Hybrid vehicle

Abstract

To improve the exhaust performance of an internal combustion engine of a hybrid vehicle.SOLUTION: A hybrid vehicle 1 includes: an electric power train 3; a first coolant path 5 for cooling a part of a cylinder head 4 of an internal combustion engine 2; and a second coolant path 6 for cooling the engine 2 independently of the first coolant path 5. Disposed in the first coolant path 5 are an electric power train 3, a first water jacket 7, a fuel supply pipe 8, a heater 9, a first radiator 10, and a first pump 11. Before starting the engine 2 while traveling, the hybrid vehicle 1 warms the cylinder head 4 of the engine 2 with first coolant warmed by the electric power train 3 or with the first coolant warmed by the heater 9.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a hybrid vehicle.

Background Art

[0002] For example, Patent Document 1 discloses a configuration in which an intake port lower side cooling water passage that crosses below the intake port, an exhaust port lower side cooling water passage that crosses below the exhaust port, and a combustion chamber upper side cooling water passage that is located between the intake port and the exhaust port and crosses above the center of the combustion chamber are each provided independently of each other in a cylinder head.

[0003] Knocking in an internal combustion engine often occurs not at the center of the combustion chamber but on the side of the intake port or the exhaust port. Therefore, in the internal combustion engine of Patent Document 1, the flow rate of the cooling water flowing through the intake port lower side cooling water passage and the exhaust port lower side cooling water passage is made larger than the flow rate of the cooling water flowing through the combustion chamber upper side cooling water passage. That is, in the internal combustion engine of Patent Document 1, the minimum passage cross-sectional area of the combustion chamber upper side cooling water passage is set to be smaller than the minimum passage cross-sectional areas of the intake port lower side cooling water passage and the exhaust port lower side cooling water passage to suppress knocking.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the internal combustion engine of Patent Document 1 starts in a cold state with a low cooling water temperature, the warming of the intake port is suppressed by the cooling water flowing through the intake port lower side cooling water passage.

[0006] Therefore, in the internal combustion engine of Patent Document 1, when fuel adheres to the wall surface of the intake port at startup, the vaporization of this adhered fuel is suppressed, and the PN (Particulate Number) increases due to the fuel that flows into the combustion chamber as droplets from the intake port, which may deteriorate the exhaust performance.

Means for Solving the Problems

[0007] The hybrid vehicle of the present invention includes an internal combustion engine for power generation that performs port injection, a driving force generation unit that generates a driving force transmitted to drive wheels, A first cooling water path for cooling an intake port of a cylinder head of the internal combustion engine, and a second cooling water path for cooling a cylinder block of the internal combustion engine, and has The The cylinder head is warmed by circulating warm water warmed by the driving force generation unit or warm water warmed using a heater before starting the internal combustion engine. , in a hybrid vehicle that circulates warm water heated by the driving force generation unit or warm water heated using the heater through the first cooling water path before starting the internal combustion engine, the first cooling water path for cooling the intake port and a cooling water path for cooling portions other than the intake port are independently provided in the cylinder head, and the same cooling water as that of the second cooling water path is circulated through the cooling water path for cooling portions other than the intake port It is characterized by this.

Effects of the Invention

[0008] The hybrid vehicle of the present invention can promote the vaporization of fuel adhering to the intake port and intake valve at startup of the internal combustion engine, and can reduce the PN at startup of the internal combustion engine.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0011] FIGS. 1 to 3 relate to a hybrid vehicle 1 according to a first embodiment to which the present invention is applied. FIG. 1 is an explanatory diagram schematically showing a cooling water path of an internal combustion engine 2 in the hybrid vehicle 1 according to the first embodiment. FIG. 2 is a cross-sectional view of a main part of the internal combustion engine 2 mounted on the hybrid vehicle 1 according to the first embodiment. FIG. 3 is an explanatory diagram schematically showing an example of a fuel supply pipe 8 for supplying fuel to the internal combustion engine 2 mounted on the hybrid vehicle 1 according to the first embodiment.

[0012] In the hybrid vehicle 1 according to the first embodiment, the internal combustion engine 2 to be mounted is for power generation that performs port injection, and the drive wheels are driven by an electric motor (not shown) of an electric power train 3. That is, the hybrid vehicle 1 according to the first embodiment is a series hybrid vehicle in which all the power of the internal combustion engine 2 is used for power generation. The internal combustion engine 2 is connected to a power generation motor generator (not shown).

