JPH09195805A - Valve timing adjuster for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the sliding motion property of an oil pressure control valve by restricting precipitation and deposition of impurity and/or foreign matter inside of the oil pressure control valve in the case of valve timing adjuster for an internal combustion engine. SOLUTION: A feedback control signal for the purpose of making an actual valve timing coincide with a target valve timing is calculated in a control signal calculator 102 and the feedback control signal is converted to an output current by means of an output current calculating part 105 so as to drive an oil pressure control valve 30 to adjust valve timing. In this case, a cleaning condition is established when such a state as throttling the oil pressure control valve 30 below its specified opening continues for more than a specified period of time, a cleaning demand is outputted to an output current calculation part 105 from a cleaning condition judging part 104 so as to forcibly open/close the oil pressure control valve 30. Thereby, the quantity of oil flowing inside the oil pressure control valve 30 is temporarily increased so as to discharge precipitation/deposition inside the oil pressure control valve 30 is discharged outward and the inside of the oil pressure control valve 30 is subjected to cleaning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing adjusting device for an internal combustion engine for adjusting the opening / closing timing (valve timing) of an intake valve and an exhaust valve according to operating conditions of the internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, for example, in an engine intake air amount control device described in Japanese Patent Publication No. 1-59406, a relative rotational position adjusting device is provided between a cam shaft of an intake valve and a crank shaft of an engine. By supplying hydraulic pressure from the oil pump to the advance chamber or the retard chamber of the relative position adjusting device via the hydraulic control valve, and adjusting this hydraulic pressure with the hydraulic control valve,
The piston that divides the advance chamber and the retard chamber is moved to adjust the relative rotational position between the cam shaft and the crank shaft, thereby adjusting the valve timing of the intake valve.

This valve timing adjusting device can control the switching speed of the valve timing adjusting device arbitrarily by adopting a hydraulic control valve that controls the hydraulic pressure by controlling the opening degree together with the oil passage switching control. The configuration is such that the relative rotation angle with respect to the camshaft can freely follow a target rotation angle that continuously changes according to the operating state of the engine.

[0004]

By the way, in the above-mentioned valve timing adjusting device, when the change in the target rotation angle between the crankshaft and the camshaft is gradual, the opening of the hydraulic control valve is controlled to be small. A small amount of oil will flow through the hydraulic control valve. Further, even if the above-described target rotation angle is constant, it is necessary to compensate for the leak in the hydraulic circuit of the valve timing adjusting device, so that a small amount of oil continues to flow in the hydraulic control valve.

When the amount of oil flowing in the hydraulic control valve is reduced as described above, the flow velocity of the oil in the hydraulic control valve is reduced, so that impurities in the oil are likely to precipitate and accumulate.
Further, foreign matter such as cutting dust floating in the engine oil during cutting cannot pass through the valve because the opening degree of the hydraulic control valve is small, and the foreign matter tends to accumulate in the valve.

This phenomenon becomes more prominent as the deteriorated engine oil is used, and there is a risk that the hydraulic control valve may impair the slidability due to deposits or may cause foreign matter to be caught and locked. Furthermore, if the engine is stopped and left for a long time with foreign matter deposits remaining in the hydraulic control valve,
There is also a risk that deposits will stick to the inside of the valve and the hydraulic control valve will malfunction.

Further, if the valve timing control is continued in a state where the hydraulic control valve does not operate normally due to foreign matter being caught in the hydraulic control valve, there is a risk that excessive current may continue to flow in order to force the hydraulic control valve to operate. May cause overheating and deterioration.

In view of the above problems of the prior art, the present invention suppresses the precipitation / accumulation of impurities and foreign matters in the hydraulic control valve in the valve timing adjusting device of an internal combustion engine, and causes the precipitation / accumulation. The first purpose is to prevent the slidability of the hydraulic control valve from deteriorating and to prevent foreign matter from being caught. In the unlikely event that the hydraulic control valve malfunctions, excessive energization to the hydraulic control valve is required. Prohibit and overheat the hydraulic control valve
The second purpose is to prevent deterioration.

[0009]

In order to achieve the above object, a valve timing adjusting device for an internal combustion engine according to claim 1 of the present invention is provided with at least one of an intake valve and an exhaust valve according to an operating state of the internal combustion engine. The target valve timing of the target valve timing is set by the target valve timing setting means, and the actual valve timing of at least one of the intake valve and the exhaust valve is detected by the actual valve timing detection means based on the relative rotation angle between the crankshaft and the camshaft, A control signal for feedback-controlling the detected actual valve timing to match the target valve timing is output from the control signal output means to the opening adjustment means. With this control signal, the opening adjustment means adjusts the opening of the hydraulic control valve and controls the hydraulic pressure to the phase difference adjusting device, so that the actual valve timing of at least one of the intake valve and the exhaust valve becomes the target valve timing. Feedback control is performed so that they match.

At this time, the cleaning condition is satisfied when the state in which the opening degree adjusting means throttles the hydraulic pressure control valve to a predetermined opening degree or less continues for a predetermined time or longer, and the cleaning request means adjusts the opening degree. Output to the means. In response to this cleaning request, the opening adjustment means opens and closes the hydraulic control valve.

Therefore, if the state in which the hydraulic control valve is throttled to a predetermined opening or less continues for a predetermined time or longer, the hydraulic control valve is opened and closed each time, and the amount of oil flowing in the hydraulic control valve temporarily increases. As a result, precipitates and deposits inside the hydraulic control valve are discharged to the outside of the hydraulic control valve. As a result, the inside of the hydraulic control valve can be cleaned at an appropriate timing, and it is possible to prevent the slidability of the hydraulic control valve from being deteriorated and the foreign matter trapped and locked due to sedimentation and deposits.

Further, in the present invention, the control signal output means changes the control signal from the small opening state to the large opening state when there is a cleaning request from the cleaning requesting means. At the time of changing, a control signal for making the hydraulic control valve a predetermined opening or more is output. That is, according to the second aspect, when there is a cleaning request, the inside of the hydraulic control valve is cleaned by utilizing the timing of changing the state of the hydraulic control valve from the state of small opening to the state of large opening. The inside of the hydraulic control valve is cleaned without lowering the pressure.

Further, in claim 3, before starting the internal combustion engine,
In at least one of the idle state and the stopped state, a cleaning request is output from the cleaning request means to the opening adjustment means to open / close the hydraulic control valve. This allows
The interior of the hydraulic control valve is cleaned every time at least one of the internal combustion engine start state, the idle state, and the stop state occurs.

Further, according to the present invention, when there is a cleaning request from the cleaning requesting means, the input from the control signal outputting means is invalidated and the hydraulic control valve is forcibly opened and closed. As a result, the inside of the hydraulic control valve is reliably cleaned every time there is a cleaning request.

Further, according to the present invention, when the hydraulic control valve is forcibly opened and closed to clean the inside of the hydraulic control valve, the opening time of the hydraulic control valve is adjusted so that the change amount of the actual valve timing falls within a predetermined value. To control. As a result, fluctuations in the operating state of the internal combustion engine when cleaning the inside of the hydraulic control valve can be suppressed.

Further, in claim 6, whether or not there is an abnormality in the feedback control of the actual valve timing is determined by the abnormality determining means, and when it is determined that the abnormality is present, the opening adjusting means energizes the hydraulic control valve to a predetermined level or less. Restrict. As a result, even if the hydraulic control valve malfunctions, the hydraulic control valve will not be over-energized and the hydraulic control valve will not overheat.
Deterioration can be prevented.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment (1) in which the present invention is applied to a vehicle double overhead cam type internal combustion engine will be described below with reference to FIGS. 1 to 12. First, a schematic configuration of the entire system will be described with reference to FIG. Internal combustion engine 1
The power from the crankshaft 2 is transmitted by the timing chain 3 to the exhaust side camshaft 4 and the intake side camshaft 5 via the sprockets 13a and 13b. The intake-side camshaft 5 is provided with a phase difference adjusting device 40 (a shaded area in FIG. 1). A cam shaft position sensor 44 is attached to the intake side cam shaft 5, and a crank position sensor 42 is attached to the crank shaft 2.

Here, when the crank position sensor 42 generates N detection pulse signals with one rotation of the crankshaft 2, the camshaft position sensor 44 outputs 2N detection pulse signals with one rotation of the camshaft 5. Is to occur.
Further, when the maximum value of the timing conversion angle of the cam shaft 5 is θmax crank angle, the number N of detection pulse signals is set so that N <360 degrees / θmax. As a result, the detection pulse signal from the crank position sensor 42,
The actual valve timing of the intake valve (not shown) is calculated by the relative rotation angle θ between the detection pulse signal and the detection pulse signal from the camshaft position sensor 44 which is generated subsequently.

Specifically, each detection pulse signal from the crank position sensor 42 and the cam shaft position sensor 44 is input to the microcomputer 48 of the internal combustion engine controller 46, and the actual valve timing is calculated based on this. Although not shown, various detection signals output from various sensors such as an intake air amount sensor, a water temperature sensor, and a throttle sensor that detect the operating state of the internal combustion engine are also input to the microcomputer 48, and the intake valve is based on these sensor data. The target valve timing of is calculated.

Further, in the microcomputer 48, feedback control calculation is performed so that the actual valve timing of the intake valve matches the target valve timing. As a result, a control signal representing a target current to be supplied to the linear solenoid 64, which is an electromagnetic actuator for driving the hydraulic control valve 30, is output to the current control circuit 49 of the internal combustion engine controller 46. The current control circuit 49 is provided with a current detection circuit (not shown) that detects the current flowing through the linear solenoid 64. Then, the current control circuit 49 performs feedback control based on the control signal from the microcomputer 48 so that the detected current matches the target current. It should be noted that the current feedback control portion is converted to software and its function is performed by the microcomputer 4
It may be realized by the software processing of 8.

The hydraulic control valve 30 is controlled under the feedback control as described above. Then, the hydraulic oil from the oil pan 28 is pressure-fed by the oil pump 29 via the hydraulic control valve 30 thus controlled, and the amount of hydraulic oil to the phase difference adjusting device 40 is controlled.

The structure of the phase difference adjusting device 40 described above will be described in detail below with reference to FIG. Phase difference adjusting device 40
Are attached to the cylinder head 25 of the internal combustion engine 1. The phase difference adjusting device 40 includes a cam shaft sleeve 11 having a substantially cylindrical shape, and the cam shaft sleeve 11 is
The large diameter cylindrical portion is fitted coaxially with the left end portion of the cam shaft 5 in FIG. And this camshaft sleeve 1
The hollow part partition wall 11c of 1 is press-fitting of the pin 12 and the bolt 10
It is connected to the end of the cam shaft 5 by tightening. As a result, the cam shaft sleeve 11 rotates integrally with the cam shaft 5. An external tooth helical spline 11 a is formed on the outer peripheral surface of the large diameter cylindrical portion of the camshaft sleeve 11.

Further, the camshaft sleeve 11 is provided with a small-diameter cylindrical portion 11b, and the small-diameter cylindrical portion 11b extends coaxially into the substantially cylindrical hollow portion of the housing 23. The housing 23 is attached to the cylinder head 25 by tightening bolts 24 at its flange portion 23a.

The sprocket 13a is coaxially rotatably relative to the cam shaft 5 while being sandwiched between the annular rib 5a of the cam shaft 5 and the open end of the large diameter cylindrical portion of the cam shaft sleeve 11. It is pivotally supported. Figure 2 of this sprocket 13a
On the left side, a sprocket sleeve 1 with a substantially cylindrical shape
5 is coaxially attached by press-fitting the pin 14 and fastening the bolt 16 through the respective flange portions. As a result, the sprocket sleeve 15 is attached to the sprocket 1
It is designed to rotate integrally with 3a. The sprocket sleeve 15 has a cylindrical portion 15b, and the cylindrical portion 15b extends coaxially into the hollow portion of the housing 23 so as to surround the camshaft sleeve 11.

At the intermediate portion of the inner peripheral surface of the cylindrical portion 15b,
An internal tooth helical spline 15a is formed, and the internal tooth helical spline 15a is formed on the camshaft sleeve 11
The external tooth helical spline 11a is formed to have a twist in the opposite direction. Either one of the external tooth helical spline 11a and the internal tooth helical spline 15a may be formed by a spline having linear teeth parallel to the axial direction with a twist angle of zero.

An annular space 90 having a substantially uniform cross section in the axial direction is formed between the small-diameter cylindrical portion 11b of the camshaft sleeve 11 and the cylindrical portion 15b of the sprocket sleeve 15 described above. In 90, a substantially cylindrical hydraulic piston 17 is coaxially supported by the camshaft sleeve 11 so as to be slidable in the axial direction and in a liquid-tight manner.

On the right side of the inner peripheral surface of the hydraulic piston 17, the external tooth helical spline 11 of the camshaft sleeve 11 is provided.
An internal tooth helical spline 17a that meshes with a is formed. On the other hand, on the right side of the outer peripheral surface of the hydraulic piston 17,
Internal tooth helical spline 1 of sprocket sleeve 15
An external tooth helical spline 17b that meshes with 5a is formed. As a result, each of these splines 17a,
The rotation of the crankshaft 2 transmitted to the sprocket 13a via the timing chain 3 (see FIG. 1) under the meshing of 17b with each other passes through the sprocket sleeve 15, the hydraulic piston 17, and the camshaft sleeve 11 to the camshaft 5a. Be transmitted to.

An oil seal 70 is provided in the annular space 90 at the outer peripheral edge of the annular collar portion formed at the left end of the hydraulic piston 17 in the annular space 90.
It is mounted so as to make liquid-tight contact with the inner peripheral surface of b.
The annular leg portion 17c formed so as to extend in an L-shaped cross section in the left side portion of the inner peripheral surface of the hydraulic piston 17 collides with a central step portion (hereinafter, referred to as a right stopper) of the camshaft sleeve 11. The rightward movement to the hydraulic piston 17 is stopped.

By providing the hydraulic piston 17 in the annular space 90 as described above, the annular space 90 is
Is divided into two chambers. As a result, the advance side hydraulic chamber 2
2 is formed on the left side of the hydraulic piston 17, while the retard side hydraulic chamber 32 is formed on the right side of the flange portion of the hydraulic piston 17. The seal between the hydraulic chambers 22 and 32 is secured by the oil seal 70 described above.

