the first embodiment shown in FIG. 1 and the like, but the lower plate 21 of the flat tube 2 at each stage is The lower plate 21 of the lowermost flat tube 2 has the same configuration. That is, the lower plate 21 in the lowermost flat tube 2 is also provided with a pair of circular openings 25 at each end in the longitudinal direction.

  Then, on the lower surface of the lower plate 21 in the lowermost flat tube 2, a pair of mounting flanges 103, which respectively constitute an oil inlet and an outlet, are attached, as in the first embodiment. Here, each mounting flange 103 is made of a relatively thick metal plate that also has a rhombus or an ellipse, and is brazed in the form of being laminated on the lower surface of the lowermost lower plate 21. Unlike the mounting flange 3 of the embodiment, a pair of communication ports 106 corresponding to the pair of openings 25 of the lower plate 21 are opened on the surface 103a on the side contacting the lower plate 21, and the mounting surface on the opposite side. 103b has a single circular opening 6A serving as an inlet or an outlet for oil from the engine side. As shown in FIG. 17, the pair of communication ports 106 and the single circular opening 6 </ b> A are each formed as a circular recess having a depth that does not penetrate the mounting flange 103. 17 are arranged so as to partially overlap each other when projected, as shown in FIG. 16, they are in communication with each other inside the mounting flange 103, and within the overlapping range, the mounting flange 103 It is an opening that penetrates the entire plate thickness. As can be easily understood from FIG. 16, the sum of the depth of the communication port 106 and the depth of the circular opening 6 </ b> A is set so as to exceed the plate thickness of the mounting flange 3. Are overlapping.

  According to the third embodiment, the flow of oil is expanded in the width direction of the flat tubes 2 so as to go to the pair of communication ports 106 inside the mounting flange 103, and in each of the flat tubes 2, the first described above. As in the first embodiment, the oil flows in the width direction of the flat tube 2 between the pair of oil inlets (openings 25, 28) and the pair of oil outlets (openings 25, 28). Therefore, high heat exchange efficiency can be obtained. Since the oil inlet and the oil outlet (that is, the central opening 6A) in the mounting flange 103 are a single opening as in the above-described embodiments, the connection structure with the case 31 is simplified, and the existing oil It can be easily handled as a cooler replacement part.

  Even in the configuration in which the flat tube 2 has a larger number of openings as in the second embodiment, it can be similarly configured by changing the mounting flange.

DESCRIPTION OF SYMBOLS 1 ... Oil cooler 2 ... Flat tube 3 ... Mounting flange 4 ... Reinforcement plate 11 ... Oil flow path 12 ... Cooling water flow path 21 ... Lower plate 22 ... Upper plate 23 ... Fin plate 25, 25A ... Opening 25a ... Central opening 25b ... side opening 27 ... joint flange 28 ... opening 28a ... central opening 28b ... side opening 29, 29a, 29b ... boss 30 ... embossing 31 ... case

Claims (5)

A heat exchanger in which a flat tube whose inside is a flow path of a first fluid is stacked in a plurality of stages through a gap which is a flow path of a second fluid, and each flat tube is mutually connected at the periphery The first flat plate and the second plate are joined, and two adjacent flat tubes are respectively provided with openings provided at the respective ends in the longitudinal direction of the second plate of one flat tube and the other flat plate. Openings provided at the respective ends of the first plate of the tube in the longitudinal direction are joined to each other so as to communicate with each other, and the first tube extends in the longitudinal direction of each flat tube through these openings. In the heat exchanger through which the fluid flows,
At each end in the longitudinal direction of the first plate in the lowermost flat tube, a single opening serving as a fluid inlet or a fluid outlet of the heat exchanger is formed as the opening.
At each end in the longitudinal direction of the second plate combined with the first plate, as the opening, a plurality of openings are arranged extending in the width direction of the flat tube,
The second and subsequent flat tubes have a plurality of openings at each end corresponding to the second plate of the lowermost flat tube ,
A fin plate is disposed between the first plate and the second plate of each flat tube;
Among the plurality of flat tubes, the fin plate in the lowermost flat tube is characterized in that the resistance to the flow along the longitudinal direction of the flat tube is higher than the resistance of the fin plate in the other flat tubes. Heat exchanger.   A mounting flange is attached to the lower surface of the first plate of the lowermost flat tube, and a fluid inlet and a fluid outlet provided on the mounting flange are a single opening at each end of the first plate. The heat exchanger according to claim 1, wherein the heat exchanger is connected to the heat exchanger. The second plate of the lowermost flat tube and the second and subsequent flat tubes are evenly positioned at each end with a single opening in the first plate of the lowermost flat tube sandwiched between them. the heat exchanger according to claim 1 or 2, characterized in that it has openings. The second plate of the lowermost flat tube and the second and subsequent flat tubes have, at each end, a central opening whose center position coincides with a single opening in the first plate of the lowermost flat tube the heat exchanger according to claim 1 or 2, characterized in that it has an odd number of openings including part. A heat exchanger in which a flat tube whose inside is a flow path of a first fluid is stacked in a plurality of stages through a gap which is a flow path of a second fluid, and each flat tube is mutually connected at the periphery The first flat plate and the second plate are joined, and two adjacent flat tubes are respectively provided with openings provided at the respective ends in the longitudinal direction of the second plate of one flat tube and the other flat plate. Openings provided at the respective ends of the first plate of the tube in the longitudinal direction are joined to each other so as to communicate with each other, and the first tube extends in the longitudinal direction of each flat tube through these openings. In the heat exchanger through which the fluid flows,
At each end in the longitudinal direction of the first plate and the second plate, as the opening, a plurality of openings are arranged extending in the width direction of the flat tube,
A plate-like mounting flange is laminated on the lower surface of the first plate in the lowermost flat tube,
A plurality of communication ports corresponding to the plurality of openings of the flat tube are opened on the surface of the mounting flange on the first plate side, and a fluid inlet or a fluid outlet is formed on the opposite mounting surface. A plurality of communication openings and a single opening communicate with each other inside the mounting flange ,
The plurality of communication ports and the single opening are each formed as a recess having a depth that does not penetrate the mounting flange, and these recesses are arranged so as to partially overlap each other. A heat exchanger characterized by being in communication with each other .

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