Internal combustion engine
By intersecting the injection axes of the water and fuel injection valves and synchronizing their timings, the engine addresses the atomization issue, leading to improved water vaporization and distribution, thereby enhancing performance.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2023-04-05
- Publication Date
- 2026-06-23
Smart Images
Figure 0007878129000001 
Figure 0007878129000002 
Figure 0007878129000003
Abstract
Description
Technical Field
[0001] The present invention relates to an internal combustion engine Seki .
Background Art
[0002] The internal combustion engine of Patent Document 1 includes a cylinder and an intake passage. The intake passage has a first passage, a surge tank, and a second passage. The surge tank is connected to the downstream end of the first passage. The second passage is connected to the downstream end of the surge tank. The cylinder is connected to the downstream end of the second passage. Further, the internal combustion engine includes a port injection valve, an in-cylinder injection valve, and a water injection valve. The port injection valve injects fuel into the second passage. The in-cylinder injection valve injects fuel into the cylinder. The water injection valve injects water into the first passage.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the internal combustion engine as described in Patent Document 1, the finer the water injected from the water injection valve, the easier the water is to vaporize. That is, the finer the injected water, the more the temperature of the intake air flowing into the cylinder can be reduced by the heat of vaporization. However, in the internal combustion engine described in Patent Document 1, no consideration has been given to the atomization of the water injected from the water injection valve.
Means for Solving the Problems
[0005] To solve the above problems, the present invention provides an internal combustion engine comprising a cylindrical cylinder having a central axis, a water injection valve for injecting water into the cylinder, and a fuel injection valve for injecting gaseous fuel into the cylinder, wherein, when viewed in cross-section in a plane parallel to the central axis of the cylinder and including the tip of the water injection valve and the tip of the fuel injection valve, the injection axis of the water injection valve and the injection axis of the fuel injection valve intersect within the cylinder.
[0007] With the above configuration, much of the water injected from the water injection valve collides with the gaseous fuel injected from the fuel injection valve. As a result of colliding with the gaseous fuel, the water particles become smaller. In other words, with the above configuration, the water injected from the water injection valve becomes finer. [Brief explanation of the drawing]
[0008] [Figure 1] Figure 1 is a schematic diagram of an internal combustion engine. [Figure 2] Figure 2 illustrates the water injection timing of the water injection valve and the fuel injection timing of the fuel injection valve. [Figure 3] Figure 3 illustrates the injection axis of the water injection valve and the injection axis of the fuel injection valve. [Modes for carrying out the invention]
[0009] An embodiment of an internal combustion engine will be described below with reference to the drawings. <Outline of the internal combustion engine's configuration> As shown in Figure 1, the vehicle 500 is equipped with an internal combustion engine 10. The internal combustion engine 10 is the power source for the vehicle 500. The internal combustion engine 10 comprises a crankshaft 11, four cylinders 12, four pistons 13, four connecting rods 14, and four spark plugs 15. Note that in Figure 1, only one of the four sets of cylinders 12, pistons 13, connecting rods 14, and spark plugs 15 is illustrated.
[0010] Cylinder 12 is a space for burning a mixture of fuel and intake air. Cylinder 12 is cylindrical with a central axis C. Piston 13 is located inside cylinder 12. Piston 13 reciprocates inside cylinder 12 as the mixture burns. Piston 13 is connected to the crankshaft 11 via a connecting rod 14. Therefore, "inside cylinder 12" refers to the space on the top dead center side relative to piston 13 at bottom dead center. The connecting rod 14 transmits the reciprocating motion of piston 13 as rotational motion of the crankshaft 11. The tip of the spark plug 15 is located inside cylinder 12. The spark plug 15 ignites the mixture inside cylinder 12. The crankshaft 11 is the output shaft of the internal combustion engine 10. The crankshaft 11 is connected to the drive wheels 502 via an automatic transmission 501 and a differential (not shown).
[0011] As shown in Figure 1, the internal combustion engine 10 is equipped with an intake passage 21 and an exhaust passage 31. The intake passage 21 is the passage for intake air. The intake passage 21 is connected to each cylinder 12. The exhaust passage 31 is the passage for exhaust air. The exhaust passage 31 is connected to each cylinder 12. The exhaust passage 31 is located on the opposite side of the intake passage 21, with the central axis C of the cylinder 12 in between.
[0012] The internal combustion engine 10 has four intake valves 21A and four exhaust valves 31A. Note that in Figure 1, only one of the four intake valves 21A and only one of the four exhaust valves 31A are shown. An intake valve 21A is provided for each cylinder 12. The intake valve 21A is located between the intake passage 21 and the cylinder 12. The intake valve 21A opens and closes the opening on the cylinder 12 side of the intake passage 21. An exhaust valve 31A is provided for each cylinder 12. The exhaust valve 31A is located between the exhaust passage 31 and the cylinder 12. The exhaust valve 31A opens and closes the opening on the cylinder 12 side of the exhaust passage 31.
[0013] The internal combustion engine 10 has a throttle valve 22. The throttle valve 22 is located in the middle of the intake passage 21. The throttle valve 22's opening degree is adjustable. The throttle valve 22 adjusts the amount of intake air flowing into the cylinder 12 according to its opening degree.
[0014] The internal combustion engine 10 is equipped with four water injection valves 51. Note that only one of the four water injection valves 51 is shown in Figure 1. A water injection valve 51 is provided for each cylinder 12. The water injection valve 51 is located in the intake passage 21. Specifically, the water injection valve 51 is located near the intake valve 21A within the intake passage 21. The water injection valve 51 injects water into the cylinder 12. Note that the water injection valve 51 is connected to a tank (not shown). The water injection valve 51 receives water from the tank and injects water.
[0015] The internal combustion engine 10 is equipped with four fuel injectors 52. Note that only one of the four fuel injectors 52 is shown in Figure 1. A fuel injector 52 is provided for each cylinder 12. The fuel injector 52 injects hydrogen gas as a gaseous fuel. The fuel injector 52 injects the gaseous fuel directly into the cylinder 12 without passing through the intake passage 21.
[0016] Vehicle 500 is equipped with an accelerator pedal sensor 81, a crank angle sensor 82, and a vehicle speed sensor 83. The accelerator pedal sensor 81 detects the amount of operation of the accelerator pedal of vehicle 500 as accelerator operation amount ACCP. The crank angle sensor 82 detects the angular position CA of the crankshaft 11. The vehicle speed sensor 83 detects the vehicle speed SP of vehicle 500. Each of these sensors outputs a signal corresponding to the value of the detected value.
[0017] <About the control device> As shown in Figure 1, the vehicle 500 is equipped with a control device 100. The control device 100 may be configured as one or more processors that execute various processes according to a computer program (software). Alternatively, the control device 100 may be configured as a circuit including one or more dedicated hardware circuits, such as application-specific integrated circuits (ASICs), or a combination thereof, that execute at least some of the various processes. The processor includes a CPU and memory such as RAM and ROM. The memory stores program code or instructions configured to cause the CPU to execute processes. Memory, or computer-readable media, includes any available media that can be accessed by a general-purpose or dedicated computer. Memory includes electrically rewritable non-volatile memory.
[0018] The control device 100 acquires a signal indicating the accelerator operation amount ACCP from the accelerator pedal sensor 81. The control device 100 acquires a signal indicating the angular position CA from the crank angle sensor 82. The control device 100 acquires a signal indicating the vehicle speed SP from the vehicle speed sensor 83.
[0019] The control device 100 controls the internal combustion engine 10. Specifically, the control device 100 controls the opening of the throttle valve 22 and the ignition timing of the spark plug 15 based on the accelerator pedal operation amount ACCP, angular position CA, vehicle speed SP, etc. The control device 100 also controls the amount of water injected from the water injection valve 51 and the amount of fuel injected from the fuel injection valve 52 based on the accelerator pedal operation amount ACCP, angular position CA, vehicle speed SP, etc.
