DE112006002253T5 - Adjustable valve actuator - Google Patents

Abstract

Adjustable valve actuator with:
a valve mechanism having a switching mechanism for switching between a dual valve timing control mode in which valve opening amounts of a first valve and a second valve provided for the same cylinder and of the same kind are continuously or multi-stepped, and a single valve timing control mode; wherein the valve opening amount of the first valve is adjusted continuously or in a plurality of steps, wherein the valve opening amount of the second valve is set;
memory means for storing rules for dividing an operating range of an internal combustion engine into a dual valve timing control range for which the dual valve timing control mode should be selected, and a single valve timing control range for which the single valve timing control mode should be selected;
normal control means for causing the switching mechanism to perform a switching operation in accordance with the rules;
a state judging means for judging when the operating state of the internal combustion engine changes from the dual valve timing control region to the one-valve valve timing control region, or vice versa, whether a predefined condition is established for foreseeing that the ...

Description

Technical area

The The invention relates to an adjustable valve actuator and more particularly to an adjustable valve actuator, which is capable of mechanically changing a valve opening amount.

State of the art

It It is known that an adjustable valve actuator of the prior art, as for example in the patent document 1, the amount of lift and working angle of a valve in accordance with the operating condition of an internal combustion engine mechanically changes.

at the adjustable valve actuator, the in Patent Document 1, two rotary cams are over a camshaft installed. Two inlet valves are for provided a single cylinder. A first intake valve is opened and closed by a first rotary cam. One second inlet valve is opened by a second rotary cam and closed. An adjustable valve transmission mechanism, which has a four-joint link mechanism is between the first rotary cam and the first intake valve and between the second rotary cam and the second inlet valve positioned.

Of the Four-joint connection mechanism of the protruding adjustable Valve actuator has an input lever, having an input section adjacent to the rotary cams; a transmission lever that swings to the input lever is coupled; a rocker arm, which is swingable to the transmission lever is coupled, which can oscillate on a rotary control shaft, and the picks up a driving force from the rotary cams and turns them into one Output area that opens / closes the inlet valves; and a control lever that rotates on the rotary control shaft and is swingably coupled to the input lever. The working angles and lift amounts of the intake valves may be mechanical be changed by the position of the four-joint linkage mechanism is controlled to the positional relationship between the rotary cam and the input area.

Further has the above adjustable valve actuator a coupling mechanism for coupling a first link mechanism, which is a four-link linkage mechanism with the first intake valve communicates with a second connection mechanism, the a four-link linkage mechanism is the second Inlet valve communicates, and a mechanism for maintaining the position of the second link mechanism at the time of Uncouple to the working angle of the second inlet valve maximize. The coupling mechanism has a through hole, in the control lever of each four-link linkage mechanism is configured, and a coupling pin to insert into the through hole is. The mechanism for maintaining the position of the second link mechanism too The time of decoupling has a through hole, which in one Fixed plate is designed, a through hole, in a second control lever (the control lever for the second Connection mechanism) is generated, and the above-mentioned Coupling pin.

Of the Coupling pin is constantly in the through hole in the second Control lever introduced and can be a first control lever, the control lever for the first link mechanism is, or move towards the fixed plate while he inserted into the through hole in the second control lever is. When the coupling pin approaches the first control lever moved and into the through hole in the first control lever, the second control lever is connected to the first control lever Coupled the coupling pin. When the control levers are coupled together the first and second link mechanisms retain the same position. In this case, a controller is exercised that the valve opening amounts of the first and the second valve are the same.

If in contrast, the coupling pin to the fixed plate moved and into the through hole in the fixed plate device, is the second control lever via the coupling pin coupled with the fixed plate. If the second control lever coupled to the fixed plate, the second retains Link mechanism at a predetermined position. In this Case when controlling the position of the first link mechanism is the positional relationship between the rotary cams and a Input range to change, only the valve opening amount the first valve to be changed mechanically while the valve opening amount of the second valve is fixed.

• Patentdokument 1: Japanische Patentanmeldungsoffenlegungsschrift Nr. 2004-100555

In other words, the foregoing variable valve operating apparatus may select an operation mode in which the first and second intake valves have the same valve opening amount, or a mode in which the first and second intake valves have a different valve opening amount. The valve opening amounts, particularly the lift amounts, of the first and second intake valves may then be made different from each other. Because this is too different Chen inlet flow rates, a swirl flow can be generated within a combustion chamber to ensure increased combustion resistance in the combustion chamber.

• Patent Document 1: Japanese Patent Application Publication No. 2004-100555

Disclosure of the invention

To be solved by the invention problem

As indicated above, the above adjustable valve operating device between a dual valve timing control mode in which the Valve opening amounts of the first and the second Inlet valve can be adjusted, and a Einzelventilverstellsteuerungsbetriebsart with only the valve opening amount of the first intake valve is adjusted, wherein the valve opening amount from the second inlet valve is fixed. When from the dual valve timing control mode is switched to the Einzelventilverstellsteuerungsbetriebsart it is necessary to perform two operations, that is, the coupling pin from the pin hole of the pull out the first control lever and the coupling pin in the Insert pin hole in the fixed plate. If on the other hand from the Einzelventilverstellsteuerungsbetriebsart in the dual valve timing control mode is switched it is necessary to perform two operations, that is, the coupling pin from the pin hole in the pulled out fixed plate and the coupling pin in the pin hole in the first control lever.

The The internal combustion engine described above switches between the Dual and Einzelventilverstellsteuerungsbetriebsart in accordance with the operating state. At a low speed / in one Low load range, for example, the Einzelventilverstellsteuerungsbetriebsart selected because it is required that a twist within of a cylinder is generated in order for a combustion improvement to care. At a high engine speed / in a high load range On the other hand, the dual valve timing control mode is selected. because it is required that a large amount of air is absorbed becomes. More specifically, a control device stores for the engine rules for subdividing an operating range in a dual valve timing control range for which the dual valve timing control mode should be selected, and a Einzelventilverstellsteuerbereich, for the Einzelventilverstellsteuerungsbetriebsart selected should be. When the operating state of the engine of switches one area to another, the control device switches accordingly between the dual and the Einzelventilverstellsteuerungsbetriebsart around.

If however, the control device is often between the dual and the single valve displacement control mode switches It is likely that the durability of a switching mechanism due to premature wear of the above-mentioned coupling pin and the pin hole, which form the switching mechanism disadvantageous being affected. Furthermore, such frequent switching lead to a switching error. If a switching error occurs should not have suitable valve opening characteristics to be obtained. This leads to the failure, one expected fuel efficiency and expected driving behavior achieve.

The Invention has been made in light of the above facts. A The object of the invention is to provide an adjustable valve actuating device, which is a switching mechanism for switching between the dual and the Einzelventilverstellsteuerungsbetriebsart and the Shelf life of the switching mechanism improved.

Advantages of the invention

Means of solving the problem

A first aspect of the invention is an adjustable valve actuator having:
a valve mechanism having a switching mechanism for switching between a dual valve timing control mode in which the valve opening amounts of a first valve and a second valve provided for the same cylinder and of the same kind are continuously or multi-stepped, and a single valve timing control mode in which the valve opening amount of the first valve is adjusted continuously or in several steps, wherein the valve opening amount of the second valve is set;
memory means for storing rules for dividing an operating range of an internal combustion engine into a dual valve timing control region for which the dual valve timing control mode should be selected, and a single valve timing control range for which the single valve timing control mode should be selected;
a normal control means for causing the switching mechanism to perform a switching operation in accordance with the rules;
a state judging means for judging, when the operating state of the internal combustion engine changes from the dual valve timing control region to the single valve timing control region or vice versa, whether a predefined condition is established for anticipating that the operating state will return to the previous region within a short period of time; and
a suppressing means for suppressing the switching process when the predefined condition is established.

One second aspect of the invention is the variable valve operating device according to the first aspect, wherein the predefined Condition indicates a condition at which a predetermined period of time has passed since a gearshift through a gearbox that between the internal combustion engine and vehicle drive wheels positioned is.

One third aspect of the invention is the adjustable valve actuator according to the first aspect, wherein the predefined Condition specifies a condition in which a transmission is between the internal combustion engine and vehicle drive wheels positioned is on neutral or parked.

A fourth aspect of the invention is the variable valve operating apparatus according to any one of the first to third aspects, further comprising:
a releasing means for enabling the switching operation when the operating state of the internal combustion engine does not return to a previous range within a predetermined period of time after a shift from the dual valve timing control range to the single valve timing control range or vice versa.

A fifth aspect of the invention is the variable valve operating apparatus according to any one of the first to fourth aspects, further comprising:
a measuring means for measuring the frequency with which the switching operation was suppressed or the cumulative time during which the switching operation was suppressed; and
A permission device that, when a predetermined value is exceeded by the number of times that the switching operation is suppressed or the cumulative time during which the switching operation has been suppressed, allows the switching mechanism to perform a switching operation irrespective of whether the predefined condition is established.

A sixth aspect of the invention is the variable valve operating apparatus according to any one of the first to fifth aspects, further comprising:
a valve opening amount limiting means for limiting a target valve opening amount when the switching operation by the suppressing means is suppressed.

A seventh aspect of the invention is the variable valve operating apparatus according to the sixth aspect.
wherein the valve mechanism drives a main cam that drives both the first valve and the second valve in the dual valve timing control mode and drives only the first valve in the single valve timing control mode; and a sub cam that drives the second valve in the single valve advance control mode; and
wherein the valve opening amount limiting means limits the target valve opening amount to prevent the sub cam from leaving a counter cam of the sub cam when the suppression means suppresses switching from the single valve timing control mode to the dual valve timing control mode to maintain the single valve timing control mode.

Effects of the invention

According to the The first aspect of the invention may be the switching mechanism between the dual valve timing control mode and the single valve timing control mode switch. This switching process is in accordance with rules for dividing the operating range of the internal combustion engine in the dual valve timing control range and the single valve timing control range depending on the operating state of the internal combustion engine carried out. However, the switching is suppressed, if, when the operating state of the Dualventilverstellsteuerbereich switched to the Einzelventilverstellsteuerbereich or vice versa, a predefined condition for predicting that is made the operating state within a short period of time to the previous one Area will return. Therefore allows it is the first aspect of the invention, the frequency a switching process by reducing unnecessary switching be avoided. As a result, the durability of the switching mechanism by avoiding excessive wear and a scratching of the switching mechanism can be increased. Furthermore, the possibility of a switching malfunction may occur be reduced to steady valve opening characteristics to realize according to the operating condition and satisfactory fuel efficiency characteristics, Get exhaust properties and driving behavior exactly.

According to the second aspect of the invention, it is possible a completely avoid unnecessary switching process, the tends to go immediately after a gearshift through the transmission occur. Therefore, the frequency of a switching operation be reduced while the vehicle is moving.

According to the third aspect of the invention, it is possible to provide an unnecessary switching during an operation of free acceleration (so-called spin-up) completely avoided, which is performed while the transmission is in a neutral or parking position. Therefore, the frequency of a switching operation during free acceleration can be reduced.

If the operating state of the internal combustion engine is not within a short time period returns to a previous area, after moving from the dual valve timing control area to the single valve timing control area or vice versa, the fourth aspect the invention release the switching and the switching carry out. Therefore, if the switching process actually is needed in a situation where it is assumed that switching is not required, the switching process to achieve preferred valve opening characteristics to realize.

If a predetermined value by the frequency with which the Switching was suppressed, or the cumulative Time during which the switching process is suppressed was exceeded, the fifth point of view can of the invention perform the switching operation even in a situation at a condition to predict is made that the switching operation is unnecessary. Therefore, the switching operation in each Situation with a required frequency to maintain the function of the switching mechanism are performed. This makes it possible to avoid problems by, for example prevents the switching mechanism due to a long-term inactivity stuck.

If the process of switching between the dual valve timing control mode and the single valve displacement control mode is suppressed is the sixth aspect of the invention, the target valve opening amount limit. This makes it possible to make sounds and others To completely avoid problems that can occur when the switching process is suppressed.

If the process of switching from the Einzelventilverstellsteuerungsbetriebsart is suppressed to the dual valve timing control mode, about the single valve displacement control mode in a situation maintain, in which the valve mechanism has the main cam, in the dual valve timing control mode, both the first Valve and the second valve drives and in the Einzelventilverstellsteuerungsbetriebsart only the first valve drives, and has the secondary cam, the in the Einzelventilverstellsteuerungsbetriebsart the second valve drives, the seventh aspect of the invention, the target valve opening amount limit so that the secondary cam does not leave its counterpart component. Because this feature completely prevents the secondary cam from the Counterpart leaves and comes back in contact with it comes (collides), it is possible to create a sound completely avoid and prevent the collision that the surfaces of the secondary cam and its counterpart component to be damaged.

Brief description of the drawings

1 FIG. 10 illustrates the structure of a system including an adjustable valve operating apparatus according to a first embodiment of the invention.

2 FIG. 15 is a perspective view illustrating the structure of a valve mechanism included in the variable valve operating apparatus according to the first embodiment of the invention. FIG.

3 illustrates the construction of an adjustable valve mechanism incorporated in the in 2 shown valve mechanism is included.

4 is an exploded perspective view, the adjustable valve mechanisms and in 2 represents fixed valve mechanisms shown.

5 Fig. 11 is a schematic diagram showing the structure of a hydraulic system for operating a switching pin.

6 FIG. 12 shows a map for switching between a dual valve timing control mode and a single valve timing control mode. FIG.

7 FIG. 12 shows a map for switching between the dual valve timing control mode and the single valve timing control mode. FIG.

8th Fig. 10 is a flowchart illustrating a routine executed by the first embodiment of the invention.

9 Fig. 10 is a flowchart illustrating a routine executed by a second embodiment of the invention.

10 Fig. 10 is a flowchart illustrating a routine executed by a third embodiment of the invention.

11 shows valve lift curves of a first intake valve and a second intake valve.

Best way to carry out the invention

First embodiment

[System Structure]

1 FIG. 10 illustrates the structure of a system including an adjustable valve operating apparatus according to a first embodiment of the invention. The illustrated system according to the first embodiment has an internal combustion engine 1 , which is mounted in a vehicle as a drive source. The internal combustion engine 1 has a variety of cylinders 2 , 1 shows only one of the plurality of cylinders 2 ,

The internal combustion engine 1 also has a cylinder block 4 , The cylinder block 4 houses a piston 3 inside a cylinder. The piston 3 is about a connecting rod with a crankshaft 5 connected. A crank angle sensor 6 is near the crankshaft 5 built-in. The crank angle sensor 6 is constructed, the angle of rotation of the crankshaft 5 capture.

A cylinder head 8th is at the top of the cylinder block 4 appropriate. A combustion chamber 10 is through the space between the top surface of the piston 3 and the cylinder head 8th educated. The cylinder head 8th is with a spark plug 11 provided an air-fuel mixture in the combustion chamber 10 ignites.

The cylinder head 8th has an inlet opening 12 that with the combustion chamber 10 communicates. The connection between the inlet opening 12 and the combustion chamber 10 is with an inlet valve 14 Mistake. A valve mechanism 18 is between the inlet valve 14 and an intake cam 16 on an intake camshaft 15 built-in. The valve mechanism 18 will be described in detail later.

The inlet opening 12 is with an inlet route 19 connected. An injection device 20 is near the inlet opening 12 fitted to fuel in the inlet opening 12 inject. A surge tank 21 is in the middle of the inlet path 19 positioned.

A throttle valve 22 is upstream of the surge tank 21 built-in. The throttle valve 22 is an electronically controlled valve driven by a throttle motor 23 is driven. The throttle valve 22 is driven in accordance with an accelerator opening AA provided by an accelerator opening sensor 24 is detected. A throttle opening sensor 25 is near the throttle valve 22 built-in. The throttle opening sensor 25 is configured to detect a throttle opening TA. An air flow meter 26 is upstream of the throttle valve 22 built-in. The air flow meter 26 is configured to detect an intake air amount Ga. An air filter 27 is upstream of the air flow meter 26 built-in.

Furthermore, the cylinder head has 8th an outlet opening 28 that with the combustion chamber 10 communicates. The connection between the outlet opening 28 and the combustion chamber 10 is with an exhaust valve 29 Mistake. The outlet opening 28 is with an exhaust path 30 connected. An air-fuel ratio sensor 31 is in the exhaust path 30 installed to detect an exhaust gas air-fuel ratio.

The system according to the embodiment also has an ECU (electronic control unit) 60 as a control device. The issue end of the ECU 60 is for example with an exhaust valve 84 (please refer 5 ), which will be described later, and additionally with the spark plug 11 , a valve mechanism 18 , the injector 20 and the throttle motor 23 connected. The input end of the ECU 60 is for example with the crank angle sensor 6 , the throttle opening sensor 25 , the accelerator opening sensor 24 , the air flow meter 26 and the air-fuel ratio sensor 31 connected. In accordance with outputs generated by the sensors, the ECU exercises 60 a control over the entire internal combustion engine, such as a fuel injection control and an ignition timing control.

A transmission (not shown) is between the internal combustion engine 1 and drive wheels of the vehicle positioned. The ECU 60 is also with a shift position sensor 62 connected, which detects the position in which the transmission is connected. The transmission can be either of a manual type or an automatic type.

[Construction of an adjustable valve train]

2 is a perspective view showing the structure of the valve mechanism 18 represents, which is included in the variable valve operating device according to the embodiment.

As it is in 2 shown has the intake camshaft 15 two intake cams (a first intake cam 16 and a second intake cam 17 ) for each cylinder. Two intake valves (a first intake valve 14L and a second inlet valve 14R ) are positioned so that the first inlet valve 14L and the second intake valve 14R in relation to the first intake cam 16 are left-right symmetric. Adjustable valve mechanisms 40L . 40R indicating the strokes of the intake valves 14L . 14R with the rotational movement of the first intake cam 16 are each between the first intake cam 16 and the intake valves 14L . 14R positioned. Meanwhile, the second intake cam 17 positioned so that the second inlet valve 14R between the second intake cam 17 and the first intake cam 16 is interposed. A stationary valve mechanism 70 is between the second intake cam 17 and the second intake valve 14R positioned to the lifting movement of the second inlet valve 14R with the rotational movement of the second intake cam 17 to coordinate. The valve mechanism 18 is fitted to either the adjustable valve mechanism 40R or the stationary valve mechanism 70 as a coordination target for the lift of the second intake valve 14R select.

(1) Detailed structure of an adjustable valve mechanism

3 shows the construction of the adjustable valve mechanism 40 in the valve mechanism 18 who in 2 is shown.

More specifically shows 3 the adjustable valve mechanism 40 as it is in the axial direction of the intake camshaft 15 is seen. As the left side and right side adjustable valve mechanisms 40L . 40R basically symmetrical with respect to the first intake cam 16 are their construction without a distinction between the left-side and right-side adjustable valve mechanisms 40L . 40R described. In this document and the accompanying drawings, the term "variable valve mechanism 40 used, if not required, between the left side and the right side adjustable valve mechanism 40L . 40R to distinguish. Similarly, the letters L and R indicating the left and right parts, respectively, do not match the names of the component parts of the variable valve mechanisms 40L . 40R , the intake valves 14L . 14R and other symmetrically arranged parts, unless it is necessary to distinguish between them.

As it is in 3 is shown, the valve mechanism has 18 a rocker arm 35 , the intake valve 14 in the opening direction presses. The adjustable valve mechanism 40 is between the first intake cam 16 and the rocker arm 35 positioned. The adjustable valve mechanism 40 is constructed, the vote between the rotation of the first intake cam 16 and the swinging motion of the rocker arm 35 to adjust constantly.

The adjustable valve mechanism 40 has a control shaft 41 next to the intake camshaft 15 is positioned. A control lever 42 is at the control shaft 41 with a bolt 43 attached. A part of the control lever 42 is in the radial direction of the control shaft 41 out. An intermediate lever 44 is at the projection of the control lever 42 with a pen 45 attached. The pencil 45 is relative to the center of the control shaft 41 positioned eccentrically. That's why the intermediate lever swings 44 on the pen 45 ,

A swing cam lever 50 is swingable by the control shaft 41 supported. The swing cam lever 50 has a sliding surface 50a that the first intake cam 16 is facing. The sliding surface 50a is shaped to be in contact with a second roll 53 to get to. The sliding surface 50a is curved so that its distance to the first intake cam 16 gradually decreases when the second role 53 from the front end of the swing cam lever 50 to the axial center of the control shaft 41 moved. The swing cam lever 50 also has a swing cam surface 51 facing the sliding surface 50a is positioned. The swinging cam surface 51 has a non-actuating surface 51a and an actuating surface 51b , The non-actuating surface 51a is formed so that its distance from the center of vibration of the swing cam lever 50 is fixed. The actuating surface 51b is shaped so that its distance from the axial center of the control shaft 41 in relation to an increase in the distance to the non-actuating surface 51a increases.

A first role 52 and the second role 53 are between the sliding surface 50a and the peripheral surface of the first intake cam 16 positioned. More precisely, the first role 52 positioned to be in contact with the peripheral surface of the first inlet cam 16 while the second role 53 is positioned to be in contact with the sliding surface 50a the swing cam lever 50 get. The first and second roles 52 . 53 Both are rotatable by a coupling shaft 54 supported at the front end of the intermediate lever 44 is attached. Because the intermediate lever 44 on the pen 45 swing, swing these roles 52 . 53 along the sliding surface 50a and the peripheral surface of the first intake cam 16 while keeping a fixed distance from the pin 45 maintained.

There is also a spring seat 50b on the swing cam lever 50 formed. One end of a lost motion spring 38 is with the spring seat 50b engaged. The other end of the lost motion spring 38 is attached to a fixed part of the internal combustion engine. The dead return spring 38 is a compression spring. The of the backlash spring 38 received force pushes the sliding surface 50a the swing cam lever 50 against the second role 53 and the first role 52 against the first intake cam 16 , This positions the first and second rolls 52 . 53 so that they are between the sliding surface 50a and the peripheral surface of the first intake cam 16 are interposed.

The above-mentioned rocker arm 35 is under the swing cam lever 50 positioned. A dump roll 36 is on the rocker arm 35 so attached, that the dump roller 36 the swing cam surface 51 is facing. The dump roll 36 is rotatable on the middle part of the rocker arm 35 attached. One end of the rocker arm 35 is adjacent to a valve shaft 14a of the valve 14 and the other end of the rocker arm 35 is rotatable by a hydraulic valve lash adjuster 37 supported. When a lift operation is performed, a valve spring (not shown) pushes the valve stem 14a in a closing direction, that is, in a direction of pushing up the rocker arm 35 , The dump roll 36 is against the swing cam surface 51 the swing cam lever 50 by the force of the valve spring and by the hydraulic valve lash adjuster 37 pressed.

According to the structure of the above-described adjustable valve mechanism 40 becomes the pressing force of the first intake cam 16 about the first and the second role 52 . 53 to the sliding surface 50a transferred when the first intake cam 16 rotates. If this is the contact point between the swing cam surface 51 and the tipper 36 from the non-actuating surface 51a to the actuating surface 51b moves, the rocker arm 35 pressed down to the valve 14 to open.

Further, when the rotational position of the control shaft 41 changes, the structure of the adjustable valve mechanism changes 40 the position of the second roll 53 on the sliding surface 50a , whereby the swinging range of the swing cam lever 50 is changed for a stroke movement. More precisely, when the control shaft 41 in 3 rotates counterclockwise, the position of the second roller moves 53 on the sliding surface 50a to the front end of the swing cam lever 50 out. The angle of rotation of the swing cam lever 50 between the position where the swing cam lever 50 a swinging motion upon receiving a pressing force from the first intake cam 16 starts, and the position at which the rocker arm 35 actually begins to be depressed, then increases when the control shaft 41 in 3 turns counterclockwise. In other words, the working angle and the lift amount of the valve can be 14 by turning the control shaft 41 in counterclockwise direction in 3 be reduced. In contrast, a rotation of the control shaft increases 41 clockwise the working angle and the stroke amount of the valve 14 ,

As described above, the variable valve mechanism adjusts 40 according to the embodiment both the working angle, as well as the lifting amount of the valve 14 , In this document, the operation angle and the lift amount are collectively referred to as a "valve opening amount". It should be noted, however, that the variable valve mechanism according to the invention may alternatively be configured to adjust either the working angle or the amount of lift.

(2) Detailed structure of a fixed one valve mechanism

The structure of the fixed valve mechanism 70 will now be detailed with reference to the 2 and 4 described. 4 FIG. 11 is an exploded perspective view illustrating the variable valve mechanism. FIG 40 and a fixed valve mechanism 70 who in 2 shown shows.

As it is in 2 is shown is the fixed valve mechanism 70 between the second intake cam 17 and the second swing cam lever 50R positioned. The fixed valve mechanism 70 coordinates the swinging motion of the second swing cam lever 50R to the rotational movement of the second intake cam 17 , The fixed valve mechanism 70 has a big lift lever 71 passing through the second intake cam 17 is driven, and a lever coupling mechanism 72 (please refer 4 ), the big lifting lever 71 with the second swing cam lever 50R coupled. The lever coupling mechanism 72 has a switching pin 74 , a hydraulic chamber 75 , a pin hole 76 , a return spring 77 and a piston 78 which will be described later.

The big lift lever 71 who is at the control shaft 41 is mounted and near the second rocker cam lever 50R is positioned independently of the second swing cam lever 50R swing. An input role 73 in contact with the peripheral surface of the second inlet cam 17 comes is through the big stroke lever 71 rotatably supported.

As it is in 4 shown is a spring seat 71a on the big lift lever 71 educated. As with the above-mentioned swing cam lever 50 the case is a lost motion spring (not shown) with the spring seat 71a engaged. The force of the backlash spring presses the input roller 73 against the peripheral surface of the second inlet cam 17 ,

The big lift lever 71 has the switching pin 74 in the swing cam lever 50R introduced and pulled out of this. The big lift lever 71 is with the hydraulic chamber 75 provided with an opening leading to the second swing cam lever 50R is positioned. The switching pin 74 is in the hydraulic chamber 75 fit. The hydraulic chamber 75 is connected to a hydraulic system which will be described later. When the hydraulic system is the hydraulic pressure in the hydraulic chamber 75 increases, the resul pushes ting hydraulic pressure the Umschaltstift 74 from the hydraulic chamber 75 and to the second swing cam lever 50R out.

Meanwhile, the second swing cam lever 50R with the pin hole 76 provided having an opening leading to the Großhubhebel 71 is positioned. The switching pin 74 and the pin hole 76 are from the middle of the control shaft 41 equidistant away. From bottom to top are the items in the pin hole 76 are placed, the return spring 77 and the piston 78 which serves as a lifting device.

5 is a schematic representation showing the structure of the hydraulic system for actuating the switching pin 74 represents. As it is in 5 shown is an oil route 81 in the control shaft 41 educated. The oil route 81 is with the hydraulic chamber 75 , a sliding gap between the control shaft 41 and the big-lift lever 71 , and a sliding gap between the control shaft 41 and the second swing cam lever 50R connected. The oil route 81 is also with a pump 82 connected. A delivery route 83 is with the middle of the oil route 81 connected. The delivery route 83 is at the exhaust valve 84 intended. Further, a throttle 85 downstream of the exhaust valve 84 in the delivery route 83 built-in.

Through the pump 82 For example, pressurized lubricating oil becomes the protruding sliding gaps through the oil path 81 fed. Part of the lubricating oil that is in the oil path 81 flows, becomes the hydraulic chamber 75 fed. Therefore, the hydraulic pressure in the hydraulic chamber 75 increase. Meanwhile leaves an opening of the exhaust valve 84 the lubricating oil from the discharge path 83 out. This reduces the hydraulic pressure in the hydraulic chamber 75 , The switching pin 74 can by controlling the hydraulic pressure in the hydraulic chamber 75 be operated.

[Features of First Embodiment]

(Individual valve actuation control mode)

The big lift lever 71 swings constantly when passing through the second intake cam 17 is driven. However, during the base circle of the second intake cam 17 in contact with the input role 73 is, is the big lift lever 71 temporarily stationary. The second swing cam lever 50R also resonates when passing through the first intake cam 16 is driven. However, during the base circle of the first intake cam 16 in contact with the first roll 52 is, is the second swing cam lever 50R temporarily stationary. The periods during which the big-lift lever 71 and the second swing cam lever 50R are stationary, overlapping each other. In other words, there is a period of time during which the high-lift lever 71 and the second swing cam lever 50R are stationary at the same time.

The angle of the second swing cam lever 50R in the above steady state varies with the rotational position of the control shaft 41 , Therefore, there is a rotational position of the control shaft 41 in which the switching pin 74 with the pin hole 76 is aligned while the big lift lever 71 and the second swing cam lever 50R are stationary. This rotational position of the control shaft 41 hereinafter referred to as the "pin switching position." In the valve mechanism 18 is the pin hole 76 after the switching pin 74 aligned when the rotational position of the control shaft 41 matches the pin switch position. In this state, therefore, the Hebelkoppiungsmechanismus 72 perform a switching operation as described below.

If the pin hole 76 with the switching pin 74 is aligned, the switch pin is adjacent 74 to the piston 78 at. When in this condition the hydraulic pressure in the hydraulic chamber 75 to press the switchover pin 74 applied force is greater than the force caused by the return spring 77 to push the piston 78 is exercised, the switching pin occurs 74 into the pin hole 76 one to the piston 78 all the way into the pin hole 76 to press. In other words, the switching pin 74 into the pin hole 76 by allowing the hydraulic system to control the hydraulic pressure in the hydraulic chamber 75 elevated. When the switching pin 74 into the pin hole 76 is introduced, is the second swing cam lever 50R to the high-lift lever 71 coupled. The coordination target for the lifting movement of the second inlet valve 14R then changes from the adjustable valve mechanism 20R to the fixed valve mechanism 70 ,

In the above case, the rotational movement of the intake camshaft 15 from the second intake cam 17 to the second swing cam lever 50R over the big lift lever 71 transfer. The valve opening amount of the second intake valve 14R becomes mechanically through the shapes of the second inlet cam 17 , the big-lift lever 71 and the second swing cam lever 50R and determines the positional relationship between them. It is constantly fixed as predetermined (to provide a large stroke and a large working angle) regardless of the rotational position of the control shaft 41 , Meanwhile, the first one transfers intake cams 16 the rotational movement of the first intake cam 16 to the first swing cam lever 50L about the first and the second role 52 . 53L , As a result, the valve opening amount of the first intake valve varies 14L with the rotational position of the control shaft 41 ,

This document states a condition the valve opening amount of the first intake valve 14L with the rotational position of the control shaft 41 varies while the valve opening amount of the second intake valve 14R is large as described above as the "single valve displacement control mode." In this single valve displacement control mode, it is possible to use the second intake valve 14R with a large lift and the first inlet valve 14L to provide with a small stroke. This causes through the second inlet valve 14R a large amount of air flows into the cylinder and that through the first inlet valve 14L a small amount of air flows into the cylinder. Since the air flow rates differ as mentioned above, a swirling flow can be generated inside the cylinder. Generating the swirl flow provides for combustion improvement in a low speed / low load range.

(Dual valve variable control)

The switching pin 74 can from the pin hole 76 by reducing the hydraulic pressure in the hydraulic chamber 75 be pulled out when the pin hole 76 with the switching pin 74 is aligned. The big lift lever 71 is then from the second swing cam lever 50R decoupled. As a result, the coordination target for the lifting movement of the second intake valve 14R from the fixed valve mechanism 70 to the adjustable valve mechanism 20R be changed.

In the above case, the rotational movement of the camshaft 15 from the first intake cam 16 to the sliding surfaces 50a from the first and second swing cam levers 50L . 50R about the first and the second role 52 . 53 transfer. Therefore, the valve opening amounts of the first and second intake valves vary 14L . 14R both in accordance with the rotation of the control shaft 41 , Thus, the valve opening amounts of the first and second intake valves 14L . 14R both in accordance with the rotational position of the control shaft 41 be changed. In this document, a state in which the valve opening amounts of the first and second intake valves 14L . 14R both are adjustable as described above, referred to as the "dual valve timing control mode".

The ECU 60 switches between the dual valve timing control mode and the single valve timing control mode in accordance with the operating state (more specifically, the engine speed NE and a load) of the internal combustion engine 1 around. 6 shows a switching map that in the ECU 60 is stored and used to switch between the dual valve timing control mode and the single valve timing control mode. This switching map shows an operating range of the internal combustion engine 1 by indicating the engine speed NE along the horizontal axis and the load along the vertical axis.

Here, the term "load" indicates an engine torque, a load rate, an accelerator opening AA, or another index, that of the load on the internal combustion engine 1 equivalent. The ECU 60 may calculate the value of the load in accordance with outputs from the accelerator opening sensor 24 , an air flow meter 26 and the like. Furthermore, the ECU 60 calculate the engine speed NE in accordance with an output obtained from the crank angle sensor 6 is produced. In this way, the ECU 60 the current operating state of the internal combustion engine 1 determine with reference to the switching map.

In 6 A switch pin operation line P represents a boundary for switching between the dual and single valve timing control modes. Two circuits positioned side by side constitute the first and second intake valves 14L . 14R and the words within the circles indicate whether the valve opening amount is large or small.

As it is in 6 1, an area having a lower engine speed and a lower load than the switch pin operation line P is a range of the single valve displacement control mode. In the embodiment, this area is referred to as the "single valve small lift area." The single valve small lift area provides a coupled state in which the switchover pin 74 the lever coupling mechanism 72 into the pin hole 76 is introduced.

On the other hand, an area having a higher engine speed and a higher load than the switch pin operation line P is a range of the dual valve timing control mode. In the embodiment, this range is referred to as the "dual valve full lift range." The dual valve full lift range provides an uncoupled condition in which the switch pin 74 the lever coupling mechanism 72 from the pin hole 76 pulled out.

The ECU 60 typically switches between the single and dual valve timing control modes in accordance with the shift map described above. Generally, unstable and incomplete combustion tends to result in low engine speed / low load range. However, the embodiment may be a twist for combustion combustion generate by the second inlet valve 14R with a big stroke and the first intake valve 14L with a small stroke in the single-valve small lift range corresponding to a low engine speed / low load range. This makes it possible to reduce fuel consumption and exhaust emissions. On the other hand, in the dual-valve full-lift range corresponding to a high engine speed / high-load range, the embodiment can introduce an appropriate amount of air into the cylinder by both intake valves 14 be provided with a large stroke.

When the operating condition of the internal combustion engine 1 changes from the single valve small lift range to the dual valve high lift range, the ECU switches 60 usually in the dual valve timing control mode by switching the switching pin 74 without a delay from the pin hole 76 pulls out. However, it is conceivable that the ECU 60 returns to the one-valve small-lift range within a short period of time depending on the state even when the operating state is changed from the single-valve small-lift range to the dual-valve large-lift range.

The above situation may occur when, for example, the vehicle accelerates after it has started to move. Before the vehicle starts to move, the internal combustion engine is located 1 idle, as indicated by a point A in 6 is specified. When the vehicle accelerates after starting in a first gear, the operating state changes from point A to point B in FIG 6 and then from point B to point C. Subsequently, an accelerator pedal is released, disengaging a clutch to shift to second gear. Because this is the internal combustion engine 1 causes to return to an idling state, the operating state changes from point C to point A.

Upshifting to a third gear and then to a fourth gear has the same changes as described above. In other words, when the vehicle accelerates after it has started to move, the operating state of the internal combustion engine changes 1 from point A to point B, point C and then back to point A in 6 , within a relatively short period of time. If, in such a case, the lever coupling mechanism 72 a switching operation in accordance with the in 6 immediately executes the switching map shown, the switching pin 74 from the pin hole 76 pulled out when the operating state changes from point B to point C, and then back into the pin hole 76 introduced when the operating state changes from point C to point A. This means that the dual valve timing control mode is maintained for an extremely short period of time as the operating state changes from point B through point C to point A. Therefore, switching to the dual valve timing control mode does not provide a significant advantage. Instead, such switching is a significant drawback. More specifically, frequent insertion / removal of the switching pin 74 premature wear and scratching of the switchover pin 74 and the pin hole 76 cause. As a result, the embodiment performs a switching operation for the switching pin 74 in the above situation taking into consideration durability of the lever coupling mechanism 72 not from.

The above switching operation, which should be avoided, takes place due to the gear shift by the transmission. Therefore, the embodiment identifies and avoids a shift operation caused by gear shifting by preliminarily suppressing the shifting action of the lever coupling mechanism 72 during a predetermined period of time after a gear change by the transmission.

When the above process is performed, a shifting operation that is not absolutely necessary can be identified and avoided, not only when the vehicle accelerates after the start of a movement, but also in the following situation. The points D to K in 7 indicate operational state changes that occur when the vehicle starts to climb a mountain during a high-speed drive. In this situation, the operating state of the internal combustion engine changes 1 as described below. When the vehicle starts to climb, the vehicle speed gradually decreases due to the gradient resistance, whereby the engine speed NE gradually decreases (point D to point E). A driver of the vehicle then shuts down for the purpose of restoring the previous speed. When the accelerator pedal is released and the clutch is disengaged for downshifting, the engine changes 1 to an idle state (point E to point F). When the accelerator pedal is depressed after a downshift, the engine changes 1 to a high speed / high load state (point F to point E). When acceleration continues, the engine speed NE (point G to point H) increases. When the vehicle speed is adequately restored, the driver turns on. When the accelerator pedal is released and the clutch is disengaged to upshift, the engine changes 1 towards idle state (point H to point I). After an upshift, the machine spin falls count NE below a level that prevailed before an upshift (point I to point J). Stationary operation then takes place in the newly selected gear (point J to point K).

If, in the above situation, the lever coupling mechanism 72 a switching operation in accordance with the in 7 Immediately executes the switching map shown, the switching pin 74 from the pin hole 76 pulled out when the operating state of point F changes to point G, and after a short time, the switching pin 74 into the pin hole 76 reintroduced when the operating state changes from point H to point I. Also in this case, the dual valve timing control mode persists for an extremely short period of time. Therefore, switching to the dual valve timing control mode does not provide a significant advantage. Instead, such a switch constitutes a significant drawback because of premature wear of the switchover pin 74 and the pin hole 76 can cause. This means that the switching operation in the above case should also be avoided. The embodiment may refrain from performing the above switching operation that should be avoided by detecting the execution of a speed change at the point F and the switching operation of the lever coupling mechanism 72 for a predetermined period of time after detection overrides.

[Details of a process by the first embodiment is executed]

8th is a flowchart illustrating a routine that the ECU 60 according to the embodiment, to realize the above functionality. It is assumed that this routine is executed periodically at predetermined time intervals. First, the leads in 8th shown routine step 100 to judge whether a gear change is performed by the transmission. The shift position sensor 62 detects whether a gear change is performed. If the judgment result in step 100 is received, indicates that no gear change is performed, the routine does not perform the following processing steps, because it is not necessary, the switching operation of the lever coupling mechanism 72 override. In this case, a normal control is continuously applied to immediately switch between the single and the dual valve timing control modes in accordance with the switching map.

If that in step 100 obtained judgment result indicates that a gear change is performed, step follows 102 to judge whether the operating condition of the internal combustion engine 1 has changed from the Einzelventilkleinhubbereich in the Dualventilgroßhubbereich within a predetermined period of time after the gear change. For example, the predetermined period of time is based on information obtained by examining the time required for a change from point B to point C to point A in FIG 6 and a change from point F to point G, point H to point I in FIG 7 is necessary, and will be in the ECU 60 saved.

If that in step 102 If the judgment result obtained does not indicate a change from the single valve small lift range to the dual valve full lift range, it means that the lever coupling mechanism 72 is not instructed to perform a switching operation. In this case, it is not necessary to suppress the switching operation; therefore, the routine continuously executes normal control without performing the following process steps.

If, on the other hand, in step 102 becomes the result of judgment indicating a change from the one-valve small-lift range in the dual-valve full-lift range becomes step 104 performed to the switching operation of the lever coupling mechanism 72 to suppress. In other words, the routine omits to switch to the dual valve timing control mode with the switch pin 74 into the pin hole 76 is introduced, although the operating condition of the internal combustion engine 1 has switched to the Dualventilgroßhubbereich. If at step 102 a change from the single valve small lift range to the dual valve full lift range is found, this corresponds to a change from point B to point C in FIG 6 or a change from point F to point G in 7 and the operating state is expected to return to the single-valve small lift range within a short period of time. step 104 which is mentioned above is performed to avoid a switching operation in such a case.

Next comes the in 8th shown routine step 106 to judge whether a predetermined period of time has been reached by the elapsed time since an operating state change from the single valve small lift region to the dual valve high lift region. The embodiment leads step 104 to avoid switching to the dual valve timing control mode because it is expected that the operating state will return to the single valve small lift range within a short period of time. However, the operating state may remain in the dual-valve full-lift range without immediately returning to the single valve small-lift range, depending on the vehicle drive conditions and operations performed by the driver. In such a case, switching to the dual valve timing control mode should Art be made to the internal combustion engine 1 to deliver their expected performance. Therefore, when the operating state does not return to the Einzelventilkleinhubbereich when the predetermined period of time by the elapsed time since a change to the dual valve Großhubbereich in step 106 is reached, the embodiment ends the process of the routine (Back) and resumes normal control. When normal control is resumed, switching to the dual valve timing control mode is made in accordance with the shift map. It is believed that the predetermined period of time normally ranges from a few seconds to a little more than 10 seconds, though its ideal value, for example, with the type of internal combustion engine 1 and the use of the vehicle varies in which the internal combustion engine 1 is mounted.

Next comes the in 8th shown routine step 108 to judge whether the operating condition has changed to a range other than the Einzelventilkleinhubbereich and the dual valve Großhubbereich. The range other than the single valve small lift range and the dual valve full lift range is a dual valve displacement stroke range. In the dual valve displacement range, a control in the dual valve timing control mode is applied so that the lift amounts of both intake valves 14 vary between a medium lift and a small lift. The dual valve displacement range is set for the purpose of, for example, improving the effect of an engine brake when the engine 1 delayed. The range of the dual valve displacement range becomes separate from the shift map in the ECU 60 saved.

If at step 108 when it is found that the operating condition has changed to the dual valve displacement range, the routine is terminated (return) to resume normal control. When normal control is resumed, switching to the dual valve timing control mode is made in accordance with predetermined rules. The dual valve displacement range may be adjusted as required, for example, for low load driving, idling, low temperature starting, and in a cold climate, as well as for deceleration.

Next comes the in 8th shown routine step 110 to judge whether the operating state has changed back from the dual valve Großhubbereich in the Einzelventilkleinhubbereich. In this case, switching to the dual valve timing control mode by the above step 104 prevented process. In this case, when the operating state returns to the Einzelventilkleinhubbereich, no instruction is issued to switch to the Dualventilverstellsteuerungsbetriebsart; therefore, it is not necessary to suppress the switching operation. In this case, the routine (back) ends to resume normal control. When the operating state in the dual-valve large-lift region in the above step 110 remains, the routine repeats the steps 106 and following.

When the switching operation of the lever coupling mechanism 72 is not absolutely necessary, the process described above blocks such a switching operation. This allows excessive wear of the lever coupling mechanism 72 to avoid and to improve its durability.

The first embodiment described above assumes that the shift position sensor 62 detected a gear change by the transmission. However, an alternative gear shift detection method may be used. For example, a clutch sensor for detecting clutch engagement / disengagement may be used to detect a gear shift in a clutch release (in a case where a manual transmission is used). Another alternative would be to detect a gear change in accordance with the relationship between the engine speed NE and a vehicle speed. Since a vehicle speed sensor is generally installed in each vehicle, the use of a method based on the vehicle speed makes it possible to detect a gear shift without adding a new sensor.

The first embodiment, which has been described above, suppresses the switching process in a situation where the operating state of the Einzelventilkleinhubbereich in the dual valve full lift range under predefined conditions has changed. However, the invention may alternatively use the Suppress switching in a situation where the operating condition is reversed from the dual valve full lift range has changed into the single valve small lift range.

The first embodiment described above employs a valve mechanism that determines the valve opening amounts of the first and second intake valves 14L . 14R (in the dual valve timing control mode) or the valve opening amount of the first intake valve 14L (in the Einzelventilverstellsteuerungsbetriebsart) continuously adjusted. However, the invention may alternatively use a valve mechanism which reduces the above-mentioned valve opening amounts in several changes.

The first embodiment, which has been described above, assumes that the invention in an adjustable valve actuator for an intake valve is applied. However, the invention can also with an adjustable valve actuator be applied for an exhaust valve.

The The above modifications may also apply to the other embodiments which are described below.

In the first embodiment described above, the single valve small lift range corresponds to the "single valve displacement control range" according to the first aspect of the invention, and the dual valve full lift range corresponds to the "dual valve displacement control range" according to the first aspect of the invention; corresponds to the lever coupling mechanism 72 the "switching mechanism" according to the first aspect of the invention, and corresponds to ECU 60 The "normal controller" according to the first aspect of the invention is realized when the ECU 60 causes the lever coupling mechanism 72 performs a shift in accordance with the shift map; the "condition judging means" according to the first aspect of the invention is realized when the ECU 60 the steps 100 and 102 performs; the "suppression device" according to the first aspect of the invention is realized when the ECU 60 step 104 performs; and the "release device" according to the fourth aspect is realized when the ECU 60 step 106 performs.

Second embodiment

[Features of Second Embodiment]

A second embodiment of the invention will now be described with reference to FIG 9 described. However, mainly the differences between the foregoing embodiment and the second embodiment will be described, while the description of features common to these two embodiments will be omitted or such features will be briefly described. The system according to the second embodiment can be realized by using the same hardware configuration as in the first embodiment, and by the ECU 60 allows an in 9 shown routine, which will be described below.

While the vehicle is stopped, the driver can step on the accelerator pedal to the internal combustion engine 1 to perform a free acceleration operation (so-called spin up). This operation of free acceleration is rarely performed for a longer period of time. Therefore, even when the operating state changes from the single valve small lift range to the dual valve large lift range during free acceleration operation, it is anticipated that the operating state will return to the single valve small lift range within a short period of time. In view of such circumstances, even in the above case, the embodiment omits to switch to the dual valve timing control mode in order to preserve the durability of the linkage mechanism 72 to improve.

[Details of a process by the second embodiment is executed]

9 is a flowchart illustrating a routine that the ECU 60 according to the embodiment, to realize the above functionality. First, the leads in 9 shown routine step 120 in order to be in accordance with an output from the shift position sensor 62 to judge whether the transmission is switched to neutral (when a manual or automatic transmission is used) or to parking (when an automatic transmission is used). When the transmission is not switched to neutral or parking, the routine does not perform the following processing steps because free acceleration operation does not take place.

If at step 120 If it is found that the transmission is in neutral or parked, the routine will step 122 to judge whether the operating condition of the internal combustion engine 1 from the single valve small lift range to the dual valve big lift range. If that in step 122 As a result, if the result of judgment obtained indicates a change in the dual-valve full-lift range, it can be inferred that free-acceleration operation is being performed. In this case, therefore, step 124 performed to the switching operation of the lever coupling mechanism 72 to suppress. More specifically, although the operating state of the internal combustion engine 1 is changed to the dual-valve full-stroke range, the switching pin becomes 74 in the pin hole 76 to prevent switching to the dual valve timing control mode.

Next comes the in 9 shown routine step 126 to judge whether the operating condition has changed to a range other than the dual valve full lift range, that is, the single valve small lift range or the dual valve verstellhubbereich. If the obtained judgment result indicates a change to a range other than the dual-valve full-lift range, it can be concluded that the free-acceleration operation is completed. Therefore, the routine ends to resume normal control (Back). On the other hand, if the obtained judgment result does not indicate a change to a range other than the dual-valve full-swing range, it can be concluded that the free-acceleration operation is still being performed. In this case, the routine returns to step 124 and retains the suppressed switchover.

When the above process is performed, it is possible to prevent the lever coupling mechanism 72 performs an extra switching operation during a free acceleration operation, and the durability of the lever coupling mechanism 72 to increase.

Third embodiment

[Features of Third Embodiment]

A third embodiment of the invention will now be described with reference to FIG 10 described. However, the differences between the foregoing embodiments and the third embodiment will be described mainly, while the description of features common to these three embodiments will be omitted or such features will be briefly described. The third embodiment has the same hardware configuration as the first embodiment. The system according to the third embodiment can be realized by the ECU 60 is allowed, an in 10 to execute the routine described below, in addition to the process according to the first or second embodiment.

As mentioned earlier, the linkage mechanism moves 72 the switching pin 74 by using the hydraulic pressure of the lubricating oil for the internal combustion engine 1 , While the internal combustion engine 1 In operation, oil residue (a viscous material) can be generated in the lubricating oil. If by chance the switching pin 74 does not work for a longer period of time, while the oil residue around the switching pin 74 can be deposited, the switching pin 74 in the hydraulic chamber 75 or the pin hole 76 jam and become ineffective.

As described above, the first and second embodiments omit the switching operation of the lever coupling mechanism 72 in a predefined situation. This reduces the frequency with which the lever coupling mechanism 72 performs the switching operation. When the frequency of switching operation of the lever coupling mechanism 72 decreases, the switching pin tends 74 to stay in place for a prolonged period of time. As a result, it is highly likely that the switching pin 74 stuck due to the oil residues.

Therefore, when a predetermined value of the frequency with which the switching operation of the lever coupling mechanism 72 was suppressed, or the cumulative time during which the switching operation of the lever coupling mechanism 72 is suppressed, the embodiment allows the switching operation to prevent the switching pin 74 jammed.

[Details of a process by the third embodiment is carried out]

10 is a flowchart illustrating a routine that the ECU 60 according to the embodiment, to realize the above functionality. In the 10 The routine shown is used in conjunction with in 8th or 9 executed routine executed.

In the 10 shown routine leads step 130 through to the frequency, which is the switching operation of the lever coupling mechanism 72 through the in 8th or 9 has been suppressed, and to measure the cumulative time during which the switching operation of the lever coupling mechanism 72 through the in 8th or 9 routine shown was suppressed and the measured frequency and cumulative time in the ECU 60 save. The routine then takes step 132 to judge whether predetermined values were exceeded by the frequency or cumulative time, respectively. The predetermined values are based on the characteristics of the internal combustion engine 1 and the vehicle in which the internal combustion engine 1 is mounted, and are in the ECU 60 saved. These values are predetermined to ensure that the switching operation is performed before the switchover pin 74 jammed.

If that at step 132 judgment result obtained indicates that one of the predetermined values has been exceeded by the measured frequency or cumulative time, becomes step 134 to stop the control of the routine to suppress the switching operation in 8th or 9 is shown, and the normal control is resumed. While the normal control is exercised, the lever coupling mechanism performs 72 its switching operation in accordance with the switching map by.

Next is step 136 executed to judge whether the switching operation under the normal control by the lever coupling mechanism 72 was carried out. When the switching operation is actually through the lever coupling mechanism 72 has been performed, it means that the switching operation has been performed to prevent the switching pin 74 jammed. In this case, step 138 performed to prohibit the switching operation suppression control by the in 8th or 9 and to release a switching override control function. The measured frequency and cumulative time at step 130 are then reset to zero (0). In the above process, by checking whether the switching operation is actually performed by the lever coupling mechanism 72 is performed determines whether the switching operation suppression control function should be allowed. However, an alternative determination method can be used. For example, the fact as to whether the switching operation suppression control function should be allowed to be determined alternatively by checking whether the lever coupling mechanism 72 instructed to perform a switching operation.

When the above process is performed, it is possible to accurately prevent the switching pin 74 jammed due to a decrease in the frequency with which the lever coupling mechanism 72 performs a switching operation during the process according to the first or second embodiment.

In the third embodiment described above, the "measuring device" according to the fifth aspect of the invention is realized when the ECU 60 step 130 performs; and the "approval device" according to the fifth aspect of the invention is realized when the ECU 60 the steps 132 and 134 performs.

Fourth embodiment

[Features of the Fourth Embodiment]

A fourth embodiment of the invention will now be described with reference to FIG 11 described. However, the differences between the foregoing embodiments and the fourth embodiment will be described mainly, while the description of features common to these four embodiments will be omitted or such features will be briefly described. The fourth embodiment has the same hardware configuration as the first embodiment. Furthermore, the fourth embodiment basically executes the same process as the first or second embodiment.

11 shows valve lift lines from the first intake valve 14L and the second intake valve 14R , The embodiment assumes that in the dual valve timing control mode, the valve lift of the first intake valve 14L substantially equal to that of the second inlet valve 14R is. 11 shows valve lifts A to E, which are described below.

The valve lift A is the maximum valve lift in the dual valve full lift range (dual valve advance control mode). This valve lift is in accordance with maximum power requirements for the engine 1 preset.

The valve lift B prevails in a state where the rotational position of the control shaft 41 coincides with the pin switching position, that is, when the switching pin 74 with the pin hole 76 is in a line. More specifically, the valve lift B prevails during the high-lift lever 71 not to the second rocker lever 50R is coupled.

The valve lift C prevails in a state where the high-lift lever 71 to the second swing cam lever 50R is coupled so that the valve opening amount of the second intake valve 14R remains large. More specifically, the valve lift C is the valve lift of the second intake valve 14R at the single valve timing control mode.

The valve lift D is the minimum valve lift caused by the adjustable valve mechanism 40 can be adjusted. The valve lift E is the maximum valve lift caused by the adjustable valve mechanism 40 can be adjusted. In the embodiment, the valve lift A represents the upper limit of its operating range; therefore, the valve lift E is actually not used.

In the single-valve small lift range, a target valve lift is set within a range from a valve lift D to a valve lift B. In other words, the target position of the control shaft 41 in the single-valve small lift range within a range starting at the pin switching position and extending to a smaller stroke, a smaller working angle range. On the other hand, in the dual-valve full-lift range, the target valve lift is set within a range from a valve lift B to a valve lift A. In other words, the target position of the control shaft 41 in the dual-valve full-lift range, within a range from the pin switching position corresponding to the valve lift B to a position corresponding to the valve lift A occurring in a larger stroke, a range located at a larger working angle.

As described above, the upper limit of the target valve lift at the single valve small lift range is represented by the valve lift B. While the normal control is exercised, the single-valve-displacement control mode, that is, a state where the large-lift lever becomes 71 with the second swing cam lever 50R is coupled, realized in the Einzelventilkleinhubbereich. Therefore, if the valve mechanism 18 In the one-valve open control mode, control is generally applied while the area under the valve lift B is defined as the target valve lift.

Meanwhile, the first and second embodiments can suppress the function to switch from the single valve timing control mode to the dual valve timing control mode and remain in the single valve timing control mode as described above even when the operating state has changed from the single valve small lift range to the dual valve full lift range (step 104 in 8th or step 124 in 9 ). Therefore, a target valve lift larger than the valve lift B may be set while the valve mechanism 18 in the Einzelventilverstellsteuerungsbetriebsart is. In this case, the following situation occurs.

In the single valve displacement control mode, the second inlet cam drives 17 usually the big stroke lever 71 then, the second swing cam lever 50R over the switching pin 74 drives as described above. However, if the control shaft 41 beyond the pin switching position corresponding to the valve lift B, and turning to a large stroke and a wide working angle range in the Einzelventilverstellsteuerungsbetriebsart, is the area over which the first intake cam 16 the second swing cam lever 50R vibrates, larger than the area over which the second intake cam 17 the second swing cam lever 50R swings. This causes the second swing cam lever 50R the big lift lever 71 over the switching pin 74 to drive in reverse. In this case, therefore, the input role leaves 73 for the high-lift lever 71 the second intake cam 17 ,

When the engine speed NE and the load suddenly decrease in a situation where the input roller 73 for the high-lift lever 71 from the second intake cam 17 is disconnected, as described above, the control shaft rotates 41 immediately to a small stroke and an area with a small working angle. The input role 73 for the high-lift lever 73 then again in contact with the second intake cam 17 (collide), causing a noise or the surfaces of the input roller 73 and the second intake cam 17 to be damaged.

In order to avoid the above problem, the embodiment restricts the target valve lift to the valve lift B or less when switching from the single valve advance control mode to the dual valve advance control mode is inhibited (step 104 in 8th or step 124 in 9 ), that is, when the operating state in the single valve displacement control mode enters the dual valve high lift region. This prevents the control shaft 41 turns beyond the pin switching position corresponding to the valve lift B out, and to a large stroke and a large working angle portion, while the valve mechanism 18 in the Einzelventilverstellsteuerungsbetriebsart is. This makes it possible to properly prevent the input role 73 for the high-lift lever 71 the second intake cam 17 leaves. As a result, the embodiment can completely avoid noise generation and prevent the surfaces of the input roller 73 and the second intake cam 17 to be damaged.

at In the embodiment, the Anfangszielventilhub in the dual valve full lift range within a range of one Valve lift B to a valve lift A, as described above. Therefore, if the Zielventilhub on the valve lift B or smaller is limited in a situation where switching from the Single valve displacement control mode in the dual valve timing control mode is prevented, the actual Zielventilhub is on the valve lift B fixed.

There the embodiment is the same as the first one and second embodiment except for the above described here is omitted a further description.

In the fourth embodiment described above, the "valve opening amount limiting means" according to the sixth and seventh aspects of the invention is realized when the ECU 60 limits the target valve lift (target valve opening amount) to the valve lift B or smaller in a situation where switching from the single-valve advance control mode to the dual-valve advance control mode is prohibited (step 104 in 8th or step 124 in 9 ). Further, the first intake valve corresponds 16 to the "main cam" according to the seventh aspect of the invention, the second intake valve corresponds to the "sub cam" according to the seventh aspect of the invention; and the input role corresponds 73 for the high-lift lever 71 to the "counterpart part" according to the seventh aspect of the invention.

Summary

The The invention relates to an adjustable valve actuator with a switching mechanism for switching between a dual valve timing control mode and a Einzelventilverstellsteuerungsbetriebsart and increases the Durability of the switching mechanism.

at an idle state that prevails before a vehicle starts, to move is the operating state of an internal combustion engine in a single valve small lift range (point A). In this case prevails the one-valve control mode. After yourself When the vehicle begins to move, the operating state changes from point A via point B to point C and switches to one Dual valve full range around.

Subsequently, when an accelerator pedal is released and a clutch for Upshift is disengaged, the operating state returns Point A in the single-valve small lift range back. at the above situation when the operating condition for a short period of time remains in the dual valve full lift range, forms a switch to the dual valve timing control mode no significant advantage. That's why switching to the dual valve timing control mode prevents when the operating state changes from point B to point C.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - JP 2004-100555 [0008]

Claims (7)

Adjustable valve actuator With: a valve mechanism with a switching mechanism for switching between a dual valve timing control mode, in which the valve opening amounts of a first Valve and a second valve, for the same cylinder are provided and of the same kind, steadily or in several Steps are adjusted, and a Einzelventilverstellsteuerungsbetriebsart, wherein the valve opening amount of the first valve is adjusted continuously or in several steps, wherein the valve opening amount the second valve is set; a storage device for storing rules for dividing an operating area an internal combustion engine in a Dualventilverstellsteuerungsbereich, for which the dual valve timing control mode is selected and a single valve displacement control section, for which the single valve displacement control mode is selected should; a normal control means for causing the switching mechanism is a switching operation in accordance with the rules; a condition judging means for judging when the operating state of the internal combustion engine from the dual valve timing control section to the single valve timing control section or vice versa, whether a predefined condition is established is to predict that the operating state within a short Time will return to the previous area; and one Suppressing means for suppressing the Switching process when the predefined condition is established. Adjustable valve actuator according to claim 1, wherein the predefined condition indicates a condition at which a predetermined period of time has elapsed a gear change by a between the internal combustion engine and Vehicle drive wheels positioned gear has not passed is. Adjustable valve actuator according to claim 1, wherein the predefined condition indicates a condition in which one between the internal combustion engine and vehicle drive wheels positioned gearbox in neutral or parking is switched. Adjustable valve actuator according to one of claims 1 to 3, which further comprising: a release device for sharing the switching operation when the operating state of the internal combustion engine not within a predetermined period of time after switching from the dual valve timing control section to the single valve timing control section or vice versa returns to a previous area. Adjustable valve actuator according to one of claims 1 to 4, which further comprising: a measuring device for measuring the number of times the switchover is suppressed was, or the cumulative time, during the switching process was suppressed; and an approval device, the then, if a predetermined value of the frequency, with that the switching was suppressed or cumulative Time during which the switching process is suppressed was exceeded, admits that the switching mechanism performs a switching without regard to whether the predefined condition is established. Adjustable valve actuator according to one of claims 1 to 5, which further comprising: a valve opening amount limiting device for Limit a target valve opening amount when the switching operation suppressed by the suppression device becomes. Adjustable valve actuator according to claim 6, the valve mechanism a main cam, which in the Dualventilverstellsteuerungsbetriebsart both the first valve and the second valve drives and at the Einzelventilverstellsteuerungsbetriebsart drives only the first valve; and a minor cam that is in the Einzelventilverstellsteuerungsbetriebsart the second valve is driving; and wherein the valve opening amount limiting means limits the target valve opening amount to prevent that the secondary cam leaves a counter component of the secondary cam, when the suppression means switching from the Einzelventilverstellsteuerungsbetriebsart in the dual valve timing control mode is suppressed to maintain the single valve displacement control mode.