Internal combustion engine control device

Abstract

To provide an internal combustion engine control device reducing time from an On-operation of a start switch to fuel injection.SOLUTION: A control device executes: a fuel injection processing for executing fuel injection by a fuel injection valve under the condition that a start switch is operated to be turned on; a determination processing for determining presence / absence of leakage of fuel from a fuel supply system under the condition that the start switch is operated to be turned on; and an estimation processing for estimating presence / absence of probability that the start switch is turned on before the On-operation of the start switch. The fuel injection processing is such one as not to execute the fuel injection when the determination processing is not completed even when the start switch is operated to be turned on. The determination processing is such one as to start when there is probability of execution of the On-operation of the start switch in the estimation processing even when the start switch is not operated to be turned on.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control device for an internal combustion engine. [Background technology]

[0002] Patent Document 1 discloses a control device for an internal combustion engine, which detects whether or not there is a fuel leak. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-250141 Summary of the Invention [Problem to be solved by the invention]

[0004] The control device described in Patent Document 1 starts determining whether or not there is a fuel leak from the fuel supply system when the start switch is turned on. Therefore, if the leakage determination method described in Patent Document 1 is applied to an internal combustion engine that performs fuel injection from a fuel injection valve on the condition that there is no fuel leak, there is a risk that the time from turning on the start switch to fuel injection will be long. [Means for solving the problem]

[0005] The control device for an internal combustion engine for solving the above problem is a control device for an internal combustion engine mounted on a vehicle, and executes a fuel injection process that executes fuel injection by a fuel injection valve on the condition that a start switch of the internal combustion engine has been turned on, a determination process that determines whether or not there is fuel leakage from a fuel supply system on the condition that the start switch has been turned on, and an estimation process that estimates whether or not there is a possibility that the start switch will be turned on before the start switch is turned on, and the gist of the process is that the fuel injection process is a process that does not execute the fuel injection if the determination process has not been completed even if the start switch has been turned on, and the determination process is a process that is started when the estimation process estimates that there is a possibility that the start switch will be turned on, even if the start switch has not been turned on.

[0006] According to the above configuration, the control device also starts the determination process when it is estimated that the start switch will likely be turned on. In this case, the determination process is completed earlier than when the determination process is started when the start switch is turned on. Therefore, the time from when the start switch is turned on to when fuel injection begins can be shortened. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of an embodiment of a control device. [Figure 2] FIG. 2 is a flowchart showing the procedure of the process executed by the control device. [Figure 3] FIG. 3 is a timing chart showing the relationship between the timing at which the start switch is turned on and the timing at which the determination process is started. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, one embodiment of a control device for an internal combustion engine will be described with reference to FIGS. <Internal combustion engine and control device> 1 is an internal combustion engine that runs on hydrogen gas as fuel. The internal combustion engine 10 is mounted on a vehicle 200. Hereinafter, hydrogen gas may also be referred to as fuel.

[0009] The internal combustion engine 10 includes a fuel supply system 10a. The fuel supply system 10a includes a tank 20, a first shutoff valve 21, a second shutoff valve 22, a pressure reducing valve 30, a fuel pipe 41, a delivery pipe 42, and a plurality of fuel injection valves 52.

[0010] The tank 20 stores fuel in a compressed state. The fuel pipe 41 is a fuel passage through which the fuel flows, and connects the tank 20 to a delivery pipe 42. Each fuel injection valve 52 is connected to the delivery pipe 42.

[0011] The fuel stored in the tank 20 is supplied to the fuel injection valve 52 via the fuel pipe 41 and the delivery pipe 42. The fuel injection valve 52 injects fuel into the cylinder 51 of the internal combustion engine 10.

[0012] In the fuel pipe 41, a first shutoff valve 21, a pressure reducing valve 30, and a second shutoff valve 22 are arranged in this order in the direction of fuel flow from the tank 20 to the fuel injection valve 52. The first shutoff valve 21 is disposed near the outlet of the tank 20. When the first shutoff valve 21 is open, fuel is supplied from the tank 20 to the fuel pipe 41. When the first shutoff valve 21 is closed, the supply of fuel from the tank 20 to the fuel pipe 41 is stopped.

[0013] The pressure reducing valve 30 is a valve that adjusts the pressure of the fuel supplied to the fuel injection valve 52 to a pressure that corresponds to the operating state of the internal combustion engine 10. The second shutoff valve 22 is disposed near the delivery pipe 42. When the second shutoff valve 22 is open, fuel is supplied from the fuel pipe 41 to the delivery pipe 42. When the second shutoff valve 22 is closed, the supply of fuel from the fuel pipe 41 to the delivery pipe 42 is stopped.

[0014] When the internal combustion engine 10 is stopped, the first shutoff valve 21 and the second shutoff valve 22 are both closed. On the other hand, when the internal combustion engine 10 is operating, the first shutoff valve 21 and the second shutoff valve 22 are both open.

[0015] The control unit 100 of the internal combustion engine 10 includes a CPU 110 and a memory 120 configured from a ROM, a RAM, etc. The control unit 100 performs various processes by the CPU 110 executing programs stored in the memory 120. Some or all of the components of the control unit 100 may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by a combination of software and hardware.

[0016] The control unit 100, pressure sensor 81, first to third hydrogen sensors 91 to 93, start switch 70, door open / close switch 71, lock sensor 72, seating sensor 73, and buckle sensor 74 are examples of components that make up a control device for an internal combustion engine.

[0017] <Various sensors> A pressure sensor 81 is provided in a portion of the fuel pipe 41 between the pressure reducing valve 30 and the second shutoff valve 22. The pressure sensor 81 outputs a signal corresponding to the fuel pressure P1 in the fuel supply system 10a.

[0018] A first hydrogen sensor 91 is provided near the tank 20. The first hydrogen sensor 91 outputs a signal corresponding to a first hydrogen concentration H1, which is the concentration of hydrogen near the tank 20. A second hydrogen sensor 92 is provided in the fuel pipe 41 near a portion between the pressure reducing valve 30 and the second shutoff valve 22. The second hydrogen sensor 92 outputs a signal corresponding to a second hydrogen concentration H2, which is the concentration of hydrogen in the vicinity of that portion.

[0019] A third hydrogen sensor 93 is provided near the delivery pipe 42. The third hydrogen sensor 93 outputs a signal corresponding to a third hydrogen concentration H3, which is the concentration of hydrogen near the delivery pipe 42.

[0020] The control unit 100 controls the fuel injection valve 52 to inject fuel into the cylinder 51. The control unit 100 detects the fuel pressure P1 based on the output signal of the pressure sensor 81. The control unit 100 detects the hydrogen concentration of each of the first to third hydrogen sensors 91 to 93 based on the output signals of the first to third hydrogen sensors 91 to 93.

[0021] The control unit 100 and pressure sensor 81 are an example of a pressure detection device that detects the pressure of the fuel supply system 10a. The control unit 100 and the first to third hydrogen sensors 91 to 93 are an example of a concentration detection device that detects the concentration of hydrogen. The concentration detection device is an example of a detection device that detects fuel leakage. Of the fuel leakage, fuel leakage from the fuel injection valve 52 into the cylinder 51 does not necessarily need to be detected by the detection device.

[0022] The vehicle 200 has a door opening / closing switch 71 that detects the open / closed state of the entry / exit door 61. The vehicle 200 has a lock sensor 72 that detects that the lock mechanism 62 of the entry / exit door 61 of the vehicle 200 has changed from a locked state to an unlocked state. The vehicle 200 has a seating sensor 73 that detects whether or not an occupant is seated in the seat 63 of the vehicle 200. The vehicle 200 has a buckle sensor 74 that detects whether or not the tongue of the seat belt of the vehicle 200 is inserted into the buckle 64.

[0023] <Processing performed by the control unit> The control unit 100 executes a fuel injection process. In the fuel injection process, fuel injection by the fuel injection valve 52 is executed on the condition that the start switch 70 of the internal combustion engine 10 is turned on.

[0024] The control unit 100 executes an estimation process before the start switch 70 is turned on. The estimation process is a process for estimating whether or not there is a possibility that the start switch 70 will be turned on during a start preparation period, which is the period from the opening operation of the entry / exit door 61 to the turning on operation of the start switch 70. Note that the opening operation of the entry / exit door 61 may include the operation of releasing the lock mechanism 62 of the entry / exit door 61.

[0025] The control unit 100 detects the following [1] to [4] based on the output signals of the lock sensor 72, the door open / close switch 71, the seating sensor 73, and the buckle sensor 74. [1] The boarding / exiting door 61 is unlocked by the locking mechanism 62. [2] The boarding door 61 was opened. [3] The seat 63 of the vehicle 200 has changed to a state supporting the occupant. [4] The seat belt of vehicle 200 has changed to a state that restrains the occupant. When at least one of [1] to [4] is detected during the start preparation period, the control unit 100 estimates that there is a possibility that the start switch 70 will be turned on. Note that the vehicle 200 does not need to be equipped with the lock sensor 72. In this case, the unlocking of the boarding / alighting door 61 may be detected based on the control unit 100 outputting a signal to the lock mechanism 62 to unlock the door.

[0026] The control unit 100 performs a determination process to determine whether or not there is a fuel leak from the fuel supply system 10a. When starting the determination process, the control unit 100 turns on a fuel cut flag to stop fuel injection and turns on the first to third hydrogen sensors 91 to 93. In the determination process, the control unit 100 references the first to third hydrogen concentrations H1 to H3 to determine whether or not there is a fuel leak. Specifically, if the first to third hydrogen concentrations H1 to H3 are all equal to or less than a predetermined value HL, the control unit 100 determines that there is no fuel leak. If any of the first to third hydrogen concentrations H1 to H3 exceeds the predetermined value HL, the control unit 100 determines that there is a fuel leak.

[0027] The flow of the fuel injection process, estimation process, and determination process executed by the control unit 100 will be described with reference to FIG. 2, when the start switch 70 is turned on (S100: YES), the control unit 100 executes a determination process (S120 to S150). When the start switch 70 is not turned on (S100: NO), the control unit 100 executes an estimation process (S110). Even when the start switch 70 is not turned on (S100: NO), the control unit 100 starts the determination process (S120 to S150) when the estimation process estimates that the start switch 70 may be turned on (S110: YES).

[0028] When the control unit 100 starts the determination process, the control unit 100 turns on the fuel cut flag (S120). The control unit 100 measures the elapsed time since the start of the determination process and determines whether the elapsed time has reached a predetermined response time (step S130). If the response time has elapsed (S130: YES), the control unit 100 determines whether or not there is a fuel leak (S140). If there is no fuel leak (S140: YES), the control unit 100 changes the fuel cut flag from on to off (S150). As a result, fuel injection becomes possible in the fuel injection process (S160, S170). That is, if the start switch 70 is on (S160: YES), fuel injection is performed (S170). Therefore, even if the start switch 70 is turned on, the fuel injection process does not perform fuel injection unless the determination process is completed. If it is determined that there is a fuel leak (S140: NO), the fuel cut flag remains on. Therefore, the control unit 100 does not perform fuel injection.

[0029] There is a response delay, for example, several seconds to several tens of seconds, from when the first to third hydrogen sensors 91 to 93 are turned on until the sensors 91 to 93 output a detection value corresponding to the hydrogen concentration around the sensors 91 to 93. The response time mentioned above is the time corresponding to this response delay.

[0030] <Operation of this embodiment> At timing t1 in Figure 3, when the determination process is started when it is estimated that the start switch 70 may be turned on, the time counter value increases from timing t1. The time counter value is a counter value that increases according to the elapsed time since the determination process started. At timing t3, when the time counter value reaches a predetermined value C1, if none of the first to third hydrogen concentrations H1 to H3 exceed the predetermined value HL (this embodiment (no abnormality)), the fuel cut flag is switched from on to off. The predetermined value C1 is a determination value that determines whether the elapsed time has reached a predetermined response time.

[0031] As a result of the fuel cut flag being switched off, fuel injection can be performed when the start switch 70 is on. Note that, as shown by the dashed line in Figure 3, if any of the first to third hydrogen concentrations H1 to H3 exceeds the predetermined value HL at timing t3 (this embodiment (abnormality present)), the fuel cut flag remains on, and fuel injection is not performed.

[0032] In the case where the determination process is started when the start switch 70 is turned on at timing t2 in Fig. 3 (comparative example (no abnormality)), the time counter value reaches the predetermined value C1 at timing t4, as indicated by the dashed dotted line. Therefore, even if the start switch 70 is on at timing t1, fuel injection cannot be performed until timing t4. In other words, the start of fuel injection is delayed by the time T1 shown in Fig. 3 compared to when the determination process is started when it is estimated that the start switch 70 may be turned on.

[0033] <Effects of this embodiment> According to this embodiment, the following effects can be obtained. (1) The control unit 100 of the internal combustion engine 10 can reduce the time from when the start switch 70 is turned on until the fuel injection valve 52 is ready to inject fuel by the time T1 shown in FIG.

[0034] (2) The vehicle 200 is equipped with an on-board device that switches between two different states during a start preparation period, which is the period from the opening operation of the access door 61 to the turning on of the start switch 70. The opening operation may include the release operation of the lock mechanism 62 of the access door 61. The estimation process is a process that estimates that there is a possibility that the turning on of the start switch 70 will be performed based on the detection of a change in the state of the on-board device.

[0035] When the state of the in-vehicle device is switched, there is a high possibility that the start switch 70 will be turned on following the switch. Therefore, with the above configuration, the estimation accuracy of the estimation process is high. (3) The entry / exit door 61, the locking mechanism 62, the seat 63, and the seat belt of the vehicle 200 are all in-vehicle devices whose states change between two different states during the start preparation period, and are examples of in-vehicle devices essential to the vehicle 200. Therefore, the estimation process can be performed based on the states of the in-vehicle devices essential to the vehicle 200.

[0036] (4) The internal combustion engine 10 is equipped with a detection device that detects the concentration of hydrogen. When fuel leaks from the fuel supply system 10a, the concentration of hydrogen detected by the control unit 100 increases. Therefore, the accuracy of the determination process is high.

[0037] (5) The detection device requires a predetermined response time to detect a fuel leak. The detection device measures the elapsed time from the start of the determination process and detects a fuel leak based on the hydrogen concentration when the elapsed time reaches the predetermined response time. Therefore, the determination process has high accuracy.

[0038] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0039] The estimation process may be a process in which the time at which the start switch 70 is turned on is obtained multiple times and an estimation is made that there is a possibility that the start switch 70 will be turned on at a time before a time period in which the start switch 70 is turned on frequently.

[0040] If the vehicle 200 is equipped with an electronic key system, the procedure of the estimation process may be modified as follows. The electronic key system is a system that permits unlocking of the locking mechanism 62 of the access door 61 when the ECU of the vehicle 200 wirelessly communicates with an electronic key located near the vehicle 200 and authenticates that the electronic key is a legitimate electronic key capable of unlocking the locking mechanism 62 of the access door 61. In this case, the estimation process may be a process that estimates that there is a possibility that the start switch 70 will be turned on when the authentication is successful.

[0041] The estimation process may be a process that estimates that there is a possibility that the start switch 70 will be turned on when it is detected that an occupant has entered the vehicle cabin by a camera that photographs the interior of the vehicle cabin or an ultrasonic sensor installed in the vehicle cabin.

[0042] In the above embodiment and its modified examples, multiple events are exemplified as being detected when the estimation process estimates that the start switch 70 may be turned on. The control unit 100 may be configured to detect at least one of these multiple events. The estimation process may also be a process that estimates that the start switch 70 may be turned on when any one of these multiple events is detected, or a process that estimates that the start switch 70 may be turned on when two or more events are detected.

[0043] The detection device that detects fuel leakage may be a pressure detection device. For example, when the control unit 100 starts the determination process, it closes the fuel injection valve 52 and opens the first shutoff valve 21, the second shutoff valve 22, and the pressure reducing valve 30. The control unit 100 detects a change in the fuel pressure P1 in the fuel supply system 10a after the determination process starts based on the output signal of the pressure sensor 81. When the control unit 100 detects a decrease in the fuel pressure P1 in the fuel supply system 10a, it determines that a fuel leakage has occurred.

[0044] In this modification, for example, the control unit 100 measures the elapsed time from the start of the determination process and detects the fuel pressure P1 and the amount of decrease in the fuel pressure P1 when the elapsed time reaches a predetermined response time. The control unit 100 determines that a fuel leak has occurred when the fuel pressure P1 is smaller than a predetermined pressure value or when the amount of decrease in the fuel pressure P1 is greater than a predetermined amount. Note that when a fuel leak has occurred, there is a response delay in the decrease in the fuel pressure P1 that occurs after the start of the determination process. The response time corresponds to this response delay.

[0045] In this modified example, the control unit 100 may determine that a fuel leak has occurred when the fuel pressure P1 after the start of the determination process has dropped to atmospheric pressure or to a pressure value that can be regarded as atmospheric pressure. In another example, the control unit 100 may determine that a fuel leak has occurred when the rate of change of the fuel pressure P1 after the start of the determination process is greater than a predetermined rate of change.

[0046] Fuel leakage may be detected based on both the pressure detection device and the concentration detection device. The hydrogen sensor may be installed at any position and in any number as long as it can detect the hydrogen concentration, which changes in response to fuel leakage. The pressure sensor may be installed at any position and in any number as long as it can detect the pressure in the fuel supply system 10a, which changes in response to fuel leakage.

[0047] After starting the determination process, the control unit 100 may determine that there is a hydrogen leak based on the fact that the output signal of the hydrogen sensor has converged to a value indicating a fuel leak. The number of control devices that execute multiple processes, such as fuel injection process, determination process, estimation process, detection process by the concentration detection device, and detection process by the pressure detection device, is arbitrary. For example, the multiple processes may each be executed by a separate control device. For example, one control device may execute some of the multiple processes, and another control device may execute the remaining processes. For example, one process may be executed by multiple control devices working together.

[0048] The fuel is not limited to hydrogen gas, but may be, for example, natural gas, propane gas, gasoline, diesel, or a mixture of these. Furthermore, the internal combustion engine 10 may be an internal combustion engine that runs on two or more types of fuel.

[0049] The phrase "at least one" as used herein means "one or more" of the desired options. As an example, the phrase "at least one" as used herein means "only one option" or "both of two options" when the number of options is two. As another example, the phrase "at least one" as used herein means "only one option" or "any combination of two or more options" when the number of options is three or more. [Explanation of symbols]

[0050] 10...internal combustion engine, 10a...fuel supply system, 20...tank, 21...first shut-off valve, 22...second shut-off valve, 30...pressure reducing valve, 41...fuel piping, 42...delivery pipe, 51...cylinder, 52...fuel injection valve, 61...entrance door, 62...lock mechanism, 63...seat, 64...buckle, 70...start switch, 71...door opening / closing switch, 72...lock sensor, 73...seating sensor, 74...buckle sensor, 81...pressure sensor, 91...first hydrogen sensor, 92...second hydrogen sensor, 93...third hydrogen sensor, 100...control unit, 110...CPU, 120...memory, 200...vehicle

Claims

1. A control device for an internal combustion engine mounted on a vehicle, a fuel injection process in which fuel injection by a fuel injection valve is performed on the condition that a start switch of the internal combustion engine is turned on; a determination process for determining whether or not there is a fuel leak from the fuel supply system on the condition that the start switch has been turned on; an estimation process for estimating whether or not there is a possibility that the start switch will be turned on before the start switch is turned on; Run the fuel injection process is a process in which the fuel injection is not performed when the determination process has not been completed even if the start switch has been turned on, The determination process is a process that is started when the estimation process estimates that there is a possibility that the start switch will be turned on even if the start switch has not been turned on. Control device for internal combustion engines.

2. the vehicle includes an on-board device whose state is switched between two different states during a start preparation period, which is a period from when an entry / exit door is opened to when the start switch is turned on; The estimation process includes: This is a process of estimating that there is a possibility that the start switch will be turned on based on the detection of the change in the state of the in-vehicle device. The control device for an internal combustion engine according to claim 1.

3. The estimation process includes: The locking mechanism of the vehicle's entry / exit door has been released. The boarding / alighting door has been opened; The vehicle seat has changed to a state supporting the occupant; and the vehicle's seat belt has changed to a state that restrains the occupant. is a process for estimating that there is a possibility that the start switch will be turned on based on the detection of at least one of the above. The control device for an internal combustion engine according to claim 1.

4. A concentration detection device for detecting the concentration of hydrogen is provided, the fuel injection valve is a valve that injects hydrogen gas as the fuel, The determination process includes: A process for determining whether the fuel is leaking from the fuel supply system based on the concentration of hydrogen detected by the concentration detection device. The control device for an internal combustion engine according to claim 1.

5. The determination process includes: a process for determining whether or not there is a hydrogen leak based on the hydrogen concentration detected by the concentration detection device when the elapsed time from the start of the determination process reaches a predetermined response time; The control device for an internal combustion engine according to claim 4.

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