JP2014118953A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To downsize a heat exchanger including a filter.SOLUTION: A heat exchanger (an EGR cooler 7) comprises: a core 71 which has a first flow passage and a second flow passage and exchanges heat between first fluid and second fluid; and a case 8 which is constituted to store the core. The case has: a space section 811 arranged close to an inflow section of the first flow passage in the core; and an entrance section 821 to introduce the first fluid into the core through the space section. The heat exchanger also has a first fluid filter 822 which is attached to the entrance section and arranged in the space section.

Description

  The technology disclosed herein relates to a heat exchanger, and more particularly to a heat exchanger that is used for cooling the exhaust gas when the exhaust gas of the engine is recirculated to the intake side.

  Patent Document 1 describes a heat exchanger (that is, an EGR cooler) used for cooling exhaust gas in an exhaust gas recirculation (EGR) system that recirculates engine exhaust gas to the intake side. This heat exchanger is configured by housing a core including a plurality of flat tubes in a case body formed into a long and narrow box shape with an upper end opening by deep drawing and closing the upper end opening of the case body with a lid. Has been. In this heat exchanger, an inlet part for introducing exhaust gas and an outlet part for extracting exhaust gas cooled by passing through the core are provided at both longitudinal ends of the elongated case body. It has been.

  Patent Document 2 describes a heat exchanger used as an EGR cooler similar to Patent Document 1. In this heat exchanger, a space portion that can function as a header tank is provided in the case adjacent to the core, and an exhaust gas inlet portion is provided on the side surface of the case so as to communicate with the space portion. For this reason, in this heat exchanger, the exhaust gas that has flowed into the space portion from the side surface of the case through the inlet portion bends the flow direction by 90 ° and flows into the core.

  Patent Document 3 describes a configuration in an engine EGR system in which two filters are arranged in parallel in the middle of an EGR passage that recirculates exhaust gas, and exhaust gas that has passed through the filter is introduced into an EGR cooler. This filter captures foreign substances such as particulate matter (Particulate Matter) in the exhaust gas, and suppresses the accumulation of the foreign substances on the core of the EGR cooler.

Japanese Patent No. 4602714 JP 2009-228930 A Japanese Utility Model Publication No. 3-82865

  As described in Patent Document 3, a heat exchanger used as an EGR cooler causes a decrease in cooling performance and an increase in pressure loss due to accumulation of foreign matters in exhaust gas. If it is desirable to provide a filter, and a filter cannot be provided, measures such as increasing the exhaust gas passage cross section in the core of the heat exchanger in advance are taken in order to allow some accumulation of foreign matter. However, if measures such as increasing the cross section of the exhaust gas passage are taken, the core must be enlarged to achieve the desired cooling performance. This is disadvantageous for layout in the engine room.

  On the other hand, as described in Patent Document 3, even if a filter separate from the EGR cooler is to be interposed in the EGR passage, a space for arranging the filter is required, which is disadvantageous for layout in the engine room. become.

  In particular, when the EGR cooler is applied to a low pressure EGR system in a turbocharged engine, exhaust gas is recirculated to the upstream side of the compressor, so that foreign matter does not accumulate in the core of the heat exchanger. In addition, in order not to supply the foreign matter to the compressor, it is desirable to provide a filter, and it is required to lay out the EGR cooler and the filter in a compact manner.

  The technology disclosed herein has been made in view of such a point, and an object thereof is to make a heat exchanger including a filter compact.

  The technology disclosed herein relates to a heat exchanger, and the heat exchanger includes a first flow path through which a first fluid flows and a second flow path through which a second fluid flows, and the first and second fluids. A core configured to exchange heat between the two and a case configured to accommodate the core.

  A space portion is provided in the case at a position adjacent to the inflow portion of the first flow path of the core, and the case communicates with the space portion and the first fluid is passed through the case. An inlet for introducing the first flow path of the core through the space is provided.

