JP2009133292A - Negative pressure generator of internal combustion engine with supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To generate a negative pressure, and optionally adjust the magnitude of the negative pressure when supercharging is done by a supercharger. <P>SOLUTION: This negative pressure generator is installed in an engine 1 provided with a supercharger 5 in an intake passage 2, and generates a negative pressure by air flowing in the intake passage 2. This generator comprises a bypass passage 9 provided in the intake passage 2 between the supercharger 5 and the engine 1, an ejector 10 generating the negative pressure by the air flowing in the bypass passage 9, a first valve 12 for adjusting an air flow rate of the intake passage 2, and a second valve 13 for adjusting an air flow rate of the bypass passage 9. An electronic control unit (ECU) 38 controls an opening of the first valve 12 and an opening of the second valve 13, so that the air flow rate of the bypass passage 9 is larger than the air flow rate of the intake passage 2, when the air is flowed to the bypass passage 9. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a negative pressure generator provided in an intake passage of an internal combustion engine with a supercharger.

  Conventionally, a technique described in Patent Document 1 below is known as this type of technique. This technology includes an internal combustion engine, a compressor of a supercharger provided on the intake passage, a bypass passage that bypasses the intake passage between the compressor and the internal combustion engine, and an ejector provided on the bypass passage. A negative pressure generator is described. In this technique, when the internal combustion engine is operated, negative pressure is generated in the ejector by the air flowing through the bypass passage via the compressor. In this technology, the tip of the blow-by gas reduction passage extending from the crank chamber is provided in communication with the ejector, and the blow-by gas is led out from the crank chamber to the blow-by gas reduction passage using the negative pressure generated in the ejector, and further bypassed. The passage is returned to the combustion chamber of the internal combustion engine via the intake passage.

JP 2003-201927 A JP 2005-171925 A

  However, in the technique described in Patent Document 1, since the negative pressure generated in the ejector increases in proportion to the increase in the supercharging pressure by the compressor, the magnitude of this negative pressure cannot be arbitrarily adjusted. Depending on the operating state of the engine, it may be necessary to adjust the amount of blow-by gas reduction. However, in the technique described in Patent Document 1, since the blow-by gas reduction amount is determined by the magnitude of the negative pressure proportional to the supercharging pressure, the blow-by gas reduction amount cannot be arbitrarily adjusted. Further, depending on the opening of the throttle valve provided in the intake passage, the air flow rate in the intake passage may be larger than the air flow rate in the bypass passage. In this case, there is a possibility that negative pressure is not generated in the ejector.

  The present invention has been made in view of the above circumstances, and an object thereof is to generate a negative pressure when supercharging is performed by a supercharger, and to arbitrarily adjust the magnitude of the negative pressure. An object of the present invention is to provide a negative pressure generator for an internal combustion engine with a supercharger that makes it possible.

  In order to achieve the above object, an invention according to claim 1 is a negative pressure generating device for an internal combustion engine with a supercharger having a supercharger in an intake passage, and is provided between the supercharger and the internal combustion engine. A bypass passage provided in the intake passage, an ejector for generating negative pressure by the air flowing through the bypass passage, a first flow rate adjusting means for adjusting an air flow rate of the intake passage, and an air flow rate of the bypass passage. It is intended that the second flow rate adjusting means for adjusting is provided.

  According to the configuration of the above invention, when the internal combustion engine is operated, the first flow rate adjusting means and the second flow rate adjusting means are operated, whereby air flows in both or one of the intake passage and the bypass passage. The flow rate of air flowing through the intake passage is adjusted by the first flow rate adjusting means, and the flow rate of air flowing through the bypass passage is adjusted by the second flow rate adjusting means. When supercharging is performed by the supercharger, negative pressure is generated in the ejector by allowing air to flow through the bypass passage by the first flow rate adjusting means and the second flow rate adjusting means and arbitrarily adjusting the air flow rate. The magnitude of the negative pressure can be arbitrarily changed.

  In order to achieve the above object, according to a second aspect of the present invention, in the first aspect of the invention, the air flow rate in the bypass passage is larger than the air flow rate in the intake passage when air is allowed to flow through the bypass passage. The present invention is provided with a control means for controlling the first flow rate adjusting means and the second flow rate adjusting means.

