JP2007154677A - Intake controller for turbocharged engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake controller capable of increasing the turbocharging capacity of an engine at low rotational speed in a supercharged engine in which a first exhaust passage is reduced in volume more than a second exhaust passage. <P>SOLUTION: The portion of an exhaust system for connecting an engine body to the turbine of an exhaust turbocharger comprises a first exhaust passage composed of independent exhaust passages guided from ones of even number of cylinders having firing order of odd number or even number and a collective exhaust passage formed by collecting the downstream parts of the independent exhaust passages and a second exhaust passage composed of independent exhaust passages guided from the remaining cylinders and a collective exhaust passage formed by collecting the downstream parts of the independent exhaust passages. In the supercharged engine in which the first exhaust passage is reduced in volume more than the second exhaust passage, the first exhaust passage has intake control valves 16, 17 capable of adjusting the distribution of intake air. The intake control valves 16, 17 control the intake air so that, when the engine speed is low, the distributed amount of the intake air to those cylinders #2, #3 corresponding to the first exhaust passage 20a is larger than that to those cylinders #1, #4 corresponding to the second exhaust passage 20b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an intake control device for an engine with a supercharger, and belongs to the field of engine intake technology.

  Conventionally, there are cases where a turbocharger such as an exhaust turbocharger or an electric supercharger is provided for the purpose of improving the output of an automobile engine. Among these, the output of an engine having an exhaust turbocharger can be improved. An example of such a configuration is described in Patent Document 1. As shown in FIG. 21, in the four-cylinder engine A having four cylinders # 1 to # 4, the part from the engine body B in the exhaust system C to the turbine D1 of the exhaust turbocharger D is ignited. A plurality of independent exhaust passages E2 and E3 guided from the even-numbered second cylinder # 2 and third cylinder # 3 and a collective exhaust passage F1 formed by collecting downstream portions of the independent exhaust passages E2 and E3. A plurality of independent exhaust passages E1 and E4 led from the first cylinder # 1 and the fourth cylinder # 4 having an odd ignition order, and downstream portions of the independent exhaust passages E1 and E4. This is composed of a second exhaust passage G2 formed by a collective exhaust passage F2.

  According to this, when the combustion gas discharged from each of the cylinders # 1 to # 4 is led to the turbine D1 of the supercharger D, there is no exhaust interference on the exhaust system C. Efficiency will increase and engine output will improve. The volume of the first exhaust passage G1 for the second and third cylinders # 2 and # 3 and the volume of the second exhaust passage G2 for the first and fourth cylinders # 1 and # 4 are the engine body in the exhaust system C. Since the part from B to the turbine D1 of the exhaust turbocharger D is not divided, the expansion rate of the exhaust gas discharged from each cylinder # 1 to # 4 is reduced, and the excess The exhaust pressure acting on the turbine D1 of the feeder D is increased, and the engine output is further improved.

Japanese Patent Laid-Open No. 2004-1224749

  By the way, the exhaust turbocharger D is generally intended mainly for high engine speeds, but higher engine output is desired even when the engine speed is low.

  Therefore, an object of the present invention is to provide an intake control device capable of improving the supercharging capability at the time of engine low rotation in an engine with a supercharger.

  In order to solve the above-described problems, the present invention is configured as follows.

  First, the invention according to claim 1 of the present application includes an engine body having an even number of cylinders, an exhaust system connected to the engine body, and an exhaust turbocharger provided in the exhaust system. And a part from the engine main body to the turbine of the exhaust turbocharger in the exhaust system is a plurality of independent exhausts led from either the odd numbered cylinder or the even numbered cylinder among the even number of cylinders. A first exhaust passage composed of a passage and a collective exhaust passage in which the downstream portion of the independent exhaust passage is gathered, and the other cylinders whose firing order is odd-numbered or even-numbered among the even-numbered cylinders The second exhaust passage is composed of a plurality of independent exhaust passages and a collective exhaust passage formed by collecting downstream portions of the independent exhaust passages. The first exhaust passage is a second exhaust passage. The volume is smaller than An intake control device for an engine with a supercharger, comprising an intake control valve capable of adjusting distribution of intake air to a cylinder corresponding to the first exhaust passage and a cylinder corresponding to a second exhaust passage. In addition, when the engine is running at a low speed, the intake control valve is configured such that the distribution amount of the intake air to the cylinder corresponding to the first exhaust passage is larger than the distribution amount of the intake air to the cylinder corresponding to the second exhaust passage. It is characterized by having an intake air control means for controlling so as to become.

  According to a second aspect of the present invention, in the first aspect of the present invention, the first exhaust passage has a passage length shorter than that of the second exhaust passage, and the intake control means includes: Intake control means is provided for controlling the distribution amount of the intake air to the cylinder corresponding to the first exhaust passage to be smaller than the distribution amount of the intake air to the cylinder corresponding to the second exhaust passage at a high engine speed. It is characterized by being.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the exhaust turbocharger is independent of the first exhaust passage and the second exhaust passage. It is a twin scroll type supercharger having a scroll portion.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the first intake manifold passage communicating with the cylinder corresponding to the first exhaust passage, and the second intake passage, And a second intake manifold passage communicating with the cylinder corresponding to the exhaust passage. The intake control valve is provided for each intake manifold passage.

  Furthermore, the invention according to claim 5 is the invention according to any one of claims 1 to 3, wherein the intake control valve is provided for each cylinder.

  Next, the effect of the present invention will be described.

