JP6357848B2 - Intake device for internal combustion engine - Google Patents

Description

  The present invention relates to an intake device for an internal combustion engine, and more particularly, to an intake device for an internal combustion engine that includes an intake flow control valve, a storage portion in which the intake flow control valve is stored, and an exhaust gas inlet provided in the storage portion. About.

  2. Description of the Related Art Conventionally, an intake device for an internal combustion engine is known that includes an intake flow control valve, a storage portion in which the intake flow control valve is stored, and an exhaust gas inlet provided in the storage portion (for example, Patent Document 1). reference).

  Patent Document 1 discloses an internal combustion engine intake passage structure in which an exhaust gas recirculation (EGR) passage is connected to each intake passage of a multi-cylinder internal combustion engine. In the intake passage structure of the internal combustion engine described in Patent Document 1, an intake flow control valve for controlling the degree of deflection of the intake flow is rotatably provided in each intake passage. When the opening of the intake flow control valve is controlled to a fully closed state in accordance with the operating state of the internal combustion engine, a tumble flow (longitudinal vortex (deflection flow)) is formed in the intake air in the cylinder. The intake passage has a housing portion that can be retracted when the intake flow control valve is fully opened, and an exhaust gas recirculation passage for recirculating a part of the exhaust gas into the cylinder is formed in the intake passage at the bottom of the housing portion. It is open. The intake flow control valve is controlled in two stages, a fully opened state in which the valve body is retracted to the housing portion and a fully closed state, and the amount of exhaust gas introduced into the intake passage is the amount of the air flow control valve. It is adjusted in two steps according to the fully open state and the fully closed state. That is, in the fully opened state where the intake flow control valve is retracted to the accommodating portion, the exhaust gas recirculation passage passes through the intake flow control valve and communicates with a through passage having an inner diameter smaller than that of the exhaust gas recirculation passage. And exhaust gas is introduce | transduced into an intake passage through this narrow penetration path. On the other hand, in the fully closed state in which the intake flow control valve is rotated from the fully open state to the closed state, the exhaust gas recirculation passage at the bottom of the housing portion is completely opened and the maximum amount of exhaust gas is introduced.

JP 2009-114918 A

  However, in the intake passage structure of the internal combustion engine disclosed in Patent Document 1, since the opening degree of the intake flow control valve is controlled only in two stages of fully open and fully closed, an optimal tumble flow (deflection flow) cannot be generated. There is a problem. Further, when the intake flow control valve is fully opened, the exhaust gas introduction amount is suppressed to the minimum amount through the through passage, while when the intake flow control valve is rotated from the fully open state to the fully closed state, the exhaust gas recirculation is performed. The inner diameter of the passage is suddenly enlarged and the exhaust gas introduction amount is switched to the maximum amount. For this reason, the EGR passage for introducing the maximum amount of exhaust gas is opened at all openings other than the fully opened state of the intake flow control valve, and the communication of the intake port by the EGR passage is larger than necessary. As a result, the inertia supercharging effect is remarkably lowered, and as a result, the output of the engine (internal combustion engine) is also lowered.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to enable optimal control of an intake flow control valve, and to detect any of the intake flow control valves. It is another object of the present invention to provide an intake device for an internal combustion engine that can suppress a decrease in inertial supercharging effect to a minimum even at an opening degree.

In order to achieve the above object, an intake device for an internal combustion engine according to one aspect of the present invention is provided rotatably in an intake passage of the internal combustion engine, and includes an intake flow control valve for controlling the flow of intake air, and an intake passage. Provided on the lower surface of the intake flow control valve opposite to the storage portion, the storage portion in which the intake flow control valve is provided, the exhaust gas introduction port provided in the storage portion and into which the recirculated exhaust gas is introduced. And a groove portion that constitutes an exhaust gas passage by a space between the housing portion and the exhaust gas passage, and the groove portion of the intake flow control valve has a minimum cross-sectional area of the exhaust gas passage. The intake flow control valve is formed in a shape that changes according to the opening of the intake flow control valve, the housing portion has a concave arc shape, and the lower surface of the intake flow control valve has a convex shape corresponding to the concave arc shape storage portion And has an arc shape of The upper surface of the intake flow control valve is provided so that the upper surface of the intake flow control valve is flush with the inner surface of the intake passage when the opening of the intake flow control valve is fully opened. Is provided on the lower surface of the convex arcuate shape of the intake flow control valve so as to extend along the direction of rotation of the intake flow control valve, and the groove has a minimum cross-sectional area of the exhaust gas passage that opens the intake flow control valve. At least one of the groove depth and the groove width of the groove is changed so as to change according to the degree.

  In the intake device for an internal combustion engine according to one aspect of the present invention, as described above, the lower surface of the intake flow control valve facing the housing portion is connected to the exhaust gas inlet of the housing portion and between the housing portion and the intake portion. A groove that constitutes an exhaust gas passage is provided by the space. Then, the groove of the intake flow control valve is formed in a shape such that the minimum cross-sectional area of the exhaust gas passage changes according to the opening of the intake flow control valve, and the minimum cross-sectional area of the exhaust gas passage is The groove portion is configured such that at least one of the groove depth and the groove width of the groove portion changes so as to change according to the opening degree. Thus, unlike the case where the exhaust gas introduction amount is adjusted only in two stages according to the open / close state of the intake flow control valve, the intake flow control valve is rotated to a desired opening degree to perform optimum control on the intake flow. Can do. When optimal control of the intake flow control valve is performed, the exhaust gas always has the minimum cross-sectional area of the groove on the lower surface of the intake flow control valve regardless of the opening degree of the intake flow control valve. The introduction amount is suppressed to a minimum through the portion having the same. In other words, since the expansion of the internal volume of the intake passage accompanying the communication between the intake passage and the exhaust gas inlet can always be minimized, the inertial supercharging effect is reduced at any opening of the intake flow control valve (internal combustion Engine output) can be minimized.

  Further, in the one aspect described above, the intake flow that changes the minimum cross-sectional area of the exhaust gas passage according to the opening degree of the intake flow control valve by providing a groove portion in which at least one of the groove depth and the groove width changes. A control valve can be obtained easily. As a result, it is possible to always recirculate the minimum amount of exhaust gas together with the optimal control of the intake flow control valve without reducing the inertia supercharging effect.

In the intake device for an internal combustion engine according to the above aspect, the housing portion has a concave arc shape, and the lower surface of the intake flow control valve has a convex arc shape corresponding to the concave arc shape housing portion, In addition, the upper surface of the intake flow control valve is flush with the inner surface of the intake passage in a state where the intake flow control valve is fully opened by being rotated about a rotation shaft positioned above the accommodating portion. The groove portion is provided on the convex arc-shaped bottom surface of the intake flow control valve so as to extend along the rotation direction of the intake flow control valve. This ensures that the region opposed to the inner bottom surface of the concave accommodating portion and the convex lower surface of the intake flow control valve, the exhaust gas such that the minimum cross-sectional area of the groove varies according to the rotation position of the intake flow control valve The passage can be easily formed. In other words, the intake flow control valve that changes the cross-sectional shape of the intake passage (intake cross-sectional area of the intake flow) by attitude control is used to respond to the operating condition of the internal combustion engine while minimizing the decrease in inertia supercharging effect. Therefore, it is possible to achieve both optimal control of the intake air flow and optimal control of the exhaust gas introduction amount.

  In the intake device for an internal combustion engine according to the above aspect, the minimum cross-sectional area of the exhaust gas passage is preferably minimized when the intake flow control valve is fully open, and the intake flow control valve is fully open. The shape of the groove is configured so that the minimum cross-sectional area of the exhaust gas passage is maximized when closed. If comprised in this way, when an internal combustion engine is put in a high output region, the opening degree of the intake flow control valve is fully opened to suppress a decrease in the inertia supercharging effect (a decrease in the output of the internal combustion engine) while minimizing Exhaust gas can be recirculated to improve fuel consumption (fuel consumption rate). Also, when the internal combustion engine is in a low output range, the opening of the intake flow control valve is fully closed and the exhaust gas is recirculated to the maximum, thereby reducing pumping loss (intake and exhaust loss). it can. As a result, the fuel consumption of the internal combustion engine can always be improved while minimizing the decrease in the inertia supercharging effect from the low output range to the high output range.