[0013] The hybrid vehicle 1 has an electric power train 3, a first cooling water path 5 for cooling a part of a cylinder head 4 of the internal combustion engine 2, and a second cooling water path 6 for cooling the internal combustion engine 2. The first cooling water path 5 and the second cooling water path 6 are independent cooling water paths from each other.

[0014] The first cooling water path 5 is a circulation path through which first cooling water as a first refrigerant circulates. In the first cooling water path 5, an electric power train 3, a first water jacket 7, a fuel supply pipe 8, a heater 9, a first radiator 10, and a first pump 11 are arranged.

[0015] The electric power train 3 corresponds to a driving force generation unit, and has, for example, an electric motor (not shown) that generates a driving force for driving drive wheels, an inverter (not shown) that supplies AC power to this electric motor, and a battery (not shown) that supplies power to this inverter.

[0016] The first water jacket 7 is formed in the cylinder head 4 of the internal combustion engine 2 and mainly aims to cool the intake port 12. As shown in FIG. 2, the first water jacket 7 is formed below the intake port 12. Specifically, the first water jacket 7 is formed along the cylinder row direction below the vicinity of the downstream end of the intake port 12. Further, the first water jacket 7 is formed below the intake port 12 at a position downstream of the fuel injection valve 13 that injects fuel into the intake port 12, and is closer to the valve body 14a of the intake valve 14 than the fuel injection valve 13. The supply of the first cooling water to the first water jacket 7 can be stopped by the electric first control valve 15 provided in the first cooling water path 5. The first control valve 15 can control the flow rate of the first cooling water flowing through the first water jacket 7.

[0017] As shown in FIGS. 2 and 3, the fuel supply pipe 8 supplies fuel to the fuel injection valves 13 of each cylinder of the internal combustion engine 2. The fuel supply pipe 8 has an elongated rectangular parallelepiped shape along the cylinder row direction so as to straddle each cylinder of the internal combustion engine 2. The fuel supply pipe 8 is disposed above the cylinder head 4. In the fuel supply pipe 8, a cooling water passage 16 through which the first cooling water flows and a fuel passage 17 through which the fuel supplied to the fuel injection valve 13 flows are formed. The cooling water passage 16 is a straight passage that penetrates the inside of the fuel supply pipe 8 in the cylinder row direction (longitudinal direction). Also, the flow of the cooling water in the cooling water passage 16 and the flow of the fuel in the fuel passage 17 are in a parallel flow relationship. Note that the fuel supply pipe 8 may be configured such that the flow of the cooling water in the cooling water passage 16 and the flow of the fuel in the fuel passage 17 are in a counterflow relationship.

[0018] The fuel supply pipe 8 shown in FIG. 3 shows the case where the internal combustion engine 2 has three cylinders and each cylinder has two intake ports 12, two fuel injection valves 13, and two intake valves 14. Also, reference numeral 18 in FIG. 3 is the fuel inlet of the fuel supply pipe 8. Reference numeral 19 in FIG. 3 is the cooling water inlet of the fuel supply pipe 8. Reference numeral 20 in FIG. 3 is the cooling water outlet of the fuel supply pipe 8.

[0019] The supply of the first cooling water to the fuel supply pipe 8 can be stopped by the first control valve 15. The first control valve 15 can control the flow rate of the first cooling water flowing through the fuel supply pipe 8. The first control valve 15 can circulate the first cooling water so as to bypass the first water jacket 7 and the fuel supply pipe 8 simultaneously.

[0020] The heater 9 is arranged in parallel with the first cooling water path 5 and can warm the first cooling water in the first cooling water path 5. For example, it is a component of the air conditioning device in the passenger compartment of the hybrid vehicle 1. The heater 9 may be a heat pump. The supply of the first cooling water to the heater 9 can be stopped by closing the electric second control valve 21. The second control valve 21 can control the flow rate of the first cooling water flowing through the heater 9. The second control valve 21 can circulate the first cooling water so as to bypass the heater 9.

[0021] The first radiator 10 is arranged in parallel with the first cooling water path 5 and can cool the first cooling water in the first cooling water path 5. The supply of the first cooling water to the first radiator 10 can be stopped by closing the electric third control valve 22. The third control valve 22 can control the flow rate of the first cooling water flowing through the first radiator 10. The third control valve 22 can circulate the first cooling water so as to bypass the first radiator 10.

[0022] The first pump 11 is, for example, an electric pump, and circulates the first cooling water in the first cooling water path 5 clockwise in FIG. 1.

[0023] The second cooling water path 6 is a circulation path through which the second cooling water as the second refrigerant circulates. In the second cooling water path 6, a second water jacket 27, a third water jacket 28, a second radiator 29, and a second pump 30 are arranged.

[0024] The second water jacket 27 is formed in the cylinder head 4 and is mainly for cooling the parts other than the intake port. As shown in Fig. 2, the second water jacket 27 is formed along the cylinder row direction above the combustion chamber of each cylinder and below the exhaust port (not shown).

[0025] The third water jacket 28 is formed in the cylinder block 31 and is for cooling the cylinder block 31.

[0026] The second radiator 29 cools the second cooling water in the second cooling water passage 6. Also, the flow rate of the second cooling water supplied to the second radiator 29 is controlled by the thermostat 32.

[0027] The second pump 30 is, for example, a water pump driven by the internal combustion engine 2, and circulates the second cooling water in the second cooling water passage 6 clockwise in Fig. 1.

[0028] As described above, the first cooling water passage 5 is configured such that the first cooling water that has cooled the electric power train 3 can flow into the first water jacket 7 and the fuel supply pipe 8 before passing through the first radiator 10. That is, the hybrid vehicle 1 has the first cooling water passage 5 capable of circulating the first cooling water heated by parts (components) other than the internal combustion engine 2, and the cylinder head 4 of the internal combustion engine 2 can be warmed up by the first cooling water circulating in the first cooling water passage 5.

[0029] The hybrid vehicle 1 runs for a certain period after starting without starting the internal combustion engine 2. That is, the internal combustion engine 2 of the hybrid vehicle 1 starts during running. Also, the hybrid vehicle 1 can raise the temperature of the first cooling water in the first cooling water passage 5 by receiving heat from the electric power train 3 and the heater 9. Further, the PN (Particulate Number) of the internal combustion engine 2 depends on the wall temperature of the intake port 12, and can be reduced as the wall surface temperature of the intake port 12 becomes higher.

[0030] Therefore, before starting the internal combustion engine 2 during driving, the hybrid vehicle 1 warms up the cylinder head 4 of the internal combustion engine 2 with warm water (first cooling water) warmed by the electric power train 3 or warm water (first cooling water) warmed by the heater 9 capable of heating the first cooling water in the first cooling water path 5.

[0031] Before starting the internal combustion engine 2 after starting to drive, the hybrid vehicle 1 can warm up the periphery of the intake port 12 of the cylinder head 4 by flowing the first cooling water warmed by the electric power train 3 or the heater 9 into the first water jacket 7.

[0032] When the cylinder head 4 of the internal combustion engine 2 is warmed up and the intake port 12 is warmed up before starting, the hybrid vehicle 1 can promote the vaporization of the fuel injected from the fuel injection valve 13 and adhering to the intake port 12 and the intake valve 14.

[0033] Therefore, the hybrid vehicle 1 can suppress the fuel liquid and liquid film from flowing directly into the combustion chamber of the internal combustion engine 2 at startup, and reduce the PN at startup of the internal combustion engine 2.

[0034] In addition, the first water jacket 7 that cools the intake port 12 of the cylinder head 4 of the hybrid vehicle 1 belongs to an independent cooling path different from the second water jacket 27 that cools parts other than the intake port 12 of the cylinder head 4 and the third water jacket 28 that cools the cylinder block 31. That is, the first cooling water path 5 that cools the intake port 12 of the cylinder head 4 of the hybrid vehicle 1 is an independent cooling path different from the second cooling water path 6 that cools parts other than the intake port 12 of the cylinder head 4 and the cylinder block 31.

[0035] Therefore, the hybrid vehicle 1 can suppress the generation of PN at startup of the internal combustion engine 2 with a small amount of warm water (first cooling water).

