Drive sound determination device

Abstract

To provide a driving sound determination device capable of determining whether or not driving sound of a diesel engine is caused by resonance sound.SOLUTION: A drive sound determination device comprising: a measurement section that measures a drive sound of a diesel engine; a first calculation section that calculates a drive sound frequency that is a frequency of the drive sound; a second calculation section that calculates a resonant frequency that is a frequency of a resonant sound caused by a combustion pressure in a cylinder of the diesel engine based on information on a model of the diesel engine and information on an operating state of the diesel engine; and a determination section that determines whether the drive sound is caused by the resonant sound based on the drive sound frequency and the resonant frequency.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a drive noise determination device. [Background technology]

[0002] There is a technique for suppressing resonance noise caused by combustion pressure inside a cylinder of a diesel engine (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-060264 Summary of the Invention [Problem to be solved by the invention]

[0004] It is difficult to determine whether the driving noise of a diesel engine is caused by the above-mentioned resonance noise or by some other cause, such as a malfunction.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a drive noise determination device that can determine whether the drive noise of a diesel engine is caused by resonance noise. [Means for solving the problem]

[0006] The above object can be achieved by a drive noise determination device including: a measurement unit that measures drive noise of a diesel engine; a first calculation unit that calculates a drive noise frequency, which is the frequency of the drive noise; a second calculation unit that calculates a resonance frequency, which is the frequency of resonance noise caused by combustion pressure in cylinders of the diesel engine, based on information related to the model of the diesel engine and information related to an operating state of the diesel engine; and a determination unit that determines whether the drive noise is caused by the resonance noise, based on the drive noise frequency and the resonance frequency. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a drive noise determination device that can determine whether the drive noise of a diesel engine is caused by resonance noise. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating the configuration of a drive noise determination system. [Figure 2] 4 is a flowchart illustrating a drive sound determination control. DETAILED DESCRIPTION OF THE INVENTION

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

[0011] The determination 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 determination terminal 40 is, for example, a smartphone or tablet terminal, and is an example of a drive noise determination device. The determination 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 components are capable of communicating with each other via a communication line 58. The storage device 44 is an electrically rewritable non-volatile memory.

[0012] A drive noise determination program 44a is stored in the storage device 44. The drive noise determination program 44a is a program for causing the determination terminal 40 to function as a device for determining whether the drive noise of the diesel engine 1 of the vehicle A is caused by resonance noise. The CPU 42 executes drive noise determination control by functionally realizing a measurement unit, a first calculation unit, a second calculation unit, and a determination unit, which will be described in detail later, in accordance with the drive noise determination program 44a. The display 46 is configured by, for example, an LCD or an LED. The touch panel 48 is disposed on top of the display 46.

[0013] [Drive noise detection control] 2 is a flowchart showing an example of drive noise determination control. This control is assumed to be executed by an determiner operating the determination terminal 40 near or inside vehicle A that is stopped with the diesel engine 1 running. This control is also executed by the CPU 42 in accordance with the drive noise determination program 44a.

[0014] First, the CPU 42 measures the drive noise of the vehicle A via the microphone 52 (step S1). Step S1 is an example of processing executed by a measurement unit. Next, the CPU 42 calculates the frequency of the measured drive noise (step S2). Step S2 is an example of processing executed by a first calculation unit.

[0015] Next, the CPU 42 reads information about the model of the diesel engine 1 and information about the operating state via the dongle 21 (step S3). The information about the model of the diesel engine 1 is, for example, the model and serial number of the diesel engine. The information about the operating state of the diesel engine 1 includes, for example, the engine speed, the state of fuel injection, the intake air amount, the oil / water temperature, the intake air temperature, the state of the variable valve system, the gear position of the transmission, the remaining battery charge, and pressure and temperature values ​​of various sensors.

[0016] Next, the CPU 42 determines based on the above information whether or not the diesel engine 1 is in an operating state in which fuel injection is being performed (step S4), that is, whether or not a fuel cut is being executed.

[0017] If the answer is Yes in step S4, the CPU 42 estimates the combustion gas temperature by referring to a table that defines the combustion gas temperature according to the engine speed and the fuel injection amount (step S5).

[0018] Next, the CPU 42 calculates the resonance frequency, which is the frequency of resonance sound caused by the combustion pressure inside the cylinder of the diesel engine 1 (step S6). The resonance frequency is proportional to the speed of sound inside the combustion chamber and inversely proportional to the cylinder diameter and the combustion chamber diameter. The CPU 42 calculates the resonance frequency at the estimated combustion gas temperature and a combustion gas temperature set for each model of the diesel engine 1. Step S6 is an example of processing executed by the second calculation unit.

[0019] Next, the CPU 42 determines whether the drive sound frequency is within the range of the resonance frequency (step S7).

[0020] If the answer is Yes in step S7, it is determined that the cause of the drive noise is combustion pressure resonance in the diesel engine 1 (step S8). In this case, the fact that the cause of the drive noise is combustion pressure resonance in the diesel engine 1 is displayed on the display 46. Step S8 is an example of processing executed by the determination unit.

[0021] If the answer is No in step S4 or S7, it is determined that the cause of the drive noise is other than combustion pressure resonance in the diesel engine 1 (step S9). The fact that the cause of the drive noise is other than combustion pressure resonance in the diesel engine 1 is displayed on the display 46.

[0022] As described above, by using the determination terminal 40 having the drive noise determination program 44a installed, it is possible to accurately determine whether the drive noise of the diesel engine 1 is due to resonance noise. This allows the determiner, even if he or she has no knowledge of abnormal noises, to easily identify the cause of the drive noise. Furthermore, by installing the drive noise determination program 44a in the determination terminal 40, such determination can be achieved at low cost.

[0023] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as defined in the claims. [Explanation of symbols]

[0024] Vehicle A 1. Diesel engine 40 Determination terminal (drive sound determination device, measurement unit, first calculation unit, second calculation unit, determination unit)

Claims

[Claim 1] a measurement unit that measures the driving noise of a diesel engine; a first calculation unit that calculates a drive sound frequency, which is the frequency of the drive sound; a second calculation unit that calculates a resonance frequency, which is a frequency of a resonance sound caused by combustion pressure in a cylinder of the diesel engine, based on information related to the model of the diesel engine and information related to an operating state of the diesel engine; a determination unit that determines whether the drive noise is caused by the resonance noise based on the drive noise frequency and the resonance frequency.

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