JP2003314507A - Cleaning method for hydraulic control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep to a minimum an undesirable behavior of an actuator associated with cleaning while enabling foreign matters of a hydraulic control valve to be removed by cleaning. <P>SOLUTION: The hydraulic control valve 64 for controlling oil pressure supplied to a hydraulically controlled actuator, wherein a duty solenoid 67 of the hydraulic control valve 64 is energized to move a spool 66, removing the foreign matters c thrust into the spool 66. By making an operating time of the hydraulic control valve 64 at a low oil temperature at which a viscosity of an operating oil gets higher longer than at a high oil temperature at which the viscosity of the operating oil gets lower, the foreign matters c are certainly removed at the low temperatures and further the undesirable behavior of the actuator associated with the cleaning at the high temperatures is suppressed to the minimum. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention operates a hydraulic control valve separately from the control of the actuator in order to eliminate foreign matter from being caught in the hydraulic control valve for controlling the hydraulic pressure supplied to the hydraulically controlled actuator. The present invention relates to a method for cleaning a hydraulic control valve that performs cleaning.

[0002]

2. Description of the Related Art A valve operating characteristic variable mechanism is used as a countermeasure against foreign matter trapping in a hydraulic control valve for controlling a valve operating characteristic variable mechanism of a cam phase variable type for continuously controlling the opening / closing timing of an intake valve and an exhaust valve of an engine. It is known from Japanese Patent Laid-Open No. 2001-234764 that the hydraulic control valve is opened and closed separately from the above control to perform cleaning for removing foreign matter.

[0003]

The conventional method for cleaning a hydraulic control valve has the following problems because the hydraulic control valve is opened and closed for a fixed time regardless of the oil temperature of the hydraulic oil. That is, the hydraulic oil of the variable valve operating characteristic mechanism has a high viscosity when the oil temperature is low and a low viscosity when the oil temperature is high. For this reason, it is necessary to set the time for operating the hydraulic control valve to be long to promote the removal of foreign matter. However, at high temperatures where foreign matter is easily removed due to the low viscosity of the hydraulic oil, the hydraulic control valve operates longer than the time required to remove foreign matter, so the variable valve operation characteristic mechanism operates undesirably. There is a problem that ends up. On the contrary, if the time for operating the hydraulic control valve is set to be short so that the variable valve operation characteristic mechanism does not operate undesirably at high temperature, there is a problem that foreign matter cannot be removed at low temperature.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to minimize the undesired operation of the actuator due to the cleaning while allowing the foreign matter of the hydraulic control valve to be removed by the cleaning.

[0005]

In order to achieve the above-mentioned object, according to the invention described in claim 1, the foreign matter biting of the hydraulic control valve for controlling the hydraulic pressure supplied to the hydraulically controlled actuator is prevented. In order to solve the problem, in the cleaning method of the hydraulic control valve that operates by cleaning the hydraulic control valve separately from the control of the actuator, in the cleaning method performed when the oil temperature is low, the operating time of the hydraulic control valve is the cleaning performed when the oil temperature is high. A method for cleaning a hydraulic control valve is proposed, which is characterized in that it is set longer than the operating time of the hydraulic control valve.

According to the above construction, the operating time of the hydraulic control valve for cleaning performed at low oil temperature is set longer than the operating time of the hydraulic control valve for cleaning performed at high oil temperature, so that the oil temperature is low. When the viscosity of the hydraulic oil is high and it is difficult to remove the foreign matter, the hydraulic control valve can be operated for a long time to remove the foreign matter, and because the oil temperature is high, the viscosity of the hydraulic oil is low and the foreign matter can be removed. When easy to remove, the hydraulic control valve can be actuated for a short period of time to minimize unwanted actuation of the actuator associated with cleaning.

Further, according to the invention described in claim 2,
In addition to the configuration of claim 1, the difference between the operating time of the hydraulic control valve in the cleaning performed at the time of abnormality detection when the oil temperature is low and the operating time of the high oil temperature is the difference of the operating time of the hydraulic control valve in the cleaning performed in the normal time. A method for cleaning a hydraulic control valve is proposed, which is characterized in that it is set to be smaller than the difference between the oil temperature and the high oil temperature.

According to the above construction, the difference between the operating time of the hydraulic control valve when the abnormality is detected is set to be small when the oil temperature is low and when the oil temperature is high, so that foreign matter can be removed while allowing some operation of the actuator. By performing the cleaning with the highest priority, it is possible to remove the foreign matter and quickly eliminate the abnormal state. On the other hand, since the difference between the operating time of the hydraulic control valve during normal operation at low oil temperature and high oil temperature is set to be large, the operation of the hydraulic control valve due to cleaning should be made as small as possible to minimize undesired operation of the actuator. Can be suppressed.

According to the invention described in claim 3,
In addition to the configuration of claim 1 or claim 2, there is proposed a method for cleaning a hydraulic control valve, characterized in that the operating time of the hydraulic control valve during cleaning is reduced in response to an increase in the oil temperature.

According to the above construction, the operating time of the hydraulic control valve in cleaning decreases as the oil temperature rises, so that the operating time of the hydraulic control valve can be optimally set according to the oil temperature.

The valve operating characteristic changing mechanism V of the embodiment corresponds to the actuator of the present invention. Further, the cleaning at the time of abnormal advancement of the embodiment corresponds to the cleaning performed at the time of abnormality detection of the present invention, and the cleaning at the time of fully closing the throttle of the embodiment corresponds to the cleaning performed at the normal time of the present invention.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

1 to 13 show an embodiment of the present invention. FIG. 1 is an overall perspective view of an internal combustion engine, FIG. 2 is a two-direction enlarged arrow view of FIG. 1, and FIG. 3 is a sectional view taken along line -3, FIG. 4 is a hydraulic circuit diagram of the valve operating characteristic variable mechanism, FIG. 5 is a longitudinal sectional view of the hydraulic control valve, FIG. 8 is a flowchart of the cleaning process at the time of abnormal advance, FIG. 8 is a time chart of the cleaning process at the time of fully advancing the throttle, FIG. 9 is a flowchart of the cleaning process at the time of fully closing the throttle, FIG. 10 is a time chart of the cleaning process at the time of fully closing the throttle, and FIG. FIG. 12 is a flowchart of the process, FIG. 12 is a time chart of the cleaning process at the time of engine stall, and FIG. 13 is a diagram illustrating a difference between a restart after a normal engine stall and a restart after a failed engine stall.

As shown in FIG. 1, a four-cylinder DOHC type internal combustion engine E includes a crankshaft 3 in which four pistons 1 ... Are connected via connecting rods 2. A drive sprocket 4 provided at the shaft end of the crankshaft 3, an intake camshaft 5 and an exhaust camshaft 6
Driven sprockets 7 and 8 respectively provided at the shaft ends of the crankshaft 3 are connected through a timing chain 9, and the intake camshaft 5 and the exhaust camshaft 6 are rotationally driven at a rate of one rotation for every two rotations of the crankshaft 3. It

Two intake valves 10, 1 driven by the intake camshaft 5 are provided for each of the four cylinders.
0 and two exhaust valves 11, 11 driven by the exhaust camshaft 6 are provided. Intake camshaft 5
A valve operation characteristic varying mechanism V for advancing or retarding the opening / closing timing of the intake valves 10, 10 in a stepless manner is provided at the shaft end of the.

Next, the structure of the variable valve operation characteristic mechanism V provided at the shaft end of the intake camshaft 5 will be described with reference to FIGS. 2 and 3.

A support hole 41a formed at the center of a substantially cylindrical boss member 41 is coaxially fitted to the axial end portion of the intake camshaft 5, and is joined by a pin 42 and a bolt 43 so that they cannot rotate relative to each other. The driven sprocket 7 around which the timing chain 9 is wound has a circular recess 7a and is formed in a substantially cup shape, and sprocket teeth 7b are formed on the outer periphery thereof. An annular housing 44 that fits into the recess 7a of the driven sprocket 7 and a plate 45 that is superposed on the outer side in the axial direction are connected to the driven sprocket 7 by four bolts 46 that penetrate them. Therefore, the boss member 4 integrally connected to the intake camshaft 5
1 is accommodated in a space surrounded by the driven sprocket 7, the housing 44 and the plate 45 so as to be relatively rotatable. A lock pin 47 is slidably fitted in a pin hole 41b penetrating the boss member 41 in the axial direction, and the lock pin 47 is attached to the driven sprocket 7 by a spring 48 mounted in a compressed state between the lock pin 47 and the plate 45. It is urged in a direction to engage with the formed lock hole 7c.

Inside the housing 44, fan-shaped recesses 44a ... 90 ° about the axis of the intake camshaft 5 are formed.
Four vanes 49, which are formed at intervals and radially protrude from the outer periphery of the boss member 41, are fitted into the recesses 44a so that they can relatively rotate within a central angle range of 30 °. Four sealing members 50 provided at the tips of the four vanes 49 abut slidably on the ceiling wall of the recesses 44a.
Further, the four seal members 51 provided on the inner peripheral surface of the housing 44 slidably contact the outer peripheral surface of the boss member 41, so that the advance chamber 52 and the retard chamber 53 are formed on both sides of each vane 49. Each is divided.

An advancing oil passage 54 and a retarding oil passage 55 are formed inside the intake camshaft 5, and the advancing oil passage 54 has four oil passages that penetrate the boss member 41 in the radial direction. The retard angle oil passages 55 communicate with the four advance chambers 52 through the passages 56, and the four retard passages 55 extend through the four boss members 41 in the radial direction. Corner room 53 ...
Communicate with each. Further, the lock hole 7c of the driven sprocket 7 into which the head of the lock pin 47 is fitted communicates with one of the advance chambers 52 via an oil passage (not shown).

However, when hydraulic pressure is not supplied to the advance chambers 52 ..., the head of the lock pin 47 has a spring 48.
Is fitted into the lock hole 7c of the driven sprocket 7, and the intake camshaft 5 is locked in the most retarded state in which the intake camshaft 5 rotates counterclockwise relative to the driven sprocket 7 as shown in FIG. When the hydraulic pressure supplied to the advance chambers 52 is increased from this state, the lock pin 47 locks the driven sprocket 7 against the elastic force of the spring 48 by the hydraulic pressure transmitted from any of the advance chambers 52. As the vanes 49 are pushed by the hydraulic pressure difference between the advance chamber 52 ... and the retard chamber 53, the intake camshaft 5 moves clockwise relative to the driven sprocket 7 (in FIG. The crankshaft 3 of the engine E rotates in a counterclockwise direction (opposite to the rotation direction), the cam phase integrally advances, and the opening timing and closing timing of the intake valves 10, 10 are both advanced. Change. Therefore, the advance chamber 5
2 by controlling the hydraulic pressure of the retard chamber 53.
The opening / closing timing of the intake valves 10, 10 can be changed steplessly.

Next, the control system of the valve operating characteristic changing mechanism V will be described with reference to FIG.

The oil pumped from the oil pan 62 at the bottom of the crankcase via the oil passage 63a is used as the oil around the crankshaft 3 of the internal combustion engine E and as the lubricating oil for the valve operating mechanism, and the variable valve operating characteristic mechanism. The V hydraulic oil is discharged to the oil passage 63b. The oil passage 63b communicating with the variable valve operation characteristic mechanism V is provided with a hydraulic control valve (OCV) 64 that is a duty solenoid valve that controls the hydraulic pressure steplessly.

TDC for detecting the top dead center of the pistons 1 ... Based on the signal from the camshaft sensor Sa for detecting the phase of the intake camshaft 5 and the phase of the exhaust camshaft 6.
A signal from the sensor Sb, a signal from the crankshaft sensor Sc that detects the phase of the crankshaft 3, a signal from the intake negative pressure sensor Sd that detects the intake negative pressure, a signal from the cooling water temperature sensor Se that detects the cooling water temperature, A signal from the throttle opening sensor Sf that detects the throttle opening,
The electronic control unit U as a control unit to which a signal from the engine speed sensor Sg that detects the engine speed is input controls the operation of the hydraulic control valve 64 of the variable valve operation characteristic mechanism V.

Next, the structure of the hydraulic control valve 64 of the variable valve operating characteristic mechanism V will be described with reference to FIG.

The hydraulic control valve 64 has a cylindrical sleeve 65.
A spool 66 slidably fitted in the sleeve 65, a duty solenoid 67 fixed to the sleeve 65 to drive the spool 66, and a spring 68 urging the spool 66 toward the duty solenoid 67.
With. By duty-controlling the current of the duty solenoid 67 in accordance with a command from the electronic control unit U, the axial position of the spool 66 slidably fitted in the sleeve 65 can be changed steplessly.

The sleeve 65 has a central input port 69.
And a retard port 70 and an advance port 71 located on both sides thereof, and a pair of drain ports 72, 73 located on both sides thereof. On the other hand, the spool 66 slidably fitted in the sleeve 65 has a groove 74 at the center.
And a pair of lands 75 and 76 located on both sides thereof and a pair of grooves 77 and 78 located on both sides thereof. The input port 69 is connected to the oil pump 61, the retard port 70 is connected to the retard chamber 53 of the valve operation characteristic changing mechanism V, and the advance port 71 is connected to the advance chamber 52 of the valve operation characteristic changing mechanism V. Connected.

Next, the operation of the valve operating characteristic changing mechanism V will be described.

When the internal combustion engine E is stopped, the valve operating characteristic changing mechanism V is in the state of FIG. 3 in which the retard chambers 53 ... Have the maximum volume and the advance chambers 52 ... 47 is fitted in the lock hole 7c of the driven sprocket 7 and is held in the most retarded state. When the internal combustion engine E is started to operate the oil pump 61 and the hydraulic pressure transmitted to the advance chambers 52 through the hydraulic control valve 64 exceeds a predetermined value, the lock pin 47 is disengaged from the lock hole 7c by the hydraulic pressure. As a result, the valve operating characteristic changing mechanism V becomes operable.

From this state, the duty solenoid 67
5 is increased to 50% or more, the spool 66 moves to the right of the neutral position against the spring 68 in FIG. 5, and the input port 69 connected to the oil pump 61 advances through the groove 74. The retard port 70 communicates with the port 71 and the drain port 72 through the groove 77. As a result, hydraulic pressure acts on the advance chambers 52 of the variable valve operating characteristic mechanism V, so that the intake camshaft 5 rotates clockwise relative to the driven sprocket 7 in FIG. 3, and the cam phase of the intake camshaft 5 changes. Changes to the advance side continuously. Then, when the target cam phase is obtained, the duty ratio of the duty solenoid 67 is set to a set value (for example, 50%) corresponding to the high-speed valve timing described later, and the spool 66 of the hydraulic control valve 64 is shown. 5, the input port 69 is closed between the pair of lands 75 and 76, and the retard port 70 and the advance port 71 are closed by the lands 75 and 76, respectively. The intake camshaft 5 can be integrated to maintain the cam phase.

In order to continuously change the cam phase of the intake camshaft 5 to the retard side, the duty ratio of the duty solenoid 67 is reduced to 50% or less to move the spool 66 leftward from the neutral position and the oil pump 61 is moved. It is sufficient that the input port 69 connected to the above is communicated with the retard port 70 through the groove 74 and the advance port 71 is communicated with the drain port 73 through the groove 78. When the target phase is obtained, the duty solenoid 6
If the duty ratio of No. 7 is set to 50% and the spool 66 is stopped at the neutral position shown in FIG. 5, the input port 69, the retard port 70 and the advance port 71 are closed to maintain the cam phase. You can

By changing the phase of the intake camshaft 5 with respect to the phase of the crankshaft 3 by the variable valve operation characteristic mechanism V, the opening / closing timing of the intake valves 10 and 10 is determined by the rotation angle of the intake camshaft 5. Of 50
Range of ° (converted to the rotation angle of the crankshaft 3 is 1
It is possible to advance and retard infinitely over the range (00 °).

By the way, as shown in FIG. 6 (A), the duty ratio of the duty solenoid 67 is set to 50% or more and the spool 66 of the hydraulic control valve 64 is moved to the right to operate from the advance port 71 to the advance chamber 52. When the oil is supplied and the hydraulic oil is discharged from the retard chamber 53 to the drain port 72 via the retard port 70, as shown in FIG. 6B, the foreign matter c contained in the hydraulic oil is delayed by the retard port 70. There is a case where it is caught in the gap between the land and the land 75 of the spool 66. At this time, even if the duty solenoid 67 is demagnetized, the spool 66 is biased to the left by the elastic force of the spring 68, so that the foreign matter c is encouraged to be caught and the spool 66 is prevented from moving to the left. There is a problem that the cam phase is locked and the cam phase cannot be controlled to the retard side.

In such a case, the duty solenoid 67 is temporarily excited to move the spool 66 rightward against the elastic force of the spring 68, whereby the retard port 70 and the land 75 of the spool 66 are separated. The gap c can be widened to allow the foreign matter c to flow away into the drain port 72 together with the hydraulic oil.
Further, even if the foreign substance c cannot be removed only by widening the gap, by demagnetizing the duty solenoid 67 and moving the spool 66 leftward toward the original position by the elastic force of the spring 68, the retard angle port 70 and the spool 66 lands 7
The foreign matter c is bitten by 5 and the drain port 7 together with the hydraulic oil.
Can be flushed to 2.

The reciprocating motion of the spool 66 for removing the foreign matter c can be performed not only once but repeatedly.
The number of reciprocating movements is limited to a short time of about several tens of msec. This is to prevent the hydraulic oil from being supplied to the advance chamber 52 due to the right movement of the spool 66, and the cam phase from largely deviating to the advance side.

In the foreign matter removal (cleaning) of the hydraulic control valve 64 described above, when the cam phase exceeds the set range and becomes abnormally advanced due to the foreign matter c being bitten, the change in the cam phase due to the cleaning changes the operating state of the engine E. When the influence is small The throttle valve is fully closed This is executed when the engine E is stopped. Hereinafter, the methods of cleaning the hydraulic control valve 64 in the above three cases will be sequentially described.
Although not described in detail in this specification, the hydraulic control valve 6
The cleaning of No. 4 is also executed at the time of deceleration fuel cut of the vehicle.

First, based on the flow chart of FIG. 7, the cleaning action when the cam phase exceeds the set range and abnormally advances due to biting of the foreign matter c will be described.

First, in step S1, it is determined whether or not a failure has been detected in the valve operation characteristic changing mechanism V, the hydraulic control valve 64, various sensors used for controlling the valve operation characteristic changing mechanism V, and the failure is detected. When the abnormality is caused, the cleaning at the time of abnormal advance is not executed, and when the failure is not detected, the routine proceeds to step S2. In step S2, it is determined by the timer TAFTCL whether or not other cleaning (cleaning at the time of deceleration fuel cut) is being executed. If TAFTCL is not 0, another cleaning is being performed, or a predetermined time has passed since the end of other cleaning. If it has not elapsed, the cleaning at abnormal advance is not executed, and if TAFTCL = 0, the process proceeds to step S3. In step S3, it is determined whether or not the abnormal advance cleaning is being executed by a flag F. Determined by VTCCLN2, F If VTCCLN2 is not 1 and abnormal advance cleaning is not being executed, the process proceeds to step S4.

In step S4, it is determined whether the engine E is in the starting mode by the flag F. Determined by STMOD, F
When STMOD = 1 and the engine E is in the start mode, the cleaning at abnormal advance is not executed, and F S
If TMOD = 1 is not satisfied, the process proceeds to step S5. The reason why the cleaning at abnormal advance angle is prohibited in the starting mode is to prevent malfunction due to fluctuation of the actual cam angle CAIN. In step S5, the actual cam angle CAIN is compared with the cleaning execution determination cam angle # CAVTCLN2.
The actual cam angle CAIN can be changed from 0 ° (the most retarded position) to 50 ° (the most advanced position).
N is the cleaning execution determination cam angle # CAVTCLN2
When the angle exceeds (for example, 48 °) or more, it is determined that the lead angle is abnormal. Therefore, in step S5, CAI ≧ # CAV
If TCLN2 is not satisfied, the cleaning at abnormal advance is not executed, and if it is satisfied, the process proceeds to step S6.

In step S6, it is determined by the timer TVCL2DL whether or not the delay time (for example, 200 msec) has elapsed since the abnormal advance angle was determined, and the TV
If CL2DL is not 0 and 200 msec has not elapsed, the cleaning at abnormal advance is not executed and 200
When smec has elapsed, the process proceeds to step S7. In step S7, the duty generation frequency counter CVTCCLN2 for cleaning is compared with the duty generation frequency maximum value # CVTCLN2 (for example, 5 times) to determine CVT.
If CCLN2 = # CVTCLN2 and the duty generation for five times (that is, the temporary operation of the hydraulic control valve 64 for cleaning) is completed, the abnormal advance cleaning is not executed, and the duty is generated five times. If not completed, the process proceeds to step S8.

In step S8, the time interval of duty generation
The timer T determines whether (for example, 10 seconds) has elapsed.
It is judged by AFCLN2, and TAFCLN2 = 0
If 10 seconds do not elapse without clearing, the
Without executing the training, TAFCLN2 = 0 and 10
If sec has elapsed, the flag F is determined in step S9. V
Set TCCCLN2 to 1 (cleaning execution)
After executing the cleaning during normal advance, in step S10
Timer TAFTCL2 which prohibits other cleaning
Set to # TMAFTCL2 for a predetermined time.

Different in steps S1, S2, S4 and S5.
If execution of cleaning during normal advance is prohibited,
Counter CVTC for the number of duty generations at step S11
CLN2 is reset to 0 and abnormal progress is made in step S12.
Timer that measures the delay time after the corner is determined
Set TVCL2DL to set time # TMVCL2DL (for example,
Set to 200 msec). Also the above step
Execution of cleaning at abnormal advance is prohibited in S6, S7 and S8
If stopped, the flag F is determined in step S13. VTCC
Reset LN2 to 0 (cleaning not executed) and
A timer T that defines the duty generation time in step S14
Set VCL2ACT to set time # TMVC2ACT (for example,
For example, set it to 40 msec).

In step S3, F VTCCLN2 =
If 1, the abnormal advance cleaning is being executed, and the timer TVCL2ACT (for example, 40 msec) that defines the duty generation time is not timed up in step S15, the process proceeds to step S9 and the abnormal advance is performed. Continue execution of cleaning. Then, in step S15, the timer T for defining the duty generation time is set.
If VCL2ACT times out, step S16
The duty generation counter CVTCCCLN2 is incremented by and the timer TAFCLN2 defining the duty generation time interval is set to the set value #T in step S17.
MAFCLN2 (for example, 10 sec) is set, and a flag F indicating whether or not to execute the cleaning at abnormal advance in step S18 Reset VTCCLN2 to 0 (no cleaning).

Next, an example of the above operation will be described with reference to the time chart of FIG.

When the actual cam angle CAIN becomes equal to or greater than the cleaning execution determination cam angle # CAVTCLN2 of 48 °, it is determined that the foreign matter c is caught, and the timer TVCL
2DL set time # TMVCL2DL 200ms
After waiting the delay time of ec, timer TVC
L2ACT set time # TMVC2ACT 40m
During sec, the duty solenoid 6 of the hydraulic control valve 64
By setting the duty ratio of No. 7 to 100% (a value close to 100% is also possible), the spool 76 is moved to the right in order to remove the caught foreign matter c, and the duty generation frequency counter CVTCCLN2 is incremented.

As a result of the first cleaning, if the actual cam angle CAIN is still equal to or higher than the cleaning execution determination cam angle # CAVTCLN2 of 48 °, the timer TAFCLN2 for defining the time interval of duty generation.
After waiting 10 seconds, which is the set value # TMAFCLN2, the duty solenoid 6 of the hydraulic control valve 64 is again set.
After the duty ratio of No. 7 is set to 100% for 40 msec to remove the foreign matter c, the duty generation counter CVTCCLN2 is incremented.

As a result of the second cleaning, the actual cam angle CAIN is the cleaning execution determination cam angle #CAVT.
If CLN2 is less than 48 °, it is determined that the foreign matter c is removed, the cleaning is terminated, and the duty generation counter CVTCCCLN2 is reset to zero.
Even if the foreign substance c is not removed even if the count value of the duty generation counter CVTCCCLN2 reaches 5, the removal of the foreign substance c is abandoned and the cleaning is finished.

Next, the operation of cleaning performed when the throttle is fully closed will be described with reference to the flowchart of FIG. While the cleaning when the above-described cam phase exceeds the set range and is abnormally advanced is executed only when there is an abnormality, this cleaning also aims at preventing the foreign matter c from being caught and the throttle opening is fully closed. Every time. The reason why cleaning is performed when the throttle is fully closed is that the influence of the change in the cam phase due to the cleaning can be minimized when the throttle is fully closed.

First, in step S21, the valve operating characteristics can be set.
The flag F indicates whether the operation of the variable mechanism V is prohibited. V
Determined by TCSTP, F VTCSTP = 0
The operation of the variable valve operating characteristic mechanism V is prohibited.
In that case, do not perform cleaning when the throttle is fully closed,
F VTCSTP = 0 and variable valve operating characteristic mechanism
If the operation of V is permitted, the process proceeds to step S22.
To do. Slot engine speed NE in step S22
Maximum engine speed to perform cleaning when fully closed
Compared with # NEVCL3H (eg 4000 rpm)
However, when NE ≦ # NEVCL3H is not satisfied, the engine E
If the throttle is closed at high speed, clean it when the throttle is fully closed.
The engine is not executed and NE ≦ # NEVCL3H is satisfied.
If E is rotating at a low speed, the process proceeds to step S23. Su
In step S23, a flag F is used to determine whether the throttle is fully closed.
Determined by THIDLE, F THIDLE = 0
If the throttle is not fully closed,
F without performing cleaning THIDLE = 0 and
If the throttle is fully closed, the process proceeds to step S24.

In step S24, it is determined by the timer TAFTCL whether or not other cleaning (cleaning at the time of deceleration fuel cut) is being executed, and TAFTC is determined.
If L = 0 and other cleaning is in progress, or if a predetermined time has not passed from the end of other cleaning, cleaning at the time of fully closing the throttle is not executed and TAFT is not executed.
When CL = 0, the process proceeds to step S25. In step S25, it is determined by the timer TAFTCL2 whether or not the abnormal advance cleaning is being executed, and the TAFTC is set.
If L2 = 0 is not satisfied and cleaning is being performed during abnormal advance, or if a predetermined time has not elapsed after the completion of the cleaning, the cleaning is not performed when the throttle is fully closed.
If CL2 = 0, the process proceeds to step S26.

In step S26, it is determined by the timer TVCL3DL whether or not the delay time (for example, 500 msec) has elapsed since the throttle was fully closed, and the TVCL3CL
If 3mL = 0 and 500msec has not elapsed, cleaning is not executed when the throttle is fully closed.
When 00 msec has elapsed, the process proceeds to step S27. In step S27, the duty generation frequency counter CVTCCLN3 for cleaning is compared with the maximum duty generation frequency value # CVTCLN3 (for example, three times), and CVTCCCLN2 = # CVTCLN3, and three times of duty generation (that is, the hydraulic pressure for cleaning is generated). If the temporary operation of the control valve 64) is completed, the cleaning at the time of fully closing the throttle is not executed, and if the three duty generations are not completed, the process proceeds to step S28.

In step S28, the timer T determines whether or not the time interval of duty generation (for example, 1 sec) has elapsed.
If it is determined by AFCLN3 that TAFCLN3 = 0 and 1 sec has not elapsed, cleaning at the time of fully closing the throttle is not executed, and if TAFCLN3 = 0 and 1 sec has elapsed, the process proceeds to step S29. In step S29, the duty generation time (for example, 4
The timer TVCL3ACT determines whether 0 msec or 20 msec has elapsed, and the TVCL3
40msec or 20msec after ACT = 0
If the time has elapsed, cleaning is not executed when the throttle is fully closed, and TVCL3ACT = 0 does not become 40 mse.
If c or 20 msec has not elapsed, the flag F is determined in step S30. VTCCLN3 is set to 1 (cleaning execution) and cleaning is performed when the throttle is fully closed.

When the execution of cleaning when the throttle is fully closed is prohibited in steps S21, S22 and S23, the timer TVCL3DL for measuring the delay time after the throttle is fully closed is determined in step S31. TMVCL3DL (for example, 500 mse
c) and the counter CVTCCLN3 of the duty generation frequency for cleaning is set to 0 in step S32.
Reset to.

When TAFTCL is not 0 in step S24 and another cleaning is being performed, or when a predetermined time has not elapsed from the end of the cleaning, and in step S25 T
Not cleaning AFTCL2 = 0, cleaning during abnormal advance,
Alternatively, if the predetermined time has not elapsed from the end, the duty generation frequency counter CVTCCLN3 for cleaning is set to the maximum duty generation frequency value # CVTCLN3, which is three times, in step S33.

In step S29, TVCL3ACT =
When the duty generation time reaches 0 and the duty generation time of 40 msec or 20 msec elapses, the duty generation frequency counter CVTCLN3 is incremented in step S34, and the timer TAFCLN3 defining the duty generation time interval is set in the set value #TMAF in step S35.
Set CLN3 to 1 sec.

Then, the steps S32, S33, S3
In step S36 subsequent to 5, the flag F VTCCLN3
Is set to 0 (cleaning not executed) to prohibit cleaning when the throttle is fully closed, and in the subsequent step S37, the cooling water temperature TW is compared with the set value # TWVC3ACT, and TW is set.
When the water temperature is low such that ≧ # TWVC3ACT is not established, the timer T that defines the duty generation time in step S38
Set VCL3ACT to the first set time # TMC3ACTL
(For example, 40 msec) and TW ≧
At the time of high water temperature where # TWVC3ACT is established, the timer TVC that defines the duty generation time in step S39.
L3ACT is set to the second set time # TMC3ACTH (for example, 20 msec). The set value # TWVC3ACT of the cooling water temperature TW is, for example, 70 ° C to 80 ° C, which is about 40 ° C when converted to the oil temperature.

Next, an example of the above operation will be described with reference to the time chart of FIG.

The engine speed NE is the upper limit speed 3
When the throttle is fully closed at a speed of 800 rpm / 4000 rpm (with hysteresis) or more, when the engine speed NE falls below the upper limit rotation speed, or when the engine speed NE is lower than the upper limit rotation speed, the throttle is closed. When the throttle is fully closed, cleaning is performed when the throttle is fully closed when the throttle is fully closed. That is, 5 measured by the timer TVCL3DL after the throttle is fully closed.
# TMVCL3DL, which is a delay time of 00 msec
Is elapsed, the first set time # TMC3ACTL is 40 msec or the second set time # TMC3AC is set.
By setting the duty ratio of the duty solenoid 67 of the hydraulic control valve 64 to 100% for 20 msec which is TH, the spool 76 is set to remove the foreign matter c that has been caught.
Is moved to the right to perform cleaning, and the duty generation counter CVTCCLN3 is incremented.

After the first set time # TMC3ACTL or the second set time # TMC3ACTH has elapsed, if the throttle fully closed state continues even after 1 second, which is the time interval of duty generation measured by the timer TAFCLN3, has elapsed. Again, the duty ratio of the duty solenoid 67 of the hydraulic control valve 64 is set to 100% to perform cleaning, and the duty generation counter CV is displayed.
Increment TCLCLN3. This cleaning is repeated with the maximum value of 3 times which is the maximum value of the number of duty generation # CVTCLN3. Then, whether the fully closed throttle state is released, whether the engine speed NE is equal to or higher than the upper limit speed, or the duty generation counter CVT.
When CCLN3 reaches three times, the cleaning ends.

By the way, since the viscosity of the hydraulic oil becomes high when the temperature of the hydraulic oil of the variable valve operating characteristic mechanism V is low, it is necessary to move the spool 66 largely in order to remove the caught foreign matter c. When the oil temperature of the hydraulic oil of the variable valve operating characteristic mechanism V is high, the viscosity of the hydraulic oil becomes low.
All you have to do is move 6 a small amount. Since the cooling water temperature TW is almost proportional to the oil temperature of the hydraulic oil, the cooling water temperature TW
Is low (oil temperature is low), the first set time # TMC3ACTL for setting the duty ratio of the duty solenoid 67 of the hydraulic control valve 64 to 100% is relatively long 40 m.
By setting to sec, the spool 66 can be largely moved to reliably discharge the foreign matter c, and conversely, when the cooling water temperature TW is high (oil temperature is high), the hydraulic control valve 64 is provided.
The duty ratio of the duty solenoid 67 is 100%
By setting the second set time # TMC3ACTH to be 20 msec which is relatively short, the spool 66 can be moved a small amount and the change in the cam phase can be minimized.

Next, the operation of cleaning performed at the time of engine stall will be described based on the flowchart of FIG.
When the throttle is fully closed, the hydraulic control valve 64 is originally in the most retarded state, but if the hydraulic control valve 64 is not in the most retarded state due to the foreign matter c being caught at this time, engine stall occurs during idle operation or it is difficult to start. Therefore, when the engine stall occurs, cleaning is performed to remove the foreign matter c. Since there are two modes in the engine stall referred to here, prior to the explanation with the flowchart, FIG.
The stalling mode will be described in advance based on the above.

The mode shown in FIG. 13A is for the engine E.
This is the case where an engine stall occurs while the vehicle is rotating normally and the driver restarts. In this case, the driver releases the ignition key when the engine stalls, so normally the shortest time is 1.5 before the restart.
Time of about sec passes. On the other hand, the mode shown in FIG. 13B is a case where the driver restarts the engine E once it has failed to start. In this case, since the driver touches the ignition key when the engine stalls (when the restart fails), normally a minimum time of about 0.5 sec elapses before the restart is started.

In order to perform the cleaning during the engine stall in which the engine E is not operating and the starter motor is not operating, in the mode shown in FIG.
It is necessary to finish the cleaning during the period c.
In the mode shown in (B), it is necessary to finish the cleaning within 0.5 sec. Therefore, the maximum number of times that the duty ratio of the duty solenoid 67 of the hydraulic control valve 64 is 100% during the engine stall is set to, for example, 8 times in the mode shown in FIG. 13A, and the mode shown in FIG. Then, for example, it is set to twice. It should be noted that the engine stall here means a state excluding a state in which the engine E is operating and a state in which the engine E is cranking.

Now, in step S41, the valve operating characteristic changing mechanism V, the hydraulic control valve 64, and the valve operating characteristic changing mechanism V are used.
It is determined whether or not a failure has been detected by various sensors used for the control, and cleaning is not performed at the time of engine stall when the failure is detected, and the routine proceeds to step S42 when the failure is not detected. Step S
At 42, it is determined whether the engine E is in the starting mode (the state before the complete explosion) or the basic mode (the state after the complete explosion).
Determined by STMOD, F If STMOD = 1 is not satisfied and the engine E is in the basic mode, step S
The flag F is used to determine that the engine E has a history of entering the basic mode at 51. Set OUTSTMOD to 1. On the other hand, in step S42, F STMOD =
If 1 is satisfied and the engine E is in the starting mode, the engine is not stalled in step S43, and the engine is stalled in the previous loop in step S52, that is, if the engine E is started for the first time in the current loop, the step is executed. S5
In order to delete the history that the engine E entered the basic mode in 3, the flag F Set OUTSTMOD to 0.

In step S54 following steps S51, S52 and S53, a flag F for determining that the engine is not in the stalled state at least once (starting is attempted at least once) Set OUTENST to 1. Then, a timer TVCL4DL for measuring the delay time after the engine stall is determined in step S55 following steps S41 and S54 is set to the set time # TMVCL4DL.
(For example, 100 msec), and step S5
At 6, the counter CVTCCLN4 that counts the number of duty generations for cleaning is reset to 0.

Now, in the step S43, the flag F is for judging that the engine is currently in the stalled state, and in the following step S44, the engine is once in the stalled state. OUTENST
If is set to 1, the process proceeds to step S45. The step S44 is provided to confirm that at least one start-up is attempted in order to prevent the cleaning from being executed in the engine stall state from the insertion of the ignition key to the operation of the starter motor. This is because the cleaning is performed later.

In the subsequent step S45, the engine stall is determined.
Delay time (for example, 100 msec) after
Whether the timer TVCL4DL to be measured has timed up
It is determined whether TVCL4DL = 1 and the engine stall is determined.
100 msec of the delay time has elapsed since the
If so, the process proceeds to step S46. F in step S46 OU
A history of entering the basic mode when TSTMOD = 1 is established
If you have it, that is, after engine E starts once,
If the installation has failed (see FIG. 13A), step S
The duty count for cleaning is counted at 47.
Counter CVTCCCLN4 to the first set value #CV
Compare with TCLN4 (eg, 8 times). On the other hand,
Step S46 F Without OUTSTMOD = 1
If you have no history of entering basic mode,
When the engine E fails to start and is stalled (Fig. 13
(See (B)).
CVT for counting the number of duty generations for
CCLN4 is set to the second set value # CVTCLN4S (for example,
2 times).

The counter C in steps S47 and S57.
The count number of VTCCLN4 is the first set value #CVTCL.
If N4 or the second set value # CVTCLN4S has not been reached, it is determined in step S48 by the timer TAFCLN4 whether the time interval of duty generation (for example, 50 msec) has elapsed, and TAmCLN2 = 0, and 50 msec has elapsed. In case of step S49
Move to. Timer TVCL4A that defines the duty generation time (for example, 40 msec) in step S49
If CT has not timed up, a flag F indicating whether or not the engine stall cleaning is executed in step S50. Set VTCCLN4 to 1 (clean execution).

In step S49, the timer TVCL that defines the duty generation time (for example, 40 msec)
If 4ACT has timed out, a counter CVTCC that counts the number of duty occurrences in step S58
The timer TAFCLN4 which increments LN4 and defines the time interval of duty generation in step S59
Set value # TMAFCLN4 (for example, 50 msec)
Set to. And the steps S56, S48, S
In step S60 subsequent to 59, a flag F indicating whether or not to perform the engine stall cleaning Set VTCCLN4 to 0
A timer TVCL4AC which is set to (non-execution of cleaning) and defines the duty generation time in step S61.
T is set value # TMVCL4ACT (for example, 40 mse
Set to c).

Next, an example of the above operation will be described with reference to the time chart of FIG.

When the engine stall occurs, the delay time #TMVC measured by the timer TVCL4DL from that point
After waiting for the passage of 100 msec which is L4DL, the timer TVCL4ACT
Set value # TMVCL4ACT measured at 40 ms
The duty solenoid 6 of the hydraulic control valve 64 over ec
The duty ratio of 7 is set to 100%, and then the set value # TMAFCLN4 measured by the timer TAFCLN4.
The duty ratio of the duty solenoid 67 of the hydraulic control valve 64 is set to 0% alternately for 50 msec. The maximum number of times the duty is turned on and off is the first set value #CVT when the engine E is once started and then stalled.
CLN4 is eight times, and if the engine E fails to start and the engine stalls, the second set value # CVTCLN4S is two times. Then, when the engine stall is eliminated or the number of times the duty cycle is repeated on and off reaches the maximum number, the cleaning is terminated.

In the above-mentioned cleaning at the time of engine stall,
The engine stall mode shown in FIG. 13 (A) after the engine E has rotated normally and the engine stall mode shown in FIG. 13 (B) due to a failure to start the engine E are identified and corresponding to each mode. By performing the separate cleaning, the starting of the engine E can be ensured while ensuring the effect of removing the foreign matter c. That is, FIG. 13 (A)
In the former mode shown in FIG. 13, it is estimated that it takes a long time for the driver to attempt restarting, and cleaning is performed a large number of times (up to eight times in the embodiment) during that time.
In the latter mode shown in (B), it is estimated that it takes a short time for the driver to try to restart the engine, and a small number of cleanings (maximum 2 times in the embodiment) are performed during that time. In the engine stall mode after rotating, the effect of removing foreign matter by cleaning can be secured to the maximum, and in the engine stall mode due to the failure of the start of the engine E, the hydraulic control valve 64 operates during the engine E cleaning. It is possible to prevent the start of the engine from being started, and avoid a situation where the start becomes difficult or the idle operation becomes unstable.

Although the embodiments of the present invention have been described above, the present invention can be modified in various ways without departing from the scope of the invention.

For example, the present invention can be applied to the hydraulic control valve 64 of any actuator other than the valve operating characteristic changing mechanism V.

Further, in the embodiment, the cooling water temperature TW of the engine E is
Although the oil temperature of the hydraulic oil is estimated from the above, an oil temperature sensor can be provided to directly detect the oil temperature of the hydraulic oil.

Further, in the embodiment, in the cleaning at the abnormal advance angle, the duty generation time is set to the fixed time (4
Although it is set to 0 msec), if it is set to be long at low temperature and short at high temperature, it is possible to minimize the undesirable operation of the variable valve operating characteristic mechanism V while enhancing the effect of removing the foreign matter c. However, the difference in duty generation time between high temperature and low temperature is 20 msec in cleaning when the throttle is fully closed (that is, 40 ms at low temperature).
ec and the difference between 20 msec at high temperature).

The reason is that, in the abnormal advance cleaning which is executed at the time of abnormality detection, the foreign matter c is reliably removed by giving the highest priority to the removal of the foreign matter c while allowing some operation of the valve operating characteristic changing mechanism V. This is because it is necessary to remove the abnormal state to quickly eliminate the abnormal state. On the other hand, in the throttle full-closed cleaning that is executed in the normal state, it is necessary to minimize the undesirable operation of the valve operating characteristic changing mechanism V that accompanies the cleaning.

Further, in the embodiment, the cleaning is performed when the throttle is fully closed, and the duty generation time is set to 40 according to the rise of the oil temperature.
Although it is reduced stepwise in two steps of msec and 20 msec, it is reduced in multiple steps of three steps or more, or the duty generation time is reduced steplessly (for example, ramp-like) according to the rise of the oil temperature. Therefore, the duty generation time of the hydraulic control valve 64 can be optimally set according to the oil temperature.

[0078]

As described above, according to the invention described in claim 1, the operating time of the hydraulic control valve for cleaning performed at a low oil temperature is more than the operating time of the hydraulic control valve for cleaning performed at a high oil temperature. Since the oil temperature is low, it is possible to remove foreign matter by operating the hydraulic control valve for a long time when the viscosity of the hydraulic oil is high and it is difficult to remove foreign matter. Therefore, when the viscosity of the hydraulic oil becomes low and the foreign matter is easily removed, the hydraulic control valve can be operated for a short time to minimize the undesirable operation of the actuator due to the cleaning.

According to the invention described in claim 2,
Since the difference between the operating time of the hydraulic control valve at the time of abnormality detection at low oil temperature and high oil temperature is set to be small, it is possible to allow foreign matter removal while allowing the actuator to operate slightly. Therefore, it is possible to remove foreign matter and quickly eliminate the abnormal state. On the other hand, since the difference between the operating time of the hydraulic control valve during normal operation at low oil temperature and high oil temperature is set to be large, the operation of the hydraulic control valve due to cleaning should be made as small as possible to minimize undesired operation of the actuator. Can be suppressed.

According to the invention described in claim 3,
Since the operating time of the hydraulic control valve in cleaning decreases as the oil temperature rises, the operating time of the hydraulic control valve can be optimally set according to the oil temperature.

[Brief description of drawings]

FIG. 1 is an overall perspective view of an internal combustion engine

FIG. 2 is an enlarged view from the direction of the arrow in FIG.

3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is a hydraulic circuit diagram of a valve operating characteristic changing mechanism.

FIG. 5 is a vertical sectional view of a hydraulic control valve.

FIG. 6 is an explanatory view of a foreign matter removal operation of the hydraulic control valve.

FIG. 7 is a flowchart of a cleaning process during abnormal advance.

FIG. 8 is a time chart of cleaning processing during abnormal advance.

FIG. 9 is a flowchart of cleaning processing when the throttle is fully closed.

FIG. 10 is a time chart of cleaning processing when the throttle is fully closed.

FIG. 11 is a flowchart of a cleaning process at the time of engine stall.

FIG. 12 is a time chart of cleaning processing at the time of engine stall.

FIG. 13 is a diagram illustrating a difference between a restart after a normal engine stall and a restart after a failed start.

[Explanation of symbols]

64 Hydraulic control valve c Foreign object V Valve operating characteristic variable mechanism (actuator)

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3G016 AA08 AA12 AA19 BA03 BA06                       BA23 BA28 BB11 CA24 DA06                       DA22                 3G018 AB04 AB17 BA33 CA20 DA52                       DA58 DA60 EA11 EA17 EA21                       EA22 EA23 FA01 FA07 GA04                       GA39                 3H082 AA12 BB14 CC02 DB11 EE20

Claims (3)

[Claims] 1. A hydraulically controlled actuator (V)
Hydraulic control for cleaning by operating the hydraulic control valve (64) separately from the control of the actuator (V) in order to eliminate the foreign substance (c) from being caught in the hydraulic control valve (64) that controls the hydraulic pressure supplied to the hydraulic control valve (64). In the valve cleaning method, the operating time of the hydraulic control valve (64) for cleaning performed at a low oil temperature is set to be longer than the operating time of the hydraulic control valve (64) for cleaning performed at a high oil temperature. How to clean the hydraulic control valve. 2. The operating time of the hydraulic control valve (64) in the cleaning performed in the normal time is calculated by calculating the difference between the operating time of the hydraulic control valve (64) in the cleaning performed when the abnormality is detected at the time of low oil temperature and the high oil temperature. The method for cleaning a hydraulic control valve according to claim 1, wherein the difference is set to be smaller than the difference between the low oil temperature and the high oil temperature. 3. A hydraulic control valve (6) for cleaning.
The method for cleaning a hydraulic control valve according to claim 1 or 2, wherein the operation time of 4) is decreased according to the increase of the oil temperature.