  In the intake device for an internal combustion engine according to the above aspect, the shape of the groove is preferably configured so that the minimum cross-sectional area of the exhaust gas passage decreases stepwise as the opening of the intake flow control valve increases. Yes. With this configuration, the opening degree of the intake flow control valve is increased to increase the cross-sectional area of the intake passage, and the introduction amount (recirculation amount) of exhaust gas into the intake passage is decreased stepwise. Can do. That is, in an internal combustion engine in which the opening degree of the intake flow control valve is optimally controlled in a multistage manner, the exhaust gas recirculation amount corresponding to the multistage opening degree control of the intake flow control valve is easily controlled. be able to.

  In the intake device for an internal combustion engine according to the above aspect, the shape of the groove is preferably configured such that the minimum cross-sectional area of the exhaust gas passage continuously decreases as the opening of the intake flow control valve increases. Yes. With this configuration, the opening of the intake flow control valve is increased to increase the cross-sectional area of the intake passage, and the introduction amount (recirculation amount) of exhaust gas into the intake passage is continuously and continuously reduced. Can be reduced. That is, the amount of exhaust gas introduced into the intake passage (between the fully closed state of the intake flow control valve that controls the intake flow by narrowing the cross-sectional area of the intake passage and the fully open state that hardly controls the flow of intake air ( The amount of recirculation) can be finely adjusted. As a result, it is possible to always operate the internal combustion engine under the optimum combustion state while suppressing the decrease in the inertia supercharging effect to the minimum.

  In the intake device for an internal combustion engine according to the above aspect, the groove portion preferably extends from a portion between the upstream end portion and the downstream end portion of the lower surface of the intake flow control valve to the downstream end portion. Even when the opening degree of the intake flow control valve is fully open, the downstream end of the groove and the intake passage are communicated with each other. With this configuration, even when the intake flow control valve is fully opened and the sectional area of the intake passage is maximized, the downstream end of the groove portion having the minimum sectional area and communicating with the intake passage is provided. Thus, exhaust gas can be introduced into the intake passage. Therefore, it is possible to easily improve fuel efficiency by recirculating a minimum amount of exhaust gas while minimizing a decrease in inertia supercharging effect (a decrease in output of the internal combustion engine) in a high output range of the internal combustion engine.

  In the intake device for an internal combustion engine according to the aforementioned aspect, the groove preferably extends from a portion between the upstream end and the downstream end of the lower surface of the intake flow control valve to a position before the downstream end. Thus, the downstream end of the groove and the intake passage are not communicated with each other when the opening of the intake flow control valve is in the vicinity of the fully open position. With this configuration, it is possible to prevent the intake passage, the exhaust gas passage (groove), and the exhaust gas introduction port from communicating with each other when the opening degree of the intake flow control valve is in the vicinity of the fully open position. . That is, the increase in the internal volume of the intake passage due to the communication between the intake passage and the exhaust gas passage (exhaust gas introduction port) is prevented, thereby reliably preventing the inertia supercharging effect from being reduced in the high output range of the internal combustion engine. can do. Therefore, the internal combustion engine can reliably exert a high output.

  In the intake device for an internal combustion engine according to the above aspect, preferably, the portion having the minimum cross-sectional area of the exhaust gas passage when the opening degree of the intake flow control valve is fully closed is the exhaust gas inlet of the exhaust gas passage. It is the boundary part. With this configuration, when the intake flow control valve is fully closed (the state in which the passage cross-sectional area of the intake passage is minimized), the exhaust gas is not the cross-sectional area of the groove provided on the lower surface of the intake flow control valve. The amount of exhaust gas introduced can be uniquely determined by the cross-sectional area near the outlet of the inlet. As a result, in an operating state that requires the largest amount of exhaust gas recirculation, the flow rate (recirculation amount) can be stably controlled by the cross-sectional area near the outlet of the exhaust gas inlet. Therefore, a good fuel consumption state of the internal combustion engine can be maintained.

  In the intake device for an internal combustion engine according to the above aspect, the groove preferably has a cross-sectional shape with an aspect ratio close to 1 so that the minimum cross-sectional area of the exhaust gas passage changes according to the opening of the intake flow control valve. Both the groove depth and the groove width of the groove part are changed in the state of having. If comprised in this way, at the time of opening degree control of an intake flow control valve, exhaust gas will be distribute | circulated to an exhaust-gas channel | path via the part of the groove part which has a square cross-sectional shape whose aspect ratio as minimum cross-section is close to 1. Can do. Thus, for example, unlike the case of a rectangular (thin groove) groove portion where the groove depth is large and the groove width is narrow, carbon deposits (carbon deposits) contained in the exhaust gas adhere to the groove portion and the groove portion is It can be made difficult to block.

  In the present application, the following configuration is also conceivable in the intake device for an internal combustion engine according to the above aspect.

(Additional notes)
That is, in the intake device for an internal combustion engine according to the above-described one aspect, the exhaust gas passage and the accommodating portion are horizontal or descending toward the downstream side of the intake passage, and the downstream end of the accommodating portion is the accommodating portion. And is connected to the inner surface of the intake passage. If comprised in this way, the water | moisture content (exhaust condensed water) contained in exhaust gas can be easily discharged | emitted to an intake passage side via an exhaust gas passage with exhaust gas.

  According to the present invention, as described above, it is possible to perform the optimal control of the intake flow control valve, and to suppress the decrease in the inertia supercharging effect to the minimum at any opening degree of the intake flow control valve. It is possible to provide an intake device for an internal combustion engine that can be used.

It is sectional drawing which showed the state by which the intake device by 1st Embodiment of this invention was attached to the engine. It is the disassembled perspective view which showed the whole structure of the intake device by 1st Embodiment of this invention. It is the perspective view which showed the structure of the valve main body which comprises the intake flow control valve integrated in the intake device by 1st Embodiment of this invention. It is a figure at the time of seeing the valve main body shown in FIG. 3 from the lower surface side in which the groove part was provided. It is sectional drawing which showed the structure around the valve body in the state in which the intake flow control valve was integrated in the intake device by 1st Embodiment of this invention. It is sectional drawing for demonstrating operation | movement (fully opened state) of the intake flow control valve in the intake device by 1st Embodiment of this invention. It is sectional drawing for demonstrating operation | movement (intermediate opening degree state) of the intake flow control valve in the intake device by 1st Embodiment of this invention. It is sectional drawing for demonstrating operation | movement (fully closed state) of the intake flow control valve in the intake device by 1st Embodiment of this invention. It is sectional drawing which showed the state with which the intake device by 2nd Embodiment of this invention was attached to the engine. It is sectional drawing for demonstrating operation | movement (fully closed state) of the intake flow control valve integrated in the intake device by 2nd Embodiment of this invention. It is sectional drawing which showed the state with which the intake device by 3rd Embodiment of this invention was attached to the engine. It is a figure at the time of seeing the valve body which constitutes the intake flow control valve built in the intake device by a 3rd embodiment of the present invention from the undersurface side in which the slot was provided. It is sectional drawing which showed the state with which the intake device by 4th Embodiment of this invention was attached to the engine. It is sectional drawing for demonstrating operation | movement (fully opened state) of the intake flow control valve integrated in the intake device by 4th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
With reference to FIGS. 1-8, the structure of the intake device 90 by 1st Embodiment of this invention is demonstrated.

  The intake device 90 according to the first embodiment of the present invention is provided in an in-line four-cylinder engine 100 for an automobile as shown in FIG. In addition, as shown in FIG. 2, the intake device 90 includes a surge tank 10 and an intake port 20 connected to the outlet side of the surge tank 10 (downstream side in the flow direction of intake air). The intake port 20 has an intake passage 20 a branched into four from the surge tank 10. An intake flow control valve 30 is incorporated in the vicinity of the outlet of each intake passage 20a. Structurally, the resin surge tank 10 and the four intake ports 20 are integrally formed by vibration welding. The open end 21 of the intake port 20 is connected to the cylinder head 203 of the engine 100. The engine 100 is an example of the “internal combustion engine” in the present invention.

  A cylinder head 203 is connected to the upper end of a cylinder block 202 containing the piston 201. In each cylinder head 203, an intake valve 204 that intakes air into the combustion chamber 203a, an exhaust valve 205 that discharges combustion gas, an ignition plug 206 that ignites the mixture in the combustion chamber 203a, and fuel into the combustion chamber 203a. An injector (not shown) is provided. During the intake operation of the piston 201, the intake valve 204 is opened to intake air into the combustion chamber 203a, and fuel is supplied from the injector to the combustion chamber 203a. Following the compression operation, the spark plug 206 ignites the air-fuel mixture in the combustion chamber 203a to perform combustion, and the expansion force due to this combustion is transmitted from the piston 201 to a crankshaft (not shown). In engine 100, power is extracted from the crankshaft.

  In addition, engine 100 includes an intake system that is disposed on the upstream side including intake device 90. In the intake system, an air cleaner (not shown), an air duct (not shown), and a throttle valve (not shown) are connected in this order along the flow direction of intake air. A throttle valve is connected to an inlet (not shown) of the surge tank 10.

  The engine 100 also supports EGR (Exhaust Gas Recirculation), which recirculates a part of the exhaust gas exhausted from the combustion chamber 203a to the intake system. Specifically, as shown in FIG. 1, the intake port 20 is provided with one EGR chamber 22 across an intake passage 20a and a partition wall (accommodating portion 25 described later). Further, an EGR introduction path 23 extending from the EGR chamber 22 toward each intake passage 20a is provided. An EGR pipe 42 extending from the EGR valve 41 is connected to the bottom of the EGR chamber 22. Thus, the exhaust gas that has passed through the EGR pipe 42 is configured to be introduced into the corresponding intake passage 20a through each EGR introduction path 23 after the EGR chamber 22 is filled.

  By applying EGR to the engine 100, the pumping loss (intake and exhaust loss) is reduced and the fuel consumption rate is improved. However, the amount of exhaust gas introduced (EGR rate) varies depending on the operating state (rotation speed and load state) of engine 100. A relatively large EGR rate is preferable for reducing pumping loss when the engine 100 is operated in a low engine speed range and a low load state. Further, it is preferable that the EGR rate is relatively low when the engine 100 is operated in a high speed range and a high load state in order to obtain a high output.

  In addition, the intake device 90 is configured to be able to control the degree of deflection of the intake air flowing through the intake passage 20a by the intake air flow control valve 30. That is, when the intake flow control valve 30 is opened and closed, the cross-sectional shape (flow passage cross-sectional area) of the intake passage 20a is controlled, and a predetermined air flow shape is imparted to the intake air supplied to the combustion chamber 203a. In engine 100, a vertical vortex (tumble flow) is created in combustion chamber 203a in a predetermined rotational speed range (load state). Further, by controlling the tumble flow in the combustion chamber 203a, the combustion efficiency of the mixed air is improved, leading to improvement of exhaust gas components including nitrogen oxides. Therefore, intake flow control valve 30 is configured to be appropriately (optimally) controlled in accordance with the operating state (rotation speed and load state) of engine 100.

  Specifically, as shown in FIG. 2, the intake device 90 is provided with an actuator 50 that drives the intake flow control valve 30 and a sensor unit 60 that detects the opening degree of the intake flow control valve 30. . The engine 100 includes an ECU (control unit) (not shown), and the opening degree of the intake flow control valve 30 detected by the sensor unit 60 is grasped on the ECU side. Then, by driving the actuator 50 based on the opening information of the intake flow control valve 30, the posture of the intake flow control valve 30 is set to an optimum opening according to the operating state (load state) of the engine 100. Control is performed.

  Here, the structure around the intake flow control valve 30 will be briefly described. As shown in FIG. 2, the four intake ports 20 are formed with through holes 24 that pass through each of them continuously in the X direction. The through hole 24 is arranged slightly upstream (Y2 side) from the opening end 21. In addition, the intake flow control valve 30 has four valve bodies 31 connected to each other via a rotating shaft 32. In addition, a bearing member 33 is rotatably fitted to each rotation shaft 32. The entire intake flow control valve 30 including the frame member 34 is incorporated into the intake port 20 with the bearing member 33 fitted in the frame member 34. The actuator 50 is attached to the outer surface of the intake port 20 closest to the X1 side, and the sensor unit 60 is attached to the outer surface of the intake port 20 closest to the X2. At this time, the intake flow control valve 30 and the actuator 50 are connected via a shaft member 51, and the intake flow control valve 30 and the sensor unit 60 are connected via a shaft member 52. Then, the rotation shaft 32 is rotatably held by the spacer 91 inserted in the arrow Y2 direction from the opening end 21 side. The opening end 21 of the intake port 20 is fastened to the cylinder head 203 (see FIG. 1) via a gasket 92. The valve body 31 is an example of the “intake flow control valve” in the present invention.

  Next, a detailed structure around the valve body 31 in a state where the intake flow control valve 30 is incorporated in the intake port 20 will be described.

  As shown in FIGS. 2, 3, and 5, the resin valve body 31 has a U-shaped cross-sectional shape when viewed along the intake flow direction (the direction of the arrow Y <b> 1). That is, the valve body 31 has a pair of support portions 31b each having a shaft portion 31a on each of the X1 side and the X2 side, and end portions of the support portion 31b opposite to the shaft portion 31a in the lateral direction (X direction). And a main valve portion 31c to be connected. As shown in FIG. 5, the main valve portion 31c has a flat upper surface 31d and a lower surface 31e protruding in a convex shape on the opposite side of the upper surface 31d. As shown in FIG. 3, the lower surface 31e has an arc shape having a predetermined radius of curvature around the shaft portion 31a. The lower surface 31e extends in an arc shape along the approximate Y direction.

  Further, as shown in FIGS. 5 and 6, the intake port 20 is provided with a housing portion 25 having an inner bottom surface 25a so as to correspond to the position where the valve body 31 (see FIG. 1) is disposed. The inner bottom surface 25 a of the housing part 25 has a concave arc shape with a predetermined radius of curvature centering on the shaft part 31 a of the valve body 31. That is, the convex arc shape of the lower surface 31 e of the main valve portion 31 c corresponds to the concave arc shape of the inner bottom surface 25 a of the housing portion 25. The cross-sectional shape of the main valve portion 31 c corresponds to the cross-sectional shape of the space of the housing portion 25. Thereby, the accommodating part 25 is comprised so that the main valve part 31c rotated centering on the axial part 31a of the upper part (Z1 side) may be accommodated. In addition, the intake passage 20a has an inner surface 20b having no noticeable unevenness as a portion other than the inner bottom surface 25a of the accommodating portion 25.

  The valve body 31 is rotated in the arrow P direction or the arrow Q direction around the shaft portion 31a in the intake passage 20a. Specifically, when the actuator 50 (see FIG. 2) is operated, the valve main body 31 is in a fully open state (opening posture) shown in FIG. 6 and an intermediate opening state (posture control state) shown in FIG. Control is performed steplessly to an arbitrary posture between the fully closed state (posture control state) shown in FIG.

  Assume that the valve main body 31 is rotated in the direction of the arrow Q from the fully closed state shown in FIG. 8 to be described later and controlled to the fully open state (opening posture) shown in FIG. In this case, the main valve portion 31 c is completely accommodated (retracted) in the accommodating portion 25. Further, the upper surface 31d of the main valve portion 31c is flush with the inner surface 20b of the intake passage 20a. That is, the entire region of the lower surface 31e of the main valve portion 31c including the upstream end portion 31f and the downstream end portion 31g is hidden in the accommodating portion 25. Therefore, in the fully open state (see FIG. 6), the cross-sectional shape (passage cross-sectional area of the intake air flow) of the intake passage 20a is maximized. As a result, the intake air is drawn into the combustion chamber 203a (see FIG. 1) without controlling the airflow by the valve body 31.

