Abnormal noise diagnostic device

Abstract

We provide a noise diagnostic device that can determine whether the source of the abnormal noise is the purge valve or the check valve in the purge system. [Solution] A noise diagnostic device for a purge system, comprising: an acquisition unit for acquiring information; a measurement unit for measuring abnormal noises of a vehicle; a first diagnostic unit that diagnoses the purge valve as the cause of the abnormal noise when the period of the measured abnormal noise corresponds to the opening / closing cycle, the coolant temperature is above the warm-up temperature, and the purge valve is closed; and a second diagnostic unit that diagnoses the check valve provided between the purge valve in the purge passage and the intake passage to prevent backflow of evaporated fuel as the cause of the abnormal noise when the period of the measured abnormal noise corresponds to the opening / closing cycle, the coolant temperature is below the warm-up temperature, and the engine has a supercharger, or when the coolant temperature is above the warm-up temperature, the purge valve is open, and the engine has a supercharger.

Description

Technical Field

[0006]

[0001] The present invention relates to a abnormal sound diagnosis device.

Background Art

[0002] There is a technique for diagnosing that any one of a plurality of components mounted on an object is the cause of abnormal sound based on the frequency of the sound generated from the object and the rotational speed of the rotating device mounted on the object (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a vehicle equipped with a purge system. The purge system has a purge valve. Also, when the engine has a supercharger, the purge system has a check valve. In such a purge system, the cause of abnormal sound may be the purge valve or the check valve. However, in the above technique, since the purge valve and the check valve are not rotating devices, it is impossible to diagnose whether the cause of the abnormal sound is the purge valve or the check valve.

[0005] Therefore, an object of the present invention is to provide an abnormal sound diagnosis device that can diagnose whether the cause of abnormal sound is a purge valve or a check valve of a purge system.

Means for Solving the Problems

[0006] The above objective is to provide a noise diagnostic device for a purge system mounted on a vehicle, comprising a canister for adsorbing evaporated fuel from the engine's fuel tank, a purge passage for purging the evaporated fuel adsorbed by the canister into the engine's intake passage, and a purge valve for opening and closing the purge passage, comprising: an acquisition unit for acquiring information on whether the engine has a supercharger, information on the opening and closing cycle and state of the purge valve, and information on the temperature of the engine's coolant; a measurement unit for measuring abnormal noise in the vehicle; and a detection unit for determining if the measured abnormal noise cycle corresponds to the opening and closing cycle, the coolant temperature is above the warm-up temperature, and the purge valve is closed. This can be achieved by an abnormal noise diagnostic device comprising: a first diagnostic unit that diagnoses the purge valve as the cause of the abnormal noise when it is present; and a second diagnostic unit that diagnoses the check valve provided between the purge valve in the purge passage and the intake passage to prevent backflow of evaporated fuel as the cause of the abnormal noise when the measured period of the abnormal noise corresponds to the opening and closing cycle, the coolant temperature is below the warm-up temperature, and the engine has a supercharger, or when the measured period of the abnormal noise corresponds to the opening and closing cycle, the coolant temperature is above the warm-up temperature, the purge valve is open, and the engine has a supercharger. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a noise diagnostic device that can diagnose whether the cause of the abnormal noise is the purge valve or the check valve of the purge system. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the abnormal noise diagnosis system. [Figure 2] This is a schematic diagram of the engine system. [Figure 3] This is a flowchart illustrating the diagnostic control of abnormal noises. [Modes for carrying out the invention]

[0009] [Outline configuration of the abnormal sound diagnosis system] Figure 1 is a schematic diagram of the abnormal noise diagnostic system 100. The abnormal noise diagnostic system 100 includes a vehicle A and a diagnostic terminal 40. Vehicle A is equipped with an engine system B. Engine system B, as will be described in more detail later, includes an engine 1, an ECU (Electronic Control Unit) 90, a dongle 91, and a purge system. The ECU 90 is a computer that includes a CPU (Central Processing Unit) and a memory device. The ECU 90 controls the operation of the engine 1.

[0010] The dongle 91 is configured as a communication device equipped with a wireless communication module. The dongle 91 is attached to a connection terminal located, for example, below the steering wheel. This connection terminal is connected to the ECU 90. The dongle 91 wirelessly transmits information about vehicle A from the ECU 90 to the diagnostic terminal 40.

[0011] The diagnostic terminal 40 is configured as a portable terminal that can be carried by staff at a vehicle dealership or workers at a repair shop. The diagnostic terminal 40 is, for example, a smartphone or tablet and is an example of a noise diagnostic device. 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.

[0012] The storage device 44 stores the abnormal noise diagnosis program 44a. The abnormal noise diagnosis program 44a is a program that causes the diagnostic terminal 40 to function as a device that determines whether or not the abnormal noise in vehicle A is caused by the purge system described later. The CPU 42 performs abnormal noise diagnosis control by functionally realizing the acquisition unit, measurement unit, first diagnostic unit, and second diagnostic unit, which will be described in detail later, according to the abnormal noise diagnosis program 44a. The display 46 is composed of, for example, an LCD or LED. The touch panel 48 is placed on top of the display 46.

[0013] Figure 2 is a diagram of the engine system B. Engine system B includes an engine 1, an intake passage 10, an intercooler 12, an exhaust passage 11, a supercharger 13, a purge system 20, a fuel tank 30, etc. Engine 1 has a supercharger 13. Fuel stored in the fuel tank 30 is pumped by a fuel pump 31 through a delivery pipe 32 to an injector 4 located in the engine body 2. The injector 4 directly injects the pumped fuel into the cylinder 3.

[0014] When intake air is introduced into the intake passage 10, it is pressurized by the compressor 13a of the supercharger 13 and introduced into the cylinder 3 of the engine body 2. The intake air introduced into the cylinder 3 is burned together with fuel within the cylinder 3. The exhaust gas produced by combustion is discharged from the cylinder 3 to the exhaust passage 11 and passes through the turbine 13b of the supercharger 13. The intercooler 12 is located above the intake passage 10 and cools the intake air that has been pressurized by the compressor 13a.

[0015] The purge system 20 includes an evaporative fuel passage 22, a canister 23, a purge passage 24, a purge valve 25, and a check valve 26. The purge system 20 releases evaporated fuel generated from the fuel stored in the fuel tank 30 into the intake system. The evaporated fuel generated in the fuel tank 30 is temporarily adsorbed by the canister 23 via the evaporative fuel passage 22. When the purge valve 25 is opened during engine 1 startup, the evaporated fuel adsorbed by the canister 23 is drawn into the intake passage 10 via the purge passage 24 by the intake negative pressure. As a result, the evaporated fuel is used for combustion in the engine 1. The purge valve 25 is a solenoid valve whose opening and closing operation is controlled by the ECU 90.

[0016] The check valve 26 is located on the intake passage 10 side of the purge passage 24, closer to the purge valve 25. The check valve 26 allows the flow of evaporated fuel from the purge passage 24 to the intake passage 10, but restricts the inflow of intake air from the intake passage 10 to the purge passage 24. This prevents the intake air pressurized by the compressor 13a from flowing from the intake passage 10 into the purge passage 24 and causing evaporated fuel to backflow. In engines without a supercharger, the intake air is not pressurized, so such a check valve 26 is not provided.

[0017] The ECU 90 controls the operating state of the engine 1 by controlling the injectors 4 and other components based on information from various sensors. The ECU 90 also controls the purge system 20 by outputting open / close commands to the purge valve 25. The ECU 90 obtains the temperature of the coolant based on information from the water temperature sensor 92, which detects the temperature of the coolant that cools the engine 1.

[0018] [Abnormal Sound Diagnosis Control] Figure 3 is a flowchart showing an example of abnormal noise diagnosis control. This control is assumed to be performed when a judge operates the diagnostic terminal 40 in the vicinity of or inside vehicle A while the engine 1 is running and the vehicle is stationary. This control is also executed by the CPU 42 according to the abnormal noise diagnosis program 44a.

[0019] The CPU 42 obtains information from the ECU 90 via the dongle 91 regarding whether the engine 1 has a supercharger, the opening and closing cycle and state of the purge valve 25, and the temperature of the engine 1's coolant (step S1). The CPU 42 obtains information from the ECU 90 via the dongle 91 regarding the opening and closing cycle and state of the purge valve 25, and the temperature of the coolant, at predetermined intervals. Step S1 is an example of the processing performed by the acquisition unit.

[0020] Next, the CPU 42 measures abnormal noises of the vehicle A via the microphone 52 (step S2). Step S2 is an example of the processing executed by the measurement unit. Next, the CPU 42 determines whether or not the purge system 20 is in operation based on the above-described information (step S3).

[0021] If the result in step S3 is Yes, the CPU 42 determines whether or not the period of the abnormal noise is approximately the same as the period of the opening and closing of the purge valve 25 based on the measured abnormal noise and the information regarding the operation of the purge system 20 obtained (step S4). If the result in step S3 or S4 is No, the CPU 42 diagnoses that the cause of the abnormal noise is other than the purge system 20 (step S5).

[0022] If the result in step S4 is Yes, the CPU 42 determines whether or not the temperature of the cooling water is equal to or higher than the warm-up temperature (step S6). If the result in step S6 is Yes, the CPU 42 determines whether or not the purge valve 25 is closed at the generation timing of the abnormal noise (step S7). If the result in step S7 is Yes, the CPU 42 diagnoses that the cause of the abnormal noise is the purge valve 25 (step S8). Here, when the temperature of the cooling water of the engine 1 is equal to or higher than the warm-up temperature, the purge valve 25 is also at a high temperature due to the radiant heat from the engine 1. When the purge valve 25 is at a high temperature, so-called chattering occurs in which the valve body of the purge valve 25 repeatedly opens and closes with respect to the seat at the closing timing of the valve body of the purge valve 25. In the above case, it is diagnosed as an abnormal noise caused by such chattering of the purge valve 25. Step S8 is an example of the processing executed by the first diagnosis unit.

[0023] If the answer in step S6 or S7 is No, the CPU 42 determines whether or not engine 1 has a supercharger based on the acquired information about the engine 1 model (step S9). If the answer in step S9 is Yes, the CPU 42 diagnoses that the cause of the abnormal noise is the check valve 26 (step S10). The abnormal noise caused by the check valve 26 can occur when the purge valve 25 is open. Specifically, when the purge valve 25 opens, the valve body of the check valve 26 opens against the biasing force of the biasing spring due to the pressure from the purge passage 24 and the negative pressure in the intake passage 10. When the valve body of the check valve 26 opens, the pressure from the purge passage 24 decreases, and the valve body of the check valve 26 closes again due to the biasing force of the biasing spring. When the valve body of the check valve 26 closes, the pressure from the purge passage 24 increases again, and the valve body of the check valve 26 opens again. Thus, the abnormal noise when the purge valve 25 is open is thought to be caused by chattering during the opening and closing of the check valve 26. Step S10 is an example of a process performed by the second diagnostic unit.

[0024] The CPU 42 displays the above diagnostic results on the display 46. If the answer in step S9 is No, the CPU 42 terminates this control without performing the diagnosis. In this case, the CPU 42 may display on the display 46 that the cause of the abnormal noise is unknown.

[0025] As described above, by using the diagnostic terminal 40 on which the abnormal noise diagnostic program 44a is installed, it is possible to diagnose whether the cause of the abnormal noise is the purge valve 25 or the check valve 26 of the purge system 20. This allows even a diagnostician without expertise in abnormal noises to easily identify the cause of the noise. Furthermore, by installing the abnormal noise diagnostic program 44a on the diagnostic terminal 40, such a diagnosis can be achieved at low cost.

[0026] Although embodiments of the present invention have been described in detail above, the present invention is not limited to specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]

[0027] Vehicle A B Engine System 1 Engine 13 Supercharger 20 Purge System 25 Purge valve 26 Check valve 40. Judgment terminal (abnormal sound diagnostic device, acquisition unit, measurement unit, first diagnostic unit, second diagnostic unit)

Claims

[Claim 1] A noise diagnostic device for a purge system mounted on a vehicle, comprising a canister for adsorbing evaporated fuel from the engine's fuel tank, a purge passage for purging the evaporated fuel adsorbed by the canister into the engine's intake passage, and a purge valve for opening and closing the purge passage, An acquisition unit that acquires information on whether the engine has a supercharger, information on the opening and closing cycle and state of the purge valve, and information on the temperature of the engine's coolant. A measuring unit for measuring abnormal noises in the aforementioned vehicle, A first diagnostic unit diagnoses that the purge valve is the cause of the abnormal noise when the measured period of the abnormal noise corresponds to the opening and closing cycle, the temperature of the coolant is above the warm-up temperature, and the purge valve is closed. An abnormal noise diagnostic device comprising: a second diagnostic unit that diagnoses that a check valve provided between the purge valve in the purge passage and the intake passage to prevent backflow of evaporated fuel is the cause of the abnormal noise when the measured period of the abnormal noise corresponds to the opening / closing cycle, the temperature of the coolant is below the warm-up temperature, and the engine has a supercharger, or when the measured period of the abnormal noise corresponds to the opening / closing cycle, the temperature of the coolant is above the warm-up temperature, the purge valve is open, and the engine has a supercharger.

Images