Noise diagnosis program

Abstract

To accurately diagnose that noise of a vehicle is caused by inflow of oil into an oil tank after stop of an engine.SOLUTION: A noise diagnosis program for a vehicle including: an engine with throttle valve arranged on an intake pipe; an oil tank storing oil for lubrication of the engine; first piping to feed oil and blow-by gas from the engine to the oil tank; and second piping to feed blow-by gas from the oil tank to downstream of the throttle valve of the intake pipe. The noise diagnosis program causes execution of: determination processing for determining whether or not a magnitude of noise after stop of the engine in a second state where a pressure in the intake pipe is higher than that in a first state is smaller than a magnitude of the noise after stop of the engine in the first state where the pressure in the intake pipe downstream of the throttle valve is a negative pressure; and diagnosis processing for, when an affirmative determination is made in the determination processing, diagnosing that the noise is caused by inflow of oil into the oil tank after the stop of the engine.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an abnormal sound diagnosis program. [Background technology]

[0002] After the engine is stopped while the pressure inside the oil tank is negative, oil may flow into the oil tank (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-044448 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle equipped with an engine, abnormal noises may occur due to oil flowing into the oil tank after the engine is stopped. For example, it is difficult for a person who has no knowledge of abnormal vehicle noises to identify the cause of the abnormal noises.

[0005] SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide an abnormal sound diagnosis program that can accurately diagnose that the cause of an abnormal sound in a vehicle is oil flowing into an oil tank after the engine has been stopped. [Means for solving the problem]

[0006] The above object can be achieved by an abnormal sound diagnosis program for diagnosing abnormal sounds in a vehicle equipped with an engine having a throttle valve provided in an intake pipe, an oil tank for storing oil for lubricating the engine, a first pipe for flowing oil and blow-by gas from the engine to the oil tank, and a second pipe for flowing blow-by gas from the oil tank to a portion of the intake pipe downstream of the throttle valve, the abnormal sound diagnosis program causing a computer to execute a judgment process for determining whether the volume of the abnormal sound after the engine is stopped in a second state in which the intake pipe pressure is higher than in the first state, is smaller than the volume of the abnormal sound after the engine is stopped in a first state in which the intake pipe pressure, which is the pressure downstream of the throttle valve in the intake pipe, is negative pressure, and a diagnostic process for diagnosing that the cause of the abnormal sound is oil flowing into the oil tank after the engine is stopped, if a positive judgment is made by the judgment process. Effect of the Invention

[0007] According to the present invention, it is possible to provide an abnormal sound diagnosis program that can accurately diagnose that the cause of an abnormal sound from a vehicle is oil flowing into the oil tank after the engine is stopped. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating an abnormal sound diagnosis system. [Diagram 2] FIG. 2 is a schematic configuration diagram of an engine system. [Diagram 3] 1 is a flowchart showing an example of an abnormal sound diagnosis process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Outline of abnormal sound diagnosis system] 1 is a schematic diagram of an abnormal sound diagnosis system 100. The abnormal sound diagnosis system 100 includes a vehicle A and a diagnosis terminal 40. An engine system B is mounted on the vehicle A. The engine system B includes an engine 1, an ECU (Electronic Control Unit) 20, and a dongle 21, which will be described in detail later. The ECU 20 is a computer including a CPU (Central Processing Unit) and a storage device. The ECU 20 controls the operation of the engine 1.

[0010] The dongle 21 is configured as a communication device equipped with a wireless communication module. The dongle 21 is attached to a connection terminal provided, for example, below the steering wheel. This connection terminal is connected to the ECU 20. The dongle 21 wirelessly transmits information related to the vehicle A from the ECU 20 to the diagnosis terminal 40.

[0011] The diagnostic terminal 40 is configured as a mobile terminal that can be carried by a staff member of a vehicle dealer or a worker of a repair shop. The diagnostic terminal 40 is, for example, a smartphone or a tablet terminal, which is an example of a computer. The diagnostic terminal 40 includes a CPU 42, a storage device 44, a display 46, a touch panel 48, a speaker 50, a microphone 52, and a camera 54. These can communicate with each other via a communication line 58. The storage device 44 is an electrically rewritable non-volatile memory. An abnormal sound diagnosis program 44a is stored in the storage device 44. The abnormal sound diagnosis program 44a is a program for causing the diagnostic terminal 40 to function as a device for diagnosing abnormal sounds of the vehicle A. The CPU 42 executes a determination process and a diagnosis process, which will be described in detail later, according to the abnormal sound diagnosis program 44a. The display 46 is, for example, configured of an LCD, an LED, or the like. The touch panel 48 is arranged on top of the display 46.

[0012] [Outline of engine system configuration] 2 is a schematic diagram of an engine system B. The engine 1 includes a pair of banks 2L and 2R and a cylinder block 3. That is, the engine 1 is a so-called V-type engine, but may be an in-line engine. The engine 1 is a gasoline engine, but may be a diesel engine. A crankshaft 3a is rotatably provided in the cylinder block 3.

[0013] Each of the banks 2L and 2R has a plurality of cylinders. An intake pipe 4L is connected to the bank 2L via an intake manifold 5L. An intake pipe 4R is connected to the bank 2R via an intake manifold 5R. A throttle valve 6L is provided in the intake pipe 4R. An exhaust pipe is connected to each of the pair of banks 2L and 2R via an exhaust manifold (not shown).

[0014] An ignition switch S1 and a pressure sensor S2 are connected to the ECU 20. The ignition switch S1 detects the on / off state of the ignition. The pressure sensor S2 detects the pressure downstream of the throttle valve 6L in the intake pipe 4L or the pressure downstream of the throttle valve 6R in the intake pipe 4R (hereinafter referred to as intake pipe pressure). In addition, the ECU 20 adjusts the opening degree of the throttle valves 6L and 6R according to the operating state of the engine 1.

[0015] The oil tank 7 is a dry sump tank that stores oil for lubricating the engine 1. The oil tank 7 is connected to the cylinder block 3 of the engine 1 via an oil pipe 11. When the scavenging pump P is driven, the oil used in the engine 1 flows into the oil tank 7 via the oil pipe 11. In addition, blow-by gas generated in the engine 1 also flows into the oil tank 7 via the oil pipe 11. The scavenging pump P is a mechanical oil pump that is driven in conjunction with the rotation of the crankshaft 3a of the engine 1. The oil pipe 11 is an example of a first pipe that flows oil and blow-by gas from the engine 1 to the oil tank 7. The oil stored in the oil tank 7 is pressure-fed to the lubrication parts of the engine 1 by a feed pump (not shown).

[0016] An oil separator 8 is provided on the upper part of the oil tank 7. The oil separator 8 separates oil from the blow-by gas introduced into the oil tank 7. The oil separated from the blow-by gas is stored in the oil tank 7. The oil separator 8 is provided with two check valves 9L and 9R. The blow-by gas pipe 12L connects the oil separator 8 to the intake manifold 5L via the check valve 9L. The blow-by gas pipe 12R connects the oil separator 8 to the intake manifold 5R via the check valve 9R. The check valve 9L allows gas to flow from the oil separator 8 to the intake manifold 5L, but restricts gas to flow from the intake manifold 5L to the oil separator 8. The check valve 9R allows gas to flow from the oil separator 8 to the intake manifold 5R, but restricts gas to flow from the intake manifold 5R to the oil separator 8.

[0017] When the check valve 9L opens, the blow-by gas in the oil separator 8 is supplied to the intake manifold 5L via the blow-by gas pipe 12L. When the check valve 9R opens, the blow-by gas in the oil separator 8 is supplied to the intake manifold 5R via the blow-by gas pipe 12R. This allows the blow-by gas to be used for combustion in the engine 1. The blow-by gas pipe 12L is an example of a second pipe that allows the blow-by gas to flow from the oil tank 7 to a portion downstream of the throttle valve 6L in the intake pipe 4L. The blow-by gas pipe 12R is an example of a second pipe that allows the blow-by gas to flow from the oil tank 7 to a portion downstream of the throttle valve 6R in the intake pipe 4R.

[0018] When the engine 1 stops, the engine 1 is in an idle state. Therefore, the openings of the throttle valves 6L and 6R are relatively small. Therefore, the intake pipe pressure is also negative. Accordingly, the pressure in the oil tank 7, which is connected to the intake manifolds 5L and 5R via the blow-by gas pipes 12L and 12R, respectively, is also negative. When the engine 1 stops in this state, the negative pressure in the oil tank 7 may cause oil to flow from the cylinder block 3 into the oil tank 7 via the oil pipe 11. If oil flows into the oil tank 7 after the engine 1 stops, an abnormal sound may be generated due to the inflow of oil. In this embodiment, the diagnostician can use the diagnostic terminal 40 to diagnose whether the cause of the abnormal sound generated in the vehicle A is the inflow of oil into the oil tank 7 after the engine 1 stops.

[0019] [Abnormal sound diagnosis control] 3 is a flowchart showing an example of abnormal sound diagnosis control. It is assumed that this control is executed by a diagnoser operating the diagnosis terminal 40 in the vicinity of or inside vehicle A that is stopped with the engine 1 running. This control is also executed by the CPU 42 in accordance with the abnormal sound diagnosis program 44a.

[0020] First, the CPU 42 reads information about the vehicle A via the dongle 21 (step S1). The information about the vehicle A includes, for example, the vehicle model, the engine model, the serial number, the presence or absence of a dry sump oil tank, the engine speed, the intake air amount, the fuel injection state, the oil / water temperature, the intake air temperature, the state of the variable valve system, the gear position of the transmission, the remaining charge of the hybrid battery, the pressure values ​​and temperature values ​​of various sensors, and the like.

[0021] Next, the CPU 42 starts recording the abnormal sound of the vehicle A through the microphone 52 (step S2). Next, the CPU 42 judges whether or not the vehicle A is equipped with a dry sump type oil tank based on the vehicle information (step S3). Note that step S3 is not limited to being judged by the CPU 42 based on the vehicle information. For example, the CPU 42 may display a selection screen for the presence or absence of a dry sump type oil tank on the display 46, and the diagnostician may manually select the presence or absence. The case of No in step S3 will be described later.

[0022] If the answer is Yes in step S3, the CPU 42 judges whether the diagnosis target is abnormal noise after the engine 1 is stopped (step S4). Specifically, the CPU 42 displays on the display 46 a selection screen for selecting whether the diagnosis target is abnormal noise after the engine 1 is stopped, and the person performing the diagnosis manually selects the selection. The case where the answer is No in step S4 will be described later.

[0023] If the answer is Yes in step S4, the CPU 42 transmits an instruction to the ECU 20 to stabilize the intake pipe pressure in a negative pressure state and then stop the engine 1 (step S5). Here, the state in which the intake pipe pressure is negative corresponds to the first state. When the intake pipe pressure is stabilized in a negative pressure state, it is presumed that the pressure in the oil tank 7 is also in a negative pressure state. Therefore, by stopping the engine 1 in this state, it is considered that oil will flow into the oil tank 7 after the engine 1 is stopped. Note that in step S5, the CPU 42 may display the above instruction on the display 46 for the diagnostician. By executing step S5, the engine 1 is stopped after a predetermined time has elapsed.

[0024] Next, the CPU 42 determines whether or not an abnormal sound has occurred after the engine 1 has been stopped based on the abnormal sound recording result (step S6). A case where the result in step S6 is No will be described later.

[0025] If the answer is Yes in step S6, the CPU 42 sends an instruction to the ECU 20 to restart the engine 1 and stop the engine 1 in a state where the negative pressure of the intake pipe pressure is reduced (step S7). The state where the negative pressure of the intake pipe pressure is reduced is a state where the intake pipe pressure is higher than the intake pipe pressure in step S5. Here, by increasing the openings of the throttle valves 6L and 6R from the openings in step S5, the intake pipe pressure can be increased to be higher than the intake pipe pressure in step S5. As a result, the pressure in the oil tank 7 is also higher than the pressure in the oil tank 7 in step S5. Therefore, in this state, it is considered that the inflow of oil into the oil tank 7 after the engine 1 is stopped is suppressed. The state of the intake pipe pressure in step S7 corresponds to the second state. By executing step S7, the engine 1 is stopped after a predetermined time has elapsed.

[0026] Next, based on the abnormal sound recording results, the CPU 42 determines whether the volume of the abnormal sound after the engine 1 is stopped in step S7 is smaller than the volume of the abnormal sound after the engine 1 is stopped in step S5 (step S8). Step S8 is an example of a determination process. If the answer is Yes in step S8, the CPU 42 diagnoses that the cause of the abnormal sound is oil flowing into the oil tank 7 after the engine 1 is stopped (step S9). Step S9 is an example of a diagnosis process.

[0027] If the answer is No in any of steps S3, S4, S6, and S8, the CPU 42 uses a machine-learned discrimination model through supervised learning to extract candidate causes of the abnormal sound (step S10). By inputting the abnormal sound into the discrimination model, the discrimination model outputs candidate causes of the abnormal sound. Candidate causes of the abnormal sound include, for example, valve opening / closing control performed after the engine 1 is stopped, initialization control for adjusting the zero point of the valve position, thermal expansion difference of the exhaust pipe gasket after the engine 1 is stopped, flow of the air conditioner or coolant, and blow-through due to damage to the pipes.

[0028] After execution of step S9 or S10, the CPU 42 displays the diagnosis result on the display 46 (step S11). When step S9 is executed, this causes the abnormal sound to be caused by oil leaking into the oil tank 7, which is displayed on the display 46. When step S10 is executed, the candidates for the cause of the abnormal sound extracted by the judgment model are displayed on the display 46.

[0029] As described above, by using the diagnostic terminal 40 in which the abnormal sound diagnosis program 44a is installed, it is possible to accurately diagnose that the cause of the abnormal sound of the vehicle A is oil flowing into the oil tank 7 after the engine 1 is stopped. This allows the diagnostician to easily identify the cause of the abnormal sound even if he or she has no knowledge of abnormal sounds. Furthermore, by installing the abnormal sound diagnosis program 44a in the diagnostic terminal 40, such a diagnosis can be realized at low cost.

[0030] If vehicle A is a hybrid vehicle, instead of step S7, an instruction may be sent to ECU 20 to restart engine 1, increase the opening of throttle valves 6L and 6R beyond that in step S5, stop fuel injection, continue rotating engine 1 using the motor, and then stop engine 1.

[0031] Instead of step S7, the CPU 42 may transmit an instruction similar to that of step S5 to the ECU 20, and may also cause the display 46 to display an instruction to the diagnostician to open the filler cap of the oil tank 7 when the engine 1 is stopped. This is because by opening the filler cap of the oil tank 7 when the engine 1 is stopped, the pressure in the oil tank 7 can be increased to atmospheric pressure, thereby eliminating the negative pressure.

[0032] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0033] A. Engine system 1 Engine 4L, 4R intake pipe 6L, 6R throttle valve 7. Oil Tank 11 Oil piping (first piping) 12L, 12R Blow-by gas piping (second piping) 20 ECU (control unit) 40 Diagnostic terminal (computer) 44a Abnormal noise diagnosis program

Claims

[Claim 1] An engine having a throttle valve provided in an intake pipe; an oil tank that stores oil for lubricating the engine; a first pipe for passing oil and blow-by gas from the engine to the oil tank; a second pipe for allowing blow-by gas to flow from the oil tank to a portion of the intake pipe downstream of the throttle valve, a determination process for determining whether or not the volume of the abnormal noise after the engine is stopped in a second state in which the intake pipe pressure is higher than the volume of the abnormal noise after the engine is stopped in a first state in which the intake pipe pressure, which is the pressure downstream of the throttle valve in the intake pipe, becomes negative; a diagnosis process for diagnosing, when a positive determination is made by the determination process, that the cause of the abnormal noise is oil flowing into the oil tank after the engine is stopped; An abnormal noise diagnosis program that causes a computer to execute the above.

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