JP2009041424A - Variable valve gear of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain miniaturization of a device and improvement of manufacturing and assembling efficiency by simplification of structure and reduction of the number of components, and to improve a degree of freedom in layout of a drive cam. <P>SOLUTION: The single drive cam 5 is provided on an outer periphery of a camshaft 4, two control cams 22 different from each other in an eccentric amount to an axis center P of a control shaft are provided on an outer periphery of a control shaft 21 arranged in parallel to the camshaft, and two oscillating cams 7, 7 are provided for respectively opening and closing intake valves 3 which are provided two per one cylinder. Two rocker arms 15 are provided for respectively linking the drive cam and the respective oscillating cams through two link arms 16 and link rods 17, by rotating the respective control cams through the control shaft, postures of the two rocker arms are relatively varied and a valve lift difference between the two intake valves is provided in at least small lift control of the respective intake valves. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine that can vary valve lift amounts of intake valves and exhaust valves, which are engine valves, in accordance with engine operating conditions.

  As this type of conventional variable valve operating device, there are those described in the following Patent Documents 1 previously filed by the present applicant.

  First, the outline will be described. This variable valve operating apparatus is applied to an internal combustion engine having two intake valves per cylinder, and is provided on the side of one intake valve with respect to the pair of intake valves. Two variable valve mechanisms, one variable valve mechanism and a first variable valve mechanism provided on the other intake valve side, are provided independently. These variable valve mechanisms are provided on the outer periphery of the camshaft to which the rotational force is transmitted from the crankshaft, the two drive cams whose axis is eccentric from the axis of the camshaft, and the respective drive cams A pair of transmission mechanisms that convert the rotational force into a swinging motion by two link arms, rocker arms, and link rods, respectively, and upper surfaces of two valve lifters that are linked to the link rods and that are provided at the upper ends of the intake valves. Two swing cams that slide the cam surface to open each intake valve against the spring force of the valve spring, a control mechanism that makes the lift amount of each intake valve variable according to the engine operating state, It has.

  The control mechanism includes a control shaft whose rotational position is controlled by an electric actuator, and two control cams that are fixed to the outer periphery of the control shaft and have different phases and eccentric amounts, respectively. The rocking fulcrum position of each rocker arm is changed according to the rotation angle.

Then, when the control shaft is rotationally controlled by the electric actuator according to the engine operating state, the rotation angle of each control cam is changed, and the posture of each transmission mechanism is relatively changed. The valve lift amount of the valve is varied so as to be continuously variable from a minute lift to a maximum lift, and the lift amounts are controlled to be different from each other.
JP 2000-38910 A

  However, in the conventional variable valve operating apparatus for an internal combustion engine, two variable valve mechanisms including a drive cam are provided independently in order to make the valve lifts of the intake valves different from each other. As a result, the structure of the entire apparatus becomes complicated, and a large number of parts are required, which complicates the manufacturing and assembling operations, and inevitably increases the cost.

  In addition, since the drive cams are arranged using the empty space between the adjacent cylinders, the degree of freedom in layout of the drive cams is limited.

  The present invention has been devised in view of the technical problem of the conventional variable valve operating device, and the invention according to claim 1 is particularly provided on the outer periphery of a camshaft to which power is transmitted from a crankshaft. The drive cam is formed as a single unit, and one end portion of a pair of rocker arms supported in a swingable manner on the outer periphery of each control cam is linked to the single drive cam, and the control shaft of each control cam The amount of eccentricity with respect to the shaft center of the engine valve is made different so that a valve lift difference is provided for each engine valve at least during small lift control.

  According to the present invention, at the time of small valve lift amount control, it is possible to generate a swirl in a cylinder by providing a lift difference between two engine valves, for example, two intake valves, Can promote combustion. As a result, fuel consumption and output torque can be improved.

  Further, the unification of the drive cam can simplify the structure of the entire apparatus, improve the manufacturing and assembly work efficiency, and improve the flexibility of layout because the drive cam can be arranged at any location.

  In addition, since the cam profiles of the two swing cams can be set to be the same, the manufacturing operation of the swing cam is facilitated, and the cost can be reduced in this respect as well.

  According to the second aspect of the present invention, during the maximum lift control of the two engine valves, the postures of the two rocker arms of the transmission mechanism are substantially the same, and the valve lift amounts of the two engine valves are substantially the same. Thus, during the operation state such as high engine speed and high load during the maximum lift control, the occurrence of swirl in the cylinder can be suppressed, the intake charging efficiency can be improved, and the output torque can be increased.

  The invention according to claim 3 clarifies the structure of the transmission mechanism, and includes two rocker arms swingably supported on the outer peripheral surfaces of the two control cams, the drive cam, and the rocker arms. A link arm that links one end to the other end of each rocker arm and a link rod that links each rocking cam, and one end of the link arm is arranged on the outer periphery of the single drive cam. It is characterized by being fitted.

  The invention described in claim 4 is characterized in that the link arm is formed as a single unit corresponding to the drive cam.

  By simplifying the link arm, the apparatus can be further simplified, and the manufacturing and assembly work efficiency can be improved and the cost can be reduced.

  Embodiments of a variable valve operating apparatus for an internal combustion engine according to the present invention will be described below in detail with reference to the drawings. In each of the embodiments, the variable valve device is applied to the intake side of a V-type 6-cylinder internal combustion engine.

[First embodiment]
That is, the variable valve operating apparatus in this embodiment is slidably provided on the cylinder head 1 via the valve guide 2 as shown in FIGS. Two first and second intake valves 3 and 3 per cylinder for opening and closing the port 1a, an internal hollow camshaft 4 disposed in the longitudinal direction of the engine, and one camshaft 4 fixed to the camshaft 4 for each cylinder. A drive cam 5 provided, and a pair of swing cams 7, 7 for opening each intake valve 3, 3 via each swing arm 6, 6 disposed at the upper end of each intake valve 3, 3; The transmission between the drive cam 5 and the swing cams 7 and 7 is linked to convert the rotational force of the drive cam 5 into the swing motion and transmit it as the swing force (valve opening force) of the swing cams 7 and 7. The valve lift amount of each of the intake valves 3 and 3 by changing the operating position (posture) of the mechanism 8 and the transmission mechanism 8 And a control mechanism 9 for variably controlled in accordance with engine operating conditions.

  The two intake valves 2, 2 are valve springs 11, 11 that are elastically mounted between a bottom surface of a substantially cylindrical bore 1 b accommodated in the upper end portion of the cylinder head 1 and a spring retainer 10 at the upper end portion of the valve stem. Is biased in a direction to close the open ends of the intake ports 1a and 1a.

  The camshaft 4 is disposed along the longitudinal direction of the engine, and a predetermined portion thereof is rotatably supported by a bearing portion 12 (described later) provided on the upper portion of the cylinder head 1 and provided at one end portion. Rotational force is transmitted from the crankshaft of the engine via a driven sprocket (not shown) and a timing chain wound around the driven sprocket.

  As shown in FIG. 2, the drive cam 5 is formed in a substantially cylindrical shape that is relatively long in the axial direction, and is disposed between the swing cams 7 and 7, and at a predetermined position of the camshaft 4. It is fixed to the unit. The outer peripheral surface of the drive cam 5 is formed in an eccentric cam profile, and the shaft center Y is offset from the shaft center X of the camshaft 4 by a predetermined amount in the radial direction.

  Each swing arm 6 has a concave lower surface at one end in contact with a stem end of each intake valve 3, and a spherical lower surface at the other end in a holding hole 1 c formed in the cylinder head 1. The hydraulic lash adjuster 13 is held in contact with and supported by the hydraulic lash adjuster 13 so that the hydraulic lash adjuster 13 swings around the pivot fulcrum. The swing arm 6 is rotatably supported by a needle roller 14 with which each swing cam 7 abuts at a substantially hollow center position.

  The hydraulic lash adjuster 13 has a general structure, and is provided with a bottomed cylindrical body 13a inserted into and fixed to the holding hole 1c, and slidable upward from the body 13a. And a plunger 13b whose spherical tip is in contact with the other end of the swing arm 6, and a high-pressure chamber 13c defined between the inner bottom of the body 13a and the partition wall of the plunger 13b. By appropriately supplying the hydraulic pressure via the check valve 13e, a gap (between the cam surface of the swing cam 7 and the needle roller 14) between the tip of the plunger 13b and the other end of the swing arm 6 is always provided. It is supposed to be zero.