[0020] As shown in Figure 2, the control device 100 controls the injection timing of the water injection valve 51 in accordance with the opening and closing of the intake valve 21A. The injection timing of the water injection valve 51 refers to the water injection start timing W1, which is when the water injection of the water injection valve 51 begins, and the water injection end timing W2, which is when the water injection of the water injection valve 51 ends.
[0021] In this embodiment, from the time when the intake valve 21A is in the open state in a specific cylinder 12 to the time when the intake valve 21A once becomes in the closed state and then becomes in the open state again, one combustion cycle in the cylinder 12 is defined. During one combustion cycle, the specific cylinder 12 experiences an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke once each. In this embodiment, as an example, the intake valve 21A is in the open state at the start of the intake stroke. Also, the intake valve 21A is in the closed state at the end of the intake stroke. Note that the intake valve 21A being in the open state means that the intake valve 21A is separated from the opening on the cylinder 12 side and the opening degree of the intake valve 21A is greater than 0%. And the intake valve 21A being in the closed state means that the intake valve 21A contacts the opening on the cylinder 12 side and the opening degree of the intake valve 21A is 0%.
[0022] The control device 100 controls to inject water from the water injection valve 51 when the intake valve 21A is in the open state, while not injecting water from the water injection valve 51 when the intake valve 21A is in the closed state. Specifically, the control device 100 sets the water injection start timing W1 of the water injection valve 51 to be simultaneous with the start timing of the intake stroke. Also, the control device 100 sets the water injection end timing W2 of the water injection valve 51 to be simultaneous with the end timing of the intake stroke. Thus, the control device 100 controls the injection timing of the water injection valve 51 so that the water injected from the water injection valve 51 hardly hits the valve body of the intake valve 21A.
[0023] Also, the control device 100 controls the injection timing of the fuel injection valve 52 according to the opening and closing of the intake valve 21A. The injection timing of the fuel injection valve 52 is the fuel injection start timing G1 at which the fuel injection of the fuel injection valve 52 starts and the fuel injection end timing G2 at which the fuel injection of the fuel injection valve 52 ends.
[0024] The control device 100 controls the fuel injection start timing G1 at the moment when the gaseous fuel injected from the fuel injector 52 and the water injected from the water injector 51 can collide. Specifically, the control device 100 sets the fuel injection start timing G1 of the fuel injector 52 during the intake stroke. That is, the control device 100 injects gaseous fuel from the fuel injector 52 before the intake valve 21A closes. The control device 100 also sets the fuel injection end timing G2 of the fuel injector 52 in the middle of the compression stroke.
[0025] <Regarding the injection axis of water and fuel injection valves> As shown in Figure 3, the water injection valve 51 is substantially cylindrical with a central axis V1. A nozzle is opened at the tip of the water injection valve 51. Water is injected from this nozzle. The fuel injection valve 52 is also substantially cylindrical with a central axis V2. A nozzle is opened at the tip of the fuel injection valve 52. Gaseous fuel is injected from this nozzle. Note that the intake valve 21A and exhaust valve 31A are not shown in Figure 3.
[0026] Here, we assume that the cross-sectional view is taken from a plane parallel to the central axis C of cylinder 12 and including the tip of the water injection valve 51 and the tip of the fuel injection valve 52. In the following explanation, this cross-sectional view will be referred to as a specific cross-sectional view.
[0027] In a specific cross-sectional view, the intake side region IA is defined as the intake passage 21 side with respect to the central axis C of cylinder 12. Also, in a specific cross-sectional view, the exhaust side region EA is defined as the exhaust passage 31 side with respect to the central axis C of cylinder 12. As described above, the water injection valve 51 is located in the intake passage 21. Therefore, the water injection valve 51 is located in the intake side region IA. On the other hand, the fuel injection valve 52 is located in the exhaust side region EA.
[0028] The water injected from the water injection valve 51 is ejected around the injection axis WJ. The injection axis WJ of the water injection valve 51 is an axis determined by the position and size of the nozzle of the water injection valve 51. Specifically, it identifies the direction of the line of sight that maximizes the apparent area of the nozzle of the water injection valve 51. If the opening edges of the nozzles are on the same plane, this line of sight is perpendicular to that plane. The injection axis WJ is a straight line parallel to the above line of sight and passing through the center of the nozzle opening. In this embodiment, the injection axis WJ of the water injection valve 51 coincides with the central axis V1 of the water injection valve 51.
[0029] The gaseous fuel injected from the fuel injector 52 is injected around the injection axis GJ. The injection axis GJ of the fuel injector 52 is an axis determined by the position and size of the nozzle of the fuel injector 52. Specifically, the direction of the line of sight that maximizes the apparent area of the nozzle of the fuel injector 52 is identified. The injection axis GJ is a straight line parallel to the above line of sight and passing through the center of the nozzle opening. In this embodiment, in a specific cross-sectional view, the injection axis GJ of the fuel injector 52 is located on the side farther from the water injector 51 with respect to the central axis V2 of the fuel injector 52. In other words, the injection axis GJ of the fuel injector 52 is located on the bottom dead center side of the piston 13 with respect to the central axis V2 of the fuel injector 52. In a specific cross-sectional view, the injection axis WJ of the water injector 51 and the injection axis GJ of the fuel injector 52 intersect within the cylinder 12. In this embodiment, in a specific cross-sectional view, the angle formed by the injection axis WJ of the water injection valve 51 and the injection axis GJ of the fuel injection valve 52 is approximately 90 degrees.
[0030] <Operation of this embodiment> In a specific cross-sectional view, the injection axis WJ of the water injection valve 51 and the injection axis GJ of the fuel injection valve 52 intersect within the cylinder 12. Therefore, the water injected from the water injection valve 51 collides with the gaseous fuel injected from the fuel injection valve 52.
[0031] <Effects of this embodiment> (1) According to the above embodiment, much of the water injected from the water injection valve 51 collides with the gaseous fuel injected from the fuel injection valve 52. As a result of the collision with the gaseous fuel, the water particles become smaller. In other words, according to the above configuration, the water injected from the water injection valve 51 becomes finer.
[0032] (2) In the above embodiment, the water injection valve 51 is located in the intake side region IA, while the fuel injection valve 52 is located in the exhaust side region EA. With this configuration, water from the water injection valve 51 is sprayed from the intake side region IA to the exhaust side region EA, while gaseous fuel from the fuel injection valve 52 is sprayed from the exhaust side region EA to the intake side region IA. In other words, water and gaseous fuel are injected in opposite directions overall. This allows the gaseous fuel to collide with the water with force, thereby promoting the atomization of the water.
[0033] (3) In the above embodiment, the injection axis GJ of the fuel injector 52 is located on the side farther from the water injector 51 with respect to the central axis V2 of the fuel injector 52. That is, the gaseous fuel is injected toward the side farther from the water injector 51 with respect to the central axis V2 of the fuel injector 52. In other words, the configuration makes it difficult for water to collide with the injected fuel. Even in this configuration where collision is difficult, the injection axis WJ of the water injector 51 and the injection axis GJ of the fuel injector 52 intersect, which makes it possible to atomize the water injected from the water injector 51.
[0034] (4) In the above embodiment, the control device 100 injects water from the water injection valve 51 when the intake valve 21A is open. The control device 100 also injects gaseous fuel from the fuel injection valve 52 before the intake valve 21A closes. That is, while the water from the water injection valve 51 is flowing into the cylinder 12, gaseous fuel is injected from the fuel injection valve 52. Therefore, it is possible to collide gaseous fuel with a large amount of water, so the water can be atomized efficiently.
[0035] (5) In the above embodiment, the control device 100 sets the water injection start timing W1 of the water injection valve 51 to coincide with the start timing of the intake stroke. The control device 100 also sets the water injection end timing W2 of the water injection valve 51 to coincide with the end timing of the intake stroke. With this configuration, it is possible to suppress the formation of large droplets when the injected water collides with the intake valve 21A. In other words, it is possible to suppress the inflow of large droplets into the cylinder 12.
[0036] <Example of changes> The above embodiments and the following modifications can be combined and implemented to the extent that they do not conflict with each other technically.
[0037] The configuration of the internal combustion engine 10 in the above embodiment is an example and can be modified as appropriate. For example, the number of cylinders 12 is not limited to four; it may be three or fewer, or five or more. In addition to the fuel injection valve 52 of the above embodiment, a port injection valve for injecting fuel into the intake passage 21 may also be provided. If a port injection valve is provided, the relationship between the injection axis of the port injection valve and the injection axis WJ of the water injection valve 51 is not considered.
[0038] The gaseous fuel injected by the fuel injector 52 is not limited to hydrogen gas. For example, it may be natural gas such as propane gas. The opening and closing timing of the intake valve 21A described in the above embodiment is merely an example. For example, the timing at which the intake valve 21A opens may be during the exhaust stroke or during the intake stroke. Similarly, the timing at which the intake valve 21A closes may be during the intake stroke or during the compression stroke.
[0039] In the above embodiment, the water injection start timing W1 and water injection end timing W2 of the water injection valve 51 are not limited to the example of the above embodiment. The control device 100 only needs to inject water from the water injection valve 51 when the intake valve 21A is open. That is, a portion of the period during which water is being injected from the water injection valve 51 may overlap with the period during which the intake valve 21A is closed. Similarly, the fuel injection start timing G1 and fuel injection end timing G2 of the fuel injection valve 52 are not limited to the example of the above embodiment. The control device 100 only needs to inject gaseous fuel from the fuel injection valve 52 before the intake valve 21A is closed.
[0040] In the above embodiment, the angle between the injection axis WJ of the water injection valve 51 and the injection axis GJ of the fuel injection valve 52 is not specified. Any angle is acceptable as long as the injection axis WJ and the injection axis GJ are not parallel and the two axes intersect within the cylinder 12.
[0041] In the specific cross-sectional view of the above embodiment, the injection axis GJ of the fuel injector 52 may be located on the side closer to the water injector 51 with respect to the central axis V2 of the fuel injector 52. Also, the injection axis GJ of the fuel injector 52 may coincide with the central axis V2 of the fuel injector 52. Furthermore, in the specific cross-sectional view, the injection axis WJ of the water injector 51 does not have to coincide with the central axis V1 of the water injector 51.
[0042] In the specific cross-sectional view of the above embodiment, both the water injection valve 51 and the fuel injection valve 52 may be located in the intake side region IA. With this configuration, the water from the water injection valve 51 can be diffused into the exhaust side region EA by the flow of gaseous fuel from the intake side region IA to the exhaust side region EA. Therefore, it becomes easier to distribute the water throughout the entire cylinder 12. [Explanation of symbols]
[0043] C…Central axis EA... Exhaust side region GJ…Jet axis IA…Intake side region WJ…Jet axis 10... Internal combustion engine 12 cylinders 21…Intake passage 21A... Intake valve 31... Exhaust passage 51...Water injection valve 52…Fuel injector 100...Control device 500...vehicles
Claims
1. A cylindrical cylinder having a central axis, An intake passage connected to the cylinder, A water injection valve located in the intake passage and injecting water into the cylinder via the intake passage, A fuel injection valve that injects gaseous fuel directly into the cylinder without passing through the intake passage, An exhaust passage connected to the cylinder, Equipped with, When viewed in cross-section from a plane parallel to the central axis of the cylinder and including the tip of the water injection valve and the tip of the fuel injection valve, The injection axis of the water injection valve and the injection axis of the fuel injection valve intersect within the cylinder. In the aforementioned cross-sectional view, when the intake passage side with respect to the central axis of the cylinder is defined as the intake side region, and the exhaust passage side with respect to the central axis of the cylinder is defined as the exhaust side region, The water injection valve is located in the intake side region, and the fuel injection valve is located in the exhaust side region. Internal combustion engine.
2. In the aforementioned cross-sectional view, The injection axis of the fuel injection valve is located on the side furthest from the water injection valve with respect to the central axis of the fuel injection valve. The internal combustion engine according to claim 1.