  According to the first aspect of the present invention, the distribution of intake air to the cylinder corresponding to the first exhaust passage and the cylinder corresponding to the second exhaust passage can be adjusted. In this case, when the engine is running at a low speed, the intake air distribution amount to the cylinder corresponding to the first exhaust passage is controlled to be larger than the intake air distribution amount to the cylinder corresponding to the second exhaust passage. The intake distribution amount to the cylinder corresponding to the first exhaust passage increases and the intake distribution amount to the cylinder corresponding to the second exhaust passage decreases compared to the case where the distribution is evenly distributed to all the cylinders. Become. Therefore, the exhaust pressure in the first exhaust passage increases and the exhaust pressure in the second exhaust passage decreases. However, the second exhaust passage has a relatively large volume, so that the exhaust pressure is originally low. The change (decrease) in the exhaust pressure due to the decrease in the intake distribution amount is small, whereas the first exhaust passage has a relatively small volume, so the change (increase) in the exhaust pressure due to the increase in the intake distribution amount. Becomes larger. Therefore, as a whole, the supercharging capability is improved, and high engine output is achieved.

By the way, in the configuration as described in Patent Document 1, as described above, exhaust in the first and second exhaust passages G1 and G2 (corresponding to the first and second exhaust passages in claim 1). Since the expansion rate of the gas is smaller than that in the case where the portion from the engine main body B to the turbine D1 of the exhaust turbocharger D in the exhaust system C is not divided, the temperature of the exhaust gas supplied to the exhaust turbocharger D Decrease is reduced. In particular, the first exhaust passage G1 for the second and third cylinders # 2 and # 3 is compared with the second exhaust passage G2 for the first and fourth cylinders # 1 and # 4 as shown in FIG. Therefore, the heat dissipation to the outside is small, and the volume is small, so that the expansion rate becomes smaller and the temperature drop of the exhaust gas is further reduced. That is, the temperature of the exhaust gas supplied from the first exhaust passage G1 for the second and third cylinders # 2 and # 3 to the supercharger D is for the first and fourth cylinders # 1 and # 4. Although it becomes higher than the temperature of the exhaust from the second exhaust passage G2, in this case, the following problems occur.

  That is, the exhaust turbo supercharger D is usually set to a heat resistant temperature to prevent damage due to overheating. However, according to the above-described configuration, the exhaust temperature of the second exhaust passage G2 is particularly high when the engine is running at high speed. In some cases, the exhaust temperature of the first exhaust passage G1 reaches the heat-resistant temperature, although there is room for the heat-resistant temperature. Therefore, further increase in engine output is restricted for protection of the supercharger D, and the supercharging capability of the supercharger D cannot be fully exhibited. As a countermeasure, for example, the exhaust system can be cooled by the heat of vaporization of the unburned component by increasing the amount of fuel. In this case, however, the fuel consumption is deteriorated.

  However, according to the second aspect of the invention, at the time of high engine rotation, the intake distribution amount to the cylinder corresponding to the first exhaust passage is larger than the intake distribution amount to the cylinder corresponding to the second exhaust system. Since the control is performed to reduce the intake amount, the intake distribution amount to the cylinder corresponding to the first exhaust passage is smaller than the case where the distribution is evenly distributed to all the cylinders, and the distribution to the cylinder corresponding to the second exhaust passage is reduced. The intake air distribution amount will increase. Therefore, the exhaust temperature from the cylinder corresponding to the first exhaust passage decreases and the exhaust temperature from the cylinder corresponding to the second exhaust passage increases, but the volume of the first exhaust passage is relatively small. As a result, the exhaust temperature change (decrease) due to the decrease in the intake air distribution amount is large, and the exhaust turbocharger is less likely to overheat. As a result, the exhaust passage length is relatively long and the volume is relatively large, so that the exhaust temperature is originally low and the change (increase) in the exhaust temperature due to the increase in the intake air distribution amount is small. It is possible to greatly increase the exhaust pressure (exhaust energy) of the second exhaust passage having a margin with respect to the heat-resistant temperature of the machine. Therefore, as a whole, the supercharging capability is improved, and high engine output is achieved. Further, the necessity of cooling due to the increase in fuel is reduced, and the deterioration of fuel consumption is suppressed.

  According to a third aspect of the invention, the exhaust turbocharger is a twin scroll type turbocharger having independent scroll portions corresponding to the first exhaust passage and the second exhaust passage. Therefore, the loss of exhaust energy in the supercharger is also suppressed, and as a result, the supercharging capability is further improved, and further increase in engine output is achieved.

  According to the fourth aspect of the present invention, the intake amount of the first and second intake passages corresponding to the first and second exhaust passages can be controlled for each intake system.

  Further, according to the fifth aspect of the present invention, the intake air amount to the cylinder can be controlled for each cylinder without largely changing the configuration of the intake system.

  Hereinafter, an intake air control apparatus for a supercharged engine according to an embodiment of the present invention will be described.

  As shown in FIG. 1, a supercharged engine 1 according to the present invention (hereinafter referred to as “engine 1”) includes first to fourth four cylinders # 1 to # 4 arranged in series. It is an inline 4-cylinder engine. In each of the cylinders # 1 to # 4 provided in the main body 2 of the engine 1, when an intake valve (not shown) is opened, the combustion chambers 2a to 2 are connected from the intake system 10 via the intake port. Air for fuel combustion is sucked into 2d. An amount of fuel (gasoline) corresponding to the amount of intake air is directly injected into the air in each of the combustion chambers 2a to 2d from a fuel injection valve (not shown) at a predetermined timing to form an air-fuel mixture. . This air-fuel mixture is compressed by a piston (not shown), and is ignited and burned by a spark plug (not shown) at a predetermined timing. In the engine 1, ignition is performed in the order of the first cylinder # 1, the third cylinder # 3, the fourth cylinder # 4, and the second cylinder # 2. The combustion gas, that is, the exhaust gas is discharged to the exhaust system 20 via the exhaust port when an exhaust valve (not shown) is opened.

