JP5910071B2 - Engine failure determination device - Google Patents

Description

  The present invention relates to a failure determination apparatus for determining a failure in an internal combustion engine, particularly in relation to a change in the oil pressure of lubricating oil, and preventing engine damage.

  Gasoline engines and the like are equipped with a device that detects the oil pressure in order to prevent damage due to a drop in the oil pressure of the lubricating oil. When the oil pressure drops and the oil pressure value falls below the threshold value, the engine control unit receives the signal and issues a warning to reduce the oil pressure and prevents engine damage by using a method such as restricting the rotation of the engine. . Since this type of device is an important device for preventing engine breakage, a function for detecting the failure is incorporated in the engine control unit.

JP 2000-45745 A

  When the oil pressure detection device is a sensor, the conventional sensor output is detected as an open state or a short state to determine a failure. However, the oil pressure of the lubricating oil differs between the cold state and the warm state, and particularly when the engine is suddenly fully opened in the cold state, the oil pressure is greatly increased as compared to the normal warm-up state. If the sensor range is determined based on the hydraulic pressure at the time of warm-up, the hydraulic pressure value reaches the failure determination value in the cold-open suddenly open hydraulic pressure, and there is a possibility that the failure is erroneously determined as it is. On the other hand, if the detection range of the sensor is increased in consideration of the oil pressure in the cold state, there is a problem that the oil pressure detection accuracy during the warm-up steady state is lowered.

  Patent Document 1 discloses an apparatus for determining this type of failure.

  In view of such circumstances, an object of the present invention is to provide an engine failure determination device that can reliably determine sensor failure while ensuring sensor detection accuracy.

An engine failure determination apparatus according to the present invention detects a hydraulic pressure of a lubricating oil of an engine and outputs a predetermined low pressure signal when the hydraulic pressure drops below a reference pressure, and an output signal of the hydraulic sensor is a predetermined value. And a failure determination means for determining that the hydraulic sensor is in failure when the output is outside the first range and detecting the temperature of the engine, and the temperature is a reference temperature. An engine temperature sensor for outputting a predetermined cold machine signal when the engine temperature is lower, an engine temperature judging means for judging that the engine is cold when the cold machine signal is outputted from the engine temperature sensor, and the failure judgment Control means for driving the warning means to execute a warning operation when the hydraulic pressure sensor determines that the hydraulic sensor is in failure. The output of the engine temperature sensor No. is detected whether or not the cold signal, whereas if the engine is not cold sets the delay time to the first delay time, the said delay time when the engine is cold The second delay time is set longer than the first delay time .

  In the engine failure determination apparatus of the present invention, an engine rotation sensor that detects the rotation speed of the engine, and an engine rotation speed determination means that determines whether the rotation speed of the engine is faster than a predetermined rotation speed. When the engine is cold, the delay time is set to the first delay time when the engine rotation speed is slower than the predetermined rotation speed, while the engine rotation speed is set to the predetermined rotation speed. When the speed is higher than the rotation speed, the delay time is set to the second delay time.

  In the engine failure determination device of the present invention, it is detected whether the output signal of the hydraulic sensor is within the second range, and when the output signal is output within the second range, the amount of lubricating oil is normal. A lubricating oil amount determining means for determining that the engine temperature is cold and the delay time is set to the second delay time when the lubricating oil amount is determined to be normal; On the other hand, the delay time is set to the first delay time when it is determined that the amount of lubricating oil is abnormal.

  In the engine failure determination apparatus according to the present invention, the delay time is determined when the engine is cold and the amount of the lubricating oil is determined to be normal, and the rotational speed of the engine is higher than the predetermined rotational speed. Is set to the second delay time, and when the engine rotation speed is slower than the predetermined rotation speed, the delay time is set to the first delay time.

  According to the present invention, it is possible to improve the reliability of determination by first determining whether the engine is in a cold state or a warm-up state and setting the failure determination time according to them. In particular, when the engine is in a cold state, by setting the failure determination time longer when performing the failure determination of the hydraulic sensor, it is possible to reliably prevent erroneous determination and to ensure proper operation of the hydraulic sensor.

1 is an external side view of an outboard motor according to the present invention. It is a figure which shows the state which removed the exterior cover of the outboard motor which concerns on this invention. It is a sectional side view which shows the internal structure of the outboard motor which concerns on this invention. It is a block diagram which shows the structural example of the control system in the outboard motor which concerns on this invention. It is a flowchart which shows the operation example by 1st Embodiment of the failure determination apparatus of the engine by this invention. It is a flowchart which shows the operation example by 2nd Embodiment of the failure determination apparatus of the engine by this invention. It is a flowchart which shows the operation example by 3rd Embodiment of the engine failure determination apparatus by this invention. It is a flowchart which shows the operation example by 4th Embodiment of the failure determination apparatus of the engine by this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of an engine failure determination apparatus according to the present invention will be described with reference to the drawings.
1 is an external side view of an outboard motor according to the present invention, FIG. 2 is a diagram showing a state in which an exterior cover of the outboard motor shown in FIG. 1 is removed, and FIG. 3 is a diagram of the outboard motor shown in FIG. It is a side view which shows an internal structure.
As shown in FIG. 1, the outboard motor 1 used in this embodiment is mounted on a transom (stern beam) 101 of a hull 100 via a bracket 2. The outboard motor 1 has a hollow body extending in the vertical direction at the rear portion of the bracket 2 and has a spindle-shaped drive shaft housing 3 having a horizontal cross section. An engine holder 4 is arranged on the upper part, and an engine 6 covered with an engine cover 5 is mounted on the upper part of the engine holder 4. A gear case 7 is connected to the lower portion of the drive shaft housing 3, and a propeller shaft with a propeller 8 facing horizontally rearward is rotatably supported on the gear case 7.

  As shown in FIGS. 2 and 3, the engine 6 is a water-cooled four-cycle four-cylinder engine having a cylinder head 9, a cylinder block 10 and a crankcase 11 (the number of cylinders other than four cylinders may be different). Fuel is injected from an unillustrated fuel tank to an intake port in the cylinder head 9 via an injector 12 (see FIG. 4). A crankshaft 13 is supported in the crankcase 11 so as to be rotatable along a substantially vertical direction, and a flywheel 14 of a generator is fixed to the shaft end of the crankshaft 13. A crank angle sensor 15 (see FIG. 4) for detecting 13 rotation angles is provided.

  In the hydraulic circuit of the outboard motor 1, oil stored in an oil pan 16 provided at the lower part of the crankcase 11 is sucked by the oil strainer 17, sucked up by the oil pump 18, and oil filter 19. Carried to. In this case, if the oil pressure becomes excessive, the seal of the gasket may be breached. Therefore, the relief valve 20 is set in front of the oil filter 19 so that the upper limit of the oil pressure of the lubricating oil is managed. The oil passing through the oil filter 19 passes through the main gallery, is distributed to the crankshaft 13, the cylinder head 9, the camshaft 21, and the like, and returns to the oil pan 16 using natural fall. ing. Further, a hydraulic pressure sensor 22 installed in the main gallery detects the hydraulic pressure on the downstream side of the oil filter 19.

  Further, FIG. 4 shows a configuration example of a control system of the outboard motor 1 in this embodiment. This control system includes a control unit 30, and an input device 23 for inputting various set values, a crank angle sensor 15 and a hydraulic pressure sensor 22, and an engine temperature sensor 24 are connected on the input side of the control unit 30. Is done. As the engine temperature sensor 24, any one that detects the temperature of the cooling water flowing through the water jacket of the engine 6 or one that detects the temperature of the lubricating oil can be employed. On the other hand, on the output side of the control unit 30, each injector 12 provided in the cylinder head 9 of each cylinder, an ignition coil 25 for each cylinder, a warning device 26 and the like are connected. The control unit 30 controls the injector 12, the warning device 26, and the like based on signals output from the input side hydraulic sensor 22, the engine temperature sensor 24, and the like.

Here, the oil pressure sensor 22 outputs an output signal P in response to the hydraulic pressure of the lubricating oil of the engine 6, and outputs a predetermined low pressure signal S _P when the hydraulic pressure is lower than the reference pressure P _0. In this case, the direct output signal from the hydraulic pressure sensor 22 is a voltage value, but the control unit 30 calculates the hydraulic pressure value from the voltage value in the calculation unit 31. In the following description, it is assumed that the output signal of the hydraulic pressure sensor 22 indicates the hydraulic pressure. The engine temperature sensor 24 detects the oil temperature of the cooling water or lubricating oil, to output a predetermined cold signal S _T at that time the temperature is lower than the reference temperature T _0. The warning device 26 includes a buzzer that generates a warning sound, an LED that displays a warning, and the like.

  Further, the control unit 30 has a configuration as shown in FIG. 4, that is, has a calculation unit 31 that performs various calculations, control, determination, and the like. A digital signal is input to the input side by an A / D converter 36 a. In response to the detection signal from the crank angle sensor 15 converted into a signal, the engine receives the signal from the rotation speed detector (rotation speed detector) 36 and the hydraulic pressure sensor 22 for detecting the engine speed (crankshaft speed). A hydraulic pressure determination unit 37 that determines whether a hydraulic pressure abnormality has occurred, an engine temperature determination unit 38 that determines whether the engine temperature is lower than a reference temperature, a counter (timer) 34 that performs a counting or timing operation, and A memory 35 for storing various data such as table data of delay time corresponding to the engine speed is connected.

  Further, on the output side of the calculation unit 31, a warning drive control unit 32 that controls the warning device 26, a fuel injection control unit 33 that controls driving of each injector 12, and an ignition control unit 39 that performs ignition control in each ignition coil 25. The warning drive control unit 32, the fuel injection control unit 33, the ignition control unit 39, and the like are controlled based on data signals output from these units.

  Next, an operation example of the engine failure determination device will be described. FIG. 5 is a flowchart showing the basic operation of the failure determination apparatus of the present invention. In this flowchart, power is first turned on and the engine of the outboard motor is started (steps S1 and S2). Next, when the EEPROM is loaded in step S3 and stopped last time in step S4, it is confirmed whether or not there has been a failure determination in the hydraulic sensor 22 (step S11). 6 is limited, typically stopped (step S12).

On the other hand, when there is no failure determination, a timer, that is, a failure determination time is set. In this case firstly, the engine 6 is determined whether the cold state in step S5, that is, the output of the engine temperature sensor 24 is higher than the reference temperature T _0, thus if the cold signal S _T is not outputted, the delay time t Is set to t = t ₁ , that is, the first delay time (step S6). Failure determination is not performed instantaneously in order to prevent erroneous determination, but is determined as failure when the failure state continues for a certain period of time, thereby ensuring reliability of determination. The delay time t ₁ set here is, for example, about 5 seconds. In this way, when the engine temperature is high, there is no erroneous determination, so there is no problem even if the delay time t is set short.

On the other hand, when the engine temperature is low, there is a possibility of erroneous determination, so the delay time t is set long. In this case, the delay time t is set to t = t ₂ , that is, the second delay time (step S7). When the engine 6 is in the cold state, the viscosity of the lubricating oil is relatively large, and accordingly, the output of the hydraulic sensor 22 is also increased. Therefore, by setting the delay time t as the failure determination time to be long, it is possible to secure a time for the hydraulic pressure to return to the normal value by increasing the oil temperature of the lubricating oil, and to prevent erroneous determination. The relationship between the delay times t ₁ and t ₂ is t ₁ <t ₂ .

Next, in step S8, it is determined whether or not the output of the hydraulic pressure sensor 22 is in the normal value range. When the hydraulic sensor 22 fails, the output voltage at that time is fixed at about 0 (V) or 5 (V), so the range of 0.2 to 4.8 (V) is actually a normal value range. (First range), and a case outside this range is determined as a failure of the hydraulic sensor 22 itself. When converted into the oil pressure of the lubricating oil, the reference pressure P ₀ here corresponds to 0.2 (V), and the upper limit pressure P _{1 in the} normal value range corresponds to 4.8 (V). That is, the normal value range of the output signal P of the hydraulic sensor 22 is P _{0 to} P ₁ .

  If it is determined in step S8 that the hydraulic sensor 22 is in an abnormal state, it is continuously checked whether or not the hydraulic sensor 22 is in an abnormal state in order to prevent erroneous determination. That is, in step 9 and step 10, here, for example, if it is continued for 5 seconds, it is determined that a failure has occurred, and the delay time t is counted down from 5 seconds by 1 second (t-1). It is determined that there are 22 failures. In step 11, a buzzer or display informs that there is a failure.

Thereafter, the hydraulic sensor 22 is repaired or replaced, and the failure is released when the output of the hydraulic sensor 22 falls within the normal value range. Note that a timer is set in step S13 in order to prevent erroneous determination even when the failure is cleared. The delay time t _{1 in} this case may be about 5 seconds, for example. In step 14, it is determined whether the output signal P of the hydraulic pressure sensor 22 is P ₀ ≦ P ≦ P ₁ , that is, in the normal value range. Also in this case, the delay time t is counted down from 5 seconds to 1 second (steps S15 and S16), and when 5 seconds have elapsed, the hydraulic sensor 22 is determined to be normal, and the failure is eliminated in step S17.

  In the present invention, when determining the failure of the hydraulic system of the engine 6, the determination is not based on the output signal of the hydraulic sensor 22, but the engine temperature is first detected first, and the failure determination condition is set according to the engine temperature. Make it different. That is, as described above, the temperature of the cooling water or the temperature of the lubricating oil is detected to determine whether the engine 6 is in a cold state or a warm-up state, and the failure determination time is set accordingly. Reliability can be improved.

In particular, when the engine 6 is in a cold state, an erroneous determination can be reliably prevented by setting the failure determination time longer when performing the failure determination of the hydraulic sensor 22. By assuring the proper operation of the hydraulic sensor 22 in this way, high reliability can be ensured when a failure of the hydraulic system of the engine 6 itself is subsequently determined.
Further, by detecting the engine temperature from the temperature of the cooling water, the cost can be reduced by determining with the existing sensor. Further, by detecting the engine temperature with the oil temperature, the determination accuracy can be improved by directly detecting the oil temperature.

Next, a second embodiment of the present invention will be described. In this example, the engine speed is used as a failure determination condition in addition to the engine temperature. The oil pressure of the lubricating oil reaches the upper limit pressure P ₁ (the output voltage of the oil pressure sensor 22 is 4.8 (V)) when the engine is cold and the engine speed is high. This is particularly the case, for example, when the cooler is suddenly fully opened, and the hydraulic pressure rises significantly compared to that during steady warm-up. Therefore, in this embodiment, when the engine speed is set as a failure determination condition, the failure determination time is set to be longer when the failure determination time is set longer.

FIG. 6 is a flowchart illustrating the operation of the failure determination device according to the second embodiment. In the following description, substantially the same operations as those in the flowchart of FIG. 5 are denoted by the same reference numerals, detailed description thereof will be omitted, and only characteristic operations of the present embodiment will be described. And As shown in FIG. 6, when it is determined in step S5 that the engine 6 is lower than the reference temperature T ₀ based on the output of the engine temperature sensor 24, that is, is in a cold state, the engine speed is detected by the engine speed detector 36 in step S21. The number of revolutions is calculated. When the engine rotation speed Ne is slower than the predetermined rotation speed N ₀ , the delay time t is set to the _first delay time t ₁ (step S6).

On the other hand, when the rotational speed Ne of the engine is faster than the predetermined rotational speed N ₀ (step S21), the delay time t is set to the _second delay time t ₂ in step S22. In this case it corresponds to the cold suddenly fully opened engine 6, setting only the second delay time t ₂ in this case. That is, in the case of a cold machine, the failure determination can be performed appropriately and efficiently by narrowing the region in which the delay time is changed long in relation to the engine speed, instead of setting the delay time t ₂ uniformly.

  Next, a third embodiment of the present invention will be described. In this example, in addition to the engine temperature, the presence / absence of lubricating oil is detected from the output signal of the hydraulic sensor 22 immediately after the engine 6 is started, and the failure determination condition is used as different from normal only when it is determined that there is lubricating oil. As described above, in the failure determination, the determination is originally made on the assumption that there is an appropriate amount of lubricating oil. If the failure determination is continued in a state where there is no lubricating oil, the engine 6 may become so-called empty if left as it is. Therefore, in this embodiment, such a situation is prevented in advance by adding the presence or absence of lubricating oil as a failure determination condition.

FIG. 7 is a flowchart illustrating the operation of the failure determination apparatus according to the third embodiment. As shown in FIG. 7, since the engine 6 is just started in step S5, it is basically determined that the engine is in a cold state, and then in step S31, the presence or absence of lubricating oil is determined. Here, as described above, the normal value range of the output signal P of the hydraulic sensor 22 is the _first range of P _{0 to} P ₁ (voltage value is 0.2 to 4.8 (V)). In the third embodiment, if the output signal P of the hydraulic sensor 22 is in the second range of P ₂ ≦ P ≦ P ₃ (1.0 to 4.0 (V) in voltage value), the lubricating oil Has a predetermined oil pressure, and it is determined that the amount of lubricating oil is normal. In this case, the delay time t is set to the _second delay time t ₂ (step S32).

On the other hand, when it is determined in step S31 that the amount of lubricating oil is abnormal, that is, there is no predetermined amount of lubricating oil pressure, the engine 6 is in the cold state, but the first delay time t without increasing the delay time t. Set to ₁ . If the oil pressure sensor 22 fails if there is no lubricant, the timing for notifying the vessel operator will be delayed if the determination time is long, and in the extreme case, the engine 6 may be blown. Also in this case, the failure determination can be performed appropriately and efficiently by narrowing the region in which the delay time is changed long in relation to the presence or absence of the lubricating oil.

In the third embodiment, the upper limit pressure P ₃ is not necessarily considered for the second range (P _{2 to} P ₃ ) of the output signal of the hydraulic sensor 22. That is, if there is a hydraulic pressure equal to or higher than the lower limit pressure P ₂ (P ₂ ≦ P), it may be determined that the lubricating oil is present.

  Next, a fourth embodiment of the present invention will be described. In this example, in addition to the engine temperature, both the engine speed and the presence or absence of lubricating oil are used as failure determination conditions. That is, it is determined that the engine 6 is cold and the amount of lubricating oil is normal, and the delay time is set to the second delay time when the rotational speed of the engine 6 is higher than a predetermined rotational speed. On the other hand, when the rotational speed of the engine 6 is slower than the predetermined rotational speed, the delay time is set to the first delay time.

FIG. 8 is a flowchart illustrating the operation of the failure determination device according to the fourth embodiment. As shown in FIG. 8, when it is determined in step S5 that the engine 6 is higher than the reference temperature T ₀ based on the output of the engine temperature sensor 24, that is, in a warm-up state, the delay time t is set to the first delay time. set to t ₁ (step S6). On the other hand, when it is determined that the engine 6 is in the cold state, first, if the output signal P of the hydraulic sensor 22 is in the second range of P ₂ ≦ P ≦ P ₃ , the lubricating oil has a predetermined hydraulic pressure. Then, it is determined that the amount of lubricating oil is normal (step S41), and then the engine speed is determined. If the output signal P of the hydraulic sensor 22 is not within the second range, the delay time t is set to the _first delay time t ₁ .

In step S42, the engine speed is calculated by the engine speed detector 36. When the engine speed Ne is slower than the predetermined engine speed N ₀ , the delay time t is set to the _first delay time t ₁ . On the other hand, when the rotational speed Ne of the engine is faster than the rotational speed N ₀ , the delay time t is set to the _second delay time t ₂ (step S43).

  As described above, in the present embodiment, the sensor temperature is reliably determined while ensuring the detection accuracy of the hydraulic sensor 22 by setting all of the engine temperature, the engine speed, and the presence / absence of lubricating oil as determination conditions. The effect can be realized most effectively.

As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention.
For example, the present invention has been described using an example of an engine of an outboard motor. However, the present invention can be applied to an engine related to a vehicle, an industrial machine, or the like other than the outboard motor.

1 outboard motor, 2 bracket, 3 drive shaft housing, 4 engine holder, 5 engine cover, 6 engine, 7 gear case, 8 propeller, 9 cylinder head, 10 cylinder block, 11 crank case, 12 injector, 13 crank shaft, 14 Flywheel, 15 Crank angle sensor, 16 Oil pan, 17 Oil strainer, 18 Oil pump, 19 Oil filter, 20 Relief valve, 21 Camshaft, 22 Hydraulic sensor, 23 Input device, 24 Engine temperature sensor, 25 Ignition coil, 26 warning device, 30 control unit, 31 calculation unit, 32 warning drive control unit, 33 fuel injection control unit, 34 counter, 35 memory, 36 rotation speed detection unit, 37 oil pressure determination unit, 38 Engine temperature determination unit, 39 Ignition control unit.

Claims (4)

A hydraulic sensor that detects the hydraulic pressure of the lubricating oil of the engine and outputs a predetermined low-pressure signal when the hydraulic pressure drops below a reference pressure;
A failure determining means for determining that the hydraulic sensor is in failure when the output signal of the hydraulic sensor continues for a predetermined delay time and is output outside the first range;
An engine temperature sensor that detects the temperature of the engine and outputs a predetermined cold signal when the temperature is lower than a reference temperature;
Engine temperature determination means for determining that the engine is cold when the cold engine signal is output from the engine temperature sensor;
Control means for driving the warning means and executing a warning action when the failure determination means determines that the hydraulic sensor is in failure.
While detecting whether the output signal of the engine temperature sensor is the cold signal, and setting the delay time to the first delay time when the engine is not cold,
When the engine is cold, the delay time is set to a second delay time that is set longer than the first delay time . An engine rotation sensor that detects the rotation speed of the engine, and an engine rotation speed determination unit that determines whether the rotation speed of the engine is faster than a predetermined rotation speed,
When the engine is cold, the delay time is set to the first delay time when the rotation speed of the engine is lower than the predetermined rotation speed,
2. The engine failure determination device according to claim 1, wherein the delay time is set to the second delay time when the rotation speed of the engine is faster than the predetermined rotation speed. Lubricating oil amount determining means for detecting whether or not the output signal of the hydraulic pressure sensor is within the second range and determining that the lubricating oil amount is normal when the output signal is within the second range is provided. ,
While determining that the engine temperature is cold, and determining that the amount of lubricating oil is normal, setting the delay time to the second delay time,
The engine failure determination device according to claim 1 or 2, wherein the delay time is set to the first delay time when it is determined that the amount of lubricating oil is abnormal. While determining that the engine is cold and the amount of lubricating oil is normal, and the rotational speed of the engine is faster than the predetermined rotational speed, the delay time is set to the second delay time,
4. The engine failure determination device according to claim 3, wherein when the rotation speed of the engine is slower than the predetermined rotation speed, the delay time is set to the first delay time.

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