JP2004293346A - Engine valve timing measuring device and engine valve timing measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine valve timing measuring device and an engine valve timing measuring method capable of easily measuring a valve lift volume of a supply/exhaust valve and estimating data even in an engine having a plurality of cylinders. <P>SOLUTION: This device comprises an encoder (crank angle measuring sensor) 9 measuring a crank angle of the engine; a non-contact type sensor (valve lift volume measuring sensor) 18 measuring a supply/exhaust valve lift volume; and a judging device for finding a difference between a target lift volume of the supply/exhaust valve relative to a crank angle measured by the encoder and a valve lift volume measured by the non-contact type sensor, and estimating whether the difference is within a tolerance or not so as to judge need of adjusting a cam of the supply/exhaust valve. A crankshaft is turned by one cycle, and the data of each of the supply/exhaust valve lift volume are fetched and compared with the target valve lift volume, to judge the need of adjusting the cam. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an engine valve timing measurement device and an engine valve timing measurement method for adjusting the opening / closing timing of a supply / exhaust valve during engine production.
[0002]
[Prior art]
During engine production, the operation of the supply / exhaust valve is measured to adjust the cam operation of the supply / exhaust valve.
As a conventional technique for measuring the operation of the supply / exhaust valve, there is a technique described in Japanese Patent Application Laid-Open No. 9-88528. In this technique, a rotation angle of a cam shaft of a supply / exhaust valve and a displacement amount of the supply / exhaust valve are detected. Then, the relationship between the rotation angle of the camshaft and the valve stroke is obtained, and the open position, the closed position, and the position of the inflection point of the supply / exhaust valve are obtained. Thereby, the distance from the zero valve stroke line when the valve opening / closing timing occurs is actually measured.
[0003]
[Patent Document 1]
JP-A-9-88528
[Problems to be solved by the invention]
However, in the conventional measuring method, since the rotation angle of the camshaft is used as a reference, it is necessary to measure each cylinder in an engine having a plurality of cylinders, and it is difficult to measure a plurality of cylinders simultaneously.
Further, in the above-described measuring method, the movement of the supply / exhaust valve is simply measured, and the evaluation of the measurement result is not performed.
[0005]
The present invention has been made in view of the above circumstances, and is an engine capable of easily measuring a valve lift amount of a supply / exhaust valve even in an engine having a plurality of cylinders and further performing data evaluation. It is an object to provide a valve timing measurement device and an engine valve timing measurement method.
[0006]
[Means for Solving the Problems]
The engine valve timing measurement device according to claim 1, wherein the crank angle measurement sensor measures an engine crank angle, the valve lift amount measurement sensor measures an intake / exhaust valve lift amount, and the crank angle measurement sensor measures the crank angle measurement sensor. The difference between the target lift amount of the supply / exhaust valve with respect to the crank angle and the valve lift amount measured by the valve lift amount measurement sensor is determined, and whether or not this difference is within an allowable range is evaluated to determine whether the difference is within the allowable range. A determination device for determining whether or not there is a cam adjustment.
[0007]
The supply and exhaust valves must move in synchronization with the crankshaft timing. That is, when the crank angle is a certain value, it is necessary to adjust the lift amount of the supply / exhaust valve so as to be within a predetermined allowable value at the crank angle.
The determination device calculates a difference between the target lift amount with respect to the crank angle and the actual (pre-adjustment) lift amount of the air supply / exhaust valve, and this difference (the difference between the target amount and the actual value) is within a predetermined range. It is determined whether or not.
[0008]
According to a second aspect of the present invention, in the engine valve timing measuring apparatus according to the first aspect, the determination device determines a cam based on a relationship between a valve lift amount and a cam rotation angle when the calculated difference is not within an allowable range. The adjustment amount is calculated.
[0009]
When the intake / exhaust valve is not synchronized with the timing of the crankshaft, a large difference between the valve lift amount and the target value is detected. Since the valve lift corresponds to the rotation angle of the cam that lifts the supply / exhaust valve, the determination device calculates how much the cam should be displaced with respect to the cam shaft from the deviation of the valve lift. This allows the operator to easily adjust the cam.
[0010]
According to a third aspect of the present invention, in the engine valve timing measurement apparatus according to the first or second aspect, the determination device obtains a difference between a valve lift amount and a target lift amount at a crank angle at which the cylinder becomes TDC. It is characterized by.