  The intake system 10 is provided with one common intake passage 11. The common intake passage 11 has an air intake (not shown), an air cleaner (not shown) for removing dust in the air, and an air flow rate in order from the upstream side in the air flow direction. An air flow sensor (not shown) for detection, a compressor 12p of the twin scroll turbocharger 12, and an intercooler 13 for cooling the air that has been pressurized by the compressor 12p and heated to a high temperature are provided.

  The downstream end of the common intake passage 11 is connected to the first and second collective intake passages 14 and 15. First and second throttle valves 16 and 17 for adjusting the air amount are provided in the vicinity of the connection portion of the first and second collective intake passages 14 and 15 with the common intake passage 11. Portions downstream of the throttle valves 16 and 17 in the first and second collective intake passages 14 and 15 each have a function as a surge tank that stabilizes the air flow. Are connected to independent intake passages 18b and 18c for the second and third cylinders # 2 and # 3 whose downstream ends are connected to the intake ports of the second and third cylinders # 2 and # 3, respectively. Connected to the collective intake passage 15 are independent intake passages 18a and 18d for the first and fourth cylinders # 1 and # 4 whose downstream ends are connected to the intake ports of the first and fourth cylinders # 1 and # 4. Has been. Hereinafter, the independent intake passages 18b and 18c and the first collective intake passage 16 in the intake system 10 will be collectively referred to as a first intake passage 10a, and the independent intake passages 18a and 18d and the second collective intake passage as required. 17 is collectively referred to as a second intake passage 10b.

  The exhaust system 20 is provided with independent exhaust passages 21a to 21d for the first to fourth cylinders # 1 to # 4 whose upstream ends are connected to the exhaust ports of the first to fourth cylinders # 1 to # 4, respectively. It has been. Here, the independent exhaust passages 21a to 21d are arranged in such a way that the independent exhaust passages of the cylinders whose ignition order is not continuous and whose exhaust strokes are not adjacent belong to the same exhaust group. Grouped into exhaust groups. Specifically, the independent exhaust passages 21b and 21c led from the second and third cylinders # 2 and # 3 having the even ignition order belong to the first group, and the first and fourth ignition orders having the odd ignition order are included. The independent exhaust passages 21a and 21d led from the cylinders # 1 and # 4 belong to the second exhaust group.

  The downstream portions of the independent exhaust passages 21b and 21c belonging to the first exhaust group are gathered and connected to the first collective exhaust passage 22, and the downstream portions of the independent exhaust passages 21a and 21d belonging to the second exhaust group are the second collective exhaust passage. 23. The downstream end of the first collective exhaust passage 22 is connected to the first scroll portion 12a of the twin scroll turbocharger 12, and the downstream end of the second collective exhaust passage 23 is gathered and connected to the second scroll portion 12b. Has been. The downstream ends of both scroll portions 12 a and 12 b are connected to one common exhaust passage 24. Hereinafter, the independent exhaust passages 21b and 21c and the first collective exhaust passage 22 belonging to the first exhaust group will be collectively referred to as a first exhaust passage 20a, and the independent exhaust passages 21a and 21a belonging to the second exhaust group will be referred to as necessary. 21d and the second collective exhaust passage 23 are collectively referred to as a second exhaust passage 20b.

  In the turbine 12t of the exhaust turbocharger 12, a partition wall extending in a direction substantially perpendicular to the turbine axis is provided in the housing, and the exhaust spiral chamber or scroll is divided into two in the turbine axis direction by the partition wall. Yes. One of the exhaust swirl chamber or scroll (one closer to the compressor 12p) divided in this way is the first scroll portion 12a, and the other is the second scroll portion 12b. Therefore, in the exhaust turbo supercharger 12 or the turbine 12t, the occurrence of exhaust interference is prevented, and the supercharging efficiency is increased.

  Here, as described above, the first exhaust system 20a is a group of the second and third cylinders # 2 and # 3 arranged adjacent to each other, and the second exhaust system 20b is arranged separately. Since the first cylinders # 1 and # 4 are grouped, the first exhaust passage 20b has a longer passage length than the second exhaust passage 20a, as is apparent from FIG. And the volume is large. The volume refers to the volume of the portion of the exhaust port of the engine body 2 and the first exhaust passage 20a portion of the exhaust system 20, and the portion of the exhaust port of the engine body 2 and the second exhaust passage 20b portion of the exhaust system 20. This is the volume of the combined part.

  FIG. 2 shows a general relationship between the volume of the exhaust passage (passage length) and the supercharging pressure and the exhaust pressure in the exhaust passage. As is clear from this figure, The exhaust pressure of each tends to decrease as the exhaust passage length increases. Therefore, in the configuration of the present embodiment shown in FIG. 1, as indicated by the solid line in FIG. 3, the exhaust pressure in the first exhaust passage 20a having a short exhaust passage length and a small exhaust volume is greater than the exhaust passage length. Becomes longer than the exhaust pressure in the second exhaust passage 20b having a large exhaust volume.

