JP2998565B2 - Valve timing control device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve timing control device for varying the opening / closing timing of a valve of an internal combustion engine by utilizing the hydraulic pressure of hydraulic oil. More specifically, a valve of an internal combustion engine having a hydraulic control valve for controlling the pressure of hydraulic oil introduced from an oil pump to a variable valve timing mechanism, and having an oil filter between the oil pump and the hydraulic control valve The present invention relates to a timing control device.

[0002]

2. Description of the Related Art Conventionally, as this kind of technology, for example, a technology disclosed in Japanese Patent Application Laid-Open No. 4-269309 is known. In addition to this technology, a ring-shaped piston (ring gear) having a helical spline is provided on an outer periphery of a camshaft in an internal combustion engine having a general variable valve timing mechanism. This ring gear is urged in one axial direction by a spring. Also, the hydraulic oil pressure from the oil pump is
For example, the pressure is adjusted by a linear solenoid type hydraulic control valve and supplied to a hydraulic chamber.

[0003] That is, the hydraulic control valve includes a sleeve housed inside a housing and a spool slidably provided inside the sleeve. During the operation of the engine, the moving amount of the spool is adjusted by controlling the linear solenoid. With this adjustment, the hydraulic pressure from the hydraulic control valve is adjusted, and the hydraulic oil whose hydraulic pressure has been adjusted is introduced into the hydraulic chamber. With this introduction, the ring gear receives the oil pressure in the axial direction of the camshaft, and moves appropriately. At this time, due to the presence of the helical spline, the rotation phase of the camshaft and the pulley that is drivingly connected to the engine changes, and as a result, the opening and closing timing of the valve is adjusted.

In the above technique, an oil filter for filtering hydraulic oil is provided between an oil pump and a hydraulic control valve. A bypass oil passage is provided so as to bypass the oil filter, and a relief valve is provided in the middle of the passage. This relief valve is normally closed, and the hydraulic oil always passes through the oil filter and flows to the engine lubrication system after branching off on the hydraulic control valve or on the way. Then, foreign matter in the hydraulic oil is captured by the oil filter,
The hydraulic oil is cleaned. On the other hand, when a foreign substance accumulates on the oil filter and causes clogging, and the pressure difference between the upstream side and the downstream side of the oil filter exceeds a predetermined value, the relief valve is opened. With this opening,
The hydraulic oil is introduced into the engine lubrication system or the hydraulic control valve without passing through the filter, that is, through the bypass oil passage. For this reason, a situation in which hydraulic oil is not supplied to the engine lubrication system due to clogging of the filter is avoided.

[0005]

However, in the above-mentioned prior art, when the pressure difference between the upstream side and the downstream side of the oil filter becomes a predetermined value or more, the relief valve is provided under any circumstances. Had been opened. For this reason, the relief valve may be opened even when it is not necessary to open the relief valve. For example, at the beginning of the engine start, the operating oil in the engine main body lubrication system and the valve timing mechanism has been exhausted during the stop period, and the air has entered. In this state, when the engine is started and the valve timing mechanism is operated, the pressure on the downstream side of the oil filter is higher than the pressure on the upstream side until the engine body lubrication system and the valve timing mechanism are filled with hydraulic oil. In many cases, and the relief valve was often opened. Meanwhile, due to the narrow bearing clearance of the engine body lubrication system and the low viscosity of the hydraulic oil at the time of starting, the hydraulic oil does not flow to the engine body lubrication system, and mainly the valve timing It flows toward the mechanism. Therefore, at least until the valve timing mechanism is filled with hydraulic oil, the pressure on the downstream side of the oil filter is significantly lower than the pressure on the upstream side, and the relief valve is often opened.

Further, when the oil filter is deteriorated, a pressure difference between the upstream side and the downstream side of the oil filter tends to be generated particularly on the high rotation speed side of the engine. Therefore, in this case, the relief valve may be opened.

If the relief valve is opened even when it is not necessary to open the relief valve in this way, a large amount of hydraulic oil containing foreign matter does not pass through the filter. There is a risk that the oil will be introduced into the hydraulic control valve at a stretch. As a result, the foreign matter may enter the hydraulic control valve or the valve timing mechanism or the like together with a large amount of hydraulic oil, and a malfunction of the hydraulic control valve or the valve timing mechanism may occur.

The present invention has been made in view of the above circumstances, and has as its object to provide a hydraulic control valve for controlling the pressure of hydraulic oil introduced from an oil pump to a valve timing mechanism, In a valve timing control device for an internal combustion engine having an oil filter between an oil pump and a hydraulic control valve, a bypass passage that bypasses the oil filter, and a relief valve provided in the passage, foreign matter in hydraulic oil The present invention provides a valve timing control device for an internal combustion engine, which can suppress unnecessary flow into a hydraulic control valve or a valve timing mechanism, and can thereby avoid a malfunction of the hydraulic control valve or the valve timing mechanism. Is to do.