  According to the configuration of the above invention, in addition to the operation of the invention described in claim 1, when air is allowed to flow through the bypass passage, the control means causes the first air flow rate in the bypass passage to be greater than the air flow rate in the intake passage. By controlling the flow rate adjusting means and the second flow rate adjusting means, a pressure difference can be reliably obtained between the upstream side and the downstream side of the ejector.

  In order to achieve the above object, the invention according to claim 3 is the invention according to claim 1 or 2, further comprising a flow regulator provided at a branch portion between the intake passage and the upstream end of the bypass passage, The first flow rate adjusting means includes a first valve that is provided in the flow rate adjuster and adjusts the opening degree of the intake passage, and the second flow rate adjusting means is provided in the flow rate adjuster and is open degree of the bypass passage. It is intended to include a second valve that adjusts.

  According to the configuration of the invention described above, in addition to the operation of the invention according to claim 1 or 2, the flow rate adjuster provided at the branch portion of the intake passage and the bypass passage is adjusted to adjust the air flow rates of the intake passage and the bypass passage. One valve and the second valve are provided integrally.

  In order to achieve the above object, according to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, one end is connected to the negative pressure generating portion of the ejector and the other end is a gas supply. It is intended to include a gas outlet passage that is connected to a source and guides gas from a gas supply source by negative pressure generated by an ejector.

  According to the configuration of the invention described above, in addition to the operation of the invention according to any one of claims 1 to 3, when the negative pressure is generated in the ejector, the gas is supplied from the gas supply source to the gas outlet passage by the negative pressure. Is derived. Further, the amount of gas derived from the gas supply source is adjusted by adjusting the magnitude of the negative pressure generated in the ejector.

  In order to achieve the above object, according to a fifth aspect of the present invention, in the fourth aspect of the present invention, a branch passage branched from the middle of the gas outlet passage and connected to the intake passage, a gas outlet passage and a branch It is intended to include gas flow switching means provided at a branch portion with the passage and for switching the gas flow in the gas outlet passage to the branch passage.

  According to the configuration of the above invention, in addition to the operation of the invention according to claim 4, the gas flow in the gas outlet passage is switched to the branch passage by the gas flow switching means. At this time, when supercharging by the supercharger is not performed, negative pressure generated in the intake passage acts on the branch passage, and gas is sucked from the gas lead-out passage through the branch passage to the intake passage.

  According to the first aspect of the present invention, a negative pressure can be generated when supercharging is performed by a supercharger, and the magnitude of the negative pressure can be arbitrarily adjusted.

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the negative pressure can be reliably generated by the ejector.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, the configuration for adjusting the air flow rates of the intake passage and the bypass passage can be compactly gathered.

  According to the invention described in claim 4, in addition to the effect of the invention described in any one of claims 1 to 3, when supercharging is performed, the negative pressure generated causes the gas supply source to the internal combustion engine. Gas can be supplied and the gas flow rate can be adjusted.

  According to the invention described in claim 5, in addition to the effect of the invention described in claim 4, when supercharging is not performed, gas can be supplied from the gas supply source to the internal combustion engine, and the gas flow rate thereof Can be adjusted.

[First Embodiment]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment that embodies a negative pressure generator for an internal combustion engine with a supercharger according to the present invention will be described in detail with reference to the drawings.

  1 and 2 are schematic configuration diagrams showing an engine system including the negative pressure generating device of this embodiment. This engine system includes an engine 1 as an internal combustion engine of the present invention, an intake passage 2 is connected to an intake port of the engine 1, and an exhaust passage 3 is connected to an exhaust port of the engine 1. An air cleaner 4 is provided at the inlet of the intake passage 2. The intake passage 2 and the exhaust passage 3 downstream of the air cleaner 4 are provided with a supercharger 5 for boosting the air flowing through the intake passage 2.

  The supercharger 5 includes a compressor 6 disposed in the intake passage 2, a turbine 7 disposed in the exhaust passage 3, and a rotating shaft 8 that rotates the compressor 6 and the turbine 7 together. The supercharger 5 rotates the turbine 7 by the exhaust gas flowing through the exhaust passage 3 and rotates the compressor 6 integrally through the rotating shaft 8 to increase the pressure of the air flowing through the intake passage 2, that is, supercharging. To do.

