JP2010065632A - Valve gear of internal combustion engine and hydraulic lash adjuster used in valve gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve gear which can suppress a very small opening of an intake valve in a case where other cylinders are closed due to deflective deformation of a drive shaft when the intake valve is opened, and which can prevent destabilization of engine operation and deterioration of fuel consumption. <P>SOLUTION: In the valve gear, rotation of a drive cam 5a disposed on a drive shaft 5 swings a swing cam 7 via a link arm 16, a rocker arm 15, and a link rod 17, which opens or closes each of intake valves 3, 3 via a swing arm 6 against a spring force of a valve spring 12. A hydraulic lash adjuster 10 coming into contact with other end portion 6b of the swing arm includes a disk spring 34 elastically disposed between a body 24 and a retention hole 1a. In the hydraulic lash adjuster, compressive deformation of the disk spring absorbs a very small downward movement of each swing arm one end portion 6a of other cylinders due to deflective deformation generated at the drive shaft when the intake valve is opened, to thereby maintain a valve-closed state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a valve operating apparatus for an internal combustion engine provided with a variable mechanism that variably controls a valve lift amount of an engine valve that is an intake valve or an exhaust valve in accordance with an engine operating state.

  As a conventional valve operating device for an internal combustion engine, one described in the following Patent Document 1 previously filed by the present applicant is known.

  This valve operating device is provided on a drive shaft provided with a drive eccentric cam on the outer periphery and a camshaft rotatably supported on the outer periphery of the drive shaft so that the intake valve is opposed to the spring force of the valve spring. A swing cam to be opened, a rocker arm having one end rotatably connected to the drive eccentric cam via a link arm and the other end rotatably connected to the swing cam via a link rod; A control cam provided on a control shaft disposed in the longitudinal direction of the engine and changing a rocking fulcrum of the rocker arm.

  A swing arm is interposed between the swing cam and the intake valve, and this swing arm is swingably supported by a hydraulic lash adjuster whose one end is held in a holding hole of the cylinder head. On the other hand, the other end is in contact with the stem end of the intake valve. Also, the swinging force of the swing cam is transmitted as the valve opening force of the intake valve while the cam surface of the swing cam is in rolling contact with the outer peripheral surface of the roller provided at substantially the center position of both ends. Yes.

  Further, the hydraulic lash adjuster pushes up the other end portion of the swing arm by the internal hydraulic pressure, so that the swing cam opens the intake valve as well as the base circle of the swing cam. Even when the intake valve is not opened, the valve clearance is set to zero lash and the roller and the swing cam are always in contact with each other.

Then, the control cam is rotationally controlled by the actuator via the control shaft in accordance with the engine operation state, thereby changing the rocking fulcrum of the rocker arm, whereby the rocking cam moves the intake valve operating angle and lift amount. Is to change.
Special table 2004-332550 gazette

  However, when the conventional valve operating device is applied to, for example, a V-type 6-cylinder gasoline internal combustion engine, when looking at the one-side bank side, the roller for opening the swing cam of the # 1 cylinder intake valve When a pressure is applied via the link rod, a force that pushes down the drive cam is exerted via the link rod, the rocker arm and the link arm by the spring reaction force of the valve spring. This input causes the drive shaft to bend and deform slightly downward while reducing the clearance between the drive shaft and the swing cam and the clearance between the swing cam and the bearing.

  As a result, the swing cam of the # 3 cylinder adjacent to the # 1 cylinder is in the base circle, that is, the valve is closed, but the # 3 cylinder swing cam is lowered as the drive shaft is deformed. There is a risk that the # 3 cylinder intake valve may be slightly opened.

  This phenomenon may cause the intake valve of the # 5 cylinder in the closed state to be slightly opened even when the intake valve is opened by the swing cam of the # 3 cylinder.

  As a result, for example, during the idling operation, the air-fuel mixture in the combustion chamber may flow out of the intake valve that is slightly opened, leading to instability of engine rotation and a reduction in fuel consumption.

  The present invention has been devised in view of the technical problem of each of the conventional variable valve gears, and the invention according to claim 1 is driven to the outer periphery by the rotational driving force transmitted from the crankshaft of the engine. A drive shaft provided with a cam; a cam that is driven via the drive cam and opens the engine valve against the spring force of the valve spring in the lift region; and an interposition between the cam and the engine valve. An interposition member that contacts at least the cam, and an urging mechanism that has a spring load smaller than a spring load of the valve spring and urges the interposition member toward the cam. It is a feature.

  According to this invention, the spring reaction force of the valve spring is transmitted from the engine valve on the valve opening side to the drive shaft, and the engine valve of the adjacent cylinder in the valve closing state passes through the interposing member in the valve opening direction. When a pressing force is applied, the urging mechanism compresses and deforms the pressing force to slightly move the interposition member backward to absorb the pressing force. For this reason, transmission of the pressing force from the interposition member to the engine valve in the valve closing state is avoided, and the valve closing state is reliably maintained. As a result, the outflow of intake air from the engine valve is sufficiently suppressed, and instability of the engine performance can be eliminated.

  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 three-cylinder cylinder on one side of a V-type six-cylinder internal combustion engine, and includes a variable mechanism that variably controls the operating angle and valve lift amount of the intake valve.

[First Embodiment]
1 to 5 show a first embodiment, two intake valves 3 and 3 per cylinder for opening and closing a pair of intake ports 2 and 2 formed in the cylinder head 1, and # 1 cylinder and # 3. A drive shaft 5 disposed along the engine longitudinal direction on the upper side of the cylinder and the # 5 cylinder and having a drive cam 5a on the outer periphery, and an outer peripheral surface of the drive shaft 5 is rotatably supported, and is an interposed member A pair of swing cams 7 for opening and closing each intake valve 3 via a swing arm 6; and a transmission mechanism 8 for converting the rotational force of the drive cam 5a into a swing force and transmitting the swing force to each swing cam 7. , A control mechanism 9 for controlling the operating angle and lift amount of each intake valve 3, 3 via the transmission mechanism 8, a cylinder head 1, and each intake valve 3 via each swing arm 6. A pair of valve clearances between the rocking cams 7 is always zero-lash. It includes a pressure lash adjuster 10, a. 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 3a. Is biased in the closing direction by each valve spring 12 elastically contacted between each spring retainer 11 provided in the vicinity of the cylinder head 1 and the inner upper surface of the cylinder head 1.

  The drive shaft 5 is rotatably supported by a plurality of bearing portions 13 provided at the upper end portion of the cylinder head 1 via a camshaft 7a of the swing cam 7, and a timing (not shown) provided at one end portion. 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 swing arm 6 is formed in the center while the lower surface of one end portion 6a is in contact with the stem end 3a of each intake valve 3 and the other end portion 6b is in contact with the hydraulic lash adjuster 10. The roller 14 is rotatably accommodated in the accommodating hole via the roller shaft 14a.

  As shown in FIG. 1 and the like, both the swing cams 7 are integrally provided at both ends of a cylindrical cam shaft 7a, and the cam shaft 7a is connected to the drive shaft 5 via an inner peripheral surface. Is supported rotatably. Further, a cam surface 7b composed of a base circle surface, a ramp surface and a lift surface is formed on the lower surface, and the base circle surface, the ramp surface and the lift surface are arranged in accordance with the swing position of the swing cam 9 according to the swing arm. The upper surface of the six rollers 14 is in rolling contact. 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 minute clearance, and the drive shaft 5 has a minute clearance therein. Is supported in a freely rotatable manner.

  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 disposed in the longitudinal direction of the engine in parallel with the drive shaft 5 and is rotationally controlled by an actuator (not shown). 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.

  The actuator is composed of an electric motor fixed to one end of the housing, and a ball screw transmission means that is provided inside the housing and transmits a rotational driving force of the electric motor to the control shaft 21. Yes.

  The electric motor is constituted by a proportional type DC motor and is driven by a control signal from a control unit that detects an engine operating state.

  As shown in FIGS. 1, 3A, and 3B, the hydraulic lash adjuster 10 includes a bottomed cylindrical body 24 that is slidably held in a cylindrical holding hole 1a of the cylinder head 1, and the body The plunger 27 is accommodated in the upper and lower parts of the body 24 and is formed in the lower part of the body 24 through the partition wall 25 integrally formed in the lower part. A high-pressure chamber 28 that communicates with the reservoir chamber 26 through the communication hole 25a, and is provided inside the high-pressure chamber 28 to allow the hydraulic oil in the reservoir chamber 26 to flow only in the direction of the high-pressure chamber 28. And a check valve 29. Further, a through hole 1b is formed inside the cylinder head 1 for discharging the hydraulic oil accumulated in the holding hole 1a to the outside.

  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.

  As shown in FIG. 1, the oil passage 30 communicates with a main oil gallery 30a for supplying lubricating oil formed in the cylinder head 1, and the main oil gallery 30a includes an unillustrated oil. Lubricating oil is pumped from the pump.

  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. A second passage hole 32 that communicates is formed so as to penetrate along the radial direction, and the tip surface of the tip portion 27b is spherical to ensure good slidability with the lower surface of the other end portion 6b of the swing arm 6. Is formed. 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, and a cup-shaped retainer 29c that holds a first coil spring 29b that biases the check ball 29a in the closing direction. The second coil spring 29d is elastically mounted between the inner bottom surface of the bottom wall 24c of the body 24 and the annular upper end of the retainer 29c, and biases the retainer 29c toward the partition wall 25.

  When the inside of the high pressure chamber 28 becomes low pressure with the advancement of the plunger 27, the hydraulic oil supplied from the oil passage 30 into the holding hole 1a is transferred from the first groove 24a to the first passage hole 31 and the second groove. The oil flows into the reservoir chamber 26 through the groove 27 a and the second passage hole 32, further pushes the check ball 28 a against the spring force of the first coil spring 29 b, and causes the hydraulic oil to flow into the high pressure chamber 28.

  As a result, the plunger 27 constantly pushes up the other end portion 6 b of the swing arm 6, and the gap between the swing cam 7, the one end portion 6 a of the swing arm 6 and the stem end 3 a of the intake valve 3 via the roller 14. It is designed to adjust to zero lash.

  Further, a disc spring 34 as an urging mechanism is mounted between the bottom surface of the holding hole 1a and the outer bottom surface of the bottom wall 24c of the body 24. The disc spring 34 has a circular outer peripheral portion that is in contact with and supported by the bottom surface of the holding hole 1 a, while a small-diameter circular inner peripheral portion that is bent and deformed upward is normally the bottom wall of the body 24. It is in contact with the outer bottom surface of 24c. The disc spring 34 is set so that its spring load during compression deformation is smaller than the spring load of the valve spring 12.

  In other words, in the present embodiment, the spring load (solid line) of the valve spring 12 rises as shown in FIG. The spring load (broken line) is less than the spring load of the valve spring 12, and the spring load is set so that the lost motion load at the required minute stroke of the hydraulic lash adjuster 10 is at most the spring load of the valve spring 12. Yes. That is, since the valve opening of the intake valve 3 is started when the spring load of the valve spring 12 acts on the swing arm 6, it is set below the spring load of the valve spring 12.

  Further, the cam profile of the cam surface 7b of each swing cam 7 is set in consideration of the later-described compression deformation amount of the disc spring 34.

  Hereinafter, the basic operation of the valve gear in the present embodiment will be described with reference to FIGS. 4 and 5.

  First, for example, in a low rotation range such as an idling operation of an engine, the electric motor is rotationally driven by a control current output from the control unit, and this rotational torque is transmitted to the control shaft 21 via a ball screw mechanism. When the control shaft 21 is driven to rotate in one direction, as shown in FIGS. 4A and 4B, the control cam 22 also rotates in one direction so that the shaft center rotates around the shaft center of the control shaft 21 with the same radius. Then, the thick portion moves away from the drive shaft 5 in the upper right direction as illustrated. 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, so that each swing cam 7 moves the link rod 17 to 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 L is sufficiently small as shown in FIG.

  For example, when the engine shifts to a high rotation region, when the electric motor reversely rotates by the control current from the control unit and rotates the ball screw mechanism in the same direction, the rotation is performed as shown in FIGS. 5A and 5B. Accordingly, 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 from the position shown in FIG. 4 by a predetermined amount. Therefore, as shown in FIG. 5A, 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 is increased against the spring force, and the valve lift amount increases while continuously changing as indicated by L1 in FIG.

  As described above, when the intake valve 3 of the # 1 cylinder shown in FIGS. 1, 4A, and B is opened in a low rotation region such as during idling, the push from the drive cam 5a is performed. The one end 15a of the rocker arm 15 is pushed up by the pressure via the link arm 16 and the other end 15b is pushed down to push down the cam nose portion of each swing cam 7. Then, the roller 14 of each swing arm 6 is pushed down by the lift portion of the cam surface 7b of each swing cam 7 to open each intake valve 3 (open arrow), and a large spring reaction force of each valve spring 12 Acts on the drive cam 5a from the swing arm 6 through the swing cam 7, the link rod 17, the rocker arm 15 and the link arm 16 as a push-down force (black arrow in FIG. 8).

  For this reason, the drive shaft 5 moves downward as shown by a one-dot chain line in FIG. 8 while reducing the clearance between the drive shaft 5 and the camshaft 7a and the clearance between the camshaft 7a and the bearing portion 13. Slightly bends and deforms. At this time, the intake valves 3 of the # 3 cylinder adjacent to the # 1 cylinder are in the closed state, but due to the downward deformation of the drive shaft 5, the intake valves 3 of the adjacent # 3 cylinder are The valve is slightly opened downward via the swing cams 7 and the swing arm 6.

  FIGS. 9A and 9B show the lift states of the intake valves 3 of the # 1, # 3, and # 5 cylinders as the driving shaft 5 is bent downward. In other words, at the maximum lift (maximum valve opening) of the # 1 cylinder, the intake valves 3 on the # 3 and # 5 cylinders are originally closed, but the influence of the bending deformation of the drive shaft 5 is affected. It is clear that the valve is opened minutely. In particular, the intake valve 3 of the # 3 cylinder has a larger valve opening amount than the intake valve 3 of the # 5 cylinder because the influence of the bending deformation is larger.

  Therefore, in the present embodiment, the entire hydraulic lash adjuster 10 provided for each cylinder is slightly lowered (lost motion) in each holding hole 1a with the compression deformation of the disc spring 34, and the drive shaft 5 is bent. By absorbing the deformation, the minute opening of the intake valves 3 of the # 3 and # 5 cylinders is suppressed.

  That is, as described above, for example, each intake valve 3 of the # 1 cylinder opens and lifts to the maximum and the drive shaft 5 bends and deforms, so that the swing cams 7 of the # 3 cylinder and # 5 cylinder swing each swing. When the roller 14 of the arm 6 is pressed, the other end 6 b side of the swing arm 6 depresses the plunger 27 of the hydraulic lash adjuster against the spring force of the disc spring 34 and the body 24 via the hydraulic oil in the high pressure chamber 28. Also press together.

  As a result, as shown in FIG. 3B, the disc spring 34 is compressed and deformed, and the entire hydraulic lash adjuster 10 is slightly lost in the downward direction to absorb the pressing force. Therefore, the swing arm 6 is slightly lowered only on the other end 6b side and is not lowered on the one end 6a side. Therefore, the intake valves 3 of the # 3 and # 5 cylinders in the closed state are reliably maintained in the closed state.

  As a result, the outflow of the intake air from the intake valves 3 of the # 3 and 4 cylinders is sufficiently suppressed, and the instability of the engine performance can be eliminated.

  In this embodiment, since the disc spring 34, which is a spring member, is used as the biasing mechanism, a stable lost motion effect can be obtained without being affected by oil viscosity, engine speed, oil temperature, etc. Since the existing disc spring 34 can be used, an increase in cost can be suppressed.

  Further, the hydraulic oil accumulated in the holding hole 1a is automatically discharged from the through hole 1b, and functions as an air inflow into the holding hole 1a when the hydraulic lash adjuster 10 is raised. The smooth movement of the hydraulic lash adjuster 10 can be ensured at all times.

  Furthermore, in the present embodiment, the case of low engine rotation has been described, but a minute clearance is formed between the drive shaft 5 and the camshaft 7a and between the camshaft 7a and the bearing portion 13, respectively. Even in the high rotation range, a slight lift may occur in any of the intake valves 3 in the closed state due to the violent swing of each swing cam 7. Therefore, in this embodiment, the lost motion action of the hydraulic lash adjuster 10 by the disc spring 34 is applied to any cylinder. As a result, the cam profile of the cam surface 7b of the swing cam 7 can be made common.

[Second Embodiment]
FIGS. 10A and 10B show a second embodiment in which a coil spring 35 is used instead of a disc spring as an urging mechanism. That is, a substantially cap-shaped stopper member 36 is placed and held on the bottom surface of the holding hole 1a, and the upper surface of the flange portion 36a on the outer periphery of the lower end of the stopper member 36 and the bottom wall of the body 24 of the hydraulic lash adjuster 10 are provided. A coil spring 35 is mounted between the outer bottom surface of 24c. The coil spring 35 has a cylindrical load whose spring load is set in the same manner as the disc spring of the first embodiment, and whose maximum compressive deformation is integrally formed on the upper surface of the flange portion 36a of the stopper member 36. The protrusion 36b is regulated. This is because, when the amount of compression deformation (stroke) of the coil spring 35 is increased and used in a bottomed state (close contact state), it becomes easy to cause sag, so that the stroke is regulated by the protrusion 36b.

  Other configurations are the same as those of the first embodiment. Therefore, when the drive shaft 5 is bent and deformed by the spring force of the coil spring 35, the lost motion action of the hydraulic lash adjuster 10 can be obtained as shown in FIG. 10B. Therefore, the same effect as the first embodiment can be obtained. can get.

[Third Embodiment]
FIGS. 11A and 11B show a third embodiment in which an urging mechanism is integrally provided at the lower portion of the body 24 of the hydraulic lash adjuster 10.

  That is, a cylindrical protrusion 37 is integrally formed on the lower outer periphery of the bottom wall 24c of the body 24, and a cup-shaped spring retainer 38 is slidably disposed inside the protrusion 37. A coil spring 39 is mounted between the bottom surface of the bottom portion 38 a of the spring retainer 38 and the bottom surface of the bottom wall 24 c of the body 24.

  The spring retainer 38 has an outer bottom surface of the bottom portion 38 a placed and held on the bottom surface of the holding hole 1 a, and a step portion 38 b is formed at the lower portion of the outer peripheral surface. The maximum upward movement position of the body 24 is regulated by abutting against a stopper claw 40a formed on the inner periphery of the lower portion of the stopper ring 40 fitted and fixed to the body. Further, a through hole 41 similar to that of the first embodiment is formed in the bottom portion 38a of the spring retainer 38 in an inclined shape.

  The spring load of the coil spring 39 is set to the same size as the disc spring of the first embodiment. Other configurations are the same as those of the first embodiment.

  Therefore, according to this embodiment, when the drive shaft 5 bends and deforms downward due to the above-described action and, for example, a pressing force acts on the distal end portion 27a of the plunger 27 of the hydraulic lash adjuster 10 in the # 3 cylinder, FIG. As described above, the hydraulic lash adjuster 10 moves downward against the spring force of the coil spring 39 and moves down until the upper end edge of the spring retainer 38 contacts the outer bottom surface of the bottom wall 24 a of the body 24. Such lost motion can absorb the bending deformation of the drive shaft 5 and sufficiently suppress the valve opening action of each intake valve 3.

  Therefore, the same effect as the first embodiment can be obtained.

[Fourth Embodiment]
12 and 13 show a fourth embodiment in which an urging mechanism is interposed between the stem end 3 a of the intake valve 3 and one end 6 a of the swing arm 6.

  That is, the urging mechanism includes a substantially cylindrical holding member 42 fitted and held on the stem end 3 a, a covered cylindrical cap portion 43 that closes the upper end opening of the holding member 42, and the holding member 42. A sliding portion 44 that is slidably housed inside and whose upper end abuts against one end 6 a of the swing arm 6, and a projecting portion 42 a formed inside the holding member 42 and the sliding portion 44. The coil spring 45 is disposed between the coil springs and biases the sliding portion 44 toward the one end portion 6a of the swing arm 6.

  The holding member 42 is formed with a fitting groove 42c that is fitted to the stem end 3a from above at substantially the center of the outer bottom surface of the bottom portion 42b, and an annular guide groove 42d is formed on the outer periphery of the protrusion 42a. Has been.

  The cap portion 43 is press-fitted and fixed from above the holding member 42, and a sliding hole 43b is formed through substantially the center of the disc-shaped upper wall 43a.

  The sliding portion 44 is integrally projected from the cylindrical portion 44a that slides in the vertical direction inside the holding member 42, and substantially at the center of the upper surface of the upper end wall of the cylindrical portion 44a. And a cylindrical pressing portion 44b guided so as to be slidable up and down. The pressing portion 44b is formed with a through hole 46 for obtaining smooth vertical sliding of the pressing portion 44b.

  The coil spring 45 is set to have a spring load smaller than that of the valve spring 12 as in the first embodiment.

  Therefore, in this embodiment, as described above, when a pressing force acts on the pressing portion 44b from each swing cam 7 through the one end portion 6a of the swing arm 6 in accordance with the downward deformation of the drive shaft 5, As shown in FIG. 13B, the pressing portion 44 b moves down against the spring force of the coil spring 45, that is, with the compression deformation of the coil spring 45, and absorbs the bending deformation of the drive shaft 5. As a result, the closed state of the intake valves 3 of the # 3 and # 5 cylinders is maintained. As a result, the same effects as those of the first embodiment can be obtained.

  The through hole 46 ensures smooth sliding of the pressing portion 44b, and lubricating oil supplied from the through hole 46 to the inside of the holding member 42 is the inner periphery of the pressing member 44b and the holding member 42. Since it flows between the surface and the outer peripheral surface of the protrusion 42a and lubricates these parts, the pressing part 44b can be slid more smoothly.

  In this embodiment, the body 24 of the hydraulic lash adjuster 10 is press-fitted and fixed in the holding hole 1a, and a zero lash of each intake valve 3 and the like is secured by a normal basic operation.

[Fifth Embodiment]
14 and 15 show a fifth embodiment, in which the swing arm 6 is divided into two parts on one end 6a side and the other end 6b side, and these two divided first and second divided members 47, 48 are provided so as to be able to bend and rotate with respect to a pivot 49 that is inserted through the opposite end portions of the two, and as shown in FIGS. An urging mechanism for urging in the bending direction is provided.

  The biasing mechanism includes a first locking portion 50 projecting from the outer surface of the first split member 47 on the pivot 49 side, and a first latching portion projecting from the outer surface of the second split member 48 on the pivot 49 side. The second locking portion 51 is wound around the protruding end portion of the pivot 49, and one end portion 52a is elastically locked to the first locking portion 50 from the inside, and the other end portion 52b is locked to the second locking portion. And a torsion spring 52 which is elastically locked to the portion 51 from the inside.

  Further, the first and second split members 47 and 48 are provided with two stopper projections 47a and 48a at the upper end portions of the first and second split members 47 and 48, which are opposed to each other in the rotational direction. .

  Therefore, according to this embodiment, as described above, for example, in the base circle region of the rocking cam 7 of the # 3 cylinder, the swing arm 6 has the spring force of the torsion spring 52 as shown in FIGS. Thus, both the stopper protrusions 47a and 48a are separated from each other and are biased in a state where the whole is bent into a square shape. For this reason, in the base circle region, the valve opening force to each intake valve 3 does not act and the valve is closed.

  Here, as described above, when a downward pressing force is applied to the swing arm 6 via the roller 14 from each swing cam 7 as the drive shaft 5 is bent downward, FIGS. As shown in the figure, both split members 47 and 48 rotate in the horizontal direction against each other against the spring force of the torsion spring 52 (lost motion), and the opposing surfaces of both stopper projections 47a and 48a come into contact with each other. The rotation in the same direction is restricted. As a result, the pressing force is absorbed via the spring force of the torsion spring 52, and the valve closing state of each intake valve 3 is maintained. Therefore, the same effects as those of the first embodiment can be obtained.

  Further, when a normal valve opening force is applied to the intake valve 3 via the cam surface 7b of the swing cam 7 in this state, the stopper protrusions 47a and 48a are in contact with each other and locked. The original valve opening force is effectively transmitted to open the valve. Thereafter, when the base circle region is reached, the swing arm 6 returns to the initial bent state shown in FIGS.

[Sixth Embodiment]
16 and 17 show a sixth embodiment. A hydraulic lash adjuster 60 is further provided between the urging mechanism and each of the swing cams 7 by using the urging mechanism of the fourth embodiment. A valve lifter 61 is interposed.

  Since the urging mechanism is the same as that of the fourth embodiment, the same reference numerals are given and the detailed description is omitted.

  The valve lifter 61 is formed of a ferrous metal in a covered cylindrical shape, a cylindrical skirt portion 61b is integrally formed on the outer peripheral edge of a disc-shaped crown portion 61a, and a predetermined portion of the cylinder head 1 is formed. The entire inner surface of the formed sliding hole 1c is slidable up and down and is rotatably arranged. An oil passage 64 for supplying lubricating oil is formed in the cylinder head 1 between the outer peripheral surface of the valve lifter 61 and the sliding hole 1c.

  A conical holding portion 62 is integrally formed in the valve lifter 61, and a trumpet-like support portion 63 is connected and fixed to the upper portion of the holding portion 62. The hydraulic lash adjuster 60 is accommodated in the holding portion 62.

  The crown portion 61a has a cam surface 7b of the swing cam 7 slidably in contact with a crown surface which is an upper surface, and communicates the inside of the hydraulic lash adjuster 60 and the inside of the support portion 63 to the lower surface. An oil groove 65 is formed.