[0011]
In the present invention, the timing at which the determination device measures the lift amount of the supply / exhaust valve is based on the time when the crank angle is TDC (Top Dead Center; top dead center). In TDC (exhaust TDC in the case of a four-cycle engine), both the intake valve and the exhaust valve have a predetermined lift amount of zero or more, so the lift amount is measured.
[0012]
According to a fourth aspect of the present invention, in the engine valve timing measuring apparatus according to any one of the first to third aspects, the determination device is configured to determine that one cylinder is a TDC based on a crank angle at which one cylinder is TDC. The crank angle at which another cylinder becomes TDC is determined from the relative crank angle of the cylinder, and the difference between the supply / exhaust valve lift amount and the target lift amount at each TDC position of each cylinder is evaluated.
[0013]
If the crank angle at which one cylinder becomes TDC is known, the crank angle at which the other cylinder becomes TDC can be determined by using the data of each cylinder (the relative crank angle relationship between one cylinder and another cylinder). Therefore, by using the crank angle of one cylinder as a reference, it is possible to measure the difference between the lift amount of the supply / exhaust valve in TDC and the target value in each of the other cylinders.
[0014]
According to a fifth aspect of the present invention, in the engine valve timing measuring device according to the fourth aspect, a storage device for storing a TDC timing table of each cylinder for each type of engine is provided, and the determination device is configured to execute the TDC timing. Referring to a table, a crank angle at which one cylinder becomes TDC is obtained based on a crank angle at which one cylinder becomes TDC.
[0015]
In the present invention, since cylinder data (relative crank angle relationship between one cylinder and another cylinder) for each type of engine is stored in the storage device in advance, the type of engine that the operator intends to measure, and the like. To the determination device, the determination device can measure the difference between the lift amount of the supply / exhaust valve in the TDC and the target value for each cylinder of the engine.
[0016]
According to a sixth aspect of the present invention, in the engine valve timing measuring device according to any one of the first to fifth aspects, the determination device determines a movement of the supply / exhaust valve when the crank of the engine is rotated for one cycle. It is characterized in that a lift amount position of the air supply / exhaust valve is calculated from this data and a difference between a relative lift amount and a target lift amount of the air supply / exhaust valve from the zero lift amount position is evaluated.
[0017]
By determining the lift amount zero position (cam reference position) by the determination device, the lift amount (= relative displacement from the lift amount zero position) of the supply / exhaust valve can be determined. Therefore, by rotating the crank for one cycle, the correspondence between the lift amount of the supply / exhaust valve and the crank angle is obtained, and the relationship between the lift amount of the supply / exhaust valve and the target lift amount at a predetermined crank angle (for example, TDC) is obtained. By taking the difference, the cam adjustment amount can be evaluated.
Further, when the crank rotates one cycle, the lift amounts of the supply / exhaust valves of a plurality of cylinders can be simultaneously measured and data can be taken in. Therefore, the crank angle at which each cylinder becomes TDC is obtained as in the invention of claim 5. Thus, the evaluation of the lift amount in the TDC of each cylinder can be performed only by rotating the crank for one cycle.
[0018]
In the engine valve timing measurement method according to the present invention, the lift amount of the supply / exhaust valve with respect to the crank angle of the engine is measured, and the difference between the lift amount of the supply / exhaust valve and the target lift amount is taken as an allowable value. It is characterized in that it is evaluated whether or not cam adjustment of the supply / exhaust valve is performed.
[0019]
The supply and exhaust valves must move in synchronization with the crankshaft timing. That is, when the crank angle is a certain value, it is necessary to adjust the lift amount of the supply / exhaust valve so as to be within a predetermined allowable value at the crank angle.
In the present invention, the difference between the target lift amount with respect to the crank angle and the actual (pre-adjustment) lift amount of the supply / exhaust valve is determined, and this difference (the difference between the target amount and the actual value) is within a predetermined range. It is determined whether or not there is.
[0020]
According to an eighth aspect of the present invention, in the engine valve timing measuring method according to the seventh aspect, when the difference between the lift amount of the supply / exhaust valve and the target lift amount is not within an allowable range, the valve lift amount and the cam are set. A cam adjustment amount is calculated from a relationship with the rotation angle.
