JP4816427B2 - Internal combustion engine with a supercharger - Google Patents

Description

  The present invention relates to an internal combustion engine with a supercharger, and more particularly, to an internal combustion engine with a supercharger that includes a plurality of superchargers and that switches the operating state of the supercharger according to the operating state of the internal combustion engine.

  For the internal combustion engine, the main turbocharger and the sub-turbocharger are arranged in parallel, and only the main turbocharger is operated in the low intake air volume range, and the operation is performed with one turbocharger. Then, there is known a supercharged internal combustion engine that employs a so-called parallel sequential turbo system, in which both turbochargers are operated to operate with two turbochargers.

  In this parallel sequential turbo system, the main turbocharger and the subturbocharger are driven using exhaust pressure, respectively, and the main and subturbochargers are passed through the intake passages branched from one intake port equipped with an air cleaner. Intake air is supplied to supply compressed air to the internal combustion engine.

  In the parallel sequential turbo system, an oil lubrication system is provided in each of the main turbocharger and the subturbocharger, and the main turbocharger and the subturbocharger are smoothly rotated by the oil lubrication system.

  Specifically, if the amount of lubricating oil supplied to the secondary turbocharger is large when the secondary turbocharger is stopped or rotated at a low rotational speed, the oil leaks to the compressor and turbine, and the secondary turbocharger The excess oil at the start of rotation increases the friction, and the start-up of the sub turbocharger deteriorates, affecting the operation.

  Further, if the amount of lubricating oil is small when the auxiliary turbocharger rotates at a high speed, the lubricating performance is deteriorated, and the cooling action of the auxiliary turbocharger is reduced, resulting in a problem that the oil is burnt or worn.

In order to solve these problems, for example, a lubricating oil supply map for determining the supply of lubricating oil according to the operating state of the internal combustion engine and a lubricating oil cut map for determining cutting of the lubricating oil are provided. Based on the oil supply map, the switching means for connecting the sub turbocharger and the lubricating oil supply unit is controlled so that the lubricating oil is supplied to the bearing portion of the sub turbocharger during the operation of the sub turbocharger. In operation, there is one in which the switching means is controlled so as to block or throttle the lubricating oil in the bearing portion of the sub turbocharger (see, for example, Patent Document 1).
JP-A-6-10688

  However, in such an internal combustion engine with a supercharger, the compressors of the main turbocharger and the sub turbocharger are always in communication with each other through an intake passage branched from one intake port. Due to the negative pressure generated at the compressor inlet of the main turbocharger due to pressure loss that further increases due to pressure loss or clogging, etc., when the sub turbocharger stops or from the shaft seal part of the compressor impeller of the sub turbocharger in the low intake air volume range Lubricating oil will leak. As a result, there is a risk of malfunction due to lack of lubricating oil during operation of the turbocharger or burning of the engine.

  The present invention has been made in order to solve the conventional problems. When the engine is in an operation state using only the first supercharger, the influence of the negative pressure upstream of the suction portion of the first supercharger is reduced. Accordingly, it is possible to prevent the lubricating oil from leaking from the second supercharger, and to stably operate the second supercharger and to prevent the internal combustion engine from being burned. An object is to provide an internal combustion engine with a supercharger.

  An internal combustion engine with a supercharger according to the present invention is (1) at least one first supercharger provided in each of an intake passage and an exhaust passage of the internal combustion engine and operating in at least all operating regions of the internal combustion engine. And at least one or more second superchargers operating with the first supercharger in a specific operating region, and supplying lubricating oil to the first supercharger and the second supercharger In the internal combustion engine with a supercharger provided with lubricating oil supply means, the intake passage includes a first intake passage for supplying intake air to an intake portion of the first supercharger, and the first intake passage. And a second intake passage that supplies intake air to the intake portion of the second supercharger, and the first intake passage includes a first intake port that sucks air and And a first air cleaner for cleaning air sucked from the first air inlet. The second intake passage is constituted by having a second air cleaner for cleaning the second intake port for sucking air, an air sucked from said second inlet.

  With this configuration, since the first intake passage and the second intake passage are provided independently, even if a large negative pressure is generated upstream of the suction portion of the first supercharger, the negative intake passage is provided. It is possible to prevent the lubricating oil from leaking out from the intake portion of the second supercharger under the influence of pressure. For this reason, it is possible to sufficiently supply the lubricating oil to the second supercharger during operation of the second supercharger and to prevent the internal combustion engine from being burned.

  Further, the internal combustion engine with a supercharger according to the present invention is (2) at least one first supercharger that is provided in each of the intake passage and the exhaust passage of the internal combustion engine and operates in at least all operating regions of the internal combustion engine. At least one or more second superchargers that operate together with the first supercharger in a specific operating region, and lubricating oil to the first supercharger and the second supercharger. Lubricating oil supply means for supplying, and exhaust amount control means for controlling the amount of exhaust gas supplied from the internal combustion engine through the exhaust passage to the exhaust portion of the second supercharger, wherein the intake passage includes air An air inlet provided with an air cleaner for purifying the air, a branch portion branched from the air inlet, a first branch communicating with the branch portion and supplying intake air to the air intake portion of the first supercharger The second passage communicates with the intake passage and the branch portion. In the internal combustion engine with a supercharger provided with a second branch intake passage for supplying intake air to the intake portion of the engine, the second branch intake air between the branch portion and the intake portion of the second supercharger Based on the detection result of the operating state detecting means, the opening and closing means provided in the passage for opening and closing the second branch intake passage, the operating state detecting means for detecting the operating state of the second supercharger, And a control means for controlling the opening / closing means.

  With this configuration, the second branch intake passage between the branch portion and the suction portion of the second supercharger is provided with opening / closing means for opening and closing the second branch intake passage, and is based on the operating state of the second supercharger. Therefore, even when a large negative pressure is generated on the upstream side of the suction portion of the first supercharger when a pressure loss of the air cleaner occurs, this negative pressure is controlled. It is possible to prevent the lubricating oil from leaking from the intake portion of the second supercharger under the influence. For this reason, it is possible to sufficiently supply the lubricating oil to the second supercharger during operation of the second supercharger and to prevent the internal combustion engine from being burned.

  In the internal combustion engine with a supercharger according to the present invention having the configuration of (2) above, (3) the operating state detecting means is a rotation speed detector for detecting the rotation speed of the second supercharger. It is comprised from what provided.

  With this configuration, the operating state of the second supercharger can be reliably detected, and the opening / closing control can be performed at an optimal timing according to the operating state of the second supercharger.

  Moreover, in the internal combustion engine with a supercharger of the present invention having the configuration of (2), (4) the exhaust passage includes a downstream side of the exhaust part of the second supercharger and the first supercharger. An exhaust bypass passage communicating with the downstream side of the exhaust portion of the machine, wherein the exhaust amount control means includes an exhaust bypass valve for adjusting an opening degree of the exhaust bypass passage, and the operating state detection means includes the exhaust bypass It is comprised from what is provided with the opening degree detector which detects the opening degree of a valve.

  With this configuration, the operating state of the second supercharger can be reliably detected, and the opening / closing control can be performed at an optimal timing according to the operating state of the second supercharger.

  Further, in the internal combustion engine with a supercharger according to the present invention having the configuration of (3), (5) the control means is a rotation speed of the second supercharger detected by the rotation speed detector. Is less than a predetermined value, the opening / closing means is closed, and the opening / closing means is opened when the rotational speed of the second supercharger is equal to or higher than a predetermined value.

  With this configuration, if the rotation speed of the second supercharger is less than a predetermined value, it is determined as a low intake air amount region, the opening / closing means is closed, and the rotation speed of the second supercharger is equal to or higher than the predetermined value. If there is, the open / close means is opened based on the high intake air amount range, so that in the low intake air amount region, it is possible to prevent the lubricating oil from leaking from the second supercharger or the internal combustion engine. In the intake air amount range, sufficient intake air can be supplied to the second supercharger, and compressed air can be supplied to the internal combustion engine from both the first supercharger and the second supercharger.