  The hydraulic lash adjuster 60 is provided with a bottomed cylindrical body 66 that can slide up and down in a small-diameter cylindrical portion 62a of a holding portion 62, a slidable portion inside the body 66, and a partition wall 68 in the lower portion. A cylindrical retainer 67, a reservoir chamber 69 that is formed inside the retainer 67 and communicates with the inside of the support portion 63 via the oil groove 65, and a lower portion of the body 66. A high-pressure chamber 70 that communicates with the reservoir chamber 69 through a communication hole 68a that is formed in the center of the partition wall 68, and the hydraulic oil in the reservoir chamber 69 is connected to the communication hole 68a. And a check valve 71 that allows inflow only to the high-pressure chamber 70 side.

  Further, the upper surface of the pressing portion 44 b of the urging mechanism is always in elastic contact with the outer bottom surface of the bottom wall 66 a of the body 66 by the spring force of the coil spring 45.

  The reservoir chamber 69 is always supplied with lubricating oil introduced into the support 63 via an oil hole (not shown) via an oil groove 65.

  The check valve 71 includes a check ball 71a that closes the communication hole 68a by the spring force of the coil spring 71b, and a cup-shaped spring retainer 71c that holds the coil spring 71b.

  Therefore, according to this embodiment, when a pressing force acts on the pressing portion 44b from each swing cam 7 via the valve lifter 61 and the hydraulic lash adjuster 60 as the driving shaft 5 is bent downward, The pressing portion 44 b moves down against the spring force of the coil spring 45, that is, with the compression deformation of the coil spring 45, and absorbs the bending deformation of the drive shaft 5. As a result, the closed state of the intake valves 3 of the # 3 and # 5 cylinders is maintained. As a result, the same effects as those of the first embodiment can be obtained.

  In the hydraulic lash adjuster 60, when the pressure in the high pressure chamber 70 becomes low as the valve lifter 61 moves upward, the oil in the reservoir chamber 69 pushes the check ball 71a through the communication hole 68a and flows into the high pressure chamber 70. For this reason, the clearance between the crown surface and the swing cam 7 is constantly adjusted so that the clearance is zero.

  The present invention is not limited to the configuration of each of the embodiments described above. For example, a wave spring or other spring members can be used as the spring member of the biasing mechanism.

  In addition to the intake valve 3, the engine valve can also be applied to the exhaust valve side. Further, the internal combustion engine can be applied not only to the V type 6 cylinder but also to a V type 8 cylinder and other engines.

1 is a side view showing a partial cross section of a first embodiment in which a valve gear according to the present invention is applied to one bank side. It is the sectional view on the AA line of FIG. 1 shows a hydraulic lash adjuster provided in the present embodiment, in which A is a state in which the disk spring is advanced upward by the spring force of the disc spring, and B is a longitudinal sectional view showing a state in which the disc spring is compressed and retreated. FIGS. 7A and 7B are operation explanatory diagrams for controlling the minimum operating angle and the valve lift amount according to the present embodiment. FIGS. A and B are explanatory drawings of the operation at the time of controlling the maximum operating angle and the valve lift amount according to the present embodiment. It is a valve lift characteristic view of this embodiment. It is a characteristic view of the spring load of a valve spring and a disc spring. It is a schematic diagram which shows the bending deformation state of a drive shaft. A is a characteristic diagram of the opening / closing timing of each intake valve in each of the cylinders # 1, # 3, and # 5, and B is a partially enlarged view of A. FIG. The hydraulic lash adjuster used for 2nd Embodiment is shown, A is the state which advanced upwards with the spring force of the coil spring, B is a longitudinal cross-sectional view which shows the state which the coil spring compressed and retreated. The hydraulic lash adjuster used for 3rd Embodiment is shown, A is the state which advanced upwards with the spring force of a coil spring, B is a longitudinal cross-sectional view which shows the state which the coil spring compressed and retreated. It is principal part sectional drawing of 4th Embodiment. FIG. 4A is a perspective view showing a state in which the main part of the present embodiment is partially sectioned and a coil spring is extended, and FIG. The swing arm with which 5th Embodiment is provided is shown, A is a perspective view which shows the state which each division member bent by the spring force of the torsion spring, B is a side view. The swing arm with which the same embodiment is provided is shown, A is a perspective view showing a state in which each divided member is rotated almost horizontally against the spring force of a torsion spring, and B is a side view. It is principal part sectional drawing of the valve gear of 6th Embodiment. It is a principal part expanded sectional view of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cylinder head 1a ... Holding hole 3 ... Intake valve (engine valve)
DESCRIPTION OF SYMBOLS 5 ... Cam shaft 5a ... Drive cam 6 ... Swing arm 6a ... One end part 6b ... Other end part 7 ... Swing cam 8 ... Transmission mechanism 9 ... Control mechanism 10/60 ... Hydraulic lashia adjuster 12 ... Valve spring 13 ... Bearing part 14 ... Roller 24 ... Body 27 ... Plunger 34 ... Belleville spring (biasing mechanism)
35 ... Coil spring (biasing mechanism)
39 ... Coil spring (biasing mechanism)
45 ... Coil spring (biasing mechanism)
52 ... Torsion spring (biasing mechanism)
61 ... Valve lifter

Claims (8)

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;
A cam that is driven through the drive cam and opens the engine valve against the spring force of the valve spring in the lift region;
An interposed member interposed between the cam and the engine valve, and at least abutting the cam;
A biasing mechanism that has a spring load smaller than a spring load of the valve spring, and biases the interposed member toward the cam;
A valve operating apparatus for an internal combustion engine, comprising: The valve operating apparatus for an internal combustion engine according to claim 1,
The interposition member has one end abutting against the stem end of the engine valve, and the other end supported by a hydraulic lash adjuster so as to be swingable, and is provided between the one end and the other end. The contact portion is configured by a swing arm that contacts the cam,
The valve operating apparatus for an internal combustion engine, wherein the urging mechanism is provided between a bottom surface of a holding hole for holding the hydraulic lash adjuster and a bottom portion of the hydraulic lash adjuster. The valve operating apparatus for an internal combustion engine according to claim 1,
The interposition member has one end abutting on the stem end side of the engine valve and the other end supported by a hydraulic lash adjuster so as to be swingable, and is provided between the one end and the other end. A contact portion formed by a swing arm contacting the cam;
The valve operating apparatus for an internal combustion engine, wherein the biasing mechanism is provided between one end of the swing arm and a stem end of the engine valve. The valve operating apparatus for an internal combustion engine according to claim 1,
The interposition member has one end abutting against the stem end of the engine valve, and the other end supported by a hydraulic lash adjuster so as to be swingable, and is provided between the one end and the other end. The abutting portion is constituted by a swing arm that abuts on the cam,
The swing arm is divided and formed at a substantially central position in the longitudinal direction of the swing arm, and one end and the other end are rotatably connected to each other,
The valve mechanism for an internal combustion engine, wherein the urging mechanism is interposed between one end and the other end of the swing arm, and urges the other end toward the hydraulic lash adjuster. The valve operating apparatus for an internal combustion engine according to claim 1,
The intervention member has a crown surface with which the cam abuts, and a contact portion provided on the back side of the crown surface, and the contact portion is configured by a valve lifter supported by a hydraulic lash adjuster,
The valve operating device for an internal combustion engine, wherein the urging mechanism is interposed between the contact portion and a stem end of the engine valve. The valve operating apparatus for an internal combustion engine according to claim 1,
The valve mechanism for an internal combustion engine, wherein the urging mechanism is constituted by a frustoconical disc spring. A bottomed cylindrical body slidably held in a holding hole formed in a predetermined position of the cylinder head;
A plunger that is slidably provided inside the body and has a spherical tip.
A reservoir chamber formed inside the plunger;
A high pressure chamber separated from the reservoir chamber via a partition;
A communication hole formed in the partition wall for communicating the high pressure chamber and the reservoir chamber;
A check valve that only allows inflow of hydraulic oil from the reservoir chamber to the high-pressure chamber through the communication hole;
And comprising
One end is in contact with the engine valve, and the other end of the swing arm having a contact portion with which the cam driven by the rotational driving force transmitted from the crankshaft contacts is swingably supported.
A hydraulic pressure for an internal combustion engine having a biasing mechanism that biases the engine valve in a swing arm direction through a body that is set to a spring load smaller than a spring load of a valve spring that biases the engine valve in a closing direction. Lassia Justa 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;
A cam that is driven through the drive cam and opens the engine valve against the spring force of the valve spring in the lift region;
An interposition member interposed between the cam and the engine valve and contacting at least the cam;
The valve operating device for an internal combustion engine, wherein the interposition member does not transmit the pressure by the cam to the engine valve until a predetermined position, and transmits the pressure to the engine valve when the predetermined position is reached.

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