  The heat exchanger further includes a filter for the first fluid attached to the inlet and configured to be disposed in the space.

  According to this configuration, in the heat exchanger configured to include the core and the case, the space portion provided at a position adjacent to the inflow portion of the first flow path of the core in the case is an inlet provided in the case. It can function as a header tank for dispersing and introducing the first fluid that has flowed into the case from the portion into the inflow portion of the first flow path of the core. In this way, introducing the first fluid in a dispersed manner with respect to the inflow portion of the first flow path of the core is advantageous in increasing the heat exchange efficiency of the core.

  And in the said structure, the filter attached to the inlet_port | entrance part is arrange | positioned in the space part in a case which can function as a header tank. The filter may be disposed in the space portion, for example, so as to be inserted into the case from the inlet portion. This means that the filter is arranged using a space part that can function as a header tank, so that a separate space for arranging the filter becomes unnecessary. In this way, it is possible to configure a heat exchanger with a built-in filter for the first fluid without increasing the size of the case.

  The case has a plurality of inlet portions arranged in parallel along the inflow portion of the first flow path of the core, and the filter is attached to each of the plurality of inlet portions. Good.

  By disposing a plurality of inlet portions in parallel along the inflow portion of the first flow path of the core, the dispersibility of the first fluid introduced into the first flow path is increased. This is advantageous in increasing the heat exchange efficiency of the core.

  Disposing a filter at each of the plurality of inlets arranged side by side in this manner is advantageous in increasing the filter area while suppressing an increase in pressure loss and enhancing the effect of capturing foreign matter. In addition, since the plurality of inlet portions where the filters are arranged are arranged in parallel along the inflow portion of the first flow path of the core, the case does not increase in size even if a plurality of filters are arranged. That is, it is advantageous for downsizing the heat exchanger.

  The core is configured by alternately laminating a plurality of first flow paths and a plurality of second flow paths, and the case closes a case main body that houses the core and an opening of the case main body. The inlet portion of the case is formed in the lid body, and the case main body flows into the bottom portion that defines a part of the space portion, and flows from the inlet portion. A curved portion that guides the first fluid to flow toward the inflow portion of the first flow path of the core may be formed.

  The core configured by alternately laminating the plurality of first flow paths and the plurality of second flow paths has high heat exchange efficiency and is advantageous for miniaturization of the core. In particular, since the heat exchanger incorporates the filter for the first fluid to suppress the accumulation of foreign substances, the cross section of the first flow path can be made relatively small. This is advantageous for further downsizing of the core, and further downsizing of the heat exchanger.

  In addition, a curved portion that guides the first fluid flowing in from the inlet portion of the lid so as to flow toward the inflow portion of the first flow path of the core is formed in the bottom portion that defines a part of the space portion of the case body. By doing so, it becomes possible to reduce the pressure loss of the first fluid of the heat exchanger. This is advantageous for improving the heat exchange efficiency and makes it possible to use the heat exchanger even when the flow rate of the first fluid is relatively low.

  Here, if the case main body is configured to be deep so that almost the entire core can be accommodated, it is possible to increase the radius of the curved portion provided in the case in the depth direction. This is advantageous in further reducing the pressure loss of the first fluid.

  Furthermore, configuring the case body in a deep shape also contributes to facilitating the manufacture of the heat exchanger. That is, it becomes possible to assemble the entire core while laminating the first flow path and the second flow path in the deep case body, and after the assembly is completed, the opening of the case body is closed by the lid. For example, the entire case and core can be brazed and integrated. In particular, if the stacking direction of the first flow path and the second flow path is the same as the depth direction of the case body, the first flow path and the second flow path are alternately arranged in the deep case body. The assembly of the heat exchanger is completed by stacking and finally placing the lid on the case body. This further facilitates the manufacturing operation.