[0036] Furthermore, before starting the internal combustion engine 2 during travel, the hybrid vehicle 1 warms the fuel supplied to the fuel injection valve 13 with warm water (first cooling water) heated by the electric power train 3 or warm water (first cooling water) heated by a heater 9 capable of heating the first cooling water in the first cooling water passage 5.

[0037] The PN of the internal combustion engine 2 depends on the temperature of the fuel injected from the fuel injection valve 13, and can be reduced as the temperature of the fuel injected from the fuel injection valve 13 increases.

[0038] Therefore, in the hybrid vehicle 1, by warming the fuel injected from the fuel injection valve 13 before starting, the vaporizability of the injected fuel is increased, and the PN at the start of the internal combustion engine 2 can be reduced.

[0039] Hereinafter, other embodiments of the present invention will be described. Note that the same components as those in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0040] FIG. 4 is an explanatory diagram schematically showing a cooling water passage of the internal combustion engine 2 in the hybrid vehicle 41 according to the second embodiment of the present invention.

[0041] The hybrid vehicle 41 according to the second embodiment has substantially the same configuration as the hybrid vehicle 1 according to the first embodiment described above, but the cylinder head 4 of the internal combustion engine 2 is cooled only by the first cooling water in the first cooling water passage 5. That is, the second water jacket 27 of the cylinder head 4 is disposed in the first cooling water passage 5.

[0042] Such a hybrid vehicle 1 according to the second embodiment can achieve substantially the same operational effects as the hybrid vehicle 1 according to the first embodiment described above.

[0043] As described above, the specific embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit thereof.

[0044] In the hybrid vehicles 1 and 41 of the above-described first and second embodiments, when the internal combustion engine 2 stops, all the intake valves 14 may be seated using the above-described power generation motor generator.

[0045] In the hybrid vehicles 1 and 41 of the above-described first and second embodiments, since the internal combustion engine 2 is a three-cylinder internal combustion engine, if the operating angle of the intake valve 14 is smaller than a predetermined angle (for example, 60°), there is a timing at which the intake valves 14 close (seat) in all cylinders. By seating the intake valves 14 when the internal combustion engine 2 stops in the hybrid vehicles 1 and 41, the heat from the cylinder head 4 can be transmitted to the intake valves 14, and before the start of the internal combustion engine 2, the intake valves 14 and the back of the umbrella portion of the intake valves 14 can be warmed by the heat from the warmed cylinder head 4.

[0046] Therefore, the hybrid vehicles 1 and 41 can promote the vaporization of the fuel adhering to the back of the umbrella of the intake valve 14 when the internal combustion engine 2 starts, and can further suppress the generation of PN when the internal combustion engine 2 starts.

[0047] In the hybrid vehicles 1 and 41 of the above-described first and second embodiments, when all the intake valves 14 cannot be seated simultaneously when the internal combustion engine 2 stops, before the start of the internal combustion engine 2, the crankshaft (not shown) of the internal combustion engine 2 may be rotated using the above-described power generation motor generator, and the intake valves 14 may be seated one by one for a predetermined time each.

[0048] For an internal combustion engine with four or more cylinders or a three-cylinder internal combustion engine with a specification in which the operating angle of the intake valve is 60° or more, there is no timing at which the intake valves 14 close (seat) in all cylinders.

[0049] In the case where the hybrid vehicles 1 and 41 are designed such that there is no timing at which the intake valves 14 close (seat) with all cylinders of the internal combustion engine 2, before starting the internal combustion engine 2, the above power generation motor generator is rotated to seat the intake valves 14 one by one for a predetermined time each, so that the heat from the cylinder head 4 can be transmitted to the intake valves 14, and all the intake valves 14 and the back sides of the umbrellas of all the intake valves 14 can be warmed up.

[0050] Therefore, the hybrid vehicles 1 and 41 can promote the vaporization of the fuel adhering to the back sides of the umbrellas of the intake valves 14 when starting the internal combustion engine 2, and can further suppress the generation of PN when starting the internal combustion engine 2.

