JP6327272B2 - Control device for gas fuel direct injection engine - Google Patents

Description

  The present invention belongs to a technical field related to a control device for a gaseous fuel direct injection engine.

  In particular, in a hybrid vehicle, the operation and stop of the engine are often repeated, and therefore the combustion state during operation of the engine is poor. In particular, when the engine is stopped when the engine is in a cold state, the combustion state during operation of the engine is deteriorated. In such an engine, during operation of the engine, deposits easily adhere to and accumulate on members facing the combustion chamber (particularly, the opening portion of the spark plug, the plug hole, and the valve seat portion of the exhaust valve).

  Here, for example, Patent Document 1 discloses a hybrid vehicle control device including an engine using, for example, hydrogen as a fuel, and a motor generator that drives and starts the engine and generates power by being driven by the engine after the startup. Discloses that the fuel remaining in the combustion chamber of the engine is scavenged without performing fuel injection and ignition until a predetermined time has elapsed since the start of driving of the engine by the motor generator.

JP 2014-113942 A

  By the way, in the cranking operation for starting the gaseous fuel direct injection engine having the fuel injection valve for directly injecting the gaseous fuel into the combustion chamber, in order to remove the deposits attached during the previous engine operation, As in Patent Document 1, it is conceivable to scavenge the fuel remaining in the combustion chamber without performing fuel injection and ignition.

  However, with this method, unburned fuel remaining in the combustion chamber can be removed, but it is difficult to remove deposits adhering to the member facing the combustion chamber. If such deposits remain attached, there is a concern that the sealing performance of the combustion chamber and the ignition of fuel by the spark plug will be adversely affected, resulting in engine starting failure.

  The present invention has been made in view of such a point, and an object of the present invention is to perform cranking operation for starting a gaseous fuel direct injection engine having a fuel injection valve for directly injecting gaseous fuel into a combustion chamber. Another object is to improve the starting performance of the engine by removing the deposits on the member facing the combustion chamber of the engine.

In order to achieve the above object, according to the present invention, there is provided a gas fuel direct injection engine having a fuel injection valve that directly injects gaseous fuel into the combustion chamber and an ignition plug that ignites the fuel injected by the fuel injection valve. For the control device, the engine has a starting device for starting the engine, engine water temperature detecting means for detecting the temperature of the cooling water of the engine, the fuel injection valve, the spark plug, and the starting device. Control means for controlling the operation of the engine, including the operation, and the control means is configured to crank the engine by the starting device without operating the fuel injection valve and the spark plug during normal starting. On the other hand, at the time of a specific start, the engine is cranked without operating the spark plug and the crank is operated. Cranking for controlling the fuel injection valve so that the combustion air-fuel ratio in the combustion chamber becomes a combustion air-fuel ratio in which the gaseous fuel in the combustion chamber does not ignite even when ignited by a spark plug during the compression stroke during the combustion operation And the control means determines whether or not the engine has reached a predetermined warm state from the temperature detected by the engine water temperature detecting means, and the engine At the time of cranking, assuming that the starting time is the specific starting time at the next starting of the engine after the operation of the engine is stopped when it is determined that the warm state has not been reached. The fuel injection control is configured to be executed .

With the above configuration, the execution of the fuel injection control at the time of cranking makes it easy to remove the deposits attached to the member facing the combustion chamber by the high-pressure compressed air-fuel mixture containing the gaseous fuel. Moreover, it becomes easier to remove deposits by utilizing the momentum of the jet of gaseous fuel injected. Therefore, during the cranking operation of the engine at the specific start, the deposits on the member facing the combustion chamber can be removed, and the startability of the engine can be improved. The specific start time is a time when the engine is started after an operation where there is a high possibility that deposits adhere to the member facing the combustion chamber is stopped . Ie, the operation of the previous engine, is when was stopped in the state does not reach the predetermined hot state, during its operation, since it is likely that deposits are adhered to a member facing the combustion chamber, At the time of the next engine start, assuming that the start time is the specific start time, it is possible to effectively remove the deposit by executing the fuel injection control at the time of cranking.

  In one embodiment of the control device for the gaseous fuel direct injection engine, the engine uses a first fuel and a second fuel as the gaseous fuel, and the fuel injection valve is the first fuel. A first fuel injection valve that injects fuel and a second fuel injection valve that injects the second fuel, and the ignition plug ignites when the fuel in the combustion chamber is only the second fuel. The minimum combustion air-fuel ratio at which the second fuel is not ignited is the minimum combustion air-fuel ratio at which the first fuel is not ignited even when ignited by the spark plug when the fuel in the combustion chamber is only the first fuel. The control means is the second fuel that is the fuel having the lower minimum combustion air-fuel ratio among the first fuel and the second fuel when the cranking fuel injection control is executed. Volume injection of fuel But to be larger than the volume injection amount of the first fuel, and is configured to control the first and second fuel injection valves.

  As a result, the total volume injection amount of the first fuel and the second fuel can be increased, and as a result, the deposits can be further easily removed.

  In another embodiment of the control device for the gaseous fuel direct injection engine, the engine uses a first fuel and a second fuel different from the first fuel as the gaseous fuel. The injection valve includes a first fuel injection valve for injecting the first fuel and a second fuel injection valve for injecting the second fuel, and the volume residual amounts of the first fuel and the second fuel are respectively determined. The control means further comprises a remaining amount detecting means for detecting, and when the cranking fuel injection control is executed, the volume injection amount of the fuel with the larger remaining volume detected by the remaining amount detecting means is: The first and second fuel injection valves are controlled so as to be larger than the volume injection amount of the smaller fuel.

  By doing this, it is possible to prevent the remaining amount of the first fuel and the second fuel from being biased and to prevent only one of the fuels from disappearing early, and as a result, to prevent the cruising distance from being shortened. Can do.

  In still another embodiment of the control device for the gaseous fuel direct injection engine, the engine is a rotary piston engine, and the fuel injection valve includes a leading side fuel injection valve and a trailing arranged in parallel in the rotation direction of the rotor. The control means includes a fuel injection valve on the cranking side, and when the fuel injection control during cranking is executed, the volume injection amount of the gaseous fuel from the leading fuel injection valve The leading side fuel injection valve and the trailing side fuel injection valve are controlled so as to be larger than the volume injection amount of the gaseous fuel.

  In other words, in a rotary piston engine, deposits are particularly likely to adhere to the opening of the spark plug or plug hole, but the volume injection amount of gaseous fuel from the leading fuel injection valve close to the spark plug (plug hole) should be increased. Thus, the deposits adhering to the opening of the spark plug and the plug hole can be effectively removed.

  In still another embodiment of the control device for the gaseous fuel direct injection engine, the engine is a reciprocating engine in which a piston reciprocates in a cylinder, and the fuel injection valve is disposed at a central portion of a ceiling portion of the combustion chamber. A first injection mode in which at least the gaseous fuel is injected from the central part of the cylinder toward the entire periphery thereof when viewed from the central axis direction of the cylinder, and the gaseous fuel is injected into the central part of the cylinder The control means is configured to be able to switch to the second injection mode for injecting toward the exhaust valve, and when the cranking fuel injection control is executed, the control means has the gaseous fuel in the second injection mode. The fuel injection valve is controlled to inject.

  That is, in the reciprocating engine, deposits are likely to adhere particularly to the valve seat portion of the exhaust valve, but by adhering gaseous fuel toward the exhaust valve, the deposits attached to the valve seat portion of the exhaust valve are effectively removed. It is possible to ensure the sealing performance of the combustion chamber.

  In still another embodiment of the control device for the gaseous fuel direct injection engine, the engine is a reciprocating engine in which a piston reciprocates in a cylinder, and the fuel injection valve is disposed at a central portion of a ceiling portion of the combustion chamber. A first injection mode in which at least the gaseous fuel is injected from the central part of the cylinder toward the entire periphery thereof when viewed from the central axis direction of the cylinder, and the gaseous fuel is injected into the central part of the cylinder The control means is configured to be able to switch to a second injection form that injects toward the spark plug, and the control means has the gaseous fuel in the second injection form during execution of the cranking fuel injection control. The fuel injection valve is controlled to inject.

  Thereby, the deposit | attachment adhering to a spark plug can be removed effectively, and it can prevent that misfire arises at the time of engine starting.

As described above, according to the control device for a gas fuel direct injection engine of the present invention, the cranking operation of the engine is performed without operating the spark plug at the specific start, and the compression stroke during the cranking operation is performed. The fuel injection control during cranking is executed to control the fuel injection valve so that the combustion air-fuel ratio in the combustion chamber of the engine becomes a combustion air-fuel ratio in which the gaseous fuel in the combustion chamber does not ignite even when ignited by the spark plug. Further, when it is determined that the engine has not reached the predetermined warm state, the start time of the engine after the operation of the engine is stopped is the same as the specific start time. as is, by which is adapted to perform the cranking time fuel injection control during cranking operation of the engine, in the member facing the combustion chamber To remove deposits, thereby improving the startability of the engine.

It is the schematic of the hybrid vehicle by which the gaseous fuel direct injection engine control apparatus which concerns on Embodiment 1 of this invention is mounted. It is a block diagram which shows the structure of the gaseous fuel direct injection engine of the said hybrid vehicle, and its control system. It is a flowchart which shows the processing operation at the time of starting of the gaseous fuel direct injection engine by a control unit. It is sectional drawing of the gaseous fuel direct injection engine in Embodiment 2 of this invention. It is sectional drawing of the gaseous fuel direct injection engine in Embodiment 3 of this invention. It is the figure which looked at the ceiling part of the combustion chamber of the gaseous fuel direct injection engine in Embodiment 3 from the combustion chamber side.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic diagram of a hybrid vehicle 1 (hereinafter referred to as a vehicle 1) equipped with a gaseous fuel direct injection engine control apparatus according to Embodiment 1 of the present invention. The vehicle 1 is a series hybrid vehicle, and includes a gas fuel direct injection engine 10 (hereinafter simply referred to as an engine 10) that uses gaseous fuel as a fuel, a generator 20 that is driven by the engine 10 to generate electric power, A high-voltage / large-capacity battery 30 in which the power generated by the generator 20 is stored (charged), and the generated power of the generator 20 driven by the engine 10 and the stored power (discharged power) of the battery 30 And a drive motor 40 driven by at least one of them. In the present embodiment, the generator 20 is a motor generator that also has a function of a motor (starting device), and the engine 10 is driven (cranked) by the generator 20 as a motor so as to start the engine 10. Has been made.

  A first inverter 50 is provided between the generator 20 and the battery 30, and a second inverter 51 is provided between the battery 30 and the drive motor 40. The first inverter 50 and the second inverter 51 are connected to each other, and the battery 30 is connected to the connection line. The power generated by the generator 20 is supplied to the battery 30 via the first inverter 50 and also supplied to the drive motor 40 via the first and second inverters 50 and 51. Discharged power from the battery 30 is supplied to the drive motor 40 via the second inverter 51.

  The output of the drive motor 40 is transmitted to the drive wheels 61 (the left and right front wheels steered by the steering wheel 62) via the differential device 60, whereby the vehicle 1 travels.

  The drive motor 40 is capable of generating regenerative power and operates as a generator when the vehicle 1 is decelerated, and the generated power (regenerative power) is charged in the battery 30. In the charging travel mode described later, the engine 10 is started and the battery 30 is charged with the generated power of the generator 20. The battery 30 can be externally charged by a power source external to the vehicle 1.

  The engine 10 is a power generation engine used to drive the generator 20 to generate power. The engine 10 is a multi-fuel engine configured such that hydrogen gas stored in the hydrogen tank 70 and natural gas (CNG) stored in the CNG tank 71 can be supplied as gaseous fuels.

  As shown in FIG. 2, in this embodiment, the engine 10 is a twin-rotor (two-cylinder) rotary piston engine, and includes a rotor housing formed in two saddle-shaped rotor housings 11 (inside cylinders). The chambers 11a are configured so that the substantially triangular rotors 12 are respectively accommodated therein. The two rotor housings 11 are integrated with the side housings so as to be sandwiched between three side housings (not shown), and each rotor housing chamber 11a is composed of each rotor housing 11 and the side housings on both sides thereof. Is formed. In FIG. 2, the two rotor housings 11 (two cylinders) are shown in an unfolded state, and the eccentric shafts 13 respectively drawn in the central portions in the two rotor housings 11 are the same.

  Each of the rotors 12 has apex seals (not shown) at the apexes of the triangles, and the apex seals are in sliding contact with the inner surface of the trochoid of the rotor housing 11. Three working chambers (corresponding to combustion chambers) are defined in 11a (each cylinder). Each rotor 12 rotates around the eccentric shaft 13 in a state where the three apex seals of the rotor 12 are in contact with the inner peripheral surface of the trochoid of the rotor housing 11, and around the axis of the eccentric shaft 13. To revolve around. While the rotor 12 makes one revolution, the working chambers formed between the tops of the rotor 12 move in the circumferential direction, and the intake, compression, expansion (combustion), and exhaust strokes are performed. The rotating force is output from the eccentric shaft 13 as the output shaft through the rotor 12.

  An intake passage 14 is connected to each of the rotor accommodating chambers 11a so as to communicate with an intake opening that opens to the working chamber in the intake stroke, and communicates with an exhaust opening that opens to the working chamber in the exhaust stroke. An exhaust passage 15 is connected to the front. There is one intake passage 14 on the upstream side, but on the downstream side, the intake passage 14 branches into two branch passages and communicates with each of the rotor accommodating chambers 11a. The cross-sectional area (valve opening degree) of the intake passage 14 is adjusted by being driven by a throttle valve actuator 90 such as a stepping motor on the upstream side of the branch portion of the intake passage 14 (downstream side of an intercooler 86 described later). A throttle valve 16 is provided. The throttle valve 16 adjusts the amount of intake air into each rotor accommodating chamber 11a (the working chamber in the intake stroke). In the present embodiment, the throttle valve 16 is basically fully opened during engine control described later (during medium load or high load operation of the engine 10) and during fuel injection control during cranking described later.

  Hydrogen ports from which hydrogen gas from the hydrogen tank 70 and natural gas from the CNG tank 71 are respectively injected into the intake passage 14 in each branch passage downstream of the branch portion of the intake passage 14. An injection valve 17A and a CNG port injection valve 17B are provided. The hydrogen gas and natural gas injected by the hydrogen and CNG port injection valves 17A and 17B, respectively, are mixed with air and supplied to the working chamber in the intake stroke.

  The hydrogen and CNG port injection valves 17A and 17B are set in advance because the temperature of the cooling water of the engine 10 (hereinafter referred to as engine cooling water) is extremely low even when the engine 10 is extremely cold (even when the engine is cold). Used when starting at a temperature lower than the set temperature. In other cases, fuel (hydrogen gas and natural gas) is directly injected into the working chamber (combustion chamber) from hydrogen and CNG direct injection valves 18A and 18B described later. When the engine 10 is extremely cold, the fuel injection openings of the hydrogen and CNG direct injection valves 18A and 18B may be blocked by freezing of water generated by fuel combustion. Therefore, the fuel is exceptionally injected from the hydrogen and CNG port injection valves 17A and 17B. It is also possible to inject fuel by the hydrogen and CNG direct injection valves 18A and 18B and the hydrogen and CNG port injection valves 17A and 17B when the engine 10 is started and operated. . Alternatively, the port injection valves 17A and 17B for hydrogen and CNG can be eliminated. In the following description, it is assumed that fuel (hydrogen gas and natural gas) is injected by the hydrogen and CNG direct injection valves 18A and 18B.

  Two exhaust passages 15 are provided on the upstream side so as to communicate with the respective rotor accommodating chambers 11a, but are joined together on the downstream side. A low temperature active three-way catalyst 81 and a NOx occlusion reduction catalyst 82 for purifying exhaust gas are disposed downstream of the merging portion of the exhaust passage 15. The low temperature active three-way catalyst 81 is a three-way catalyst having a catalyst activation temperature lower than that of the NOx storage reduction catalyst 82, and is disposed upstream of the NOx storage reduction catalyst 82. In FIG. 2, arrows shown in the intake passage 14 and the exhaust passage 15 indicate the flow of intake and exhaust.

  The NOx occlusion reduction catalyst 82 is configured, for example, by supporting a NOx occlusion agent such as barium (Ba) or potassium (K) on a carrier containing a noble metal such as platinum (Pt) or palladium (Pd). The NOx in the exhaust gas of the engine 10 is occluded in a lean air-fuel ratio atmosphere, and the occluded NOx is released in a rich air-fuel ratio atmosphere to cause the NOx to react with HC and CO in the exhaust gas. Have the function of reducing

  In each of the rotor housings 11 (each cylinder), hydrogen direct injection valve 18A (first cylinder) for directly injecting hydrogen gas from the hydrogen tank 70 into the working chamber (combustion chamber) in the compression stroke of the rotor accommodating chamber 11a. 1) and a CNG direct injection valve 18B (second injection) for directly injecting natural gas from the CNG tank 71 into the working chamber (combustion chamber) in the compression stroke of the rotor accommodating chamber 11a. Equivalent to a fuel injection valve).

  Each rotor housing 11 is provided with two spark plugs 19 for igniting hydrogen gas and natural gas respectively injected from hydrogen and CNG direct injection valves 18A and 18B. These spark plugs 19 are ignited in the order of the leading side and the trailing side in the vicinity of the compression top (TDC), and ignite the air-fuel mixture in the working chamber in the compression or expansion stroke. The leading side ignition plug 19 is ignited before the compression top, and the trailing side ignition plug 19 is ignited simultaneously with or immediately after the compression top.

The engine 10 is provided with an exhaust turbocharger 85 that supercharges intake air into the working chamber (combustion chamber) in the intake stroke in each rotor accommodating chamber 11a of the engine 10. The exhaust turbocharger 85 includes a compressor 85a disposed upstream of the throttle valve 16 in the intake passage 14 and a downstream side of the merging portion in the exhaust passage 15 and the low temperature active three-way catalyst 81. And a turbine 85b disposed on the upstream side. The turbine 85b is rotated by the exhaust gas flow, and the rotation of the turbine 85b activates the compressor 85a connected to the turbine 85b to compress the air taken into the intake passage 14. The compressed air is cooled by an intercooler 86 disposed downstream of the compressor 85a and upstream of the throttle valve 16 in the intake passage 14, and then accommodated in each rotor via each branch passage. Inhaled into the working chamber in the intake stroke of the chamber 11a.

  The vehicle 1 includes a battery current / voltage sensor 101 that detects a current flowing in and out of the battery 30 and a voltage of the battery 30, and an accelerator that detects an amount of depression of an accelerator pedal by an occupant of the vehicle 1 (accelerator opening by an occupant's operation). An opening sensor 102, a vehicle speed sensor 103 that detects the vehicle speed of the vehicle 1, a rotation angle sensor 104 that is provided on the eccentric shaft 13 and detects the rotation angle position of the eccentric shaft 13, and a low-temperature active three-way catalyst in the exhaust passage 15 An air-fuel ratio sensor 105 (configured by a linear O2 sensor in this embodiment) that is disposed between the turbine 81 and the turbine 85 b and detects the air-fuel ratio of the exhaust gas of the engine 10, and the rotor housing 11 It faces the formed water jacket (not shown) and flows through the water jacket. Engine water temperature sensor 106 (engine water temperature detecting means) for detecting the temperature of the engine coolant (engine water temperature), the pressure in the hydrogen tank 70 (that is, the remaining volume of hydrogen gas in the hydrogen tank 70), and the CNG tank 71 Tank pressure sensors 107 (provided separately for the hydrogen tank 70 and the CNG tank 71) for detecting the pressure of the gas (that is, the remaining volume of natural gas in the CNG tank 71) and the intake passage 14 respectively. An air flow sensor 108 for detecting the intake flow rate, a battery temperature sensor 109 for detecting the temperature of the battery 30, operation control of the engine 10, and operation control of the first and second inverters 50 and 51 (that is, the generator 20 and the drive). A control unit 100 that performs operation control of the motor 40 and the like is provided. The rotation angle sensor 104 also serves as an engine rotation speed sensor that detects the rotation speed of the engine 10. The tank pressure sensor 107 constitutes remaining amount detecting means for detecting the remaining volume of hydrogen gas and natural gas, respectively.

  The control unit 100 is a controller based on a well-known microcomputer, and includes a central processing unit (CPU) that executes a program, a memory that is configured by, for example, a RAM or ROM, and stores a program and data, and an electrical signal An input / output (I / O) bus. The control unit 100 includes a battery current / voltage sensor 101, an accelerator opening sensor 102, a vehicle speed sensor 103, a rotation angle sensor 104, an air-fuel ratio sensor 105, an engine water temperature sensor 106, a tank pressure sensor 107, an air flow sensor 108, a battery temperature sensor. Various information signals from 109 etc. are input.

  The generator 20 transmits information on the voltage and current generated by the generator 20 to the control unit 100. The control unit 100 inputs the information and generates power generated by the generator 20 from the information. (Power generation amount) is detected.

  The drive motor 40 transmits information on the rotational speed of the drive motor 40 and information on the regenerative power generation voltage and regenerative power generation current generated by the drive motor 40 to the control unit 100, and the control unit 100 transmits the information. The input is used to control the operation of the drive motor 40.

  Then, based on the input signal, the control unit 100 controls the throttle valve actuator 90, the hydrogen port injection valve 17A, the CNG port injection valve 17B, the hydrogen direct injection valve 18A, the CNG direct injection valve 18B, and A control signal is output to the spark plug 19 to control the engine 10, and a control signal is output to the first and second inverters 50 and 51 to control the generator 20 and the drive motor 40. The control unit 100 constitutes control means for controlling the operation of the engine 10 including the operations of the hydrogen direct injection valve 18A and the CNG direct injection valve 18B.

  The vehicle 1 is driven by the battery 30 in the battery running mode (at this time, the engine 10 is stopped), the engine 10 is operated, and the output of the engine 10 causes the battery to pass through the generator 20. And a charging travel mode in which the vehicle travels while charging 30. In the present embodiment, since the vehicle 1 is a series hybrid vehicle, in the charging travel mode, charging of the battery 30 and driving of the drive motor 40 are performed with electric power generated by the generator 20 that generates electric power from the output of the engine 10. Do.

  The control unit 100 detects the remaining capacity (SOC) of the battery 30 based on the current flowing into and out of the battery 30 and the voltage of the battery 30 detected by the battery current / voltage sensor 101.

  Then, when the detected SOC of the battery 30 is lower than a first predetermined value (for example, 30%) in the battery running mode, the control unit 100 switches to the charging running mode while the charging running mode Sometimes, when the detected SOC of the battery 30 becomes higher than a second predetermined value (for example, 70%) set to a value higher than the first predetermined value, the battery driving mode is switched. Thereby, the SOC of battery 30 can be maintained within a preferable range that is neither too low nor too high.

  In the battery running mode, the control unit 100 determines whether or not there is an operation request for the engine 10 based on the required output of the drive motor 40 and the SOC value of the battery 30 (in this embodiment, the same as the presence or absence of a power generation request). If there is an operation request (power generation request) for the engine 10, the engine 10 is cranked by the generator 20 as a motor to start the engine 10, and after that start, the generator 20 generates power. The engine 10 is operated as much as possible. That is, when the SOC of the battery 30 is lower than the first predetermined value or the required output of the drive motor 40 exceeds the maximum dischargeable power of the battery 30 in the battery running mode. Sometimes, the engine 10 is operated on the assumption that there is a request for operating the engine 10.

  Here, the maximum dischargeable power varies depending on the temperature of the battery 30. The relationship between the temperature of the battery 30 and the maximum dischargeable power is stored as a map in the memory of the control unit 100, and the control unit 100 uses the map to detect the battery detected by the battery temperature sensor 109. The maximum dischargeable power is detected from 30 temperatures.

  In the charging travel mode, the control unit 100 basically operates the engine 10 at a predetermined rotational speed, and the engine rotational speed during the engine steady operation (the predetermined rotational speed) is the highest efficiency point of the engine 10. Is a value in an efficient region including 1800 rpm to 2200 rpm, for example, 2000 rpm in this embodiment. The engine load during the engine steady operation is a medium load or a high load larger than a predetermined load. At this time, the battery 30 is charged and the drive motor 40 is driven with the power generated by the generator 20 that generates power by the output of the engine 10 (the remaining power obtained by subtracting the required output of the drive motor 40 from the generated power). Is charged to the battery 30). Further, when the required output of the drive motor 40 becomes larger than the engine output (generated power) at 2000 rpm as in the case of the acceleration request of the vehicle 1 or more during the steady engine operation, the shortage is reduced. It is supplemented by the discharge power of the battery 30 (not charged). However, if the required output of the drive motor 40 cannot be satisfied even if the discharge power of the battery 30 reaches the maximum dischargeable power of the battery 30, the engine speed is exceptionally made higher than the predetermined speed. .

  The operation of the engine 10 when the required output of the drive motor 40 exceeds the maximum dischargeable power of the battery 30 in the battery running mode is also a steady operation at the predetermined rotational speed (2000 rpm), and the discharge power of the battery 30 is reduced. It adjusts so that the required output of the drive motor 40 may be satisfied.

  When the engine 10 is in operation, the control unit 100 controls the hydrogen direct injection valve 18A and the CNG direct injection valve 18B to supply hydrogen gas and natural gas to the engine 10 at a predetermined ratio. In this embodiment, hydrogen gas and natural gas are injected into the combustion chamber with substantially the same volume ratio (both 50%).

  In addition, when the engine 10 is operated, the control unit 100 basically sets the combustion air-fuel ratio in the combustion chamber of the engine 10 to a predetermined lean air-fuel ratio (for example, an excess air ratio λ = 1.9). When the NOx occluded in the NOx occlusion reduction catalyst 82 is released, the combustion air-fuel ratio in the combustion chamber is made rich (for example, the excess air ratio λ = 0.9).

  Here, when the fuel in the combustion chamber of the engine 10 is only natural gas, even if it is ignited by the spark plug 19, the minimum combustion air-fuel ratio at which the natural gas does not ignite is only hydrogen gas in the combustion chamber. Even if it is ignited by the spark plug 19, the hydrogen gas is lower than the minimum combustion air-fuel ratio at which it does not ignite. The minimum combustion air-fuel ratio at which hydrogen gas (corresponding to the first fuel) does not ignite is 3.0 in terms of the excess air ratio λ, and the minimum combustion air-fuel ratio at which natural gas (corresponding to the second fuel) does not ignite. Is 1.5 in terms of the excess air ratio λ. The minimum combustion air-fuel ratio (excess air ratio λ) at which the mixed gas of hydrogen gas and natural gas does not ignite is in the range of 1.5 to 3.0, and becomes a lower value as the mixing ratio of natural gas increases. . When hydrogen gas and natural gas are injected into the combustion chamber with substantially the same volume ratio, the minimum combustion air-fuel ratio (excess air ratio λ) is about 2.0, so if λ = 1.9, This mixed gas is sufficiently ignited. The second fuel is not limited to natural gas, but may be propane or butane, for example. Natural gas, propane, and butane are fuels having a higher calorific value per unit volume than hydrogen gas.

  In the vehicle 1 as described above, the operation and stop of the engine 10 are frequently repeated, and therefore, the combustion state during operation of the engine 10 is poor. In particular, when the operation of the engine 10 is stopped when the engine 10 is in a cold state, the combustion state during the operation of the engine 10 is deteriorated. In such an engine 10, during operation of the engine 10, members facing the combustion chamber (particularly the spark plug 19 and the plug hole for housing the spark plug 19 (see the plug hole 11b in FIG. 4 showing Embodiment 2)). The deposits are easily deposited and deposited on the opening).

  Therefore, in the present embodiment, during the cranking operation at the specific start time, which is the start time of the engine 10 after the operation that is highly likely to adhere to the members facing the combustion chamber is stopped, The deposits adhered during the operation of 10 are removed. Specifically, the control unit 100 performs the cranking operation of the engine 10 by the generator 20 without operating the spark plug 19, and in the compression stroke during the cranking operation, the combustion air-fuel ratio in the combustion chamber of the engine 10. However, even when ignited by the spark plug 19, the direct injection for hydrogen and CNG so that the gaseous fuel in the combustion chamber (in this embodiment, the mixed gas of hydrogen gas and natural gas) does not ignite. The cranking fuel injection control for controlling the injection valves 18A and 18B is executed, and the deposits are removed by executing the cranking fuel injection control. That is, by removing the adhering matter adhering to the member facing the combustion chamber with a high-pressure compressed air-fuel mixture containing gaseous fuel (the above-mentioned mixed gas), or by using the momentum of the injected gaseous fuel jet, Remove deposits. While the cranking fuel injection control is being executed, the spark plug 19 is basically not operated, but the spark plug 19 may be operated.

  In the present embodiment, the control unit 100 is configured such that when performing the cranking fuel injection control, the volume injection amount of natural gas, which is the fuel having the lower minimum combustion air-fuel ratio among hydrogen gas and natural gas, is The direct injection valves 18A and 18B for hydrogen and CNG are controlled so as to be larger than the volume injection amount of hydrogen gas. That is, the volume ratio of the natural gas of the mixed gas in the combustion chamber is more than 50% and less than 100%. The combustion air-fuel ratio at which the gaseous fuel (the mixed gas) in the combustion chamber does not ignite may be equal to or higher than the minimum combustion air-fuel ratio of the mixed gas according to the mixing ratio of the natural gas (in the present embodiment, the minimum air-fuel ratio). The combustion air-fuel ratio of the engine or a value close to it).

  The gaseous fuel in the combustion chamber may be only natural gas. In this case, the combustion air-fuel ratio at which the gaseous fuel (natural gas) in the combustion chamber does not ignite is set to 1.5. Conversely, the gaseous fuel in the combustion chamber may be only hydrogen gas. In this case, the combustion air-fuel ratio at which the gaseous fuel (hydrogen gas) in the combustion chamber does not ignite is set to 3.0.

  The combustion air-fuel ratio at which the gaseous fuel in the combustion chamber does not ignite is preferably as low as possible. This is because the total volume injection amount of gaseous fuel can be increased, and the effect of removing the deposits is enhanced. For this reason, the volume ratio of the natural gas in the mixed gas is preferably increased or only natural gas is used.

During execution of the cranking time fuel injection control, instead of more than the volume injection amount of the hydrogen gas volume injection of natural gas, the volume amount of fuel injected towards the volume remaining by tank pressure sensor 107 is large However, the hydrogen and CNG direct injection valves 18A and 18B may be controlled so as to be larger than the volume injection amount of the smaller fuel. This is particularly advantageous when hydrogen gas and natural gas are injected into the combustion chamber at different volume ratios when the engine 10 is in operation. Can be prevented from disappearing early, thereby preventing the cruising distance from being shortened.

  In the present embodiment, the control unit 100 determines whether or not the engine 10 has reached a predetermined warm state from the temperature detected by the engine water temperature sensor 106, and the engine 10 has not reached the predetermined warm state. The cranking fuel injection control is executed on the assumption that the starting time is the specific starting time at the next starting of the engine 10 after the operation of the engine 10 is stopped. . That is, when the previous operation of the engine 10 is stopped in a state where the predetermined warm state has not been reached, there is a high possibility that deposits will adhere to the member facing the combustion chamber during the operation. The control unit 100 executes the cranking fuel injection control while performing the cranking operation of the engine 10 by the generator 20 at the time of starting the next engine 10.

  The predetermined warm state is a state where the temperature of the engine cooling water is equal to or higher than the predetermined temperature, and even if the deposit adheres when the temperature is lower than the predetermined temperature, the deposit is removed. State.

  The injection timing of hydrogen gas and natural gas in the fuel injection control at the time of cranking may be any timing as long as it is a compression stroke, but at the spark plug 19 and the opening of the plug hole that accommodates the spark plug 19. Since deposits are likely to adhere, the apex seal that divides the working chamber in the compression stroke and the working chamber in the expansion stroke is injected before reaching the ignition plug 19 on the trailing side (plug hole on the trailing side). It is preferable to do. In particular, since more deposits are likely to adhere to the opening of the spark plug 19 on the leading side and the plug hole on the leading side, an apex seal that divides the working chamber in the compression stroke and the working chamber in the expansion stroke. May be injected when positioned between the trailing-side spark plug 19 and the leading-side spark plug 19. Alternatively, in each cylinder, in a certain compression stroke, the apex seal is injected before reaching the trailing-side ignition plug 19, and in the next compression stroke, the apex seal is leading with the trailing-side ignition plug 19. It is also possible to inject fuel when it is positioned between the ignition plug 19 and the fuel injection at these different timings.

  Thus, when the apex seal is positioned before reaching the trailing spark plug 19 or between the trailing spark plug 19 and the leading spark plug 19, the hydrogen gas If natural gas is injected, when the apex seal passes through the plug hole on the trailing side or the plug hole on the leading side, the plug hole causes the trochoid inner peripheral surface of the rotor housing 11 and the apex seal to pass through. Since a gap is instantaneously generated between the two and the gas flows through the gap, the adhering matter attached to the spark plug 19 and the opening of the plug hole can be removed by the gas flow. Moreover, the deposit | attachment adhering to the said apex seal can also be removed by the said gas flow.

  Then, when the rotational speed of the engine 10 reaches a preset rotational speed (for example, 800 to 1000 rpm), the hydrogen and CNG direct injection injection valves are ignited so that the mixed gas is ignited by the spark plug 19. The engine 10 is started by executing ignition control for operating the 18A, 18B and the spark plug 19. At the time of this ignition control, the ratio of hydrogen gas to natural gas in the mixed gas and the combustion air-fuel ratio in the combustion chamber may be the same as those during the operation of the engine 10, but in order to further improve the startability The ratio of hydrogen gas to the ratio during operation of the engine 10 (both 50%) is increased, or the combustion air-fuel ratio in the combustion chamber is set to be higher than the combustion air-fuel ratio during operation of the engine 10 (λ = 1.9). It may be lowered.

  On the other hand, when the control unit 100 determines that the engine 10 has reached the predetermined warm state, the control unit 100 starts the engine 10 after the operation of the engine 10 is stopped. It is assumed that the start time is a normal start time, and at the normal start time, the normal start control is executed without executing the cranking fuel injection control. In this normal start control, the cranking operation of the engine 10 by the generator 20 is performed without operating the hydrogen direct injection valve 18A, the CNG direct injection valve 18B, and the ignition plug 19. When the rotational speed of the engine 10 reaches the set rotational speed, the ignition control is executed to start the engine 10.

