JP4314177B2 - Variable valve mechanism and variable valve mechanism reference state adjusting method - Google Patents

Description

  The present invention relates to a variable valve mechanism that adjusts valve characteristics of an internal combustion engine and a reference state adjustment method for the variable valve mechanism.

  A variable valve mechanism is known in which a mechanism provided on a cylinder head of an internal combustion engine is driven by an axial movement of a control shaft to adjust valve characteristics such as a valve lift amount and a valve working angle of an intake valve and an exhaust valve. (For example, refer to Patent Document 1).

  In such a variable valve mechanism, a support pipe (hereinafter referred to as a “rocker shaft”) having a control shaft disposed therein is provided in order to swingably support each intermediary drive mechanism disposed for each cylinder. It is inserted through the center axis position of the mediation drive mechanism. Thus, the intermediate drive mechanism can swing while being supported by the rocker shaft when the valve is driven.

The rocker shaft is supported by standing walls provided on the cylinder head side on both sides of each intermediate drive mechanism. As a result, the reference position in the axial direction of the intermediate drive mechanism of each cylinder is determined with reference to the standing wall portion. By setting the reference position determined by such a standing wall portion with high accuracy for each cylinder, the valve characteristic adjustment amount by the control shaft can be prevented from varying among the cylinders.
Japanese Patent Laid-Open No. 2001-263015 (page 7-8, FIG. 5-20)

  However, in practice, after the reference wall portion such as the standing wall portion is formed, the reference position setting accuracy by the reference wall portion is not always sufficient. Therefore, by inserting a shim between the mediation drive mechanism and the reference wall portion in order to set the reference position with high accuracy, the clearance between the mediation drive mechanism in the reference position state and the reference wall portion is absorbed. .

  However, in such clearance absorption work, in addition to the selective placement work for placing a shim of an appropriate thickness between the reference wall and the mediation drive mechanism, the reference wall is opposite to the mediation drive mechanism. The operation | work which selects and arrange | positions the shim of the thickness which can absorb the clearance which has arisen between the wall parts provided in the side is also needed.

  The clearance between the wall portion on the opposite side of the reference wall portion and the mediation drive mechanism does not affect the deviation of the valve characteristics between the cylinders and is not important for valve characteristic control. It is not preferable in terms of work efficiency to repeat the work equivalent to that of the reference wall portion for such a low-importance clearance absorbing work.

  The present invention provides a variable valve mechanism and a variable valve mechanism reference state adjustment method that do not cause variations in valve characteristic adjustment amounts between cylinders and that can improve the working efficiency when a variable valve mechanism is formed. The purpose is to provide.

In the following, means for achieving the above object and its effects are described.
The variable valve mechanism according to claim 1 adjusts the valve characteristic of the internal combustion engine by linking the valve characteristic adjustment amount by the valve characteristic adjustment mechanism to the axial position of the control shaft that is axially moved by the actuator. The variable valve mechanism is provided with a reference wall portion for setting a reference position of the valve characteristic adjusting mechanism body by preventing the valve characteristic adjusting mechanism body from following the axial movement of the control shaft. A first member separate from the reference wall portion is disposed between the reference wall portion and the valve characteristic adjusting mechanism main body, and on the side opposite to the reference wall portion with the valve characteristic adjusting mechanism interposed therebetween . The urging member, which is a second member for urging the valve characteristic adjusting mechanism main body toward the reference wall , is provided.

  The variable valve mechanism of the present invention includes a biasing member that biases the valve characteristic adjusting mechanism main body toward the reference wall portion on the side opposite to the reference wall portion. On the reference wall side, the reference position is set with high accuracy by selecting and arranging an appropriate clearance absorbing member such as a shim. On the other hand, the valve characteristic adjustment mechanism main body is urged toward the reference wall by the urging member on the side opposite to the reference wall, so there is no need to select and place a shim or the like that accurately absorbs the clearance. The clearance is naturally absorbed so as to conform to the reference position adjustment on the reference wall side.

Therefore, variation in valve characteristic adjustment amount between cylinders does not occur, and work efficiency when a variable valve mechanism is formed can be improved.
The variable valve mechanism according to claim 2 is characterized in that in claim 1, the first member is a shim .

  More specifically, the clearance is absorbed by the selection and arrangement of shims on the reference wall side. As a result, the reference position is set with high accuracy so that variation in valve characteristic adjustment amount does not occur between cylinders.

  A variable valve mechanism according to a third aspect of the present invention is the variable valve mechanism according to the first or second aspect, wherein the urging member includes a wall provided on the opposite side of the reference wall from the valve characteristic adjusting mechanism main body. It is a wave washer, a disc spring, a coil spring, a leaf spring or a spring washer provided between the valve characteristic adjusting mechanism main body.

  As described above, the urging member may include a wave washer, a disc spring, a coil spring, a leaf spring, or a spring washer, and does not cause variation in the valve characteristic adjustment amount among the cylinders and forms a variable valve mechanism. The working efficiency in case can be improved.

  According to a fourth aspect of the present invention, in the variable valve mechanism according to any one of the first to third aspects, the valve characteristic adjusting mechanism includes an input unit that receives a driving force from a cam that rotates in conjunction with a crankshaft of the internal combustion engine; And an output unit that drives the valve by the driving force received by the input unit, and the positional relationship between the input unit and the output unit is interlocked with the axial position of the control shaft to control the valve lift amount and the valve working angle. It is characterized by adjusting one or both.

  Examples of the valve characteristic adjusting mechanism include those having the input unit and the output unit. In the valve characteristic adjusting mechanism having such a configuration, the reference position of the valve characteristic adjusting mechanism body is set on the reference wall side so as not to cause variation in the valve characteristic adjusting amount between the cylinders, and on the side opposite to the reference wall part. Then, the valve characteristic adjusting mechanism main body is urged toward the reference wall by the urging member. As a result, the valve characteristic adjustment amount does not vary among the cylinders, and the working efficiency when the variable valve mechanism is formed can be improved.

