JP2007332884A - Variable valve system for internal combustion engine and adjustment method of swirl thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust the strength of a swirl generated in a cylinder without changing the design of the basic part of a variable valve system. <P>SOLUTION: The variable valve system 9 comprises an intervention drive mechanism 20 rockably supported on an axis X and driving each valve 8 by each output part 31a, 31b at both ends when an input part 21 is driven by a rotary cam 10, and a rotating phase difference variable mechanism 41 changing the relative rotating phase difference between the input part 21 and the output part 31 by driving a slider gear 44 having meshing of helical splines differed in angle with the input part 21 and with the output part 31, respectively, in an axial direction F, R. A shim 36 for position-adjusting one output part 31b in the axial direction F, R is interposed between the input part 21 and the output part 31b, and the one output part 31b is minutely rotated by meshing with the helical spline according to the position adjustment, whereby a relative rotating phase difference G is formed between both the output parts 31a and 31b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a variable valve mechanism that changes a lift amount and timing of a valve in accordance with an operating state of an internal combustion engine.

  Among this type of variable valve mechanism, as in the conventional variable valve mechanism 90 shown in FIG. 7 such as that described in Patent Document 1, it is supported on the same axis X so as to be swingable. One input portion 93 and two output portions 94a and 94b arranged on both sides thereof are provided. When the input portion 93 is driven by a rotating cam (not shown), the same cylinder ( An intermediate drive mechanism 92 that drives each valve 8 provided for the valve 8 and a slider gear 97 in which helical splines 98 having different angles are engaged with each other between the input portion 93 and the output portions 94a and 94b. Some include a rotation phase difference variable mechanism 96 that varies the relative rotation phase difference between the input unit 93 and the output units 94a and 94b by driving in the axial directions F and R.

In the conventional example shown in FIG. 7, both output portions 94a and 94b having substantially the same shape are inverted in the axial directions F and R, and are arranged in phase in the rotation directions O and C, that is, both output portions. Reference numerals 94a and 94b indicate that both valves 8 are opened and closed at substantially the same timing and lift amount. However, in Patent Document 1, the opening and closing of both valves 8 by both output portions 94a and 94b are described in this patent document 1. It is also described that the swirl strength generated in the cylinder during operation of the internal combustion engine is increased by shifting the timing and the lift amount relative to each other to improve the agitation of the intake gas in the cylinder. As a method of shifting the opening / closing timing and the lift amount, the shape of the helical spline 98 is made different between the output portions 94a and 94b, or the output nose for driving the valve 8 provided in both the output portions 94a and 94b. The method of providing a difference in 95 shape or position is described.
JP 2001-263015 A

  However, in the above method, when the strength of the swirl is changed according to the difference in the internal combustion engine, etc., it is necessary to slightly change the design of the helical spline 98, the output nose 95, etc. for each strength. As a result, it becomes impossible to make all the variable valve mechanisms 90 have a common design in the process of mass production, which is wasteful in terms of cost and labor.

  Accordingly, it is an object of the present invention to make it possible to adjust the strength of a swirl generated in a cylinder without changing the design of a basic part of a variable valve mechanism such as a helical spline or an output nose.

  In order to achieve the above object, a swirl adjusting method using a variable valve mechanism of an internal combustion engine according to the present invention includes one input unit arranged on the same axis and supported so as to be swingable, and two input units arranged on both sides thereof. An intermediate drive mechanism that drives each valve provided for the same cylinder at each output unit when the input unit is driven by a rotating cam; and the input unit and the output unit. A rotation phase difference variable mechanism that varies the relative rotation phase difference between the input unit and the output unit by driving in the axial direction a slider gear engaged with helical splines of different angles between each other. In the method for adjusting swirl by the variable valve mechanism of the internal combustion engine, a desired relative rotational phase difference is formed between the output portion and at least one of the output portions. A shim having a corresponding thickness is selected from a plurality of shims having different thicknesses, and the position of the one output portion is adjusted in the axial direction so that the one output portion is moved to the slider. The desired rotational phase difference is formed between both output parts by minute rotation by meshing of the helical spline with the gear, and thus the swirl generated in the cylinder is adjusted to the desired strength. Features.