[0009]

In order to achieve the above-mentioned object, according to the present invention, as shown in FIG.
A valve timing mechanism M2 for changing the rotation phase of the camshaft with respect to the rotation of the crankshaft 1 using hydraulic pressure of hydraulic oil to adjust the opening / closing timing of a valve driven by the camshaft; An oil pump M3 that pressurizes and discharges the oil to the valve timing mechanism M2; a main oil passage M4 that communicates between the valve timing mechanism M2 and the oil pump M3; and an oil pump M3 that is provided in the middle of the main oil passage M4. , The oil pump M
An oil filter M5 for filtering the operating oil discharged from the oil filter M3, a bypass oil passage M6 that bypasses the oil filter M5, and an intermediate portion of the bypass oil passage M6 that is provided upstream of the oil filter M5. When the pressure difference between the downstream side and the downstream side becomes a predetermined value or more, the bypass oil passage M6
The relief valve M7 is provided between the valve timing mechanism M2 and the oil filter M5, and the displacement of the valve element is controlled by the actuator M8. Hydraulic control valve M9 for adjusting the oil pressure to the valve timing mechanism M2 by adjustment, operating state detecting means M10 for detecting an operating state of the internal combustion engine M1, and detection results of the operating state detecting means M10 The hydraulic control valve M9 is controlled by controlling the actuator M8 based on
The valve timing control device for an internal combustion engine, comprising: a valve control unit M11 for controlling the operation of the relief valve M7 based on the detection result of the operation state detection unit M10. The valve opening probability determining means M12 for determining whether or not the valve opening probability is high is determined by the valve opening probability determining means M12 in order to suppress the opening of the relief valve M7. The gist is that a moving amount adjustment control means M13 for adjusting and controlling the moving amount of the spool of M9 is provided.

[0010]

According to the above arrangement, as shown in FIG. 1, the oil pump M3 pressurizes and discharges hydraulic oil. The hydraulic oil passes through the main oil passage M4 and passes through the valve timing mechanism M
2 is introduced. Then, the valve timing mechanism M2
Accordingly, the rotation phase of the camshaft with respect to the rotation of the crankshaft of the internal combustion engine M1 changes by using the hydraulic pressure of the hydraulic oil, and the opening / closing timing of the valve driven by the camshaft is adjusted.

The hydraulic oil discharged from the oil pump M3 is filtered by an oil filter M5 provided in the middle of the main oil passage M4, and foreign matters in the hydraulic oil are captured. Further, the hydraulic control valve M9 provided between the valve timing mechanism M2 and the oil filter M5 adjusts the hydraulic pressure to the valve timing mechanism M2 by adjusting the amount of movement of the valve element by controlling the actuator M8. . Further, the operating state detecting means M10 controls the internal combustion engine M1.
Is detected. Then, the operating state detecting means M
Based on the detection result of 10, the valve control means M11 controls the hydraulic control valve M9 by controlling the actuator M8. With this control, the valve timing mechanism M2
To control the opening / closing timing of the valve.

Here, the relief valve M7 provided in the middle of the bypass oil passage M6 that bypasses the oil filter M5 operates when the differential pressure between the upstream side and the downstream side of the oil filter M5 becomes equal to or higher than a predetermined value. Then, the bypass oil passage M6 is opened, and otherwise, the bypass oil passage M6 is closed.
For this reason, when the oil filter M5 is clogged, the relief valve M7 is opened, and the hydraulic oil is introduced into the hydraulic control valve M9 or the like without passing through the oil filter M5, and the priming of the hydraulic oil is performed. Supply is secured.

In the present invention, based on the detection result of the operating state detecting means M10, the valve opening probability determining means M1 is determined.
According to 2, it is determined whether or not the vehicle is in an operating state in which the relief valve M7 is likely to be opened at the present time.
When the valve opening probability determining means M12 determines that the probability of valve opening is high, the moving amount adjustment control means M1
3, the amount of movement of the spool of the hydraulic control valve M9 is adjusted and controlled, and the opening of the relief valve M7 is suppressed. For this reason, it is possible to suppress the foreign matter trapped in the oil filter M5 from flowing into the hydraulic control valve or the valve timing mechanism unnecessarily along with a large amount of hydraulic oil.

[0014]

【Example】

(First Embodiment) Hereinafter, a first embodiment of a valve timing control apparatus for an internal combustion engine according to the present invention will be described in detail with reference to the drawings.

FIG. 2 is a diagram schematically showing a hydraulic oil circuit of an engine (internal combustion engine) including the valve timing control device according to the present embodiment. The hydraulic oil circuit is oil pan 4
2. an oil pump 41, an oil filter 43, a valve operating mechanism, a crank mechanism, a linear solenoid type hydraulic control valve (hereinafter simply referred to as OCV) 44, and a variable valve timing actuator (V
VT actuator) 47 and various oil passages connecting them.

Hereinafter, each element will be described in detail. The camshaft 1 is provided for driving an intake valve or an exhaust valve of an engine (not shown).
The journal 2 is rotatably supported between a bearing portion 4 of the cylinder head 3 and a bearing cap 5.
The journal 2 is formed with two journal grooves 6 and 7 extending along the outer periphery. Further, a first head oil passage 8 and a second head oil passage 9 for guiding hydraulic oil to each of the journal grooves 6 and 7 and the journal 2 are formed in the cylinder head 3.

One end of each of the head oil passages 8 and 9 is connected to an OCV 44, and the OCV 44 is connected to the oil pan 42 by a main oil passage 46. An oil filter 43, an oil pump 41 and an oil strainer 45 are interposed in the main oil passage 46. The oil pump 41 is connected to the engine, and pumps up and discharges hydraulic oil in an oil pan 41 via an oil strainer 45 in conjunction with operation of the engine. After passing through the oil filter 43, the operating oil is supplied to the head oil passages 8 and 9 with a predetermined pressure by the operation of the OCV 44, and is supplied to the journal grooves 6 and 7 and the journal 2. Here, the supply of the working oil to the head oil passages 8 and 9 can be arbitrarily adjusted by the OCV 44. The detailed configuration of the OCV 44 will be described later.

