EP0777039B1 - Dispositif d'entraínement de soupape pour un moteur à combustion interne ayant une cale de forme convexe entre une came et une soupape - Google Patents

Dispositif d'entraínement de soupape pour un moteur à combustion interne ayant une cale de forme convexe entre une came et une soupape Download PDF

Info

Publication number
EP0777039B1
EP0777039B1 EP19960119089 EP96119089A EP0777039B1 EP 0777039 B1 EP0777039 B1 EP 0777039B1 EP 19960119089 EP19960119089 EP 19960119089 EP 96119089 A EP96119089 A EP 96119089A EP 0777039 B1 EP0777039 B1 EP 0777039B1
Authority
EP
European Patent Office
Prior art keywords
shim
cam
valve
transmitting member
force transmitting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19960119089
Other languages
German (de)
English (en)
Other versions
EP0777039A1 (fr
Inventor
Takao Naruoka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyota Motor Corp filed Critical Toyota Motor Corp
Publication of EP0777039A1 publication Critical patent/EP0777039A1/fr
Application granted granted Critical
Publication of EP0777039B1 publication Critical patent/EP0777039B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/18—Rocking arms or levers
    • F01L1/185—Overhead end-pivot rocking arms
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/14—Tappets; Push rods
    • F01L1/143—Tappets; Push rods for use with overhead camshafts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
    • F01L13/0036—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
    • F01L13/0042—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction with cams being profiled in axial and radial direction

