DE60215077T2 - Control device and method for variable valve control and lifting device - Google Patents

Description

Subject the invention

The The invention relates to a control device and to a control method a variable valve event and lift (VEL) mechanism for continuously changing one Valve movement and a valve lift amount of a motor valve by a Control shaft of the VEL mechanism is rotated by a motor.

To the invention related art

The above VEL mechanism is in the JP 2001 003773 disclosed.

Of the VEL mechanism is with a control shaft, which is essentially parallel is arranged to a camshaft, a control cam, which is substantially attached to a periphery of the control shaft, a rocker arm, which is carried axially by the control cam so as to be able to be swinging, a connecting arm and an eccentric one Cams that run around one end of the rocker arm depending on pivoting a rotation of the camshaft, a pivoting cam, the connected to the other end of the lever arm and so pivots, to open an engine valve, and a DC servo motor which rotates the control shaft.

In This VEL mechanism becomes a valve movement and a valve lift amount successively by changing a rotation angle of the control shaft by the DC servo motor varies.

In such a conventional one VEL mechanism becomes a detection signal from an angle sensor via a Wiring harness is input to a motor control unit with detection signals from Sensors that detect engine operating conditions, and a fuel injection and ignition timing a motor controls.

In the engine control unit becomes a target rotation angle of the control shaft is calculated, and at the same time, a feedback control signal based on a deviation between a fact neuter turning angle and the Target rotation angle of the control shaft calculated so that the calculated Feedback control signal is output to the DC servo motor.

Indeed is it, according to such a structure, likely that the noise from the wiring harness and the detection signal from the angle sensor influence each other.

As a result, becomes the detection accuracy of the rotation angle due to the noise deteriorates and it is hard to exactly the rotation angle of the control shaft and also becomes a calculation load of the control unit elevated.

Summary the invention

in the In view of the above problems, the present invention has a task, a control device and a control method of a VEL mechanism to create that are able to function in terms of a resistance against To improve noise of a rotation angle detection signal and also to reduce a calculation load of an engine control unit.

Around to solve the above problem will, according to the present Invention, a VEL control unit is provided which is integral with one Angle sensor is equipped, and the VEL control unit calculated a control signal of an engine based on a detection signal from the angle sensor.

Other Objects and features of this invention will become apparent from the following Description will be understood with reference to the accompanying drawings.

Short explanation the drawings

1 shows a cross-sectional view illustrating a VEL mechanism (cross-sectional view AA of 2 ).

2 shows a side elevational view of the VEL mechanism.

3 shows a top plan view of the VEL mechanism.

4 shows a perspective view illustrating an eccentric cam for use in the VEL mechanism.

5A and 5B 12 are cross-sectional views illustrating an operation of the VEL mechanism under a low speed and low load state of an engine (cross sectional view BB of FIG 2 ).

6A and 6B 12 are cross-sectional views illustrating an operation of the VEL mechanism under a high-speed and high-load condition of the engine (cross-sectional view BB of FIG 2 ).

7 FIG. 12 is a diagram showing the valve lift characteristic corresponding to a cam surface of a swing cam in the VEL mechanism. FIG.

8th shows a diagram in a block diagram of a control device of the VEL mechanism.

9 shows a characteristic diagram illustrating a valve timing and a valve lift of the VEL mechanism.

detailed Description of the preferred embodiment

1 to 3 illustrate a variable valve lift (VEL) mechanism that sequentially varies an amount of valve lift and valve movement of each of two intake valves as engine valves provided for a cylinder ,

Of the VEL mechanism can be designed to use exhaust valves, such as the Engine valves, to move.

A VEL mechanism 100 who in 1 to 3 1, a pair includes intake valves 12 . 12 , a hollow camshaft 13 rotatable by a cam bearing 14 a cylinder head 11 worn, two eccentric cams 15 . 15 as a rotary cam, axially through the camshaft 13 are worn, a control shaft 16 rotatable by the same cam bearing 14 at an upper position of the camshaft 13 is worn, a pair of rocker arms 18 . 18 , which are pivotable by the control shaft 16 over a camshaft 17 are worn, and a pair of independent swing cams 20 . 20 located at upper portions of the inlet valve 12 . 12 each via valve tappets 19 . 19 , are arranged.

The eccentric cams 15 . 15 are each with the rocker arms 18 . 18 by connecting arms 25 . 25 connected. The rocker arms 18 . 18 are with the swivel cams 20 . 20 through fasteners 26 . 26 connected.

Each eccentric cam 15 as he is in 4 is formed in a substantially annular shape and comprises a cam body 15a with a small diameter, a flange area 15b integral with an outer surface of the cam body 15a is formed. A camshaft insertion hole 15c is formed by the inside of the eccentric cam in an axial direction, and also is a center axis X of the cam body 15a from a center axis Y of the camshaft 13 biased by a predetermined amount.