[0051] Also, in the hybrid vehicles 1 and 41 of the above-described first and second embodiments, if the valve operating mechanism of the intake valves 14 of the internal combustion engine 2 can push all the intake valves 14 into the combustion chamber by a predetermined amount simultaneously, when stopping the internal combustion engine 2 during traveling, all the intake valves 14 may be pushed into the combustion chamber by a predetermined amount so that all the intake valves 14 do not seat.

[0052] A valve operating mechanism that can push all the intake valves 14 into the combustion chamber by a predetermined amount simultaneously, for example, has a first cam for traveling that the camshaft driving the intake valves 14 has a cam profile for traveling, a second cam for non-traveling that lifts the intake valves 14 by a predetermined amount, and a switching mechanism that switches between the first cam and the second cam.

[0053] If the hybrid vehicles 1 and 41 are in a state where all the intake valves 14 are pushed into the combustion chamber by a predetermined amount so that all the intake valves 14 do not seat when stopping the internal combustion engine 2 during traveling, the contact area between the cylinder head 4 and the intake valves 14 can be reduced, and heat can be prevented from escaping from the cylinder head 4 to the intake valves 14.

[0054] Therefore, the hybrid vehicles 1 and 41 can quickly increase the temperature of the intake port 12 when warming up the cylinder head 4 before starting the internal combustion engine 2 during traveling.

[0055] Note that the cooling water passage 16 formed in the fuel supply pipe 8 is not limited to a straight passage, and may be formed such that the cooling water goes back and forth in the longitudinal direction of the fuel supply pipe 8, or may be formed such that the cooling water meanders in the fuel supply pipe 8.

Explanation of Signs

[0056] 1…Hybrid vehicle 2…Internal combustion engine 3…Electric power train 4…Cylinder head 5…First cooling water passage 6…Second cooling water passage 7…First water jacket 8…Fuel supply pipe 9…Heater 10…First radiator 11…First pump 12…Intake port 13…Fuel injection valve 14…Intake valve 14a…Valve body 15…First control valve 16…Cooling water passage 17…Fuel passage 18…Fuel inlet 19…Cooling water inlet 20…Cooling water outlet 21…Second control valve 22…Third control valve 27…Second water jacket 28…Third water jacket 29…Second radiator 30…Second pump 31…Cylinder block 32…Thermostat

Claims

1. An internal combustion engine for power generation that performs port injection, A driving force generation unit that generates a driving force transmitted to the drive wheels, A first cooling water path that cools the intake port of the cylinder head of the internal combustion engine, A second cooling water path that cools the cylinder block of the internal combustion engine, and has, Before starting the internal combustion engine, the cylinder head is warmed by circulating warm water warmed by the driving force generation unit or warm water warmed using a heater, In a hybrid vehicle that circulates warm water warmed by the driving force generation unit or warm water warmed using the heater through the first cooling water path before starting the internal combustion engine, In the cylinder head, the first cooling water path that cools the intake port and the cooling water path that cools the portion other than the intake port are provided independently, and the cooling water common to the second cooling water path is circulated through the cooling water path that cools the portion other than the intake port. A hybrid vehicle characterized by that.

2. The fuel supplied to the fuel injection valve of the internal combustion engine is warmed by warm water warmed by the driving force generation unit or warm water warmed using the heater. The hybrid vehicle according to claim 1.

3. The internal combustion engine is connected to a motor generator for power generation, The internal combustion engine is characterized in that, when the internal combustion engine stops, the intake valve is seated using the motor generator for power generation. The hybrid vehicle according to claim 1 or 2.

4. The internal combustion engine is a three-cylinder. The hybrid vehicle according to claim 3.

5. The internal combustion engine is connected to a motor generator for power generation, When the internal combustion engine cannot seat all the intake valves simultaneously, before starting the internal combustion engine, the crankshaft of the internal combustion engine is rotated using the motor generator for power generation, and the intake valves are seated in order. The hybrid vehicle according to claim 1 or 2.

6. The internal combustion engine is four cylinders or more. The hybrid vehicle according to claim 5.

7. The camshaft of the internal combustion engine has a first cam for traveling and a second cam for non-traveling that lifts the intake valve by a predetermined amount, When stopping the internal combustion engine during travel, the hybrid vehicle according to claim 1 or 2, characterized in that all intake valves are projected into the combustion chamber by a predetermined amount so that all intake valves are in a state of not seating using the second cam.

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