heat exchanger

Abstract

This prevents the brazing process from becoming too large while also preventing molten brazing material from entering areas that should not be brazed. [Solution] The heat exchanger comprises a main body including a heat exchange section that performs heat exchange between a cooling fluid and a fluid to be cooled; a flange having an inlet for the fluid to be cooled to flow in and an outlet for the fluid to be cooled that has flowed through the main body to flow out; a first pipe for the cooling fluid to flow in; and a second pipe for the cooling fluid that has flowed through the main body to flow out. The flange, the first pipe, and the second pipe are joined to the main body by brazing. In at least one of the flange, the first pipe, and the second pipe, a groove is formed between the brazed portion and the portion that is not to be brazed. A flow-preventing material is formed in the groove to prevent the flow of molten brazing material.

Description

Technical Field

[0001] The present disclosure relates to a heat exchanger.

Background Art

[0002] In Patent Document 1, when brazing a flange or a bracket to a heat exchanger body, a groove is provided so that the molten brazing material does not enter around the bolt holes of the bracket or the flange. However, especially when the wettability of the brazing material is high or the groove is shallow, the molten brazing material may spread beyond the groove, so it is necessary to ensure a certain distance between the brazed portion and the portions where brazing is not desired, such as the bolt holes of the bracket or the flange.

Prior Art Documents

Patent Documents

[0003] [[ID=2又3]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a heat exchanger that prevents the molten brazing material from entering portions where brazing is not desired while preventing enlargement.

Means for Solving the Problems

[0005] A heat exchanger according to one aspect for achieving the above object includes a main body portion including a heat exchange portion that performs heat exchange between a cooling fluid and a fluid to be cooled, a flange having an inlet through which the fluid to be cooled flows in and an outlet through which the fluid to be cooled flowing through the main body portion flows out, a first pipe through which the cooling fluid flows in, a second pipe through which the cooling fluid flowing through the main body portion flows out, and is provided with The flange, the first pipe, and the second pipe are joined to the main body by brazing. In at least one of the flange, the first pipe, and the second pipe, a groove is formed between the portion joined by brazing and the portion that is not to be brazed. The groove is formed with a flow-preventing material to prevent the flow of molten brazing material. [Effects of the Invention]

[0006] According to this disclosure, it is possible to provide a heat exchanger that prevents the size from increasing while preventing molten brazing material from entering areas that are not to be brazed. [Brief explanation of the drawing]

[0007] [Figure 1] This is a front perspective view illustrating the configuration of the EGR cooler according to this embodiment. [Figure 2] This is a rear view of the entrance / exit header. [Figure 3] This is a left side view of the entrance / exit header. [Figure 4] Figure 3 is a magnified view of the upper part of the entrance / exit header. [Figure 5] This is a front perspective view illustrating the configuration of an EGR cooler according to a modified example. [Modes for carrying out the invention]

[0008] The embodiments will be described in detail below with reference to the attached drawings. In the drawings used in the following description, the scale has been appropriately changed to make each element recognizable. In the drawings, arrow U indicates the upward direction of the illustrated structure. Arrow D indicates the downward direction of the illustrated structure. Arrow F indicates the forward direction of the illustrated structure. Arrow B indicates the backward direction of the illustrated structure. Arrow R indicates the rightward direction of the illustrated structure. Arrow L indicates the leftward direction of the illustrated structure. These directions are relative directions set for the EGR cooler 10 shown in Figure 1.

[0009] Figure 1 is a front perspective view illustrating the configuration of an EGR (Exhaust Gas Recirculation) system used according to this embodiment. The EGR cooler 10 is a device for cooling exhaust gas. The EGR cooler 10 has passages through which exhaust gas and coolant flow. The exhaust gas is cooled by heat exchange between the exhaust gas and coolant flowing through each passage within the EGR cooler 10. The EGR cooler 10 is an example of a heat exchanger according to this disclosure. Exhaust gas is an example of a fluid to be cooled according to this disclosure. Coolant is an example of a cooling fluid according to this disclosure.

