Method and device for evaluating sound quality of wastegate valve

Abstract

This sound quality evaluation method for a wastegate valve comprises: a vibration data acquisition step for acquiring a plurality of pieces of vibration data that indicate vibration occurring in a wastegate valve and that are in a prescribed time period during which the degree of openness of the wastegate valve changes; a POA data acquisition step for acquiring POA values at a prescribed frequency band of 0.5 kHz or greater from a plurality of frequency spectra attained by performing frequency analysis on each of the plurality of pieces of vibration data; and a vibration noise evaluation step for evaluating vibration noise occurring in the wastegate valve on the basis of the plurality of POA values.

Description

[Technical field]

[0001] The present disclosure relates to a sound quality evaluation method and a sound quality evaluation device for a wastegate valve. [Background technology]

[0002] Conventionally, a wastegate valve provided in a turbocharger is known. The flow rate of exhaust gas from an engine flowing into a turbine of the turbocharger is adjusted by the wastegate valve. For example, the wastegate valve disclosed in Patent Document 1 is fixed to a drive shaft via a lever. When the drive shaft rotates, a valve body constituting the wastegate valve opens and closes a wastegate flow passage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015-097786 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, due to vibrations from a driving engine, at least one of the components constituting the wastegate valve may vibrate intermittently within the clearance formed around it, generating vibration noise. Since it is difficult to analyze and predict the intermittent vibration phenomenon of components through simulation, in order to determine whether a wastegate valve has an appropriate structure that does not generate abnormal vibration noise, it has been necessary to rely on a sensory evaluation that evaluates the quality of the vibration noise that is actually generated based on human hearing.

[0005] An object of the present disclosure is to provide a sound quality evaluation method and sound quality evaluation device for a wastegate valve that can quantitatively evaluate the sound quality of vibration noise. [Means for solving the problem]

[0006] A method for evaluating sound quality of a wastegate valve according to at least one embodiment of the present disclosure includes: a vibration data acquiring step of acquiring a plurality of vibration data representing vibrations occurring in a wastegate valve during a predetermined time period during which an opening degree of the wastegate valve changes; a POA data acquisition step of acquiring a POA value in a predetermined frequency band of 0.5 kHz or more from each of a plurality of frequency spectra obtained by frequency analysis of each of the plurality of vibration data; a vibration noise evaluation step of evaluating a vibration noise generated in the wastegate valve based on a plurality of the POA values; Equipped with.

[0007] A sound quality evaluation device for a wastegate valve according to at least one embodiment of the present disclosure includes: a vibration data acquisition unit for acquiring a plurality of vibration data representing vibrations occurring in a wastegate valve during a predetermined time period during which an opening degree of the wastegate valve changes; a POA data acquisition unit for acquiring a POA value in a predetermined frequency band of 0.5 kHz or more from each of a plurality of frequency spectra obtained by frequency analysis of each of the plurality of vibration data; A vibration noise evaluation unit for evaluating a vibration noise generated in the wastegate valve based on a plurality of the POA values; Equipped with. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a sound quality evaluation method and a sound quality evaluation device for a wastegate valve that can quantitatively evaluate the sound quality of vibration noise. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram conceptually illustrating a sound quality evaluation device for a wastegate valve according to an embodiment of the present disclosure. [Diagram 2]4 is a diagram conceptually illustrating vibration data acquired by a vibration data acquisition unit according to an embodiment of the present disclosure. FIG. [Diagram 3] 1 is a diagram conceptually illustrating a POA value acquired by a POA data acquisition unit according to an embodiment of the present disclosure. [Figure 4] 11 is a graph conceptually showing a comparison result between a POA value when an abnormal vibration sound occurs and a POA value when an abnormal vibration sound does not occur. [Diagram 5] 13 is a diagram conceptually illustrating a ratio acquired by a ratio acquisition unit according to an embodiment of the present disclosure. FIG. [Figure 6] 2 is a diagram conceptually illustrating a detailed configuration of a vibration sound evaluation unit according to an embodiment of the present disclosure. FIG. [Figure 7] 10 is a diagram conceptually illustrating a multiplication value acquired by a multiplication value acquisition unit according to an embodiment of the present disclosure. FIG. [Figure 8] 11 is a graph showing a relationship between a sum acquired by a sum acquisition unit according to an embodiment of the present disclosure and a sensory evaluation. [Figure 9] 4 is a flowchart illustrating a method for evaluating the sound quality of vibration noise of a wastegate valve according to an embodiment of the present disclosure. [Figure 10] 1 is a flowchart illustrating a sound quality evaluation method based on a POA value of vibration data according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure. For example, expressions expressing relative or absolute configuration, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such a configuration, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions indicating that things are in an equal state, such as "identical," "equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to rectangular shapes, cylindrical shapes, etc. in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained. On the other hand, the expressions "comprise", "include", or "have" a certain element are not exclusive expressions excluding the presence of other elements. In addition, the same components are denoted by the same reference numerals and the description thereof may be omitted.

