Engine equipment

Abstract

To inhibit an air-fuel ratio from becoming lean when a state where an engine is operated only by injecting fuel from a cylinder injection valve from start of the engine is switched to a state where the engine is operated by injecting fuel from a port injection valve.SOLUTION: When a state where an engine is operated only by injecting fuel from a cylinder injection valve from start of the engine is switched to a state where the engine is operated by injecting fuel from a port injection valve, predetermined fuel amount increase control for increasing a fuel injection amount on the basis of a temperature of cooling water at start of the engine and a temperature of the cooling water when the engine is stopped previously is executed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an engine device, and more particularly to an engine device including an engine having a port injection valve and a direct injection valve. [Background technology]

[0002] Conventionally, as an engine device of this type, a device has been proposed in which, when starting an engine having a port injection valve, the fuel injection amount is increased as the time that has elapsed between stopping the engine and starting increases (see, for example, Patent Document 1). In this engine device, the fuel increase value increases as the time that has elapsed between stopping the engine and starting increases, thereby improving the startability of the engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-124167 Summary of the Invention [Problem to be solved by the invention]

[0004] In engines equipped with port injection valves and in-cylinder injection valves, fuel is injected through the in-cylinder injection valves when the engine is started, and then fuel injection is switched to the port injection valve. When the engine is started while it is still warm and the engine is operated with fuel injection through the in-cylinder injection valve, fuel adhering to the inner wall of the intake port, the intake valve, etc., completely evaporates. If the engine is switched from operating with fuel injection through the in-cylinder injection valve to operating with fuel injection through the port injection valve under this condition, the fuel will adhere to the inner wall of the intake port, the intake valve, etc., resulting in a lean air-fuel ratio.

[0005] The main purpose of the engine device disclosed herein is to prevent the air-fuel ratio from becoming lean when switching from a state in which the engine is operated solely by fuel injection from the in-cylinder injection valve at engine start to a state in which the engine is operated by fuel injection from the port injection. [Means for solving the problem]

[0006] The engine device of the present disclosure employs the following measures to achieve the above-mentioned main object.

[0007] The engine device of the present disclosure comprises: An engine device including an engine having a port injection valve and an in-cylinder injection valve, and a control device that controls the engine, when switching from a first fuel injection operating state in which the engine is operated only by fuel injection from the in-cylinder injection valve since the start of the engine to a second fuel injection operating state in which the engine is operated by fuel injection from the port injection valve, the control device executes a predetermined fuel increase control to increase the fuel injection amount based on a start-up cooling water temperature which is the temperature of the cooling water at the start of the engine and a previous stop-time cooling water temperature which is the temperature of the cooling water when the engine was previously stopped. It is characterized by:

[0008] In the engine apparatus disclosed herein, when switching from a first fuel injection operating state in which the engine is operated only by fuel injection from the direct injection valves from engine start to a second fuel injection operating state in which the engine is operated by fuel injection from the port injection valves, a predetermined fuel increase control is executed to increase the fuel injection amount based on the start-up coolant temperature, which is the temperature of the coolant at engine start, and the previous stop-time coolant temperature, which is the temperature of the coolant the last time the engine was stopped. This makes it possible to prevent the air-fuel ratio from becoming lean when switching from the first fuel injection operating state to the second fuel injection operating state. The increase in the fuel injection amount is preferably adjusted to decrease as the start-up coolant temperature increases, and is preferably adjusted to decrease as the difference between the previous stop-time coolant temperature and the start-up coolant temperature decreases.

[0009] In the engine system of the present disclosure, the control device may calculate an initial value of a fuel increase amount based on the engine start-up coolant temperature and the engine previous shutdown coolant temperature when the engine is started, and then gradually attenuate the fuel increase amount. In this case, the control device may calculate the fuel increase amount based on a fuel injection distribution ratio between the port injection valve and the direct injection valve in the second fuel injection operating state. When fuel injection from the port injection valve and the direct injection valve is performed in the second fuel injection operating state, the fuel increase amount is preferably adjusted so that it increases as the fuel injection distribution ratio from the port injection valve increases. This is based on the fact that the amount of fuel adhering to the inner wall of the intake port, the intake valve, etc. increases as the fuel injection distribution ratio from the port injection valve increases.

[0010] In the engine system of the present disclosure, the control device may maintain the fuel increase value without attenuation from when the engine is switched to the second fuel injection operating state until fuel injection is performed in all cylinders of the engine, in order to cause fuel to adhere to inner walls of the intake ports, intake valves, etc. of all cylinders of the engine.

[0011] In the engine system of the present disclosure, the control device may permit updating of the coolant temperature at the time of the previous stop when an integrated value of the intake air amount since the start of the engine reaches a predetermined value, in order to avoid updating of the coolant temperature at the time of the previous stop when the engine is stopped shortly after being started.

[0012] In the engine device of the present disclosure, when the engine is stopped before the fuel increase value becomes 0, the control device may use the fuel increase value when the engine is stopped as a lower limit guard for the initial value of the fuel increase value when the engine is started next time. Even if the initial value of the fuel increase value becomes small when the engine is started next time because the difference between the cooling water temperature when the engine was previously stopped and the cooling water temperature when the engine is started is small, the lower limit guard allows a more appropriate fuel increase to be performed.

[0013] In the engine system of the present disclosure, the control device may use the larger of the initial value of the fuel increase value and an initial value of the fuel increase value calculated based on other factors as the initial value of the fuel increase value, thereby making it possible to determine a more appropriate fuel increase value taking into account the other factors. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a configuration diagram showing an outline of the configuration of an engine device 10 according to an embodiment of the present invention. [Figure 2] 4 is a flowchart showing an example of a fuel increase process at the time of switching injection modes, which is executed by an electronic control unit 70 according to the embodiment. [Figure 3] FIG. 4 is an explanatory diagram showing an example of the relationship between the cooling water temperature Twstart at startup and the fuel increase value Qadd. [Figure 4] FIG. 10 is an explanatory diagram showing an example of the relationship between the difference between the cooling water temperature at the previous stop Twstop and the cooling water temperature at the start Twstart and the fuel increase value Qadd. [Figure 5] 10 is a timing chart showing an example of time variations in the coolant temperature Tw, the engine speed Ne, the injection mode, and the fuel increase amount Qadd during engine start-up. DETAILED DESCRIPTION OF THE INVENTION

[0015] Next, a mode (embodiment) for carrying out the present disclosure will be described. Fig. 1 is a configuration diagram showing an outline of the configuration of an engine device 10 according to an embodiment of the present disclosure. As shown in the figure, the engine device 10 of the embodiment includes an engine 12, a fuel supply device 50, and an electronic control unit 70. The engine device 10 is mounted on a general vehicle that runs using power from the engine 12, various hybrid vehicles that include a motor in addition to the engine 12, and stationary equipment (such as construction equipment) that operates using power from the engine 12.

[0016] The engine 12 is configured as an internal combustion engine that uses fuel such as gasoline or a mixture of gasoline and alcohol, and outputs power through four strokes: intake, compression, expansion, and exhaust. The engine 12 is equipped with a port injection valve 25 that injects fuel into the intake port, and an in-cylinder injection valve 26 that injects fuel into the cylinder. By being equipped with the port injection valve 25 and the in-cylinder injection valve 26, the engine 12 can be operated in any of a port injection mode, an in-cylinder injection mode, and a common injection mode.

[0017] In the port injection mode, air purified by the air cleaner 22 is drawn into the intake pipe 23 and passes through the throttle valve 24, while fuel is injected from the port injection valve 25 to mix the air and fuel. This mixture is drawn into the combustion chamber 29 via the intake valve 28 and is explosively combusted by an electric spark from the spark plug 30. The reciprocating motion of the piston 32, which is pushed down by the energy from the explosive combustion, is then converted into rotational motion of the crankshaft 14. In the direct injection mode, as in the port injection mode, air is drawn into the combustion chamber 29, and fuel is injected from the direct injection valve 26 midway through the intake stroke and / or during the compression stroke, and is explosively combusted by an electric spark from the spark plug 30 to rotate the crankshaft 14. In the shared injection mode, fuel is injected from the port injection valve 25 when air is drawn into the combustion chamber 29, and fuel is injected from the in-cylinder injection valve 26 during the intake stroke and the compression stroke, and the fuel is explosively burned by an electric spark from the spark plug 30, generating rotational motion of the crankshaft 14. These injection modes are switched depending on the operating state of the engine 12. Exhaust gas discharged from the combustion chamber 29 into the exhaust pipe 33 via the exhaust valve 31 is discharged into the outside air via a purification device 34 having a purification catalyst (three-way catalyst) 34a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

[0018] The fuel supply device 50 is configured as a device that supplies fuel in a fuel tank 51 to the port injection valves 25 and the in-cylinder injection valves 26 of the engine 12. The fuel supply device 50 includes the fuel tank 51, a feed pump (first pump) 52, a low-pressure supply pipe (first supply pipe) 53, a check valve 54, a relief flow path 55, a relief valve 56, a high-pressure pump (second pump) 57, and a high-pressure supply pipe (second supply pipe) 58.

[0019] Feed pump 52 is configured as an electric pump that operates by receiving power from a battery (not shown), and is disposed inside fuel tank 51. Feed pump 52 supplies fuel from inside fuel tank 51 to low-pressure supply pipe 53. Low-pressure supply pipe 53 is connected to port injection valve 25. Check valve 54 is provided in low-pressure supply pipe 53 and allows fuel to flow in the direction from feed pump 52 to port injection valve 25, while restricting fuel flow in the opposite direction.

[0020] The relief flow passage 55 is connected to the low-pressure supply pipe 53 and the fuel tank 51. The relief valve 56 is provided in the relief flow passage 55, and closes when the fuel pressure in the low-pressure supply pipe 53 is below a threshold value Pflolim, and opens when the fuel pressure in the low-pressure supply pipe 53 is equal to or higher than the threshold value Pflolim. When the relief valve 56 opens, a portion of the fuel in the low-pressure supply pipe 53 is returned to the fuel tank 51 via the relief flow passage 55. In this way, the fuel pressure in the low-pressure supply pipe 53 is prevented from becoming excessive.

[0021] The high-pressure pump 57 is driven by power from the engine 12 (in this embodiment, rotation of the intake camshaft that opens and closes the intake valve 28), and is configured as a pump that pressurizes fuel in the low-pressure supply pipe 53 and supplies it to the high-pressure supply pipe 58. The high-pressure pump 57 has an electromagnetic valve 57a connected to its intake port that opens and closes when pressurizing the fuel, a check valve 57b connected to its discharge port that regulates backflow of fuel and maintains the fuel pressure in the high-pressure supply pipe 58, and a plunger 57c that is actuated (moves vertically in FIG. 1 ) by the rotation of the engine 12 (rotation of the intake camshaft). During operation of the engine 12, when the electromagnetic valve 57a is open, the high-pressure pump 57 sucks fuel from the low-pressure supply pipe 53, and when the electromagnetic valve 57a is closed, the high-pressure pump 57 pressurizes the fuel to be supplied to the high-pressure supply pipe 58 by intermittently sending fuel compressed by the plunger 57c into the high-pressure supply pipe 58 via the check valve 57b. When the high-pressure pump 57 is driven, the fuel pressure in the low-pressure supply pipe 53 and the fuel pressure (fuel pressure) in the high-pressure supply pipe 58 pulsate in accordance with the rotation of the engine 12 (the rotation of the intake camshaft). The high-pressure supply pipe 58 is connected to the in-cylinder injection valve 26.

[0022] The electronic control unit 70 includes a microcomputer having a CPU 71, ROM 72, RAM 73, flash memory 74, and input / output ports. Signals from various sensors are input to the electronic control unit 70 via the input ports. Examples of signals input to the electronic control unit 70 include a crank angle θcr from a crank position sensor 14a that detects the rotational position of the crankshaft 14 of the engine 12, and a coolant temperature Tw from a water temperature sensor 40 that detects the temperature of the coolant for the engine 12. Other examples of signals input to the electronic control unit 70 include cam angles θci and θco from a cam position sensor 44 that detects the rotational position of an intake camshaft that opens and closes the intake valve 28 and the rotational position of an exhaust camshaft that opens and closes the exhaust valve 31. Other examples include the throttle opening TH from a throttle position sensor 24a that detects the position of the throttle valve 24, the intake air amount Qa from an air flow meter 23a attached upstream of the throttle valve 24 in the intake pipe 23, and the intake air temperature Ta from a temperature sensor 23t attached upstream of the throttle valve 24 in the intake pipe 23. Other examples include the air-fuel ratio AF from an air-fuel ratio sensor 35 attached upstream of the purification device 34 in the exhaust pipe 33, and an oxygen signal O2 from an oxygen sensor 36 attached downstream of the purification device 34 in the exhaust pipe 33. Other examples include the fuel temperature Tftnk from a fuel temperature sensor 51t attached to the fuel tank 51, the rotation speed Nlp of the feed pump 52 from a rotation speed sensor 52a attached to the feed pump 52, the low-pressure fuel pressure (the pressure of the fuel supplied to the port injection valve 25) Pflo from a fuel pressure sensor 53p attached to the low-pressure supply pipe 53 near the port injection valve 25 (e.g., the low-pressure delivery pipe), and the high-pressure fuel pressure (the pressure of the fuel supplied to the in-cylinder injection valve 26) Pfhi from a fuel pressure sensor 58p attached to the high-pressure supply pipe 58 near the in-cylinder injection valve 26 (e.g., the high-pressure delivery pipe).

[0023] Various control signals are output from the electronic control unit 70 via the output port. Examples of signals output from the electronic control unit 70 include a control signal to the throttle valve 24 of the engine 12, a control signal to the port injection valve 25, a control signal to the in-cylinder injection valve 26, and a control signal to the spark plug 30. Other examples include a control signal to the feed pump 52 of the fuel supply device 50 and a control signal to the electromagnetic valve 57a of the high-pressure pump 57.

[0024] The electronic control unit 70 calculates the rotation speed Ne of the engine 12 based on the crank angle θcr from the crank position sensor 14a. The electronic control unit 70 also calculates a load factor KL (the ratio of the volume of air actually taken in per cycle to the stroke volume per cycle of the engine 12) based on the intake air amount Qa from the air flow meter 23a and the rotation speed Ne of the engine 12. The electronic control unit 70 also estimates the temperature Tc of the catalyst 34a of the purification device 34 based on the coolant temperature Tw from the water temperature sensor 40, the rotation speed Ne of the engine 12, and the load factor KL. In addition, the electronic control unit 70 estimates the fuel temperature Tfhp in the high-pressure pump 57 based on the coolant temperature Tw from the temperature sensor 40 and the intake air temperature Ta from the temperature sensor 23t.

[0025] In the engine device 10 of this embodiment configured as described above, the CPU 71 of the electronic control unit 70 controls the intake air volume, fuel injection, and ignition of the engine 12 as part of the operation control of the engine 12, and also controls the feed pump 52 and high-pressure pump 57 (electromagnetic valve 57a) of the fuel supply device 50.

[0026] For example, the intake air amount control of the engine 12 involves setting a required air amount Qa* based on the accelerator pedal position and the engine speed Ne of the engine 12, setting a target opening TH* of the throttle valve 24 so that the intake air amount Qa becomes the required air amount Qa*, and controlling the throttle valve 24 using the target opening TH*. For fuel injection control of the engine 12, a basic fuel injection amount Qbase is set based on the required air amount Qa* and the target air-fuel ratio AF*, and a fuel increase value Qadd is set as needed, and a required injection amount Qfuel* is set as the sum of the basic fuel injection amount Qbase and the fuel increase value Qadd. Then, based on the injection mode and the required injection amount Qfuel*, the fuel injection time Tp from the port injection valve 25 and the number of injections from the direct injection valve 26 and each fuel injection time Tf(n) are set, and the start times Tp and Tf of each fuel injection are set. The port injection valve 25 and the direct injection valve 26 are controlled to open so that fuel is injected at the start times Tp and Tf for the fuel injection times Tp and Tf(n). Ignition control of the engine 12 involves setting a target ignition timing Ti* for the spark plug 30 based on the engine speed Ne, required air amount Qa*, etc., and controlling the spark plug 30 using the set target ignition timing Ti*.

[0027] Next, the operation of the engine device 10 of the embodiment configured as described above will be described, in particular the operation when adjusting the fuel injection amount when switching from a first fuel injection operating state in which the engine 12 is operated only by fuel injection from the direct injection valve 26 from the start of the engine 12 to a second fuel injection operating state in which the engine 12 is operated by fuel injection from the port injection valve 25. Here, the first fuel injection operating state is a state in which the engine 12 is operated in the direct injection mode. The second fuel injection operating state includes a state in which the engine 12 is operated in the port injection mode and a state in which the engine 12 is operated in the shared injection mode.

[0028] 2 is a flowchart showing an example of a fuel increase process at injection mode switching executed by the electronic control unit 70 when switching from the first fuel injection operating state to the second fuel injection operating state. This fuel increase process at injection mode switching is executed when the engine 12 is started.

[0029] When the injection mode switching fuel increase process is executed, the electronic control unit 70 first inputs the engine 12 coolant temperature (start-time coolant temperature) Twstart detected by the temperature sensor 40 when the engine 12 is started and the engine 12 coolant temperature (previously stopped coolant temperature) Twstop detected when the engine 12 was last stopped (step S100). The previous-stop coolant temperature Twstop is input by reading the previous-stop coolant temperature Twstop stored in a predetermined area of ​​the flash memory 74. In this embodiment, in order to exclude cases where the engine 12 is stopped shortly after being started, the previous-stop coolant temperature Twstop is updated based on the coolant temperature Tw detected by the temperature sensor 40 when the engine 12 is stopped after the integrated value of the intake air amount Qa since the engine 12 was started reaches a predetermined value or more.

[0030] Next, an initial value of the temporary fuel increase value Qadd1 is set based on the difference (Twstop-Twstart) between the cooling water temperature at the previous stop, Twstop, and the cooling water temperature at the start, Twstart, and the cooling water temperature at the start, Twstart (step S110). As shown in an example of the relationship between the cooling water temperature at the start, Twstart, and the fuel increase value Qadd in Fig. 3, the temporary fuel increase value Qadd1 is preferably set to decrease as the cooling water temperature at the start, Twstart, increases. Furthermore, as shown in an example of the relationship between the difference between the cooling water temperature at the previous stop, Twstop, and the cooling water temperature at the start, Twstart, and the fuel increase value Qadd in Fig. 4, the temporary fuel increase value Qadd1 is preferably set to increase as the difference (Twstop-Twstart) increases.

[0031] Next, the fuel increase value Qadd0 when the engine 12 was last stopped (previously stopped fuel increase value) and the fuel increase value Qadd2 set for another requirement (other requirement fuel increase value) are input (step S120). The fuel increase value Qadd is set as the fuel increase value Qadd (step S130) by multiplying the largest value among the tentative fuel increase value Qadd1, the previously stopped fuel increase value Qadd0, and the other requirement fuel increase value Qadd2. Here, the first half of the right-hand side of the process in step S130 can be considered as a process of selecting the larger of the tentative fuel increase value Qadd1 with a lower limit guard set to the previously stopped fuel increase value Qadd0, or the other requirement fuel increase value Qadd2. Therefore, when the fuel increase value Qadd0 at the previous stop is 0, the larger of the temporary fuel increase value Qadd1 and the other requirement fuel increase value Qadd2 is selected, and when the other requirement fuel increase value Qadd2 is 0, the temporary fuel increase value Qadd1 is limited to the previous requirement fuel increase value Qadd0 as a lower limit. The reason why the first half of the right side of the processing in step S130 is multiplied by the port injection distribution ratio k is that the larger the port injection distribution ratio k, the more fuel injected from the port injection valve 25 will adhere to the wall surface of the intake pipe 23 after the port injection valve 25 and to the intake valve 28.

[0032] Once the fuel increase value Qadd is set in this manner, a process of attenuating the fuel increase value Qadd is started every 360 degrees of rotation of the crankshaft 14 (step S140). The fuel increase value Qadd may be attenuated by subtracting a fixed amount from the fuel increase value Qadd determined for each cylinder each time fuel is injected into that cylinder, or by multiplying the fuel increase value Qadd determined for each cylinder by a attenuation coefficient.