[0010] Specifically, as illustrated in Figure 1, the EGR cooler 10 comprises an inlet / outlet header 11, a shell 12, a duct section 13, a connecting header 14, an inlet pipe 15, and an outlet pipe 16. The inlet / outlet header 11, shell 12, duct section 13, connecting header 14, inlet pipe 15, and outlet pipe 16 are made of, for example, stainless steel or SUS.

[0011] The inlet / outlet header 11 is configured to have a first opening 111 and a second opening 112. The first opening 111 is an opening through which exhaust gas flows in. The second opening 112 is an opening through which exhaust gas cooled inside the EGR cooler 10 flows out. The inlet / outlet header 11 corresponds to the flange of this disclosure. The first opening 111 corresponds to the inlet of this disclosure. The second opening 112 corresponds to the outlet of this disclosure.

[0012] Other equipment and components (hereinafter referred to as "other parts"), not shown in the figures, are attached to the front surface 113 of the entrance / exit header 11. Specifically, with a gasket sandwiched between the front surface 113 of the entrance / exit header 11 and the other parts, the other parts are fastened and secured to the front surface 113 of the entrance / exit header 11 with bolts.

[0013] The shell 12 is formed in a rectangular tube shape and is configured to surround a heat exchange section 20 that performs heat exchange between the exhaust gas flowing into the shell 12 from the inlet / outlet header 11 and the coolant flowing into the shell 12 from the inlet pipe 15. The heat exchange section 20 has a first section 21 and a second section 22.

[0014] The first section 21 forms a passage through which the exhaust gas flows in the first direction. In this example, the first direction is the right direction from the inlet / outlet header 11 toward the connection header 14. A plurality of flat tubes (not shown) are stacked and arranged in the vertical direction in the first section 21. Inner fins (not shown) are inserted into each tube. The exhaust gas flowing in from the inlet / outlet header 11, passing through the duct section 13, and supplied to the shell 12 passes through the interiors of the plurality of tubes in the first section 21.

[0015] The second section 22 forms a passage through which the exhaust gas flows in the second direction. The second direction is the direction opposite to the first direction. In this example, the second direction is the left direction from the connection header 14 toward the inlet / outlet header 11. A plurality of flat tubes (not shown) are stacked and arranged in the vertical direction in the second section 22. Inner fins (not shown) are inserted into each tube. The exhaust gas supplied to the shell 12 through the connection header 14 passes through the interiors of the plurality of tubes in the second section 22.

[0016] The duct section 13 is configured to connect the inlet / outlet header 11 and the shell 12. The duct section 13 changes the direction of the exhaust gas flow path so that the exhaust gas flowing in from the inlet / outlet header 11 toward the rear flows into the shell 12 in the right direction. The duct section 13 is joined to the rear surface 114 (see FIG. 2) of the inlet / outlet header 11 by brazing. The duct section 13 is joined to the shell 12 by brazing.

[0017] The duct portion 13 has a partition plate 131. The partition plate 131 is provided inside the duct portion 13. The partition plate 131 divides the inside of the duct portion 13 into a first passage 132 and a second passage 133. The first passage 132 connects the first opening 111 of the entrance / exit header 11 and the first part 21 of the heat exchange portion 20. The second passage 133 connects the second opening 112 of the entrance / exit header 11 and the second part 22 of the heat exchange portion 20. The duct portion 13 and the shell 12 constitute the main body portion of the present disclosure.

[0018] The connection header 14 is connected to the shell 12. The connection header 14 is joined to the shell 12 by brazing. The connection header 14 is configured to close the end of the shell 12 and connect the first part 21 and the second part 22 of the heat exchange portion 20.

[0019] The inlet pipe 15 is connected to the shell 12 and communicates with the second part 22. The inlet pipe 15 is joined to the shell 12 by brazing. The inlet pipe 15 is connected to, for example, a supply pipe of a coolant tank (not shown). The coolant in the coolant tank flows in from the inlet pipe 15 and is supplied to the inside of the shell 12. The inlet pipe 15 corresponds to the first pipe of the present disclosure.

[0020] The outlet pipe 16 is connected to the shell 12 and communicates with the first part 21. The outlet pipe 16 is joined to the shell 12 by brazing. The outlet pipe 16 is connected to, for example, a recovery pipe of a coolant recovery tank. The coolant inside the shell 12 is discharged from the outlet pipe 16 and recovered in the coolant recovery tank. The outlet pipe 16 corresponds to the second pipe of the present disclosure.

[0021] In the EGR cooler 10 configured in this way, exhaust gas flowing in from the first opening 111 of the inlet / outlet header 11 passes through the first passage 132 of the duct section 13, flows through a tube located in the first part 21 of the heat exchange section 20 of the shell 12, makes a U-turn at the connecting header 14, flows through a tube located in the second part 22 of the heat exchange section 20, passes through the second passage 133 of the duct section 13, and flows out from the second opening 112 of the inlet / outlet header 11. Coolant supplied to the inside of the shell 12 from the inlet pipe 15 flows between the outside of the tube and the shell 12 and flows out from the outlet pipe 16. The exhaust gas passing through the tube is cooled by the coolant flowing around the tube.

[0022] When manufacturing the EGR cooler 10, brazing material is applied to the joints of the components, and the components are temporarily assembled. The temporarily assembled products are then brazed together in a furnace to join the components. During this brazing process, if molten brazing material adheres to parts of the components to which other parts are attached, it will affect the accuracy of the attachment. For example, if excess brazing material flows from the joint between the rear surface 114 of the inlet / outlet header 11 and the duct section 13 onto the front surface 113 of the inlet / outlet header 11, it will affect the attachment to other parts.

[0023] In contrast, the EGR cooler 10 of this disclosure has a groove 17 formed between the front surface 113 and the rear surface 114 of the inlet / outlet header 11 where the duct portion 13 is joined, in order to prevent molten brazing material from flowing into the front surface 113 of the inlet / outlet header 11 during brazing, and a flow-preventing material 18 is formed in the groove 17 to prevent the flow of molten brazing material.

[0024] The grooves 17 and flow prevention material 18 formed in the inlet / outlet header 11 will be described in detail below with reference to Figures 2 to 4. Figure 2 is a rear perspective view of the inlet / outlet header 11. Figure 3 is a left side view of the inlet / outlet header 11. Figure 4 is an enlarged view of the upper part of the inlet / outlet header 11 in Figure 3. In Figure 2, hatching is applied to the area 114A where the duct portion 13 of the rear surface 114 is joined. In Figure 3, dashed lines indicate other components attached to the inlet / outlet header 11. In Figure 4, hatching is applied to the flow prevention material 18.

[0025] As illustrated in Figure 2, a groove 17 is formed on the outer peripheral surface 115 between the front surface 113 and the rear surface 114 of the entrance / exit header 11. In this example, the groove 17 is formed around the entire circumference of the outer peripheral surface 115.

[0026] As described above, the front surface 113 is the part to which other parts are attached and is a part that should not be brazed. The area 114A of the rear surface 114 to which the duct portion 13 is joined is a part that is joined by brazing. In other words, in the entrance / exit header 11, a groove 17 is formed between the part that is joined by brazing and the part that should not be brazed.

[0027] Furthermore, as illustrated in Figure 3, the front portion of the outer circumferential surface 115 of the entrance / exit header 11 engages with the claw portion 101 of another component 100. In other words, the front portion of the outer circumferential surface 115 of the entrance / exit header 11 is the part to which other components are attached and is a part that should not be brazed. Therefore, in this example, the groove 17 is provided on the rear portion of the outer circumferential surface 115 of the entrance / exit header 11.

[0028] As illustrated in Figure 4, the groove 17 is provided with a flow-preventing material 18 to prevent the flow of molten brazing material. For example, when nickel (Ni) is used as the brazing material, titanium oxide is used as the flow-preventing material 18. When an organic solvent containing titanium oxide is applied to the groove 17 and brazing is performed, the titanium oxide remains in the groove 17 as the flow-preventing material 18.

[0029] Now, let's consider the case where either a groove 17 or a flow-preventing material 18 is formed on the outer circumferential surface 115 of the inlet / outlet header 11. If only a groove 17 is formed on the outer circumferential surface 115 of the inlet / outlet header 11, for example, if the brazing material has high wettability or the groove is shallow, the molten brazing material may flow over the groove 17 during brazing and onto the front surface 113 of the inlet / outlet header 11. On the other hand, if only a flow-preventing material 18 is formed on the outer circumferential surface 115 of the inlet / outlet header 11, if there are any gaps in the application of the flow-preventing material 18 or if the flow-preventing material 18 is interrupted, the molten brazing material may flow out from there.

[0030] In contrast, the EGR cooler 10 of this disclosure uses both grooves 17 and flow-preventing material 18, so that even if the brazing material has high wettability or the grooves are shallow, the flow of molten brazing material can be blocked by the flow-preventing material 18. Alternatively, even if the flow-preventing material 18 is not applied properly or is interrupted, the flow of molten brazing material can be blocked by the grooves 17. In other words, by using both grooves 17 and flow-preventing material 18, it is possible to prevent molten brazing material from flowing from the joint between the rear surface 114 of the inlet / outlet header 11 and the duct section 13 onto the front surface 113 of the inlet / outlet header 11 during brazing.

[0031] Furthermore, the organic solvent that serves as the flow-preventing material 18 is applied by an operator using, for example, a pen-type applicator. For example, if there is no groove 17, skilled technique is required to apply the flow-preventing material 18 to the correct position. In particular, because the inlet / outlet header 11 is thin, it is difficult to apply the flow-preventing material 18 to the narrow outer surface 115. For example, although using a jig makes it easier to apply the flow-preventing material 18 to the correct position, the flow-preventing material 18 adhering to the jig may come into contact with unintended areas, causing the brazing material to adhere to them.

[0032] In contrast, with the EGR cooler 10 of this disclosure, since the flow-preventing material 18 is applied inside the groove 17, even when applying the flow-preventing material 18 to a narrow area such as the outer surface 115 of the inlet / outlet header 11, the flow-preventing material 18 can be accurately applied to the desired position without the use of a jig.

[0033] In this example, the groove 17 is formed around the entire circumference of the outer surface 115 of the inlet / outlet header 11, but it may also be formed over only a portion of the outer surface 115. For example, on the outer surface 115 of the inlet / outlet header 11, the groove 17 can be formed in a portion where excess brazing material is likely to flow from the joint between the rear surface 114 of the inlet / outlet header 11 and the duct portion 13, and a flow-preventing material 18 can be formed in the groove 17. This prevents molten brazing material from flowing onto the front surface 113 of the inlet / outlet header 11.

[0034] Furthermore, the groove 17 and the flow prevention material 18 are provided on the rear portion of the outer circumferential surface 115 in the inlet / outlet header 11. However, if, for example, there are no other parts to engage with the front portion of the outer circumferential surface 115, the groove 17 may be provided on the front portion of the outer circumferential surface 115.

[0035] Figure 5 is a front perspective view illustrating the configuration of a modified EGR cooler 30. Components that are substantially the same as those of the EGR cooler 10 according to the above embodiment are given the same reference numerals, and redundant explanations are omitted.

[0036] As illustrated in Figure 5, grooves 17 and flow-preventing material 18 are formed on the outer circumferential surface 115 of the inlet / outlet header 11.

[0037] Furthermore, a groove 17 is also formed between the tip 152 into which the coolant flows in the inlet pipe 15 and the portion that is joined to the shell 12. In this example, the groove 17 is formed around the entire circumference of the outer surface 151 of the inlet pipe 15.

[0038] The tip 152 of the inlet pipe 15 is the part to which the coolant tank supply pipe is attached, as described above, and is a part that should not be brazed. The part of the inlet pipe 15 that is joined to the shell 12 is a part that is joined by brazing. In other words, a groove 17 is formed in the inlet pipe 15 between the part that is joined by brazing and the part that should not be brazed.

[0039] Furthermore, a groove 17 and a flow-preventing material 18 are also formed between the tip 162 from which the coolant flows out of the outlet pipe 16 and the portion that is joined to the shell 12. In this example, the groove 17 is formed around the entire circumference of the outer surface 161 of the outlet pipe 16.

[0040] The tip 162 of the outlet pipe 16 is the part to which the recovery pipe of the coolant recovery tank is attached, as described above, and is a part that should not be brazed. The part of the outlet pipe 16 that is joined to the shell 12 is a part that is joined by brazing. In other words, a groove 17 is formed in the outlet pipe 16 between the part that is joined by brazing and the part that should not be brazed.

[0041] A flow-preventing material 18 is formed in grooves 17 on the outer surface 151 of the inlet pipe 15 and the outer surface 161 of the outlet pipe 16 to prevent the flow of molten brazing material.

[0042] According to the modified EGR cooler 30, by using both the groove 17 and the flow prevention material 18, it is possible to prevent molten brazing material from flowing from the joint between the shell 12 and the inlet pipe 15 into the tip 152 of the inlet pipe 15 during brazing. Furthermore, it is possible to prevent molten brazing material from flowing from the joint between the shell 12 and the outlet pipe 16 into the tip 162 of the outlet pipe 16 during brazing.

[0043] Furthermore, when applying the organic solvent that will act as the flow-preventing material 18, it is difficult to apply the flow-preventing material 18 because the inlet pipe 15 and outlet pipe 16 are cylindrical. However, according to the modified EGR cooler 30, grooves 17 are first formed on the outer surface 151 of the inlet pipe 15 and the outer surface 161 of the outlet pipe 16, and the flow-preventing material 18 is applied to the grooves 17, so the flow-preventing material 18 can be accurately applied to the desired position without using a jig.

[0044] Note that the positions in which the grooves 17 are formed in the inlet pipe 15 and outlet pipe 16 are not limited to this example.

[0045] Furthermore, although the groove 17 and flow-preventing material 18 are formed in the inlet pipe 15 and outlet pipe 16 respectively, they may also be formed on the outer surface of either the inlet pipe 15 or the outlet pipe 16. For example, depending on the orientation of the assembled product during brazing, there is a direction in which excess brazing material is more likely to flow. Therefore, the groove 17 and flow-preventing material 18 may be formed on the side of the inlet pipe 15 or the outlet pipe 16 in which the excess brazing material is more likely to flow towards the tip.

[0046] Furthermore, the grooves 17 and flow-preventing material 18 are formed in the inlet / outlet header 11, the inlet pipe 15, and the outlet pipe 16, but the grooves 17 and flow-preventing material 18 may be formed in at least one of these.

[0047] Furthermore, the modified EGR cooler 30 is equipped with a bracket 19. The bracket 19 has bolt holes 191 formed therein, and the bracket 19 is fastened to other parts by bolts (not shown). The bracket 19 is joined to the shell 12 by brazing.

[0048] In the bracket 19, a groove 17 is formed between the bolt hole 191 and the portion 193 to which the shell 12 is joined. In this example, the groove 17 is formed on the front surface 192 of the bracket 19. The bracket 19 is formed such that the minimum distance L1 between the bolt hole 191 and the portion 193 to which the shell 12 is joined is less than 20 mm.

[0049] The bolt hole 191 is the part through which the bolt is inserted, and is a part that should not be brazed. The part 193 to which the shell 12 is joined is a part that is joined by brazing. In other words, a groove 17 is formed between the part that is joined by brazing and the part that should not be brazed.

[0050] A flow-preventing material 18 is formed in the groove 17 to prevent the flow of molten brazing material.

[0051] With this configuration, by using both the groove 17 and the flow-preventing material 18, it is possible to prevent molten brazing material from entering the bolt hole 191 from the joint between the shell 12 and the bracket 19 during brazing. This makes it possible to shorten the minimum distance L1 between the bolt hole 191 of the bracket 19 and the part 193 where the shell 12 is joined. Therefore, it is possible to prevent molten brazing material from entering the bolt hole 191 while preventing the bracket 19 from becoming larger.