[0011] <Outline of Sound Quality Evaluation System 10> 1 is a diagram conceptually illustrating a sound quality evaluation device for a wastegate valve according to an embodiment of the present disclosure. In the illustrated embodiment, a sound quality evaluation device 1 for a wastegate valve (hereinafter, may be simply referred to as "sound quality evaluation device 1") is incorporated into a sound quality evaluation system 10. In addition to the sound quality evaluation device 1, the sound quality evaluation system 10 includes an engine (not shown) and a turbocharger 15. Each component of the sound quality evaluation system 10 will be described below.

[0012] <Overview of Turbocharger 15 Configuration> 1, a cross-sectional view of a turbocharger 15 is shown diagrammatically. The turbocharger 15 includes a gas inlet portion 13 into which exhaust gas G discharged from an engine flows, an exhaust turbine 2 that is rotated by the inflowing exhaust gas G, a compressor 3 that is driven by the exhaust turbine 2 to compress the intake air of the engine, a wastegate valve 5 for opening and closing a wastegate passage 14 that bypasses the exhaust turbine 2, and an actuator 6 for driving the wastegate valve 5.

[0013] The gas inlet portion 13 communicates with an upstream exhaust passage 22 through which exhaust gas G from the engine flows. A turbine wheel 21 is housed inside the exhaust turbine 2, and a compressor wheel 31 is housed inside the compressor 3. The turbine wheel 21, the compressor wheel 31, and the rotating shaft 4 connecting the turbine wheel 21 and the compressor wheel 31 constitute a rotating body that is rotationally driven by the exhaust gas G. The exhaust gas G that passes through the turbine wheel 21 and the exhaust gas G that bypasses the turbine wheel 21 and flows through the wastegate passage 14 can flow into the downstream exhaust passage 23.

[0014] <Configuration of wastegate valve 5 and actuator 6> In the illustrated embodiment, the wastegate valve 5 is connected to the actuator 6 via a rod 73 and a link mechanism 74. The actuator 6 is, for example, an electric actuator that moves the rod 73 back and forth linearly.

[0015] The wastegate valve 5 includes a shaft 7 that is rotatably held via a bush (not shown) at a wall portion 14W that defines the wastegate flow passage 14, and a valve 8 that is provided at one end of the shaft 7 (the lower end in the example of FIG. 1). The other end of the shaft 7 is connected to a link plate 74P that constitutes a link mechanism 74. Therefore, when the driving force of the actuator 6 is transmitted to the shaft 7 via a rod 73 and the link mechanism 74, the shaft 7 rotates in the axial direction, and the valve 8 opens and closes the wastegate flow passage 14. The opening degree of the wastegate flow passage 14 (i.e., the opening degree of the wastegate valve 5) is adjusted by controlling the actuator 6. The control of the actuator 6 is executed according to the elapsed time since the engine started, the engine speed, the rate of change of the engine speed, or a combination of these.