  Further, it is assumed that the valve body 31 is rotated in the arrow P direction from the state shown in FIG. 6 with the operation of the actuator 50 (see FIG. 2). In this case, the main valve portion 31c rises obliquely in the direction of the arrow Z1 from the housing portion 25 toward the downstream side (Y1 side). That is, in the main valve portion 31c, the downstream end portion 31g gradually protrudes from the housing portion 25 into the intake passage 20a to the state shown in FIG. 8 through the state shown in FIG. Therefore, in the posture control state shown in FIGS. 7 and 8, the cross-sectional shape of the intake passage 20a (the cross-sectional area of the intake flow) is reduced according to the inclination of the main valve portion 31c.

  As shown in FIG. 8, when the downstream end portion 31g of the valve body 31 protrudes the maximum amount from the accommodating portion 25, the upper surface 31d of the main valve portion 31c has a maximum angle with respect to the inner surface 20b of the intake passage 20a. Be inclined. That is, the gap between the downstream end portion 31g of the main valve portion 31c and the inner surface 20c on the Z1 side of the intake passage 20a is most narrowed. In this case, the cross-sectional shape (passage cross-sectional area of the intake air flow) of the intake passage 20a is minimized. In addition, by reducing the cross-sectional area of the intake passage 20a, the intake air is air-flow controlled to create a tumble flow (longitudinal vortex (deflection flow)). Thereby, in the engine 100, the mixed air is combusted in a state where a tumble flow is created in the combustion chamber 203a (see FIG. 1).

  A control table (control map) (not shown) for causing the above-described airflow control by the intake flow control valve 30 to function is stored in advance in a storage area in the ECU. In the control table, the opening degree of the intake flow control valve 30 corresponding to the operating state (the rotational speed range and the load state) of the engine 100 is set. The actuator 50 is driven based on the opening setting information referred to in the control table, so that the attitude of the valve body 31 is optimally controlled. Further, the opening degree information of the valve body 31 detected by the sensor unit 60 is fed back to the drive control, whereby the posture control of the intake flow control valve 30 is repeatedly performed.

  Note that when the engine 100 is operated in a relatively low engine speed range and a low load state, the valve main body 31 is controlled to be closed, and the intake air having a tumble flow is mixed with fuel and burned. On the contrary, when the engine 100 is operated in a relatively high engine speed range and a high load state, the valve body 31 is controlled to be in the open state, and the intake air with the reduced tumble flow ratio is mixed with the fuel. Burned. Opening degree setting information for performing such control is set in the control table.

  Here, in the first embodiment, during the operation of the engine 100, the exhaust gas is introduced into the intake passage 20a by using the airflow control of the intake flow by the intake flow control valve 30 and the rotation operation of the valve body 31. Configured to recirculate.

  Specifically, as shown in FIGS. 1 and 6, the inner bottom surface 25 a of the housing portion 25 is provided with an opening 23 a through which the EGR introduction path 23 opens. The opening 23a has a circular cross section having an inner diameter A (see FIG. 6) and a cross section orthogonal to the direction in which the exhaust gas flows. Moreover, the opening part 23a is arrange | positioned at the downstream end part 25b (refer FIG. 6) of the accommodating part 25, and the EGR introduction path 23 has penetrated the inner bottom face 25a toward diagonally upward from diagonally downward. Then, when the valve main body 31 (main valve portion 31c) is rotated in the arrow P direction with respect to the accommodating portion 25 from the fully opened state shown in FIG. 6, as shown in FIGS. The exhaust gas passage including the opening is configured to open toward the intake passage 20a. As a result, the intake device 90 is configured to be capable of simultaneously controlling whether or not the exhaust gas is introduced into the intake passage 20a as well as controlling the flow of the intake air. Further, the exhaust gas introduction amount (EGR rate) can be controlled (increased or decreased) according to the opening degree of the intake flow control valve 30. The opening 23a is an example of the “exhaust gas inlet” in the present invention.

  More specifically, as shown in FIGS. 3 to 5, the valve main body 31 is provided with a groove portion 35 for constituting an exhaust gas passage. The groove part 35 is provided in the lower surface 31e of the valve body 31 (main valve part 31c) facing the housing part 25 (see FIG. 6). Moreover, the groove part 35 is extended along the rotation direction (arrow P direction) of the valve main body 31 in the lower surface 31e. That is, as shown in FIGS. 3 and 4, the groove 35 extends in the direction of the arrow P starting from a portion between the upstream end 31f and the downstream end 31g on the lower surface 31e. And the groove part 35 extends to the near side of the downstream edge part 31g, and reaches an end point. Moreover, the groove part 35 is extended along the convex circular arc shape which the lower surface 31e has.

  In addition, as shown in FIG. 6, the groove 35 is connected to the opening 23 a of the EGR introduction path 23 of the accommodating portion 25, and a space (exhaust gas) is formed between the main valve portion 31 c and the accommodating portion 25 by the groove 35. A passage) is formed. Therefore, the intake port 20 has exhaust gas that has passed through the opening 23a having the inner diameter A in a region facing the concave inner bottom surface 25a of the accommodating portion 25 and the convex lower surface 31e of the valve body 31 (main valve portion 31c). The exhaust gas passage is formed so as to circulate and discharge to the intake passage 20a. At this time, the shape of the groove portion 35 is formed so that the minimum cross-sectional area S (see FIG. 7) of the exhaust gas passage is changed according to the opening degree of the main valve portion 31c.

  That is, as shown in FIG. 4, the groove part 35 has the inlet part 35a formed in the upstream edge part 31f side, and the outlet part 35b formed in the downstream edge part 31g side. The inlet portion 35a has a groove depth D1 and a groove width W1. Further, the outlet portion 35b has a groove depth D2 and a groove width W2 that are smaller than those of the inlet portion 35a. Then, by changing both the groove depth D (see FIG. 5) and the groove width W (see FIG. 5) of the groove 35, the groove 35 has a minimum cross-sectional area S of the exhaust gas passage so that the opening degree of the valve body 31 is increased. It is comprised so that it may change according to.

  Further, as shown in FIG. 5, the groove portion 35 changes both the groove depth D and the groove width W in a state where the aspect ratio (D to W) has a square cross-sectional shape close to 1. In FIG. 4, the groove depth D1: groove width W1 = 1: 1 at the entrance 35a. Further, also in the outlet portion 35b, the groove depth D2: the groove width W2 = 1: 1. Also, the aspect ratio is maintained at 1 in the intermediate portion 35c between the inlet portion 35a and the outlet portion 35b. In FIG. 4, since the lower surface 31 e having an arc shape is seen in a plan view, the aspect ratio of the groove portion 35 is shown to be apparently not 1. Further, as shown in FIG. 5, both end portions (X direction) of the inner side surface 35d of the groove portion 35 have rounded shapes, and the inner side surface 35d of the groove portion 35 has an inverted U-shaped cross-sectional shape when viewed in the Y direction. have.

  Moreover, in 1st Embodiment, the opening degree of the valve main body 31 (main valve part 31c) and the magnitude | size (cross-sectional area) of the groove part 35 have the following relationship. In other words, when the main valve portion 31c is rotated to a predetermined position, the channel cross-sectional area of the groove 35 at the position where the opening 23a faces (the minimum cross-sectional area of the cross section orthogonal to the direction in which the exhaust gas flows). S) is determined as follows.

  Specifically, as shown in FIG. 6, first, the shape of the groove 35 is set so that the minimum cross-sectional area S of the exhaust gas passage is minimized (in this case, zero) when the opening of the valve body 31 is fully open. Is formed. That is, when the opening degree of the valve body 31 (main valve portion 31c) is fully open and in the vicinity thereof, the downstream end portion 31g of the groove portion 35 and the intake passage 20a are closed without being communicated. Thus, the exhaust gas is configured not to be introduced into the intake passage 20a when the opening of the valve body 31 is in the vicinity of the fully open position.