  In the internal combustion engine with a supercharger according to the present invention having the configuration of (4), (6) the control means is configured such that the opening degree of the exhaust bypass valve detected by the opening degree detector is a predetermined value. The opening / closing means is closed when the opening / closing means is lower, and the opening / closing means is opened when the opening degree of the exhaust bypass valve is equal to or greater than a predetermined value.

  With this configuration, if the opening degree of the exhaust bypass valve is less than a predetermined value, it is determined as a low intake air amount region and the opening / closing means is closed, and if the opening degree of the exhaust bypass valve is equal to or greater than the predetermined value, Since the opening / closing means is opened based on the determination of the amount range, it is possible to prevent the lubricating oil from leaking from the second supercharger or the internal combustion engine in the low intake air amount region, and in the high intake air amount region, Sufficient intake air can be supplied to the second supercharger, and compressed air can be supplied to the internal combustion engine from both the first supercharger and the second supercharger.

  In the present invention, when only the first supercharger is in operation, the lubricating oil leaks from the second supercharger due to the negative pressure upstream of the suction portion of the first supercharger. Therefore, it is possible to provide an internal combustion engine with a supercharger that can stably operate the second supercharger and can prevent the internal combustion engine from burning.

Embodiments of an internal combustion engine with a supercharger according to the present invention will be described below with reference to the drawings.
(First embodiment)
1 to 7 are views showing a first embodiment of an internal combustion engine with a supercharger according to the present invention.

  First, the configuration will be described. FIG. 1 is a view showing an internal combustion engine (hereinafter referred to as an engine). FIG. 1 is a schematic configuration diagram of an in-line 6-cylinder supercharged engine mounted on a vehicle. In FIG. 1, the intake system of the engine 1 is provided with a surge tank 2 for preventing intake arteries or intake interference, and a throttle body 3 is provided upstream of the surge tank 2.

  Inside the throttle body 3, there is provided a throttle valve 4 that is opened and closed in conjunction with the operation of an accelerator pedal (not shown). By opening and closing the throttle valve 4, the amount of intake air to the surge tank 2 is reduced. Adjusted. Further, the opening degree Tsv of the throttle valve 4 is detected by a throttle opening degree sensor 101.

  Further, on the downstream side of the surge tank 2, an intake manifold 5 branched for each cylinder # 1, # 2, # 3, # 4, # 5, and # 6 of the engine 1 is provided. Are provided with injectors 6A, 6B, 6C, 6D, 6E, and 6F, respectively, for injecting fuel for each of the engines # 1 to # 6.

  Each injector 6A to 6F is supplied with fuel at a predetermined pressure from a fuel tank by the operation of a fuel pump (not shown). Further, spark plugs 7A, 7B, 7C, 7D, 7E, and 7F are provided in accordance with the cylinders # 1 to # 6 of the engine 1, respectively.

  On the other hand, an exhaust manifold 8 is provided in the exhaust system of the engine 1, and the exhaust manifold 8 is assembled into two groups of cylinder groups # 1 to # 3 and # 4 to # 6 without exhaust interference. The collecting portions 8a and 8b are communicated with each other by the communication passage 9.

  Further, an intake system and an exhaust system of the engine 1 are respectively provided with a main turbocharger 10 constituting a first supercharger and a sub turbocharger 11 constituting a second supercharger in parallel.

  Further, the turbine 10 a that is the exhaust part of the main turbocharger 10 and the turbine 11 a that is the exhaust part of the sub turbocharger 11 are communicated with the collecting parts 8 a and 8 b of the exhaust manifold 8 on the upstream side.

  That is, the cylinder groups # 1 to # 3 of the engine 1 are communicated with the main turbocharger 10 and the cylinder groups # 4 to # 6 of the engine 1 are communicated with the sub turbocharger 11. However, as described above, the cylinder groups # 1 to # 3 and the cylinder groups # 4 to # 6 are communicated by the communication passage 9.

  A main exhaust passage 12 as an exhaust passage is communicated with the downstream side of the turbine 10a, and a sub exhaust passage 13 as an exhaust passage is communicated with the downstream side of the turbine 11a.

  The main exhaust passage 12 and the sub exhaust passage 13 are merged on the downstream side thereof, and the main exhaust passage 12 and the sub exhaust passage 13 communicate with the outside through a catalytic converter 14 incorporating a three-way catalyst and a muffler (not shown). ing.

  On the other hand, the upstream side of the compressor 10b, which is the intake portion of the main turbocharger 10, communicates with the main intake passage 15 as an intake passage, and the upstream side of the compressor 11b, which is the intake portion of the sub turbocharger 11, serves as an intake passage. It communicates with the auxiliary intake passage 16.

  The upstream sides of the main intake passage 15 and the sub intake passage 16 communicate with the outside through air flow meters 102a and 102b and air cleaners 18a and 18b, respectively. That is, the main intake passage 15 communicates with the compressor 10b of the main turbocharger 10 from the intake port 15a as the first intake port via the air cleaner 18a as the first air cleaner. The main turbocharger 10 is supplied to the compressor 10b.

  The auxiliary intake passage 16 communicates with the compressor 11b of the auxiliary turbocharger 11 from an intake port 16a as a second intake port via an air cleaner 18b as a second air cleaner, and external air is supplied from the intake port 16a. The auxiliary turbocharger 11 is supplied to the compressor 11b. Therefore, the main intake passage 15 and the sub intake passage 16 of the present embodiment are independent of each other and are not in communication.

  The downstream side of each compressor 10b communicates with a main intake passage 19 serving as an intake passage, and the downstream side of the compressor 11b communicates with a sub intake passage 20 serving as an intake passage. The downstream side of the auxiliary intake passage 20 joins and communicates with one common intake passage 21 and communicates with the surge tank 2 via the intake air cooling intercooler 22 and the throttle body 3.

  The main turbocharger 10 operates from a low intake air amount region to a high intake air amount region, that is, from a low rotation region of the engine 1 to a middle / high rotation region of the engine 1. The main turbocharger 10 is operated in the entire operation region of the engine 1, and the auxiliary turbocharger 11 is stopped in the low intake air amount region and is operated in the high intake air region which is a specific operation region. It has become. In the present embodiment, the main turbocharger 10 and the sub turbocharger 11 constitute a so-called “parallel sequential turbo system”.

  An exhaust switching valve 23 is provided in the middle of the auxiliary exhaust passage 13 communicating with the turbine 11a of the auxiliary turbocharger 11, and an intake switching valve 24 is disposed in the middle of the auxiliary intake passage 20 communicating with the compressor 11b. The exhaust switching valve 23 and the intake switching valve 24 are opened and closed by diaphragm type actuators 25 and 26, respectively.

  When both the exhaust switching valve 23 and the intake switching valve 24 are fully opened, the process proceeds to a “twin turbo stage” in which the main turbocharger 10 and the sub turbocharger 11 operate, and both the exhaust switching valve 23 and the intake switching valve 24 are operated. When is fully closed, the process proceeds to a “single turbo stage” in which the main turbocharger 10 operates.

  In addition, an exhaust bypass passage 27 that connects the downstream side of the turbine 11 a of the secondary turbocharger 11 and the downstream side of the turbine 10 a of the main turbocharger 10 is provided in the secondary exhaust passage 13 that communicates with the turbine 11 a of the secondary turbocharger 11. The exhaust bypass passage 27 is opened to prevent a temperature rise due to idling of the sub turbocharger 11 when only the main turbocharger 10 is operating.

  The exhaust bypass passage 27 is provided with an exhaust bypass valve 28 for opening and closing the exhaust bypass passage 27. The exhaust bypass valve 28 is variable in opening degree, that is, the opening amount of the exhaust bypass valve 28 by a diaphragm actuator 29. Be controlled. In the present embodiment, the exhaust bypass valve 28 and the actuator 29 constitute an exhaust amount control means.

  Further, the auxiliary intake passage 20 and the main intake passage 15 are communicated between the auxiliary intake passage 20 upstream of the intake air switching valve 24 and the main intake passage 15 upstream of the compressor 10 b of the main turbocharger 10. The intake bypass passage 30 is opened in order to smoothly switch from the operation of only the main turbocharger 10 to the main turbocharger 10 and the sub turbocharger 11.

  An intake bypass valve 32 driven by a diaphragm actuator 31 is provided on one end side of the intake bypass passage 30 to open and close the intake bypass passage 30.

  The auxiliary intake passage 20 is connected to the upstream side and the downstream side of the intake switching valve 24 by a bypass passage 33, and a reed valve 34 is provided in the bypass passage 33. When the outlet pressure at the compressor 11 b of the auxiliary turbocharger 11 becomes larger than the outlet pressure of the main turbocharger 10, the upstream side of the intake air switching valve 24 from the upstream side through the bypass passage 33 and the reed valve 34. Air is to be bypassed.

  On the other hand, in the main turbocharger 10, a waste gate passage 35 is provided between the upstream side and the downstream side of the turbine 10a, and a waste gate valve 36 for opening and closing the waste gate passage 35 is provided in the waste gate passage 35. Is provided.

  The waste gate valve 36 supplies the exhaust gas flowing into the turbine 10a to the outlet of the turbine 10a in order to prevent the supercharging pressure by the main turbocharger 10 and the sub turbocharger 11 from exceeding a preset supercharging pressure. By bypassing to the side, the output of the turbines 10a and 11a is adjusted, and the supercharging pressure by the main turbocharger 10 and the sub turbocharger 11 is controlled. The opening of the waste gate valve 36 is variably controlled by the actuator 37, that is, the opening amount of the waste gate passage 35.

  On the other hand, the first, second, third, fourth, and fifth electromagnetic valves 111, 112, 113, 114, and 115 are connected to the actuators 25, 26, 29, 31, and 37, respectively. -115 are switched based on a command from ECU 100 (see FIG. 2).

  The actuators 29 and 37 introduce the supercharging pressure from the main intake passage 19 or the common intake passage 21 into the respective diaphragm chambers, and the duty of the air cleaner 18a is controlled by the fourth electromagnetic valve 114 and the fifth electromagnetic valve 115, respectively. By adjusting the return amount to the downstream side, the pressure in the diaphragm chamber is adjusted.

  The actuators 25, 26, and 31 introduce the supercharging pressure from the positive pressure tank 50 into the respective diaphragm chambers, and the first electromagnetic valve 111, the second electromagnetic valve 112, and the third electromagnetic valve 113 respectively. The pressure in the diaphragm chamber is adjusted by controlling whether the air in the diaphragm chamber is returned to the downstream side of the air cleaner 18a by the on / off control or not.

The first solenoid valve 111 is composed of a vacuum switching valve. When the first solenoid valve 111 is turned “ON”, the actuator 26 is operated so as to fully open the intake air switching valve 24, and “OFF”. Then, the actuator 26 is operated so that the intake air switching valve 24 is fully closed.
The third solenoid valve 113 is composed of a vacuum switching valve. When the third solenoid valve 113 is “ON”, the actuator 25 is actuated so that the exhaust switching valve 23 is fully opened, and is turned “OFF”. Then, the actuator 25 is operated so that the exhaust switching valve 23 is fully closed.

  The second solenoid valve 112 is constituted by a vacuum switching valve. When the second solenoid valve 112 is “ON”, the actuator 31 is operated to fully close the intake bypass valve 32, and “OFF” is selected. Then, the actuator 31 is operated so that the intake bypass valve 32 is fully opened.

  Further, the fifth solenoid valve 115 is not an on / off control, but is constituted by a duty-controlled vacuum switching valve as described above, and the opening degree of the waste gate valve 36 is introduced into the diaphragm chamber of the actuator 37. The amount of return of the supercharged air to the downstream side of the air cleaner 18 a can be varied by varying the duty control of the fifth solenoid valve 115.

  On the other hand, the exhaust bypass valve 28 is composed of a swing arm valve that opens to the exhaust downstream side as shown in FIG. 3, and a diaphragm actuator 29 connected to the exhaust bypass valve 28 has a diaphragm chamber 29 a formed therein. Yes. The diaphragm chamber 29a is partitioned by a diaphragm 29c, and a spring 29d that presses the diaphragm 29c toward the diaphragm chamber 29a is housed in the chamber 29b on the opposite side of the diaphragm chamber 29a.

  The supercharging pressure is guided to the diaphragm chamber 29a from the main intake passage 19, and the supercharged air guided to the diaphragm chamber 29a is returned to the downstream side of the air cleaner 18a by the fourth electromagnetic valve 114. It is like that.

  During operation of the engine 1, exhaust gas exhaust pressure acts on the valve body 28 a of the exhaust bypass valve 28, and the force applied to the valve body 28 a by this exhaust pressure Pb and the diaphragm connected to the exhaust bypass valve 28. When the sum of the force generated by the supercharging pressure acting in the diaphragm chamber 29a of the actuator 29 of the type exceeds a certain value, the exhaust bypass valve 28 is opened. Further, the closing operation of the exhaust bypass valve 28 is performed by the biasing force of the spring 29d.

  Further, the fourth solenoid valve 114 for introducing the supercharging pressure to the actuator 29 that operates the exhaust bypass valve 28 is not an on / off control, but is constituted of a duty-controlled vacuum switching valve as described above. The opening degree control of the exhaust bypass valve 28 is variable by varying the return amount of the supercharged air introduced into the diaphragm chamber 29 a of the actuator 29 to the downstream side of the air flow meter 102 b by duty control of the fourth electromagnetic valve 114. It is possible.

  On the other hand, the air flow meters 102a and 102b provided in the main intake passage 15 and the auxiliary intake passage 16 respectively detect the intake air amount. The engine 1 is provided with a crank angle sensor 103. The crank angle sensor 103 detects the engine speed Ne together with the crank angle from the rotation of the crankshaft or the camshaft. In addition, an oxygen sensor 104 is provided in the main exhaust passage 12, and this oxygen sensor 104 detects the oxygen concentration in the exhaust gas.

  4 and 5 are diagrams showing a configuration for supplying lubricating oil to the main turbocharger 10 and the auxiliary turbocharger 11, FIG. 4 is a schematic diagram of a supply path of the lubricating oil, and FIG. FIG. 2 is a configuration diagram of the auxiliary turbocharger 11. Since the main turbocharger 10 and the sub-turbocharger 11 have the same configuration, both turbochargers 10 and 11 will be described with reference to FIG.

  In FIG. 4, the lubricating oil in the oil pan (not shown) is sucked by the oil pump, supplied to the main lubricating portion of the engine 1 from a number of lubricating oil supply passages, and then returned to the oil pan. An oil cooler that cools the lubricating oil and an oil element that removes foreign matter in the lubricating oil are provided at a predetermined position of the lubricating oil supply passage, and part of the lubricating oil from which the foreign matter has been removed is part of the lubricating oil supply passage. The first supply passage 52 and the second supply passage 53 are branched through 51.

  The first supply passage 52 supplies lubricating oil to the main turbocharger 10, and the lubricating oil that has lubricated the main turbocharger 10 is returned to the oil pan through the first return passage 54.

  The second supply passage 53 is configured to supply lubricating oil to the sub turbocharger 11, and the lubricating oil that has lubricated the sub turbocharger 11 is returned to the oil pan via the second return passage 55.

  On the other hand, in FIG. 5, the main turbocharger 10 and the sub turbocharger 11 include a bearing housing 61, a turbine housing 62 provided on one side of the bearing housing 61, and a compressor housing 63 provided on the other side of the bearing housing 61. The turbines 10a and 11a rotatably provided in the turbine housing 62, the compressors 10b and 11b rotatably provided in the compressor housing 63, and the turbines 10a and 11a and the compressors 10b and 11b, And a shaft 65 rotatably supported from the bearing housing 61 via a bearing 64.

