JPH09291806A - Intake/exhaust valve drive controller of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent hitting sound of an operating mechanism as well as to sufficiently drawn performance of an engine by improving accuracy of the maximum rotational position of a control shaft. SOLUTION: An intake/exhaust valve drive controller is provided with a control mechanism for variably controlling the operation angle of an intake valve by changing the relative angular velocity between a driving shaft 1 and a cam shaft 2 through a process of being coaxially or eccentrically moved in relation to an axis of the driving shaft 1, and an operating mechanism provided with a control shaft 27 for oscillating the control mechanism according to the engine operating state. A regulating means 16 composed of a pair of stopper members 17, 18 provided on a main body 12a side of a cam bearing 12 of the cam shaft 2, and a stopper pin 19 projecting on the outer periphery of the control shaft 27 in the radial direction and to be brought in contact with the stopper members in the maximum rotational position is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake / exhaust valve drive control device for variably controlling the opening / closing timing of intake / exhaust valves in accordance with the operating state of an internal combustion engine for an automobile.

[0002]

2. Description of the Related Art As a conventional intake / exhaust valve drive control device of this type, there is known one described in Japanese Patent Application Laid-Open No. 6-2516 filed by the present applicant.

The outline will be described with reference to FIG. 11. The drive shaft 81 to which the rotational force is transmitted from the crank shaft of the engine and the outer periphery of the drive shaft 81 are coaxially arranged with a certain clearance and each cylinder is arranged. The camshaft 82 is divided into parts and has a cam 82a for operating an intake valve (not shown) on the outer periphery, and is provided between the end of each camshaft 82 and the drive shaft 81. Variable control mechanism 8 for changing angular velocity
3 and an operating mechanism 84 for eccentrically moving the variable control mechanism 83 in accordance with the engine operating state.

The variable control mechanism 83 includes a camshaft 8
The first and second flange portions 85 and 86 respectively provided on the end portion of 2 and the drive shaft 1, and between the flange portions 85 and 86, an annular disk 87 is rotatably held on the inner circumference. A disc housing 88 and slidable locking pins 89, 90 interposed between the annular disc 87 and the flange portions 85, 86 for transmitting the rotational force of the drive shaft 81 to the cam shafts 82 are provided. Have

Further, as shown in FIG. 10, the operating mechanism 84 is connected to an eccentric cam (not shown) of the disk housing 88 and has a pinion 91 at its end portion.
4a, a slide member 94 slidably provided in the body 92 and provided with a rack 93 that meshes with the pinion 91 on the upper surface, and a cylinder 95 provided inside the slide member 94 to supply and discharge hydraulic pressure. A hydraulic circuit 97 that slides the slide member 94 via the piston 96 and a linear stepping motor 99 that axially slides a spool valve 98 that switches the flow path of the hydraulic circuit 97 are provided.

Along with the change of the engine operating condition, a control pulse signal is output from the controller 100 to the stepping motor 99 to operate the spool valve 98, whereby the pressure receiving chambers 95a sandwiching the piston 96 of the cylinder 95, Hydraulic pressure is relatively supplied to and discharged from the inside of 95b. Therefore, the slider member 94 slides in the left-right direction in FIG. 10 to rotate the control shaft 84a via the rack 93 and the pinion 91, thereby swinging the disk housing 88. As a result, the center of the annular disc 87 moves concentrically or eccentrically with the shaft center of the drive shaft 81 to change the relative angular velocity between the drive shaft 81 and each cam shaft 82,
A rotational phase difference is generated. As a result, the intake valve opening / closing timing is controlled to be advanced or delayed according to the engine operating state.

[0007]

However, in the conventional device, the slider member 94 has a maximum movement position in the left-right direction on both end surfaces 96a, 9 of the piston 96.
6b includes front and rear end surfaces 95c, 95 of the pressure chambers 95a, 95b.
It is regulated when d hits. That is, in the left direction, the inner end surface 9 of one pressure receiving chamber 95a is
5d abuts on the other end surface 96b of the opposing piston 96, and in the right direction, the innermost end surface 95c of the other pressure-receiving chamber 95b abuts on the one end surface 96a of the opposing piston 96 so that the left and right maximum movement positions are restricted. Has become.

Therefore, there is an assembling tolerance of the piston 96 and the slide member 94 with respect to the body 92 and a cumulative tolerance.
Further, when a processing error or the like occurs, the left and right maximum movement positions of the slide member 94 are likely to deviate due to these. As a result, the control accuracy of the minimum and maximum operating angle of the intake valve is reduced, and the advance angle control of the opening / closing timing cannot be controlled with high accuracy according to the engine operating state, making it difficult to sufficiently exert the engine performance. .

Further, the rotational torque fluctuation generated in the camshaft 82 due to the spring force of the valve spring or the like is transmitted to the control shaft 84a, and the rack 93 and the pinion 9 are connected.
There is a problem that rattling occurs between the piston 1 and the piston 96 and between the slide member 94 and the tapping sound.

[0010]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned conventional problems.
A drive shaft that is rotationally driven by the engine, a cam shaft that is provided relatively rotatably on the same axis as the drive shaft, and has a cam that operates an intake / exhaust valve on the outer periphery, and a cam shaft that is concentric with the shaft center of the drive shaft. A control mechanism that variably controls the operating angle of the intake and exhaust valves by eccentrically moving to change the relative angular velocity between the drive shaft and the camshaft, and the control mechanism that controls the control mechanism via the control shaft according to the engine operating state. In an intake / exhaust valve drive control device including an actuating mechanism that causes the control shaft to swing in a concentric or eccentric direction. It is characterized by the provision of.

According to a second aspect of the invention, the regulating means is
From a regulating member provided on the side of the cam bearing of the cam shaft, and a stopper pin that is provided in a radial direction from the outer peripheral portion of the control shaft and abuts on the stopper member at a predetermined forward and reverse rotational position of the control shaft. It is characterized by being configured.

Therefore, the maximum forward / reverse rotational position of the control shaft is regulated by the regulating means provided outside the actuating mechanism and comprising the stopper member and the stopper pin, so that the minimum operating angle position and the maximum operating angle position of the intake / exhaust valve are controlled. Therefore, the positional accuracy of each is improved.

According to a third aspect of the present invention, the actuating mechanism controls the rotational drive of the control shaft, a hydraulic cylinder for supplying and discharging hydraulic pressure to and from the hydraulic cylinder, and a hydraulic circuit for controlling the engine operating condition. A proportional solenoid type electromagnetic actuator that operates a switching valve that switches the flow path of the hydraulic circuit, and a controller that controls the electromagnetic actuator are provided.

According to a fourth aspect of the present invention, when the forward / reverse maximum rotational position of the control shaft is regulated by the regulation means, the inner end surfaces axially located in the hydraulic cylinder slide in the hydraulic cylinder. It is characterized in that a clearance is formed between the inner end surfaces of the piston at the maximum sliding position of the piston and the opposite end surfaces of the piston.

According to the third and fourth aspects of the present invention, the rattling in the connecting means between the hydraulic cylinder and the control shaft is effectively absorbed by the hydraulic pressure in the regulating means and the clearance, so Generation of noise is prevented.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the intake / exhaust valve drive control device according to the present invention will be described in detail below with reference to FIGS.

That is, in FIGS. 2 and 3, 1 is a drive shaft having an internal hollow shape, 2 is a cam shaft which is coaxially arranged on the outer periphery of the drive shaft 1, and is formed separately for each cylinder. 3 is a control mechanism. Four
Is an operating mechanism for swinging the control mechanism 3. The camshaft 2 is provided with two cams 2a per cylinder for opening the intake valve 25 via the bubble lifter 24 against the spring force of the valve spring 23 on the outer circumference.

The cam shaft 2 is a cylinder head 1.
1 is supported by a cam bearing 12 provided at the upper end of the shaft 1. As shown in FIGS. 1 and 3, the cam bearing 12 includes a flat plate block-shaped main body 12a and a bracket 12b mounted on an upper end portion of the main body 12a, and a vertical direction is applied from both sides of the bracket 12b. It is fixed on the cylinder head 11 by a pair of bolts 13, 13 penetrating therethrough. A semi-arcuate bearing groove 14a for supporting the upper half of the camshaft 2 is formed substantially at the center of the bottom surface of the main body 12a, and the bracket 1 is provided substantially at the center of the upper surface.
A semi-arcuate bearing groove 14b for bearing a control shaft 27, which will be described later, is formed in cooperation with a flat arc-shaped bearing groove 15 at the center of the lower surface of 2b.

The control mechanism 3 is rotatably held on the inner circumference of the disk housing 8 and the first and second flange portions 5 and 6, a substantially annular disk housing 8 disposed between the first and second flange portions 5 and 6. And the one end of which is fixed to the diametrical position of the annular disc 7 so as to be rotatable along the axial direction of the camshaft, and the tip end of which is located in the U-shaped engagement grooves 5a and 6a of the flange portions 5 and 6, respectively. Locking pins 9,1 slidably engaged
It is mainly composed of 0 and 0. Further, as shown in FIG. 3, the disc housing 8 slides diagonally up and down with a support shaft 21 inserted in a U-shaped support groove 8c formed in a boss portion 8a on one side of the upper end as a fulcrum. While being swingably supported, it is swung by the rotation of an eccentric cam 22 which is a part of the actuating mechanism 4 arranged in a cam hole 8d formed in the boss portion 8b on the other side of the upper end side. It is like this. The eccentric cam 22 has an annular shape, and is fixed to the control shaft 27 of the actuating mechanism 4 in a through hole 22a that is formed through the axial direction.

As shown in FIGS. 2 and 5, the actuating mechanism 4 includes the control shaft 27 arranged substantially parallel to the camshaft 2 and the other end 27b of the control shaft 27 in the direction perpendicular to the axis. A hydraulic cylinder 28 provided along the hydraulic cylinder 28, a hydraulic circuit 29 for supplying / discharging hydraulic pressure to / from the hydraulic cylinder 28, and a switching valve 3 provided in the middle of the hydraulic circuit 29 for switching a flow path.
0, a proportional solenoid type electromagnetic actuator 31 for operating the switching valve 30, and the other end portion 2 of the control shaft 27.
7b, a potentiometer 32 which is a position detection sensor for detecting the rotational position of the control shaft 27,
The engine operating state is detected and the potentiometer 32
The controller 33 controls the electromagnetic actuator 31 based on the information signal fed back from the controller 33.

The control shaft 27 is formed in an inner hollow shape, and a substantially raindrop-shaped control plate 34 is fixed to the other end 27b. This control plate 3
As shown in FIG. 6, 4 is press-fitted and fixed to the other end portion 27b through a fixing hole 34a provided in the center of a substantially annular base portion, and hangs downward from the base portion to control shaft 27 at the tip portion. Slit-shaped groove 35 notched along the direction perpendicular to the axis of
And a locking groove 36 formed in a direction orthogonal to the slit-shaped groove 35.

The hydraulic cylinder 28 has a cylindrical shape,
The front end is fixed to the upper part of the cylinder head via a base plate 37, and is separated into a front and rear first pressure receiving chamber 39 and a second pressure receiving chamber 40 by a piston 38 slidably provided inside. Also, the piston 38 has
One end of a piston rod 41 that penetrates the base plate 37 in a liquid-tight manner is connected. This piston rod 4
As shown in FIGS. 5 and 6, 1 has a flat portion 41a having a width across flats which is engaged with the locking groove 36 at the tip end side thereof, and the flat portion 41a has a substantially central portion in the longitudinal direction. A pin 43 that engages with the slit groove 35 of the control plate 34 is rotatably provided in the insertion hole 42 at the position. The pin 43 has a flat plate shape that can be inserted into the slit groove 35, and has outer surface arcuate projections 43a and 43a that are rotatably supported by the insertion holes 42 at the center positions of both side surfaces, and have a cross section. It is formed in a circular shape. The piston rod 41 has a tip portion 41b held in a sliding hole 75a of a holding member 75 as shown in FIG.

As shown in FIG. 5, the hydraulic circuit 29 is formed on a hydraulic pressure supply passage 45 communicating with an oil main gallery 44 to which hydraulic pressure is pumped from an oil pump (not shown), and on the downstream side of the hydraulic pressure supply passage 45. Also, the first and second oil passages 47 and 48, which are branched through a valve hole 46 described later and one end of which communicates with the first and second pressure receiving chambers 39 and 40, and the front end portion and the rear end portion of the valve hole 46. It is mainly composed of drain passages 49 and 50 connected to.

