Engine valve clearance abnormality detection device and engine valve clearance abnormality detection method

Abstract

An engine valve clearance abnormality detection device (100) for detecting abnormalities in a valve clearance (102) of an engine valve (101) comprises: a driving sound detection device (103) for detecting the driving sound of the engine valve (101); and an abnormality determination device (104) for determining whether the valve clearance (102) is abnormal based on the driving sound of the engine valve (101) detected by the driving sound detection device (103).

Description

Technical Field

[0001] The present disclosure relates to an engine valve clearance abnormality detection device and an engine valve clearance abnormality detection method for detecting abnormality in a valve clearance of an engine valve. Background Art

[0002] When the engine is warm, the engine valves (specifically, the intake and exhaust valves) expand due to the heat of combustion, thereby increasing the valve lift compared to when the engine is cold. Therefore, in order to obtain the optimal valve lift when the engine is warm (that is, under the normal operating state of the engine), when the engine is cold, there is a specified valve clearance in the path where power is transmitted from the cam to the engine valve (for example, between the cam and the tappet, or between the cam and the rocker arm).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-316762

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2012-132420 Summary of the Invention

[0007] Technical problem to be solved by the invention

[0008] However, for example, if the cam is worn, the valve clearance deviates from the specified value and becomes abnormal, causing the valve lift amount to fluctuate and possibly reducing engine performance. Therefore, it is preferable to detect abnormality in the valve clearance.

[0009] In view of the above circumstances, an object is to provide an engine valve clearance abnormality detection device and an engine valve clearance abnormality detection method capable of detecting abnormality in the valve clearance of an engine valve.

[0010] Technical means for solving technical problems

[0011] An engine valve clearance abnormality detection device is provided, which is an engine valve clearance abnormality detection device for detecting an abnormality in the valve clearance of an engine valve, comprising: a driving sound detection device for detecting the driving sound of the engine valve; and an abnormality determination device for determining whether the valve clearance is abnormal based on the driving sound of the engine valve detected by the driving sound detection device.

[0012] The abnormality determination device preferably determines whether the valve clearance is abnormal based on the sound pressure of the driving sound of the engine valve in an operating range where the engine speed is relatively low.

[0013] The abnormality determination device preferably determines whether the valve clearance is abnormal based on a frequency of a driving sound of the engine valve in an operation region where the engine speed is relatively high.

[0014] In addition, an engine valve clearance abnormality detection method is provided, which is an engine valve clearance abnormality detection method for detecting an abnormality in the valve clearance of an engine valve, comprising: a step of detecting a driving sound of the engine valve; and a step of determining whether the valve clearance is abnormal based on the detected driving sound of the engine valve.

[0015] Effects of the Invention

[0016] An engine valve clearance abnormality detection device and an engine valve clearance abnormality detection method capable of detecting abnormality of a valve clearance of an engine valve can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a diagram illustrating the structure of an engine valve clearance abnormality detection device.

[0018] Figure 2 This is a diagram for explaining the operation of the engine valve clearance abnormality detection device. DETAILED DESCRIPTION

[0019] [structure]

[0020] like Figure 1 As shown, the engine valve clearance abnormality detection device 100 is a device for detecting abnormality in a valve clearance 102 of an engine valve 101 , and includes a driving sound detection device 103 and an abnormality determination device 104 .

[0021] The engine valve 101 is an intake / exhaust valve. A valve clearance 102 exists between a rocker arm 106 swung by a cam 105 and the engine valve 101 and is adjusted by an adjustment screw 107 attached to the rocker arm 106 .

[0022] The driving sound detection device 103 is a device that detects the driving sound of the engine valve 101 , and is implemented by, for example, a directional microphone that can efficiently collect the driving sound of the engine valve 101 .

[0023] The abnormality determination device 104 is a device that determines whether the valve clearance 102 is abnormal based on the driving sound of the engine valve 101 detected by the driving sound detection device 103 , and is implemented by, for example, a partial function of the electronic control unit 108 .

[0024] Specifically, the abnormality determination device 104 determines whether the valve clearance 102 is abnormal by comparing the driving sound of the engine valve 101 detected by the driving sound detection device 103 with the driving sound of the engine valve 101 when the valve clearance 102 does not deviate from a predetermined value. For example, the comparison can be made by recording the sound pressure, frequency, and / or waveform.

[0025] The driving sound of the engine valve 101 when the valve clearance 102 does not deviate from the specified value is recorded in advance, for example, through testing using an actual engine. Alternatively, the driving sound of the engine valve 101 when the valve clearance 102 does not deviate from the specified value can be determined by mechanically learning the driving sound of the engine valve 101 detected by the driving sound detection device 103 during a specified engine driving time after the valve clearance 102 is adjusted.

[0026] The abnormality determination device 104 determines whether the valve clearance 102 is abnormal based on the sound pressure (volume) of the driving sound of the engine valve 101 in a relatively low engine speed operating range, and determines whether the valve clearance 102 is abnormal based on the frequency (height) of the driving sound of the engine valve 101 in a relatively high engine speed operating range. The engine speed is detected by an engine speed sensor 109.

[0027] In the operating range where the engine speed is relatively low, the opening and closing speed of the engine valve 101 is relatively slow, and the frequency of the driving sound of the engine valve 101 is relatively low. Therefore, even a slight change in the opening and closing speed of the engine valve 101 has a significant impact on the change in the frequency of the driving sound of the engine valve 101, making it difficult to accurately compare the driving sounds of the engine valve 101.

[0028] Therefore, in an operating range where the engine speed is low, it is preferable to determine whether the valve clearance 102 is abnormal by comparing the sound pressure of the driving sound of the engine valve 101 with the sound pressure of the driving sound of the engine valve 101 when the valve clearance 102 does not deviate from a predetermined value.

[0029] Furthermore, in an operating region where the engine speed is relatively high, the opening and closing speed of the engine valve 101 is relatively fast, and the frequency of the driving sound of the engine valve 101 is relatively high. Therefore, even if the opening and closing speed of the engine valve 101 changes slightly, the effect on the frequency of the driving sound of the engine valve 101 is relatively small.

[0030] Therefore, in a high engine speed operating range, by comparing the frequency of the driving sound of the engine valve 101 with the frequency of the driving sound of the engine valve 101 when the valve clearance 102 does not deviate from a predetermined value, it is possible to accurately determine whether the valve clearance 102 is abnormal.

[0031] Furthermore, the low engine speed operating range and the high engine speed operating range are distinguished. For example, if the engine speed is equal to or higher than a threshold, the engine speed operating range is the high engine speed operating range, and if the engine speed is less than the threshold, the engine speed operating range is the low engine speed operating range.

[0032] When comparing the driving sound of the engine valve 101 , the engine speed at which the abnormality of the valve clearance 102 can be determined more accurately based on the sound pressure of the driving sound of the engine valve 101 than based on the frequency is determined in advance through experiments and set as the threshold.

[0033] In addition, when the abnormality determination device 104 determines that the valve clearance 102 is abnormal, the engine valve clearance abnormality detection device 100 can also notify the engine operator (for example, a person driving a vehicle equipped with the engine), a manager (for example, a person who manages a vehicle equipped with the engine), and / or an operator (for example, a person who prepares a vehicle equipped with the engine) of the abnormality of the valve clearance 102.

[0034] The notification can be made, for example, by displaying it on an indicator or screen of the vehicle equipped with the engine, or by displaying it on an information terminal of a manager located at a service center separate from the vehicle equipped with the engine via a communication line, or by displaying it on an information terminal of an operator located near the vehicle equipped with the engine. Furthermore, in the case of a stationary engine, the notification can be made by displaying an indicator or screen showing the engine's operating status.

[0035] [action]

[0036] like Figure 2 As shown, in the engine valve clearance abnormality detection device 100 , in step S101 , the driving sound detection device 103 detects the driving sound of the engine valve 101 , or the abnormality determination device 104 reads the driving sound of the engine valve 101 detected by the driving sound detection device 103 .

[0037] In the next step S102 , the abnormality determination device 104 determines whether the engine speed detected by the engine speed sensor 109 is equal to or greater than a threshold value, and proceeds to step S103 if it is equal to or greater than the threshold value, and proceeds to step S104 if it is less than the threshold value.

[0038] In step S103, the abnormality determination device 104 compares the frequency of the driving sound of the engine valve 101 detected by the driving sound detection device 103 with the frequency of the driving sound of the engine valve 101 when the valve clearance 102 does not deviate from the prescribed range. If the two are within the prescribed similar range, it is determined that the valve clearance 102 is normal; otherwise, it is determined that the valve clearance 102 is abnormal.

[0039] In addition, in step S104, the abnormality judgment device 104 compares the sound pressure of the driving sound of the engine valve 101 detected by the driving sound detection device 103 with the sound pressure of the driving sound of the engine valve 101 when the valve clearance 102 does not deviate from the specified range. If the two are within the specified similar range, it is judged that the valve clearance 102 is normal; otherwise, it is judged that the valve clearance 102 is abnormal.

[0040] In addition, even if the valve clearance 102 remains the same, the driving sound of the engine valve 101 may vary slightly due to other reasons. Therefore, a similar range is predetermined in consideration of this variation. As long as the deviation when comparing the driving sound of the engine valve 101 is within this range, it can be determined that the driving sound of the engine valve 101 detected by the driving sound detection device 103 is consistent with the pre-recorded driving sound of the engine valve 101.

[0041] As described above, the engine valve clearance abnormality detecting device 100 can detect abnormality in the valve clearance of the engine valve.

[0042] This application is based on Japanese patent application (Japanese Patent Application No. 2020-063500) filed on March 31, 2020, the contents of which are incorporated herein by reference.

[0043] Industrial Availability

[0044] The engine valve clearance abnormality detection device and the engine valve clearance abnormality detection method disclosed herein are useful in that they can detect abnormality in the valve clearance of an engine valve.

[0045] Description of Reference Numerals

[0046] 100 Engine valve clearance abnormality detection device

[0047] 101 Engine Valve

[0048] 102 Valve clearance

[0049] 103 Driving sound detection device

[0050] 104 Abnormality determination device

[0051] 105 Cam

[0052] 106 rocker arm

[0053] 107 Adjusting screw

[0054] 108 Electronic Control Unit

[0055] 109 Engine speed sensor

Claims

1. An engine valve clearance anomaly detection device for detecting an abnormality in the valve clearance of an engine valve, comprising: a driving sound detection device that detects the driving sound of the engine valve; as well as an abnormality determination device for determining whether the valve clearance is abnormal based on the driving sound of the engine valve detected by the driving sound detection device, The abnormality determination device determines whether the valve clearance is abnormal based on the sound pressure of the driving sound of the engine valve in an operation range where the engine speed is relatively low.

2. The engine valve clearance abnormality detection device according to claim 1, The abnormality determination device determines whether the valve clearance is abnormal based on the frequency of the driving sound of the engine valve in an operation range where the engine speed is relatively high.

3. An engine valve clearance anomaly detection device for detecting an abnormality in the valve clearance of an engine valve, comprising: a driving sound detection device that detects the driving sound of the engine valve; as well as an abnormality determination device for determining whether the valve clearance is abnormal based on the driving sound of the engine valve detected by the driving sound detection device, The abnormality determination device determines whether the valve clearance is abnormal based on the frequency of the driving sound of the engine valve in an operation range where the engine speed is relatively high.

4. A method for detecting an abnormality in an engine valve clearance, comprising: a step of detecting a driving sound of the engine valve; as well as a step of determining whether the valve clearance is abnormal based on the detected driving sound of the engine valve, In an operating range where the engine speed is relatively low, whether or not the valve clearance is abnormal is determined based on the sound pressure of the driving sound of the engine valve.

5. The engine valve clearance abnormality detection method according to claim 4, In an operating range where the engine speed is relatively high, whether or not the valve clearance is abnormal is determined based on the frequency of the driving sound of the engine valve.

6. A method for detecting an abnormality in an engine valve clearance, comprising: a step of detecting a driving sound of the engine valve; as well as a step of determining whether the valve clearance is abnormal based on the detected driving sound of the engine valve, In an operating range where the engine speed is relatively high, whether or not the valve clearance is abnormal is determined based on the frequency of the driving sound of the engine valve.

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