  6. The variable valve mechanism reference state adjusting method according to claim 5, wherein the valve characteristic adjustment amount by the valve characteristic adjusting mechanism is interlocked with the axial position of the control shaft that is axially moved by the actuator. A reference state adjusting method for a variable valve mechanism that adjusts characteristics, wherein the axial position of the control shaft is fixed so that the valve characteristic adjusting mechanism main body does not follow the axial movement of the control shaft. The valve characteristic adjusting mechanism main body is biased toward the reference wall portion side between the valve characteristic adjusting mechanism main body and the wall provided on the opposite side of the valve characteristic adjusting mechanism main body. A biasing member is arranged, and the clearance between the reference wall and the valve characteristic adjusting mechanism main body is shim so that the same valve characteristic adjusting amount is set for each cylinder. Ri, characterized in that it absorbs.

  After arranging the biasing member in this way, an appropriate shim is selected and the clearance between the reference wall portion and the valve characteristic adjusting mechanism main body is absorbed to obtain the same valve characteristic adjustment amount for each cylinder. This eliminates the need for shim selection on the side opposite the part. As a result, a variable valve mechanism that does not cause variation in the valve characteristic adjustment amount between the cylinders is formed, and the working efficiency in this forming work can be improved.

  According to a sixth aspect of the present invention, there is provided a variable valve mechanism reference state adjustment method in which a valve characteristic adjustment amount by a valve characteristic adjustment mechanism is interlocked with an axial position of a control shaft that is axially moved by an actuator. A method for adjusting a reference state of a variable valve mechanism for adjusting characteristics, wherein the axial position of the control shaft is fixed, and the control shaft is moved in the axial direction so that the same valve characteristic adjustment amount is obtained for each cylinder. The clearance between the reference wall portion that prevents the valve characteristic adjusting mechanism main body from following and the valve characteristic adjusting mechanism main body is absorbed by shims, and the reference wall portion is provided on the opposite side of the valve characteristic adjusting mechanism main body. An urging portion for urging the valve characteristic adjusting mechanism main body toward the reference wall portion side between the wall portion and the valve characteristic adjusting mechanism main body Characterized by arranging the.

  After selecting the appropriate shim and absorbing the clearance between the reference wall and the valve characteristic adjusting mechanism main body, the biasing member is disposed on the opposite side of the reference wall, and the shim on the opposite side is arranged. No selection work is required. As a result, a variable valve mechanism that does not cause variation in the valve characteristic adjustment amount between the cylinders is formed, and the working efficiency in this forming work can be improved.

[Embodiment 1]
FIG. 1 shows the configuration of a variable valve mechanism in a gasoline engine (hereinafter abbreviated as “engine”) 2 as a multi-cylinder internal combustion engine to which the above-described invention is applied. FIG. 1 shows a longitudinal section of one cylinder. FIG. 2 is a plan view mainly illustrating the configuration on the cam carrier 150 in the upper configuration of the engine 2.

The engine 2 of the present embodiment is for a vehicle and includes a cylinder block 4, a piston 6, and a cylinder head 8 attached on the cylinder block 4.
The cylinder block 4 is formed with a plurality of cylinders, in this embodiment, four cylinders 2a. Each cylinder 2a is formed with a combustion chamber 10 partitioned by the cylinder block 4, the piston 6 and the cylinder head 8. ing. The number of cylinders may be 1 to 3, and may be 5 or more. Further, as in the present embodiment, it may not be an in-line 4-cylinder, but may be a V-type or other arrangement.

  In each cylinder 2a, four valves, two intake valves 12 and two exhaust valves 16, are arranged. The intake valve 12 opens and closes the intake port 14, and the exhaust valve 16 opens and closes the exhaust port 18. The intake ports 14 of all the cylinders 2a are connected to a surge tank via an intake manifold, and distribute the air supplied from the surge tank side to each cylinder 2a. A fuel injection valve is arranged in each intake port 14 or intake manifold so as to inject fuel into the intake port 14 of each cylinder 2a. In addition to the configuration in which fuel is injected on the upstream side of the intake valve 12 as described above, a direct injection gasoline engine that directly injects fuel into each combustion chamber 10 may be used.

  The engine 2 of the present embodiment can adjust the intake air amount by changing the valve lift amount of the intake valve 12. Actually, when the valve lift amount changes, the valve working angle also changes at the same time. Therefore, the description of the valve lift amount also serves as an explanation of the valve working angle.

  In the engine 2 of the present embodiment, a throttle valve is disposed in the intake passage upstream of the surge tank. The throttle valve is normally fully opened when the intake air amount is adjusted by adjusting the valve lift amount of the intake valve 12. As the throttle valve opening control, for example, the throttle valve is fully opened when the engine 2 is started, and the throttle valve is fully closed when the engine 2 is stopped. If the valve lift adjustment of the intake valve 12 becomes impossible for some reason, or if the intake air amount cannot be adjusted sufficiently by adjusting the valve lift of the intake valve 12, the throttle valve opening The intake air amount is controlled by the control.

  The lift drive of the intake valve 12 is possible by transmitting the valve drive force of the intake cam 45a provided on the intake camshaft 45 via the intermediate drive mechanism 120 and the roller rocker arm 52 arranged in the cylinder head 8. It has become. In this valve driving force transmission, the valve lift amount of the intake valve 12 is adjusted by adjusting the transmission state by the mediation driving mechanism 120 by the function of the slide actuator 100. The intake camshaft 45 is interlocked with the rotation of the crankshaft 49 of the engine 2 via the timing sprocket 140a (FIG. 14) provided in the variable valve timing mechanism 140 disposed at one end and the timing chain 47. Yes.

  The exhaust valve 16 of each cylinder 2a is opened and closed by a constant valve lift amount via a roller rocker arm 54 by an exhaust cam 46a provided on an exhaust camshaft 46 that rotates in conjunction with the rotation of the engine 2. The exhaust camshaft 46 is interlocked with the rotation of the crankshaft 49 of the engine 2 via the timing sprocket 142a (FIG. 14) provided in the variable valve timing mechanism 142 disposed at one end and the timing chain 47. Yes. Each exhaust port 18 of each cylinder 2a is connected to an exhaust manifold, and exhaust is discharged to the outside through a catalytic converter for purification.

  The intake camshaft 45, the exhaust camshaft 46, the slide actuator 100, the intermediate drive mechanism 120, and the variable valve timing mechanisms 140 and 142 described above are integrated on the cam carrier 150.

  As shown in FIG. 2, the cam carrier 150 forming a part of the cylinder head 8 is integrally formed as a whole in a rectangular shape corresponding to the outer peripheral shape of the upper surface of the cylinder head 8 on the main body side. In the side walls 154, 156, 158, 160, four bearings 162 are arranged in parallel and are integrally formed with the side walls 154 to 160. Of the side walls 154 to 160, the front side wall 154 also serves as a bearing.

  An intake camshaft 45 and an exhaust camshaft 46 are rotatably supported in parallel by the four bearings 162 and the front side wall 154. Furthermore, between the intake camshaft 45 and the side wall 158, four intermediary drive mechanisms 120 provided for each cylinder are arranged. For each intermediary drive mechanism 120, a wave washer 164 is disposed between the bearing 162 on the slide actuator 100 side, and a shim 166 is disposed between the front side wall 154 or the bearing 162 on the opposite side of the slide actuator 100. Has been placed. One rocker shaft 130 common to the four mediating drive mechanisms 120 is supported in a penetrating state with respect to the mediating drive mechanism 120, the wave washer 164, and the shim 166. A cam cap 152 is attached to the front side wall 154 and the bearing 162 to prevent the intake camshaft 45, the exhaust camshaft 46, and the rocker shaft 130 from falling off.

  Here, the configuration of the wave washer 164 is shown in FIG. 3A is a perspective view of the wave washer 164, and FIG. 3B is a front view thereof. The wave washer 164 has a ring shape having a through hole 164a at the center. The ring-shaped main body 164b is wavy in the axial direction, and thus has three top portions 164c and bottom portions 164d in the axial direction. The top part 164c and the bottom part 164d may be two each, or four or more.

  As shown in FIG. 2, the ring-shaped main body 164b of the wave washer 164 supported by the rocker shaft 130 passing through the through hole 164a has one of a top portion 164c and a bottom portion 164d in contact with the bearing 162 and the cam cap 152. The other is in contact with the mediation drive mechanism 120. As a result, the wave washer 164 is compressed between the bearing 162 and the cam cap 152 and the intermediate drive mechanism 120, so that a biasing force in the shim 166 direction can be applied to the intermediate drive mechanism 120.

  The configuration of the shim 166 is shown in FIG. 4, (A) is a plan view of the shim 166, (B) is a bottom view, (C) is a perspective view, (D) is a left side view, and (E) is a front view. The shim 166 includes a disk-shaped base portion 166a, a pickup portion 166b provided so as to protrude from the outer periphery of the base portion 166a, and a concave portion 166c formed from the side facing the pickup portion 166b to the center portion of the base portion 166a. Yes.

  On the opposite side to the slide actuator 100, a shim 166 is inserted between the bearing 162 or the front side wall 154 and the intermediate drive mechanism 120, and the rocker shaft 130 is disposed in the recess 166 c of the shim 166. As a result, the shim 166 is supported by the rocker shaft 130 as shown in FIG. 2, and the clearance between the bearing 162 or the front side wall 154 and the mediation drive mechanism 120 in the reference state is high due to the thickness ds of the base portion 166a. Absorbed to accuracy. At the time of adjusting the variable valve mechanism reference state, a plurality of types of shims 166 having different thicknesses ds of the base portion 166a are prepared, so that the valve lift amount adjustment amount of the mediation drive mechanism 120 is the same between the cylinders. A shim 166 having a proper thickness ds is selected and inserted. As a result, the axial position of the mediation drive mechanism 120 is adjusted to an accurate reference state, and the valve lift amounts of the intake valves 12 of all the cylinders 2a by the slide actuator 100 are always set to the same adjustment amount.

  Next, the mediation drive mechanism 120 will be described. FIG. 5 is a perspective view of the mediation drive mechanism 120, and FIG. 6 is a partially cutaway perspective view. 6A is a partially broken perspective view of the front side, and FIG. 6B is a partially broken perspective view of the back side. 7 is an exploded perspective view, and FIG. 8 is a cutaway perspective view showing the configuration of the outer portion (corresponding to the main body) of the intermediate drive mechanism 120 corresponding to FIG.

  The intermediate drive mechanism 120 includes an input portion 122 provided in the center of FIG. 5, a first swing cam 124 provided on one end side of the input portion 122, and a first swing cam 124 provided on the opposite side of the first swing cam 124. 2 oscillating cam 126 and slider gear 128 (FIGS. 6 and 7) disposed inside.

  A housing 122a of the input part 122 forms a space in the axial direction inside, and a helical spline 122b (FIG. 8) formed in a spiral shape of a right-hand screw is formed in the axial direction on the inner peripheral surface of this space. Further, two parallel arms 122c and 122d are formed so as to protrude from the outer peripheral surface of the housing 122a. A shaft 122e parallel to the axial direction of the housing 122a is stretched over the tips of the arms 122c and 122d, and a roller 122f is rotatably attached. As shown in FIG. 1, a biasing force is applied to the arms 122c, 122d or the housing 122a by a spring or the like, so that the roller 122f is always in contact with the intake cam 45a side. Such a spring is provided between the input part 122 and the cylinder head 8 or the rocker shaft 130, for example.