The oil filter 43 and the OCV 4
4, a part of the main oil passage 46 is formed so as to be branched, and the branched part of the oil passage 46 is used to lubricate the engine main body constituted by a valve mechanism, a crank mechanism, and the like. He is in communication with the system.

Further, a bypass oil passage 48 is provided so as to bypass the oil filter 43,
A relief valve 49 is provided on the way.
The relief valve 49 opens the bypass oil passage 48 when the differential pressure between the upstream side and the downstream side of the oil filter 43 becomes a predetermined value or more, and closes the bypass oil passage 48 otherwise. I do.

Next, the VVT actuator 47 will be described. A timing pulley housing 10 is provided at a distal end (left end in FIG. 2) of the camshaft 1. The housing 10 includes a pulley body 11 and a cover 12 assembled so as to cover one side surface of the pulley body 11 and the tip of the camshaft 1. The pulley body 11 has a substantially disk shape, a plurality of external teeth 13 are formed on the outer periphery, and a boss 14 is formed in the center. The pulley body 11 is mounted by its boss 14 so as to be rotatable relative to the camshaft 1. Further, a timing belt 15 is attached to the external teeth 13, and the timing pulley housing 10 is connected to a crankshaft (not shown) of the engine via the timing belt 15. On the other hand, the cover 12 has a bottomed cylindrical shape, a flange 16 is formed on the outer periphery thereof, and a communication hole 17 is formed in the center of the bottom. A plurality of internal teeth 12 a are formed on the inner periphery of the cover 12. The cover 12 is fixed to one side surface of the pulley main body 11 by a plurality of bolts 18 and pins 19 at its flange 16. In addition, communication hole 1
A cover 20 is detachably attached to 7. The space surrounded by the pulley body 11 and the cover 12 is a housing space 21 formed inside the timing pulley housing 10.

In the housing space 21, an inner cap 22 having a bottomed cylindrical shape is fastened by a hollow bolt 23 to the tip of the camshaft 1 and is prevented from rotating by a pin 24. The peripheral wall 22a of the inner cap 22 is mounted so as to enclose the boss 14 of the pulley body 11, and the two 11 and 22 are relatively rotatable. A plurality of external teeth 22b are formed on the outer periphery of the peripheral wall 22a of the inner cap 22.

A ring gear 25 is interposed between the timing pulley housing 10 and the camshaft 1, and the ring gear 25 connects the two 10, 1 to each other. That is, the ring gear 25 has an annular shape, and the camshaft 1 is accommodated in the accommodation space 21 of the timing pulley housing 10.
Are accommodated so as to be able to reciprocate along the axial direction. A plurality of teeth 25a and 25b are provided on the inner and outer circumferences of the ring gear 25. Then, the inner teeth 25 of the ring gear 25
a is the outer gear 22b of the inner cap 22 and the ring gear 2
The teeth 25b on the outer periphery of the gear 5 mesh with the internal teeth 12a of the cover 12, respectively. Therefore, when the timing pulley housing 10 is rotated, the timing pulley housing 10 and the inner cap 22 connected by the ring gear 25 are integrally rotated, and the camshaft 1 is further integrally rotated with the timing pulley housing 10. You. Further, these two teeth 25a and 25b are helical teeth. Therefore, the camshaft 1 is moved by the axial movement of the ring gear 25 so that the timing pulley housing 1
It rotates relatively to zero.

In the housing space 21, a first hydraulic chamber 26 is provided between one axial end of the ring gear 25 and the bottom wall of the cover 12. Similarly, in the accommodation space 21, the space between the other end of the ring gear 25 in the axial direction and the pulley body 11 is
The second hydraulic chamber 27 is provided.

Here, a first shaft oil passage 28 is formed in the camshaft 1 so as to extend along the center of the camshaft 1 in order to supply hydraulic pressure to the first hydraulic chamber 26 with hydraulic oil. The distal end side of the shaft oil passage 28 communicates with the first hydraulic chamber 26 through the center hole 23 a of the hollow bolt 23. The proximal end of the shaft oil passage 28 communicates with the journal groove 6 through an oil hole 29 extending in the radial direction of the camshaft 1.

On the other hand, in order to supply hydraulic pressure by hydraulic oil to the second hydraulic chamber 27, the second shaft oil passage 3 extends in the camshaft 1 so as to extend in parallel with the first shaft oil passage 28.
0 is formed. One peripheral groove 31 is formed at a position near the tip of the camshaft 1 along the outer peripheral surface thereof. A part of the circumferential groove 31 communicates with the second shaft oil passage 30. Further, the boss 1 of the pulley body 11
An oil hole 32 is formed in a part of the hole 4 to allow the above-mentioned peripheral groove 31 to communicate with the second hydraulic chamber 27. The proximal end side of the second shaft oil passage 30 communicates with the journal groove 7. In addition, a spring 33 is provided between the ring gear 25 and the pulley main body 11 in the second hydraulic chamber 27 to urge the ring gear 25 to return to the initial position (retard side position) shown in FIG. Have been.

Then, as shown in FIG. 3, the operating oil is supplied to the first head oil passage 8 by the OCV 44,
When the second head oil passage 9 is opened to the oil pan 42, the hydraulic pressure of the working oil is reduced to the journal groove 6 and the oil hole 2.
9, is supplied to the first hydraulic chamber 26 through the first shaft oil passage 28 and the center hole 23a of the hollow bolt 23. When this hydraulic pressure is applied to one end of the ring gear 25,
The ring gear 25 rotates while being moved in the axial direction against the urging force of the spring 33 and the hydraulic pressure in the second hydraulic chamber 27, so that the camshaft 1 is twisted. As a result, the camshaft 1 and the timing pulley housing 10
Is changed in the rotation direction, and the operation timing of the intake valve or the exhaust valve is changed (for example, advanced).