  Each of the swing cams 7 has a substantially raindrop shape of the same shape, and a substantially U-shaped fitting groove 7a that fits to the outer peripheral surface of the camshaft 4 is formed on the base end side. The cam shaft 4 is swingably supported about the axis X of the camshaft 4 through the groove 7a, and the cam surface 7b is formed on the lower surface.

  The cam surface 7b includes a base circle surface on the base end side, a ramp surface extending in an arc shape from the base circle surface to the cam nose portion 7c, and a peak of a maximum lift from the ramp surface to the distal end side of the cam nose portion 7c. The base surface, the ramp surface, the lift surface and the top surface are formed on the outer peripheral surface of the needle roller 14 of each swing arm 6 according to the swing position of the swing cam 7. It comes in contact with the displaced position. Each cam surface 7b of each swing cam 7 is formed in the same cam profile.

  Further, on the cam nose portion 7c side of the swing cam 7, a pin hole through which a pin 20 connected to the other end portion of the link rod 17 to be described later is inserted is formed penetrating in both side surfaces.

  As shown in FIGS. 1 and 2, the transmission mechanism 8 includes a pair of left and right rocker arms 15 and 15 disposed above the camshaft 4, and one end portions 15a and 15a of the rocker arms 15 and 15 and a drive cam. A pair of link rods 16, 16 that link 5, and a pair of link rods 17 that link the other end portions 15 b, 15 b of each rocker arm 15 and cam nose portions 7 b, 7 b of both swing cams 7, 7, 17.

  Each rocker arm 15 has one end portion 15a projecting inward from the center of each cylindrical base to the inner side of the engine via a pin 18 and is rotatably connected to the projecting end of each link arm 16 while projecting to the outer side of the engine. Each other end portion 15 b is rotatably connected to one end portion of each link rod 17 by a pin 19. A large-diameter support hole 15c is formed through the cylindrical base portion.

  Each link arm 16 includes an annular portion 16a having a relatively large diameter, and the protruding end 16b projecting at a predetermined position on the outer peripheral surface of the annular portion 16a. A fitting hole 16c for fitting and supporting the outer peripheral surface of the drive cam 5 rotatably is formed therethrough.

  Each of the link rods 17 is integrally formed by press molding and has a substantially U-shaped cross section, and the inside is bent in a substantially arc shape for compactness. The cam nose portions 7c of the swing cams 7 are rotatably connected through pins 20 having end portions inserted into pin holes formed respectively.

  Both ends of the pins 19 and 20 are caulked, and are connected while being prevented from coming out from the pin holes of the other end portions 15b of the rocker arms 15 and the cam nose portions 7b of the swing cams 7. Yes.

  The control mechanism 9 includes a control shaft 21 disposed above the camshaft 4, and two control cams 22, 22 that are integrally fixed to the outer periphery of the control shaft 21 and serve as rocking fulcrums for the rocker arms 15. And an actuator (not shown) for controlling the rotation of the control shaft 21 and an electronic controller for controlling the rotation of the actuator.

  The control shaft 21 is disposed in the longitudinal direction of the engine in parallel with the camshaft 4 and is rotatably supported by a sub bracket 23 provided on the upper portion of the bearing portion 12.

  On the other hand, as shown in FIG. 1, each of the control cams 22 has a cylindrical shape, and each of the shaft centers P1 and P2 is eccentric from the shaft center P of the control shaft 21 by a predetermined amount by the thick portion. These eccentric amounts are different from each other. For this reason, the positions of the axes P1 and P2 are deviated, and accordingly, the support positions of the rocker arms 15 and 15 are slightly deviated in the radial direction as shown by the solid line and the broken line in FIG.

  The actuator includes an electric motor fixed to the rear end of the cylinder head 1 and a speed reducer that transmits the rotational driving force of the electric motor to the control shaft 21. The electric motor is constituted by a proportional DC motor, and is driven by a control signal from the electronic controller for detecting the operating state of the engine.

  The electronic controller includes various sensors such as a crank angle sensor that detects the engine speed, an air flow meter that detects the intake air amount, a water temperature sensor that detects the engine water temperature, and a potentiometer that detects the rotational position of the control shaft 21. The detection signal from the control signal is fed back to detect the current engine operating state by calculation or the like, the control signal is output to the electric motor, and the control shaft 21 is rotated forward or reverse, for example, to rotate the control cams 22. The position is controlled.

  When the control shaft 21 is rotationally controlled by the control mechanism 9 and the valve lift amount of each intake valve 3 is controlled to a small lift, the swing cams 7 are controlled by the different eccentric amounts of the control cams 22. , 7 so that a slight lift difference is generated in each intake valve 3, 3, and when the maximum lift is controlled, a lift difference is not generated in each intake valve 3, 3. Has been.

  As shown in FIG. 1, the bearing portion 12 includes a support frame 24 mounted and fixed on the upper deck upper surface of the cylinder head 1 in addition to the sub bracket 23, and an engine longitudinal direction on the upper surface of the support frame 24. The main bracket 25 is mounted and fixed at the equally spaced positions. The main bracket 25 and the sub bracket 23 are fastened together in a superposed state on the support frame 24 by a plurality of bearing bolts 26 and 26 inserted through left and right bolt insertion holes, respectively.

  The support frame 24 is formed of an aluminum alloy material or the like into a substantially rectangular frame shape along the outer shape of the cylinder head 1, and the vertical width thereof is set to a predetermined uniform width so that both side portions and front and rear end portions are formed. A plurality of mounting bolts 27 are fixed to the upper surface of the cylinder head 1.

  Hereinafter, the operation of the present embodiment will be described. First, in a low rotation range including, for example, idling operation of the engine, the electric motor is driven to rotate in one direction by a control signal from the electronic controller, and this rotational torque is The torque is transmitted to the control shaft 21 via the speed reducer, and the control shaft 21 is rotated by a predetermined amount in one direction. As a result, as shown in FIGS. 4A and 4B, the control cams 22 and 22 rotate in one direction, and the shaft centers P1 and P2 rotate around the shaft center P of the control shaft 21 with the same radius. Each thick part moves away from the camshaft 4 upward.

  Therefore, the other end portions 15b and 15b of the rocker arms 15 and 15 and the pivot points of the link rods 17 and 17 move upward with respect to the camshaft 4 as shown in FIG. The cams 7 and 7 are forcibly pulled up by a predetermined amount on the cam nose portions 7 b and 7 b through the link rods 17 and 17.

  Therefore, when the drive cam 5 rotates and pushes up the one end portions 15a and 15a of the rocker arms 15 and 15 through the link arms 16 and 16, the valve lift force swings through the link rods 17 and 17, respectively. It is transmitted from the cams 7 and 7 to the needle rollers 14 and 14 of the swing arms 6 and 6, and the valve lift amount of the intake valves 3 and 3 becomes sufficiently small as shown in FIG. 6A.

  Therefore, in the low rotation region of such an engine, the valve lift amount of each intake valve 3, 3 becomes small, the opening timing of each intake valve 3, 3 is delayed, and the valve overlap with the exhaust valve becomes small. For this reason, improvement in fuel consumption and stable rotation of the engine can be obtained.

  In addition, at the time of such small lift control, there is a difference in the valve lift amount between the first intake valve 3 and the second intake valve 3 via the swing cams 7, 7 due to the difference in eccentricity between the two control cams 22, 22. As a result (see FIG. 6A), a strong intake swirl can be generated in the cylinder. For this reason, combustion is accelerated | stimulated and the stabilization of the said fuel consumption and engine rotation can further be improved.

  Further, when the engine shifts from the middle rotation to the high rotation region, when the electric motor rotates in reverse by the control signal from the controller and rotates the speed reducer in the same direction, the control shaft 21 controls each control along with this rotation. As the cams 22 and 22 are rotated in the other direction, the shaft centers P1 and P2 of the control cams 22 and 22 move downward as shown in FIGS. For this reason, the rocker arms 15 and 15 are now moved in the direction of the camshaft 4 so that the cam noses 7c and 7c of the swing cams 7 and 7 are connected to the link rods 17 and 15b by the other ends 15b and 15b. By pressing downward through 17, the entire swing cams 7, 7 are rotated counterclockwise by a predetermined amount.

  Accordingly, the contact positions of the cam surfaces 7b and 7b with respect to the needle rollers 14 and 14 of the swing arms 6 and 6 of the swing cams 7 and 7 move to the cam nose portion 7c side (lift portion side). For this reason, when the drive cam 5 rotates during the opening operation of the intake valves 3 and 3 and the one end portions 15a and 15a of the rocker arms 15 and 15 are pushed up via the link arms 16 and 16, respectively, The lift amount with respect to 6 is sufficiently large.

  Therefore, in such a high rotation region, the valve lift amount of each intake valve 3, 3 is maximized as shown in FIG. 6B, and the opening timing of each intake valve 3, 3 is advanced and the closing timing is delayed. . As a result, the intake charging efficiency is improved and sufficient output torque can be secured.

  Further, in the maximum lift control region, as shown in FIG. 6B, the lift amounts of the first and second intake valves 3 and 3 are almost the same. Therefore, the occurrence of swirl in the cylinder is sufficiently suppressed, so that the above-described intake charging efficiency can be improved and the output torque can be increased.

  Further, in this first embodiment, the structure of the entire apparatus can be simplified by making the drive cam 5 single, and the manufacturing and assembly work efficiency is improved. In addition, with the unification of the drive cam 5, restrictions on the arrangement location of the drive cam 5 are reduced, so that the degree of freedom in layout is improved.

In addition, since the cam profiles of the two swing cams 7 and 7 can be set to be the same, the manufacturing operation of the swing cams 7 and 7 can be facilitated, and the cost can be reduced in this respect.
[Second Embodiment]
7 and 8 show a second embodiment of the present invention. In addition to the drive cam 5, the link arm 16 is also formed in a single structure, and the outer peripheral surface of the drive cam 5 is fitted through the fitting hole 16c. An annular portion 16a to be joined is formed as a single unit, and a protruding end 16b provided integrally with an end portion of the annular portion 16a is formed in a bifurcated shape.

  The drive cam 5 is formed with a smaller width W in the axial direction than in the first embodiment, while the annular portion 16a also has a width W substantially equal to that of the drive cam 5. Are formed identically.

  Further, the projecting end 16b is formed in a U shape by being bifurcated to the left and right from the base portion of the annular portion 16a, and the rocker arms 15 and 15 are adjacent to each other between the bifurcated pieces 16d and 16d. The one end portions 15a and 15a bent in this way are accommodated and arranged, and the one end portion 15a and 15a is inserted into the pin holes 15d and 15e formed therein, respectively. Are pivotally connected. In this case, one pin hole 15e out of the pin holes 15d and 15e formed in the one end portions 15a and 15a is an oblong oblong hole along the longitudinal direction of the one end portion 15a as shown in FIG. So that the relative displacement of one of the rocker arms 15 accompanying the rotation of the control cams 22, 22 can be absorbed.

  Further, the center positions of the one end portions 15a, 15a (center line in FIG. 7) are arranged so as to be located at least inside the width length W of the drive cam 5, and thus are generated in the link arm 16 during operation. An increase in the falling moment is prevented. Other configurations are the same as those of the first embodiment.

  Therefore, according to this embodiment, the same operation effect as the first embodiment can be obtained, and the link arm 16 is also unified, so that the number of parts can be further reduced and the manufacturing and assembly work efficiency is improved. In addition, the cost can be reduced.

  Further, the entire apparatus can be made compact, the layout flexibility is further improved, and the mounting property to the internal combustion engine is improved.

[Third embodiment]
9 to 11 show a third embodiment, in which the link arm 16 is eliminated and the end portions 15a and 15a of the rocker arms 15 and 15 are directly connected to the outer peripheral surface of the drive cam 5 via the rollers 30 and 30, respectively. Are linked together.

  That is, the drive cam 5 is integrally formed in a general oval shape as shown in FIG. 11, and the width in the axial direction is that of the W2 second embodiment as shown in FIG. Is formed into divided cams 5b and 5c which are divided into left and right in the axial direction by an annular groove 5a formed at a substantially central position in the axial direction. These cams are formed in the same cam profile. In this way, since the adjacent cam profiles are the same, they can be machined together with a large grindstone, which has the advantage of facilitating the machining operation. Note that the drive cam 5 can be integrally formed on the left and right without forming the annular groove 5a.

  On the other hand, rollers 30 and 30 are rotatably attached to the bifurcated end portions of the rocker arm one end portions 15a and 15a via roller shafts 31 and 31, respectively. The divided cams 5b and 5c of the drive cam 5 are in rolling contact with each other. Further, the one end portions 15a and 15a of the rocker arms are biased so that the rollers 30 and 30 are always elastically contacted by the spring members 32 on the outer peripheral surfaces of the divided cams 5b and 5c. The spring member 32 is a torsion spring, and one end portion 32a is locked and fixed to the bearing 12, and the other end portion 32b is elastically contacted with the one end portions 15a and 15a of the rocker arm so that the rollers 30 and 30 are divided. The cams 5b and 5c are pressed in the direction. Other configurations are the same as those of the first embodiment.

  Therefore, this embodiment can obtain the same operation effect as the first embodiment, and also eliminates the link arm, so that the production and assembly work efficiency is greatly improved by further reducing the number of parts.

  In addition, with the abolition of the link arm, the rollers 30 and 30 are brought into rolling contact with the divided cams 5b and 5c of the drive cam 5, so that the friction between the rollers 30 and 30 is greatly reduced, and the lift force of the drive cam 5 is increased. Can be transmitted efficiently.

  The present invention is not limited to the configuration of each of the embodiments described above, and can be applied to the exhaust valve side, and the structure of the swing cams 7, 7 of the transmission mechanism 8 and the structure of the link rod 17. The link rod 17 can be eliminated and the other end portions 15b and 15b of the rocker arms 15 and 15 can be directly connected to the swing cams 7 and 7, respectively.

  Further, it is also possible to provide a lift difference between the intake valves 3 and 3 when shifting from a low engine speed to a middle engine speed or during a medium engine rotation.

It is principal part sectional drawing of the variable valve apparatus in 1st Example. It is a principal part front view of the variable valve apparatus in a present Example. It is a top view which shows the principal part of the variable valve apparatus in a present Example. A is a schematic diagram illustrating a valve closing state during minimum lift control in the present embodiment, and B is a schematic diagram illustrating a valve opening state. A is a schematic diagram showing a valve closing state during maximum lift control in this embodiment, and B is a schematic diagram showing a valve opening state. A is a lift characteristic diagram of both intake valves during the small lift control of this embodiment, and B is a lift characteristic diagram of both intake valves during the maximum lift control. It is a principal part side view of the variable valve apparatus of 2nd Example of this invention. It is a principal part top view of the variable valve apparatus of the 2nd Example. It is a principal part side view of the variable valve apparatus of 3rd Example. It is a principal part top view of the variable valve apparatus of the 3rd Example. It is principal part sectional drawing of the variable valve apparatus of the 3rd Example.

Explanation of symbols

1 ... Cylinder head 3 ... Intake valve (engine valve)
DESCRIPTION OF SYMBOLS 4 ... Cam shaft 5 ... Drive cam 7 ... Swing cam 8 ... Transmission mechanism 9 ... Control mechanism 15 ... Rocker arm 16 ... Link arm 17 ... Link rod 21 ... Control shaft 22 ... Control cam

Claims (4)

A camshaft to which rotational force is transmitted from the crankshaft;
A single drive cam provided on the outer periphery of the camshaft;
A control shaft disposed parallel to the camshaft;
Two control cams provided on the outer periphery of the control shaft and having different eccentric amounts with respect to the axis of the control shaft;
Two swing cams each for opening and closing two engine valves provided per cylinder on the intake side or exhaust side;
There are two rocker arms that link the drive cam and the swing cams while being supported by the control cams so as to be swingable, and transmit a swing force to the swing cams as the drive cams rotate. A transmission mechanism;
By rotating the respective control cams via the control shaft, the postures of the two rocker arms are relatively changed, and at least the small lift control of the engine valve is performed, the valve lift difference between the two engine valves is determined. A variable valve operating apparatus for an internal combustion engine, comprising The variable valve operating apparatus for an internal combustion engine according to claim 1,
The variable valve for an internal combustion engine, wherein the two rocker arms are set to have substantially the same posture and the valve lift amounts of the two engine valves are set to be substantially the same during the maximum lift control of the two engine valves. apparatus. The variable valve operating apparatus for an internal combustion engine according to claim 1 or 2,
The transmission mechanism is
The two rocker arms swingably supported on the outer periphery of the two control cams;
A link arm that links the drive cam and one end of each rocker arm;
A link rod that links the other end of each rocker arm and each rocking cam;
A variable valve operating apparatus for an internal combustion engine, wherein one end of the link arm is fitted to the outer periphery of the single drive cam. The variable valve operating apparatus for an internal combustion engine according to claim 3,
A variable valve operating apparatus for an internal combustion engine, wherein the link arm is formed as a single unit corresponding to the drive cam.

Images