  The housing 124a of the first swing cam 124 forms a space in the axial direction inside, and a helical spline 124b (FIG. 8) formed in a spiral shape of a left-hand screw in the axial direction is formed on the inner peripheral surface of the internal space. Forming. One end of the internal space of the housing 124a is covered with a ring-shaped bearing portion 124c having a center hole with a small diameter. Further, a substantially triangular nose 124d protrudes from the outer peripheral surface. One side of the nose 124d forms a cam surface 124e.

  The housing 126a of the second rocking cam 126 forms a space in the axial direction inside, and a helical spline 126b (FIG. 8) formed in a spiral shape of a left-hand screw in the axial direction is formed on the inner peripheral surface of the internal space. Forming. One end of the internal space of the housing 126a is covered with a ring-shaped bearing portion 126c having a center hole with a small diameter. Further, a substantially triangular nose 126d protrudes from the outer peripheral surface. One side of the nose 126d forms a cam surface 126e.

  As shown in FIG. 7, the first rocking cam 124 and the second rocking cam 126 are arranged so that the end faces are coaxially in contact with the input portion 122 from both sides, and the whole is shown in FIG. As shown, it has a substantially cylindrical shape with an internal space.

  As shown in FIG. 2, a wave washer 164 is disposed between the first swing cam 124 and the bearing 162 in the intermediate drive mechanism 120, and the second swing cam 126 and the front side wall 154 or the bearing 162. A shim 166 is disposed therebetween.

  Details of the slider gear 128 disposed in the internal space constituted by the input unit 122 and the two swing cams 124 and 126 are shown in FIGS. 9A is a plan view, FIG. 9B is a front view, and FIG. 9C is a right side view. FIG. 10 is a perspective view, and FIG. 11 is a perspective view cut vertically along the axis.

  The slider gear 128 has a substantially cylindrical shape, and an input helical spline 128a formed in a spiral shape of a right-hand thread is formed at the center of the outer peripheral surface. A first output helical spline 128c is formed on one end side of the input helical spline 128a so as to have a left-handed spiral shape with a small diameter portion 128b interposed therebetween. On the opposite side of the first output helical spline 128c, a second output helical spline 128e formed in a spiral shape of a left-hand thread with a small diameter portion 128d interposed therebetween is formed. These output helical splines 128c and 128e have the same outer diameter, but the input helical spline 128a has a smaller outer diameter than the groove portion of the input helical spline 128a.

  A through hole 128f is formed in the slider gear 128 in the central axis direction. A circumferential groove 128g is formed in the circumferential direction on the inner circumferential surface of the through hole 128f at the position of the input helical spline 128a. The circumferential groove 128g is formed with a pin insertion hole 128h penetrating to the outside in one radial direction.

  In the through hole 128f of the slider gear 128, a rocker shaft 130, a part of which is shown in the perspective view of FIG. As shown in FIG. 2, the rocker shaft 130 is provided in common with the four mediating drive mechanisms 120. The rocker shaft 130 has a long hole 130a formed in the axial direction at a position corresponding to each intermediate drive mechanism 120. The long hole 130 a is formed to penetrate to the internal space 130 b of the rocker shaft 130.

  Further, a control shaft 132, a part of which is shown in the perspective view of FIG. 12B, penetrates the inner space 130b of the rocker shaft 130 so as to be slidable in the axial direction as shown in FIG. Has been placed.

  Although the control shaft 132 is formed in a round bar shape, a support hole 132b in a direction perpendicular to the axis is provided at a position corresponding to each intermediate drive mechanism 120 as shown in FIG. By inserting the base end portion of the control pin 132a into each of the support holes 132b, the control pin 132a can be supported by protruding in the direction perpendicular to the axis.

  When the control shaft 132 is disposed inside the rocker shaft 130, the tip of each control pin 132a penetrates the long hole 130a formed in the rocker shaft 130, as shown in the partially cutaway view of FIG. The slider gear 128 is inserted into a circumferential groove 128g formed on the inner circumferential surface.

  One end side (right side in FIG. 2) of the control shaft 132 is a free end, but the base end side (left side in FIG. 2) forms a ball screw shaft driven by the slide actuator 100. As a result, a driving force in the axial direction can be received from the slide actuator 100 via the ball screw mechanism 210. Note that a ball screw shaft may be formed separately from the control shaft 132 and incorporated in the ball screw mechanism 210. In this case, for example, the control shaft 132 can be driven in the axial direction by the slide actuator 100 by contacting or joining the base end side of the control shaft 132 and the tip end side of the ball screw shaft on the cam carrier 150. To do.

  The variable valve mechanism is assembled as follows. First, the control shaft 132 is inserted into the rocker shaft 130, and the intermediate drive mechanism 120 and the wave washer 164 described above are fitted into the rocker shaft 130 for each cylinder and disposed on the cam carrier 150. At the same time, the intake camshaft 45 and the exhaust camshaft 46 are also arranged on the cam carrier 150. The cam cap 152 is rotatably fixed.

  Next, the base end side of the control shaft 132 is incorporated into the ball screw mechanism 210 of the slide actuator 100. Alternatively, the base end side of the control shaft 132 is brought into contact with or joined to the tip of the ball screw shaft incorporated in the ball screw mechanism 210. At this time, the slide actuator 100 is set to the initial driving position, so that the control shaft 132 is disposed at the initial position in the axial direction.

  However, even if the control shaft 132 inside the rocker shaft 130 is in the initial position, the mediation drive mechanism 120 is not necessarily in the reference arrangement corresponding to the initial position of the control shaft 132. Actually, as shown in FIG. 14, the wave washer 164 is extended in the axial direction, and the mediation drive mechanism 120 is shifted on the rocker shaft 130 in the direction opposite to the slide actuator 100 side from the reference arrangement. Exists.

  Here, in the mediation drive mechanism 120, the reference arrangement corresponding to the initial position of the control shaft 132 is a state of the minimum valve lift amount shown in FIG. However, in the state of being arranged on the cam carrier 150, as shown in FIG. 15A, the positional relationship between the noses 124d and 126d and the roller 122f is closer to the minimum valve lift amount.

  Therefore, the variable valve mechanism reference state adjusting method is executed as follows. First, the cam carrier 150 is fixed on a jig for adjusting the reference arrangement. As a result, as shown in FIG. 15A, the tips of positioning pivots p1 and p2 provided on the jig come into contact with the cam surfaces 124e and 126e of the noses 124d and 126d.

  The base circle portion of the intake camshaft 45 is directed toward the roller 122f. However, at this time, as described above, since the positions of the noses 124d and 126d and the roller 122f are closer than the minimum valve lift amount, the roller 122f is not in contact with the intake camshaft 45. When the intake camshaft 45 is disposed later on the cam carrier 150, a special jig corresponding to the shape of the base circle portion of the intake camshaft 45 may be used.

  Next, the wave washer 164 is contracted by pushing the mediation drive mechanism 120 in the axial direction toward the slide actuator 100 by a mechanical force such as hydraulic pressure or manually. As a result, the mediation drive mechanism 120 moves to the slide actuator 100 side. The slider gear 128 inside the intermediate drive mechanism 120 is not moved in the axial direction because it is engaged with the control shaft 132 by the control pin 132a. Therefore, the slider gear 128 relatively moves in the H direction shown in FIGS. In conjunction with this movement, the noses 124d and 126d and the roller 122f begin to separate.

  Finally, as shown in FIG. 15B, the roller 122f comes into contact with the base circle portion of the intake camshaft 45, and further movement of the intermediate drive mechanism 120 in the axial direction becomes impossible. The axial position of the mediation drive mechanism 120 on the rocker shaft 130 at this time is a reference arrangement corresponding to the initial position of the control shaft 132, and corresponds to the state shown in FIG. Therefore, a shim 166 having a thickness ds that matches the clearance between the intermediate drive mechanism 120 formed at this time and the bearing 162 or the front side wall 154 is selected so that the intermediate drive mechanism 120 does not return from the position at this time. The intermediate drive mechanism 120 and the bearing 162 or the front side wall 154 are disposed. As a result, the reference arrangement of the mediation drive mechanism 120 is determined.

  If the force in the direction of compressing the wave washer 164 is removed from the mediation drive mechanism 120, the mediation drive mechanism 120 is pressed against the shim 166 by the urging force of the wave washer 164. As a result, the axial position of the mediation drive mechanism 120 is maintained in the reference arrangement.

  By repeating this variable valve mechanism reference state adjusting method for the intermediate drive mechanism 120 of each cylinder, the reference arrangement of the intermediate drive mechanism 120 can be set with high accuracy for all cylinders.

  Thus, the configuration of the cam carrier 150 is completed. As shown in FIGS. 1 and 2, the variable valve mechanism can be incorporated into the engine 2 by attaching the cam carrier 150 to the main body of the cylinder head 8.

  In the engine 2 using the cam carrier 150 configured in this way, the ball screw mechanism 210 is driven by the slide actuator 100 and the control shaft 132 is moved in the axial direction, so that the slider gear 128 inside the mediation drive mechanism 120 is moved. The axial position can be adjusted.

  As shown in FIG. 13, since the slider gear 128 is locked to the control pin 132a by the circumferential groove 128g, the slider gear 128 can swing about the axis regardless of the position of the control pin 132a. Further, in the slider gear 128, the input helical spline 128 a is meshed with the helical spline 122 b inside the input unit 122. The first output helical spline 128 c is meshed with the helical spline 124 b inside the first swing cam 124, and the second output helical spline 128 e is meshed with the helical spline 126 b inside the second swing cam 126. Here, the input side splines 122b, 128a and the output side splines 124b, 128c, 126b, 128e have different twist angles. Actually, the twist direction itself has a different shape.

  As shown in FIG. 2, one end of the mediation drive mechanism 120 of each cylinder 2 a is positioned by the shim 166, and the other end is urged toward the shim 166 by the wave washer 164. In particular, when the intake valve 12 is lifted, axial force toward the shim 166 is generated in the input portion 122 and the swing cams 124 and 126 of the mediation drive mechanism 120. Therefore, the input portion 122 and the swing cams 124 and 126 are fixed in the axial direction with respect to the rocker shaft 130. Thus, even if the slide actuator 100 moves the slider gear 128 in the axial direction via the control shaft 132, the input unit 122 and the swing cams 124 and 126 do not move in the axial direction.

  From this, by adjusting the axial movement amount of the slider gear 128 in the internal space of the mediation drive mechanism 120, the function of the helical splines 128a, 122b, 128c, 124b, 128e, 126b and the input portion 122 are swung. The cams 124 and 126 can be rotated relative to each other. Thus, the positional relationship between the roller 122f and the noses 124d and 126d can be changed, and the valve lift amount of the intake valve 12 can be adjusted.

  Here, FIG. 16 shows a state of the mediation drive mechanism 120 when the drive force of the slide actuator 100 is adjusted to move the control shaft 132 in the L direction (arrow in FIGS. 5 and 6) as much as possible. 16A is when the intake valve 12 is closed, and FIG. 16B is when the valve is open. In this case, the positional relationship between the roller 122f of the input unit 122 and the noses 124d and 126d of the swing cams 124 and 126 is the closest, that is, the same state as FIG. Therefore, as shown in FIG. 16B, even if the intake cam 45a pushes down the roller 122f of the input portion 122 to the maximum extent, the push-down amount of the rocker roller 52a by the cam surfaces 124e and 126e of the noses 124d and 126d is minimized. The valve lift amount of the intake valve 12 is minimized. Therefore, the amount of intake air from the intake port 14 into the combustion chamber 10 is also minimized.