As shown in FIGS. 5 and 7, the switching valve 30 has a bottomed rectangular tubular valve body 51 fixed to the side of the hydraulic cylinder 28 and a tubular shape fixed in the valve body 51. A spool valve body 53 slidably provided in the valve hole 46 provided in the portion 52.

The valve body 51 has a supply hole 54 formed at one side thereof for connecting the hydraulic pressure supply passage 45 and the valve hole 46, and the other side thereof at the first and second oil passages 47, 48.
And first and second communication holes 55 and 56 that communicate with the valve hole 46. Further, first and second drain holes 57 and 58 that connect the first and second drain passages 49 and 50 to the valve hole 46 are formed in the rear end portion and the front end side bottom wall of the one side portion.
One end of the tubular portion 52 is fixed to the casing 70 of the electromagnetic actuator 31, and the through holes 60 to 64 are provided at positions corresponding to the supply holes 54 and the communication holes 55, 56 of the valve body 51. Has been formed.

As shown in FIGS. 5 and 7, the spool valve body 53 has a supply hole 54 and first and second supply holes 54 in the outer peripheral surface at the substantially center.
An annular groove 65 is formed to communicate with the second communication holes 55 and 56 through the through holes 61 and 62, and the drain holes 57 and 58 and the communication holes 55 and 56 are relatively formed on the outer circumference of the front and rear ends. Valve parts 66 and 67 that open and close are formed. Also,
By the spring force of the coil spring 69 elastically held by the retainer 68 fixed to the front end of the cylindrical portion 52, the supply hole 54 and the first communication hole 55 are communicated with each other in the right direction in the drawing, that is, the valve portions 66 and 67.
The second communication hole 56 and the second drain hole 50 are urged to a position where they communicate with each other.

The electromagnetic actuator 31 has an electromagnetic coil 71, a fixed core 72, a movable core 73 and other components housed inside a casing 70 fixed to the valve body 51. A drive rod 74 whose tip 74a presses the center of the end of the spool valve body 53 is provided.

As shown in FIG. 4, the potentiometer 32 has a bolt 75 at the other end 27b of the control shaft 27.
The sliding rod 77 abuts on the cam surface 76a of the cam 76 fixed by the above, and the resistance voltage is changed by the sliding position of the sliding rod 77 which advances and retreats according to the rotating position of the cam 76.

The controller 33 includes a crank angle sensor, an air flow meter, a
Information signals from various sensors such as a water temperature sensor and a throttle valve opening sensor are input to detect the current engine operating state, and a control shaft 27 rotational position information signal from the potentiometer 32 is input to electromagnetically input. A control pulse signal is output to the actuator 31. The controller 33 also estimates the cam operating angle of the camshaft 2 based on the information signal from the potentiometer 32.

Further, between the cam bearing 12 and the control shaft 27, as shown in FIGS. 1 and 2, there is provided a regulation means 16 for regulating the maximum forward / reverse rotation position of the control shaft 27. The restricting means 16 is provided in the cam bearing body 1
A pair of left and right stopper members 17, 18 provided on the side of the control mechanism 3 of 2a, and a control shaft 27.
And a stopper pin 19 provided between the stopper members 17 and 18 so as to project from the outer periphery of the stopper pin.

The stopper members 17 and 18 each have a shape of a shaft pin and are provided at a horizontal position of the cam bearing 12. The vertical position is determined by the relative relationship with the rotational movement position of the stopper pin 19. Are set at positions corresponding to the minimum operating angle position and the maximum operating angle position of the intake valve due to the swinging of the disk housing 8.

On the other hand, the stopper pin 19 has a base end portion 1
9a is press-fitted and fixed in a press-fitting hole formed in the outer peripheral portion of the control shaft 27 along the radial direction, and the length of the tip end portion 19b thereof is set to be slightly longer than the position where the stopper members 17 and 18 are formed. ing.

Further, the control shaft 27 has the regulating means 1
As shown in FIGS. 5 and 8, clearances C1 and C2 are formed between the piston 38 and the axially inner end surface of the hydraulic cylinder 28 at the position where rotation is restricted by 6. That is, when the piston 38 advances and retracts, the stopper pin 19 of the control shaft 27 hits the stopper members 17 and 18, and when the left and right rotation positions are further regulated, the pressure receiving chambers 39 and
40 inner end surfaces 39a, 40a and the inner end surfaces 39a, 40a
Clearances C1 and C2 are formed between the opposite end surfaces 38a and 38b of the piston 38 facing a.

