JP2014005756A - Variable valve device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable valve device capable of suppressing falling or the like of a swing arm with respect to a pivot by inhibiting valve stopping control when a lost motion amount (stroke amount) of a valve stopping mechanism during one valve stopping exceeds a predetermined value.SOLUTION: An oscillation cam 7 is oscillated via a transmission mechanism in accordance with rotation of a driving cam 5a and, thereby, respective intake valves 3, 3 are openably and closably operated by a pair of swing arms 6. A valve stopping mechanism is provided for stopping one side intake valve by subjecting a first hydraulic lash adjuster 10a which is brought into contact with the other edge part 6b of one side swing arm to get to an oscillation fulcrum to lost motion in accordance with an engine operation state. Meanwhile, when a lost motion amount of the valve stopping mechanism exceeds a predetermined value, a solenoid selection valve 55 is controlled by a valve stopping inhibition circuit of a control unit 53 such that the valve stopping is inhibited by a regulation pin 41.

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine that can variably control a valve lift amount of an engine valve according to an engine operating state and can perform valve stop.

  As a conventional variable valve operating apparatus for an internal combustion engine, one described in Patent Document 1 below is known.

  This variable valve operating device includes a variable mechanism that continuously changes the lift amount and operating angle of two intake valves per cylinder, and a valve stop mechanism that stops the opening and closing operation of one intake valve. By losing motion on one side and stopping the operation of one intake valve and operating only the other intake valve, the intake swirl is enhanced to improve fuel efficiency and combustion performance, while engine torque is required In the operation region, both valves are operated and the operating angles of both valves are made substantially the same to improve the intake charging efficiency.

  When the required engine torque increases in the single valve operation state, if the required engine torque is smaller than the maximum torque in the single valve operation, the operating angle (lift amount) is increased while maintaining the single valve operation state. It has become.

JP 2010-007636 A (FIG. 8)

  However, in the conventional variable valve operating apparatus, as described above, if the required engine torque is smaller than the maximum torque in the single valve operation in the single valve operation state, the single valve operation state is maintained. The valve operating mechanism on the valve stop side is forced to have a large lost motion amount as the operating angle increases, that is, the lift amount increases.

  For this reason, is it impossible for the posture of the valve mechanism on the valve stop side to become uneven, and the gap between one end of the swing arm that opens and closes the intake valve and the pivot that is the swing fulcrum of the swing arm is uneven? Due to the local contact, a deviation occurs between the two, and in some cases, one end of the swing arm may fall off the pivot.

  The present invention has been devised in view of the technical problem of the conventional variable valve operating apparatus, and when the lost motion amount (stroke amount) of the valve stop mechanism during the single valve stop exceeds a predetermined value. The purpose of this is to inhibit the valve stop control and suppress irregular behavior such as the swing arm slipping or dropping off from the pivot.

  In the present invention, a rotational driving force is transmitted from the crankshaft of an engine, a driving shaft provided with a driving cam on the outer periphery, and two engine valves per cylinder are opened against the spring force of a valve spring. The swing cam, a transmission mechanism for converting the rotational motion of the drive cam into a swing motion and transmitting the swing cam to the swing cam, and interposed between each swing cam and each engine valve, A pair of swing arms that opens and closes each engine valve by a swinging force of a moving cam and a spring force of the valve spring, a pair of fulcrum members that serve as swinging fulcrums of the swing arms, and a posture of the transmission mechanism are changed. And a control mechanism for variably controlling the lift amount of each engine valve, and by causing at least one of the pair of fulcrum members to have a lost motion, the opening and closing drive of the one engine valve is stopped. Provided with a valve stop mechanism that, when the lost motion amount of the valve stop mechanism exceeds a predetermined value is characterized in that a valve stop inhibiting means for inhibiting the valve stop.

  According to the present invention, when the lost motion amount (stroke amount) of the valve stop mechanism exceeds a predetermined value while the valve is stopped, the valve stop state is prohibited to prevent the valve mechanism from dropping off. Can do.

1 is a perspective view showing a first embodiment in which a valve gear according to the present invention is applied to one bank side of a V-type 6-cylinder internal combustion engine. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. A is a longitudinal sectional view showing a first hydraulic lash adjuster provided in the present embodiment, and B is a longitudinal sectional view showing an operation of the first hydraulic lash adjuster. It is a longitudinal cross-sectional view of the 2nd hydraulic lash adjuster of this embodiment. It is the schematic which shows the control hydraulic circuit of this embodiment. A is an operation explanatory view of the first hydraulic lash adjuster when the valve is closed when the lift amount of the intake valve is controlled to L2, and B is an operation explanatory view of the first hydraulic lash adjuster at the time of valve opening. is there. A is an operation explanatory view of the second hydraulic lash adjuster when the valve is closed when the lift amount of the intake valve is controlled to L2, and B is an operation explanatory view of the second hydraulic lash adjuster at the time of valve opening. is there. FIG. 10 is an operation explanatory diagram of a first hydraulic lash adjuster when valve stop control is performed from a state in which the lift amount of the intake valve is controlled to L3 in the present embodiment. A is an operation explanatory view of the first hydraulic lash adjuster when the valve is closed when the maximum lift amount (L7) of the intake valve in the present embodiment is controlled, and B is an operation description of the first hydraulic lash adjuster when the valve is opened. FIG. A is an operation explanatory view of the second hydraulic lash adjuster when the valve is closed when the maximum lift amount (L7) of the intake valve in the present embodiment is controlled, and B is an operation description of the second hydraulic lash adjuster when the valve is opened. FIG. It is a valve lift characteristic view of an intake valve in this embodiment. It is a characteristic view showing the relationship between the amount of lost motion of the first hydraulic lash adjuster and the rotation angle of the control shaft in the present embodiment. It is a characteristic view which shows the relationship between the lift amount of an intake valve and the rotation angle of a control shaft in this embodiment. It is a control flowchart figure of the control unit with which this embodiment is provided. It is the schematic which shows the control hydraulic circuit in 2nd Embodiment. It is a longitudinal cross-sectional view which shows the 1st hydraulic lash adjuster in 3rd Embodiment. It is a longitudinal cross-sectional view which shows the 1st hydraulic lash adjuster in 4th Embodiment.

  Embodiments of a valve operating apparatus for an internal combustion engine according to the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a V-type 6-cylinder internal combustion engine and includes a variable mechanism that variably controls the operating angle and valve lift amount of an intake valve that is an engine valve. The right bank is composed of # 1 cylinder, # 3 cylinder, and # 5 cylinder, and the left bank is composed of # 2 cylinder, # 4 cylinder, and # 6 cylinder, but the configuration is the same.

[First Embodiment]
1 to 3 show a first embodiment of the present invention, in which two first and second intake valves 3, 3 per cylinder for opening and closing a pair of intake ports 2, 2 formed in a cylinder head 1 are shown. The # 1 cylinder, the # 3 cylinder, and the # 5 cylinder are disposed along the longitudinal direction of the engine on the upper side of the # 1 cylinder and the # 5 cylinder. A pair of swing cams 7 and 7 that are supported to open and close each intake valve 3 via each swing arm 6 that is an interposed member, and the rotational force of each drive cam 5a is converted into swing force. A transmission mechanism 8 that transmits to each swing cam 7, a control mechanism 9 that controls the operating angle and lift amount of each intake valve 3, 3 via the transmission mechanism 8, and a cylinder head 1, Valve cleaners between the intake valves 3, 3 and the swing cams 7 via the swing arms 6. The first and second hydraulic lash adjusters 10a and 10b, which are two fulcrum members (pivots) that make the lance zero-lash, and the one of the one via the first hydraulic lash adjuster 10a on the one side according to the engine operating state. And three valve stop mechanisms 11 for stopping the opening / closing operation of the first intake valve 3.

  The drive shaft 5, the swing cam 7, the transmission mechanism 8, and the control mechanism 9 constitute a variable mechanism.

Hereinafter, for convenience, each component in one cylinder, for example, the # 1 cylinder will be described. Each intake valve 3 is slidably held by the cylinder head 1 via a valve guide 4 and each stem end. The springs 3b are urged in the closing direction by the valve springs 12 elastically contacted between the spring retainers 3b provided in the vicinity of 3a and the inner upper surface of the cylinder head 1.

  The drive shaft 5 includes a plurality of bearings 13 provided at the upper end of the cylinder head 1 and the swing cam 7 is rotatably supported via a camshaft 7a. The rotational force of the crankshaft is transmitted by the timing belt via the pulley. Further, the drive cam 5a provided on the outer periphery of the drive shaft 5 per cylinder has an axis X that is eccentric in the radial direction from the axis Y of the drive shaft 5, and the outer cam profile is normal. It is formed in a substantially circular shape.

  Each of the swing arms 6 has a concave lower surface of one end portion 6a in contact with the stem end 3a of each intake valve 3, while a lower surface recess 6c of the other end portion 6b contacts with each of the hydraulic lash adjusters 10a and 10b. In addition, the roller 14 is rotatably accommodated in the accommodation hole formed in the center via the roller shaft 14a.

  As shown in FIG. 1 and the like, each of the swing cams 7 is integrally provided at both ends of a cylindrical cam shaft 7a, and has a base circle surface, a ramp surface, and a lift surface on the lower surface. A surface 7 b is formed, and the base circle surface, the ramp surface, and the lift surface are brought into rolling contact with the upper surface of the roller 14 of the swing arm 6 according to the swing position of the swing cam 9.

  In the camshaft 7a, a journal portion formed at a substantially central position in the axial direction of the outer peripheral surface is rotatably supported by the plurality of bearing portions 13 with a small clearance, and the outer periphery of the drive shaft 5 is supported by an inner peripheral surface. The surface is rotatably supported.

  The transmission mechanism 8 includes a rocker arm 15 disposed above the drive shaft 5, a link arm 16 that links the one end 15a of the rocker arm 15 and the drive cam 5a, and the other end 15b of the rocker arm 15. And a link rod 17 that links the moving cam 7.

  The rocker arm 15 has a cylindrical base portion at the center thereof rotatably supported by a control cam, which will be described later, via a support hole, and one end portion 15 a is rotatably connected to the link arm 16 by a pin 18. On the other hand, the other end 15 b is rotatably connected to the upper end of the link rod 17 via a pin 19.

  In the link arm 16, the cam body of the drive cam 5a is rotatably fitted in a fitting hole 16a at the center position of an annular base portion, while the protruding end is connected to the rocker arm one end portion 15a by the pin 18. It is connected.

  The link rod 17 has a lower end portion rotatably connected to a cam nose portion of the swing cam 7 via a pin 20.

  An adjusting mechanism 23 is provided between the other end 15b of the rocker arm 15 and the upper end of the link rod 17 to finely adjust the lift amount of each intake valve 3 when each component is assembled.

  The control mechanism 9 is slidably fitted in a support hole of the rocker arm 15 on the outer periphery of the control shaft 21, and is rotatably supported on the same bearing portion above the drive shaft 5. A control cam 22 serving as a rocking fulcrum of the rocker arm 15 is fixed.

  The control shaft 21 is arranged in the longitudinal direction of the engine in parallel with the drive shaft 5 and is rotationally controlled by an actuator 50 shown in FIG. On the other hand, the control cam 22 has a cylindrical shape, and the axial center position is deviated from the axial center of the control shaft 21 by a predetermined amount.

  As shown in FIG. 6, the actuator 50 is provided inside the housing with an electric motor 51 fixed to one end of the housing (not shown), and the rotational driving force of the electric motor 51 is applied to the control shaft 21. And a ball screw mechanism 52 as a speed reduction mechanism for transmission.

  The electric motor 51 is composed of a proportional DC motor, and is controlled to rotate forward and backward by a control signal from a control unit 53 (described later) that detects the engine operating state.

  As shown in FIGS. 1 to 5, the first and second hydraulic lash adjusters 10 a and 10 b each have a bottomed cylindrical shape that is slidably held in a columnar holding hole 1 a of the cylinder head 1. A body 24, a plunger 27 that is accommodated in the body 24 so as to be slidable in the vertical direction, and that forms a reservoir chamber 26 through a partition wall 25 that is integrally formed at a lower portion, and a lower portion of the body 24. A high-pressure chamber 28 communicating with the reservoir chamber 26 through a communication hole 25a formed in the partition wall 25, and the hydraulic oil in the reservoir chamber 26 is supplied to the high-pressure chamber 28. And a check valve 29 that allows inflow only in the direction. Further, a discharge hole 1b for discharging the hydraulic oil accumulated in the holding hole 1a to the outside is formed in the cylinder head 1.

  The body 24 has a cylindrical first concave groove 24a formed on the outer peripheral surface thereof, and is formed on the peripheral wall of the first concave groove 24a inside the cylinder head 1 so that the downstream end is the first concave groove. A first passage hole 31 that communicates between the oil passage 30 opened in the groove 24a and the inside of the body 24 is formed penetrating in the radial direction.

  Further, as shown in FIGS. 4A and 4B, the body 24 on the first hydraulic lash adjuster 10a side is formed in a substantially cylindrical shape with the bottom 24b side extending downward from the body 24 on the second hydraulic lash adjuster 10b side. Has been.

  The oil passage 30 communicates with a main oil gallery 30a for supplying lubricating oil formed in the cylinder head 1, and lubricating oil is pumped to the main oil gallery 30a from an oil pump 54 shown in FIG. It is like that.

  The plunger 27 is formed with a cylindrical second concave groove 27a on the outer peripheral surface substantially in the center in the axial direction, and the first passage hole 31 and the reservoir chamber 26 are formed on the peripheral wall of the second concave groove 27a. The 2nd channel | path hole 32 which connects is penetrated and formed along the radial direction. Further, the distal end surface of the distal end head portion 27b of the plunger 27 is formed in a spherical shape in order to ensure good slidability with the spherical lower surface concave portion 6c of the other end portion 6b of the swing arm 6.