[0052] The position where the groove 17 is formed on the front surface 192 of the bracket 19 is not limited to this example. Furthermore, the groove 17 and the flow prevention material 18 may be formed on the rear surface of the bracket 19.

[0053] The embodiments described above are merely illustrative examples to facilitate understanding of the present invention. The configurations of the above embodiments may be modified or improved as appropriate without departing from the spirit of the present invention.

[0054] In the embodiments and modifications described above, the EGR coolers 10 and 30 have a duct section 13, but the duct section 13 may be omitted. In this case, the shell 12 constitutes the main body of the disclosure, and the inlet / outlet header 11 is directly joined to the shell 12 by brazing.

[0055] In the above embodiments and modifications, the EGR coolers 10 and 30 are of the U-turn type, in which exhaust gas flows in and out from an inlet / outlet header 11 provided at one end of the shell 12, and the exhaust gas flowing inside the shell 12 is returned by a connecting header 14 provided at the other end of the shell 12. However, the EGR coolers 10 and 30 may also be of the linear type, in which the exhaust gas flowing inside the shell 12 proceeds in a straight line. A linear EGR cooler has an inlet header provided at one end of the shell 12 and having an inlet for the exhaust gas, and an outlet header provided at the other end of the shell and having an outlet for the exhaust gas. In this case, the groove 17 and the flow prevention material 18 may be provided on one or both of the inlet header and the outlet header.

[0056] In the embodiments and modifications described above, an example of a part that should not be brazed was given as a part to which other parts are attached, but this is not limited to that.

[0057] In the above embodiments and modifications, the EGR coolers 10 and 30 are configured so that exhaust gas flows from top to bottom inside the EGR coolers 10 and 30, but they may also be configured so that the gas flows from bottom to top.

[0058] In the embodiments and modifications described above, an EGR cooler for cooling exhaust gas was described as an example of a heat exchanger. However, the heat exchanger may also be one that cools a fluid other than exhaust gas. [Explanation of Symbols]

[0059] 10: EGR cooler, 11: Inlet / outlet header, 12: Shell, 13: Duct section, 14: Connecting header, 15: Inlet pipe, 16: Outlet pipe, 17: Groove, 18: Flow prevention material, 19: Bracket, 20: Heat exchange section, 21: First section, 22: Second section, 30: EGR cooler, 100: Other parts, 101: Claw section, 111: First opening, 112: Second opening, 113: Front, 114: Rear, 114A: Area where the duct section is joined, 115: Outer surface, 131: Partition plate, 132: First passage, 133: Second passage, 151: Outer surface, 152: Tip, 161: Outer surface, 162: Tip, 191: Bolt hole, 192: Front, 193: Part where the shell is joined

Claims

1. A main body including a heat exchange section that performs heat exchange between the cooling fluid and the fluid to be cooled, A flange having an inlet into which the fluid to be cooled flows and an outlet into which the fluid to be cooled that has flowed through the main body flows out, The first pipe through which the cooling fluid flows, A second pipe through which the cooling fluid that has flowed inside the main body flows out, It is equipped with, The flange, the first pipe, and the second pipe are joined to the main body by brazing. In at least one of the flange, the first pipe, and the second pipe, a groove is formed between the portion joined by brazing and the portion that is not to be brazed. A heat exchanger in which a flow-preventing material is formed in the groove to prevent the flow of molten brazing material.

2. The heat exchanger according to claim 1, wherein the groove is provided around the entire circumference of the outer surface of the flange.

3. The heat exchanger according to claim 1, wherein the groove is provided around the entire circumference of at least one of the outer surfaces of the first pipe and the second pipe.

4. The main body has a bracket that is joined to it by brazing, In the bracket, a groove is formed between the portion joined by brazing and the portion that is not to be brazed, and the groove contains a flow-preventing material to prevent the flow of molten brazing material. The heat exchanger according to claim 1, wherein the minimum distance between the portion joined by brazing and the portion not to be brazed is less than 20 mm.

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