  Further, the variable valve mechanism for an internal combustion engine of the present invention includes one input portion arranged on the same axis line and supported so as to be swingable, and two output portions arranged on both sides thereof, and the rotation cam is used to When the input unit is driven, an intermediate drive mechanism that drives each valve provided for the same cylinder at each output unit, and helical splines having different angles between the input unit and the output unit, respectively. In a variable valve mechanism for an internal combustion engine comprising a rotation phase difference variable mechanism that varies a relative rotation phase difference between the input unit and the output unit by driving the meshed slider gear in the axial direction. A shim for adjusting the position of the one output unit in the axial direction is interposed between the input unit and at least one of the output units, and the one output unit is moved to the slider along with the position adjustment. With gear And small pivot meshing helical spline, wherein the relative rotational phase difference between both the output unit is formed.

  The thickness of the shim is not particularly limited, but is preferably 1.0 to 3.0 mm, and more preferably 2.0 to 3.0 mm.

  Although the magnitude | size of the relative rotation phase difference between both output parts is not specifically limited, It is preferable that it is 2.1-6.2 degrees, and it is more preferable that it is 4.1-6.2 degrees. In addition, the magnitude of the relative rotation phase difference may vary with the variation of the relative rotation phase difference between the input unit and the output unit, or may be constant regardless of the variation. .

  According to the present invention, a shim is interposed between the input unit and one of the output units to form a desired relative rotational phase difference between the two output units. The strength of the swirl generated in the cylinder can be adjusted with little change in the design of the mechanism.

  The variable valve mechanism 9 of the internal combustion engine 5 according to the present invention includes one input portion 21 that is slidably supported on the same axis X, and two output portions 31a and 31b arranged on both sides thereof. When the input unit 21 is driven by the rotary cam 10, the intermediate drive mechanism 20 that drives each valve 8 provided for the same cylinder 6 at each output unit 31a, 31b, the input unit 21 and the output unit 31a. , 31b are driven in the axial directions F, R by driving the slider gear 44 engaged with helical splines having different angles from each other, thereby causing a relative rotational phase difference g1, between the input unit 21 and the output units 31a, 31b. A rotation phase difference varying mechanism 41 that varies g2 is provided.

  Here, a shim 36 having a thickness T corresponding to forming a desired relative rotation phase difference G between the output portions 31a and 31b between the input portion 21 and at least one of the output portions 31b. The plurality of shims having different thicknesses are selected and interposed, and the position of the one output portion 31b in the axial direction F, R is adjusted so that the one output portion 31b is connected to the slider gear 44. The desired relative rotation phase difference G is formed between the output portions 31a and 31b by slightly rotating with the meshing of the helical spline, thereby adjusting the swirl generated in the cylinder 6 to the desired strength.

  The variable valve mechanism 9 shown in FIGS. 1 to 3 of the present embodiment is a mechanism that continuously changes the opening / closing amount of the valve in accordance with the operating state of the internal combustion engine. It is attached to the valve 8. Specifically, there is one variable valve mechanism 9 for each cylinder 6, and each variable valve mechanism 9 is installed in the cylinder head 7 for each cylinder 6, and the intake valve described above. Two 8 are pressed simultaneously.

  The variable valve mechanism 9 includes a rotary cam 10 that is rotationally driven as the internal combustion engine 5 is operated, a rocker arm 15 that swings and opens and closes the valve 8 when power is transmitted, and the rotary cam 10 and the rocker arm 15. An intermediate drive mechanism 20 that adjusts the amount of opening and closing of the valve 8 by transmitting the power from the rotary cam 10 to the rocker arm 15 in a variable amount is interposed therebetween.

  The rotating cam 10 is formed on a camshaft 10 x that is rotatably installed above the cylinder head 7, and includes a base circle portion 11 that is a basic portion and a cam nose 12 that protrudes from the base circle portion 11. Has been. A cam surface 10 s for pressing the mediating drive mechanism 20 is formed on the outer peripheral surface of the rotating cam 10.

  There are two rocker arms 15 for each variable valve mechanism 9, and one rocker arm 15 is installed for each valve 8. Each rocker arm 15 has a base end portion 15 a supported by the lash adjuster 17 so as to be swingable, and a tip end portion 15 b abutting against the stem end 8 e of the valve 8. A roller 16 that is pressed by the mediating drive mechanism 20 is pivotally attached to the intermediate portion of the rocker arm 15.