  FIG. 4 shows the general relationship between the exhaust passage length and the exhaust temperature at the position immediately before the turbine of the turbocharger. As is clear from this figure, the exhaust temperature at the position immediately before the turbine becomes lower as the exhaust passage length becomes longer. Tend to be. Further, although not shown, the larger the exhaust volume, the lower the expansion and the lower the tendency. Therefore, in the configuration of the present embodiment shown in FIG. 1, the exhaust temperature at the position immediately before the turbine 12t of the turbocharger 12 is the exhaust gas in the first exhaust passage 20a having a short exhaust passage length and a small exhaust volume. The passage length is longer than that of the second exhaust passage 20b having a large exhaust volume.

  As shown in FIG. 1, the intake control device of the engine 1 includes a control unit (ECU) 30 and an engine rotation sensor 31 that detects an engine speed, and the control unit 30 includes an engine rotation sensor. A signal related to the engine speed is input from 31 and an opening degree control signal is output to an actuator (not shown) of each of the throttle valves 16 and 17.

  Next, an example of control by the control unit 30 will be described with reference to the flowchart of FIG. 5. First, in step S 1, a signal related to the current engine speed is input from the engine speed sensor 31. Next, in step S2, the opening degree of the first and second throttle valves 16 and 17 is controlled based on the engine speed. Specifically, as shown in FIG. 6, the throttle valves 16, 17 are controlled so that the opening degree of the first throttle valve 16 becomes larger than the opening degree of the second throttle valve 17 at the time of low engine rotation. To do. On the other hand, during high engine rotation, the throttle valves 16 and 17 are controlled so that the opening of the first throttle valve 16 is smaller than the opening of the second throttle valve 17. The valve opening is linearly changed according to the engine speed.

  According to this, as shown in FIG. 7, at the time of engine low rotation, the distribution amount (inflow) of the intake air to the cylinders # 2 and # 3 corresponding to the first exhaust passage 20a is all cylinders # 1 to # 4. And the distribution amount of the intake air to the cylinders # 1 and # 4 corresponding to the second exhaust passage 20b is larger than that when equally distributed (50% each). Will decrease. Therefore, as shown in FIG. 8, the exhaust pressure of the first exhaust passage 20a is increased and the exhaust pressure of the second exhaust passage 20b is decreased, but the second exhaust passage 20b has a volume comparison. Since the exhaust pressure is originally low and the change (decrease) in the exhaust pressure due to the decrease in the intake distribution amount is small, the first exhaust passage 20a has a relatively small volume, so that the intake distribution amount is small. The change (increase) in the exhaust pressure due to the increase of becomes larger. Therefore, as a whole, the supercharging capability is improved, and high output of the engine 1 is achieved.

  On the other hand, at the time of high engine speed, the intake distribution amount to the cylinders # 2 and # 3 corresponding to the first exhaust passage 20a is smaller than when evenly distributed to all the cylinders # 1 to # 4. The intake distribution amount to the cylinders # 1 and # 4 corresponding to the two exhaust passages 20b increases. Accordingly, the exhaust temperature from the cylinders # 2 and # 3 corresponding to the first exhaust passage 20a decreases, and the exhaust temperature from the cylinders # 1 and # 4 corresponding to the second exhaust passage 20b increases. However, since the first exhaust passage 20a has a relatively small volume, a change (decrease) in the exhaust temperature due to a decrease in the intake distribution amount is large, so the exhaust turbocharger 12 is less likely to overheat. As a result, the exhaust passage length is relatively long and the volume is relatively large, so that the exhaust temperature is originally low and the change (increase) in the exhaust temperature due to the increase in the intake air distribution amount is small. It becomes possible to greatly increase the exhaust pressure (exhaust energy) of the second exhaust passage 20a having a margin with respect to the heat-resistant temperature of the machine 12. Therefore, as a whole, the supercharging capability is improved, and high output of the engine 1 is achieved. Further, the necessity of cooling due to the increase in fuel is reduced, and the deterioration of fuel consumption is suppressed.

  Next, a second embodiment will be described with reference to FIG. The supercharger-equipped engine intake control device according to the second embodiment is obtained by changing the configuration of the intake system 110 with respect to the first embodiment. The engine 101 and the exhaust system 120 have the same configuration as that of the engine 1 and the exhaust system 20 of the first embodiment, and the description thereof will be omitted. (The code | symbol which added 100 to the code | symbol of what corresponds in 1st Embodiment is attached | subjected).

  That is, as shown in FIG. 9, the intake system 110 of the second embodiment is provided with one common intake passage 111. The common intake passage 111 has an air intake (not shown), an air cleaner (not shown), an air flow sensor (not shown), and a twin scroll type in order from the upstream side in the air flow direction. The turbocharger 112 includes a compressor 112p, an intercooler 113, and a throttle valve 116 for adjusting the amount of air. The portion of the common intake passage 111 downstream of the throttle valve 116 functions as a surge tank that stabilizes the air flow, and the downstream end is connected to the intake ports of the first to fourth cylinders # 1 to # 4. The independent intake passages 118a to 118d for the first to fourth cylinders # 1 to # 4 are connected.

  Further, first to fourth distribution valves 141a to 141d are provided on the first to fourth independent passages 118a to 118d, and the second and third distribution valves 141b and 141c are provided in the vicinity of the independent passage 118d. A first actuator 142 that adjusts the opening of the first and fourth distribution valves 141a and 141d and a second actuator 143 that adjusts the opening of the first and fourth distribution valves 141a and 141d are provided. Each of the first to fourth distribution valves 141a to 141d is provided with a notch so that the intake air flow into the cylinders # 1 to # 4 is not completely blocked in the closed position.

