JP2017014953A - Intake manifold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake manifold for improving the property of mixing EGR gas and intake air.SOLUTION: The intake manifold includes an EGR passage 4 provided as a flow path for EGR gas to recirculate therethrough from an exhaust system for an engine to an intake system, an EGR opening 5 provided in an intake passage between an intercooler 10 and the engine for opening the EGR passage 4, and a separation part 8 provided between the intercooler 10 and the EGR passage 4, projecting from a wall face 18 where the EGR opening 5 is formed toward the intake passage, for separating an intake flow from the wall face 18.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an intake manifold incorporating an intercooler for cooling engine intake air.

  Conventionally, an engine in which an intercooler for cooling supercharged air (intake air) introduced into the engine is incorporated in an intake manifold has been developed. That is, the intake air is cooled immediately before the intake air is introduced into the intake port of the engine. When a water-cooled intercooler is employed, for example, engine coolant is used as the refrigerant. With such a cooling structure, the refrigerant piping of the intercooler can be shortened and simplified, and the vehicle mountability of the engine can be improved (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-051907

  By the way, an EGR (Exhaust Gas Recirculation) system that improves fuel efficiency and environmental performance by recirculating engine exhaust gas from an exhaust system to an intake system is known. That is, the exhaust passage and the intake passage are connected by an EGR passage, and a part of the exhaust gas is introduced as EGR gas into the cylinder again. When such an EGR passage of the EGR system is connected to the intake manifold, the distance and time from when the EGR gas flowing into the intake manifold and the intake air merge and sucked into the engine cylinder are shortened. Therefore, the mixability of EGR gas and intake air may be reduced. Thereby, the combustion stability of the engine may be reduced, or the exhaust performance may be deteriorated.

  One of the purposes of the present case was invented in view of the above-described problems, and is to improve the mixing of EGR gas and intake air in an intake manifold having a built-in intercooler. It should be noted that the present invention is not limited to this purpose, and is an operational effect that is derived from each configuration shown in “Mode for Carrying Out the Invention” to be described later. Can be positioned as a purpose.

  (1) The intake manifold disclosed here is an intake manifold in which an intercooler for cooling the intake air of the engine is incorporated. The intake manifold includes an EGR passage serving as an EGR gas passage that recirculates from the exhaust system of the engine to the intake system, and an EGR opening that opens the EGR passage to the intake passage between the intercooler and the engine. Is provided. In addition, a separation portion is provided between the intercooler and the EGR opening portion so as to protrude from the wall surface where the EGR opening portion is formed toward the intake passage and separate the intake air flow from the wall surface.

(2) It is preferable that the said peeling part is extended in the shape of a wall in the direction which cross | intersects the intake air flow direction downstream from the said intercooler.
(3) It is preferable that the said peeling part is extended along the edge of the said EGR opening part.
(4) The EGR passage is disposed at an extending portion extending in a direction intersecting the intake air flow direction downstream from the intercooler, and at an inlet of the EGR gas flowing into the extending portion, It is preferable to have a deflecting unit that deflects the flow of the EGR gas in the extending part in a direction intersecting the extending direction of the extending part.

(5) It is preferable that the EGR opening is disposed at a position upstream of the intercooler in the intake air circulation direction in the EGR passage. In this case, it is preferable that the deflection unit deflects the flow of the EGR gas toward a position closer to the downstream side in the intake air circulation direction in the EGR passage.
(6) It is preferable to include a first bulging portion that bulges toward the inside of the EGR passage and generates turbulence in the flow of the EGR gas.

(7) It is preferable to include a second bulge portion that bulges toward the inside of the intake passage through which the intake air flows and generates turbulence in the flow of the intake air.
(8) It is preferable that the said peeling part has a recessed part whose projecting dimension from the said wall surface is smaller than the circumference | surroundings, and the said recessed part is provided in the position corresponding to the cylinder part of the said engine.

  (9) It is preferable that the EGR passage has a first wall surface formed in a shape that is inclined so as to be separated from the core as the distance from the opening portion into which the core of the intercooler is inserted. Further, it is preferable that the EGR passage has a second wall surface formed in a shape along the intake air flow direction downstream of the intercooler and formed with the EGR opening.

  Since the intake air that has passed through the intercooler is rectified in a direction along the passage in the core, it is difficult to mix with the EGR gas. On the other hand, by providing a separation portion between the intercooler and the EGR opening, the intake air flow separated from the wall surface can collide with the EGR gas. Thereby, mixing of intake air and EGR gas can be promoted, and combustion stability and exhaust performance of the engine can be improved.

It is a lineblock diagram of an engine to which an intake manifold (intake manifold) as an embodiment is attached. It is a perspective view of an intake manifold. It is a disassembled perspective view of an intake manifold (AA cut | disassembled perspective view of FIG. 2). It is sectional drawing (BB sectional drawing of FIG. 2) of an intake manifold. It is a perspective view which shows the back surface of a top plate. It is sectional drawing (CC arrow sectional drawing of FIG. 3, FIG. 4) of an intake manifold. It is sectional drawing (DD arrow sectional drawing of FIG. 3, FIG. 4) of an intake manifold. It is an expanded sectional view of an EGR passage part. (A)-(C) are conceptual diagrams which show the flow of EGR gas and intake air.

  An intake manifold (intake manifold) as an embodiment will be described with reference to the drawings. The embodiment described below is merely an example, and there is no intention of excluding various modifications and technical applications that are not explicitly described in the following embodiment. Each configuration of the present embodiment can be implemented with various modifications without departing from the spirit thereof. Further, they can be selected as necessary, or can be appropriately combined. In the following description, “upstream” and “downstream” mean directions based on the flow direction of the intake flow and the exhaust flow.

[1. engine]
The intake manifold 1 of this embodiment is applied to the engine 30 including the dual loop EGR system shown in FIG. In FIG. 1, one of the four cylinders provided in the engine 30 is illustrated. The engine 30 is a diesel engine using light oil as fuel. An intake port 31 and an exhaust port 32 connected to each cylinder are provided inside the cylinder head forming the top surface of the cylinder, and an intake valve and an exhaust valve are provided in each port opening. An upstream end opening in the intake port 31 is opened to the outside on the side surface of the cylinder head.

  An intake manifold 1 (I / C built-in manifold) incorporating a water-cooled intercooler 10 is attached upstream of the end opening of the intake port 31. The intake manifold 1 of this embodiment is directly attached to the side surface of the cylinder head, and is attached so as to cover the end opening of the intake port 31. Hereinafter, the direction in which the end openings of the intake ports 31 are arranged on the side surface of the cylinder head is referred to as “port juxtaposition direction L”. In the case of a four-cylinder engine, the port juxtaposition direction L is the same as the direction in which four cylinders are arranged (cylinder row direction), and is a direction parallel to the crankshaft center of the engine 30.

  The engine 30 is provided with a turbocharger 33 (supercharger) that operates using exhaust pressure. The turbocharger 33 has a structure in which a rotating shaft of a turbine and a compressor is connected via a bearing. The turbine is interposed in an exhaust system and the compressor is interposed in an intake system. In the intake system, an air cleaner 34 (filter), a low-pressure throttle valve 35, a turbocharger 33, and a high-pressure throttle valve 36 are provided in order from the upstream side of the intake flow, and the intake manifold 1 is disposed immediately downstream of the high-pressure throttle valve 36. The The exhaust system is provided with a turbocharger 33 and an exhaust purification device 37 in order from the upstream side of the exhaust flow. The exhaust purification device 37 includes a diesel oxidation catalyst, a NOx reduction catalyst, a DPF (diesel particulate filter), and the like.

  The engine 30 is provided with two EGR passages for recirculating a part of the exhaust gas to the intake side, that is, a high pressure EGR passage 38 and a low pressure EGR passage 39. The high-pressure EGR passage 38 is an EGR passage that communicates the intake system and the exhaust system at a position closer to the cylinder than the turbocharger 33. On the other hand, the low pressure EGR passage 39 is an EGR passage that communicates the downstream side of the turbine of the turbocharger 33 in the exhaust system and the upstream side of the compressor of the turbocharger 33 in the intake system. A high pressure EGR valve 40 is interposed in the high pressure EGR passage 38, and a low pressure EGR valve 41, an EGR cooler 42, and an EGR filter 43 are interposed in the low pressure EGR passage 39. The high pressure EGR passage 38 of the present embodiment is provided so as to connect the exhaust manifold of the engine 30 and the intake manifold 1, and supplies EGR gas to the downstream side of the intercooler 10.

  The intercooler 10 is a water-cooling type cooling device that cools supercharged air (intake air) introduced into the engine 30, and is interposed on a cooling circuit 44 that uses, for example, engine cooling water as a refrigerant. The cooling circuit 44 is provided separately from a circuit for cooling the engine 30, and includes a radiator 45 and a pump 46 for the intercooler 10. By operating the pump 46 to circulate the refrigerant, the refrigerant cooled by the radiator 45 is supplied to the core 20 of the intercooler 10, and the intake air passing through the interior of the core 20 is cooled by the refrigerant.

[2. I / C built-in intake]
The external appearance of the intake manifold 1 is illustrated in FIG. 2, an exploded perspective view of the intake manifold 1 cut along the section AA is shown in FIG. 3, and a longitudinal sectional view of the intake manifold 1 cut along the section BB is shown in FIG. 4. The internal structure of the intake manifold 1 introduces an EGR gas into a central part 51 where the intercooler 10 is mounted, an upstream part 52 that is an upstream part thereof, a downstream part 53 that is a downstream part thereof, and an intake system. It is divided roughly into four parts with the EGR passage part 4 which becomes a flow path for this purpose.

  The central part 51 is a box-shaped part in which the core 20 of the intercooler 10 is accommodated. An opening 2 into which the core 20 is inserted is formed in a substantially rectangular shape on the upper surface of the central portion 51, and a planar edge 3 is provided on the outer periphery thereof. The core 20 of the present embodiment is formed in a rectangular parallelepiped shape having the largest dimension in the port juxtaposition direction L, and its upper surface 55 and lower surface 58 are closed. Of the other four surfaces, the two surfaces having the largest area are the inflow surface 56 and the outflow surface 57 of the intake air. A direction from the inflow surface 56 toward the outflow surface 57 is a flow direction F of intake air. In FIG. 3 and FIG. 4, the flow direction F of intake air is indicated by a thick arrow. A direction perpendicular to the distribution direction F in the horizontal plane is the refrigerant distribution direction inside the core 20.

  The core 20 is attached so that the lower surface 58 of the core 20 is inclined downward from the inflow surface 56 toward the outflow surface 57. That is, it is fixed inside the central portion 51 of the intake manifold 1 so that the inflow surface 56 faces slightly upward with respect to the upstream portion 52 and the outflow surface 57 faces slightly downward with respect to the downstream portion 53. Thereby, the dew condensation water which may be generated inside the intercooler 10 is easily moved from the outflow surface 57 to the downstream portion 53, and clogging or breakage of the core 20 due to freezing of moisture is suppressed.

  The upstream portion 52 is a portion that is introduced into the core 20 of the intercooler 10 while bending the flow of intake air that has passed through the high-pressure throttle valve 36. For example, an intake passage and a throttle body are attached to the upstream portion 52. The flow direction G of the intake air flowing into the upstream portion 52 is set non-parallel to at least the flow direction F so that the intake flow does not go straight toward the inflow surface 56 of the core 20. As shown in FIG. 3, the upstream portion 52 of the present embodiment has a structure that allows intake air to flow upward from below the intercooler 10.

  The EGR passage portion 4 is a cylindrical portion that supplies EGR gas to the downstream side of the intercooler 10. The EGR passage portion 4 extends in a direction intersecting with the flow direction F in the top view of the intake manifold 1. The extending direction of the EGR passage portion 4 of the present embodiment is set parallel to the port juxtaposition direction L. Thereby, the flow direction E of the EGR gas flowing through the inside of the EGR passage portion 4 is substantially perpendicular to the flow direction F of the intake air as shown in FIG.

  The downstream portion 53 is a portion that supplies the intake port 31 while mixing the intake air flowing out from the outflow surface 57 of the core 20 and the EGR gas. As shown in FIG. 4, the bottom surface 63 of the downstream portion 53 is formed with a downward slope slightly downward from the outflow surface 57 of the core 20. A mixture of intake air and EGR gas flows into the intake ports 31 while spreading in the port juxtaposition direction L in the downstream portion 53, and is introduced into the cylinders according to the open state of the intake valve of the engine 30. The Note that the number of end openings of the intake port 31 perforated on the side surface of the cylinder head is plural. Therefore, it is good also as a shape which branched the downstream part 53 according to the number and position of the edge part opening part.

  The downstream portion 53 is provided with a fixing portion 66 for fastening and fixing the intake manifold 1 to the cylinder head of the engine 30. The fixing portion 66 is formed with a screw hole 67 that is screwed into the fastening fixture. A screw hole similar to the screw hole 67 is also formed on the side surface of the cylinder head to be fastened by the fastener. The screw holes are arranged separately above and below the end opening of the intake port 31. Corresponding to this, the fixed portions 66 on the intake manifold 1 side are also arranged in an upper and lower direction with an outlet portion of intake air interposed therebetween.

  As shown in FIG. 3, the lower fixing portion 66 among the fixing portions 66 arranged in two upper and lower rows is arranged outside the downstream portion 53 (that is, outside the intake manifold 1). On the other hand, the upper fixing portion 66 is disposed inside the downstream portion 53 through which the intake air flows. The position of the upper fixing portion 66 is set in the inter-cylinder portion of the engine 30. The position of the fixed portion 66 in the present embodiment is set between the first cylinder and the second cylinder and between the third cylinder and the fourth cylinder.

  A work opening 68 for attaching a fastening fixture to the fixing portion 66 is provided in the upstream portion 52. As shown in FIG. 4, the position of the working opening 68 is set to a position where a perpendicular to the fixing surface extends from the fixing portion 66. The intake manifold 1 is fastened and fixed to the cylinder head before the intercooler 10 is mounted. Thereafter, the working opening 68 is sealed with a lid member 69 as shown in FIG.

[2-1. Intercooler]
The structure of the intercooler 10 will be described in detail. As shown in FIG. 3, the intercooler 10 is provided with a flange 11 brazed to the upper surface 55 of the core 20, and a top plate 12 separate from the flange 11. The flange 11 is a metal plate having a size larger than that of the upper surface 55 of the core 20. When the core 20 is inserted into the opening 2, the flange 11 is in contact with the outer surface of the edge 3 of the opening 2. It is formed in a fixed size. The flange 11 is attached along the upper surface 55 of the core 20 so as to extend in a planar shape from the upper surface 55 toward the outside. Further, a hole 60 for inserting a fastening fixture 59 such as a bolt or a long screw is formed in the outer peripheral portion of the flange 11. The flange 11 can be cooled by a coolant flowing through the core 20.

  The top plate 12 is a metal plate having substantially the same size as the flange 11 and having a plate thickness larger than that of the flange 11. A hole 60 for inserting the fastening fixture 59 is also formed in the outer peripheral portion of the top plate 12. Further, corresponding to these holes 60, screw holes 61 for fixing the fastening fixture 59 are also provided in the edge 3 of the opening 2. By screwing the fastening fixture 59 into the screw hole 61 in a state where the fastening fixture 59 is inserted through the hole 60 of the flange 11 and the top plate 12, the opening 2 is closed by the flange 11 and the top plate 12, and the flange 11 is the edge 3. And the intercooler 10 is fixed to the intake manifold 1. In the present embodiment, the intercooler 10 is attached with a metal gasket 14 sandwiched between the flange 11 and the edge 3 of the opening 2. Since the gasket 14 is pressed and attached via the flange 11 with the top plate 12 having a thickness larger than that of the flange 11, the seal surface pressure of the gasket 14 can be improved. The plate thickness of the top plate 12 can be set according to the fixing strength and fastening pressure of the intercooler 10.

  The top plate 12 of the present embodiment is formed to a size that overlaps with the EGR passage portion 4 when the opening 2 is viewed from the front (as viewed in the direction in which the core 20 is inserted into the opening 2). That is, one side of the top plate 12 has a size that partially covers the EGR passage portion 4. In other words, the EGR passage portion 4 is disposed so as to pass directly below the top plate 12. Similarly, the flange 11 is formed to have a size that overlaps with the EGR passage portion 4 when the intercooler 10 is viewed from above. The edge 3 of the opening 2 of the present embodiment functions as a part of the wall body that constitutes the EGR passage 4. Thereby, the EGR gas passing through the inside of the EGR passage portion 4 can be cooled by the core 20 of the intercooler 10 through the flange 11 and the top plate 12.

  The top surface of the top plate 12 has a planar shape, and a vacuum pipe 48 and a solenoid valve 49 are attached thereto. The vacuum pipe 48 is a negative pressure supply path introduced into the actuator of the turbocharger 33 and the master back of the braking booster, and the solenoid valve 49 is an electromagnetic on-off valve interposed on the supply path. A vacuum pump that sucks air is provided at one end of the vacuum pipe 48, and a turbocharger 33 and a braking booster are connected to the other end. The turbocharger 33 has a function of changing a supercharging pressure by driving a variable nozzle of the turbine using a pressure difference. The braking booster has a function of doubling the depressing force of the brake pedal using negative pressure. Thus, by attaching the vacuum pipe 48 and the solenoid valve 49 to the surface of the top plate 12, it becomes possible to indirectly cool the air in the negative pressure supply path, and the turbocharger 33 and braking can be performed without cost. The controllability of the booster can be improved.

  Inside the top plate 12, a heat generating member 47 that functions as a heater (for example, a nichrome wire or a Peltier element that generates heat upon receiving power supply) is routed. The heat generating member 47 is energized when the engine 30 is started in an extremely cold environment, for example, and functions to raise the temperature of the flange 11 and the core 20 of the intercooler 10. As a result, overcooling of the flange 11 during cold start is suppressed, and clogging and breakage of the core 20 due to freezing of moisture are suppressed.

  As shown in FIG. 5, the back surface 62 which is a contact surface with the flange 11 among the surfaces of the top plate 12 is provided with a recessed portion 64 which is recessed in a shape recessed from its periphery, and a groove shape. And a groove portion 65 (for example, a portion formed by connecting recesses linearly). The concave portion 64 and the groove portion 65 are structures for reducing the frictional resistance while securing the fastening pressure between the flange 11 and the top plate 12, and function to absorb deformation due to thermal expansion and contraction of the flange 11. To do. The concave portion 64 is mainly provided in the vicinity of the center portion of the top plate 12, and a groove portion 65 is disposed outside thereof. The arrangement direction of the grooves 65 is set to a direction from the central part of the top plate 12 toward the outside. Thus, by providing the concave portion 64 and the groove portion 65 on the surface of the top plate 12, slight deformation (thermal strain) due to temperature change of the flange 11 is allowed, and the possibility that the flange 11 is cracked or broken is reduced. To do. In addition, what is necessary is just to set suitably about the shape and arrangement | positioning of the concrete recessed part 64 and the groove part 65 according to the distribution state of the internal stress accompanying the temperature change of the flange 11. FIG.

[2-2. EGR passage section]
The structure of the EGR passage portion 4 will be described in detail. As shown in FIG. 3, the EGR passage portion 4 is provided adjacent to the opening portion 2 and is disposed along the inner surface of the edge portion 3. That is, the EGR passage portion 4 is disposed adjacent to the core 20 of the intercooler 10. The extending direction of the EGR passage portion 4 is a direction perpendicular to the intake flow direction F. As a result, the flow direction E of the EGR gas inside the EGR passage portion 4 is a direction perpendicular to the flow direction F of the intake air and is substantially parallel to the outflow surface 57 of the core 20. Therefore, EGR gas can be introduced evenly in the width direction in the top view with respect to the intake air flow that flows out from the outflow surface 57 of the core 20, and the mixing property between the intake air and the EGR gas is improved.

  The horizontal cross-sectional shape of the EGR passage portion 4 is illustrated in FIGS. The EGR passage portion 4 is provided with an extending portion 15 and a deflecting portion 16. The extending portion 15 is a portion that is linearly extended in a direction perpendicular to the intake flow direction F. The horizontal cross-sectional shape of the extending portion 15 is formed in a shape in which the flow path narrows as it goes deeper into the EGR passage portion 4. In addition, the extending portion 15 is provided with a slit 5 (EGR opening) through which the EGR gas flows out to the downstream side of the core 20. The slit 5 is an elongated opening extending in the flow direction E of EGR gas, and is disposed upstream of the intake flow direction F (that is, at a position closer to the core 20) inside the extended portion 15. .

  The deflecting portion 16 is a portion arranged at the inlet of the EGR gas flowing into the EGR passage portion 4, and intersects the flow direction of the EGR gas with the extending direction of the extending portion 15 (that is, the EGR gas flow direction E). Has a function to deflect in the direction. As shown in FIGS. 6 and 7, the flow path shape of the deflection unit 16 is a shape bent in a crank shape so as to avoid the slit 5 in a top view (in other words, a shape curved in an S shape). . In the present embodiment, the slit 5 is disposed upstream of the flow direction F, while the EGR gas is deflected so that the EGR gas is introduced downstream of the flow direction F (that is, a position farther from the core 20). The channel shape of the part 16 is set. As a result, the flow of EGR gas tends to be biased to the side opposite to the slit 5 inside the extended portion 15, and the EGR gas easily reaches the depth of the extended portion 15.

As shown in FIG. 8, the cross-sectional shape of the EGR passage portion 4 is formed in a trapezoidal shape with the edge 3 of the opening 2 as an upper base. That is, the cross-sectional shape of the EGR passage portion 4 can be similar to a trapezoidal shape surrounded by the edge portion 3, the first wall surface 17, the second wall surface 18, and the third wall surface 19.
The first wall surface 17 is a portion formed in an inclined shape so as to be further away from the core 20 as it is further away from the opening 2 toward the lower side. The first wall surface 17 can collide with intake air that has passed through the portion close to the opening 2 in the core 20. The intake air that has collided with the first wall surface 17 flows obliquely downward along the surface of the first wall surface 17.
The second wall surface 18 is a portion corresponding to the lower base of the trapezoidal shape, and is formed in a shape along the intake flow direction F. Further, the above-described slit 5 is formed in the second wall surface 18.
The third wall surface 19 is a part corresponding to the hypotenuse of the trapezoidal shape, and is disposed opposite to the first wall surface 17 on the downstream side in the intake flow direction F from the first wall surface 17.

  Inside the extended portion 15, a first bulge portion 6 that bulges along the slit 5 and generates turbulence in the flow of EGR gas is provided. The first bulging portion 6 is a part of a cylindrical boss formed by reinforcing the periphery of the screw hole 61 in which the fastening fixture 59 for mounting the intercooler 10 to the central portion 51 is fixed in the diameter-expanding direction. is there. A portion of the boss that protrudes outside the EGR passage portion 4 is referred to as a second bulging portion 7. The second bulging portion 7 functions to generate turbulence in the intake air flow. The arrangement positions of the first bulging portion 6 and the second bulging portion 7 correspond to the mounting position of the fastening fixture 59 as shown in FIG. The fastening fixture 59 is disposed so as to surround the opening 2 and is disposed not only on the downstream side of the core 20 but also on the upstream side of the core 20. As shown in FIG. 3, the boss disposed on the upstream side of the core 20 is also referred to as the second bulging portion 7.

  As shown in FIG. 8, a peeling portion 8 that protrudes downward from the second wall surface 18 is provided upstream of the slit 5 in the flow direction F of the intake air. The peeling part 8 is a part having a function of peeling the intake air flow from the second wall surface 18 and acts, for example, so that the intake air flow that has flowed along the surface of the first wall surface 17 goes straight diagonally downward. . The cross-sectional shape of the peeling portion 8 is at least a shape protruding from the second wall surface 18 toward the inside of the intake passage. Preferably, the first wall surface 17 has a slope with an extended surface. Thereby, the pressure in the vicinity of the slit 5 located on the downstream side of the peeling portion 8 is slightly reduced, and the EGR gas in the EGR passage portion 4 is easily sucked downward from the slit 5. Further, the vortex of the intake air flow is likely to occur in the vicinity of the slit 5, and the mixing property of the EGR gas and the intake air is improved.

  As shown in FIG. 3, the peeling portion 8 extends in the flow direction E of the EGR gas along the edge of the slit 5. In other words, the extending direction of the peeling portion 8 is a direction (vertical direction in the present embodiment) that intersects the flow direction F of intake air. The peeling portion 8 is formed over substantially the entire width of the region where the intake air flows in a top view. However, since a tool for attaching the fastening fixture can be inserted in a range from the working opening 68 to the corresponding fixing portion 66, a recess portion for preventing interference between the tool and the peeling portion 8 is possible. 9 is provided in the peeling part 8. That is, as shown in FIG. 3, the projecting dimension from the second wall surface 18 is extended so that the perpendicular to the stationary surface extends from the stationary portion 66 disposed inside the downstream portion 53 so that the perpendicular and the peeling portion 8 do not interfere with each other. The recess 9 is formed by partially reducing. As a result, disturbance in the intake air flow is likely to occur, and the mixing of EGR gas and intake air is improved.

[3. Action]
[3-1. Intercooler]
The flange 11 of the intercooler 10 built in the intake manifold 1 is easily cooled by the refrigerant flowing through the core 20 and has a relatively low temperature. On the other hand, since the intake manifold 1 is attached to the cylinder head of the engine 30, it is easily affected by the heat generated in the engine 30, and the portion of the flange 11 close to the cylinder head becomes relatively hot. Such a thermal imbalance causes local thermal expansion and contraction inside the flange 11, resulting in an environment in which the flange 11 is liable to crack and break. In particular, in the intake manifold 1 described above, the EGR passage portion 4 is disposed adjacent to the core 20 of the intercooler 10, so that the flange 11 located immediately above the EGR passage portion 4 is likely to be hot and local thermal expansion occurs. Cheap.

  With respect to such a problem, in the intake manifold 1, as shown in FIG. 3, the top plate 12 of the intercooler 10 is provided separately from the flange 11 brazed to the core 20. Are fastened and fixed on the opening 2 in a state of being superimposed. Thereby, even if the temperature of the flange 11 is locally low or high, it is easy to allow the flange 11 to be deformed and moved relative to the top plate 12.

  Further, as shown in FIG. 5, a recess 64 and a groove 65 are provided in the back surface 62 of the top plate 12. These concave portions 64 and groove portions 65 function to absorb deformation due to thermal expansion and thermal contraction of the flange 11. Therefore, the flange 11 is more reliably allowed to be deformed and moved relative to the top plate 12. Further, since the frictional resistance is reduced without excessively reducing the fastening pressure between the flange 11 and the top plate 12, the fixing strength of the intercooler 10 is also ensured.

  Further, the top plate 12 is formed in a shape that overlaps with the EGR passage portion 4 in a top view. That is, the EGR gas flowing through the EGR passage portion 4 is cooled by the intercooler 10 via the top plate 12. Thereby, the volume of EGR gas becomes smaller and the volume efficiency is improved. Moreover, since the combustion temperature of the engine 30 falls, the production amount of nitrogen oxides is reduced.

[3-2. EGR passage section]
As shown in FIG. 6, the EGR passage portion 4 provided in the intake manifold 1 is provided with an extending portion 15 for linearly circulating EGR gas and a deflecting portion 16 for circulating EGR gas while bending it. . The deflection unit 16 functions to bias the flow of EGR gas toward one side without the slit 5. Further, as the third wall surface 19 extends from the deflecting portion 16 to the back of the extending portion 15, the third wall surface 19 is provided so as to approach the opposing first wall surface 17, and the back of the EGR passage portion 4 (extending portion 15). The channel is formed in a shape that narrows as it goes on. As a result, as shown in FIG. 9A, the EGR gas easily reaches the depth of the extending portion 15, and the EGR gas flows out uniformly from every part of the slit 5. Therefore, the mixing property of EGR gas and intake air is improved.

  The first bulging portion 6 is provided inside the extending portion 15, and turbulence is generated in the flow of EGR gas. For example, as shown in FIG. 9B, when the EGR gas flows in the vicinity of the first bulging portion 6, a vortex-like disturbance occurs on the downstream side of the EGR gas from the first bulging portion 6. Thereby, the flow of EGR gas including turbulence passes through the slit 5, and the mixing property of EGR gas and intake air is improved. In this embodiment, the starting point at which the flow path of the extending portion 15 is narrowed on the third wall surface 19 facing the first wall surface 17 at a position between the first bulging portions 6 provided on the first wall surface 17. Is formed.

  A peeling portion 8 is provided upstream of the slit 5 in the intake air flow direction F. As a result, as indicated by a white arrow in FIG. 9C, the flow of the intake air flowing through the surface of the first wall surface 17 is peeled off from the second wall surface 18, and a spiral shape is formed on the downstream side of the intake air from the peeling portion 8. Disturbance occurs. As a result, the flow of the intake air including turbulence is mixed with the EGR gas, and the mixability of the EGR gas and the intake air is further improved.

  Further, as shown in FIG. 3, the peeling portion 8 is provided with a dent portion 9 whose projecting dimension from the second wall surface 18 is smaller than the surroundings. That is, as indicated by a broken line white arrow in FIG. 9C, a part of the flow of the intake air flowing through the surface of the first wall surface 17 is along the second wall surface 18 (that is, in the intake air flowing direction F). Circulate. On the other hand, in the portion where the recess 9 is not provided, such an intake flow is inhibited. As a result, as shown by white arrows in FIG. 9A, spiral disturbance occurs on both sides of the recess 9. Therefore, the mixability of EGR gas and intake air is further improved.

[4. effect]
(1) Since the intake air flow that has passed through the core 20 of the intercooler 10 is rectified in a direction along the passage in the core 20, it is difficult to mix with the EGR gas. On the other hand, by providing the separation portion 8 between the intercooler 10 and the slit 5, the intake air flow separated from the second wall surface 18 can collide with the EGR gas. Thereby, mixing of intake air and EGR gas can be promoted, and combustion stability and exhaust performance of the engine 30 can be improved.
(2) As shown in FIG. 3, the peeling portion 8 extends in the shape of a wall in a direction intersecting the intake flow direction F. The intake air flow can be efficiently separated from the wall surface 18. Therefore, mixing of intake air and EGR gas can be promoted.

  (3) Moreover, the pressure of the exit part of the slit 5 can be reduced by providing the peeling part 8 along the edge of the slit 5. As a result, the EGR gas can be easily sucked from the extending portion 15 to the intake air flow side, and the amount of recirculation of the EGR gas can be increased. Therefore, the fuel consumption of the engine 30 can be improved. In addition, when the distance between the slit 5 and the peeling portion 8 is long, the intake flow immediately after peeling from the wall surface can collide with the EGR gas when the distance is short. Therefore, the mixing property between the intake air and the EGR gas can be improved.

  (4) As shown in FIG. 6, by providing the extending portion 15 and the deflecting portion 16 in the EGR passage 4, the flow of EGR gas can be biased. That is, as shown in FIG. 9 (A), the EGR gas can flow in a place where there is no slit 5. Thereby, EGR gas can be distribute | circulated to the back of the extension part 15, and mixing with intake and EGR gas can be accelerated | stimulated. Further, by separating the region where the EGR gas flows and the region where the slit 5 is disposed in the EGR passage 4, the EGR gas can be uniformly supplied from the slit 5, and mixing of the intake air and the EGR gas is performed. Can be promoted.

  (5) In addition, by disposing the slit 5 upstream of the flow direction F inside the extended portion 15, the distance from the position where the intake air and the EGR gas are mixed to the cylinder (that is, the intake air in the intake system) The length of the portion where EGR gas and EGR gas are mixed can be increased, and mixing of intake air and EGR gas can be promoted.

  (6) By providing the first bulging portion 6 inside the extended portion 15, turbulence can be generated in the flow of EGR gas flowing through the EGR passage portion 4, and mixing of EGR gas and intake air Can increase the sex. The first bulging portion 6 is a boss that reinforces the periphery of the screw hole 61 for attaching the intercooler 10 to the intake manifold 1 in the diameter increasing direction. By adding a turbulent flow generation function to such an existing boss, it is possible to improve the cooling and mixing properties of the EGR gas without adding new members, and to reduce the product cost.

  (7) As shown in FIG. 3, by providing the second bulging portion 7 in the intake passage, it is possible to cause disturbance in the flow of intake air, and to improve the mixability of EGR gas and intake air. . Moreover, like the case of the 1st bulging part 6, by using the existing boss | hub, and realizing the function of the 2nd bulging part 7, a mixing property can be improved, without adding a new member. The product cost can be reduced.

  (8) By providing the recessed portion 9 in the separation portion 8, it is possible to generate an intake flow that is not partially separated (high flow velocity). Thereby, as shown by the white arrow in FIG. 9 (A), the vortex which turns in the extension direction of the peeling part 8 can be produced | generated. Therefore, mixing of intake air and EGR gas can be further promoted.

  (9) By providing the recessed portion 9 at a position corresponding to the inter-cylinder portion of the engine 30, it is possible to prevent an intake flow having a high flow velocity from immediately flowing into the intake port and to promote mixing of intake air and EGR gas. be able to. Further, as shown in FIG. 4, when the positions of bolts and bolt holes for fastening and fixing the intake manifold 1 to the cylinder head of the engine 30 are set in the inter-cylinder part, the recessed part 9 is used for fastening. The tool can be inserted to the vicinity of the bolt and the bolt hole, and workability can be improved. Furthermore, by arranging the recess 9 at a position where it can interfere with the fastening tool during work, the mixing property can be improved without incurring additional costs, and the product cost can be reduced.

(10) As shown in FIG. 8, by inclining the first wall surface 17 of the EGR passage 4 with respect to the outflow surface 57 of the core 20, the intake air easily passes through the core 20 and passes through the core 20. Thus, the intake air flow is easily circulated along the first wall surface 17, and the intake resistance can be reduced.
(11) Further, by forming the second wall surface 18 of the EGR passage 4 along the intake flow direction F, as shown in FIG. 9C, negative pressure generated by the intake flow separated at the separation portion 8. A region (a region where a swirl flow is generated) can be secured, and the mixing property between the intake air and the EGR gas can be improved.

[5. Modified example]
In the above-described embodiment, the intake manifold 1 attached to the diesel engine 30 is illustrated, but the type of the engine 30 is not limited thereto. The EGR system of the engine 30 is not an essential element in this case and can be omitted as appropriate. Further, the mounting angle of the intake manifold 1 with respect to the engine 30 can be arbitrarily set. In the above-described embodiment, the lower surface 58 of the core 20 of the intercooler 10 is provided to be inclined with respect to the horizontal plane. However, the intake manifold 1 itself may be inclined with respect to the horizontal plane, and the engine 30 may be inclined with respect to the horizontal plane. It may be inclined.

1 Intake manifold 2 Opening 3 Edge 4 EGR passage (EGR passage)
5 Slit (EGR opening)
6 First bulging portion 7 Second bulging portion 8 Separating portion 9 Recessed portion 10 Intercooler 11 Flange 12 Top plate 14 Gasket 15 Extension portion 16 Deflection portion 20 Core 47 Heating member (heater)
48 Vacuum pipe 64 Recess 65 Groove

Claims (9)

Intake manifold with built-in intercooler that cools engine intake air
An EGR passage serving as a flow path for EGR gas flowing back from the exhaust system of the engine to the intake system;
An EGR opening that opens the EGR passage to an intake passage between the intercooler and the engine;
A peeling portion that protrudes from the wall surface where the EGR opening portion is formed toward the intake passage between the intercooler and the EGR opening portion, and separates the intake air flow from the wall surface;
An intake manifold characterized by comprising: 2. The intake manifold according to claim 1, wherein the peeling portion extends in a wall shape in a direction crossing an intake air flow direction downstream of the intercooler. The intake manifold according to claim 1, wherein the peeling portion extends along an edge of the EGR opening. The EGR passage is
An extending portion extending in a direction intersecting the intake air flow direction downstream from the intercooler,
A deflecting unit that is disposed at an inlet of the EGR gas flowing into the extending part and deflects the flow of the EGR gas in the extending part in a direction intersecting the extending direction of the extending part. The intake manifold according to any one of claims 1 to 3, wherein the intake manifold is characterized. The EGR opening is disposed in the EGR passage at a position closer to the upstream side in the intake air flow direction than the intercooler, and
The intake manifold according to claim 4, wherein the deflecting portion deflects the flow of the EGR gas toward a position closer to the downstream side in the intake air circulation direction in the EGR passage. The intake manifold according to any one of claims 1 to 5, further comprising a first bulge portion that bulges toward an inner side of the EGR passage and generates turbulence in the flow of the EGR gas. The apparatus according to claim 1, further comprising a second bulge portion that bulges toward an inner side of an intake passage through which the intake air flows and generates a turbulence in the flow of the intake air. Intake manifold. The peeling portion has a recess having a projecting dimension from the wall surface smaller than the surroundings,
The intake manifold according to any one of claims 1 to 7, wherein the recessed portion is provided at a position corresponding to an inter-cylinder portion of the engine. The EGR passage has a first wall surface formed in a shape that is inclined so as to be separated from the core as the distance from the opening into which the core of the intercooler is inserted, and along the intake air flow direction downstream of the intercooler. The intake manifold according to any one of claims 1 to 8, further comprising a second wall surface formed with a shape and the EGR opening.

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