  The intermediary drive mechanism 20 includes a single input portion 21 that is swingably supported side by side on the same support pipe 20x, and two output portions 31a and 31b disposed on both sides thereof. 21 is a mechanism for driving each valve 8 by each output unit 31a, 31b when it is driven, and inside it is a helical with different angles between the input unit 21 and both output units 31a, 31b. By rotating the slider gear 44 engaged with the spline in the axial directions F and R, the rotation phase difference variable mechanism 41 that varies the relative rotation phase differences g1 and g2 between the input unit 21 and the output units 31a and 31b. Is provided. In the following description, one of the length directions (axis direction) of the axis X that is the center line of the support pipe 20x is the front F, the other is the rear R, and the rotation direction is about the axis X. The direction in which the mediating drive mechanism 20 drives the rocker arm 15 to open the valve 8 is the opening direction O, and the opposite direction is the closing direction C.

  The support pipe 20x is a single pipe shared by the plurality of variable valve mechanisms 9, and is turned around the plurality of standing wall portions 7v arranged in parallel at intervals in the front-rear directions F and R on the upper portion of the cylinder head 7. It is fixed immovable. Then, between the two of the plurality of standing wall portions 7v, the input portion 21 and the output portions 31a and 31b of one intermediary drive mechanism 20 are arranged side by side with the adjacent members and the end surfaces thereof aligned with each other. It is supported. The input portion 21 and the output portions 31a and 31b are prevented from moving in the front-rear directions F and R by the two ends of the arrangement being in contact with the standing wall portions 7v on both sides. However, between the input unit 21 and one output unit 31b, by adjusting the position of the one output unit 31b in the front-rear direction F, R with respect to the input unit 21 and the other output unit 31a, A phase adjusting shim 36 that forms a relative rotation phase difference G of a desired size between the output portions 31a and 31b by slightly rotating one output portion 31b by meshing the helical spline with the slider gear 44 is interposed. It is disguised. In addition, gap adjusting shims 37a and 37b are provided between the output parts 31a and 31b and the standing wall parts 7v adjacent to the output parts 31a and 31b, respectively, in order to fill the gaps between them without excess or deficiency. In the following description, the one output unit 31b is referred to as an adjustment-side output unit 31b, and the other output unit 31a is referred to as a reference-side output unit 31a.

  The input part 21 is disposed at a substantially center between the standing wall parts 7v. The input portion 21 includes a cylindrical base circle portion 22 serving as a basic portion, an input arm 24 that supports an input roller 25 that contacts the rotating cam 10, and a return arm 27 to which a return spring 28 is attached. A shaft hole through which the slider gear 44 is inserted is formed at the center of the base circle 22. Two input arms 24 are formed so as to protrude in parallel to the outer peripheral surface of the base circular portion 22, and the above-described input roller 25 is axially attached via a shaft 26 between the tips of both input arms 24. . The return arm 27 is formed so as to protrude substantially opposite to the radial direction of the input portion 21 with respect to both the input arms 24, and the return arm 27 is moved in the closing direction C between the return spring 27 and the external spring mounting portion 29. The return spring 28 is attached so that the input roller 25 always abuts against the cam surface 10 s of the rotating cam 10 by urging. Since the input unit 21 always abuts against the rotating cam 10 by the above-described mechanism, even when the relative rotational phase differences g1 and g2 with the output units 31a and 31b change, the basics of the input unit 21 can be obtained. The position does not change. However, the basic position refers to a position on the most closing direction C side that is located while swinging in the opening and closing directions O and C, and the same applies to both output portions 31a and 31b.

  The two output portions 31a and 31b are arranged one by one on both sides in the front-rear direction F and R of the input unit 21, and are inverted in the front-rear directions F and R and have the same shape. Each of the output portions 31a and 31b includes a cylindrical base circle portion 32 serving as a basic portion and an output nose 34 provided with an output cam surface 34s for pressing the rocker arm 15. A shaft hole for inserting the slider gear 44 is formed in the part. Moreover, the bearing part 33 provided with the center hole for inserting the support pipe 20x is provided in the end surface on the opposite side to the input part side of each output part 31a, 31b. The output nose 34 of each of the output portions 31a and 31b is formed so as to protrude from the outer peripheral surface of the base circular portion 32, and the outer peripheral surface on the opening direction O side from the top of the output nose 34 is curved in a concave shape. An output cam surface 34s is formed.

  A plurality of phase adjusting shims 36 having different thicknesses T are prepared, and thicknesses corresponding to the formation of a desired relative rotation phase difference G between the output portions 31a and 31b are prepared. T's are selected and used. Here, a shim having a thickness T of about 3.0 mm is selected and used, so that a relative rotation phase difference of about 2.1 ° of the desired size is provided between the output portions 31a and 31b. G is formed. Due to the relative rotation phase difference G, when the internal combustion engine 5 is in operation, an appropriate difference occurs in the opening / closing timing and lift amount of the valves 8 by the output portions 31a and 31b, and a swirl having a desired strength is generated in the cylinder 6. A flow will be generated. The phase adjusting shim 36 is a circular frame member having a recess for allowing the slider gear 44 to be inserted inside.

  As with the phase adjusting shim 36, a plurality of gap adjusting shims 37a and 37b having different thicknesses are prepared, and each of the standing portions 7v adjacent to the output portions 31a and 31b is provided. Those having a thickness corresponding to filling each gap between them without excess or deficiency are selected and used. Therefore, even when the phase adjusting shim 36 of any thickness T is used, the gap corresponding to the thickness is selected and used, so that each gap is always filled without excess or deficiency. The gap adjusting shims 37a and 37b are horseshoe-shaped members each having a recess for allowing the support pipe 20x to be inserted therethrough.

  The rotation phase difference variable mechanism 41 includes the slider gear 44 described above, a control shaft 48 that slides on the axis X in the front and rear directions F and R, and the slider gear 44 that moves to the control shaft 48 in the front and rear directions F and R. And a connecting mechanism 52 that is slidably connected in the opening and closing directions O and C.

  The slider gear 44 is inserted between the support pipe 20x and the input portion 21 and the output portions 31a and 31b. The slider gear 44 is provided on the outer peripheral surface of the input portion 21 on the outer peripheral surface. An input helical spline 45 that meshes with the input portion helical spline 42 and an output helical spline 46 that meshes with the output portion helical spline 43 provided on the inner peripheral surfaces of both the output portions 31a and 31b are provided. The details of these helical splines are such that the input helical spline 45 and the input portion helical spline 42 meshing with the helical spline 45 rotate in the closing direction C from the front F toward the rear R (in the figure, a right-handed spiral). The output helical spline 46 and the output portion helical spline 43 that mesh with the output helical spline 46 are formed in a spiral shape (left-handed spiral shape in the drawing) that turns in the opening direction O as it advances from the front F to the rear R. . The shape of the slider gear 44 is substantially cylindrical, the inner peripheral surface is in sliding contact with the support pipe 20x, and the input helical spline 45 and the output helical spline 46 are arranged in the front-rear direction F, on the outer peripheral surface. Formed at an interval to R. And between these both helical splines 45 and 46, the small diameter part 47 in which the diameter became small compared with the other part is formed.

  Like the support pipe 20x, the control shaft 48 is a single shaft shared by the plurality of variable valve mechanisms 9 and is inserted into the support pipe 20x. One end of the control shaft 48 is connected to a variable lift amount actuator 49 that drives the control shaft 48 in the front-rear directions F and R.

  The coupling mechanism 52 protrudes from the control shaft 48 and has a slit hole 54 provided in the slider gear 44 extending in the opening and closing directions O and C, a long hole 55 provided in the support pipe 20x extending in the front-rear directions F and R, and a long length. And an engaging pin 53 that is inserted through the hole 55 and engaged with the slit hole 54.

  The state in which the intermediate drive mechanism 20 shown above is driven by the rotating cam 10 to swing to open and close the valve 8 shows that the base circle portion 11 of the rotating cam 10 contacts the input roller 25. (i) Base circle The following description will be made separately on the part contact and the cam nose 12 of the rotating cam 10 contacting the input roller 25 (ii) cam nose contact.

(I) At the time of contact with the base circle portion As shown in FIG. 4A, both the input portion 21 and the output portions 31a and 31b remain stationary at the basic position, and the relative rotation between the output portions 31a and 31b is maintained. Although there is a dynamic phase difference G, the output nose 34 of any of the output portions 31 a and 31 b does not contact the rocker arm 15. Therefore, neither valve 8 is pressed, and both valves 8 remain closed.

(Ii) At cam nose contact As shown in FIG. 4B, the input portion 21 and the output portions 31a and 31b are integrally rotated in the opening direction O with the slider gear 44 coupled by meshing of the helical splines. To do. At this time, since both the output portions 31a and 31b have a relative rotational phase difference G between them, the output portions 31a and 31b are rotated in the opening direction O with their phases shifted from each other, so that both valves 8 have different timings and It will open with the lift amount.

  Next, when the variable valve mechanism 9 described above opens and closes the valve 8, (a) when the valve opening / closing amount is constant, (b) when the valve opening / closing amount increases, and (c) when the valve opening / closing amount decreases. This will be described in order in three categories.

(A) When the valve opening / closing amount is constant (when the rotation phase difference variable mechanism 41 is stationary)
When the opening / closing amount of the valve 8 is kept constant, there is no need to change the relative rotational phase difference g1, g2 between the input unit 21 and the output units 31a, 31b, so the slider gear 44 moves in the front-rear direction F, R. It is never driven. Therefore, the input unit 21 and the output units 31a and 31b are connected to the slider gear 44 while the relative rotation phase difference g1 and g2 between the input and output units and the relative rotation phase difference G between the output units are fixed. It rotates integrally and opens and closes both valves 8.

(A) When the valve opening / closing amount increases (when the rotation phase difference variable mechanism 41 is actually operated)
When the opening / closing amount of the valve 8 is increased, as shown in FIG. 5A, the slider gear 44 is also moved to the engagement pin 53 as the control shaft 48 is pushed forward and slid by the lift amount variable actuator 49. It is pressed and slides forward F while swinging in the opening and closing directions O and C. As a result, the input unit 21 and the output units 31a and 31b rotate in opposite directions due to the meshing of the helical splines, and the relative rotational phase differences g1 and g2 between the input and output units respectively increase. At this time, since the basic position of the input unit 21 is fixed by the return spring 28 and the rotary cam 10 as described above, the slider gear 44 rotates in the opening direction O based on the position of the input unit 21. Further, both the output portions 31a and 31b are rotated in the opening direction O with respect to the rotating slider gear 44. As a result, both output portions 31a and 31b swing relative to the opening and closing directions O and C in a state in which a relative rotation phase difference G is formed between them, and relative rotation phase differences g1 and g1 with the input unit 21, respectively. The basic position is shifted in the opening direction O by the increase in g2. Thereby, the drive amount of both the rocker arms 15 by the rotating cam 10 increases, and the opening / closing amount of both valves 8 increases.

(C) When the valve opening / closing amount decreases (when the rotation phase difference variable mechanism 41 is actually operated)
When the opening / closing amount of the valve 8 is decreased, as shown in FIG. 5 (b), the slider gear 44 is also moved to the engaging pin 53 as the control shaft 48 is pushed rearward by the lift amount variable actuator 49 and slides. It is pressed and slides backward R while swinging in the opening and closing directions O and C. As a result, the input unit 21 and the output units 31a and 31b rotate in opposite directions due to the meshing of the helical splines, and the relative rotational phase differences g1 and g2 between the input and output decrease, respectively. At this time, since the basic position of the input unit 21 is fixed as in the case of (A), the slider gear 44 rotates in the closing direction C with reference to the position of the input unit 21, and the rotation is further performed. Both output portions 31 a and 31 b rotate in the closing direction C with respect to the moving slider gear 44. As a result, both output portions 31a and 31b swing relative to the opening and closing directions O and C in a state in which a relative rotation phase difference G is formed between them, and relative rotation phase differences g1 and g1 with the input unit 21, respectively. The basic position is shifted in the closing direction C by the decrease of g2. As a result, the amount of drive of both rocker arms 15 by the rotating cam 10 decreases, and the amount of opening and closing of both valves 8 decreases.

  The relationship between the stroke of the slider gear 44 in the front-rear direction F, R accompanying the actual operation of the rotation phase difference variable mechanism 41 described above and the lift amount of each valve 8 by each output portion 31a, 31b is shown in FIG. Shown in the image diagram. At this time, the curve indicating the lift amount by the adjustment-side output unit 31b is different from the curve indicating the lift amount by the reference-side output unit 31a by the thickness T of the phase adjustment shim 36. It will shift in the stroke direction. Then, due to the deviation, a steering region D where the slider gear 44 does not move even during actual operation is formed at the end of the adjustment-side output portion 31b on the bearing portion 33 side, whereas the output portion 31b. An additional area A in which the slider gear 44 is newly movable is formed at the end of the phase adjusting shim 36 side.

  According to the present embodiment, by forming a phase adjustment shim 36 between the input unit 21 and the output unit 31b to form a desired relative rotation phase difference G between the output units 31a and 31b, The parts other than the phase adjusting shim 36 and the gap adjusting shims 37a and 37b do not change the design of the variable valve mechanism 9, and the opening / closing timing and lift amount of both valves 8 by both the output portions 31a and 31b can be set. By shifting from each other, the swirl generated in the cylinder 6 can be adjusted to a desired strength. Therefore, when mass-producing the variable valve mechanism 9 having the strength of each swirl, all parts other than the shims 36, 37a, and 37b can be designed in common, and the manufacturing cost and labor can be kept low. .

  In addition, this invention is not limited to the structure of the said Example, It can also change and embody in the range which does not deviate from the meaning of invention.

It is a whole side view which shows the variable valve mechanism of the Example of this invention. It is a perspective view which shows the mediation drive mechanism of the Example, and its periphery. It is a disassembled perspective view which shows the mediation drive mechanism of the Example. In the same example, (a) is a front view showing the state of the intermediate drive mechanism and its surroundings when the rotating cam comes into contact with the base circle portion, and (b) when the rotating cam is brought into cam nose contact. In the embodiment, (a) is a top sectional view showing an intermediate drive mechanism and its surroundings when the valve opening / closing amount is increased, and (b) when the valve opening / closing amount is decreased. In the Example, it is an image figure which shows the relationship between the stroke of a slider gear, and the lift amount of a valve | bulb. It is a perspective view which shows the mediation drive mechanism of a prior art example, and its periphery.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Internal combustion engine 8 Valve 9 Variable valve mechanism 10 Rotating cam 20 Mediating drive mechanism 21 Input part 31a Reference | standard output part 31b Output part (one output part) of adjustment
36 Phase Adjustment Shim (Shim)
41 Rotating phase difference variable mechanism 44 Slider gear X Axis F Front (Axial direction)
R rear (axial direction)
O Open direction C Closed direction g1 Relative rotation phase difference between input unit and output unit g2 Relative rotation phase difference between input unit and output unit G Relative rotation phase difference between both output units

Claims (2)

One input unit arranged on the same axis and supported so as to be swingable and two output units arranged on both sides thereof, and when the input unit is driven by a rotating cam, the same output unit By driving in the axial direction the intermediary drive mechanism that drives each valve provided for the cylinder, and the slider gear engaged with the helical splines having different angles from each other between the input unit and the output unit, In the swirl adjustment method by the variable valve mechanism of the internal combustion engine provided with the rotation phase difference variable mechanism that varies the relative rotation phase difference between the input unit and the output unit,
A plurality of shims having different thicknesses are formed between the input unit and at least one of the output units, with a thickness corresponding to the formation of a desired relative rotational phase difference between the output units. And selecting one of the two output portions by adjusting the position of the one output portion in the axial direction so that the one output portion is slightly rotated by the meshing of the helical spline with the slider gear. A method for adjusting swirl by a variable valve mechanism of an internal combustion engine, wherein the desired relative rotation phase difference is formed between the swirl, thereby adjusting the swirl generated in the cylinder to a desired strength. One input unit arranged on the same axis and supported so as to be swingable and two output units arranged on both sides thereof, and when the input unit is driven by a rotating cam, the same output unit By driving in the axial direction the intermediary drive mechanism that drives each valve provided for the cylinder, and the slider gear engaged with the helical splines having different angles from each other between the input unit and the output unit, In a variable valve mechanism for an internal combustion engine comprising a rotation phase difference variable mechanism that varies a relative rotation phase difference between the input unit and the output unit,
A shim for adjusting the position of the one output unit in the axial direction is interposed between the input unit and at least one of the output units, and the one output unit is moved to the slider along with the position adjustment. A variable valve mechanism for an internal combustion engine characterized in that a relative rotation phase difference is formed between both output portions by minute rotation by meshing of a helical spline with a gear.

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