[0033] Next, the process waits for a switch from a first fuel injection operating state in which the engine 12 is operated solely by fuel injection from the direct injection valves 26 from the start of the engine 12 to a second fuel injection operating state in which the engine 12 is operated by fuel injection from the port injection valves 25 (step S150). When the first fuel injection operating state is switched to the second fuel injection operating state, the process stops attenuating the fuel increase value Qadd and holds the fuel increase value Qadd (step S160), waits for the crankshaft 14 to rotate 720 degrees (step S170), and resumes the process of attenuating the fuel increase value Qadd every time the crankshaft 14 rotates 360 degrees (step S180). The reason for holding the fuel increase value Qadd and waiting for the crankshaft 14 to rotate 720 degrees when the process is switched from the first fuel injection operating state to the second fuel injection operating state is to inject fuel using the same fuel increase value Qadd in all cylinders of the engine 12.

[0034] When the fuel increase value Qadd becomes less than the threshold value Qref (step S190), it is determined that the fuel increase is complete, and this process ends. A value close to 0 can be used as the threshold value Qref.

[0035] FIG. 5 is a timing chart showing an example of time variations in the coolant temperature Tw, engine speed Ne, injection mode, and fuel increase value Qadd during engine start. When the engine 12 is stopped at time T1, the coolant temperature Tw gradually decreases. When the engine 12 is started at time T2 and operated in direct injection mode, the initial value of the fuel increase value Qadd is set based on the coolant temperature Twstop at the previous stop and the coolant temperature Twstart at the start. Thereafter, the fuel increase value Qadd decays and the coolant temperature Tw gradually increases. At time T3, when the integrated value of the intake air amount Qa since the start of the engine 12 at time T2 reaches a predetermined value, updating of the coolant temperature Twstop at the previous stop is permitted. Therefore, when the engine 12 is stopped after this time, the coolant temperature Tw detected by the temperature sensor 40 at that time is stored in a predetermined area of ​​the flash memory 74 as the coolant temperature Twstop at the previous stop, thereby updating the coolant temperature Tw. When the direct injection mode is switched to the port injection mode at time T4 and the first fuel injection operating state is switched to the second fuel injection operating state, the fuel increase value Qadd is held until time T5 when the crankshaft 14 rotates 720 degrees, and then decays.

[0036] In the engine device of the embodiment described above, when switching from the first fuel injection operating state in which the engine 12 is operated only by fuel injection from the direct injection valves 26 at the start of the engine 12 to the second fuel injection operating state in which the engine 12 is operated by fuel injection from the port injection valves 25, control is executed to increase the fuel injection amount using the fuel increase value Qadd obtained based on the coolant temperature at start Twstart and the coolant temperature at the previous stop Twatop. This makes it possible to prevent the air-fuel ratio from becoming lean when switching from the first fuel injection operating state to the second fuel injection operating state.

[0037] In the engine system of the embodiment, the fuel increase value Qadd is set by applying a lower limit guard to the temporary fuel increase value Qadd1 using the fuel increase value Qadd0 at the previous engine stop. This prevents the fuel increase value Qadd from becoming unnecessarily small due to a decrease in the difference (Twstop-Twstart) between the cooling water temperature at the previous engine stop, Twstop, and the cooling water temperature at engine start, Twstart. Furthermore, the fuel increase value Qadd is set by selecting the larger of the temporary fuel increase value Qadd1 and the other requirement fuel increase value Qadd2. This allows a more appropriate fuel increase value Qadd to be set, taking other requirements into account. Furthermore, the fuel increase value Qadd is set using the port injection distribution ratio k. This prevents the air-fuel ratio from becoming lean, and also prevents the air-fuel ratio from becoming rich due to a small port injection distribution ratio k.

[0038] In the engine device of the embodiment, when the operation state is switched from the first fuel injection operation state to the second fuel injection operation state, the fuel increase value Qadd is maintained until the crankshaft 14 rotates 720 degrees. This allows fuel to be injected into all cylinders of the engine 12 using the same fuel increase value Qadd.

[0039] In the engine device 10 of the embodiment, the port injection valve 25 is attached to the side of the combustion chamber 29, but it may also be attached as an in-cylinder injection valve at the top of the combustion chamber.

[0040] The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem will be explained below. In the embodiment, the engine 12 corresponds to the "engine" and the electronic control unit 70 corresponds to the "controller."

[0041] The correspondence between the main elements of the embodiments and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, since the embodiments are examples for specifically explaining the mode for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the embodiments are merely specific examples of the invention described in the "Means for Solving the Problem" section.

[0042] The above describes the form (embodiment) for carrying out the present invention, but the present invention is not limited to such an embodiment in any way, and it goes without saying that the present invention can be carried out in various forms within the scope that does not deviate from the gist of the present invention. [Industrial Applicability]

[0043] The present invention can be used in the engine device manufacturing industry and the like. [Explanation of symbols]

[0044] 10 engine device, 12 engine, 14 crankshaft, 14a crank position sensor, 15 crank position sensor, 22 air cleaner, 23 intake pipe, 23a air flow meter, 23t temperature sensor, 24 throttle valve, 24a throttle position sensor, 25 port injection valve, 26 in-cylinder injection valve, 28 intake valve, 29 combustion chamber, 30 spark plug, 31 exhaust valve, 32 piston, 33 exhaust pipe, 34 purification device, 34a catalyst, 35 air-fuel ratio sensor, 36 oxygen sensor, 40 water temperature sensor, 44 cam position sensor, 50 fuel supply device, 51 fuel tank, 51t fuel temperature sensor, 52 feed pump, 52a rotation speed sensor, 53 low-pressure supply pipe, 53p fuel pressure sensor, 54 check valve, 55 relief flow path, 56 relief valve, 57 High-pressure pump, 57a solenoid valve, 57b check valve, 57c plunger, 58 high-pressure supply pipe, 58p fuel pressure sensor, 70 electronic control unit, 71 CPU, 72 ROM, 73 RAM, 74 flash memory.

Claims

1. An engine device including an engine having a port injection valve and an in-cylinder injection valve, and a control device that controls the engine, when switching from a first fuel injection operating state in which the engine is operated by fuel injection only from the in-cylinder injection valve since the start of the engine to a second fuel injection operating state in which the engine is operated by fuel injection from the port injection valve, the control device executes a predetermined fuel increase control to increase the fuel injection amount based on a start-up cooling water temperature that is the temperature of the cooling water at the start of the engine and a previous stop-time cooling water temperature that is the temperature of the cooling water when the engine was previously stopped, the control device permits updating of the cooling water temperature at the previous stop when an integrated value of the intake air amount since the start of the engine reaches a predetermined value. Engine equipment.

2. 2. The engine device according to claim 1, the control device calculates an initial value of a fuel increase value based on the cooling water temperature at the time of engine start and the cooling water temperature at the time of previous engine stop when the engine is started, and thereafter gradually attenuates the fuel increase value, and further calculates the fuel increase value based on a distribution ratio of fuel injection from the port injection valve and fuel injection from the in-cylinder injection valve in the second fuel injection operating state. Engine equipment.

3. An engine device according to claim 2, When the engine is stopped before the fuel increase value becomes zero, the control device uses the fuel increase value when the engine is stopped as a lower limit guard for the initial value of the fuel increase value when the engine is started next time. Engine equipment.

4. An engine device including an engine having a port injection valve and an in-cylinder injection valve, and a control device that controls the engine, when switching from a first fuel injection operating state in which the engine is operated by fuel injection only from the in-cylinder injection valve since the start of the engine to a second fuel injection operating state in which the engine is operated by fuel injection from the port injection valve, the control device executes a predetermined fuel increase control to increase the fuel injection amount based on a start-up cooling water temperature that is the temperature of the cooling water at the start of the engine and a previous stop-time cooling water temperature that is the temperature of the cooling water when the engine was previously stopped, the control device calculates an initial value of a fuel increase amount based on the cooling water temperature at the time of engine start and the cooling water temperature at the time of previous engine stop when the engine is started, and thereafter gradually attenuates the fuel increase amount, and further calculates the fuel increase amount based on a distribution ratio of fuel injection from the port injection valve and fuel injection from the direct injection valve in the second fuel injection operating state, the control device uses, as the initial value of the fuel increase value, a larger value of the initial value of the fuel increase value or an initial value of the fuel increase value calculated based on other requirements. Engine equipment.

5. An engine device according to claim 4, When the engine is stopped before the fuel increase value becomes zero, the control device uses the fuel increase value when the engine is stopped as a lower limit guard for the initial value of the fuel increase value when the engine is started next time. Engine equipment.

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