  Note that the maximum protrusion amount of the plunger 27 is regulated by an annular stopper member 33 fitted and fixed to the upper end portion of the body 24.

  The second concave groove 27a is formed to have a relatively large width in the axial direction, whereby the first passage hole 31 and the second passage hole 32 are formed at any of the vertically sliding positions of the plunger 27 with respect to the body 24. It always comes to communicate.

  The check valve 29 includes a check ball 29a that opens and closes a lower opening edge (seat) of the communication hole 25a, a first coil spring 29b that urges the check ball 29a in a closing direction, and the first coil spring 29b. It is elastically mounted between the cup-shaped retainer 29c to be held, the inner bottom surface of the bottom wall 24c of the body 24, and the annular upper end of the retainer 29c, and urges the retainer 29c in the direction of the partition wall 25 so as to urge the entire plunger 27. The second coil spring 29d biases upward.

  In the base circle section of the swing cam 7, when the pressure in the high pressure chamber 28 becomes low as the plunger 27 moves forward (upward movement) by the biasing force of the second coil spring 29 d, the oil passage 30 holds the pressure. The hydraulic fluid supplied into the hole 1a flows into the reservoir chamber 26 from the first concave groove 24a through the first passage hole 31, the second concave groove 27a, and the second passage hole 32, and further causes the check ball 29a to pass through the first concave groove 24a. The hydraulic oil is pushed open against the spring force of the one coil spring 29 b, and hydraulic oil flows into the high pressure chamber 28.

  As a result, the plunger 27 constantly pushes up the other end 6 b of the swing arm 6 and contacts the roller 14 and the swing cam 7 so that the swing cam 7, one end 6 a of the swing arm 6, and each intake valve 3 are in contact with each other. The gap with the stem end 3a is adjusted to zero lash.

  In the lift section of the swing cam 7, a downward load acts on the plunger 27, so that the hydraulic pressure in the high pressure chamber 28 rises, and the oil in the high pressure chamber 28 leaks from the gap between the plunger 27 and the body 24. The plunger 27 is slightly lowered (leak down).

  In the base circle section of the swing cam 7 again, as described above, the clearance of each part is adjusted to zero lash by the advancement movement (upward movement) of the plunger 27 by the urging force of the second coil spring 29d. is there.

  Both the first and second hydraulic lash adjusters 10a and 10b have such a lash adjustment function.

  As shown in FIGS. 4A and 4B, the valve stop mechanism 11 is provided only on the first hydraulic lash adjuster 10a side, and is a cylindrical sliding hole 34 formed continuously on the bottom side of the holding hole 1a. And a lost motion spring 35 that is elastically mounted between the bottom surface of the sliding hole 34 and the lower surface of the body 24 to urge the first hydraulic lashia adjuster 10a upward, and the first hydraulic rascia adjuster 10a. And a regulating mechanism 36 that regulates the lost motion.

  The sliding hole 34 is set to have the same inner diameter as the inner diameter of the holding hole 1a, and the body 24 is held so as to be slidable in the vertical direction continuously from the holding hole 1a.

  The lost motion spring 35 is formed of a coil spring, and biases the bottom surface of the body 24 upward so that the distal end portion 27a of the plunger 27 elastically contacts the lower surface of the other end portion 6b of the swing arm 6. It has become.

  Further, the body 24 is restricted in its maximum upward movement position by a stopper pin 37 inserted and arranged in the cylinder head 1. That is, the stopper pin 37 is disposed in the cylinder head 1 in a direction perpendicular to the axis toward the body 24, and the distal end portion 37 a is slidably disposed in the first concave groove 24 a, so that the body 24 With the upward movement, the tip end portion 37a comes into contact with the lower end edge of the first concave groove 24a so that the maximum sliding position of the body 24 is regulated.

  Accordingly, the first hydraulic lash adjuster 10a causes the lost motion by stroking up and down between the holding hole 1a and the sliding hole 34 through the spring force of the lost motion spring 35 as the swing arm 6 swings. As a result, the function as the swing fulcrum of the swing arm 6 is lost, and the opening / closing operation of the first intake valve 3 is stopped.

  The restriction mechanism 36 includes a movement hole 38 formed through the bottom 24b of the body 24 in the inner radial direction, a restriction hole 39 formed in the cylinder head 1 in a direction perpendicular to the holding hole 1a, A retainer 40 fixed to one end of the inner side of the moving hole 38 and a slidably provided inside the moving hole 38 and movable across the restricting hole 39 from the moving hole 38. It is mainly composed of a restriction pin 41 and a return spring 42 that is elastically mounted between the rear end of the restriction pin 41 and the retainer 40 and biases the restriction pin 41 toward the restriction hole 39. .

  The restriction hole 39 is adapted to coincide with the movement hole 38 from the axial direction when the body 24 is restricted to the maximum upper position by the stopper pin 37, and the inner diameter thereof is the movement hole 38. The signal hydraulic pressure is introduced from an oil passage hole 43 formed in the cylinder head 1 on one end side.

  Here, the restriction of the rotation direction of the body 24 slightly increases the amount of protrusion of the stopper pin 37 and provides a longitudinal slit in the first concave groove 24a of the body 24 so that the tip of the stopper pin 37 It can be easily realized by engaging with. Alternatively, a separate rotation restricting member may be mounted between the cylinder head 1 and the body 24.

  As shown in FIG. 4B, the retainer 40 is formed in a cylindrical shape with a lid, and a breathing hole 40a is formed through the bottom to ensure smooth movement of the restriction pin 41, and the axial length is as shown in FIG. 4B. When the restricting pin 41 is completely accommodated in the movement hole 38, the length is set such that the rear end of the restricting pin 41 comes into contact with the front end edge to restrict further backward movement.

  The restriction pin 41 is formed in a solid cylindrical shape, and has an outer diameter slightly smaller than the inner diameter of the movement hole 38 and the restriction hole 39 to ensure smooth slidability. Further, the restriction pin 41 moves backward against the spring force of the return spring 42 by receiving the hydraulic pressure supplied from the oil passage hole 43 to the restriction hole 39 by the pressure receiving surface of the tip end portion 41a. The front end portion is pulled out of the restriction hole 39 and accommodated in the movement hole 38, so that the restriction is released.

  As shown in FIG. 6, the oil pressure fed from the oil pump 54 is supplied to the oil passage hole 43 (regulation hole 39) as a signal oil pressure through an electromagnetic switching valve 55.

  The electromagnetic switching valve 55 switches a spool valve slidably provided inside a valve body (not shown) in two stages, on and off, by the electromagnetic force of the solenoid and the spring force of the coil spring. The control current is supplied to the solenoid from the same control unit 53 that controls the driving of the electric motor 51, and the pump discharge passage and the oil passage hole 43 are communicated with each other. Switching is controlled so that the oil passage hole 43 and the drain passage 44 are communicated with each other, and the signal oil pressure is controlled in two stages of large and small.

  The control unit 53 detects an engine operating state (engine operating condition) based on information signals from various sensors such as a crank sensor, an air flow meter, a water temperature sensor, a throttle valve angle sensor, and the like. The electric motor 51 is driven and controlled by an information signal from a rotational position sensor (not shown) that detects the current rotational position of the control shaft 21 to control the rotational position of the control shaft 21. As a result, the lift amount and the operating angle of each of the intake valves 3 and 3 are changed.

  The control unit 53 has a valve stop prohibiting circuit which is a valve stop prohibiting means for prohibiting the lost motion of the valve stop mechanism 11 via the electromagnetic switching valve 55. The valve stop prohibiting circuit performs control for communicating the oil passage hole 43 and the drain passage 44 via the electromagnetic switching valve 55 based on the rotation angle θ of the control shaft 21. As a result, the restriction pin 41 is moved in the direction of the restriction hole 39 by the spring force of the return spring 42, and the front end portion 41a of the restriction pin 41 is engaged with the restriction hole 39, whereby the body 24 ( The first hydraulic lash adjuster 10a) is locked to the cylinder head 1, and the lost motion of the first hydraulic lash adjuster 10a is prohibited.

  The rotational angle position of the control shaft 21 for controlling the drive of the electromagnetic switching valve 55 by the valve stop prohibiting circuit can be arbitrarily set according to the engine operating state or the like, but in this embodiment, the lift amount of the first intake valve 3 Is set to a rotation angle position at which the control shaft 21 becomes θ3 so that L3 shown in FIG.

That is, it is detected at the rotational angle position θ of the control shaft 21 that the stroke amount of the lost motion of the first hydraulic lash adjuster 10a exceeds the lift amount of the first intake valve 3 that is proportional to the stroke amount. At this time, if the valve is stopped, the control current to the electromagnetic switching valve 55 is cut off, the oil passage hole 43 and the drain passage 44 are communicated, and the first hydraulic pressure is generated by the restriction pin 41. The lassia adjuster 10a is forcibly locked. If the restriction pin 41 is already locked and the valve is in the two-valve lift operation state when the distance L3 is exceeded, this state is maintained.
[Operation of variable valve gear]
Hereinafter, the operation of the variable valve operating apparatus in the present embodiment will be described.

  For example, in the low rotation range from the idling operation of the engine, the electric motor 51 is rotationally driven by the control current output from the control unit 53, and this rotational torque is transmitted to the control shaft 21 via the ball screw mechanism 52. When the control shaft 21 is driven to rotate in one direction, the control cam 22 also rotates in one direction as shown in FIGS. 7A, 7B, 8A, and 8B, and the shaft center rotates around the shaft center of the control shaft 21. Are rotated with the same radius, and the thick portion moves away from the drive shaft 5 in the upper right direction as shown in the figure. As a result, the other end 15b of the rocker arm 15 and the pivot point (connecting pin 19) of the link rod 17 move upward with respect to the drive shaft 5. Therefore, each swing cam 7 moves the link rod 17 through the link rod 17. The cam nose portion side is forcibly pulled up through.

  Therefore, when the drive cam 5a rotates and pushes up the one end portion 15a of the rocker arm 15 via the link arm 16, the lift amount is transmitted to each swing cam 7 and each swing arm 6 via the link rod 17, The intake valve 3 is opened against the spring reaction force of the valve spring 12, and the lift amount becomes sufficiently small, for example, L1 to L3 shown in FIG.

  For example, when the engine shifts from the low rotation to the middle and high rotation regions, when the electric motor 51 rotates in reverse by the control current from the control unit 53 and rotates the ball screw mechanism 52 in the same direction, FIGS. 11A and 11B, with this rotation, the control shaft 21 rotates the control cam 22 in the other direction, and the shaft center moves downward.

  For this reason, the rocker arm 15 is now moved in the direction of the drive shaft 5 and the cam nose portion of the swing cam 7 is pressed downward via the link rod 17 by the other end portion 15b. The whole is rotated counterclockwise by a predetermined amount from the position shown in FIGS. Therefore, as shown in FIGS. 10 and 11, the contact position of the cam surface 7b with respect to the outer peripheral surface of the roller 14 of each swing arm 6 of each swing cam 7 moves to the cam nose portion side (lift portion side).

For this reason, when the drive cam 5a rotates and the one end 15a of the rocker arm 15 is pushed up via the link arm 16 when the intake valve 3 is opened, each intake valve 3 is connected to each valve spring 12 via each swing arm 6. The valve lift amount is increased from L4 to L7 as the rotation increases while continuously changing until the valve lift amount reaches the maximum L7 shown in FIGS. As a result, the intake charging efficiency is improved and the output can be improved.
[Operation of valve stop mechanism]
When the lift amount of each of the intake valves 3 and 3 is in the small lift amount region of L1 to L3 shown in FIG. 12 in the low rotation range from the idling operation described above, the specific operation condition for particularly improving the fuel consumption is desired. , A control current is output from the control unit 53 to the electromagnetic switching valve 55, and a large discharge hydraulic pressure from the oil pump 54 is introduced into the restriction hole 39 through the oil passage hole 43 as a signal hydraulic pressure.

  For this reason, the regulation pin 41 that has received this large signal oil pressure moves backward against the spring force of the return spring 42, the tip 41 a comes out of the regulation hole 39, and the first hydraulic lash against the cylinder head 1. The lock of the adjuster 10a is released.

  Therefore, as shown in FIG. 4B, the entire first hydraulic lash adjuster 10a can perform a lost motion, and the inside of the holding hole 1a and the sliding hole 34 is moved in the vertical direction through the spring force of the lost motion spring 35. Repeated movement and lost motion state. For this reason, the 1st intake valve 3 will be in a valve closing state (valve stop state).

  That is, until the valve is stopped, the swing cam 7 changes between the zero lift (valve closing) position shown in FIG. 7A and the maximum valve opening lift position shown in FIG. 7B, and the lift amount L2 is opened. If the valve is stopped, even if the swing cam 7 swings to the maximum extent, the first hydraulic lash adjuster 10a performs the lost motion by the stroke amount M2 shown in FIG. 7B, and actually performs the valve lift. There is no valve stop state. The opening angle α (see FIG. 7B) formed between the first swing arm 6 and the first hydraulic lash adjuster 10a at that moment is shown in FIG. 13 at the position where the swing cam 7 is at the peak lift. Although it becomes (alpha) 2 shown, this is not an excessive opening angle.

  Therefore, a smooth valve stop operation can be obtained even when the rocking cam 7 reaches a peak lift (maximum valve opening operation).

  On the other hand, since the second hydraulic lash adjuster 10b side functions as a normal swing fulcrum for the second swing arm 6 as shown in FIGS. 8A and 8B, the second intake valve 3 still has the lift amount L2. The opening / closing operation is performed, whereby the intake swirl is strengthened to improve fuel consumption and combustion.

  Next, for example, the engine speed is further increased, the required torque is increased and the state is shifted again to the two-valve lift operation state, and the lift amount is further increased to rotate the control shaft 21 clockwise to θ3. In other words, a case where the lift amount of both intake valves 3 and 3 becomes L3 shown in FIG. Assuming a case where the demand for fuel consumption increases again from this state and the valve shifts to a stop, as shown in FIG. 9, the opening angle formed between the first swing arm 6 and the first hydraulic lash adjuster 10a is It becomes α3 and is in a very open state.

  For this reason, the contact of the distal end head portion 27b of the first hydraulic lash adjuster 10a with the lower surface recess 6c of the other end portion 6b of the first swing arm 6 becomes uneven.

  In other words, the tip head portion 27b of the hydraulic lash adjuster 10a normally has a balance between the contact at the spherical portion on the lost motion 4 side and the contact at the spherical portion on the anti-roller 14 side. Although the lower surface recess 6c of the end portion 6b is stably held, when the α3 increases, the contact at the spherical portion on the roller 14 side moves upward, and the contact portion at the spherical portion on the opposite roller side moves downward. It will move.

  When the load from the roller 14 acts on the load, the load received at the contact portion of the spherical portion on the side of the roller 14 that has moved upward increases extremely, and the balance is lost and local contact tends to occur.

  As a result, in addition to the fact that the contact portion has moved above the tip head portion 27b, the contact tends to shift due to the load of the roller 14 and the like, and the phenomenon that the first swing arm 6 tends to shift to the opposite valve side is likely to occur. In some cases, the lower surface recess 6c of the other end 6b of the first swing arm 6 may be detached from the distal end head 27b. However, this α3 level is somehow within the allowable range, but if this α3 is exceeded, the possibility that the above-described detachment phenomenon actually occurs increases.

  Therefore, when the lift amount of L3 is exceeded, the control current from the valve stop prohibiting circuit of the control unit 53 to the electromagnetic switching valve 55 is cut off, and the oil passage hole 43 and the drain passage 44 are communicated with each other for restriction. The oil pressure in the hole 39 and the oil passage hole 43 is discharged into the oil pan 45 to bring it into a low pressure state.

  As a result, as shown in FIG. 4A, the restriction pin 41 moves toward the restriction hole 39 by the spring force of the return spring 42, and the first hydraulic lash adjuster 10 a is moved in the base circle region of the swing cam 7. When the upward movement is restricted by the stopper pin 37 and the movement hole 38 and the restriction hole 39 coincide with each other, the tip end portion 41a of the restriction pin 41 enters the restriction hole 39. The first hydraulic lash adjuster 10a is locked to the cylinder head 1.

  Therefore, the lost motion of the first hydraulic lash adjuster 10a is restricted at this point.

  The dashed-dotted line shown in FIG. 13 shows the correlation between the rotation angle θ of the control shaft 21 and the amount of lost motion (stroke length M) when the valve is stopped, and the broken line in FIG. The correlation between the rotation angle θ of the control shaft 21 and the lift amount L of the intake valve 3 when the lift operation is performed is shown.

  That is, as shown in FIG. 13, the lost motion amount (stroke length M) of the first hydraulic lash adjuster 10a and the rotation angle θ of the control shaft 21 are correlated, and as shown in FIG. Since the rotation angle θ of the control shaft 21 and the lift amount L of the intake valve 3 are also correlated, the control unit 53 determines that the rotation angle of the control shaft 21 is θ3 based on the information signal from the rotation angle sensor. When it exceeds, energization to the electromagnetic switching valve 55 is forcibly cut off.

  These operations are shown by solid lines in FIGS. 13 and 14, but when the lost motion amount exceeds M3, that is, when the lift amount of the intake valve 3 exceeds L3. The lost motion operation of the first hydraulic lash adjuster 10a is mechanically prohibited. As a result, the first intake valve 3 is opened and closed together with the second intake valve 3, and the engine is driven by both valves.

  Accordingly, when the lift amount of the intake valve 3 exceeds L3, the lost motion of the first hydraulic lash adjuster 10a disappears, so that the lower surface recess 6c on the other end 6b side of the first swing arm 6 and the first hydraulic lash. Nonuniform and local contact with the tip head portion 27b of the plunger 27 of the adjuster 10a is avoided. Therefore, a smooth operating state can be obtained at all times without the bottom surface recess 6c of the first swing arm 6 falling off from the distal end head portion 27b of the plunger 27, for example.

  Further, for example, in the case where the engine speed further increases and the rotation angle of the control shaft 21 becomes larger than θ3, and therefore, the lost motion amount of the first hydraulic lost motion 10a further exceeds M3 (each intake air When the lift amount of the valves 3 and 3 further exceeds L3 in FIG. 12), the non-energized state from the control unit 53 to the electromagnetic switching valve 55 is continued and the signal hydraulic pressure is not introduced into the restriction hole 39. The first hydraulic lashia adjuster 10a continues to be in a state of no lost motion, and functions as a swing fulcrum as in the case of the second hydraulic rascia adjuster 10b.

  In other words, until the lost motion amount of the first hydraulic lash adjuster 10a reaches M3 (the rotation angle of the control shaft 21 is θ3), the first hydraulic lash adjuster 10a allows the lost motion to be performed. When M3 is exceeded, the valve stop is prohibited and the lost motion is restricted and fixed, and functions as a normal swing fulcrum.

  FIG. 15 shows a specific control flowchart by the valve stop prohibiting circuit of the control unit 53.

  That is, in step 1, the current engine operating state is read based on the information signals from the various sensors described above, and in step 2, the target lift amount of the first and second intake valves 3 and 3 according to the engine operating state. Is read from a preset control map, for example, an engine speed and load control map. This time, if the target lift amount of the second intake valve 3 is L2, the target lift amount of the first intake valve 3 is zero (valve stop), and the current lift amount is L3 for both the first and second intake valves 3, 3b. Suppose that it was near.

  In step 3, it is determined whether or not the target lift amount of the first intake valve 3 on the first hydraulic lash adjuster 10a side is zero. If it is determined that the target lift amount is zero, that is, the valve is stopped, the process proceeds to step 4. In this step 4, it is determined whether or not the actual lift amount of each intake valve 3, 3 is L3 or less from the angle θ obtained from the rotation angle sensor of the control shaft 21, and it is determined that it is L3 or less. If so, go to Step 5.

In step 5, a process for outputting an ON signal to the electromagnetic switching valve 55 or continuing the ON signal is performed. That is, since it is equal to or less than L3, the signal hydraulic pressure is supplied to the restriction hole 39 to shift to the lost motion of the first hydraulic lash adjuster 10a, or the lost motion is continued to enter the one-valve stopped state. (In this case, an ON signal is output to the electromagnetic switching valve 55, and the motion shifts to the lost motion.)
Thereafter, in step 6, the electric motor 51 is controlled toward the target lift amount to control the rotation angle θ of the control shaft 21, and the process returns.