[0016] A clearance is formed between the shaft 7 and the bush (not shown) and between the shaft 7 and the link plate 74P. Therefore, when vibrations caused by the driving of the engine or the like are transmitted to the wastegate valve 5, the shaft 7 may vibrate intermittently. According to the inventor's knowledge, this vibration tends to occur particularly during a time period when the opening degree of the wastegate valve 5 is changing. When the vibrating shaft 7 collides with at least one of the bush or the link plate 74P, a vibration noise may be generated in the wastegate valve 5. Note that this is only one example of a cause of the generation of the vibration noise in the wastegate valve 5. Apart from this cause (or together with this cause), the vibration noise may be generated in the wastegate valve 5 due to another cause. For example, when the other end of the shaft 7 is connected to the link plate 74P via another member, the vibration noise may be generated by the collision of the other vibrating member with the link plate 74P. Alternatively, when the wastegate valve 5 is at a predetermined opening degree, the vibrating valve 8 may collide with, for example, the wall portion 14W that defines the wastegate flow passage 14, causing the vibration noise.

[0017] <Outline of the configuration of sound quality evaluation device 1> The configuration of a sound quality evaluation device 1 will be described with reference to Figs. 1 to 3. Fig. 2 is a diagram conceptually showing vibration data acquired by a vibration data acquisition unit according to an embodiment of the present disclosure. Fig. 3 is a diagram conceptually showing a POA value acquired by a POA data acquisition unit according to an embodiment of the present disclosure. Fig. 4 is a graph conceptually showing a comparison result between a POA value when an abnormal vibration sound occurs and a POA value when an abnormal vibration sound does not occur.

[0018] The sound quality evaluation device 1 is configured to quantitatively evaluate the sound quality of vibration sound generated in a wastegate valve 5. The sound quality evaluation device 1 is realized, for example, by one or more arithmetic devices equipped with a processor and a memory. The processor is a CPU, a GPU, an MPU, a DSP, or a combination of these. Alternatively, the processor may be realized by an integrated circuit such as a PLD, an ASIC, an FPGA, or an MCU. The memory electrically connected to the processor temporarily or non-temporarily stores data processed by the processor, etc. The memory is realized by a RAM, a ROM, a flash memory, or a combination of these.

[0019] The sound quality evaluation device 1 according to one embodiment includes a vibration data acquisition section 51, a POA data acquisition section 52, and a vibration sound evaluation section 53.

[0020] In the embodiment shown in FIG. 1 and FIG. 2, the vibration data acquisition unit 51 is configured to acquire a plurality of vibration data 11 indicating vibrations occurring in the wastegate valve 5. Here, the upper graph in FIG. 2 indicates the change over time in the opening degree of the wastegate valve 5, and the lower graph in FIG. 2 indicates the change over time in the vibration of the wastegate valve 5 at the same time. Each of the plurality of vibration data 11 indicates vibration in a predetermined time period. This predetermined time period includes a time period in which the opening degree of the wastegate valve 5 changes. As a more specific example, the opening degree of the wastegate valve 5 may change throughout this predetermined time period, or may change only temporarily during the predetermined time period. In addition, the predetermined time periods corresponding to each of the plurality of vibration data 11 acquired by the vibration data acquisition unit 51 may be time periods that do not overlap each other at all, or may be time periods that partially overlap each other (in the example of FIG. 2, the predetermined time periods do not overlap each other at all).

[0021] The vibration data acquisition unit 51 is configured to acquire a plurality of vibration data 11 based on the detection result of the vibration sensor 12 for detecting vibrations occurring in the wastegate valve 5. The vibration sensor 12 in FIG. 1 is merely illustrated conceptually, and the position at which the vibration sensor 12 is disposed may be anywhere as long as it can detect vibrations of the wastegate valve 5. For example, the vibration sensor 12 may be provided on the shaft 7, the valve 8, the link mechanism 74, the actuator 6, a wall portion 14W that defines the wastegate flow passage 14, or a component of the turbocharger 15. The vibration sensor 12 is an accelerometer as an example, but may be a microphone as another example.

[0022] The vibration data acquisition unit 51 acquires data associating vibration with time based on the detection result of the vibration sensor 12. This data corresponds to the lower graph conceptually illustrated in Fig. 2. Then, from this data, data corresponding to each of a plurality of predetermined time periods is extracted as vibration data 11.

[0023] In the embodiment shown in FIG. 1 and FIG. 3, the POA data acquisition unit 52 is configured to acquire a POA (Partial Overall) value in a predetermined frequency band from each of a plurality of frequency spectra obtained by frequency analysis of each of a plurality of vibration data 11 acquired by the vibration data acquisition unit 51. The frequency analysis is FFT, BPF, simple Fourier transform, or the like. The frequency analysis in this example is Short-Term Fourier Transform (STFT). The above-mentioned predetermined frequency is a frequency band of 0.5 kHz or more. Since 0.5 kHz is a value sufficiently larger than the frequency corresponding to the general rotation speed of the engine, the influence of engine vibration is unlikely to appear as noise in the acquired POA value. The predetermined frequency is more preferably 1 to 5 kHz, and more preferably 2 to 5 kHz. The graph conceptually illustrated in FIG. 3 shows the change over time of the POA value acquired by the POA data acquisition unit 52.

[0024] The vibration sound evaluation unit 53 is configured to evaluate the vibration sound generated by the waste gate valve 5 based on a plurality of POA values acquired by the POA data acquisition unit 52. According to the inventor's findings as shown in FIG. 4, when comparing the POA values of the waste gate valve 5 (NG product) determined to generate abnormal vibration sound (hereinafter sometimes referred to as abnormal sound) by sensory evaluation based on hearing with the POA values of the waste gate valve 5 (OK product) determined otherwise, distinguishable differences in trends such as different peak value trends appear. Thereby, the vibration sound evaluation unit 53 can evaluate the vibration sound generated by the waste gate valve 5.

[0025] According to the above configuration, the vibration data acquisition unit 51 acquires a plurality of vibration data 11 in a predetermined time period when the opening degree of the waste gate valve 5 with a strong tendency to generate abnormal sound changes. Then, each of the plurality of vibration data 11 is subjected to frequency analysis, and a plurality of POA values in a predetermined frequency band of 0.5 kHz or higher are acquired by the POA data acquisition unit 52 from each of the plurality of frequency spectra. Since 0.5 kHz is sufficiently larger than the frequency corresponding to the rotational speed of the engine in which the waste gate valve 5 is provided, POA values with little influence from the engine vibration are acquired. Also, according to the inventor's findings, these POA values to be evaluated by the vibration sound evaluation unit 53 are correlated with the sound quality of the vibration sound generated by the waste gate valve 5. Therefore, the sound quality evaluation device 1 of the waste gate valve that can quantitatively evaluate the sound quality is realized.

[0026] <Details of the POA values acquired by the POA data acquisition unit 52> As conceptually illustrated in FIG. 3, the POA value acquired by the POA data acquisition unit 52 constitutes at least a part of a graph with the horizontal axis representing time and the vertical axis representing the POA value. The POA data acquisition unit 52 acquires the POA value in a time period excluding the time periods when the opening degree of the wastegate valve 5 is 0% and 100%. The POA value corresponding to the above time period is the POA value surrounded by the two-dot chain line Q in FIG. 2. According to the inventor's knowledge, when the opening degree of the wastegate valve 5 is 0% or 100%, there is a low possibility that abnormal noise will occur in the wastegate valve 5. According to the above configuration, the acquired POA value changes significantly depending on the quality of the vibration noise generated by the wastegate valve 5. Therefore, it is possible to accurately evaluate whether abnormal vibration noise will occur in the wastegate valve 5.

[0027] Furthermore, it is more preferable that the opening degree of the wastegate valve 5 is 25% to 62.5% during the time period surrounded by the two-dot chain line Q. In other words, it is more preferable that the POA data acquisition unit 52 acquires a POA value during the time period during which the opening degree of the wastegate valve 5 is 25% to 62.5%. According to the inventor's findings, there is an even higher possibility that abnormal noise will occur in the wastegate valve 5 when the opening degree of the wastegate valve 5 is 25% to 62.5%. With the above configuration, it is possible to more accurately evaluate whether abnormal vibration noise will occur in the wastegate valve 5 for the reasons described above.