An end plate 50 is coaxially attached to the left end opening of the sprocket sleeve 15. The end plate 50 is formed in a reverse L-shape in cross section by a cylindrical portion and an annular flange portion, and the annular flange portion of the end plate 50 is coaxially fixed to the left end opening of the sprocket sleeve 15. An annular groove is formed on the outer peripheral surface of the cylindrical portion of the end plate 50, and an oil seal 71 is mounted in the annular groove. The annular flange portion of the end plate 50 also functions as a stopper (hereinafter, referred to as a left side stopper) that stops the movement of the hydraulic piston 17 in the left direction by hitting the annular flange portion of the hydraulic piston 17.

End plate 50 and camshaft sleeve 1
On the left side of FIG. 1, a ring plate 51 formed in an annular shape having a U-shaped cross section is coaxially attached to the cam shaft sleeve 11 on the inner surface of the annular left side wall of the housing 23 by press fitting the knock pin 53. The cylindrical portion of the end plate 50 and the small diameter cylindrical portion 11b of the camshaft sleeve 11 are rotatably supported in the U-shaped right side surface of the ring plate 51.

An oil seal 72 is mounted in an annular groove formed on the outer peripheral surface of the small diameter side cylindrical portion of the ring plate 51. The oil seal 72 is provided between the ring plate 51 and the camshaft sleeve 11. To secure the sealing property of. On the other hand, the oil seal 71 described above ensures the sealing performance between the end plate 50 and the ring plate 51. As a result, the sealing property in the advance side hydraulic chamber 22 is secured.

A bolt 52 is coaxially fitted in a small-diameter cylindrical portion of the ring plate 51 and a hollow portion of the annular left side wall of the housing 23. The bolt 52 has a small diameter of the camshaft sleeve 11 at its right end surface. A cylindrical space 91 is formed between the inner peripheral surface of the cylindrical portion and the hollow partition wall 11c.
Further, inside the bolt 52, the hydraulic passage 61b has a section T
The hydraulic passage 61b is formed in a V shape and communicates with the inside of the cylindrical space 91 at its axial passage portion. The hydraulic passage 61b communicates with the annular groove formed on the outer peripheral surface of the bolt 52 at both ends of the radial passage portion.

A hydraulic passage 61a is formed in the left wall portion of the housing 23, and the hydraulic passage 61a is formed.
Is communicated with the inside of the cylindrical space 91 through the annular groove of the bolt 52 and the hydraulic passage 61b, and further passes through the hydraulic passage 61c formed in the camshaft sleeve 11 so as to open in the cylindrical space 91 and is retarded. It communicates with the side hydraulic chamber 32. A hydraulic passage 60 communicating with the advance-side hydraulic chamber 22 is formed in the left wall portion of the housing 23. These hydraulic passages 6
1a and 60 are formed in a left wall portion of the housing 23 and open in a cylindrical hollow portion 95 that accommodates a hydraulic control valve 30 described later. Further, in the cylindrical hollow portion 95,
The hydraulic pressure supply passage 65 is open at the tip thereof, and the hydraulic pressure supply passage 65 supplies the working oil pressure-fed by the oil pump 29 from the oil pan 28 of the internal combustion engine 1 to the cylindrical hollow portion 9.
Supply within 5. The oil pressure release passage 66 is connected to the oil pan 2
8 is opened to return the hydraulic oil into the oil pan 28.

Next, the structure of the hydraulic control valve 30 will be described with reference to FIG. The hydraulic control valve 30 is a spool including a cylinder 30a formed by the inner wall of the cylindrical hollow portion 95, and a spool 31 having a pair of left and right lands fitted in the cylinder 30a so as to be slidable in the axial direction. It is a valve. The cylinder 30a includes a hydraulic port 30b communicating with the hydraulic passage 61a and a hydraulic port 60.
And a hydraulic port 30c communicating with.

Further, the cylinder 30a has a suction port 30d communicating with the hydraulic pressure supply passage 65 and a hydraulic pressure release passage 66.
Both discharge ports 30e, 30f communicating with the. The switching of the communication between the hydraulic ports 30b and 30c, the suction port 30d, and the discharge ports 30e and 30f and the control of the communication degree (opening of the hydraulic control valve 30) are performed by sliding the spool 31 in the cylinder 30a. Done. A coil spring 31a is interposed in the right end portion of the cylinder 30a in FIG. 3 on the right end side of the spool 31.
Always urges the spool 31 to the left in the drawing.

On the other hand, a linear solenoid 64 is provided on the left end side of the spool 31 in the figure, in the left end portion of the cylinder 30a in the figure. When an electromagnetic force is induced in the linear solenoid 64 according to the value of the current flowing through the linear solenoid 64, the electromagnetic force causes the spool 31 to slide to the right against the urging force of the coil spring 31a. Has become.

Hereinafter, the hydraulic control valve 30 thus constructed will be described.
The switching of communication of each hydraulic passage and the opening degree control by sliding the spool 31 will be described.

As shown in FIG. 3A, the spool 31
However, when an electromagnetic force is received from the linear solenoid 64 and slides to the right against the urging force of the coil spring 31a, the suction port 30d and the hydraulic port 30c communicate with each other by the right movement of the right side land of the spool 31 and the hydraulic pressure. Supply path 65
Communicates with the hydraulic passage 60. Therefore, the oil pressure from the oil pump 29 is pumped into the advance side hydraulic chamber 22.
At the same time, the discharge port 30e and the hydraulic port 30b are communicated by the rightward movement of the left land of the spool 31 to communicate the hydraulic passage 61a and the hydraulic release passage 66. Therefore, the hydraulic pressure in the retard side hydraulic chamber 32 is released.
As a result, the hydraulic piston 17 is pushed to the right in the annular space 90 (see FIG. 2), so that the camshaft 5 rotates and advances relative to the sprocket 13a, that is, the crankshaft 2.

Further, as shown in FIG. 3B, when the spool 31 is located at the center, the communication of the hydraulic port 30b with the discharge port 30e and the communication of the hydraulic port 30c with the suction port 30d are performed by the spool 31. It is blocked by the lands on both sides. Therefore, when there is no leakage of hydraulic oil from the hydraulic chambers 22 and 32 on the advance side and the retard side,
The position of the hydraulic piston 17 is maintained as it is. Therefore, the rotational phase difference between the sprocket 13a and the cam shaft 5, that is, the actual valve timing does not change.

On the other hand, as shown in FIG. 3 (c), when the spool 31 is biased by the coil spring 31a and slides to the left under the stop of the generation of the electromagnetic force from the linear solenoid 64, the suction port 30b. And hydraulic port 30d
However, the hydraulic supply passage 65 and the hydraulic passage 61a are communicated by communicating with each other by moving the left side land of the spool 31 to the left. For this reason, the oil pressure from the oil pump 29 is pressure-fed to the retard side hydraulic chamber 32. On the other hand, the discharge port 30f and the hydraulic port 30c communicate with each other by the movement of the right side land of the spool 31 to the left, so that the hydraulic passage 60 and the hydraulic release passage 66 communicate with each other. Therefore, the hydraulic pressure in the advance side hydraulic chamber 22 is released. As a result, the hydraulic piston 17
Since the camshaft 5 is pushed to the left in the annular space 90, the camshaft 5 rotates in the opposite direction to the above, and retards relatively to the sprocket 13a, that is, the crankshaft 2.

3 (a), 3 (b) and 3 (c), port 30b and port 30e (or port 30)
d) the degree of communication with port 30c and port 30d
(Or port 30f), the degree of communication with the spool 31
Is controlled by the opening degree of each land on both the left and right sides with respect to each port 30b and 30c accompanying the rightward movement (or leftward movement).

FIG. 4 is a characteristic diagram showing the relationship between the position of the spool 31 in the hydraulic control valve 30 (hereinafter referred to as the spool position) and the actual valve timing change speed under certain operating conditions of the internal combustion engine 1. In this characteristic diagram, the area where the actual valve timing change speed is positive corresponds to the area moving in the advance direction, while the area where the actual valve timing change speed is negative corresponds to the area moving in the retard direction. Equivalent to. The spool position on the horizontal axis in this characteristic diagram is proportional to the linear solenoid current.

In this characteristic diagram, each symbol (a),
3B and 3C respectively show spool positions corresponding to the positions of the spool 31 shown in FIGS. 3A, 3B, and 3C. The linear solenoid current at the point where the actual valve timing does not change as indicated by the symbol (b) is hereinafter referred to as the holding current. The phase difference adjusting device 40 can be controlled by increasing the linear solenoid current when advancing the valve timing based on this holding current and decreasing the linear solenoid current when retarding the valve timing. it can.

FIG. 5 shows various sensors shown in FIG. 1, a microcomputer 48, a current control circuit 49, and a hydraulic control valve 3.
0 is a block diagram showing functionally divided configurations corresponding to 0, the phase difference adjusting device 40, and other various elements.

The target valve timing calculation unit 100 (corresponding to target valve timing setting means) includes an intake air amount sensor,
The target valve timing is calculated based on the operating conditions of the internal combustion engine detected from various signals such as the water temperature sensor and the throttle opening sensor.

The actual valve timing calculation unit 101 (corresponding to actual valve timing detecting means) calculates the actual valve timing based on the signals from the crank position sensor 42 and the cam shaft position sensor 44.

The control signal calculation unit 102 (corresponding to the control signal output means) uses the target valve timing and the actual valve timing, and the control current to be supplied to the hydraulic control valve 30 so that the actual valve timing matches the target valve timing. To calculate.

The control abnormality determining unit 103 (corresponding to abnormality determining means) determines the abnormality of the feedback control of the valve timing based on the target valve timing and the actual valve timing.

The cleaning condition determination unit 104 (corresponding to cleaning request means) determines the cleaning request for the hydraulic control valve 30 based on the output current.

The output current calculation unit 105 (corresponding to the opening adjustment means) manipulates the output current based on the actual valve timing, the control current, the control abnormality judgment, and the cleaning request judgment to open the opening of the hydraulic control valve 30. Is adjusted and the phase difference adjusting device 40 is operated.

The electronic control unit 46, as shown in FIG.
It has a microcomputer 48 and a current control circuit 49. The microcomputer 48 is shown in FIGS.
By executing each routine shown in FIG.
Each function of ~ 105 is realized. Hereinafter, FIG. 6 to FIG.
The processing contents of each routine shown in will be described.

FIG. 6 is a flow chart showing the overall processing flow of the main routine. This main routine is
The processing is repeated every predetermined time or every predetermined crank angle. When the microcomputer 48 starts the processing of the main routine, first in step 110, the crank position sensor 42, the cam position sensor 44, the detection signals of various sensors for detecting the internal combustion engine operating state such as the cooling water temperature signal and the intake air amount signal. Read. Thereafter, in step 111, the ROM (not shown) of the microcomputer 48 is determined based on the operating state of the internal combustion engine such as the cooling water temperature, the intake air amount, the engine speed, and the like.
The optimum target valve timing is calculated by referring to the data stored in.

Then, in the next step 112, the phase difference between the crank position sensor 42 and the cam shaft position sensor 44 is detected based on the timing of input to the microcomputer 48, and the actual valve timing is calculated. To do. Thereafter, in step 113, the control current Ifb for feedback control of the actual valve timing is calculated. The control current Ifb is calculated by the following equation based on the PD control equation corresponding to the control deviation e between the target valve timing r and the actual valve timing y with the holding current Ih as a reference.

E = r−y Ifb = Ih + f (Kp × e + Kd × de / dt) In the above equation, Kp and Kd each represent a constant. The function f () is a function for correcting the non-linearity of the actual valve timing change characteristic, as shown in FIG.
The amount of current change from the holding current is calculated so that the actual valve timing change speed proportional to Kp × e + Kd × de / dt can be obtained.

In the next step 114, a control abnormality determination routine shown in FIG. 7 which will be described later is executed to determine whether or not there is an abnormality in the feedback control of the actual valve timing. Then, in step 115, a cleaning condition determination routine shown in FIG. 8 described later is executed to determine whether or not the cleaning condition is satisfied.

Thereafter, in step 116, the process shown in FIG.
The output current calculation routine shown in FIG.
The output current to 0 is calculated, and in the following step 117, this output current is output to the hydraulic control valve 30. As a result, the opening degree of the hydraulic control valve 30 is adjusted, and the supply amount of the hydraulic oil pressure-fed by the oil pump 29 from the oil pan 28 to the phase difference adjusting device 40 is controlled.

On the other hand, FIG. 7 is a flow chart showing the flow of processing of the control abnormality determination routine. This routine is
A subroutine call is made in step 114 of the main program of FIG. When the processing of this routine is started, first, at step 120, it is judged if the absolute value | r−y | of the difference between the target valve timing r and the actual valve timing y is greater than or equal to a predetermined value α. Here, if | r−y | <α, the feedback control is determined to be normal, and step 1
22, the fail determination counter Tf that measures the time during which the control abnormality state continues is reset to "0", and in the following step 125, the control abnormality flag Xfail is set to "0" indicating normality and the control abnormality is set. The determination process ends.

On the other hand, when | r−y | ≧ α,
The feedback control of the actual valve timing may be abnormal. In this case, the process proceeds to step 121 and the fail determination counter Tf is counted up to measure the time during which the control abnormality state continues. After that, in step 123, it is determined whether or not the fail determination counter Tf is greater than or equal to a predetermined value β, and if Tf ≧ β, the control abnormal state has continued for a predetermined time or more, and thus the control abnormality is detected. Then, the process proceeds to step 124, the control abnormality flag Xfail is set to "1" indicating the control abnormality, and the control abnormality determination processing is ended.

On the other hand, if Tf <β, the control abnormality state continues for less than the predetermined time. Therefore, at this stage, the control abnormality is not judged yet, and the routine proceeds to step 125, where the control abnormality flag is set. Xfail is maintained at "0" indicating normality, and the control abnormality determination ends. Through this series of processes, it is possible to determine whether or not there is an abnormality in the feedback control of the actual valve timing.

On the other hand, FIG. 8 is a flow chart showing the processing flow of the cleaning condition determination routine. This routine is called as a subroutine at step 115 of the main routine of FIG. When the processing of this routine is started, first, at step 130, it is judged from the engine speed whether it is before the engine is started or stopped. Before the engine is started or when the engine is stopped, the cleaning condition is satisfied, and the cleaning of the hydraulic control valve 30 is executed. Therefore, the process proceeds to step 137, the cleaning request flag Xcl is set to "1" indicating the cleaning request, and the cleaning condition determination is performed. The process ends.

On the other hand, if it does not correspond to either before engine start or stop, the routine proceeds to step 131, where it is judged from the throttle opening signal whether or not the engine is idle to judge the next cleaning condition. When the engine is in the idle state, the cleaning condition is satisfied and the hydraulic control valve 30 is cleaned.
Proceeding to 37, the cleaning request flag Xcl is set to "1" indicating the cleaning request, and the cleaning condition determination processing is ended.

If none of the conditions before engine start, stop, and idle is met, the routine proceeds to step 132, where the difference between the output current I and the holding current Ih is below a predetermined value γ in order to judge the next cleaning condition. Determine whether or not. If the output current I is equal to the holding current Ih, the actual valve timing becomes constant, and the advance side hydraulic chamber 22 of the hydraulic control valve 30.
To the retard side hydraulic chamber 32 is closed. From this, when the difference between the output current I and the holding current Ih is small,
It can be determined that the opening degree of the hydraulic control valve 30 is small. If this state continues for a long time, the amount of oil passing through the hydraulic control valve 30 decreases, and impurities and foreign matters in the engine oil are likely to settle and accumulate in the hydraulic control valve 30.

Therefore, in step 132, | I-I
When it is determined that h | ≦ γ (that is, when the opening degree of the hydraulic control valve 30 is small), the routine proceeds to step 133, where the hydraulic control valve 30 is opened by counting up the valve opening small time counter Th. Measure the amount of time that you are in a small state. After that, in step 135, it is determined whether or not the valve opening small time counter Th is equal to or more than a predetermined value δ. If Th ≧ δ, the small opening state of the hydraulic control valve 30 continues for a long time. Therefore, impurities or foreign matters in the engine oil may be accumulated in the hydraulic control valve 30, so that the step 137 is performed.
Then, the process proceeds to step S1, where the cleaning request flag Xcl is set to "1" indicating the cleaning request, and the cleaning condition determination process is ended.

On the other hand, when Th <δ, the opening time of the hydraulic control valve 30 is short and the cleaning of the hydraulic control valve 30 is not necessary. Therefore, the routine proceeds to step 138. The cleaning request flag Xcl is set to "0" indicating that cleaning is unnecessary, and the cleaning condition determination processing is ended.

On the other hand, in step 132 described above, | I-
When it is determined that Ih |> γ (that is, the opening degree of the hydraulic control valve 30 is large), the routine proceeds to step 134, where the valve opening small time counter Th is reset to “0”, and at the following step 136, Whether or not the cleaning operation is being performed is determined by whether or not the cleaning request flag Xcl = 1 and the cleaning end flag Xend = 0 are satisfied.
If the cleaning operation is in progress (Xcl = 1 and Xen
If d = 0), the cleaning condition determination is ended as it is so as not to hinder the execution of the cleaning operation, but if the cleaning operation is not being executed, the routine proceeds to step 138, and the cleaning request flag Xcl is set to "0" indicating that cleaning is unnecessary. , ”And the cleaning condition determination process ends.

It is desirable to clean the hydraulic control valve 30 by a series of these operations. Before the engine is started, when the engine is stopped, when the engine is idling, and when the hydraulic control valve 30 has a small opening for a long time, it is detected and a cleaning request is made. Can be output to the output current calculation unit 105. It should be noted that the present invention uses, as cleaning conditions, before the engine is started, when the engine is stopped,
At the time of idling, it is not limited to the judgment of all the conditions when the hydraulic control valve 30 has a small opening for a long time.
You may make it determine 1 to 3 conditions of said-) as a cleaning condition.

FIG. 9 is a flowchart showing the processing flow of the output current calculation routine. This routine is called as a subroutine at step 116 of the main routine of FIG. When the processing of this routine is started, first, at step 140, it is determined whether or not the control abnormality flag Xfail is "1" indicating the control abnormality. If Xfail = 1, the processing at the time of the feedback control abnormality of the valve timing is performed. In order to adjust the output current I to the minimum value I
The value is set to min, and the output current calculation process ends. Here, Imin is a small current that causes the hydraulic control valve 30 to hardly generate heat even when the hydraulic control valve 30 is energized.

On the other hand, Xfail = 0 (normal control)
In the case of, the process proceeds to step 141, it is determined whether or not the cleaning request flag Xcl is “1” indicating the cleaning request, and in the case of Xcl ≠ 1 (cleaning unnecessary), the process proceeds to step 142 and the cleaning is completed. The flag Xend = 0 and the cleaning counter CC = 0 are set to prepare for the next cleaning execution. Then, in the next step 145, the output current I is set to the control current Ifb for feedback controlling the valve timing, and the output current calculation process is ended.

On the other hand, if it is determined in step 141 that the cleaning request flag Xcl is "1" indicating the cleaning request, the hydraulic control valve 30 is cleaned. Therefore, the process proceeds to step 143, and the cleaning end flag Xend is cleaned. It is determined whether or not it is “0” indicating that the hydraulic pressure control valve 30 has not ended yet. If Xend = 0 (before the end of cleaning), the process proceeds to step 146 to execute a cleaning current calculation routine shown in FIG. The cleaning current Ic for cleaning is calculated, and the output current calculation process is ended.

If Xend = 1 (cleaning is completed) in step 143, the process proceeds to step 145.
The output current I is set to the control current Ifb for feedback controlling the valve timing, and the output current calculation process ends.

FIG. 11 is a time chart showing an example of changes in this output current I, control abnormality flag Xfail, and valve timing. In the valve timing chart, the solid line represents the actual valve timing y and the dotted line represents the target valve timing r. In this example, at the point A of the valve timing chart, the hydraulic control valve 30 locks due to foreign matter being caught, and then at the point B, the difference between the actual valve timing y and the target valve timing r becomes larger than α, At the point C after the time β has elapsed, the control abnormality flag is set to Xfail = 1 by the control abnormality determination. The change in the output current I during this time is such that after the point B has passed, the state in which the maximum value Imax is reached continues for a while due to an attempt to force the feedback control, and there is a concern that the hydraulic control valve 30 may be overheated. . However, at point C, the control abnormality process (Xfai
Due to l = 1), the output current I is suppressed to a low value, and the hydraulic control valve 30 is prevented from overheating.

On the other hand, FIG. 10 is a flow chart showing the flow of processing of the cleaning current calculation routine. This routine is step 14 of the output current calculation routine of FIG.
The subroutine is called at 6. When the processing of this routine is started, first in step 150, it is determined whether or not the cleaning execution start timing is based on whether or not the cleaning counter CC = 0, and if CC = 0 (cleaning execution start timing), the step is executed. In step 151, the process at the start of cleaning, that is, the actual valve timing y at the start of cleaning is stored as yc, the cleaning time counter Tc is reset to “0”, and the cleaning counter CC is set to “1”. Various variables are initialized, and the process proceeds to step 152.

In step 150, if the cleaning counter CC ≠ 0 (that is, if initialization is completed), the process immediately proceeds to step 152, where the actual valve timing yc at the start of cleaning and the actual actual valve timing y are set. It is determined whether or not the absolute value of the difference is larger than the predetermined value ε. Here, if | yc−y |> ε, in order to suppress the fluctuation of the actual valve timing due to the cleaning process, the flow proceeds to step 154 so as to open the oil passage on the side opposite to the currently opened oil passage. , The cleaning time counter Tc is reset to “0”, the cleaning counter CC is incremented, and the routine proceeds to step 156.

On the other hand, in step 152, | y
If c−y | ≦ ε, the routine proceeds to step 153, where it is determined whether the cleaning time counter Tc is larger than a predetermined value ζ. If Tc> ζ, the routine proceeds to step 154, where the cleaning time counter is Tc is reset and the cleaning counter CC is incremented, but Tc ≦
In the case of ζ, the routine proceeds to step 155, where the cleaning time counter Tc is counted up to measure the time during which the hydraulic control valve 30 remains in the large opening state, and the routine proceeds to step 156.

In step 156, it is determined whether the cleaning counter CC has exceeded 10, and CC> 10.
In this case, to end the cleaning process, the process proceeds to step 158, the cleaning end flag Xend is set to "1" indicating the cleaning end, and the cleaning current calculation process ends.

On the other hand, when the cleaning counter CC is 10 or less, the cleaning process is continued, and step 1
In step 57, it is determined whether or not the cleaning counter CC is odd. If CC is odd, the process proceeds to step 160, where the cleaning current Ic is set to the maximum value Imax,
If CC is an even number, the process proceeds to step 159, the cleaning current Ic is set to the minimum value Imin, and the cleaning current calculation process is ended. Here, Imax is a current that maximizes the oil passage from the oil pump 29 in the hydraulic control valve 30 to the advance side hydraulic chamber 22 of the phase adjusting device 40, and Imin is the oil pump 2 in the hydraulic control valve 30.
It is a current that maximizes the oil passage from 9 to the retard side hydraulic chamber 32 of the phase adjusting device 40.

Through this series of processing, every time the cleaning counter CC is counted up, the hydraulic control valve 3
The opening and closing of the oil passage from the oil pump 29 of 0 to the advance side hydraulic chamber 22 and the opening and closing of the oil passage to the retard side hydraulic chamber 32 are alternately repeated five times each. Further, by switching the oil passage while monitoring the fluctuation of the actual valve timing, the fluctuation of the actual valve timing can be suppressed and the engine state during the cleaning process can be kept stable.

An example of the control described above is shown in a time chart in FIG. FIG. 12 shows changes in the cleaning request flag Xcl, the cleaning end flag Xend, the output current I, and the valve timing. In the valve timing chart, the solid line represents the actual valve timing y and the dotted line represents the target valve timing r. In this example, the valve timing becomes stable at point D, and the hydraulic control valve 30
The state in which the opening degree is small continues for time δ or more. Then E
At that point, the cleaning condition is satisfied, and the cleaning request flag Xcl = 1. After this, the output current I = Ima
The stepwise changes to x and Imin are repeated alternately.
When the stepwise change of the output current I is repeated 10 times in total (point F), the cleaning end flag Xend
= 1, and the cleaning process ends.

The fluctuation of the actual valve timing during this period is monitored, and the fluctuation is kept within the range of ± ε. In other words, every time the actual valve timing fluctuation reaches ± ε,
The output current I is swung to the opposite side (for example, if the current output current I is Imax, it is swung to Imin, and if the current output current I is Imin, it is swung to Imax), and the changing direction of the actual valve timing is reversed each time. Then, the fluctuation is kept within the range of ± ε.

On the other hand, FIGS. 13 to 18 show an embodiment (2) of the present invention.

FIG. 13 shows various sensors shown in FIG. 1, a microcomputer 48, a current control circuit 49, and a hydraulic control valve 3.
0 is a block diagram showing functionally divided configurations corresponding to 0, the phase difference adjusting device 40, and other various elements.

The target valve timing calculation section 170 (corresponding to target valve timing setting means) is an intake air amount sensor,
The target valve timing is calculated based on the internal combustion engine operating conditions detected by various sensors such as a water temperature sensor and a throttle opening sensor.

The actual valve timing calculating section 171 (corresponding to the actual valve timing detecting means) calculates the actual valve timing based on the signals from the crank position sensor 42 and the cam shaft position sensor 44.

The cleaning condition judging section 172 (corresponding to the cleaning requesting means) judges whether or not there is a cleaning request for the hydraulic control valve 30 based on the output current I.

The control signal calculator 173 (corresponding to control signal output means) controls the hydraulic control valve 30 so as to match the actual valve timing with the target valve timing based on the target valve timing, the actual valve timing, and the result of the cleaning request determination. Calculate the control current to be applied to the.

The control abnormality determining section 174 (corresponding to abnormality determining means) determines whether or not there is an abnormality in the feedback control of the actual valve timing based on the target valve timing and the actual valve timing.

The output current calculation unit 175 (corresponding to the opening adjustment means) operates the output current based on the actual valve timing, the control current, and the control abnormality judgment, so that the hydraulic control valve 30 is operated.
And the phase difference adjusting device 40 is operated.

The electronic control unit 46, as shown in FIG.
It has a microcomputer 48 and a current control circuit 49. The microcomputer 48 is shown in FIG. 7 and FIG.
4 to 17 to execute the routines shown in FIG.
The functions 170 to 175 shown in FIG. 3 are realized. Hereinafter, the processing content of each routine will be described.

FIG. 14 is a flow chart showing the flow of processing of the entire main routine. This main routine is repeatedly processed every predetermined time or every predetermined crank angle. When the microcomputer 48 starts the processing of the main routine, first in step 180, the crank position sensor 42, the cam position sensor 44, the detection signals of various sensors for detecting the operating state of the internal combustion engine such as the cooling water temperature signal and the intake air amount signal. Read. Thereafter, in step 181, the optimum target valve timing is determined by referring to the data stored in the ROM (not shown) of the microcomputer 48 based on the internal combustion engine operating states such as the cooling water temperature, the intake air amount, and the engine speed. calculate.

Then, in the next step 182, the phase difference between the signals from the crank position sensor 42 and the cam shaft position sensor 44 is detected based on the timing when the signals are input to the microcomputer 48, and the actual valve timing is calculated. To do. After that, in step 183, FIG.
The cleaning condition determination routine shown in is executed to determine whether or not the cleaning condition is satisfied.

Thereafter, in step 184, the process shown in FIG.
By executing the control current calculation routine of No. 6, the control current If for the feedback control of the actual valve timing
Calculate b. Then, in the next step 185, the control abnormality determination routine shown in FIG. 7 is executed to determine whether or not there is an abnormality in the feedback control of the actual valve timing. Regarding the processing contents of this control abnormality determination routine,
Since it has already been described in the above embodiment (1), description thereof will be omitted here.

At the next step 186, FIG.
The output current is calculated by executing the output current calculation routine. After that, in step 187, the output current is output to the hydraulic control valve 30. As a result, the hydraulic control valve 30
Adjust the opening of the oil pan 28 to the oil pump 29.
The supply amount of the hydraulic oil pressure-fed to the phase difference adjusting device 40 is controlled.

On the other hand, FIG. 15 is a flowchart showing the processing flow of the cleaning condition determination routine. This routine is called as a subroutine at step 183 of the main routine of FIG. When the processing of this routine is started, first, at step 190, it is judged if the difference between the output current I and the holding current Ih is less than or equal to a predetermined value γ. If the output current I is equal to the holding current Ih, the actual valve timing becomes constant, and the advance side hydraulic chamber 22 of the hydraulic control valve 30.
To the retard side hydraulic chamber 32 is closed. From this, when the difference between the output current I and the holding current Ih is small,
It can be determined that the opening degree of the hydraulic control valve 30 is small. When this state continues for a long time, the amount of oil that passes through the hydraulic control valve 30 decreases, and impurities in the engine oil tend to settle and accumulate in the hydraulic control valve 30.

Therefore, in step 190, | I-I
When it is determined that h | ≦ γ (that is, when the opening degree of the hydraulic control valve 30 is small), the process proceeds to step 191, and the hydraulic control valve 30 is opened by counting up the valve opening small time counter Th. Measure the amount of time that you are in a small state. After that, in step 193, it is determined whether or not the valve opening small time counter Th is equal to or larger than a predetermined value δ. If Th ≧ δ, the small opening state of the hydraulic control valve 30 continues for a long time. Therefore, impurities or foreign matter in the engine oil may be accumulated in the hydraulic control valve 30.
Then, the process proceeds to step S1, where the cleaning request flag Xcl is set to "1" indicating a cleaning request, and the cleaning condition determination is completed.

On the other hand, when Th <δ, the opening time of the hydraulic control valve 30 is short and the cleaning of the hydraulic control valve 30 is not necessary. Therefore, the routine proceeds to step 195. The cleaning request flag Xcl is set to "0" indicating that cleaning is unnecessary, and the cleaning condition determination is completed.

On the other hand, in step 190 described above, | I-
When it is determined that Ih |> γ (that is, when the opening degree of the hydraulic control valve 30 is large), the routine proceeds to step 192, the valve opening small time counter Th is reset, and the routine proceeds to step 195 and the cleaning request flag Xcl. Is set to "0" indicating that cleaning is unnecessary, and the cleaning condition determination is completed.

It is desirable to clean the hydraulic control valve 30 by a series of these operations, and it is detected when the hydraulic control valve 30 has a small opening for a long period of time, and a cleaning request is output to the output current calculation unit 173. You can

On the other hand, FIG. 16 is a flow chart showing the flow of processing of the control current calculation routine. This routine is called as a subroutine at step 184 of the main routine of FIG. When the processing of this routine is started, first in step 200, the control deviation e between the target valve timing r and the actual valve timing y and the PD control current Ipd calculated on the basis of the PD control equation are calculated by the following equation. Calculate

E = r−y Ipd = f (Kp × e + Kd × de / dt) In the above equation, Kp and Kd each represent a constant. The function f () is a function for correcting the non-linearity of the actual valve timing change characteristic, as shown in FIG.
A current change amount from the holding current is calculated so that an actual valve timing change speed proportional to Kp × e + Kd × de / dt can be obtained.

After this calculation, the routine proceeds to step 201, where it is judged whether or not the cleaning request flag Xcl is "1" indicating the cleaning request. If the cleaning request flag Xcl = 0 (cleaning unnecessary), the process proceeds to step 202, the cleaning end flag Xend is reset to "0", and the process proceeds to step 206 in preparation for the next cleaning operation. In this step 206, the control current Ifb is set to the normal current, that is, the holding current Ih by PD.
The control current Ifb is calculated by adding the current Ipd, and the control current calculation process ends.

On the other hand, if the cleaning request flag Xcl = 1 (cleaning request) in step 201, the process proceeds to step 203, in which the cleaning end flag Xend = 0 and the absolute value of the PD control current Ipd is greater than the predetermined value γ. If the condition is satisfied, the routine proceeds to step 204, where the cleaning end flag Xend is set to "1" indicating the end of cleaning. Then, in step 205, it is determined whether the absolute value of the PD control current Ipd is larger than the predetermined value IL, and | I
If pd | ≦ IL, the opening degree of the hydraulic control valve 30 is a small control current. Therefore, the opening degree of the hydraulic control valve 30 should be sufficiently large so that the cleaning effect can be expected. Then, the process proceeds to step 207. In this step 207, the control current Ifb is changed from the holding current Ih to IL.
It is calculated by the following formula as a value that has changed.

Ifb = Ih + IL × sign (Ipd) Here, sign () is a function for calculating the positive / negative of the numerical value in (), and returns “1” if the numerical value in () is positive, In the case of, "-1" is returned. That is, if the PD control current Ipd is positive, Ifb = Ih + IL, and if the PD control current Ipd is negative, Ifb = Ih.
-Becomes IL.

On the other hand, when it is judged "No" in the above step 203 (that is, Xend = 1 or | Ipd | ≦ γ
If it is determined to be “Yes” in step 205 (if | Ipd |> IL), the hydraulic control valve 3
Since the control current capable of sufficiently increasing the opening degree of 0 is supplied, the process proceeds to step 206 so that the normal control current is obtained. In this step 206, the control current Ifb is calculated by the usual method, that is, the PD current Ipd is added to the holding current Ih to calculate the control current Ifb, and the control current calculation process is ended.

With this series of processing, when the valve timing changes from the steady state, if there is a cleaning request, it is possible to guarantee the opening degree of the hydraulic control valve 30 above a predetermined value, and to exert a sufficient cleaning effect. can do.

On the other hand, FIG. 17 is a flow chart showing the flow of processing of the output current calculation routine. This routine is
A subroutine call is made at step 186 of the main routine of FIG. When the processing of this routine is started, first, at step 210, it is judged whether or not the control abnormality flag Xfail is "1" indicating the control abnormality. If Xfail = 1, it is determined when the valve timing feedback control is abnormal. In order to perform processing, the process proceeds to step 211, where the output current I
Is set to the minimum value Imin, and the output current calculation process ends. Here, Imin is a small current that causes the hydraulic control valve 30 to hardly generate heat even when the hydraulic control valve 30 is energized.

On the other hand, in step 210, Xf
When ail = 0 (normal), the process proceeds to step 212, the control current I is set to the current Ifb for feedback controlling the valve timing, and the output current calculation process is ended.

The control operation according to the embodiment (2) described above will be described with reference to the time chart shown in FIG. This time chart shows changes in the cleaning request flag Xcl, the output current I, and the valve timing. In the valve timing chart, the solid line represents the actual valve timing y and the dotted line represents the target valve timing r. In this example, the valve timing becomes stable at point G, and thereafter the state in which the opening degree of the hydraulic control valve 30 is small continues. Then, when the state in which the opening degree of the hydraulic control valve 30 is small continues for a time δ or more (point H), the cleaning condition is satisfied and the cleaning request flag Xcl = 1. After that, since the target valve timing advances at point J, the output current is changed and feedback control is performed. At that time, the output current is maintained in order to secure the opening of the hydraulic control valve 30 at a predetermined value or more. The current Ih is changed by IL or more. Thereby, the cleaning effect of the hydraulic control valve 30 is obtained. After that, at the point K, the cleaning current flag Xcl = 0 due to the movement of the control current, and the cleaning is completed.

The above-mentioned two embodiments (1),
In (2), the example in which the present invention is applied to the valve timing adjustment device that adjusts the opening / closing timing of the intake valve of the internal combustion engine 1 has been described. However, instead of this, the opening / closing timing of the exhaust valve of the internal combustion engine 1 The present invention may be applied to and implemented by a valve timing adjusting device that adjusts the opening / closing timing of both the intake valve and the exhaust valve.

In the above embodiment, the chain drive system is used as the transmission mechanism for rotating the cam shaft in synchronization with the crank shaft, but a belt drive system or a gear drive system may be used. Further, the present invention is not limited to a vehicle, and the present invention may be applied to an overhead cam type internal combustion engine such as a motorcycle or a ship.

In implementing the present invention, the valve timing adjusting device may be adopted not only in the overhead cam type internal combustion engine but also in the overhead valve type internal combustion engine, and the present invention may be applied thereto.

Further, the function of each step in each routine of the above-described embodiment may be realized by a hardware logic configuration as a function executing means.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an entire system showing an embodiment (1) of the present invention.

FIG. 2 is a sectional view showing the configuration of a phase difference adjusting device.

FIG. 3 is a sectional view for explaining the operation of the hydraulic control valve.

FIG. 4 is a characteristic diagram showing a relationship between an actual valve timing change speed and a spool position.

FIG. 5 is a functional block diagram of a control system

FIG. 6 is a flowchart showing a processing flow of a main routine.

FIG. 7 is a flowchart showing a processing flow of a control abnormality determination routine.

FIG. 8 is a flowchart showing a processing flow of a cleaning condition determination routine.

FIG. 9 is a flowchart showing a processing flow of an output current calculation routine.

FIG. 10 is a flowchart showing a processing flow of a cleaning current calculation routine.

FIG. 11 is a time chart showing changes over time in a control abnormality flag, output current, and valve timing.

FIG. 12 is a time chart showing changes over time in a cleaning request flag, a cleaning end flag, an output current, and valve timing.

FIG. 13 is a functional block diagram of a control system in the embodiment (2) of the present invention.

FIG. 14 is a flowchart showing the flow of processing of a main routine.

FIG. 15 is a flowchart showing a processing flow of a cleaning condition determination routine.

FIG. 16 is a flowchart showing a processing flow of a control current calculation routine.

FIG. 17 is a flowchart showing a processing flow of an output current calculation routine.

FIG. 18 is a time chart showing changes over time in a cleaning request flag, output current, and valve timing.

[Explanation of symbols]

1 ... Internal combustion engine, 2 ... Crank shaft, 4 ... Exhaust side cam shaft, 5
... intake side camshaft, 17 ... hydraulic piston, 22 ... advance side hydraulic chamber, 28 ... oil pan, 29 ... oil pump, 30 ...
Hydraulic control valve, 32 ... Retardation side hydraulic chamber, 40 ... Phase difference adjusting device, 42 ... Crank position sensor, 44 ... Cam shaft position sensor, 46 ... Internal combustion engine control device, 48 ... Microcomputer, 49 ... Current control circuit, 64 ... Linear solenoid,
100 ... Target valve timing calculation unit (target valve timing setting unit), 101 ... Actual valve timing calculation unit (actual valve timing detection unit), 102 ... Control signal output unit (control signal output unit), 103 ... Control abnormality determination unit ( Abnormality determination unit), 104 ... Cleaning condition determination unit (cleaning request unit), 105 ... Output current calculation unit (opening degree adjustment unit), 170 ... Target valve timing calculation unit (target valve timing setting unit), 171 ... Actual valve timing Calculation unit (actual valve timing detection means),
172 ... Cleaning condition determination section (cleaning request means), 173 ... Control signal output section (control signal output means),
174 ... Control abnormality determination section (abnormality determination means), 175 ... Output current calculation section (opening degree adjustment means).

Claims (6)

[Claims] 1. A phase difference adjusting device for adjusting a phase difference between a crankshaft and a camshaft of an internal combustion engine according to a hydraulic pressure, a hydraulic control valve for controlling a hydraulic pressure to the phase difference adjusting device, and the hydraulic pressure. An opening degree adjusting means for adjusting the opening degree of the control valve; an actual valve timing detecting means for detecting the actual valve timing of at least one of the intake valve and the exhaust valve based on the relative rotation angle between the crankshaft and the camshaft; Target valve timing setting means for setting a target valve timing of at least one of the intake valve and the exhaust valve according to the operating state of the internal combustion engine, and feedback control for matching the actual valve timing with the target valve timing. A valve timing adjustment device for an internal combustion engine, comprising: a control signal output means for outputting a control signal to the opening adjustment means. Degree adjusting means comprises a cleaning requesting means for outputting a cleaning request to the opening adjusting means when the state in which the hydraulic control valve is throttled to a predetermined opening or less continues for a predetermined time or more, and the opening adjusting means, A valve timing adjusting device for an internal combustion engine, wherein the hydraulic control valve is opened and closed when a cleaning request is issued from the cleaning requesting means. 2. A phase difference adjusting device for adjusting a phase difference between a crankshaft and a camshaft of an internal combustion engine according to the oil pressure, a hydraulic control valve for controlling the hydraulic pressure to the phase difference adjusting device, and the hydraulic pressure. An opening degree adjusting means for adjusting the opening degree of the control valve; an actual valve timing detecting means for detecting the actual valve timing of at least one of the intake valve and the exhaust valve based on the relative rotation angle between the crankshaft and the camshaft; Target valve timing setting means for setting a target valve timing of at least one of the intake valve and the exhaust valve according to the operating state of the internal combustion engine, and feedback control for matching the actual valve timing with the target valve timing. A valve timing adjustment device for an internal combustion engine, comprising: a control signal output means for outputting a control signal to the opening adjustment means. Degree adjusting means is provided with a cleaning request means for outputting a cleaning request to the control signal output means when the state in which the control valve is throttled to a predetermined opening degree or less continues for a predetermined time or more, and the control signal output means comprises: When there is a cleaning request from the cleaning requesting means, when the control signal is changed from the small opening state to the large opening state, the hydraulic control valve is controlled to have a predetermined opening or more. A valve timing adjusting device for an internal combustion engine, which outputs a signal. 3. A phase difference adjusting device for adjusting a phase difference between a crankshaft and a camshaft of an internal combustion engine according to the oil pressure, a hydraulic control valve for controlling the oil pressure to the phase difference adjusting device, and the hydraulic pressure. An opening degree adjusting means for adjusting the opening degree of the control valve; an actual valve timing detecting means for detecting the actual valve timing of at least one of the intake valve and the exhaust valve based on the relative rotation angle between the crankshaft and the camshaft; Target valve timing setting means for setting a target valve timing of at least one of the intake valve and the exhaust valve according to the operating state of the internal combustion engine, and feedback control for matching the actual valve timing with the target valve timing. A valve timing adjustment device for an internal combustion engine, comprising: a control signal output means for outputting a control signal to the opening adjustment means, wherein: The engine includes a cleaning requesting unit that outputs a cleaning request to the opening adjusting unit in at least one state of starting the fuel engine, idling, and stopping. The opening adjusting unit has a cleaning request from the cleaning requesting unit. In this case, a valve timing adjusting device for an internal combustion engine, which opens and closes the hydraulic control valve. 4. The opening adjustment means forcibly opens and closes the hydraulic control valve by invalidating the input from the control signal output means when a cleaning request is issued from the cleaning requesting means. Claim 1 or 3
5. A valve timing adjusting device for an internal combustion engine according to item 1. 5. The opening adjustment means, when there is a cleaning request from the cleaning request means, invalidates an input from the control signal output means and forcibly opens and closes the hydraulic control valve, The valve timing adjusting device for an internal combustion engine according to claim 4, wherein the opening time of the hydraulic control valve is controlled so that the amount of change in actual valve timing falls within a predetermined value. 6. An abnormality determining means for determining whether or not there is an abnormality in the feedback control of the actual valve timing, the hydraulic control valve is controlled by energization from the opening adjusting means, and the opening adjusting means comprises: 6. The internal combustion engine according to claim 1, wherein energization to the hydraulic control valve is limited to a predetermined value or less when the abnormality determination means determines that the feedback control of the actual valve timing is abnormal. Valve timing adjustment device for engines.