  FIG. 17 shows the state of the mediation drive mechanism 120 when the drive force of the slide actuator 100 is adjusted and the control shaft 132 is moved in the H direction (arrows in FIGS. 5 and 6) as much as possible. 17A is when the intake valve 12 is closed, and FIG. 17B is when the valve is opened. In this case, the positional relationship between the roller 122f of the input unit 122 and the noses 124d and 126d of the swing cams 124 and 126 is the farthest. For this reason, as shown in FIG. 17B, when the intake cam 45a pushes down the roller 122f of the input portion 122 to the maximum extent, the push-down amount of the rocker roller 52a by the cam surfaces 124e and 126e of the noses 124d and 126d becomes the maximum. The valve lift amount of the intake valve 12 is maximized. Therefore, the amount of intake air from the intake port 14 into the combustion chamber 10 is also maximized.

  By adjusting the axial position of the control shaft 132 continuously between the state of FIG. 16 and the state of FIG. 17 by the slide actuator 100, the valve lift amount of the intake valve 12 can be continuously adjusted. That is, in the present embodiment, it is possible to adjust the intake air amount steplessly without using a throttle valve.

  As shown in FIG. 16B, in the initial position state, the valve lift amount when the intake valve 12 is opened has a certain degree of opening, but as another form of the initial position state, the valve lift amount The amount “0”, that is, the intake valve 12 may be completely closed. In this case, the intake air amount is “0”.

  In the configuration described above, the intermediary drive mechanism 120 is the valve characteristic adjusting mechanism, the input unit 122 and the swing cams 124 and 126 (corresponding to the output unit) are the valve characteristic adjusting mechanism body, and the wave washer. 164 corresponds to an urging member. The front side wall 154 and the bearing 162 that are on the opposite side of the slide actuator 100 with respect to each intermediary drive mechanism 120 correspond to a reference wall portion. A bearing 162 (including an overlap with the reference wall portion) opposed to the front side wall 154 and the bearing 162 as the reference wall portion with the intermediate drive mechanism 120 interposed therebetween, and the reference wall portion sandwiches the valve characteristic adjusting mechanism main body. This corresponds to the wall provided on the opposite side.

According to the first embodiment described above, the following effects can be obtained.
(I). 2 and 14, the variable valve mechanism of the present embodiment has a right reference wall (bearing 162 or front side wall 154) between the bearing 162 and the intermediate drive mechanism 120 on the left side of each intermediate drive mechanism 120 in FIGS. A wave washer 164 that biases the mediation drive mechanism 120 to the side is provided.

  Here, between each intermediate drive mechanism 120 and each right reference wall, a shim 166 having an appropriate thickness is selected and arranged as a clearance absorbing member, so that the reference position of the intermediate drive mechanism 120 is set with high accuracy. it can.

  On the other hand, a wave washer 164 is disposed between the wall portion (bearing 162) opposite to the reference wall portion, and the input portion 122 and the swing cams 124 and 126 are urged toward the reference wall portion side. Yes. Further, as described above, the axial force toward the reference wall portion is generated at the time of lift for the structural reason of the mediation drive mechanism 120. For this reason, on the side opposite to the reference wall, the clearance is naturally absorbed so that it can be adapted to the reference position adjustment on the reference wall side without having to select and place a shim that accurately absorbs the clearance. The

  Therefore, there is no variation in the valve characteristic adjustment amount (here, the adjustment amount of the valve lift amount) between the cylinders 2a, and the working efficiency when the variable valve mechanism is formed can be improved.

  (B). In the variable valve mechanism reference state adjusting method of the present embodiment, a shim 166 having an appropriate thickness ds is selected after the wave washer 164 is disposed, and the clearance between the reference wall portion and the swing cam 126 is absorbed. The same valve characteristic adjustment amount is set for each cylinder 2a. This eliminates the need for shim selection on the side opposite the reference wall.

  (C). In the present embodiment, the wave washer 164 is sufficiently long in the axial direction as shown in FIG. 14 in the expanded state. Thus, after the reference position adjustment of the mediation drive mechanism 120 by the shim 166, the input portion 122 and the swing cams 124 and 126 of the mediation drive mechanism 120 are always pressed with a sufficient biasing force. Therefore, even when the axial force toward the reference wall portion is not generated during the period when the intake valve 12 is not lifted, the adhesion between the input portion 122 and the swing cams 124 and 126 can be improved, and some vibrations are generated. Even if a shock occurs, the swing cams 124 and 126 and the input unit 122 can be prevented from falling off the slider gear 128.

[Embodiment 2]
FIG. 18 is a plan view showing the configuration on the cam carrier 150 in the present embodiment. In the present embodiment, a leaf spring 264 is used as the urging member instead of the wave washer. Since the configuration other than the leaf spring 264 is the same as that of the first embodiment, the same configuration will be described with the same reference numerals with reference to the drawings of the first embodiment.

  The configuration of the leaf spring 264 is shown in FIG. 19A is a plan view of the leaf spring 264, FIG. 19B is a perspective view, FIG. 19C is a bottom view, FIG. 19D is a left side view, and FIG. 19E is a front view. Here, the leaf spring 264 includes a substrate 264a, and a left leaf spring portion 264b and a right leaf spring portion 264c fixed to the left and right of the substrate 264a by welding or the like.

  The substrate 264a has an arcuate recess 264d at the end extending to the space between the left leaf spring portion 264b and the right leaf spring portion 264c. The arc-shaped recess 264d is formed with the same diameter as the rocker shaft 130. When the arc-shaped recess 264d is disposed between the intermediate drive mechanism 120 and the bearing 162 as shown in FIG. To fit in half.

  In the present embodiment, the variable valve mechanism reference state adjusting method is executed as follows. First, the rocker shaft 130 is mounted on the cam carrier 150 together with the intake camshaft 45 and the exhaust camshaft 46 in a state where the shim 166 and the leaf spring 264 are not disposed and only the mediation drive mechanism 120 is disposed. Is fixed on a jig for adjusting the reference arrangement. As in the case of the first embodiment, the leading ends of the positioning pivots p1 and p2 provided on the jig are the cam surfaces 124e and 126e of the noses 124d and 126d, as shown in FIG. Abut. Further, the base circle portion of the intake camshaft 45 is directed toward the roller 122f. In this state, the intake camshaft 45 is not in contact with the roller 122f.

