JP2000154707A - Variable valve gear of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a variable valve gear with small arrangement space by dividing and forming one tip part side and the other tip part side of a rocker arm and making both the divided arm parts detachable according to an engine operation state, in a variable mechanism in which an oscillating fulcrum of the locker arm is made variable and lift amount of an engine valve is made variable. SOLUTION: When a vehicle is started and the vehicle is transferred to stationary operations of low revolution low load and medium revolution and medium load, an electromagnetic switching valve is switched, high pressure oil from an oil pump is supplied to a pressure receiving chamber 43 and a connecting pin 41 is advanced and moved against a coil spring 42 at a location where a hole for operation 38 and a hole for sliding 40 are matched in a base circle area of an oscillating cam in each independent oscillating locus of both divided arm parts 35, 36 constituting a rocker arm 18. As a result, both the divided arm parts 35, 36 are linked each other via the connecting pin 41. As a result, the whole of the rocker arm 18 is oscillated in a cooperation with a driving cam, two intake valves are operated, intake filling efficiency is enhanced and an output improvement is contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve operating apparatus for an internal combustion engine, which can change the opening / closing timing of an intake / exhaust valve and the valve lift in accordance with the operating state of the engine.

[0002]

2. Description of the Related Art As is well known, in order to improve fuel efficiency at low engine low speed and low load, to ensure stable driving performance, and to secure sufficient output by improving intake air filling efficiency at high speed and high load, intake air intake and air intake are controlled. Various variable valve devices for variably controlling the opening / closing timing of an exhaust valve and the valve lift amount according to the engine operating state have been conventionally provided.
No. 137305 is known.

Referring to FIG. 28, the camshaft 2 is provided at an upper position near the center of the upper deck of the cylinder head 1, and a cam 2 a is provided integrally on the outer periphery of the camshaft 2. ing. Also,
A control shaft 3 is disposed parallel to a side portion of the camshaft 2, and a rocker arm 5 is pivotally supported on the control shaft 3 via an eccentric cam 4.

On the other hand, at the upper end of an intake valve 6 slidably provided on the cylinder head 1, a swing cam 8 is arranged via a valve lifter 7. The swing cam 8 is swingably supported by a support shaft 9 disposed above the valve lifter 7 and in parallel with the camshaft 2, and a cam surface 8 a at the lower end is in contact with the upper surface of the valve lifter 7. . The rocker arm 5 has one end 5a in contact with the outer peripheral surface of the cam 2a and the other end 5b connected to the upper end surface 8b of the swing cam 8.
, And the lift of the cam 2 a is transmitted to the intake valve 6 via the swing cam 8 and the valve lifter 7.

The rotation of the control shaft 3 is controlled within a predetermined angle range by an actuator (not shown) to control the rotation position of the eccentric cam 4, thereby changing the swing fulcrum of the rocker arm 5. ing.

[0006] When the eccentric cam 4 is controlled to a predetermined forward / reverse rotation position, the swing fulcrum of the rocker arm 5 changes.
The contact position of the other end portion 5b with the upper end surface 8b of the swing cam 8 changes in the vertical direction in the drawing, whereby the contact position of the cam surface 8a of the swing cam 8 with the upper surface of the valve lifter 7 changes. By changing the swing trajectory of the swing cam 8, the opening / closing timing (valve timing) of the intake valve 6 and the valve lift amount are variably controlled. Incidentally, 10 in the figure
Is a spring that constantly biases the upper end surface 8b of the swing cam 8 against the other end 5b of the rocker arm 5.

[0007]

However, in the above-described conventional valve gear, the cam 2a and the swing cam 8 are provided on the camshaft 2 and the support shaft 9, respectively.
Numerals 8 are separately and independently arranged at positions largely separated in the width direction of the engine. For this reason, a large arrangement space for the cam 2a and the swing cam 8 is required.

Further, since the cam 2a and the swing cam 8 are largely separated in the width direction of the engine, both ends 5
a, 5b must inevitably extend substantially in the width direction of the engine. Therefore, the rocker arm 5 is increased in size in conjunction with the increase in the arrangement space, so that the mountability of the valve train on the engine is deteriorated, and the engine is increased in size and weight is inevitable.

Further, since the support shaft 9 is required in addition to the camshaft 2, the number of parts is increased, and the center of the camshaft 2 and the support shaft 9 are easily shifted from each other. Timing control accuracy may be reduced.

Further, since the end 5b of the rocker arm 5 directly swings on the upper end face 8b of the swing cam 8 to swing the swing cam 8, the pushing point of the rocker arm 5 (the contact position). ) May be detached from the upper end surface 8b of the swing cam 8. Therefore, the position of the swing fulcrum of the rocker arm 5 is restricted, and the swing trajectory of the swing cam 8 and thus the valve timing / lift amount of the intake valve 6 cannot be set relatively large. Also, when a conventional valve train is applied to an engine having a plurality of intake or exhaust valves,
No consideration was given to stopping some valves depending on the operating state of the engine.

[0011]

SUMMARY OF THE INVENTION The present invention has been devised in view of the problems of the above-mentioned conventional variable valve operating system, and has the following features.
The described invention is rotationally driven by the crankshaft of the engine,
A drive shaft having a drive cam fixed to the outer periphery, a swing cam provided on the drive shaft so as to be swingable, for opening and closing the engine valve while rolling on the top surface of the valve lifter, and one end via a link arm A rocker arm rotatably linked to the drive cam and the other end mechanically linked to the swing cam, a variable mechanism for changing the swing fulcrum of the rocker arm, and the variable mechanism according to the engine operating state. Control means for controlling operation,
A variable valve apparatus that variably controls a rocking fulcrum of the rocker arm to change a rocking position of a rocking cam with respect to a top surface of the valve lifter to vary a lift amount of an engine valve. A link switching mechanism for forming one end and the other end separately and for linking or releasing the link between the one first split arm and the other second split arm according to the operating state of the engine. It is characterized by having been provided.

According to a second aspect of the present invention, the linkage switching mechanism comprises a plunger slidably provided in an operation hole formed in a side portion of one of the divided arm portions, and is opposed to the operation hole. A sliding hole drilled on the side of the other split arm portion to be slidably received in the sliding hole, and slidably received by the first pressing means at a position straddling the sliding hole and the operating hole. A connecting pin for slidingly connecting the two divided arm portions; and a second pressing means provided at the bottom of the operating hole for storing and moving the connecting pin to the sliding hole via a plunger. I have.

According to a third aspect of the present invention, the linkage switching mechanism is characterized in that an operation hole formed in a side of one of the divided arms and a side of the other divided arm facing the operation hole. And the two split arm portions are slid by the first pressing means into a position straddling the sliding hole and the operating hole, the sliding arm being housed inside the sliding hole and being connected to the sliding hole. A connecting pin,
And a second pressing means provided in the operating hole for storing and moving the connecting pin into the sliding hole.

According to a fourth aspect of the present invention, the linkage switching mechanism includes a locking projection provided on one of the upper surfaces of the two split arms and a support supported on the upper surface of the other split arm. A lever swingably supported by a shaft, a lost motion mechanism provided at one end of the lever for pressing and tilting the lever in one direction, and a punching mechanism formed on the upper portion of the other split arm along the vertical direction. A plunger that is slidably provided in the provided sliding hole and pushes the other end of the lever in the other direction against the pressing force of the lost motion mechanism, and a plunger provided in the sliding hole. A first pressing means for pushing in the direction of the lever; and a second pressing means for moving the plunger backward into the sliding hole against the pressing force of the first pressing means, wherein the first pressing means is provided. Push up the other end of the lever It is characterized in that one end of the bar is engaged with the locking projection to connect the two split arms, while the pressing force of the lost motion mechanism releases the connection between the two split arms. I have.

The invention according to claim 5 is characterized in that the first pressing means and the second pressing means are constituted by a spring member or a hydraulic circuit.