  The first fluid is exhaust gas of the engine, the second fluid is cooling water of the engine, and the core is disposed in the middle of the EGR passage for returning the exhaust gas to the intake side of the engine. It is good also as being comprised so that may be cooled with the said cooling water.

  As described above, the heat exchanger having this configuration (that is, the EGR cooler) can be made compact while incorporating a filter, so that foreign matter including PM in the exhaust gas is captured and foreign matter is accumulated in the core. To suppress. As a result, the cooling performance of the exhaust gas can be stably maintained, and it is advantageous for improving the layout in the engine room.

  The case is attached to an exhaust gas treatment device that performs post-treatment of the exhaust gas, and an amount of exhaust gas to be recirculated to the intake side is adjusted at an outlet portion of the first fluid provided in the case. An EGR control valve configured as described above may be attached.

  In this way, the heat exchanger used as the EGR cooler can be installed in the engine room efficiently by attaching it to the exhaust gas treatment device, and an EGR control valve is installed in the case of the heat exchanger. By mounting, the layout property of the EGR path including the heat exchanger and the EGR control valve is enhanced.

  The case is attached to an end portion of the exhaust gas processing device extending in the longitudinal direction of the engine at a side position of the engine, and the exhaust gas processing device, the case, and the EGR control valve are connected to the longitudinal direction of the engine. It is good also as arrange | positioning along with this order in the direction.

  By doing so, the exhaust gas treatment device, the heat exchanger, and the EGR control valve are arranged side by side along the longitudinal direction of the engine on the side of the engine, which is advantageous for improving the layout in the engine room. become.

  Here, the exhaust gas treatment device may be a DPF (Diesel Particulate Filter) that is attached to an exhaust system of a diesel engine and captures PM. If the heat exchanger with a built-in filter is arranged on the downstream side of the DPF, it is possible to more effectively suppress the accumulation of foreign matters on the core of the heat exchanger. This is advantageous for downsizing of the exchanger. This improves the layout in the engine room.

  As described above, according to the above heat exchanger, the first fluid can be obtained without disposing the case by arranging the filter in the space that can function as a header tank in the case that accommodates the core. It becomes possible to constitute a heat exchanger with a built-in filter, and the heat exchanger is reduced in size.

It is the schematic which shows the whole structure of a diesel engine. It is a partially broken top view which shows arrangement | positioning of the EGR cooler and EGR control valve in a low pressure EGR system. FIG. 3 is a sectional view taken along line III-III in FIG. 2. FIG. 4 is an end view taken along the line IV-IV in FIG. 2. It is a disassembled perspective view of an EGR cooler.

  Hereinafter, the heat exchanger which concerns on embodiment is demonstrated based on drawing. In addition, the following embodiment is an illustration. FIG. 1 is a diagram conceptually illustrating a configuration of an engine 1 in which the heat exchanger according to the embodiment is used as an EGR cooler. The engine 1 is a diesel engine that is mounted on a vehicle and is supplied with fuel mainly composed of light oil. The cylinder block 11 is provided with a plurality of cylinders 11a (only one is shown), and the cylinder A cylinder head 12 disposed on the block 11 and an oil pan 13 disposed on the lower side of the cylinder block 11 and storing lubricating oil are provided. The engine 1 is an in-line four-cylinder engine in which, for example, four cylinders 11a are arranged in a row so as to extend along the crankshaft 15 (that is, in a direction orthogonal to the paper surface of FIG. 1). In FIG. A piston 14 is fitted in each cylinder 11a so as to be reciprocally movable, and the piston 14 is connected to the crankshaft 15 via a connecting rod 14b.

  In the cylinder head 12, an intake port 16 and an exhaust port 17 are formed for each cylinder 11a, and an intake valve 21 and an exhaust valve 22 that open and close the opening of the intake port 16 and the exhaust port 17 on the cylinder 11a side are respectively provided. It is arranged.