  If it is determined in step 3 that the target lift amount of the first intake valve 3 is not zero, or if it is determined in step 4 that the actual lift amount of each of the intake valves 3 and 3 exceeds L3, step 7

  In step 7, an off signal is output to the electromagnetic switching valve 55, or a process of continuing the off signal is performed (in this case, the off signal is continued).

  That is, when L3 is exceeded, the supply of the signal oil pressure into the restriction hole 39 is interrupted or continuously interrupted, and the restriction pin 41 is engaged in the restriction hole 39 by the spring force of the return spring 42. Alternatively, the engagement is continued and the first hydraulic lash adjuster 10a is locked or locked to the cylinder head 1. Accordingly, the first intake valve 3 is prohibited from being stopped, and the first swing arm 6 is opened / closed (lifted) by using the first hydraulic lash adjuster 10a as a swing fulcrum. Therefore, as described above, an excessive lost motion of the first hydraulic lash adjuster 10a is prohibited, thereby causing irregular behavior due to local contact of the lower surface recess 6c of the other end 6b of the first swing arm with the tip head 27b. Is avoided and a smooth operating state is obtained.

  In the present embodiment, the condition for forcibly prohibiting the lost motion of the first hydraulic lash adjuster 10a is that the amount of lost motion exceeds M3 (the target lift of the first intake valve 3 exceeds L3). However, on the control map, even if the lift amount is lower than L3, the first intake valve 3 may not be stopped and the lift operation may be controlled for both the first and second intake valves 3, 3. Needless to say.

  For example, in the case of a cold engine that needs a combustion torque that overcomes engine friction even at a small operating angle (for example, a small lift amount L2) that is advantageous for exhaust emission such as when starting a cold engine, the two intake valves 3 are not used without lost motion. , 3 is preferably opened / closed, so that the lost motion can be prohibited even if the lift amount is less than L3.

  The point in time when the lift amount L3 or the lost motion M3 is exceeded is only a reference for forcibly prohibiting the lost motion, and the control map makes a valve stop transition with a lift amount smaller than L3 (lost motion operation). The two-valve operation may be performed without depending on the operating conditions.

  On the other hand, depending on the engine state, the settings of the values L3 and M3, which are standards for forcibly prohibiting the above-described lost motion, may be changed. For example, in the high engine speed range, slight separation tends to occur between the parts of the valve operating mechanism, so that irregular behavior such as displacement and dropout of the swing arm 6 with respect to the pivot is more likely to occur. , M3 may be set smaller.

  Further, a supplementary description will be given of the point that the present embodiment is superior to the prior art disclosed in the above-described prior art (Japanese Patent Laid-Open No. 2010-007636).

  That is, in the prior art, as shown in FIG. 4 of the same publication, the body is fixed to the cylinder head and the valve is stopped by causing the plunger itself to undergo a lost motion.

  Specifically, by reducing the operating oil pressure acting on the body, the lost motion amount of the plunger is increased to stop the valve, but the lost motion amount cannot be increased instantaneously during the process of decreasing the operating oil pressure. In addition, there is an unstable intermediate lost motion moment, the lift curve in that case is unstable, and the behavior of the valve mechanism becomes irregular, which is disadvantageous for the suppression of irregular behavior. There are concerns about phenomena such as unstable performance.

  On the other hand, in the present embodiment, the lift operation state and the valve stop state (lost motion state) are alternatively selected by fastening and unfastening with the restriction pin, and there is no intermediate lift curve. There is no concern.

  In addition, since the body of the above prior art is fixed to the cylinder head and the plunger itself is lost, the return spring that pushes up the plunger has a spring function (small stroke) for adjusting the hydraulic rascia adjuster and the plunger is lost. Combined with spring function (large stroke) for motion. Therefore, if the spring load is reduced with emphasis on the lash adjustment, the followability at the time of lost motion deteriorates.On the other hand, if the spring load is increased, the pump up phenomenon that the rassia adjustment does not work well and the plunger rises excessively. Will occur.

  On the other hand, in this embodiment, the spring 29d for adjusting the lash and the spring 35 for lost motion can be set separately, so there is no such concern.

  Further, as described above, the valve is stopped when the hydraulic pressure from the oil pump is low in the prior art, so the valve is stopped at the time of engine cranking or starting at which the hydraulic pressure from the oil pump cannot be expected. End up. Therefore, there is a problem that the intake air intake amount is insufficient at the time of starting, and the startability is deteriorated due to insufficient torque.

  On the other hand, in this embodiment, when the signal oil pressure does not act as described above, the two-valve operation is performed, so that there is no such concern and a good startability can be obtained.

[Second Embodiment]
FIG. 16 shows a second embodiment in which a mechanical structure is further added as valve stop prohibiting means.

  That is, a part of the oil passage hole 43 is formed with a pair of oil holes 43 a and 43 b penetrating in a direction perpendicular to the control shaft 21 of the bearing portion 13 bearing the control shaft 21. On the other hand, in the direction perpendicular to the internal axis of the control shaft 21, a communication hole 46 is formed penetratingly communicating with the oil holes 43 a and 43 b as appropriate. Arc-shaped oil grooves 46 a and 46 b are formed at both ends of the communication hole 46.

  When the rotational angle position of the control shaft 21 is θ2 (L2), the communication hole 46 has both oil holes 43a, 43a of the oil passage hole 43 through the oil grooves 46a, 46b. 43b, but when the rotational angle position of the control shaft 21 exceeds the angle θ3 (L3), as shown by the broken line, both the oil grooves 46a, 46b are displaced and the oil holes 43a, 43b Communication is blocked.

  Therefore, when the engine rotation is in the low rotation range and the rotation angle of the control shaft 21 is in the range of θ1 to θ3 (the lift amounts of the intake valves 3 and 3 are L1 to L3), as shown by the solid line, the oil passage 43 and the communication hole 46 are in communication with each other, and the signal oil pressure is supplied into the restriction hole 39. However, when the rotation angle exceeds θ3 (L3), the outer circumference of the control shaft 21 is indicated by the broken line as shown by the broken line. Both oil holes 43a and 43b are closed on the surface, and the communication with the oil passage hole 43 is mechanically blocked.

For this reason, it is possible to obtain the same effects as those of the first embodiment. In particular, in this embodiment, for example, the control unit 53 fails and the electromagnetic switching valve 55 operates abnormally to Even if an abnormal signal oil pressure is supplied to the upstream side of the passage hole 43, the passage is blocked by the control shaft 21, so that the lost motion of the first hydraulic lash adjuster 10a is restricted whenever θ3 (L3) is exceeded. Therefore, the valve stop is prohibited.
[Third Embodiment]
FIG. 17 shows a third embodiment, and a bottomed cylindrical holding member 47 in which the first hydraulic lash adjuster 10a can slide up and down is placed in the holding hole 1a of the cylinder head 1 on the first hydraulic lash adjuster 10a side. While being press-fitted and fixed, a projection 47 b is integrally provided at the center position of the inner surface of the bottom wall 47 a of the holding member 47.

  The protrusion 47b is formed on the bottom surface of the body 24 of the first hydraulic lash adjuster 10a when the first hydraulic lash adjuster 10a performs a lost motion and the amount of lost motion slightly exceeds M3 as shown in FIG. The height is set so as to abut and restrict further lost motion strokes.

  Note that the peripheral wall of the holding member 47 is formed with a communication passage 47c for communicating the first concave groove 24a and the oil passage 30 and a breathing hole 47d on the bottom wall 47a side.

  As described above, in the present embodiment, since the lost motion stroke of the first hydraulic lash adjuster 10a can be mechanically restricted by the protrusion 47b to suppress excessive lost motion, the first swing arm 6 and the plunger It is possible to more reliably avoid local contact with the distal end head 27b of the 27.

Further, the holding member 47 is made of a ferrous material different from the cylinder head 1 (usually aluminum material), so that the holding member 47 slides with a restriction hole in which the restriction pin slides or a body 24 of the hydraulic lash adjuster 10a. Abrasion resistance such as sliding holes can be improved. Needless to say, such a holding member 47 can be applied to the first embodiment in a form excluding the protrusion 47b.
[Fourth Embodiment]
FIG. 18 shows the fourth embodiment, and the basic configuration is the same as that of the first embodiment. However, the entire lift amount variable mechanism including the swing cams 7 and 7 is arranged in a mirror in the direction opposite to that of the respective embodiments. It is a thing.

  As a result, the swing cam 7 swings and lifts clockwise in the figure to open and lift the swing arms 6 and 6 and the intake valves 3 and 3.

  In this embodiment, compared with the configuration shown in FIG. 9 of the first embodiment, the swing lift direction of the swing cam 7 is the same as the lost motion direction of the first hydraulic lash adjuster 10a. The cam nose portion 7 and the swing arm 6 are less likely to interfere during operation.

  Further, since the contact point between the swing cam 7 and the roller 14 of the swing arm 6 approaches the first hydraulic lasher adjuster 10a side and presses the vicinity of the center of the swing arm 6 exactly, The contact property of the swing arm 6 is improved and it is difficult to come off. This is because the contact at the spherical portion on the roller 14 side and the contact at the spherical portion on the opposite roller side are balanced at the tip head portion 27b of the first hydraulic lash adjuster 10a.

  Thus, in the present embodiment, a good contact state between the first hydraulic lash adjuster 10a and the swing arm 6 can be obtained, and interference between components can be suppressed.

  The present invention is not limited to the configuration of each of the above embodiments. For example, as an internal combustion engine, not only the V type 6 cylinder but also a V type 8 cylinder, an in-line 4 cylinder corresponding to these single banks, It can also be applied to other institutions.

  In addition, the cam profiles of the two rocking cams 7 and 7 may be made different, thereby improving the combustion by a slight swirl while maintaining the intake charge efficiency in both valve operation regions where the engine load is high. I can plan. The engine valve can be applied to the exhaust valve side in addition to the intake valve 3. In this case, the exhaust gas swirl can be strengthened, so that the exhaust emission conversion performance of the catalyst can be improved.

  Moreover, although embodiment which stops one valve | bulb among a pair of engine valves was shown, it is applicable also to what is called a cylinder stop which stops both valves. Further, the member that performs the lost motion may be a member that does not have a lash function, in addition to the hydraulic lash adjuster.

  In addition, a valve stop mechanism can be provided in the first swing arm 6. In this case, for example, a roller element that can be displaced (lost motion) is provided in the main swing arm as shown in Japanese Translation of PCT International Publication No. 2009-503345. And the main swing arm may be switched between fastening and non-fastening. Even in this case, a smooth operation can be realized by suppressing an unreasonable posture such as the contact between the roller element and the swing cam coming off or interfering due to excessive lost motion, interference, or bottoming during the lost motion.

  Further, the present invention can also be applied to a lifter type valve operating mechanism that does not have a hydraulic lash adjuster described in JP 2010-270633 A. In this case, a valve stop mechanism built in the valve lifter as shown in JP-A-63-16112 may be used. Furthermore, it can be applied to a both-valve stop mechanism.

The technical ideas of the invention other than the claims ascertained from the embodiment will be described below.
[Claim a] The variable valve operating apparatus for an internal combustion engine according to claim 1,
The valve stop mechanism includes a holding hole for movably holding the fulcrum member;
Biasing means for biasing the fulcrum member in the swing arm direction;
A variable valve operating apparatus for an internal combustion engine, wherein the fulcrum member is moved against the urging force of the urging member to perform a lost motion.
[Claim b] In the variable valve operating apparatus for an internal combustion engine according to claim a,
The variable valve operating apparatus for an internal combustion engine, wherein the fulcrum member is a hydraulic lash adjuster.
[Claim c] In the variable valve operating apparatus for an internal combustion engine according to claim 1,
The valve stop mechanism is provided on only one of the pair of fulcrum members,
A variable valve operating apparatus for an internal combustion engine, wherein when the amount of lost motion is less than or equal to a predetermined value, the valve stop mechanism is allowed to stop only the corresponding engine valve.

According to this invention, the swirl effect is increased by stopping the single valve, and the fuel consumption can be improved.
[Claim d] In the variable valve operating apparatus for an internal combustion engine according to claim 1,
The valve stop mechanism is provided on both of the pair of fulcrum members,
A variable valve operating apparatus for an internal combustion engine, wherein when the amount of lost motion is equal to or less than a predetermined amount, the valve stop mechanism is allowed to stop both engine valves.

According to the present invention, the pumping loss can be reduced because both of the engine valves are stopped and the cylinders are stopped, so that the throttle valve of the cylinder that is not stopped can be opened widely.
[Claim e]
The variable valve operating apparatus for an internal combustion engine according to claim c,
The variable valve operating apparatus for an internal combustion engine, wherein the pair of swing cams are integrally formed.
[Claim f] The variable valve operating apparatus for an internal combustion engine according to claim a,
The swing fulcrum is formed by a spherical concave portion provided in the swing arm and a spherical convex portion provided in the fulcrum member and engaged with the concave portion. Variable valve gear for engine.
[Claim g] In the variable valve operating apparatus for an internal combustion engine according to claim a,
The valve stop prohibiting means mechanically prohibits the lost motion of the fulcrum member when the amount of lost motion exceeds a predetermined value.
(Claim h) In the variable valve operating apparatus for an internal combustion engine according to claim a,
The control shaft has a control cam eccentric with respect to the axis;
The variable valve operating apparatus for an internal combustion engine, wherein the transmission mechanism is inserted into the control cam and changes its posture when the control cam rotates.
[Claim i] In the variable valve operating apparatus for an internal combustion engine according to claim g,
The variable motion valve device for an internal combustion engine according to claim 1, wherein the lost motion is regulated such that movement of the fulcrum member is regulated by a protrusion in a movable range of the fulcrum member.
[Claim j] The variable valve operating apparatus for an internal combustion engine according to claim g,
The valve stop prohibiting means includes a movement hole and a restriction hole provided in the inner wall of the fulcrum member and the holding hole, and a restriction pin provided to be movable across the movement hole and the restriction hole. Configured, the state where the fulcrum member is locked by the restriction pin being disposed across the movement hole and the restriction hole,
A variable valve operating apparatus for an internal combustion engine, configured to control a state in which the restriction pin is accommodated in the movement hole and the fulcrum member is capable of lost motion.
[Claim k] The variable valve operating apparatus for an internal combustion engine according to claim j,
The valve stop prohibiting means is provided in a movement hole of the fulcrum member, and urges the urging member to urge the restriction pin toward the restriction hole, and against the urging force of the urging member. A variable valve operating apparatus for an internal combustion engine, comprising: a hydraulic circuit that supplies a hydraulic pressure that presses the restriction pin toward the moving hole.
[Claim 1] In the variable valve operating apparatus for an internal combustion engine according to claim k,
The hydraulic circuit has an oil passage hole provided in a bearing portion of the control shaft, and a communication hole that is formed through the control shaft in a diameter direction and communicates with the oil passage hole as appropriate.
The variable valve operating apparatus for an internal combustion engine, wherein the oil passage hole and the communication hole communicate with each other when the control shaft is equal to or less than a predetermined rotation angle, and the communication is cut off when a predetermined rotation angle is exceeded.
[Claim m] In the variable valve operating apparatus for an internal combustion engine according to claim k,
When it is smaller than the predetermined lost motion amount of the fulcrum member, hydraulic pressure is supplied to move the restriction pin against the biasing member, and when the predetermined lost motion amount is exceeded, the biasing force of the biasing member causes A variable valve operating apparatus for an internal combustion engine, wherein the restriction pin is moved in the direction of the restriction hole.
(Claim n) In the variable valve operating apparatus for an internal combustion engine according to claim a,
The angle obtained by subtracting 90 ° from the angle formed between the swing arm and the fulcrum member when the amount of lost motion of the fulcrum member is a predetermined value is the difference between the swing arm and the fulcrum member at the time of valve opening during the maximum lift control of the intake valve. A variable valve operating apparatus for an internal combustion engine, wherein the variable valve operating apparatus is smaller than an angle subtracted from an angle of 90 °.

According to the present invention, it is possible to make the degree of the posture of the swing arm bad when the amount of lost motion is a predetermined value, better than the posture of the swing arm at the valve opening position at the time of maximum lift control. Can be made smoother.
(Claim o) The variable valve operating apparatus for an internal combustion engine according to claim a,
The valve stop prohibiting means includes a restricting member that restricts the lost motion by urging the fulcrum member toward the swing arm when the amount of lost motion of the fulcrum member exceeds a predetermined value. Variable valve device.
[Claim p] The variable valve operating apparatus for an internal combustion engine according to claim k,
The valve stop prohibiting means is constituted by a valve stop prohibiting circuit in which when the amount of lost motion exceeds a predetermined value, the control unit shuts off the supply of hydraulic pressure via the electromagnetic switching valve of the hydraulic circuit. Variable valve gear.
(Claim q) In the variable valve operating apparatus for an internal combustion engine according to claim p,
The variable valve operating apparatus for an internal combustion engine, wherein the predetermined value of the predetermined lost motion amount can be arbitrarily set according to an operating state of the engine.

  According to the present invention, the forbidden lost motion amount can be set arbitrarily, so that irregular behavior when the valve is stopped can be effectively suppressed, for example, in a high rotation range.

DESCRIPTION OF SYMBOLS 1 ... Cylinder head 1a ... Holding hole 3 ... Intake valve (engine valve)
DESCRIPTION OF SYMBOLS 5 ... Camshaft 5a ... Drive cam 6 ... Swing arm 6a ... One end part 6b ... Other end part 7 ... Swing cam 8 ... Transmission mechanism 9 ... Control mechanism 10a, 10b ... 1st, 2nd hydraulic lashia adjuster (fulcrum member)
DESCRIPTION OF SYMBOLS 11 ... Valve stop mechanism 12 ... Valve spring 13 ... Bearing part 14 ... Roller 24 ... Body 27 ... Plunger 27b ... Tip head 34 ... Sliding hole 35 ... Lost motion spring 36 ... Restriction mechanism 38 ... Movement hole 39 ... For regulation Hole 40 ... Retainer 41 ... Restriction pin 42 ... Return spring 43 ... Oil passage hole 44 ... Drain hole 54 ... Oil pump 55 ... Electromagnetic switching valve

Claims (3)

A drive shaft in which a rotational drive force is transmitted from the crankshaft of the engine and a drive cam is provided on the outer periphery;
Two swing cams that open two engine valves per cylinder against the spring force of the valve spring;
A transmission mechanism that converts the rotational motion of the drive cam into a swing motion and transmits the swing motion to the swing cam;
A pair of swing arms interposed between the swing cams and the engine valves to open and close the engine valves by the swing force of the swing cams and the spring force of the valve spring;
A pair of fulcrum members to be the swing fulcrum of each swing arm;
A control mechanism that variably controls the lift amount of each engine valve by changing the attitude of the transmission mechanism;
A variable valve operating apparatus for an internal combustion engine comprising:
While providing a valve stop mechanism for stopping the opening and closing drive of the one engine valve by causing at least one of the pair of fulcrum members to lose motion,
A variable valve operating apparatus for an internal combustion engine, characterized by comprising valve stop prohibiting means for prohibiting valve stop when the amount of lost motion of the valve stop mechanism exceeds a predetermined value. A drive cam to which rotational force is transmitted from the crankshaft;
Two engine valves provided per cylinder, and urged in the valve closing direction by the spring force of the valve spring;
A swing cam for opening each engine valve against the spring force of the valve spring;
A transmission mechanism that converts the rotational motion of the drive cam into a swing motion and transmits the swing motion to the swing cam;
A control mechanism that variably controls the lift amount of each engine valve by changing the attitude of the transmission mechanism;
A pair of actuating members that swing according to the swing motion of the swing cam to open and close the engine valves;
A valve stop mechanism that absorbs the swing amount of the one operating member and stops the opening and closing operation of the one engine valve;
A variable valve operating apparatus for an internal combustion engine, comprising: a valve stop prohibiting means for prohibiting absorption of the swing motion of the valve stop mechanism when the swing amount of the actuating member exceeds a predetermined amount. A drive cam that is rotationally driven by a crankshaft;
A pair of engine valves biased in the closing direction by the spring force of the valve springs;
A pair of swing cams for driving the pair of engine valves via a pair of actuating members by swinging;
A transmission mechanism for converting the rotational motion of the drive cam into a swing motion and transmitting it to the pair of swing cams;
A control mechanism that changes the operating characteristics of the pair of engine valves by changing the attitude of the transmission mechanism;
A valve stop mechanism that is provided on at least one of the pair of actuating members and stops driving of the one engine valve by performing a lost motion;
With
A variable valve operating apparatus for an internal combustion engine, wherein a valve stop operation by a valve stop mechanism is prohibited when a valve lift amount of the one engine valve exceeds a predetermined value.

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