Therefore, according to the present invention, the drive cam and the swing cam are provided together with the drive shaft, so that the apparatus can be made compact, and in particular, the linkage switching mechanism can be used depending on the engine operating state. Thus, for example, the operation of the intake valve on one side can be stopped.

That is, for example, when the engine is started or the engine is idling, the supply of the hydraulic pressure from the hydraulic circuit to the pressure receiving chamber in the sliding hole is cut off. Therefore, the connecting pin is stored and held in the sliding hole by the spring force of the spring member. It has been done. For this reason, the two split arm portions are free from each other without being connected, and the first split arm portion linked to the drive cam swings in a so-called idling state due to the eccentric rotation of the drive cam, The second split arm is in the swing stop state. Therefore, the swing cam stops the opening and closing operation of one of the engine valves without swinging. As a result, the starting torque by the crankshaft at the time of starting is reduced, the starting performance is improved, and the fuel efficiency during idle operation can be improved.

On the other hand, when the engine shifts to, for example, a steady operation and a high-speed high-load region, hydraulic pressure is supplied from the hydraulic circuit to the hydraulic chamber, so that the connecting pin is slid against the spring force of the spring member. The tip advances from the hole, enters the working hole, and is held at a position straddling between the holes. As a result, the two split arm portions are integrally connected. For this reason, the eccentric rotational force of the drive cam is transmitted from one split arm to the other split arm, and the swing cam swings with the swing of the entire rocker arm, thereby opening and closing one engine valve. . As a result, it is possible to improve the intake charging efficiency during the operation.

The invention according to claim 6 is used for a part of cylinders of an internal combustion engine having a plurality of cylinders.
The split arm portions are connected to each other by operating hydraulic pressure, and the connection is released by the force of a return spring member.

In the case of the present invention, when the opening / closing operation of the engine valves of some of the cylinders is to be stopped at the time of starting the engine, the supply of the operating oil pressure is cut off and the divided arm portions are mutually moved by the force of the return spring member. Break the connection. This makes it possible to immediately stop the opening and closing operation of the engine valves of some cylinders without waiting for the rise of the operating oil pressure.

The invention according to claim 7 is used in an internal combustion engine provided with a pair of intake valves or exhaust valves per cylinder, wherein the drive cam, link arm, rocker arm, swing arm,
7. The variable valve operating device according to claim 1, wherein the variable valve operating unit including the linkage switching mechanism is provided corresponding to each of the pair of the intake valve and the exhaust valve. The linking switching mechanism of the variable valve operating unit connects the divided arm parts with each other by operating hydraulic pressure, and releases the connection by the force of the return spring member, and the linkage switching mechanism of the other variable valve operating unit The split arm portions are connected to each other by the force of the spring member, and the connection is released by operating hydraulic pressure.

In the case of the present invention, when the supply of the operating oil pressure to both the variable valve units is interrupted, one of the variable valve units releases the connection of the divided arm portions by the force of the return spring member, The other variable valve unit connects the divided arm portions to each other by the force of the return spring member. Therefore, when the engine is started, if the supply of the hydraulic pressure to both the variable valve units is cut off, it is possible to reliably operate only one engine valve without waiting for the rise of the operating hydraulic pressure.

The invention according to claim 8 provides a drive shaft rotatably driven by a crankshaft of an engine and having a drive cam connected to an outer periphery thereof, the drive shaft being swingably provided, and a top surface of a valve lifter. A swinging cam that opens and closes the engine valve while rolling on the top, a rocker arm having one end rotatably linked to the drive cam via a link arm and the other end mechanically linked to the swing cam; A variable mechanism for varying the rocking fulcrum of the rocker arm; and control means for controlling the operation of the variable mechanism in accordance with the operating state of the engine. The valve of the rocking cam is controlled by variably controlling the rocking fulcrum of the rocker arm. A variable valve apparatus for varying a lift amount of an engine valve by changing a swing position with respect to a top surface of a lifter, wherein the drive cam is mounted on a drive shaft so as to be relatively rotatable. In response Is characterized in that a linkage switching mechanism to release the association or linkage Te.

In the case of the present invention, for example, when the operation of the engine valves of some of the cylinders is stopped at the time of starting the engine or idling, the linkage between the drive shaft and the drive cam is released by the linkage switching mechanism. As a result, the drive cam does not follow the rotation of the drive shaft, and the swing cam linked to the drive cam via the link arm, the rocker arm, or the like is in a stopped state. Then, at this time, the drive shaft is separated from the drive cam, link arm, rocker arm and the like having a relatively large mass and freely rotates, so that the starting torque at the time of starting the engine is reduced and the power loss of the engine is also reduced.

The ninth aspect of the present invention is used for a part of a plurality of cylinders of an internal combustion engine. The linkage switching mechanism connects a drive cam and a drive shaft by operating hydraulic pressure, and a force of a return spring member. The connection is released by the

In the case of the present invention, when the opening and closing operation of the engine valves of some cylinders is to be stopped when the engine is started, the supply of the operating oil pressure is cut off and the drive cam and the drive shaft are driven by the force of the return spring member. Break the connection of. This allows
The opening / closing operation of the engine valves of some cylinders can be immediately stopped without waiting for the rise of the operating oil pressure.

[0027]

1 to 3 show a first embodiment of a variable valve apparatus according to the present invention, which is applied to an internal combustion engine having two intake valves per cylinder. .

That is, the variable valve apparatus comprises a pair of intake valves 12, 12 slidably provided on a cylinder head 11 via a valve guide (not shown), and a cylinder head 1.
1, a hollow drive shaft 13 rotatably supported by an upper bearing 14, a pair of drive cams 15, 15 fixed to the outer peripheral surface of the drive shaft 13 by press fitting or the like, and coaxial with the drive shaft 13. A pair of swing cams 17, 17 rotatably provided above for pressing and opening the intake valves 12, 12 via valve lifters 16, 16, respectively, and are disposed above the drive shaft 13. One end 18a, 18a is a pair of link arms 1
A pair of rocker arms 1 linked to the drive cams 15, 15 via the link members 9, 19, and the other end portions 18b, 18b linked to the swing cams 17, 17 via the link members 20.
8, 18; variable mechanisms 21 and 21 for varying the rocking fulcrum positions of the rocker arms 18 and 18; and control means (not shown) for controlling the operation of each variable mechanism 21 according to the engine operating state. It is configured.

The drive shaft 13 is arranged along the longitudinal direction of the engine, and is driven by a crank of the engine via a driven sprocket (not shown) provided at one end or a timing chain wound around the driven sprocket. Torque is transmitted from the shaft.

The bearing 14 is provided at an upper end of the cylinder head 11 and supports a drive shaft 13 (not shown), and a control shaft 28 which is provided at an upper end of the main bracket and is rotatable. A supporting sub-bracket 14a, and both brackets
The cylinder head 11 is fixed to the cylinder head 11 from above by b and 14b.

As shown in FIGS. 1 and 3, each of the drive cams 15 has a substantially ring shape, and has a drive shaft insertion hole 15a formed in the inner axial direction. 13 is eccentric in the radial direction by a predetermined amount. The two drive cams 15 are press-fitted and fixed to the drive shaft 13 on both outer sides not interfering with the valve lifters 16, 16 via drive shaft insertion holes 15 a.

Each of the valve lifters 16 has a closed cylindrical shape as shown in FIG. 1, and comprises a cylindrical skirt portion 16a and a curved top wall 16b integrally formed at the upper end of the skirt portion 16a. Each of the swing cams 17 in which the skirt portion 16a is slidably held in holding holes 11a formed in the cylinder head 11, has a substantially horizontal U-shape as shown in FIGS. Present each one 1
Support holes 17a, 17a rotatably inserted into the drive shaft 13 are formed through the substantially central portions 7, 17, and pin holes 24, 24 are formed in the upper portions of the cam nose portions 17b, 17b, respectively. Are formed through. Also,
A cam face 25 is formed on the lower surface of each swing cam 17. This cam face 25 has a base circular surface 25.
a, a cam surface 25b extending in an arc shape from the base circular surface 25a to the cam nose portion 17b side, and a cam lift portion 25c provided on the tip side of the cam surface 25b, that is, on the cam nose portion 17b side.
And the base circular surface 25a and the cam surface 25b.
The cam lift portion 25c comes into contact with a predetermined position on the upper surface of each valve lifter 16 in accordance with the swing position of the swing cam 17. That is, as shown in FIG. 1, the predetermined angle range θ1 of the base circular surface 25a is a base circle section, the predetermined angle range θ2 of the cam surface 25b is a so-called ramp section, and further, the cam lift portion 25 is moved from the cam surface 25b.
The predetermined angle range θ3 up to c is set to be the lift section.