The eccentric cam 15 . 15 becomes on both outer sides of the camshaft 13 over the camshaft insertion hole 13c at positions that are not the valve lifters 19 . 19 disturb, pressed and fastened.

Each rocker arm 18 is how in 3 is bent and formed in a substantially crank shape and formed, and a central base portion 18a of which is rotatable by the control cam 17 held.

A pin hole 18d is through an end area 18b formed to be formed from an outer end portion of the base portion 18a preside. A pen 21 that with a pointed area of the connecting arm 25 is to be connected, is in a pin hole 18d pressed. A pin hole 18e is through the outer end area 18c formed to be formed from an inner end portion of the base portion 18a preside. A pen 28 that has an end area 26a (which will be described later) of each connector 26 is to be connected, is in the pin hole 18e pressed.

The control cam 17 is formed in a cylindrical shape and on a circumference of the control shaft 16 attached. As in 1 is a position P1 of the center axis of the control cam 17 to a position P2 of a center axis of the control shaft 16 biased by α.

The swing cam 20 is formed in a substantially lateral U-shape as shown in FIG 1 . 5 and 6 is shown, and a carrying hole 22a is through a substantially annular base end region 22 educated. The camshaft 13 is in the base end region 22 so used to be rotatable. Also is a pin hole 23a through an end area 23 , positioned at the other end area 18c of the rocker arm 18 , educated.

A circular base area 24a one side of a base end region 22 and a cam surface 24b extending in an arcuate shape from the circular base surface 24a to an edge of an end region 23 extends are on a bottom surface of a swing cam 20 educated. The circular base area 24a and the cam surface 24b stand with a predetermined position of an upper one. Surface of each valve lifter 19 , corresponding to a pivot position of the swing cam 20 , in contact.

A predetermined angular range θ1 of the circular base surface 24a is, in accordance with a valve lift characteristic, the in 7 is shown as in 1 is shown, a base circle interval, and a range from the base circle interval θ1 of the cam surface 24b to a predetermined angular range θ2 is a so-called ramp interval, and a range from the ramping interval θ2 of the cam surface 24b at a given time th angle range θ3 is a lift interval.

The connecting arm 25 includes an annular base area 25a and a projection end 25b protruding at a predetermined position of an outer surface of the base portion 25a is formed. A mounting hole 25c pivotally connected to an outer surface of the cam body 15a eccentric cam 15 fitted, is at a central position of the base portion 25a educated. Also is a pin hole 25b into which a pen 21 is inserted through the projection end 25b formed through.

A pivot drive element is out of the link arm 25 and the eccentric cam 15 composed.

The connecting element 26 is formed in a linear shape of a predetermined length and pin insertion holes 26c . 26d are through both circular end regions 26a . 26b formed through. End portions of the pins 28 . 29 in the pin hole 18d the outer Endbe rich 18c of the rocker arm 18 are pressed into it, and a pin hole 23a an end region 23 of the swing cam 20 are each rotatable in pin insertion holes 26c . 26d used.

Snap rings 30 . 31 . 32 that causes an axial displacement of the connecting arm 25 and the connecting element 26 limit, are at respective end portions of the pins 21 . 28 . 29 arranged.

The control shaft 16 is driven so as to be within a predetermined angular range by a DC servomotor 101 which is disposed at an end portion thereof.

The DC servo motor 101 as he is in 8th is represented by a control signal from a VEL control unit (VEL-C / U) 102 controlled.

A rotation of a rotary shaft of the DC servo motor 101 is via a speed reduction mechanism 103 on the control shaft 16 transfer.

The VEL control unit 102 is integral with an angle sensor 104 provided that a rotation angle of the control shaft 16 detected in a contactless manner, and is in the vicinity of the control shaft 16 arranged.

An optical angle sensor or a magnetic angle sensor may be used for the angle sensor 104 be used by the non-contact type.

The VEL control unit 102 receives a target rotation angle signal from an engine control unit (ECU) 105 and supplies a control signal to the DC servo motor via a feedback control 101 to, so an actual angle of rotation, detected by the angle sensor 104 to match with a target rotation angle.

Because the angle sensor 104 integral to the VEL control unit 102 is arranged, there is a small possibility of interference by noise, until the detection signal of the angle sensor 104 at the VEL control unit 102 is read.

Accordingly, it is avoided that the detection accuracy of a rotation angle is deteriorated due to an influence of noise of the angle detection signal, thereby enabling the rotation angle of the control shaft 16 to control with high accuracy.

When the feedback control of the control signal at the VEL control unit 102 is performed, a calculation load of the engine control unit 105 reduced compared to the case where such a calculation on the engine control unit 105 is carried out.

The VEL control unit 102 also performs a fault diagnosis of the VEL mechanism 100 and outputs the diagnosis result to the engine control unit 105 out.

In the fault diagnosis it is judged that the VEL mechanism 100 works incorrectly when the rotation angle of the control shaft 16 can not be brought in accordance with the target angle by the feedback control.

The engine control unit 105 , which has received an error judgment signal, forcibly sets the target angle to the VEL control unit 102 is output to a predetermined value and also performs failsafe processing of turning on a warning lamp 106 by.

The engine control unit 105 receives detection signals from an engine operating condition sensor 108 , which is a crankshaft sensor that measures an angle of a crankshaft of an engine 107 detects an air flow meter, which is an intake air quantity of the engine 107 detected, and the like.

Based on the detection signals from the engine operating condition sensor 108 calculates the engine control unit 105 the target rotation angle to a signal of the target rotation angle to the VEL control unit 102 via a CAN (Controller Area Network) communication, and also receives a signal about the fault diagnosis result from the VEL control unit 102 via the CAN-Kom communication.

The engine control unit 105 calculates a fuel injection pulse signal based on various detection signals to apply this fuel injection pulse signal to an injector of the engine 107 and calculates an ignition control signal to apply this ignition control signal to a power transistor connected to a spark plug of the engine 107 is arranged to spend.

An operation of the VEL mechanism 100 is described below.

At a time of low speed and low load of the engine, the target angle of the control shaft becomes 16 corresponding to an opening characteristic having a required value under such a state of the VEL control unit 102 from the engine control unit 105 output and the DC servo motor 101 is driven to, due to the control signal from the VEL control unit 102 to turn in one direction.

As a result, the center axis P1 of the control cam becomes 17 like this in the 5A and 5B is shown at a rotational position of an upper left side of the center axis P2 of a control shaft 16 kept and a thick area 17a of the control cam 17 moves in the upper direction of the camshaft 13 path.

Accordingly, the entire rocker arm moves 18 upwards relative to the camshaft 13 and as a result, the end region becomes 13 every swing cam 20 Forced a little over the connector 26 raised and the entire swing cam 20 turns in the left direction.

Therefore, as in 5A and 5B is shown when the eccentric cam 15 so turns to an end area 18b of the rocker arm 18 over the connecting arm 25 to push up, a lifting amount on the swing cam 20 and the valve key 19 over the connecting element 26 However, the lifting amount L1 becomes relatively smaller as shown in FIG 5B is shown.

As a result, under such a low-speed, low-load condition, the amount of valve lift as indicated by a dotted line becomes 9 is shown smaller, as well as the opening timing of each intake valve is delayed (a valve movement becomes smaller). As a result, the valve overlap between the intake valve and the exhaust valve becomes smaller.

On the other hand, when the state is shifted to a high-speed, high-load state, the target angle of the control shaft becomes 16 corresponding to the required valve opening characteristic under such a condition to the VEL control unit 102 from the engine control unit 105 output and the DC servo motor 101 is controlled by the control signal from the VEL control unit 102 so driven to turn in the opposite direction.

Accordingly, as in 6A and 6B is shown, the control shaft 16 the control cam 17 in a clockwise direction from a position in 5 is shown, and moves the center axis P1 (thick area 17a ) downward.

Therefore, the entire rocker arm moves 18 in the direction of the camshaft 13 (downward). The other end area 18c pushes the end area 23 of the swing cam 20 down over the connecting element 26 to the entire swing cam 20 to turn in the clockwise direction by a predetermined amount.

Accordingly, the contact position of a lower surface of the swing cam moves 20 to the upper surface of the valve lifter 19 in the direction of the left position, as in 6A and 6B represents is.

As a result, when the eccentric cam 15 so turns to an end area 18b of the rocker arm 18 over the connecting arm 25 to push, the lifting amount L2 of the valve lifter 19 bigger, like this 6B is shown.

As a result, under such a high-speed and high-load condition, the cam-lifting characteristic is increased as compared with that under a low-speed, low-load condition, and as indicated by the solid line in FIG 9 is shown, the amount of valve lift (valve movement) is also increased, as well as an opening timing of each intake valve is advanced and a closing time thereof is delayed.

While only selected embodiments selected to illustrate the present invention will be apparent to those skilled in the art in the relevant field from this description be that different changes and Modifications can be made in it, without the scope of protection of the invention as defined in the appended claims.

Furthermore, the foregoing description of the embodiments according to the invention is provided for illustration only, and not for the purpose of Invention as defined in the appended claims and their equivalents.

Claims (17)

A variable valve event and lift (VEL) mechanism of an engine for rotating a control shaft by an engine to continuously change a valve movement and a valve lift amount of engine valves, comprising: an angle sensor detecting a rotation angle of the control shaft; and a VEL control unit that receives a detection signal from the angle sensor and calculates a control signal of the motor based on the detection signal to output the control signal to the motor; the device being characterized in that the VEL control unit is integral with the angle sensor. Control device of a VEL mechanism after addressing 1, wherein the VEL mechanism comprises: a control cam, which is mounted eccentrically on a circumference of the control shaft; one Rocker arm, which is supported by the control cam axially so that he can pan a swivel drive element that drives that there is an end portion of the rocker arm in response to rotation the engine is panning; and a swing cam, the one with the other End of the rocker arm is connected and pivots to the engine valves to open and close. Control device of a VEL mechanism according to claim 1, wherein the angle sensor is a sensor which determines the angle of rotation the control shaft detected contactless. Control device of a VEL mechanism according to claim 1, the VEL control unit having the feedback control signal so controls that the angle of rotation detected by the angle sensor Control shaft coincides with a desired rotation angle of the control shaft. Control device of a VEL mechanism according to claim 4, further comprising: an operating condition sensor, detects an engine operating condition; and an engine control unit, receiving a detection signal from the operating condition sensor and a target rotation angle signal of the control shaft based on the detection signal calculated to the desired rotation angle signal to the VEL control unit issue. Control device of a VEL mechanism according to claim 5, the VEL control unit does a fault diagnosis of the VEL mechanism performs and outputs a result of the fault diagnosis to the engine control unit. Control device of a VEL mechanism according to claim 6 wherein the engine control unit, the desired rotational angle signal of Control shaft, which is to be output to the VEL control unit, to one previously set value fixed when the engine control unit Error detection signal of the VEL mechanism received. Control device of a VEL mechanism according to claim 5, wherein the VEL control unit receives a signal passing through the Angle sensor detected angle of rotation of the control shaft indicates to the Engine control unit outputs. Control device of a VEL (variable valve event and lift) mechanism of a motor for rotating a control shaft by an engine to a valve movement and a valve lift amount of engine valves, comprising: one Angle sensor that detects a rotation angle of the control shaft: one Operating condition sensor detecting an engine operating condition: a A motor control unit that receives a detection signal from the operating condition sensor receives; and a VEL control unit which receives a detection signal from the Angle sensor receives and is able to communicate with the engine control unit in which the device is characterized in that the engine control unit calculates a target rotational angle signal of the control shaft to the target rotational angle signal to output to the VEL control unit, and the VEL control unit is integrally provided with the angle sensor; the engine with feedback so controls that the angle of rotation detected by the angle sensor with a desired rotation angle of the control shaft coincides; and a Error diagnosis of the VEL mechanism performs and a signal that a Result of the fault diagnosis indicates, as well as a signal, which by the indicates the angle detected by the angle sensor of the control shaft the engine control unit outputs. A method of controlling a VEL (Variable Valve Event and Lift) mechanism of an engine for rotating a control shaft with an engine to continuously control valve movement and valve lift amount of engine valves, wherein a rotation angle of the control shaft is detected by an angle sensor, and a control signal of the engine based on a Erfas is calculated by a VEL control unit, wherein the method is characterized in that a detection signal is output from the angle sensor to the VEL control unit, which is integral with the angle sensor. Control method of a VEL mechanism according to claim 10 wherein the VEL mechanism comprises: a control cam, which is mounted eccentrically on a circumference of the control shaft; one Rocker arm, which is supported by the control cam axially so that he can be panned; a pivotal drive element that so it drives an end section of the rocker arm in response to Rotation of the motor pivots; and a gift token with connected to the other end of the rocker arm and pivots to the To open engine valves and close. Control method of a VEL mechanism according to claim 10 wherein the angle sensor is a sensor which determines the angle of rotation the control shaft detected contactless. Control method of a VEL mechanism according to claim 10 the VEL control unit having the feedback control signal so controls that the angle of rotation detected by the angle sensor Control shaft coincides with a desired rotation angle of the control shaft. Control method of a VEL mechanism according to claim 13 wherein a detection signal of an engine operating condition output from an operating condition sensor to a motor control unit becomes, a target rotational angle signal of the control shaft based on the Detection signal of the engine operating condition by the engine control unit is calculated, and the desired angle of rotation by the engine control unit is output to the VEL control unit. Control method of a VEL mechanism according to claim 14 the VEL control unit does a fault diagnosis of the VEL mechanism performs, and the VEL control unit displays a result of the fault diagnosis the engine control unit outputs. Control method of a VEL mechanism according to claim 15 wherein the engine control unit is the target rotational angle signal of the control shaft to be output to the VEL control unit Fixed a previously set value when the error of the VEL mechanism is detected. Control method of a VEL mechanism according to claim 14 wherein the VEL control unit receives a signal passing through the Angle sensor detected angle of rotation of the control shaft indicates to the Engine control unit outputs