  Next, the mediation drive mechanism 120 is moved toward the slide actuator 100 on the rocker shaft 130 by pushing the mediation drive mechanism 120 in the axial direction manually or by mechanical force. At this time, unlike the first embodiment, since the urging member, here, the leaf spring 264 is not disposed, the intermediary drive mechanism 120 can be moved particularly easily.

  As a result, the slider gear 128 relatively moves in the H direction shown in FIGS. 5 and 6 inside the mediation drive mechanism 120, and the noses 124d and 126d and the roller 122f start to be separated in conjunction with this movement. Finally, as shown in FIG. 15B, the roller 122f comes into contact with the base circle portion of the intake camshaft 45, and further movement of the intermediate drive mechanism 120 in the axial direction becomes impossible.

  The axial position of the mediation drive mechanism 120 at this time is a reference arrangement corresponding to the initial position of the control shaft 132, which corresponds to the state shown in FIG. Therefore, in order to determine the position of the intermediate drive mechanism 120 at this time, a shim 166 having a thickness ds that matches the clearance between the intermediate drive mechanism 120 formed at this time and the bearing 162 or the front side wall 154 is selected. The intermediate drive mechanism 120 and the bearing 162 or the front side wall 154 are disposed.

  By repeating the selection of the shim 166 for the mediation drive mechanism 120 of each cylinder 2a, the state shown in FIG. 20 is obtained, and the reference arrangement of the mediation drive mechanism 120 is determined for all the cylinders 2a.

  Then, on the opposite side to the shim 166, the leaf spring 264 is inserted between the mediation drive mechanism 120 and the bearing 162, with the left leaf spring portion 264b and the right leaf spring portion 264c sandwiching the rocker shaft 130, respectively. As a result, half of the rocker shaft 130 is accommodated in the arc-shaped recess 264d. Since the left leaf spring portion 264b and the right leaf spring portion 264c press the swing cam 124 of the mediation drive mechanism 120 toward the shim 166, the mediation drive mechanism 120 is fixed at the reference position. As a result, the same valve lift can be set for each cylinder 2a.

  Thus, the configuration of the cam carrier 150 is completed, and the variable valve mechanism can be incorporated into the engine by attaching the cam carrier 150 to the cylinder head body as shown in FIG. The leaf spring 264 may be inserted between the intermediate drive mechanism 120 and the bearing 162 after the cam carrier 150 is attached to the cylinder head body.

In the above-described configuration, the leaf spring 264 corresponds to the biasing member in relation to the claims. Other configurations are as described in the first embodiment.
According to the second embodiment described above, the following effects can be obtained.

(I). The effects (a) and (c) of the first embodiment are produced.
(B). In the variable valve mechanism reference state adjusting method of the present embodiment, a shim 166 having an appropriate thickness ds is selected to absorb the clearance between the reference wall portion and the intermediate drive mechanism 120, and then the leaf spring 264 is disposed. Yes. In this way, the urging member may be arranged last, and the same effect as in the first embodiment is produced.

[Other embodiments]
(A). In the above embodiment, an example of a wave washer and a leaf spring has been shown. However, as a biasing member other than this, a disc spring, a coil spring, or a spring washer can be cited, and a similar effect can be produced. it can.

  (B). In each of the above embodiments, an example of an engine using a cam carrier has been described. However, the present invention can also be applied to an engine in which an intermediate drive mechanism and a camshaft are arranged directly on the cylinder head body.

  The engine can be applied not only to a gasoline engine but also to a diesel engine. It can be applied not only to vehicles but also to engines for other purposes. Furthermore, it can be applied not only to the intermediate drive mechanism for adjusting the valve lift amount of the intake valve, but also to the intermediate drive mechanism for adjusting the valve lift amount of the exhaust valve, for adjusting the valve lift amount of both the intake valve and the exhaust valve. It can also be applied to a mediation drive mechanism.

  (C). In each of the above-described embodiments, the position adjustment of the mediation drive mechanism is set to the initial position, that is, the state in which the valve lift amount is minimum, but may be adjusted to a position other than this. For example, the position adjustment of the mediation drive mechanism may be set to the maximum valve lift amount by fixing the control shaft at the axial position where the maximum valve lift amount is set. Alternatively, by fixing the position of the control shaft in the axial direction to an intermediate valve lift amount, the position adjustment of the mediation drive mechanism may be set to an intermediate valve lift amount.

  Further, at the time of adjusting the position of the mediation drive mechanism, the control shaft has already been assembled to the slide actuator. However, the control shaft may be assembled to the slide actuator after the position adjustment of the mediation drive mechanism. That is, the axial position of the control shaft is fixed to adjust the position of the mediation drive mechanism, and then the relationship between the control shaft and the slide actuator is set so as to correspond to the valve lift amount adjustment state of the mediation drive mechanism, The control shaft may be assembled to the slide actuator.

FIG. 3 is a longitudinal cross-sectional view of the engine and variable valve mechanism of the first embodiment. The top view which shows the upper part structure of the said engine. FIG. 3 is a configuration explanatory diagram of a wave washer used in the first embodiment. FIG. 3 is a configuration explanatory diagram of shims used in the first embodiment. FIG. 3 is a perspective view of an intermediary drive mechanism used in the first embodiment. The fragmentary perspective view of the mediation drive mechanism. The disassembled perspective view of the said mediation drive mechanism. The fracture | rupture perspective view of the outer part of the said mediation drive mechanism. FIG. 4 is a configuration explanatory view of a slider gear arranged in the mediation drive mechanism. The perspective view of the said slider gear. The vertical fracture perspective view of the said slider gear. Structure explanatory drawing of the rocker shaft and control shaft which penetrate the inside of the said mediation drive mechanism. The fragmentary perspective view of the mediation drive mechanism. FIG. 3 is an explanatory diagram of a configuration state on a cam carrier before starting an initial position adjustment in the first embodiment. FIG. 6 is a drive state explanatory diagram of an intermediate drive mechanism at the time of initial position adjustment in the first embodiment. FIG. 5 is an operation explanatory diagram of the mediation drive mechanism of the first embodiment. FIG. 5 is an operation explanatory diagram of the mediation drive mechanism of the first embodiment. FIG. 3 is a plan view showing an upper configuration of an engine according to a second embodiment. FIG. 5 is a configuration explanatory diagram of a leaf spring used in the second embodiment. FIG. 6 is a diagram illustrating a configuration state on a cam carrier during initial position adjustment in the second embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Engine, 2a ... Cylinder, 4 ... Cylinder block, 6 ... Piston, 8 ... Cylinder head, 10 ... Combustion chamber, 12 ... Intake valve, 14 ... Intake port, 16 ... Exhaust valve, 18 ... Exhaust port, 45 ... Intake Camshaft, 45a ... intake cam, 46 ... exhaust camshaft, 46a ... exhaust cam, 47 ... timing chain, 49 ... crankshaft, 52 ... roller rocker arm, 52a ... rocker roller, 54 ... roller rocker arm, 100 ... slide actuator 120 ... Intermediate drive mechanism, 122 ... Input section, 122a ... Housing, 122b ... Helical spline, 122c, 122d ... Arm, 122e ... Shaft, 122f ... Roller, 124 ... First swing cam, 124a ... Housing, 124b ... Helical Spline, 124c ... bearing portion, 12 d ... Nose, 124e ... Cam surface, 126 ... Second swing cam, 126a ... Housing, 126b ... Helical spline, 126c ... Bearing, 126d ... Nose, 126e ... Cam surface, 128 ... Slider gear, 128a ... Input helical Spline, 128b ... small diameter portion, 128c ... first output helical spline, 128d ... small diameter portion, 128e ... second output helical spline, 128f ... through hole, 128g ... circular groove, 128h ... pin insertion hole, 130 ... rocker shaft , 130a ... long hole, 130b ... internal space, 132 ... control shaft, 132a ... control pin, 132b ... support hole, 140, 142 ... variable valve timing mechanism, 140a, 142a ... timing sprocket, 150 ... cam carrier, 152 ... cam Cap, 154 56, 158, 160 ... side wall, 162 ... bearing, 164 ... wave washer, 164a ... through hole, 164b ... ring-shaped body, 164c ... top, 164d ... bottom, 166 ... shim, 166a ... base, 166b ... pick-up part, 166c ... Recessed part, 210... Ball screw mechanism, 264... Leaf spring, 264 a .. Substrate, 264 b... Left leaf spring part, 264 c.

Claims (6)

A variable valve mechanism that adjusts the valve characteristic of the internal combustion engine by linking the valve characteristic adjustment amount by the valve characteristic adjustment mechanism to the axial position of the control shaft that is axially moved by the actuator,
A reference wall portion for setting a reference position of the valve characteristic adjusting mechanism main body is provided by preventing the valve characteristic adjusting mechanism main body from following the axial movement of the control shaft , and the reference wall portion and the valve characteristic adjusting are provided. A first member that is separate from the reference wall is disposed between the mechanism main body and the valve characteristic adjusting mechanism main body on the side opposite to the reference wall with the valve characteristic adjusting mechanism interposed therebetween. A variable valve mechanism comprising a biasing member that is a second member biasing toward the reference wall. The variable valve mechanism according to claim 1, wherein the first member is a shim . 3. The biasing member according to claim 1, wherein the biasing member is provided between the wall portion provided on the opposite side of the valve characteristic adjusting mechanism main body from the reference wall portion and the valve characteristic adjusting mechanism main body. A variable valve mechanism characterized by being a wave washer, a disc spring, a coil spring, a leaf spring, or a spring washer. 4. The valve characteristic adjusting mechanism according to claim 1, wherein the valve characteristic adjusting mechanism drives the valve by an input unit that receives a driving force from a cam that rotates in conjunction with a crankshaft of the internal combustion engine, and a driving force that the input unit receives. An output portion, and adjusting one or both of a valve lift amount and a valve working angle by interlocking a positional relationship between the input portion and the output portion with an axial position of the control shaft. Variable valve mechanism. A reference state adjustment method for a variable valve mechanism that adjusts a valve characteristic of an internal combustion engine by linking a valve characteristic adjustment amount by a valve characteristic adjustment mechanism to an axial position of a control shaft that is axially moved by an actuator. ,
A reference wall portion that fixes the axial position of the control shaft and prevents the valve characteristic adjusting mechanism body from following the axial movement of the control shaft is provided on the opposite side of the valve characteristic adjusting mechanism body. An urging member for urging the valve characteristic adjusting mechanism main body toward the reference wall part side is disposed between the wall portion and the valve characteristic adjusting mechanism main body;
A variable valve mechanism reference state adjusting method, wherein a clearance between the reference wall portion and the valve characteristic adjusting mechanism main body is absorbed by a shim so that the same valve characteristic adjusting amount is obtained for each cylinder. A reference state adjustment method for a variable valve mechanism that adjusts a valve characteristic of an internal combustion engine by linking a valve characteristic adjustment amount by a valve characteristic adjustment mechanism to an axial position of a control shaft that is axially moved by an actuator. ,
A reference wall portion that fixes the axial direction position of the control shaft and prevents the valve characteristic adjustment mechanism body from following the axial movement of the control shaft so that the same valve characteristic adjustment amount is obtained for each cylinder. The clearance with the valve characteristic adjustment mechanism body is absorbed by the shim,
The valve characteristic adjusting mechanism main body is attached to the reference wall portion side between the valve characteristic adjusting mechanism main body and the wall provided on the opposite side of the valve characteristic adjusting mechanism main body. A variable valve mechanism reference state adjusting method, wherein a biasing member for biasing is arranged.

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