JP2018146145A - Heat exchanger and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger capable of increasing an allowable range of accuracy of finishing for a flow passage tube in which fluid to be heated flows, and excellent in heat exchange efficiency and durability.SOLUTION: A heat exchanger 1 is configured such that a flat tube 2 in which fluid to be heated flows is formed on a non-partition wall; a plurality of flat tubes 2 are aligned at intervals in parallel; a plurality of fins 3 are disposed at intervals in an axis direction of the flat tube 2; open holes 31 of the plurality of fins 3 are provided so that the plurality of flat tubes 2 penetrate them; at a portion of the flat tube 2 positioned between the fins 3, 3, formed is an expansion part 22 extending in a circumferential direction; a root 221 of the expansion part 22 presses a peripheral edge of the open hole 31 of the fin 3 to fix the flat tube 2 to the fin 3; and the plurality of flat tube 2 are arranged so as to cross a circulation pipe 4 for heating fluid.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat exchanger for exchanging heat between a heated fluid such as exhaust gas of an internal combustion engine of an automobile and a heated fluid, and a method for manufacturing the same.

  Conventionally, as a heat exchanger that performs heat exchange between exhaust gas generated in an internal combustion engine of an automobile and a fluid to be heated, a plurality of flat tubes through which the fluid to be heated flows are arranged in parallel at intervals, and the plurality of flat tubes are connected. A heat exchanger is known in which fins are provided and the heat exchange area is increased by the flat portions of the flat tubes and the fins, thereby improving the heat exchange efficiency (see Patent Document 1).

Japanese Patent Laid-Open No. 2006-114331

  By the way, as shown in FIG. 10A, a plurality of flat tubes 101 are arranged in parallel at intervals, and these flat tubes 101 are inserted into the insertion holes 105 of the common fins 104, and the flat tubes 101 and the fins 104 are inserted. In the structure in which the peripheral portion of the insertion hole 105 is joined by brazing or welding, when there is a gap 102 due to welding distortion in the flat tube 101, it cannot be joined and fixed at that portion, and the flat tube 101 and the fin When the gap 102 to which the 104 does not adhere is large, the heat conduction is also greatly reduced. Further, as shown in FIG. 10B, the same problem occurs even when there is a gap 103 because the flat surface shape of the flat tube 101 is poor.

  That is, in the structure in which the channel pipe and the fin through which the fluid to be heated flows are fixed by brazing or welding, the strength and stability of fixing the channel pipe and the fin are greatly affected by the processing accuracy of the channel pipe. Furthermore, if the processing accuracy of the flow channel pipe is low and a large part is formed that does not adhere closely between the flow channel tube and the fin, even if the heat exchange area is increased by the fin, the heat conduction is greatly reduced, and the heat exchange efficiency is reduced. It will drop significantly. In addition, when such a large portion that cannot be adhered is generated, the fixing of the flow path pipe and the fin is weakened, and the durability is also lowered. Therefore, there is a demand for a heat exchanger that has a large tolerance for processing accuracy of the flow path pipe and that is excellent in heat exchange efficiency and durability.

  The present invention is proposed in view of the above problems, and provides a heat exchanger that can increase the allowable range of the processing accuracy of the flow path pipe and is excellent in heat exchange efficiency and durability, and a method for manufacturing the same. With the goal.

In the heat exchanger according to the present invention, the flow path pipe through which the fluid to be heated flows is formed without a partition wall, the plurality of flow path pipes are arranged side by side at intervals, and the plurality of fins are shafts of the flow path pipe The plurality of flow channel tubes are provided so as to pass through the through holes of the plurality of fins, and are disposed between the fins. A bulging portion extending in the circumferential direction is formed, a root of the bulging portion presses a peripheral edge of the through hole of the fin, the channel pipe is fixed to the fin, and the plurality of the channel pipes are heated. It is arranged so as to cross the fluid circulation pipe.
According to this, a bulging portion extending in the circumferential direction is formed in the flow channel tube, and the flow channel tube is fixed to the fin by pressing the peripheral edge of the through hole of the fin at the base of the bulge portion. However, the strict machining accuracy is not required, and the allowable range of the machining accuracy of the flow path pipe fixed to the fin can be increased, thereby improving the yield. Further, in the structure in which the peripheral edge of the through hole of the fin is pressed at the base of the bulging portion extending in the circumferential direction without being interrupted in the middle, and the flow path pipe is fixed to the fin, the large gap that does not adhere between the flow path pipe and the fin. Without the occurrence of a portion, it is possible to prevent the heat conduction from being reduced at the boundary portion between the channel tube and the fin, and the heat exchange efficiency can be increased. In addition, since a large portion that does not adhere to the channel pipe and the fin does not occur, the fixing strength between the channel pipe and the fin is increased, and the durability can be improved.

In the heat exchanger according to the present invention, the heating fluid is exhaust of an internal combustion engine of an automobile, the distance between the fins is 1.0 mm to ²⁰ mm, and the pipe cross-sectional area of the flow path pipe is 7.0 mm ^{2 to} 1500 mm. ^2. The height difference between the outer end of the bulging portion and the base of the bulging portion is 0.1 mm to 20 mm.
According to this, by setting the distance between the fins to 1.0 mm to 20 mm, the required heat exchange can be ensured, and the exhaust flow path is narrowed due to the dense fins, and the exhaust pressure loss and back pressure are reduced. It is possible to prevent the rise and increase the exhaust efficiency, intake efficiency, and combustion efficiency of the internal combustion engine of the automobile. Further, 7.0 mm ² the pipe cross-sectional area of the flat tube ~1500mm ^2, by the difference in height between the base of the outer end and the bulging portion of the bulged portion and 0.1Mm～20mm, heated fluid Therefore, a turbulent flow having a required size can be generated to promote heat exchange.

In the heat exchanger according to the present invention, the flow path tube is a flat tube, and the plurality of flat tubes are arranged in parallel so as to oppose the flat surfaces, and the flat surfaces of the flat tubes are heated fluid. And the bulging portion is formed so as to bulge over substantially the entire length of the flat surface on both sides.
According to this, the flow path tube through which the fluid to be heated flows is a flat tube, and the flat surface is arranged along the flow direction of the heating fluid, thereby widening the heat transfer area and heat exchange between the heating fluid and the fluid to be heated. Can be promoted. Further, by forming the bulging portion over substantially the entire length of the width of the flat surface on both sides, it is possible to secure a sufficient adhesion region between the flat tube and the fin, and heat at the boundary between the flat tube and the fin. A decrease in conduction can be reliably prevented and heat exchange efficiency can be improved. Further, the flat tube is secured so that a sufficient contact area between the flat tube and the fin is secured and the bulging portions of the flat surfaces on both sides are linearly pressed and clamped from both sides by the fin through-hole portions to be pressed. Is fixed to the fin, the fixing strength between the flat tube and the fin can be further increased, and the durability can be further improved.

In the heat exchanger according to the present invention, a separate sill member is provided on the flat tube, and a sill portion shorter than the length of the flat tube of the sill member is inserted into the flat tube, and a partition of the sill portion is provided. A flow path of a fluid to be heated which is longer than the length of the flat tube is formed in the flat tube.
According to this, the flow path of the to-be-heated fluid longer than the length of a flat tube can be formed, and heat exchange efficiency can be improved further.

In the heat exchanger according to the present invention, a plurality of the separate sill members are provided, the sill part is inserted with a space in the long axis direction of the flat tube, and the sill part is one of the flat tubes. The meandering flow path of the fluid to be heated is formed in the flat tube by a plurality of partitions of the sill portions, alternately inserted from one end side and the other end side.
According to this, a heat exchanger for a heated fluid that requires high heating can be easily configured, heat exchange efficiency can be further increased, and a heat exchanger having a different heat exchange efficiency can be easily changed. It can be a highly flexible heat exchanger.

The method for manufacturing a heat exchanger according to the present invention is a method for manufacturing the heat exchanger according to the present invention, wherein a tubular work without a partition wall is formed in a through hole at a corresponding position of a plurality of fins arranged at intervals. A first step of inserting and penetrating the plurality of tubular workpieces through the through-holes of the plurality of fins; closing one end of the tubular workpiece; and pressurizing and injecting fluid from the other end A portion of the tubular workpiece located between the fins to bulge into a bulging portion extending in the circumferential direction, and a base of the bulging portion presses the peripheral edge of the through hole of the fin. It is characterized by including the 2nd process of forming.
According to this, by using a tubular work with no partition wall and uniformly applying fluid pressure to the peripheral wall, it is possible to reliably form a bulging portion extending in the circumferential direction without interruption in a simple manufacturing process. The channel tube can be fixed to the fin by pressing the peripheral edge of the through hole of the fin at the base of the bulging portion extending in the circumferential direction.

In the method for manufacturing a heat exchanger according to the present invention, the tubular workpiece is a flat tubular workpiece, and the flat plane width of at least both sides of the flat tubular workpiece is substantially reduced by pressurizing the fluid in the second step. A bulging portion is formed by bulging over the entire length.
According to this, a sufficient adhesion area between the flat tube and the fin can be secured, and the structure in which the flat tube is fixed to the fin so as to be pressed linearly from both sides at the through-hole portion of the fin is simplified. It can be reliably formed by a simple manufacturing process.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to enlarge the tolerance | permissible_range of the processing precision of the flow pipe of a heat exchanger, the heat exchanger excellent in heat exchange efficiency and durability can be obtained.

The perspective view of the heat exchanger of 1st Embodiment by this invention. The top view of the heat exchanger of 1st Embodiment. (A) is AA expanded sectional drawing of FIG. 2, (b) is the elements on larger scale of the figure (a). (A) is a perspective view which shows the flat tubular work and fin in 1st Embodiment, (b) is a perspective view which shows the assembly which penetrated the several flat tubular work to the through-hole of the several fin. (A) is a front view of an assembly in which a plurality of flat tubular workpieces are passed through through holes of a plurality of fins in the first embodiment, and (b) is a diagram showing a structure in which the assembly is attached to a jig for fluid pressurization. The partial cross section front view which shows the state in the middle of pressurizing, (c) is a front view which shows the state after the fluid pressurization of the assembly. The cross-sectional view of the heat exchanger of 2nd Embodiment by this invention. The perspective view of the assembly of the flat tube, fin, and sill member in 2nd Embodiment. (A) is a front view of the assembly of the flat tube, fin, and sill member in 2nd Embodiment, (b) is the BB sectional drawing. (A) is a partial cross-sectional view of the flat tube and fin of the first modified example of the present invention, (b) is a partial cross-sectional view of the flat tube and fin of the second modified example, and (c) is a flat tube of the third modified example. And (d) is a partial cross-sectional view of a flat tube and fins of a fourth modification. (A) is partial explanatory drawing which shows the case where there exists a clearance gap between a flat tube and a fin by welding distortion with the conventional joining structure, (a) is a conventional joining structure, and the accuracy of the surface shape of a flat tube is inferior, and a flat tube Partial explanatory drawing which shows the case where a clearance gap exists between a fin and a fin.

[The heat exchanger of the first embodiment and its manufacturing method]
The heat exchanger 1 according to the first embodiment of the present invention includes a flat tube 2 corresponding to a flow channel tube through which a fluid to be heated flows as shown in FIGS. The inside of the state as it is is a single flow path. A plurality of flat tubes 2 are provided, and the plurality of flat tubes 2 are arranged side by side so as to face the flat surface 21. In the example shown in the figure, three flat tubes 2 are stacked and arranged so as to face each other with the flat surface 21 facing each other.

  A plurality of fins 3 are arranged at intervals in the tube axis direction of the flat tube 2. The fins 3 in the present embodiment are substantially plate-shaped, and in the illustrated example, are substantially rectangular plate-shaped, and each fin 3 is formed in the same shape and size. Each fin 3 is formed with a number of elongated through holes 31 corresponding to the number of flat tubes 2 arranged side by side, and the through holes 31 of each fin 3 are formed at corresponding positions. Each of the plurality of flat tubes 2 is provided so as to penetrate the plurality of fins 3 arranged at intervals, and is provided so as to penetrate the through holes 31 of the plurality of fins 3.

  The distance between the fins 3 and 3 can be set as appropriate as long as it can be used as a heat exchanger. For example, the heat exchanger 1 is an automobile heat exchanger, and the heating fluid is exhausted from an internal combustion engine of the automobile. In this case, the distance between the fins 3 and 3 is preferably 1.0 mm to 20 mm, and more preferably 3 mm to 5 mm. As a result, the required heat exchange can be ensured, and the exhaust passage is narrowed due to the denseness of the fins 3 to prevent the exhaust pressure loss and the back pressure from increasing, and the exhaust efficiency of the internal combustion engine of the automobile can be reduced. Intake efficiency and combustion efficiency can be increased.

  The portion of the flat tube 2 provided at predetermined intervals and positioned between the fins 3 and 3 extends in the circumferential direction of the flat tube 2 and swells over substantially the entire length of the flat surfaces 21 on both sides. In this way, the bulging portion 22 is formed. In the present embodiment, a bulging portion 22 that bulges over the entire circumference so as to substantially follow the cross-sectional shape of the flat tube 2 is formed in the portion of the flat tube 2 positioned between the fins 3 and 3. In addition, a bulging portion 22 that bulges outward in a substantially arc shape in a longitudinal sectional view is formed.

  The base 221 of the bulging portion 22 presses the peripheral edge of the through hole 31 of the fin 3, and in this embodiment, presses over the entire periphery, and the flat tube 2 is fixed to the fin 3 at a predetermined position by this pressing. ing. In the present embodiment, the fins 3 positioned on the outermost sides in the tube axis direction of the flat tube 2 press the periphery of the through hole 31 over the entire circumference by the root 221 of the bulging portion 22 positioned on the inner side. It is fixed by pressing only at the base 221 of the bulging portion 22 on one side. In addition, in the tube axis direction of the flat tube 2, each fin 3 positioned between the outermost fins 3 has the periphery of the through hole 31 formed by the roots 221 of the bulging portions 22 positioned on both sides thereof. It is pressed and fixed over the entire circumference, and is pressed and fixed at the root 221 of the bulging portion 22 on both sides.

The pipe cross-sectional area of the flat tube 2 and the height difference H between the outer end 222 of the bulging portion 22 and the root 221 of the bulging portion 22 can be appropriately set within a range that can be used as a heat exchanger. It is. For example, when the heat exchanger 1 and the heat exchanger for motor vehicles, the conduit cross-sectional area of the flat tube 2 is preferable to a 7.0 mm ² ～1500Mm ^2, and more preferable to the 120 mm 2 ～400Mm ² In addition, the height difference H between the outer end 222 of the bulging portion 22 and the root 221 of the bulging portion 22 is preferably 0.1 mm to 20 mm, and more preferably 0.2 mm to 1.5 mm. It is. By setting the pipe cross-sectional area of the flat tube 2 and the height difference H between the outer end 222 of the bulging portion 22 and the root 221 of the bulging portion 22 within these numerical ranges, the required size of the fluid to be heated is obtained. Turbulent flow can be generated and heat exchange can be promoted.

  The assembly 6 of the flat tube 2 and the fin 3 is built in the flow tube 4 through which the heated fluid flows. The flow pipe 4 in the illustrated example is an exhaust flow pipe through which the exhaust gas from an internal combustion engine of an automobile flows. The assembly 6 is built in the flow pipe 4 of the exhaust flow pipe that is substantially rectangular in cross section and substantially cylindrical. Flow holes 42 and 42 are formed in both side walls 41 and 41 on the short side of the flow pipe 4, and open ends 23 and 23 at both ends of the flat tube 2 are respectively fixed to the peripheral edges of the flow holes 42 and 42. The flat tube 2 is arranged so as to cross the flow tube 4. The flat surface 21 of the flat tube 2 is arranged along the flow direction EF of the heated fluid such as the exhaust flow direction of the flow tube 4.

