JP4414871B2 - Variable valve mechanism for internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve mechanism for an internal combustion engine that adjusts valve characteristics by moving a control shaft in the axial direction in the internal combustion engine.

A variable valve mechanism for an internal combustion engine that adjusts valve characteristics such as valve operating angle and valve lift by moving the control shaft in the axial direction by an actuator and moving the slider gear engaged with the control shaft in the axial direction is known. (See, for example, Patent Document 1).
JP 2001-263015 A (page 7-12, FIG. 5-28)

  Thus, since the control shaft of the variable valve mechanism moves the slider gear in the axial direction, a large force is applied to the engaging portion with respect to the slider gear. In particular, when the slider gear is moved in the direction of increasing the valve lift, a large force tends to act on the engaging portion. For this reason, if the strength of the control shaft is insufficient, the engaging portion may be deformed. In order to prevent such deformation, a high-strength material such as an iron-based material is used for the control shaft.

  However, when a light alloy material such as an aluminum alloy is used for the cylinder head in order to reduce the weight of the engine, the thermal expansion coefficient of the cylinder head is considerably larger than that of the iron material. Specifically, it becomes about twice as large. Therefore, if an iron-based material is used for the control shaft of the variable valve mechanism, the position of the engaging portion on the control shaft is relatively large with respect to the cylinder head when the engine is cold and after the engine is warmed up. It will shift. For this reason, even if the actuator side detects the amount of movement of the control shaft and tries to control the amount of movement of the control shaft, the axial position of the engaging part is shifted due to temperature, so valve characteristics such as valve lift amount are highly accurate. May be out of control.

  By changing the control shaft to a light alloy material such as an aluminum alloy that is the same material as the cylinder head, the valve characteristic control can be maintained with high accuracy if the coefficient of thermal expansion is adapted to the cylinder head. However, light alloy materials such as aluminum alloys are not as strong as iron materials, and the engaging portion may be deformed by the reaction force from the slider gear side.

  An object of the present invention is to realize a variable valve mechanism for an internal combustion engine that enables highly accurate valve characteristic control while maintaining the strength of a control shaft.

In the following, means for achieving the above object and its effects are described.
(1) In the first aspect of the present invention, the valve driving force from the cam side is transmitted to the valve side by an intermediate driving mechanism whose position in the axial direction is determined by a reference surface formed on the cylinder head side of the internal combustion engine. And a variable valve mechanism for an internal combustion engine that adjusts a valve characteristic of the internal combustion engine by engaging a valve characteristic operation portion provided in the intermediate drive mechanism and moving the valve characteristic operation portion in the axial direction. And an interval variable means for varying an interval between the reference surface and the mediation drive mechanism by being arranged between the reference surface and the mediation drive mechanism and making the length in the axial direction variable. And a valve characteristic adjustment error suppression means for suppressing an adjustment error of the valve characteristic due to a difference in the internal combustion engine temperature by reflecting the internal combustion engine temperature in the axial length of the interval variable means. The interval variable means includes two spacers arranged between the reference surface and the mediation drive mechanism, and the interval is changed by relative rotation. The valve characteristic adjustment error suppression means is the internal combustion engine temperature. The length of the interval varying means in the axial direction is changed by relatively rotating the two spacers according to the change, and is made of a material having a coefficient of thermal expansion different from that of the cylinder head along the control shaft. A spacer adjusting shaft, one end of which is fixed to the cylinder head side on the drive end side of the control shaft, and the reference surface in the axial direction due to a change in temperature of the internal combustion engine and the spacer adjusting shaft. And a relative rotation means for rotating the two spacers relative to each other based on a relative position change. It is summarized in that it.

Valve characteristic adjustment error suppression means reflects the internal combustion engine temperature in the axial length of the interval variable means. As a result, the distance between the reference plane and the intermediate drive mechanism is adjusted by the internal combustion engine temperature, and the deviation of the valve characteristic operation portion caused by the difference in thermal expansion between the control shaft and the cylinder head can be suppressed.
Therefore, even if the material of the control shaft is selected from the viewpoint of strength and the material of the cylinder head is selected from the viewpoint of weight reduction, the function of the valve characteristic adjustment error suppression means and the interval variable means enables the valve due to the difference in internal combustion engine temperature. Characteristic adjustment errors can be suppressed.
In this way, it is possible to realize a variable valve mechanism for an internal combustion engine that enables highly accurate valve characteristic control while maintaining the strength of the control shaft.
Further, the method of changing the length in the axial direction of the interval variable means can be realized by using two spacers whose interval changes due to relative rotation. Since the relative rotation is sufficient, the length of the interval varying means in the axial direction can be changed relatively easily.
In addition, since the spacer adjusting shaft having a different coefficient of thermal expansion from the cylinder head is fixed to the cylinder head side as described above, if there is a change in the internal combustion engine temperature, there is a difference in thermal expansion between the reference plane and the spacer adjusting shaft. Due to this, a positional difference occurs, and a relative position change occurs between the interval variable means and the relative rotation means. By this relative position change, the relative rotation means relatively rotates the two spacers.
For this reason, the valve characteristic adjustment error suppression means can reflect the internal combustion engine temperature in the axial length of the interval variable means, and can suppress the valve characteristic adjustment error due to the difference in the internal combustion engine temperature.
In this way, it is possible to realize a variable valve mechanism for an internal combustion engine that enables highly accurate valve characteristic control while maintaining the strength of the control shaft.

