JPH10132709A - Method for inspecting internal combustion engine for improper assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which an internal combustion engine can be inspected quickly and surely for its assembled state. SOLUTION: The pressures at an exhaust port 100 and in a surge tank 96 are respectively detected with pressure sensors 106 and 98 while the port 100 is closed and a crank shaft is rotated at a constant speed. When a preset state change occurs, at least one of the pressure value in the changed state and the occurring timing of the state change is measured from at least two cylinders and the assembled state of an engine 90 to be inspected is inspected by comparing the pressure values or occurring time of the cylinders with each other. The preset state change includes such a state that each pressure value becomes the maximum, the rate of change of each pressure value becomes larger from a constant state, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an internal combustion engine assembly inspection method for inspecting the assembled state of an assembled internal combustion engine.

[0002]

2. Description of the Related Art At the time when assembly of an internal combustion engine (hereinafter simply referred to as an engine) is completed, no defective assembly such as a missing part of each part of the engine or a shift in operation timing between components has occurred. It is necessary for the engine to perform as designed. One such inspection method for an assembled engine is described in U.S. Pat. No. 5,355,713. This inspection method rotates the internal combustion engine without burning fuel,
This is to detect the presence or absence of a defective assembly by detecting the pressure waveform on the exhaust side or the intake side and comparing the detected pressure waveform with the corresponding pressure waveform of a normal internal combustion engine.
It is described that the comparison of the pressure waveforms is performed by comparing the characteristics of the pressure waveforms, and as a feature, it is possible to employ the amplitude of at least one of a portion indicating the positive pressure and a portion indicating the negative pressure of the pressure waveform. Have been described. Further, the pressure on the exhaust side of the internal combustion engine to be inspected at the same rotational phase as the crankshaft rotational phase (referred to as crank angle) exceeds the predetermined value when the pressure on the exhaust side of the normal internal combustion engine exceeds the predetermined value. If not exceeded, it is also described that a crankshaft assembly failure has occurred. As exemplified above, the inspection method for an internal combustion engine described in the above-mentioned U.S. Patent Specification discloses that a specific value such as a maximum value, a minimum value, or a value at a specific crank angle of the exhaust-side or intake-side pressure is set to normal. This is a method of finding an assembly failure of the internal combustion engine by comparing with a corresponding specific value of the internal combustion engine.

[0003]

Further, the above-mentioned U.S. Pat. No. 6,077,098 discloses that an assembly failure is detected based on a pressure waveform on either the exhaust side or the intake side of each cylinder of the internal combustion engine. It is just that. Further, when one type of assembly failure is found, the inspection is terminated. Therefore, when a plurality of types of assembly failure occur in one internal combustion engine, the plurality of types of assembly failure are detected. Failure cannot be detected.

[0004] The present invention has been made in view of the above circumstances, and an object of the first invention according to claim 1 is to provide an internal combustion engine which is assembled by a method different from the method described in the above-mentioned US specification. The purpose of this is to make it possible to find out the assembly failure of the engine. A second object of the present invention is to provide an internal combustion engine having a first bank and a second bank, in which an assembly failure which can occur independently of each of the two banks is favorably detected. An object of the third invention according to claim 3 and the fourth invention according to claim 4 is to easily and accurately detect a defective assembly. A fifth object of the present invention according to claim 5 is to easily detect an assembly defect particularly likely to occur.

[0005]

Means for Solving the Problems, Functions and Effects of the Invention
In order to solve the above-mentioned problem, the method for inspecting a defective assembly of an internal combustion engine according to the first invention rotates an internal combustion engine including a plurality of cylinders each having an intake valve and an exhaust valve. At least a pressure value in a predetermined change state of at least one pressure of at least one of an intake-side space communicating with the intake valve and an exhaust-side space outside of each exhaust valve and communicating with the exhaust valve, and an occurrence timing of the change state. One is detected for at least two of the plurality of cylinders,
At least one of the pressure values of the two cylinders and the generation time are compared with each other, and when they do not match, it is determined that there is a defective assembly in the internal combustion engine.

[0006] The predetermined specific change state of the pressure in the intake space and the pressure in the exhaust space (hereinafter, simply referred to as intake pressure and exhaust pressure, respectively) is determined by the linear reciprocating motion of the piston in the cylinder. And the timing at which the intake and exhaust valves open and close. The pressure in the cylinder increases as the piston approaches the top dead center, and conversely, decreases as the piston approaches the bottom dead center. In the reciprocal engine, the exhaust valve starts to open first, and then the intake valve starts to open from the state where the intake and exhaust valves are closed. Then, after the exhaust valve is closed, the intake valve is closed. In this one cycle, for example, as described later in the embodiment of the present invention, when the timing at which the intake valve starts to open is earlier than in a normal internal combustion engine (the crank angle is smaller), the exhaust pressure peaks. As the value becomes smaller, the time when the maximum value is reached becomes earlier (the crank angle becomes smaller). Conversely, if the timing at which the intake valve starts to open is later than in a normal internal combustion engine (the crank angle is larger), the maximum value of the exhaust-side pressure increases and the time at which the maximum value is reached is delayed. Therefore, for example, by knowing the timing when the exhaust side pressure reaches the local maximum value, it is possible to know the relative relationship between the crank angle and the opening / closing timing of the intake valve. This indicates that a phase shift between the crankshaft and the camshaft has occurred due to a defective assembly. Also, for example, if the opening / closing timing of the exhaust valve changes relative to the crank angle, it affects the changing state of the intake side pressure. Can be detected. Thus, by knowing at least one of the pressure value in the predetermined change state of at least one of the intake side pressure and the exhaust side pressure and the occurrence time of the change state, without disassembling the engine,
The occurrence of the assembly failure can be detected.

In the method of inspecting a defective assembly of an internal combustion engine according to the present invention, at least one of a pressure value in a predetermined change state and a time of occurrence of the change state is determined by at least two.
By comparing the two cylinders, an assembly failure of the engine is detected. For example, when an assembly failure occurs in a certain cylinder, a difference may occur in a pressure value in a predetermined change state between the cylinder and a normally assembled cylinder. If the difference is detected, it can be determined that at least one of the two has a defective assembly. Furthermore, if the pressure values corresponding to a larger number of cylinders are compared, more information regarding the assembly state of each cylinder is obtained, and the possibility of correctly identifying the cylinder in which assembly failure has occurred increases. . According to such a method,
Since it is not necessary to know the value of the crank angle, the configuration of the inspection device can be simplified. Note that the comparison here is a pattern including a set of a plurality of detection values acquired for each cylinder,
This is a concept that also includes determining whether there is a difference from that of the other cylinders. In this case, the match means that the difference is found in all of the corresponding ones of the respective detection values constituting each of the patterns. That is not acceptable.

In the method of inspecting an assembly failure of an internal combustion engine according to the present invention, the values of the intake side pressure and the exhaust side pressure of each cylinder in a predetermined specific change state are compared with those in a normal assembly state. Detecting assembly failures is not precluded. For example, a comparison result between the maximum value of the exhaust-side pressure and the value in a normal assembly state may be taken into consideration. Also, the internal combustion engine to be tested can be rotated by burning the fuel in itself, or it can be rotated in connection with another rotary drive. The former is called a firing inspection, and the latter is called a motoring inspection. In general, motoring is easier than firing. In order to drive the engine by the energy of the explosion of the engine itself, it is necessary to supply fuel,
It takes time and effort to process exhaust gas. Further, the acquired values of the intake side pressure and the exhaust side pressure contain more noise. When the engine is rotated by another rotary drive device, such a problem is reduced, and the inspection of the assembled state can be performed more easily.

[0009] In the second invention, when the internal combustion engine includes a first bank and a second bank, the comparison in the first invention is performed by comparing at least one cylinder of the first bank and the second bank. The problem is solved by performing with at least one cylinder. For example, when a phase shift of the camshaft of one bank of a V-type engine having two banks occurs, the cylinders included in the bank where the phase shift of the camshaft occurs and the cylinders not included in the bank are previously determined. The manner of affecting the pressure value in the determined change state and at least one of the generation time of the change state is different. According to the internal combustion engine assembly defect inspection method of the present invention, it is possible to satisfactorily detect such an assembly defect that may occur in each bank.

According to a third aspect of the present invention, in the method of inspecting a defective assembly according to the first or second aspect, the comparison is performed by comparing an average value of at least one of the detected pressure value and the occurrence time with each cylinder. Is solved between at least one of the pressure value and the generation time. Further, in the fourth invention, the problem is that the assembly failure inspection method according to any one of the first to third inventions comprises a group of ones which are close to each other with respect to at least one detected value of the pressure value and the occurrence time. And the comparison is performed between the groups. The pressure value and the generation timing detected for each cylinder may vary in various sizes. These variations can include both the effects of some assembly failures and the mere detection errors. Among them, it is desirable to remove the influence of the latter as much as possible. According to the internal combustion engine assembly failure inspection methods of the third invention and the fourth invention, these effects can be reduced, and the inspection of the assembly state can be performed with high accuracy.

According to a fifth aspect of the present invention, there is provided an assembly failure inspection method according to any one of the first to fourth aspects, wherein the occurrence of the predetermined change state is detected for all of the plurality of cylinders. The above problem can be solved by comparing the intervals of the occurrence timings of the cylinders that are adjacent to each other in the explosion order of the plurality of cylinders. As will be described later in the embodiments of the present invention, particularly simple assembly defects can be easily detected by comparing the intervals between the occurrence timings of successive cylinders in the explosion order of a plurality of cylinders. can do. Such an assembly defect includes, for example, a valve clearance defect of the intake and exhaust valves. When the engine to be inspected includes the first bank and the second bank, cam pulley inspection, driven gear inspection, and the like can be further performed.

[0012]

Preferred embodiments of the present invention can be carried out in the following embodiments in addition to the embodiments described in the above claims. The embodiments are conveniently described as an embodiment of the same type as the claims. However, an embodiment that further depends on an embodiment that depends on a plurality of claims or embodiments cannot necessarily read all of the plurality of claims or embodiments, and logically contradicts it. It should be read only for sections that do not have them. (1) The internal combustion engine assembly failure inspection method according to any one of claims 1 to 5, wherein at least one of the pressure value and the generation timing is detected for all of the plurality of cylinders. (2) For at least one of the detected values of the pressure value and the generation time, a group is divided into groups that are close to each other, and the comparison is performed between the detected values included in each group. The method according to any one of claims 1 to 5, wherein the defective assembly is inspected. (3) detecting a pressure value in the predetermined change state for all of the plurality of cylinders, and comparing the pressure values of successive ones in the order of explosion of the plurality of cylinders. The method for inspecting an assembly failure of an internal combustion engine according to any one of claims 1 to 5, wherein the method comprises the steps of: (4) an exhaust-side pressure maximum state in which the predetermined change state is a state in which the pressure value of the exhaust-side space is maximum;
An exhaust-side pressure unchanged state in which the pressure value of the exhaust-side space does not change, an exhaust-side pressure decrease start state in which the pressure value of the exhaust-side space starts to decrease from a state in which the exhaust-side space does not change, At least one of an intake-side pressure maximum state where the pressure value is a local maximum value and an intake-side pressure increase start state where the pressure value of the intake side space starts to increase from a state where the pressure value does not change. The method for inspecting a defective assembly of an internal combustion engine according to any one of claims 1 to 5, characterized in that it is performed. (5) The pressure value in the predetermined change state is:
An embodiment including at least one of an exhaust-side pressure maximum value that is an exhaust-side pressure in the exhaust-side pressure maximum state and an exhaust-side pressure invariable value that is an exhaust-side pressure in the exhaust-side pressure unchanged state. Item 5. The method for inspecting a defective assembly of an internal combustion engine according to Item 4. (6) When the predetermined change state occurs, the exhaust-side pressure maximum value, which is the time when the exhaust-side pressure maximum state occurs, and the exhaust-side pressure, which occurs when the exhaust-side pressure unchanged state occurs, Change state transition time, exhaust-side pressure decrease start time, which is the occurrence time of the exhaust-side pressure decrease start state, intake-side pressure maximum value arrival time, which is the intake-side pressure maximum state occurrence time, and intake-side pressure increase start state The internal combustion engine assembly failure inspection method according to claim 4 or 5, wherein the method includes at least one of the intake-side pressure increase start timings, which are the timings at which the occurrence of (i) occurs.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an engine assembly defect inspection method according to each embodiment of the present invention will be described together with an engine inspection apparatus suitable for carrying out the method. FIG. 1 is a perspective view showing a main operating portion of a V-type 6-cylinder DOHC gasoline engine (hereinafter, simply referred to as a V6 engine) as an example of an engine. In this type of engine, reciprocating motion in a cylinder (not shown) such as the pistons 10 and 12 is converted into rotational motion of the crankshaft 18 via the corresponding connecting rod 14, and the rotational force of the crankshaft 18 is used as power. It is taken out as outside. In order to continue the operation of the engine, a valve train including exhaust and intake valves is operated in association with the rotation angle of the crankshaft 18. Note that the piston 10 and the piston 12 are illustrated on behalf of three pistons each of a left bank as a first bank and a right bank as a second bank of the V6 engine.

In the V6 engine of this embodiment, the crank pulley 2 attached to the crankshaft 18
0, timing belt 22, cam pulleys 24, 26 of the left and right banks, exhaust camshafts 28, 30, to which cam pulleys 24, 26 are respectively attached, intake camshafts 32, 34, and exhaust camshafts 28, 3.
0, drive gears 36, 38 respectively attached to
A camshaft rotation mechanism 44 is constituted by driven gears 40, 42 and the like attached to the intake-side camshafts 32, 34, respectively, as main components. Further, a valve train 52 is constituted by a plurality of cams 46 of each camshaft, and an exhaust valve 48 and an intake valve 50 which are opened and closed by their rotation as main elements.

When the crankshaft 18 is rotated, the exhaust valve 48 and the intake valve 50 operate via the crank pulley 20, the timing belt 22, the cam pulleys 24 and 26 of the left and right banks, and the exhaust camshafts 28 and 30. Let me do. Therefore, when the timing belt 22 becomes loose, the opening / closing timing of each valve fluctuates. To suppress this, a belt idler 54 having an auto tensioner (not shown) is provided. Further, belt idlers 56 and 58 without an auto tensioner are also attached. These belt idlers 54 to 58 are effective in increasing the number of meshing teeth of the timing belt 22, the crank pulley 20, and the cam pulleys 24 and 26. So-called scissor gears 60, 6 are provided on the intake side camshafts 32, 34, respectively.
2 are mounted so as to be relatively rotatable. The scissors gears 60 and 62 are combined with the driven gears 40 and 42, respectively, and are driven by spring members (not shown).
The drive gears are biased so as to rotate relative to the drive gear, so that the backlash of the engagement between the driven gears 40 and and the drive gears 36 and 38 is suppressed, and the noise of the engine is reduced.

The rotation angle of the crankshaft 18 and the opening / closing timing of each exhaust valve 48 and intake valve 50 need to correspond accurately. Since the V6 engine as the engine to be inspected in the present embodiment is a 4-cycle gasoline engine, the number of teeth of the crank pulley 20 and the number of teeth of each of the cam pulleys 24 and 26 are set to 1: 2. The number of teeth of the crank pulley 20 is 24, and the number of teeth of each cam pulley is 48. The number of teeth of the drive gears 36, 38 and the driven gears 40, 42 is one.
There is one pair, each having 40 sheets.

When assembling the engine, the rotation angle of the crankshaft 18 and each of the exhaust valve 48 and the intake valve 5
In order to match the opening / closing timing of 0, a mark for phase matching is provided on the crank pulley 20, the cam pulleys 24 and 26, and the timing belt 22, and these phase matching marks are shown in the enlarged portion of FIG. As shown, the assembly is performed so as to match. The same applies to the drive gears 36, 38 and the driven gears 40, 42. If the phase adjustment is not performed correctly, the relationship between the rotation angle of the crankshaft 18 and the opening / closing timing of each valve is broken. For example, if the phase alignment mark between the crank pulley 20 and the timing belt 22 is 1
As shown in the enlarged view of FIG. 2, when the crank pulley 20 is advanced by one tooth (hereinafter referred to as crank pulley one tooth advanced), the positions of the pistons 10, 12 and the like in the cylinder are shifted by one tooth. And the relationship between the opening and closing timing of each valve is broken, and the rotation angle of the crankshaft 18 is 36
The opening / closing timing of each valve is delayed with respect to the positions of the pistons 10 and 12 by 0/24 = 15 degrees.

The cam pulley 24 and the timing belt 22
As shown in the enlarged view of FIG. 2, when the cam pulley 24 is advanced by one tooth, the phase is shifted by one tooth (hereinafter, referred to as one cam pulley advanced), as shown in the enlarged view of FIG. The opening / closing timing of each valve advances by 360/48 = 7.5 degrees with respect to the positions of the pistons 10, 12, and the like. In addition, in a state where the drive gear 38 and the driven gear 42 are shifted by one tooth and the driven gear 42 is advanced by one tooth as shown in the enlarged view of FIG. 2 (hereinafter, referred to as a driven gear one tooth advanced), The opening / closing timing of each valve advances relative to the positions of the pistons 10 and 12 by 360/40 = 9 degrees in the rotation angle of the intake camshaft 34. The above-described phase misalignment has been exemplified only for one tooth advance of the cam pulley 20 and the like, but these may be delayed. It is extremely rare that lead / lag of two or more teeth occurs. The invention of the present application is such a 2
Although the present invention is applicable to advance / delay beyond a tooth, only one tooth advance / delay occurs in the following for the sake of simplicity. It should be noted that the structure of the portion where the crankshaft 18 and the crank pulley 20 are connected is generally configured so as not to be assembled with the relative phases shifted. Therefore, the relative phase between the crankshaft 18 and the crank pulley 20 does not always deviate even in the state where the one tooth of the crank pulley is advanced / delayed. The same applies to the relative phase between each exhaust-side camshaft and the cam pulley, and the relative phase between each intake-side camshaft and the driven gear.

In order for the engine to exhibit the expected performance, the rotation angle of the crankshaft 18 and the exhaust valves 4
8 and the opening / closing timing of the intake valve 50 must be in a relationship as designed. Therefore, in addition to the assembly alignment of the camshaft rotation mechanism 44 by the phase alignment mark, the rotation angles of the exhaust-side camshafts 28 and 30 constituting the valve train 52 and the corresponding exhaust valves 4
8 and the intake-side camshaft 3
The rotation angles 2 and 34 and the opening / closing timing of each corresponding intake valve 50 must be in a designed relationship.
These relationships depend on the valve clearance. Abnormal valve clearance due to poor engine assembly may be caused by a shim 72 having an incorrect thickness, a valve seat member 74 not being properly fitted to the cylinder head 76, or the like. What is valve clearance?
As shown in FIG. 3, this is the maximum clearance between the cam 46 and the shim 72 mounted between the lifter 70. For example, when the valve clearance is larger than the normal product, the timing of opening each valve is later than that of the normal product, and the closing timing is earlier. If the valve clearance is smaller than the normal product, the reverse is true.

Next, the configuration of an engine inspection apparatus commonly used for implementing the first to fifth inventions' internal assembly failure inspection methods will be described. FIG. 4 is a conceptual diagram of the engine inspection device. The engine 90 to be inspected (only the left bank is shown for simplicity) is attached to the cylinder head 76, and communicates with the intake port 92 of each cylinder inside the cylinder head 76. The inspection apparatus includes an intake manifold 94 provided in each of the right banks and one surge tank 96 communicating with the two intake manifolds 94. The present inspection apparatus includes a pressure sensor 98 for measuring the pressure in the surge tank 96. , A cover member 102 attached to shut off the exhaust port 100 for each cylinder formed inside the cylinder head 76 from the outside, and an O-ring 104 as a seal member used to more reliably shut off the exhaust port 100.
An A / D converter 110, which includes a pressure sensor 106 for measuring the pressure inside the exhaust port 100, and an amplifier for amplifying the output signals of the pressure sensors 98, 106, respectively.
112, the crank angle sensor 114, and the inspection control device 1
19 as a main component.

The inspection control device 119 includes a microcomputer (not shown) and a display 118. The microcomputer constitutes a judging unit 117 for judging the engine assembly state based on the signals from the A / D converters 110 and 112 and the crank angle sensor 114. The judgment result of the judging unit 117 is displayed on the display unit. It is displayed at 118. A pressure sensor 98 for measuring the pressure on the intake side is mounted on a surge tank 96 common to all cylinders, whereas a pressure sensor 106 for measuring the pressure on the exhaust side is provided for each cylinder. Installed independently. Therefore, the number of the A / D converters 110 may be one, but the number of the A / D converters 112 is required as many as the number of cylinders of the engine 90 to be inspected.
As described above, in the present embodiment, the space inside the intake port 92, the intake manifold 94, and the surge tank 96 is the intake side space, the inside of the exhaust port 100 is the exhaust side space, and the exhaust side space is The portion of the exhaust port 100 that opens to the outside of the cylinder head 76 is closed as a closing position. Although the intake side space is not closed, the intake side space may be closed. Also,
It is also possible to use only the intake port 92 or the space inside the intake port 92 and the intake manifold 94 as the intake side space. In the former case, a pressure sensor 9 is provided for each cylinder.
In the latter case, the intake manifold 9 is required.
Four pressure sensors 98 are required.

The engine 90 to be inspected is fixed on a base 120 as shown in FIG.
22, is accurately rotated at a constant speed by a motor 125 connected to the crankshaft 18 via a drive shaft 124. The drive shaft 124 includes bearings 126 and 128
Supported by the two bearings 12
6, 128 and the motor 125 are fixed to the base 120. When the motor 125 is rotated by the inspection control device 119, the pressure sensors 98, 1
By detecting the fluctuation of the output of 06, the assembly state of the engine is inspected.