[0021]
When the intake / exhaust valve is not synchronized with the timing of the crankshaft, a large difference between the valve lift amount and the target value is detected. Since the valve lift and the rotation angle of the cam that lifts the supply / exhaust valve correspond to each other, it is possible to calculate how much the cam should be shifted with respect to the camshaft from the difference between the valve lift and the target value. .
[0022]
According to a ninth aspect of the present invention, in the engine valve timing measuring method according to the seventh or eighth aspect, a difference between a lift amount of the supply / exhaust valve and a target lift amount at a crank angle of the engine whose cylinder is TDC is evaluated. It is characterized by the following.
[0023]
In the present invention, the timing when the lift amount of the supply / exhaust valve is measured is based on the time when the crank angle is TDC. In TDC (exhaust TDC in the case of a four-cycle engine), both the intake valve and the exhaust valve have a predetermined lift amount of zero or more, so the lift amount is measured.
[0024]
According to a tenth aspect of the present invention, in the engine valve timing measurement method according to the ninth aspect, the crank angle at which one cylinder is TDC is used as a reference, and the crank angle of the one cylinder and the other cylinder is calculated based on the other crank angle. It is characterized in that a crank angle at which a cylinder becomes TDC is obtained, and a difference between a supply / exhaust valve lift amount and a target lift amount is evaluated at a TDC position of each cylinder.
[0025]
If the crank angle at which one cylinder becomes TDC is known, the crank angle at which the other cylinder becomes TDC can be determined by using the data of each cylinder (the relative crank angle relationship between one cylinder and another cylinder). Therefore, by using the crank angle of one cylinder as a reference, it is possible to measure the difference between the lift amount of the supply / exhaust valve in TDC and the target value in each of the other cylinders.
[0026]
According to an eleventh aspect of the present invention, in the engine valve timing measuring method according to any one of the seventh to tenth aspects, the movement of the supply / exhaust valve when the crank is rotated for one cycle is recorded, and the recording is performed based on the recording. Is calculated, and the difference between the relative displacement of the supply / exhaust valve from the zero lift amount position and the target lift amount is evaluated.
[0027]
By determining the lift amount zero position (cam reference position) by the determination device, the lift amount (= relative displacement from the lift amount zero position) of the supply / exhaust valve can be determined. Therefore, by rotating the crank for one cycle, the correspondence between the lift amount of the supply / exhaust valve and the crank angle is obtained, and the difference between the lift amount of the supply / exhaust valve and the target lift amount at a predetermined crank angle (for example, TDC) is obtained. By taking the difference, the cam adjustment amount can be evaluated.
Further, since the lift amounts of the supply / exhaust valves of a plurality of cylinders can be simultaneously measured and recorded when the crank rotates one cycle, it is necessary to obtain the crank angle at which each cylinder becomes TDC as in the invention of claim 10. Thereby, the evaluation of the lift amount in the TDC of each cylinder can be performed only by rotating the crank for one cycle.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
In the present embodiment, the valve timing is measured as follows.
FIG. 1 shows a valve timing measurement procedure using the valve timing measurement device according to the present embodiment. In this procedure, an encoder (crank angle measurement sensor) is attached to the free end of the crankshaft in step ST1, and 0 degree of the crankshaft is set in step ST2. Next, at step ST3, a valve lift measuring sensor for measuring the lift is attached, and at step ST4, the lift of the supply / exhaust valve is measured and evaluated. First, the configuration of the engine with the encoder and the valve lift measurement sensor attached will be described below.
[0029]
FIG. 2 shows a diesel engine. The diesel engine 1 includes a cylinder 2, a piston 3, a crankshaft 5, a connecting rod 6, and a camshaft 7 as main components. The present diesel engine 1 includes a plurality of cylinders 2 on the left and right sides, respectively.
The crankshaft 5 converts a reciprocating motion of the piston 3 into a rotary motion, and is connected to the piston 3 via a piston pin 3a and a connecting rod 6.
At one end of the crankshaft 5, an encoder (crank angle measuring sensor) 9 for detecting a rotation angle of the crankshaft 5 is provided. The encoder 9 is attached when measuring the lift amount of the supply / exhaust valve.
The camshaft 7 is arranged so that its rotation axis is substantially parallel to the rotation axis of the crankshaft 5, and rotates in accordance with the rotation of the crankshaft 5. 7a and an exhaust valve driving cam 7b are provided.
Rollers 10a provided below the push rod 10 are in contact with the air supply valve driving cams 7a, respectively. The air supply valve 11 is driven by an air supply valve driving cam 7a via a roller 10a, a push rod 10, and a rocker arm 12, respectively.
The exhaust valve 13 is also driven by the same mechanism as the above-described air supply valve 11. That is, the roller 10a provided below the push rod 10 is also in contact with the exhaust valve driving cam 7b. The exhaust valve 13 is driven by an exhaust valve driving cam 7b via a roller 10a, a push rod 10, and a rocker arm 12, respectively.
[0030]
FIG. 3 is an enlarged view of a portion A in FIG. Reference numeral 15 denotes a spring that applies an urging force opposing the cam 7a to the air supply valve 11, and reference numeral 16 denotes a spring receiver. Reference numeral 18 denotes a non-contact type sensor (a valve lift measuring sensor) that detects the displacement of the spring receiver 16, that is, the lift of the air supply valve 11. As this sensor, an optical or magnetic linear immediate-length gauge such as a laser interferometer can be used.
The non-contact sensor 18 is attached to the supply / exhaust valves 11 and 13 of each cylinder 2 when measuring the lift amount of the supply / exhaust valves.
[0031]
The encoder 9 in FIG. 2 and the non-contact sensor 18 in FIG. 3 form a part of an engine valve timing measuring device.
FIG. 4 shows the configuration of the engine valve timing measurement device 20. In the figure, reference numeral 21 denotes a measuring device main body, which includes a determining device 22, an input / output device 23, and a storage device 24. The output of the non-contact sensor 18 for detecting the lift amount of the supply valve 11 and the exhaust valve 13 of each cylinder and the output of the encoder 9 for detecting the angle of the crankshaft 5 are input to the determination device 22. The input / output device 23 is a device that displays a screen, receives an instruction from an operator, and the like, and the storage device 24 stores a TDC timing table of each cylinder for each type of engine.
[0032]
Next, an engine valve timing measurement method using the engine valve timing measurement device 20 of the present embodiment will be described.
In the present engine valve timing measurement method, a worker performs a predetermined operation according to an instruction on a monitor screen provided in the input / output device 23. The initial setting screen is as shown in FIG. The operator inputs the construction number and the delivery destination of the engine in the input box 25, and then selects the type of the engine to be measured and the number of cylinders from the button groups 26 and 27, respectively.
Next, the screen shifts to the measurement screen shown in FIG. In FIG. 6, reference numeral 28 denotes a button for each cylinder name, reference numeral 29 denotes a column for displaying whether the lift amount of the supply / exhaust valves 11 and 13 is within an allowable range, and reference numeral 30 denotes a button for setting 0 ° of the crankshaft. , 31 are columns for displaying that the lift is being measured, and 32 is a button to be pressed when the lift amount is measured again.
[0033]
Next, a procedure for measuring the valve timing according to the procedure of FIG. 1 will be described.
First, the operator attaches the encoder 9 to the free end of the crankshaft 5 (step ST1). The state in which the encoder 9 is attached has already been shown in FIGS.
Next, 0 ° of the crankshaft 5 is set. When the button 30 in FIG. 6 is pressed for three seconds, the current crank angle is set to 0 °. In the present embodiment, one cylinder (hereinafter, referred to as a reference cylinder) is adjusted to the position of the exhaust TDC, and this state is set to 0 ° of the crankshaft (step ST2).
Next, the non-contact type sensor 18 is attached (step ST3). The state where the non-contact type sensor 18 is attached is already shown in FIG.
[0034]
Next, the lift amounts of the supply / exhaust valves 11, 13 are measured and evaluated (step ST4).
First, the cylinder name button 28 of the cylinder to be measured is pressed and selected from FIG.
The crankshaft 5 is turned and rotated for one cycle. In this embodiment, it is rotated by 720 °. The determination device 22 captures the data of each sensor 18 and the encoder 9 and obtains the relationship between the crank angle for each cylinder and the lift amount of the supply / exhaust valves 11 and 13 shown in FIG. When the number of cylinders is N, N data are obtained. Although each cylinder has a different exhaust TDC timing, since the crank angle 0 ° is the exhaust TDC of the reference cylinder, the relationship between the exhaust TDC and the crank angle of the other cylinders is different for each type of engine that the storage device 24 has. It is calculated from the TDC timing table of each cylinder.
The determination device 22 evaluates the lift amount of the supply / exhaust valves 11 and 13 of each cylinder as follows. FIG. 8 shows an enlarged view of the vicinity of the exhaust TDC of the reference cylinder of FIG. Hereinafter, evaluation of the reference cylinder will be described with reference to FIG. 8, but the following evaluation is performed for each cylinder.
(1) A position where the lift amount of the air supply / exhaust valves 11, 13 is not changed is defined as a zero lift amount position (cam reference position) of the air supply / exhaust valves 11, 13. That is, the zero position on the vertical axis in FIG. 8 is determined.
(2) The lift amount of the supply / exhaust valves 11 and 13 at the exhaust TDC is obtained. That is, the relative displacement from the zero position obtained in (1) is obtained. This is the amount indicated by reference numeral 35 in FIG.
(3) The lift amount obtained in (2) is compared with the target lift amount of the supply / exhaust valves 11 and 13 included in the storage device 24 for evaluation. When these differences are not within the allowable range, the predetermined position in the column 29 of FIG. 6 is displayed in red, and when the difference is within the allowable range, it is displayed in blue (step ST5).
(4) The worker adjusts the cams 7a and 7b that are not within the allowable range (step ST6).
(5) Select the cylinder that needs re-measurement from the cylinder name button 28, press the button 32 to perform re-measurement, and confirm that the adjusted lift amount of the supply / exhaust valves 11, 13 is within the allowable range.
[0035]
As described above, in the present embodiment, the lift amounts of the supply / exhaust valves 11, 13 of all the cylinders can be easily measured and evaluated only by turning the crankshaft 5 for one cycle. In particular,
By calculating the zero lift position (cam reference position) of the supply / exhaust valves 11, 13, the valve lift can be automatically calculated.
The determination device 22 automatically evaluates the cam adjustment amount by comparing the lift amount of the supply / exhaust valves 11 and 13 with the target lift amount.
The exhaust TDC positions of all the cylinders can be obtained simply by specifying the crank angle at which the reference cylinder becomes the exhaust TDC, and the supply / exhaust valve lift amount at the exhaust TDC position of each cylinder can be evaluated. That is, it is possible to evaluate the supply / exhaust valve lift amounts of all the cylinders only by turning the crankshaft 5 for one cycle.
-Since the TDC timing table of the cylinder for each engine is stored in the storage device 24, it is possible to evaluate the lift amount according to each engine and cylinder simply by specifying the type of engine and the number of cylinders by the operator. it can.
[0036]
Further, the following modifications can be made.
The relationship between the valve lift amount and the rotation angle of the cam that lifts the supply / exhaust valve is given to the storage device 24 in FIG. After measuring the lift amount of the supply / exhaust valves 11 and 13, the determination device 22 converts the difference between the measured lift amount of the supply / exhaust valve and the target lift amount into a cam rotation angle. That is, it is calculated how much the cam should be shifted with respect to the camshaft from the deviation of the valve lift. Then, the cam angle to be adjusted is displayed in the column 29 of FIG.
Thereby, the operator can easily proceed with the adjustment work.
[0037]
【The invention's effect】
As described above, in the present invention, even in an engine having a plurality of cylinders, the valve lift of the supply / exhaust valve can be easily measured, and the data can be evaluated.
Also, by converting the difference between the supply / exhaust valve lift amount and the target lift amount into a cam rotation angle, and calculating how much the cam should be shifted with respect to the camshaft from the deviation of the valve lift amount, the operator can easily work. The adjustment work can proceed (claims 2 and 8).
The TDC positions of all the cylinders can be obtained simply by designating the crank angle at which one cylinder becomes TDC, and the supply / exhaust valve lift amount at the TDC position of each cylinder can be evaluated. (Claims 4, 5, 10)
In addition, the valve lift amount can be automatically calculated by determining the zero lift amount position (cam reference position) of the supply / exhaust valve. Therefore, it is possible to evaluate the lift amounts of the supply / exhaust valves of all the cylinders only by turning the crankshaft for one cycle. (Claims 6 and 11)
[Brief description of the drawings]
FIG. 1 is a flowchart showing a valve timing measurement procedure using a valve timing measurement device shown as one embodiment of the present invention.
FIG. 2 is a diagram showing a diesel engine to be measured by the valve timing measuring device.
FIG. 3 is a partially enlarged view of the diesel engine.
FIG. 4 is a diagram showing a configuration of a valve timing measurement device shown as the present embodiment.
FIG. 5 is a setting screen of the valve timing measurement device.
FIG. 6 is a measurement screen of the valve timing measurement device.
FIG. 7 is a diagram showing a lift amount of a supply / exhaust valve of each cylinder with respect to a crank angle, which is measured by the valve timing measurement device.
FIG. 8 is an enlarged view of a lift amount of a supply / exhaust valve of the same cylinder in the vicinity of an exhaust TDC of a reference cylinder.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Diesel engine 2 Cylinder 3 Piston 5 Crankshaft 7 Camshaft 7a Cam 7b for air supply valve drive Cam 9 for exhaust valve drive Encoder (crank angle measurement sensor)
11 Air supply valve 16 Spring receiver 18 Non-contact type sensor (valve lift amount measurement sensor)
Reference Signs List 20 engine valve timing measurement device 22 judgment device 24 storage device

Claims (11)

A crank angle measurement sensor for measuring an engine crank angle,
A valve lift measurement sensor for measuring the supply / exhaust valve lift,
A difference between a target lift amount of the supply / exhaust valve with respect to a crank angle measured by the crank angle measurement sensor and a valve lift amount measured by the valve lift amount measurement sensor is determined, and whether the difference is within an allowable range or not. A judging device for judging the presence or absence of cam adjustment of the supply / exhaust valve by evaluating
An engine valve timing measuring device, comprising: The engine valve timing measuring device according to claim 1,
The engine valve timing measuring device, wherein the determining device calculates a cam adjustment amount from a relationship between a valve lift amount and a cam rotation angle when the calculated difference is not within an allowable range. The engine valve timing measuring device according to claim 1 or 2,
An engine valve timing measurement device according to claim 1, wherein the determination device obtains a difference between a valve lift amount and a target lift amount at a crank angle at which the cylinder becomes TDC. The engine valve timing measuring device according to any one of claims 1 to 3,
The determination device obtains a crank angle at which one cylinder becomes TDC based on a crank angle at which one cylinder becomes TDC, and obtains a crank angle at which another cylinder becomes TDC from a crank relative angle of the one cylinder and another cylinder. An engine valve timing measurement device for evaluating a difference between a supply / exhaust valve lift amount and a target lift amount. The engine valve timing measuring device according to claim 4,
A storage device for storing a TDC timing table for each cylinder for each type of engine is provided, and the determination device refers to the TDC timing table and determines whether another cylinder has a TDC timing based on a crank angle at which one cylinder is TDC. An engine valve timing measurement device characterized in that a crank angle is obtained. The engine valve timing measuring device according to any one of claims 1 to 5,
The determination device captures the movement of the supply / exhaust valve when the crank of the engine is rotated for one cycle, determines the lift amount zero position of the supply / exhaust valve from this data, and operates the supply / exhaust valve from the zero lift position. An engine valve timing measurement device for evaluating a difference between a relative lift amount and a target lift amount. The lift amount of the supply / exhaust valve with respect to the crank angle of the engine is measured, and the difference between the lift amount of the supply / exhaust valve and the target lift amount is determined. An engine valve timing measuring method, wherein the presence or absence of the engine valve is determined. The engine valve timing measurement method according to claim 7,
An engine valve timing measurement method, comprising: calculating a cam adjustment amount from a relationship between a valve lift amount and a cam rotation angle when a difference between a lift amount of the supply / exhaust valve and a target lift amount is not within an allowable range. . The engine valve timing measuring method according to claim 7 or 8,
An engine valve timing measurement method characterized by evaluating a difference between a lift amount of a supply / exhaust valve and a target lift amount at a crank angle of an engine in which a cylinder is TDC. The engine valve timing measurement method according to claim 9,
Based on the crank angle at which one cylinder is at TDC, the crank angle at which the other cylinder is at TDC is determined from the relative crank angle of the one cylinder and the other cylinder. A method for measuring an engine valve timing, comprising: evaluating a difference between a lift amount and a target lift amount. The engine valve timing measurement method according to any one of claims 7 to 10,
The movement of the supply / exhaust valve when the crank is rotated for one cycle is recorded, and a zero lift amount position of the supply / exhaust valve is determined from the record, and the relative displacement of the supply / exhaust valve from the zero lift position, the target lift amount, and the like are calculated. A method for measuring engine valve timing, comprising: evaluating a difference in engine valve timing.

Images