  Next, contrary to the above, as shown in FIG. 8, the shape of the groove 35 is formed so that the minimum cross-sectional area S of the exhaust gas passage is maximized when the valve body 31 is fully closed. Has been. When the valve body 31 is fully closed, the exhaust gas passage is configured to have a minimum cross-sectional area S (maximum value) at a boundary portion of the exhaust gas passage with the EGR introduction passage 23. That is, the cross-sectional area of the opening 23a having the inner diameter A is smaller than the cross-sectional area of the groove 35 when the valve body 31 is fully closed. That is, the exhaust gas introduction amount when the valve main body 31 is in the fully closed state is regulated by the cross-sectional area of the opening 23 a having the inner diameter A, not the cross-sectional area in the vicinity of the inlet 35 a of the groove 35. Thereby, when the opening degree of the valve main body 31 is in the fully closed state, the exhaust gas that has passed through the opening 23a having the inner diameter A is guided to the intake passage 20a without the flow rate being suppressed by the groove 35. .

  Further, in the first embodiment, as the opening degree of the valve main body 31 (main valve portion 31c) increases from the state of FIG. 8 to the state of FIG. 6 through the state of FIG. The shape of the groove 35 is configured so that S continuously decreases from the maximum value to the minimum value. That is, as shown in FIG. 3 and FIG. 4, the groove portion 35 has a U-shaped (square shape) inner side surface 35 d continuously from the inlet portion 35 a having the largest sectional area toward the outlet portion 35 b having the smallest sectional area. It is formed in a shape that decreases to a minimum. Accordingly, the opening degree of the valve body 31 is increased from the state of FIG. 8 to increase the cross-sectional area of the intake passage 20a, and the introduction amount of exhaust gas into the intake passage 20a (exhaust gas recirculation amount) is continuous. Will be reduced. For example, as shown in FIG. 7, when the opening degree of the valve body 31 is in an intermediate opening state, the exhaust gas that has passed through the opening 23a is the minimum of the exhaust gas passage of the groove 35 at the rotation position. The flow rate is suppressed by the cross-sectional area S, and the air is guided to the intake passage 20a. On the other hand, the opening of the valve body 31 is decreased from the state of FIG. 6 to reduce the cross-sectional area of the intake passage 20a, and the amount of exhaust gas introduced into the intake passage 20a (exhaust gas recirculation amount). Is continuously increased. In FIG. 4, the relative movement trajectory of the opening 23a when the valve body 31 is rotated is indicated by a one-dot chain line.

  As described above, when the engine 100 is operated in a relatively low engine speed range and a low load state, the intake flow control valve 30 is controlled so that the valve body 31 is closed, and the tumble flow is made together with the exhaust gas. The intake air having is mixed with the fuel. Therefore, both reduction of the pumping loss and improvement of the combustion efficiency of the mixed air can be achieved. Further, when the engine 100 is operated in a relatively high engine speed range and a high load state, the valve body 31 is controlled to be in an open state, and the intake air in which the ratio of the tumble flow is reduced without introducing exhaust gas. Air is mixed into the fuel. Therefore, engine 100 is operated in a state where the reduction of inertial supercharging effect (decrease in output of engine 100) is suppressed and high output is the highest priority.

  In addition to the above, when the valve body 31 is rotated to any intermediate position in response to the engine 100 being operated in the medium speed rotation range (medium load state), the valve body An amount of exhaust gas corresponding to the opening of 31 is introduced, and intake air having a tumble flow is mixed with fuel. Also at this time, regardless of the degree of opening of the valve body 31, the exhaust gas is always introduced through the portion having the minimum cross-sectional area S of the groove 35 (see, for example, FIG. 7) (recirculation amount). Minimized. That is, the expansion of the internal volume of the intake passage 20a associated with the communication between the intake passage 20a and the EGR introduction passage 23 (opening 23a) is always minimized. Therefore, engine 100 operated in the medium speed rotation region is configured such that a decrease in inertia supercharging effect (a decrease in output of engine 100) is suppressed to a minimum.

  In the control table (not shown) in the ECU, the opening degree of the intake flow control valve 30 (valve body 31) so that an optimum tumble flow (longitudinal vortex) is formed according to the operating state of the engine 100. Is defined. Then, the shape (groove depth D and groove width W) of the groove portion 35 is determined so as to obtain an optimum EGR rate (exhaust gas introduction amount) according to each opening degree of the intake flow control valve 30. As a result, the minimum required exhaust gas is supplied into the intake port 20 while minimizing the decrease in the inertia supercharging effect without compromising the optimal control of the intake flow using the intake flow control valve 30. Is configured to be possible.

  Further, as shown in FIG. 1, the exhaust gas passage and the accommodating portion 25 are inclined downward toward the downstream side of the intake passage 20a (the side closer to the combustion chamber 203a). And the downstream end 25b (refer FIG. 6) of the accommodating part 25 is the lowest point in the orthogonal | vertical direction of the accommodating part 25, and is connected to the inner surface 20b of the intake passage 20a. Thereby, the water (exhaust condensed water) contained in the exhaust gas is configured to be easily discharged to the intake passage 20a side through the exhaust gas passage (EGR introduction passage 23 and groove portion 35) together with the exhaust gas. In this way, the intake device 90 in the engine 100 is configured.

  In the first embodiment, the following effects can be obtained.

  In the first embodiment, as described above, the exhaust gas passage is connected to the lower surface 31e of the main valve portion 31c facing the housing portion 25 by the space between the opening portion 23a of the housing portion 25 and the housing portion 25. A groove portion 35 is provided. The groove portion 35 of the main valve portion 31c is formed in a shape such that the minimum cross-sectional area S of the exhaust gas passage changes according to the opening degree of the valve main body 31, and the minimum cross-sectional area S of the exhaust gas passage is the valve main body 31. The groove portion 35 is configured so that at least one of the groove depth and the groove width of the groove portion 35 changes so as to change according to the opening degree. Thus, unlike the case where the exhaust gas introduction amount is adjusted only in two stages according to the open / close state of the intake flow control valve 30, the intake flow control valve 30 is rotated to a desired opening degree to optimize the intake flow. Control can be performed. When the optimal control of the intake flow control valve 30 is performed, the exhaust gas always has the minimum cross-sectional area of the groove portion 35 of the lower surface 31e of the valve body 31 regardless of the opening degree of the valve body 31. The introduction amount is suppressed to a minimum through the portion having S. That is, the expansion of the internal volume of the intake passage 20a associated with the communication between the intake passage 20a and the EGR introduction passage 23 (opening 23a) can always be minimized, so that the intake flow control valve 30 can be opened at any opening degree. A decrease in inertia supercharging effect (a decrease in engine 100 output) can be minimized.

  Further, in the first embodiment, as described above, the exhaust gas according to the opening degree of the valve body 31 is provided by providing the valve body 31 with the groove portion 35 in which both the groove depth D and the groove width W change. The intake flow control valve 30 that changes the minimum cross-sectional area S of the passage can be easily obtained. As a result, the necessary minimum amount of exhaust gas can always be recirculated together with the optimal control of the intake flow control valve 30 without deteriorating the inertial supercharging effect.

  In the first embodiment, the housing portion 25 is configured to have a concave arc shape, and the lower surface 31e of the main valve portion 31c has a convex arc shape corresponding to the concave arc shape housing portion 25. Configure. Further, the upper surface 31d of the main valve part 31c is rotated around the turning shaft 32 (shaft part 31a) positioned above the housing part 25 so that the opening degree of the valve body 31 is fully opened. The valve body 31 is provided so as to be flush with the inner surface 20b of the valve. And the groove part 35 is provided in the convex circular-arc-shaped lower surface 31e of the main valve part 31c so that it may extend along the rotation direction of the valve main body 31. FIG. Thereby, the minimum cross-sectional area S of the groove part 35 changes in the opposing area | region of the concave inner bottom face 25a of the accommodating part 25 and the convex lower surface 31e of the main valve part 31c according to the rotation attitude | position of the valve main body 31. A simple exhaust gas passage can be easily formed. That is, by using the intake flow control 30 that changes the cross-sectional shape (passage cross-sectional area of the intake flow) of the intake passage 20a by posture control, the operating condition of the engine 100 is reduced while minimizing the decrease in the inertia supercharging effect. Accordingly, the optimum control of the intake air flow and the optimum control of the exhaust gas introduction amount can be made compatible.