On the other hand, as shown in FIG. 4, the operating oil is supplied to the second head oil passage 9 by the OCV 44 and the first head oil passage 8 is opened to the oil pan 42 to operate the second head oil passage 8. The oil pressure of the oil is supplied to the second hydraulic chamber 27 through the journal groove 7, the second shaft oil passage 30, the circumferential groove 31 and the oil hole 32. When this oil pressure is applied to the other end of the ring gear 25, the ring gear 25 is rotated while being moved in the axial direction against the oil pressure in the first hydraulic chamber 26, and the camshaft 1 is turned in the opposite direction to the above. Torsion is imparted. As a result, the relative position of the camshaft 1 and the timing pulley housing 10 in the rotation direction is changed, and the operation timing of the intake valve or the exhaust valve is retarded, for example.

In this embodiment, when the supply of hydraulic oil to both head oil passages 8 and 9 is stopped by the OCV 44, the ring gear 25 is returned to the stroke end on the maximum retard side by the urging force of the spring 33. Thus, it returns to the position described in FIG. Further, in this embodiment, the ring gear 25 can be moved in the axial direction and held at an arbitrary position by adjusting the balance of the hydraulic pressure supplied to the two hydraulic chambers 26 and 27 by the OCV 44.

Next, the OCV 44 will be described. As described above, the OCV 44 selectively opens and closes the first head oil passage 8 and the second head oil passage 9 and
Is used to switch the stop position. 2 to 4, the OCV 44 includes a housing 50, a sleeve 51, a spool 52, and a solenoid 53 as an actuator. The sleeve 51 is the housing 50
Of the supply port 54 and the first
, A second discharge port 56, a first drain port 57, and a second drain port 58. The supply port 54 is connected to the oil pump 41. Further, the first discharge port 55 is connected to the first head oil passage 8, and the second discharge port 56 is connected to the second head oil passage 9. Further, the first drain port 57 and the second drain port 58 are connected to the oil pan 42.

The spool 52 is slidably disposed in the sleeve 51 in the front-rear direction (the left-right direction in FIG. 2). On the outer periphery of the spool 52, three annular concave portions 6 are provided.
1, 60, 59 are formed in a state separated from each other in the front-rear direction.

A solenoid 53 is provided in the latter half (the right side in the figure) of the OCV 44, and the spool 52 moves depending on whether or not the solenoid 53 is excited. The duty of this solenoid 53 is controlled by an electronic control unit (hereinafter simply referred to as “ECU”) 71 that constitutes a valve control unit, a valve opening probability determination unit, and a movement amount adjustment control unit. That is, the solenoid 53 may or may not be excited depending on the presence or absence of a current supplied to itself. Then, the spool 52 reciprocates in the sleeve 51 according to the excitation state.

That is, the spool 52 is provided with a solenoid 53
Is not excited (for example, duty ratio = 0%), it is held at the position shown in FIG. 4 by the urging force of the spring 62 housed at the front end of the sleeve 51. In this embodiment, the 0% is the basic duty ratio, and the basic control is performed based on this value.

On the other hand, when the solenoid 53 is excited (for example, duty ratio = 100%), the spring 62
3 to the position shown in FIG. When the solenoid 53 repeats the excitation and the non-excitation in a short cycle (for example, the duty ratio = 5).
0%), and held at an appropriate intermediate position, that is, the position shown in FIG.

More specifically, the solenoid 5
3 (duty ratio = 0%), the spool 5
When 2 moves back to the position shown in FIG. 4, the main oil passage 46, the supply port 54, the central annular recess 60, and the second discharge port 56 communicate with each other. Further, the first discharge port 55, the front annular concave portion 61, and the first drain port 57 communicate with each other.
Then, the operating oil from the oil pump 41 is supplied from the second discharge port 56 to the second head oil passage 9. On the other hand, the hydraulic oil from the first head oil passage 8 is discharged from the first discharge port 55 to the oil pan 42 via the first drain port 57.

When the spool 52 advances to the position shown in FIG. 3 by the excitation of the solenoid 53 (duty ratio = 100%), the main oil passage 46, the supply port 5
4. The central annular recess 60 and the first discharge port 55 communicate with each other. The second discharge port 56, the rear annular concave portion 59, and the second drain port 58 communicate with each other. Then
The operating oil from the oil pump 41 is supplied to the first discharge port 5
5 to the first head oil passage 8. On the other hand, the second
The hydraulic oil from the head oil passage 9 of the second discharge port 56
From the oil pan 42 via the second drain port 58.

When the spool 52 is held at the position shown in FIG. 2 by repeating the excitation and non-excitation of the solenoid 53 (duty ratio = 50%), the central annular recess 6
0 will be closed at the exit side. That is, the hydraulic oil introduced from the supply port 54 is supplied to the central annular recess 6.
0, the first and second discharge ports 55, 56
Is not ejected to any of them. Then, the hydraulic oil passes through the main oil passage 46 and is supplied only to the engine body lubrication system such as the valve operating mechanism and the crank mechanism.

