JP2008128159A - Internal combustion engine with supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine with a supercharger capable of improving operation of a second supercharger by supplying an optimal lubricating oil quantity corresponding to an operation state of the second supercharger to the second supercharger. <P>SOLUTION: This internal combustion engine has a main turbocharger 10 operating in the whole operation area of an engine 1, a sub-turbocharger 11 operating together with the main turbocharger 10 in a high suction air volume area, an exhaust bypass valve 28 and an actuator 29 controlling an exhaust quantity supplied to a turbine 11a of the sub-turbocharger 11, a gap sensor for detecting a rotating speed of the sub-turbocharger 11, a variable valve and a solenoid for controlling a lubricating oil quantity supplied to the sub-turbocharger 11, and controls the lubricating oil quantity supplied to the sub-turbocharger 11 based on an operation state of the sub-turbocharger 11 detected by the gap sensor. <P>COPYRIGHT: (C)2008,JPO&INPIT

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, an oil lubrication system is provided for smooth operation of the main and auxiliary turbochargers by supplying lubricating oil to the main and auxiliary turbochargers. Is required to supply properly.

  Specifically, if there is a large amount of lubricating oil supplied to the sub turbocharger while the sub turbocharger is stopped or rotated at a low rotation speed, oil leaks from the compressor or turbine of the sub turbocharger, The excess oil at the start of the rotation of the sub turbocharger increases the friction, which deteriorates the start-up of the sub turbocharger and affects 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, and this lubrication is performed. Based on the oil supply map, when the auxiliary turbocharger is operated, the switching means for communicating the auxiliary turbocharger and the oil pan is controlled so as to supply lubricating oil to the bearing portion of the auxiliary turbocharger, and when the auxiliary turbocharger is inoperative. 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 amount of lubricating oil supplied to the auxiliary turbocharger is controlled based on the operating state of the internal combustion engine, so an appropriate amount of lubricating oil is supplied to the auxiliary turbocharger. It was difficult to supply.

  That is, the operation state of the internal combustion engine is determined based on various detection information such as the intake air amount, the oxygen concentration in the exhaust gas, the throttle valve opening, and the like. May occur.

  When the amount of lubrication supplied to the sub turbocharger is determined by estimating the operation state of the sub turbocharger based on the operation state in which these variations are accumulated, this amount of lubricating oil is the actual operation state of the sub turbocharger. There is a risk of becoming unsuitable.

  As a result, it is not possible to supply an appropriate amount of lubricating oil to the auxiliary turbocharger, and it is not possible to improve the oil leakage in the low intake air amount region and the deterioration of the start-up at the start of rotation of the auxiliary turbocharger. There is a possibility that oil burn and wear of the auxiliary turbocharger cannot be reliably prevented in the intake air amount region.

  The present invention has been made to solve the conventional problems, and is capable of supplying the second supercharger with an optimum amount of lubricating oil according to the operating state of the second supercharger. An object of the present invention is to provide an internal combustion engine with a supercharger that can improve the operation of the second 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 second supercharger operating together with the first supercharger in a specific operating region, and being supplied from the internal combustion engine to the exhaust section of the second supercharger through the exhaust passage. The exhaust amount control means for controlling the exhaust amount to be controlled, the operating state detecting means for detecting the operating state of the second supercharger, the first supercharger and the second supercharger with lubricating oil And a lubricating oil amount control means for controlling the amount of lubricating oil supplied to at least the second supercharger. The lubricating oil amount control means is detected by the operating state detecting means. Based on the operating state of the second supercharger There are, and a controls the amount of lubricating oil supplied to the second turbocharger.

  With this configuration, the operation state of the second supercharger is not directly estimated from the operating state of the internal combustion engine, but the operation state of the second supercharger is directly detected by detecting the operation state of the second supercharger. Since the amount of lubricating oil supplied to the second supercharger is controlled according to the state, the amount of lubricating oil corresponding to the operating state of the second supercharger can be supplied to the second supercharger.

  For this reason, in the low intake air amount region, the lubricating oil leaks from the intake part or the exhaust part of the second supercharger, or the friction during rotation of the second supercharger increases due to the excess lubricating oil. It is possible to prevent the rise of the second supercharger from deteriorating and affecting the operation.

  Further, in the high intake air amount region, the lubrication performance of the second supercharger can be improved, the cooling action of the second supercharger can be improved, and the occurrence of oil scorching and wear can be prevented. As a result, the operation of the second supercharger can be performed satisfactorily.

  In the internal combustion engine with a supercharger according to the present invention having the configuration of (1), (2) 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, since the amount of lubricating oil supplied to the second supercharger is controlled by directly detecting the rotation speed of the second supercharger, the optimum according to the actual operating state of the second supercharger A sufficient amount of lubricating oil can be supplied to the second supercharger.

  In the internal combustion engine with a supercharger according to the present invention having the above-described configuration (1) or (2), (3) the exhaust passage may be disposed downstream of the exhaust section of the second supercharger and An exhaust bypass passage communicating with a downstream side of the exhaust portion of the first supercharger; and the exhaust amount control means includes an exhaust bypass valve for adjusting an opening degree of the exhaust bypass passage; Comprises an opening detector for detecting the opening of the exhaust bypass valve.

  With this configuration, since the amount of lubricating oil supplied to the second supercharger is controlled based on the opening degree of the exhaust bypass valve, the actual operating state of the second supercharger according to the exhaust flow rate of the bypass passage is set. The optimal amount of lubricating oil can be supplied to the second supercharger.

  In the internal combustion engine with a supercharger according to the present invention having the configuration of (2), (4) the lubricating oil amount control means is the second supercharger detected by the rotational speed detector. When the rotational speed of the second supercharger is less than a predetermined value, the amount of lubricating oil supplied to the second supercharger is smaller than when the rotational speed of the second supercharger is equal to or higher than the predetermined value. Has been.

  With this configuration, the operating state of the second supercharger is less than a predetermined value, for example, at a low speed rotation, the operating state of the second supercharger is equal to or higher than a predetermined value, for example, the second supercharger is at a second speed. Since the amount of lubricating oil supplied to the supercharger is reduced, at the time of low speed rotation, the optimum amount of lubricating oil is supplied according to the run-up of the second supercharger, and the second supercharger The start-up at the start of the engine can be improved, and at the time of high-speed rotation after the end of the run, the second supercharger can be prevented from being worn, or the second supercharger can be burned out due to insufficient cooling. It can be prevented from occurring.

  In the internal combustion engine with a supercharger according to the present invention having the configuration of (3), (5) the amount of lubricating oil control means is the opening of the exhaust bypass valve detected by the opening detector. Is less than a predetermined value, the amount of lubricating oil supplied to the second supercharger is smaller than when the opening degree of the exhaust bypass valve is greater than or equal to a predetermined value.

  With this configuration, when the opening degree of the exhaust bypass valve is less than a predetermined value, for example, a small opening degree, the opening degree of the exhaust bypass valve is greater than a predetermined value, for example, supplied to the second supercharger than when the opening degree is large. Since the amount of lubrication oil is reduced, at the time of low speed rotation, the optimum amount of lubrication oil is supplied according to the second turbocharger's approach, and the second turbocharger starts up at the start of rotation. In addition, the second supercharger can be prevented from wearing during high speed rotation after the end of the run, and the second supercharger can be prevented from being burned due to insufficient cooling. be able to.

  The present invention makes it possible to supply an optimal amount of lubricating oil according to the operating state of the second supercharger to the second supercharger, thereby improving the operation of the second supercharger. An internal combustion engine with a supercharger that can be provided can be provided.

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)
FIGS. 1-8 is a figure which shows 1st Embodiment of the internal combustion engine with a supercharger which concerns on this 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 as fuel injection valves 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 path 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 side of the main intake passage 15 and the sub intake passage 16 is joined by a single common intake passage 17, and the common intake passage 17 communicates with the outside via an air flow meter 102 and an air cleaner 18.

  The downstream side of the 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 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 only 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 18 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. By controlling whether the air in the diaphragm chamber is returned to the downstream side of the air cleaner 18 or not to be returned by the on / off control, the pressure in the diaphragm chamber is adjusted.

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 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.

  A supercharging pressure is guided from the main intake passage 19 to the diaphragm chamber 29a, and the supercharged air guided to the diaphragm chamber 29a is returned to the downstream side of the air cleaner 18 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 can be varied 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 cleaner 18 by duty control of the fourth electromagnetic valve 114. It has become.

  On the other hand, the air flow meter 102 provided in the common intake passage 17 detects 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 by rotating the crankshaft. 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. 2 is a cross-sectional view 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.

  The second supply passage 53 is provided with a variable valve 56 that can reduce the amount of lubricating oil in the second supply passage 53, and the opening of the variable valve 56 is controlled by a solenoid 57. The amount of lubricating oil passing through the second supply passage 53 is controlled. That is, the opening of the variable valve 56 is varied from the fully closed state to the fully opened state, thereby changing the inner diameter of the second supply passage 53, that is, the flow path, thereby changing the lubricating oil supplied to the sub turbocharger 11. The amount is adjusted.

  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 lubricating oil that has been lubricated by the charger 10 and the sub turbocharger 11 is returned to the oil pan through the first return passage 54 and the second return passage 55.

  On the other hand, in the present embodiment, the sub turbocharger 11 is provided with a gap sensor 105 as an operating state detection means and a rotation speed detector. For example, the blade of the turbine 11a passes through the gap sensor 105. The fluctuation of the gap caused by this, that is, modulation is detected and a detection signal is output to an ECU (Engine Control Unit) 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.

  As shown in FIG. 2, the ECU 100 is connected to a throttle opening sensor 101, an air flow meter 102, a crank angle sensor 103, an oxygen sensor 104, and a gap sensor 105. 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 into a digital quantity, and injectors 6A, 6B, 6C, 6D based on detection information from throttle opening sensor 101, air flow meter 102, crank angle sensor 103, and oxygen sensor 104. , 6E, 6F To your.

  Further, the ECU 100 turns the actuators 25, 26 “on / off” based on detection information from the throttle opening sensor 101, the air flow meter 102, the crank angle sensor 103, and the oxygen sensor 104. , 26 are turned on, the exhaust switching valve 23 and the intake switching valve 24 are fully opened, and when the actuators 25, 26 are turned off, the exhaust switching valve 23 and the intake switching valve 24 are fully closed. .

  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.

  Further, the ECU 100 estimates the operating state of the sub turbocharger 11 from the rotation speed of the sub turbocharger 11 detected by the gap sensor 105, and controls the solenoid 57 to adjust the opening of the variable valve 56, thereby 2 The amount of lubricating oil supplied to the auxiliary turbocharger 11 from the supply passage 53 is adjusted.

  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. The ECU 100, the variable valve 56 and the solenoid 57 constitute lubricating oil amount control means.

  In addition, when the rotational speed of the auxiliary turbocharger 11 detected by the gap sensor 105 is less than a predetermined value, the ECU 100 opens the opening of the variable valve 56 more than when the rotational speed of the auxiliary turbocharger 11 is greater than or equal to the predetermined value. By narrowing down, the amount of lubricating oil supplied to the sub turbocharger 11 is reduced.

  Next, supercharging control will be described with reference to 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, and FIG. 8 is a diagram showing the relationship between the auxiliary turbocharger 11 and the amount of lubricating oil supplied to the auxiliary turbocharger 11. It is.

  First, the CPU 100 a of the ECU 100 determines the operating state from the engine load calculated based on the detection information of the throttle opening sensor 101, the air flow meter 102 and the oxygen sensor 104 and the engine speed calculated based on the crank angle sensor 103. Whether or not only the main turbocharger 10 is to be operated is determined 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, since the exhaust gas from the engine 1 is supplied only to the main turbocharger 10, only the turbine 10a of the main turbocharger 10 rotates. In the “single turbo stage”, the ECU 100 executes a lubricating oil amount control process (step S3).

  In this lubricating oil amount control process, the solenoid 57 controls the variable valve 56 to be fully closed. For this reason, the lubricating oil is not supplied to the second supply passage 53, and the lubricating oil corresponding to the rotational speed of the engine 1 is supplied only to the main turbocharger 10 through 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 or not it is less than the determination line B (step S4). In step S4, when the CPU 100a determines that the operating state calculated based on the engine load and the engine speed is equal to or higher than the determination line A as shown in FIG. 7, the operating state of the engine is low and high. When the load or medium speed / low load determination line A is exceeded, duty control is performed on the fourth solenoid valve 114 to activate the actuator 29, thereby opening the exhaust bypass valve 28 with a small opening (step). S5).

  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 a lubricating oil amount control process for supplying lubricating oil to the sub turbocharger 11 based on detection information from the gap sensor 105 (step S6). In this lubricating oil amount control process, the rotational speed of the auxiliary turbocharger 11 is detected, and the lubricating oil quantity corresponding to the rotational speed of the auxiliary turbocharge 11 is supplied to the auxiliary turbocharger 11.

  When the exhaust bypass passage 27 is opened, the auxiliary turbocharger 11 starts running and the rotational speed of the auxiliary turbocharger 11 gradually increases. Therefore, the opening degree of the variable valve 56 is gradually increased according to the rotation speed of the sub turbocharger 11 by driving the solenoid 57 from the time when the rotation of the sub turbocharger 11 is started.

  For this reason, the flow path of the second supply passage 53 gradually increases, and the amount of lubricating oil corresponding to the rotational speed of the sub turbocharger 11 is increased from the second supply passage 53 to the sub turbocharger 11 as shown in FIG. Supplied.

  Specifically, the lubricating oil is supplied from the second supply passage 53 to the shaft 65 and the bearing 64 of the auxiliary 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.

  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 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. Further, the duty of the fourth electromagnetic valve 114 is controlled to operate the actuator 29, whereby the exhaust bypass valve 28 is fully closed, and the auxiliary turbocharger 11 finishes the running rotation (step S7).

  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 shifting to the “twin turbo stage”, the CPU 100a of the ECU 100 executes a lubricating oil amount control process for supplying lubricating oil to the auxiliary turbocharger 11 based on detection information from the gap sensor 105 (step S8). . In this lubricating oil amount control process, the rotational speed of the auxiliary turbocharger 11 is detected and the lubricating oil quantity corresponding to the rotational speed of the auxiliary turbocharge 11 is supplied to the auxiliary turbocharger 11 as described above.

  Further, the CPU 100a compares the rotation speed of the sub turbocharger 11 with a predetermined rotation speed rpm1, and when the rotation speed exceeds the predetermined rotation speed rpm1, drives the solenoid 57 to make the opening degree of the variable valve 56 constant. A constant amount of lubricating oil is supplied from the second supply passage 53 to the auxiliary turbocharger 11 with the flow path of the second supply passage 53 kept constant.

  That is, when the amount of lubricating oil is determined based on the operating state of the engine 1, when the detection information from the throttle opening sensor 101, the air flow meter 102, the crank angle sensor 103, and the oxygen sensor 104 varies, the sub turbocharger It is conceivable that the amount of lubricating oil supplied to the sub-turbocharger 11 is reduced in spite of having reached the rotational speed at which the rotational speed of 11 has reached the determination line B.

  In the present embodiment, for example, the rpm 1 is set to be the rotation speed of the auxiliary turbocharger 11 when it reaches the determination line B, and when the auxiliary turbocharger 11 reaches the determination line B, the auxiliary turbocharger 11 is set. The optimal amount of lubricating oil corresponding to the number of rotations can be supplied to the auxiliary turbocharger 11. Therefore, it is possible to avoid the influence of variations in detection information of the throttle opening sensor 101, the air flow meter 102, the crank angle sensor 103, and the oxygen sensor 104.

  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.

  Further, when shifting from the “twin turbo stage” to the “single turbo stage”, when the CPU 100a becomes less than the determination line B, the duty control of the actuator 29 is performed to open the exhaust bypass valve 28, and The actuators 25 and 26 are turned off, and the exhaust switching valve 23 and the intake switching valve 24 are fully closed to decelerate the sub turbocharger 11.

  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 in the running region between the determination line A and the determination line B, the CPU 100a supplies the lubricating oil to the auxiliary turbocharger 11 based on the detection information from the gap sensor 105. Execute.

  In this lubricating oil amount control process, the rotational speed of the auxiliary turbocharger 11 is detected, and the lubricating oil quantity corresponding to the rotational speed of the auxiliary turbocharge 11 is supplied to the auxiliary turbocharger. Specifically, when the exhaust bypass passage 27 is opened with the exhaust switching valve 23 and the intake switching valve 24 fully closed, the rotational speed of the sub turbocharger 11 gradually decreases. Therefore, by driving the solenoid 57 according to the rotation of the sub turbocharger 11, the opening degree of the variable valve 56 is gradually decreased according to the rotation speed of the sub turbocharger 11.

  For this reason, the flow path of the second supply passage 53 gradually decreases, and the amount of lubricating oil corresponding to the rotational speed of the sub turbocharger 11 is increased from the second supply passage 53 to the sub turbocharger 11 as shown in FIG. Supplied.

  As described above, in the present embodiment, the rotational speed of the auxiliary turbocharger 11 is not directly estimated from the operating state of the engine 1 but by directly detecting the rotational speed of the auxiliary turbocharger 11. Accordingly, the amount of lubricating oil supplied to the sub turbocharger 11 is controlled, so that the amount of lubricating oil corresponding to the operating state of the sub turbocharger 11 can be supplied to the sub turbocharger 11.

  For this reason, in a low intake air amount region where only the main turbocharger 10 is operated, lubricating oil leaks from the turbine 11a and the compressor 11b of the sub turbocharger 11, or friction during rotation of the sub turbocharger 11 due to excess lubricating oil. As a result, it is possible to prevent the sub turbocharger 11 from getting worse and affecting the operation.

  Further, in the high intake air amount region where the main turbocharger 10 and the sub turbocharger 11 are operated, the lubricating performance of the sub turbocharger 11 is improved, the cooling action of the sub turbocharger 11 is improved, and oil scorching and wear occur. Can be prevented. As a result, the operation of the auxiliary turbocharger 11 can be performed satisfactorily.

  Further, in the present embodiment, the amount of lubricating oil supplied to the sub turbocharger 11 is controlled by directly detecting the rotation speed of the sub turbocharger 11, so that the optimum according to the actual operating state of the sub turbocharger 11 is controlled. A sufficient amount of lubricating oil can be supplied to the auxiliary turbocharger 11.

  Further, in the present embodiment, the rotation speed of the sub turbocharger 11 is less than the predetermined value rpm1, that is, at the time of low speed rotation, the rotation speed of the sub turbocharger 11 is equal to or higher than the predetermined value rpm1, that is, at the time of high speed rotation. Since the amount of lubricating oil supplied to the auxiliary turbocharger 11 is reduced, the optimum amount of lubricating oil corresponding to the running of the auxiliary turbocharger 11 is supplied when the auxiliary turbocharger 11 rotates at a low speed. The start-up at the start of rotation of the turbocharger 11 can be improved, and the secondary turbocharger 11 can be prevented from being worn during high-speed rotation after the end of the run, or burning due to insufficient cooling of the secondary turbocharger 11 can occur. Can be prevented.

(Second Embodiment)
FIGS. 9-11 is a figure which shows 2nd Embodiment of the internal combustion engine with a supercharger which concerns on this invention, The same number is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted. To do.

  In the present embodiment, as shown in FIGS. 9 and 10, 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 amount of lubricating oil supplied to the auxiliary turbocharger 11 is controlled 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 rotary shaft of the exhaust bypass valve 28 to electrically control the rotation angle of the rotary shaft, in other words, the opening of the exhaust bypass valve 28. A sensor or the like that detects the above may be used.

  In the present embodiment, in order to start the run-up rotation of the auxiliary turbocharger 11, the exhaust bypass valve 28 is duty-controlled to gradually increase the opening of the exhaust bypass valve 28, thereby increasing the exhaust pressure and the auxiliary turbocharger 11. The number of rotations of the charger 11 is gradually increased.

  The CPU 100a of the ECU 100 responds to the opening degree of the exhaust bypass valve opening degree sensor 106 from the second supply passage 53 to the auxiliary turbocharger 11 based on detection information from the exhaust bypass valve opening degree sensor 106 as shown in FIG. Supply the amount of lubricating oil.

  Here, the ECU 100 refers to the map shown in FIG. 7 on the basis of detection information from the throttle opening sensor 101, the air flow meter 102, the crank angle sensor 103, and the oxygen sensor 104, and controls the exhaust gas bypass valve 28 by controlling the duty of the actuator 29. The degree of opening is controlled.

  However, when the detection information of the throttle opening sensor 101, the air flow meter 102, the crank angle sensor 103, and the oxygen sensor 104 varies and the variation of the detection information is accumulated, the opening Q of the exhaust bypass valve 28 is increased. When the lubricating oil is supplied to the auxiliary turbocharger 11 based on the operating condition, the amount of the lubricating oil is determined by the actual operation of the auxiliary turbocharger 11. There is a possibility that oversupply or supply shortage will occur without being able to respond.

  In the present embodiment, the actual opening degree Q of the exhaust bypass valve 28 is detected, and the amount of lubricating oil corresponding to the opening degree Q of the exhaust bypass valve 28 is supplied to the sub turbocharger 11 as shown in FIG. Thus, the optimum amount of lubricating oil corresponding to the actual operating state of the auxiliary turbocharger 11 corresponding to the exhaust flow rate of the bypass passage 27 can be supplied to the auxiliary turbocharger 11, as in the first embodiment. The auxiliary turbocharger 11 can be operated satisfactorily.

  When the opening degree of the exhaust bypass valve 28 exceeds the predetermined opening degree Q1, the solenoid 57 is driven to make the opening degree of the variable valve 56 constant and the flow path of the second supply passage 53 constant. As in the first embodiment, a constant amount of lubricating oil is supplied from the second supply passage 53 to the auxiliary turbocharger 11.

  In each of 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 supercharger-equipped internal combustion engine according to the present invention can supply the optimum amount of lubricating oil corresponding to the operating state of the second supercharger to the second supercharger. The second supercharger has an effect that the operation can be improved, and is provided with a plurality of superchargers, and the operation state of the supercharger is switched according to the operation state of the internal combustion engine. It is useful as an internal combustion engine with a feeder.

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 figure which shows the relationship between the amount of lubricating oil supplied to the sub turbocharger of the internal combustion engine with a supercharger which concerns on the 1st Embodiment of this invention, and a sub turbocharger. 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 figure which shows the relationship between the amount of lubricating oil supplied to the sub turbocharger of the internal combustion engine with a supercharger which concerns on the 2nd Embodiment of this invention, and a sub turbocharger.

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)
16, 20 Auxiliary intake passage (intake passage)
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)
56 Variable valve (lubricating oil amount control means)
57 Solenoid (lubricating oil amount control means)
66 1st communication path (lubricant supply means)
67 Second communication path 68 Third communication path (lubricating oil supply means)
100 ECU (lubricating oil amount 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 (5)

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 At least one or more second superchargers;
An exhaust amount control means for controlling an exhaust amount supplied from the internal combustion engine to the exhaust portion of the second supercharger through the exhaust passage;
An operating state detecting means for detecting an operating state of the second supercharger;
Lubricating oil supply means for supplying lubricating oil to the first supercharger and the second supercharger;
Lubricating oil amount control means for controlling the amount of lubricating oil supplied to at least the second supercharger,
The lubricating oil amount control means controls the amount of lubricating oil supplied to the second supercharger based on the operating state of the second supercharger detected by the operating state detecting means. An internal combustion engine with a supercharger. 2. The internal combustion engine with a supercharger according to claim 1, wherein the operating state detection unit includes a rotation speed detector that detects a rotation speed of the second supercharger. 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,
3. The internal combustion engine with a supercharger according to claim 1, wherein the operating state detection unit includes an opening detector that detects an opening of the exhaust bypass valve. When the rotational speed of the second supercharger detected by the rotational speed detector is less than a predetermined value, the lubricating oil amount control means has a rotational speed of the second supercharger equal to or higher than a predetermined value. The internal combustion engine with a supercharger according to claim 2, wherein the amount of lubricating oil supplied to the second supercharger is less than that in step (2). When the opening degree of the exhaust bypass valve detected by the opening degree detector is less than a predetermined value, the lubricating oil amount control means is more effective than when the opening degree of the exhaust bypass valve is not less than a predetermined value. The internal combustion engine with a supercharger according to claim 3, wherein the amount of lubricating oil supplied to the supercharger of 2 is reduced.

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