As shown in FIGS. 1 and 3, the one side (right side in FIGS. 2 and 3) rocker arm 18 is integrally bent substantially in a shape of a letter, and the engine is positioned above the drive shaft 13 at an upper position. The base 18 which is disposed along the width direction and has a center
c is swingably supported by a control shaft 28 described later, and one end 18a is rotatably connected to the protruding end 19b of the link arm 19 via the pin 23, while the other end 18b is It is rotatably connected to one end 20a of the link member 20 via a pin 26.

The rocker arm 18 on the other side (the left side in FIGS. 2 and 3) is arranged along the engine width direction at a position above the drive shaft 13 similarly to the rocker arm 18 on one side. Side and the other end side are formed separately from the direction perpendicular to the axis of the drive shaft 13.
Reference numerals 36 freely swing independently of each other. That is, the first split arm portion 35 on the link arm 19 side has a substantially rectangular shape as shown in FIGS. 1 and 4A and 4B, and is inserted into the control shaft 28 on one end portion 35a side and supported swingably. A first support hole 35c is formed to penetrate, and a pin hole 35d through which a pin 23 rotatably connected to the link arm 19 is inserted is formed below the other end 35b.

On the other hand, as shown in FIGS. 1 and 5A and 5B, the second divided arm portion 36 is bent in an inverted letter shape.
A second support hole 36c inserted through the control shaft 28 is formed at the center, and a pin hole 3 through which the pin 26 rotatably connected to one end of the link member 20 is inserted through one end 36a.
6d, while the other end 36b is substantially rectangular.
One side is slidably disposed on the opposite side of the other end 35 b of the first split arm 35.

Each of the link arms 19 has an annular base 19a having a relatively large diameter and a projecting end 19b protruding from a predetermined position on the outer peripheral surface of the base 19a. The base 1
At the center of 9a, a fitting hole 19c is formed, which is rotatably fitted to the outer peripheral surface of each drive cam 15. On the other hand, a pin hole 19d through which the pin 23 connected to the other end 35b of the first split arm portion 35 is rotatably inserted is formed through the protruding end 19b.

Each of the link members 20 is provided in a pair for each of the rocker arms 18, and is formed in a linear shape having a predetermined length as shown in FIG.
0a is the end 18b of the rocker arm 18, or
The end 36a of the second split arm 36 is rotatably connected to the end 36a via the pin 26.
7 is also rotatably connected via a pin 27.

The ends of the pins 23, 26, 27 are
Snap rings 31 are provided to restrict the axial movement of the link arm 19 and the link member 20, respectively.

The variable mechanism 21 has a control shaft 28 supported by the sub-bracket 14 a of the bearing 14, and is press-fitted and fixed to the control shaft 28.
8c and a control cam 29 rotatably inserted into the first and second support holes 35c and 36c of the other rocker arm 18.

The control cam 29 has a substantially cylindrical shape.
An insertion hole 29a that is fitted and fixed to the control shaft 28 by press-fitting is formed in the inner axial direction, and its axis P1 is offset from the axis P2 of the control shaft 28 by α.

The control shaft 28 is controlled by an electromagnetic actuator (not shown) provided at one end so as to rotate within a predetermined rotation angle range. The electromagnetic actuator is a control means for detecting an operating state of the engine. Is driven by a control signal from a controller (not shown). The controller detects a current engine operation state by calculation or the like based on detection signals from various sensors such as a crank angle sensor, an air flow meter, and a water temperature sensor, and outputs a control signal to the electromagnetic actuator.

A link switching mechanism 37 is provided between the two split arm portions 35 and 36 to link or release the link between the two split arm portions 35 and 36 as appropriate.
As shown in FIGS. 2, 4 and 5, the linkage switching mechanism 37 includes an operation hole 38 formed in parallel with the pin hole 36d on the upper side of the other end 35b of the first split arm 35, A plunger 39 slidably provided in the operating hole 38,
A sliding hole 40 formed in a position opposite to the operating hole 38 at a predetermined swing position in the other end portion 36b of the second split arm portion 36
And a connecting pin 41 which is slidably accommodated in the sliding hole 40 and can advance into the operating hole 38.

The connecting pin 41 is urged to be accommodated in the sliding hole 40 via the plunger 39 by a spring force of a coil spring 42, which is a spring member elastically mounted on the bottom of the operating hole 38, and is slidable. The distal end portion 41a moves into the operation hole 38 by hydraulic pressure supplied via a hydraulic circuit 44 into a pressure receiving chamber 43 formed on the bottom side of the operation hole 40. The outer peripheral edge of the distal end portion 41b of the connecting pin 41 and the hole edge of the operating hole 38 are formed in a tapered shape so as to ensure good insertion of the connecting pin 41 into the operating hole 38. Have been. In addition, the operation hole 3
An air hole 45 for ensuring the slidability of the plunger 39 is formed in the bottom wall 8.

As shown in FIG. 6, the hydraulic circuit 44 has a hydraulic supply passage 48 whose one end faces an oil pan 47 via a strainer 46, an inner axial direction of the control shaft 28, and the second split arm 36. A supply / discharge passage 49 having one end connected to the downstream side of the hydraulic supply passage 48 and the other end connected to the pressure receiving chamber 43, and an oil pump 50 provided in the middle of the hydraulic supply passage 48. , Provided between the hydraulic supply passage 48 and the supply / discharge passage 49 to connect the supply / discharge passage 49 to the hydraulic supply passage 4.
8 to switch and communicate with one of the drain passages 51
And a port 2 position type electromagnetic switching valve 52.

The electromagnetic switching valve 52 is switched based on a control signal from the controller 53 for detecting the operating state of the engine. In a hydraulic pressure supply passage 48 between the oil pump 50 and the electromagnetic switching valve 52, a pilot type pressure regulating valve 54 for adjusting the hydraulic pressure supplied to the pressure receiving chamber 43 is provided.

Further, as shown in FIG. 1, the second divided arm portion 36 is restrained from swinging upward by a predetermined amount by a stopper mechanism 56 provided on a rocker cover 55 or the like. Regulated within the swing range of 35,
A large displacement between the operating hole 38 and the sliding hole 40 due to the co-rotation accompanying the swinging (sliding) of the first split arm portion 35 is prevented. The stopper mechanism 56 includes a pressing plunger 56b that slides in a sliding hole 56a in a lower portion of the rocker cover 55, and a coil spring 56c that urges the pressing plunger 56b downward.

In the following, the operation of the present embodiment will be described. First, at the time of starting the engine and at the time of idling operation, the electromagnetic switching valve 52 establishes communication between the hydraulic supply passage 48 and the supply / discharge passage 49 by a control signal from the controller 53. The oil pressure in the pressure receiving chamber 43 is returned to the inside of the oil pan 47 so as to lower the pressure in order to make the supply / discharge passage 49 and the drain passage 51 communicate with each other. Therefore, the connecting pin 41 is not shown in FIGS.
As shown in FIG. 7, the plunger 39 is moved forward by the spring force of the coil spring 42 and is stored and held in the sliding hole 40.

For this reason, the two split arm portions 35 and 36
The linkage is released, and the first divided arm portions 35 freely swing, and the first eccentric arm portion 35 transmits the eccentric rotational force of the drive cam 15 via the link arm 19, and swings in a so-called idling state. The two-split arm portion 36 is substantially in a swing stop state. Therefore, the one swing cam 17 stops the opening and closing operation of the one intake valve 12 without swinging.