  An intake passage 30 is connected to one side of the engine 1 so as to communicate with the intake port 16 of each cylinder 11a. On the other hand, an exhaust passage 40 for discharging burned gas (exhaust gas) from the combustion chamber of each cylinder 11a is connected to the other side of the engine 1. The intake passage 30 and the exhaust passage 40 are provided with a turbocharger 61 that supercharges intake air, as will be described in detail later.

  An air cleaner 31 that filters intake air is disposed at the upstream end of the intake passage 30. On the downstream side of the air cleaner 31 in the intake passage 30, a compressor 61a of the turbocharger 61, an intercooler 35 that cools the air compressed by the compressor 61a, and a throttle that adjusts the amount of intake air to each cylinder 11a. The valves 36 are arranged in this order.

  The upstream portion of the exhaust passage 40 is constituted by an exhaust manifold having an independent passage branched for each cylinder 11a and connected to the outer end of the exhaust port 17 and a collecting portion where the independent passages gather. . A turbine 61b of the turbocharger 61, an exhaust gas treatment device 41 for purifying harmful components in the exhaust gas, and a silencer 42 are arranged in this exhaust passage 40 downstream from the exhaust manifold. It is installed. An exhaust bypass passage 65 that bypasses the turbine 61b is connected to the exhaust passage 40, and a waste gate valve 65a for adjusting the amount of exhaust flowing to the exhaust bypass passage 65 is connected to the exhaust bypass passage 65. It is arranged.

The exhaust gas processing device 41 includes an oxidation catalyst 41a and a diesel particulate filter (DPF) 41b, which are arranged in this order from the upstream side. The oxidation catalyst 41a has an oxidation catalyst supporting platinum or platinum added with palladium, etc., and promotes a reaction in which CO and HC in the exhaust gas are oxidized to produce CO ₂ and H ₂ O It is. The DPF 41 b collects particulate matter such as soot contained in the exhaust gas of the engine 1. The DPF 41b may be coated with an oxidation catalyst.

  A portion downstream of the throttle valve 36 in the intake passage 30 (that is, a portion downstream of the compressor 61a of the turbocharger 61) and a portion of the exhaust passage 40 upstream of the turbine 61b of the turbocharger 61. Is connected by an exhaust gas recirculation passage 50 for recirculating a part of the exhaust gas to the intake passage 30 (that is, a high pressure EGR system). The exhaust gas recirculation passage 50 is a main passage in which an exhaust gas recirculation valve 51a for adjusting the recirculation amount of the exhaust gas to the intake passage 30 and an EGR cooler 52 for cooling the exhaust gas with engine cooling water are disposed. 51 and a cooler bypass passage 53 for bypassing the EGR cooler 52. The cooler bypass passage 53 is provided with a cooler bypass valve 53 a for adjusting the flow rate of the exhaust gas flowing through the cooler bypass passage 53.

  Separately from the high pressure EGR system, as a low pressure EGR system, a portion of the intake passage 30 upstream of the compressor 61a and a portion of the exhaust passage 40 downstream of the DPF 41b return a part of the exhaust gas to the intake passage 30. Are connected by an exhaust gas recirculation passage 54. The exhaust gas recirculation passage 54 includes an EGR control valve 54a for adjusting the recirculation amount of the exhaust gas to the intake passage 30 and an EGR cooler 7 for cooling the exhaust gas.

(Configuration of EGR cooler of low pressure EGR system)
2 to 4 show the configuration of the EGR cooler 7 of the low-pressure EGR system. FIG. 2 corresponds to a plan view of the EGR cooler 7 arranged in the engine room as viewed from above. The front side of the vehicle, the lower side in the figure corresponds to the rear side of the vehicle. Further, the left-right direction in FIG. 1 corresponds to the vehicle width direction, which corresponds to the longitudinal direction of the horizontally placed engine 1. 3 is a cross-sectional view taken along the line III-III of FIG. 2, and is a view of the EGR cooler 7 as viewed from the front side to the rear side of the engine 1 along the vehicle width direction. 4 is a cross-sectional view taken along the line IV-IV in FIG. In the following description, the vertical direction, the vehicle front-rear direction, and the vehicle width direction are defined in a state where the EGR cooler 7 is attached to the vehicle.