That is, as shown in FIG.
2 moves in the front-rear direction according to the duty ratio at that time, and switches the flow of hydraulic oil. Then, when the duty ratio is around 50% (40% to 60%), the spool 52 is held at the intermediate position, and the supply amount of the hydraulic oil becomes almost “0”.

As shown in FIG. 2, the solenoid 53 of the OCV 44 is driven and controlled by the ECU 71. Specifically, the input side of the ECU 71 is provided with an engine speed NE.
, A cam angle sensor 82 for detecting a cam angle, a crank shaft rotation reference position,
For example, a crank angle sensor 8 for detecting the detection of the rotational position of the crankshaft with respect to the top dead center of the specific cylinder
3. Throttle sensor 8 for detecting throttle valve opening
4. A water temperature sensor 85 for detecting a cooling water temperature, an intake pressure sensor 86 for detecting an intake air pressure (intake pressure) PiM, a vehicle speed sensor 87 for detecting a vehicle speed, and a starter signal STS to output whether or not the present time is a start time. Starter 8 for judgment
8 etc. are connected. These sensors 81 to 88 constitute operating state detecting means.

The output of the ECU 71 is connected to the OCV.
Forty-four solenoids 53 are connected. And EC
U71 determines the operating state of the engine at that time based on the detection signals from the various sensors 81 to 88,
A control signal for driving the solenoid 53 is output. Note that the ECU 71 also has a counter function.

Next, the operation and effect of the embodiment constructed as described above will be described. First, among the various processing operations executed by the ECU 71 described above, the processing operations for valve timing control will be described with reference to FIG.

The flowchart shown in FIG. 6 shows an "OCV control subroutine" incorporated in a part of the "OCV control routine" for controlling the valve timing, among various processes executed by the ECU 71.
It is executed by a periodic interruption every fixed time.

When the processing of this routine is started, first, in step 101, based on the detection signals from the various sensors 81 to 87 and the starter 88, the engine speed NE, the intake pressure PiM, the starter signal STS, etc. Reads various signals related to the operating state.

Next, in step 102, it is determined whether or not the currently read starter signal STS has just switched from "1" to "0". Here, the starter signal STS outputs “1” when the engine is started, that is, at the time of cranking, and outputs “0” when the start is completed. That is, in this step 102,
It is determined whether the current time is when the engine is started. It should be noted that whether or not it is at the time of starting the engine here is determined by
The determination may be made separately based on the engine speed NE or the like. If it is determined that the current time is at the time of starting the engine, the process proceeds to step 105, and the count value C of the counter is incremented by "1".

On the other hand, if the present time is not the time when the engine is started, that is, if at least a predetermined time has elapsed since the start, the process proceeds to step 103. In step 103, the count value C is set to a predetermined second predetermined value C2.
It is determined whether or not it exceeds. Here, the second predetermined value C2 means that when the count value C exceeds the value, a considerable amount of time has elapsed since the start of the engine, and it is not necessary to execute this control. Is a value sufficient for Therefore, when the count value C exceeds the second predetermined value C2, the count value C of the counter is cleared to "0" in step 104, and the subsequent processing is temporarily terminated.

The count value C is still at the second predetermined value C
If it does not exceed 2, it is determined that this control needs to be executed, and the routine proceeds to step 105, where the count value C is incremented by "1".

Next, in step 106, it is determined whether or not the count value C is less than a first predetermined value C1. Here, the first predetermined value C1 is a time that is sufficient for the engine body lubrication system to be substantially filled with the working oil from the time of starting the engine, and is a value smaller than the second predetermined value C2. . If the count value C is still less than the first predetermined value C1, it is determined that the engine body lubrication system has not been fully filled with hydraulic oil, and the routine proceeds to step 107. In step 107, the target duty ratio is set to, for example, 60%,
Thereafter, the processing is temporarily terminated.

When the count value C is equal to or more than the first predetermined value C1, the duty ratio is set to the above 60%
Is set to gradually approach, for example, 40%, and the subsequent processing is temporarily terminated.

As described above, in the "OCV control subroutine", the spool 52 is held at the intermediate position until the predetermined time elapses from the start of the engine, and the hydraulic oil is supplied to the first and second head oil passages. Little is supplied to either of 8 and 9. More specifically, from when the engine is started until the count value C reaches the first predetermined value C1,
The duty ratio is controlled to 60%, and the count value C is set to the first
Is controlled from 60% to gradually approach 40% from the predetermined value C1 to the second predetermined value C2.

As described above, at the beginning of the engine start, the engine body lubrication system and the V
The hydraulic oil in the VT actuator 47 has been completely exhausted, and the air has entered. In this state,
When the engine is started, the hydraulic oil hardly flows toward the engine main body lubrication system due to the narrow bearing clearance of the engine main body lubrication system and the low viscosity of the hydraulic oil at the start. Therefore, in the case of the related art [when the basic duty ratio (for example, 0%) is set immediately after the start of the engine], the flow mainly flows toward the VVT actuator 47 as shown by the broken line in FIG. There is a tendency. After that, the hydraulic pressure of the main oil passage 46 increases. Therefore, at least VV
Until the T-actuator 47 is filled with hydraulic oil (during a period in which the probability of opening the valve is high), the pressure on the downstream side of the oil filter 43 may be significantly lower than the pressure on the upstream side.

On the other hand, in the present embodiment, the spool 52 is held at the intermediate position for a predetermined time (until the count value C reaches the second predetermined value C2) from the start of the engine.
More specifically, the duty ratio is controlled to 60% from the time when the engine is started until the count value C reaches the first predetermined value C1. Further, the duty ratio is controlled so as to gradually approach 60% from 60% until the count value C changes from the first predetermined value C1 to the second predetermined value C2. For this reason, as shown by the solid line in FIG.
The oil pressure in the engine body lubrication system begins to increase relatively quickly,
During the predetermined time from the start of the engine, the flow does not flow much toward the VVT actuator 47. Therefore, the pressure on the downstream side of the oil filter 43 does not become lower than the pressure on the upstream side, and the opening of the relief valve 49 can be suppressed. Therefore, when the engine does not need to be opened at the beginning of the engine, the relief valve 49 is not opened. As a result, there is no danger that a large amount of hydraulic oil containing foreign matter will be introduced into the OCV 44 at once without passing through the oil filter 43, and the OCV 44 or V
An operation failure of the VT actuator 47 can be avoided.

In this embodiment, the count value C is equal to the first value.
Is controlled from 60% to gradually approach 40% from the predetermined value C1 to the second predetermined value C2. The numerical value of the duty ratio of 40% is a value that can suppress the flow of the hydraulic oil to the VVT actuator 47, and the basic duty ratio (0%) of the present embodiment.
Is the value closest to For this reason, after the count value C exceeds the second predetermined value C2 and the control of this embodiment is completed, so-called normal OCV control can be executed smoothly and quickly. That is, it is possible to minimize the sense of discomfort when shifting from the control of the present embodiment to the normal OCV control.

Further, in this embodiment, the OCV 44 is not used until a predetermined time elapses after the engine is started.
To prevent the supply of hydraulic oil to any of the head oil passages 8 and 9. For this reason, the supply of the hydraulic oil to the downstream side of the OCV 44 is prohibited, and the hydraulic oil circulation volume of the entire lubrication system is reduced to the same level as when the VVT actuator 47 is not provided. Therefore,
The hydraulic oil discharged from the oil pump 41 is promptly supplied to the valve mechanism and the crank mechanism through the main oil passage 46. As a result, the lubricity of the valve mechanism and the crank mechanism is quickly improved, and the occurrence of a tapping sound or the like due to insufficient lubrication can be rapidly reduced. That is,
The level of noise generated after starting the engine can be reduced quickly.

(Second Embodiment) Next, a second embodiment in which the present invention is embodied in a valve timing control device for an internal combustion engine will be described in detail with reference to the drawings. However, the configuration in this embodiment is substantially the same as that in the first embodiment described above, and therefore, the same members will be given the same names and reference numerals, and the following description will focus on the differences.

In the first embodiment, the control of the OCV 44 from the start of the engine until the predetermined time has elapsed has been described. On the other hand, in the present embodiment, the oil filter 43 is deteriorated,
The second embodiment differs from the first embodiment in that the OCV 44 controls the OCV 44 in consideration of the case where a pressure difference occurs between the upstream side and the downstream side.

The flowchart shown in FIG.
Shows the "OCV control routine" for controlling the valve timing among the various processes executed by the CPU, and is executed by a periodic interruption every predetermined time.

When the processing of this routine is started, first, in step 201, various signals indicating the operating state such as the engine speed NE are read based on the detection signals from the various sensors 81 to 87 and the starter 88. .

Next, at step 202, it is determined whether or not the currently read engine speed NE is equal to or greater than a first predetermined speed NE1 and equal to or less than a second predetermined speed NE2. . And the engine speed N
If E is not within the range of not less than the first predetermined rotation speed NE1 and not more than the second predetermined rotation speed NE2, it is determined that the current engine rotation speed NE is not within the control target region, and the routine proceeds to step 205. I do.

In step 205, based on the engine speed NE and the intake pressure PiM read this time, FIG.
By referring to a map A shown in FIG. 0, a target phase at that time is determined, a target duty ratio is calculated, and the OCV 44 is controlled based on the duty. Here, the numerical value in the map A indicates the target phase, and the formal target phase is interpolated by the map A. Then, the subsequent processing ends once.

On the other hand, if the engine speed NE is within the range of not less than the first predetermined speed NE1 and not more than the second predetermined speed NE2 in step 202, the current engine speed NE is determined. Is in the control target area, and the process proceeds to step 203. Step 203
In, the response speed V of the VVT actuator 47 is calculated. The response speed V calculates the actual phase based on the relative difference between the detected value of the crank angle sensor and the detected value of the cam angle sensor, and calculates the difference between the actual phase and the separately calculated target phase. It is calculated by considering the fluctuation speed.

Then, in the subsequent step 204,
The response speed V calculated this time is a predetermined specified value V1.
It is determined whether or not this is the case. Here, when the oil filter 43 is functioning normally, as shown in FIG. 9, the engine speed NE falls within a predetermined range (NE1 ≦ N).
It is empirically known that the response speed V is equal to or higher than the specified value V1 when E ≦ NE2). Therefore, when the response speed V is equal to or higher than the specified value V1, it can be estimated that the oil filter 43 is functioning normally. In such a case, the process proceeds to step 205 as described above. Then, based on the engine speed NE and the intake pressure PiM read this time, the target phase is determined and the target duty ratio is calculated by referring to the map A shown in FIG. Further, based on the duty ratio, the OCV 44
, And the subsequent processing is temporarily terminated.

On the other hand, when the response speed V falls below the specified value V1, it has been found from experience that the oil filter 43 has deteriorated and is not functioning properly, as indicated by the two-dot chain line in FIG. I have. Therefore, when the response speed V is less than the specified value V1, it can be estimated that the oil filter 43 has deteriorated. In such a case, the process proceeds to step 206. Then, based on the engine speed NE and the intake pressure PiM read this time, a target phase is determined by referring to a map B shown in FIG. 11, and a target duty ratio is calculated. The OCV 44 is controlled. However, the target duty ratio at this time is also calculated by complementing the target phase with the map B in the same manner as described above. Here, FIG.
The difference between the map A of FIG. 0 and the map B of FIG. 11 will be described.
Is set to be half of the target phase calculated by. For example, based on the current engine speed NE and intake pressure PiM, the target phase is set to 60
° even if it is calculated to be
Is calculated to be half of 30 °. Then, after the above processing is performed, the subsequent processing is temporarily terminated. As described above, according to the “OCV control routine”, the VV when the engine speed NE is within the predetermined range is determined.
The response speed V of the T actuator 47 is calculated, and the control map adopted by the response speed V is:
Whether it is the map A or the map B is determined. And
The target phase is calculated based on one of the maps, and OC
V44 is controlled.

As described above in detail, according to the second embodiment, the VVT actuator 4
If the response speed V of 7 is lower than the specified value V1, it is determined that the oil filter 43 has deteriorated. Here, when the OCV control is performed as usual, the filter 43
Even if the degree of deterioration of the oil filter 43 is not great, the pressure on the upstream side of the oil filter 43 becomes smaller than the pressure on the downstream side,
There is a possibility that the relief valve 49 is unnecessarily opened.

However, in the present embodiment, when the above-mentioned deterioration is determined, the map B is adopted, and the target phase is set to a value smaller than that in the normal state. Therefore, the OCV 44 is controlled so that the opening area of the first discharge port 55 is reduced, and the flow rate of the working oil supplied to the VVT actuator 47 is controlled to be small. Therefore, the difference between the pressure on the downstream side of the oil filter 43 and the pressure on the upstream side becomes relatively small, and unnecessary opening of the relief valve 49 can be suppressed. Therefore, even if a relatively small degree of deterioration occurs in the oil filter 44 during the control of the OCV 44, the relief valve 49 is unnecessarily opened when there is no need to open the relief valve 49. Disappears. As a result, as in the case of the first embodiment, there is no possibility that a large amount of hydraulic oil including foreign matter is introduced into the OCV 44 at once without passing through the oil filter 43, and the OCV 44 or the VVT
An operation failure of the actuator 47 can be avoided.

The present invention is not limited to the above-described embodiment, and may be configured as follows, for example. (1) In the first embodiment, since the basic duty ratio of the main routine of the OCV control is 0%, the duty is not changed until the count value C becomes the first predetermined value C1 becomes the second predetermined value C2. The control was performed such that the ratio was gradually reduced from 60% to 40%. However, when the basic duty ratio in the main routine is, for example, 100%, the control may be such that it gradually increases from 40% to 60% at first. Further, the value of the duty ratio is not limited at all, and the supply of the hydraulic oil to the VVT actuator 47 is not performed until a predetermined period (a period sufficient for the relief valve 49 not to be opened) from the start of the engine. What is necessary is just to perform control which is suppressed. Further, at the end of the present control, it is more preferable that the control gradually approaches a value close to the basic duty ratio.

(2) In both of the above embodiments, as a specific example in which the probability that the relief valve 49 will be opened is high, control from the start of the engine until a predetermined time has elapsed (the first embodiment) and the case where the oil filter 43 is deteriorated are described. Control (second
Although the embodiment has been described, the control in other cases may be embodied. A specific example of this is, for example, a sudden acceleration. That is, when the engine speed NE suddenly increases, the oil pump 41 is connected to the engine output shaft, so that the discharge amount from the oil pump 41 sharply increases, and the differential pressure across the oil filter 43 increases. , The relief valve 49 may be opened. Therefore, in such a case, the unnecessary opening of the relief valve 49 can be suppressed by detecting the engine speed NE.

(3) In the above-described embodiment, the OCV 44 having the spool 52 is employed as the hydraulic control valve. However, an electromagnetic valve, a rotary valve, or the like may be used. (4) In the above embodiment, the oil pump 51 is connected to the output shaft of the engine. However, an oil pump may be used separately.

(5) In the above embodiment, the OCV 44 having the two discharge ports 55 and 56 is employed.
OC of the type having one or more discharge ports
V may be used. The OCV 44 is a solenoid 53
Although the spool 52 moves depending on the presence or absence of the excitation described above, a configuration in which the spool is separately adjusted by hydraulic pressure may be employed. Further, the configuration of the VVT actuator 47 is not limited to the type of the above embodiment. Therefore, for example, the following (6),
It can also be configured as in (7).

(6) In the above-described embodiment, the structure is adopted in which the spring 33 is interposed between the ring gear 25 and the pulley body 11, but this spring 33 may be omitted. (7) In the above embodiment, both the inner and outer teeth 25a and 25b of the ring gear 25 are helical teeth, but only one of the inner and outer teeth 25a and 25b may be helical teeth. The technical ideas which are not described in the claims and can be grasped from the above embodiments are described below together with their effects.

(A) In the valve timing control device for an internal combustion engine according to claim 1, adjustment of the movement amount of the spool of the hydraulic control valve by the movement amount adjustment control means is performed by supplying hydraulic oil to the valve timing mechanism. It is characterized in that it is performed to suppress the inflow. With this configuration, the differential pressure between the upstream side and the downstream side of the oil filter can be suppressed to substantially the same level as when no valve timing mechanism is provided.

(B) In the valve timing control device for an internal combustion engine according to claim 1 or (a), the valve opening probability determining means is within a predetermined period from the start of the internal combustion engine, and It is characterized in that the probability of valve opening is affirmatively determined by determining at least one of the filters that has been degraded to a predetermined extent. With such a configuration, the probability of valve opening can be more reliably determined.

(C) In the valve timing control apparatus for an internal combustion engine according to claim 1 or the above (a) or (b), the hydraulic control valve is duty-controlled depending on whether or not a solenoid is energized. There is a feature. With such a configuration, the hydraulic control valve can be easily and reliably controlled by appropriately controlling the duty ratio.

(D) Claim 1 or the supplementary note (a),
The valve timing control device for an internal combustion engine according to (b) or (c), wherein the control is performed to suppress the flow of hydraulic oil into the valve timing mechanism until at least a certain time has elapsed since the start of the internal combustion engine. And
With such a configuration, the hydraulic oil is promptly supplied to the lubrication system of the main body of the internal combustion engine, and it is possible to rapidly reduce the occurrence of a tapping sound or the like due to insufficient lubrication.

[0073]

As described in detail above, according to the present invention,
A hydraulic control valve for controlling the pressure of hydraulic oil introduced from the oil pump to the valve timing mechanism; an oil filter between the oil pump and the hydraulic control valve; a bypass passage for bypassing the oil filter; In a valve timing control device for an internal combustion engine having a relief valve provided in a passage, it is possible to suppress foreign substances in hydraulic oil from flowing into a hydraulic control valve or a valve timing mechanism unnecessarily, Accordingly, an excellent effect that an operation failure of the hydraulic control valve or the valve timing mechanism can be avoided can be achieved.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram schematically showing a valve timing control device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 3 is a configuration diagram illustrating a state of the valve timing control device when the spool moves in the first embodiment.

FIG. 4 is a configuration diagram illustrating a state of the valve timing control device when the spool moves in the first embodiment.

FIG. 5 is a graph showing a relationship between a forward movement amount and a duty ratio of a spool and a supply amount of lubricating oil to a head oil passage in the first embodiment.

FIG. 6 is a flowchart illustrating an “OCV control subroutine” executed by an ECU in the first embodiment.

FIG. 7 is a timing chart illustrating a relationship between an engine speed, a main oil pressure, a duty ratio, and a flow rate of hydraulic oil flowing into a VVT actuator with respect to a time after the engine is started in the first embodiment.

FIG. 8 shows a second embodiment of the present invention.
9 is a flowchart illustrating an “OCV control routine” executed by U.

FIG. 9 is a graph showing a relationship between response speed and engine speed in the second embodiment.

FIG. 10 is a diagram showing a map A in which a target phase determined by an engine speed and an intake pressure is determined in the second embodiment.

FIG. 11 is a diagram showing a map B in which a target phase determined by an engine speed and an intake pressure is determined in the second embodiment.

[Explanation of symbols]

Reference Signs List 1 camshaft 41 oil pump 43 oil filter 44 OCV as a hydraulic control valve 46 main oil passage 47 VV constituting a valve timing mechanism
T actuator, 48 ... bypass oil passage, 49 ... relief valve, 52 ... spool as valve body, 53 ... solenoid as actuator, 71 ... valve control means, valve opening probability determination means and EC constituting movement amount adjustment control means
U, 81: a rotational speed sensor constituting an operating state detecting means;
82: a cam angle sensor constituting an operating state detecting means, 83
... Crank angle sensor constituting operating state detecting means, 84
... Throttle sensor constituting operating state detecting means, 85
... A water temperature sensor constituting the operating state detecting means, 86 an intake pressure sensor constituting the operating state detecting means, 87 a vehicle speed sensor constituting the operating state detecting means, and 88 a starter constituting the operating state detecting means.

Claims (1)

(57) [Claims] 1. A valve timing mechanism for changing a rotation phase of a camshaft with respect to a rotation of a crankshaft of an internal combustion engine using hydraulic pressure of hydraulic oil to adjust opening / closing timing of a valve driven by the camshaft. An oil pump that pressurizes the hydraulic oil and discharges the oil to the valve timing mechanism; a main oil path communicating between the valve timing mechanism and the oil pump; and an oil pump provided in the middle of the main oil path. An oil filter for filtering hydraulic oil discharged from the oil pump; a bypass oil passage that bypasses the oil filter; and an oil filter provided in the middle of the bypass oil passage, and an upstream side and a downstream side of the oil filter. The bypass oil passage is opened when the pressure difference between the two becomes equal to or more than a predetermined value, and otherwise, the bypass oil passage is closed. A hydraulic control valve provided between the relief valve, the valve timing mechanism, and the oil filter, for adjusting a hydraulic pressure to the valve timing mechanism by adjusting an amount of movement of the valve body by controlling an actuator; A valve for an internal combustion engine, comprising: operating state detecting means for detecting an operating state of the internal combustion engine; and valve control means for controlling the hydraulic control valve by controlling an actuator based on a detection result of the operating state detecting means. In the timing control device, based on a detection result of the operating state detecting means, a valve opening probability determining means for determining whether or not the relief valve is in an operating state with a high probability of being opened at the present time; and the valve opening probability. When the determining means determines that the probability of opening the valve is high, the opening of the relief valve is suppressed. So, the movement amount adjustment control means and valve timing control apparatus for an internal combustion engine, characterized in that a for adjusting and controlling the amount of movement of the spool of the hydraulic control valve.