On the other hand, the other swing cam 17 pushes the valve lifter 16 by the cam face 25 when the rocker arm 18 swings by the eccentric rotation of the other drive cam 15 and swings via the link member 20. Thus, the other intake valve 12 is opened and closed.

As described above, by stopping the operation of the intake valve 12 on one side, the starting torque (cranking torque) by the crankshaft at the time of starting is reduced, so that the startability is improved and the intake swirl is increased. Combustion during idle operation is improved, and fuel efficiency is improved by reducing drive loss. In addition, engine noise can be reduced by one-side valve stop.

Thereafter, when the vehicle is started to shift to a steady operation with a low rotation and a low load and a middle rotation and a medium load, the switching operation of the electromagnetic switching valve 52 causes the hydraulic supply passage 48 and the supply / discharge passage 4 to move.
9 is communicated and the drain passage 51 is shut off, so that the high oil pressure fed from the oil pump 50 is applied to the pressure receiving chamber 4.
3 is supplied.

Therefore, in the base circle area of the swing cam 17 in the independent swing locus of the two split arm portions 35 and 36, the connecting pin 41 is located at the position where the operating hole 38 and the sliding hole 40 match. Move out against the spring force of the coil spring 42 as shown in FIG.
1b presses the plunger 39 toward the bottom of the operating hole 38, and advances into the operating hole 38 so that both holes 38,
It is held at a position that straddles between the forties. As a result, the two split arm portions 35 and 36 are integrally connected to each other.

Therefore, the entire rocker arm 18 swings by receiving the eccentric rotational force of the drive cam 15 and the one swing cam 1
7, and one intake valve 12 is also opened and closed. Therefore, by the opening and closing operation of the two intake valves 12, 12,
The output can be improved by improving the intake charging efficiency.

Further, even at the time of high engine speed and high load, the connected state of the two split arm portions 35 and 36 is maintained in the same manner as in the low-medium-speed low-medium load region, so that the output can be improved.

Further, when the engine is running at a low speed and a low load, the electromagnetic actuator is driven to rotate to one side by a control signal from the controller. As shown in FIG. 1, the shaft P1 is rotated so that the shaft P1 is positioned above the shaft P2 of the control shaft 28, whereby the thick portion 29b is moved to the drive shaft 13.
Move in the direction away from. Therefore, the other rocker arm 18 moves upward with respect to the drive shaft 13 as a whole, and pulls the link member 20 upward by the other end 18b. For this reason, one end (cam nose 17b side) of the oscillating cams 17 is forcibly pulled up slightly, and the whole is held at a position rotated counterclockwise as shown in the figure.

Therefore, the rocker arms 18, 18 swing with the control cam 29 as a swing fulcrum through the link arm 19 by the rotation of the drive cam 15, and the swinging power of the rocker arms 18, 18 through the link member 20. 17 and 17 are transmitted. The oscillating cams 17, 17 are provided with a base circular surface 25a and a cam surface 2a.
5b, the cam lift 25c rolls on the top surface 16c of the valve lifter 16 to press or release the pressure to open and close both intake valves 12, but the lift amount is relatively small.

Therefore, in such a low rotation and low load range, the valve lift amount becomes small, the opening timing of each intake valve 12 is delayed, and the valve overlap with the exhaust valve becomes small. Therefore, further improvement in fuel efficiency and stable rotation of the engine can be obtained.

On the other hand, when the engine shifts to the high engine speed and high load range, the electromagnetic actuator is driven to rotate in the other direction by the control signal from the controller. Therefore, the control shaft 28 rotates a predetermined amount in the counterclockwise direction (the direction of the arrow in the figure) to rotate the control cam 29 a predetermined amount in the counterclockwise direction from the position shown in FIG. 29b) is moved downward. For this reason, the rocker arms 18, 18 move in the direction approaching the drive shaft 13 as a whole, and press the cam nose 24 of the swing cams 17, 17 downward via the link member 20 to swing. The entire cams 17 and 17 are rotated clockwise by a predetermined amount.

Therefore, the rolling contact position of each swing cam 17 with respect to the upper surface of the valve lifter 16 moves to the right edge position on the cam nose portion 17b side. Therefore, the driving cam 15
Is rotated to swing the rocker arms 18, 18 to swing the swing cams 17, 17 within a predetermined range, the lift amount of the valve lifters 16, 16 increases.

Therefore, in such a high-rotation, high-load region, the cam lift characteristics are larger than those in the low-rotation, low-load region, and the valve lift is increased.
The opening timing is advanced, while the closing timing is delayed. As a result, the intake charging efficiency is improved, and a sufficient output can be secured.

Further, according to this device, the drive cam 15 and each swing cam 17 are provided on the drive shaft 13 coaxially.
The arrangement space in the engine width direction can be made sufficiently small.

Further, by providing the drive cam 15 and the swing cam 17 coaxially with the drive shaft 13, a conventional support shaft for supporting the swing cam 17 becomes unnecessary, and the number of parts is reduced accordingly. And the driving shaft 13 and the swing cam 17
Since there is no deviation between the axes, the control accuracy of the valve timing can be prevented from lowering.

Further, since the driving cam 15 is offset from each valve lifter 16 and arranged at a position where they do not interfere with each other, the outer shape of the driving cam 15 can be made large.
The degree of freedom in designing the outer peripheral surface 15a of the drive cam 15 can be improved, whereby a sufficient lift amount for securing the swing amount of the swing cam 17 can be secured.
A sufficient cam width for reducing the driving surface pressure of the driving cam 15 can be secured.

In particular, the drive cam 15 is formed in a ring shape, and the entire outer peripheral surface is formed in the fitting hole 19 of the link arm base 19a.
Since the entire inner peripheral surface of c is in sliding contact, the surface pressure on the outer peripheral surface is dispersed, and the surface pressure can be sufficiently reduced. Therefore, the occurrence of wear between the inner peripheral surfaces of the fitting holes 19c can be suppressed, and
Easy lubrication. In addition, the driving cam 1
The degree of freedom in selecting the material of No. 5 is improved, and a material which is easy to process and can be selected at low cost can be selected.

Further, since the present apparatus employs a so-called six-link system as a whole, it is possible to increase the rocker ratio of the rocker arms 18 and 18, thereby setting a large offset amount of the drive cam 15 with respect to the drive shaft 13. The swing angle of the swing cam 17 can be obtained without performing the above operation, that is, without setting the outer diameter of the drive cam 15 to be large. As a result, the overall size of the apparatus can be further reduced.

Further, since the rocker arms 18, 18 and the oscillating cams 17, 17 are linked via the link members 20, 20, even if the rocker ratio of the rocker arms 18, 18 is set relatively large, the rocker arm 18, , 18 and the oscillating cams 17, 17 are always maintained in a linked state. Therefore,
By obtaining a large swing angle of the swing cams 17, 17, it is possible to increase the ramp section θ2 of the swing cams 17, 17, whereby the valve lifter 1
The collision speed between the swing cams 17, 16 and the swing cams 17, 17 can be reduced, and as a result, the generation of driving noise can be suppressed.

Further, the present apparatus has two intake valves 12, 1
The control shaft 28 can also be supported together with the bearing 14 provided between the cylinder heads 2, so that it is possible to mount the control shaft 28 as it is on a conventional internal combustion engine.
1 does not require a change in shape, and can prevent a rise in manufacturing cost. In addition, since the drive shaft 13 can be located at the same position as in the related art, it is not necessary to change the shape of the cylinder.

Further, in the present apparatus, since the rocker arm 18 is merely disposed at a position above the drive shaft 13, the overall height can be sufficiently reduced.

Further, in this apparatus, the link switching mechanism 37 attached to the other rocker arm 18 includes a connecting pin 41 for connecting the first split arm 35 and the second split arm 36,
A hydraulic circuit 44 for operating the connecting pin 41 in a direction for connecting the arms 35 and 36 and a coil spring 42 for urging the connecting pin 41 in a direction for releasing the connection between the arms 35 and 36 are provided. Since the supply of the operating pressure by the hydraulic circuit 44 is shut off (the electromagnetic switching valve 52 is connected to the drain passage 51 side), the connection between the arms 35 and 36 is released. When starting the engine, the operation of only one engine valve (the intake valve 12) can be immediately performed without waiting for the rise of the oil pressure due to the start of the oil pump 50. Therefore, it is possible to always reliably start the engine by the one-sided engine valve, thereby improving the startability of the engine.

FIGS. 9 and 10 show a second embodiment of the present invention. The rocker arm 18 on the other side is also formed into two parts similarly to the rocker arm 18 on one side.
5 and 36 are configured to be released by different linkage switching mechanisms 37 and 37a in accordance with the operation state.

The linkage switching mechanisms 37 and 37a are slightly different in structure from those of the first embodiment, and the plunger in the operating hole 38 of the first split arm 35 is eliminated, and the second split arm 36 A connecting pin 41 (41a) is slidably provided in a sliding hole 40 (40a) formed in the other end portion 36b of the connecting hole 41, and the connecting pin 41 (41a) is provided at the bottom of the sliding hole 40 (40a). A coil spring 42 (42a), which is a spring member for urging in the direction of the operation hole 38 (38a), is provided, and a small diameter portion on the outer periphery of the front end of the connection pin 41 (41a) and the slide hole 40 (40a). A pressure receiving chamber 43 (43a) is formed between the pressure receiving chamber 43 and the inner peripheral surface. Therefore, the connecting pin 41 (41a) is connected to the pressure receiving chamber 43 (43a).
The arm is retracted by the hydraulic pressure inside the arm, and the two split arm portions 35, 3
6 is released.

As shown in FIG. 11, the hydraulic circuit 44 is provided with a second supply / discharge passage 49a based on the hydraulic circuit 44 of the first embodiment. A second electromagnetic switching valve 52a, which is controlled to be switched by the controller 53, is provided.

The second solenoid-operated directional control valve 52a is connected to the first
The same switching operation is performed at the same timing as the electromagnetic switching valve 52.
The hydraulic supply passage 48 communicates with the supply / discharge passages 49 and 49a,
During normal operation, the supply / discharge passages 49 and 49a and the drain passage 5
1 and communicate with each other.

As in the present embodiment, both rocker arms 18, 18 are formed in two parts and the link switching mechanism 37,
For example, in the case of a four-cylinder engine, a control device for linking and releasing by the 37a is provided for two cylinders, and the other two cylinders have no linkage switching mechanism.

Therefore, according to this embodiment, the hydraulic pressure is supplied into the pressure receiving chambers 43, 43a by the electromagnetic switching valves 52, 52a when the engine is started or during idling, so that the connecting pins 41, 41a are slid. It is retracted and held in the holes 40 and 40a. For this reason, each rocker arm 18,
The linking of the divided arm portions 35, 36, 35, 36 of 18 is released, and the respective intake valves 12, 1 of the corresponding two cylinders are released.
While the opening and closing operations of 2, 12, and 12 are stopped, the intake valves of the other two cylinders are opened and closed. Accordingly, the operation of each cylinder whose linkage has been released is stopped, and only the other cylinders are operated. Therefore, the cranking torque can be further reduced, and the fuel efficiency during idling can be greatly improved. Further, the pumping loss can be reduced, and the driving loss can be significantly reduced.

On the other hand, at the time of the engine steady operation, as shown in FIG. 10, the supply of the hydraulic pressure to the pressure receiving chambers 43, 43a is cut off and the hydraulic pressure in the pressure receiving chambers 43, 43a is discharged to the outside.
Each connecting pin 41, 41a is a coil spring 42, 42.
The tip portions 41b and 41c are turned into the respective operating holes 38 by the spring force of a.
38a. Thereby, each divided arm part 3
5, 36, 35, 36 are connected to each intake valve 12, 1
Since the opening, closing, and opening operations of 2, 12, and 12, the output can be improved.

FIGS. 12 to 14 show a third embodiment of the present invention. In this embodiment, as in the second embodiment, both of the two rocker arms 18 on the intake side are divided into two parts. Each rocker arm 18 has a different linkage switching mechanism 3
7 and 37a, the linkage is released in accordance with the operation state. However, the linkage switching mechanisms 37 and 37a are configured with one rocker arm 18 side and the other rocker arm 1 side.
8 are different.

To explain this point, the linkage switching mechanism 37 on one rocker arm 18 (left side in the figure) is the same as that of the first embodiment, and the linkage switching mechanism 37 on the other rocker arm 18 (right side in the figure) is used. The switching mechanism 37a is similar to that of the second embodiment. That is, the linkage switching mechanism 37 on one side includes the plunger 39 and the plunger 3 in the operation hole 38 of the first split arm portion 35.
A coil spring 42 as a spring member for urging the second arm 9 toward the second split arm 36 is accommodated, and a connecting pin 41 is slidably accommodated in a sliding hole 40 of the second arm 36. The connecting pin 41 moves forward and backward (sliding hole 40) by hydraulic pressure introduced into the pressure receiving chamber 43 at the bottom of the moving hole 40.
And the release over the operation hole 38) are controlled. Then, the other side of the linkage switching mechanism 3
7a is in the sliding hole 40a of the second split arm portion 36,
A connecting pin 41a and a coil spring 4 serving as a spring member for urging the connecting pin a toward the first split arm 35 side
2a is accommodated, and a pressure receiving chamber 43 is provided between the small diameter portion on the outer periphery of the front end of the connecting pin 42a and the inner peripheral surface of the sliding hole 40a.
a is formed, and the hydraulic pressure introduced into the pressure receiving chamber 43a controls the advancing and retreating operation of the connecting pin 41a (fitting over the sliding hole 40a and the operating hole 38a and release thereof). .

The hydraulic circuit 44 for sucking and discharging the hydraulic pressure to the two-coupling switching mechanism 37, 37a is the same as that of the second embodiment, and the first and second electromagnetic switching valves 52, 52a are used.
Are set so that the suction / discharge passages 49 and 49a communicate with the drain passages 51 and 51a in the off state. Therefore, when the engine is stopped when the first and second electromagnetic switching valves 52 and 52a are turned off, as shown in FIG.
The connection pin 41 of the first linkage switching mechanism 37 is pushed into the slide hole 40 by the force of the coil spring 42 to maintain the state in which the linkage between the first divided arm 35 and the second divided arm 36 is released. On the other hand, the connecting pin 41a of the second linkage switching mechanism 37a is inserted into the operating hole 38a by the force of the coil spring 42a, and maintains the two arms 35, 36 in the linked state.

In the apparatus of this embodiment configured as described above, when the engine is started, the first and second solenoid-operated directional control valves 52 and 52a are both maintained in the off state, as in the case where the engine is stopped. See FIG. 12). For this reason, only the second linkage switching mechanism 37a side has the arm portions 35, 3 of the rocker arm 18.
6 are connected to each other, and the engine is started with one valve stopped.

At this time, the first and second electromagnetic switching valves 5
Since both the second linkage switching mechanism 37a and the second linkage switching mechanism 37a can be brought into the linked state by turning off both the second and 52a, the single valve stop of the engine is realized immediately without waiting for the oil pressure to rise by the oil pump 50. be able to. Therefore, since the engine is started immediately in the one-valve stop state, the starting torque at this time is reduced, and as a result, the starting performance of the engine is reliably improved.

When the normal operation is started after the engine is started, only the first electromagnetic switching valve 52 is turned on by the control of the control unit 53, and the high pressure receiving chamber 43 of the first linkage switching mechanism 37 is supplied to the high pressure receiving chamber 43. Is supplied. As a result, the connecting pin 41 of the first linkage switching mechanism 37 projects as shown in FIG. 13 and is pushed into the operating hole 38 of the first split arm 35, so that the two arms 35 and 36 are linked. As a result, both valves of the engine operate together, and the engine output is increased.

Further, when the engine becomes extremely loaded,
While the first electromagnetic switching valve 52 is switched off, the second electromagnetic switching valve 52a is switched on,
As a result, as shown in FIG.
The eighteen arm portions 35, 36, 35, 36 are operated in a state where the linkage is released. Therefore, at this time, both valves of some cylinders of the engine are maintained in a stopped state, and only the other cylinders are operated, so that the fuel efficiency can be greatly improved.

FIGS. 15 to 20 show a fourth embodiment of the present invention. This embodiment is of a one-valve stop type as in the first embodiment. It has been changed.

That is, the link switching mechanism 37 includes a long plate-shaped projection 58 extending along the axial direction of the drive shaft 13 on the upper surface of one end of the first divided arm 35 of the rocker arm 18 on one side. A lever 61 swingably supported on a support shaft 60 pivotally supported by a pair of brackets 59 on the upper surface of the second divided arm portion 36, and a lever 61 provided on one end 61 a side of the lever 61. A lost motion mechanism 62 for inclining the lever 61 in one direction and a sliding hole 63 provided in the upper part of the second divided arm part 36 along the up and down direction, and the lower surface of the other end part 61b of the lever 61 A plunger 64 that pushes up against the pressing force of the lost motion mechanism 62 and tilts in the other direction, and is elastically mounted on the bottom of the sliding hole 63.
A coil spring 65 serving as a spring member that pushes up the plunger 64 to push up the other end 61 b of the lever 61;
A hydraulic circuit 44 (FIG. 6) similar to that of the first embodiment in which hydraulic pressure is supplied to a pressure receiving chamber 66 formed inside the sliding hole 63 to retract the plunger 64 into the sliding hole 63 against the spring force of the coil spring 65. And

The lever 61 has a substantially T-shape in plan view, and one end 61a on the head side is provided with the first and second divided arm portions 3a.
The other end portion 61b on the leg side extends along the longitudinal direction on the upper surface of the second split arm portion 36 while extending in the axial direction of the drive shaft 13 over the upper surfaces of the second and third arm portions 36. Have been.
In the one end 61a, a locking groove 67 is formed on the lower surface on the side of the first split arm portion 35 so that the locking projection 58 is fitted and locked as appropriate.

As shown in FIG. 17, the lost motion mechanism 62 has an operating hole 62 formed in the upper part of the second split arm 36 on one end 61a side of the lever 61 along the vertical direction.
a and a piston 62b which extends upward from the operating hole 62a to push up the lower surface of one end 61a of the lever 61
And a return spring 62c for urging the piston 62b upward. The return spring 62c has a spring set load set smaller than that of the coil spring 65.

The plunger 64 has a substantially T-shaped vertical cross section, and the upper end surface 64a is always in contact with the lower surface of the other end 61b of the lever 61 by the relative pressure with the lost motion mechanism 62, and the flange-shaped lower end is formed. The portion 64b functions as a pressure receiving portion that receives the oil pressure in the pressure receiving chamber 66.

The hydraulic circuit 44 is substantially the same as that of the first embodiment except that the supply / discharge passage 49b is formed in the axial direction of the control shaft 28 in the axial direction. One end of the portion 36 is formed in the axial direction hole 49c and the other end thereof is formed of a passage hole 49d connected to the pressure receiving chamber 66. Incidentally, reference numeral 68 in the drawing denotes an air vent hole formed in the second split arm portion 36 to ensure good sliding of the plunger 64.

Therefore, according to this embodiment, the hydraulic pressure supply passage and the supply / discharge passage 49b are communicated by the current switching valve (not shown) at the time of engine start or idling operation, so that the pressure receiving chamber 6
6 is supplied with hydraulic pressure, so that the plunger 64
Moves backward in the downward direction of the sliding hole 63 as shown in FIGS. For this reason, the lever 61 is pushed up at one end 61 a side by the lost motion mechanism 62, and the engagement between the locking groove 67 and the locking projection 58 is released,
The two split arm portions 35 and 36 are free from each other without being connected. At this time, it is needless to say that the swing of the second divided arm portion 36 by a predetermined amount or more is restricted by the stopper mechanism 56.

Therefore, the same operation as that of the first embodiment, such as improvement of startability and improvement of fuel efficiency, can be obtained.

On the other hand, when the engine shifts to the steady operation or the high-speed high-load region, the supply / discharge passage 46 is operated by the operation of the electromagnetic switching valve.
The d and the drain passage communicate with each other, and the hydraulic pressure in the pressure receiving chamber 66 is discharged to reduce the pressure. Therefore, the plunger 64 is
As shown in FIG. 20, the other end 61b of the lever 61 is pushed up by the spring force of the coil spring 65.
When the locking groove 67 and the locking projection 58 are aligned with each other, they are engaged with each other, and the divided arm portions 35 and 36 are integrally connected. Thereby, both intake valves 12,
The same operation and effect as in the first embodiment can be obtained, for example, the opening and closing operation of the engine 12 can improve the output of the engine.

It is to be noted that the valve timing and the valve lift can be variably controlled by changing the rocking fulcrum of the rocker arms 18 by the variable mechanism 21 in accordance with the operation state, as in the first to third embodiments. .

FIGS. 21 to 27 show a fifth embodiment of the present invention. The device of this embodiment comprises a hollow drive shaft 113 rotatably supported by bearings 14 and a drive shaft 113 having a hollow shape. A drive cam 115 which is fitted on the drive shaft 113 and rotates integrally with the drive shaft 113 when transmitting power, and is rotatably provided on the drive shaft 113 so that the intake valves 12 are connected to each other via valve lifters 16. Rocking cam 117 for pressing and rotating,
117 and a control shaft 28 above the drive shaft 113 so as to be rotatable. One end is linked to the drive cam 115 via the link arm 19, and the other end is connected to the link member 20.
The point that the rocker arm 18 linked to the swing cams 117 and 117 via the link 20 and the variable mechanism 21 that makes the rocking fulcrum of the rocker arm 18 variable according to the operating state of the engine is provided as described above. This is the same as the first to fourth embodiments.

However, in this variable valve operating device, the left and right swing cams 117, 117 are formed integrally with the cylindrical connecting portion 80, and one of the swing cams 117 is moved from the drive cam 115 to the link arm 19, the rocker arm 18 and the like. And the power is transmitted through the link members 20 and 20 to perform a rocking operation,
In conjunction with this one swing cam 117, the other swing cam 1
17 also operates synchronously. Further, the rocker arm 18 is formed integrally instead of being formed separately. Instead, the drive cam 115 is mounted on the drive shaft 113 so as to be relatively rotatable, and these are linked and released by the linkage switching mechanism 137 as appropriate. It has become.

As shown in FIGS. 21, 26, and 27, the linkage switching mechanism 137 includes a sliding hole 140 formed in the boss 115a on the outer side in the axial direction of the drive cam 115 along the radial direction, and A cylindrical connecting pin 41 having a bottom and slidably housed in the moving hole 140;
A coil spring 42 interposed between the bottom of the connector and the connecting pin 41 to urge the pin 41 in the direction of the drive shaft 113;
An operating hole 138 formed at a position corresponding to the sliding hole 140 on the outer peripheral surface of the drive shaft 113, and is formed at the bottom of the operating hole 138 along the radial direction of the drive shaft 113. The control oil pressure is introduced into the pressure receiving chamber 143 from the suction / discharge passage 49 of the hydraulic circuit 44.

More specifically, the bottom of the sliding hole 140 is formed of a separate disk-shaped member having an air hole 81, and the tip of the connecting pin 41 and the operating hole 138 into which the connecting pin 41 is inserted are formed. The opening edge is chamfered, such as a taper or a curved surface, to facilitate engagement between the two.
An annular groove 82 for hydraulic guide is formed in the outer peripheral surface of the drive shaft 113 at a position passing through the center of the operation hole 138, as shown in FIG. The hydraulic pressure of the suction / discharge passage 49 always and reliably acts on the distal end surface of the connection pin 41 regardless of the relative rotation position of the connection pin 115 and the reference position 115.

The apparatus of this embodiment is used for an internal combustion engine having a plurality of cylinders. In the internal combustion engine, the linkage switching mechanism 137 is applied to only some of the cylinders, and the other cylinders are driven by a drive shaft. The driving cam 115 is always connected to the driving cam 113. That is, for example, in the case of a four-cylinder engine, the linkage switching mechanism 137 is provided only in two of the cylinders.

Since the variable valve apparatus of this embodiment has the above-described configuration, it can be used at the time of starting the engine or idling.
The electromagnetic switching valve 52 is turned on by a signal from the control unit 53, whereby the hydraulic supply passage 48
Is introduced into the pressure receiving chamber 143 through the suction / discharge passage 49, and the connecting pin 41 receives the oil pressure and retreats into the sliding hole 140 as shown in FIG. The link between the drive shaft 113 and the drive cam 115 is thereby released. At this time, the drive shaft 113 idles, and the power of the drive shaft 113 is not transmitted to the swing cam 117.

Therefore, when the engine is started, some of the cylinders provided with the linkage switching mechanism 137 are kept in a stopped state, whereby the starting torque is reduced and the power loss is reduced, so that the fuel efficiency during idling is also reduced. improves.

When the engine shifts to the steady operation from this state, the electromagnetic switching valve 52 is turned off by a signal from the control unit 53, and the pressure receiving chamber 143 of the linkage switching mechanism 137 communicates with the drain passage 51. For this reason,
The connecting pin 41 is pressed forward by the force of the coil spring 42, and when the sliding hole 140 of the drive cam 115 and the operating hole 138 of the drive shaft 113 match, the connecting pin 4
1 is inserted into the operation hole 138. As a result, the power of the drive shaft 113 is transmitted to the left and right swing cams 117, 117 via the drive cam 115, and the swing cam 1
The opening and closing operations of the intake valves 12 and 12 by 17 and 117 are performed.

Accordingly, all the cylinders of the engine are operated, and a high output can be obtained. By the way, in the variable valve apparatus of this embodiment, the drive cam 115 is mounted so as to be relatively rotatable with respect to the drive shaft 113, and the two are appropriately linked by the linkage switching mechanism 137.
Since it is configured to be released, the power loss when the valve is stopped is reliably reduced as compared with the first to fourth embodiments in which the divided arm portions of the rocker arm 18 are linked and released.

That is, in the case of the apparatus of this embodiment, only the drive shaft 113 idles when the valve is stopped, and the drive cam 115 and the link arm 19 and the like having a large mass rotate together as in the first to fourth embodiments. Therefore, power loss is reliably reduced by these masses.

Further, in the above description, the operating oil pressure is supplied to the linkage switching mechanism 137 to cut off the linkage between the drive shaft 113 and the drive cam 115, and to link the drive shaft 113 and the drive cam 115 by the force of the coil spring 42. However, conversely, the linkage between the drive shaft and the drive cam may be interrupted by the force of the coil spring, and the hydraulic pressure may be supplied to the linkage switching mechanism to interrupt the linkage between the drive shaft and the drive cam. . In such a case, when the engine is started, the supply of the operating oil pressure to the linkage switching mechanism is cut off,
The valve operation of some cylinders can be immediately stopped without waiting for the hydraulic pressure to rise.

The present invention is not limited to the configuration of each of the above embodiments. For example, the linkage switching mechanism may have a further different configuration, and the configuration of the stopper mechanism may be changed. It is possible. In addition, this device
The present invention is applicable not only to two engine valves per cylinder but also to one engine valve, and further to an exhaust valve side in addition to an intake valve.

[0106]

As apparent from the above description, according to the present invention, not only the valve timing and the valve lift of the engine valve can be variably controlled, but also the drive cam and the swing cam are coaxial with the drive shaft. Since it is provided on the upper side, the arrangement space in the engine width direction can be made sufficiently small, and it is not necessary to extend the rocker arm in the engine width direction.
The entire device can be made compact. As a result, the mountability of the device on the engine is improved.

Further, by providing the swing cam together with the drive cam on the drive shaft, a conventional support shaft is not required, so that the number of parts can be reduced, and the drive shaft and the swing cam can be mutually connected. Since there is no displacement of the shaft center, it is possible to prevent a decrease in control accuracy of the valve timing.

According to the first to seventh aspects of the present invention, the two switching arm portions of the divided rocker arms are linked or released by the link switching mechanism in accordance with the operating state of the engine. Can be activated or deactivated, the starting torque at startup can be reduced and the fuel consumption during idle operation can be increased by releasing the linkage between the two split arms during engine startup and idle operation. Wide improvement can be achieved. Further, even when the rocking fulcrum of the rocker arm is displaced toward the low lift side by the actuator at the time of engine start, the required torque of the actuator is reduced by releasing the connection of the two split arm portions at this time, and the variable mechanism Responsiveness can be improved.

Further, when the engine is suddenly stopped for some reason in the state where the camshaft is controlled to the high lift side by the variable mechanism during the medium / high load operation, even if the engine is suddenly stopped for some reason, the two splits are performed at the time of engine start. If the linkage between the arms is released, the starting torque at the time of restart is reduced, so that the engine can be started smoothly and reliably. That is,
In a valve timing control device having no mechanism for linking and releasing the rocker arm, if the engine suddenly stops for some reason during medium or high load operation, the engine must be started with a large valve lift when starting the engine immediately thereafter. However, according to the device of the present invention, the starting torque at the time of restarting the engine is reduced by stopping the operation of some engine valves. Thus, it is possible to avoid a decrease in the engine startability.

Further, since the device of the present invention can control not only the single-valve stop but also the double-valve stop, the pumping loss can be reduced, the drive loss can be suppressed, and the startability and fuel consumption can be greatly reduced. Improvement can be achieved.

In particular, according to the sixth and seventh aspects of the present invention, when the engine is started, the force of the return spring member causes
Since the connection of the split arm portion corresponding to at least one engine valve can be released, the opening / closing operation of at least one engine valve can be immediately stopped without waiting for the rise of the operating oil pressure. The starting torque at the time of starting the engine is reliably reduced, and the startability is further improved. Also, in the event of an unexpected stop of the engine with the camshaft controlled to the high lift side, the connection of the split arm part is automatically released, the starting torque at the time of restart is reduced, and the Restart can be realized.

According to the eighth and ninth aspects of the present invention, the engine valve can be operated or stopped by linking or releasing the link between the drive cam and the drive shaft according to the engine operating state. Therefore, it is possible to reduce the starting torque at the time of starting the engine and to improve the fuel efficiency at the time of idling. In particular, in the case of the present invention, when the engine valve is stopped by the linkage switching mechanism, the drive shaft is separated from the drive cam, link arm, rocker arm and the like having a relatively large mass so that only the drive shaft can freely rotate. Engine startability and fuel efficiency are more reliably improved. Further, in the case of the present invention, even when the engine is suddenly stopped in a state where the camshaft is controlled to the high lift side by the variable mechanism, the linkage between the drive cams and the drive shafts of some cylinders is started when the engine is started. If it cancels, starting torque will be reduced and a reliable restart will be attained.

According to the ninth aspect of the present invention, when the engine is started, the connection between the drive shaft and the drive cam corresponding to some cylinders can be released by the force of the return spring member. It is possible to quickly stop the operation of the engine valves of some cylinders without waiting for the rise of the operating oil pressure, thereby reliably reducing the starting torque at the time of starting the engine. In addition, the present invention is applicable to a case where the engine is suddenly stopped while the camshaft is controlled to the high lift side.
In some cylinders, the spring member automatically releases the connection between the drive cam and the drive shaft, so that the starting torque at the time of restart is reduced, and a reliable restart immediately after the stop is made possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention as viewed from the direction indicated by an arrow A in FIG. 2;

FIG. 2 is a plan view of the embodiment.

FIG. 3 is a perspective view of the embodiment.

FIG. 4A is a front view of a first split arm portion provided in the embodiment, and FIG. 4B is a cross-sectional view taken along line BB of A.

FIG. 5A is a front view of the second split arm portion, and FIG.
Sectional drawing which follows the -C line.

FIG. 6 is a schematic diagram showing a hydraulic circuit of the embodiment.

FIG. 7D shows a state in which both split arm portions are connected.
Arrow view.

FIG. 8 is a plan view showing a state in which the two split arm portions are connected.

FIG. 9 is a plan view partially showing a second embodiment of the present invention;

FIG. 10 is a plan view showing a state where both divided arm portions of the second embodiment are connected.

FIG. 11 is a schematic diagram showing a hydraulic circuit according to the second embodiment.

FIG. 12 is a schematic configuration diagram including a partially cutaway plan view and a hydraulic circuit diagram of a third embodiment of the present invention.

FIG. 13 is a partially broken plan view of the third embodiment.

FIG. 14 is a partially broken plan view of the third embodiment.

FIG. 15 is a view as seen from an arrow E in FIG. 16, showing a fourth embodiment of the present invention.

FIG. 16 is a plan view showing the fourth embodiment.

FIG. 17 is an enlarged view of a main part of the fourth embodiment.

FIG. 18 is a view as viewed in the direction indicated by the arrow F in FIG. 16, showing a connection state of both divided arm portions according to the fourth embodiment.

FIG. 19 is a plan view of the fourth embodiment.

FIG. 20 is an enlarged view of a main part of the fourth embodiment.

FIG. 21 is a schematic configuration diagram including a vertical sectional view and a hydraulic circuit diagram of a fifth embodiment of the present invention.

FIG. 22 is a side view of the fifth embodiment.

FIG. 23 is a view on arrow G of FIG. 22 of the fifth embodiment.

FIG. 24 is a plan view of the fifth embodiment.

FIG. 25 is a perspective view of a drive shaft according to the fifth embodiment.

FIG. 26 is a sectional view taken along the line HH showing the connection state of the fifth embodiment.

FIG. 27 is an H- showing a disconnected state of the fifth embodiment.
Sectional drawing which follows the H line.

FIG. 28 is a sectional view showing a conventional variable valve operating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Cylinder head 12 ... Intake valve 13, 113 ... Drive shaft 15, 115 ... Driving cam 16 ... Valve lifter 17, 117 ... Swing cam 18 ... Rocker arm 18a ... One end 18b ... Other end 19 ... Link arm 20 ... Link Member 21 Variable mechanism 35 First split arm part 36 Second split arm part 37, 137 Linkage switching mechanism 38, 138 Operating hole 39 Plunger 40, 140 Sliding hole 41 Connection pin 42 Coil Spring (spring member) 43 ... Pressure receiving chamber

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seinosuke Hara 1370 Onna, Atsugi-shi, Kanagawa Prefecture Inside Unisia Gex Co., Ltd. 72) Inventor Tsuneyasu Nohara 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd.

Claims (9)

[Claims] 1. A rotary drive by a crankshaft of an engine,
A drive shaft having a drive cam fixed to the outer periphery, a swing cam provided on the drive shaft so as to be swingable, for opening and closing the engine valve while rolling on the top surface of the valve lifter, and one end via a link arm A rocker arm rotatably linked to the drive cam and the other end mechanically linked to the swing cam, a variable mechanism for changing the swing fulcrum of the rocker arm, and the variable mechanism according to the engine operating state. Control means for controlling operation,
A variable valve apparatus that variably controls a rocking fulcrum of the rocker arm to change a rocking position of a rocking cam with respect to a top surface of the valve lifter to vary a lift amount of an engine valve. One end side and the other end side are formed separately, and a link switching mechanism for linking or releasing the link between the one split arm and the other split arm in accordance with the operating state of the engine is provided. A variable valve device for an internal combustion engine, characterized by: 2. The linkage switching mechanism comprises: a plunger slidably provided in an operation hole formed in a side of one of the divided arm portions; and the other divided arm portion facing the operation hole. And a sliding hole bored on the side of the sliding hole, slidably received in the sliding hole, and sliding by a first pressing means to a position straddling the sliding hole and the operating hole. 2. A connecting pin according to claim 1, further comprising a connecting pin for connecting the arm portion, and a second pressing means provided at a bottom of the operating hole for storing and moving the connecting pin to the sliding hole via a plunger. Variable valve gear for internal combustion engines. 3. The linkage switching mechanism according to claim 1, further comprising an operation hole formed on a side of one of the divided arms, and a slide formed on a side of the other divided arm opposite to the operation hole. Working hole,
A connecting pin that is housed inside the sliding hole and slides to a position straddling the sliding hole and the operating hole by the first pressing means to connect the two divided arm portions; and a connecting pin provided in the operating hole. 2. A variable valve operating apparatus for an internal combustion engine according to claim 1, further comprising a second pressing means for storing and moving the connecting pin into the sliding hole. 4. The linkage switching mechanism includes a locking projection provided on an upper surface of one of the divided arm portions and a support shaft supported on an upper surface of the other divided arm portion. A supported lever, a lost motion mechanism provided at one end of the lever for pressing and tilting the lever in one direction, and a sliding hole formed in the upper part of the other split arm along the vertical direction. A plunger slidably provided to push the other end of the lever in the other direction against the pressing force of the lost motion mechanism, and a plunger provided in the sliding hole to push the plunger in the lever direction. First pressing means;
A second pressing means for retreating the plunger into the sliding hole against the pressing force of the first pressing means, wherein the first pressing means pushes up the other end of the lever to cause one end of the lever to move upward. The arm and the locking projection are engaged to connect the two split arms, while the pressing force of the lost motion mechanism releases the connection between the two split arms. 2. The variable valve train for an internal combustion engine according to claim 1. 5. The variable valve train for an internal combustion engine according to claim 2, wherein said first pressing means and said second pressing means are constituted by a spring member or a hydraulic circuit. 6. A linkage switching mechanism, which is used for a part of a plurality of cylinders of an internal combustion engine, connects the divided arm portions with each other by operating hydraulic pressure, and releases the connection by the force of a return spring member. The variable valve train for an internal combustion engine according to any one of claims 1 to 5, characterized in that: 7. A variable valve unit used in an internal combustion engine having a pair of intake valves or exhaust valves per cylinder, and having the drive cam, link arm, rocker arm, rocking arm, and linkage switching mechanism, The variable valve apparatus according to any one of claims 1 to 6, wherein the variable valve apparatus is provided in correspondence with the pair of the intake valve or the exhaust valve. The split arm portions are connected to each other, and the connection is released by the force of the return spring member. The linkage switching mechanism of the other variable valve operating unit connects the split arm portions to each other by the force of the return spring member. A variable valve mechanism for an internal combustion engine, wherein the connection is released by operating hydraulic pressure. 8. A rotary drive by a crankshaft of the engine,
A drive shaft having a drive cam connected to the outer periphery thereof, a swing cam provided on the drive shaft so as to be swingable, and opening and closing the engine valve while rolling on the top surface of the valve lifter; A rocker arm rotatably linked to the drive cam and the other end mechanically linked to the swing cam, a variable mechanism for changing the swing fulcrum of the rocker arm, and the variable mechanism according to the engine operating state. Control means for controlling operation,
A variable valve apparatus that variably controls a rocking fulcrum of the rocker arm to change a rocking position of a rocking cam with respect to a top surface of the valve lifter to change a lift amount of an engine valve. A variable valve actuation device for an internal combustion engine, characterized in that a variable switching mechanism is mounted on a drive shaft so as to be relatively rotatable, and a linkage switching mechanism is provided for engaging or disengaging the two according to the operating state of the engine. 9. A linkage switching mechanism, which is used for a part of a plurality of cylinders of an internal combustion engine, connects a drive cam and a drive shaft by operating hydraulic pressure, and releases the connection by the force of a return spring member. 9. The variable valve apparatus for an internal combustion engine according to claim 8, wherein: