TW202120903A - Diagnosis method for vehicles can diagnose whether or not engine oil pressure of the engine is too low through conditional determination - Google Patents

Abstract

A diagnosis method for vehicles includes: (a) electronic control unit determining whether or not the engine rotational speed is higher than a first engine rotational speed threshold; (b) when the engine rotational speed is higher than the first engine rotational speed threshold, the electronic control unit determining whether or not the time for the engine rotational speed that is continuously higher than the first engine rotational speed threshold reaches a first preset time; (c) when the time for the engine rotational speed that is continuously higher than the first engine rotational speed threshold reaches the first preset time, the electronic control unit determining whether or not the engine oil pressure switch is conducted; and (d) when the engine oil pressure switch is conducted, the electronic control unit determining whether or not the time for continuously conducting the engine oil pressure switch reaches a second preset time, if yes, the electronic control unit diagnoses that the engine oil pressure is too low.

Description

Vehicle diagnosis method

The present invention relates to a vehicle diagnosis method, in particular to a vehicle diagnosis method.

Oil pressure refers to the pressure of the oil sprayed from the oil pump. This pressure is very important for the internal components of the engine. When the oil pressure is too low, the metal components inside the engine will rub against each other and cause wear and tear, which will shorten the life of the engine.

Referring to Fig. 1, the oil pressure diagnosis of a general vehicle uses the spring of the oil pressure switch 11 to sense the oil pressure. When the oil pressure switch 11 senses that the oil pressure is too low, the oil pressure switch 11 will be turned on to the ground, thus illuminating the oil indicator light 13 set on the meter 12, on the contrary, if the oil pressure switch 11 senses the oil When the pressure is high enough, the oil pressure switch 11 will be turned off to make the oil indicator light 13 go out.

However, when the engine is stationary, the oil pressure is already too low, so the oil indicator light 13 will also light up when the engine is stationary. As a result, the oil indicator light 13 will still light up when the engine is stationary. The user is confused as to whether the amount of oil is insufficient. Furthermore, the existing oil pressure sensing system architecture of FIG. 1 can only light up or not light up the oil indicator light 13 respectively according to whether the oil pressure switch 11 is on or off, without diagnosing whether the oil pressure switch 11 is malfunctioning or not. Function. Therefore, it is necessary to find a solution.

[The problem to be solved by the invention]

Therefore, the purpose of the present invention is to provide a vehicle diagnosis method.

[Technical means to solve the problem]

Therefore, the vehicle diagnosis method in the first technology of the patent application of the present invention is applicable to a vehicle that includes an engine, an electronic control unit, and an oil pressure switch installed on the engine, and includes the following steps:( a) The electronic control unit determines whether an engine speed of the engine is greater than a first engine speed threshold; (b) if the engine speed is greater than the first engine speed threshold, the electronic control unit determines that the engine speed is continuously greater than the first engine speed threshold. Whether the time for the first engine speed threshold has reached a first predetermined time; (c) if the engine speed continues to be greater than the first engine speed threshold for the first predetermined time, the electronic control unit determines the engine oil Whether the pressure switch is turned on; and (d) if the oil pressure switch is turned on, the electronic control unit determines whether the oil pressure switch has been continuously turned on for a second predetermined time; if so, the electronic control unit diagnoses the engine oil The pressure is too low.

The method for diagnosing a vehicle in the technology of the second patent application of the present invention further includes a step (e) after the step (d), wherein the vehicle further includes an indicator light, and in the step (d) , The electronic control unit sets a first flag to on, indicating that the oil pressure of the vehicle is too low, and then in the step (e), the electronic control unit limits the engine power output so that the engine speed is lower than one Below a certain speed, and the indicator light is lit to remind the user to add oil as soon as possible.

In the method for diagnosing a vehicle in the technology of the third item of the patent application of the present invention, in the step (e), the electronic control unit lights the indicator light in a way that the indicator light is always on.

In the method for diagnosing a vehicle in the technology of the fourth item of the patent application of the present invention, in the step (e), the electronic control unit lights the indicator light in a way to flash the indicator light.

The method for diagnosing a vehicle in the technology of the fifth patent application of the present invention further includes a step (f) after the step (e), wherein the vehicle further includes a main switch, and the user first sets the main switch Switching to a non-conducting state, and then to a conducting state, so that the electronic control unit resets the first flag, so that the engine can resume normal operation, and at the same time controls the indicator light to go out.

In the method for diagnosing a vehicle in the technology of the sixth patent application of the present invention, the first engine speed threshold value is 2000 RPM.

The vehicle diagnosis method in the seventh technology of the patent application of the present invention is applicable to a vehicle that includes an engine, an electronic control unit, and an oil pressure switch set on the engine, and includes the following steps: (A) The electronic control unit determines whether an engine speed of the engine is less than a second engine speed threshold; (B) if the engine speed is less than the first engine speed threshold, the electronic control unit determines that the engine speed is continuously lower than the second engine speed threshold. Whether the time for the engine speed threshold has reached a third predetermined time; (C) if the engine speed continues to be less than the second engine speed threshold for the third predetermined time, the electronic control unit determines the oil pressure switch Whether it is disconnected; and (D) If the oil pressure switch is disconnected, the electronic control unit determines whether the continuous disconnection of the oil pressure switch has reached a fourth predetermined time, and if so, the electronic control unit diagnoses the oil pressure Switch failure.

The method for diagnosing a vehicle in the technology of the eighth patent application of the present invention further includes a step (E) after the step (D), wherein the vehicle further includes an indicator light, and in the step (D) , The electronic control unit sets a second flag to be on, indicating that the oil pressure switch is faulty, and then in this step (E), the electronic control unit lights up the indicator to remind the user to replace the oil pressure switch as soon as possible .

The method for diagnosing a vehicle in the technology of the ninth patent application of the present invention further includes a step (F) after the step (E), wherein the vehicle further includes a main switch, and the user first sets the main switch The switch is switched to a non-conducting state, and then switched to a conducting state, so that the electronic control unit resets the second flag and controls the indicator light to turn off at the same time.

In the vehicle diagnosis method in the technology of the tenth item of the patent application of the present invention, the second engine speed threshold value is 100 RPM.

[Effects of Invention]

The effect of the present invention according to the first item of the scope of patent application is that the electronic control unit can determine whether the oil pressure of the engine is too low according to the conditional expression.

The effect of the present invention according to item 7 of the scope of patent application is that the electronic control unit can determine whether the oil pressure switch is malfunctioning or not by using a conditional formula.

Referring to FIG. 2, a vehicle 2 implementing the method for diagnosing a vehicle of the present invention at least includes an engine 27, a main switch 20, an oil pressure switch 21 provided on the engine 27, a crankshaft position sensor 22, and an electronic control unit (ECU) 23, a reminder lamp 24, a fuel injection unit 25, and an ignition unit 26 and other components.

Referring to Figures 2 and 3, the first embodiment of the vehicle diagnosis method of the present invention includes the following steps. As shown in step S301 in FIG. 3, the electronic control unit 23 determines whether an engine speed received from the crankshaft position sensor 22 is greater than a first engine speed threshold. In this first embodiment, the first engine speed threshold may be, for example, about 2000 RPM. If the determination result of step S301 is negative, it means that the engine speed is not high enough, and no determination is made, so step S301 is executed again.

Conversely, if the determination result of step S301 is yes, then as shown in step S304, the electronic control unit 23 determines whether the duration of the engine speed greater than the first engine speed threshold has reached a first predetermined time, where In the first embodiment, the first predetermined time may be, for example, about 1 second, etc. If not, the subsequent steps such as step S301 are executed again.

If the determination result of step S304 is YES, it means that the oil pressure has increased. Then, as shown in step S306, the electronic control unit 23 determines whether the oil pressure switch 21 is turned on, if not, step S306 is executed again. In the first embodiment, the oil pressure switch 21 uses a spring to sense the oil pressure. When the oil pressure switch 21 senses that the oil pressure is less than a pressure threshold (for example, 0.2 kg/cm ² ), The oil pressure switch 21 will be turned on. On the contrary, if the oil pressure switch 21 senses that the oil pressure is greater than the pressure threshold, the oil pressure switch 21 will be turned off.

On the contrary, if the determination result of step S306 is yes, then as shown in step S309, the electronic control unit 23 determines whether the duration of the oil pressure switch 21 being turned on has reached a second predetermined time. In this first embodiment, Here, the second predetermined time may be, for example, about 2 seconds, etc. If not, the subsequent steps such as step S301 are executed again.

On the contrary, if the determination result of step S309 is yes, then as shown in step S311, the electronic control unit 23 sets the first flag to ON to diagnose that the oil pressure of the engine 27 is too low. Then, as shown in step S312, the electronic control unit 23 limits the power output of the engine, and at the same time lights up the indicator light 24 to remind the user to add oil as soon as possible. In the first embodiment, the electronic control unit 23 can limit the engine power output by controlling the fuel injection unit 25 to reduce the amount of fuel injection, or can even control the fuel injection unit 25 to stop fuel injection or control the ignition. The unit 26 stops the ignition to limit the power output of the engine, so that the engine speed is lower than a specific speed (for example, 4000 RPM, etc.), so that the vehicle 2 can be driven at a low speed, thereby reducing the wear of the metal components inside the engine. In addition, in the first embodiment, the electronic control unit 23 can light up the indicator light 24 in a way that the indicator light 24 is always on, or it flashes, etc...

In addition, in the above-mentioned first embodiment, when the vehicle diagnosis method of the present invention diagnoses that the oil pressure is too low (that is, the first flag is turned on), the power output of the engine 23 will be restricted, so If the user wants the engine 23 to temporarily return to the normal operating state without being restricted in speed, he can first switch the main switch 20 to a key OFF state by operating the main switch 20, and then switch to a key OFF state. ON) state, so that the electronic control unit 23 resets the first flag, so that the engine 27 can resume normal operation, and at the same time controls the indicator light 24 to go out.

Referring to Figures 2 and 4, the second embodiment of the vehicle diagnosis method of the present invention includes the following steps. As shown in step S321 in FIG. 4, the electronic control unit 23 determines whether the engine speed received from the crankshaft position sensor 22 is less than a second engine speed threshold. In the second embodiment, the second engine speed threshold may be, for example, about 100 RPM. If the determination result of step S321 is negative, it means that the engine is not stationary, and no determination is made, so step S321 is executed again.

Conversely, if the determination result of step S321 is yes, it means that the engine speed is sufficiently low and the engine is at a standstill. Therefore, as shown in step S324, the electronic control unit 23 determines that the engine speed is less than the second engine speed threshold for the duration Whether a third predetermined time has elapsed, where, in the second embodiment, the third predetermined time may be, for example, about 1 second, etc. If not, the subsequent steps such as step S321 are executed again.

If the determination result of step S324 is yes, it means that the oil pressure has been reduced, and then as shown in step S326, the electronic control unit 23 determines whether the oil pressure switch 21 is off. If the determination result of step S326 is no, step S326 is executed again.

On the contrary, if the result of the determination of step S326 is yes, then as shown in step S329, the electronic control unit 23 determines whether the duration of the oil pressure switch 21 being turned off has reached a fourth predetermined time. In an example, the fourth predetermined time may be, for example, about 2 seconds, etc. If not, the subsequent steps such as step S321 are executed again.

On the contrary, if the result of the determination in step S329 is yes, then as shown in step S331, the electronic control unit 23 sets the second flag to ON to diagnose that the oil pressure switch 21 is malfunctioning, and then as shown in step S332 As shown, the electronic control unit 23 lights the indicator light 24 to remind the user to replace the oil pressure switch 21 as soon as possible.

In addition, in the above-mentioned second embodiment, when the indicator light 24 lights up due to the failure of the oil pressure switch 21, the user can first switch the main switch 20 to non-conduction (Key OFF) by operating the main switch 20 The state is switched to the Key ON state, so that the electronic control unit 23 resets the second flag and controls the indicator light 24 to turn off at the same time.

In summary, the features and advantages of the vehicle diagnosis method of the present invention are: (1) The first embodiment uses the electronic control unit 23 to diagnose whether the oil pressure of the engine 27 is too low, and to diagnose the oil pressure When it is too low, the reminder light 24 is lit to remind the user to add oil as soon as possible, and the power output of the engine 27 is restricted to avoid the problem of damage to the components of the engine 27 due to insufficient oil lubrication; (2) the second embodiment The electronic control unit 23 can be used to diagnose whether the oil pressure switch 21 is faulty, and when the oil pressure switch 21 is diagnosed as faulty, the prompt light 24 is lit to remind the user to replace the oil pressure switch 21 as soon as possible; purpose.

However, the above are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still belong to Within the scope covered by the patent of the present invention.

2: Vehicle 20: Main switch 21: Oil pressure switch 22: Crankshaft position sensor 23: Electronic control unit 24: indicator light 25: Fuel injection unit 26: Ignition unit 27: Engine S301~S312: steps S321~S332: steps

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is a block diagram illustrating that the existing oil pressure sensing system architecture is to light or not light the oil indicator light according to whether the oil pressure sensed by the oil pressure switch is too low or high enough; Figure 2 is a block diagram illustrating a vehicle implementing the vehicle diagnosis method of the present invention; Figure 3 is a flowchart illustrating the first embodiment of the vehicle diagnosis method of the present invention; and Fig. 4 is a flowchart illustrating the second embodiment of the vehicle diagnosis method of the present invention.

S301~S312: steps

Claims (10)

A vehicle diagnosis method is suitable for a vehicle including an engine, an electronic control unit and an oil pressure switch provided on the engine, wherein the vehicle diagnosis method includes the following steps: (a) The electronic control unit determines whether an engine speed of the engine is greater than a first engine speed threshold; (b) If the engine speed is greater than the first engine speed threshold, the electronic control unit determines whether the engine speed continues to be greater than the first engine speed threshold for a first predetermined time; (c) If the engine speed continues to be greater than the first engine speed threshold for the first predetermined time, the electronic control unit determines whether the oil pressure switch is turned on; and (d) If the oil pressure switch is turned on, the electronic control unit determines whether the continuous conduction time of the oil pressure switch has reached a second predetermined time, and if so, the electronic control unit diagnoses that the oil pressure of the engine is too low. The method for diagnosing a vehicle according to claim 1, further comprising a step (e) after the step (d), wherein the vehicle further comprises an indicator light, and in the step (d), the electronic control unit Setting a first flag to on means that the oil pressure of the vehicle is too low, and then in step (e), the electronic control unit limits the power output of the engine so that the engine speed is lower than a specific speed, and The indicator light is lit to remind the user to add oil as soon as possible. The method for diagnosing a vehicle according to claim 2, wherein, in the step (e), the electronic control unit lights the indicator light in a way that the indicator light is always on. The method for diagnosing a vehicle according to claim 2, wherein, in the step (e), the electronic control unit illuminates the indicator light by flashing the indicator light. The method for diagnosing a vehicle according to claim 2, further comprising a step (f) after the step (e), wherein the vehicle further comprises a main switch, and the user first switches the main switch to a non-conducting The state is switched to an on state, so that the electronic control unit resets the first flag, so that the engine can resume normal operation, and at the same time controls the indicator light to go out. The vehicle diagnosis method according to claim 1, wherein the first engine speed threshold value is 2000 RPM. A method for diagnosing a vehicle is applicable to a vehicle including an engine, an electronic control unit, and an oil pressure switch provided on the engine, and includes the following steps: (A) The electronic control unit determines whether an engine speed of the engine is less than a second engine speed threshold; (B) If the engine speed is less than the first engine speed threshold, the electronic control unit determines whether the engine speed has been continuously lower than the second engine speed threshold for a third predetermined time; (C) If the engine speed has been less than the second engine speed threshold for the third predetermined time, the electronic control unit determines whether the oil pressure switch is off; and (D) If the oil pressure switch is turned off, the electronic control unit determines whether the oil pressure switch has been continuously turned off for a fourth predetermined time. If so, the electronic control unit diagnoses the oil pressure switch as malfunctioning. The method for diagnosing a vehicle according to claim 7, further comprising a step (E) after the step (D), wherein the vehicle further comprises an indicator light, and in the step (D), the electronic control unit Setting a second flag to ON indicates that the oil pressure switch is malfunctioning, and then in step (E), the electronic control unit lights the indicator light to remind the user to replace the oil pressure switch as soon as possible. The method for diagnosing a vehicle according to claim 8, further comprising a step (F) after the step (E), wherein the vehicle further comprises a main switch, and the user first switches the main switch to a The conduction state is switched to a conduction state, so that the electronic control unit resets the second flag and controls the indicator light to turn off at the same time. The vehicle diagnosis method according to claim 7, wherein the second engine speed threshold value is 100 RPM.

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