  The EGR cooler 7 includes a core 71 and a case 8 that houses the core 71. Although not shown in detail in the core 71, a plurality of first flow paths through which exhaust gas passes and a plurality of second flow paths through which engine cooling water passes are alternately stacked in the vehicle width direction. It is a laminated type configured. Although illustration is omitted, fins for expanding the heat transfer area are disposed in the first flow path, and the core 71 includes a plate and fins that partition the first flow path and the second flow path. Are laminated in a predetermined order and integrated by brazing. While the core 71 has a relatively long height corresponding to the vertical direction (that is, the vertical direction of the paper in FIG. 3) and a length corresponding to the vehicle longitudinal direction (that is, the horizontal direction of the paper in FIG. 3), The depth corresponding to the vehicle width direction (that is, the left-right direction in FIG. 2) is a relatively short flat rectangular parallelepiped shape. In the core 71, the inflow portion of the first flow path (that is, the portion where the exhaust gas flows into the core) is set on the front end surface side (that is, the upper side of the drawing in FIG. 2), while the first flow path The outflow portion (that is, the portion through which the exhaust gas that has passed through the core 71 flows out) is set on the rear end surface side (that is, the lower side in FIG. 2). Further, in the core 71, the opening of the second flow path through which the engine coolant passes is provided in the upper end surface and the lower end surface of the core 71. Thus, the core 71 is configured in a cross flow type in which the exhaust gas and the engine cooling water flow so as to be orthogonal.

  The case 8 includes a case main body 81 and a lid body 82 that closes the upper end opening of the case main body 81. 2 and 5, the case main body 81 has a box shape with an opening at the upper end. For example, the case main body 81 is a deep mold that can accommodate the entire rectangular parallelepiped core 71 by deep drawing. It is configured. As is clear from FIGS. 2 and 3, the case main body 81 has an accommodation space for accommodating the core 71 in the center in the vehicle front-rear direction, and the inflow side of the first flow path of the core 71 with the accommodation space interposed therebetween. A first space portion 811 adjacent to the first flow path, and a second space portion 812 adjacent to the outflow side of the first flow path. The first space portion 811 has a function of an inflow side header tank for dispersing the exhaust gas introduced into the case 8 and flowing into the core 71, and the second space portion 812 flows out of the core 71. It has the function of an outflow header tank for collecting the exhaust gas collected and leading out from the case 8.

  An outlet 813 is provided through the bottom of the case body 81 so as to communicate with the second space 812, and the EGR control valve 54 a is directly connected to the outlet 813 of the case body 81. It is attached.

  An engine cooling water inlet opening 814 and an outlet opening 815 are also provided through the bottom of the case body 81 so as to communicate with the accommodation space of the core 71 (see the broken line in FIG. 3). An inlet pipe 85 and an outlet pipe 86 connected to an engine coolant circulation circuit (not shown) are attached to the inlet opening 814 and the outlet opening 815 of the case body 81, respectively. Here, as shown in FIG. 3, the case main body 81 has a lower side wall bulging downward, and the engine cooling water inlet opening 814 is provided at a position corresponding to the bulging portion. Yes. On the other hand, the engine cooling water outlet opening 815 is provided in the vicinity of the side wall located on the opposite side of the inlet opening 814, that is, on the upper side of the case body, and as shown by the dashed arrow in FIG. The engine cooling water that has flowed into the case 8 from 85 through the inlet opening 814 flows into the opening provided in the lower end surface of the core 71 and out of the opening provided in the upper end surface of the core 71, and then exits the outlet opening 815. Is discharged out of the case 8 through the outflow pipe 86. As described above, providing both the engine cooling water inlet opening 814 and the outlet opening 815 at the bottom of the case main body 81 is advantageous for the layout layout of the engine cooling water passage as will be described later.

  The lid 82 is attached to the case body 81 so as to cover the upper end opening of the case body 81. As shown in FIGS. 2, 4 and 5, the lid 82 has inlet portions 821 and 821 communicating with the first space portion 811 at positions corresponding to the first space portion 811 in the case body 81. Is provided. The inlet portions 821 are ports through which exhaust gas flows into the case 8, and two inlet portions 821 are arranged in the vertical direction along the inflow portion of the first flow path of the core 71. As shown in FIGS. 2 and 4, a cylindrical filter 822 is attached to each inlet portion 821. The filter 822 has a function of capturing foreign matter in the exhaust gas, thereby preventing foreign matter from accumulating in the core 71 and preventing foreign matter from flowing into the intake-side compressor 61a. . The filter 822 has a shape such that one end opening of a cylindrical wire mesh is crushed and closed, and is inserted from the inlet portion 821 and disposed in the first space portion 811. The filter 822 is fixed to the mounting bracket 83 that is fixed to the inlet portion 821 of the lid 82, and the filter 822 is attached to the lid 82 together with the mounting bracket 83.

  In addition to the mounting bracket 83 positioned on the front side in the vehicle front-rear direction, a second mounting bracket 84 positioned on the rear side in the vehicle front-rear direction is attached to the lid 82 by brazing as will be described later. .

  Thus, the EGR cooler 7 has the exhaust gas introduced into the first space portion 811 in the case 8 from each of the two inlet portions 821 provided in the lid 82, as indicated by solid arrows in FIG. After passing through the filter 822, the gas flows into the core 71 from the inflow portion of the first flow path in the core 71. The exhaust gas exchanges heat with the engine coolant while passing through the core 71 in the longitudinal direction of the vehicle, and the exhaust gas cooled by the exhaust gas passes through the second space portion 812 and the outlet portion 813. Thus, it is derived out of the case 8.

  Here, in the first space portion 811, since the flow direction of the exhaust gas is changed from the vehicle width direction to the vehicle front-rear direction, from the viewpoint of reducing the pressure loss by smoothing the flow of the exhaust gas, FIG. As shown, a curved portion 816 for guiding the flow of exhaust gas is provided at the bottom of the case main body 81, more specifically at the corner between the bottom of the case main body 81 and the front side wall. The curved portion 816 has a sufficient depth because the case body 81 is formed in a deep shape, and is configured to have a relatively large radius. This is advantageous in reducing the pressure loss of the exhaust gas.

  The EGR cooler 7 (that is, the heat exchanger) having such a configuration can be manufactured by brazing as follows. That is, as shown in FIG. 5, a case body 81 prepared in advance is arranged with the opening facing upward, and a plate and fins for configuring the core 71 are placed in a predetermined order at a predetermined position in the case body 81. Pile up at. Then, when all of the plates and the fins are stacked and thereby the structure of the core 71 is completed, the lid body 82 is attached to the case body 81 and the opening of the case body 81 is closed. By attaching the lid 82, the core 71 in the case main body 81 is pressed in the stacking direction. After that, all the attached parts of the heat exchanger such as the mounting bracket 83, the second mounting bracket 84, the filter 822, the inflow pipe 85 and the outflow pipe 86 of the engine cooling water are assembled and then integrated in the brazing furnace. . Constructing the case body 81 in a deep shape is advantageous in facilitating the manufacture of the heat exchanger because it is possible to stack all the plates and fins constituting the core 71 in the case body 81. Become.

  2 to 4, the completed heat exchanger (that is, the EGR cooler 7) has a mounting bracket 83 attached to the inlet portion 821 of the lid 82 as shown in FIG. A second mounting bracket 84 fixed on the front side of the lid 82 and attached to the rear side of the lid 82 is attached to the front side of the DPF 41b on the front side of the front side of the DPF 41b. Secure to the side with bolts. Thus, the EGR cooler 7 of the low pressure EGR system is disposed adjacent to the side of the vehicle width direction with respect to the DPF 41b. Although not shown, an opening communicating with the exhaust gas inlet 821 of the EGR cooler 7 is formed on the side surface of the DPF 41b, and the exhaust gas main flow direction is provided on the rear side surface of the DPF 41b. An exhaust pipe 401 is connected.

  Here, the DPF 41b is at a height position near the joint between the cylinder head 12 and the cylinder block 11 on the rear side in the vehicle front-rear direction with respect to the engine 1 placed horizontally in the engine room (FIG. 2, 3), the exhaust gas is arranged extending in the longitudinal direction of the engine 1 so that the exhaust gas flows in the vehicle width direction. The EGR cooler 7 of the low-pressure EGR system is located at a side position of the DPF 41b in the vehicle width direction. After being arranged so as to substantially overlap with the DPF 41b in the vehicle front-rear direction, the vehicle is fixed to the DPF 41b and configured to flow exhaust gas from the front side to the rear side in the vehicle front-rear direction. Thus, the EGR control valve 54a is disposed on the opposite side of the vehicle width direction with respect to the DPF 41b with the EGR cooler 7 interposed therebetween. Further, the inflow pipe 85 and the outflow pipe 86 of the engine cooling water are also disposed at positions opposite to the DPF 41b in the vehicle width direction with respect to the EGR cooler 7 attached to the DPF 41b.

  As described above, although the EGR cooler (heat exchanger) 7 includes the filter 822, the filter 822 functions as an exhaust gas inflow header tank in the case 8 that houses the core 71. The first space portion 811 is disposed. For this reason, it is not necessary to separately secure an arrangement space for the filter, and the heat exchanger with a built-in filter can be configured compactly.

  Corresponding to the provision of the two inlet portions 821 in the lid 82 of the case 8, in addition to providing the two filters 822, each of the filters 822 is configured in a cylindrical shape, thereby increasing the arrangement space. Therefore, it is possible to secure a large filter area, and it is possible to improve the foreign matter capturing performance without increasing the pressure loss of the exhaust gas. In particular, the EGR cooler 7 is a heat exchanger used in a low pressure EGR system, and since the pressure difference between the exhaust side and the intake side is small, suppressing the pressure loss of the exhaust gas to reduce the flow rate of the exhaust gas. It is advantageous in securing.

  Further, the two inlet portions 821 and the two filters 822 are arranged in parallel in the vertical direction so as to follow the inflow portion of the first flow path of the core 71, so that the filter area can be increased without increasing the EGR cooler 7. Is expanded. Further, arranging the two inlet portions 821 side by side along the inflow portion of the first flow path of the core 71 is advantageous in improving the dispersibility of the exhaust gas flowing into the core, and heat exchange of the core 71 Increases efficiency.

  Furthermore, since the EGR cooler 7 is disposed on the downstream side of the DPF 41b and incorporates the filter 822 as described above, it is effectively avoided that foreign matter accumulates on the core 71. This also makes it possible to reduce the cross-sectional area of the first flow path in the core 71 to increase the heat exchange efficiency, and accordingly to shorten the length of the core 71 (the length in the vehicle front-rear direction). That is, since the core is downsized, the layout of the EGR cooler 7 in the engine room is improved.

  Further, in the case main body 81, the flow direction between the two inlet portions 821 and the core 71 described above is provided by providing a curved portion 816 having a relatively large radius at the bottom portion that defines the first space portion 811. It is possible to suppress as much as possible an increase in pressure loss of the exhaust gas to be converted. As described above, this is advantageous in securing the flow rate of the exhaust gas as the EGR cooler 7 in the low pressure EGR system in which the pressure difference between the intake and exhaust is small.

  As described above, the layout performance can be improved by arranging the compact EGR cooler 7 side by side in the vehicle width direction with respect to the DPF 41b while realizing high heat exchange efficiency and low pressure loss. In particular, by configuring the longitudinal direction of the EGR cooler 7 (exhaust gas flow direction) to be the vehicle front-rear direction, the EGR cooler 7 can be arranged in a small empty space in the vehicle width direction. Further, the DGR 41b, the EGR control valve 54a, the engine cooling water inflow pipe 85 and the outflow pipe 86 are arranged at positions opposite to the DPF 41b across the EGR cooler 7, and the DPF 41b, the EGR cooler 7 and the EGR control are arranged. By arranging the components of the low-pressure EGR system including the valve 54a side by side in the vehicle width direction, it becomes possible to arrange them in a compact manner. This is advantageous for improving the layout in the engine room.

  In the above configuration, the case 8 that houses the core 71 is configured by the case main body 81 and the lid body 82, and the case main body 81 is configured in a deep type that can accommodate the entire core 71. The way of dividing 8 is not necessarily limited to this. Further, the stacking direction of the cores 71 accommodated in the case 8 is not necessarily the same as the split direction of the case.

  In addition to attaching the EGR cooler 7 to the DPF 41b, the EGR cooler 7 may be attached to, for example, an oxidation catalyst.

  The heat exchanger disclosed herein is optimal for low pressure EGR systems, but can also be applied to high pressure EGR systems. Moreover, the heat exchanger disclosed here can be used for various purposes besides being used as an EGR cooler of an engine system.

1 Diesel engine (engine)
41 Exhaust gas treatment device 41b DPF (Exhaust gas treatment device)
54 EGR passage 54a EGR control valve 71 Core 8 Case 81 Case main body 811 First space portion 816 Bending portion 82 Lid 821 Inlet portion 822 Filter

Claims (6)

A core having a first flow path through which the first fluid flows and a second flow path through which the second fluid flows, and configured to exchange heat between the first and second fluids;
A case configured to accommodate the core,
A space portion is provided in the case at a position adjacent to the inflow portion of the first flow path of the core, and the case communicates with the space portion and the first fluid is passed through the case. An inlet for introducing the first flow path of the core through the space is provided;
The heat exchanger further comprising a filter for the first fluid attached to the inlet and configured to be disposed in the space. The heat exchanger according to claim 1,
In the case, a plurality of inlet portions are arranged in parallel along the inflow portion of the first flow path of the core,
The filter is a heat exchanger attached to each of the plurality of inlet portions. The heat exchanger according to claim 1 or 2,
The core is configured by alternately laminating a plurality of the first flow paths and a plurality of the second flow paths,
The case is composed of a case main body that houses the core, and a lid that closes an opening of the case main body,
The entrance portion of the case is formed in the lid,
In the case body, the first fluid that has flowed from the inlet portion is guided to a bottom portion that defines a part of the space portion so as to flow toward the inflow portion of the first flow path of the core. A heat exchanger in which a curved portion is formed. The heat exchanger according to any one of claims 1 to 3,
The first fluid is engine exhaust gas, and the second fluid is engine cooling water;
The core is a heat exchanger configured to cool the exhaust gas with the cooling water in the middle of an EGR passage for returning the exhaust gas to the intake side of the engine. The heat exchanger according to claim 4, wherein
The case is attached to an exhaust gas treatment device that performs post-treatment of the exhaust gas,
A heat exchanger in which an EGR control valve configured to adjust an amount of exhaust gas recirculated to the intake side is attached to an outlet portion of the first fluid provided in the case. The heat exchanger according to claim 5,
The case is attached to an end portion of the exhaust gas treatment device extending in a longitudinal direction of the engine at a side position of the engine,
The exhaust gas treatment device, the case, and the EGR control valve are arranged in this order in the longitudinal direction of the engine.

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