As described above, when the engine 90 to be inspected is rotated by the motor 125, each valve is opened and closed with a change in the crank angle. When the rotation speed of the motor 125 becomes constant and the pressure in each cylinder changes steadily, the output of each of the pressure sensors 98 and 106 (hereinafter simply referred to as the intake pressure P _IN and the exhaust pressure P _EX respectively) becomes
Assuming that the inspected engine 90 is a good one, the state changes as shown in FIG. FIG. 6 shows a change in a position of one piston, for example, the piston 10 in the cylinder (hereinafter, simply referred to as a piston position PP), an exhaust-side pressure P _{EX of} the piston, and a change of an intake-side pressure P _IN common to each piston. It is a thing. This piston 10 is simply called a piston #
No. 1. The engine 90 to be inspected is a V6 engine, and three pistons in the left bank are pistons # 1 and #
3, # 5, 3 pistons in right bank are piston # 2
(Corresponding to the piston 12), # 4, and # 6 are arranged in each bank in this order. When the V6 engine is rotated on its own by the explosion energy in the cylinder, it is exploded, for example, in the order of pistons # 1 to # 6.

First, the exhaust pressure P_EXWill be described.
The crankshaft 18 is rotated by the operation of the motor 125.
Turned, crank angle θ_crankIs the angle θ_EXopenNana
Then, the exhaust valve 48 corresponding to the piston # 1 opens
Begin. At this time, piston # 1 moves to bottom dead center BDC
The air in the exhaust port 100 is
Exhaust side where the pressure was constant because it began to be sucked into
Pressure P_EXBegins to decrease. This constant pressure is the exhaust side pressure
Force change value P_EXconst, Exhaust side pressure P_EXBegins to decrease
Crank angle θ_crank= Θ_EXopenStart decreasing the pressure on the exhaust side
Angle θ_EXdecCalled. Piston # 1 passes through bottom dead center BDC
To the same position as when the exhaust valve 48 was opened.
After being returned, the cylinder and exhaust port 100
Exhaust gas pressure P_EXBegan to rise,
Crank angle θ_crankIs θ_INopenAnd the intake valve 50
When the pressure starts to open, the exhaust pressure maximum value P_EXmaxTona
You. The crank angle θ at this time_crank= Θ_INopenThe exhaust side
Maximum pressure reaching angle θ_EXmaxCalled. Intake valve 50
Exhaust side pressure P when opened_EXDecrease sharply.
Little is crank angle θ_crank= Θ_EXcloseExhaust valve at
Is stopped by closing the valve 48, and the exhaust side pressure P_EX
No longer changes. In that sense, the crank angle θ _crank=
θ_EXcloseTo the exhaust-side pressure unchanged state transition angle θ_EXconstWhen
The exhaust side during the period when the exhaust valve 48 is closed
Pressure P_EXTo the exhaust side pressure invariance value P_{EXcons t}Called. K
Rank angle θ_crankGoes further, θ_INcloseBecomes
The intake valve 50 is closed. Note that the following description is for convenience.
Above, the exhaust pressure maximum value P in the normal assembly state shown in FIG.
_EXmaxOther pressures are expressed as relative values with the size of
You. For example, the exhaust-side pressure invariable value P in a normal assembly state
_EXconstIs about 10. The rotation of the motor 125
The number of rotations is arbitrary.
A gin assembly inspection may be performed.

Exhaust pressure P_EXIs independent for each cylinder.
While the intake pressure P _INIs one pressure sensor
Acquired as common data for all cylinders
You. In the example shown in FIG. 6, each of the pistons # 1 to # 6
Due to the state change of the intake valve 50, the intake side pressure P_INBut
The changing places are indicated by piston numbers # 1 to # 6.
These six points are the crank angle θ_crankIs 0 to 720
Appear at equal intervals once in one cycle
You. Hereinafter, the shape of the intake valve 50 corresponding to the piston # 1 will be described.
Intake side pressure P due to state change_INRepresentatively explain changes in
I do.

When the crank angle θ _crank becomes θ _INopen ,
Since the intake valve 50 starts to open, the compressed air in the cylinder and the exhaust port 100 flows to the intake manifold 94, and the pressure in the intake manifold 94 starts to increase. At this time, the air in the intake manifold 94 is being sucked into the cylinder corresponding to the piston # 6.
Since the outflow flow rate of the air from 0 is larger, the pressure in the intake manifold 94 starts to increase. The crank angle θ _crank at the start of the increase is referred to as an intake-side pressure increase start angle θ _INinc . Then, the position PP of the piston # 1
Near the point at which TDC reaches the top dead center TDC, the flow rate of air decreases due to a decrease in the pressure in the cylinder and the exhaust port 100 and a decrease in the valve clearance of the exhaust valve 48.
Since the intake flow rate of the piston # 6 into the cylinder is balanced and becomes smaller than the intake flow rate thereafter, a maximum value of the intake pressure P _IN appears. The crank angle theta _crank at this point is referred to as the intake side pressure maxima reaching angle theta _{Inma x.} After the position PP of the piston # 1 reaches the top dead center TDC, the increase in the cylinder volume of the piston # 1 also promotes the decrease of the intake pressure P _IN . The change in the intake-side pressure P _IN shown in FIG.
₍ every 120 degrees with _crank ).

FIG. 7 shows that the engine under inspection 90 is normally assembled.
If it is, stand alone for each cylinder described above.
Exhaust side pressure P acquired_EXAnd the crank reference signal
Change the crank angle θ_crankWith the horizontal axis
It is. The crank reference signal is a crank angle sensor
114, which is a signal output from the
In the engine 90, twice a cycle, that is,
Crank angle θ_crankIs output twice for every 720 degrees change
This is a pulse signal. It should be noted that the inspection target
The crank angle sensor 114 of the gin 90 is a crank pulley.
20 which is not shown and is integrated with the
To be detected formed at one place on the outer circumference of the motor
Pickup such as an electromagnetic pickup that detects the passage of
Is included. However, the crank angle sensor 114
Such an embodiment is the engine of the present invention.
It is not essential for implementing the inspection method. Most
Most modern engines have different mounting points
A sensor corresponding to the crank angle sensor 114 is provided.
However, when such a sensor is not provided,
For example, use a reflection type photoelectric switch, proximity switch, etc.
And rotating crank pulley 20, crankshaft
A configuration capable of detecting 18 specific phases may be adopted. In addition,
The crank reference signal provides a more accurate crank angle value.
The signal may be a detectable signal. For example, crankshaft
Shaft 18 for detecting the rotation angle of an encoder, resolver, etc.
The output can be used as a crank reference signal.
No. The output of such a sensor and the exhaust that changes every moment
Side pressure P_EXAnd intake side pressure P _INAnd the value of
It is made to be acquired in the state where it was done. By this
Crankshaft rotated by a motor 125
Even if the rotation speed of the
The constant accuracy can be kept good. It is clear from FIG.
U, each exhaust side pressure P_EXIs the crank angle θ_crankAt 12
Although shifted by 0 degrees, they show almost the same change. this
But the crank pulley advance / delay, cam pulley advance /
Delay, driven gear advance / delay, large valve clearance
/ Small and missing compression ring
It has not occurred.

The determiner 117 includes a crank angle sensor 1
Measure the time interval of generation of the crank reference signal from 14,
Because the time interval is substantially constant,
Function to detect that the rotation speed of the
Have. In addition, the A / D converter 11
0, 112, pressure detection of pressure sensors 98, 106
Read the value, analyze the change state of the detected pressure value,
The exhaust side pressure invariable value P_EXconst, Its exhaust side pressure
Change value P_EXconstPressure start, exhaust side pressure maximum value P
_EXmax, Exhaust pressure P_EXExhaust side pressure change value P
_EXconstShift to intake side pressure P_INPressure increase, intake side
Pressure P_INTo detect a specific pressure change state such as the maximum value of
In addition, a machine that detects when these specific pressure changes occur
Functions and the clans corresponding to the point of occurrence of each specific pressure change state.
Angle θ_crankFunction, ie, crank reference
Twice the signal generation time interval is
Exhaust side pressure reduction opening corresponding to a rotation angle of 20 degrees
Start angle θ_EXdec, Exhaust side pressure maximum angle θ_EXmax,exhaust
Side pressure unchanged state transition angle θ_EXconst, Intake side pressure increase open
Start angle θ _INinc, Angle of attainment of pressure maximum at intake side θ_INmaxSpecially
Has a function to determine These functions are used for waveform analysis.
It is well known in the art and its details
Details are not essential for understanding the present invention,
Description is omitted.

Next, when each of the above-mentioned assembly defects occurs,
Exhaust pressure P_EXOr intake side pressure P _INExplain the change in
You. In the following description, each of the above assembly failures may occur.
Pressure and crank angle values when
Indicates the pressure and lock in normal assembly
It shall be distinguished from the rank angle. First, the intake valve
The lube clearance defect will be described. FIG. 8 shows one
Clear run of two intake valves 50 of cylinder
The valve clearance is normal and one valve clearance
Exhaust pressure P when the pressure is small_EXGroup that shows the change of
It is rough. The solid line shows the intake valve clearance
Is normal, and the broken line indicates that the intake valve clearance is
It is small. The former is in the normal assembly state, the latter is the intake
It is called a lube clearance small state. Intake valve clearer
In the small state, the intake valve 50 starts opening early.
The exhaust-side pressure maximum value reaching angle θ _EXmax′ Is a normal group
Standing (θ_EXmax). Normal group
Exhaust in a standing state and a small intake valve clearance state
Difference in the angle of arrival at the side pressure maximum (θ _EXmax'-Θ_EXmax)
It will be referred to as a gas side pressure maximum value arrival angle difference Γ. Exhaust side
The maximum pressure difference angle Γ is the value when the valve clearance is normal.
The smaller the value compared to the standing state, the smaller the value.
The logarithmic value increases).

Further, in the small intake valve clearance state, the intake valve 50 starts to open earlier as described above, so that the pressure in the cylinder compressed by the piston becomes smaller than that in the normal assembly state, and the exhaust side of the cylinder is reduced. The pressure maximum value P _EXmax ′ is smaller than the exhaust-side pressure maximum value P _{EXmax in the} normally assembled state. In addition, since the exhaust-side pressure maximum value P _EXmax 'is small and the period from when one of the intake valves 50 is opened to when the exhaust valve 48 is closed is long, the exhaust-side pressure _invariable value P _EXconst ' is also normally assembled. It is smaller than that of the state (P _EXconst ). As a result, in the example of FIG. 8, the exhaust-side pressure _invariable value P _EXconst ′ is a negative pressure. The difference (P _EXmax ′ −P _EXmax ) between the maximum value of the exhaust pressure and the maximum value of the exhaust pressure between the assembly failure state (here, the valve clearance small state) and the normal assembly state is referred to as the exhaust side pressure maximum value difference α. Value difference (P
_{EXconst'- PEXconst} ) is referred to as an exhaust-side pressure _invariable value difference β. The exhaust-side pressure maximum value difference α and the exhaust-side pressure invariable value difference β also decrease as the valve clearance decreases, similarly to the exhaust-side pressure maximum value arrival angle difference Γ. The exhaust-side pressure maximum value difference α, the exhaust-side pressure invariable value difference β, the exhaust-side pressure maximum value arrival angle difference Γ, and the like can take both positive and negative values. Absolute values will be used if circumstances permit. The same applies to other pressure values and differences in crank angle.

FIG. 9 shows a change in the exhaust pressure P _EX between a normal assembly state in which the valve clearances of the two intake valves 50 of one cylinder are both normal and a large intake valve clearance state in which one of the valve clearances is large. It is a graph superimposed and shown. In this large intake valve clearance state, the intake valve 48 starts to open later by the absolute value of the exhaust-side pressure maximum value reaching angle difference 、, so that the pressure in the cylinder becomes higher than in the normal intake valve clearance assembly state.
The exhaust pressure maximum P _EXmax ′ is the exhaust pressure maximum P
_{It becomes larger} than _EXmax by the absolute value of the exhaust pressure maximum value difference α. Also, the exhaust pressure maximum value P _EXmax ′ is large,
In addition, since the period from when one of the intake valves 50 is opened to when the exhaust valve 48 is closed is short, the exhaust-side pressure _invariable value P _{EXcon nst} ′ is also _smaller than the exhaust-side pressure _invariable value β compared to P _EXconst. By the absolute value of.

FIG. 10 shows the crank angle θ._crankAgainst changes in
Normal assembly, small intake valve clearance,
And intake valve pressure when intake valve clearance is large
P_IN6 is a graph showing a change in the graph. Two of piston # 1
In response to changes in the timing when one of the intake valves 50 is opened
And the intake side pressure P_INIs the maximum crank angle
Side pressure maximum value reaching angle θ_INmax′ Is that in the normal assembly state
Has changed. This change is detected when the intake pressure maximum reaches
Angle of arrival difference Λ (= θ_INmax'-Θ_INmax). Also suck
Air side pressure P_INIs the crank angle at which the crank angle starts to increase
Pressure increase start angle θ _INinc′ Is also the angle of arrival of the maximum value on the intake side
A change similar to the difference 示 す is shown. This change is taken to increase the intake side pressure.
Start angle difference Ψ (= θ_INinc'-Θ_INinc). These sucking
Air pressure local maximum angle difference Λ and intake pressure increase start angle
The difference Ψ is also the same as the exhaust side pressure maximum value arrival angle difference 上 記, etc.
The smaller (larger) the valve clearance, the smaller
(growing.

Next, defective valve clearance of the exhaust valve will be described. FIG. 11 is a graph showing a change in the exhaust-side pressure P _EX between a case where the exhaust valve 48 is in a normal assembly state and a case where one of the two exhaust valves 48 is in a state where the exhaust valve clearance is small. In the small exhaust clearance state, one of the exhaust valves 48 starts to open earlier, so that the exhaust side pressure decrease start angle θ _EXdec ′ becomes smaller than that in the normal assembly state. This deviation is shown in FIG. 11 as the exhaust-side pressure decrease start angle difference Φ (= θ _EXdec '−θ _EXdec ). In addition, the exhaust valve 48, which starts to open earlier, is completely closed later than in the normally assembled state. This is indicated by an exhaust-side pressure unchanged state transition angle difference Σ. The magnitudes of the exhaust-side pressure decrease start angle difference Φ and the exhaust-side pressure unchanged state transition angle difference Σ have substantially the same value. Since the timing at which the exhaust valve 48 is closed is late, the exhaust-side pressure _invariable value P _EXconst ′ becomes smaller by the absolute value of the exhaust-side pressure _invariable value difference β, and the amount of air sealed in the exhaust port 100 is small. The exhaust pressure maximum value P _EXmax ′ is smaller than that in the normal assembly state by the absolute value of the exhaust pressure maximum value difference α.

FIGS. 12A and 12B show the case of the normal assembly state and the case of 2
7 is a graph showing a change in the exhaust-side pressure P _EX when one of the two exhaust valves is in a large exhaust clearance state. In this case, one of the exhaust valves 48 in the large exhaust clearance state is slower to start opening than the other and is quickly closed completely, but the opening and closing of the other exhaust valve is normal. Since it is performed at the same time as the assembled state, the exhaust-side pressure decrease start angle θ _EXdec ', the exhaust-side pressure maximum value reaching angle θ _EXmax ', and the exhaust-side pressure unchanged state transition angle θ _EXconst 'are almost the same as those in the normal assembled state. Is the same. However, since one of the exhaust valves 48 in the large exhaust clearance state closes quickly, the exhaust-side pressure _invariable value P _EXconst ′ increases, and the amount of air sealed in the exhaust port 100 increases. The maximum value P _EXmax ′ also increases. The abnormality in the valve clearance of the exhaust valve hardly affects the intake-side pressure increase start angle θ _INinc or the intake-side pressure maximum value reaching angle θ _INmax .

Next, when the compression ring is missing
explain about. The piston ring 134 is shown in FIG.
Like the top ring 136, the second ring 138
And an oil ring 140. Of these,
The pull ring 136 and the second ring 138
Keep the airtightness between the engine and cylinder, and ensure the performance of the engine.
Ring 144 is an important part of
Is configured. Top ring 136 and second ring 13
If at least one of 8 is missing, the function to maintain airtightness
Is lower than when installed correctly.
And the above exhaust side pressure P_EXThe absolute value of
Air side pressure maximum value reaching angle θ_EXmax′, Exhaust side pressure unchanged
State transition angle θ_EXconst'And others are almost the same as those in the normal assembly state.
Almost unchanged. FIG. 13 shows a case in a normal assembly state.
And the top ring 136 and the second ring 138
Exhaust side pressure P when one of the gaps is missing_EXStrange
It is a graph which showed chemical conversion. In the latter case, exhaust pressure
Maximum value P_EXmax'Is the absolute value of the maximum difference α on the exhaust side pressure.
Smaller. The top ring 136 and SECA
With the ring 138 missing
Is the above exhaust side pressure P _EXIs even smaller, so this
It is also possible to detect such an assembly failure. But,
If at least one is missing, disassemble the engine
Because it will be reassembled after correction,
Inspection is virtually unnecessary.

Next, the influence of the advance / delay of the cam pulley and the advance / delay of the crank pulley will be described. FIGS. 14 and 15 are graphs showing changes in the exhaust-side pressure P _EX corresponding to each piston in a state where the cam pulley 26 in the right bank is advanced by one tooth of the cam pulley and delayed by one tooth of the cam pulley, respectively. In these figures, the exhaust-side pressure decrease start angle θ _EXdec 'and the exhaust-side pressure maximum value reaching angle θ of the cylinder whose value indicated by the corresponding piston number is an even number
_EXmax ′, the transition angle θ _{EXcons t} ′ of the exhaust-side pressure _invariable state, and the like deviate from those in the normal assembly state. As described above, in the state where the advance / delay abnormality of only one of the left and right banks of the cam pulley has occurred, the exhaust pressure maximum value reaching angle θ of the cylinder having the odd or even piston number is obtained.
_EXmax 'etc. all change.

When the advance / delay of the crank pulley occurs, the change is the same as when the advance or delay of the cam pulley occurs simultaneously in both the left and right banks. However, the effect of the crank pulley advance is opposite to the effect of the simultaneous advance of the left and right cam pulleys, and is the same as the simultaneous delay of the left and right cam pulleys. Specifically, when one tooth delay of the crank pulley occurs, the exhaust-side pressures P _EX of all the cylinders change in the same manner as the exhaust-side pressures P _EX of the cylinders having even-numbered piston numbers shown in FIG. Show. When the crank pulley advances by one tooth, the exhaust-side pressure P _EX of all cylinders exhibits the same change as the exhaust-side pressure P _EX of the cylinder having an even piston number shown in FIG. In addition, when the crank pulley advances or delays, values such as the exhaust-side pressure decrease start angle θ _EXdec ', the exhaust-side pressure maximum value reaching angle θ _EXmax ', and the exhaust-side pressure unchanged state transition angle θ _{EXcons t} 'are also set. , Respectively, is the same as the change when the cam pulley delay or advance occurs simultaneously in both the left and right banks.

Incidentally, the cam pulley of the right bank is advanced by one tooth /
In the case of delay, advance / delay of one tooth of crank pulley,
The intake pressure P _IN changes as shown in FIG. In this drawing, in the case of one cam lead / lag of the right cam pulley,
The intake side pressure _PIN of the cylinder having an even piston number is different from the normal assembly state. On the other hand, when the crank pulley is advanced or delayed by one tooth, the intake-side pressures P _IN of all the cylinders are shifted.

FIG. 17 shows one crank pulley delay.
Is the exhaust-side pressure P when the cam pulley advances one tooth.
_EX6 is a graph showing an example of a change in the graph. However, the latter
Included in banks where cam pulley 1 tooth advance has occurred
Cylinder pressure P _EXIt is. In this case,
Exhaust side pressure decrease start angle θ_EXdec′, Exhaust pressure maximum
Angle of arrival θ_EXmax'And the transition angle θ
_EXconst′ Are those in the normal assembly state_EXdec, Θ_EXmax
And θ_EXconstRespectively, the exhaust pressure decrease
Start angle difference Φ, exhaust side pressure maximum value arrival angle difference Γ, and exhaust side pressure
The value is smaller by the absolute value of the transition angle difference
You. These exhaust side pressure decrease start angle difference Φ, exhaust side pressure maximum
Value difference angle Γ, exhaust side pressure unchanged state transition angle difference Σ, etc.
Is almost the same. Also, the intake valve 50 is opened.
Time will be earlier than normal assembly
Therefore, as is apparent from FIG.
Start to open at a position closer to the bottom dead center BDC compared to the standing state
As a result, the exhaust pressure maximum value P _EXmax′ Is the exhaust side pressure
It becomes smaller by the absolute value of the maximum value difference α. On the other hand, the exhaust side pressure
Invariable value P_EXconst'Is the exhaust pressure maximum P_EXmax'of
Not as small, almost the same size as normal assembly
Becomes

The exhaust-side pressure decrease start angle difference Φ, the exhaust-side pressure maximum value reaching angle difference Γ, and the exhaust-side pressure unchanged state transition angle difference Σ.
Is an angle corresponding to one tooth of the cam pulleys 24 and 26 when the cam pulley advances by one tooth. That is, the rotation angle of the cam pulleys 24 and 26 is 360 degrees / 48 sheets = 7.5 degrees, and this angle corresponds to the rotation angle of the crank pulley 20 of 15 degrees. On the other hand, when one tooth delay occurs in the crank pulley 20, the magnitude of the exhaust-side pressure maximum value arrival angle difference Γ or the like is 360 degrees / 24 sheets = 15 degrees in rotation angle of the crank pulley 20. in this way,
For example, when the right cam pulley 26 has advanced one tooth,
The occurrence of one tooth delay in the crank pulley 20 is substantially the same for the cylinder in the right bank,
Exhaust side pressure maximum value P of the cylinder included in the right bank
_EXmax ', the exhaust-side pressure maximum value arrival angle difference Γ, etc. are also substantially the same.

When one tooth of the crank pulley is advanced or one tooth of the cam pulley is delayed, the start of compression by the piston (included in the bank in which the latter occurs) is relatively shorter than in the normal assembly state. As shown in FIG. 18, the exhaust-side pressure decrease start angle θ _EXdec ',
The exhaust-side pressure maximum value reaching angle θ _EXmax ′ and the exhaust-side pressure unchanged state transition angle θ _EXconst ′ are those in the normal assembly state.
_EXdec , _θEXmax, and _θEXconst are larger by the absolute values of the exhaust-side pressure decrease start angle difference Φ, the exhaust-side pressure maximum value arrival angle difference Γ, and the exhaust-side pressure unchanged state transition angle difference Σ, respectively. The values of the exhaust-side pressure decrease start angle difference Φ, the exhaust-side pressure maximum value arrival angle difference Γ, and the exhaust-side pressure unchanged state transition angle difference Σ have substantially the same magnitude. Intake valve 50
The time when the opening starts is delayed as compared with the normal assembly state.
Therefore, as apparent from FIG. 6, the position of the piston starts to open at a position closer to the top dead center TDC as compared with the normal assembly state, and the exhaust-side pressure maximum value P _EXmax ′ is different from the exhaust-side pressure maximum value difference α. By the absolute value of. On the other hand, the exhaust-side pressure _invariable value P _{EXcons t} ′ is the exhaust-side pressure maximum value P
_{It does} not become as large as _EXmax ', and is almost the same size as the normal assembly state.

The magnitude of the exhaust-side pressure maximum value arrival angle difference Γ or the like depends on the above-described crank pulley 1 tooth delay or the cam pulley 1
As in the case where the tooth advance occurs, the rotation angle of the cam pulleys 24 and 26 is 360 degrees / 48 sheets = 7.5 degrees, or the rotation angle of the crank pulley 20 is 360 degrees / 24 sheets = 15 degrees. For example, the occurrence of one tooth delay in the right cam pulley 26 and the occurrence of one tooth advance in the crank pulley 20 are substantially the same for the cylinder in the right bank, and the exhaust side of the cylinder in the right bank. Maximum pressure value P
_EXmax ', the exhaust-side pressure maximum value arrival angle difference Γ, etc. are also substantially the same.

Next, the influence of the driven gear advance / delay will be described. 19 and FIG. 20 is a graph showing changes in the exhaust pressure P _EX of each cylinder when the right driven gear one tooth advances and delays occur each with a crank reference signal. As is apparent from these graphs, the change in the exhaust pressure _PEX of the piston included in the right bank is different from that in the normal assembly state. Details will be described later. When the right driven gear advances or delays by one tooth, the intake pressure P _IN also changes as shown in FIG. As is clear from this figure, when the right driven gear is advanced by one tooth, the intake-side pressure maximum value reaching angle θ _INmax and the intake-side pressure increase start angle θ _{INinc, which} are indicated by even numbers, are:
The value is smaller than that in the normal assembly state. If the right driven gear is one tooth behind, on the other hand, the intake-side pressure maximum value reaching angle θ _INmax becomes larger than in the normal assembly state. When the left driven gear is advanced / delayed by one tooth, the intake pressure P _IN of the cylinder corresponding to the cylinder having an odd piston number changes.

[0044] Figure 22 is a graph showing a normal assembled condition, and if the right driven gear one tooth advances occurs, a change in the exhaust pressure P _EX of cylinders included in the right bank.
The driven gear 42 determines the opening / closing timing of the intake valve 50 in the right bank. Since the driven gear advances by one tooth, the exhaust-side pressure maximum value reaching angle θ _EXmax ′ is determined by the driven gear 42.
Becomes smaller by an angle corresponding to one tooth. In the present embodiment, the number of teeth of the driven gears 40 and 42 is 40, so that the rotation angle of the driven gear 42 is 360 degrees /
40 sheets = about 9 degrees. This angle is the crank pulley 2
0 corresponds to a rotation angle of 18 degrees. With this angle change, the exhaust-side pressure maximum value P _EXmax 'and the exhaust-side pressure invariant value P _EXconst ' decrease by the absolute value of the exhaust-side pressure maximum value difference α and the exhaust-side pressure _invariable value difference β, respectively. .
In addition, the exhaust-side pressure unchanged state transition angle θ _EXconst ′ becomes smaller than the exhaust-side pressure unchanged state transition angle θ _EXconst in the normal assembly state by the absolute value of the exhaust-side pressure unchanged state transition angle difference Σ. . Normally, the exhaust-side pressure unchanged state transition angle θ _EXconst is determined by the timing at which the exhaust valve 48 closes. However, when the driven gear is advanced by one tooth, the exhaust-side pressure maximum value reaching angle θ _EXmax ′ is low. This is because the exhaust side pressure P _EX reaches an equilibrium state before 48 closes.

FIG. 23 shows a normal assembly state and a right driven state.
Included in right bank with one gear delay
Exhaust pressure P of cylinder_EX6 is a graph showing a change in the graph.
In this case, contrary to the case shown in FIG.
Maximum force reaching angle θ_EXmax′ Is the exhaust-side pressure maximum value arrival angle
The absolute value of the difference 大 き is larger than the value in the normal assembly state
It becomes. In addition, the transition angle of the exhaust side pressure unchanged state
θ_EXconst′ And the transition angle difference Σ
The size does not change. Exhaust pressure maximum value arrival angle
θ_EXmax', The exhaust-side pressure maximum P
_EXmax'And the exhaust side pressure unchanged value P _EXconst′
Exhaust side pressure maximum value difference α and exhaust side pressure invariable value
It increases by the absolute value of the difference β.

FIG. 24 shows the exhaust-side pressure maximum value arrival angle difference Γ, the exhaust-side pressure unchanged state transition angle difference Σ, and the exhaust-side pressure maximum value when only one of the various types of assembly failure described above occurs. This shows an example of values such as the difference α and the exhaust-side pressure invariable value difference β. In FIG. 24, the value of each pressure difference is
As described above, the exhaust-side pressure maximum value P in the normal assembly state
It is represented by a relative value with _EXmax being 100, and is measured based on a crank reference signal output by the crank angle sensor 114. In addition, in the case where the advance / delay of one crank pulley occurs, the respective values for both the left and right banks indicate the same magnitude, whereas in the case of advance / delay of one tooth of the cam pulley and advance / delay of one driven gear. Indicates that the pressure and angle of only the bank on which it occurred changes. Although very rare, the advance / delay of one tooth of the cam pulley or the advance / delay of one tooth of the driven gear may occur in both the left and right banks. The values when the intake-side valve clearance and the exhaust-side valve clearance are too small or too large change continuously according to the size of the clearance. The values in FIG. 24 indicate that the clearance is too small or too large. This is just an example of a value that can be detected.

The values of the angles such as the exhaust-side pressure maximum value arrival angle difference 排 気, the exhaust-side pressure unchanged state transition angle difference 排 気, and the exhaust-side pressure decrease start angle difference Φ shown in FIG. , The reference angle (for example, zero crank angle) is determined, and is a value that cannot be obtained unless the difference between the reference angle and the current crank angle is calculated. Comparison of side pressure maximum value arrival angle difference Γ etc. (for example, the difference between cylinders that are adjacent to each other in the explosion order, the difference between even-numbered cylinders, etc.)
It cannot be obtained based on This can be understood from the definitions of the exhaust-side pressure maximum value arrival angle difference Γ, the exhaust-side pressure unchanged state transition angle difference Σ, and the exhaust-side pressure decrease start angle difference Φ described above with reference to FIGS. it is obvious. But,
Each value shown in FIG. 24 is closely related to the information obtained by comparing the values obtained for each cylinder, and if the information obtained based on the comparison for each cylinder is used, the In some cases, it is possible to inspect the assembled state of the engine without knowing the value of the crank angle itself based on the output of the angle sensor 114. Hereinafter, the description will be made.

Obtained based on the comparison of each cylinder
As an example of such information, the exhaust-side pressure maximum value arrival angle
θ_EXmax, Exhaust pressure start angle θ_EXdecAnd exhaust side
Pressure change state transition angle θ_EXconstPhase in the explosion order
Exhaust-side pressure maximum value, which is the difference between preceding and following cylinders
Angle of arrival relative value Δ 相 対_i, Exhaust side pressure decrease start angle relative value ΔΦ_i
And exhaust-side pressure unchanged state transition angle relative value ΔΣ_i(I =
Inspection of engine assembly condition that can be performed using 1) to 6)
explain about. Note that the exhaust side pressure maximum value arrival angle relative value
ΔΓ_iIs the exhaust-side pressure maximum value of the (i + 1) th cylinder
Arrival angle θ_EXmaxFrom that of the ith cylinder
The exhaust side pressure decrease start angle relative value ΔΦ _i, Exhaust
Air side pressure unchanged state transition angle relative value ΔΣ_iThe same applies to
(However, if the value of i + 1 exceeds 6, then
It shall be read as a value obtained by subtracting 6 from the value. The following theory
The same applies to the following.)

FIG. 25 shows the relative value Δ 排 気_{i of the} maximum value of the exhaust-side pressure, the relative value ΔΦ _{i of the} angle at which the exhaust-side pressure starts decreasing, and the relative angle of the transition of the exhaust-side pressure unchanged state in the waveform of the exhaust-side pressure P _EX of each cylinder. is a diagram illustrating the magnitude of the value .DELTA..SIGMA _i. To obtain these values, the output of the crank angle sensor 114 is unnecessary. For example, to get the exhaust side pressure maximal value reached angle relative value [Delta] [gamma] _i, first, obtains the time at which the output of the pressure sensor 106 is the maximum value for every cylinder (This time, in this embodiment , Decision unit 117
, Which are obtained by a timer (not shown) included in the above), and the difference between these values is taken between adjacent cylinders. This difference is a time difference obtained by the timer. To convert the difference into a crank angle difference, 720 degrees (one cycle of one cycle) is obtained by dividing each time difference by the sum of the six time differences. (Crank angle). To get the exhaust side pressure decrease start angle relative value .DELTA..PHI _i, the output value of the pressure sensor 106 state (exhaust pressure P _EX) may considered to be constant (as is clear from FIG. 6, the present embodiment Inspection engine 9
0, this period is 60% or more of one cycle), and when the time at which it begins to rapidly decrease is specified for each cylinder, the exhaust-side pressure maximum value reaching angle relative value ΔΓ _i It can be obtained in the same way. Also, to get the exhaust side pressure immutable state transition angle relative values .DELTA..SIGMA _i is contrary to the exhaust side pressure decrease start angle relative values .DELTA..PHI _i, exhaust pressure P
_The time at which the state in which _EX can be considered to be fluctuating can be specified for each cylinder from the state in which it can be considered to be constant. These exhaust-side pressure maximum value arrival angle relative values ΔΓ
_i , the method of acquiring the exhaust side pressure decrease start angle relative value ΔΦ _i and the exhaust side pressure unchanged state transition angle relative value ΔΣ _i are referred to as a time difference dependent angle relative value acquisition method.

Exhaust-side pressure maximum value arrival angle relative value ΔΓ_i, Exhaust
Air side pressure decrease start angle relative value ΔΦ_iAnd exhaust side pressure unchanged
Transition angle relative value ΔΣ_iIs the exhaust side pressure
Maximum value arrival angle difference Γ_i, Γ_{i + 1} , Exhaust side pressure decrease start angle difference
Φ_i, Φ_{i + 1} And exhaust side pressure unchanged state transition angle difference
Σ_i, Σ_{i + 1} Is affected by the value of
It changes depending on the state. For example, Kampoo in the right bank
In the state where the tooth is advanced by one tooth (the state shown in FIG. 25)
Exhaust pressure maximum value arrival angle relative value ΔΓ_iIs shown in FIG.
As shown. In this figure, 1 is arranged on the circumference.
The numbers from 6 to 6 indicate the cylinder numbers, and their numbers
The position of the letter indicates the exhaust side pressure P in a normal assembly state._EXIs a pole
This shows a large phase. Also, one circumference of this circumference is 7
It corresponds to 20 degrees. In the present embodiment,
Since the position with the crank angle of zero is unnecessary, it is not shown.
Was. Exhaust-side pressure maximum value arrival angle relative to normal assembly state
Value ΔΓ _iIs 720 degrees / 6 cylinders = 120 degrees.
Is the average of the exhaust-side pressure maximum value arrival angle relative value ΔΓ_mExpressed by

When the cam pulley of the right bank advances by one tooth
The maximum pressure on the exhaust side of the odd-numbered cylinder
The angle difference ゼ ロ is zero, while the even-numbered cylinder
The exhaust pressure maximum value reaching angle difference Γ is no longer zero, and FIG.
According to 4, Γ₁ = Γ_Three = Γ _Five = 0, Γ_Two = Γ_Four = Γ₆ 
= −15. Based on these values,
Corresponding exhaust-side pressure maximum value arrival angle relative value ΔΓ_iThe exhaust
Side pressure maximum value arrival angle difference Γ_iAnd expressed as
be able to. ΔΓ_i= ΔΓ_m+ Γ_{i + 1} −Γ_i (1) Specifically, the following values are obtained. ΔΓ₁ = ΔΓ_m+ Γ_Two −Γ₁ = 120 + (-15) -0
= 105 ΔΓ_Two = ΔΓ_m+ Γ_Three −Γ_Two = 120 + 0-(-15)
= 135 ΔΓ_Three = ΔΓ_m+ Γ_Four −Γ_Three = 120 + (-15) -0
= 105 ΔΓ_Four = ΔΓ_m+ Γ_Five −Γ_Four = 120 + 0-(-15)
= 135 ΔΓ_Five = ΔΓ_m+ Γ₆ −Γ_Five = 120 + (-15) -0
= 105 ΔΓ₆ = ΔΓ_m+ Γ₁ −Γ₆ = 120 + 0-(-15)
= 135 According to the above rules, when the value of the variable i is 6,
i + 1 was read as 1. Thus, the normal assembly state
Then, the phases indicated by 2, 4 and 6 are
In the one-tooth advanced state, 2 ', 4',
6 '.

Exhaust-side pressure decrease start angle relative value ΔΦ_i,exhaust
Side pressure unchanged state transition angle relative value ΔΣ _iAbout (1)
An expression similar to the expression holds. ΔΦ_i= ΔΦ_m+ Φ_{i + 1} −Φ_i ... (2) ΔΣ_i= ΔΣ_m+ Σ_{i + 1} −Σ_i ... (3) The average of the relative values of the exhaust-side pressure decrease start angle ΔΦ_m= Exhaust side
Pressure change state transition angle relative value average ΔΣ_m= Exhaust pressure pole
Large value arrival angle relative value average ΔΓ_m= 120 degrees. Even now
If the values shown in FIG. 24 are known, those values are
Substituting into equations (1), (2) and (3) gives
Exhaust-side pressure maximum value arrival angle in the state where goodness occurs
Relative value ΔΓ_i, Exhaust side pressure decrease start angle relative value ΔΦ_iAnd
And exhaust-side pressure unchanged state transition angle relative value ΔΣ_iGet value of
can do. And a plurality of assembly defects occur.
In this case, Γ in equations (1), (2) and (3)
_{i + 1} −Γ_i, Φ_{i + 1} −Φ_iAnd Σ_{i + 1} −Σ_iAnd it
For each assembly defect, collect and add
Angle phase at which the exhaust-side pressure local maximum value is reached when assembly failure occurs
Logarithmic value ΔΓ_i, Exhaust side pressure decrease start angle relative value ΔΦ_iand
Exhaust side pressure unchanged state transition angle relative value ΔΣ_iGet the value of
Can be However, the converse is not always true. Duplicate
When an unspecified number of assembly defects can occur,
The exhaust side pressure pole is determined by the time difference dependent angle relative value acquisition method described above.
Large value arrival angle relative value ΔΓ_i, Exhaust side pressure decrease start angle relative value
ΔΦ_iAnd exhaust-side pressure unchanged state transition angle relative value ΔΣ_i
Even after obtaining the
In some cases, it cannot be specified.

For example, as is apparent from FIG.
If one pulley leads / lags,
One pulley advance / delay of driven pulley and one tooth advanced / delay of driven gear
Occurs simultaneously in both the left and right banks,
Cylinder exhaust side pressure maximum value arrival angle difference Γ, exhaust side pressure decrease
Small start angle difference Φ and exhaust side pressure unchanged state transition angle difference Σ
Since they have the same value, equations (1), (2) and (3)
ΔΓ_i= ΔΓ _m= ΔΦ_i= ΔΦ_m= ΔΣ_i= Δ
Σ_m= 120 degrees, and cannot be distinguished from the normal assembly state.
In addition, the cam pulley advances one tooth in the right bank, and
The case where the left bank is in a normal assembly state and the case where the right bank is
Normally assembled and left bank is one tooth behind cam pulley
It is indistinguishable. In addition, the intake valve
The state of the clearance and the exhaust valve clearance are all
The same defective assembly state (for example, all cylinder suction
If the air valve clearance is small, the normal set
Indistinguishable from standing. Thus, the exhaust pressure maximum value
Arrival angle relative value ΔΓ_iInspection based on normal assembly
Although it is not always possible to reliably check for
As explained below, several assembly failures occur simultaneously.
If you know you may be
To identify at least candidates for multiple assembly defects
You can do it. In addition, this candidate for assembly failure
Contains all the actual assembly defects
There is no guarantee. However, at least those multiple
If good candidates could be identified, those assembly defects were eliminated
Later, the engine assembly defect inspection of this embodiment is further performed.
This allows inspection to be performed despite the presence of defective assembly.
Avoid the situation where the inspection result becomes non-defective
Can be

FIG. 27 shows an R (not shown) in the decision unit 117.
9 is a flowchart illustrating an example of a main process of an assembly state inspection program stored in the OM and executed by the CPU and the RAM. In this main process,
The presence or absence of a defective assembly is inspected based on values such as the exhaust-side maximum pressure value P _EXmax corresponding to each of the pistons # 1 to # 6 of the engine 90 to be inspected. A display indicating that the inspection has passed is performed on the display (see FIG. 28). If there is a defective assembly, the defective portion is estimated, and then based on the estimation result, a display indicating that the inspection has failed is displayed. And a display indicating the defective portion.

First, in step 102 (hereinafter simply referred to as S102; the same applies to other steps), the variable count
t is initialized to zero. Then, in S104, the variable i
Is substituted for zero corresponding to piston # 1. The value obtained by adding 1 to the value of the variable i indicates the piston number. Next, in S106, it is determined whether the absolute values of the exhaust-side pressure maximum value difference α _i and the exhaust-side pressure invariable value difference β _i of the (i + 1) -th piston are all less than 3, and the result is NO. If there is, after the value of the variable count is incremented in S108, and if YES, directly in S110, the value of the variable i is 5 (piston # 6).
Is determined, and if not 5, 1 is added to the value of the variable i in S111 and S106
Are repeated.

In step S106, the exhaust-side pressure maximum value difference α
The absolute value of _i and the exhaust-side pressure invariable value difference β _i is compared with 3 because, as is clear from FIG. This is because the inspection target engine 90 can be said to be in a normal assembly state. If the decision result in S110 is YES, S11
In step S2, it is determined whether the value of the variable count is equal to 0, and if the result is YES, the display 1
After the process of displaying a display indicating the pass of the inspection at 18 is executed, the main process ends. If the determination result in S112 is NO, it means that the engine 90 to be inspected has failed the inspection.
8, a defective portion estimation process, which is a subroutine, is executed. Based on the estimation result, in S120,
The display lamp corresponding to the estimated defective portion on the display 118 is turned on, and the main processing ends.

As the display 118, for example, FIG.
The following can be used. In FIG. 28, reference numeral 200 denotes an OK lamp that is turned on when the inspection result passes, and reference numeral 202 denotes an NG lamp that is turned on when the inspection fails. If the inspection result is unsuccessful, the following lamp group indicating the content is turned on. That is, the crank pulley advance ramp 204 and the crank pulley delay ramp 2
06, left bank cam pulley advance ramp 208, left bank cam pulley delay ramp 210, right bank cam pulley advance ramp 212, right bank cam pulley delay ramp 214, left bank driven gear advance ramp 216, left bank driven gear delay ramp 218, right bank The driven gear advance lamp 220 and the right bank driven gear delay lamp 222 can be turned on independently of each other. Further, for each piston number, a small intake valve clearance lamp 224 and a large intake valve clearance lamp 22 are provided.
6, each lamp of the small exhaust valve clearance lamp 228, the large exhaust valve clearance lamp 230, and the compression ring missing lamp 232 can be turned on independently. Also, as described later, when the inspection result is unclear, that is, when there is a possibility that an assembly defect has occurred but it cannot be said that it has necessarily occurred, the lamp at the unclear point blinks. Can be These lamp groups indicating defective assembly locations are collectively referred to as defective assembly position indicating lamp groups.

FIG. 29 is a flowchart showing an example of the content of the defective portion estimation processing shown in S118 of FIG. In this defective portion estimation routine, first, S200
In the above, 0x is set to the flag indicating the presence or absence of each
00 is set (cleared to zero). These flags are collectively referred to as defective location flags. The defective portion flag in the present embodiment is composed of eight 1-byte data defined as shown in FIG.
If x00, it indicates that there is no assembly failure. flag
_drvn and flag _cam are defective portion flags indicating whether or not the lower 4 bits have a driven gear advance / delay and a cam pulley advance / delay of the left and right banks. The defective part flag flag _crnk indicates the presence / absence of advance / delay of the crank pulley by using lower two bits. Also, flag _ins ,
flag _inl , flag _exs , flag _exl , flag
_ring is a defective portion flag indicating whether there is an assembly failure such as a small intake valve clearance, a large intake valve clearance, a small exhaust valve clearance, a large exhaust valve clearance, and a missing compression ring by a state of lower 6 bits corresponding to each cylinder. It is.

The bit number 7 of each defective portion flag
The two bits (the most significant bit) and bit number 6 are error possibility indication bits, and are called error 1 and error 2 bits, respectively. When the error 1 bit is set to 0, the error 2 bit is always set to 0, and the state of the other bits of each defective portion flag indicates the inspection result. However, when the error 1 bit is 1, the error 2 bit has a value of 0 or 1. First, when the error 2 bit is 0, assembling of the bit corresponding to the bit set to 0 among the other bits of each defective portion flag (excluding the bits having no meaning indicated by "-"). It is adapted to indicate that the condition includes a possible bad condition. Then, each of the display lamps corresponding to the lower 6 bits set to 0 is blinked. In addition, when the error 2 bits are 1, it indicates that the assembly state corresponding to the bit set to 1 out of the lower 6 bits includes the possibility of failure. Then, each of the display lamps corresponding to the bit set to 1 of the lower 6 bits is caused to blink. In other words,
In the case of (1), it is determined that an assembly failure corresponding to the bit set to 1 has occurred.
That is, it is specified that no assembly failure corresponding to the determined bit has occurred. In addition, in the case of, the lamp corresponding to the bit set to 0 is blinked, and the lamp corresponding to the bit set to 1 is turned on.
In the case of, the lamp corresponding to the bit set to 1 blinks, and the lamp corresponding to the bit set to 0 remains turned off.

Subsequent to S200, in S202, a driven gear 1 tooth advance inspection which is a subroutine for inspecting whether one of the left and right banks is in a driven gear 1 tooth advanced state is executed. Then, S
After a small exhaust valve clearance test, which is a subroutine for checking whether the exhaust valve of each cylinder is in a small exhaust valve clearance state, is performed in 204, in S206, one of the left and right banks is set to a cam pulley. A cam pulley inspection, which is a subroutine for inspecting whether one tooth is advanced or delayed, is executed. Subsequently, in step S208, the subroutine for checking whether one of the left and right banks is behind the driven gear by one tooth, and the state of the valve clearance of the intake valve of each cylinder is performed. A valve clearance inspection is performed. Next, after a large exhaust valve clearance inspection is performed in S210, a compression ring missing inspection is performed in S212. And finally, S2
In 14, after the auxiliary processing is performed, the defective portion estimation processing ends. Note that, in the defective portion estimating process of the present embodiment, an inspection for specifying advance / delay of one tooth of the crank pulley is not performed. Therefore, if the determination result in S112 of FIG. 27 is NO, the defective portion flag flag
The most significant bit of _crnk is always set to 1 (described later).

FIG. 31 is a flowchart showing the contents of the driven gear 1 tooth advance inspection which is a subroutine called in S202 of FIG. This process is performed on the basis of the value of the exhaust-side pressure decrease start angle relative value ΔΦ _i and the value of the exhaust-side pressure unchanged state transition angle relative value ΔΣ _i irrespective of whether or not another assembly defect has occurred. It is to check whether the driven gear of any bank is in a state of being advanced by one tooth. As described above, in the left and right banks, it is not possible to distinguish between the case where the driven gear advances one tooth at the same time and the normal assembly state. Therefore, this fact is reflected in the left bank driven gear advance ramp 216 and the right bank driven gear advance ramp 22 as described below.
0 is indicated by blinking together.

First, in S300, the left and right banks
Transition of exhaust side pressure unchanged state for cylinders included in
Angle relative value ΔΣ_iAnd exhaust side pressure decrease start angle relative value ΔΦ_iWhen
Variable for each cylinder based on_iIs given by
Is calculated. ζ_i= (ΔΣ_i+ ΔΦ_i)% 30 (4) Exhaust-side pressure unchanged state transition angle relative value ΔΣ_iAnd exhaust side pressure
Decrease start angle relative value ΔΦ _iMeans, as described above,
Exhaust pressure P_EXObtained by analyzing the changing state of
You. “%” Is a so-called modulo operator, and “a%
b ″ represents the remainder of dividing a by b. The value of the variable i
Is odd (the cylinder indicated by the variable i is
Variable (if included in the link)_iΖ_odd, Is even
(If included in the right bank)_evenIndicated by

Thus, the variable ζ_iNo change in exhaust side pressure
State transition angle relative value ΔΣ_iAnd relative value of the exhaust side pressure decrease start angle
ΔΦ_iThe i-th value is set based on the sum of
Cylinder is in the small exhaust valve clearance state
The exhaust-side pressure unchanged state transition angle relative value ΔΣ_iAnd exhaust
Air side pressure decrease start angle relative value ΔΦ_iHave different signs
Because they have almost the same effect,
Therefore, the effect can be canceled. What
Note that the exhaust-side pressure unchanged state transition angle relative value ΔΣ_iAnd exhaust side
Pressure decrease starting angle relative value ΔΦ_iAnd affect the exhaust valve
The magnitude of the effect of the rear assembly condition is always constant.
Not necessarily. In fact, with small exhaust valve clearance
In some cases, the exhaust side pressure does not change compared to the normal assembly state
State transition angle difference だ け is any value within the range of 2 to 10
And the exhaust side pressure does not change as shown in FIG.
The value (6.4) of the state transition angle difference 範 囲 is in the range of 2 to 10.
Is just an example of the values in. Exhaust side pressure unchanged state transition angle
The difference Σ (and, consequently, the exhaust-side pressure-invariable state transition angle relative value ΔΣ
_i), The magnitude of which fluctuates, but the exhaust side pressure
Force decrease start angle difference Φ (and the exhaust side pressure decrease start angle relative
Value ΔΦ_i) Will vary as well,
Since the signs of the influences are opposite, the exhaust side pressure
Force change state transition angle relative value ΔΣ_iAnd exhaust side pressure decrease start
Angle relative value ΔΦ _iThe value of the sum with the exhaust valve clearance
It is not affected by small states. Where ΔΣ_odd+
ΔΦ_oddAnd ΔΣ_even+ ΔΦ_evenThe calculation of
It is necessary to use the value in the same cylinder. this child
Is the equation (4) calculated in the process of actual engine inspection
ΔΣ that is part of_i+ ΔΦ_iCalculation of the same cylinder
Exhaust-side pressure unchanged state transition angle relative value ΔΣ_iAnd
And exhaust side pressure decrease start angle relative value ΔΦ_iDone based on
Indicates that it needs to be done. It should be noted that
Exhaust side pressure is unchanged when exhaust valve clearance is large
The transition angle difference Σ and the exhaust side pressure decrease start angle difference Φ are affected.
As a result, the transition angle relative to the exhaust-side pressure unchanged state
Value ΔΣ_iAnd exhaust side pressure decrease start angle relative value ΔΦ_iSum with
Is affected by both large and small exhaust valve clearances.
It will not be.

[0064] Then, the variable zeta _i, and the exhaust side pressure immutable state transition angle relative values .DELTA..SIGMA _i exhaust pressure decrease start angle relative value Δ
The remainder obtained by dividing the sum of Φ _i (the value from which the influence of the small exhaust valve clearance is removed) by 30 is set because the assembled state of the cam pulley is the exhaust-side pressure unchanged state transition angle relative value ΔΣ _i And exhaust side pressure decrease start angle relative value ΔΦ
The value of the sum with _i is a value in units of 30 (15 + 15 = 3
0) is added or subtracted. On the other hand, the effect of one tooth advance of the driven gear is smaller than 30, so that only the effect of the assembled state of the cam pulley can be removed by such calculation. Eventually, the value of the variable zeta _i which is set based on equation (4), an exhaust valve without being affected by the clearance of state and assembled state of the cam pulley and the driven gear of the left or right of the bank 1 tooth proceeds state It is a value that is affected by whether or not.

Now, the equation (4) is replaced by the equations (2) and (3)
By substituting the exhaust-side pressure decrease start angle relative value ΔΦ _i and the exhaust-side pressure unchanged state transition angle relative value ΔΣ _i expressed by the equations, the following equation is obtained. ζ _i = (ΔΣ _m + Σ _{i + 1} −Σ _i + ΔΦ _m + Φ _{i + 1} −
Φ _i )% 30 Here, the exhaust-side pressure decrease start angle relative value average ΔΦ _m = the exhaust-side pressure unchanged state transition angle relative value average ΔΣ _m = 120 degrees. This expression, the value of the variable zeta _i have shown that can be calculated from the value of the exhaust side pressure decrease start angle difference Φ and the exhaust side pressure immutable state transition angle difference Σ shown in FIG. 24. Actual during engine testing the value of the exhaust pressure decrease start angle difference Φ and the exhaust side pressure immutable state transition angle difference Σ of Figure 24 is not known, the variable zeta _i is is being calculated by the equation (4), Using the values in FIG. 24, the above equation (ΔΣ _m + Σ _{i + 1} −Σ
_i + ΔΦ _m + Φ _{i + 1} −Φ _i )% 30 is easier to understand, so the following description will be made using this formula.

Next, in step S302, the value calculated in step S300 is set as a set of values of the variable ζ _i (ζ _odd , ζ _even ).
Are (0,0), (8.4, 21.6) and (2
(1.6, 8.4) is determined. The value of (ζ _odd , ζ _even ) is one of these three. Hereinafter, the reason will be described. First, the driven gear are assembled correctly, if a state does not occur even other defective assembly, the value of the exhaust side pressure immutable state transition angle relative values .DELTA..SIGMA _odd and .DELTA..SIGMA _{ev en,}
The values of the exhaust-side pressure decrease start angle relative values ΔΦ _odd and ΔΦ _even are as follows. ΔΣ _odd = ΔΣ _m + Σ _even -Σ _odd = 120 + 0-0 =
120 ΔΣ _even = ΔΣ _m + Σ _odd -Σ _even = 120 + 0-0 =
120 ΔΦ _odd = ΔΦ _m + Φ _even -Φ _odd = 120 + 0-0 =
120 ΔΦ _even = ΔΦ _m + Φ _odd -Φ _even = 120 + 0-0 =
120 Based on these values, the values of the variables ζ _odd and ζ _even are as follows. ζ _odd = (ΔΣ _odd + ΔΦ _odd )% 30 = (120 + 1)
20)% 30 = 0ζ _even = (ΔΣ _even + ΔΦ _even )% 30 = (120 + 1)
20)% 30 = 0

On the other hand, when the driven gear in the left bank is advanced by one tooth and no other assembly failure occurs, the following values are obtained. ΔΣ _odd = ΔΣ _m + Σ _even -Σ _odd = 120 + 0-(-
8.4) = 128.4 ΔΣ _even = ΔΣ _m + Σ _odd −Σ _even = 120 + (− 8.
4) −0 = 1111.6 ΔΦ _odd = ΔΦ _m + Φ _even −Φ _odd = 120 + 0−0 =
120 ΔΦ _even = ΔΦ _m + Φ _odd -Φ _even = 120 + 0-0 =
120 Based on these values, the values of the variables ζ _odd and ζ _even are as follows. ζ _odd = (ΔΣ _odd + ΔΦ _odd )% 30 = (128.4
+120)% 30 = 8.4 ζ _even = (ΔΣ _even + ΔΦ _even )% 30 = (111.6)
+120)% 30 = 21.6

When the driven gear in the right bank is in a state where only one tooth is advanced, the following values are obtained. ΔΣ _odd = ΔΣ _m + Σ _even -Σ _odd = 120 + (− 8.
4) −0 = 1111.6 ΔΣ _even = ΔΣ _m + Σ _odd −Σ _even = 120 + 0 − (−
8.4) = 128.4 ΔΦ _odd = ΔΦ _m + Φ _even -Φ _odd = 120 + 0-0 =
120 ΔΦ _even = ΔΦ _m + Φ _odd -Φ _even = 120 + 0-0 =
120 Based on these values, the values of the variables ζ _odd and ζ _even are as follows. ζ _odd = (ΔΣ _odd + ΔΦ _odd )% 30 = (111.6
+120)% 30 = 21.6 ζ _even = (ΔΣ _even + ΔΦ _even )% 30 = (128.4)
+120)% 30 = 8.4 For the above reasons, if no other assembly failure has occurred, the value of (ζ _odd , ζ _even ) is (0, 0) when the driven gear is normally assembled. ), When the driven gear in the left bank is advanced by one tooth (8.4, 21.).
6), (21.6, 8.4) when the driven gear in the right bank advances only one tooth.

Therefore, which of these is S3
02, when the value of (ζ _odd , ζ _even ) is (0, 0), after the indefinite processing is performed in S304, and when the value is (8.4, 21.6),
After the processing indicating that the driven gear in the left bank is advanced by one tooth in 306 is executed, (21.
In the case of (6, 8.4), after performing the processing indicating that the driven gear in the right bank is advanced by one tooth in S308, the driven gear one tooth advance inspection ends. S304
The processing content of 0x01 indicating that the driven gear of the left bank is advanced by one tooth is set in the defective portion flag flag _drvn.
Of 0x05, which is the logical sum of 0x04 indicating the advance of the driven gear in the right bank and 1x of the driven gear, and 0xC0 (0xC0)
This is a process for setting C5). The logical OR with 0xC0 means that the driven gears of the left and right banks are advanced by one tooth and, at the same time, the error possibility indication bits consisting of the upper two bits are both set to 1. The left bank driven gear advance ramp 216 and the right bank driven gear advance ramp 220
Will blink together. The processing content of S306 is to substitute 0x01 indicating that the driven gear is advanced by one tooth in the left bank into the defective portion flag flag _drvn , and the processing content of S308 is that the defective portion flag fl
ag _drvn is 0 indicating that the driven gear in the right bank advances by one tooth
x04.

In the above description, (ζ _odd ,
ζ _even ) is assumed to be one of three values (0, 0), (8.4, 21.6) and (21.6, 8.4). Incorrect. Actually, both the variables ζ _odd and ζ _even include an error, but the magnitude of this error can be known by actual measurement.
For example, the value is at most about ± 2. Therefore, the values of (ζ _odd , ζ _even ) are (−2 to 2, −2), respectively.
2), (6.4 to 10.4, 19.6 to 23.6) and (19.6 to 23.6, 6.4 to 10.4). . (Ζ _odd , ζ _even )
Falls within any of these ranges. The above (ζ _odd , ζ _even ) may be used alone, or may be used while taking into account the value of the variable ζ _i of a cylinder different from the cylinder from which those values were obtained. Performing an inspection using the average value of the variables ζ _odd and ζ _even obtained for the three cylinders of each bank is an example. Therefore, it can be understood that in the driven gear one tooth advance inspection shown in FIG. 31, comparison is performed between at least one cylinder included in each of the left and right banks. In this test, the value of the variable ζ _i obtained for each cylinder is classified into odd and even values of the variable i, and it is understood that the comparison is performed between the groups. You can also.

Next, the exhaust valve clearance small inspection which is a subroutine called in S204 will be described. FIG. 32 is a flowchart showing the contents. First, in S400, the value of the variable eta _i for each cylinder indicated by the variable i is calculated by the following equation. η _i = {ΔΦ _i −ΔΣ _i −f (ζ _i )} / 2 (5) The values of the exhaust-side pressure decrease start angle relative value ΔΦ _i and the exhaust-side pressure unchanged state transition angle relative value ΔΣ _i are: As described above, it is obtained by analyzing the change state of the exhaust-side pressure P _EX of each cylinder. Further, the function f ( _i ) is used to remove the influence of the case where one of the right and left banks, which can be included in the value of the exhaust-side pressure invariable state transition angle relative value ΔΣ _i , is one step ahead of the driven gear. In the case where the bank including the cylinder indicated by the variable i is advanced by one tooth of the driven gear according to the variable ζ _i obtained by the above equation (4),
8.4 is set to 8.4 when the bank that does not include the cylinder indicated by the variable i is driven gear one tooth advance, and 0 when both the left and right banks are not driven gear one tooth advance (or both are one tooth advanced). These are functions that return. The value of the function f (ζ _i), similar to the variable zeta _i, shows the same value as when the case where it is proceeds left driven gear 1 tooth both banks left no advances driven gear 1 tooth both banks, the This does not affect the inspection of whether the exhaust valve clearance is small.

By substituting the exhaust-side pressure decrease start angle relative value ΔΦ _i and the exhaust-side pressure unchanged state transition angle relative value ΔΣ _i expressed by the equations (2) and (3) into the above equation (5), ,
The following equation is obtained. η _i = ｛(ΔΦ _m + Φ _{i + 1} −Φ _i ) − (ΔΣ _m + Σ _{i + 1}
−Σ _i ) −f (ζ _i )｝ / 2 = {Φ _{i + 1} −Φ _i − (Σ
_{i + 1} −Σ _i ) −f (ζ _i ) こ こ / 2 where exhaust-side pressure decrease start angle relative value average ΔΦ _m = exhaust-side pressure unchanged state transition angle relative value average ΔΣ _m = 120 degrees Was used. In this equation, the exhaust-side pressure decrease start angle difference Φ and the exhaust-side pressure unchanged state transition angle difference Σ shown in FIG.
Is substituted for the value of the function f ( _i ), a variable η _i is obtained as exemplified below. This calculation gives the same result as the calculation performed by equation (5) at the time of actual engine inspection.

[0073] For example, the first cylinder is the exhaust valve clearance small state, when the left and right banks does not proceeds both driven gear one tooth, the value of the variable eta _i for each cylinder is as follows. η ₁ = {Φ ₂ −Φ ₁ − (Σ ₂ −Σ ₁ ) −f (ζ ₁ )} /
2 = {0 − (− 6.4) − (0−6.4) −0} / 2 =
6.4 η ₂ = {Φ ₃ −Φ ₂ − (Σ ₃ −Σ ₂ ) −f (ζ ₂ )} /
2 = {0-0- (0-0) -0} / 2 = 0 η ₃ = {Φ ₄ −Φ ₃ − (Σ ₄ −Σ ₃ ) −f (ζ ₃ )} /
2 = {0-0- (0-0) -0 } / 2 = 0 η 4 = {Φ 5 -Φ 4 - (Σ 5 -Σ 4) -f (ζ 4)} /
2 = {0-0- (0-0) -0} / 2 = 0 η ₅ = {Φ ₆ -Φ _5- (Σ ₆ -Σ ₅ ) -f (ζ ₅ )} /
2 = {0-0- (0-0) -0} / 2 = 0 η ₆ = {Φ ₁ −Φ ₆ − (Σ ₁ −Σ ₆ ) −f (ζ ₆ )} /
2 = {-6.4-0- (6.4-0) -0} / 2 =-
6.4

For example, if the first and second cylinders are in the exhaust valve clearance small state, and the left and right banks are not advanced by one tooth of the driven gear, the value of the variable η _i for each cylinder is as follows: become that way. η ₁ = {Φ ₂ −Φ ₁ − (Σ ₂ −Σ ₁ ) −f (ζ ₁ )} /
2 = ｛-6.4-(-6.4)-(6.4-6.4)-
0｝ / 2 = 0 η ₂ = {Φ ₃ -Φ _2- (Σ ₃ -Σ ₂ ) -f (ζ ₂ )} /
2 = {0 − (− 6.4) − (0−6.4) −0} / 2 =
6.4 η ₃ = {Φ ₄ -Φ _3- (Σ ₄ -Σ ₃ ) -f (ζ ₃ )} /
2 = {0-0- (0-0) -0 } / 2 = 0 η 4 = {Φ 5 -Φ 4 - (Σ 5 -Σ 4) -f (ζ 4)} /
2 = {0-0- (0-0) -0} / 2 = 0 η ₅ = {Φ ₆ -Φ _5- (Σ ₆ -Σ ₅ ) -f (ζ ₅ )} /
2 = {0-0- (0-0) -0} / 2 = 0 η ₆ = {Φ ₁ −Φ ₆ − (Σ ₁ −Σ ₆ ) −f (ζ ₆ )} /
2 = {-6.4-0- (6.4-0) -0} / 2 =-
6.4

Also, for example, the first, second and fifth
Cylinder is the exhaust valve clearance small state with the second, and, when the driven gear of the right bank is to be advanced by one tooth, the value of the variable eta _i for each cylinder, the exhaust side pressure decrease start angle shown in FIG. 24 It is the same as the value calculated as follows using the value of the difference Φ and the value of the exhaust-side pressure unchanged state transition angle difference Σ. η ₁ = {Φ ₂ −Φ ₁ − (Σ ₂ −Σ ₁ ) −f (ζ ₁ )} /
2 = [-6.4-(-6.4)-｛(6.4-8.4)
−6.4} −8.4] / 2 = 0 η ₂ = {Φ ₃ −Φ ₂ − (Σ ₃ −Σ ₂ ) −f (ζ ₂ )} /
2 = [0-(-6.4)-{0- (6.4-8.4)}
− (− 8.4)] / 2 = 6.4 η ₃ = {Φ ₄ −Φ ₃ − (Σ ₄ −Σ ₃ ) −f (ζ ₃ )} /
2 = [0-0-{(-8.4) -0} -8.4] / 2 =
_{0 η 4 = {Φ 5 -Φ} 4 - (Σ 5 -Σ 4) -f (ζ 4)} /
2 = [0-0- {0-(-8.4)}-(-8.4)]
/ 2 = 0 η ₅ = {Φ ₆ -Φ _5- (Σ ₆ -Σ ₅ ) -f (ζ ₅ )} /
2 = [0-(-6.4)-{(-8.4) -6.4}-
8.4] /2=6.4 η ₆ = {Φ ₁ -Φ _6- (Σ ₁ -Σ ₆ ) -f (ζ ₆ )} /
2 = [-6.4-0- {6.4-(-8.4)}-(-
8.4)] / 2 = -6.4

As described above, the cylinder in which the value of the variable η _i is 6.4 (indicated by the variable i) is in the exhaust valve clearance small state, and 1 is repeatedly subtracted from the value of the variable i. First, the value of the variable η _i is −
It can be seen that the exhaust valve clearance is small up to the cylinder indicated by a value one greater than the value of the variable i, which is 6.4. For example, η ₅ = 6.4, η ₄ = η ₃ = η ₂ =
If 0, η ₁ = −6.4, η ₆ = 0, the fifth cylinder, the fourth cylinder, the third cylinder, and the second cylinder are in the small exhaust valve clearance state, and the first cylinder and the sixth cylinder are The exhaust valve clearance is not in the small state. In S402, it is determined whether or not each cylinder indicated by the variable i is in the exhaust valve clearance small state based on the value of the variable η _i calculated according to the procedure described above, and the result is Defective part flag fl
ag _exs . In the above description,
For simplicity, the values of the variables η _i are 0 and 6.4.
And -6.4, but are actually values belonging to any of the ranges -2 to 2, 2 to 10, and -2 to -10.

It should be noted that the exhaust valve clearance
Is small, but at least everything in each bank
The assumption that no cylinders occur simultaneously
If it can be considered to stand, for example, the variable defined by the following equation
ΔΔΦ_iSmall exhaust valve clearance based on the value of
It may be determined whether or not the answer is yes. ΔΔΦ_i= ΔΦ_i+ ΔΦ_{i + 1} -2 · ΔΦ_m ... (6) Variable ΔΔΦ_iIs the exhaust-side pressure decrease start angle relative value ΔΦ
_iThe value of the variable i is odd and even
Cam pulley and driven gear
Offset the effects of assembly failure. Therefore, the exhaust valve
Only affected by small clearance
Value. It should be noted that the exhaust side represented by the equation (2) is replaced by the equation (6).
Pressure decrease starting angle relative value ΔΦ_iAnd ΔΦ_{i + 1} Assign
And ΔΔΦ _i= Φ_{i + 2} −Φ_iBecomes So this
Variable ΔΔΦ_iInspection using the value of
The two of which the value of the number i is even and that which is odd
Into groups, and based on comparisons between the values in each group
It can be understood that the inspection is performed based on the above.

The above equation ΔΔΦ_i= Φ_{i + 2} −Φ_iIs shown in FIG.
Calculation based on the indicated value of the exhaust side pressure decrease start angle difference Φ
And the result is performed in the actual inspection (6)
This is consistent with the calculation result using the formula. Hereinafter, using this equation
Here are some examples of calculations performed. For example, the variable i =
The cylinder indicated by 1 has a small exhaust valve clearance.
, Then ΔΔΦ₁ = Φ_Three −Φ₁ = 6.4, ΔΔΦ_Five =
Φ₁ −Φ_Five = -6.4, ΔΔΦ_Two (= Φ_Four −Φ_Two ) = Δ
ΔΦ_Three (= Φ_Five −Φ_Three ) = ΔΔΦ_Four (= Φ₆ −Φ_Four ) =
ΔΔΦ₆ (= Φ_Two −Φ₆ ) = 0. The value of variable i is even
Variable ΔΔΦ which is a number_iAre all 0.
The right bank has a small exhaust valve clearance.
Indicates that there is no Linda. In addition, the variable i = 1
The exhaust valve clearance of the two cylinders indicated by the number i = 3
If Alance is in a small state, ΔΔΦ₁ = ΔΔΦ_Two =
0, ΔΔΦ_Three = 6.4, ΔΔΦ_Four = 0, ΔΔΦ_Five = −
6.4, ΔΔΦ₆ = 0. The following are examples
However, the exhaust valve clearer that can exist in each of the left and right banks
It can be assumed that there are at most two cylinders in the small
Variable ΔΔΦ _iIs excluded by the pattern of each value pair of
Identify cylinders with low valve clearance
It is. A similar test was performed for the exhaust-side pressure unchanged state transition angle.
Relative value ΔΣ_iVariable ΔΔΣ derived from each value of_i(= ΔΣ
_i+ ΔΣ_{i + 1} -2 · ΔΣ_m) Can also be used. What
In the above example, the exhaust valve clearance is small.
Pressure decrease start angle difference Φ_iFigure 24 shows the values of
It was calculated as the indicated value (-6.4), but this value was -2.
Variable 得 る ΔΦ_iOf the value of
When obtaining a set of patterns, the value of each variable i
Variable ΔΔΦ_iIs -2 to 2, 2 to 10, and -2 to -1.
A determination is made as to which of the ranges 0 belongs to.
You.

Next, the service called in S206
The cam pulley inspection, which is a routine, will be described. Figure
33 is a flowchart showing the contents. First,
In S500, for each cylinder indicated by the variable i,
Variable ρ_iIs calculated by the following equation. ρ_i= ΔΦ_i−ΔΦ_m− ｛G_{i + 1} (Η_j) -G_i(Η_j)｝ (7) Here, the exhaust-side pressure decrease start angle relative value ΔΦ_iIs actually taken
This is the value obtained, and the average value of the relative values of the exhaust side pressure decrease start angle Δ
Φ_mIs 120 degrees. Function g_i(Η_j) Is the exhaust side pressure
Decrease start angle relative value ΔΦ_iEmissions that may be included in the
Used to eliminate the effects of small valve clearances
Is a function that can be_jDepending on the value of
The cylinder indicated by the value of the number i is a small exhaust valve clearance
0 if not in the state
This function returns -6.4 in some cases. Note that the variable η_j
Is a subscript of ρ_i"J" to distinguish it from the subscript
However, this is because the cylinder indicated by the variable i
The variable η_iOnly
Can not be specified in all cylinders as described above
Variable η_jMust be determined in consideration of the value of
And corresponds to. Note that, by referring to equation (2),
And ΔΦ in the left side of equation (7)_i−ΔΦ_mIs Φ _{i + 1} −Φ
_iIt turns out that it is equal to. That is, equation (7) is
Can be transformed as follows. ρ_i= Φ_{i + 1} −Φ_i− ｛G_{i + 1} (Η_j) -G
_i(Η_j) 変 数 Variable ρ described later_iThe specific example of the calculation of
Based on the value of the exhaust-side pressure decrease start angle difference Φ
Is calculated. However, engine inspection is actually performed.
When the calculation is performed, calculation using the equation (7) is performed.

The magnitude of the effect of the small exhaust valve clearance on the exhaust-side pressure decrease start angle difference Φ _i and, consequently, on the exhaust-side pressure decrease start angle relative value ΔΦ _i varies as described above. Therefore, it is desirable that the magnitude of the value returned by the function g _i (η _j ) according to the variable η _j also reflects the magnitude of the influence. Therefore, for example, the actually obtained exhaust-side pressure decrease start angle relative value Δ
From the value of Φ _i, the relative value ΔΦ _{i of the} exhaust side pressure decrease start angle
Of a value obtained by subtracting the nearest 15 multiple of the value, the function g _i (eta
_With the value of _j ), the effect of this variation can be eliminated. The value of the variable ρ _i corresponding to each cylinder calculated in this way is a value (any of 0, ± 15, ± 30) that is not affected by whether or not the exhaust valve clearance is normal.

A set (ρ _odd , ρ _odd) of the value ρ _odd of the variable ρ _{i when} the value of the variable _i is _odd and the value ρ _even when the value of the variable _i is _even
even ) is (0, 0), (15, -15), (-15,
15), (30, -30) and (-30, 30)
Limited to one. Each of these five sets corresponds to a cam pulley assembly state described below. (0,0) Both left and right banks normal, or both left and right banks advance or delay one tooth (15, -15) (Left bank one tooth advanced and right bank normal), or (Left bank normal and (Right bank one tooth delayed) (-15,15) (left bank normal and right bank one tooth advanced) or (left bank one tooth delayed and
(Right bank normal) (30, -30) Left bank one tooth advanced and right bank one tooth delayed (-30,30) Left bank one tooth delayed and right bank one tooth advanced Thus, (ρ _odd , When the set of ρ _even ) is the above or, the assembled state of the cam pulleys can be completely specified. However, when the set is any of the above, the assembled state of the cam pulleys of both the left and right banks cannot be completely specified.
However, at least one of two (in the case of) and three (in the case of) assembly state can be specified, which is useful information in a correction process following an actual engine inspection. In this case, it is extremely rare that both the left and right banks are advanced or delayed by one cam pulley.

[0082] S502 is a process of setting, the value in the defective portion flag flag _{ca m} based on the value of (ρ _odd, ρ _even). Of the above five sets, if
0xCf (110011) is added to the defective portion flag flag _cam.
11) is set. As is clear from FIG. 30, this value is set to 0x05 (00000101) when both the left and right banks are advanced by one cam pulley, and to 0x0a (00001) when both the left and right banks are delayed by one cam pulley. 00001010) is a value obtained by setting 1 to the upper 2 bits of the logical sum with (001001010). Since 1 is set to the error 1 bit and the error 2 bit, all the bits set to 1 are blinked. Incidentally, for example, a defective portion flag flag _cam 0x80 (1000
0000) may be set. Also, if it is, the defective portion flag flag _cam 0xC9 (1100
1001) is set. The value is set to 0x01 (00000001) when the left bank is one cam pulley advanced and the right bank is normal, and is set when the left bank is normal and the right bank is one cam pulley delayed. This is a value obtained by setting 1 to the upper 2 bits of the logical sum with 0x08 (00001000).

If so, the defective part flag flag
0x86 (10000110) is set in _cam .
This value is set to 0x02 (0x0) when the left bank is one tooth behind the cam pulley and the right bank is normal.
000000] which is set when the left bank is normal and the right bank is advanced by one tooth of the cam pulley.
1 in the upper 2 bits of the logical sum with
Is set. In addition, in the case of, 0x09 (00001001) is set in the defective portion flag flag _cam.
Is set. This value indicates that the left bank is cam pulley 1
This indicates that the teeth are advanced and the right bank is one tooth behind the cam pulley. , The defective portion flag f
0x06 (00000110) is set in the flag _cam . This value indicates that the left bank is one cam pulley delay and the right bank is one cam pulley advance. Defective portion flag flag _cam upper two bits of the (error possibility indicator bit) is 1 and when the are, the lamp corresponding to the bit 1 is set outside the upper two bits of the defective portion flag flag _cam (see FIG. 28) Flashes.

The above (ρ _odd , ρ _even ) may be used in consideration of or in place of the value of the variable ρ _i of a cylinder different from the cylinder from which those values were obtained. For example, three variables ρ _odd , ρ _even
Can be used. Therefore, in the cam pulley inspection shown in FIG.
It can be seen that a comparison is made between two cylinders. Also, this test is a test in which the value of the variable ρ _i obtained for each cylinder is divided into odd and even values of the variable i, and a comparison is made between these groups. It can be understood.

Next, a description will be given of the subroutine called at step S208 in FIG. 29, which is a test of the driven gear one tooth delay and the intake valve clearance. FIG.
Is a flowchart showing the contents. First, S6
00, the variable λ is set for each cylinder indicated by the variable i.
The value of _i is calculated by the following equation. λ _i = ΔΓ _i −ρ _i −h _i (ζ _j ) (8) Here, the function h _i (ζ _j ) is a function of the above-mentioned variable ζ _j , and both left and right banks are driven gears. 0 is set if the gear is advanced by one tooth or both gears are not driven by one tooth, 18 is set if the bank including the cylinder indicated by the variable i is advanced by one tooth, and the cylinder indicated by the variable i is set. -18 when contained no bank is state of the driven one tooth advances, which returns each actually influence the advance driven gear 1 tooth exhaust pressure maximal value reached angle relative value [Delta] [gamma] _i may comprise as measured Used to remove. It should be noted that the subscript of the variable _ｊ j is set to j instead of i in the case of only the variable ζ _i (subscript i) corresponding to the cylinder of interest, the bank including the cylinder indicated by the variable i corresponds to the driven gear 1. It is not possible to specify whether or not it is a tooth advance, and at least the method shown in FIG.
_This corresponds to the fact that a combination of _odd and the variable ζ _even (ζ _odd , ζ _even ) must be used. Further, by subtracting the value of the variable ρ _i from the exhaust-side pressure maximum value arrival angle relative value ΔΓ _i , the influence of the advance / delay of one tooth of the cam pulley can be eliminated.

The value of the variable λ _i calculated on the basis of the equation (8) is determined based on the effects of the delay of one tooth of the driven gear and the small intake valve clearance or the large intake valve clearance after the influence of the above-mentioned defective assembly is removed. May be included. Substituting equation (1) into equation (8) and transforming it,
The following equation instead of equation (8) is obtained. _{λ i -ΔΓ m = Γ i +} 1 -Γ i -ρ i -h i (ζ j) right side of this equation may be calculated based on the value of the exhaust side pressure maximal value reached angle difference gamma shown in FIG. 24 . This calculation is different from the calculation by the formula (8) performed in the actual engine inspection, but is a calculation that gives the same result when the inspected engine is in the same assembled state. The value on the left side of the above equation (from the variable λ _i to the exhaust-side pressure maximum value arrival angle relative value average ΔΓ
_m = 120) is the value of the driven gear one tooth delay,
Depending on whether the intake valve clearance is small or large, it belongs to any of the following ranges (1) to (11). Range (1): −30 ≦ λ _i −ΔΓ _m <−20 Range (2): −20 ≦ λ _i −ΔΓ _m <−16 Range (3): −16 ≦ λ _i −ΔΓ _m <−12 Range ( 4): −12 ≦ λ _i −ΔΓ _m <−6 Range (5): −6 ≦ λ _i −ΔΓ _m <−2 Range (6): −2 ≦ λ _i −ΔΓ _m <2 Range (7): 2 ≦ λ _i −ΔΓ _m <6 Range (8): 6 ≦ λ _i −ΔΓ _m <12 Range (9): 12 ≦ λ _i −ΔΓ _m <16 Range (10): 16 ≦ λ _i −ΔΓ _m < 20 range (11): 20 ≦ λ _i −ΔΓ _m <30

FIG. 35 is a diagram showing these ranges (1) to (11) on a number line. Driven gear one tooth delay state, discretely affects the value of λ _i -ΔΓ _m. Specifically, the magnitude of the effect is -1 when the bank including the cylinder indicated by the variable i is one tooth behind the driven gear.
8 if the bank not including the cylinder indicated by the variable i is one tooth behind the driven gear, and 18 if both the left and right banks are one tooth behind the driven gear or are in a normal assembly state. 0. On the other hand, even when the intake valve clearance is normal, there is a possibility that the exhaust-side pressure maximum value arrival angle difference Γ varies in the range of −2 or more and less than 2 (in other words, whether or not the difference is within the range of ± 2). Thus, it can be determined whether or not the intake valve clearance is normal.) Further, even when the intake valve clearance is small, the exhaust-side pressure maximum value reaching angle difference Γ does not become smaller than -10 than in a normal case, and even when the intake valve clearance is large, the exhaust-side pressure maximum value reaching angle difference Γ. Is not greater than 10 than normal. Thus, the region of the value of λ _i −ΔΓ _m is −18 ±
(10 + 2), -18 ± 2, 0 ± (10 + 2), 0 ±
It is divided into a plurality of ranges with boundary values of 2, 18 ± (10 + 2) and 18 ± 2.

These ranges correspond to the following states of whether or not the driven gear has one tooth lag in the bank including the cylinder indicated by the variable i and the state of assembly of the intake valve clearance of the cylinder indicated by the variable i. I do. Range (1): One tooth behind driven gear and large intake valve clearance Range (2): One tooth behind driven gear and normal intake valve clearance Range (3): One tooth behind driven gear and small intake valve clearance ( 4): (Driving gear 1 tooth delayed and intake valve clearance small), or (Driving gear in both banks is normal and intake valve clearance is large), or
(Driven gear of both banks is delayed by one tooth and intake valve clearance is large) Range (5): (Driven gear of both banks is normal and intake valve clearance is large) or (Driven gear of both banks is delayed by one tooth and intake is large) Range (6): (Driven gears in both banks are normal and intake valve clearances are normal) or (Driven gears in both banks are one tooth behind and intake valve clearances are normal) Range (7): (Both banks) (8): (Driving gear of both banks is normal and intake valve clearance is small), or (Driven gear of both banks is small and intake valve clearance is small) or (Driven gear of both banks is one tooth delayed and intake valve clearance is small) Or (one tooth behind the driven gears of both banks and small intake valve clearance),
Or (the other bank's driven gear one tooth delayed and the intake valve clearance large) Range (9): The driven gear one tooth delayed and the intake valve clearance large in the other bank Range (10): The driven gear 1 of the other bank Tooth delay and normal range of intake valve clearance (11): One tooth of driven gear of the other bank is delayed and intake valve clearance is small.

Thus, the value of λ _i −Δ − _m
If it belongs to any of (1) to range (3), range (9) to range (11), the assembly state of the intake valve clearance of the cylinder indicated by the variable i can be specified, and that cylinder is included It can be determined whether or not the driven gear in the bank is in a state of being delayed by one tooth. On the other hand, range (4) to range
If it belongs to any of (8), a plurality of candidates for the assembly state relating to the cylinder indicated by the variable i are shown. Note that even when the value of λ _i −ΔΓ _m corresponding to the cylinder indicated by the variable i belongs to any of the range (4) to the range (8),
In some cases, the assembled state of the cylinder can be specified as one. For example, the value of λ _i −ΔΓ _m for a cylinder is in the range
If the value of λ _i −Δλ _m of another cylinder included in the same bank as that of (8) belongs to the range (9), and the cylinder has a large intake valve clearance, It is clear that the bank including the cylinder is not in a state where the driven gear is one tooth behind. As described above, in the case of an engine having two banks on the left and right, the assembly state of the left and right banks can be obtained independently, and if these two pieces of information are used, more information on the assembly state can be obtained. Becomes S
In step 602, the determination result based on the above procedure is used to determine the defective portion flags flag _drvn , flag _inl , and flag _ins.
Is reflected in the value of However, when a plurality of assembly state candidates are indicated, 1 is set in the upper two bits of the corresponding defective portion flag, indicating that the defective assembly cannot be clearly identified.

Next, the exhaust gas clearance large inspection which is a subroutine called in S210 of FIG. 29 will be described. This inspection was performed on cam pulleys,
If other assembly conditions, such as driven gear and intake valve clearance, are not normal, it may not be possible to inspect correctly. However, cylinders with all normal assembly conditions, such as cam pulleys, and large exhaust valve clearances, may fail. If present, a test that can identify that cylinder. Therefore, in each of the inspections described above, this is not performed when an assembly failure is found, and it is determined that it is unknown whether or not the exhaust valve clearance of each cylinder is large, and the failure location flag flag is determined. The most significant bit (error possibility indication bit) of _exl is set to 1 and the process ends. As a result, the lamps corresponding to all cylinders blink.

FIG. 36 is a flowchart showing an example of a large exhaust valve clearance inspection which is sequentially performed (for each cylinder) with the value of the variable i being 1 to 6. First,
In S700, the maximum value of the values of the exhaust side pressure invariable value difference beta _i acquired for each cylinder a variable beta _MAX, the minimum value is set to the variable beta _MIN. Next, in step S702, the value obtained by subtracting the variable β _MIN from the variable β _MAX becomes the threshold β
It is determined whether or not _th has been _exceeded , and if so, S7
In 04, it is determined that the cylinder indicated by the variable i in which the value of the exhaust-side pressure invariable value difference β _i , which has been set to the maximum value (the value of the variable β _MAX ) in S700, is in the exhaust valve clearance large state. The bit corresponding to the cylinder in the location flag flag _exl is set to 1, and the large exhaust valve clearance inspection is terminated. The value of the threshold value β _th is a predetermined constant. If the determination result in S702 is NO, the exhaust valve clearance large inspection is terminated as it is.

The processing shown in FIG. 36 is based on the assumption that there is only one cylinder having a large exhaust valve clearance, even if it exists. Even if this assumption may not hold, if it can be considered that the assumption that the exhaust valve clearance of at least one cylinder is normal holds, in other words, the exhaust valve clearances of all cylinders increase simultaneously. If it can be considered that this is not the case, this exhaust valve clearance inspection is meaningful. However, in that case, the exhaust valve clearance large inspection is a process performed to find a cylinder having the largest exhaust valve clearance. If there is a cylinder whose exhaust valve clearance is determined to be large in this exhaust valve clearance large inspection, there are other (but not all) cylinders.
This means that there may be a cylinder with a large exhaust valve clearance. Therefore, in this case, 1 is set to the bit corresponding to the cylinder determined to have a large exhaust valve clearance in the defective portion flag flag _exl , and 1 is set to the most significant bit (error 1 bit).
Is set, and the lamp corresponding to the cylinder (FIG. 2)
8) is turned on, and the lamps corresponding to the other cylinders are turned on and off. This indicates that not all cylinders, but there may be other cylinders with large exhaust valve clearances.

Further, if the possibility that the exhaust valve clearances of all the cylinders are large cannot be denied, if the exhaust valve clearance large inspection determines that the exhaust valve clearances of all the cylinders are normal, the reverse is performed. Need to show that the exhaust valve clearances of all cylinders can be large. Therefore, when it is determined that all the exhaust valve clearances of each cylinder are normal, the defective portion flag fl
1 is set to the most significant bit (error possibility indication bit) of ag _exl , and 0 is set to the first to sixth bits of the defective portion flag flag _exl . Is flashed), and it is necessary to indicate that the possibility that the exhaust valve clearances of all the cylinders are large is present.

FIG. 37 is a flowchart showing a large exhaust valve clearance inspection different from the large exhaust valve clearance inspection shown in FIG. This processing is an inspection processing based on a comparison between the value of the exhaust-side pressure invariable value difference β _i acquired for each cylinder and their average value.
First, in S800, the average value of the exhaust-side pressure invariant value difference β _i obtained for each cylinder is set in a variable β _MEAN . Next, in S802, it is determined whether or not a value obtained by subtracting the value of the variable β _MEAN from the value of each exhaust-side pressure invariable value difference β _i exceeds a threshold value β _th (a predetermined constant). Is done. If the determination result in S802 is YES, S
At 804, it is determined that the exhaust valve clearance of the cylinder indicated by the variable i is large,
The corresponding bit of ag _exl is set to 1 and the large exhaust valve clearance inspection is completed. If the determination result in S802 is NO, the exhaust valve clearance large inspection is terminated as it is. The large exhaust valve clearance inspection is an inspection suitable for the case where it is assumed that the number of cylinders in which the exhaust valve clearance is large is small (about one or two) even if it exists. Therefore, when there is a possibility that such an assumption does not hold, one of the tests based on the latter two possibilities out of the tests based on the three possibilities described in conjunction with the description of FIG. Should be done.

FIG. 38 is a flowchart showing an exhaust valve clearance large inspection according to still another embodiment different from those shown in FIGS. 36 and 37. This processing is an inspection processing that is performed based on a comparison between the two groups by dividing the value of the exhaust-side pressure invariable value difference β _i acquired for each cylinder into two groups. First, in S900, the difference between values of adjacent magnitudes of the exhaust-side pressure invariant value difference β _i acquired for each cylinder is set in the variable Δβ _k . There are five such values. Therefore, the subscript k of the variable Δβ _k has a value of 1 to 5. Next,
In S902, the maximum value of the variable Δβ _k is set to the variable Δβ
_MAX , and in S904, the variable Δβ
It is determined whether or not the value of _MAX exceeds the threshold value _Dth . The value of the threshold value D _th is, for example, the smaller value (β _{S of} the two values of the exhaust-side pressure invariance value difference β _i used for calculating the value of the variable Δβ _MAX . larger one can be the magnitude of variations in the value of beta _L hereinafter) or less of the exhaust-side pressure invariable value difference beta _i. This determination result is Y
If it is ES, in S906, it is determined that the cylinder indicated by the variable i in which the exhaust-side pressure invariance value difference β _i having the magnitude of β _L or more is obtained is in the state of the large exhaust valve clearance, After 1 is set to the corresponding bit of the defective portion flag flag _exl, the large exhaust valve clearance inspection is terminated. If the determination result in S904 is NO, the exhaust valve clearance large inspection is terminated as it is.

As described above, the variable Δβ _MAX obtained from the value of the exhaust-side pressure invariable value difference β _i obtained for each cylinder
Values, Again greater than the threshold D _th is calculated from the value of the exhaust side pressure invariable value difference beta _i is a cylinder beta _L or more exhaust side pressure invariable value difference beta _i are acquired, It is determined that the cylinders from which the exhaust-side pressure invariable value difference β _i equal to or smaller than β _S are included in different groups. And
Of these two groups, the cylinder for which the exhaust-side pressure invariance value difference β _i included in the former is obtained is determined to be in the state of large exhaust valve clearance. Note that the large exhaust valve clearance inspection shown in FIG. 38 is based on the assumption that the variation in the exhaust-side pressure invariable value difference β _i of the cylinder having the normal exhaust valve clearance is sufficiently small. If there is a possibility that this assumption does not hold, the processing shown in FIG. 36 or 37 (or other large exhaust valve clearance inspection) should be performed.

In the large exhaust valve clearance inspection shown in FIG. 38, the variable Δβ _k and the variable Δβ _k calculated from the exhaust-side pressure invariable value difference β _i obtained for each cylinder are used.
beta _{MA X,} whether the exhaust valve clearance is larger based on the value of such threshold D _th test is performed. In this case, the adjustment of the threshold often required for the inspection based on the comparison between the value of the exhaust-side pressure invariable value difference β _i and a certain threshold (constant) can be omitted. Although the exhaust valve clearance large inspection shown in FIGS. 36 to 38 can be executed independently, two or more of them may be executed. In that case, the results of the respective exhaust valve clearance large inspections may not match. In that case, for example, it is determined that a cylinder determined to have a large exhaust valve clearance in at least one of the plurality of tests may be in a state of a large exhaust valve clearance. can do.

Next, the compression ring missing inspection which is a subroutine called in S212 of FIG. 29 will be described. It should be noted that this inspection may not be performed properly when other assembly states such as the cam pulley, the driven gear, and the intake valve clearance are not normal. However, if all other assembly conditions are normal and there is a cylinder with a missing compression ring, the inspection is to identify that cylinder. Therefore, in the above-described inspections, when an assembly failure is identified, it is determined that it is unknown whether or not the compression ring of each cylinder is missing, and the most significant bit of the failure portion flag flag _ring is determined. The processing is terminated after 1 is set, and further, 0 is set in the bit of the defective portion flag flag _ring corresponding to all cylinders. As a result, the lamps corresponding to all the cylinders blink.

FIG. 39 shows a compression ring missing detection.
It is a flowchart which shows an example of the content of an examination. First, S
The exhaust side pressure obtained for each cylinder at 1000
Force maximum value difference α_iThe maximum value of_MAXTo the minimum
Variable α_MINSet to. Next, smell S1002
And the variable α_MAXFrom the variable α_MINIs the threshold α
_thIs determined, and if so, S1
004, the minimum value (variable α)_MINof
Value) and the maximum difference α_iValue was obtained
The cylinder indicated by the variable i is the compression ring
Is determined to be missing, and the defective portion flag f
lag_ringIs set to 1 for the bit corresponding to that cylinder.
Compression ring missing inspection
Let me do. Here, the threshold α_thIs a predetermined
Is a number. If the decision result in S1002 is NO, that
The exhaust valve clearance large inspection is completed as it is.

The above-described processing is performed in the following manner.
This is a process based on the assumption that there is only one. If this assumption may not hold, but the assumption that the compression ring of at least one cylinder is installed correctly can be considered, in other words, the compression rings of all cylinders are missing at the same time. This compression ring missing check is meaningful if it is not necessary to do so. However, in this case, the compression ring missing inspection is a process performed to find any one of the cylinders in which the compression ring is missing. If there is a cylinder whose compression ring is determined to be missing in the compression ring missing test, there may be other (but not all) cylinders where the compression ring is missing. It will be. Therefore, in this case, 1 is set to the bit corresponding to the cylinder determined to be missing the compression _ring of the defective portion flag flag _ring , and 1 is set to the most significant bit (error possibility indication bit). Then, a lamp corresponding to the cylinder (see FIG. 28) is turned on, and a lamp corresponding to another cylinder is turned on and off. This indicates that not all cylinders, but there may be other cylinders with missing compression rings.

Further, if the possibility that the compression rings of all the cylinders are missing cannot be denied, if the compression ring missing inspection determines that the compression rings of all the cylinders are properly mounted, Conversely, it is necessary to indicate that the compression rings of all cylinders may be missing. Therefore, even when it is determined that all the compression rings of each cylinder are properly mounted, the defective portion flag fl
The most significant bit (error possibility indication bit) of the ag _ring is set to 1 and the first to sixth bits of the defective portion flag flag _ring are set to 0, and the compression rings of all cylinders are lost. Will be shown.

As is clear from the above description, the processing shown in FIG. 39 is performed by converting the exhaust-side pressure invariable value difference β _i in the exhaust valve clearance large inspection shown in FIG. 36 into the exhaust-side pressure maximum value difference α _i . 36, and S702 in FIG.
Is changed to the threshold value α _th in S1002, which is processing corresponding to
004 is slightly modified. FIG.
By taking into account the similarity between the process shown in FIG. 39 and the process shown in FIG. 39, another compression ring missing test similar to the exhaust valve clearance large test shown in FIGS. 37 and 38 is obtained. In this case, however, it is necessary to change the content of the process corresponding to S802 in FIG. 37 so that α _MEAN −α _i > α _th is determined after performing the above replacement. in the process corresponding to S906, the cylinder indicated by alpha _S (the β corresponding to _S) the following size of the exhaust-side pressure maximal value difference alpha _i is obtained variable i, compression ring is missing It is necessary to be determined to be a state.

Next, the auxiliary processing executed in S214 of FIG. 29 will be described. The auxiliary process of S214 is a process of setting 1 to the most significant bit of the defective portion flag flag _crnk . In the defective portion estimating process of the present embodiment, the inspection for specifying the advance / delay of one tooth of the crank pulley is not performed. Therefore, if the determination result in S112 of FIG. 27 is NO, the crank pulley 1
Tooth advance / lag may have occurred. This is a process performed to indicate this.

Next, another embodiment of the engine assembly defect inspection method according to the present invention will be described. The engine assembly defect inspection method according to the present embodiment employs the cam pulley 1 tooth advance /
A method capable of inspecting any one of a delay, a driven gear one tooth advance / delay, an intake valve clearance small / large, an exhaust valve clearance small / large, and a missing compression ring. This is an example. In this embodiment, the respective states of the intake valve clearance small / large, the exhaust valve clearance small / large, and the compression ring missing are as follows.
Assume that it occurs in at most one cylinder. In addition, in the engine assembly failure inspection method of the present embodiment, no inspection is performed on the crank pulley.

Cam pulley 1 tooth advance / delay, driven gear
1 tooth advance / delay, intake valve clearance small / large, exhaust
Small / large valve clearance and compression ring
Check for missing assembly failures for each cylinder shown below.
Obtained exhaust side pressure maximum value difference δP_EXmaxi, Exhaust side pressure
Invariable value difference δP_EXconsti, Exhaust side pressure peak value reaching
Logarithmic difference δΓ_i, Exhaust side pressure unchanged state transition angle relative value difference
Min δΣ_i, Exhaust side pressure decrease start angle relative value difference δΦ_i, Sucking
Air side pressure maximum value arrival angle relative value difference δΛ_iAnd intake side pressure
Force increase start angle relative value difference δΨ_iIs detected using each value of
You. These values are based on the aforementioned exhaust side pressure for each cylinder.
Maximum value P_EXmaxi, Exhaust side pressure change value P _EXconsti(Subscript
With an i at the end to indicate that the value is for each cylinder.
Shown), exhaust-side pressure maximum value arrival angle relative value ΔΓ_i,exhaust
Side pressure unchanged state transition angle relative value ΔΣ_i, Exhaust side pressure decrease
Start angle relative value ΔΦ_i, Relative value Δ of the intake-side pressure maximum value reaching angle
Λ _iAnd intake side pressure increase start angle relative value ΔΨ_iBased on the value of
Equations (9) to (15) shown below are
Is calculated by

ΔP _EXmaxi = P _{EXmaxi + 1} −P _EXmaxi (9) _{δP EXconsti} = P _{EXconsti + 1} −P _EXconsti (10) δΓ _i = ΔΓ _i −ΔΓ _m (11) δΣ _i = ΔΣ _i −ΔΣ _m (12) δΦ _i = ΔΦ _i −ΔΦ _m (13) δΛ _i = ΔΛ _i −ΔΛ _m (14) δΨ _i = ΔΨ _i −ΔΨ _m · ... (15) where the suction side pressure maxima reach angle relative values .DELTA..LAMBDA _i and the intake-side pressure increases start angle relative value [Delta] [Psi] _i is expressed by the following equation. _{ΔΛ i = ΔΛ m + Λ i} + 1 -Λ i ··· (16) ΔΨ i = ΔΨ m + Ψ i + 1 -Ψ i ··· (17) The intake-side pressure maxima reach angle relative value average .DELTA..LAMBDA _m = Intake side pressure increase start angle relative value average ΔΨ _m = 120 degrees.
When the value of the subscript i + 1 exceeds 6, it is to be replaced with a value obtained by subtracting 6 from that value.

At the time of actual engine inspection, the exhaust-side pressure maximum value difference δP
_EXmaxi, exhaust pressure invariable value difference δP _EXconsti, exhaust pressure maximal value reached angle difference difference [Delta] [gamma] _i, exhaust pressure immutable state transition angle difference difference .DELTA..SIGMA _i, exhaust pressure decrease start angle difference difference δΦ
_i, the value of such intake pressure maximum value reached angle difference difference [Delta] [lambda] _i and the intake-side pressure increases starting angle difference difference [delta] [Psi] _i is the calculated, in the following description, use the values shown in Figure 24 For convenience, values calculated by the following seven equations are used. _{δP EXmaxi} = α _{i + 1} + α _{i δP EXconsti} = β _{i + 1} + β _i δΓ _i = Γ _{i + 1} −Γ _i δΣ _i = Σ _{i + 1} −Σ _i δΦ _i = Φ _{i + 1} −Φ _i δΛ _i = Λ _{i + 1} −Λ _i δΨ _i = Ψ _{i + 1} −Ψ _i

The values of the variables on the right side of the above seven equations are shown in FIG. 24 for each assembly defect. That is, at the time of actual engine inspection, the same value as the value calculated by Expressions (9) to (15) is obtained by using the above seven expressions.
It can be calculated for each assembly defect from the values in FIG.
For example, the maximum value P _EX on the exhaust side pressure in a normal assembly state
_Assuming that _max is P _EXmaxSTD , α _i = P _EXmaxi −P _EXmaxSTD α _{i + 1} = P _{EXmaxi + 1} −P _EXmaxSTD, and by substituting these equations into equation (9),
The first of the above seven equations is obtained. That is, (9)
The equation is equivalent to the first of the above seven equations. Regarding the exhaust-side pressure invariant value difference _{δP EXconsti} ,
It can be easily derived that the second of the two equations is equivalent to the equation (10). Also, the exhaust-side pressure maximum value arrival angle relative value ΔΓ _i , which is included in the right side of the equations (11) to (15),
The exhaust-side pressure unchanged state transition angle relative value ΔΣ _i , the exhaust-side pressure decrease start angle relative value ΔΦ _i , the intake-side pressure maximum value arrival angle relative value ΔΛ _i, and the intake-side pressure increase start angle relative value ΔΨ _i ,
By substituting the right sides of the equations (1) to (3), (16) and (17), the following five of the seven equations are derived. As described above, the calculation process of the values exemplified below is different from the calculation using the equations (9) to (15) performed in the actual inspection. However, the calculation results based on the above seven equations match the calculation results based on the equations (9) to (15), and the calculations based on the above seven equations can be calculated from the values in FIG. Therefore, the result calculated based on the above seven equations is used as a value calculated in an actual inspection.

First, the advance / delay of one tooth of the cam pulley will be described. Exhaust-side pressure maximum value difference δ between the case where the left bank has one cam pulley advance and the case where the right bank has one cam pulley delay.
P _EXmaxi , exhaust-side pressure invariance value difference _{δP EXconstii} , exhaust-side pressure maximum value arrival angle relative value difference δΓ _i , exhaust-side pressure unchanged state transition angle relative value difference δΣ _i , exhaust-side pressure decrease start angle relative value difference δΦ _i, the intake-side pressure maxima reach angle relative value difference [Delta] [lambda] _i and the intake-side pressure increases start angle relative value difference [delta] [Psi] _i
Are the following values according to the above seven equations. Note that the subscript “ _odd ” and the subscript “ _even ”
Indicates a case where the value of the variable i is an odd number and a case where the value of the variable i is an even number, respectively. Further, the following calculation process shows only the case where the left pulley is advanced by one tooth of the cam pulley. _{δP EXmaxodd} = α _even −α _odd = 0 − (− 17) = 17 _{δP EXmaxeven} = α _odd −α _even = −17−0 = −17 _{δP EXconstodd} = β _even −β _odd = 0−0 = 0 _{δP EXconsteven} = β _odd −β _even = 0−0 = 0 δΓ _odd = Γ _even −Γ _odd = 0 − (− 15) = 15 δΓ _even = Γ _odd −Γ _even = −15-0 = −15 δΣ _odd = Σ _even − Σ _odd = 0 − (− 15) = 15 δΣ _even = Σ _odd −Σ _even = −15−0 = −15 δΦ _odd = Φ _even −Φ _odd = 0 − (− 15) = 15 δΦ _even = Φ _odd − _{Even even} = −15−0 = −15 δΛ _odd = Λ _even −Λ _odd = 0 − (− 14) = 14 δΛ _even = Λ _odd −Λ _even = −14−0 = −14 δΨ _odd = Ψ _even −Ψ _odd = 0-(-15) = 15 δΨ _even = Ψ _odd -Ψ _even = −15-0 = −15

The following values are obtained when the left bank has a one-tooth delay of the cam pulley and when the right bank has one-tooth advance of the cam pulley. The following calculation process is a calculation process in the case where a delay of one cam pulley occurs in the left bank. _{δP EXmaxodd} = α _even −α _odd = 0−17 = −17 _{δP EXmaxeven} = α _odd −α _even = 17−0 = 17 _{δP EXconstodd} = β _even −β _odd = 0−0 = 0 _{δP EXconsteven} = β _odd −β _even = 0-0 = 0 δΓ _odd = Γ _even -Γ _odd = 0-15 = -15 δΓ _even = Γ _odd -Γ _even = 15-0 = 15 δΣ _odd = Σ _even -Σ _odd = 0-15 =- _{15 δΣ even = Σ odd -Σ even} = 15-0 = 15 δΦ odd = Φ even -Φ odd = 0-15 = -15 δΦ even = Φ odd -Φ even = 15-0 = 15 δΛ odd = Λ even - Λ _odd = 0−14 = −14 δΛ _even = Λ _odd −Λ _even = 14−0 = 14 δΨ _odd = Ψ _even −Ψ _odd = 0−15 = −15 δΨ _even = Ψ _odd −Ψ _even = 15-0 = 15

When the left bank is advanced by one tooth of the driven gear, the following values are obtained. _{δP EXmaxodd} = α _even −α _odd = 0 − (− 42) = 42 _{δP EXmaxeven} = α _odd −α _even = −42−0 = −42 _{δP EXconstodd} = β _even −β _odd = 0 − (− 10) = 1
0 _{δP EXconsteven} = β _odd -β _even = -10-0 = -1
0 δΓ _odd = Γ _even −Γ _odd = 0 − (− 18) = 18 δΓ _even = Γ _odd −Γ _even = −18-0 = −18 δΣ _odd = Σ _even −Σ _odd = 0 − (− 8.4 _{) = 8.4 δΣ even = Σ odd} -Σ even = -8.4-0 = -8.4 δΦ odd = Φ even -Φ odd = 0-0 = 0 δΦ even = Φ odd -Φ even = 0- 0 = 0 δΛ _odd = Λ _even −Λ _odd = 0 − (− 17) = 17 δΛ _even = Λ _odd −Λ _even = −17−0 = −17 δΨ _odd = Ψ _even -Ψ _odd = 0 − (− 18 ) = 18 δΨ _even = Ψ _odd −Ψ _even = −18−0 = −18

When the left bank has a one-tooth delay of the driven gear, the following values are obtained. _{δP EXmaxodd} = α _even −α _odd = ₀₋₄₂ = −42 _{δP EXmaxeven} = α _odd −α _even = 42−0 = 42 _{δP EXconstodd} = β _even −β _odd = ₀₋₃₆ = −36 _{δP EXconsteven} = β _odd − β _even = 36−0 = 36 δΓ _odd = Γ _even −Γ _odd = 0−18 = −18 δΓ _even = Γ _odd −Γ _even = 18−0 = 18 δΣ _odd = Σ _even −Σ _odd = 0−0 _{0 δΣ even = Σ odd -Σ even} = 0-0 = 0 δΦ odd = Φ even -Φ odd = 0-0 = 0 δΦ even = Φ odd -Φ even = 0-0 = 0 δΛ odd = Λ even -Λ _odd = 0−17 = −17 δΛ _even = Λ _odd −Λ _even = 17−0 = 17 δΨ _odd = Ψ _even −０ _odd = 0−18 = −18 δΨ _even = Ψ _odd −Ψ _even = 18−0 = 18

When the driven gear is advanced by one tooth in the right bank, the following values are obtained. _{δP EXmaxodd} = α _even −α _odd = −42−0 = −42 _{δP EXmaxeven} = α _odd −α _even = 0 − (− 42) = 4
2 _{δP EXconstodd} = β _even -β _odd = −10−0 = −10 _{δP EXconsteven} = β _odd −β _even = 0 − (− 10) =
10 δΓ _odd = Γ _even -Γ _odd = −18−0 = −18 δΓ _even = Γ _odd −Γ _even = 0 − (− 18) = 18 δΣ _odd = Σ _even -Σ _odd = −8.4-0 = _{-8.4 δΣ even = Σ odd -Σ even} = 0 - (- 8.4) = 8.4 δΦ odd = Φ even -Φ odd = 0-0 = 0 δΦ even = Φ odd -Φ even = 0- 0 = 0 δΛ _odd = Λ _even -Λ _odd = −17−0 = −17 δΛ _even = Λ _odd −Λ _even = 0 − (− 17) = 17 δΨ _odd = Ψ _even -Ψ _odd = −18-0 = −18 δΨ _even = Ψ _odd −Ψ _even = 0 − (− 18) = 18

Further, when the driven bank is delayed by one tooth in the right bank, the following values are obtained. _{δP EXmaxodd} = α _even −α _odd = 42−0 = 42 _{δP EXmaxeven} = α _odd −α _even = ₀₋₄₂ = −42 _{δP EXconstodd} = β _even −β _odd = 36−0 = 36 _{δP EXconsteven} = β _odd −β _even = 0-36 = -36 δΓ _odd = Γ _even -Γ _odd = 18-0 = 18 δΓ _even = Γ _odd -Γ _even = 0-18 = -18 δΣ _odd = Σ _even -Σ _odd = 0-0 = _{0 δΣ even = Σ odd -Σ even} = 0-0 = 0 δΦ odd = Φ even -Φ odd = 0-0 = 0 δΦ even = Φ odd -Φ even = 0-0 = 0 δΛ odd = Λ even -Λ _odd = 17−0 = 17 δΛ _even = Λ _odd −Λ _even = 0−17 = −17 δΨ _odd = Ψ _even −Ψ _odd = 18−0 = 18 δΨ _even = Ψ _odd −Ψ _even = 0−18 = − 18

FIG. 40 shows the values calculated above (equal to the values calculated based on the equations (9) to (15)).
3 is a table showing the contents of assembly failures, which are the conditions under which they are calculated. Note that the variable δ (Γ−
Φ) _i is represented by the following equation. δ (Γ−Φ) _i = ΔΓ _m −ΔΦ _m − (ΔΓ _i −ΔΦ _i ) = ΔΦ _i −ΔΓ _i (18) where, the exhaust side pressure local maximum value arrival angle relative value average ΔΓ _m = exhaust The average of the side pressure decrease start angle relative value ΔΦ _m (= 120) was used. By substituting equations (1) and (2) into equation (18), the following equation is obtained. δ (Γ−Φ) _i = Γ _i −Φ _i − (Γ _{i + 1} −Φ _{i + 1} ) The value shown in FIG. 40 is not the equation (18) but this equation,
This is a value calculated based on the values shown in FIG. When the value of the variable δ (Γ−Φ) _i is referred to in the actual engine inspection, the value calculated based on the expression (18) is referred to. Note that the value of the variable δ (Γ−Φ) _i becomes the same value as another variable δ (Ψ−Φ) _i as is clear when れ ば and Ψ are exchanged in equation (18). This is apparent from the values in FIG. Therefore, a variable δ (Ψ−Φ) _i may be used instead of the variable δ (Γ−Φ) _i .

According to FIG. 40, the exhaust-side pressure maximum value difference δ
P _EXmaxi , exhaust-side pressure invariance value difference _{δP EXconsti} , exhaust-side pressure maximum value arrival angle relative value difference δΓ _i , exhaust-side pressure unchanged state transition angle relative value difference δΣ _i , exhaust-side pressure decrease start angle relative value difference δΦ _i, the combination of the intake pressure maximum value reached angle relative value difference [Delta] [lambda] _i and the intake-side pressure increases start angle relative value difference [delta] [Psi] _i values, such as, that is, if the pattern of the difference value is different for each defective assembly Many. For example, when one tooth of the driven gear leads / delays in one of the left and right banks, it can be clearly distinguished from other assembly defects. However, with respect to the advance / delay of the cam pulley by one tooth, the difference value pattern of the advance of the cam pulley of the left bank, the delay of the cam pulley of the right bank by one tooth, the delay of the cam pulley of the left bank by one tooth, and the advance of the cam pulley of the right bank are respectively different. Same and indistinguishable.

Next, small / large intake valve clearance,
A case where the exhaust valve clearance is small / large and the compression ring is missing will be described. FIG.
According to the values shown in (1) and (2), when only the i-th cylinder has a small intake valve clearance, the i-th cylinder
The values of the above seven equations corresponding to the calculation results of the above equations (9) to (15) for the cylinder number, and δ (Γ−
Φ) The values of _i are as follows, respectively. _{δP EXmaxi} = α _{i + 1} −α _i = 0 − (− 47) = 47 _{δP EXconsti} = β _{i + 1} −β _i = 0 − (− 16) = 16 δΓ _i = Γ _{i + 1} −Γ _i = 0 − (− 6.4) = 6.4 δΣ _i = Σ _{i + 1} −Σ _i = 0−0 = 0 δΦ _i = Φ _{i + 1} −Φ _i = 0−0 = 0 δΛ _i = Λ _{i + 1} −Λ _i = 0 − (− 6) = 6 δΨ _i = Ψ _{i + 1} −Ψ _i = 0 − (− 6.4) = 6.4 δ (Γ−Φ) _i = −6.4-0− (0-0) =-6.4

When only the i-th cylinder has a large intake valve clearance, the following values are obtained. _{δP EXmaxi} = α _{i + 1} −α _i = 0−18 = −18 _{δP EXconsti} = β _{i + 1} −β _i = 0−20 = −20 δΓ _i = Γ _{i + 1} −Γ _i = 0-5.4 _{= -5.4 δΣ i = Σ i +} 1 -Σ i = 0-0 = 0 δΦ i = Φ i + 1 -Φ i = 0-0 = 0 δΛ i = Λ i + 1 -Λ i = 0- 5 = −5 δΨ _i = Ψ _{i + 1} −Ψ _i = 0−5.4 = −5.4 δ (Γ−Φ) _i = 5.4-0− (0−0) = 5.4

When only the i-th cylinder has a small exhaust valve clearance, the following values are obtained. _{δP EXmaxi} = α _{i + 1} −α _i = 0 − (− 8) = 8 _{δP EXconsti} = β _{i + 1} −β _i = 0 − (− 10) = 10 δΓ _i = Γ _{i + 1} −Γ _i = 0 −0 = 0 δΣ _i = Σ _{i + 1} −Σ _i = 0−6.4 = −6.4 δΦ _i = Φ _{i + 1} −Φ _i = 0 − (− 6.4) = 6.4 δΛ _i = Λ _{i + 1} -Λ _i = 0-0 = 0 δΨ _i = Ψ _{i + 1} -Ψ _i = 0-0 = 0 δ (Γ-Φ) _i = 0-(-6.4)-(0- 0) = 6.
4

When only the ith cylinder has a large exhaust valve clearance, the following values are obtained. _{δP EXmaxi} = α _{i + 1} −α _i = 0−12 = −12 _{δP EXconsti} = β _{i + 1} −β _i = 0-14 = −14 δΓ _i = Γ _{i + 1} -Γ _i = 0-0 = 0 _{δΣ i = Σ i + 1 -Σ} i = 0-0 = 0 δΦ i = Φ i + 1 -Φ i = 0-0 = 0 δΛ i = Λ i + 1 -Λ i = 0-0 = 0 δΨ i = Ψ _{i + 1} -Ψ _i = 0-0 = 0 δ (Γ-Φ) _i = 0-0- (0-0) = 0

Further, when only the i-th cylinder is in the compression ring missing state, the following values are obtained. _{δP EXmaxi} = α _{i + 1} −α _i = 0 − (− 10) = 10 _{δP EXconsti} = β _{i + 1} −β _i = 0 − (− 1) = 1 δΓ _i = Γ _{i + 1} −Γ _i = 0 _{-0 = 0 δΣ i = Σ i} + 1 -Σ i = 0-0 = 0 δΦ i = Φ i + 1 -Φ i = 0-0 = 0 δΛ i = Λ i + 1 -Λ i = 0-0 = 0 δΨ _i = Ψ _{i + 1} −Ψ _i = 0-0 = 0 δ (Γ−Φ) _i = 0-0- (0-0) = 0 FIG. 41 is a chart summarizing the above results. . However,
Among the values shown in FIG. 41, the values relating to the intake valve clearance and the exhaust valve clearance may vary continuously. One example is the case where the thickness of the shim 72 shown in FIG. 3 can be continuously changed. Therefore, the values related to the intake valve clearance and the exhaust valve clearance in FIG. 41 are merely examples, and when the engine is actually inspected, continuously varied values can be obtained. .

As shown in FIGS. 40 and 41, the exhaust-side pressure maximum value difference _{δP EXmaxi} , the exhaust-side pressure _invariable value difference _{δP EXconsti} , the exhaust-side pressure maximum value arrival angle relative value difference δΓ
Each value such as _i indicates a different value for each assembly defect. Hereinafter, an example of an inspection utilizing this will be described. In addition,
The determination as to whether the assembly is in a normal state is made based on the exhaust-side pressure maximum value difference _{δP EXmaxi} and the exhaust-side pressure non-change value difference δ.
P _EXconsti , exhaust side pressure local maximum value arrival angle relative value difference δ
Γ _i , the exhaust-side pressure unchanged state transition angle relative value difference δΣ _i ,
The exhaust side pressure decrease start angle relative value difference δΦ _i , the intake side pressure maximum value arrival angle relative value difference δΛ _i , the intake side pressure increase start angle relative value difference δ 差分_i, and the variable δ (Γ−Φ) _i are: This is performed based on whether or not all are 0. However, since the measurement results of these values include errors, even in a normal assembly state, they often have small values other than 0. Therefore, in the present embodiment, a large number (for example, 1000
The standard deviation σ of each of these values is calculated from the above values for a normally assembled engine, and in an actual engine inspection, if all the above values are within 0 ± 3σ, It is determined that it is in a normal assembly state (described later). The value of the standard deviation σ of each of the above values, the exhaust side pressure maximal value difference [delta] P _EXmaxi, although it is common to a different value for each value such as an exhaust side pressure invariable value difference δP _{EXcons ti,} the following In the above, for the sake of simplicity, the same display (σ) will be used.

First, the inspection for the cam pulley will be described. Whether the left bank is advanced by one tooth of the cam pulley or the right bank is delayed by one tooth is determined based on whether or not all the calculation results of the following determination formula group are TRUE (see FIG. 40). ). As described above, the subscripts “ _odd ” and “ _even ” indicate the case where the value of the variable i is an odd number and the case where the value of the variable i is an even number, respectively. In addition, in order for the calculation result of each determination formula described below to be TRUE, if the subscript is “ _odd ”, the calculation results for all cylinders included in the left bank must be TRUE. When the subscript is " _even ", it is assumed that all cylinders included in the right bank must be TRUE. _{0 + 3σ <δP EXmaxodd δP EXmaxeven} <0-3σ 0-3σ ≦ δP EXconstodd ≦ 0 + 3σ 0-3σ ≦ δP EXconsteven ≦ 0 + 3σ 0 + 3σ <δΓ odd δΓ even <0-3σ 0 + 3σ <δΣ odd δΣ even <0-3σ 0 + 3σ <δΦ odd δΦ _even <0-3σ 0 + 3σ <δΛ _odd δΛ _even <0-3σ 0 + 3σ <δΨ _odd δΨ _even <0-3σ 0-3σ ≦ δ (Γ−Φ) _odd ≦ 0 + 3σ 0-3σ ≦ δ (Γ−Φ) _even ≤0 + 3σ

However, the following judgment formula group may be used instead of this judgment formula group. The following determination formula group specifies the assembly state of the cam pulley by more positively using the values shown in FIG. Other inspections for the cam pulley and the driven gear, which will be described below, will not be described one by one, but a similar group of determination formulas can be used. 17-3σ ≦ _{δP EXmaxodd} ≦ 17 + 3σ −17-3σ ≦ _{δP EXmaxeven} ≦ −17 + 3σ 0-3σ ≦ _{δP EXconstodd} ≦ 0 + 3σ 0-3σ ≦ _{δP EXconsteven} ≦ 0 + 3σ 15-3σ ≦ δΓ _odd ≦ 15 + 3σ −15-3σ ≦ δΓ _even ≦ _{-15 + 3σ 15-3σ ≦ δΣ odd ≦} 15 + 3σ -15-3σ ≦ δΣ even ≦ -15 + 3σ 15-3σ ≦ δΦ odd ≦ 15 + 3σ -15-3σ ≦ δΦ even ≦ -15 + 3σ 14-3σ ≦ δΛ odd ≦ 14 + 3σ -14-3σ ≦ δΛ _even ≦ −14 + 3σ 15-3σ ≦ δΨ _odd ≦ 15 + 3σ −15-3σ ≦ δΨ _even ≦ −15 + 3σ 0-3σ ≦ δ (Γ−Φ) _odd ≦ 0 + 3σ 0-3σ ≦ δ (Γ−Φ) _even ≦ 0 + 3σ

Whether the cam pulley of the left bank is delayed by one tooth or the cam pulley of the right bank is advanced by one tooth is determined as follows.
The determination is made based on whether or not all the calculation results of the next determination formula group are TRUE (see FIG. 40). _{δP EXmaxodd} <0-3σ 0 + 3σ < _{δP EXmaxeven} 0-3σ ≦ _{δP EXconstodd} ≦ 0 + 3σ 0-3σ ≦ _{δP EXconsteven} ≦ 0 + 3σ δΓ _odd <0-3σ 0 + 3σ <δΓ _even δΣ _odd <0-3σ 0 + 3σ <δΣ _even δΦ _odd <0 -3σ 0 + 3σ <δΦ _even δΛ _odd <0-3σ 0 + 3σ <δΛ _even δΨ _odd <0-3σ 0 + 3σ <δΨ _even 0-3σ ≦ δ (Γ−Φ) _odd ≦ 0 + 3σ 0-3σ ≦ δ (Γ−Φ) _even ≤0 + 3σ

Whether or not the driven gear in the left bank is advanced by one tooth is determined by the following formula
The determination is made based on whether or not an RUE occurs (see FIG. 40). 0 + 3σ < _{δP EXmaxodd δP EXmaxeven} <0-3σ 0 + 3σ < _{δP EXconstodd δP EXconsteven} <0-3σ 0 + 3σ <δΓ _odd δΓ _even <0-3σ 0 + 3σ <δΣ _odd δΣ _even <0-3σ 0-3σ ≦ δΦ _odd ≦ 0 + 3σ 0- 3σ ≦ δΦ _even ≦ 0 + 3σ 0 + 3σ <δΛ _odd δΛ _even <0-3σ 0 + 3σ <δΨ _odd δΨ _even <0-3σ δ (Γ−Φ) _odd <0-3σ 0 + 3σ <δ (Γ−Φ) _even

Whether or not the driven gear in the left bank is in a state of being delayed by one tooth is determined by the following formula
The determination is made based on whether or not an RUE occurs (see FIG. 40). _{δP EXmaxodd} <0-3σ 0 + 3σ < _{δP EXmaxeven δP EXconstodd} <0-3σ 0 + 3σ < _δP EXconsteven δΓ _odd <0-3σ 0 + 3σ <δΓ _even 0-3σ ≦ δΣ _odd ≦ 0 + 3σ 0-3σ ≦ δΣ _even ≦ 0 + 3σ 0-3σ ≦ δΦ _odd ≦ 0 + 3σ 0-3σ ≦ δΦ _even ≦ 0 + 3σ δΛ _odd <0-3σ 0 + 3σ <δΛ _even δΨ _odd <0-3σ 0 + 3σ <δΨ _even 0 + 3σ <δ (Γ−Φ) _odd δ (Γ−Φ) _even <0 -3σ

Whether or not the driven gear of the right bank is in the advanced state by one tooth is determined by the following formulas as a result
The determination is made based on whether or not an RUE occurs (see FIG. 40). _{δP EXmaxodd} <0-3σ 0 + 3σ < _{δP EXmaxeven δP EXconstodd} <0-3σ 0 + 3σ < _δP EXconsteven δΓ _odd <0-3σ 0 + 3σ <δΓ _even δΣ _odd <0-3σ 0 + 3σ <δΣ _even 0-3σ ≦ δΦ _odd ≦ 0 + 3σ 0− 3σ ≦ δΦ _even ≦ 0 + 3σ δΛ _odd <0-3σ 0 + 3σ <δΛ _even δΨ _odd <0-3σ 0 + 3σ <δΨ _even 0 + 3σ <δ (Γ−Φ) _odd δ (Γ−Φ) _even <0-3σ

Whether or not the driven gear of the right bank is one tooth behind is determined by the following formula
The determination is made based on whether or not an RUE occurs (see FIG. 40). 0 + 3σ < _{δP EXmaxodd δP EXmaxeven} <0-3σ 0 + 3σ < _{δP EXconstodd δP EXconsteven} <0-3σ 0 + 3σ <δΓ _odd δΓ _even <0-3σ 0-3σ ≦ δΣ _odd ≦ 0 + 3σ 0-3σ ≦ δΣ _even ≦ 0 + 3σ 0-3σ ≦ δΦ _odd ≦ 0 + 3σ 0-3σ ≦ δΦ _even ≦ 0 + 3σ 0 + 3σ <δΛ _odd δΛ _even <0-3σ 0 + 3σ <δΨ _odd δΨ _even <0-3σ δ (Γ−Φ) _odd <0-3σ 0 + 3σ <δ (Γ−Φ _Even )

Next, the inspection of the intake valve clearance will be described. First, whether or not the cylinder indicated by the variable i is in the small intake valve clearance state is determined based on whether or not all the calculation results of the following determination formula group are TRUE (see FIG. 41). 0 + 3σ < _{δP EXmaxi} 0 + 3σ < _{δP EXconsti} 0 + 3σ <δΓ _i 0-3σ ≦ δΣ _i ≦ 0 + 3σ 0-3σ ≦ δΦ _i ≦ 0 + 3σ 0 + 3σ <δΛ _i 0 + 3σ <δΨ _i δ (Γ−Φ) _i <0-3σ

Whether or not each cylinder is in the large intake valve clearance state is determined based on whether or not all the calculation results of the following determination formulas are TRUE (see FIG. 41). _{δP EXmaxi} <0-3σ δP _EXconsti <0-3σ δΓ _i <0-3σ 0-3σ ≦ δΣ _i ≦ 0 + 3σ 0-3σ ≦ δΦ _i ≦ 0 + 3σ δΛ _i <0-3σ δΨ _i <0-3σ 0 + 3σ <δ ( Γ-Φ) _i

Next, the inspection of the exhaust valve clearance will be described. Whether or not the cylinder indicated by the variable i is in the small exhaust valve clearance state is determined based on whether or not all the calculation results of the following determination formula group are TRUE (see FIG. 41). 0 + 3σ < _{δP EXmaxi} 0 + 3σ < _{δP EXconsti} 0-3σ ≦ δΓ _i ≦ 0 + 3σ δΣ _i <0-3σ 0 + 3σ <δΦ _i 0-3σ ≦ δΛ _i ≦ 0 + 3σ 0-3σ ≦ δΨ _i ≦ 0 + 3σ 0 + 3σ <δ (Γ−Φ) _i

Whether or not each cylinder is in the exhaust valve clearance large state is determined based on whether or not all the calculation results of the following determination formula group are TRUE (see FIG. 41). _{δP EXmaxi} <0-3σ δP _EXconsti <0-3σ 0-3σ ≦ δΓ _i ≦ 0 + 3σ 0-3σ ≦ δΣ _i ≦ 0 + 3σ 0-3σ ≦ δΦ _i ≦ 0 + 3σ 0-3σ ≦ δΛ _i ≦ 0 + 3σ 0-3σ ≦ δΨ _i ≦ 0 + 3σ 0−3σ ≦ δ (Γ−Φ) _i ≦ 0 + 3σ

Next, a compression ring missing inspection will be described. Whether or not the cylinder indicated by the variable i is in the compression ring missing state is determined based on whether or not all the calculation results of the following determination formula group are TRUE (see FIG. 41). 0 + 3σ < _{δP EXmaxi} 0 + 3σ < _{δP EXconsti} 0-3σ ≦ δΓ _i ≦ 0 + 3σ 0-3σ ≦ δΣ _i ≦ 0 + 3σ 0-3σ ≦ δΦ _i ≦ 0 + 3σ 0-3σ ≦ δΛ _i ≦ 0 + 3σ 0-3σ ≦ δΨ _i ≦ 0 + 3σ 0− 3σ ≦ δ (Γ−Φ) _i ≦ 0 + 3σ

The above-described determination formulas for inspecting each assembly defect can lead to a correct conclusion only when a certain assumption is correct. The assumption is that the absolute value of each value other than 0 shown in FIG. 40 and FIG. 41 is sufficiently larger than 3σ representing the substantial end of the range of the variation of the corresponding value in each normal assembly state ( It is assumed that “the range of the variation of each value other than 0 and the range of the variation of the corresponding value in the normal assembly state do not partially overlap at all.” The 0 shown in FIGS.
It is known that the absolute value of each value other than the above is approximately larger than the corresponding 3σ in the normal assembly state. But there are exceptions. For example, the magnitude of the exhaust-side pressure _invariable value difference _{δP EXconsti} in the compression ring missing state shown in FIG. 41 is “1”, which may be smaller than 3σ. In such a case, the determination formula regarding the exhaust-side pressure _invariable value difference _{δP EXconsti} is T
If the RUE is used for the compression ring missing inspection, the compression ring is erroneously determined not to be missing even though the compression ring is missing. In order to eliminate such inconvenience, if the absolute value of each value shown in FIGS. 40 and 41 is likely to be smaller than 3σ in each normal assembly state, a judgment formula relating to the value is determined. , Must not be used for inspection. Even if the value of the exhaust-side pressure _invariable value difference _{δP EXconsti} is not taken into account, the compression ring missing state and another state (including the normal assembly state) are erroneously determined based on the other values shown in FIG. It will not be lost. Inspection using all of the above-mentioned determination formula groups may include redundancy. For example, from FIG. 40 and FIG. 41, and the exhaust side pressure maximal value reached angle relative value difference [Delta] [gamma] _i and the intake-side pressure increases start angle relative value difference [delta] [Psi] _i, in the case where the defective assembly occurs, and exactly the same value It turns out that it becomes. Therefore, processing based on any one of these values may be omitted.

FIG. 42 shows the state in which the processing described above is performed.
9 is a flowchart showing the contents of a program for executing the program. This
Is included in the determiner 117 shown in FIG.
Stored in ROM (not shown) and stored in microcomputer
Therefore, the process is executed using the RAM. This process is
Based on each judgment formula group, the assembly failure corresponding to the judgment formula group is determined.
This is a process to be executed for each good. Specifically, S1
In each of 100 to S1114, the above-mentioned d
Exhaust-side pressure maximum difference obtained using the engine inspection device
Min δP_EXmaxi, Exhaust-side pressure invariant value difference δP_EXconsti,
Exhaust pressure maximum value arrival angle relative value difference δΓ_i, Exhaust side pressure
Transition state relative angle difference δΣ_i, Exhaust side pressure reduction open
Start angle relative value difference δΦ_i, Relative value of the intake side pressure maximum value arrival angle
Difference δΛ _i, Intake side pressure increase start angle relative value difference δΨ_iYou
And the variable δ (Γ−Φ)_iBased on each value of
The result of the expression group is TRUE or FALSE
Is determined.

[0137] All the calculation results by a certain judgment formula group are TR.
If it is a UE, it is determined that an assembly failure corresponding to the determination formula group has occurred. In this case, the following S111
In step 6, after a process indicating that an assembly failure corresponding to the above-mentioned determination formula group has occurred is performed, the assembly failure inspection is terminated. As described above, depending on the contents of the assembly failure, it may be necessary to omit the determination included in the determination formula group corresponding to the content of the assembly failure. For example, in the inspection as to whether or not the exhaust valve clearance is in a small state, the determination formula based on the value of the exhaust-side pressure maximum value difference _{δP EXmaxi} may need to be omitted. In this case, the process of S1100 is omitted.

The processing in step S1116 is similar to the processing performed in the above-described embodiment. For example, the processing for turning on one of the lamps of the display 118 shown in FIG. It can be. If the result of any of steps S1100 to S1114 is NO, the assembly failure inspection is terminated without performing anything. By performing the above processing for each assembly defect using each of the above-described determination formula groups,
It is possible to inspect whether or not each assembly defect has occurred. In addition, as is apparent from the values shown in FIG. 40, it is not possible to distinguish between a state in which the left bank is advanced by one tooth and a state in which the right bank is delayed by one tooth. Also,
It is not possible to distinguish between a state where the left bank is one tooth delayed and a state where the right bank is one tooth advanced. Therefore, these assembly failures can be specified only in a state where any one of the two assembly failures occurs.

The process shown in FIG. 42 can also be used to determine only whether or not a normal assembly state is present.
The determination formula group in this case is shown below. _{0-3σ ≦ δP EXmaxi ≦ 0 + 3σ} 0-3σ ≦ δP EXconsti ≦ 0 + 3σ 0-3σ ≦ δΓ i ≦ 0 + 3σ 0-3σ ≦ δΣ i ≦ 0 + 3σ 0-3σ ≦ δΦ i ≦ 0 + 3σ 0-3σ ≦ δΛ i ≦ 0 + 3σ 0- 3σ ≦ δΨ _i ≦ 0 + 3σ 0−3σ ≦ δ (Γ−Φ) _i ≦ 0 + 3σ In this case, the process of S1116 needs to be changed to a process indicating that it is in a normal assembly state.

As described above, the processing shown in FIG.
The reason for this is that the emissions of multiple engines
Side pressure maximum value difference δP_EXmax, Exhaust side pressure change value difference
δP _EXconst, Exhaust side pressure local maximum value arrival angle relative value difference δ
Γ, Exhaust side pressure unchanged state transition angle relative value difference δΣ, Exhaust
Side pressure decrease start angle relative value difference δΦ, intake side pressure maximum value reached
Attachment angle relative value difference δ 側, intake side pressure increase start angle relative value difference
Based on the values of δΨ and the variable δ (Γ−Φ),
Is required to be obtained in advance. this thing
In order to avoid this, the processing shown in FIG.
May be changed to

First, when the cam pulley inspection and the driven gear inspection are performed, the exhaust-side pressure maximum value difference δP
_EXmax , the exhaust-side pressure _invariable value difference _{δP EXconst} and the determination on the intake-side pressure maximum value arrival angle relative value difference δΛ, that is, S1100, S1102 and S1 in FIG.
The process of 1110 is omitted. In other words, the exhaust-side pressure maximum value arrival angle relative value difference δΓ, the exhaust-side pressure unchanged state transition angle relative value difference δΣ, the exhaust-side pressure decrease start angle relative value difference δΦ, the intake-side pressure increase start angle relative value difference δΨ, and The inspection is performed based only on each value of the variable δ (Γ−Φ). These values are values that can be understood without actually measuring each assembly defect (values that can be theoretically known). For example, cam pulley 1 tooth advance /
If a delay occurs, the exhaust-side pressure maximum value arrival angle relative value difference δΓ, the exhaust-side pressure unchanged state transition angle relative value difference δ
Σ, the exhaust side pressure decrease start angle relative value difference δΦ, and the intake side pressure increase start angle relative value difference δΨ are +15 or −15.
However, this can be theoretically understood without measurement. On the other hand, the exhaust-side pressure maximum value difference δP
_{The values of EXmax} , the exhaust-side pressure unchangeable value difference _{δP EXconst} and the intake-side pressure maximum value arrival angle relative value difference δΛ are values that cannot be known unless the engine is actually manufactured and measured. The process based on the above is omitted.

Next, when an inspection is performed to determine whether the intake valve clearance is small / large or whether the exhaust valve clearance is small, the relative value of the exhaust-side pressure maximum value relative angle is determined. Value difference δΓ, exhaust-side pressure unchanged state transition angle relative value difference δΣ, exhaust-side pressure decrease start angle relative value difference δΦ, intake-side pressure maximum value arrival angle relative value difference δΛ,
Intake side pressure increase start angle relative value difference δΨ and variable δ (Γ
−Φ) so that a determination is made based on the sign of each value of
The processing shown in FIG. 42 is changed. The sign in the normal meaning indicates either positive or negative. In this case, “0” is added to “sign”, and positive, negative or 0 is added.
It shall indicate which value the degree is. here,
Specifically, the value of about 0 is, for example, a value larger than -2 and smaller than 2. The value of 2 is an empirically known value and is not a value directly derived from a value obtained in an individual engine test. In addition, for each of the exhaust-side pressure maximum value arrival angle relative value difference δΓ, the exhaust-side pressure unchanged state transition angle relative value difference δΣ, and the like,
The values may be different from each other. Accordingly, the positive value is a value larger than about 0 (in this case, a value of 2 or more), and the negative value is a value smaller than about 0 (in this case, 2 or less). Value). FIG.
The value itself of each value shown in 1 cannot be known unless it is actually measured. However, in each assembly state, at least one of the above positive, negative, or approximately 0 values can often be theoretically derived based on information such as the structure of the engine. 41. Among the values shown in FIG. 41, the values used in the determination (including those used in the later-described inspection of a large exhaust valve clearance and a missing compression ring) include the states of the codes (positive and positive). Either negative or 0)
Was added.

Whether the intake valve clearance is small or not
If an inspection is performed, the above-mentioned cam pulley inspection and
As in the case where the driven gear inspection is performed, FIG.
The processing of S1100 and S1102 in is omitted.
You. Then, each determination processing of S1104 to S1114
Indicates that the operation result of the following logical expression is TRUE
This is replaced by a determination process of whether or not the data is valid. δΓ_i≧ 2 (S1104) δΣ_i~ 0 (S1106) δΦ_i~ 0 (S1108) δΛ_i≧ 2 (S1110) δΨ_i≧ 2 (S1112) δ (Γ−Φ)_i≦ −2 (S1114) Here, for example, δΓ_i≧ 2 is relative to the exhaust side maximum value arrival angle
Value difference δΓ_iIs greater than about 0 (being positive
) And δΣ_i0 to shift to the exhaust side pressure unchanged state
Angle relative value difference δΣ_iIndicates that the value of
Δ (Γ−Φ) _i≦ -2 is the variable δ (Γ−Φ)_iThe value of the
Is less than about 0 (negative)
You.

If it is determined whether or not the intake valve clearance is in the large state, the processing of S1104 to S1114 is performed when the operation result of the following logical expression is TRUE.
Is determined. δΓ ≦ -2 (S1104) δΣ-0 (S1106) δΦ-0 (S1108) δΛ ≦ -2 (S1110) δΨ ≦ -2 (S1112) δ (Γ−Φ) ≧ 2 (S1114)

When checking whether or not the exhaust valve clearance is in the small state, the processing of S1104 to S1114 is replaced by a determination processing of whether or not the calculation result of the following logical expression is TRUE. δΓ-0 (S1104) δΣ ≦ -2 (S1106) δΦ ≧ 2 (S1108) δΛ-0 (S1110) δΨ-0 (S1112) δ (Γ−Φ) ≧ 2 (S1114)

Next, when inspection is performed to determine whether the exhaust valve clearance is large and the compression ring is missing, whether the intake valve clearance is small or large, or In addition to the determination based on the above-mentioned code used for checking whether or not the exhaust valve clearance is small, the exhaust-side pressure maximum value difference δP
_A process based on the sign of _EXmax is added (it is added as the process of S1100). Specifically, when it is determined whether or not the exhaust valve clearance is in the large state, the processing in S1100 and S1104 to S1104 in FIG.
The processing of 114 is replaced with a determination processing of whether or not the operation result of the following logical expression is TRUE. _{δP EXmax} ≦ −2 (S1100) δΓ-0 (S1104) δΣ-0 (S1106) δΦ-0 (S1108) δΛ-0 (S1110) δΨ-0 (S1112) δ (Γ−Φ) -0 (S1114)

When it is determined whether or not the compression ring is missing, S1100 and S1104
The processing of steps S1114 to S1114 is replaced with a determination processing of whether or not the operation result of the following logical expression is TRUE. _{δP EXmax} ≧ 2 (S1100) δΓ-0 (S1104) δΣ-0 (S1106) δΦ-0 (S1108) δΛ-0 (S1110) δΨ-0 (S1112) δ (Γ−Φ) -0 (S1114) FIG. 42 According to such a change in the content of the processing shown in,
There is no need to obtain the value of the standard deviation σ in the normal assembly state.

As described above, in the engine assembly failure inspection method according to the present embodiment, the equations (9) to (1) are used.
As shown in the expression 5), the inspection of the assembly failure is performed based on the comparison between the adjacent cylinders. However, as with the engine 90 to be inspected, such as the engine 90 to be inspected, such as the engine 90 of the present embodiment, In other words, the present inspection method is to be interpreted as an inspection based on a comparison between the cylinders included in the left bank (the value of the variable i is odd) and the cylinders included in the right bank (the value of the variable i is even). Can also.

Further, even if the type of the engine to be inspected is different, even if the exhaust-side pressure maximum value arrival angle relative value difference δΓ, the exhaust-side pressure unchanged state transition angle relative value difference δΣ, the exhaust-side pressure decrease The sign of the start angle relative value difference δΦ, the intake side pressure local maximum value arrival angle relative value difference δΛ, the intake side pressure increase start angle relative value difference δΨ, and the sign of the variable δ (Γ−Φ) is any of the above positive, negative or about zero. In some cases, it does not affect whether or not the engine belongs to the engine. In such a case, the engine assembly failure inspection method according to the present embodiment can be applied to inspection for assembly failure of a plurality of types of engines.

[0150] In each embodiment described above, the exhaust side pressure maximal value P _EXmax and exhaust pressure maximal value reached angle relative value [Delta] [gamma] _i, and the like, and a value calculated on the basis of their values obtained for each cylinder Since the inspection is performed by comparing each other, it is not necessary to know the value of the crank angle itself in each change state. Therefore, the crank angle sensor 114 shown in FIG. 4 is unnecessary in an actual inspection, and the configuration of the inspection device can be simplified.

In addition, in each of the above-described embodiments, the intake side pressure is obtained in the surge tank, but may be obtained for each intake port 92. In this case, the intake side pressure corresponding to each cylinder can be obtained, and the assembly state can be inspected based on the specific change state of the intake side pressure. Further, although the space inside the intake port 92, the intake manifold 94, and the surge tank 96 is set as the intake side space, for example, only the space inside the intake port 92 may be set as the intake side space. in this case,
In addition to or instead of the exhaust-side space, the intake-side space is closed, and an engine assembly failure test is performed.

For example, when the intake side space is only the space inside the intake port 92, the exhaust side pressure maximum value P _EXmax and the exhaust side pressure maximum value P _EXmax and the exhaust side pressure in the engine inspection apparatus of FIG. Exhaust side pressure unchanged value P
Pressure value corresponding to _EXconst and, because it can get an angular difference corresponding to the exhaust side pressure decrease start angle relative value .DELTA..PHI _i like, it is possible to inspect the assembled state in consideration of these values.

In each of the embodiments described above, the V6DOHC gasoline engine is targeted for inspection, but the invention of the present application is applicable to inspection of other types of engines. For example, in the SOHC engine, the above-described inspection on the driven gear may be omitted. In a DOHC engine in which the intake-side camshafts 32 and 34 are driven by different cam pulleys, an inspection on another cam pulley can be performed instead of an inspection on a driven gear. Also,
Exhaust pressure P _EX characteristic value a is the exhaust side pressure maximal value P _{EXma x} for changes in the exhaust side pressure maximal value reached angle θ
_Although the engine assembly inspection is performed based on a value derived from a value such as _EXmax (for example, the exhaust-side pressure maximum value arrival angle relative value ΔΓ, etc.), the other values shown in FIG. The inspection may be performed based on another characteristic amount of the curve shown in the graph. For example, the inspection can be performed by further taking into account the maximum value of the slope of the curve, the time at which it occurs, and the length and position of the section where the rate of change of the curve is equal to or greater than a preset change rate. . Further, the present invention can be applied not only to a gasoline engine but also to a diesel engine.

Also, a plurality of the above-mentioned assembly defects occur simultaneously.
The assembly failures that occur at the same time
To use more information to determine
Is also good. For example, the above-mentioned assembly
A state where a defect has occurred is intentionally caused, and
Exhaust-side pressure local maximum value P in standing state_EXmax, Exhaust side
Pressure maximum value arrival angle relative value ΔΓ_i, Exhaust side pressure decrease start angle
Relative value ΔΦ_iGet a set of values such as
Compare with the set of values obtained from the engine under test
The state corresponding to the set of values closest to each other is
It is determined that the target engine is assembled. In addition, each of the above
In the embodiment, a crank pulley, a cam pulley and
Poor assembly of driven gears leads / lags only one tooth
Configuration that can detect the lead / lag of two or more teeth
May be. In this case, it was used for each of the above determinations.
Exhaust pressure maximum P_EXmax, Exhaust side pressure peak value reaching
Logarithmic value ΔΓ_i, Exhaust side pressure decrease start angle relative value ΔΦ_iEqual value
Can be processed in more stages.
it can. In the case described above, the exhaust pressure maximum value P
_EXmaxIt is necessary that subtle differences in values such as
However, in the engine inspection device of each embodiment of the present invention,
To obtain a lot of data quickly for each of the above values.
Can be improved by performing statistical processing, etc.
Reliable inspections can also be performed. that's all,
Although several embodiments of the present invention have been illustrated, these
It is a literal example, and the present invention departs from the scope of the claims.
Without any modification or improvement.
Can be.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a partially omitted internal configuration of a V6 gasoline engine.

FIG. 2 is a perspective view showing a state in which assembly failure of a crank pulley and a cam pulley has occurred in the V6 gasoline engine of FIG. 1;

FIG. 3 is an enlarged sectional view showing a part of a valve train of a general engine.

FIG. 4 is a system diagram showing a main part of an engine inspection apparatus used for implementing an engine inspection method which is one embodiment common to the first to eighth inventions of the present application.

FIG. 5 is a front view schematically showing the whole of the engine inspection device.

FIG. 6 shows a piston position PP in a normal assembly state and an exhaust pressure P _EX obtained by the engine inspection device.
And the change in the intake side pressure P _IN with the crank angle θ _crank
It is a graph shown by the relationship with.

[7] obtained by the engine testing apparatus, the change of the crank reference signal and the exhaust pressure P _EX of each cylinder in the normal assembled condition, is a graph showing the relationship between the crank angle theta _crank.

FIG. 8 is a graph showing a change in the exhaust-side pressure P _EX in a normal assembly state and a small intake valve clearance state obtained by the engine inspection apparatus, in relation to a crank angle θ _crank .

FIG. 9 is a graph showing a change in the exhaust-side pressure P _EX in a normal assembly state and a large intake valve clearance state obtained by the engine inspection apparatus in relation to a crank angle θ _crank .

FIG. 10 is a graph showing changes in the intake-side pressure P _IN in a normal assembly state, a small intake valve clearance state, and a large intake valve clearance state, obtained by the engine inspection apparatus, in relation to a crank angle θ _crank. .

FIG. 11 is a graph showing the relationship between the exhaust side pressure P _EX and the crank angle θ _{crank in} a normal assembly state and a small exhaust valve clearance state obtained by the engine inspection device.

FIG. 12 is a graph showing the relationship between the exhaust side pressure P _EX and the crank angle θ _{crank in} a normal assembly state and a large exhaust valve clearance state, obtained by the engine inspection device.

FIG. 13 is a graph showing a relationship between an exhaust side pressure P _EX and a crank angle θ _{crank in} a normal assembly state and a compression ring missing state, obtained by the engine inspection device.

FIG. 14 is a graph showing a relationship between a crank reference signal and an exhaust-side pressure P _EX of each cylinder and a crank angle θ _crank in a state where the cam pulley is advanced by one tooth, obtained by the engine inspection device.

FIG. 15 is a graph showing a relationship between a crank reference signal and an exhaust-side pressure P _EX of each cylinder and a crank angle θ _crank obtained by the engine inspection device in a state in which one tooth of the cam pulley is delayed.

FIG. 16 is a graph showing a relationship between a crank reference signal and an intake pressure P _IN and a crank angle θ _{crank in} a normal assembly state, a cam pulley one tooth advance state, and a cam pulley one tooth delay state acquired by the engine inspection device. It is.

FIG. 17 is a graph showing a relationship between the exhaust side pressure P _EX and the crank angle θ _{crank in} a normal assembly state and a cam pulley one-tooth advanced state acquired by the engine inspection device.

FIG. 18 is a graph showing the relationship between the exhaust side pressure P _EX and the crank angle θ _crank in a normal assembly state and a state in which the cam pulley is one tooth delayed.

FIG. 19 is a diagram illustrating a crank reference signal and an exhaust-side pressure P _EX and a crank angle θ _crank in a driven gear 1 tooth advanced state.
6 is a graph showing a relationship with the graph.

FIG. 20 is a diagram illustrating a crank reference signal and an exhaust-side pressure P _EX and a crank angle θ _crank in a driven gear one tooth delay state;
6 is a graph showing a relationship with the graph.

FIG. 21 is a graph showing a relationship between a crank reference signal and an intake pressure P _IN and a crank angle θ _crank in a normal assembly state, a driven gear one tooth advanced state and a driven gear one tooth delayed state.

FIG. 22 is a graph showing the relationship between the exhaust side pressure P _EX and the crank angle θ _crank in a normal assembly state and a driven gear 1 tooth advanced state.

FIG. 23 is a graph showing a relationship between the exhaust-side pressure P _EX and the crank angle θ _crank in a normal assembly state and a driven gear one tooth delay state.

FIG. 24 shows the exhaust-side pressure maximum value difference α, the exhaust-side pressure unchangeable value difference β, the exhaust-side pressure maximum value arrival angle difference Γ, and the exhaust-side pressure unchanged state transition angle when each assembly failure occurs independently. 5 is a table showing an example of a difference Σ, an exhaust-side pressure decrease start angle difference Φ, an intake-side pressure maximum value arrival angle difference Λ, and an intake-side pressure increase start angle difference Ψ.

FIG. 25 shows the exhaust-side pressure P of each cylinder in the cam pulley one tooth advance state obtained by the engine inspection device.
FIG. 7 is a graph showing the relative value ΔΓ _i of the exhaust-side pressure maximum value arrival angle, the relative value ΔΦ _{i of} the exhaust-side pressure decrease start angle, and the relative value ΔΣ _i of the exhaust-side pressure unchanged state transition angle of _EX .

26 is a diagram showing the exhaust side pressure maximal value reached angle relative value [Delta] [gamma] _i in cam pulley 1 tooth proceeds condition.

FIG. 27 shows R included in a decision unit of the engine inspection device.
It is a flowchart showing the main processing of the assembly state inspection stored in OM.

FIG. 28 is a front view showing a configuration of a display unit of the engine inspection device.

FIG. 29 is a flowchart illustrating a defective portion estimation process executed in S118 of FIG. 25;

FIG. 30 is a diagram showing a bit configuration of a defective portion flag stored inside a RAM included in the determination unit.

FIG. 31 is a flowchart illustrating a driven gear 1 tooth advance inspection performed in S202 of FIG. 29;

FIG. 32 is a flowchart showing a small exhaust valve clearance inspection performed in S204 of FIG. 29;

FIG. 33 is a flowchart showing a cam pulley inspection performed in S206 of FIG. 27.

FIG. 34 is a flowchart showing a driven gear 1 tooth delay and intake valve clearance inspection performed in S208 of FIG. 27;

FIG. 35 shows λ _i − used for determination in S602 of FIG. 34;
It is a graph showing the range of values of [Delta] [gamma] _m.

FIG. 36 is a flowchart showing a large exhaust valve clearance inspection performed in S210 of FIG. 27.

FIG. 37 is a flowchart illustrating another example of the large exhaust valve clearance inspection performed in S210 of FIG. 27.

38 is a flowchart illustrating yet another example of the large exhaust valve clearance inspection performed in S210 of FIG. 27.

FIG. 39 is a flowchart showing a compression ring missing test performed in S212 of FIG. 27.

FIG. 40: Exhaust side pressure maximum value difference δP when cam pulley and driven gear assembly failures occur independently of each other.
_EXmax , exhaust-side pressure _invariable value difference _{δP EXconst} , exhaust-side pressure maximum value arrival angle relative value difference δΓ, exhaust-side pressure unchanged state transition angle relative value difference δΣ, exhaust-side pressure decrease start angle relative value difference δΦ, intake Side pressure local maximum value arrival angle relative value difference δΛ,
9 is a chart showing an example of values such as an intake side pressure increase start angle relative value difference δΨ.

FIG. 41: Intake valve clearance and exhaust valve clear
Mis-assembly due to missing lance and compression ring
Exhaust-side pressure maximum value difference δ when each occurs independently
P _EXmax, Exhaust-side pressure invariant value difference δP_EXconst,exhaust
Side pressure local maximum value arrival angle relative value difference δΓ, exhaust side pressure unchanged
State transition angle relative value difference δΣ, exhaust side pressure decrease start angle relative
5 is a table showing an example of a value such as a value difference ΔΦ.

FIG. 42 shows R included in a determinator of the engine inspection device.
FIG. 28 is a flowchart showing the content of an assembly failure inspection according to another embodiment, which is stored in the OM and is different from the processing shown in FIG. 27.

[Explanation of symbols]

10, 12: piston 20: crank pulley 2
4, 26: cam pulley 40, 42 driven gear 48: exhaust valve 5
0: intake valve 60, 62: scissor gear 7
6: Cylinder head 90: Engine to be inspected 92: Intake port 94: Intake manifold 9
6: Surge tank 98, 106: Pressure sensor 1
00: Exhaust port 102: Cover member 110, 112: A / D converter 114: Crank angle sensor 117: Judge 118 Display 11
9: Inspection control device 120: Base 122: Drive coupling 124: Drive shaft 125: Motor 134: Piston ring 136: Top ring 138: Second ring 140: Oil ring 144: Compression ring 200: OK
Lamp 202: NG lamp

Claims (5)

[Claims] An internal combustion engine having a plurality of cylinders each having an intake valve and an exhaust valve is rotated, and an intake space communicating with the intake valve outside each intake valve and an exhaust gas outside each exhaust valve. At least one of a pressure value in a predetermined change state of the pressure of at least one of the exhaust-side space communicating with the valve and a generation time of the change state is detected for at least two of the plurality of cylinders, At least one of the pressure values of the at least two cylinders and the occurrence timing are compared with each other, and when they do not match, it is determined that there is an assembly failure in the internal combustion engine. 2. The engine according to claim 1, wherein the internal combustion engine includes a first bank and a second bank, and the comparison is performed between at least one cylinder of the first bank and at least one cylinder of the second bank. The method for inspecting an assembly failure of an internal combustion engine according to claim 1. 3. The method according to claim 2, wherein the comparing is performed between an average value of the detected values of at least one of the pressure value and the generation timing and at least one of the pressure value of each cylinder and the generation timing. 3. The method for inspecting an assembly failure of an internal combustion engine according to any one of 1 and 2. 4. The method according to claim 1, wherein the detected values of at least one of the pressure value and the generation time are divided into groups each of which is close to each other, and the comparison is performed between the groups. 3. The method for inspecting a defective assembly of an internal combustion engine according to any one of 3. 5. The method according to claim 1, further comprising detecting an occurrence timing of the predetermined change state for all of the plurality of cylinders, and comparing intervals of occurrence timings of the plurality of cylinders which are adjacent to each other in an explosion order. The method for inspecting an assembly failure of an internal combustion engine according to any one of claims 1 to 4, wherein: