JP2006003309A - Engine valve closing motion timing evaluation method and engine valve closing motion timing evaluation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine valve closing motion timing evaluation method for accurately evaluating a valve closing motion timing, and to provide an engine valve closing motion timing evaluation system. <P>SOLUTION: The engine valve closing motion timing evaluation method comprises detecting engine vibration in the neighborhood of a valve with a vibration detection means 2 while rotating an engine 1 by a rotating drive means 3 at a prescribed engine speed, determining whether a plurality of vibration peaks exist or not in a vibration signal waveform corresponding to opening and closing of the valve respectively by a waveform analysis means 15 on the basis of the vibration signal waveform and a crank angle from a crank angle calculation means 12, enlarging vibration during valve opening and closing by heightening the engine speed of the engine 1 by the rotating drive means 3 through a rotation control means 4 when the plurality of the vibration peaks exist, detecting the crank angle of the vibration peak corresponding opening and closing of the valve, and evaluating closing motion timing of the valve by an evaluation means 16 on the basis of the crank angle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a valve opening / closing timing evaluation method and a valve opening / closing timing evaluation apparatus for an engine that evaluate the opening / closing timing of an intake valve and an exhaust valve by rotating the engine.

  Conventionally, in the production process of an engine, in order to ensure shipping quality, the produced engine is rotated at a constant rotation speed by an electric motor or the like, and the clearances of the intake valve and the exhaust valve are determined. I try to readjust.

  As an engine diagnostic device for determining such valve clearance, for example, a vibration sensor is installed near the valve to detect vibration during engine rotation, and the detected vibration signal and cam angle detection from the engine control unit are detected. A device that determines the clearance of a valve based on a signal, a crank angle detection signal, and previously input cam profile data is known (see, for example, Patent Document 1).

JP 2001-21455 A

  As disclosed in Patent Document 1, in order to determine the valve clearance by detecting the engine vibration in the vicinity of the valve by the vibration sensor, it is necessary to detect the timing (crank angle) when the valve is opened and closed, For that purpose, it is necessary to detect the generation timing of the peak (vibration peak) of the vibration signal output from the vibration sensor in accordance with opening and closing of the valve.

  However, the vibration signal obtained from the vibration sensor is subjected to, for example, squaring processing and further subjected to envelope processing. The vibration signal waveform obtained by opening or closing one valve is, for example, bounce or noise of the valve. Due to the influence, there may be a plurality of vibration peaks as shown in FIG. In FIG. 6, the horizontal axis indicates the crank angle (° CA), and the vertical axis indicates the vibration level.

  Moreover, in the diagnostic test during the engine production process, if the engine is in the engine production process and cooling water is not supplied into the engine, and the engine is continuously rotated at a high speed without supplying cooling water into the engine, Since problems such as wear occur in the water pump, etc., the engine is rotated at a relatively low speed, so the valve opening / closing operation (speed) is slow, and the valve opens and closes with the slow opening / closing operation. The vibration at the time is also reduced. Therefore, the amplitude value of the vibration peak obtained from the vibration sensor is also relatively small, and a sufficient amplitude difference does not occur with the vibration peak due to noise or the like.

  For this reason, as shown in FIG. 6, when a plurality of vibration peaks appear, even if the threshold value V1 is set high, a plurality of vibration peaks still remain. When there are a plurality of vibration peaks in this way, particularly when there are a plurality of intake valves and exhaust valves (for example, two each) in one cylinder, it is difficult to specify a vibration peak due to opening and closing of the valves. Therefore, there is a concern that the opening / closing timing of the valve, that is, the valve clearance cannot be accurately determined. FIG. 6 shows an averaged vibration signal waveform for a plurality of rotations of the engine to be evaluated.

  Accordingly, an object of the present invention made in view of the above points is to provide an engine valve opening / closing timing evaluation method capable of accurately evaluating the valve opening / closing timing even when a plurality of vibration peaks appear, and a valve opening / closing timing evaluation apparatus that implements the same. It is to provide.

  The invention of the valve opening / closing timing evaluation method for an engine according to claim 1, which achieves the above object, detects engine vibration in the vicinity of the valve while rotating the engine at a predetermined rotational speed, and corresponds to each of opening and closing of the valve. In the valve opening / closing timing evaluation method for an engine that evaluates the opening / closing timing of the valve based on the occurrence timing of the vibration peak in the vibration signal to be transmitted, there are a plurality of vibration peaks in the vibration signal corresponding to each opening and closing of the valve. In the case where there are a plurality of vibration peaks, the opening / closing timing of the valve is evaluated by rotating the engine at a rotational speed higher than the predetermined rotational speed.

  According to a second aspect of the present invention, there is provided an engine valve opening / closing timing evaluation device comprising: a rotation driving means for rotating the engine; a vibration detecting means for detecting vibration in the vicinity of the valve of the engine; and vibration detected by the vibration detecting means. Square processing means for squaring a signal, envelope processing means for envelope processing the output waveform of the square processing means, crank angle calculation means for calculating the crank angle of the engine, and vibration obtained from the envelope processing means Based on the signal waveform and the crank angle calculated by the crank angle calculation means, it is determined whether there is only one or a plurality of vibration peaks in the vibration signal waveform corresponding to the opening and closing of the valve. Based on the result, when there is only one vibration peak, the crank angle corresponding to the vibration peak occurrence timing is A waveform analysis means for outputting, a rotation control means for controlling the rotation drive means to increase the engine speed when there are a plurality of vibration peaks based on the determination result of the waveform analysis means, and the waveform analysis means And evaluation means for evaluating the opening / closing timing of the valve based on the crank angle detected in step (1).

  According to a third aspect of the present invention, there is provided an engine valve opening / closing timing evaluation method that detects vibrations in the vicinity of a rotating engine valve, and generates vibration peak generation timings in vibration signals corresponding to opening and closing of the valve. In the valve opening / closing timing evaluation method for an engine that evaluates the opening / closing timing of the valve based on the above, it is determined whether or not there are a plurality of vibration peaks in the vibration signal corresponding to each of the opening and closing of the valve. In the case where there are a plurality of valves, the valve opening / closing timing is evaluated by identifying a highly stable vibration peak based on the vibration signal for a plurality of rotations of the engine.

  According to a fourth aspect of the present invention, in the method for evaluating valve opening / closing timing of the engine according to the third aspect, when there are a plurality of vibration peaks, the peak value of each vibration peak is determined from the vibration signal for each rotation of the engine. Detecting the difference between the maximum value and the minimum value of the vibration peak with the same generation timing for multiple revolutions of the engine, and finding the vibration peak with the minimum difference in the generation timing as the vibration peak with high stability. It is characterized by specifying.

  According to a fifth aspect of the present invention, there is provided an engine valve opening / closing timing evaluation device comprising: a vibration detecting means for detecting vibration in the vicinity of a rotating engine valve; and a square that squares a vibration signal detected by the vibration detecting means. Processing means, envelope processing means for envelope processing the output waveform of the square processing means, crank angle calculation means for calculating the crank angle of the engine, vibration signal waveform obtained from the envelope processing means and calculation of the crank angle Based on the crank angle calculated by the means, it is determined whether there is only one or a plurality of vibration peaks in the vibration signal waveform corresponding to each of opening and closing of the valve. In one case, when the crank angle corresponding to the occurrence timing of the vibration peak is detected and there are a plurality of vibration peaks, A waveform analysis means for identifying a highly stable vibration peak based on the vibration signal for a plurality of revolutions of the engine and detecting a crank angle corresponding to the occurrence timing of the identified vibration peak; and the waveform analysis means Evaluation means for evaluating the opening / closing timing of the valve based on the detected crank angle.

  According to a sixth aspect of the present invention, in the engine valve opening / closing timing evaluation apparatus according to the fifth aspect, the waveform analyzing means is configured to detect each vibration from the vibration signal for each rotation of the engine when there are a plurality of vibration peaks. The peak value of the peak is detected, and the difference between the maximum and minimum values of the vibration peak with the same generation timing is obtained for multiple revolutions of the engine, and the vibration peak with the minimum difference is detected It is characterized by specifying a vibration peak with high characteristics.

  According to the first aspect of the present invention, when there are a plurality of vibration peaks in the vibration signal corresponding to opening or closing of the valve, the engine is rotated at a rotational speed higher than the predetermined rotational speed, so that the valve opening and closing operation is fast. As a result, the vibration at the time of opening and closing of the valve increases. As a result, the amplitude value of the vibration peak obtained from the vibration sensor becomes large, and a sufficient amplitude difference is generated between the vibration peak and other vibration peaks. Therefore, since one vibration peak can be easily extracted by setting the threshold value to an appropriate height, when there are a plurality of intake valves and exhaust valves (for example, two each) in one cylinder. However, it is possible to accurately evaluate the opening / closing timing of the intake valve and the exhaust valve, that is, the valve clearance. Moreover, since the engine is normally rotated at a predetermined rotational speed and is rotated at a rotational speed higher than the predetermined rotational speed only when there are a plurality of vibration peaks, the water pump or the like can be set by appropriately setting the rotational speed. Can be avoided.

  According to the second aspect of the present invention, the valve has a simple and inexpensive configuration having a rotation drive unit, a vibration detection unit, a square processing unit, an envelope processing unit, a crank angle calculation unit, a waveform analysis unit, a rotation control unit, and an evaluation unit. It is possible to reliably evaluate the opening / closing timing of the motor, and the components other than the rotation drive means, vibration detection means, and rotation control means can be configured with a personal computer, for example, so that the configuration can be further simplified. It becomes.

  According to the invention of claim 3, when there are a plurality of vibration peaks in the vibration signal corresponding to the opening or closing of the valve, the vibration peak with high stability is specified from the vibration signal for a plurality of rotations of the engine. It is possible to reliably identify the vibration peak that occurs when the valve is opened and closed. In other words, the vibration peak that occurs when the valve is actually opened or closed has the property that the stability at each engine rotation is higher than other vibration peaks such as noise. By specifying a vibration peak with high stability from the above, it is possible to reliably specify the vibration peak that occurs when the valve is actually opened or closed. Therefore, even when a plurality of vibration peaks appear, it is possible to accurately evaluate the valve opening / closing timing, that is, the valve clearance.

  According to the invention of claim 4, when a plurality of vibration peaks are generated, the generation timing at which the difference between the maximum value and the minimum value of the vibration peak having the same generation timing for the plurality of rotations of the engine is minimum is minimized. Since the vibration peak is specified as a vibration peak with high stability, the vibration peak generated when the valve is actually opened or closed can be easily and reliably specified.

  According to the invention of claim 5, the valve opening / closing timing is reliably evaluated with a simple and inexpensive configuration having vibration detecting means, square processing means, envelope processing means, crank angle calculating means, waveform analyzing means, and evaluating means. In addition, since the components other than the vibration detection means can be configured with a personal computer, for example, the configuration can be further simplified.

  According to the invention of claim 6, when there are a plurality of vibration peaks, the waveform analysis means minimizes the difference between the maximum value and the minimum value of the vibration peak having the same generation timing for a plurality of rotations of the engine. Since the vibration peak at the generation timing is specified as a highly stable vibration peak, the vibration peak generated when the valve is actually opened or closed can be reliably specified with a simple configuration.

Embodiments of an engine valve opening / closing timing evaluation method and a valve opening / closing timing evaluation apparatus according to the present invention will be described below with reference to the drawings.
(First embodiment)
1 and 2 show a first embodiment of the present invention. FIG. 1 is a functional block diagram showing a schematic configuration of a valve opening / closing timing evaluation apparatus, and FIG. 2 is a signal waveform diagram for explaining its operation. is there.

  In the present embodiment, as shown in FIG. 1, a vibration sensor 2 as a vibration detecting means is attached in the vicinity of a valve of the engine 1 as a sample, and the engine 1 is rotated by a rotation driving means 3 made of, for example, an electric motor. While detecting the vibration of the engine 1. The rotation drive unit 3 is controlled by the rotation control unit 4 to control the rotation speed of the engine 1. In FIG. 1, only the vibration sensor 2 corresponding to one valve is shown for the sake of clarity.

  The vibration signal detected by the vibration sensor 2 is amplified by an amplifier 5, and then unnecessary noise components are removed by a high-pass filter (HPF) 6 and a low-pass filter (LPF) 7, and a personal computer (PC). Is taken into the arithmetic unit 11 including. Further, the calculation device 11 takes in a cylinder discrimination signal and a crank angle detection signal output from the engine 1.

  The arithmetic unit 11 includes a crank angle calculation unit 12, a square processing unit 13, an envelope processing unit 14, a waveform analysis unit 15, an evaluation unit 16, and a display unit 17, and includes a crank angle detection signal from the engine 1 and cylinder discrimination. The signal is supplied to the crank angle calculation means 12 to calculate the crank angle, and the calculated crank angle is supplied to the waveform analysis means 15.

  The vibration signal output from the LPF 7 is supplied to the square processing means 13, squared here, and then envelope processed by the envelope processing means 14 and supplied to the waveform analysis means 15.

  Based on the vibration signal waveform obtained from the envelope processing means 14 and the crank angle from the crank angle calculation means 12, the waveform analysis means 15 generates vibration signal waveforms corresponding to the opening and closing of the evaluation target valve according to a predetermined threshold. Whether or not there is only one vibration peak is determined, and if there is only one vibration peak based on the determination result, the crank angle corresponding to the vibration peak occurrence timing is detected and the evaluation means 16 When there are a plurality of vibration peaks, the rotational speed of the engine 1 is controlled by the rotation driving means 3 via the rotation control means 4.

  The evaluation unit 16 evaluates the opening / closing timing of the evaluation target valve corresponding to the vibration sensor 2, that is, the valve clearance based on the crank angle detected by the waveform analysis unit 15, and displays the evaluation result on the display unit 17. The evaluation of the valve opening / closing timing by the evaluation means 16 is performed by inputting cam profile data in advance as disclosed in Patent Document 1, for example, and the cam profile data and the crank angle detected by the waveform analysis means 15. Based on the comparison of.

  Next, an outline of the operation of the valve opening / closing timing evaluation apparatus according to the present embodiment will be described.

  In the present embodiment, first, the rotation control unit 4 drives the rotation driving unit 3 to rotate the engine 1 at a preset first rotation number that is a predetermined rotation number. The first rotational speed is a rotational speed in a normal test operation, and is set to a relatively low rotational speed within a predetermined rotational speed region that does not cause problems such as wear on the water pump or the like.

  In this state, the vibration sensor 2 detects the vibration of the engine 1 in the vicinity of the valve, and the waveform analysis unit 15 first sets the vibration signal waveform corresponding to each of the opening and closing of the evaluation target valve to a first threshold (for example, FIG. 6 threshold V1), it is determined whether there is only one or more vibration peaks.

  Here, when there is only one vibration peak, next, a crank angle corresponding to the vibration peak occurrence timing is detected and supplied to the evaluation means 16.

  On the other hand, when there are a plurality of vibration peaks, the rotation control means 4 controls the rotation driving means 3 to make the engine 1 higher than the first rotation speed within the predetermined rotation speed range. The rotation is performed at a second rotation number, for example, twice the first rotation number.

  Thus, when the engine speed is doubled, the opening / closing speed of the valve is also doubled, and the vibration at the time of opening and closing of the valve increases accordingly, so that the vibration signal corresponding to the opening or closing of the valve is increased. The waveform is as shown by a solid line in FIG. That is, the amplitude value of the vibration peak when the valve is opened or closed is larger than that at the first rotational speed indicated by the broken line, and a sufficient amplitude difference is generated between the vibration peak and other vibration peaks. become. In FIG. 2, the horizontal axis represents the crank angle (° CA), and the vertical axis represents the vibration level.

  The waveform analysis unit 15 determines whether the vibration signal waveform corresponding to each of the opening and closing of the evaluation target valve at the second rotation number has only one or a plurality of vibration peaks according to the second threshold value V2 (V2> V1). If there is only one vibration peak, the crank angle corresponding to the generation timing is detected and supplied to the evaluation means 16.

  In the vibration signal waveform at the second rotational speed, when there are a plurality of vibration peaks at the second threshold value V2, the threshold value is sequentially increased so that only one vibration peak appears, or Then, the rotational speed of the engine 1 is sequentially increased within the predetermined rotational speed region, and the threshold value is sequentially increased accordingly so that only one vibration peak appears.

  As described above, when the waveform analysis unit 15 detects the crank angle when the evaluation target valve is opened and closed, the evaluation unit 16 evaluates the opening / closing timing of the valve, that is, the valve clearance based on the crank angle. Then, the evaluation result is displayed on the display unit 17.

  As described above, in this embodiment, normally, the opening / closing timing of the valve is evaluated while rotating the engine 1 at the first rotational speed, and the first rotational speed vibrates in the vibration signal corresponding to the opening or closing of the valve. When there are a plurality of peaks, the engine 1 is rotated at a rotational speed higher than the first rotational speed within the predetermined rotational speed range, so that vibration peaks corresponding to the opening and closing of the valve can be easily performed. And it can extract reliably. Therefore, even when there are a plurality of intake valves and exhaust valves (for example, two each) in one cylinder, it is possible to accurately evaluate the opening / closing timing of the intake valves and the exhaust valves, that is, the valve clearance. In addition, normally, the engine 1 is rotated at the first rotation speed that is a low rotation speed, and only when there are a plurality of vibration peaks, the rotation speed higher than the first rotation speed is within the predetermined rotation speed region. Since it is rotated, it is possible to avoid problems with water pumps and the like.

  In addition, the arithmetic device 11 having the crank angle calculation means 12, the square processing means 13, the envelope processing means 14, the waveform analysis means 15, the evaluation means 16, and the display unit 17 can be configured with a PC, so that the entire apparatus Can be made easily and cheaply.

(Second Embodiment)
FIGS. 3 to 5 show a second embodiment of the present invention. FIG. 3 is a functional block diagram showing a schematic configuration of the valve opening / closing timing evaluation apparatus. FIG. 4 is a signal waveform diagram for explaining the operation. FIG. 5 is a diagram for explaining the operation.

  In the present embodiment, as shown in FIG. 3, a vibration sensor 2 that is a vibration detecting means is attached in the vicinity of a valve of the engine 1 that is a sample, and the engine 1 is, for example, an electric motor, as in the first embodiment. The vibration of the engine 1 is detected while being rotated by the rotation driving means. In FIG. 3, only the vibration sensor 2 corresponding to one valve is shown for the sake of clarity.

  As in the first embodiment, the vibration signal detected by the vibration sensor 2 is amplified by the amplifier 5, then unnecessary noise components are removed by the HPF 6 and the LPF 7, and an operation including a personal computer (PC) is performed. Capture to device 21. Further, the arithmetic unit 21 receives a cylinder discrimination signal and a crank angle detection signal output from the engine 1.

  The arithmetic unit 21 includes a crank angle calculation unit 22, a square processing unit 23, an envelope processing unit 24, a waveform analysis unit 25, an evaluation unit 26, and a display unit 27. A crank angle detection signal and cylinder discrimination from the engine 1 are provided. The signal is supplied to the crank angle calculation unit 22 to calculate the crank angle, and the calculated crank angle is supplied to the waveform analysis unit 25.

  The vibration signal output from the LPF 7 is supplied to the square processing means 23, squared here, and then envelope processed by the envelope processing means 24 and supplied to the waveform analysis means 25.

  Based on the vibration signal waveform obtained from the envelope processing means 24 and the crank angle from the crank angle calculation means 22, the waveform analysis means 25 has vibration peaks in the vibration signal waveforms corresponding to the opening and closing of the valve to be evaluated. Based on the determination result, if there is one vibration peak, the crank angle corresponding to the generation timing of the vibration peak is detected and supplied to the evaluation means 26, and the vibration peak is determined. If there are a plurality of the engine 1, a highly stable vibration peak is identified based on the vibration signal waveform for a plurality of revolutions of the engine 1, and a crank angle corresponding to the occurrence timing of the identified vibration peak is detected and evaluated. 26.

  In the present embodiment, when there are a plurality of vibration peaks in the vibration signal waveform corresponding to each of the opening and closing of the evaluation target valve in the waveform analysis means 25, each of the vibration signal waveforms from the vibration signal waveform for each rotation of the engine 1. The peak value of the vibration peak is detected, the difference between the maximum value and the minimum value of the peak value of the vibration peak having the same generation timing is obtained for a plurality of revolutions of the engine 1, and the vibration peak of the generation timing with the minimum difference is obtained. A vibration peak having high stability is identified, and a crank angle corresponding to the generation timing of the vibration peak is detected.

  Based on the crank angle detected by the waveform analysis unit 25, the evaluation unit 26 evaluates the opening / closing timing of the evaluation target valve corresponding to the vibration sensor 2, that is, the valve clearance, as in the first embodiment, and evaluates the evaluation. The result is displayed on the display unit 27.

  Next, an outline of the operation of the valve opening / closing timing evaluation apparatus according to the present embodiment will be described.

  In the present embodiment, while the engine 1 is rotated, the vibration sensor 2 detects the vibration of the engine 1 in the vicinity of the valve. Based on the vibration signal, the waveform analysis unit 25 first opens and closes the evaluation target valve. It is determined whether there is only one or a plurality of vibration peaks in the vibration signal waveform corresponding to each.

  Here, when there is only one vibration peak, next, the crank angle corresponding to the generation timing is detected and supplied to the evaluation means 26.

  On the other hand, when there are a plurality of vibration peaks, the peak value of each vibration peak is detected from the vibration signal waveform for each rotation of the engine 1, and the generation timings of the vibration peaks having substantially the same timing for the plurality of rotations of the engine 1 are detected. Find the difference between the maximum and minimum peak values, identify the vibration peak with the smallest occurrence timing as a highly stable vibration peak, and detect the crank angle corresponding to the vibration peak occurrence timing. .

  That is, the vibration peak that occurs when the valve is actually opened or closed has a property that the stability at each rotation of the engine 1 is higher than that of other vibration peaks such as noise as shown in FIG. Therefore, when there are a plurality of vibration peaks, the peak values of the plurality of vibration peaks are first obtained for each rotation of the engine 1 by utilizing the property of high stability. Thereafter, for a plurality of rotations of the engine 1, for example, for 4 rotations, as shown in FIG. 5, the maximum value and the minimum value of the peak values of the vibration peaks having substantially the same generation timing are detected and the difference between them is obtained. The vibration peak at the generation timing with the smallest difference is identified as a vibration peak with high stability, and the crank angle corresponding to the generation timing of the vibration peak is detected. 4 and 5, the horizontal axis indicates the crank angle (° CA), and the vertical axis indicates the vibration level.

  As described above, the waveform analysis unit 25 detects the crank angle when the evaluation target valve is opened and closed, and the evaluation unit 26 uses the crank angle based on the crank angle to detect the valve as in the first embodiment. The valve opening / closing timing, that is, the valve clearance is evaluated, and the evaluation result is displayed on the display unit 27.

  As described above, in the present embodiment, when there are a plurality of vibration peaks in the vibration signal corresponding to the opening or closing of the valve in the waveform analysis means 25, vibrations having substantially the same generation timing for a plurality of rotations of the engine 1 are performed. Since the vibration peak at the occurrence timing at which the difference between the maximum peak value and the minimum value of the peak is the minimum is extracted and the crank angle corresponding to the occurrence timing is detected, the actual opening of the valve or The crank angle of the vibration peak generated at the time of closing can be detected easily and reliably. Therefore, even when there are a plurality of intake valves and exhaust valves (for example, two each) in one cylinder, it is possible to accurately evaluate the opening / closing timing of the intake valves and the exhaust valves, that is, the valve clearance.

  In addition, the computing device 21 having the crank angle calculating means 22, the square processing means 23, the envelope processing means 24, the waveform analyzing means 25, the evaluating means 26, and the display unit 27 is similar to the PC of the first embodiment. The entire apparatus can be made simple and inexpensive.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention. For example, in the second embodiment, when there are a plurality of vibration peaks in the vibration signal corresponding to the opening or closing of the valve, the maximum peak value of the vibration peak having substantially the same generation timing for a plurality of rotations of the engine 1 is obtained. The difference from the minimum value was obtained, and the vibration peak at the generation timing at which the difference was the minimum was specified as the vibration peak that occurs when the valve is actually opened or closed. The peak value can be statistically processed to identify a vibration peak with high stability based on a statistic such as a standard deviation.

It is a functional block diagram which shows schematic structure of the valve opening / closing timing evaluation apparatus of the engine which concerns on 1st Embodiment of this invention. It is a signal waveform diagram for demonstrating operation | movement of 1st Embodiment. It is a functional block diagram which shows schematic structure of the valve opening / closing timing evaluation apparatus of the engine which concerns on 2nd Embodiment of this invention. It is a signal waveform diagram for demonstrating operation | movement of 2nd Embodiment. Similarly, it is a figure for demonstrating operation | movement of 2nd Embodiment. It is a figure for demonstrating the subject which this invention tends to solve.

Explanation of symbols

1 Engine 2 Vibration sensor (vibration detection means)
3 Rotation drive means 4 Rotation control means 5 Amplifier 6 High pass filter (HPF)
7 Low-pass filter (LPF)
DESCRIPTION OF SYMBOLS 11 Computation device 12 Crank angle calculation means 13 Square processing means 14 Envelope processing means 15 Waveform analysis means 16 Evaluation means 17 Display part 21 Computation device 22 Crank angle calculation means 23 Square processing means 24 Envelope processing means 25 Waveform analysis means 26 Evaluation Means 27 Display unit

Claims (6)

An engine that detects engine vibration in the vicinity of the valve while rotating the engine at a predetermined rotational speed, and evaluates the opening / closing timing of the valve based on the occurrence timing of the vibration peak in the vibration signal corresponding to each opening and closing of the valve. In the valve opening / closing timing evaluation method,
It is determined whether or not there are a plurality of vibration peaks in the vibration signal corresponding to each of the opening and closing of the valve. A valve opening / closing timing evaluation method for an engine, characterized in that the valve opening / closing timing is evaluated by rotating. Rotational drive means for rotating the engine;
Vibration detecting means for detecting vibration in the vicinity of the valve of the engine;
A square processing means for squaring a vibration signal detected by the vibration detection means;
Envelope processing means for performing envelope processing on the output waveform of the square processing means;
Crank angle calculating means for calculating the crank angle of the engine;
Based on the vibration signal waveform obtained from the envelope processing means and the crank angle calculated by the crank angle calculating means, the vibration signal waveform corresponding to each of the opening and closing of the valve has only one or more vibration peaks. Waveform analysis means for determining whether or not there is a crank angle corresponding to the vibration peak occurrence timing when there is only one vibration peak based on the determination result;
Rotation control means for controlling the rotation drive means to increase the engine speed when there are a plurality of vibration peaks based on the determination result of the waveform analysis means;
Evaluation means for evaluating the opening / closing timing of the valve based on the crank angle detected by the waveform analysis means;
A valve opening / closing timing evaluation apparatus for an engine characterized by comprising: A valve opening / closing timing evaluation method for an engine that detects vibration in the vicinity of a rotating engine valve and evaluates the opening / closing timing of the valve based on the generation timing of a vibration peak in a vibration signal corresponding to each of opening and closing of the valve. In
It is determined whether or not there are a plurality of vibration peaks in the vibration signal corresponding to each of the opening and closing of the valve. A valve opening / closing timing evaluation method for an engine, characterized by identifying a vibration peak having high characteristics and evaluating valve opening / closing timing.   When there are a plurality of vibration peaks, the peak value of each vibration peak is detected from the vibration signal for each rotation of the engine, and the peak value of the vibration peak having the same generation timing for the plurality of rotations of the engine is detected. 4. The engine valve opening / closing timing evaluation method according to claim 3, wherein a difference between a maximum value and a minimum value is obtained, and a vibration peak at a generation timing with the smallest difference is identified as the vibration peak having high stability. Vibration detecting means for detecting vibration near the valve of the rotating engine;
A square processing means for squaring the vibration signal detected by the vibration detection means;
Envelope processing means for performing envelope processing on the output waveform of the square processing means;
Crank angle calculating means for calculating the crank angle of the engine;
Based on the vibration signal waveform obtained from the envelope processing means and the crank angle calculated by the crank angle calculating means, the vibration signal waveform corresponding to each of the opening and closing of the valve has only one or more vibration peaks. If there is one vibration peak based on the determination result, the crank angle corresponding to the generation timing of the vibration peak is detected. If there are a plurality of vibration peaks, multiple rotations of the engine are performed. Waveform analysis means for identifying a highly stable vibration peak based on the vibration signal in minutes and detecting a crank angle corresponding to the occurrence timing of the identified vibration peak;
Evaluation means for evaluating the opening / closing timing of the valve based on the crank angle detected by the waveform analysis means;
A valve opening / closing timing evaluation apparatus for an engine characterized by comprising:   The waveform analysis means detects a peak value of each vibration peak from the vibration signal for each rotation of the engine when there are a plurality of vibration peaks, and vibrations having substantially the same generation timing for the plurality of rotations of the engine. 6. The engine valve according to claim 5, wherein a difference between a maximum value and a minimum value of a peak value of a peak is obtained, and a vibration peak at a generation timing with the smallest difference is specified as the vibration peak having high stability. Opening / closing timing evaluation device.

Images