  In the first embodiment, the minimum cross-sectional area S of the exhaust gas passage is minimized when the opening of the valve body 31 (main valve portion 31c) is fully open, and the valve body 31 (main valve portion 31c) The shape of the groove 35 is configured so that the minimum cross-sectional area S of the exhaust gas passage is maximized when the opening is fully closed. As a result, when the engine 100 is in a high output range, the opening degree of the valve body 31 (intake flow control valve 30) is fully opened to suppress a decrease in the inertia supercharging effect (a decrease in the output of the engine 100) while minimizing the opening. A limited amount of exhaust gas can be recirculated to improve fuel efficiency. Further, when the engine 100 is in a low output range, the opening of the valve body 31 is fully closed and the exhaust gas is recirculated to the maximum, so that pumping loss (intake and exhaust loss) can be reduced. . As a result, the fuel efficiency of the engine 100 can always be improved while suppressing a decrease in the inertia supercharging effect from the low output range to the high output range to a minimum.

  Moreover, in 1st Embodiment, the shape of the groove part 35 is comprised so that the minimum cross-sectional area S of an exhaust gas passage may reduce continuously, as the opening degree of the valve main body 31 (main valve part 31c) increases. As a result, the opening of the valve body 31 is increased to increase the cross-sectional area of the intake passage 20a, and the introduction amount (recirculation amount) of exhaust gas into the intake passage 20a is continuously and continuously reduced. Can do. That is, the amount of exhaust gas introduced into the intake passage 20a between the fully closed state of the valve body 31 that controls the intake flow largely by narrowing the cross-sectional area of the intake passage 20a and the fully open state that hardly controls the intake flow. (Recirculation amount) can be finely adjusted. As a result, the engine 100 can always be operated under an optimal combustion state while minimizing a decrease in the inertia supercharging effect.

  In the first embodiment, the groove 35 is formed so as to extend from a portion between the upstream end 31f and the downstream end 31g of the lower surface 31e of the main valve portion 31c to a position before the downstream end 31g. To do. And in the state which the opening degree of the valve main body 31 is a full open vicinity, it comprises so that the downstream edge part 31g of the groove part 35 and the intake passage 20a may not communicate. Thereby, it is possible to prevent the intake passage 20a, the exhaust gas passage (groove portion 35), and the EGR introduction passage 23 from communicating with each other when the opening of the valve body 31 is in the vicinity of the fully open position. That is, the increase in the internal volume of the intake passage 20a associated with the communication between the intake passage 20a and the exhaust gas passage (EGR introduction passage 23) is prevented, so that the inertia supercharging effect is surely reduced in the high output region of the engine 100. Can be prevented. Therefore, the engine 100 can reliably exhibit a high output.

  In the first embodiment, the portion having the minimum cross-sectional area of the exhaust gas passage when the opening of the valve body 31 is fully closed is a boundary portion with the EGR introduction passage 23 in the exhaust gas passage. That is, the exhaust gas introduction amount when the opening degree of the valve body 31 is fully closed is uniquely determined by the opening 23a. As a result, when the valve main body 31 is fully closed (the passage cross-sectional area of the intake passage 20a is most reduced), not the cross-sectional area of the groove 35 provided in the lower surface 31e of the valve main body 31 but the EGR introduction path 23 The exhaust gas introduction amount can be uniquely determined by the cross-sectional area in the vicinity of the opening 23a. As a result, in an operating state that requires the largest amount of exhaust gas recirculation, the flow rate (recirculation amount) can be stably controlled by the cross-sectional area near the opening 23 a of the EGR introduction path 23. Therefore, a good fuel economy state of engine 100 can be maintained.

  In the first embodiment, the aspect ratio is close to 1 so that the minimum cross-sectional area S of the exhaust gas passage changes according to the opening of the valve body 31 (main valve portion 31c). Both the groove depth D and the groove width W of the groove part 35 are changed. Thus, when the opening degree of the valve body 31 is controlled, the exhaust gas passes through the portion of the groove portion 35 having a square cross-sectional shape in which the aspect ratio (groove depth D: groove width W) as the minimum cross-sectional area is close to 1: 1. Can be circulated through the exhaust gas passage. Accordingly, for example, unlike the case of a rectangular (thin groove) groove portion where the groove depth D is large and the groove width W is narrow, carbon deposits (carbon deposits) contained in the exhaust gas are fixed to the groove portion 35. Thus, it is possible to make it difficult to close the groove 35.

  In the first embodiment, the exhaust gas passage and the accommodating portion 25 that constitute the groove portion 35 are inclined downward toward the downstream side of the intake passage 20a, and the downstream end portion 31g of the accommodating portion 25 is accommodated. The intake device 90 is configured to be the lowest point of the portion 25 and to be connected to the inner surface 20b of the intake passage 20a. Thus, moisture (exhaust condensed water) contained in the exhaust gas can be easily discharged to the intake passage 20a side along with the exhaust gas through the exhaust gas passage.

(Second Embodiment)
The second embodiment will be described with reference to FIGS. 6, 9 and 10. The second embodiment is different from the first embodiment in which the exhaust gas passage is closed while the opening of the valve body 31 (see FIG. 6) is in the vicinity of the fully open position. That is, an example in which the intake flow control valve 230 is configured so that the exhaust gas passage communicates with the intake passage 20a even when the valve body 231 (main valve portion 231c) is in the vicinity of the fully open position (see FIG. 10) will be described. . The valve body 231 is an example of the “intake flow control valve” in the present invention. In the drawing, the same reference numerals as those in the first embodiment are attached to the same components as those in the first embodiment.

  The engine 200 according to the second embodiment of the present invention includes an intake device 290. Further, as shown in FIG. 9, in the intake device 290, an intake flow control valve 230 is incorporated in the intake port 20. The intake flow control valve 230 includes four valve bodies 231. The engine 200 is an example of the “internal combustion engine” in the present invention.

  Here, in the second embodiment, as shown in FIG. 10, each valve main body 231 is provided with a groove portion 235 constituting an exhaust gas passage on the lower surface 231 e. Moreover, the groove part 235 is extended from the part between the upstream edge part 231f and the downstream edge part 231g in the lower surface 231e to the downstream edge part 231g. Therefore, the downstream end 231g of the groove 235 and the intake passage 20a communicate with each other even when the valve body 231 is fully open.

  As a result, when the engine 200 is operated in a high rotational speed range and a high load state, the valve main body 231 is controlled to be in an open state, and a minimum amount of exhaust gas enters the intake passage 20a via the groove portion 235. be introduced. Therefore, in the engine 200, even in an operating state in which a decrease in the inertia supercharging effect is suppressed and a high output is obtained, the fuel consumption (fuel consumption rate) is improved as much as the pumping loss (intake and exhaust loss) is reduced. It is configured as follows. In addition, the other structure of the intake device 290 by 2nd Embodiment is the same as that of the said 1st Embodiment.

  In the second embodiment, the following effects can be obtained.

  In the second embodiment, as described above, the groove portion 235 is extended so as to extend from the portion between the upstream end portion 231f and the downstream end portion 231g of the lower surface 231e of the main valve portion 231c to the downstream end portion 231g. Form. In addition, the downstream end 231g of the groove 235 and the intake passage 20a communicate with each other even when the valve body 231 (main valve 231c) is fully open. As a result, even when the main valve portion 231c is fully opened and the cross-sectional area of the intake passage 20a is maximized, the downstream end 231g of the groove portion 235 having the minimum cross-sectional area S and communicating with the intake passage 20a is reduced. The exhaust gas can be introduced into the intake passage 20a. Therefore, fuel consumption can be easily improved by recirculating a minimum amount of exhaust gas while minimizing a decrease in inertia supercharging effect (a decrease in engine 200 output) in a high output range of engine 200.

  Moreover, in 2nd Embodiment, the groove part 235 is formed so that it may extend from the part between the upstream edge part 231f and the downstream edge part 231g among the lower surfaces 231e of the main valve part 231c to the downstream edge part 231g. Thereby, even when the main valve portion 231c is fully opened, an exhaust gas passage for introducing a small amount (minimum amount) of exhaust gas into the intake passage 20a is easily provided on the valve body 231 (main valve portion 231c) side. Can be provided. The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

(Third embodiment)
The third embodiment will be described with reference to FIGS. 4, 11, and 12. This third embodiment is different from the first embodiment in which the shape of the groove 35 (see FIG. 4) is configured so that the minimum cross-sectional area S of the exhaust gas passage continuously decreases. That is, an example will be described in which a groove 335 (see FIG. 12) in which the minimum cross-sectional area S of the exhaust gas passage decreases stepwise is formed in the valve body 331. The valve body 331 is an example of the “intake flow control valve” in the present invention. In the drawing, the same reference numerals as those in the first embodiment are attached to the same components as those in the first embodiment.

  The engine 300 according to the third embodiment of the present invention includes an intake device 390. As shown in FIG. 11, the intake device 390 has an intake flow control valve 330 incorporated in the intake port 20. The intake air flow control valve 330 includes four valve bodies 331. Engine 300 is an example of the “internal combustion engine” in the present invention.

  Further, as shown in FIG. 12, each valve body 331 (main valve portion 331c) is provided with a groove portion 335 constituting an exhaust gas passage on the lower surface 331e. The groove portion 335 has an inlet portion 335a formed on the upstream end portion 331f side and an outlet portion 335b formed on the downstream end portion 331g side. The inlet portion 335a has a groove depth D1 and a groove width W1. The outlet portion 335b has a groove depth D2 and a groove width W2 that are smaller than those of the inlet portion 335a. Moreover, the groove part 335 is extended from the part between the upstream edge part 331f and the downstream edge part 331g in the lower surface 331e to the downstream edge part 331g. The main valve portion 331c is an example of the “intake flow control valve” in the present invention.

  Here, in the third embodiment, the shape of the groove portion 335 is configured such that the minimum cross-sectional area S of the exhaust gas passage decreases stepwise as the opening of the valve body 331 increases. That is, the groove portion 335 is intermediate between the inlet portion 335a and the outlet portion 335b in addition to the inlet portion 335a having the groove depth D1 and the groove width W1 and the outlet portion 335b having the groove depth D2 and the groove width W2. The intermediate portion 335c has a groove depth D3 and a groove width W3. Further, in the vicinity of the inlet portion 335a, the groove depth D1 and the groove width W1 are maintained by a certain distance in the direction of the arrow Y1. In the vicinity of the intermediate portion 335c, the groove depth D3 and the groove width W3 are maintained by a certain distance in the arrow Y1 direction. Finally, in the vicinity of the outlet 335b, the groove depth D2 and the groove width W2 are maintained for a certain distance in the direction of the arrow Y1. It should be noted that the ratio of the extending distances of the inlet portion 335 a, the intermediate portion 335 c, and the outlet portion 335 b on the lower surface 331 e can be appropriately changed depending on the characteristics of the engine 300.

  Moreover, the groove part 335 is extended from the part between the upstream edge part 331f and the downstream edge part 331g in the lower surface 331e to the downstream edge part 331g. Therefore, even when the valve body 331 is fully open, the downstream end 331g of the groove 335 and the intake passage 20a communicate with each other.

  As a result, in the engine 300 (see FIG. 11), as shown in FIG. 12, the opening of the valve body 331 is opened until the valve body 331 is fully open and is inclined between the fully open state and the first angle range. The portion 23a (indicated by the alternate long and short dash line) faces the portion of the groove portion 335 (region near the outlet portion 335b) corresponding to the groove depth D2 and the groove width W2. The minimum value of the minimum cross-sectional area S of the exhaust gas passage is maintained. Further, in a state where the opening degree of the valve body 331 is further tilted within the second angle range that is larger than the first angle range, the opening 23a has a groove 335 corresponding to the groove depth D3 and the groove width W3. Opposite the portion (region near the intermediate portion 335c). The minimum cross-sectional area S of the exhaust gas passage is maintained at an intermediate size larger than the minimum value. In the fully closed state in which the opening of the valve body 331 reaches the third angle range larger than the second angle range and reaches its maximum value, the opening 23a corresponds to the groove depth D1 and the groove width W1. It faces the portion of the groove portion 335 (region near the inlet portion 335a). The minimum cross-sectional area S of the exhaust gas passage is maintained at the maximum value (in this case, the cross-sectional area of the opening 23a).

  In this way, the exhaust gas introduction amount (EGR rate) into the intake passage 20a according to the opening of the valve body 331 is configured to increase or decrease in stages (three stages). In FIG. 12, the relative movement trajectory of the opening 23a when the valve body 331 is rotated is indicated by a one-dot chain line. In addition, the other structure of the intake device 390 by 3rd Embodiment is the same as that of the said 2nd Embodiment.

  In the third embodiment, the following effects can be obtained.

  In the third embodiment, as described above, the groove portion 335 is formed so that the minimum cross-sectional area of the exhaust gas passage decreases stepwise (three steps) as the opening of the valve main body 331 (main valve portion 331c) increases. Configure the shape. Thus, the opening of the valve body 331 is increased to increase the cross-sectional area of the intake passage 20a, and the introduction amount of exhaust gas into the intake passage 20a (exhaust gas recirculation amount) is decreased stepwise. Can do. That is, in the engine 300 that optimally controls the opening degree of the intake flow control valve 330 in a multi-stage (three-stage) system, the exhaust gas recirculation amount corresponding to the multi-stage opening degree control of the intake flow control valve 330 Can be easily controlled. The remaining effects of the third embodiment are similar to those of the aforementioned second embodiment.

(Fourth embodiment)
The fourth embodiment will be described with reference to FIGS. 4, 10, 13, and 14. In the fourth embodiment, an example in which the groove portion 436 is formed also on the housing portion 425 side will be described. In the figure, components similar to those in the first and second embodiments are denoted by the same reference numerals as those in the first and second embodiments.

  The engine 400 according to the fourth embodiment of the present invention includes an intake device 490. As shown in FIG. 13, the intake device 490 has an intake flow control valve 30 incorporated in the intake port 20. The engine 400 is an example of the “internal combustion engine” in the present invention.

  Here, in 4th Embodiment, as shown in FIG. 14, the groove part 436 is formed also in the accommodating part 425 side. The groove portion 436 is an elongated channel in which an end region 425b located on the most downstream side of the housing portion 425 is recessed downward from the downstream end portion 31g of the main valve portion 31c with a predetermined interval. Further, an exhaust gas passage for discharging the exhaust gas having passed through the opening 23a to the intake passage 20a is formed by the groove 436.

  Thereby, even when the opening degree of the valve main body 31 (main valve portion 31c) is fully open, the opening 23a of the EGR introduction path 23, a part of the groove 35, the groove 436, and the intake passage 20a communicate with each other. It is configured as follows. The groove portion 436 has a groove depth and a groove width in a state where the groove portion 436 has a square cross-sectional shape with an aspect ratio close to 1, as with the groove portion 35. Further, the groove depth and the groove width of the groove part 436 linearly extend to the intake passage 20a so as to take over the groove depth D2 and the groove width W2 (see FIG. 4) at the outlet part 35 of the groove part 35.

  As a result, in the engine 400, as in the case of the engine 200 (see FIG. 10) in the second embodiment, the valve body 231 is controlled to be in the open state when the engine 400 is operated in a high speed range and a high load state. In addition, a minimum amount of exhaust gas is introduced into the intake passage 20a through the groove 436. Therefore, the engine 200 is configured to improve fuel consumption as much as the pumping loss is reduced even in a high-power operating state in which the decrease in the inertia supercharging effect is minimized. In addition, the other structure of the intake device 490 by 4th Embodiment is the same as that of the said 2nd Embodiment.

  In the fourth embodiment, the following effects can be obtained.

  In the fourth embodiment, as described above, even when the opening degree of the valve body 31 (main valve portion 31c) is fully open, the opening portion 23a of the EGR introduction path 23 and a part of the groove portion 35 via the groove portion 436. (In the vicinity of the outlet portion 35b), the groove portion 436, and the intake passage 20a are configured to communicate with each other. As a result, even when the main valve portion 31c is fully opened and the cross-sectional area of the intake passage 20a is maximized, the exhaust gas is discharged through the groove portion 436 having the minimum cross-sectional area S and communicating with the intake passage 20a. It can be introduced into the intake passage 20a. Therefore, fuel consumption can be easily improved by recirculating a minimum amount of exhaust gas while minimizing a decrease in inertia supercharging effect (a decrease in output of engine 400) in a high output range of engine 400.

  Further, in the fourth embodiment, the groove portion 436 is provided on the housing portion 425 side. As a result, an exhaust gas passage for introducing exhaust gas into the intake passage 20a when the main valve portion 31c is fully opened can be easily provided on the side of the housing portion 425. Further, under the situation where the intake device 490 is arranged so that the exhaust gas passage and the accommodating portion 25 are inclined downward toward the downstream side of the intake passage 20a (side closer to the combustion chamber 203a), the intake system of the engine 400 The groove 436 can be disposed at the lowermost part in the vertical direction. Thereby, the exhaust condensed water contained in the exhaust gas can be reliably discharged to the intake passage 20a side through the exhaust gas passage together with the exhaust gas. The remaining effects of the fourth embodiment are similar to those of the aforementioned second embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first to fourth embodiments, the example in which the intake devices 90 to 490 are applied to the in-line four-cylinder engines 100 to 400 for automobiles is shown, but the present invention is not limited to this. The intake device for an internal combustion engine of the present invention may be applied to a multi-cylinder engine other than an in-line four-cylinder engine, a V-type multi-cylinder engine, or the like. Further, the present invention may be applied not only to automobile engines but also to engines other than automobile engines. For example, the present invention may be applied to an intake device for an internal combustion engine (engine) mounted on equipment or the like. The internal combustion engine can be applied to any of gasoline engines, diesel engines, gas engines, and the like.

  In the first to fourth embodiments, the groove portions 35 to 335 have been described with respect to an example in which both the groove depth D and the groove width W are changed in a state in which the aspect ratio is close to 1. The present invention is not limited to this. That is, the minimum cross-sectional area S of the exhaust gas passage may be changed according to the opening degree of the valve body 31 by changing only the groove width W while keeping the groove depth D constant. Alternatively, only the groove depth D may be changed while keeping the groove width W constant, and the minimum cross-sectional area S of the exhaust gas passage may be changed according to the opening degree of the valve body 31.

  Moreover, in the said 1st-4th embodiment, although shown about the example which formed the EGR introduction path 23 so that it might penetrate the inner bottom face 25a of the accommodating part 25 from diagonally downward toward diagonally upward, this invention is shown to this. Not limited. That is, you may form the EGR introduction path 23 so that it may penetrate in the direction orthogonal to the inner bottom face 25a of the accommodating part 25. FIG.

  In the first to fourth embodiments, the example in which the intake devices 90 to 490 are arranged so that the exhaust gas passage and the accommodating portion 25 are inclined downward toward the downstream side of the intake passage 20a has been described. The invention is not limited to this. In other words, even when the engine (internal combustion engine) is mounted on the vehicle in a vertical or horizontal position, the intake device incorporating the intake flow control valve of the present invention can be mounted on the engine. Therefore, the mounting angle of the intake port 20 with respect to the cylinder head 203 may be in the horizontal direction or in the vertical direction.

  Moreover, although the said 1st-4th embodiment showed about the example which comprised the intake flow control valve 30 so that the vertical vortex (tumble flow) might be produced in the combustion chamber 203a, this invention is not limited to this. That is, if the intake flow control valve 30 is capable of controlling the degree of deflection of the intake flow, the intake flow control valve 30 may be configured so that a lateral vortex (swirl flow) is created in the combustion chamber 203a.

  Moreover, in the said 1st-4th embodiment, although the example which comprised the intake flow control valves 30-330 using the resin-made valve main bodies 31 (231, 331) was shown, this invention is not limited to this. . The intake flow control valve 30 may be configured using a metal valve body 31. That is, the groove portion 35 may be formed on the lower surface 31e of the main valve portion 31c by performing metal processing.

DESCRIPTION OF SYMBOLS 10 Surge tank 20 Intake port 20a Intake passage 20b Inner surface 23 EGR introduction path 23a Opening part (exhaust gas introduction port)
25, 425 Housing portion 25a Inner bottom surface 25b Downstream side end portion 30, 230, 330 Intake flow control valve 31, 231, 331 Valve body 31a Shaft portion 31b Support portion 31c, 231c, 331c Main valve portion (intake flow control valve)
31d Upper surface 31e, 231e, 331e Lower surface 31f, 231f, 331f Upstream end portion 31g, 231g, 331g Downstream end portion 32 Rotating shaft 35, 235, 335, 436 Groove portion 35a, 335a Inlet portion 35b, 335b Outlet portion 35c, 335c Intermediate part 42 EGR piping 50 Actuator 60 Sensor part 90, 290, 390, 490 Intake device 100, 200, 300, 400 Engine (internal combustion engine)

Claims (8)

An intake flow control valve that is rotatably provided in the intake passage of the internal combustion engine and controls the flow of intake air;
An accommodating portion provided in the intake passage and accommodating the intake flow control valve;
An exhaust gas inlet provided in the housing portion and into which recirculated exhaust gas is introduced;
A groove portion provided on a lower surface of the intake flow control valve facing the housing portion, connected to the exhaust gas introduction port of the housing portion, and constituting an exhaust gas passage by a space between the housing portion and Prepared,
The groove portion of the intake flow control valve is formed in a shape such that the minimum cross-sectional area of the exhaust gas passage changes according to the opening of the intake flow control valve,
The accommodating portion has a concave arc shape, and a lower surface of the intake flow control valve has a convex arc shape corresponding to the concave arc-shaped accommodating portion, and is higher than the accommodating portion. And the upper surface of the intake flow control valve is provided so that the upper surface of the intake flow control valve is flush with the inner surface of the intake passage. And
The groove is provided on the lower surface of the convex arcuate shape of the intake flow control valve so as to extend along the rotation direction of the intake flow control valve,
In the internal combustion engine, the groove portion has at least one of a groove depth and a groove width changed so that a minimum cross-sectional area of the exhaust gas passage changes according to an opening of the intake flow control valve. Intake device. The minimum cross-sectional area of the exhaust gas passage is minimized when the opening degree of the intake flow control valve is fully open, and the minimum cross-sectional area of the exhaust gas passage when the opening degree of the intake flow control valve is fully closed There so that the maximum, the shape of the groove is configured, an intake device for an internal combustion engine according to claim 1. The internal combustion engine according to claim 1 or 2 , wherein the shape of the groove portion is configured such that the minimum cross-sectional area of the exhaust gas passage decreases stepwise as the opening of the intake flow control valve increases. Inhalation device. 3. The internal combustion engine according to claim 1, wherein the shape of the groove portion is configured such that the minimum cross-sectional area of the exhaust gas passage continuously decreases as the opening of the intake flow control valve increases. Inhalation device. The groove is formed so as to extend from a portion between an upstream end and a downstream end of the lower surface of the intake flow control valve to the downstream end,
Even when the opening is fully open the intake flow control valve, wherein said downstream end of the groove and the intake passage is configured to communicate, according to any one of claims 1-4 Intake device for internal combustion engine. The groove portion is formed so as to extend from a portion between the upstream end portion and the downstream end portion of the lower surface of the intake flow control valve to a position before the downstream end portion,
In the state of opening fully opened near the intake flow control valve, wherein said downstream end of the groove and the intake passage is configured not to communicate, according to any one of claims 1-4 Intake device for internal combustion engine. The portion having the minimum cross-sectional area of the exhaust gas passage when the opening degree of the intake flow control valve is fully closed is a boundary portion with the exhaust gas introduction port in the exhaust gas passage. The intake device for an internal combustion engine according to claim 6 . The groove portion has a groove depth and a groove with a cross-sectional shape having an aspect ratio close to 1 so that the minimum cross-sectional area of the exhaust gas passage changes according to the opening of the intake flow control valve. The intake device for an internal combustion engine according to any one of claims 1 to 7 , wherein both of the widths are changed.

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