  Covers 5 and 5 each having a substantially U-shaped cross-sectional view are provided on the outside of the side walls 41 and 41, respectively, and are fixed to the flow pipe 4 by welding or the like. One cover 5 protrudes outwardly and is provided with a fluid introduction port 51, communicates with the inside of one cover 5, and the other cover 5 protrudes outwardly and is provided with a fluid outlet port 52, It communicates with the inside of the other cover 5. Opening portions on both sides of the covers 5, 5 in the tube axis direction of the flow pipe 4 are closed with a closing member (not shown), and the closing member is fixed to the cover 5 and the flow pipe 4 by welding or the like. Thereby, a substantially sealed space is formed between the cover 5 and the side wall 41 of the flow pipe 4, in other words, on both sides of the flat pipe 2 in the pipe axis direction. In addition, the thick line arrow HF of FIG.3 (b) is a distribution direction of the to-be-heated fluid.

  When manufacturing the heat exchanger 1 of the first embodiment, as shown in FIG. 4, for example, a substantially flat and flat tubular workpiece 2m provided at a position where a substantially flat flat surface 21m faces, A fin 3 having a rectangular plate shape and an elongated through hole 31 is used. The through-holes 31 are formed so that the long axis thereof follows the long side of the fin 3, and a plurality of the through-holes 31 are arranged in parallel at intervals in the short side direction of the fin 3. Holes 31 are arranged side by side.

  A plurality of fins 3 are arranged at predetermined intervals, a flat tubular work 2m is inserted into the through-hole 31 at a corresponding position of the plurality of fins 3, and flattened on the plurality of fins 3 juxtaposed at a predetermined interval. The tubular workpiece 2m is penetrated. This is performed for each through-hole 31 formed at a different position in the fin 3, and a plurality of flat tubular workpieces 2m are passed through the through-holes 31 of the plurality of fins 3, and FIG. An assembly 6m shown in 5 (a) is obtained. In the illustrated example, three flat tubular workpieces 2m are respectively passed through three through holes 31 formed at different positions in the fin 3 to obtain an assembly 6m.

  Thereafter, one end 23 m of the flat tubular workpiece 2 m in the assembly 6 m is fitted into the recess 111 formed in the jig 11. The recess 111 is closed on the back side, is formed in a shape that follows the outer shape of the flat tubular workpiece 2m, and is formed in a size corresponding to the workpiece 2m. One end 23m of the workpiece 2m fitted in the recess 111 is closed by the jig 11 and held by the jig 11 in a shape following the outer shape (see FIG. 5B).

  Further, the other end 24m of the flat tubular work 2m in the assembly 6m is fitted into the recess 121 formed in the jig 12. The recess 121 is formed in a shape that follows the outer shape of the flat tubular workpiece 2m, and is formed in a size corresponding to the workpiece 2m. The other end 24m of the workpiece 2m fitted in the recess 121 is held by the jig 12 in a shape that follows the outer shape (see FIG. 5B).

  Further, the jig 12 is provided with a fluid pipe 122 through which a pressurized fluid flows. A branch pipe 123 of the fluid pipe 122 is introduced to the back side of the recess 121, and the branch pipe 123 and the recess 121 communicate with each other. The fluid pipe 122 and the branch pipe 123 are pressurized and flowed by a pressurizing pump (not shown), and the pressurized fluid is discharged from the recess 121.

  Then, with one end 23m of the flat tubular workpiece 2m fitted into the recess 111 of the jig 11 and the other end 24m fitted into the recess 121 of the jig 12, the fluid pipe 122 and the branch pipe 123 are connected. When the fluid is pressurized and injected through the fluid, the fluid is pressurized and injected into the workpiece 2m from the other end 24m of the flat tubular workpiece 2m. It should be noted that the fluid to be injected under pressure is appropriate as long as it can be used, such as water or high-pressure gas.

  By pressurizing and injecting the fluid, a portion located between the fins 3 and 3 provided at predetermined intervals in the flat tubular work 2m is bulged into the bulging portion 22, and the root 221 of the bulging portion 22 is the fin. The flat tube 2 which presses the periphery of the 3 through-holes 31 is formed, and the assembly 6 is obtained (refer FIG.5 (b), (c)). In this embodiment, the portion located between the fins 3 and 3 is bulged by pressurizing the fluid to form the bulging portion 22, and the root 221 of the bulging portion 22 is formed in the through hole 31 of the fin 3. A flat tube 2 that presses the periphery is formed.

  Further, by the fluid pressure injection, the bulging portion 22 extends in the circumferential direction of the flat tube 2 and is formed so as to bulge over at least substantially the entire width of the flat surface 21 on both sides. The peripheral edge of the through hole 31 of the fin 3 is pressed corresponding to the bulging portion of the portion 22. In addition, the bulging part 22 of the example of illustration is formed over the perimeter of the flat tube 2, and is formed so that the periphery of the through-hole 31 of the fin 3 may be pressed over a perimeter.

  Thereafter, the assembly 6 is mounted and attached to the flow pipe 4, and is attached so as to cover the outer sides of the side walls 41 and 41 of the flow pipe 4 so as to cover a substantially U-shaped cover 5. A step of closing the open portions on both sides of the covers 5 and 5 with a closing member is performed, and the heat exchanger 1 of the first embodiment is obtained.

  According to the first embodiment, the bulging portion 22 that extends in the circumferential direction of the flat tube 2 and bulges over substantially the entire width of the flat surface 21 on both sides is formed, and the root 221 of the bulging portion 22 is formed. By pressing the peripheral edge of the through-hole 31 of the fin 3 and fixing the flat tube 2 to the fin 3, the flat tube 2 is not required to have strict processing accuracy, and the processing accuracy of the flat tube 2 to be fixed to the fin 3 can be improved. The allowable range can be increased, and as a result, the yield can be improved.

  In the structure in which the flat tube 2 is fixed to the fin 3 by pressing the peripheral edge of the through hole 31 of the fin 3 with the root 221 of the bulging portion 22 extending in the circumferential direction without being interrupted, the flat tube 2 and the fin 3 A large portion that does not adhere to each other between the flat tubes 2 and the fins 3 can be prevented from being reduced, and the heat conduction can be prevented from being lowered, and the heat exchange efficiency can be increased. In particular, by forming the bulging portion 22 over substantially the entire length of the flat surface 21 on both sides, a sufficient contact area between the flat tube 2 and the fin 3 can be secured, and the flat tube 2 and the fin 3 are secured. It is possible to reliably prevent a decrease in heat conduction at the boundary portion of the heat exchanger and improve heat exchange efficiency. Moreover, the flow path pipe | tube through which a to-be-heated fluid flows is made into the flat pipe 2, and the flat surface 21 is arrange | positioned along the distribution direction of a heating fluid, thereby expanding the heat transfer area and exchanging heat between the heating fluid and the to-be-heated fluid. Can be promoted.

  Moreover, since a large part which does not adhere closely between the flat tube 2 and the fin 3 does not occur, the fixing strength between the flat tube 2 and the fin 3 is increased, and the durability can be improved. In particular, by forming the bulging portion 22 over substantially the entire length of the flat surfaces 21 on both sides, a sufficient contact area between the flat tube 2 and the fins 3 is secured, and the flat surfaces 21 on both sides are expanded. Since the flat tube 2 is fixed to the fin 3 so as to be pressed linearly from both sides at the portion of the through hole 31 of the fin 3 pressed by the protruding portion 22, the flat tube 2 and the fin 3 are fixed. Strength can be further increased and durability can be further improved.

  Also, according to the manufacturing method of the first embodiment, by using a flat tubular work 2m with no partition wall and uniformly applying fluid pressure to the peripheral wall thereof, it is ensured by a simple manufacturing process in a circumferential direction that is not interrupted in the middle. The extended bulging portion 22 can be formed, and the flat tube 2 can be fixed to the fin 3 by pressing the peripheral edge of the through hole 31 of the fin 3 with the root 221 of the bulging portion 22 extending in the circumferential direction. Furthermore, by bulging the fluid over the entire length of at least the flat surfaces 21 on both sides of the flat tubular work 2m by pressurizing the fluid to form the bulging portion 22, the flat tube 2 and the fin 3 are A structure in which the flat tube 2 is fixed to the fin 3 in such a way that a sufficient contact area can be secured and is linearly pressed and clamped from both sides by the through hole 31 of the fin 3 is ensured by a simple manufacturing process. Can be formed.

[The heat exchanger of the second embodiment and its manufacturing method]
As shown in FIG. 6, the heat exchanger 1 a according to the second embodiment of the present invention includes the flat tube 2, the fin 3, and the flow tube 4 having the same configuration as that of the first embodiment, and includes the flat tube 2 and the fin 3. The structure of the assembly 6 is the same as that of the first embodiment. The root 221 of the bulging portion 22 presses the peripheral edge of the through hole 31 of the fin 3, and the flat tube 2 is fixed to the fin 3 at a predetermined position by this pressing. Has been.

  The assembly 6 of the flat tube 2 and the fins 3 is housed in a flow tube 4 through which a heated fluid such as exhaust flows, and the flow tube 4 has a substantially rectangular shape in a cross-sectional view. The flow holes 42 and 42 are formed in both side walls 41 and 41 on the short side of the flow pipe 4 as in the first embodiment, but in the second embodiment, from the open ends 23 and 23 at both ends of the flat pipe 2. The slightly inner portions are fixed to the peripheral edges of the flow holes 42 and 42, respectively, and both ends of the flat tube 2 slightly protrude outward from the side walls 41 and 41. The plurality of flat tubes 2 are disposed so as to cross the flow tube 4, and the flat surface 21 of the flat tube 2 is disposed so as to be along the flow direction EF of the heated fluid such as the exhaust flow direction of the flow tube 4.

  Covers 5a and 5a having substantially rectangular trays are provided on the outer sides of the side walls 41 and 41, respectively, are fixed to the flow pipe 4 by welding or the like, and are substantially sealed spaces on both sides of the flat pipe 2 in the tube axis direction. Is formed. One cover 5a projects outwardly and is provided with a fluid introduction port 51a, which communicates with the inside of one cover 5a. A fluid introduction tube 81a is attached to the fluid introduction port 51a. The other cover 5a protrudes outwardly and is provided with a fluid outlet 52a, communicates with the inside of the other cover 5a, and a fluid outlet pipe 82a is attached to the fluid outlet 52a.

  In the second embodiment, a plurality of sill members 7 a that are separate from the flat tube 2 are provided. The sill member 7a includes a base 71a extending in the stacking direction of the plurality of flat tubes 2 arranged side by side so as to be stacked at intervals, and a sill portion extending in the tube axis direction of the flat tube 2 from one side of the base 71a. 72a. A plurality of sill portions 72a corresponding to the number of flat tubes 2 stacked at intervals are extended from the base 71a, and the length of each sill portion 72a is shorter than the length of the flat tube 2. Yes.

  The base 71a of the sill member 7a extends in the stacking direction of the plurality of flat tubes 2 and is disposed close to or in close contact with the opening end of the flat tube 2, and each sill portion 72a of the sill member 7a is provided for each of the plurality of flat tubes 2. The sill member 7a is fixed to the flat tube 2 by, for example, welding the side ends of the sill portion 72a located on both outer sides in the stacking direction of the flat tube 2 to the flat tube 2 by laser welding or the like. . In the second embodiment, the sill portion 72a of the sill member 7a is inserted from one end side of the flat tube 2, and the sill portion 72a of another sill member 7a is inserted from the other end side of the flat tube 2. Thus, the sill portion 72a of the sill member 7a is alternately inserted from one end side and the other end side of the flat tube 2.

  In the example of FIG. 6, the width between one end in the width direction of the flat tube 2 and the sill part 72a of one sill member 7a, and the sill part 72a of one sill member 7a and another sill member 7a The width between the sill portion 72a and the width between the sill portion 72a of another sill member 7a and the other end portion in the width direction of the flat tube 2 are substantially the same, and the fluid inlet 51a is flat. It is provided at a position that opens toward a space between one end in the width direction of the pipe 2 and the sill part 72a of one sill member 7a, and the fluid outlet 52a is provided with a sill part 72a of another sill member 7a. The flat tube 2 is provided at a position opening toward the space between the other end in the width direction of the flat tube 2.

  Further, the outer peripheral surface of the base 71a of the sill member 7a abuts substantially linearly on the inner peripheral surface of the cover 5a, and the fluid to be heated is circulated between the outer peripheral surface of the base 71a and the inner peripheral surface of the cover 5a. In other words, the base 71a of the sill member 7a is provided so as to partition the space between the flow pipe 4 and the covers 5a and 5a. In the example of FIG. 6, the outer peripheral surface of the base 71a of one sill member 7a abuts substantially linearly on the inner peripheral surface of one cover 5a, and the outer peripheral surface of the base 71a of another sill member 7a is the other cover 5a. Is substantially linearly in contact with the inner peripheral surface.

  A flow path of the fluid to be heated that is longer than the length of the flat tube 2 is formed by a partition between the cover 5a provided on both ends of the flat tube 2 and the sill portion 72a of the sill member 7a. In the example of FIG. 6, a meandering flow path of the fluid to be heated is formed in the flat pipe 2 by the partition of the covers 5 a, 5 a on both ends of the flat pipe 2 and the plurality of sill portions 72 a, 72 a, A flow direction HF of the fluid to be heated is formed along. The number of the sill members 7a may be one, or a plurality of three or more, and a configuration may be employed in which a flow path of the fluid to be heated that is longer than the length of the flat tube 2 is formed.

  When the heat exchanger 1a of the second embodiment is manufactured, the heat exchanger 1a is configured by the flat tube 2 and the fins 3 in which the bulging portion 22 is formed by the same process as the first embodiment such as pressurized injection of fluid. An assembly 6 is obtained. Thereafter, the sill portion 72a of one sill member 7a and the sill portion 72a of another sill member 7a are inserted into predetermined positions of each flat tube 2 of the assembly 6, and a predetermined portion of the sill portion 72a is welded to the flat tube 2. To obtain an assembly 6a composed of the flat tube 2, the fin 5 and the sill member 7a shown in FIGS.

  Thereafter, the assembly 6a is mounted and attached to the flow pipe 4, and is attached so that the covers 5a and 5a are covered on the outside of the side walls 41 and 41 of the flow pipe 4, or further, the fluid introduction pipe 81a, By attaching the fluid outlet pipe 82a to the fluid outlet 52a, the heat exchanger 1a of the second embodiment is obtained.

  According to 2nd Embodiment, the flow path of the to-be-heated fluid longer than the length of the flat tube 2 can be formed, and heat exchange efficiency can be improved further. In particular, in a configuration in which a plurality of separate sill members 7a are provided to form a meandering flow path for a fluid to be heated, a heat exchanger for the fluid to be heated that requires high heating can be easily configured, and heat exchange efficiency can be improved. While being able to increase further, it can be set as a highly flexible heat exchanger which can be easily changed into a heat exchanger with different heat exchange efficiency.

[Included scope of the invention disclosed herein]
The invention disclosed in the present specification is specified by changing the partial contents to other contents disclosed in the present specification within the applicable range in addition to the inventions and embodiments listed as inventions. Or specified by adding other contents disclosed in this specification to these contents, or specified by deleting these partial contents to the extent that partial effects can be obtained and creating a higher level concept. Is included. The invention disclosed in this specification includes the following modified examples and added contents.

  For example, in the first and second embodiments, the bulging portion 22 that bulges outward in a substantially arc shape in a longitudinal sectional view is formed in the portion of the flat tube 2 positioned between the fins 3 and 3. It is also possible to adopt a configuration in which the shape of the longitudinal section of the portion is a shape other than a substantially arc shape, or a configuration in which the bulging portion is formed in the portion of the flat tube located between the fins at predetermined intervals.

  A modification of the flat tube having such a configuration is shown in FIG. In the first modification of FIG. 9A, a bulging portion 22p that bulges outward in a substantially U shape in a longitudinal sectional view is formed in a portion of the flat tube 2p located between the fins 3 and 3. It is what. The bulging portion 22p is formed so as to swell over substantially the entire length of at least the flat surfaces 21p on both sides, and is preferably formed over the entire circumference so as to substantially follow the cross-sectional shape of the flat tube 2p. .

  In the second modification of FIG. 9B, a bulging portion 22q that bulges outward in a substantially M shape in a longitudinal sectional view is formed in a portion of the flat tube 2q positioned between the fins 3 and 3. It is what. The bulging portion 22q is formed so as to bulge over at least the entire length of the flat surface 21q on both sides, and preferably formed over the entire circumference so as to substantially follow the cross-sectional shape of the flat tube 2q. . When the bulging part 22p of the first modification and the bulging part 22q of the second modification are formed by pressurized injection of fluid, for example, the bulging parts 22p and 22q of a flat tubular work attached to the fin 3 are used. In this state, a mold material having a shape corresponding to these is disposed outside the position where the fluid is formed, and fluid is injected under pressure in this state.

  In the third modified example of FIG. 9C, a bulging portion 22r that bulges outward in a substantially arc shape in a longitudinal sectional view is formed in a portion of the flat tube 2r located between every other fins 3 and 3. It is what. The bulging portion 22r is formed so as to swell over substantially the entire length of at least the flat surfaces 21r on both sides, and preferably is formed over the entire circumference so as to substantially follow the cross-sectional shape of the flat tube 2r. . When the bulging portion 22r is formed by pressure injection of fluid, for example, the flat tubular shape is formed outside the position between the fins 3 and 3 that does not form the bulging portion 22r of the flat tubular work attached to the fin 3. A mold material having a shape that makes surface contact with the entire circumference of the work is disposed, and in this state, the fluid is pressurized and injected.

  In the fourth modification of FIG. 9D, a bulging portion 22s that bulges outward in a substantially arc shape in a longitudinal sectional view is formed in a portion of the flat tube 2s located between every other fins 3 and 3. In the portion of the flat tube 2s located between the fins 3 and 3 where the bulging portion 22s is not formed, a reduced diameter portion 25s reduced inward in a substantially arc shape in a longitudinal sectional view is formed. It is. The bulging portion 22s is formed so as to swell over substantially the entire length of at least the flat surfaces 21s on both sides, and preferably is formed over the entire circumference so as to substantially follow the cross-sectional shape of the flat tube 2s. . The reduced diameter portions 25 s are formed over the entire circumference so as to substantially follow the cross-sectional shape of the flat tube 2 s formed over substantially the entire width of the flat surfaces 21 s on both sides, and are scattered in the circumferential direction of the flat tube 2 s. It is possible to form such as.

  When the flat tube 2s of the fourth modification is formed, for example, the flat tubular work is formed outside the position between the fins 3 and 3 that does not form the bulging portion 22s of the flat tubular work attached to the fin 3. A mold material in surface contact over the entire circumference is arranged, and in this state, fluid is injected under pressure to form a bulging portion 22s in a flat tubular workpiece. Thereafter, the reduced diameter portion 25s can be formed by reducing the diameter of the flat tube 2s located between the fins 3 and 3 where the bulging portion 22s is not formed with a reduced diameter type.

  In addition, the flow channel tube through which the fluid to be heated in the present invention flows is not limited to a flat tube, and may be a tube having an appropriate shape such as a cylindrical tube. Even when manufacturing the heat exchanger of the present invention using these appropriately shaped tubes, a tubular work without a partition wall is inserted into through holes at corresponding positions of a plurality of fins arranged at intervals, and the plurality of fins A step of passing a plurality of tubular workpieces through the through-hole, and a portion located between the fins of the tubular workpiece by closing one end of the tubular workpiece and pressurizing fluid from the other end Bulges into a bulging part extending in the circumferential direction, and using a process of forming a flow channel tube in which the base of the bulging part presses the peripheral edge of the through hole of the fin, A bulging portion extending in the circumferential direction without interruption can be formed, and the peripheral edge of the through hole of the fin can be pressed at the base of the bulging portion extending in the circumferential direction to fix the channel tube to the fin. It is.

  In addition, the arrangement of the flow path pipe with respect to the flow pipe in the present invention is appropriate as long as the flow path pipe is arranged so as to cross the flow pipe of the heated fluid. For example, the flow pipe is crossed obliquely across the flow path of the flow pipe. The present invention includes a configuration in which a flow channel pipe through which a fluid to be heated flows is disposed.

  In addition, the fluid to be heated that flows through the flow path pipe in the present invention is appropriate, for example, cooling water, air, and the heating fluid that flows in the flow pipe in the present invention can be appropriate other than exhaust. . Further, the heat exchanger of the present invention can be a heat exchanger for an appropriate application, for example, a heat exchanger for a construction machine in addition to a heat exchanger for an automobile such as an automobile, a motorcycle, etc. It can be used as a heat exchanger for a cogeneration system.

  In addition, the bulging portion in the present invention includes an appropriate configuration formed to extend in the circumferential direction in the portion of the channel pipe positioned between the fins. For example, a small interval is provided in the circumferential direction of the channel pipe. It is possible to have a configuration in which it is opened and divided into a plurality of strips, but when the flow channel tube is a flat tube, in the region other than the curved portions on both sides in the flat tube width direction in the circumferential direction of the flat tube A configuration in which the bulging portion is continuously formed is preferable from the viewpoint of improving the adhesion between the flat tube and the fin and improving the strength of pressing and fixing.

  The present invention can be used as a heat exchanger such as an exhaust heat exchanger that performs heat exchange between an exhaust gas of an internal combustion engine of an automobile and a fluid to be heated.

DESCRIPTION OF SYMBOLS 1, 1a ... Heat exchanger 2, 2p, 2q, 2r, 2s ... Flat tube 2m ... Flat tubular work 21, 21p, 21q, 21r, 21s, 21m ... Flat surface 22, 22p, 22q, 22r, 22s ... Expansion Protruding part 221 ... Root 222 ... Outer end 23m ... One end 24m ... The other end 25s ... Reduced diameter part 3 ... Fin 31 ... Through hole 4 ... Flow pipe 41 ... Side wall 42 ... Flow hole 5, 5a ... Cover 51 , 51a ... Fluid inlet 52, 52a ... Fluid outlet 6, 6m, 6a ... Assembly 7a ... Sill member 71a ... Base 72a ... Sill portion 81a ... Fluid inlet pipe 82a ... Fluid outlet pipe 11 ... Jig 111 ... Recess 12 ... Jig 121 ... Recessed part 122 ... Fluid pipe 123 ... Branch pipe H ... Difference in height between the outer end of the bulging part and the root of the bulging part EF ... Flow direction of heated fluid HF ... Flow direction of heated fluid 101 ... Flat tube 102 , 103 ... gap 104 ... fin 105 ... insertion hole

Claims (7)

A channel pipe through which the fluid to be heated flows is formed with no partition walls,
A plurality of the flow pipes are juxtaposed at intervals,
A plurality of fins are disposed with an interval in the axial direction of the flow path pipe, and the plurality of flow path pipes are provided so as to penetrate through holes of the plurality of fins.
A bulging portion extending in the circumferential direction is formed in a portion of the flow channel pipe located between the fins,
The base of the bulging portion presses the periphery of the through hole of the fin, and the flow channel tube is fixed to the fin.
The heat exchanger, wherein the plurality of flow channel tubes are arranged so as to cross a heating fluid flow tube. The heated fluid is the exhaust of an internal combustion engine of an automobile,
The gap between the fins is 1.0 mm to ²⁰ mm, the cross-sectional area of the channel pipe is 7.0 mm ^{2 to} 1500 mm ² , and the difference in height between the outer end of the bulging portion and the root of the bulging portion The heat exchanger according to claim 1, wherein the heat exchanger is 0.1 mm to 20 mm. The flow channel tube is a flat tube;
A plurality of the flat tubes are arranged side by side so as to oppose the flat surfaces, and the flat surfaces of the flat tubes are arranged along the flow direction of the heating fluid,
The heat exchanger according to claim 1 or 2, wherein the bulging portion is formed so as to bulge over substantially the entire length of the flat surface on both sides. A separate sill member is provided on the flat tube,
A sill portion shorter than the length of the flat tube of the sill member is inserted into the flat tube,
The heat exchanger according to claim 3, wherein a flow path of a fluid to be heated that is longer than a length of the flat tube is formed in the flat tube by a partition of the sill portion. A plurality of separate sill members are provided,
The sill portion is inserted with an interval in the longitudinal direction of the flat tube, and the sill portion is alternately inserted from one end side and the other end side of the flat tube,
The heat exchanger according to claim 4, wherein a meandering flow path for a fluid to be heated is formed in the flat tube by a plurality of partitions of the sill portions. It is a manufacturing method of the heat exchanger in any one of Claims 1-5,
A first step of inserting a tubular work without a partition wall into a through hole at a corresponding position of a plurality of fins arranged at intervals, and passing the plurality of tubular works through the through holes of the plurality of fins;
One end of the tubular workpiece is closed, fluid is injected from the other end under pressure, and a portion located between the fins of the tubular workpiece is bulged to extend in the circumferential direction. And a second step of forming a flow path tube in which the base of the bulging portion presses the periphery of the through hole of the fin. The tubular workpiece is a flat tubular workpiece;
7. The bulging portion is formed by bulging over substantially the entire length of at least both flat surfaces of the flat tubular workpiece by pressurizing and injecting fluid in the second step. Method of manufacturing a heat exchanger.

Images