  A bypass passage 9 is provided in the intake passage 2 between the compressor 6 of the supercharger 5 and the engine 1. The bypass passage 9 is provided with an ejector 10 that generates a negative pressure by the air flowing through the bypass passage 9. The ejector 5 includes a divergent nozzle. The ejector 5 jets high-pressure air flowing through the bypass passage 9 as a driving gas from the divergent nozzle, thereby generating a low-pressure supersonic flow and generating a negative pressure. A flow rate adjuster 11 is provided at a branch portion between the intake passage 2 and the upstream end of the bypass passage 9. The flow regulator 11 is provided with a first valve 12 and a second valve 13 integrally. The first valve 12 corresponds to the first flow rate adjusting means of the present invention, and adjusts the opening degree of the intake passage 2 in order to adjust the flow rate of air flowing through the intake passage 2. The second valve 13 corresponds to the second flow rate adjusting means of the present invention, and adjusts the opening degree of the bypass passage 9 in order to adjust the flow rate of air flowing through the bypass passage 9. The first and second valves 12 and 13 are both butterfly valves, and are driven by a first motor 34 and a second motor 36 (see FIGS. 3 and 5), respectively. The detailed configuration of the flow rate adjuster 11 will be described later.

  In the intake passage 2, an intercooler 14 is provided between the compressor 6 of the supercharger 5 and the flow rate adjuster 11. The intercooler 14 cools the air pressurized by the compressor 6 to an appropriate temperature.

  In this embodiment, one end of the gas outlet passage 15 is connected to the negative pressure generating portion 10 a of the ejector 10. The other end of the gas outlet passage 15 is connected to a PCV valve 16 constituting the gas supply source of the present invention. The PCV valve 16 is an element constituting a blow-by gas reduction device for returning the blow-by gas leaked from the combustion chamber of the engine 1 to the crank case to the combustion chamber of the engine 1 again through the intake passage 2. The reduction flow rate is adjusted. When a negative pressure is generated in the ejector 10, the negative pressure acts on the gas outlet passage 15, and blow-by gas is guided from the PCV valve 16 to the gas outlet passage 15.

  In this embodiment, a branch passage 17 branched from the middle of the gas outlet passage 15 and connected to the intake passage 2 is provided. Further, a gas flow switching machine 18 as a gas flow switching means of the present invention for switching the flow of blow-by gas in the gas outlet passage 15 to the branch passage 17 is provided at a branch portion between the gas outlet passage 15 and the branch passage 17. It is done. The gas flow switching machine 18 includes a third valve 19 that opens and closes the gas outlet passage 15 and a fourth valve 20 that opens and closes the branch passage 17. The third and fourth valves 19 and 20 are both butterfly valves and are driven to open and close by a common third motor 39 (see FIG. 5).

  Further, a scavenging passage 21 for introducing air (fresh air) into the crank chamber is provided between the intake passage 2 and the engine 1 in order to scavenge blow-by gas in the crank chamber. The upstream end inlet of the scavenging passage 21 is connected to the intake passage 2 between the air cleaner 4 and the supercharger 5, and the downstream end outlet is connected to a head cover (not shown) of the engine 1.

  Here, as an example, the configuration of the flow rate adjuster 11 will be described in detail. FIG. 3 is a sectional view of the flow controller 11. FIG. 4 shows a cross-sectional view of the flow rate regulator 11 along the line AA in FIG. The flow regulator 11 of this embodiment includes a housing 33 including a first bore 31 that communicates with the intake passage 2 and a second bore 32 that communicates with the bypass passage 9. The upstream side of the first bore 31 is connected to the intake passage 2, and the downstream side thereof is also connected to the intake passage 2. The upstream side of the second bore 32 is connected to the intake passage 2, and the downstream side thereof is connected to the bypass passage 9. In the first bore 31, the first valve 12 is rotatably supported by the first support shaft 12a. In the second bore 32, the second valve 13 is rotatably supported by the second support shaft 13a. A first motor 34 is provided in the housing 33 adjacent to the first valve 12. The proximal end portion of the first support shaft 12 a is drivingly connected to the output shaft of the first motor 34 via the first reduction gear mechanism 35. Similarly, a second motor 36 is provided in the housing 33 adjacent to the second valve 13. The proximal end portion of the second support shaft 13 a is drivably coupled to the output shaft of the second motor 36 via the second reduction gear mechanism 37. Each reduction gear mechanism 35, 37 is composed of a plurality of gears that are drivingly connected to each other. Therefore, when the first motor 34 is driven, the first valve 12 is driven to open and close via the first reduction gear mechanism 35. The opening degree of the first valve 12 can be adjusted by the driving amount of the first motor 34. Similarly, when the second motor 36 is driven, the second valve 13 is driven to open and close via the second reduction gear mechanism 37. The opening degree of the second valve 13 can be adjusted by the driving amount of the second motor 36.