Definitions

  • the present invention relates to a valve drive apparatus according to the preamble of claim 1. More particularly, it relates to a valve drive apparatus having a shim interposed between a three-dimensional cam and a lifter.
  • variable valve timing mechanism which varies a valve operation timing and an amount of valve lift in response to an operational condition of an internal combustion engine such as an engine revolution speed or engine load.
  • the variable valve timing mechanism allows improvement in engine output and specific fuel consumption and reduction in exhaust emission.
  • a valve drive apparatus used in the variable valve timing mechanism comprises a three-dimensional (3-D) cam.
  • the 3-D cam has a slanting surface which is inclined with respect to the rotational axis of the 3-D cam, and is movable along the rotational axis.
  • Valve operation timing and an amount of valve lift are optimized by controlling an amount of shift of the 3-D cam along the rotational axis.
  • FIG. 1 shows the valve drive apparatus 1 disclosed in the above-mentioned Japanese Laid-Open Utility Model Application.
  • the valve drive apparatus 1 generally comprises a 3-D cam 2, a valve 3, a lifter 4 and a shim 5.
  • the 3-D cam 2 comprises a cam portion and a cam shaft 7.
  • a slanting surface 8 is formed on the cam portion.
  • the slanting surface 8 of the cam portion 6 is inclined with respect to the rotational axis of the cam shaft 7 by an angle ⁇ .
  • the 3-D cam 2 is movable in directions indicated by arrows X1 and X2 by an actuator not shown in the figure.
  • the valve 3 is provided to an intake port or exhaust port of a cylinder head 10 of an engine.
  • the valve 3 opens or closes the intake port or the exhaust port by being reciprocated by rotation of the 3-D cam 2.
  • a retainer 9 is provided above the valve 3.
  • the retainer 9 is urged by a spring 14 in a direction toward the cam 2.
  • the valve 3 is urged by the spring 14 in the direction toward the cam 2.
  • the valve 3 reciprocates in directions indicated by arrows Z1 and Z2.
  • the direction Z1 may be referred to as an upward direction
  • the direction Z2 may be referred to as a downward direction.
  • the lifter 4 is provided above the valve 3.
  • a top surface of the lifter 4 is formed as a convex spherical surface 11 having a shape corresponding to a part of a sphere.
  • the lifter 4 transmits a displacement of the 3-D cam 2 to the valve 3 by being guided by and reciprocated within a valve opening 10a of a cylinder head 10.
  • the shim 5 is interposed between the 3-D cam 2 and the lifter 4.
  • the shim 5 has a flat surface 12 on the top and a concave spherical surface 13 on the bottom.
  • the flat surface 12 contacts the 3-D cam 2.
  • the concave spherical surface 13 engages the convex spherical surface 11 of the lifter 4.
  • the convex spherical surface 11 and the concave spherical surface 13 have substantially the same radius of curvature.
  • the shim 5 is rotationally slidable along the convex spherical surface 11 of the lifter 4.
  • valve operation timing and an amount of valve lift can be varied, when the cam shaft 7 is moved by an actuator (not shown in the figure) in either direction X1 or X2, due to the slanting surface 8 formed on the 3-D cam 2. If the 3-D cam 2 moves, the shim 5 rotationally slides on the lifter 4. Thus, abrasion resistance between the lifter 4 and the shim 5 is improved since a large contact area is maintained between the lifter 4 and the ship 5 even when the 3-D cam 2 is shifted.
  • FIG.2 shows a state where the shim 5 rotationally slides on the lifter 4. It should be noted that, in FIG.2, the shim 5 is shown protruding inside the cylinder head 10, however, practically, the shim 5 is rotatable up to a position where an end of the shim 5 contacts the cylinder head 10.
  • the center of rotation of the shim 5 is at a position indicated by Ol which is located below the shim 5 since the spherical surface 11 of the lifter 4 is convex and the spherical surface 13 of the shim 5 is concave.
  • the shim 5 moves along an arc indicated by arrows Al and A2 with respect to the center Ol of rotation.
  • the movement of the shim 5 is a movement by which the shim 5 approaches the cylinder head 10.
  • the shim 5 interferes with an inner surface of the valve opening 10a of the cylinder head 10 when the shim 5 rotationally slides on the lifter 4.
  • the shim 5 In order to avoid such an interference, the shim 5 must be formed in a predetermined size smaller than the diameter of the valve opening 10a. However, if the shim 5 is made smaller, the contact area between the shim 5 and the lifter 4 becomes smaller. As a result, the surface contact pressure between the lifter 4 and the shim 5 is increased, and causes another problem in that the abrasion resistance is decreased.
  • the EP-A-512 698 discloses a valve drive apparatus comprising a three dimensional cam rotatable in synchronization with an operation of the internal combustion engine.
  • the cam includes a cam portion having a slanting cam surface inclined with respect to a rotational axis of the cam. Furthermore, the cam is movable along the rotational axis.
  • a force transmitting member transmits a force generated by a camming action of the cam to the valve, thereby the force transmitting member has a first surface pressing the valve and a second surface.
  • a shim is interposed between the cam and the force transmitting member and has a first surface contacting the cam and a second surface pressing the second surface of the force transmitting member.