  In addition, the bearing housing 61 extends in the front-rear direction in FIG. 5 and communicates with the first communication path 66 and the first communication path 66 that communicate with the first supply path 52 or the second supply path 53. 5 includes a second communication passage 67 extending in the left-right direction, and a pair of third communication passages 68 communicating with the second communication passage 67 and opening toward the shaft 65 and the bearing 64. The lubrication of the charger 10 and the sub turbocharger 11 is completed, and the lubricating oil is returned to the oil pan through the first return passage 54 and the second return passage 55.

  In the present embodiment, the lubricating oil supply passage 51, the first supply passage 52, the second supply passage 53, the first communication passage 66, the second communication passage 67, and the third communication passage 68 constitute a lubricating oil supply means. is doing.

  On the other hand, as shown in FIG. 2, the ECU 100 is connected to a throttle opening sensor 101, air flow meters 102 a and 102 b, a crank angle sensor 103, and an oxygen sensor 104, and the ECU 100 performs various calculations for controlling the engine 1. CPU (central processing unit) 100a, read only memory (ROM) 100b, temporary storage RAM (Random Access Memory) 100c, input / output interface (I / O interface) 100d, and various sensors A / D converter 100e for converting the analog signal of the above into a digital quantity, and an injector that is a fuel injection valve based on detection information from throttle opening sensor 101, air flow meters 102a and 102b, crank angle sensor 103, and oxygen sensor 104 6A, 6B, Controls C, 6D, 6E, and 6F.

  Further, the ECU 100 is configured to “turn on / off” the actuators 25 and 26 based on detection information from the throttle opening sensor 101, the air flow meters 102a and 102b, the crank angle sensor 103, and the oxygen sensor 104. When the actuators 25 and 26 are “on”, the exhaust switching valve 23 and the intake switching valve 24 are fully opened, and when the actuators 25 and 26 are “off”, the exhaust switching valve 23 and the intake switching valve 24 are fully closed. ing.

  Further, the ECU 100 controls the actuators 29 and 31 based on detection information from the throttle opening sensor 101, the air flow meters 102a and 10b, the crank angle sensor 103, and the oxygen sensor 104, whereby the exhaust bypass valve 28 or the intake bypass valve The exhaust flow rate in the exhaust bypass passage 27 or the intake bypass passage 30 is adjusted by adjusting the opening degree of the exhaust gas.

  Next, the supercharging control will be described based on FIGS. FIG. 6 is a flowchart of the supercharging control. This flowchart is a program stored in the ROM 100b executed by the CPU 100a of the ECU 100. FIG. 7 is a diagram showing the relationship between the operation of the turbocharger, the engine speed and the engine load.

  First, the CPU 100 a of the ECU 100 operates from the engine load calculated based on the detection information of the throttle opening sensor 101, the air flow meters 102 a and 102 b and the oxygen sensor 104 and the engine speed calculated based on the crank angle sensor 103. It is determined whether or not only the main turbocharger 10 is to be operated based on this operating state.

  Specifically, the CPU 100a of the ECU 100 determines whether or not the driving state is less than the determination line A based on the map shown in FIG. 7 (step S1). If the CPU 100a determines that it is less than the determination line A in step S1, the CPU 100a determines that it is a low-speed / high-load region or a medium-speed / low-load single turbo region, that is, a low intake air amount region. Then, the process proceeds to the “single turbo stage” in which only the main turbocharger 10 is operated with the exhaust switching valve 23 and the intake switching valve 24 closed (step S2).

  At this time, the exhaust gas from the engine 1 is supplied only to the main turbocharger 10, and only the turbine 10a of the main turbocharger 10 rotates. In this “single turbo stage”, lubricating oil corresponding to the rotational speed of the engine 1 is supplied to the main turbocharger 10 via the first supply passage 52.

  Specifically, lubricating oil is supplied from the first supply passage 52 to the shaft 65 and the bearing 64 of the main turbocharger 10 through the first communication passage 66, the second communication passage 67, and the third communication passage 68. The oil is returned to the oil pan through the first return passage 54.

  Further, the exhaust gas that has passed through the turbine 10a of the main turbocharger 10 passes through the main exhaust passage 12, reaches the junction of the main exhaust passage 12 and the sub exhaust passage 13, and further passes through the downstream catalytic converter 14 to the outside. To be discharged.

  In this way, in the low intake air amount region, since the shift to the “single turbo stage” in which supercharging is performed only by the main turbocharger 10, the supercharging is performed more than in the case where supercharging is performed by both the main turbocharger 10 and the auxiliary turbocharger 11. The feed characteristic can be improved and the rise of the load of the engine 1 can be accelerated to improve the response in the low speed range.

  On the other hand, if the CPU 100a determines in step S1 that it is greater than or equal to the determination line A, it determines whether it is less than the determination line B (step S3).

  In step S3, when the CPU 100a determines that the operating state calculated based on the engine load and the engine speed is greater than or equal to the determination line A and less than the determination line B as shown in FIG. When the operating state exceeds the low-speed / high-load determination line A, the actuator 29 is duty-controlled by the fourth electromagnetic valve 114, thereby opening the exhaust bypass valve 28 with a small opening (step S4).

  For this reason, the exhaust bypass passage 27 is opened, and a part of the exhaust gas is introduced into the auxiliary turbocharger 11. Further, the actuator 31 is operated so that the second electromagnetic valve 112 is turned “on” and the intake bypass valve 32 is fully closed. For this reason, the run-up rotation of the turbine 11a of the auxiliary turbocharger 11 is started.

  Further, when the running rotation is performed, the lubricating oil corresponding to the rotational speed of the engine 1 is supplied to the auxiliary turbocharger 11 through the second supply passage 53.

  On the other hand, if the CPU 100a determines that the determination line B is greater than or equal to the determination line B in step S3, the CPU 100a determines that the engine operating state is a high speed / high load twin turbo region, that is, a high intake air amount region. The first solenoid valve 111 and the third solenoid valve 113 are turned on to operate the actuator 26 so that the intake switching valve 24 is fully opened, and the actuator 25 is operated so that the exhaust switching valve 23 is fully opened. Further, the actuator 29 is duty-controlled by the fourth electromagnetic valve 114, so that the exhaust bypass valve 28 is fully closed, and the auxiliary turbocharger 11 finishes the running rotation (step S5).

  For this reason, the process proceeds to a “twin turbo stage” in which supercharging is performed by the main turbocharger 10 and the sub turbocharger 11. Further, since the auxiliary turbocharger 11 is rotating in a running manner, an impact does not occur at the moment of transition to the “twin turbo stage”, and the stage transition is performed smoothly.

  Further, in the case of shifting to the “twin turbo stage”, the lubricating oil is supplied to the sub turbocharger 11 and the sub turbocharger 11 via the first supply passage 52 and the second supply passage 53.

  Further, after the transition to the “twin turbo stage”, the exhaust gas from the engine 1 flows through the main turbocharger 10 and the sub turbocharger 11 to rotate the turbine 10 a of the main turbocharger 10 and the turbine 11 a of the sub turbocharger 11. .

  Further, the exhaust gas that has passed through the turbines 10a and 11a reaches the joining portion thereof through the main exhaust passage 12 and the sub exhaust passage 13, and further passes through the downstream catalytic converter 14 and flows to the outside.

  When the “twin turbo stage” is used as described above, a sufficient supercharging pressure can be obtained by the main turbocharger 10 and the sub turbocharger 11, and the output of the engine 1 in the high speed range can be improved.

  In addition, when shifting from the “twin turbo stage” to the “single turbo stage”, the CPU 100a performs duty control on the actuator 29 by the fourth electromagnetic valve 114 when it becomes less than the determination line B, and the exhaust bypass valve. 28 is opened, the actuators 25 and 26 are turned off, the exhaust switching valve 23 and the intake switching valve 24 are fully closed, and the sub turbocharger 11 is decelerated.

  Thereafter, when it becomes less than the determination line A, the actuator 29 is turned “off” and the exhaust bypass valve 28 is fully closed. Further, while the auxiliary turbocharger 11 is rotating, lubricating oil is supplied to the auxiliary turbocharger 11.

  Thus, in the present embodiment, the main intake passage 15 and the auxiliary intake passage 16 are provided independently so that the main intake passage 15 and the auxiliary intake passage 16 do not communicate with each other, so the compressor 10b of the main turbocharger 10 Even when a large negative pressure is generated on the upstream side, it is possible to prevent the lubricating oil from leaking from the compressor 11b of the sub turbocharger 11 due to the negative pressure.

For this reason, it is possible to sufficiently supply lubricating oil to the auxiliary turbocharger 11 when the auxiliary turbocharger 11 is operated, and to prevent the engine 1 from being burned.
(Second Embodiment)
FIGS. 8-12 is a figure which shows 2nd Embodiment of the internal combustion engine with a supercharger based on this invention. In addition, the same number is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

In FIG. 8, the upstream side of the compressor 10 b that is the intake portion of the main turbocharger 10 communicates with the main intake passage 71 as the first branch intake passage, and the upstream side of the compressor 11 b that is the intake portion of the sub turbocharger 11. The side communicates with the auxiliary intake passage 72 as the second branch intake passage.
The upstream side of the main intake passage 71 and the auxiliary intake passage 72 is joined by a single common intake passage 73 and communicates with the outside via an air flow meter 102 and an air cleaner 74. That is, the common intake passage 73 includes an intake port 73 a that is provided with an air cleaner 74 and communicates with the outside, and the intake passage 71 and the auxiliary intake passage 72 are branched by the common intake passage 73. In the present embodiment, the common intake passage 73 forms a branch portion.

  Further, the downstream side of each compressor 10b communicates with the main intake passage 19, and the downstream side of the compressor 11b communicates with the auxiliary intake passage 20. The downstream sides of the main intake passage 19 and the auxiliary intake passage 20 are It merges and communicates with one common intake passage 21, and communicates with the surge tank 2 via an intake air cooling intercooler 22 and a throttle body 3.

  The auxiliary intake passage 72 between the downstream side of the common intake passage 73 and the auxiliary turbocharger 11 is provided with an auxiliary intake passage opening / closing valve 75 as an opening / closing means for opening and closing the auxiliary intake passage 72. The passage opening / closing valve 75 is controlled to open and close by a diaphragm actuator 76.

  The actuator 76 is connected to a sixth solenoid valve 116 for selectively switching between the supercharging pressure from the positive pressure tank 50 and the atmospheric pressure from the downstream of the air flow meter 102. Switching of 116 is performed based on a command from ECU 100 (see FIG. 9).

  The actuator 76 introduces the supercharging pressure from the positive pressure tank 50 into the diaphragm chamber, and returns the air in the diaphragm chamber to the downstream side of the air flow meter 102 by the on / off control by the sixth electromagnetic valve 116. The pressure in the diaphragm chamber is adjusted by controlling whether or not to return it. In the present embodiment, only one air flow meter 102 is provided, and the supercharging pressure supplied to the diaphragm chambers of the actuators 25, 26, 29, 31 and 37 is returned to the downstream side of the air flow meter 102. .

  When the sixth solenoid valve 116 is turned on, the actuator 76 is operated so that the auxiliary intake passage opening / closing valve 75 is fully opened. When the sixth electromagnetic valve 116 is turned off, the auxiliary intake passage opening / closing valve 75 is fully closed. Thus, the actuator 76 is operated.

  FIG. 10 is a view showing a configuration of the auxiliary intake passage opening / closing valve 75. In FIG. 10, the auxiliary intake passage opening / closing valve 75 is composed of a swing arm valve having a valve body 75 a that opens on the intake downstream side, and a diaphragm actuator 76 connected to the auxiliary intake passage opening / closing valve 75 includes: A diaphragm chamber 76a is formed. The diaphragm chamber 76a is partitioned by the diaphragm 76c, and a spring 76d that presses the diaphragm 76c toward the diaphragm chamber 76a is housed in the chamber 76b on the opposite side of the diaphragm chamber 76a.

  A supercharging pressure is led from the positive pressure tank 50 to the diaphragm chamber 76a, and the supercharged air led to the diaphragm chamber 76a is leaked to the auxiliary intake passage 72 via the leak passage 72a. It has become.

  In the low intake air amount region, the atmospheric pressure from the downstream of the air flow meter 102 is guided to the valve body 75a of the auxiliary intake passage opening / closing valve 75 to the diaphragm chamber 76a, and this atmospheric pressure is the urging force of the spring 76d. Therefore, the valve body 75a is urged in the valve closing direction by the spring 76d, and the auxiliary intake passage 72 is closed.

  Further, in the high intake air amount region, the positive pressure from the positive pressure tank 50 is guided to the diaphragm chamber 76a by the switching control by the sixth electromagnetic valve 116, and this positive pressure is the biasing force of the spring 76d. Therefore, the valve body 75a of the auxiliary intake passage opening / closing valve 75 moves in the valve opening direction against the urging force of the spring 76d, and the auxiliary intake passage 72 is opened.

  On the other hand, the ECU 100 controls the sixth electromagnetic valve 116 on / off based on the rotational speed of the sub turbocharger 11. Specifically, the auxiliary turbocharger 11 is provided with a gap sensor 105 as an operating state detection means and a rotation speed detector. The gap sensor 105 is generated, for example, when a blade of the turbine 11a passes. A change in the gap, that is, a modulation is detected, and a detection signal is output to the ECU 100. The ECU 100 calculates the rotation speed (rpm) of the sub turbocharger 11 from the modulation frequency (number of blades / second) based on detection information from the gap sensor 105.

  The ECU 100 opens / closes the auxiliary intake passage 72 by opening / closing the auxiliary intake passage opening / closing valve 75 by the actuator 76 by performing on / off control of the sixth electromagnetic valve 116 based on detection information from the gap sensor 105. In the present embodiment, the ECU 100 and the sixth electromagnetic valve 116 constitute a control means.

  Next, supercharging control will be described based on FIGS. 11 and 12. FIG. 11 is a flowchart of the supercharging control. This flowchart is a program stored in the ROM executed by the CPU 100a of the ECU 100. FIG. 12 shows the relationship between the rotation speed of the auxiliary turbocharger and the auxiliary intake passage opening / closing valve 75.

  First, the CPU 100a of the ECU 100 determines the operating state based on the engine load and the engine speed based on the throttle opening sensor 101, the air flow meter 102, the crank angle sensor 103, and the oxygen sensor 104, and based on the operating state, It is determined whether or not only the turbocharger 10 is operated.

  Specifically, the CPU 100a of the ECU 100 determines whether or not the driving state is less than the determination line A based on the map shown in FIG. 7 (step S11). If the CPU 100a determines that it is less than the determination line A in step S11, the CPU 100a determines that it is a low-speed / high-load region or a medium-speed / low-load single turbo region, that is, a low intake air amount region. Then, with the exhaust switching valve 23 and the intake switching valve 24 closed, the process proceeds to the “single turbo stage” in which only the main turbocharger 10 is operated (step S12).

  At this time, the exhaust gas from the engine 1 flows only to the main turbocharger 10 and flows only to the turbine 10 a of the main turbocharger 10. At this time, lubricating oil corresponding to the rotational speed of the engine 1 is supplied to the main turbocharger 10 via the first supply passage 52.

  Further, the exhaust gas that has passed through the turbine 10a of the main turbocharger 10 passes through the main exhaust passage 12, reaches the junction of the main exhaust passage 12 and the sub exhaust passage 13, and further passes through the downstream catalytic converter 14 to the outside. To be discharged.

  Next, the CPU 100a executes a sub intake passage opening / closing valve control process (step S13). In this auxiliary intake passage opening / closing valve control process, the CPU 100a refers to FIG. 12 based on detection information from the gap sensor 105, and determines whether to open / close the auxiliary intake passage opening / closing valve 75 or not.

  That is, the CPU 100a determines whether or not the rotation speed rpm of the sub turbocharger 11 is greater than rpm1. The rotation speed rpm1 of the sub turbocharger 11 is set to a value corresponding to the rotation speed of the sub turbocharger 11 when it is between the determination line A and the determination line B, and this rpm1 constitutes a predetermined value. is doing.

  Therefore, when the sub turbocharger 11 is stopped, the CPU 100a determines that the rotation speed of the sub turbocharger 11 is rpm <rpm1, and turns the sixth electromagnetic valve 116 “off”. Therefore, the auxiliary intake passage opening / closing valve 75 is not opened, and the auxiliary intake passage 72 and the main intake passage 71 are blocked.

  On the other hand, if the CPU 100a determines in step S11 that it is greater than or equal to the determination line A, it determines whether or not it is less than the determination line B (step S14). In step S14, if the CPU 100a determines that the operating state calculated based on the engine load and the engine speed is greater than or equal to the determination line A and less than the determination line B as shown in FIG. When the operating state exceeds the low-speed / high-load determination line A, the actuator 29 is duty-controlled by the fourth electromagnetic valve 114, thereby opening the exhaust bypass valve 28 with a small opening (step S15).

  For this reason, the exhaust bypass passage 27 is opened, and a part of the exhaust gas is introduced into the auxiliary turbocharger 11. Further, the actuator 31 is operated so that the second electromagnetic valve 112 is turned “on” and the intake bypass valve 32 is fully closed. For this reason, the run-up rotation of the turbine 11a of the auxiliary turbocharger 11 is started.

  At the same time that the exhaust bypass valve 28 is opened, the CPU 100a executes the auxiliary intake passage opening / closing control process (step S16). In this auxiliary intake passage opening / closing control process, the CPU 100a determines whether or not the rotational speed of the auxiliary turbocharger 11 is rpm> rpm1. Since this rpm1 is set between the determination line A and the determination line B, that is, as described above, the auxiliary turbocharger 11 is set to an arbitrary number of rotations when the auxiliary turbocharger 11 is running. When the CPU 100a determines that the rotation speed of the auxiliary turbocharger 11 is rpm <rpm1, the CPU 100a turns off the sixth electromagnetic valve 116 and does not open the auxiliary intake passage opening / closing valve 75. For this reason, the auxiliary intake passage 72 and the main intake passage 71 are blocked.

  At this time, the lubricating oil is supplied from the second supply passage 53 to the shaft 65 and the bearing 64 of the sub turbocharger 11 through the first communication passage 66, the second communication passage 67, and the third communication passage 68. The oil is returned to the oil pan through the second return passage 55.

  Further, when the CPU 100a determines that the rotation speed of the auxiliary turbocharger 11 is rpm> rpm1, the CPU 100a turns on the sixth electromagnetic valve 116 to open the auxiliary intake passage opening / closing valve 75. As described above, when the rotation speed of the auxiliary turbocharger 11 sufficiently increases and the rotation speed of the auxiliary turbocharger 11 reaches rpm1 during the auxiliary running rotation of the auxiliary turbocharger 11, the auxiliary intake passage opening / closing valve 75 is opened. I do.

  On the other hand, if the CPU 100a determines that the determination line B is equal to or higher than the determination line B in step S14, the CPU 100a determines that the engine operating state is a high-speed / high-load twin turbo region, that is, a high intake air amount region. The first solenoid valve 111 and the third solenoid valve 113 are turned on to operate the actuator 26 so that the intake switching valve 24 is fully opened, and the actuator 25 is operated so that the exhaust switching valve 23 is fully opened. In addition, the duty of the actuator 29 is controlled by the fourth electromagnetic valve 114, so that the exhaust bypass valve 28 is fully closed, and the auxiliary rotation of the auxiliary turbocharger 11 is completed (step S17).

  For this reason, the process proceeds to a “twin turbo stage” in which supercharging is performed by the main turbocharger 10 and the sub turbocharger 11. Further, since the auxiliary turbocharger 11 is rotating in a running manner, an impact does not occur at the moment of transition to the “twin turbo stage”, and the stage transition is performed smoothly.

  Further, when the process shifts to the “twin turbo stage”, the ECU 100 executes the auxiliary intake passage opening / closing control process based on the detection information from the gap sensor 105 (step S18). In this auxiliary intake passage opening / closing control process, the CPU 100a determines whether or not the rotational speed of the auxiliary turbocharger 11 is rpm> rpm1.

  At this time, since the auxiliary turbocharger 11 has completed the running rotation, the CPU 100a determines that the rotation speed of the sub turbocharger 11 is rpm> rpm1, and turns on the sixth solenoid valve 116 to open / close the auxiliary intake passage. The valve 75 is opened. For this reason, the auxiliary intake passage 72 and the main intake passage 71 communicate with each other.

  Further, after the transition to the “twin turbo stage”, the exhaust gas from the engine 1 flows through the main turbocharger 10 and the sub turbocharger 11 to rotate the turbine 10 a of the main turbocharger 10 and the turbine 11 a of the sub turbocharger 11. .

  Further, the exhaust gas that has passed through the turbines 10a and 11a reaches the joining portion thereof through the main exhaust passage 12 and the sub exhaust passage 13, and further passes through the downstream catalytic converter 14 and flows to the outside.

  In addition, when shifting from the “twin turbo stage” to the “single turbo stage”, the CPU 100a performs duty control on the actuator 29 by the fourth electromagnetic valve 114 when it becomes less than the determination line B, and the exhaust bypass valve. 28, the actuators 25 and 26 are turned off, the exhaust switching valve 23 and the intake switching valve 24 are fully closed to decelerate the sub turbocharger 11, and the CPU 100a detects information detected from the gap sensor 105. The auxiliary intake passage opening / closing control process is executed based on the above.

  In this auxiliary intake passage opening / closing control process, the CPU 100a determines whether or not the rotation speed of the auxiliary turbocharger 11 is rpm> rpm1, and when determining that the rotation speed of the auxiliary turbocharger 11 is rpm <rpm1, the CPU 100a Turns off the sixth electromagnetic valve 116 and closes the auxiliary intake passage opening / closing valve 75. For this reason, the auxiliary intake passage 72 and the main intake passage 71 are blocked.

  Thereafter, when it becomes less than the determination line A, the actuator 29 is turned “off” and the exhaust bypass valve 28 is fully closed. When the operating state becomes less than the determination line A, the CPU 100a executes the auxiliary intake passage opening / closing control process based on the detection information from the gap sensor 105.

  In this auxiliary intake passage opening / closing control process, the CPU 100a determines whether or not the rotational speed of the auxiliary turbocharger 11 is rpm> rpm1. At this time, since the sub turbocharger 11 is rotating at low speed or in a stopped state, the CPU 100a determines that the rotation speed of the sub turbocharger 11 is rpm <rpm1, and the sixth electromagnetic valve 116 remains “off”. By maintaining the above, the auxiliary intake passage opening / closing valve 75 is closed. For this reason, the auxiliary intake passage 72 and the main intake passage 71 are blocked.

  Thus, in the present embodiment, the auxiliary intake passage opening / closing valve 75 for opening and closing the auxiliary intake passage 72 is provided in the auxiliary intake passage 72 between the common intake passage 73 and the compressor 11 b of the auxiliary turbocharger 11. Since the auxiliary intake passage opening / closing valve 75 is controlled to open and close based on the rotational speed of the main turbocharger 10 when a large negative pressure is generated upstream of the compressor 10b of the main turbocharger 10 when a pressure loss of the air cleaner 74 occurs. The lubricating oil can be prevented from leaking from the compressor 11b of the auxiliary turbocharger 11 due to the negative pressure. For this reason, it is possible to sufficiently supply lubricating oil to the auxiliary turbocharger 11 when the auxiliary turbocharger 11 is operated, and to prevent the engine 1 from being burned.

  In the present embodiment, the rotation speed of the auxiliary turbocharger 11 is directly detected to control the opening and closing of the auxiliary intake passage opening / closing valve 75, so that the auxiliary intake passage opening / closing is performed according to the actual operating state of the auxiliary turbocharger 11. The valve 75 can be controlled to open and close.

In the present embodiment, the auxiliary intake passage opening / closing valve 75 is closed in the low intake air amount region, and the auxiliary intake passage opening / closing valve 75 is opened in the high intake air amount region. Lubricating oil can be prevented from leaking from the auxiliary turbocharger 11 and the engine 1 in the quantity range, and sufficient intake air is supplied to the auxiliary turbocharger 11 in the high intake air quantity range so that the main turbocharger 10 and Compressed air can be supplied to the engine 1 by both the turbochargers 11.
(Third embodiment)
FIGS. 13 to 15 are views showing a third embodiment of an internal combustion engine with a supercharger according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. To do.

  In the present embodiment, as shown in FIGS. 13 and 14, an operating state detecting means for detecting the opening degree of the exhaust bypass valve 28 and an exhaust bypass valve opening degree sensor 106 as an opening degree detector are provided. The auxiliary intake passage opening / closing valve 75 is controlled to open / close based on the detection information of the exhaust bypass valve opening sensor 106.

  The exhaust bypass valve opening sensor 106 generates an electrical signal corresponding to the rotation angle of the rotation shaft of the exhaust bypass valve 28 to electrically detect the rotation angle of the rotation shaft, in other words, the opening of the exhaust bypass valve 28. What is necessary is just to use the sensor etc. which do.

  The supercharging control will be described based on the flowchart of FIG. Further, the supply of the lubricating oil is the same as that of the second embodiment, and thus the description thereof is omitted.

  First, the CPU 100a of the ECU 100 determines the operating state based on the engine load and the engine speed based on the throttle opening sensor 101, the air flow meter 102, the crank angle sensor 103, and the oxygen sensor 104, and based on the operating state, It is determined whether or not only the turbocharger 10 is operated.

  Specifically, the CPU 100a of the ECU 100 determines whether or not the driving state is less than the determination line A based on the map shown in FIG. 7 (step S11). If the CPU 100a determines that it is less than the determination line A in step S11, the CPU 100a determines that it is a single turbo region, that is, a low intake air amount region, and closes the exhaust switching valve 23 and the intake switching valve 24. After shifting to the “single turbo stage” in which only the main turbocharger 10 is operated (step S12), the process proceeds to the auxiliary intake passage opening / closing valve control process (step S13).

  In this auxiliary intake passage opening / closing valve control process, the CPU 100a determines whether to open / close the auxiliary intake passage opening / closing valve 75 with reference to FIG. 15 based on detection information from the exhaust bypass valve opening degree sensor 106.

  That is, the CPU 100a determines whether or not the opening degree Q> Q1 of the exhaust bypass valve 28. When the opening Q1 is between the determination line A and the determination line B, the opening Q1 is set to a value corresponding to the opening of the exhaust bypass valve 28. The opening Q1 constitutes a predetermined value. .

  Therefore, when the exhaust bypass valve 28 is closed and no exhaust pressure acts on the auxiliary turbocharger 11, the CPU 100a determines that Q <Q1 and turns off the sixth electromagnetic valve 116. Therefore, the auxiliary intake passage opening / closing valve 75 is not opened, and the auxiliary intake passage 72 and the main intake passage 71 are blocked.

  On the other hand, if the CPU 100a determines in step S11 that it is greater than or equal to the determination line A, it determines whether or not it is less than the determination line B (step S14). In step S14, if the CPU 100a determines that the operating state calculated based on the engine load and the engine speed is greater than or equal to the determination line A and less than the determination line B as shown in FIG. When the operating state exceeds the low-speed / high-load determination line A, the actuator 29 is duty-controlled by the fourth electromagnetic valve 114, thereby opening the exhaust bypass valve 28 with a small opening (step S15).

  For this reason, the exhaust bypass passage 27 is opened, and a part of the exhaust gas is introduced into the auxiliary turbocharger 11. Further, the actuator 31 is operated so that the second electromagnetic valve 112 is turned “on” and the intake bypass valve 32 is fully closed. For this reason, the run-up rotation of the turbine 11a of the auxiliary turbocharger 11 is started.

  At the same time that the exhaust bypass valve 28 is opened, the CPU 100a executes the auxiliary intake passage opening / closing control process (step S16). In this auxiliary intake passage opening / closing control process, the CPU 100a determines whether or not the opening degree Q <Q1 of the exhaust bypass valve 28 is satisfied. When the opening Q1 is between the determination line A and the determination line B as described above, that is, when the exhaust bypass valve 28 is opened and the auxiliary turbocharger 11 performs the running rotation, the opening Q1 is a corresponding opening. Therefore, when the CPU 100a determines that Q <Q1, the sixth electromagnetic valve 116 is turned off and the auxiliary intake passage opening / closing valve 75 is not opened. For this reason, the auxiliary intake passage 72 and the main intake passage 71 are blocked.

  Further, when the CPU 100a determines that Q> Q1, the sixth electromagnetic valve 116 is turned “ON” to open the auxiliary intake passage opening / closing valve 75. As described above, when the opening degree Q> Q1 of the exhaust bypass valve 28 is satisfied during the auxiliary rotation of the auxiliary turbocharger 11, the auxiliary intake passage opening / closing valve 75 is opened.

  On the other hand, if the CPU 100a determines that the determination line B is equal to or higher than the determination line B in step S4, the CPU 100a determines that the engine operating state is a high-speed / high-load twin turbo region, that is, a high intake air amount region. The first solenoid valve 111 and the third solenoid valve 113 are turned on to operate the actuator 26 so that the intake switching valve 24 is fully opened, and the actuator 25 is operated so that the exhaust switching valve 23 is fully opened. In addition, the duty of the actuator 29 is controlled by the fourth electromagnetic valve 114, so that the exhaust bypass valve 28 is fully closed, and the auxiliary rotation of the auxiliary turbocharger 11 is completed (step S17).

  For this reason, the process proceeds to a “twin turbo stage” in which supercharging is performed by the main turbocharger 10 and the sub turbocharger 11. Further, since the auxiliary turbocharger 11 is rotating in a running manner, an impact does not occur at the moment of transition to the “twin turbo stage”, and the stage transition is performed smoothly.

  Further, when the process shifts to the “twin turbo stage”, the ECU 100 executes the auxiliary intake passage opening / closing control process based on the detection information from the exhaust bypass valve opening degree sensor 106 (step S18). In the auxiliary intake passage opening / closing control process, the CPU 100a determines whether or not the opening degree Q> Q1 of the exhaust bypass valve 28 is satisfied.

  At this time, since the auxiliary turbocharger 11 has finished running, the CPU 100a determines that Q> Q1, turns on the sixth electromagnetic valve 116, and opens the auxiliary intake passage opening / closing valve 75. For this reason, the auxiliary intake passage 72 and the main intake passage 71 communicate with each other.

  Further, after the transition to the “twin turbo stage”, the exhaust gas from the engine 1 flows through the main turbocharger 10 and the sub turbocharger 11 to rotate the turbine 10 a of the main turbocharger 10 and the turbine 11 a of the sub turbocharger 11. .

  In addition, when shifting from the “twin turbo stage” to the “single turbo stage”, the CPU 100a performs duty control on the actuator 29 by the fourth electromagnetic valve 114 when it becomes less than the determination line B, and the exhaust bypass valve. 28, the actuators 25 and 26 are turned off, the exhaust switching valve 23 and the intake switching valve 24 are fully closed to decelerate the sub turbocharger 11, and the CPU 100a detects the exhaust bypass valve opening sensor 106. The auxiliary intake passage opening / closing control process is executed based on the detection information from the.

  In this auxiliary intake passage opening / closing control process, the CPU 100a determines whether or not the opening degree Q> Q1 of the exhaust bypass valve 28. When determining that Q <Q1, the CPU 100a controls the sixth electromagnetic valve 116. The sub intake passage opening / closing valve 75 is closed by turning it off. For this reason, the auxiliary intake passage 72 and the main intake passage 71 are blocked.

  Thereafter, when it becomes less than the determination line A, the actuator 29 is turned “off” and the exhaust bypass valve 28 is fully closed. When the operating state is less than the determination line A, the CPU 100a executes the auxiliary intake passage opening / closing control process based on the detection information from the exhaust bypass valve opening degree sensor 106.

  In this auxiliary intake passage opening / closing control process, the CPU 100a determines whether or not the opening degree Q> Q1 of the exhaust bypass valve opening degree sensor 28. At this time, since the exhaust bypass valve 28 is closed and the auxiliary turbocharger 11 is in a stopped state, the CPU 100a determines that Q <Q1, maintains the sixth electromagnetic valve 116 in the “off” state, and performs the auxiliary intake. The passage opening / closing valve 75 is closed. For this reason, the auxiliary intake passage 72 and the main intake passage 71 are cut off as they are.

  Thus, in the present embodiment, the auxiliary intake passage opening / closing valve 75 for opening and closing the auxiliary intake passage 72 is provided in the auxiliary intake passage 72 between the common intake passage 73 and the compressor 11 b of the auxiliary turbocharger 11, and the exhaust bypass valve 28. Since the auxiliary intake passage opening / closing valve 75 is controlled to be opened / closed based on the opening degree, even if a large negative pressure is generated upstream of the compressor 10b of the main turbocharger 10 due to the pressure loss of the air cleaner 74, It is possible to prevent the lubricating oil from leaking from the compressor 11b of the auxiliary turbocharger 11 due to the negative pressure. For this reason, it is possible to sufficiently supply lubricating oil to the auxiliary turbocharger 11 when the auxiliary turbocharger 11 is operated, and to prevent the engine 1 from being burned.

  Further, in the present embodiment, the opening degree of the exhaust bypass valve 28 is directly detected and the auxiliary intake passage opening / closing valve 75 is controlled to open / close, so that the auxiliary intake passage opening / closing is performed according to the actual operating state of the auxiliary turbocharger 11. The valve 75 can be controlled to open and close.

  In the above embodiments, one or more main turbochargers 10 and one or more sub turbochargers 11 are provided. However, one or more main turbochargers and one or more sub turbochargers are provided according to the size of the engine 1. Also good. Further, one main turbocharger may be provided and two sub turbochargers may be provided. In short, it is sufficient that at least one main turbocharger and at least one sub turbocharger are provided.

  As described above, the internal combustion engine with a supercharger according to the present invention is affected by the negative pressure on the upstream side of the suction portion of the first supercharger when it is in an operating state by only the first supercharger. Accordingly, it is possible to prevent the lubricating oil from leaking from the second supercharger, and to stably operate the second supercharger and to prevent the internal combustion engine from being burned. It is useful as an internal combustion engine with a supercharger, etc. that has a plurality of superchargers and that switches the operating state of the supercharger according to the operating state of the internal combustion engine.

1 is a schematic configuration diagram of an internal combustion engine with a supercharger according to a first embodiment of the present invention. 1 is a block diagram of a control system of an internal combustion engine with a supercharger according to a first embodiment of the present invention. It is the schematic of the exhaust bypass valve vicinity of the internal combustion engine with a supercharger which concerns on the 1st Embodiment of this invention. It is the schematic of the supply path | route of the lubricating oil of the internal combustion engine with a supercharger which concerns on the 1st Embodiment of this invention. 1 is a cross-sectional view of a main turbocharger and a sub turbocharger of an internal combustion engine with a supercharger according to a first embodiment of the present invention. It is a flowchart of the supercharging control performed by ECU of the internal combustion engine with a supercharger which concerns on the 1st Embodiment of this invention. It is a figure which shows the relationship between the action | operation of the turbocharger of the internal combustion engine with a supercharger which concerns on the 1st Embodiment of this invention, an engine speed, and an engine load. It is a schematic block diagram of the internal combustion engine with a supercharger which concerns on the 2nd Embodiment of this invention. It is a block diagram of the control system of the internal combustion engine with a supercharger which concerns on the 2nd Embodiment of this invention. It is a block diagram of the vicinity of the sub intake passage opening / closing valve of the internal combustion engine with a supercharger according to the second embodiment of the present invention. It is a flowchart of the supercharging control performed by ECU of the internal combustion engine with a supercharger which concerns on the 2nd Embodiment of this invention. It is a figure which shows the relationship between the rotation speed of the sub turbocharger of the internal combustion engine with a supercharger which concerns on the 2nd Embodiment of this invention, and the opening / closing timing of a sub intake passage opening / closing valve. It is a schematic block diagram of the internal combustion engine with a supercharger which concerns on the 3rd Embodiment of this invention. It is a block diagram of a control system of an internal combustion engine with a supercharger according to a third embodiment of the present invention. It is a figure which shows the relationship between the opening degree of the exhaust bypass valve of the internal combustion engine with a supercharger which concerns on the 3rd Embodiment of this invention, and the opening / closing timing of a sub intake passage opening / closing valve.

Explanation of symbols

1 engine (internal combustion engine)
10 Main turbocharger (first turbocharger)
10a, 11a Turbine (exhaust part)
10b, 11b Compressor (intake section)
11 Deputy turbocharger (second turbocharger)
12 Main exhaust passage (exhaust passage)
13 Sub exhaust passage (exhaust passage)
15, 19 Main intake passage (intake passage)
15a Inlet (first inlet)
16, 20 Auxiliary intake passage (intake passage)
16a Inlet (second inlet)
18a Air cleaner (first air cleaner)
18b Air cleaner (second air cleaner)
27 Exhaust bypass passage 28 Exhaust bypass valve (displacement control means)
29 Actuator (displacement control means)
51 Lubricating oil supply passage (lubricating oil supply means)
52 1st supply path (lubricating oil supply means)
53 Second supply passage (lubricating oil supply means)
66 1st communication path (lubricant supply means)
67 Second communication path 68 Third communication path (lubricating oil supply means)
71 Main intake passage (first branch intake passage)
72 Auxiliary intake passage (second branch intake passage)
73 Common intake passage (branch)
73a Intake port 74 Air cleaner 75 Sub intake passage opening / closing valve (opening / closing means)
100 ECU (control means)
105 Gap sensor (operating state detection means, rotation speed detector)
106 Exhaust bypass valve opening sensor (operating state detection means, opening detector)

Claims (2)

At least one first supercharger that is provided in each of an intake passage and an exhaust passage of the internal combustion engine and operates in at least all operation regions of the internal combustion engine, and operates together with the first supercharger in a specific operation region And at least one second supercharger, lubricating oil supply means for supplying lubricating oil to the first supercharger and the second supercharger, and the exhaust passage from the internal combustion engine through the exhaust passage. An exhaust amount control means for controlling the exhaust amount supplied to the exhaust part of the second supercharger,
The intake passage communicates with an intake port provided with an air cleaner for purifying air, a branch portion branched from the intake port, and the branch portion, and intake air is supplied to the intake portion of the first supercharger. An internal combustion engine with a supercharger comprising: a first branched intake passage to be supplied; and a second branched intake passage that communicates with the branched portion and supplies intake air to an intake portion of the second supercharger. ,
An opening / closing means provided in the second branch intake passage between the branch portion and the intake portion of the second supercharger for opening and closing the second branch intake passage;
An operating state detecting means for detecting an operating state of the second supercharger;
Control means for controlling the opening and closing means based on the detection result of the operating state detecting means,
The exhaust passage includes an exhaust bypass passage communicating the downstream side of the exhaust part of the second supercharger and the downstream side of the exhaust part of the first supercharger,
The exhaust amount control means includes an exhaust bypass valve that adjusts an opening degree of the exhaust bypass passage,
The internal combustion engine with a supercharger, wherein the operating state detection means includes an opening detector that detects an opening of the exhaust bypass valve . The control means closes the opening / closing means when the opening degree of the exhaust bypass valve detected by the opening degree detector is less than a predetermined value, and the opening degree of the exhaust bypass valve is equal to or larger than a predetermined value. The internal combustion engine with a supercharger according to claim 1 , wherein the opening / closing means is opened .

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