  In addition, the intake control device of the engine 101 includes a control unit 130 and an engine rotation sensor 131 that detects the engine rotation speed. The control unit 130 receives a signal related to the engine rotation speed from the engine rotation sensor 131. , And an opening degree control signal is output to the actuators 142 and 143 of the first to fourth distribution valves 141a to 141d. Note that control of the throttle valve 116 is separately performed based on the engine speed, engine load, and the like.

  Next, an example of control by the control unit 130 will be described with reference to the flowchart of FIG. 10. First, in step S 11, a signal related to the current engine speed is input from the engine speed sensor 131. Next, in step S12, the opening degree of the first to fourth distribution valves 141a to 141d is controlled based on the engine speed. Specifically, as shown in FIG. 11, at the time of low engine rotation, the opening degree of the second and third distribution valves 141b and 141c is larger than the opening degree of the first and fourth distribution valves 141a and 141d. Thus, the first and second actuators 142 and 143 are controlled. On the other hand, at the time of high engine rotation, the first and second actuators 142 are configured such that the opening degree of the second and third distribution valves 141b and 141c is smaller than the opening degree of the first and fourth valves 141a and 141d. , 143 are controlled. In addition, the opening degree of distribution valve 141a-141d is changed linearly according to an engine speed.

  According to this, as in the first embodiment, as shown in FIG. 7 described above, at the time of low engine rotation, the distribution amount of the intake air to the cylinders # 2 and # 3 corresponding to the first exhaust passage 120a is When the amount of intake air distribution to the cylinders # 1 and # 4 corresponding to the second exhaust passage 120b is equally distributed as well as when evenly distributed to all the cylinders # 1 to # 4 Will be reduced. Therefore, for the same reason as in the first embodiment, as a whole, the supercharging capability is improved, and high output of the engine 101 is achieved.

  On the other hand, at the time of high engine speed, the intake distribution amount to the cylinders # 2 and # 3 corresponding to the first exhaust passage 120a is smaller than when evenly distributed to all the cylinders # 1 to # 4. The intake distribution amount to the cylinders # 1 and # 4 corresponding to the two exhaust passages 120b increases. Therefore, for the same reason as in the first embodiment, as a whole, the supercharging capability is improved, and high output of the engine 101 is achieved. Further, the necessity of cooling due to the increase in fuel is reduced, and the deterioration of fuel consumption is suppressed.

  In particular, according to the second embodiment, the first embodiment has been described without significantly changing the intake system in which the collective intake passage generally used in the past is only one system. It is possible to obtain the same operational effects as.

  Next, a third embodiment will be described with reference to FIG. The intake air control apparatus for a supercharged engine according to the third embodiment changes the control method of the opening degree of the first to fourth valves 141a to 141d with respect to the second embodiment, and The actuators 142 and 143 of the first to fourth valves 141a to 141d are changed to actuators 142 'and 143' that can be controlled only in the open position (ON) and the closed position (OFF). Other configurations are the same as those in the second embodiment, and a description thereof will be omitted. In the description, the same reference numerals are used except for the changing unit.

  An example of control by the control unit 130 ′ will be described with reference to the flowchart of FIG. 12. First, in step S 21, a signal related to the current engine speed is input from the engine speed sensor 131. Next, in step S22, it is determined whether or not the engine speed is equal to or higher than a predetermined speed α. If the engine speed is equal to or higher than the predetermined speed α, the second and third distribution valves 141b and 141c are closed (OFF) in step S23. ), The first and second actuators 142 'and 143' are controlled so that the first and fourth valves 141a and 141d are opened (ON). On the other hand, when the rotational speed is less than the predetermined speed α, in step S24, the second and third distribution valves 141b and 141c are opened (ON), and the first and fourth valves 141a and 141d are closed (OFF). The second actuators 142 'and 143' are controlled.

  According to this, as shown in FIG. 13, when the engine speed is less than a predetermined speed α (during low engine speed), the intake air to the cylinders # 2 and # 3 corresponding to the first exhaust passage 120a is reduced. The distribution amount increases more than the case where the distribution amount is evenly distributed to all the cylinders # 1 to # 4, and the distribution amount of the intake air to the cylinders # 1 and # 4 corresponding to the second exhaust passage 120b is also equally distributed. It will be less than if it is done. Therefore, for the same reason as in the first and second embodiments, as a whole, the supercharging capability is improved, and high output of the engine 101 is achieved.

  On the other hand, when the engine speed is equal to or higher than the predetermined speed α (during high engine speed), the cylinder # 2 corresponding to the first exhaust passage 120a is more than when evenly distributed to all the cylinders # 1 to # 4. , # 3, the distribution amount of intake air decreases, and the distribution amount of intake air to cylinders # 1, # 4 corresponding to the second exhaust passage 120b increases. Therefore, for the same reason as in the first embodiment, as a whole, the supercharging capability is improved, and high output of the engine 101 is achieved. Further, the necessity of cooling due to the increase in fuel is reduced, and the deterioration of fuel consumption is suppressed.

  Note that this control has a demerit that the supercharging distribution ratio changes abruptly in the region where the engine speed is medium, as compared with the first and second embodiments. On the other hand, there is a merit that an inexpensive actuator that can only perform ON / OFF control can be used as the actuators 142 'and 143' for driving the first to fourth distribution valves 141a to 141d.

  Next, a fourth embodiment will be described. The supercharger-equipped engine intake control device according to the fourth embodiment is different from the third embodiment only in the control method of the opening degree of the first to fourth valves 141a to 141d. It is. Except for control by only the control unit 130 ″, the configuration is the same as that of the third embodiment, and a description thereof will be omitted.

  An example of control by the control unit 130 ″ will be described with reference to the flowchart of FIG. 14. First, in step S31, a signal related to the current engine speed is input from the engine rotation sensor 131. Next, in step S32, the engine It is determined whether or not the rotational speed is equal to or higher than the predetermined rotational speed α1, and when the rotational speed is equal to or higher than the predetermined rotational speed α1, the second and third distribution valves 141b and 141c are closed (OFF) in step S33, and the first and fourth valves. The first and second actuators 142 'and 143' are controlled to open (ON) 141a and 141d.On the other hand, when the rotational speed is less than the predetermined rotational speed α1, the engine rotational speed is set to the second predetermined rotational speed in step S34. It is determined whether or not the number is greater than or equal to α2. The first and second actuators 142 ′ and 143 ′ are controlled to open (ON) all of the motors 141a to 141d, whereas when the second predetermined rotational speed α2 is less than 2, the second actuator 142 ′ or 143 ′ is turned on in step S36. The first and second actuators 142 'and 143' are controlled so that the third distribution valves 141b and 141c are opened (ON) and the first and fourth valves 141a and 141d are closed (OFF).

  According to this, as shown in FIG. 15, when the engine speed is less than the second predetermined speed α2 (during low engine speed), the cylinders # 2 and # 3 corresponding to the first exhaust passage 120a are connected. The distribution amount of the intake air is larger than the case where the distribution amount is evenly distributed to all the cylinders # 1 to # 4, and the distribution amount of the intake air to the cylinders # 1 and # 4 corresponding to the second exhaust passage 120b is also equal. It will be less than if it is distributed. Therefore, for the same reason as in the first embodiment, as a whole, the supercharging capability is improved, and high output of the engine 101 is achieved.

  On the other hand, when the engine speed is equal to or higher than the first predetermined speed α1 (during high engine speed), the cylinder corresponding to the first exhaust passage 120a is more than when evenly distributed to all the cylinders # 1 to # 4. The distribution amount of intake air to # 2 and # 3 decreases, and the distribution amount of intake air to cylinders # 1 and # 4 corresponding to the second exhaust passage 120b increases. Therefore, for the same reason as in the first embodiment, as a whole, the supercharging capability is improved, and high output of the engine 101 is achieved. Further, the necessity of cooling due to the increase in fuel is reduced, and the deterioration of fuel consumption is suppressed.

  On the other hand, when the engine speed is equal to or higher than the second predetermined speed α2 and lower than the first predetermined speed α1 (during engine rotation), intake air is distributed almost evenly to all the cylinders # 1 to # 4. .

  According to the fourth embodiment, compared with the third embodiment, in particular, only the control (control unit) is changed while using substantially the same hardware, and the intake (supercharging) ) Can be changed step by step based on the engine speed, and sudden changes in the distribution rate can be mitigated.

  Next, a fifth embodiment will be described with reference to FIG. An intake air control apparatus for a supercharged engine according to the fifth embodiment is different from the second embodiment in that the first to fourth distribution valves provided on the first to fourth independent passages and While changing the configuration of the actuator, the passage areas of the independent intake passages 218b and 218c of the first intake passage 210a corresponding to the first exhaust passage 220a are changed to the passages of the independent intake passages 218a and 218d of the second intake passage 210b. It is made smaller than the area. The engine 201, the intake system 210, and the exhaust system 220 other than this are substantially the same as the engine 101, the intake system 110, and the exhaust system 120 of the second embodiment, and the description thereof is omitted (note that In the drawings, the reference numerals obtained by adding 100 to the reference numerals corresponding to those in the second embodiment are attached to those having the same configuration.

  That is, the first to fourth distribution valves 241a to 241d are provided on the first to fourth independent intake passages 218a to 218d, and the distribution valves 241a to 241d are arranged in the vicinity of the independent intake passage 218d. A single actuator 242 for adjusting the opening is provided. Each of the first to fourth distribution valves 241a to 241d is provided with a notch so as not to completely block the inflow of intake air to the cylinder in the closed state. Note that the cutout amount of the second and third valves 241b and 241c is larger than that of the first and fourth valves 241a and 241d, and all the independent valves 241a to 241d are closed to each independent intake passage 218a. In the state where .about.218d is throttled, the independent intake passages corresponding to the second exhaust passage 220b have the passage areas of the independent intake passages 218b and 218c corresponding to the first exhaust passage 220a, contrary to the opened state. The amount is set to be larger than the passage areas of 218a and 218d.

  Further, the intake control device of the engine 201 is provided with a control unit 230 and an engine rotation sensor 231 for detecting the engine rotation speed. The control unit 230 receives a signal related to the engine rotation speed from the engine rotation sensor 231. And an opening degree control signal is output to the actuator 242 of the first to fourth distribution valves 241a to 241d. The control for the throttle valve 216 is separately performed based on the engine rotation, the engine load, and the like.

  Next, an example of control by the control unit 230 will be described. The control flow is the same as the flowchart of FIG. 10, and will be described with reference to FIG. 10. First, in step S11, a signal related to the current engine speed is input from the engine rotation sensor 231. Next, in step S12, the opening degree of the first to fourth distribution valves 241a to 241d is controlled based on the engine speed. Specifically, as shown in FIG. 17, the first and second actuators 242 are controlled such that the opening degree of the first to fourth distribution valves 241a to 241d increases as the engine speed increases. In addition, the opening degree of distribution valve 241a-241d is changed linearly according to an engine speed.

  According to this, since the opening degree of the first to fourth distribution valves 241a to 241d is reduced at the time of engine low rotation, as shown in FIG. 7, the independent intake passage 218b corresponding to the first exhaust passage 220a is used. , 218c is larger than the passage areas of the independent intake passages 218a, 218d corresponding to the second exhaust passage 220b, and the cylinders # 2, # 3 corresponding to the first exhaust passage 220a More intake air flows into (distributes) the cylinders # 1 and # 4 corresponding to the two exhaust passages 220b. Therefore, for the same reason as in the first embodiment, as a whole, the supercharging capability is improved, and high output of the engine 101 is achieved.

  On the other hand, since the opening degree of the first to fourth distribution valves 241a to 241d is greatly increased during high engine rotation, the passage areas of the independent intake passages 218b and 218c corresponding to the first exhaust passage 220a are the second. The amount of intake air (distribution amount) flowing into the cylinders # 2 and # 3 corresponding to the first exhaust passage 220a is smaller than the passage areas of the independent intake passages 218a and 218d corresponding to the exhaust passage 220b. This is less than the amount of intake air (distribution amount) flowing into the cylinders # 1 and # 4 corresponding to the second exhaust passage 220b. Therefore, for the same reason as in the first embodiment, as a whole, the supercharging capability is improved, and high output of the engine 201 is achieved. Further, the necessity of cooling due to the increase in fuel is reduced, and the deterioration of fuel consumption is suppressed.

  And especially according to this 5th Embodiment, compared with 4th Embodiment, an actuator can be reduced and cost can be made cheap.

  In the fifth embodiment, the passage areas of the first and fourth independent intake passages 218a and 218d are different from the passage areas of the second and third independent intake passages 218b and 218c. Even if applicable. In this case, a cylinder whose intake valve opening / closing period and opening / closing timing can be made different for each cylinder is used, and the opening / closing timing and opening / closing timing of the intake valve are different from those of the first and fourth cylinders for the second and third cylinders. It is also possible to cope with this by setting so that a large amount of intake air can be distributed.

  Next, a sixth embodiment will be described with reference to FIG. The intake air control device for an engine with a supercharger according to the sixth embodiment is independent of the intake air control device for the engine with a supercharger according to the fifth embodiment, corresponding to the first exhaust passage 220a. The second and third distribution valves 241b and 241c on the passages 218b and 218c are omitted. Note that the control may be substantially the same as that in the fifth embodiment. According to this, the effect similar to 5th Embodiment can be achieved, reducing the cost for the 2nd, 3rd distribution valve 241b, 241c.

  In each of the above-described embodiments, the case of an in-line four-cylinder engine has been described. However, the first to sixth cylinders # 1 to # 6 as shown in FIG. 1 cylinder # 1, 4th cylinder # 4, 2nd cylinder # 2, 5th cylinder # 5, 3rd cylinder # 3, 6th cylinder # 6 are performed in this order, and engine body 302 and exhaust turbo in exhaust system 320 are performed. Portions of the turbocharger 312 connected to the turbine 312t are independent exhaust passages 321d to 321f communicating with even-numbered fourth to sixth cylinders # 4 to # 6 and downstream of the independent exhaust passages 321d to 321f. A first exhaust passage 320a including a collective exhaust passage 323 connected to the side, independent exhaust passages 321a to 321c communicating with odd-numbered first to third cylinders # 1 to # 3 and the independent exhaust Connected to the downstream side of the passages 321a to 321c V-type 6-cylinder which is constituted by a second exhaust passage 320b formed by the collective exhaust passage 322 and whose volume of the first exhaust passage 320a is set smaller than that of the second exhaust passage 320b. The present invention can also be applied to the engine 301. In this case, the first throttle valve 316 is provided on the first collective intake passage 314 and the second throttle valve 317 is provided on the second collective intake passage 315. These throttle valves 316 and 317 are controlled by the control unit 330. Control similar to that of the first embodiment may be performed. Further, similarly to the second to sixth embodiments, it is possible to adopt a configuration in which a distribution valve is provided in each of the independent exhaust passages 321a to 321f.

  In addition to the in-line 4-cylinder engine and the V-type 6-cylinder engine, the present invention can be applied, for example, to an in-line 6-cylinder engine or an in-line, V-type, horizontally opposed engine having an even number of eight or more cylinders. Is also applicable. Further, the ignition order described in the 4-cylinder engine and the 6-cylinder engine is an example, and even when the ignition order is different, the even number of portions connecting the engine main body and the turbine of the exhaust turbocharger in the exhaust system. A first exhaust passage composed of an independent exhaust passage communicating with either one of the odd-numbered cylinder and the even-numbered cylinder among the cylinders, and a collective exhaust passage connected to the downstream side of the independent exhaust passage; Consists of a second exhaust passage composed of an independent exhaust passage communicating with the other cylinder of the even number of cylinders whose ignition order is odd or even, and a collective exhaust passage connected to the downstream side of the independent exhaust passage In addition, the first exhaust passage is widely applicable to engines whose volume is smaller than that of the second exhaust passage.

  In each of the above embodiments, the case where a twin scroll type supercharger is used has been described. However, the present invention does not have a partition wall in the scroll portion of the exhaust turbine 412t as shown in FIG. The present invention can also be applied to a case where a single scroll type supercharger 412 is used. In this case, the effects of the twin scroll type described in the above embodiments are slightly reduced, but similar effects can be obtained.

  The present invention can be widely applied to engines with a supercharger.

1 is a configuration diagram of an intake air control device for a supercharged engine according to a first embodiment of the present invention. FIG. FIG. 6 is a characteristic diagram of a supercharging pressure and an exhaust pressure with respect to an exhaust passage volume (passage length). It is a characteristic view of the exhaust pressure before the turbine with respect to the crank angle. It is a characteristic view of the pre-turbine exhaust temperature with respect to the exhaust passage length. It is a flowchart which shows an example of intake control. It is a characteristic view of the valve opening degree with respect to the engine speed. It is a characteristic view of the supercharging distribution ratio with respect to the engine speed achieved by this intake control. It is a characteristic view of the exhaust pressure before the turbine with respect to the crank angle achieved by this intake control. It is a block diagram of the intake control apparatus of the engine with a supercharger which concerns on the 2nd-4th embodiment of this invention. It is a flowchart which shows an example of the intake control which concerns on 2nd Embodiment. It is a characteristic view of the valve opening degree with respect to the engine speed. It is a flowchart which shows an example of the intake control which concerns on 3rd Embodiment. It is a characteristic figure of the supercharging distribution ratio with respect to the engine speed achieved by intake control concerning a 3rd embodiment. It is a flowchart which shows an example of the intake control which concerns on 4th Embodiment. It is a characteristic view of the supercharging distribution ratio with respect to the engine speed achieved by the intake control according to the fourth embodiment. It is a block diagram of the intake control apparatus of the engine with a supercharger which concerns on the 5th Embodiment of this invention. It is a characteristic view of the valve opening degree with respect to the engine speed. It is a block diagram of the intake control apparatus of the engine with a supercharger which concerns on the 6th Embodiment of this invention. It is a block diagram of the intake control apparatus of the engine with a supercharger which concerns on the 7th Embodiment of this invention. It is a block diagram of the intake control apparatus of the engine with a supercharger which concerns on the 8th Embodiment of this invention. It is a block diagram of the engine with a supercharger which concerns on background art.

Explanation of symbols

1, 101, 201, 301 Engine 2, 102, 202, 302 Engine body 10, 110, 210, 310 Intake system 14, 314 First intake manifold passage 15, 315 Second intake manifold passage 12, 112, 212, 312, 412 Turbocharger 16, 17, 316, 317 Throttle valve (intake control valve)
141a to 141d, 241a to 241d Distribution valve (intake control valve)
20a, 120a, 220a, 320a First exhaust passages 20b, 120b, 220b, 320b Second exhaust passages 21a-21d, 121a-121d, 221a-221d, 321a-321f Independent exhaust passages 22, 23, 122, 123, 222, 223, 322, 323 Collective exhaust passage 30, 130, 130 ', 130 ", 230, 230", 330 ECU (intake control means)
31, 131, 231 and 331 Engine rotation sensors # 1 to # 6

Claims (5)

An engine body having an even number of cylinders, an exhaust system connected to the engine body, an exhaust turbocharger provided in the exhaust system, and an exhaust turbocharger from the engine body in the exhaust system The part leading to the turbine of the machine is composed of a plurality of independent exhaust passages led from either the odd-numbered or even-numbered cylinders of the even number of cylinders and the downstream portions of the independent exhaust passages A first exhaust passage composed of a collective exhaust passage, a plurality of independent exhaust passages led from the other cylinder of the odd numbered or even numbered firing order among the even number of cylinders, and a downstream portion of the independent exhaust passage Of the engine with a supercharger whose volume is smaller than that of the second exhaust passage. With the intake control device I,
An intake control valve capable of adjusting the distribution of intake air to the cylinder corresponding to the first exhaust passage and the cylinder corresponding to the second exhaust passage;
The intake control valve is controlled so that the distribution amount of intake air to the cylinder corresponding to the first exhaust passage is larger than the distribution amount of intake air to the cylinder corresponding to the second exhaust passage when the engine is running at a low speed. An intake control device for an engine with a supercharger, characterized in that intake control means is provided. The intake control apparatus for a supercharged engine according to claim 1,
The first exhaust passage has a passage length shorter than that of the second exhaust passage,
The intake control means controls the distribution amount of the intake air to the cylinder corresponding to the first exhaust passage to be smaller than the distribution amount of the intake air to the cylinder corresponding to the second exhaust passage at a high engine speed. An intake control device for an engine with a supercharger, characterized in that intake control means is provided. The intake control apparatus for a supercharged engine according to claim 1 or 2,
An exhaust turbocharger is a twin scroll type supercharger having independent scroll portions corresponding to the first exhaust passage and the second exhaust passage. Intake control device. The intake control apparatus for a supercharged engine according to any one of claims 1 to 3,
A first intake manifold passage communicating with the cylinder corresponding to the first exhaust passage, and a second intake manifold passage communicating with the cylinder corresponding to the second exhaust passage;
The intake control device for an engine with a supercharger, wherein the intake control valve is provided for each intake manifold passage. The intake control apparatus for a supercharged engine according to any one of claims 1 to 3,
The intake control device for an engine with a supercharger, wherein the intake control valve is provided for each cylinder.

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