  • the second surface of the shim has a convex spherical shape and the second surface of the force transmitting member has a corresponding concave spherical shape so as to receive the second surface of the shim.
  • the shim when the three-dimensional cam is rotated and the slant cam surface engages with the shim, the shim is rotated or swung so that the first surface of the shim follows the slant cam surface. Since the second surface of the shim has a convex spherical shape, the center of the radius of curvature of the second surface of the shim is positioned above the shim. In this construction, when the shim is rotated or swung, the shim moves substantially away from a cylinder head in which the force transmitting member is movably provided. Thus, interference of the shim with the cylinder head is prevented.
  • a contact area between the shim and the force transmitting member can be increased. This allows a surface contact pressure between the shim and the force transmitting member, resulting in increased abrasion resistance between the shim and the force transmitting member.
  • the second surface of the force transmitting member has the concave spherical shape, a lubricant is collected and remains on the second surface of the force transmitting member. Thus, a friction loss between the shim and the force transmitting member is decreased, and abrasion resistance between the shim and the force transmitting member is further increased.
  • a radius of curvature of the second surface of the shim is substantially equal to a radius of curvature of the second surface of the force transmitting member.
  • the force transmitting member may have a rim radially and outwardly extending from an outer periphery of the second surface of the force transmitting member
  • the shim may have a collar radially and outwardly extending from an outer periphery of the second surface of the shim.
  • a width of the cam portion of the three-dimensional cam may be less than a width of the first surface of the shim.
  • the first surface of the shim may have a substantially circular shape, and the width of the first surface of the shim may correspond to a diameter of the first surface of the shim.
  • the shim is rotated with respect to the force transmitting member substantially in the horizontal plane perpendicular to the moving direction of the force transmitting member when the three-dimensional cam is moved away from the center of the shim along the rotational axis of the three-dimensional cam.
  • the position of the shim relative to the force transmitting member substantially in the horizontal plane is always changed. This rotation of the shim prevents local abrasion of the shim and the force transmitting member.
  • a height of the shim is less than a radius of curvature of the shim, the height of the shim being a distance from a top of the second surface of the shim to the first surface of the shim.
  • the contact area between the shim and the force transmitting member can be increased without increasing the height of the shim.
  • the mass of inertia of the shim can be decreased as compared to a shim having a large contact area achieved by merely increasing the height of the shim. This allows a good response of the shim in a high speed operation of the engine.
  • the radius of curvature of the second surface of the shim is increased, the maximum surface contact pressure is decreased, resulting in prevention of a local abrasion between the shim and the force transmission member.
  • the force transmitting member may comprise a rocker arm having a first end adapted to be rotatably supported by a rocker shaft and a second end contacting the valve, the second surface of the force transmitting member being formed on the rocker arm between the first end and the second end.
  • FIG.3A is a side view of a valve drive apparatus 20 according to the first embodiment of the present invention
  • FIG.3B is a front view of the valve drive apparatus 20 shown in FIG.3A.
  • the valve drive apparatus 20 is used for an internal combustion engine, and is of a directly driven valve type.
  • the valve drive apparatus 20 generally comprises a 3-D cam 21, a valve 22, a lifter 23 and a shim 24.
  • the 3-D cam 21 comprises a cam portion 25 and a cam shaft 26.
  • the cam portion 25 comprises a basic circular portion 25a and a cam nose 25b which protrudes from the basic circular portion 25a.
  • a slanting surface 27 which is inclined with respect to the rotational axis (cam axis) of the 3-D cam 2 by an angle ⁇ .
  • the cam shaft 26 is connected to a crank shaft of the engine via timing gears and timing belts which are not shown in figures so that the cam shaft 26 is rotated in synchronization with a rotation of the crank shaft. Additionally, an actuator (not shown in the figures) is connected to an end of the cam shaft 26 so that the 3-D cam 21 is movable in either direction X1 or X2 in FIG.3B by being driven by the actuator.
  • the valve 22 is provided to an intake port or an exhaust port provided in a cylinder head 28 of the internal combustion engine.
  • a valve head 22a of the valve 22 opens or closes the intake port or the exhaust port by being reciprocated by a camming action of the 3-D cam 21.
  • a retainer 30 is provided above the valve 22. The retainer 30 is urged by a valve spring 29 in a direction toward the 3-D cam 21. Thus, the valve 22 is urged by the valve spring 29 in the direction toward the 3-D cam 21.
  • the valve 22 reciprocates in directions indicated by arrows Z1 and Z2.
  • the direction Z1 may be referred to as an upward direction
  • the direction Z2 may be referred to as a downward direction.
  • the lifter 23 is provided above the valve 22, and has a cylindrical shape with a bottom surface.