  Next, an electrical configuration according to the negative pressure generator of this embodiment will be described. FIG. 5 is a block diagram showing the electrical configuration. In this embodiment, an electronic control unit (ECU) 38 as control means of the present invention for controlling the flow regulator 11 and the gas flow switching machine 18 is provided. The flow rate regulator 11 includes a first valve 12, a second valve 13, a first motor 34, and a second motor 36. The gas flow switching machine 18 includes a third valve 19 and a fourth valve 20, and a third motor 39 that drives the valves 19 and 20. A first motor 34, a second motor 36 and a third motor 39 are connected to the output side of the ECU 38. Further, an accelerator sensor 41, a first valve sensor 42, a second valve sensor 43 and a supercharging sensor 44 are connected to the input side of the ECU 38. The accelerator sensor 41 detects the amount of operation (accelerator opening) AC of the accelerator pedal 45 by the driver and outputs a detection signal thereof. The first valve sensor 42 detects the actual opening (actual opening) TA1 of the first valve 12 and outputs a detection signal thereof. The second valve sensor 43 detects the actual opening degree TA2 of the second valve 13 and outputs a detection signal thereof. The supercharging sensor 44 is for detecting the operation of the supercharger 5 and outputs an ON signal when supercharging by the supercharger 5 is performed. The ECU 38 stores a control program for controlling the negative pressure generating device, and controls the flow rate adjuster 11 and the gas flow switching device 18 based on the control program.

  FIG. 6 is a flowchart showing a control program executed by the ECU 38 to control the negative pressure generator. When processing based on this control program is started, the ECU 38 determines in step 100 whether or not there is supercharging. The ECU 38 makes this determination based on a signal from the supercharging sensor 44. If the determination in step 100 is negative, the supercharger 5 has not been supercharged, so the ECU 38 proceeds to step 111 and executes the processes in steps 111 to 115. If the determination in step 100 is affirmative, the turbocharger 5 has performed supercharging, and therefore the ECU 38 proceeds to step 121 and executes the processes of steps 121 to 124.

  That is, when supercharging is not performed, the ECU 38 first switches the gas flow to the branch passage 17 by the gas flow switching device 18 in step 111. For this purpose, the ECU 38 controls the third motor 39 to close the third valve 19 and open the fourth valve 20 to switch the gas outlet passage 15 to the branch passage 17 as shown in FIG. .

  Next, in step 112, the ECU 38 controls the second motor 36 in the flow rate regulator 11 so that the second valve 13 is fully closed as shown in FIG.

  In step 113, the ECU 38 reads the accelerator opening degree AC detected by the accelerator sensor 41, and in step 114, calculates the target opening degree TTA1 of the first valve 12 corresponding to the accelerator opening degree AC.

  In step 115, the ECU 38 controls the first motor 34 so that the actual opening degree (actual opening degree) TA1 detected by the first valve sensor 42 becomes the target opening degree TTA1. Thereafter, the ECU 38 returns to the process of step 100.

  If supercharging is not performed during the operation of the engine 1 by the above-described processing of step 111 to step 115, the air sucked into the intake passage 2 from the air cleaner 4 is supplied to the compressor 6, the intercooler 14 and the supercooler 5. It passes through the flow rate regulator 11, does not flow to the bypass passage 9, flows only through the intake passage 2, and is sucked into the combustion chamber of the engine 1. At this time, the intake negative pressure of the intake passage 2 acts on the branch passage 17, whereby blow-by gas is led from the PCV valve 16 to the gas lead-out passage 15 and is sucked into the intake passage 2 from the branch passage 17 to burn the engine 1. Returned to the room.

  On the other hand, if supercharging is being performed, the ECU 38 first switches the gas flow to the ejector 10 by the gas flow switching machine 18 in step 121. For this purpose, the ECU 38 controls the third motor 39 to open the third valve 19 and close the fourth valve 20 to switch the gas outlet passage 15 to the ejector 10 as shown in FIG.

  Next, the ECU 38 reads the accelerator opening degree AC detected by the accelerator sensor 41 in step 122, and in step 123, the target opening degree TTA1 of the first valve 12 corresponding to the accelerator opening degree AC and the second opening degree TTA1. The target opening degree TTA2 of the valve 13 is calculated respectively. Here, the sum of the air flow rates flowing through the intake passage 2 and the bypass passage 9 is the air flow rate required by the engine 1, and the air flow rate flowing through the bypass passage 2 is greater than the air flow rate flowing through the intake passage 2. In addition, the target opening degree TTA1 of the first valve 12 and the target opening degree TA2 of the second valve 13 are respectively calculated. For example, the ECU 38 calculates each target opening degree TTA1, TTA2 so that the ratio of the air flow rate flowing through the bypass passage 2 and the air flow rate flowing through the intake passage 2 is “3: 2.”

  In step 124, the ECU 38 controls the first motor 34 so that the actual opening degree TA1 detected by the first valve sensor 42 becomes the target opening degree TTA1, and also detects it by the second valve sensor 43. The second motor 36 is controlled so that the actual opening degree TA2 is the target opening degree TTA2. Thereafter, the ECU 38 once returns to the process of step 100.

  When supercharging is performed during the operation of the engine 1 by the processing of step 121 to step 124 described above, the air sucked into the intake passage 2 from the air cleaner 4 is supplied to the compressor 6, the intercooler 14 and the flow rate of the supercharger 5. It passes through the regulator 11, flows through the intake passage 2 and the bypass passage 9, and is supplied in a pressurized state to the combustion chamber of the engine 1. Here, when the negative pressure is generated in the ejector 10 by the air flowing through the bypass passage 9, blow-by gas is led from the PCV valve 16 to the gas outlet passage 15, and flows from the ejector 10 through the bypass passage 9 and the intake passage 2 to the engine. Reduced to one combustion chamber.

  According to the negative pressure generating apparatus of this embodiment described above, when the engine 1 is operating, the ECU 38 controls the opening degree of the first valve 12 and the second valve 13 of the flow rate regulator 11, so that the intake passage 2 and / or bypass passage 9 air flows. The air flow rate flowing through the intake passage 2 is adjusted by the first valve 12, and the air flow rate flowing through the bypass passage 9 is adjusted by the second valve 13. When supercharging is not performed by the supercharger 5, a negative pressure is generated in the intake passage 2, and the ECU 38 controls the opening degree of the first valve 12, whereby the magnitude of the negative pressure in the intake passage 2 is increased. Can be changed arbitrarily. When supercharging is performed by the supercharger 5, the ECU 38 controls the opening degree of the first valve 12 and the second valve 13, thereby allowing air to flow through the bypass passage 9 and the air flow rate thereof. It can be adjusted arbitrarily. By adjusting the air flow rate, a negative pressure is generated in the ejector 10, and the magnitude of the negative pressure can be arbitrarily changed. For this reason, according to the negative pressure generator of this embodiment, even when supercharging is performed by the supercharger 5, a negative pressure can be generated, and the magnitude of the negative pressure can be arbitrarily adjusted. .

  In this embodiment, when supercharging is performed and air flows through the bypass passage 9, the ECU 38 controls the first valve in the flow regulator 11 so that the air flow rate in the bypass passage 9 is larger than the air flow rate in the intake passage 2. 12 and the opening degree of the second valve 13 are controlled. Therefore, a pressure difference is reliably obtained between the upstream side and the downstream side of the ejector 10. For this reason, the ejector 10 can reliably generate the negative pressure.

  In this embodiment, a first valve 12 and a second valve 13 for adjusting the air flow rates of the intake passage 2 and the bypass passage 9 are respectively provided in a flow rate adjuster 11 provided at a branch portion of the intake passage 2 and the bypass passage 9. The first motor 34 and the second motor 36 are integrally provided. For this reason, the structure for adjusting the air flow rate of the intake passage 2 and the bypass passage 9 can be made compact.

  In this embodiment, when supercharging is not performed by the supercharger 5, the flow of blow-by gas in the gas outlet passage 15 is switched to the branch passage 17 by the gas flow switching device 18. Accordingly, when the intake negative pressure generated in the intake passage 2 acts on the branch passage 17, blow-by gas is led from the PCV valve 16 to the gas outlet passage 15, and the blow-by gas is sucked from the branch passage 17 into the intake passage 2. To the combustion chamber of the engine 1. Here, by adjusting the opening degree of the first valve 12 of the flow regulator 11, the magnitude of the intake negative pressure in the intake passage 2 is adjusted, and the blow-by gas flow rate returned to the combustion chamber of the engine 1 is reduced. Adjusted. For this reason, when supercharging is not performed, blow-by gas can be supplied to the engine 1 and reduced and supplied, and the flow rate of the blow-by gas can be adjusted.

  On the other hand, in this embodiment, when supercharging is performed by the supercharger 5, the flow of blow-by gas in the gas outlet passage 15 is switched to the ejector 10 by the gas flow switching unit 18. Accordingly, when negative pressure is generated in the ejector 10, blow-by gas is led from the PCV valve 16 to the gas outlet passage 15 by the negative pressure, and the blow-by gas flows from the bypass passage 9 to the intake passage 2 to burn the engine 1. Returned to the room. In addition, by adjusting the opening degree of the first valve 12 and the second valve 13 of the flow regulator 11, the magnitude of the negative pressure generated in the ejector 10 is adjusted, and the blow-by derived from the PCV valve 16. The amount of gas is adjusted, and the flow rate of blow-by gas returned to the combustion chamber of the engine 1 is adjusted. For this reason, even when supercharging is performed, the blowby gas can be reduced and supplied to the engine 1, and the blowby gas flow rate can be adjusted.

[Second Embodiment]
Next, a second embodiment in which the negative pressure generating device for an internal combustion engine with a supercharger according to the present invention is embodied will be described in detail with reference to the drawings. In each embodiment described below, the same components as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. Hereinafter, different points will be mainly described.

  7 and 8 are schematic configuration diagrams showing an engine system including the negative pressure generating device of this embodiment. FIG. 7 shows a case where supercharging is not performed by the supercharger 5, and FIG. 8 shows a case where supercharging is performed by the supercharger 5. This embodiment differs from the first embodiment in the configuration of the gas supply source of the present invention. That is, in this embodiment, the PCV valve 16 of the first embodiment is omitted, and an EGR valve 22 as a gas supply source of the present invention is provided in the exhaust passage 3 instead. One end of the gas outlet passage 15 is connected to the EGR valve 22. The EGR valve 22 is opened as necessary when the engine 1 is in operation, and a part of the exhaust gas flowing through the exhaust passage 3 is led out to the gas outlet passage 15 as EGR gas. Other configurations are the same as those of the first embodiment.

  Therefore, in this embodiment, when supercharging is not performed during the operation of the engine 1, the air sucked into the intake passage 2 from the air cleaner 4 is converted into the compressor 6, the intercooler 14, and the flow rate adjuster 11 of the supercharger 5. , And does not flow to the bypass passage 9 but flows only through the intake passage 2 and is sucked into the combustion chamber of the engine 1. At this time, the intake negative pressure of the intake passage 2 acts on the branch passage 17, whereby EGR gas is led out from the EGR valve 22 to the gas outlet passage 15, and the EGR gas is sucked into the intake passage 2 from the branch passage 17. Reduced and supplied to the combustion chamber of the engine 1.

  On the other hand, when supercharging is performed during the operation of the engine 1, the air drawn into the intake passage 2 from the air cleaner 4 passes through the compressor 6, the intercooler 14 and the flow rate adjuster 11 of the supercharger 5, and the intake passage 2 and the bypass passage 9 and supplied to the combustion chamber of the engine 1 in a pressurized state. Here, when the negative pressure is generated in the ejector 10 by the air flowing through the bypass passage 9, EGR gas is led from the EGR valve 22 to the gas outlet passage 15, and the EGR gas is discharged from the ejector 10 to the bypass passage 9 and the intake passage 2. And is supplied to the combustion chamber of the engine 1 after being reduced.

  Therefore, also in this embodiment, the same effect as that of the first embodiment can be obtained for the generation of negative pressure. Further, in this embodiment, the EGR gas can be reduced and supplied to the engine 1 when the supercharging is performed and when the supercharging is not performed, and the EGR gas flow rate can be adjusted.

[Third Embodiment]
Next, a third embodiment in which the negative pressure generating device for an internal combustion engine with a supercharger according to the present invention is embodied will be described in detail with reference to the drawings.

  9 and 10 are schematic configuration diagrams showing an engine system including the negative pressure generating device of this embodiment. FIG. 9 shows a case where supercharging is not performed by the supercharger 5, and FIG. 10 shows a case where supercharging is performed by the supercharger 5. This embodiment differs from the first embodiment in the configuration of the gas supply source of the present invention. That is, in this embodiment, the PCV valve 16 of the first embodiment is omitted, and a canister 23 as a gas supply source of the present invention is provided instead. One end of the gas outlet passage 15 is connected to the canister 23. The canister 23 temporarily adsorbs the evaporated fuel generated in the fuel tank, and guides the evaporated fuel to the gas outlet passage 15 as vapor gas when the engine 1 is operated. Other configurations are the same as those of the first embodiment.

  Therefore, in this embodiment, when supercharging is not performed during the operation of the engine 1, the air sucked into the intake passage 2 from the air cleaner 4 is converted into the compressor 6, the intercooler 14, and the flow rate adjuster 11 of the supercharger 5. , And does not flow to the bypass passage 9 but flows only through the intake passage 2 and is sucked into the combustion chamber of the engine 1. At this time, the intake negative pressure of the intake passage 2 acts on the branch passage 17, whereby vapor gas is led from the canister 23 to the gas outlet passage 15, and the vapor gas is sucked from the branch passage 17 into the intake passage 2 to Supplied to the combustion chamber.

  On the other hand, when supercharging is performed during the operation of the engine 1, the air drawn into the intake passage 2 from the air cleaner 4 passes through the compressor 6, the intercooler 14 and the flow rate adjuster 11 of the supercharger 5, and the intake passage 2 and the bypass passage 9 and supplied to the combustion chamber of the engine 1 in a pressurized state. Here, when negative pressure is generated in the ejector 10 by the air flowing through the bypass passage 9, vapor gas is led from the canister 23 to the gas outlet passage 15, and the vapor gas flows from the ejector 10 through the bypass passage 9 and the intake passage 2. It is supplied to the combustion chamber of the engine 1.

  Therefore, also in this embodiment, the same effect as that of the first embodiment can be obtained for the generation of negative pressure. In this embodiment, the vapor gas can be supplied to the engine 1 and the flow rate of the vapor gas can be adjusted in each of the case where the supercharging is performed and the case where the supercharging is not performed.

  The present invention is not limited to the embodiments described above, and can be implemented as follows by appropriately changing a part of the configuration without departing from the spirit of the invention.

  (1) In the first embodiment, the gas outlet passage 15 is provided with the branch passage 15 and the gas flow switching machine 18, but as shown in FIG. Can be omitted. In this case, when supercharging is not performed, by opening both the first valve 12 and the second valve 13 of the flow regulator 11, air flows through both the intake passage 2 and the bypass passage 9, and the ejector 10. Thus, a negative pressure can be generated, and blow-by gas can be reduced from the gas outlet passage 15 through the ejector 10, the bypass passage 9 and the intake passage 2 to the combustion chamber of the engine 1. Even when supercharging is not performed, the first valve 12 of the flow regulator 11 is opened and the second valve 13 is closed, so that the negative pressure generated in the intake passage 2 acts on the downstream side of the ejector 10. Can be made. Thereby, blow-by gas can be reduced from the gas outlet passage 15 to the combustion chamber of the engine 1 via the ejector 10, the bypass passage 9 and the intake passage 2. It can change similarly about 2nd Embodiment and 3rd Embodiment.

  (2) In the first embodiment, the flow regulator 11 in which the first valve 12 and the second valve 13 are integrally formed is provided at a branch portion between the intake passage 2 and the upstream end of the bypass passage 9. However, as shown in FIG. 12, the flow rate regulator 11 may be omitted, and the first valve 12 and the second valve 13 may be separately provided in the intake passage 2 and the bypass passage 9. Also in this case, the first valve 12 and the second valve 13 may be individually driven by a motor. It can change similarly about 2nd Embodiment and 3rd Embodiment.

The schematic block diagram of the engine system which concerns on 1st Embodiment and contains a negative pressure generator. The schematic block diagram of the engine system which concerns on 1st Embodiment and contains a negative pressure generator. Sectional drawing which concerns on 1st Embodiment and shows a flow regulator. Sectional drawing of the flow regulator which concerns on 1st Embodiment and followed the AA line of FIG. The block diagram which shows the electrical structure which concerns on 1st Embodiment and concerns on a negative pressure generator. The flowchart which concerns on 1st Embodiment and shows a control program. The schematic block diagram of the engine system which concerns on 2nd Embodiment and contains a negative pressure generator. The schematic block diagram of the engine system which concerns on 2nd Embodiment and contains a negative pressure generator. The schematic block diagram of the engine system which concerns on 3rd Embodiment and contains a negative pressure generator. The schematic block diagram of the engine system which concerns on 3rd Embodiment and contains a negative pressure generator. The schematic block diagram of the engine system which concerns on another embodiment and contains a negative pressure generator. The schematic block diagram of the engine system which concerns on another embodiment and contains a negative pressure generator.

Explanation of symbols

1 engine (internal combustion engine)
2 Intake passage 5 Supercharger 6 Compressor 7 Turbine 8 Rotating shaft 9 Bypass passage 10 Ejector 10a Negative pressure generator 11 Flow rate adjuster 12 First valve (first flow rate adjusting means)
13 Second valve (second flow rate adjusting means)
15 Gas outlet passage 16 PCV valve (gas supply source)
17 Branch passage 18 Gas flow switching machine (gas flow switching means)
19 Third valve 20 Fourth valve 22 EGR valve (gas supply source)
23 Canister (Gas supply source)
34 1st motor 35 1st reduction gear mechanism 36 2nd motor 37 2nd reduction gear mechanism 38 ECU (control means)
39 Third motor

Claims (5)

A negative pressure generating device for a supercharged internal combustion engine having a supercharger in an intake passage,
A bypass passage provided in the intake passage between the supercharger and the internal combustion engine;
An ejector for generating a negative pressure by the air flowing through the bypass passage;
First flow rate adjusting means for adjusting the air flow rate of the intake passage;
A negative pressure generator for an internal combustion engine with a supercharger, comprising: a second flow rate adjusting means for adjusting an air flow rate in the bypass passage. Control means for controlling the first flow rate adjusting means and the second flow rate adjusting means so that the air flow rate in the bypass passage is greater than the air flow rate in the intake passage when air is passed through the bypass passage. The negative pressure generating device for an internal combustion engine with a supercharger according to claim 1. A flow rate adjuster provided at a branch portion between the intake passage and the upstream end of the bypass passage, and the first flow rate adjusting means is provided in the flow rate adjuster to adjust the opening of the intake passage. The first valve according to claim 1 or 2, wherein the second flow rate adjusting means includes a second valve that is provided in the flow rate adjuster and adjusts an opening degree of the bypass passage. The negative pressure generator for an internal combustion engine with a supercharger as described. One end is connected to the negative pressure generating portion of the ejector, the other end is connected to a gas supply source, and a gas lead-out passage is provided for leading the gas from the gas supply source by the negative pressure generated in the ejector. The negative pressure generating device for an internal combustion engine with a supercharger according to any one of claims 1 to 3. A branch passage branched from the middle of the gas outlet passage and connected to the intake passage;
5. The gas flow switching means provided at a branch portion between the gas outlet passage and the branch passage, and for switching a gas flow in the gas outlet passage to the branch passage. The negative pressure generator for an internal combustion engine with a supercharger.