control device

Abstract

The object of the present invention is to provide a control device that can reduce the probability of false positives occurring, which indicate that an abnormality has occurred in the intake pressure sensor. [Solution] The present invention is an engine control device. The engine is equipped with a crankshaft. An intake passage is connected to the engine. An intake pressure sensor is provided in the intake passage. When the crankshaft is rotating in reverse, the control device performs a masking process on the intake pressure signal output from the intake pressure sensor.

Description

Technical Field

[0001] The present invention relates to a control device.

Background Art

[0002] As an invention related to a conventional control device, for example, a reverse rotation determination device described in Patent Document 1 is known. This reverse rotation determination device determines whether the engine is in a reverse rotation state based on a cam angle signal output by a cam angle sensor and a crank angle signal output by a crank angle sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the engine is in a reverse rotation state, the pressure in the intake passage may become too high. In this case, the control device may erroneously determine that an abnormality has occurred in the intake pressure sensor provided in the intake passage.

[0005] Therefore, an object of the present invention is to provide a control device capable of reducing the probability of occurrence of an erroneous determination indicating that an abnormality has occurred in the intake pressure sensor.

Means for Solving the Problems

[0006] A first aspect is a control device for an engine, where the engine includes a crankshaft, an intake passage is connected to the engine, an intake pressure sensor is provided in the intake passage, The control device, when the crankshaft is rotating in reverse, performs a masking process on the intake pressure signal output from the intake pressure sensor. It is a control device.

[0007] The second aspect is, The control device performing a masking process on the intake pressure signal means that the control device does not determine that an abnormality has occurred in the intake pressure sensor, even if the value of the intake pressure signal is an abnormal value. This is the control device described on the first side.

[0008] The third aspect is, The aforementioned engine is further equipped with an ignition system, The intake path is provided with an injector and a throttle valve. The control device, when the crankshaft of the engine is rotating in reverse, stops ignition by the ignition device, stops fuel injection by the injector, and / or increases the opening of the throttle valve. The control device is as described on the first or second side. [Effects of the Invention]

[0009] According to the present invention, the probability of a false positive indicating that an abnormality has occurred in the intake pressure sensor can be reduced. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is an explanatory diagram of the engine system 1. [Figure 2] Figure 2 is a flowchart of the actions performed by the control device 100. [Modes for carrying out the invention]

[0011] (Embodiment) [Structure of Engine System 1] The structure of the engine system 1 according to one embodiment of the present invention will be described below with reference to the drawings. Figure 1 is an explanatory diagram of the engine system 1.

[0012] The engine system 1 is the power source for the vehicle. The vehicle is, for example, a four-wheeled automobile. The engine system 1 comprises an engine 10, an intake path member 27, an exhaust path member 28, an injector 29, a throttle valve 30, a crank angle sensor 51, a cam angle sensor 52, an intake pressure sensor 53, and a control device 100.

[0013] Engine 10 is a four-stroke engine that uses gasoline as fuel. Although Figure 2 shows one cylinder, engine 10 has three cylinders. However, since the structure of the three cylinders is the same, we will focus on one cylinder for explanation. Engine 10 comprises a engine body 12, a crankshaft 14, a connecting rod 16, a piston 18, an intake valve 20, an exhaust valve 22, and an ignition device 23.

[0014] The engine body 12 includes a cylinder block 12a, a cylinder head 12b, and a crankcase 12c. The cylinder block 12a is provided with a cylinder Sy. The cylinder Sy has a cylindrical shape with a central axis extending along the vertical axis.

[0015] The cylinder head 12b is located on top of the cylinder block 12a. The cylinder head 12b is fixed to the cylinder block 12a. The cylinder head 12b is provided with a combustion chamber Sp. The combustion chamber Sp is located on top of the cylinder Sy. The combustion chamber Sp is connected to the cylinder Sy.

[0016] The cylinder head 12b is provided with an intake port P1 and an exhaust port P2. The intake port P1 and the exhaust port P2 are connected to the combustion chamber Sp. The intake port P1 is a part of the intake passage R1. The intake passage R1 is a space through which air or a mixture of fuel and air passes. The intake passage member 27 is a cylindrical member that forms the intake passage R1. The exhaust port P2 is a part of the exhaust passage R2. The exhaust passage R2 is a space through which exhaust passes. The exhaust passage member 28 is a cylindrical member that forms the exhaust passage R2. Thus, the engine 10 is provided with a combustion chamber Sp, an intake passage R1 connected to the combustion chamber Sp, and an exhaust passage R2.

[0017] The throttle valve 30 is provided in the intake passage R1. The throttle valve 30 adjusts the amount of air (intake air amount) supplied to the engine 10 under the control of a control device 100 (described later).

[0018] The injector 29 is provided in the intake passage R1. The injector 29 is located downstream of the throttle valve 30. The injector 29 injects fuel into the engine 10. In the present embodiment, the injector 29 injects atomized fuel into the intake passage R1. That is, in the engine 10, a port injection system is adopted. Thereby, a mixture is formed.

[0019] The intake pressure sensor 53 is provided in the intake passage R1. The intake pressure sensor 53 is located downstream of the throttle valve 30. The intake pressure sensor 53 detects the pressure in the intake passage R1. The intake pressure sensor 53 generates an intake pressure signal having a value corresponding to the magnitude of the pressure in the intake passage R1. When the magnitude of the pressure in the intake passage R1 increases, the value of the intake pressure signal increases. When the magnitude of the pressure in the intake passage R1 decreases, the value of the intake pressure signal decreases. When the intake pressure sensor 53 is normal, the value of the intake pressure signal has a value between the upper limit value and the lower limit value. On the other hand, when the intake pressure sensor 53 is abnormal, the value of the intake pressure signal becomes larger than the upper limit value. The abnormality of the intake pressure sensor 53 is, for example, that a disconnection occurs in the intake pressure sensor 53.

[0020] The crankcase 12c is located below the cylinder block 12a. The crankcase 12c is fixed to the cylinder block 12a. The engine body 12 described above is made of cast iron.

[0021] The crankshaft 14 is supported by the cylinder block 12a and the crankcase 12c. The crankshaft 14 can rotate about a rotation axis perpendicular to the vertical axis.

[0022] The piston 18 is located within the cylinder Sy. The piston 18 has a cylindrical shape. The piston 18 can move upward and downward.

[0023] The connecting rod 16 connects the crankshaft 14 and the piston 18. As a result, when the crankshaft 14 rotates, the piston 18 moves up and down. The combustion chamber Sp mentioned above is the space enclosed by the piston 18 and the cylinder head 12b when the piston 18 is at top dead center (TDC).

[0024] The intake valve 20 is supported by the cylinder head 12b. The intake valve 20 is located downstream of the injector 29 in the intake path R1. The intake valve 20 opens and closes the intake path R1. When the intake valve 20 opens the intake path R1, a mixture of fuel and air flows from the intake path R1 into the combustion chamber Sp. The exhaust valve 22 is supported by the cylinder head 12b. The exhaust valve 22 opens and closes the exhaust path R2. When the exhaust valve 22 opens the exhaust path R2, exhaust gas flows out from Sp into the exhaust path R2. The intake valve 20 and exhaust valve 22 are driven by a valve train mechanism (not shown).

[0025] The ignition system 23 burns the fuel injected by the injector 29. The ignition system 23 includes a spark plug and an ignition coil. The spark plug is fixed to the cylinder head 12b. The spark plug includes a center electrode and a ground electrode. The center electrode and ground electrode are exposed to the combustion chamber Sp.

[0026] The ignition coil is electrically connected to the spark plug. Based on the ignition signal from the control device 100, the ignition coil applies a high voltage between the center electrode and the ground electrode of the spark plug. This generates a spark between the center electrode and the ground electrode of the spark plug, igniting the fuel in the combustion chamber Sp.

[0027] The control device 100 controls the operation of the engine 10. In this embodiment, the control device 100 controls the amount of fuel injected by the injector 29. The control device 100 controls the timing of the spark plug discharge. The control device 100 controls the opening degree of the throttle valve 30. The control device 100 is, for example, an ECU (Engine Control Unit) and includes a circuit board and electronic components.

[0028] [Operation of Engine System 1] Next, the operation of the engine system 1 will be explained with reference to the diagram. Figure 2 is a flowchart of the actions performed by the control device 100.

[0029] The control device 100 acquires a crank angle signal from the crank angle sensor 51 and a cam angle signal from the cam angle sensor 52 (step S1). Based on the crank angle signal and the cam angle signal, the control device 100 determines whether or not the crankshaft 14 is rotating in reverse (step S2). The determination of whether or not the crankshaft 14 is rotating in reverse is performed, for example, by the method described in Patent Document 1. If the crankshaft 14 is not rotating in reverse, the process proceeds to step S3. If the crankshaft 14 is rotating in reverse, the process proceeds to step S9.

[0030] If the crankshaft 14 is not rotating in reverse, the control device 100 allows the engine 10 to operate normally (step S3). During normal operation, the control device 100 does not stop the ignition of the ignition device 23, nor does it stop fuel injection by the injector 29.

[0031] Next, the control device 100 acquires an intake pressure signal from the intake pressure sensor 53 (step S4). Then, the control device 100 determines whether the value of the intake pressure signal is a normal value or not (step S5). If the intake pressure sensor 53 is normal, the value of the intake pressure signal will be between the upper limit and the lower limit. Therefore, in step S5, the control device 100 determines whether the value of the intake pressure signal is less than or equal to the upper limit and greater than or equal to the lower limit. If the value of the intake pressure signal is less than or equal to the upper limit and greater than or equal to the lower limit, the control device 100 determines that the value of the intake pressure signal is a normal value. In this case, the process proceeds to step S6. If the value of the intake pressure signal is not less than or equal to the upper limit and greater than or equal to the lower limit, the control device 100 determines that the value of the intake pressure signal is an abnormal value. In this case, the process proceeds to step S7.

[0032] If the intake pressure signal value is within the normal range, the control device 100 determines that there is no abnormality in the intake pressure sensor 53 (it is in a normal state) (step S6). After this, the process proceeds to step S8.

[0033] If the intake pressure signal value is abnormal, the control device 100 determines that an abnormality has occurred in the intake pressure sensor 53 (it is in an abnormal state) (step S7). In this case, the control device 100 displays on a display device (not shown) that an abnormality has occurred in the intake pressure sensor 53, and also outputs an audio message to a speaker (not shown) indicating that an abnormality has occurred in the intake pressure sensor 53. After this, the process proceeds to step S8.

[0034] In step S2, if the crankshaft 14 is rotating in reverse, the control device 100 puts the engine 10 into fail-safe mode (step S9). In fail-safe mode, the control device 100 stops ignition by the ignition device 23, stops fuel injection by the injector 29, and increases the opening of the throttle valve 30. In this embodiment, the control device 100 controls the opening of the throttle valve 30 to fully open.

[0035] Next, the control device 100 acquires an intake pressure signal from the intake pressure sensor 53 (step S10). Then, the control device 100 performs a masking process on the intake pressure signal output from the intake pressure sensor 53 (step S11). Masking the intake pressure signal by the control device 100 means that even if the value of the intake pressure signal is an abnormal value, the control device 100 does not determine that an abnormality has occurred in the intake pressure sensor 53. In other words, the control device 100 does not determine whether the value of the intake pressure signal is a normal value or not.

[0036] Next, the control device 100 determines whether or not scavenging in the intake path R1 is complete (step S12). In this embodiment, the control device 100 determines whether or not fail-safe operation is complete. If fail-safe operation is complete, the control device 100 determines that scavenging in the intake path R1 is complete. In this case, the process proceeds to step S13. If fail-safe operation is not complete, the control device 100 determines that scavenging in the intake path R1 is not complete. In this case, the process returns to step S12.

[0037] Once scavenging in the intake path R1 is complete, the control device 100 releases the mask for the intake pressure signal (step S13). After this, the process proceeds to step S5.

[0038] In step S8, the control device 100 determines whether or not to terminate this process (step S8). In this embodiment, the control device 100 determines whether or not the driver has performed an operation to stop the engine 10. If the driver has not performed an operation to stop the engine 10, this process returns to step S1. If the driver has performed an operation to stop the engine 10, this process terminates.

[0039] [effect] The control device 100 can reduce the probability of a false positive indicating that an abnormality has occurred in the intake pressure sensor 53. More specifically, when the crankshaft is rotating in reverse, the intake valve may open during the exhaust stroke. In this case, exhaust gas flows into the intake path, and the intake pressure increases. Also, when the crankshaft is rotating in reverse, backfire may occur. In this case as well, the intake pressure increases. When such an increase in intake pressure occurs, the intake pressure sensor outputs an intake pressure signal with a value greater than the upper limit. Therefore, the control device falsely determines that an abnormality has occurred in the intake pressure sensor.

[0040] Therefore, when the crankshaft 14 is rotating in reverse, the control device 100 performs a masking process on the intake pressure signal output from the intake pressure sensor 53. Masking the intake pressure signal by the control device 100 means that even if the value of the intake pressure signal is an abnormal value, the control device 100 will not determine that there is a malfunction in the intake pressure sensor. This reduces the possibility that the control device 100 will mistakenly determine that there is a malfunction in the intake pressure sensor 53 due to an increase in intake pressure caused by backfire or the like when the crankshaft is rotating in reverse.

[0041] Furthermore, when the crankshaft 14 is rotating in reverse, the control device 100 stops ignition by the ignition device 23, stops fuel injection by the injector 29, and increases the opening of the throttle valve 30. This makes it more difficult for exhaust gases to flow into the intake passage R1, and also makes it less likely for backfires to occur in the intake passage R1. As a result, the control device 100 can release the masking of the intake pressure sensor 53 earlier. Consequently, the starting performance of the engine 10 is improved.

[0042] Furthermore, because backfiring is less likely to occur, components located in the intake path R1, such as the throttle valve 30, are less likely to be damaged.

[0043] Incidentally, in automobiles equipped with a manual transmission, reverse rotation of the crankshaft 14 may occur for the following reasons. More specifically, there may be cases where the engine 10 is stopped and the gear for forward movement is selected, and the automobile is positioned on a slope. In this case, if the automobile moves backward due to gravity, the crankshaft 14 will be rotated in reverse. As a result, there is a possibility that the engine 10 will start with the crankshaft 14 rotating in reverse. In such cases, there is a possibility that a false judgment indicating an abnormality has occurred in the intake pressure sensor 53 as described above may occur. Therefore, the control device 100 is suitable for automobiles equipped with a manual transmission.

[0044] (Other embodiments) The coil cooling device according to the present invention is not limited to the control device 100, but can be modified within the scope of its gist.

[0045] In step S8, the control device 100 may stop ignition by the ignition device 23, stop fuel injection by the injector 29, and / or increase the opening of the throttle valve 30. That is, the control device 100 only needs to perform at least one of the following: stop ignition by the ignition device 23, stop fuel injection by the injector 29, or increase the opening of the throttle valve 30. [Explanation of symbols]

[0046] 1: Engine System 10: Engine 12: Engine body 12a: Cylinder block 12b: Cylinder head 12c: Crankcase 14: Crankshaft 16: Connecting Rod 18: Piston 20: Intake valve 22: Exhaust valve 23:Ignition device 29: Injector 30: Throttle valve 51: Crank angle sensor 52: Cam angle sensor 53: Intake pressure sensor 100: Control device R1: Intake path R2: Exhaust path

Claims

1. An engine control device, The aforementioned engine is equipped with a crankshaft, The aforementioned engine is connected to an intake path, An intake pressure sensor is provided in the aforementioned intake path. The control device, when the crankshaft is rotating in reverse, performs a masking process on the intake pressure signal output from the intake pressure sensor. Control device.

2. The control device performing a masking process on the intake pressure signal means that the control device does not determine that an abnormality has occurred in the intake pressure sensor, even if the value of the intake pressure signal is an abnormal value. The control device according to claim 1.

3. The aforementioned engine is further equipped with an ignition system, The intake path is provided with an injector and a throttle valve. The control device, when the crankshaft of the engine is rotating in reverse, stops ignition by the ignition device, stops fuel injection by the injector, and / or increases the opening of the throttle valve. The control device according to claim 1 or claim 2.

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