  • a top surface of the lifter 23 is formed as a concave spherical surface 32 having a shape corresponding to a part of a sphere.
  • the lifter 23 transmits a displacement of the 3-D cam 21 to the valve 22 by being guided by and reciprocated within a valve opening 28a of the cylinder head 28.
  • the shim 24 is interposed between the 3-D cam 21 and the lifter 23.
  • the shim 24 has a flat surface 33 on the top and a convex spherical surface 34 on the bottom.
  • the flat surface 33 contacts the 3-D cam 21.
  • the convex spherical surface 34 of the shim 24 engages the concave spherical surface 32 of the lifter 23.
  • the concave spherical surface 32 and the convex spherical surface 34 have substantially the same radius of curvature.
  • the centers of both the concave spherical surface 32 and the convex spherical surface 34 are located at a point O2 positioned on the center axis B of the valve 22.
  • a shim height H is less than the radius of curvature R of the convex spherical surface 34 of the shim 24, where the shim height H is a distance from a top of the convex spherical surface 34 to the flat surface 32 of the shim 24.
  • the shim 24 is rotationally slidable along the concave spherical surface 32 of the lifter 23 while the convex spherical surface 34 contacts the concave spherical surface 32.
  • a lubricant is supplied to the contact area between the 3-D cam 21 and the shim 24 and the contact area between the shim 24 and the lifter 23.
  • the lubricant supplied between the convex spherical surface 34 of the shim 24 and the concave spherical surface 32 of the lifter 23 is positively retained in the contact area since the lifter 23 is positioned below the shim 24 and has the concave spherical surface which functions as a recess retaining the lubricant.
  • good lubrication between the shim 24 and the lifter 23 is achieved, resulting in reduction in friction loss. That is, the abrasion resistance between the shim 24 and the lifter 23 is increased.
  • the contact area between the convex spherical surface 34 of the shim 24 and the concave spherical surface 32 of the lifter 23 is large since the contact is made between the spherical portions having substantially the same radius of curvature. This large area contact results in a decrease in the surface contact pressure between the shim 24 and the lifter 23. Thus, abrasion resistance is increased.
  • the lifter 23 has a rim 35 radially extending from the concave peripheral surface 32.
  • the shim 24 has a collar 36 radially extending from the convex spherical surface 34. The collar 36 prevents excessive movement (rotation) of the shim 24 by contacting the rim 35 of the lifter 23 so that the shim 24 does not come out from the area between the shim 24 and the lifter 23.
  • the diameter L1 of the flat surface 33 of the shim 24 is greater than a width L2 of the cam portion 25 of the 3-D cam 21 (L1>L2).
  • the diameter L1 may be referred to as a shim width L1
  • the width L2 may be referred to as a cam width L2.
  • FIGS.4A, 4B, 5A and 5B show a state where the shim 24 contacts the basic circular portion 25a of the cam portion 25.
  • FIGS.5A and 5B show a state where the shim 24 contacts the cam nose 25 of the cam portion 25.
  • the valve spring 29, the retainer 30 and the valve seat 31 are omitted for the sake of simplification of illustration.
  • the 3-D cam 21 rotates in synchronization with the crank shaft of the engine.
  • the cam portion 25 presses the shim 24 by being rotated from the state shown in FIGS.4A and 4B, a pressing force is transmitted to the lifter 23 via the shim 24.
  • the valve 22 is pressed via the lifter 23 and moved in the Z2 direction.
  • the cam portion 25 has the slant surface 27 formed on the cam nose 25b, and the shim 24 can be rotatably moved along the concave spherical portion 32 of the lifter 23.
  • the cam shaft 26 can be moved in either the X1 direction or X2 direction by an actuator not shown in the figures. Additionally, the slant surface 27 is formed on the cam nose 25b. Accordingly, the amount of valve lift of the valve 22 can be controlled by the cam shaft 26 being moved in the X1 direction or the X2 direction.
  • the amount of valve lift of the valve 22 is decreased when the cam shaft 26 is moved in the X1 direction, resulting in a short travel of the valve 22 which condition is suitable for low speed operation of the engine which requires a lower amount of flow through the valve.
  • the amount of valve lift of the valve 22 is increased when the cam shaft 26 is moved in the X2 direction, resulting in a longer travel of the valve 22 which condition is suitable for a high speed operation which requires a larger amount of flow.
  • the center of the radius of curvature of the concave spherical surface 32 of the lifter 23 is positioned at the same position O2 with the center of the radius of curvature of the convex spherical surface 34 of the shim 24.
  • the center O2 of the radius of curvature is positioned on the center axis B of the valve 22. Accordingly, the shim 24 can rotatably slide on the concave spherical surface 32 of the lifter 23. This enables the rotation of the shim 5 to be parallel to the slant surface 27 as shown in FIG.5B.
  • the rotational movement of the shim 24 is a movement by which the shim 24 moves away from the cylinder head 28.
  • the shim 24 does not interfere with the cylinder head 28 as is in the conventional valve drive apparatus in which the rotational direction of the shim is a direction which approaches the cylinder head.
  • the contact area between the shim 24 and the lifter 23 can be increased so as to decrease surface contact pressure between the shim 24 and the lifter 23.
  • the cam portion 25 can be moved on the flat surface 33 of the shim 24 by setting the shim width L1 to be grater than the cam width L2. Specifically, the cam portion 25 can be moved a distance in a range of (L1-L2) in the direction L1 or L2.
  • the center line D (hereinafter, referred to as a cam side contact center line B) of the contact area between the shim 24 and the lifter 23 is offset from the center axis of the lifter 23.
  • the center axis of the lifter 23 corresponds to the center axis B of the valve 22 as shown in FIG.5B, and is hereinafter referred to as a lifter side contact center line.
  • the cam side contact center line D is offset from the lifter side contact center line B by a distance dL.
  • a rotational force is generated in the shim 24 by which rotational force the shim 24 is rotated about the lifter side contact center line B in a direction E indicated by arrows E in FIG.5B.
  • the shim 24 can be rotated in any direction with respect to the lifter 23 as mentioned above, the shim 24 can be rotated about the lifter side contact center line B in either direction E by the rotational force generated by the cam side contact center line D being offset from the lifter side contact center line B.
  • FIG.6A shows a distribution of the surface contact pressure between the shim 24 and the lifter 23 in a state where the radius of curvature r of the shim 24 is substantially the same with the shim height H.
  • FIG.6B shows a distribution of the surface contact pressure between the shim 24 and the lifter 23 in a state where the radius of curvature R of the shim 24 is greater than the shim height H.
  • the surface contact pressure between the concave spherical surface 32 and the convex spherical surface 34 can be obtained by using a method for calculating a bearing pressure in a bearing.
  • the surface contact pressure P can be calculated by dividing a pressing force F applied to the shim 24 by the 3-D cam 21 by a projected area S of the convex spherical surface 34.
  • the surface contact pressure P2 can be obtained as follows. It is assumed that the pressing force F and the shim height H are the same as that of the structure shown in FIG.6A so as to facilitate a comparison therebetween.
  • the shim height H is less than the radius of curvature R of the convex spherical surface 34 (H ⁇ R).
  • H ⁇ R the radius of curvature of the convex spherical surface 34
  • the surface contact pressure P2 of the present embodiment is smaller than the surface contact pressure of the structure shown in FIG.6A by setting shim height H to be smaller than the radius of curvature R of the shim 224. This reduces abrasion between the shim 24 and the lifter 23.
  • the variation in the distribution of the surface contact pressure of the structure of the present embodiment shown in FIG.6B is smaller than that of the structure shown in FIG.6A.
  • the maximum surface contact pressure of the structure shown in FIG.6B is smaller than the maximum surface contact pressure of the structure shown in FIG.6A
  • the variation in the distribution of the surface contact pressure of the structure shown in FIG.6B is smaller than that of the structure shown in FIG.6A. That is, the surface contact pressure of the present embodiment is distributed evenly as compared to the structure shown in FIG.6A.
  • the maximum surface contact pressure between the shim 24 and the lifter 23 can be reduced by increasing the radius of curvature R of the convex spherical surface 34 with respect to the shim height H of the shim 24.
  • concentration of the surface contact pressure to a local area is prevented, resulting in preventing local abrasion of the convex spherical surface 34 of the shim 24 and the concave spherical surface of the lifter 23.
  • FIG.7A is a side view of a valve drive apparatus 20A according to the second embodiment of the present invention
  • FIG.7B is a front view of the valve drive apparatus 20A shown in FIG.7A.
  • a rocker arm 40 is provided as a force transmitting member which transmits a pressing force from the 3-D cam 21 to the valve 22.
  • rocker arm 40 One end of the rocker arm 40 is rotatably supported by a rocker shaft 41.
  • the other end of the rocker arm 40 is formed as an acting portion 43 which contacts an upper end of the valve 22.
  • a concave spherical surface 42 which is similar to the concave spherical portion 32 of the first embodiment, is formed on the rocker arm 40 between the rocker shaft 41 and the acting portion 43.
  • the shim 24 is provided on the concave spherical portion 42.
  • the 3-D cam 21 is provided above the shim 24 so that the shim 24 is pressed when the 3-D cam 21 is rotated by a rotation of the cam shaft 26.
  • the pressing force is transmitted to the valve 22 via the rocker arm 40 so that the displacement of the shim 24 is increasingly transmitted to the valve 22 due to a leverage action.
  • the shim 24 is rotatably movable on the concave spherical surface 42 similar to the above-mentioned first embodiment.
  • the present embodiment has the same effects and advantages with the first embodiment. Accordingly, local abrasion between the shim 24 and the concave spherical surface 42 of the rocker arm 40 can be prevented.
  • the present invention is not limited to the valve drive apparatus of the direct drive type or the rocker arm drive type as described in the above-mentioned embodiments.
  • the present invention may be applied to a valve drive apparatus of a swing arm drive type, or further, to a cam drive apparatus other than the valve drive apparatus for an internal combustion engine.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Valve Device For Special Equipments (AREA)

Claims (5)

  1. Un dispositif d'actionnement de soupape (20, 20A) servant à actionner une soupape (22) d'un moteur à combustion interne, ledit dispositif d'actionnement de soupape comprenant :
    une came tridimensionnelle (21) susceptible de tourner en synchronisation avec le fonctionnement dudit moteur à combustion interne, ladite came tridimensionnelle (21) comprenant une partie de came (25) ayant une surface de came inclinée (27) inclinée par rapport à l'axe de rotation de ladite came tridimensionnelle (21), ladite came tridimensionnelle (21) étant susceptible de se déplacer le long dudit axe du rotation;
    un organe de transmission de force (23, 40) transmettant une force produite par une action de contact de came de ladite came tridimensionnelle (21) à ladite soupape (22), ledit organe de transmission de force (23, 40) ayant une première surface pressant ladite soupape (22) et une deuxième surface (32); et
    une cale (24) interposée entre ladite came tridimensionnelle (21) et ledit organe de transmission de force(23), ladite cale(24) ayant une première surface (33) en contact avec ladite came tridimensionnelle (21) et une deuxième surface (34) opposée à ladite première surface (33) de ladite cale (24), ladite deuxième surface (34) de ladite cale (24) pressant ladite deuxième surface (32) dudit organe de transmission de force (23, 40),
    ladite deuxième surface (34) de ladite cale (24) présentant une forme sphérique convexe, et ladite deuxième surface(32) dudit organe de transmission de force (23, 40) présentant une forme sphérique concave, de manière à loger ladite deuxième surface (34) de ladite cale (24);
       caractérisé en ce que
    ladite cale (24) est susceptible de tourner sur la totalité du profil de ladite came tridimensionnelle (21) dans une direction quelconque y compris une direction autour d'un axe sensiblement parallèle à la direction de déplacement de ladite soupape (22) de sorte que ladite première surface (33) de ladite cale (24) s'aligne toujours avec ladite surface de came inclinée (27) de ladite partie de came (25), et que la largeur de ladite première surface (33) de ladite cale (24) soit supérieure à la largeur de ladite partie de came (25); et en ce que
    ledit organe de transmission de force (23) présente un rebord (35) s'étendant radialement et vers l'extérieur depuis la périphérie extérieure de ladite deuxième surface (32) dudit organe de transmission de force (23) et ladite cale (24) présente un collet (36) s'étendant radialement et vers l'extérieur depuis la périphérie extérieure de ladite deuxième surface (34) de ladite cale (24) de sorte que ladite cale (24) ne sorte pas de la zone entre ladite cale (24) et ledit organe de transmission de force (23), ledit collet (36) étant formé d'un seul tenant avec ladite cale (24).
  2. Le dispositif d'actionnement de soupape selon la revendication 1, caractérisé en ce que le rayon de courbure de ladite deuxième surface (34) de ladite cale (24) est sensiblement identique au rayon de courbure de ladite deuxième surface (32) dudit organe de transmission de force (23).
  3. Le dispositif d'actionnement de soupape selon la revendication 2, caractérisé en ce que ladite première surface (33) de ladite cale (24) présente sensiblement une forme circulaire et ladite largeur de ladite première surface (33) de ladite cale (24) correspond au diamètre de ladite première surface (33) de ladite cale (24).
  4. Le dispositif d'actionnement de soupape selon l'une des revendications 1 à 3, caractérisé en ce que la hauteur de ladite cale (24) est inférieure au rayon de courbure de ladite cale (24), ladite hauteur de ladite cale (24) étant la distance allant du sommet de ladite deuxième surface (34) de ladite cale (24) à ladite première surface (33) de ladite cale (24).
  5. Le dispositif d'actionnement de soupape selon l'une des revendications 1 à 4, caractérisé en ce que ledit organe de transmission de force comprend un bras culbuteur (40) ayant une première extrémité apte à être supportée à rotation par un arbre de culbuteur (41) et une deuxième extrémité (43) en contact avec ladite soupape (22), ladite deuxième surface (42) dudit organe de transmission de force étant formée sur ledit bras culbuteur (40) entre ladite première extrémité et ladite deuxième extrémité (43).
EP19960119089 1995-11-29 1996-11-28 Dispositif d'entraínement de soupape pour un moteur à combustion interne ayant une cale de forme convexe entre une came et une soupape Expired - Lifetime EP0777039B1 (fr)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP311164/95 1995-11-29
JP31116495 1995-11-29
JP31116495 1995-11-29
JP29674696 1996-11-08
JP296746/96 1996-11-08
JP29674696A JPH09209727A (ja) 1995-11-29 1996-11-08 内燃機関の動弁装置

Publications (2)

Publication Number Publication Date
EP0777039A1 EP0777039A1 (fr) 1997-06-04
EP0777039B1 true EP0777039B1 (fr) 1999-06-16

Family

ID=26560821

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19960119089 Expired - Lifetime EP0777039B1 (fr) 1995-11-29 1996-11-28 Dispositif d'entraínement de soupape pour un moteur à combustion interne ayant une cale de forme convexe entre une came et une soupape

Country Status (3)

Country Link
EP (1) EP0777039B1 (fr)
JP (1) JPH09209727A (fr)
DE (1) DE69602913T2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007042457A1 (de) 2007-09-07 2009-03-12 Schaeffler Kg Ventilbetätigungsmittel für einen vollvariablen Ventiltrieb

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007003969A1 (de) * 2007-01-26 2008-07-31 Schaeffler Kg Nockenventiltrieb mit variablem Ventilhub und variabler Ventilöffnungsdauer

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1192099A (en) * 1968-09-16 1970-05-20 Caterpillar Tractor Co Misalignment compensating cam follower
US3915129A (en) * 1974-09-18 1975-10-28 Robert H Rust Internal combustion engine
US4850311A (en) * 1988-12-09 1989-07-25 General Motors Corporation Three dimensional cam cardanic follower valve lifter
JPH0342001U (fr) 1989-08-30 1991-04-22
US5159906A (en) * 1991-05-03 1992-11-03 Ford Motor Company Adjustable valve system for an internal combustion engine

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102007042457A1 (de) 2007-09-07 2009-03-12 Schaeffler Kg Ventilbetätigungsmittel für einen vollvariablen Ventiltrieb

Also Published As

Publication number Publication date
DE69602913D1 (de) 1999-07-22
DE69602913T2 (de) 2000-03-23
EP0777039A1 (fr) 1997-06-04
JPH09209727A (ja) 1997-08-12

Similar Documents

Publication Publication Date Title
US4850311A (en) Three dimensional cam cardanic follower valve lifter
EP0405927A1 (fr) Mécanisme d'entraînement de soupapes pour moteur à quatre temps
US6055949A (en) Variable valve actuator apparatus
US4615313A (en) Automatic decompression device for internal combustion engine
JPH01294907A (ja) 内燃機関の弁作動状態切換装置
US5687683A (en) Automatic decompressor for valve-controlled internal combustion engines
US5020488A (en) Valve mechanism for an internal combustion engine
US5601056A (en) Device for actuating the valves in internal combustion engines by means of revolving cams
EP0777039B1 (fr) Dispositif d'entraínement de soupape pour un moteur à combustion interne ayant une cale de forme convexe entre une came et une soupape
US5367991A (en) Valve operating system of engine
US5832889A (en) Valve driving apparatus
US5803033A (en) Valve drive apparatus for an internal combustion engine having a convex shim between a cam and a valve
US6955146B2 (en) System for variably actuating valves in internal combustion engines
JP2003120241A (ja) 可変動弁機構
US5870984A (en) Variable engine valve driver
US5983848A (en) Finger follower
US4436062A (en) Rocker arm mechanism in overhead cam type engine
EP1059423B1 (fr) Commande de soupapes pour un moteur à combustion interne
JPWO2003074845A1 (ja) 内燃機関の可変動弁装置
JPH11229825A (ja) 動弁装置
JPH082404Y2 (ja) 内燃機関のロッカアーム
JPH11270322A (ja) 内燃機関の動弁装置
JP2550240Y2 (ja) 内燃機関の動弁装置
JP4367317B2 (ja) 内燃機関の可変動弁装置
JP4001693B2 (ja) 内燃機関の可変動弁装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19961128

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

17Q First examination report despatched

Effective date: 19971103

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 69602913

Country of ref document: DE

Date of ref document: 19990722

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20031110

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20031126

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20031211

Year of fee payment: 8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20041128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050601

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20041128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050729

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST