Abnormal sound diagnosis device

Abstract

To provide an abnormal sound diagnosis device which can accurately determine whether or not abnormal sound generated in a vehicle is generated in a belt tensioner provided in an internal combustion engine.SOLUTION: An abnormal sound diagnosis device according to the present disclosure diagnoses abnormal sound generated in a vehicle including an internal combustion engine which has a plurality of cylinders, an auxiliary machine which is driven via a belt by the internal combustion engine, and a belt tensioner which adjusts the tension of the belt. The abnormal sound diagnosis device diagnoses the generation of the abnormal sound in the belt tensioner in a case where a peak value of the sound pressure within a predetermined frequency range of data of sound acquired from the vehicle is generated within a predetermined angular range after a compression top dead point in the cylinder that is the closest to the belt tensioner in the plurality of cylinders.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a noise diagnosis device for diagnosing abnormal noises generated in a vehicle.

Background Art

[0002] Conventionally, an accessory belt system inspection device including a tester bracket, a torque pulse simulation motor attached to the tester bracket, a crankshaft pulley rotationally driven by the torque pulse simulation motor, an accessory system rotated by being connected to the crankshaft pulley via a belt, a control unit for controlling the operation of the torque pulse simulation motor, and a noise measuring device for measuring noise generated from the accessory system and the belt has been known (see, for example, Patent Document 1). The control unit of this inspection device variably controls the torque of the torque pulse simulation motor so that the operation thereof corresponds to each stroke of the engine, and outputs a signal obtained by comparing a signal output from the noise measuring device with a preset noise reference signal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the above conventional inspection device only filters noise by comparing a signal from the noise measuring device with a noise reference signal and then outputs it to a graph or the like, and it is impossible to specify at which part of the accessory system and the belt the noise measured by the noise measuring device is generated.

[0005] Therefore, the main object of the present disclosure is to provide a abnormal noise diagnosis device that can accurately determine whether the abnormal noise generated in the vehicle is generated by a belt tensioner provided in the internal combustion engine.

Means for Solving the Problems

[0006] The abnormal noise diagnosis device of the present disclosure is an abnormal noise diagnosis device for diagnosing abnormal noise generated in a vehicle including an internal combustion engine having a plurality of cylinders, an auxiliary machine driven by the internal combustion engine via a belt, and a belt tensioner for adjusting the tension of the belt. When the peak value of the sound pressure in a predetermined frequency range of the sound data acquired from the vehicle occurs within a predetermined angular range after the compression top dead center in the cylinder closest to the belt tensioner among the plurality of cylinders, it is diagnosed that abnormal noise is generated by the belt tensioner.

[0007] The inventor has conducted intensive research on the abnormal noise generated by the belt tensioner provided in the internal combustion engine. As a result, it has been found that the tension of the belt is greatly affected by the explosion of the air-fuel mixture in the cylinder closest to the belt tensioner, the tension of the belt decreases with the explosion of the air-fuel mixture in the cylinder closest to the belt tensioner, and the tension of the belt increases before the explosion of the air-fuel mixture in the next cylinder. Furthermore, the inventor has found that the abnormal noise at the belt tensioner occurs according to the amount of change in the tension when the tension of the belt decreases and then turns to increase with the explosion of the air-fuel mixture in the cylinder closest to the belt tensioner. Based on these, the abnormal noise diagnosis device of the present disclosure diagnoses that abnormal noise is generated by the belt tensioner when the peak value of the sound pressure in a predetermined frequency range of the sound data acquired from the vehicle occurs within a predetermined angular range after the compression top dead center in the cylinder closest to the belt tensioner. Thereby, it becomes possible to accurately determine whether the abnormal noise generated in the vehicle is generated by the belt tensioner provided in the internal combustion engine.

[0008] Further, the internal combustion engine may be a four-cylinder internal combustion engine, the frequency range may be in the range from 1 kHz to 10 kHz, and the angle range may be in the range from 45° after the compression top dead center to 135°.

[0009] This makes it possible to accurately determine whether the abnormal noise generated in the vehicle is generated by the belt tensioner provided in the four-cylinder internal combustion engine.

[0010] Furthermore, the abnormal noise diagnostic device may include a diagnostic module constructed by machine learning so as to diagnose the cause of the abnormal noise based on the given information. When it is determined that no abnormal noise is generated by the belt tensioner, the diagnostic module may diagnose the abnormal noise generated in the vehicle.

[0011] This makes it possible to further improve the versatility of the abnormal noise diagnostic device.

[0012] Also, the abnormal noise diagnostic device may exchange information by communication with a terminal that acquires the sound data and the inquiry information regarding the abnormal noise generated in the vehicle. When it is determined based on the inquiry information from the terminal that an abnormal noise is generated around the internal combustion engine, it may be determined whether the crank angle when the sound pressure in the frequency range is generated is within the predetermined angle range after the compression top dead center.

[0013] This makes it possible to suppress misdiagnosis related to the abnormal noise in the belt tensioner and further improve the diagnostic accuracy of the abnormal noise diagnostic device.

[0014] Furthermore, the belt tensioner may include a support member fixed to the internal combustion engine, an arm member rotatably supported by the support member, a pulley rotatably supported by an end of the arm member on the side opposite to the support member side, and a torsion spring that biases the arm member so as to press the pulley against the belt. The support member of the belt tensioner may be fixed to one end surface in the arrangement direction of the plurality of cylinders of the cylinder block so that the pulley abuts against the belt that rotates integrally with the crankshaft of the internal combustion engine and extends from the crank pulley to the nearest auxiliary machine.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0016] Next, embodiments for carrying out the invention of the present disclosure will be described with reference to the drawings.

[0017] FIG. 1 is a schematic configuration diagram showing a abnormal noise diagnosis system 1 including a server 20 as an abnormal noise diagnosis device of the present disclosure. The abnormal noise diagnosis system 1 shown in the figure is for diagnosing the cause of abnormal noise generated in a vehicle V which is an electric vehicle (BEV, FCEV), a vehicle equipped only with an engine as a power generation source, or a hybrid vehicle (HEV, PHEV). In the present embodiment, the vehicle V includes an internal combustion engine EG which is a four-cylinder gasoline engine, an alternator Alt, a water pump WP, and an air-conditioning compressor Cmp which are auxiliary machines driven by the internal combustion engine EG via an endless belt B, and a belt tensioner BT for adjusting the tension of the belt B. When the vehicle V is a hybrid vehicle, the alternator Alt may be omitted, and the air-conditioning compressor Cmp may be driven by a drive source other than the internal combustion engine EG (for example, an inverter motor or the like).

[0018] As shown in the figure, the belt B is wound around a crank pulley P0 that rotates integrally with the crankshaft CS of the internal combustion engine EG, a pulley P1 that rotates integrally with the rotating shaft of the alternator Alt, a pulley P2 that rotates integrally with the impeller shaft of the water pump WP, and a pulley P3 that rotates integrally with the rotating shaft of the air-conditioning compressor Cmp, and is driven by the internal combustion engine EG to proceed in the direction of the arrow in FIG. 1. Further, as shown in FIG. 2, the belt tensioner BT includes a support member (pivot) S, an arm member (housing) AM, a pulley Pt, a torsion spring SP, and a friction material (not shown).

[0019] The support member S of the belt tensioner BT rotatably supports the arm member AM via a connecting shaft Ax fixed to the base end portion of the arm member AM, and is fixed to the cylinder block CB of the internal combustion engine EG. The pulley Pt is rotatably supported by the tip end portion of the arm member AM (the end portion opposite to the support member S side) so as to abut on the belt B. The torsion spring SP is disposed around the support member S coaxially with the connecting shaft Ax, and biases the arm member AM so as to press the pulley Pt against the belt B. As shown in FIG. 1, the support member S of the belt tensioner BT is fixed to one end face (the end face opposite to the transmission side) in the arrangement direction of the combustion chambers (cylinders) of the cylinder block CB so that the pulley Pt abuts on the belt B that goes from the crank pulley P0 to the pulley P1 of the alternator Alt which is the nearest accessory. Thereby, the belt tensioner BT is disposed close to the first combustion chamber (cylinder No. 1) located on one end side in the arrangement direction. Further, the belt B, the crank pulley P0, the belt tensioner BT, etc. are covered by a chain cover (not shown) attached to the cylinder block CB.

[0020] As shown in FIG. 1, the abnormal noise diagnosis system 1 includes a mobile terminal 10 and a server 20 as an information processing device capable of exchanging information with the mobile terminal 10 through communication. The mobile terminal 10 is used by an operator (a user of the abnormal noise diagnosis system 1) such as a vehicle sales store or a repair shop when responding to a user (owner) such as a vehicle V where an abnormal noise has occurred, or when performing a reproduction test to reproduce the abnormal noise by running (operating) the vehicle V or the like on a road or a test bench. In the present embodiment, the mobile terminal 10 is a smartphone including a SoC, a ROM, a RAM, an auxiliary storage device (flash memory) M, a touch panel type display unit 11, a communication module 12 capable of exchanging various information with an electronic control unit (ECU) (not shown) such as the server 20 and the vehicle V through wired or wireless communication, and a microphone (not shown). Further, an abnormal noise diagnosis support application (program) is installed in the mobile terminal 10. Then, as shown in FIG. 1, the mobile terminal 10 includes an inquiry information acquisition unit 13, a sound acquisition unit 14, a vehicle state acquisition unit 15, an arithmetic processing unit 16, an extraction unit 17, and a display control unit 18, which are constructed by the cooperation of an abnormal noise diagnosis support application (software) and hardware such as the SoC of the mobile terminal 10.

[0021] The inquiry information acquisition unit 13 acquires information indicating the state of the vehicle V, etc. when abnormal noise occurs, provided by a user such as the vehicle V, etc. through the display unit 11 (hereinafter referred to as "inquiry information"). The inquiry information includes vehicle identification information such as vehicle type, vehicle identification number (chassis number), etc., order matters, date and time of occurrence, occurrence frequency, location where the abnormal noise occurs, type of sound (onomatopoeia), physical quantities that change during the running of the vehicle V, etc. such as vehicle speed, driving state of the vehicle V, etc., warm-up influence in an engine-mounted vehicle, selection items selected by the driver during the driving of the vehicle V, etc., running environment information of the vehicle V, etc., and is input by the above-mentioned operator or user of the vehicle V, etc. The sound acquisition unit 14 acquires time-axis data of sound (sound pressure) when a reproduction test is executed by the operator. The vehicle state acquisition unit 15 acquires information indicating the state of the vehicle V, etc. (hereinafter referred to as "vehicle state data") in synchronization with the acquisition of the time-axis data of sound by the sound acquisition unit 14 when the reproduction test is executed. The vehicle state data includes a plurality of physical quantities (vehicle speed, engine speed, crank angle, etc.) corresponding to the items of the inquiry information. The arithmetic processing unit 16 executes analysis processing of the time-axis data of sound acquired by the sound acquisition unit 14. The extraction unit 17 executes narrowing down, etc. of the analysis result by the arithmetic processing unit 16 according to the selection of the operator, etc. The display control unit 18 controls the display unit 11.

[0022] The server 20 as a abnormal sound diagnosis device is a computer (information processing device) including a CPU, a ROM, a RAM, an input / output device, a communication module, etc., and is installed and managed by, for example, an automobile manufacturer that manufactures the vehicle V or the like. In the server 20, a abnormal sound diagnosis unit 21 for diagnosing abnormal sounds generated in the vehicle V or the like is constructed by the cooperation of hardware such as a CPU and a pre-installed abnormal sound diagnosis application. The abnormal sound diagnosis unit 21 is constructed by supervised learning (machine learning) so as to diagnose the cause of the abnormal sound generated in the vehicle V or the like and the parts that have become the source of the abnormal sound based on the inquiry information and the time-axis data of the sound obtained by the mobile terminal 10. It includes a neural network (convolutional neural network) as a diagnosis module. Further, in the server 20, when it is found that a new abnormal sound has occurred in the vehicle V or the like, the abnormal sound diagnosis unit 21 is re-learned using the time-axis data of the sound obtained for the new abnormal sound and the contents of each item of the inquiry information as teacher data.

[0023] Furthermore, the server 20 includes a storage device 22 that stores an abnormal sound database storing information about a plurality of abnormal sounds that have been found to occur in the vehicle for each vehicle type. The abnormal sound database associates and stores information such as the time-axis data of the sound, the cause of the abnormal sound, the parts that have become the source of the sound, the contents of the inquiry information provided by the user, etc. for each of the plurality of abnormal sounds. In addition, the server 20 updates the abnormal sound database based on information obtained from a large number of vehicles including the vehicle V and information (reports) about newly discovered abnormal sounds transmitted from automobile manufacturers (developers, etc.), vehicle dealerships, repair shops, etc. As the technology for constructing the abnormal sound diagnosis unit 21, for example, those described in the following papers (1)-(5) or a combination thereof can be used. (1)Unsupervised Filterbank Learning Using Convolutional Restricted Boltzmann Machine for Environmental Sound Classification (2)Learning from Between-Class Examples for Deep Sound Recognition (3)Novel Phase Encoded Mel Filterbank Energies for Environmental Sound Classification (4)Knowledge Transfer from Weakly Labeled Audio using Convolutional Neural Network for Sound Events and Scenes (5)Novel TEO-based Gammatone Features for Environmental Sound Classification

[0024] Next, with reference to FIGS. 3 to 5, the diagnosis procedure for abnormal sounds generated in the vehicle V by the abnormal sound diagnosis system 1 will be described.

[0025] When an operator at a vehicle dealership, repair shop, etc. is requested to eliminate an abnormal sound from a user of the vehicle V or the like, the operator listens to the inquiry information from the user or the like, and then executes a reproduction test to obtain the information necessary for diagnosing the abnormal sound. When executing the reproduction test, the operator connects the mobile terminal 10 to the electronic control unit of the vehicle V, and places or fixes the mobile terminal 10 or an external microphone connected to the mobile terminal 10 at an appropriate position on the vehicle V. Further, the operator activates the abnormal sound diagnosis support application and turns on the start switch of the vehicle V. Accordingly, the mobile terminal 10 acquires information such as the vehicle identification number or the chassis number of the vehicle V from the electronic control unit. Furthermore, the operator taps the recording start button displayed on the display unit 11, drives (operates) the vehicle V on a road or a test bench, and reproduces the driving state in which the abnormal sound has occurred based on the inquiry information from the user of the vehicle V or the like.

[0026] While the vehicle V is running (operating), the sound acquisition unit 14 of the mobile terminal 10 acquires the time-axis data of the sound emitted from the vehicle V at predetermined time intervals (micro time intervals) and stores it in the auxiliary storage device M. The vehicle state acquisition unit 15 acquires the vehicle state data specified by the operator according to the inquiry information from the user of the vehicle V etc. from the electronic control device of the vehicle V at predetermined time intervals (micro time intervals) in synchronization with the acquisition of the time-axis data of the sound by the sound acquisition unit 14 and stores it in the auxiliary storage device M. When the operator taps the recording stop button displayed on the display unit 11, the acquisition of the time-axis data of the sound and the vehicle state data is completed.

[0027] After the reproduction test is completed, the arithmetic processing unit 16 performs STFT (Short-Time Fourier Transform) on the time-axis data of the sound to obtain a spectrogram (acoustic spectrogram) showing the relationship between time, frequency, and sound pressure. The display control unit 18 causes the display unit 11 to display the spectrogram. In the present embodiment, the spectrogram is a color map showing the relationship between time and sound pressure level for each frequency by using the horizontal axis as the time axis, the vertical axis as the frequency axis, and color-coding the sound pressure level. Also, the operator selects (specifies) the range (hereinafter referred to as the "diagnosis range") to be diagnosed (analyzed) by the abnormal sound diagnosis unit 21 (server 20) in the spectrogram on the display unit 11. Further, the operator inputs inquiry information to the input screen displayed on the display unit 11. Then, when the operator taps the information transmission button displayed on the display unit 11, the information necessary for diagnosing the abnormal sound is transmitted from the communication module 12 of the mobile terminal 10 to the server 20. In the present embodiment, the information transmitted from the mobile terminal 10 to the server 20 includes the time-axis data of the sound acquired by the sound acquisition unit 14, the vehicle state data acquired by the vehicle state acquisition unit 15, the inquiry information, and the information defining the diagnosis range selected by the operator.

[0028] FIG. 3 is a flowchart showing a series of processes executed by the server 20 in response to the reception of information from the mobile terminal 10. As shown in the figure, the abnormal noise diagnosis unit 21 of the server 20 acquires the time-axis data of the sound, vehicle state data, inquiry information, and information defining the diagnosis range from the mobile terminal 10 (step S100), and determines whether the location where the abnormal noise occurs in the inquiry information is within the engine compartment such as near the chain cover (step S110). When it is determined that the location where the abnormal noise occurs is within the engine compartment (step S10: YES), the abnormal noise diagnosis unit 21 uses a band-pass filter (not shown) to acquire the peak value of the sound pressure in a predetermined frequency range of the time-axis data of the sound acquired in step S100 (step S120). Further, the abnormal noise diagnosis unit 21 acquires the crank angle θ when the peak value of the sound pressure acquired in step S120 occurs from the vehicle state data acquired in step S100 (step S130). Furthermore, the abnormal noise diagnosis unit 21 determines whether the crank angle θ acquired in step S130 is included in a predetermined angle range after the top dead center of compression of the first combustion chamber (cylinder No. 1) closest to the belt tensioner BT (step S140).

[0029] Here, the inventor has intensively studied the abnormal noise generated by the belt tensioner BT provided in the internal combustion engine EG. As a result, the tension of the belt B is greatly affected by the explosion of the air-fuel mixture in the first combustion chamber closest to the belt tensioner BT, and the tension of the belt B decreases with the explosion of the air-fuel mixture in the first combustion chamber, and the tension of the belt B increases before the explosion of the air-fuel mixture in the next combustion chamber (for example, the third combustion chamber). Furthermore, the inventor has found that the abnormal noise at the belt tensioner BT occurs according to the amount of change in the tension when the tension of the belt B decreases and then turns to increase with the explosion of the air-fuel mixture in the first combustion chamber closest to the belt tensioner BT.

[0030] That is, when the air-fuel mixture explodes in the first combustion chamber, the crank pulley P0 twists in the advancing direction of the belt B, and accordingly, the tension of the belt B decreases. As a result, the pulley Pt and the arm member AM of the belt tensioner BT rotate counterclockwise around the connecting shaft Ax as shown by the solid line in FIG. 4. Thereafter, the crank pulley P0 twists in the direction opposite to the advancing direction of the belt B due to the reaction of the twist in the advancing direction of the belt B. Along with this, the tension of the belt B increases, and the pulley Pt and the arm member AM of the belt tensioner BT rotate clockwise around the connecting shaft Ax as shown by the broken line in FIG. 4. For this reason, when the change amount of the tension of the belt B is large when the tension decreases and then increases with the explosion of the air-fuel mixture in the first combustion chamber, the torsion spring SP is greatly deformed as the arm member AM rotates, and the torsion spring SP vibrates the arm member AM and the two collide, generating abnormal noise.

[0031] Further, as a result of experiments and analysis by the present inventor, in the internal combustion engine EG which is a four-cylinder gasoline engine, the abnormal noise in the belt tensioner BT becomes an impulse due to the collision between the torsion spring SP and the arm member AM, and it has been found that the abnormal noise occurs in a relatively wide range from 1 kHz to 10 kHz. Furthermore, as a result of experiments and analysis by the present inventor, in the internal combustion engine EG, the sound pressure of the abnormal noise in the belt tensioner BT is included in the angular range from 45° to 135° after the compression top dead center in the first combustion chamber closest to the belt tensioner BT, as shown in FIGS. 5(a), (b), and (c).

[0032] Based on these, in step S120, the abnormal noise diagnosis unit 21 acquires the peak value of the sound pressure from the frequency range of 1 kHz to 10 kHz. Further, the abnormal noise diagnosis unit 21 determines whether or not the crank angle θ acquired in step S130 is included in the angular range from 45° to 135° after the compression top dead center of the first combustion chamber closest to the belt tensioner BT (step S140). And when the crank angle θ is included in the angular range from 45° to 135° after the compression top dead center of the first combustion chamber closest to the belt tensioner BT (step S140: YES), the abnormal noise diagnosis unit 21 diagnoses (determines) that the abnormal noise generated in the vehicle V is generated by the belt tensioner BT (step S150). On the other hand, when it is determined that the location where the abnormal noise occurs is not within the engine compartment (step S110: NO), and when the above crank angle θ is not included in the angular range from 45° to 135° after the compression top dead center of the first combustion chamber closest to the belt tensioner BT (step S140: NO), the abnormal noise diagnosis unit 21 diagnoses the cause of the abnormal noise generated in the vehicle V by the above neural network based on the information acquired in step S100 (step S155).

[0033] After the processing of step S150 or step S155, the abnormal noise diagnosis unit 21 creates a diagnosis result based on the output of the neural network (step S160). The diagnosis result in step S160 includes the name of the abnormal noise, the component that became the source of the abnormal noise, the cause of the abnormal noise, and measures for eliminating the abnormal noise read from the storage device 22, etc. Note that examples of the cause of the abnormal noise in the belt tensioner BT include deterioration of the support member S and the torsion spring SP, wear of the friction material, slack due to deterioration of the belt B, etc. Further, the abnormal noise diagnosis unit 21 transmits the diagnosis result created in step S160 to the mobile terminal 10 (step S170), and ends the series of processes in FIG. 3. When the diagnosis result from the server 20 is received by the mobile terminal 10, the diagnosis result is displayed on the display unit 11. Thereby, the operator can accurately explain the diagnosis result from the server 20 to the user of the vehicle V, etc., and promptly proceed with measures against the abnormal noise.

[0034] As described above, the server 20 (abnormal noise diagnosis unit 21) as the abnormal noise diagnosis device in the abnormal noise diagnosis system 1 diagnoses that abnormal noise has occurred in the belt tensioner BT when the peak value of the sound pressure in the predetermined frequency range of the time-axis data of the sound acquired from the vehicle V occurs within a predetermined angular range after top dead center compression in the first combustion chamber (first cylinder) closest to the belt tensioner BT (steps S120 - S130, S140: YES) (step S150). Thereby, it becomes possible to accurately determine whether the abnormal noise generated in the vehicle V is generated by the belt tensioner BT provided in the internal combustion engine EG.

[0035] Further, the abnormal noise diagnosis unit 21 of the server 20 acquires the peak value of the sound pressure from the frequency range of 1 kHz to 10 kHz of the time-axis data of the sound (step S120), and determines whether the crank angle θ when the acquired peak value of the sound pressure occurs is included in the angular range from 45° to 135° after top dead center compression in the first combustion chamber closest to the belt tensioner BT (steps S130 - S140). Thereby, it becomes possible to accurately determine whether the abnormal noise generated in the vehicle V is generated by the belt tensioner BT provided in the 4-cylinder internal combustion engine EG.

[0036] Furthermore, the abnormal noise diagnosis unit 21 of the server 20 exchanges information with the mobile terminal 10 that acquires the time-axis data of the sound and the inquiry information regarding the abnormal noise generated in the vehicle V through communication (step S100). Also, the abnormal noise diagnosis unit 21 determines whether the location where the abnormal noise occurs is around the internal combustion engine EG, that is, within the engine compartment, based on the inquiry information from the mobile terminal 10 (step S110). Furthermore, when the abnormal noise diagnosis unit 21 determines that the location where the abnormal noise occurs is within the engine compartment (step S110: YES), it determines whether the crank angle θ when the peak value of the sound pressure in the above frequency range occurs is within a predetermined angular range after top dead center compression (steps S120 - 140). Thereby, it becomes possible to suppress misdiagnosis related to abnormal noise in the belt tensioner BT and further improve the diagnosis accuracy by the abnormal noise diagnosis unit 21.

[0037] Further, the abnormal noise diagnosis unit 21 of the server 20 includes a neural network as a diagnosis module constructed by supervised learning (machine learning) to diagnose the cause of abnormal noise generated in the vehicle V or the like based on the inquiry information, the time-axis data of the sound, etc. acquired by the mobile terminal 10. Furthermore, when it is determined that no abnormal noise is generated by the belt tensioner BT (step S110: NO, S140: NO), the server 20 diagnoses the abnormal noise generated in the vehicle V or the like by the neural network (step S155). Thereby, it becomes possible to further improve the versatility of the server 20 and thus the abnormal noise diagnosis system 1 including the server 20.

[0038] Note that the abnormal noise diagnosis support application installed in the mobile terminal 10 may be installed in a tablet terminal, a personal computer, or the like, and the tablet terminal or the like may be used instead of the mobile terminal 10. Also, a part of the functions of the abnormal noise diagnosis unit 21 may be provided in the mobile terminal 10, and the abnormal noise diagnosis system 1 may be configured by a single information processing device such as a personal computer.

[0039] And the invention of the present disclosure is not limited to the above-described embodiments at all, and it goes without saying that various changes can be made within the scope of the extension of the present disclosure. Furthermore, the above-described embodiments are merely specific forms of the invention described in the summary section of the invention, and do not limit the elements of the invention described in the summary section of the invention.

Industrial Applicability

[0040] The invention of the present disclosure is extremely useful for diagnosing abnormal noise generated in a vehicle.

Explanation of Reference Numerals

[0041] 1 Abnormal sound diagnosis system, 10 Mobile terminal, 11 Display unit, 12 Communication module, 13 Inquiry information acquisition unit, 14 Sound acquisition unit, 15 Vehicle state acquisition unit, 16 Arithmetic processing unit, 17 Extraction unit, 18 Display control unit, 20 Server (abnormal sound diagnosis device), 21 Abnormal sound diagnosis unit, 22 Memory device, Alt Alternator, AM Arm member, Ax Connecting shaft, B Belt, BT Belt tensioner, CB Cylinder block, Cmp Air conditioner compressor, EG Engine, P0 Crank pulley, P1, P2, PC Pulley, S Support member, V Vehicle, WP Water pump.

Claims

1. A noise diagnosis device for diagnosing abnormal noises generated in a vehicle, the vehicle including an internal combustion engine having a plurality of cylinders, an auxiliary machine driven by the internal combustion engine via a belt, and a belt tensioner for adjusting the tension of the belt, wherein when a peak value of sound pressure in a predetermined frequency range of sound data acquired from the vehicle is generated within a predetermined angular range after top dead center of compression in the cylinder closest to the belt tensioner among the plurality of cylinders, it is diagnosed that an abnormal noise is generated in the belt tensioner.

2. The noise diagnosis device according to claim 1, wherein the internal combustion engine is a four-cylinder internal combustion engine, the frequency range is a range from 1 kHz to 10 kHz, and the angular range is a range from 45° to 135° after top dead center of compression.

3. The noise diagnosis device according to claim 1 or 2, further comprising a diagnosis module constructed by machine learning to diagnose the cause of abnormal noise based on given information, and when it is determined that no abnormal noise is generated in the belt tensioner, diagnosing the abnormal noise generated in the vehicle by the diagnosis module.

4. The noise diagnosis device according to claim 1 or 2, wherein the noise diagnosis device exchanges information with a terminal that acquires the sound data and inquiry information regarding abnormal noises generated in the vehicle, and when it is determined based on the inquiry information from the terminal that an abnormal noise is generated around the internal combustion engine, determines whether a crank angle at which the peak value of the sound pressure in the frequency range is generated is within the predetermined angular range after top dead center of compression.

5. The noise diagnosis device according to claim 1 or 2, wherein the belt tensioner includes a support member fixed to the internal combustion engine, an arm member rotatably supported by the support member, a pulley rotatably supported by an end of the arm member on the side opposite to the support member side, and a torsion spring for biasing the arm member so as to press the pulley against the belt, and the support member of the belt tensioner is fixed to one end face in the arrangement direction of the plurality of cylinders of the cylinder block so that the pulley abuts against the belt extending from the crank pulley that rotates integrally with the crankshaft of the internal combustion engine to the nearest auxiliary machine.

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