(2) In the invention according to claim 2, the valve driving force from the cam side is transmitted to the valve side by an intermediate driving mechanism whose position in the axial direction is determined by a reference surface formed on the cylinder head side of the internal combustion engine. And a variable valve mechanism for an internal combustion engine that adjusts a valve characteristic of the internal combustion engine by engaging a valve characteristic operation portion provided in the intermediate drive mechanism and moving the valve characteristic operation portion in the axial direction. The valve characteristic adjustment error suppression means provided in a mode along the control shaft and expands or contracts in the axial direction of the control shaft in accordance with its own temperature change, and the mode of engaging with the valve characteristic adjustment error suppression means And is provided between the reference surface and the mediation drive mechanism, and the valve characteristic adjustment error suppression means itself is caused by expansion or contraction. And a pitch adjusting means for axial length changes, the pitch adjusting means is provided with a two spacers mutual spacing are arranged by relative rotation between said reference surface and the intervening drive mechanism is changed The interval between the reference plane and the mediation drive mechanism is changed by a change in the axial length of the spacer with the relative rotation of the spacers, and the valve characteristic adjustment error suppression means is accompanied by a change in the temperature of the spacer. Due to the expansion or contraction, the engagement portion with the interval variable means moves in the axial direction with respect to the reference plane, and the two spacers move relative to each other through the movement of the engagement portion in the axial direction with a change in the internal combustion engine temperature. The gist of the invention is to change the axial length of the interval varying means by rotating it .

(3) In the invention according to claim 3, the valve driving force from the cam side is transmitted to the valve side by an intermediate driving mechanism whose position in the axial direction is determined by a reference surface formed on the cylinder head side of the internal combustion engine. And a variable valve mechanism for an internal combustion engine that adjusts a valve characteristic of the internal combustion engine by engaging a valve characteristic operation portion provided in the intermediate drive mechanism and moving the valve characteristic operation portion in the axial direction. And a valve characteristic adjustment error suppressing means that expands or contracts with respect to the cylinder head based on a change in temperature due to a difference in thermal expansion coefficient with the cylinder head, and between the reference surface and the mediation drive mechanism. An interval variable means provided to change an interval between the reference surface and the mediation drive mechanism according to expansion or contraction of the valve characteristic adjustment error suppression means; For example, the pitch adjusting means is adapted with two spacers spacing by relative rotation are arranged between the intermediary drive mechanism and the reference plane changes, the valve characteristic adjusting error suppression means, the internal combustion engine The gist of the invention is to change the axial length of the interval varying means by rotating the two spacers relative to each other by temperature change .

As a method of changing the length of the interval variable means in the axial direction, it can be realized by using two spacers whose interval changes due to relative rotation. Since the relative rotation is sufficient, the length of the interval varying means in the axial direction can be changed relatively easily.

(4) According to a fourth aspect of the present invention, in the variable valve mechanism for an internal combustion engine according to any one of the first to third aspects, the two spacers both have a helical taper surface. The gist is to make the length in the axial direction of the interval variable means variable by relative rotation between the two spacers by making contact with each other on the spiral tapered surface.

The configuration in which the interval is changed by the relative rotation can be realized by a configuration in which the spacers each provided with the spiral tapered surface are in contact with each other on the spiral tapered surface. In this manner, the length of the interval varying means in the axial direction can be changed with a relatively simple configuration and with a relatively easy operation.

(5) According to a fifth aspect of the present invention, in the variable valve mechanism for an internal combustion engine according to any one of the second to fourth aspects, the valve characteristic adjustment error suppression means is thermally expanded from the cylinder head. A spacer adjusting shaft which is provided along the control shaft using a material having a different rate and whose one end is fixed to the cylinder head side on the driving end side of the control shaft, and is provided on the spacer adjusting shaft and is internal combustion The gist of the invention is to include a relative rotation means for relatively rotating the two spacers based on a relative position change with respect to the reference plane in the axial direction due to a change in engine temperature.

Since the spacer adjustment shaft, which has a different coefficient of thermal expansion from the cylinder head, is fixed to the cylinder head side as described above, if there is a change in the internal combustion engine temperature, it will be positioned between the reference plane and the spacer adjustment shaft due to the difference in thermal expansion. A difference occurs between the distance variable means and the relative rotation means. By this relative position change, the relative rotation means relatively rotates the two spacers.
  For this reason, the valve characteristic adjustment error suppression means can reflect the internal combustion engine temperature in the axial length of the interval variable means, and can suppress the valve characteristic adjustment error due to the difference in the internal combustion engine temperature.
  In this way, it is possible to realize a variable valve mechanism for an internal combustion engine that enables highly accurate valve characteristic control while maintaining the strength of the control shaft.

(6) The invention according to claim 6 is the variable valve mechanism for the internal combustion engine according to claim 1 or 5 , wherein the internal combustion engine has a plurality of cylinders arranged in series. The gist of the present invention is that it is a single shaft common to the plurality of cylinders and that relative rotation means is provided corresponding to each cylinder.

In the case of an internal combustion engine having a plurality of cylinders arranged in series in this way, a single spacer adjustment shaft common to the plurality of cylinders is provided, and relative rotation means for each cylinder is provided on the single spacer adjustment shaft. By arranging it, it can cope with multiple cylinders.
  As described above, even for a multi-cylinder internal combustion engine, it is possible to realize a variable valve mechanism for an internal combustion engine that enables highly accurate valve characteristic control while maintaining the strength of the control shaft with a simple configuration. .

(7) The invention according to claim 7 is the variable valve mechanism for the internal combustion engine according to claim 1, 5 or 6 , wherein the spacer adjusting shaft is made of a material having the same thermal expansion coefficient as that of the control shaft. The gist is that it is formed.

As described above, the spacer adjusting shaft may be made of a material having the same coefficient of thermal expansion as that of the control shaft, thereby causing a difference in thermal expansion between the spacer adjusting shaft and the cylinder head.

(8) The invention according to claim 8 is the variable valve mechanism for an internal combustion engine according to any one of claims 1 or 5 to 7 , wherein the spacer adjusting shaft is made of the same material as the control shaft. The gist is that it is formed.

As described above, the spacer adjusting shaft may be made of the same material as that of the control shaft so as to cause a thermal expansion difference with the cylinder head.

(9) The invention according to claim 9 is the variable valve mechanism of the internal combustion engine according to any one of claims 1 to 8 , wherein the valve characteristic adjustment error suppression means includes the cylinder head and the control shaft. The change in the relative position in the axial direction between the reference surface and the control shaft caused by the difference in thermal expansion with the control shaft is the same as the change in the length in the axial direction of the interval varying means due to a change in internal combustion engine temperature. Thus, the gist is to cancel the relative position fluctuation.

Thus, when the length change in the axial direction of the interval variable means is matched with the relative position fluctuation in the axial direction between the reference surface and the control shaft caused by the thermal expansion difference between the control shaft and the cylinder head, Deviation of the valve characteristic operation section due to thermal expansion can be completely eliminated.
  As a result, it is possible to realize a variable valve mechanism for an internal combustion engine that enables more accurate valve characteristic control while maintaining the strength of the control shaft.

[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 for mainly explaining 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. Yes. 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 disposed in each intake port 14 or intake manifold so that fuel is injected 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 can also 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 has a rotational speed ½ that of the crankshaft 49 of the engine 2 via a timing sprocket provided in the valve timing variable mechanism 140 disposed at one end and the timing chain 47. It is linked with.

  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 linked to the rotation of the crankshaft 49 of the engine 2 at a half speed through a timing chain 47 and a timing sprocket provided in a valve timing variable mechanism 142 disposed at one end. is doing. 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 region surrounded by the side walls 154, 156, 158, 160, four bearings 162 are arranged in parallel and are integrally formed of aluminum alloy together 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. A variable spacer 164 and an elastic shim 166 are arranged on both sides in the axial direction with respect to each intermediary drive mechanism 120. One rocker shaft 130 common to the four mediating drive mechanisms 120 supports the mediation drive mechanism 120, the variable spacer 164, and the elastic shim 166 in a penetrating state. 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.

  On the cam cap 152, an error correction spacer adjusting shaft 168 is disposed in parallel with the rocker shaft 130 so as to penetrate a bearing 152 a formed in the cam cap 152. The spacer adjusting shaft 168 is fixed to the side wall 156 by a bolt 156a at the end on the slide actuator 100 side.

  As shown in the perspective view of FIG. 3 (FIG. 3 is a perspective view of two cylinders), one spacer adjusting shaft 168 is disposed across the intermediate drive mechanism 120 of all cylinders. A mechanism 170 is configured to suppress valve characteristic adjustment errors caused by temperature changes.

4 shows a valve characteristic adjustment error suppression mechanism 170 for one cylinder, and FIG. 5 shows an exploded perspective view.
Here, the variable spacer 164 includes a first spiral spacer 180, a second spiral spacer 182, a spline ring 184, and a phasing screw 186.

  FIG. 6 shows details of the first spiral spacer 180. 6 (A) is a plan view, (B) is a left side view, (C) is a front view, (D) is a right side view, (E) is a bottom view, (F) is a rear view, and (G). FIG. The first spiral spacer 180 has a ring shape having a through hole 180a in the center, and a plurality of right-handed spiral taper surfaces 180b around the through hole 180a are formed on one surface side, in this case, 20 surfaces. . A rotation stop pin 180c is fitted and attached to the back side.

  When the valve characteristic adjustment error suppressing mechanism 170 is configured as shown in FIG. 3 and disposed on the cam carrier 150, the rocker shaft 130 is inserted into the through hole 180a. The tip of the rotation stop pin 180 c is inserted into a pin hole formed in the cam cap 152, and the first spiral spacer 180 is prevented from rotating around the rocker shaft 130.

  FIG. 7 shows details of the second spiral spacer 182. 6A is a plan view, FIG. 6B is a left side view, FIG. 6C is a front view, FIG. 6D is a right side view, FIG. 6E is a bottom view, and FIG. The second spiral spacer 182 has a ring shape having a through hole 182a in the center, and a plurality of right-handed spiral tapered surfaces 182b around the through hole 182a on one surface side, here, the spiral of the first spiral spacer 180 The same number of 20 surfaces as the tapered surface 180b is formed. A screw hole 182c for the phase determining screw 186 is formed on the outer peripheral surface. The spiral tapered surface 182b of the second spiral spacer 182 is a tapered surface having the same shape as the spiral tapered surface 180b of the first spiral spacer 180.

  As shown in FIG. 5, the spline ring 184 has a ring shape in which a left-handed helical spline 184 a is formed on the outer peripheral surface. Both the first spiral spacer 180 and the second spiral spacer 182 can be accommodated in the internal space 184b. The spline ring 184 is a phasing screw that is screwed into the second spiral spacer 182 through the long hole 184c with respect to the second spiral spacer 182 as shown in the perspective view of FIG. It is fixed at 186. Therefore, the spline ring 184 and the second spiral spacer 182 are integrated and move together.

  The elastic shim 166 is formed of an elastic member so as to adapt to the variable thickness of the variable spacer 164 and absorb the clearance between the cam cap 152 and the bearing 162 on the left side in FIG. Yes. For example, a wave washer-like elastic shim 166 shown in FIG. 9 can be used. 9A is a perspective view of the elastic shim 166, and FIG. 9B is a front view. The elastic shim 166 has a ring shape having a through hole 166a at the center. The ring-shaped main body 166b is wavy in the axial direction, and thus has three top portions 166c and bottom portions 166d in the axial direction. In addition, the top part 166c and the bottom part 166d may each be two, and may be four or more.

  As another elastic shim, a leaf spring-like elastic shim 167 shown in FIG. 10 may be used. 10A is a plan view of the elastic shim 167, FIG. 10B is a perspective view, FIG. 10C is a bottom view, FIG. 10D is a left side view, and FIG. Here, the elastic shim 167 includes a substrate 167a and a left leaf spring portion 167b and a right leaf spring portion 167c fixed to the left and right of the substrate 167a by welding or the like.

  The substrate 167a has an arcuate recess 167d at the end extending to the space between the left leaf spring portion 167b and the right leaf spring portion 167c. The arc-shaped recess 167d is formed to have the same diameter as the rocker shaft 130. When the arc-shaped recess 167d is disposed between the mediation drive mechanism 120, the cam cap 152, and the bearing 162, the rocker shaft 130 is half of the arc-shaped recess 167d. Has been.

Next, the mediation drive mechanism 120 will be described. 11 and 12 are partially broken perspective views of the intermediate drive mechanism 120, and FIG. 13 is an exploded perspective view.
As shown in FIG. 3, the mediation drive mechanism 120 includes an input portion 122 provided at the center of each mediation drive mechanism 120, a first swing cam 124 provided on one end side of the input portion 122, and a first swing cam 124. And a slider gear 128 (FIGS. 11 to 13) disposed in the inner space of the second swing cam 126 provided on the opposite side of the first swing cam 126.

  A housing 122a of the input portion 122 forms a space in the axial direction inside, and a helical spline 122b formed in a right-handed spiral shape in the axial direction is formed on the inner peripheral surface of the internal 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. Incidentally, 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. Such a spring is provided between the input part 122 and the cylinder head 8 or the rocker shaft 130, for example.

  The housings 124a and 126a of the first rocking cam 124 and the second rocking cam 126 form a space in the axial direction inside. Helical splines 124b and 126b are formed on the inner peripheral surface of the internal space in the axial direction in the form of a left-handed spiral. One end of each of the internal spaces of the housings 124a and 126a is covered with ring-shaped end face walls 124c and 126c having shaft insertion holes with small diameters. Further, substantially triangular noses 124d and 126d are formed so as to protrude from the outer peripheral surface. One sides of the noses 124d and 126d form cam surfaces 124e and 126e.

  As shown in FIG. 13, the first rocking cam 124 and the second rocking cam 126 are disposed in the axial direction so that the end faces are coaxially contacted with the input unit 122 from both sides. As a result, the main body composed of the plurality of housings 122a, 124a, 126a has a substantially cylindrical shape having an internal space as shown in FIG.

Details of the slider gear 128 are shown in FIGS. FIG. 14 is a perspective view, and FIG. 15 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 right-handed spiral is formed at the center of the outer peripheral surface. A first output helical spline 128c is formed on one end 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 side opposite to the first output helical spline 128c, a second output helical spline 128e formed in a left-handed spiral shape 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. The rocker shaft 130 is provided in common with the four mediation drive mechanisms 120, and a long hole 130a formed long in the axial direction is opened at a position corresponding to each mediation drive mechanism 120. The long hole 130 a is formed to penetrate to the internal space 130 b of the rocker shaft 130.

  Further, in the internal space 130b of the rocker shaft 130, a control shaft 132, a part of which is shown in the perspective view of FIG. 16B, penetrates slidably 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.

  In addition, since the rocker shaft 130, the control shaft 132, and each control pin 132a need to have high strength, an iron alloy is used here. Therefore, the thermal expansion coefficient is smaller than that of the cam carrier 150 made of a light alloy, here an aluminum alloy.

  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, the variable spacer 164, and the elastic shim 166 are attached to the rocker shaft 130 in combination for each cylinder, and the rocker shaft 130 is mounted on the cam carrier 150. Deploy. At the same time, the intake camshaft 45 and the exhaust camshaft 46 are also arranged on the cam carrier 150. Then, the cam cap 152 is attached.

  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. Further, the base end side of the spacer adjusting shaft 168 is fixed to the side wall 156 with a bolt 156 a, and the helical spline 168 a formed for each cylinder on the spacer adjusting shaft 168 is engaged with the spline ring 184 of each variable spacer 164.

  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 immediately after being arranged on the cam carrier 150, the phase arrangement relationship between the noses 124d and 126d and the roller 122f is not always in the state of the minimum valve lift amount, and the state of the minimum valve lift amount. It is not fixed to.

  Therefore, the housing 122a, 124a, 126a of the mediation drive mechanism 120 is moved in the axial direction by using a jig or the like that determines the standard arrangement of the mediation drive mechanism 120 to obtain a reference position that provides the minimum valve lift amount. In order to determine this reference position, the clearance (FIG. 2) between the intermediate drive mechanism 120 formed at this time and the reference surface 220 (the side surface of the cam cap 152 and the bearing 162 or the front side wall 154) shown in FIG. The thickness of the variable spacer 164 is adjusted so as to match the clearance on the right side of each of the intermediate drive mechanisms 120. This thickness adjustment is performed by relative rotation between the spiral spacers 180 and 182 while maintaining the contact state between the spiral tapered surfaces 180b and 182b of the two spiral spacers 180 and 182.

  The reference surface 220 is a surface that exists in the direction of the axial force generated in the housings 122a, 124a, 126a of the intermediate drive mechanism 120. The clearance between the reference surface 220 and the intermediate drive mechanism 120 is determined by the stroke amount of the control shaft 132 and the valve. The relationship with the lift amount is set. Therefore, it is important to set this clearance precisely in terms of highly accurate valve lift amount control and the same valve lift amount between cylinders.

  Since the helical spacer 180 is engaged with the cam cap 152 side by the rotation stopping pin 180c and cannot rotate, the thickness of the variable spacer 164 is adjusted by rotating the second helical spacer 182 side. During this adjustment, the phasing screw 186 is loosened, so that even if the spline ring 184 and the helical spline 168a of the spacer adjustment shaft 168 mesh with each other, the second helical spacer 182 is moved relative to the first helical spacer 180. Relative rotation is possible. At this time, the elastic shim 166 side bends to respond to the thickness change of the variable spacer 164.

  When the thickness adjustment of the variable spacer 164 is completed, the spline ring 184 is fixed and integrated with the second spiral spacer 182 by tightening the phasing screw 186. Thus, the reference position of the mediation drive mechanism 120 that is the minimum valve lift amount is determined. This state is shown in FIG. At this time, the thickness of the variable spacer 164 is indicated by Lt. By repeating this reference position adjustment for each intermediate drive mechanism 120 of each cylinder, the reference arrangement of the intermediate drive mechanism 120 for all cylinders is completed.

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

  In the engine 2 configured as described above, 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 shaft of the slider gear 128 disposed in the internal space of the mediation drive mechanism 120. The directional position can be adjusted.

  As shown in FIG. 12, 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.

  The intermediate drive mechanism 120 of each cylinder 2a is positioned in the axial direction by the variable spacer 164 as described above. Therefore, 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 phase relationship between the cams 124 and 126 can be changed. 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. 18 shows the 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 FIG. 11) as much as possible. 18A is when the intake valve 12 is closed, and FIG. 18B 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. Therefore, as shown in FIG. 18B, 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. 19 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 H direction (arrow in FIG. 11) as much as possible. 19A is when the intake valve 12 is closed, and FIG. 19B 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 farthest. For this reason, as shown in FIG. 19B, 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 is maximized. 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. 18 and the state of FIG. 19 by the slide actuator 100, the valve lift amount of the intake valve 12 can be continuously adjusted. That is, stepless adjustment of the intake air amount is possible without using a throttle valve.

  Note that, as shown in FIG. 18B, there is a certain degree of opening when the intake valve 12 is opened in the initial position state. However, as another form of the initial position state, the valve lift amount “0”, that is, the intake air The valve 12 may be kept completely closed, and in this case, the intake air amount becomes “0”.

  The state of the variable spacer 164 shown in FIG. 17A shows the state at the time of assembly, that is, when the engine 2 is at a low temperature. When the operation of the engine 2 is started, the engine temperature gradually increases. Along with this, the cam carrier 150 and the control shaft 132 are thermally expanded. The cam carrier 150 is made of a light alloy for reducing the weight of the engine 2, here made of an aluminum alloy, and the control shaft 132 is made of a high-strength metal, here an iron alloy for durability. For this reason, the thermal expansion coefficient of the control shaft 132 is smaller, and the thermal expansion does not occur as much as the cam carrier 150, and a thermal expansion difference occurs between the control shaft 132 and the cam carrier 150.

  Accordingly, axial displacement between the control shaft 132 and each intermediate drive mechanism 120 occurs due to a difference in thermal expansion according to the distance from the base end side in each intermediate drive mechanism 120. If this deviation occurs as it is, it appears as an axial deviation between the slider gear 128, the input portion 122, and the swing cams 124, 126 in each intermediary drive mechanism 120, so that the control by the slide actuator 100 is performed. The control accuracy of the axial position with respect to the shaft 132 may be reduced. Also, a difference in valve lift amount occurs between cylinders.

  In the present embodiment, the spacer adjusting shaft 168 is made of a material having the same thermal expansion coefficient as that of the control shaft 132, here, the same material. For this reason, the spacer adjustment shaft 168 also causes a thermal expansion difference with the cam carrier 150 due to the temperature rise, and a positional shift according to the distance occurs with the cam carrier 150 in the axial direction.

  Accordingly, the positional relationship between the spacer adjusting shaft 168 and the reference surface 220 shifts from the state shown in FIG. 17A to the state shown in FIG. That is, the helical spline 168a of the spacer adjusting shaft 168 moves to the left side in the figure while being engaged with the spline ring 184 integrated with the second spiral spacer 182.

  The movement of the helical spline 168a in the spline meshing state of the helical spline 168a and the spline ring 184 causes the spline ring 184 to rotate counterclockwise (counterclockwise rotation) when viewed from the mediation drive mechanism 120 side. The amount of rotation depends on the amount of movement of the helical spline 168a.

  Since the first spiral spacer 180 and the second spiral spacer 182 are in contact with each other with the helical taper surfaces 180b and 182b, the left spiral rotation of the second spiral spacer 182 interlocked with the spline ring 184 causes the pressing force of the elastic shim 166. In contrast, the second spiral spacer 182 moves away from the first spiral spacer 180. That is, the variable spacer 164 increases from the thickness Lt to the thickness Ht.

  Conversely, when the engine operation is stopped and the temperature is lowered, the spacer adjusting shaft 168 moves to the right in the drawing relative to the reference plane 220. This movement causes the above-described mechanism to work in reverse. That is, the spline ring 184 rotates clockwise (clockwise) when viewed from the mediation drive mechanism 120 side, and the second spiral spacer 182 interlocked with the spline ring 184 is moved to the right by the function of the spiral tapered surfaces 180b and 182b. Rotate and the second helical spacer 182 approaches the first helical spacer 180. That is, the variable spacer 164 becomes thinner from the thickness Ht to the thickness Lt.

  The spline meshing between the helical spline 168a and the spline ring 184 and the helical shape so that the difference between the thickness Lt and the thickness Ht becomes a value that absorbs the thermal expansion difference between the control shaft 132 and the cam carrier 150. The twist angles of the tapered surfaces 180b and 182b are set.

  For this reason, even if the engine temperature changes and a difference in thermal expansion occurs between the control shaft 132 and the cam carrier 150, the deviation is offset by the change in the thickness of the variable spacer 164, and the slider gear 128 in each intermediate drive mechanism 120. And the input portion 122 and the swing cams 124 and 126 do not appear as an axial shift.

  In the configuration described above, the slider gear 128 corresponds to the valve characteristic operation unit in relation to the claims. The combination of the first spiral spacer 180 and the second spiral spacer 182 is a distance variable means, the combination of the spacer adjustment shaft 168 and the spline ring 184 is a valve characteristic adjustment error suppression means, and the combination of the helical spline 168a and the helical spline 184a. Corresponds to the relative rotation means.

According to the first embodiment described above, the following effects can be obtained.
(I). When a difference in thermal expansion occurs between the cam carrier 150 and the control shaft 132 due to a change in engine temperature, the thickness of the variable spacer 164 changes correspondingly by the action of the valve characteristic adjustment error suppression mechanism 170. As a result, the distance between the reference surface 220 and the intermediate drive mechanism 120 is adjusted, and the relative position fluctuation between the reference surface 220 and the intermediate drive mechanism 120 due to the difference in thermal expansion is offset. As a result, the displacement of the slider gear 128 caused by the thermal expansion difference between the control shaft 132 and the cylinder head 8 (here, the cam carrier 150 that is a part of the cylinder head 8) can be eliminated.

  Therefore, even if the material of the control shaft 132 is selected from the viewpoint of strength and the material of the cylinder head 8 including the cam carrier 150 is selected from the viewpoint of weight reduction, the adjustment error of the valve characteristics due to the difference in engine temperature is suppressed. Can do.

In this way, it is possible to realize a variable valve mechanism that enables highly accurate valve characteristic control while maintaining the strength of the control shaft 132.
(B). The thickness adjustment of the variable spacer 164 is made possible by a combination of spiral spacers 180 and 182 having spiral tapered surfaces 180b and 182b. As a result, the length of the variable spacer 164 in the axial direction, that is, the thickness is relatively easy to operate with a relatively simple configuration by relatively rotating between the two spiral spacers 180 and 182 due to a change in engine temperature. Can be easily changed.

  (C). A spacer adjusting shaft 168 having a thermal expansion coefficient different from that of the cam carrier 150 is fixed to the cam carrier 150 at one end, and the helical spline 168a is spline-engaged with a helical spline 184a integrated with the second helical spacer 182. Thus, the second helical spacer 182 is rotated relative to the first helical spacer 180 by the change in the length of the spacer adjusting shaft 168 caused by the difference in thermal expansion.

Therefore, the thickness of the variable spacer 164 can be easily changed by changing the engine temperature, and the adjustment error of the valve characteristic due to the difference in engine temperature can be easily suppressed.
(D). The spacer adjusting shaft 168 is provided in common for a plurality of cylinders, and a helical spline 168a and a variable spacer 164 for each cylinder are arranged on the single spacer adjusting shaft 168. As a result, all the cylinders can be accommodated by one spacer adjusting shaft 168, so that a variable valve mechanism that enables highly precise valve characteristic control while maintaining the strength of the control shaft 132 with a simple configuration. Is possible.

[Embodiment 2]
The configuration of the upper part of the engine of the present embodiment is shown in the plan view of FIG. In the present embodiment, as compared with the first embodiment, the mediation drive mechanism 320 is arranged between the intake camshaft 245 and the exhaust camshaft 246, and is 180 on the vertical axis as compared with FIG. ° The difference is that it is rotated. Therefore, the slide actuator 300 is arranged on the opposite side in the axial direction with respect to the intermediate drive mechanism 320 as compared with the first embodiment. Furthermore, the point that each mechanism shown in FIG. 20 is provided on the main body of the cylinder head 350 without using a cam carrier is also different from the first embodiment.

  In this case, the reference surface 420 is a side surface of the bearing-cam cap 352 on the left side of the intermediate drive mechanism 320 in FIG. 20, and a variable spacer 364 is provided between the intermediate drive mechanism 320 and the reference surface 420. An elastic shim 366 is provided between the intermediate drive mechanism 320 and the bearing-cam cap 352 on the right side of the figure.

  The basic configuration of the input unit 322, the swing cams 324 and 326, the spacer adjustment shaft 368, the variable spacer 364, and the elastic shim 366 of the mediation drive mechanism 320 is the same as that of the first embodiment.

  In the configuration of the present embodiment, contrary to the first embodiment, the clearance between the mediation drive mechanism 320 and the reference surface 420 increases at low temperatures, and the clearance decreases at high temperatures. In the case of the present embodiment, FIG. 17B corresponds to a state at a low temperature and FIG. 17A corresponds to a state at a high temperature. As a result, even if the engine temperature changes and a difference in thermal expansion occurs between the control shaft 332 (shown by a broken line in FIG. 20) and the cylinder head 350, the slider gear and the input unit 322 in each intermediate drive mechanism 320 and It does not appear as an axial displacement between the swing cams 324 and 326.

According to the second embodiment described above, the following effects can be obtained.
(I). The effects (a) to (d) of the first embodiment are produced.
[Embodiment 3]
The valve characteristic adjustment error suppression mechanism 470 of the present embodiment is shown in a rear perspective view of FIG. 21, a plan view of FIG. 22, and a right side view of FIG. The configuration other than the valve characteristic adjustment error suppression mechanism 470 is the same as that of the first embodiment.

  Also in the valve characteristic adjustment error suppression mechanism 470, the first spiral spacer 480 and the second spiral spacer 482 of the variable spacer 464 have the same shape as the first spiral spacer 180 and the second spiral spacer 182 of the first embodiment. However, a spline ring is not attached to the second spiral spacer 482, and the pin 486 is attached so as to protrude radially on the outer peripheral surface.

  A guide plate 468a is attached to one spacer adjustment shaft 468 common to all cylinders so as to protrude toward the pin 486 for each cylinder. One side of the guide plate 468a forms a guide surface 468b having an angle with respect to the axis of the spacer adjusting shaft 468 and contacts the side surface of the pin 486. One end of the spacer adjusting shaft 468 is fixed to the cam carrier on the slide actuator side as in the first embodiment.

  Accordingly, when the clearance between the mediation drive mechanism 120 and the reference surface 520 is small and the position of the guide plate 468a is relatively on the right side in FIG. 22, the amount of push of the pin 486 in the circumferential direction by the guide surface 468b is small. . For this reason, the distance between the first spiral spacer 480 and the second spiral spacer 482 is short, and the thickness of the variable spacer 464 is thin.

  However, when the temperature of the engine increases and the clearance between the mediation drive mechanism 120 and the reference surface 520 increases, the cam carrier has a higher coefficient of thermal expansion than the spacer adjustment shaft 468, so the position of the guide plate 468a is relative to that in FIG. To the left, the amount of push of the pin 486 by the guide surface 468b increases. For this reason, the distance between the first spiral spacer 480 and the second spiral spacer 482 increases, and the variable spacer 464 increases in thickness.

  The angle of the guide surface 468b and the twist angle of the spiral tapered surfaces of the spiral spacers 480 and 482 are such that the difference in thickness is a value that absorbs the clearance between the mediation drive mechanism 120 and the reference surface 520 that varies depending on the temperature. Is set.

  For this reason, even if the engine temperature changes and a difference in thermal expansion occurs between the control shaft 132 and the cam carrier, the shaft between the slider gear in each intermediary drive mechanism 120 and the input unit 122 and the swing cams 124 and 126. It does not appear as a misalignment.

  In the structure described above, the combination of the first spiral spacer 480 and the second spiral spacer 482 is a variable distance unit, and the combination of the spacer adjusting shaft 468, the guide plate 468a and the pin 486 is a valve characteristic adjusting error suppressing unit. In addition, the combination of the guide plate 468a and the pin 486 corresponds to the relative rotation means.

According to the third embodiment described above, the following effects can be obtained.
(I). Furthermore, the effects (i) to (d) of the first embodiment can be produced with a simpler configuration.

[Other embodiments]
(A). In the first and second embodiments, the spline ring 184 forms the helical spline 184a on the entire circumference, but only the partial phase range actually meshes with the helical spline 168a of the spacer adjustment shaft 168. The helical spline 184a may be formed only on the corresponding part.

  Furthermore, although the second spiral spacer 182 and the spline ring 184 are formed separately and integrated with the phase determination screw 186, the initial position of the mediation drive mechanism 120 overlaps other members such as shims. In this case, a helical spline may be formed integrally with the second spiral spacer 182 from the beginning. Also in this case, helical splines may be integrally formed only in a part of the phase range with respect to the second spiral spacer 182.

  (B). In the third embodiment, the configuration of the first embodiment is adopted except for the valve characteristic adjustment error suppression mechanism 470. However, the configuration of the second embodiment may be adopted. In this case, the variable spacer 464 becomes thinner as the engine temperature rises.

  (C). In each of the above embodiments, the spacer adjusting shaft rotates only one of the two helical spacers of the variable spacer, but both may rotate in the opposite direction. Alternatively, the spiral spacer on the reference plane side may be rotated to fix the spiral spacer on the intermediate drive mechanism side with respect to the reference plane side.

  (D). Each of the above embodiments 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.

FIG. 3 is a longitudinal cross-sectional view of the engine and variable valve mechanism of the first embodiment. FIG. 2 is a plan view showing an upper configuration of the engine according to the first embodiment. The perspective view which shows the arrangement | positioning relationship between the mediation drive mechanism of Embodiment 1, and a valve characteristic adjustment error suppression mechanism. FIG. 3 is a perspective view of a valve characteristic adjustment error suppression mechanism according to the first embodiment. FIG. 3 is an exploded perspective view of the valve characteristic adjustment error suppressing mechanism of the first embodiment. FIG. 3 is a configuration explanatory diagram of a first spiral spacer according to the first embodiment. FIG. 4 is a configuration explanatory diagram of a second spiral spacer according to the first embodiment. The perspective view which shows the combination state of the spline ring of Embodiment 1, and the 2nd spiral spacer. FIG. 3 is a configuration explanatory diagram of an example of an elastic shim used in the first embodiment. FIG. 6 is a configuration explanatory diagram of another example of an elastic shim used in the first embodiment. FIG. 3 is a partially broken perspective view of the mediation drive mechanism according to the first embodiment. FIG. 3 is a partially broken perspective view of the mediation drive mechanism according to the first embodiment. FIG. 3 is an exploded perspective view of the mediation drive mechanism according to the first embodiment. FIG. 3 is a perspective view of the slider gear according to the first embodiment. FIG. 3 is a vertically broken perspective view of the slider gear according to the first embodiment. FIG. 3 is a configuration explanatory view of a rocker shaft and a control shaft penetrating through the intermediate drive mechanism of the first embodiment. FIG. 6 is an explanatory diagram of driving of the valve characteristic adjustment error suppression mechanism according to 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. 10 is a rear perspective view showing an arrangement relationship between a mediation drive mechanism and a valve characteristic adjustment error suppression mechanism according to a third embodiment. FIG. Similarly right side view.

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, 124,126 ... Oscillating cam, 124a, 126a ... Housing, 124b , 126b ... Helical spline 124c, 126c ... end face wall part, 124d, 126d ... nose, 124e, 126e ... cam face, 128 ... slider gear, 128a ... input helical spline, 128b ... small diameter part, 128c, 128e ... output helical spline, 128d ... small diameter 128f ... through hole, 128g ... circumferential 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, 150 ... Cam carrier, 152 ... Cam cap, 152a ... Bearing, 154,156,158,160 ... Side wall, 156a ... Bolt, 162 ... Bearing, 164 ... Variable spacer, 166 ... Elastic shim, 166a ... through hole, 166b ... phosphorus 166c ... top, 166d ... bottom, 167 ... elastic shim, 167a ... substrate, 167b ... left leaf spring, 167c ... right leaf spring, 167d ... arc shaped recess, 168 ... spacer adjustment shaft, 168a ... helical spline , 170 ... Valve characteristic adjustment error suppression mechanism, 180 ... First spiral spacer, 180a ... Through hole, 180b ... Spiral tapered surface, 180c ... Anti-rotation pin, 182 ... Second spiral spacer, 182a ... Through hole, 182b ... Spiral tapered surface, 182c ... screwing hole, 184 ... spline ring, 184a ... helical spline, 184b ... internal space, 184c ... long hole, 186 ... screw, 210 ... ball screw mechanism, 220 ... reference surface, 245 ... intake camshaft 245a ... intake cam, 246 ... exhaust camshaft, 300 ... slide actuator Eta 320 ... Intermediate drive mechanism 322 ... Input unit 324 326 ... Oscillating cam 332 ... Control shaft 350 ... Cylinder head 352 ... Bearing-cam cap 364 ... Variable spacer 366 ... Elastic shim 368 ... Spacer adjustment shaft, 368a ... bolt, 420 ... reference surface, 464 ... variable spacer, 468 ... spacer adjustment shaft, 468a ... guide plate, 468b ... guide surface, 470 ... valve characteristic adjustment error suppression mechanism, 480 ... first spiral spacer, 482 ... second spiral spacer, 486 ... pin, 520 ... reference plane.

Claims (9)

A valve driving force from the cam side is transmitted to the valve side by an intermediate drive mechanism whose position in the axial direction is determined by a reference surface formed on the cylinder head side of the internal combustion engine, and a control shaft is provided in the intermediate drive mechanism. In the variable valve mechanism of the internal combustion engine that adjusts the valve characteristic of the internal combustion engine by engaging the valve characteristic operation unit and moving the valve characteristic operation unit in the axial direction,
An interval variable means for changing the interval between the reference surface and the mediation drive mechanism by being arranged between the reference surface and the mediation drive mechanism and making the length in the axial direction variable,
Valve characteristic adjustment error suppression means for suppressing the adjustment error of the valve characteristic due to the difference in the internal combustion engine temperature by reflecting the internal combustion engine temperature in the axial length of the interval variable means;
The interval variable means includes two spacers that are arranged between the reference surface and the mediation drive mechanism, and the interval is changed by relative rotation.
The valve characteristic adjustment error suppressing means changes the axial length of the interval varying means by rotating the two spacers relative to each other according to a change in internal combustion engine temperature. A spacer adjusting shaft which is provided along the control shaft using a material having a different rate and whose one end is fixed to the cylinder head side on the driving end side of the control shaft, and is provided on the spacer adjusting shaft and is internal combustion A variable valve mechanism for an internal combustion engine, comprising: a relative rotation unit that relatively rotates the two spacers based on a relative position change with respect to the reference surface in the axial direction due to a change in engine temperature.   A valve driving force from the cam side is transmitted to the valve side by an intermediate drive mechanism whose position in the axial direction is determined by a reference surface formed on the cylinder head side of the internal combustion engine, and a control shaft is provided in the intermediate drive mechanism. In the variable valve mechanism of the internal combustion engine that adjusts the valve characteristic of the internal combustion engine by engaging the valve characteristic operation unit and moving the valve characteristic operation unit in the axial direction,
  A valve characteristic adjustment error suppression means provided in a mode along the control shaft, which expands or contracts in the axial direction of the control shaft according to its own temperature change;
  It is provided between the reference surface and the mediation drive mechanism so as to engage with the valve characteristic adjustment error suppression means, and its axial length changes as the valve characteristic adjustment error suppression means expands or contracts. And an interval variable means for
  The distance varying means includes two spacers that are arranged between the reference surface and the intermediate drive mechanism and change in distance from each other by relative rotation, and have their own axial length along with the relative rotation of these spacers. The distance between the reference plane and the mediation drive mechanism is changed by the change of
  The valve characteristic adjustment error suppression means moves in an axial direction with respect to the reference plane due to expansion or contraction accompanying its own temperature change, and is associated with a change in internal combustion engine temperature. The axial length of the distance varying means is changed by relatively rotating the two spacers through the axial movement of the joint portion.
  A variable valve mechanism for an internal combustion engine.   A valve driving force from the cam side is transmitted to the valve side by an intermediate drive mechanism whose position in the axial direction is determined by a reference surface formed on the cylinder head side of the internal combustion engine, and a control shaft is provided in the intermediate drive mechanism. In the variable valve mechanism of the internal combustion engine that adjusts the valve characteristic of the internal combustion engine by engaging the valve characteristic operation unit and moving the valve characteristic operation unit in the axial direction,
  A valve characteristic adjustment error suppression means that expands or contracts with respect to the cylinder head based on a temperature change of itself due to a difference in thermal expansion coefficient from the cylinder head;
  An interval variable means provided between the reference plane and the mediation drive mechanism and changing the interval between the reference plane and the mediation drive mechanism in accordance with expansion or contraction of the valve characteristic adjustment error suppression means;
  The interval variable means includes two spacers that are arranged between the reference surface and the mediation drive mechanism, and the interval is changed by relative rotation.
  The valve characteristic adjustment error suppression means changes the axial length of the interval variable means by rotating the two spacers relative to each other according to a change in internal combustion engine temperature.
  A variable valve mechanism for an internal combustion engine.   In the variable valve mechanism of the internal combustion engine according to any one of claims 1 to 3,
  The two spacers both have a spiral taper surface, and are in contact with each other at the spiral taper surface, so that the relative rotation between the two spacers causes an axial direction of the distance varying means. Variable length
  A variable valve mechanism for an internal combustion engine.   The variable valve mechanism for an internal combustion engine according to any one of claims 2 to 4,
  The valve characteristic adjustment error suppression means is provided along the control shaft using a material having a coefficient of thermal expansion different from that of the cylinder head, and one end is fixed to the cylinder head side on the drive end side of the control shaft. And a relative rotation means provided on the spacer adjustment shaft and relatively rotating the two spacers based on a relative position change with respect to the reference plane in the axial direction due to a temperature change of the internal combustion engine.
  A variable valve mechanism for an internal combustion engine.   The variable valve mechanism for an internal combustion engine according to claim 1 or 5,
  The internal combustion engine has a plurality of cylinders arranged in series,
  The variable valve mechanism for an internal combustion engine, wherein the spacer adjusting shaft is a single shaft common to the plurality of cylinders, and a relative rotation means is provided corresponding to each cylinder.   The variable valve mechanism for an internal combustion engine according to claim 1, 5 or 6,
  The spacer adjusting shaft is formed of a material having the same coefficient of thermal expansion as the control shaft.
  A variable valve mechanism for an internal combustion engine.   The variable valve mechanism for an internal combustion engine according to any one of claims 1 and 5-7,
  The spacer adjusting shaft is formed of the same material as the control shaft.
  A variable valve mechanism for an internal combustion engine.   The variable valve mechanism for an internal combustion engine according to any one of claims 1 to 8,
  The valve characteristic adjustment error suppression means includes a relative position variation in the axial direction between the reference surface and the control shaft caused by a difference in thermal expansion between the cylinder head and the control shaft, and a change in internal combustion engine temperature. The relative position fluctuation is canceled by making the length change in the axial direction of the interval variable means the same.
  A variable valve mechanism for an internal combustion engine.

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