[0028] <Outline of evaluation method by vibration noise evaluation unit 53> The vibration sound evaluation unit 53 illustrated in FIG. 1 is configured to evaluate the vibration sound based on a value obtained by performing statistical processing on a plurality of POA values acquired by the vibration data acquisition unit 51. For example, by comparing the value obtained by performing statistical processing with a threshold value, it is possible to evaluate the sound quality of the vibration sound. The statistical processing may be the statistical processing described later with reference to FIGS. 6 and 7, or may be a process of calculating an average value of the acquired plurality of POA values. According to the above configuration, even when the plurality of POA values acquired by the POA data acquisition unit 52 vary from each other, since statistical processing is performed on these POA values, the sound quality of the vibration sound generated in the waist gate valve 5 can be accurately evaluated.

[0029] <Range of POA values acquired by the POA data acquisition unit 52> FIG. 5 is a diagram conceptually showing the distribution of the number of POA values acquired by the POA data acquisition unit 52. The number of POA values (i.e., the total number of data) acquired by the POA data acquisition unit 52 can be conceptually shown by a histogram as shown in FIG. 5. The range of a plurality of POA values (i.e., the range in which values can be taken) acquired by the POA data acquisition unit 52 is represented by a lower limit value L and an upper limit value U. In FIG. 5, a plurality of sections S obtained by equally dividing the above range from the lower limit value L to the upper limit value U are conceptually illustrated. The sum of the number of POA values in each section S corresponds to the total number of POA values acquired by the POA data acquisition unit 52. As will be described later, the evaluation result by the vibration sound evaluation unit 53 described later changes depending on the number of POA values included in each section S.

[0030] <An example of the details of the evaluation method by the vibration sound evaluation unit 53> With reference to FIGS. 6 to 8, an example of the details of the evaluation method by the vibration sound evaluation unit 53 will be described. FIG. 6 is a diagram conceptually showing the detailed configuration of the vibration sound evaluation unit according to an embodiment of the present disclosure. FIG. 7 is a diagram conceptually showing the ratio acquired by the ratio acquisition unit according to an embodiment of the present disclosure. FIG. 8 is a graph showing the relationship between the sum obtained by the sum acquisition unit according to an embodiment of the present disclosure and the sensory evaluation.

[0031] In the embodiment shown in FIG. 6, the vibration sound evaluation unit 53 includes a ratio acquisition unit 61, a multiplication value acquisition unit 62, a summation acquisition unit 63, and an evaluation unit 64.

[0032] The ratio acquiring unit 61 is configured to acquire, for each of a plurality of intervals S (see FIG. 5), the ratio (proportion) of the number of POA values ​​included in the interval S to the total number of the acquired plurality of POA values. The ratio acquired by the ratio acquiring unit 61 can be conceptually illustrated by the graph in FIG. 7. It can be understood that each ratio acquired by the ratio acquiring unit 61 for each of the plurality of intervals S indicates the probability that any POA value acquired by the POA data acquiring unit 52 is included in the corresponding interval S. The sum of the ratios indicated by the six plot points illustrated in FIG. 7 is 1.

[0033] The multiplication value acquisition unit 62 is configured to acquire, for each of the multiple sections S, a multiplication value obtained by multiplying the representative value of the section S by the ratio in the section S. In Fig. 7, the representative values ​​of each section S are exemplified as M1 to M6 (similarly in Fig. 5). The representative value is, for example, the median value of each section S.

[0034] The summation acquisition unit 63 is configured to acquire the summation of each multiplication value acquired for each section S. This summation can be understood as a value obtained by performing statistical processing on the acquired multiple POA values, and more specifically, can be understood as indicating an expected value of the POA value acquired by the POA data acquisition unit 52. The graph illustrated in FIG. 8 shows the relationship between the summation acquired by the summation acquisition unit 63 based on the vibration data 11 of the wastegate valve 5 and the result of a sensory evaluation based on human hearing of the vibration sound of the wastegate valve 5 at the time of acquiring the vibration data 11. In this verification, eleven wastegate valves 5 were prepared as samples. In the graph of FIG. 8, the result of the sensory evaluation that no abnormal sound is detected is indicated by "○", the result of the sensory evaluation that an abnormal sound is detected is indicated by "×", and the result that is intermediate between the two is indicated by "△".

[0035] 8, the higher the sum acquired by the sum acquisition unit 63, the worse the result of the sensory evaluation. In other words, it is found that there is a correlation between the sum acquired by the sum acquisition unit 63 and the result of the sensory evaluation. Therefore, by using the sum acquired by the sum acquisition unit 63, it is possible to evaluate the vibration noise generated in the wastegate valve 5 without relying on the sensory evaluation.

[0036] The evaluation unit 64 shown in FIG. 6 is configured to evaluate the sound quality of the vibration sound generated in the wastegate valve 5 based on the sum acquired by the sum acquisition unit 63. For example, a threshold value Th1 that may be a boundary between "○" and "△" and a threshold value Th2 that may be a boundary between "△" and "×" shown in FIG. 8 are set. The evaluation unit 64 evaluates that an abnormal sound occurs in a wastegate valve 5 for which the sum acquired by the sum acquisition unit 63 is higher than the threshold value Th2. The evaluation unit 64 also evaluates that an abnormal sound does not occur in a wastegate valve 5 for which the acquired sum is lower than the threshold value Th1. According to the above configuration, the sound quality of the vibration sound generated in the wastegate valve 5 can be accurately evaluated without relying on a sensory evaluation.

[0037] In other embodiments, the evaluation unit 64 may use one threshold instead of two thresholds during evaluation, or three or more thresholds. It is not essential for the evaluation unit 64 to use a threshold. For example, by comparing the sums acquired by the sum acquisition unit 63 for each of the multiple wastegate valves 5, it is possible to perform a relative evaluation of the sound quality without using a threshold.

[0038] <Flowchart of sound quality evaluation method> Fig. 9 is a flowchart showing a method for evaluating the sound quality of vibration noise of a wastegate valve according to an embodiment of the present disclosure. Fig. 10 is a flowchart showing a method for evaluating sound quality based on the POA value of vibration data according to an embodiment of the present disclosure. Hereinafter, "step" may be abbreviated as "S".

[0039] First, for example, a plurality of vibration data 11 indicating vibrations occurring in the wastegate valve 5 due to the operation of the engine are acquired (S11). S11 is executed by the vibration data acquisition unit 51 described above. Next, a plurality of POA values ​​are acquired (S13). S13 is executed by the POA data acquisition unit 52 described above. Next, the vibration noise generated in the wastegate valve 5 is evaluated based on the plurality of POA values ​​acquired in S13 (S15). S15 is executed by the vibration noise evaluation unit 53 described above.

[0040] The method of evaluating the vibration noise executed in S15 will be described. First, for each of the above-mentioned multiple sections S (see FIG. 5), the ratio of the number of POA values ​​included in the section S to the total number of the multiple POA values ​​acquired in S13 is acquired (S21). S21 is executed by the above-mentioned ratio acquisition unit 61. Next, a multiplication value obtained by multiplying the representative value of the section S by the ratio of the section S is acquired for each of the multiple sections S (S23). S23 is executed by the above-mentioned multiplication value acquisition unit 62. Next, the sum of the multiplication values ​​acquired in S23 is acquired (S25). S25 is executed by the above-mentioned sum acquisition unit 63. Finally, the sound quality of the vibration noise is evaluated based on the sum acquired in S25 (S27). S27 is executed by the above-mentioned evaluation unit 64. Through the above steps, the evaluation of the vibration noise of the wastegate valve 5 is executed.

[0041] In another embodiment, in S11, instead of driving the engine, a vibrator may apply a vibration force to, for example, the turbocharger 15. Even in this case, it is possible to acquire vibration data 11 of vibrations occurring in the wastegate valve 5. In other words, if vibrations are transmitted to a wastegate valve 5 having some structural problem, an abnormal sound will be generated and the sum acquired in S25 will also be a high value. Also, at least a part of the steps constituting the above flowchart may be executed by a person instead of being executed by the sound quality evaluation device 1 including a processor. For example, at least one of S25 and S27 may be executed by a person.

[0042] <Summary> The contents described in the above-mentioned embodiments can be understood, for example, as follows.

[0043] 1) A method for evaluating sound quality of a wastegate valve according to at least one embodiment of the present disclosure, a vibration data acquisition step (S11) of acquiring vibration data (11) indicating vibrations occurring in a wastegate valve (5), the vibration data (11) being acquired in a predetermined time period during which an opening degree of the wastegate valve (5) changes; A POA data acquisition step (S13) of acquiring a POA value in a predetermined frequency band of 0.5 kHz or more from each of a plurality of frequency spectra obtained by frequency analysis of each of the plurality of vibration data (11); a vibration noise evaluation step (S15) of evaluating vibration noise generated in the wastegate valve (5) based on the multiple POA values; Equipped with.

[0044] According to the above configuration 1), in the vibration data acquisition step (S11), a plurality of pieces of vibration data (11) are acquired during a predetermined time period during which the opening degree of the wastegate valve (5), which is highly likely to generate abnormal noise, changes. Then, in the POA data acquisition step (S13), each of the plurality of pieces of vibration data (11) is frequency analyzed, and a plurality of POA values ​​in a predetermined frequency band of 0.5 kHz or more are acquired from each of a plurality of frequency spectra. Since 0.5 kHz is sufficiently higher than a frequency corresponding to the rotation speed of the engine in which the wastegate valve (5) is provided, a POA value that is less affected by engine vibration is acquired. Furthermore, according to the inventor's knowledge, these POA values ​​to be evaluated in the vibration sound evaluation step (S15) correlate with the sound quality of the vibration sound generated by the wastegate valve (5). Thus, a wastegate valve sound quality evaluation method capable of quantitatively evaluating the sound quality of the vibration sound is realized.

[0045] 2) In some embodiments, the sound quality evaluation method for a wastegate valve according to 1) above includes the steps of: In the POA data acquisition step (S13), the POA value is acquired in a time period excluding a time when the opening degree of the wastegate valve (5) is 0% and a time when the opening degree of the wastegate valve (5) is 100%.

[0046] According to the findings of the inventors, when the opening degree of the wastegate valve (5) is 0% or 100%, there is a low possibility that abnormal noise will occur in the wastegate valve (5). According to the above configuration 2), the acquired POA value changes significantly depending on the quality of the vibration noise generated in the wastegate valve (5). Therefore, it is possible to accurately evaluate whether abnormal vibration noise will occur in the wastegate valve (5).

[0047] 3) In some embodiments, the sound quality evaluation method for a wastegate valve according to 2) above, In the POA data acquisition step (S13), the POA value in a time period in which the opening degree of the wastegate valve (5) is 25% to 62.5% is acquired.

[0048] According to the findings of the inventors, the possibility of abnormal noise occurring in the wastegate valve (5) is even higher when the opening degree of the wastegate valve (5) is between 25% and 62.5%. According to the configuration 3) above, for the same reason as in 2) above, it is possible to more accurately evaluate whether abnormal vibration noise occurs in the wastegate valve (5).

[0049] 4) In some embodiments, the sound quality evaluation method for a wastegate valve according to any one of 1) to 3) above, The vibration noise evaluation step (S15) evaluates the vibration noise based on values ​​obtained by performing statistical processing on the multiple POA values.

[0050] According to the above configuration 4), even if the multiple POA values ​​acquired in the POA data acquisition step (S13) vary from one another, statistical processing is performed on these POA values, so that the sound quality of the vibration sound generated in the wastegate valve (5) can be accurately evaluated.

[0051] 5) In some embodiments, the sound quality evaluation method for a wastegate valve according to 4) above, The vibration noise evaluation step (S15) includes: A ratio acquisition step (S21) of acquiring a ratio of the number of POA values ​​included in each of a plurality of sections obtained by equally dividing a range from a lower limit value to an upper limit value to a total number of the plurality of POA values ​​acquired by the POA value acquisition step; a multiplication value acquisition step (S23) of acquiring a multiplication value for each of the plurality of sections by multiplying the representative value of the section by the ratio in the section; A summation acquisition step (S25) of acquiring a summation of each of the acquired multiplication values; an evaluation step (S27) of evaluating the vibration noise based on the acquired sum; Includes.

[0052] The sum, which is a statistically processed value acquired in the sum acquisition step (S25), correlates with the sound quality of the sound generated in the wastegate valve (5). Therefore, according to the above configuration 5), the sound quality of the vibration sound generated in the wastegate valve (5) can be accurately evaluated without relying on a sensory evaluation based on human hearing.

[0053] 6) The sound quality evaluation device (1) for a wastegate valve according to at least one embodiment of the present disclosure includes: a vibration data acquisition unit (51) for acquiring vibration data (11) indicating vibrations occurring in a wastegate valve (5), the vibration data (11) being a plurality of pieces of vibration data (11) during a predetermined time period during which an opening degree of the wastegate valve (5) changes; a POA data acquisition unit (52) for acquiring a POA value in a predetermined frequency band of 0.5 kHz or more from each of a plurality of frequency spectra obtained by frequency analysis of each of the plurality of vibration data (11); a vibration noise evaluation unit (53) for evaluating vibration noise generated in the wastegate valve (5) based on a plurality of the POA values; Equipped with.

[0054] According to the configuration of 6) above, for the same reason as in 1) above, a sound quality evaluation device (1) for a wastegate valve that can quantitatively evaluate the sound quality of vibration sound is realized. [Explanation of symbols]

[0055] 1: Sound quality evaluation device 5: Wastegate valve 8: Valve 11: Vibration data 51: Vibration data acquisition unit 52: POA data acquisition section 53: Vibration noise evaluation section 64: Evaluation section L: Lower limit S: Section U: Upper limit

Claims

1. a vibration data acquiring step of acquiring a plurality of vibration data representing vibrations occurring in a wastegate valve during a predetermined time period during which an opening degree of the wastegate valve changes; a POA data acquisition step of acquiring a POA value in a predetermined frequency band of 0.5 kHz or more from each of a plurality of frequency spectra obtained by frequency analysis of each of the plurality of vibration data; a vibration noise evaluation step of evaluating a vibration noise generated in the wastegate valve based on a plurality of the POA values; Equipped with In the POA data acquisition step, the POA value is acquired in a time period excluding a time period during which the opening degree of the wastegate valve is 0% and a time period during which the opening degree of the wastegate valve is 100%, In the POA data acquisition step, the POA value in a time period in which the opening degree of the wastegate valve is 25% to 62.5% is acquired. How to evaluate the sound quality of wastegate valves.

2. The vibration noise evaluation step evaluates the vibration noise based on a value obtained by performing statistical processing on the plurality of POA values. The method for evaluating sound quality of a wastegate valve according to claim 1.

3. The vibration noise evaluation step includes: a ratio acquisition step of acquiring a ratio of the number of POA values ​​included in each of a plurality of sections obtained by equally dividing a range from a lower limit value to an upper limit value to a total number of the plurality of POA values ​​acquired by the POA data acquisition step; a multiplication value acquisition step of acquiring a multiplication value for each of the plurality of intervals by multiplying the representative value for the interval by the ratio in the interval; a summation step of acquiring a summation of each of the acquired multiplication values; and evaluating the vibration noise based on the acquired sum. The method for evaluating sound quality of a wastegate valve according to claim 2.

4. a vibration data acquisition unit for acquiring a plurality of vibration data representing vibrations occurring in a wastegate valve during a predetermined time period during which an opening degree of the wastegate valve changes; a POA data acquisition unit for acquiring a POA value in a predetermined frequency band of 0.5 kHz or more from each of a plurality of frequency spectra obtained by frequency analysis of each of the plurality of vibration data; a vibration noise evaluation unit for evaluating a vibration noise generated in the wastegate valve based on a plurality of the POA values; Equipped with The POA data acquisition unit acquires the POA value in a time period excluding a time period during which the opening degree of the wastegate valve is 0% and a time period during which the opening degree of the wastegate valve is 100%, The POA data acquisition unit is a sound quality evaluation device for a wastegate valve that acquires the POA value during a time period when the opening degree of the wastegate valve is 25% to 62.5%.

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