JP4752949B2 - Variable valve operating device for internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine.

  Conventionally, for example, Patent Document 1 discloses a variable valve operating apparatus for an internal combustion engine. This conventional variable valve operating apparatus is driven by an intake or exhaust valve, a low-speed cam, a high-speed cam, a low-speed cam, a main rocker arm that drives the valve, and a high-speed cam. And a sub-rocker arm. Further, the variable valve operating apparatus includes a hydraulic piston mechanism as a mode switching unit capable of switching between a non-linked mode in which the sub rocker arm is not linked to the main rocker arm and a linked mode in which the sub rocker arm is linked to the main rocker arm.

JP-A-6-33714 Japanese Patent Laid-Open No. 10-196334 JP-T-2006-520869

  By the way, when switching the valve opening characteristics of the variable valve operating apparatus of the internal combustion engine that can switch the valve opening characteristics in accordance with the operation performed by the actuator, the inertia of the member driven by the actuator is large, If the frictional force generated on the member during driving of the actuator is large, the driving force of the actuator necessary to drive the member becomes large. Therefore, in order to switch the valve opening characteristics with power saving, it is desirable that the inertia of the member is small and the frictional force generated in the member is small.

  The present invention has been made in order to solve the above-described problems. In accordance with the operation performed by the actuator while reducing the inertia of the member driven by the actuator and reducing the frictional force generated in the member. An object of the present invention is to provide a variable valve operating apparatus for an internal combustion engine capable of satisfactorily switching the valve opening characteristics of valves provided in at least two cylinders.

A first invention is a variable valve operating apparatus for an internal combustion engine,
A transmission member that is disposed between the cam and the valve and transmits the acting force of the cam to the valve;
A camshaft to which the cam is attached;
A guide rail provided on the outer peripheral surface of the cylindrical portion attached to the camshaft;
A main displacement member having an engaging portion detachably engageable with the guide rail, and capable of being displaced in an axial direction of the camshaft;
A member connecting shaft that is connected to the main displacement member in a manner that is freely rotatable and restrains movement in the axial direction, and that is supported so as to be displaceable in the axial direction;
An actuator for generating a driving force for engaging the engaging portion with the guide rail,
During operation of the actuator, the main displacement member is rotated about the member connecting shaft, and then the engaging portion and the guide rail are engaged.
Provided in at least two cylinders by changing the operating state of the transmission member in accordance with the displacement of the main displacement member and the member connecting shaft that occur during the engagement between the engagement portion and the guide rail. The valve opening characteristic of the valve is switched.

The second invention is the first invention, wherein
The main displacement member, the guide rail, and the actuator are provided in at least one cylinder that is not all cylinders of the internal combustion engine,
The variable valve operating apparatus is further provided with a sub-displacement member that is provided in a remaining cylinder that is not provided with the main displacement member, and that is displaced in conjunction with the main displacement member via the member connecting shaft,
With the displacement of the main displacement member that occurs during the engagement of the engagement portion and the guide rail, the operating state of the transmission member of the cylinder provided with the main displacement member changes,
In accordance with the displacement of the sub-displacement member interlocked with the displacement of the main displacement member, the operating state of the transmission member of the remaining cylinders provided with the sub-displacement member changes.

The third invention is the second invention, wherein
The transmission member includes, in each of the at least two cylinders, a first rocker arm that swings in synchronization with the cam, and a second rocker arm that can push the valve,
The variable valve operating apparatus further includes a switching pin that is movably disposed in a pin hole formed in each of the first rocker arm and the second rocker arm,
The switching pin in the cylinder provided with the main displacement member is displaced in conjunction with the displacement of the main displacement member,
The switching pin in the cylinder provided with the sub-displacement member is displaced in conjunction with the displacement of the sub-displacement member,
In the cylinder provided with the main displacement member, a connection state in which the first rocker arm and the second rocker arm are connected via the switching pin in accordance with the displacement of the main displacement member, The connection with the disconnected state is switched,
In the cylinder provided with the sub-displacement member, a connection state in which the first rocker arm and the second rocker arm are connected via the switching pin in accordance with the displacement of the sub-displacement member; It is characterized by switching to a non-connected state in which the connection is released.

Moreover, 4th invention is set in 3rd invention,
The member connecting shaft is disposed inside a rocker shaft that supports the first rocker arm and the second rocker arm.

The fifth invention is the third or fourth invention, wherein
The second rocker arm is shared by a plurality of the valves provided in the same cylinder.

According to a sixth invention, in any one of the first to fifth inventions,
The member connecting shaft has an annular or arc-shaped groove on the outer peripheral surface, and penetrates the inside of the main displacement member,
The variable valve device further includes a pin that penetrates the main displacement member and engages with the groove.

  According to the first invention, since the main displacement member and the member connecting shaft are connected in a freely rotatable manner, when the actuator is operated to engage the engaging portion and the guide rail, the member connecting shaft. The main displacement member rotates independently without rotating. For this reason, according to the present invention, the inertia of the member driven by the actuator is reduced, and the friction force generated in the member is reduced, and the valve provided in at least two cylinders in accordance with the operation performed by the actuator. It is possible to switch the valve opening characteristics satisfactorily.

  According to the second invention, the configuration of the first invention makes it possible to reduce the inertia of the member driven by the actuator and reduce the frictional force generated in the member, and to displace the main displacement member and The operating state of the transmission member of each cylinder can be changed using the displacement of the interlocking sub displacement member.

  According to the third aspect of the present invention, in the variable valve operating system that switches between the state where the first rocker arm and the second rocker arm are connected and the unconnected state where the connection is released using the displacement of the switching pin. It is possible to switch between the connected state and the disconnected state while reducing the inertia of the member driven by the actuator and reducing the frictional force generated in the member.

  According to the fourth aspect of the present invention, the space on the cylinder head of the internal combustion engine is effectively used, compared with the case where the member connecting shaft is supported separately from the rocker shaft, and the variable valve operating system for the internal combustion engine is Mountability can be improved.

  According to the fifth aspect of the present invention, the second rocker arm is shared by a plurality of valves provided in the same cylinder as compared with the case where one valve is driven by one second rocker arm. It is possible to secure a mounting space for the main displacement member and the sub-displacement member for switching the operation state of the valve by using the created empty space.

  According to the sixth aspect of the invention, the main displacement member and the member connection shaft in a mode in which the groove formed in the member connection shaft and the pin passing through the main displacement member are engaged and the movement in the axial direction is restricted. Can be suitably realized.

1 is a perspective view showing a variable valve operating apparatus for an internal combustion engine according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a plane including the axis of the rocker shaft and the axis of the switching pin shown in FIG. It is a disassembled perspective view of the characteristic component of the variable valve apparatus shown in FIG. It is the figure which looked at the variable valve apparatus shown in FIG. 1 from the axial direction (more specifically, the direction of arrow A in FIG. 2 (A)) of a camshaft (and rocker shaft).

Embodiment 1 FIG.
Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS.
[Configuration of variable valve gear]
(Basic configuration of variable valve operating device)
FIG. 1 is a perspective view showing a variable valve gear 10 for an internal combustion engine 1 according to Embodiment 1 of the present invention. In FIG. 1, the camshaft 18 described later is not shown. In FIG. 1, illustrations other than some of the cylinders (# 1 and # 2) are omitted, but the internal combustion engine 1 of the present embodiment has four cylinders (# 1 to # 4) as an example. It is assumed that the engine is an in-line four-cylinder engine having In addition, each cylinder of the internal combustion engine 1 is provided with two intake valves and two exhaust valves. The variable valve operating device 10 functions as a device that drives two intake valves or two exhaust valves disposed in each cylinder.

  As shown in FIG. 1, each cylinder of the internal combustion engine 1 is provided with a first rocker arm 12 and a second rocker arm 14 adjacent to each other. The rocker arms 12 and 14 of each cylinder are supported by a single rocker shaft 16 so as to be rotatable (oscillated).

FIG. 2 is a cross-sectional view taken along a plane including the axis of the rocker shaft 16 shown in FIG. 1 and the axis of a switching pin 38 to be described later, except for the camshaft 18. 2A shows the variable valve apparatus 10 in a connected state, which will be described later, and FIG. 2B shows the variable valve apparatus 10 in an unconnected state, which will be described later.
The camshaft 18 is connected to a crankshaft (not shown) by a timing chain or a timing belt, and is configured to rotate at a half speed of the crankshaft. As shown in FIG. 2, the camshaft 18 is formed with one main cam 20 and one sub cam 22 per cylinder. The rocker shaft 16 is arranged in parallel with the camshaft 18.

  The main cam 20 is configured as a cam (lift cam) having an arc-shaped base circle portion coaxial with the camshaft 18 and a nose portion formed so as to bulge a part of the base circle radially outward. It is assumed that Moreover, in this embodiment, the subcam 22 shall be comprised as a cam (zero lift cam) which has only a base circle part.

  As shown in FIGS. 1 and 2, a first roller 24 is rotatably attached to the first rocker arm 12 at a position where it can contact the main cam 20. The first rocker arm 12 is biased by a coil spring (not shown) attached to the rocker shaft 16 so that the first roller 24 is always in contact with the main cam 20. The first rocker arm 12 configured as described above swings about the rocker shaft 16 as a fulcrum by the cooperation of the acting force of the main cam 20 and the biasing force of the coil spring.

  A second roller 26 is rotatably attached to the second rocker arm 14 at a position where it can contact the sub cam 22. Further, at the end of the second rocker arm 14 on the rocker shaft 16 side, the rocker shaft 16 is supported by a cam carrier 27 (or a cylinder head or the like) that is a stationary member of the internal combustion engine 1 via a lash adjuster (not shown). It is assumed that The second roller 26 provided on the second rocker arm 14 is urged toward the sub cam 22 by receiving a pushing force from the lash adjuster.

  Further, an abutting portion 14 a that abuts against the two valves 28 is provided at the end of the second rocker arm 14 opposite to the rocker shaft 16. That is, the second rocker arm 14 is shared by these two valves 28, and more specifically, is disposed so as to be positioned between the two valves 28 provided in the same cylinder. . Further, the valve 28 is urged in the valve closing direction by a valve spring 30 shown in FIG.

(Configuration of switching mechanism)
The variable valve operating apparatus 10 includes a connected state in which the first rocker arm 12 and the second rocker arm 14 are connected (see FIG. 2A) and an unconnected state in which the connection is released (see FIG. 2B). And a switching mechanism 32 for switching between. By providing such a switching mechanism 32, a state in which the acting force of the main cam 20 is transmitted to the second rocker arm 14 via the first rocker arm 12 (the above-described connected state), and the acting force are transmitted to the second rocker. The valve opening characteristic of the valve 28 can be switched by switching the state (not connected state) that is not transmitted to the arm 14.

The detailed configuration of the switching mechanism 32 will be described below with reference to FIGS. 3 and 4 in addition to FIGS.
As shown in FIG. 2, a first pin hole 34 a concentric with the first roller 24 is formed inside the support shaft 34 of the first roller 24, and inside the support shaft 36 of the second roller 26. A second pin hole 36a concentric with the second roller 26 is formed.

  The centers of the pin holes 34a and 36a are arranged in the same arc shape with the rocker shaft 16 being the center of rotation of the rocker arms 12 and 14 as the center. When the first roller 24 is in contact with the base circle of the main cam 20 and the second roller 26 is in contact with the base circle of the sub cam 22, the position of the first pin hole 34a and the second pin The position of the hole 36a matches.

  Further, a cylindrical switching pin 38 is movably disposed in the pin holes 34a and 36a. The first pin hole 34a is closed at the end opposite to the second rocker arm 14 and is opened at the end on the second rocker arm 14 side. A return spring 40 that urges the switching pin 38 toward the second rocker arm 14 (hereinafter referred to as “the advancement direction of the switching pin”) is disposed inside the first pin hole 34a. More specifically, the return spring 40 is configured to constantly urge the switching pin 38 toward the second rocker arm 14 in the mounted state.

  The second pin hole 36a is a through hole, and a cylindrical piston 42 is movably inserted therein. Further, in the # 1 cylinder, a first link arm 44 having an arm portion 44a that contacts the piston 42 is disposed on the side surface of the second rocker arm 14 opposite to the first rocker arm 12. The first link arm 44 is attached to the rocker shaft 16.

  On the other hand, in the # 2 cylinder, on the side surface of the second rocker arm 14 opposite to the first rocker arm 12, a second link arm 46 having an arm portion 46a that contacts the piston 42 is disposed. The second link arm 46 is attached to the rocker shaft 16.

  The difference between the first link arm 44 and the second link arm 46 is as follows. That is, a protrusion 44 b is provided at the tip of the arm portion 44 a of the first link arm 44 so as to protrude toward the peripheral surface of the camshaft 18. Further, a pressing surface 44 c that is pressed by an electromagnetic solenoid 54 described later is provided at the end of the first link arm 44 on the opposite side of the arm portion 44 a. It is assumed that the link arm provided in the # 3 and 4 cylinders, not shown, is the same as the second link arm 46 as in the # 2 cylinder.

  FIG. 3 is an exploded perspective view of the characteristic components of the variable valve operating apparatus 10 shown in FIG. In FIG. 3, the rollers 24 and 26 and the switching pin 38 disposed inside thereof are not shown. 4 shows the variable valve apparatus 10 shown in FIG. 1 as viewed from the axial direction of the camshaft 18 (and the rocker shaft 16) (more specifically, from the direction of arrow A in FIG. 2A). It is a figure.

  As shown in FIGS. 3 and 4, the rocker shaft 16 is formed in a hollow shape. A link shaft 48 is slidably inserted between the rocker shaft 16 and the rocker shaft 16. The link shaft 48 includes a first link arm 44 disposed in the # 1 cylinder and a second link arm 46 disposed in the # 2 to # 4 cylinders so that they can be simultaneously displaced in the axial direction of the rocker shaft 16. Shaft.

  As shown mainly in FIG. 3, four annular grooves 48 a are formed in the link shaft 48 corresponding to the arrangement positions of the link arms 44 and 46 of each cylinder. Further, four through holes 16 a are formed on the peripheral surface of the rocker shaft 16 corresponding to each annular groove 48 a.

  Further, as shown in FIG. 4, the link shaft 48 and the rocker shaft 16 into which the link shaft 48 is inserted penetrate the link arms 44 and 46. As shown in FIG. 3, the link arms 44 and 46 are formed with press-fit pin holes 44d and 46b for receiving the press-fit pins 50, respectively. Each press-fit pin 50 passes through the link arms 44 and 46 through the press-fit pin holes 44d and 46b, and then engages with each annular groove 48a as shown in FIG.

  The width of the annular groove 48a is set to be equal to the diameter of the press-fit pin 50. Further, each through-hole 16a of the rocker shaft 16 interferes with the press-fit pin 50 and prevents the rotation of the first link arm 44 when the first link arm 44 rotates in accordance with the operation of an electromagnetic solenoid 54 described later. It is formed in a size with a margin so that it does not occur. Furthermore, each through-hole 16a does not interfere with the press-fit pin 50 and prevent the movement of the link shaft 48 when the link shaft 48 moves in the axial direction in accordance with the operation of the electromagnetic solenoid 54. It is formed on the long hole.

  By adopting the configuration as described above, the first link arm 44 is connected to the link shaft 48 in a manner that allows rotation and restrains movement in the axial direction. Similarly, the second link arm 46 is also connected to the link shaft 48 in a manner that is free to rotate and restrains movement in the axial direction.

  As shown in FIGS. 2 and 4, in the camshaft 18, a cylindrical portion 18 a formed in a cylindrical shape is formed on the outer peripheral surface facing the protruding portion 44 b provided on the arm portion 44 a of the first link arm 44. Is formed. A spiral guide rail 52 extending in the circumferential direction is formed on the outer peripheral surface of the cylindrical portion 18a. Here, the guide rail 52 is formed as a spiral groove.

  Further, the switching mechanism 32 includes an electromagnetic solenoid 54 as an actuator that generates a driving force for engaging (inserting) the protruding portion 44 b with the guide rail 52. The electromagnetic solenoid 54 is duty-controlled based on a command from an ECU (Electronic Control Unit) 56. The ECU 56 is an electronic control unit for controlling the operating state of the internal combustion engine 1.

  The electromagnetic solenoid 54 is fixed to a stationary member such as the cam carrier 27 at a position where the drive shaft 54a can press the pressing surface 44c of the first link arm 44 toward the guide rail 52.

  Further, the direction of the spiral in the guide rail 52 is such that when the camshaft 18 rotates in the predetermined rotation direction shown in FIG. 4 with the protrusion 44b inserted therein, the first link arm 44, the first link The link shaft 48 interlocked with the link arm 44 and the second link arm 46 driven by the link shaft 48 are set to be displaced leftward in FIG. More specifically, the left direction in FIG. 2 means that each of the first link arm 44 and the second link arm 46 retracts the switching pin 38 against the urging force of the return spring 40 (the switching pin described above). And the first link arm 44 and the second link arm 46 come closer to the rocker arms 12 and 14.

  Here, the position of the first link arm 44 in FIG. 2A, that is, the switching pin 38 is inserted into both the first pin hole 34a and the second pin hole 36a by the urging force of the return spring 40. The position of the first link arm 44 at the time is referred to as “displacement end Pmax1”. When the first link arm 44 is positioned at the displacement end Pmax1, the first rocker arm 12 and the second rocker arm 14 are connected to each other. The position of the first link arm 44 in FIG. 2B, that is, the switching pin 38 receives a force utilizing the rotational force of the camshaft 18 from the link arms 44 and 46, whereby the switching pin 38 and the piston 42 are moved. The position of the first link arm 44 when only inserted into the first pin hole 34a and the second pin hole 36a is referred to as “displacement end Pmax2”. That is, when the first link arm 44 is positioned at the displacement end Pmax2, the first rocker arm 12 and the second rocker arm 14 are in the non-connected state.

  In the present embodiment, the position of the start end 52a of the guide rail 52 in the axial direction of the camshaft 18 is set to coincide with the position of the protrusion 44b when the first link arm 44 is positioned at the displacement end Pmax1. Yes. The position of the terminal end 52b of the guide rail 52 in the axial direction of the camshaft 18 is set to coincide with the position of the protrusion 44b when the first link arm 44 is positioned at the displacement end Pmax2. That is, in the present embodiment, the first link arm 44 is configured to be displaceable between the displacement ends Pmax1 and Pmax2 within the range in which the protrusion 44b is guided by the guide rail 52.

  Further, as shown in FIG. 4, the guide rail 52 gradually moves as the camshaft 18 rotates as a predetermined section on the end 52 b side after the first link arm 44 reaches the displacement end Pmax 2. A shallow bottom portion 52c that is shallower is provided. In addition, the depth of parts other than the shallow bottom part 52c in the guide rail 52 is constant.

  Further, the first link arm 44 is provided with a notch 44e formed in a concave shape by notching a part of the pressing surface 44c. The pressing surface 44c is provided so that the state in contact with the drive shaft 54a is maintained while the first link arm 44 is displaced from the displacement end Pmax1 to Pmax2. The notch 44e is driven when the projection 44b is taken out to the surface of the cylindrical portion 18a by the action of the shallow bottom portion 52c in a state where the first link arm 44 is positioned at the displacement end Pmax2. It is provided in the part which can be engaged.

  The notch 44e can restrict the rotation of the first link arm 44 in the direction in which the protrusion 44b is inserted into the guide rail 52, and the first link arm 44 moves in the advance direction of the switching pin. It is formed so as to engage with the drive shaft 54a in such a manner that it can be restricted.

  As described above, energization is controlled by the switching pin 38, the return spring 40, the piston 42, the first link arm 44, the second link arm 46, the link shaft 48, the press-fit pin 50, the guide rail 52, and the ECU 56. The switching mechanism 32 is configured by the electromagnetic solenoid 54.

[Operation of variable valve gear]
(When the valve is operating)
When the valve is in an operating state, the drive of the electromagnetic solenoid 54 is turned off, so that the first link arm 44 receives the urging force of the return spring 40 in a state of being separated from the camshaft 18 to the displacement end Pmax1. positioned. In this state, as shown to FIG. 2 (A), the 1st rocker arm 12 and the 2nd rocker arm 14 are connected via the switching pin 38 (the said connection state). As a result, the acting force of the main cam 20 is transmitted from the first rocker arm 12 to both valves 28 via the second rocker arm 14. Therefore, a normal lift operation of the valve 28 is performed according to the profile of the main cam 20.

(Valve stop control)
The valve stop operation is performed, for example, when a request for executing a predetermined valve stop operation such as a fuel cut request of the internal combustion engine 1 is detected by the ECU 56. First, energization of the electromagnetic solenoid 54 is started at a predetermined timing. As a result, the first link arm 44 rotates around the rocker shaft 16 (link shaft 48) clockwise in FIG. As described above, the first link arm 44 is connected to the link shaft 48 in a rotatable manner. Therefore, the link shaft 48 is prevented from rotating with the rotation of the first link arm 44.

  When the first link arm 44 rotates as described above, the protrusion 44 b engages with the guide rail 52. As a result, the projection 44b is guided by the guide rail 52, so that the first link arm 44 moves toward the displacement end Pmax2 using the rotational force of the camshaft 18. Then, the driving force of the first link arm 44 from the guide rail 52 is transmitted to each second link arm 46 via the press-fit pin 50 and the link shaft 48, so that the link shaft connected to the first link arm 44. 48, and further, each second link arm 46 connected to the link shaft 48 is displaced in conjunction with the first link arm 44.

  When the first link arm 44 reaches the displacement end Pmax2, the switching pin 38 is returned into the first pin hole 34a, so that the first rocker arm 12 and the second rocker arm 14 are disconnected. As a result, the acting force of the main cam 20 is not transmitted from the first rocker arm 12 to the second rocker arm 14. The sub cam 22 with which the second roller 26 abuts is a zero lift cam. For this reason, the force for driving the valve 28 is not applied to the second rocker arm 14 to which the acting force of the main cam 20 is not transmitted. As a result, the second rocker arm 14 is in a stationary state regardless of the rotation of the main cam 20, and the lift operation of the valve 28 is stopped at the valve closing position.

(Operation to keep the valve stopped)
When the first link arm 44 reaches the displacement end Pmax2, the first link arm 44 is rotated in a direction away from the camshaft 18 (guide rail 52) by the action of the shallow bottom portion 52c of the guide rail 52. . Then, when the first link arm 44 further rotates until the drive shaft 54a continuously driven by the electromagnetic solenoid 54 coincides with the notch 44e, the portion on the first link arm 44 side that contacts the drive shaft 54a is changed. It switches from the pressing surface 44c to the notch 44e. As a result, the drive shaft 54a engages with the notch 44e, so that the first link arm 44 has the projection 44b away from the camshaft 18 and the urging force of the return spring 40 by the drive shaft 54a. It will be held in a state of being received. As a result, the state where the first rocker arm 12 and the second rocker arm 14 are disconnected, that is, the valve stop state is maintained. Further, according to the holding operation of the first link arm 44 by the drive shaft 54a using such a notch 44e, friction caused by sliding between the rotating camshaft 18 and the drive shaft 54a and wear of the drive shaft 54a are caused. The valve stop state can be maintained while avoiding the occurrence.

(Valve return operation)
The valve return operation for returning from the valve stop state to the valve operation state is performed, for example, when a request for executing a predetermined valve return operation such as a return request from a fuel cut is detected by the ECU 56. Such a valve return operation is started by turning off the energization of the electromagnetic solenoid 54 at a predetermined timing. When the energization of the electromagnetic solenoid 54 is turned off, the engagement between the cutout portion 44e of the first link arm 44 and the drive shaft 54a is released. As a result, the force that keeps the switching pin 38 in the first pin hole 34a against the urging force of the return spring 40 disappears. As a result, the switching pin 38 is moved in the advancing direction by the biasing force of the return spring 40, and the first rocker arm 12 and the second rocker arm 14 are connected via the switching pin 38, that is, the main cam. The operating force 20 returns to a state in which the valve 28 can be lifted. Further, as the switching pin 38 moves in the advance direction by the urging force of the return spring 40, the first link arm 44 (and the link shaft 48 and the second link arm 46 linked thereto) are connected via the piston 42. Is returned from the displacement end Pmax2 to the displacement end Pmax1.

  According to the variable valve operating apparatus 10 of the present embodiment configured as described above, ON / OFF of energization to the electromagnetic solenoid 54, the rotational force of the camshaft 18, and the urging force of the return spring 40 are used. By moving the axial position of the first link arm 44 between the displacement ends Pmax1 and Pmax2, the valve 28 is moved between the valve operating state and the valve stopped state in the # 1 cylinder on which the first link arm 44 is mounted. The operating state can be switched, and the valve operating state and the valve stop are also applied to the remaining cylinders (# 2 to # 4) via the link shaft 48 and the second link arm 46 interlocking with the first link arm 44. It is possible to switch the operating state of the valve 28 between the states. As described above, according to the variable valve operating apparatus 10, the operation state of the valves 28 disposed in the four cylinders of the internal combustion engine 1 can be switched using one electromagnetic solenoid 54. Moreover, according to the variable valve operating apparatus 10 having the above-described configuration, the valve stop state can be brought into a highly responsive state while the camshaft 18 makes one rotation by using the rotational force of the camshaft 18.

  Moreover, in the variable valve operating apparatus 10 demonstrated above, the 1st link arm 44 is connected with the link shaft 48 in the aspect which restrained the movement of the axial direction freely. According to such a connection method, when the electromagnetic solenoid 54 presses the first link arm 44, the first link arm 44 rotates independently without the link shaft 48 rotating. Unlike such a configuration, when the first link arm is fixed to the link shaft, the link shaft rotates in conjunction with the rotation of the first link arm accompanying energization of the electromagnetic solenoid. As a result, when the protrusion is engaged with the guide rail, the inertia of the member driven by the electromagnetic solenoid is increased by the amount corresponding to the link shaft, and the frictional force generated on the member when the electromagnetic solenoid is driven is increased when the link shaft rotates. The resulting amount of sliding with the rocker shaft increases. For this reason, the required thrust of an electromagnetic solenoid becomes large and a large electromagnetic solenoid will be needed.

  On the other hand, in this embodiment, since the first link arm 44 and the link shaft 48 are configured to be rotatable, the electromagnetic solenoid 54 drives the protrusion 44b when engaging the guide rail 52. It is possible to reduce the inertia of the member and reduce the frictional force generated in the member. Thereby, the required thrust of the electromagnetic solenoid 54 can be reduced favorably, and the electromagnetic solenoid 54 can be reduced in size.

  In the variable valve operating apparatus 10, the link arms 44 and 46 are mounted on the rocker shaft 16 that functions as a support shaft for the rocker arms 12 and 14. Further, the two valves 28 in the same cylinder are simultaneously driven by the second rocker arm 14 having a contact portion 14a that contacts both. According to such a configuration, as compared with the case where a single valve is driven by a single second rocker arm, the valve is used by utilizing the empty space obtained by sharing the second rocker arm 14. The link arms 44 and 46 for switching the operation states of 28 can be mounted. Thereby, the space on the cylinder head of the internal combustion engine 1 can be effectively used, and the mountability of the variable valve apparatus 10 to the internal combustion engine 1 can be improved.

  In the variable valve operating apparatus 10, a link shaft 48 for transmitting the driving force of the first link arm 44 from the guide rail 52 to the second link arms 46 of the remaining cylinders is disposed in the rocker shaft 16. Has been. According to such a configuration, the variable valve operating system for the internal combustion engine 1 can be effectively used by utilizing the space on the cylinder head of the internal combustion engine 1 as compared with the case where the link shaft is supported separately from the rocker shaft. 10 can be improved, and parts required for supporting the link shaft can be eliminated. In addition, unlike the configuration of the present embodiment, when the rocker arm is directly supported by the link shaft, when the link shaft is displaced in the axial direction, the acting force of the cam is applied. A frictional force is generated on the link shaft with the receiving rocker arm. On the other hand, according to the configuration of the present embodiment, since the link shaft 48 is disposed in the rocker shaft 16, the acting force of the main cam 20 is directly applied to the link shaft 48 via the rocker arms 12 and 14. The frictional force generated when the link shaft 48 is displaced in the axial direction can be reduced without acting.

  By the way, in the first embodiment described above, the displacement of the first link arm 44 and the link shaft 48 that occurs when the projection 44b of the first link arm 44 and the guide rail 52 are engaged (and the second link arm 46 associated therewith). The switching pin 38 is displaced in accordance with the displacement of. Then, when the first rocker arm 12 and the second rocker arm 14 are switched between a connected state and a non-connected state via the switching pin 38 that is displaced, the valve opening characteristics of the valves 28 of each cylinder are operated. It switches between the state and the valve stop state. However, the variable valve operating apparatus according to the present invention has at least two cylinders by switching the operation state of the transmission member in accordance with the displacement of the main displacement member and the member connecting shaft that are generated when the engagement portion and the guide rail are engaged. The present invention is not limited to the above configuration as long as the valve opening characteristics of the provided valve are switched.

  Specifically, a member that is displaced so as to switch the operation state of the transmission member in accordance with the displacement of the main displacement member and the member connecting shaft that occurs when the engaging portion and the guide rail are engaged is not limited to the switching pin 38. That is, for example, in a configuration in which a rocker arm corresponding to a transmission member is rotatably supported by a rocker shaft, the rocker arm moves in the axial direction of the rocker shaft on the rocker shaft as the main displacement member and the member connecting shaft move. The operating state of the rocker arm may be switched by the displacement of the cam that contacts the rocker arm. Alternatively, for example, in a configuration including a rocker arm having a roller that contacts the cam, the roller is displaced in the axial direction of the support shaft on the rocker arm in accordance with the displacement of the main displacement member and the member connecting shaft. The operating state of the rocker arm (transmission member) may be switched by switching the cam that contacts the roller. Alternatively, for example, in the configuration in which the rocker arm corresponding to the transmission member is rotatably supported by the rocker shaft, the rocker shaft itself is displaced in the axial direction in accordance with the displacement of the main displacement member and the member connecting shaft. The operating state of the rocker arm may be switched by switching the cam that contacts the rocker arm. Further, for example, in a configuration in which a member including two types of cams is attached to a camshaft so as to be movable in the axial direction, the member including the two types of cams in accordance with the displacement of the main displacement member and the member connecting shaft is a cam. The operating state of the transmission member may be switched by displacing in the axial direction of the shaft and thereby switching the cam that contacts the transmission member.

  In the first embodiment described above, the variable valve operating apparatus 10 that drives the two valves 28 arranged in each cylinder of the internal combustion engine 1 having four cylinders has been described as an example. However, the variable valve operating apparatus according to the present invention is not limited to the above configuration as long as it switches the valve opening characteristics of the valves provided in at least two cylinders. That is, for example, it is configured as a device for driving valves of all cylinders of an internal combustion engine having two or more cylinders, or as a device for driving valves of at least two cylinders of an internal combustion engine having three or more cylinders. Anything is acceptable.

  In the first embodiment described above, only the # 1 cylinder is provided with the cylindrical portion 18a including the guide rail 52, the electromagnetic solenoid 54, and the first link arm. However, the cylinder provided with the elements corresponding to these in the present invention is not limited to this, and may be at least one arbitrary cylinder that is not all cylinders. Alternatively, the above elements may be provided separately from any cylinder, and each cylinder may be provided with a sub-displacement member such as the second link arm 46 that does not have the protrusion 44b.

  Further, in the first embodiment described above, the link arms 44 and 46 are rotatably supported using the rocker shaft 16 for supporting the rocker arms 12 and 14. However, the member that supports the main displacement member and the sub displacement member in the present invention is not limited to the rocker shaft. That is, for example, a shaft provided separately from the rocker shaft may be used. Or the main displacement member and the sub displacement member in this invention may be supported only by the member (for example, link shaft 48) which functions as a member connection shaft of this invention.

  In the first embodiment described above, the link shaft 48 is arranged inside the rocker shaft 16. However, the arrangement | positioning method of the member connection shaft in this invention is not limited to this, For example, the axis | shaft which functions as a member connection shaft may be provided in the outer peripheral side of the rocker shaft.

  In the first embodiment described above, the first link arm 44 (and also the second link arm 46) is connected to the link shaft 48 in such a manner that the first link arm 44 is rotatable and restrains axial movement. An annular groove 48a that engages with the press-fit pin 50 is provided on the shaft 48 side. However, in the present invention, the element provided for realizing the function of connecting the main displacement member in a manner that allows the main displacement member to freely rotate and restrains movement in the axial direction may not be the annular groove 48a. That is, for example, in the case of having a configuration in which a press-fit pin is press-fitted into the first link arm as in the configuration of the present embodiment, and having a groove with which the press-fit pin is engaged on the link shaft side, the groove is an electromagnetic solenoid. If the press-fitting pin when the first link arm is driven to rotate is a groove designed so that it can operate without rotating the link shaft, it may not necessarily be formed in an annular shape. It may be the upper groove.

  Moreover, in Embodiment 1 mentioned above, although the example in which the subcam 22 was comprised as a zero lift cam was demonstrated, the subcam in this invention is not restricted to a zero lift cam. That is, for example, in the case of the configuration of the variable valve operating apparatus 10 described above, a secondary cam provided with a nose portion that allows a lift smaller than that of the main cam 20 to be obtained may be used.

  In the first embodiment described above, an electromagnetic solenoid 54 is provided as an actuator for generating a driving force for engaging the protrusion 44b with the guide rail 52. Thereby, the valve opening characteristic of the valve 28 can be switched using an actuator having excellent responsiveness. However, the actuator in the present invention is not limited to this, and may be, for example, a hydraulically driven actuator.

In the first embodiment, the main cam 20 is the “cam” in the first invention, and the first rocker arm 12 and the second rocker arm 14 are the “transmission member” in the first invention. The protrusion 44b is the “engaging portion” in the first invention, the first link arm 44 is the “main displacement member” in the first invention, and the link shaft 48 is the “member connecting shaft” in the first invention. The electromagnetic solenoid 54 corresponds to the “actuator” in the first invention.
In the first embodiment described above, the second link arm 46 corresponds to the “sub-displacement member” in the second invention.
In the first embodiment, the annular groove 48a corresponds to the “groove” in the sixth invention, and the press-fit pin 50 corresponds to the “pin” in the sixth invention.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 10 Variable valve apparatus 12 1st rocker arm 14 2nd rocker arm 14a Contact part 16 Rocker shaft 16a Through-hole 18 Camshaft 18a Cylindrical part 20 Main cam 22 Sub cam 24 First roller 26 Second roller 27 Cam Carrier 28 Valve 32 Switching mechanism 34a First pin hole 36a Second pin hole 38 Switching pin 40 Return spring 42 Piston 44 First link arm 44a Arm 44b Protrusion 44c Pressing surface 44d Press-fit pin hole 44e Notch 46 Second link Arm 46a Arm portion 46b Press-fit pin hole 48 Link shaft 48a Annular groove 50 Press-fit pin 52 Guide rail 52a Start end 52b End 52c Shallow bottom 54 Electromagnetic solenoid 54a Drive shaft 56 ECU (Electronic Control Unit)
Pmax1, Pmax2 Displacement end

Claims (6)

A transmission member that is disposed between the cam and the valve and transmits the acting force of the cam to the valve;
A camshaft to which the cam is attached;
A guide rail provided on the outer peripheral surface of the cylindrical portion attached to the camshaft;
A main displacement member having an engaging portion detachably engageable with the guide rail, and capable of being displaced in an axial direction of the camshaft;
A member connecting shaft that is connected to the main displacement member in a manner that is freely rotatable and restrains movement in the axial direction, and that is supported so as to be displaceable in the axial direction;
An actuator for generating a driving force for engaging the engaging portion with the guide rail,
During operation of the actuator, the main displacement member is rotated about the member connecting shaft, and then the engaging portion and the guide rail are engaged.
Provided in at least two cylinders by changing the operating state of the transmission member in accordance with the displacement of the main displacement member and the member connecting shaft that occur during the engagement between the engagement portion and the guide rail. A variable valve operating apparatus for an internal combustion engine, wherein the valve opening characteristics of the valve are switched. The main displacement member, the guide rail, and the actuator are provided in at least one cylinder that is not all cylinders of the internal combustion engine,
The variable valve operating apparatus is further provided with a sub-displacement member that is provided in a remaining cylinder that is not provided with the main displacement member, and that is displaced in conjunction with the main displacement member via the member connecting shaft,
With the displacement of the main displacement member that occurs during the engagement of the engagement portion and the guide rail, the operating state of the transmission member of the cylinder provided with the main displacement member changes,
The operation state of the transmission member of the remaining cylinders provided with the sub-displacement member changes with the displacement of the sub-displacement member interlocked with the displacement of the main displacement member. A variable valve operating apparatus for an internal combustion engine according to claim 1. The transmission member includes, in each of the at least two cylinders, a first rocker arm that swings in synchronization with the cam, and a second rocker arm that can push the valve,
The variable valve operating apparatus further includes a switching pin that is movably disposed in a pin hole formed in each of the first rocker arm and the second rocker arm,
The switching pin in the cylinder provided with the main displacement member is displaced in conjunction with the displacement of the main displacement member,
The switching pin in the cylinder provided with the sub-displacement member is displaced in conjunction with the displacement of the sub-displacement member,
In the cylinder provided with the main displacement member, a connection state in which the first rocker arm and the second rocker arm are connected via the switching pin in accordance with the displacement of the main displacement member, The connection with the disconnected state is switched,
In the cylinder provided with the sub-displacement member, a connection state in which the first rocker arm and the second rocker arm are connected via the switching pin in accordance with the displacement of the sub-displacement member; The variable valve operating apparatus for an internal combustion engine according to claim 2, wherein the disconnected state is switched to the disconnected state.   4. The variable valve operating apparatus for an internal combustion engine according to claim 3, wherein the member connecting shaft is disposed inside a rocker shaft that supports the first rocker arm and the second rocker arm.   5. The variable valve operating apparatus for an internal combustion engine according to claim 3, wherein the second rocker arm is shared by a plurality of the valves provided in the same cylinder. The member connecting shaft has an annular or arc-shaped groove on the outer peripheral surface, and penetrates the inside of the main displacement member,
6. The variable valve for an internal combustion engine according to claim 1, wherein the variable valve device further includes a pin that passes through the main displacement member and engages with the groove. apparatus.

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