The operation of this embodiment will be described below with reference to the control flow of the controller 33 shown in FIG. First, in section S1, the rotational speed N of the crankshaft from the crank angle sensor, the intake air amount Q from the air flow meter, and the throttle opening θ _T from the throttle opening sensor are read. Next, in section S2, the basic injection amount T _P of the fuel injection valve (not shown) is calculated based on the information signals, and in section S3, the valve timing is calculated from the map preset by N and T _P. The target value S _T of the operating angle is read. Then, in section S4, the current camshaft operating angle of the camshaft 2, that is, the operating angle S with respect to the drive shaft 1, is estimated based on the information signal from the potentiometer 32. This camshaft operating angle S
Can also be calculated by the crank rotation signal K _P and the rotation position signal C _P of the camshaft 2 detected by the sensor.

Further, in section S5, the difference value ΔS is obtained by subtracting the camshaft operating angle S from the operating angle target value S _T. Subsequently, in section S6, it is determined whether or not the difference value ΔS is less than or equal to a predetermined value α, and if not, it is determined in section S7 whether the difference value ΔS is greater than 0, that is, whether the difference value ΔS is positive or negative. Determine. Here, when the difference value ΔS is negative, that is, when the camshaft operating angle S exceeds the target value S _T , it is in the low rotation and low load region, for example, so that the duty ratio is set to 0% in the section S8. Then, the electromagnetic force of the electromagnetic actuator 31 is controlled to zero.

Therefore, as shown in the upper half of FIG. 7, the spool valve body 53 is biased to the right in the figure by the spring force of the coil spring 69 so that the valve portions 66 and 67 communicate with the supply hole 54 in the first communication. The second communication hole 5 while communicating with the hole 55
6 and the second drain hole 58 communicate with each other.

Therefore, the hydraulic oil in the second pressure receiving chamber 40 is discharged to a low pressure state, and the hydraulic oil pumped from the oil pump is supplied to the first pressure receiving chamber 39 to a high pressure state. The piston 38 is slid to the maximum leftward position as shown by the solid line in FIG. Therefore, the piston rod 41 tilts the control plate 34 to the left as shown in the drawing via the pin 43, whereby the control shaft 27 rotates maximally in the clockwise direction in the drawing and rotates the eccentric cam 22 in the same direction. .

Therefore, as shown in FIG. 3, the disk housing 8 swings while slanting upward with the support shaft 21 as a fulcrum, and the center Y of the annular disk 7 is maximally eccentric from the center X of the drive shaft 1. To do. Therefore, each locking pin 9, 1
The angular velocity of the annular disk 7 changes via 0, etc., resulting in unequal angular velocity rotation. As a result, the camshaft 2 is partially accelerated with respect to the drive shaft 1, and the intake valve is controlled to a small operating angle. Therefore, in the low-speed low-load region, the valve overlap between the intake valve 25 and the exhaust valve is reduced, so that the fuel consumption is improved and the intake charging efficiency is improved due to the early closing timing, so that the output torque can be increased.

Further, if it is determined in section S7 that the difference value ΔS is positive, that is, if the camshaft operating angle S has not reached the target value S _T , it means that it is in the high rotation and high load region, and therefore section S9. Then, the processing for increasing the duty ratio to the electromagnetic actuator 31 is performed to increase the electromagnetic force, and the drive rod 74 is advanced to the maximum. Therefore, the spool valve body 53 moves to the maximum leftward direction against the spring force of the coil spring 69, as shown in the lower half of FIG. 7, and the valve portions 66 and 67 move to the first communication hole 55 and the first drain hole 55. Hole 5
7 are communicated with each other, and the second communication hole 56 and the supply hole 54 are communicated with each other.

Therefore, this time, the hydraulic oil in the first pressure receiving chamber 39 is discharged to a low pressure, and the hydraulic oil is supplied to the second pressure receiving chamber 40 to a high pressure, whereby the piston 3
8 moves to the maximum right direction as shown by the two-dot chain line in FIG. 8, and the piston rod 41 tilts the control plate 34 through the pin 43 to the maximum right direction as shown by the two-dot chain line. Therefore, the control shaft 41 is rotated in the counterclockwise direction in the drawing at maximum, and the eccentric cam 22 is rotated in the same direction.

Therefore, the disc housing 8 swings downward, and the center Y of the annular disc 7 is eccentric from the center X of the drive shaft 1 in the opposite direction to the above. For this reason, the angular velocity of the camshaft 2 becomes smaller than the above with respect to the annular disc 7, the camshaft 2 is partially decelerated with respect to the drive shaft 1, and the intake valve has a large operating angle. Controlled. Therefore, the valve overlap becomes large,
The intake charge efficiency is improved and high output torque and the like can be obtained.

If it is determined in the section S6 that the difference value ΔS is less than or equal to the predetermined value, it means that the camshaft operating angle S substantially matches the current engine operating state. Move to. Here, a process of fixing the duty ratio to 50% is performed. Therefore, the spool valve body 53 is held at a substantially intermediate position of the valve hole 46, and the valve portions 66 and 67 close the communication holes 55 and 56.

Therefore, the supply and discharge of the hydraulic oil to the pressure receiving chambers 29 and 40 are blocked, and the piston 38 is held at a predetermined arbitrary moving position. As a result, the control shaft 27
Also, the intake valve 25 can be controlled to a substantially intermediate operating angle via the control mechanism 3.

Further, even if the hydraulic oil leaks from the pressure receiving chambers 39 and 40 carelessly, the control shaft 27
Rotation position of potentiometer 32 to controller 3
3 is constantly fed back, so that the swing position of the control mechanism 3 can be corrected. As a result, the intake valve 2
A highly accurate operating angle control of 5 is obtained.

Furthermore, in the present embodiment, the hydraulic cylinder 28 or the like is simply used instead of the mechanical servo mechanism using the slide member or the like as in the conventional case.
The structure can be simplified and the stroke of the piston 38 can be made sufficiently small. As a result, the relatively inexpensive proportional solenoid type electromagnetic actuator 31 can be used, so that the manufacturing cost can be reduced. Further, the simplification of the structure also simplifies the entire sealing mechanism, so that the sealing performance is improved.

Moreover, according to this embodiment, when the piston 38 moves in the advancing or retreating direction by the relative supply and discharge of the hydraulic pressure in the pressure receiving chambers 39 and 40 as described above, the stopper pin 19 is shown in FIG. Stopper members 17, 18
And the maximum rotational position of the control shaft 27 in the leftward or rightward direction is regulated. For this reason,
The rotational position accuracy of the control shaft 27 is improved.

That is, the piston 38 is moved to the maximum rotational position of the control shaft 27, and the inner end surface 39 of the hydraulic cylinder 28 is moved.
In the case of abutting against the a and 40a to regulate the rotational position, variations in the rotational position are likely to occur due to the assembly of the hydraulic tank 28 and the piston 38, the cumulative tolerance, and the like. To regulation means 16
By providing the above, it becomes possible to significantly improve the control accuracy of the rotational position of the control shaft 27. As a result, the minimum operating angle and maximum operating angle control accuracy of the intake valve 25 is improved, and engine performance can be fully exhibited.

Further, when the piston 38 is located at the left and right maximum moving positions, the end faces 3 of the piston 38 are respectively moved.
8a, 38b and the opposing end faces 39a, 40a of the cylinder 28
Due to the hydraulic pressure in the clearances C1 and C2 formed between the pin 43 and the control plate 34, the pin 43 is pressed against the inner surfaces 35a and 35b of the slit groove 35 via the piston rod 41. Generation of a gap between the two is suppressed. Therefore, even if the positive and negative rotational torque fluctuations are transmitted from the camshaft 2 to the control shaft 27, the hydraulic pressures in the clearances C1 and C2 absorb the fluctuations, so that the pins 43 and the inner surfaces 35a of the slits 35, respectively.
It is possible to surely prevent the occurrence of an interference hammering sound with 35b.

The present invention is not limited to the above-described embodiment, and the prior art example previously filed by the present applicant (for example, Japanese Patent Laid-Open No. 6-2516) by replacing the operating mechanism 4 with a hydraulic cylinder or the like.
No.) and Japanese Patent Application No. Hei 6-29909, the invention can be applied to various working mechanisms using hydraulic pressure or electromagnetic force such as a rotary type actuator.

[0050]

As is apparent from the above description, according to the intake / exhaust valve drive control device for an internal combustion engine according to the present invention, a regulating means for regulating the maximum rotational position of the control shaft is provided inside the hydraulic cylinder, for example. Since it is provided between the external control shaft and the engine, even if there are assembly tolerances and accumulated tolerances and machining errors of each component of the operating mechanism, they are not affected by these, and the maximum rotation position of the control shaft is not affected. Can always be accurately regulated, and the rotational position accuracy is improved. As a result, the maximum and minimum operating angle control accuracy of the intake valve and the like is improved, and it becomes possible to sufficiently bring out the engine performance according to the engine operating state.

Further, the positive and negative rotational torque fluctuations transmitted from the cam shaft to the control shaft occur, but the control shaft is biased by the hydraulic pressure to the stopper pin at the maximum sliding position, so that the pin, the control plate and the piston are Since the backlash between the control shaft and the other components of the actuating mechanism is absorbed, it is possible to suppress the occurrence of interference tapping sound and the like in the drive transmission path.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line AA of FIG.

FIG. 2 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 3 is a sectional view taken along line BB of FIG. 2;

FIG. 4 is a perspective view showing an operating mechanism used in this embodiment.

FIG. 5 is a sectional view showing a hydraulic circuit of an operating mechanism.

FIG. 6 is a perspective view of an essential part of an operating mechanism.

FIG. 7 is a sectional view showing the operation of the switching valve of the operating mechanism and the electromagnetic actuator.

FIG. 8 is an explanatory view showing the action of the operating mechanism.

FIG. 9 is a control flowchart of the controller according to the present embodiment.

FIG. 10 is a cross-sectional view showing a conventional operating mechanism.

FIG. 11 is a cross-sectional view of essential parts showing a conventional intake / exhaust valve drive control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Drive shaft 2 ... Cam shaft 3 ... Control mechanism 4 ... Operating mechanism 12 ... Cam bearing 12a ... Main body 16 ... Regulating means 17,18 ... Stopper member (regulating member) 19 ... Stopper pin 25 ... Intake valve 27 ... Control shaft 28 ... hydraulic cylinder 29 ... hydraulic circuit 30 ... switching valve 31 ... electromagnetic actuator 33 ... controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shin Nakamura No. 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd.

Claims (4)

[Claims] 1. A drive shaft rotationally driven by an engine,
A cam shaft which is provided coaxially with the drive shaft and is rotatable relative to the drive shaft, and a cam shaft which has a cam for actuating an intake and exhaust valve on the outer circumference; A control mechanism for variably controlling the operating angle of the intake and exhaust valves by changing the relative angular velocity of
In an intake-exhaust valve drive control device comprising an operating mechanism that swings the control mechanism concentrically or eccentrically via a control shaft in accordance with an engine operating state, between the control shaft and the upper end of the engine, An intake / exhaust valve drive control device for an internal combustion engine, comprising: a restricting unit that restricts a maximum forward / reverse rotational position of the control shaft. 2. The restricting means is provided in a radial direction from a restricting member provided on a side portion of the cam bearing of the cam shaft, and an outer peripheral portion of the control shaft, and has a forward and reverse predetermined rotational position of the control shaft. 2. The intake / exhaust valve drive control device for an internal combustion engine according to claim 1, further comprising: a stopper pin that abuts against the stopper member. 3. The operating mechanism comprises a hydraulic cylinder for controlling the rotational drive of the control shaft, a hydraulic circuit for supplying and discharging hydraulic pressure to and from the hydraulic cylinder, and a flow path of the hydraulic circuit according to an engine operating state. 2. The intake / exhaust valve drive control device for an internal combustion engine according to claim 1, further comprising: a proportional solenoid type electromagnetic actuator that operates a switching valve that switches the electromagnetic valve, and a controller that controls the electromagnetic actuator. 4. The maximum sliding of a piston that slides in each inner end surface axially located in the hydraulic cylinder and the hydraulic cylinder when the forward / reverse maximum rotational position of the control shaft is restricted by the restricting means. 4. The intake / exhaust valve drive control device for an internal combustion engine according to claim 3, wherein a clearance is formed between each inner end surface of the piston and both end surfaces of the piston facing each other.