  Note that the cranking fuel injection control may be executed every time the engine 10 is started regardless of the previous operation of the engine 10.

  Next, the processing operation when the engine 10 is started by the control unit 100 will be described based on the flowchart of FIG. It is assumed that the battery running mode is set at the start of this flowchart.

  In the first step S1, various input signals from various sensors are read, and in the next step S2, the required output of the drive motor 40 is calculated based on the signals from the accelerator opening sensor 102 and the vehicle speed sensor 103.

  In the next step S3, it is determined whether or not there is a request for operation of the engine 10 based on the required output of the drive motor 40 and the SOC of the battery 30. That is, when the SOC of the battery 30 is lower than the first predetermined value, or when the required output of the drive motor 40 exceeds the maximum dischargeable power of the battery 30, there is a request for operation of the engine 10.

  When the determination in step S3 is NO, the process returns to step S1, while when the determination in step S3 is YES, the process proceeds to step S4.

  In step S4, it is determined whether or not the previous operation of the engine 10 has been stopped in a state where the predetermined warm state has not been reached.

  When the determination at step S4 is NO, the routine proceeds to step S5, where the normal start control is executed, and at the next step S6, it is determined whether or not the rotational speed of the engine 10 has reached the set rotational speed. . If the determination in step S6 is NO, the process returns to step S5. If the determination in step S6 is YES, the process proceeds to step S9.

  On the other hand, when the determination in step S4 is YES, the process proceeds to step S7, and the cranking fuel injection control is executed while the cranking operation of the engine 10 by the generator 20 is being performed. Then, the process proceeds to step S8. . In step S8, it is determined whether or not the rotational speed of the engine 10 has reached the set rotational speed. If the determination in step S8 is NO, the process returns to step S7 while the determination in step S8 is YES. Sometimes, the process proceeds to step S9.

  In step S9, the ignition control is executed to start the engine 10, and then the process returns.

  Therefore, in this embodiment, the cranking operation of the engine 10 is performed without operating the spark plug 19 at the specific start, and the combustion air-fuel ratio in the combustion chamber of the engine 10 is increased during the compression stroke during the cranking operation. The direct injection valves 18A and 18B for hydrogen and CNG are set so that the gaseous fuel (mixed gas of hydrogen gas and natural gas) in the combustion chamber does not ignite even when ignited by the spark plug 19. Since the fuel injection control for cranking to be controlled is executed, the deposits on the members facing the combustion chamber (particularly the opening of the spark plug and the plug hole) are removed during the cranking operation of the engine 10. The startability of the engine 10 can be improved.

(Embodiment 2)
FIG. 4 shows Embodiment 2 of the present invention, in which the engine 10 uses only hydrogen gas as the gaseous fuel, and the rotor 12 is used as a fuel injection valve for directly injecting the hydrogen gas into the combustion chamber. It has a leading direct injection valve 121A and a trailing direct injection valve 121B arranged side by side in the rotational direction, and corresponds to the CNG port injection valve 17B and the CNG direct injection valve 18B of the first embodiment. No fuel injection valve is provided. Each branch passage of the intake passage 14 is provided with a fuel injection valve corresponding to the hydrogen port injection valve 17A for the reason described in the first embodiment. The vehicle 1 is not provided with a CNG tank 71. Other hardware configurations of the engine 10 and the vehicle 1 are the same as those of the first embodiment. In FIG. 4, 11b is a plug hole for accommodating the ignition plug 19, 14a is an intake opening that opens to the working chamber in the intake stroke, and 15a is an exhaust that opens to the working chamber in the exhaust stroke. It is an opening.

  In the present embodiment, the control unit 100 injects hydrogen gas from the leading direct injection valve 121A and the trailing direct injection valve 121B into the combustion chamber at substantially the same volume ratio when the engine 10 is in operation. When the engine 10 is operated, the control unit 100 basically sets the combustion air-fuel ratio in the combustion chamber of the engine 10 to a predetermined lean air-fuel ratio (a value lower than a minimum combustion air-fuel ratio at which hydrogen gas does not ignite (for example, The excess air ratio λ = 2.3)). When the NOx occluded in the NOx occlusion reduction catalyst 82 is released, the combustion air-fuel ratio in the combustion chamber is set to a rich air-fuel ratio (for example, excess air ratio λ = 0.9).

  Also in the present embodiment, as in the first embodiment, the control unit 100 performs the cranking operation of the engine 10 without operating the spark plug 19 at the specific start, and in the compression stroke during the cranking operation. Even if the combustion air-fuel ratio in the combustion chamber of the engine 10 is ignited by the spark plug 19, the gaseous fuel (in this embodiment, hydrogen gas) in the combustion chamber does not ignite (λ = 3 in this embodiment). 0.0), the cranking time fuel injection control for controlling the leading direct injection valve 121A and the trailing direct injection valve 121B is executed. The injection timing of hydrogen gas in the compression stroke is the same as the timing described in the first embodiment. The processing operation when the engine 10 is started by the control unit 100 is also the same as that in the first embodiment (see FIG. 3). Similarly to the first embodiment, the control unit 100 determines that the engine 10 has stopped operating when it determines that the engine 10 has not reached the predetermined warm state. At the time of starting 10, assuming that the starting time is the specific starting time, the cranking fuel injection control is executed.

  In the present embodiment, the control unit 100 determines that the volume injection amount of hydrogen gas from the leading direct injection valve 121A is equal to the hydrogen from the trailing direct injection valve 121B during the cranking fuel injection control. The leading direct injection valve 121A and the trailing direct injection valve 121B are controlled so as to be larger than the gas volume injection amount.

  Therefore, in this embodiment, by increasing the volume injection amount of hydrogen gas from the leading direct injection valve 121A close to the spark plug 19 (plug hole), the attachment attached to the spark plug 19 and the opening of the plug hole is increased. The kimono can be effectively removed.

(Embodiment 3)
5 and 6 show Embodiment 3 of the present invention, in which the engine 10 is a reciprocating engine in which a piston reciprocates in a cylinder 135. The hardware configuration of the vehicle 1 other than the engine 10 is the same as that described above. This is the same as in the second mode.

  In the present embodiment, the engine 10 includes a cylinder block 131 and a cylinder head 132 placed thereon, and a plurality of cylinders 135 (cylinders) are formed inside the cylinder block 131 (FIG. 5). And FIG. 6 shows only one).

  A piston 136 is slidably inserted in each cylinder 135, and the piston 136 defines a combustion chamber 137 together with the cylinder 135 and the cylinder head 132. The piston 136 is connected to the crankshaft 139 by a connecting rod 138, and the crankshaft 139 rotates around its central axis in accordance with the reciprocating motion of the piston 136. The plurality of cylinders 135 are arranged in the direction of the central axis of the crankshaft 139.

  The cylinder head 132 is formed with two intake ports 141 for each cylinder, and each of the intake ports 141 communicates with the combustion chamber 137 by opening on the lower surface of the cylinder head 132 (the ceiling of the combustion chamber 137). ing. Also, the cylinder head 132 is formed with two exhaust ports 142 for each cylinder, and each of the exhaust ports 142 opens to the lower surface of the cylinder head 132 (the ceiling of the combustion chamber 137). Communicate. The intake port 141 is connected to the intake passage 14 through which fresh air introduced into the combustion chamber 137 flows. On the other hand, the exhaust port 142 is connected to the exhaust passage 15 through which burned gas (exhaust gas) from the combustion chamber 137 flows.

  Further, the cylinder head 132 is provided with intake valves 145A and 145B capable of shutting off (closing) the two intake ports 141 from the combustion chamber 137, and the two exhaust ports 142 are connected to the combustion chamber 137. Exhaust valves 146A and 146B that can be shut off (closed) are provided. The intake valves 145A and 145B are driven by an intake valve drive mechanism, and the exhaust valves 146A and 146B are driven by an exhaust valve drive mechanism. The intake valves 145A and 145B and the exhaust valves 146A and 146B reciprocate at a predetermined timing to open and close the intake port 141 and the exhaust port 142, respectively, and perform gas exchange in the combustion chamber 137. Although not shown, the intake valve drive mechanism and the exhaust valve drive mechanism each have an intake cam shaft and an exhaust cam shaft that are drivingly connected to the crankshaft 139, and these camshafts are synchronized with the rotation of the crankshaft 139. Then rotate.

  A fuel injection valve 151 that directly injects gaseous fuel (for example, hydrogen gas) into the combustion chamber 137 is disposed on the center axis of the cylinder 135 in the cylinder head 132 (center portion of the ceiling portion of the combustion chamber 137). . The tip end portion (fuel injection opening) of the fuel injection valve 151 faces the center portion of the cylinder 135 at the upper end portion in the combustion chamber 137.

  In the present embodiment, the fuel injection valve 151 injects gaseous fuel from the central part of the cylinder 135 toward the entire periphery thereof as viewed from the central axis direction of the cylinder 135 (injected in a cone shape), The injection mode is such that gaseous fuel is injected from the center of the cylinder 135 toward the exhaust valve 146A, and the injection mode is such that gaseous fuel is injected from the center of the cylinder 135 toward the exhaust valve 146B. Such an injection mode switching configuration is well known (see, for example, JP 2010-37958 A, JP 2007-285204 A, and JP 2000-205088 A). The injection mode in which gaseous fuel is injected from the central part of the cylinder 135 toward the entire periphery thereof as viewed from the central axis direction of the cylinder 135 corresponds to the first injection mode, and is viewed from the central axis direction of the cylinder 135. The injection mode in which gaseous fuel is injected from the center of the cylinder 135 toward the exhaust valve 146A or the exhaust valve 146B corresponds to the second injection mode.

  The cylinder head 132 is provided with one spark plug 152 for each cylinder. The spark plug 152 is disposed between the two exhaust valves 146A and 146B in the ceiling portion of the combustion chamber 137. The tip (ignition part) of the spark plug 152 faces the combustion chamber 137. In FIG. 6, the spark plug 152 can be seen only at the tip portion facing the combustion chamber 137, but the whole is shown by a solid line for easy understanding. It is preferable that the spark plug 152 is disposed so that the tip (ignition part) thereof is positioned in the vicinity of the tip of the fuel injection valve 151. Note that the spark plug 152 may be disposed anywhere in the ceiling portion of the combustion chamber 137 as long as the intake valves 145A and 145B and the exhaust valves 146A and 146B are not disposed.

  When the engine 10 is operated, the control unit 100 injects the fuel in such a manner that the gaseous fuel is injected from the central part of the cylinder 135 toward the entire circumference when viewed from the central axis direction of the cylinder 135. The valve 151 is controlled.

  Also in the present embodiment, as in the first and second embodiments, the control unit 100 performs the cranking operation of the engine 10 without operating the spark plug 152 at the time of specific start, and the compression during the cranking operation. In the stroke, the fuel injection valve 151 is controlled so that the combustion air-fuel ratio in the combustion chamber 137 of the engine 10 becomes a combustion air-fuel ratio in which the gaseous fuel in the combustion chamber 137 does not ignite even when ignited by the spark plug 152. Execute fuel injection control during cranking. The timing for injecting the gaseous fuel in the compression stroke may be any timing as long as it is a compression stroke. The processing operation when the engine 10 is started by the control unit 100 is the same as in the first and second embodiments (see FIG. 3). Similarly to the first and second embodiments, the control unit 100 determines the next time after the operation of the engine 10 is stopped when it is determined that the engine 10 has not reached the predetermined warm state. When the engine 10 is started, the cranking fuel injection control is executed on the assumption that the starting time is the specific starting time.

  In the reciprocating engine as in the present embodiment, deposits are particularly likely to adhere to the valve seats of the exhaust valves 146A and 146B. Therefore, in the present embodiment, the control unit 100 injects the gaseous fuel toward the exhaust valve 146A or the exhaust valve 146B when viewed from the central axis direction of the cylinder 135 when the cranking fuel injection control is performed. The fuel injection valve 151 is controlled so that the fuel is injected in the injection form. Thereby, the deposit | attachment adhering to exhaust valve 146A or exhaust valve 146B can be removed effectively. For example, in each cylinder, gaseous fuel is injected toward the exhaust valve 146A in a compression stroke of a certain combustion cycle, and in the compression stroke of the next combustion cycle, gaseous fuel is injected toward the exhaust valve 146B and exhausted. If the fuel injection to the valve 146A and the fuel injection to the exhaust valve 146B are repeated alternately, the deposits attached to the valve seats of both the exhaust valves 146A and 146B can be removed.

  Therefore, in this embodiment, the deposit | attachment adhering to the valve seat part of exhaust valve 146A, 146B can be removed effectively, and the sealing performance of the combustion chamber 137 can be ensured.

  In the third embodiment, the fuel injection valve 151 injects the gaseous fuel from the central portion of the cylinder 135 toward the entire circumference thereof when viewed from the central axis direction of the cylinder 135, and the gaseous fuel is injected into the cylinder. Although it is configured to be switchable between an injection mode in which the central portion of 135 is injected toward the exhaust valve 146A and an injection mode in which gaseous fuel is injected from the central portion of the cylinder 135 toward the exhaust valve 146B, these injection modes are configured. In addition, when viewed from the central axis direction of the cylinder 135, the fuel gas may be switched to an injection mode in which the gaseous fuel is injected from the central portion of the cylinder 135 toward the spark plug 152. In this case, when the fuel injection control during cranking is executed, the fuel injection valve 151 is controlled so that the gaseous fuel is injected in the injection form in which the gaseous fuel is injected toward the exhaust valve 146A, the exhaust valve 146B, or the spark plug 152. That's fine.

  Alternatively, the fuel injection valve 151 injects the gaseous fuel from the central portion of the cylinder 135 toward the entire circumference when viewed from the central axis direction of the cylinder 135, and the gaseous fuel. You may be comprised so that switching to the injection form (2nd injection form) which injects toward the ignition plug 152 from the center part of the cylinder 135 is possible. In this case, when the cranking fuel injection control is executed, the fuel injection valve 151 is set so that the gaseous fuel is injected in the injection form in which the gaseous fuel is injected toward the spark plug 152 when viewed from the central axis direction of the cylinder 135. What is necessary is just to control. When the fuel injection control at the time of cranking is performed, gaseous fuel is injected toward the spark plug 152, so that deposits attached to the spark plug 152 are effectively removed, and misfire occurs when the engine 10 is started. Can be prevented.

  There may be a plurality of spark plugs 152 (for example, the spark plug 152 is positioned between the two exhaust valves 146A and 146B in the ceiling portion of the combustion chamber 137 and the two intake valves 145A and 145B in the ceiling portion. In this case, the fuel injection valve 151 can be switched to an injection mode in which gaseous fuel is injected toward each spark plug 152 when viewed from the central axis direction of the cylinder 135. Then, the fuel injection valve 151 may be controlled so that the gaseous fuel is injected in an injection mode in which the fuel is injected toward any of the spark plugs 152 when the cranking fuel injection control is executed.

  The present invention is not limited to the embodiment described above, and can be substituted without departing from the spirit of the claims.

  The above-described embodiments are merely examples, and the scope of the present invention should not be interpreted in a limited manner. The scope of the present invention is defined by the scope of the claims, and all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The present invention is useful for a control device of a gas fuel direct injection engine having a fuel injection valve for directly injecting gaseous fuel into a combustion chamber, and particularly useful when the gas fuel direct injection engine is an engine of a hybrid vehicle. .

10 Gaseous Fuel Direct Injection Engine 18A Direct Injection Valve for Hydrogen (First Fuel Injection Valve)
18B CNG direct injection valve (second fuel injection valve)
19 Spark plug 20 Generator (starting device)
100 Control unit (control means)
106 Engine water temperature sensor (engine water temperature detection means)
107 Tank pressure sensor (remaining amount detection means)
121A Leading side fuel injection valve 121B Trailing side fuel injection valve 146A Exhaust valve 146B Exhaust valve 151 Fuel injection valve 152 Spark plug

Claims (6)

A control device for a gas fuel direct injection engine having a fuel injection valve for directly injecting gaseous fuel into a combustion chamber and an ignition plug for igniting fuel injected by the fuel injection valve,
The engine has a starting device for starting the engine,
Engine water temperature detecting means for detecting the temperature of the cooling water of the engine;
Including the operation of the fuel injection valve, the spark plug and starting device, and a control means for controlling the operation of the engine,
The control means performs the cranking operation of the engine by the starter without operating the fuel injection valve and the spark plug at the normal start, and operates the spark plug at the specific start. The combustion air-fuel ratio in the combustion chamber is set to a combustion air-fuel ratio in which the gaseous fuel in the combustion chamber does not ignite even when ignited by the spark plug in the compression stroke during the cranking operation. , Configured to execute cranking time fuel injection control for controlling the fuel injection valve ,
Further, the control means determines whether or not the engine has reached a predetermined warm condition from the temperature detected by the engine water temperature detection means, and determines that the engine has not reached the predetermined warm condition. The fuel injection control during cranking is executed on the assumption that the starting time is the specific starting time at the next starting of the engine after the operation of the engine is stopped. A control device for a gaseous fuel direct injection engine. The control device for a gas fuel direct injection engine according to claim 1 ,
The engine uses a first fuel and a second fuel as the gaseous fuel,
The fuel injection valve includes a first fuel injection valve that injects the first fuel, and a second fuel injection valve that injects the second fuel,
When the fuel in the combustion chamber is only the second fuel, the minimum combustion air-fuel ratio at which the second fuel does not ignite even when ignited by the spark plug is the only fuel in the combustion chamber. In this case, even when ignited by the spark plug, the first fuel is lower than the minimum combustion air-fuel ratio that does not ignite,
When the fuel injection control during cranking is executed, the control means has a volume injection amount of the second fuel, which is a fuel having a lower minimum combustion air-fuel ratio among the first fuel and the second fuel, A control device for a gas fuel direct injection engine, wherein the first fuel injection valve and the second fuel injection valve are controlled to be larger than a volume injection amount of the first fuel. The control device for a gas fuel direct injection engine according to claim 1 ,
The engine uses a first fuel and a second fuel different from the first fuel as the gaseous fuel,
The fuel injection valve includes a first fuel injection valve that injects the first fuel, and a second fuel injection valve that injects the second fuel,
A remaining amount detecting means for detecting the remaining volume of the first fuel and the second fuel, respectively;
When the fuel injection control at the time of cranking is executed, the control means is configured such that the volume injection quantity of the fuel with the larger remaining volume detected by the remaining quantity detection means is larger than the volume injection quantity of the smaller fuel. A control device for a gaseous fuel direct injection engine, characterized in that the first and second fuel injection valves are controlled so as to increase. The control device for a gas fuel direct injection engine according to claim 1 ,
The engine is a rotary piston engine,
The fuel injection valve includes a leading side fuel injection valve and a trailing side fuel injection valve arranged in parallel in the rotational direction of the rotor,
When the fuel injection control during cranking is executed, the control means is configured such that the volume injection amount of the gaseous fuel from the leading side fuel injection valve is the volume injection amount of the gaseous fuel from the trailing side fuel injection valve. A control device for a gas fuel direct injection engine, wherein the control device is configured to control the leading side fuel injection valve and the trailing side fuel injection valve so as to increase the number of the fuel injection valves. The control device for a gas fuel direct injection engine according to claim 1 ,
The engine is a reciprocating engine in which a piston reciprocates in a cylinder.
The fuel injection valve is disposed at the center of the ceiling of the combustion chamber and injects at least the gaseous fuel from the center of the cylinder toward the entire periphery thereof when viewed from the center axis direction of the cylinder. And a second injection mode in which the gaseous fuel is injected from the center of the cylinder toward the exhaust valve, and is configured to be switchable.
The control means is configured to control the fuel injection valve so that the gaseous fuel is injected in the second injection mode when the cranking fuel injection control is executed. A control device for a direct injection fuel gas engine. The control device for a gas fuel direct injection engine according to claim 1 ,
The engine is a reciprocating engine in which a piston reciprocates in a cylinder.
The fuel injection valve is disposed at the center of the ceiling of the combustion chamber and injects at least the gaseous fuel from the center of the cylinder toward the entire periphery thereof when viewed from the center axis direction of the cylinder. Switchable between a first injection mode and a second injection mode in which the gaseous fuel is injected from the center of the cylinder toward the spark plug,
The control means is configured to control the fuel injection valve so that the gaseous fuel is injected in the second injection mode when the cranking fuel injection control is executed. A control device for a direct injection fuel gas engine.

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