JP2004183572A - Multi-cylinder internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-cylinder internal combustion engine capable of being minimized for a dispersion between cylinders with respect to operating characteristics of a valve to be adjustable in the multi-cylinder internal combustion engine, in which axes of pairs of cylinders mounted along a crankshaft make a predetermined bank and which is equipped with a function which changes the operating characteristics for at least one of a suction valve and an exhaust valve mounted on each cylinder. <P>SOLUTION: The V-shaped multi-cylinder internal combustion engine 1 is provided with four swinging mechanisms corresponding to a left bank 3, and four swinging mechanisms corresponding a right bank 4 along a swinging support shaft 10. These eight swinging mechanisms change the phase difference angle mechanically interlocking with the motion of a control shaft 10B forming the swinging support shaft 10 to enable the change of the operating characteristics (maximum lift amount and operating angle) of the suction valves 20 and 30. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multi-cylinder internal combustion engine in which the axes of at least a pair of cylinders provided along a crankshaft form a predetermined bank, and the operation of at least one of an intake valve and an exhaust valve provided in each cylinder is performed. The present invention relates to a multi-cylinder internal combustion engine having a function of changing characteristics.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been known a variable valve mechanism that varies a maximum lift amount and a working angle of an intake valve and an exhaust valve according to an operation state of an internal combustion engine (hereinafter, referred to as an engine). In general, in such a variable valve operating mechanism, the profile of the intake cam that drives the intake valve or the profile of the exhaust cam that drives the exhaust valve is substantially changed in some way, so that the maximum lift amount of the intake valve or the exhaust valve can be increased. Change the working angle. For example, the mechanism described in Patent Document 1 includes two types of intake cams having different shapes on one rotating shaft (intake camshaft). The two kinds of intake cams are switched according to the situation, and the intake valve is driven, so that the maximum lift amount and operating angle of the intake valve are variable.
[0003]
The maximum lift amount and operating angle of the intake and exhaust valves are related to the efficiency of charging the air (intake) drawn into the combustion chamber. For this reason, if the maximum lift amount and operating angle of the intake and exhaust valves are adjusted by using such a variable valve mechanism, for example, by controlling the charging efficiency of the intake according to the engine speed and the engine load, it is possible to obtain a desired value. In order to obtain the engine output, the fuel efficiency can be optimized.
[0004]
By the way, from the viewpoint of improvement in mountability to a vehicle, a V-type engine including a plurality of cylinders arranged in two rows along the axis of a crankshaft and each cylinder row having a predetermined bank angle is known. I have. Generally, a V-type engine is provided with an intake camshaft for opening and closing an intake valve of each cylinder and an exhaust camshaft for opening and closing an exhaust valve for each cylinder row. Therefore, in order to make the maximum lift amount and operating angle of the intake and exhaust valves variable for each cylinder of the V-type engine, each of the intake camshafts (or exhaust camshafts) independently arranged for each cylinder row must be It is necessary to mount a variable valve mechanism (Patent Document 2).
[0005]
[Patent Document 1]
JP-A-11-324625
[Patent Document 2]
JP-A-7-49013
[Patent Document 3]
JP-A-9-100705
[0006]
[Problems to be solved by the invention]
However, when a variable valve operating mechanism that is different for each cylinder row is mounted, the maximum lift amount and operating angle of the intake / exhaust valve, or the change amount thereof, tend to vary between the two cylinder rows. In addition, since a single engine is provided with a plurality of variable valve mechanisms having the same function, the number of parts is increased, the size of the engine is increased, or the manufacturing cost is increased.
[0007]
The present invention has been made in view of such circumstances, and an axis of at least a pair of cylinders provided along a crankshaft forms a predetermined bank, and an intake valve and an exhaust valve provided for each cylinder. In a multi-cylinder internal combustion engine having a function of changing its operation characteristic, at least one of the above-mentioned is provided a multi-cylinder internal combustion engine capable of minimizing inter-cylinder variation with respect to a change in a variable valve operation characteristic. The purpose is to do.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides (1) at least a pair of cylinders arranged along an axis of a crankshaft, a piston reciprocating in each of the pair of cylinders, and a reciprocating motion of each piston. A connecting rod that converts the rotational motion of the crankshaft, an intake valve that is provided in each of the pair of cylinders, and that opens and closes a passage of air that is taken into the cylinder by being displaced by itself, and also each of the pair of cylinders. An exhaust valve that is provided and opens and closes a passage of exhaust gas discharged from the cylinder by being displaced by itself.In a multi-cylinder internal combustion engine in which axes of the pair of cylinders form a predetermined bank angle, For a cylinder, at least one of the intake valve and the exhaust valve has a predetermined timing with respect to rotation of the crankshaft. A power transmission mechanism for transmitting a driving force for displacing the valve to each valve; and a displacement amount for changing a displacement amount of the valve with respect to a rotation amount of the crankshaft for a valve to which a driving force is transmitted by the power transmission mechanism. And a mechanism for changing the displacement of each of the valves of the pair of cylinders by the displacement-variable mechanism.
[0009]
(2) According to another aspect of the present invention, at least a pair of cylinders arranged along an axis of a crankshaft, a piston reciprocating in each of the pair of cylinders, and a reciprocating motion of each piston are used to rotate the crankshaft. A connecting rod that converts the movement into a motion, an intake valve that is provided in each of the pair of cylinders and opens and closes a passage of air that is taken into the cylinder by displacing itself, and a displacement rod that is similarly provided in each of the pair of cylinders and displaces itself. An exhaust valve that opens and closes a passage of exhaust gas discharged from the cylinder by operating the crankshaft in a multi-cylinder internal combustion engine in which the axes of the pair of cylinders form a predetermined bank angle. A power transmission mechanism for driving at least one of an intake valve and an exhaust valve for the pair of cylinders; A main rotation shaft interlocked with the rotation of the crankshaft, a cam provided on the outer periphery of the main rotation shaft, a sub rotation shaft different from the main rotation shaft, and the main rotation shaft provided on the outer periphery of the sub rotation shaft. A first input portion which can swing in conjunction with a shaft cam; a first output portion which is also provided on the outer periphery of the sub-rotating shaft and which can swing in conjunction with the first input portion; A first swing phase difference variable mechanism that varies a phase difference between the first input unit and the first output unit around the first unit, and a first push rod that reciprocates in conjunction with the first output unit. A first rocker arm for reciprocating a valve provided in one of the cylinders in conjunction with the first push rod; and a rocker provided on the outer periphery of the sub-rotating shaft and interlocking with a cam of the main rotating shaft. A second input unit, and the second input A second output section that can swing in conjunction with the section, and a second swing phase difference variable mechanism that varies a phase difference between the second input section and the second output section about the auxiliary rotation axis. A second push rod that reciprocates in conjunction with the second output portion, and a second rocker arm that reciprocates a valve provided in one of the cylinders in conjunction with the second push rod. The point is to have a transmission mechanism.
[0010]
(3) According to another aspect of the present invention, at least one pair of cylinders arranged along an axis of a crankshaft, a piston reciprocating in each of the pair of cylinders, and a reciprocating motion of each piston is used to rotate the crankshaft. A connecting rod for converting into motion, an intake valve provided in each of the pair of cylinders, for opening and closing a passage of air taken into the cylinder by displacement of the connecting rod, and a connecting rod similarly provided in each of the pair of cylinders; An exhaust valve that opens and closes a passage of exhaust gas discharged from the cylinder by being displaced.In a multi-cylinder internal combustion engine in which the axes of the pair of cylinders form a predetermined bank angle, the rotation of the crankshaft is controlled. In conjunction with each other, at least one of the intake valve and the exhaust valve of the pair of cylinders rotates the crankshaft. A power transmission mechanism for transmitting a driving force for displacing at a predetermined timing to each valve, a displacement amount variable mechanism for changing a displacement amount of the driven valve with respect to a rotation amount of the crankshaft, And the power transmission mechanism corresponding to each of the pair of cylinders and the displacement amount variable mechanism corresponding to each of the pair of cylinders are driven based on the operation of a single camshaft. And
[0011]
(4) According to another aspect of the present invention, at least a pair of cylinders arranged along an axis of a crankshaft, a piston reciprocating in each of the pair of cylinders, and a reciprocating motion of each piston is used to rotate the crankshaft. A connecting rod that converts the movement into a motion, an intake valve that is provided in each of the pair of cylinders and that opens and closes a passage of air that is taken into the cylinder by displacing itself, An exhaust valve that opens and closes a passage of exhaust gas discharged from the cylinder by operating the crankshaft in a multi-cylinder internal combustion engine in which the axes of the pair of cylinders form a predetermined bank angle. A power transmission mechanism for driving at least one of an intake valve and an exhaust valve for the pair of cylinders; A main rotation shaft interlocked with the rotation of the crankshaft, a cam provided on the outer periphery of the main rotation shaft, a first sub rotation shaft different from the main rotation shaft, and a first sub rotation shaft provided on the outer periphery of the first sub rotation shaft. A first input portion that is swingable in conjunction with a cam of the main rotation shaft, and a first output portion that is also provided on an outer periphery of the first sub rotation shaft and that can swing in conjunction with the first input portion. A first swing phase difference variable mechanism that varies a phase difference between the first input unit and the first output unit about the first sub-rotation axis; A first push rod that reciprocates, a first rocker arm that reciprocates a valve provided in one of the cylinders in conjunction with the first push rod, and any of the main rotation shaft and the first sub rotation shaft. A different second sub-rotation shaft and the main rotation provided on the outer periphery of the second sub-rotation shaft. A second input portion that is swingable in conjunction with the cam of the second input shaft, a second output portion that is also provided on the outer periphery of the second sub-rotating shaft and that can swing in conjunction with the second input portion, A second swing phase difference variable mechanism that varies a phase difference between the second input section and the second output section about a sub-rotation axis, and a second reciprocating mechanism that reciprocates in conjunction with the second output section. It is a gist of the present invention to have a power transmission mechanism including a push rod and a second rocker arm that reciprocates a valve provided in one cylinder in conjunction with the second push rod.
[0012]
According to each of the above configurations, in a multi-cylinder internal combustion engine in which at least one pair of cylinders arranged along the axis of the crankshaft forms a predetermined bank angle, regarding the operating characteristics of the intake / exhaust valves that are variably controlled, variations between cylinders and In addition, it is possible to minimize the variation between the left and right banks.
[0013]
Further, since the entire power transmission mechanism can be generally accommodated between the left and right banks, the size of the engine body can be reduced, and the mountability thereof can be improved.
[0014]
In the configuration of (2) or (4), it is preferable that the main rotation axis is disposed on a line segment that substantially bisects the bank angle.
[0015]
In the configuration (2) or (4), preferably, the main rotation shaft includes a rotation phase difference variable mechanism that changes a phase difference of the main rotation shaft with respect to a rotation phase of the crankshaft.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described.
[0017]
[Basic structure of the engine]
FIG. 1 is a perspective view schematically showing an internal structure of a V-type multi-cylinder internal combustion engine according to one embodiment of the present invention. As shown in FIG. 1, an engine 1 is a V-type multi-cylinder internal combustion engine that is disposed along an axis of a crankshaft 2 and includes a pair of cylinder rows 3 and 4 that form a predetermined bank angle. The cylinder row (hereinafter, referred to as a left bank) 3 includes four cylinders 3A, 3B, 3C, 3D arranged in series. The cylinder row (hereinafter referred to as right bank) 4 includes four cylinders 4A, 4B, 4C, and 4D which are also arranged in series. A piston (not shown) accommodated in each of the cylinders 3A, 3B, 3C, 3D, 4A, 4B, 4C, 4D is connected to one crankshaft 2 by a connecting rod (not shown).
[0018]
The linear motion of a piston (not shown) reciprocating in each of the cylinders 3A, 3B, 3C, 3D, 4A, 4B, 4C, 4D is converted into a rotational motion of the crankshaft 2 via a connecting rod (not shown). . Each cylinder is displaced by itself, and the intake valve 20 (left bank side) or 30 (right bank side) which opens and closes the passage of the air taken into the cylinder. An exhaust valve 40 (left bank side) or 50 (right bank side) for opening and closing the passage of the exhaust gas is provided for each cylinder.
[0019]
The crankshaft 2 is drivingly connected to an intake camshaft (main rotating shaft) 7 at a rotation ratio of 2: 1 through a gear, a belt, a chain, or the like. Further, the intake camshaft 7 is drivingly connected to the exhaust camshaft 8 at a 1: 1 rotation ratio through a gear, a belt, a chain or the like. Based on such a configuration, the torque of the crankshaft 2 is transmitted to the intake camshaft 7 and further transmitted to the exhaust camshaft 8 through the intake camshaft 7. As a result, each of the intake camshaft 7 and the exhaust camshaft 8 makes one rotation while the crankshaft 2 makes two rotations. The intake camshaft 7 and the exhaust camshaft 8 are arranged immediately above the crankshaft 2, in other words, on a line segment that approximately bisects the bank angle of the engine 1.
[0020]
A rotary cam (intake cam: not shown) for reciprocating the intake valves 20 and 40 of the left bank 3 and the right bank 4 is provided on the outer periphery of the intake camshaft 7. A rotary cam (exhaust cam: not shown) for reciprocating the exhaust valves 40 and 50 of the left bank 3 and the right bank 4 is provided on the outer periphery of the exhaust camshaft 8. The intake camshaft 7 has a lift variable mechanism (variable displacement mechanism: not shown) for varying the operation characteristics (maximum lift and operating angle) of each of the intake valves 20, 30 of the left bank 3 and the right bank 4. ) Is attached. The variable lift amount mechanism can control the maximum lift amount and the operating angle of the driven valve by changing the displacement amount of the driven valve with respect to the rotation amount of the crankshaft. Here, the maximum lift means a displacement of the intake valve (or exhaust valve) in a fully closed state until the valve reaches a fully open state. Further, the operating angle means the amount of change in the rotational phase of the crankshaft from the time when the intake valve (or the exhaust valve) in the fully closed state reaches the fully opened state and returns to the fully closed state. A variable valve timing mechanism 9 that changes the rotation phase of the intake camshaft 7 relative to the rotation phase of the crankshaft 2 is provided at the tip of the intake camshaft 7.
[0021]
[Overview of power transmission mechanism]
2 and 3 show a pair of cylinders (a cylinder 3A of the left bank 3 and a right bank 4) of a mechanism (power transmission mechanism) for transmitting a driving force to an intake valve and an exhaust valve provided in each cylinder of the engine 1. FIG. 2 is a perspective view (FIG. 2) and a plan view (FIG. 3) schematically showing a portion corresponding to the cylinder 4A) of FIG.
[0022]
As shown in FIGS. 2 and 3, the intake camshaft 7 has, on its outer periphery, an intake cam 21 (shown only in FIG. 2) for driving an intake valve 20 provided in a cylinder 3 </ b> A of the left bank 3. An intake cam 31 (shown only in FIG. 2) for driving an intake valve 30 provided in the cylinder 4A of the bank 4 is provided. The intake valve 20 provided in the cylinder 3A of the left bank 3 is connected to a push rod 24 via a rocker arm 23 provided on an arm support shaft 22. Similarly, an intake valve 30 provided in a cylinder 4A of the right bank 4 is connected to a push rod 34 via a rocker arm 33 provided on an arm support shaft 32.
[0023]
Further, a swing support shaft 10 is provided at a position close to the intake camshaft 7. The swing support shaft 10 includes a swing mechanism 25 corresponding to the left bank 3 and a swing mechanism 35 corresponding to the right bank 4 on its outer periphery. The swing mechanism 25 pushes the push rod 24 in accordance with the movement of the intake cam 21 (shown only in FIG. 2). Thus, the driving force is transmitted in the order of the push rod 24, the rocker arm 23, and the intake valve 20. Similarly, the swing mechanism 35 pushes the push rod 34 in accordance with the movement of the intake cam 31 (shown only in FIG. 2). Thus, the driving force is transmitted in the order of the push rod 34, the rocker arm 33, and the intake valve 30.
[0024]
Further, an exhaust camshaft 8 is provided at a position close to the swing support shaft 10. The exhaust camshaft 8 is substantially parallel to the swing support shaft 10 and the intake camshaft 7, and is itself rotatable. The exhaust camshaft 8 has, on its outer periphery, an exhaust cam 41 for driving an exhaust valve 40 provided in the cylinder 3A of the left bank 3 and an exhaust cam for driving an exhaust valve 50 provided in the cylinder 4A of the right bank 4. 51 (shown only in FIG. 2). The exhaust valve 40 provided in the cylinder 3A of the left bank 3 is connected to a push rod 44 via a rocker arm 43 provided on an arm support shaft 42. Similarly, an exhaust valve 50 provided on a cylinder 4A of the right bank 4 is connected to a push rod 54 via a rocker arm 53 provided on an arm support shaft 52. The exhaust cam 41 pushes the push rod 44 in accordance with the rotation of the exhaust camshaft 8. Thus, the driving force is transmitted in the order of the push rod 44, the rocker arm 43, and the exhaust valve 40. Similarly, the exhaust cam 51 pushes the push rod 54 in accordance with the rotation of the exhaust camshaft 8. Thus, the driving force is transmitted in the order of the push rod 54, the rocker arm 53, and the exhaust valve 50.
[0025]
(Operation principle of power transmission mechanism)
FIG. 4 shows a portion (FIG. 4A) of the power transmission mechanism that transmits a driving force to an exhaust valve 50 provided in the cylinder 4A of the right bank 4 and a portion provided in the cylinder 4A of the right bank 4. FIG. 4B shows a portion (FIG. 4B) for transmitting a driving force to the intake valve 30 that has been driven.
[0026]
4A, the exhaust camshaft 8 drivingly connected to the intake camshaft 7 rotates in conjunction with the operation of the intake camshaft 7 at a rotation ratio of 1: 1. When the exhaust camshaft 8 rotates, the driving force is transmitted in the order of the exhaust cam 51, the push rod 54, the rocker arm 53, and the exhaust valve 50, and as a result, the valve 50 is changed from the closed state to the open state with respect to the exhaust valve 50. The shifting force acts (force acts in the direction of arrow A1). On the other hand, the coil spring 50a urges the exhaust valve 50 in the direction of the arrow B1, and constantly applies a force for shifting the valve 50 from the open state to the closed state. As a result, the exhaust valve 50 repeats a reciprocating operation (valve opening / closing operation) in conjunction with the rotation operation of the exhaust cam 51.
[0027]
In FIG. 4B, when the intake camshaft 7 rotates, the driving force is transmitted in the order of the intake cam 21, the swing mechanism 35, the push rod 54, the rocker arm 33, and the intake valve 30. A force acts on the valve 30 to move the valve 30 from the closed state to the open state (a force acts in the direction of arrow A2). On the other hand, the coil spring 30a urges the intake valve 30a in the direction of the arrow B2, and constantly applies a force for shifting the valve 30 from the open state to the closed state. As a result, the intake valve 30 repeats a reciprocating operation (valve opening / closing operation) in accordance with the rotation operation of the exhaust cam 31. Here, the swing mechanism 35 includes a swing cam (first output unit) 36 and a roller arm (first input unit) 37 on the outer periphery of the swing support shaft 10. The swing cam 36 has a substantially triangular nose 36a on the outer periphery thereof. Further, the roller arm 37 includes a rotatable roller 37a on its outer periphery. When the intake cam 21 rotates in one direction, the cam 21 periodically pushes the roller 37a, and the entire swing mechanism 35 swings about the swing support shaft 10. As a result, the nose 36a periodically pushes the tip of the push rod 34, and the intake valve 30 repeats reciprocating motion. Here, a line segment extending from the tip of the swing cam 36 to the center of the swing support shaft 10 and a line segment extending from the tip of the roller arm 37 (the roller 37a) to the center of the swing support shaft 10 are provided. The angle (hereinafter, referred to as a phase difference angle) θ is variably controlled.
[0028]
[Structure of swing mechanism]
The engine 1 is provided with a total of eight swing mechanisms for eight cylinders such that one swing mechanism corresponds to one cylinder. These eight swing mechanisms are provided on one swing support shaft 10.
[0029]
FIG. 5 shows a swing mechanism 35 corresponding to the cylinder 4A of the right bank 4 and a swing mechanism corresponding to the cylinder 3A of the left bank 3 among the eight swing mechanisms provided on the swing support shaft 10. FIG. 13 is a perspective view also showing another swing mechanism 25 provided adjacent to 35.
[0030]
The swing mechanism 35 includes a swing cam (first output section) 36 having a nose 36a and a roller arm (first input section) 37 having a roller 37a on the outer periphery of the swing support shaft 10. This is as described above (see FIG. 4). Similarly, the swing mechanism 25 also includes a swing cam (second output unit) 26 having a nose 36a and a roller arm (second output unit) having a roller 27a on the outer periphery of the swing support shaft 10 common to the swing mechanism 35. 2 input unit) 27. Two oscillating mechanisms 35 and 25 arranged substantially symmetrically along one oscillating support shaft 10 are two oscillating mechanisms similarly arranged along one intake camshaft 7 (see FIG. 2). The push rods 34 and 24 are periodically pushed in conjunction with the rotation of the intake cams 31 and 21 (see FIG. 2).
[0031]
FIG. 6 is an exploded perspective view showing various components of the swing mechanism 35 in an exploded state.
[0032]
The swing mechanism 35 includes a swing support shaft 10 (FIGS. 6A, 6B, and 6C), a roller arm 37 (FIG. 6D), and a slider gear 38 (FIG. 6E). )), And the swing cam 36 (FIG. 6F) as a main element.
[0033]
The swing support shaft 10 is obtained by inserting a control shaft 10B (see FIG. 6) into a support pipe 10A (see FIG. 6A). The support pipe 10A has an internal space penetratingly formed along the axial direction of the pipe 10A for inserting the control shaft 10B. The support pipe 10A has a long hole 10a penetrating between the outer peripheral surface of the pipe 10A and the internal space. The length of the long hole 10a along the axial direction of the support pipe 10A is longer than the width of the support pipe 10A along the circumferential direction. On the outer peripheral surface of the control shaft 10B, a columnar locking pin 10b is protruded. When the control shaft 10B is inserted into the support pipe 10A, the locking pin 10b is in a state of being accommodated in the long hole 10a. As a result, the control shaft 10B can linearly move only within a predetermined range along its own axial direction relative to the support pipe 10A. Further, the control shaft 10B cannot rotate relative to the support pipe 10A.
[0034]
The roller arm 37 has a cylindrical internal space. A left-hand spiral helical spline is formed on the inner peripheral surface 37b of the roller arm 37 along the axial direction of the roller arm 37. The swing cam 36 also has a cylindrical internal space. A right-hand spiral helical spline is formed on the inner peripheral surface 36 b of the swing cam 36 along the axial direction of the swing cam 36.
[0035]
The slider gear 38 has a substantially cylindrical small diameter portion 38a, a substantially cylindrical shape, and a roller arm side large diameter portion 38b having an outer diameter larger than the small diameter portion 38a. A swing cam side large diameter portion 38c having an outer diameter larger than the small diameter portion 38a. The roller arm-side large-diameter portion 38b has a helical spline formed on an outer peripheral surface thereof that can be engaged with a helical spline formed on the inner peripheral surface 37b of the roller arm 37. The oscillating cam-side large-diameter portion 38c has a helical spline formed on the outer peripheral surface thereof that can be engaged with a helical spline formed on the inner peripheral surface 36b of the oscillating cam 36. The small diameter portion 38a is sandwiched between the roller arm side large diameter portion 38b and the swing cam side large diameter portion 38c. The slider gear 38 has a hole 38d penetrating along the axial direction thereof, and has a substantially cylindrical shape as a whole. The small diameter portion 38a has a long hole 38e penetrating between the outer peripheral surface of the small diameter portion 38a and the hole 38d. The length of the long hole 38e along the circumferential direction of the small diameter portion 38a is longer than the width of the small diameter portion 38a along the axial direction. When the swing mechanism 35 is assembled, the locking pin 10b on the outer peripheral surface of the control shaft 10B is in a state of being accommodated in the elongated hole 38e of the slider gear 38. As a result, the slider gear 38 can rotate only within a predetermined range with respect to the support pipe 10A along its circumferential direction.
[0036]
(Operating principle of swing mechanism)
FIG. 7 shows a swing mechanism 35 (FIG. 7A) and a mechanism obtained by removing a part of the roller arm 37 and the swing cam 36 from the mechanism 35 (FIG. 7B). The support pipe 10A is fixed to the engine 1 so as not to operate in either the circumferential direction or the axial direction. The roller arm 37 and the swing cam 36 are supported by a predetermined member (not shown) so as not to move in the axial direction. The control shaft 10B can be relatively moved along the axial direction with respect to the support pipe 10A based on the driving force of a hydraulically driven or electric actuator (not shown).
[0037]
Hereinafter, the relative movement of the other elements constituting the swing mechanism 35 with respect to the support pipe 10A will be considered.
(1) When the control shaft 10B moves in the direction of the arrow C1 based on the function of the actuator, the slider gear 38 also moves in the direction of the arrow C1 according to the movement of the control shaft 10B (the locking pin 10b).
(2) As described above, the helical spline formed on the outer peripheral surface of the roller arm side large diameter portion 38b of the slider gear 38 is engaged with the helical spline formed on the inner peripheral surface 37b of the roller arm 37. . The helical spline formed on the outer peripheral surface of the swing cam side large-diameter portion 38 c of the slider gear 38 is engaged with the helical spline formed on the inner peripheral surface 36 b of the swing cam 36. Further, the roller arm 37 and the swing cam 36 are supported by a predetermined member so as not to move in the axial direction.
(3) As a result, the slider gear 38 moves in the swinging mechanism 35 in the direction of the arrow C1 while moving the roller arm 37, which is the engagement partner thereof, in the direction of the arrow D1 and the swinging cam which is the other engagement partner. 36 is rotated (followed) in the direction of arrow E1.
(4) Conversely, when the control shaft 10B moves in the direction of arrow C2, the roller arm 37 rotates (follows) in the direction of arrow D2, and the swing cam 36 rotates (follows) in the direction of arrow E1.
(5) Since the slider gear 38 can rotate in the circumferential direction only within a predetermined range by the function of the locking pin 10b that fits in the long hole 38e of the small diameter portion 38a of the slider gear 38, the slider gear 38 follows the slider gear 38. The rotating roller arm 37 and the swing cam 36 can also rotate (swing) in the circumferential direction only within a predetermined range.
Based on such an operation principle, the swing mechanism 35 can make its phase difference angle θ (see FIG. 4B) variable.
[0038]
[Variable lift control based on the function of the swing mechanism]
Next, how the reciprocating operation (valve opening / closing operation) of the intake valve 30 is affected by a change in the phase difference angle θ of the swing mechanism 35 will be described.
[0039]
FIG. 8 shows a state in which the intake valve 30 is closed (FIG. 8A) and an open state (FIG. 8A) when the phase difference angle θ of the swing mechanism 35 is set to a relatively small value θ1. FIG. On the other hand, FIG. 9 shows a state in which the intake valve 30 is closed (FIG. 9A) and an open state when the phase difference angle θ of the swing mechanism 35 is set to a relatively large value θ2 (> θ1). It is a schematic diagram also showing (FIG.9 (b)).
[0040]
As shown in FIGS. 8 and 9, regardless of the magnitude of the phase difference angle θ, the swing mechanism 35 always has a function of reciprocating (opening and closing) the intake valve 30 in accordance with the movement of the intake cam 21.
[0041]
However, considering the contact position P between the nose 36a (the swing cam 36) and the push rod 34, when the phase difference angle θ changes, the contact position P corresponding to the rotation phase of the intake cam 21 changes. Therefore, depending on the shape of the nose 36a, etc., by changing the phase difference angle θ, the operating range of the intake valve 30 corresponding to the movement of the intake cam 21, for example, the intake air when shifting from the open state to the closed state. The displacement amount (lift amount) of the valve 30 can be changed. 8 and 9, the maximum lift of the intake valve 30 changes from L1 to L2 (L2> L1) because the phase difference angle changes from θ1 to θ2 (θ2> θ1).
[0042]
Thus, the power transmission mechanism of the engine 1 can control the operating range (for example, the maximum lift amount) of the intake valve by making the phase difference angle θ of the swing mechanism 35 variable. That is, it has a function as a lift amount variable mechanism.
[0043]
[Valve timing variable mechanism]
FIG. 10A is a perspective view showing the appearance of a variable valve timing mechanism 9 provided at the tip of the intake camshaft 7, and FIG. 10B is an internal structure of the mechanism 9 (FIG. 10A). (XB-XB cross section) of FIG. The variable valve timing mechanism 9 includes an internal rotor 9a fixed to the tip of the intake camshaft and a rotating body (here, a belt or the like that is driven and connected to the crankshaft 2 by a belt or the like) that transmits the rotational force of the crankshaft 2 to the intake camshaft 7. 9b) are assembled with each other.
[0044]
The inner rotor 9a is provided on the outer peripheral surface thereof at equal intervals along the circumferential direction and includes four convex portions 9aa projecting in the radial direction. Further, the timing pulley 9b has a cylindrical internal space, is provided on the inner peripheral surface thereof at equal intervals along the circumferential direction, and projects in the radial direction (the rotation center of the intake camshaft 7). It has a plurality of protrusions 9bb. Each convex portion 9aa forms an advance hydraulic chamber S1 and a retard hydraulic chamber S2 together with the adjacent convex portion 9bb. Driving oil is supplied to each of the hydraulic chambers S1 and S2 through a predetermined oil passage (not shown). By changing the relative oil pressure of the drive oil supplied to each of the advance hydraulic chamber S1 and the retard hydraulic chamber S2, the relative rotational phase of the timing pulley 9b and the intake camshaft 7 is kept within a predetermined range. Can be changed.
[0045]
For example, under the condition that the intake camshaft 7 and the timing pulley 9b are integrally rotating in the direction of the arrow R, the oil pressure in the advance hydraulic chamber S1 becomes higher than the oil pressure in the retard hydraulic chamber S2. For example, the rotation phase of the intake camshaft 7 advances (moves in the direction of the arrow α) as compared with the rotation phase of the timing pulley 9b. Conversely, if the hydraulic pressure in the retard hydraulic chamber S2 is higher than the hydraulic pressure in the advance hydraulic chamber S1, the rotational phase of the intake camshaft 7 is retarded relative to the rotational phase of the timing pulley 9b. (Moves in the direction of arrow β).
[0046]
By changing the relative rotation phase of the two rotating bodies 7 and 9 in this manner, the opening / closing timing (valve timing) of the opening / closing operation of the intake valve 30 accompanying the rotation of the crankshaft 2 is controlled within a predetermined range. be able to.
[0047]
[Variable lift control / variable valve timing control]
The control using the above-described variable lift amount mechanism (variable lift amount control) and the control using the variable valve timing mechanism (variable valve timing control) will be described focusing on the operational effects.
[0048]
FIG. 11A shows a change in operating characteristics of the intake valve 30 when the maximum lift amount (or operating angle) of the intake valve 30 is changed by using a variable lift amount mechanism. FIG. As shown in FIG. 11A, according to the lift amount variable control, the maximum lift amount of the intake valve 30 is changed (L1 → L2 → L3), and the size of the lift amount profile on the chart changes (FIG. 11A). PRF3 → PRF2 → PRF3). At this time, the valve timing (phase of the lift amount profile) does not change, and, for example, the crank angle CA at which the intake valve 30 reaches the maximum lift amount is constant (CA = CA1).
[0049]
FIG. 11B is a chart showing changes in operating characteristics of the intake valve 30 when the valve timing of the intake valve 30 is changed using a variable valve timing mechanism, with the crank angle as a horizontal axis. is there. As shown in FIG. 11B, according to the variable valve timing control, for example, the crank angle CA corresponding to the valve opening start timing of the intake valve 30 is retarded or advanced (CA11, CA12, CA12), and the chart is performed. Only the phase of the profile of the lift amount above shifts to the advance side or the retard side (PRF11, PRF12, PRF13).
[0050]
FIG. 11C is a chart showing changes in operating characteristics of the valve 30 when both the variable lift amount mechanism and the variable valve timing mechanism are operated, with the crank angle as the horizontal axis.
[0051]
If the lift amount variable control and the valve timing variable control are performed together, both the magnitude and phase of the lift amount profile on the chart can be freely controlled within a predetermined range. For example, as shown in FIG. 11C, the maximum lift amount and the operating angle can be changed while the crank angle CA corresponding to the opening start timing of the intake valve 30 is fixed (CA = CA21) ( L21 → L22 → L23, PRF21 → PRF22 → PRF23).
[0052]
By controlling the maximum lift amount, operating angle, or opening / closing timing of the intake valve, it is possible to precisely control the flow rate, the pressure, the mode of the airflow, or the inflow timing of the gas flowing into the combustion chamber of each cylinder of the engine 1. It becomes possible. As a result, control of engine output and control for optimizing fuel efficiency can be performed.
[0053]
[Operation characteristics of intake and exhaust valves in each cylinder of the left and right banks]
The engine 1 is provided with four swing mechanisms corresponding to the left bank 3 and four swing mechanisms corresponding to the right bank 4 along the swing support shaft 10. These eight swing mechanisms mechanically interlock with the movement of one control shaft 10B constituting the swing support shaft 10 to change the phase difference angle θ, and thus the operating characteristics of the intake valves 20, 30. (Maximum lift and operating angle) are variable.
[0054]
In the engine 1, one intake camshaft 7 is mechanically connected to the intake valves (20, 30) of all cylinders, and transmits driving force to each intake valve 20, 30. In other words, the change in the rotational phase difference between the intake camshaft 7 and the crankshaft 2 controlled by one variable valve timing mechanism 9 affects the intake valves 20 and 30 provided in all the cylinders of the left and right banks 3 and 4. And transmitted mechanically.
[0055]
In a so-called V-type multi-cylinder internal combustion engine, if a variable lift amount mechanism and a variable valve timing mechanism (variable valve mechanism) are installed for each cylinder row, the maximum lift amount and operating angle of the intake and exhaust valves, or the change amount thereof, Variation tends to occur between the two cylinder rows. Further, since a single engine is provided with a plurality of variable valve mechanisms having the same function, the number of parts increases, the size of the engine increases, or the manufacturing cost increases.
[0056]
In this regard, according to the engine 1 of the present embodiment, the operating characteristics of all the intake valves provided in the cylinder rows of the left and right banks are such that the lift amount variable mechanism mechanically interlocks with one intake camshaft 7. Is controlled by Further, the swing mechanism corresponding to each cylinder mechanically works with the movement of one control shaft 10B, and controls the maximum lift amount and operating angle of the intake valve provided in each cylinder.
[0057]
As a result, in performing the variable control of the maximum lift amount and the working angle of the intake valve, it is possible to minimize the variation in the maximum lift amount and the change amount of the working angle between the cylinder rows.
[0058]
In addition, the intake camshaft 7 and the exhaust camshaft 8 are arranged directly above the crankshaft 2, in other words, on a line segment that approximately bisects the bank angle of the engine 1, so that the variable lift amount mechanism and the variable valve timing The entire mechanism (power transmission mechanism) for transmitting the rotational force of the crankshaft 2 to the intake valve and the exhaust valve of each cylinder is accommodated between the left bank 3 and the right bank 4 including the mechanism. Thereby, the mountability of the entire engine 1 is improved.
[0059]
(Other embodiments)
Next, another embodiment that embodies the present invention will be described focusing on differences from the above embodiment.
[0060]
In the above embodiment, a multi-cylinder internal combustion engine having one intake valve for each cylinder is employed. On the other hand, a configuration including a plurality of intake valves in each cylinder may be adopted.
[0061]
FIGS. 12A and 12B show a main part of a V-type multi-cylinder engine according to another embodiment. As shown in FIGS. 12 (a) and 12 (b), a V-type multi-cylinder internal combustion engine (hereinafter, referred to as an engine) 1 'has a single intake camshaft (mainly an engine) interlocked with the rotation of a crankshaft (not shown). With respect to the rotation shaft 207, an intake cam (hereinafter, referred to as a left bank cam) 221 corresponding to the cylinder of the left bank 200 and an intake cam (hereinafter, referred to as a right bank cam) 321 corresponding to the right bank 300 are provided. . Further, the engine 1 ′ includes two swing support shafts (sub-rotation shafts) 235 and 335 adjacent to the intake camshaft 207. Each of the swing support shafts 235 and 335 includes swing mechanisms 236 and 336 having basically the same structure and function as those of the above embodiment. Here, each swing mechanism 235 (335) is configured by integrally assembling one roller arm 237 (337) and two swing cams 236A, 236B (336A, 336B). The relative operation of each swing cam with respect to the roller arm 237 (337) is the same as that of the swing mechanisms 35 and 25 according to the above-described embodiment (see FIGS. 5 to 9).
[0062]
For example, referring to FIG. 12B, for any cylinder in the right bank 300, the driving force input from the intake cam 321 to the roller arm 337 with the rotation of the intake camshaft 207 is equal to the two swing cams 336 </ b> A. , 336B and transmitted to two push rods 334A, 334B, two rocker arms 333A, 333B rotatably supported by one arm support shaft 352, and two intake valves 330A, 330B. You. Similarly, for any cylinder in the left bank 200, the driving force input from the intake cam 221 to the roller arm 237 with the rotation of the intake camshaft 207 is output from the two swing cams 236A and 236B. Transmitted to two push rods (not shown), two rocker arms (not shown) rotatably supported by arm support shafts (not shown), and two intake valves (not shown). become.
[0063]
On the other hand, the engine 1 ′ operates a single exhaust valve (main rotating shaft) 208 that is linked to the rotation of a crankshaft (not shown) with an exhaust cam (hereinafter, referred to as a left bank cam) corresponding to a cylinder of the left bank 200. ) 241 and an intake cam (hereinafter, referred to as a right bank cam) 251 corresponding to the right bank 300.
[0064]
For example, referring to FIG. 12A, with respect to an arbitrary cylinder of the right bank 300, the driving force of the exhaust cam 241 accompanying the rotational movement of the exhaust camshaft 208 is rotatably supported by the push rod 354 and the arm support shaft 352. The rocker arm 353 is transmitted to the two exhaust valves 350. Similarly, with respect to any cylinder of the left bank 200, the driving force of the exhaust cam 241 accompanying the rotational movement of the exhaust camshaft 208 is controlled by the push rod 224 and the rocker arm 223 rotatably supported by the arm support shaft 222. , To the intake valve 240.
[0065]
In addition, it is preferable to provide a variable valve timing mechanism having a structure and a function equivalent to those of the above-described embodiment at the distal end of the intake camshaft 207.
[0066]
By adopting such a configuration, a plurality of intake valves and exhaust valves to be controlled by the variable lift amount mechanism and the variable valve timing mechanism can be provided for each cylinder. Thus, the intake efficiency and exhaust efficiency of each cylinder can be increased, and the engine output can be increased.
[0067]
However, in the other embodiment, two swing support shafts 210 and 310 (control shafts) are used in order to function the swing mechanisms corresponding to the left and right banks. The configuration of the engine 1 according to the above embodiment is more advantageous in reducing the variation in the operating characteristics of the intake valve between the two and reducing the number of parts.
[0068]
In each of the above embodiments, the left and right banks of the V-type multi-cylinder internal combustion engine adopt a configuration in which a swing mechanism is incorporated in a power transmission mechanism that drives an intake valve to function as a variable valve lift mechanism. On the other hand, a swinging mechanism may be incorporated in the power transmission mechanism that drives the exhaust valve to function as a variable valve amount mechanism.
[0069]
In each of the above embodiments, the exhaust camshaft 8 (208) is drivingly connected to the crankshaft 2 (202) via the intermediary of the intake camshaft 7 (207). On the contrary, a configuration in which the intake camshaft 7 (207) is drivingly connected to the crankshaft 2 (202) via the exhaust camshaft 8 (208) may be applied. Further, a configuration in which each of the intake camshaft 7 (207) and the exhaust camshaft 8 (208) is independently driven and connected to the crankshaft 2 may be applied.
[0070]
Further, the same effects as those of the above embodiments can be obtained even if the power transmission mechanism does not include the variable valve timing mechanism or employs only the variable lift amount mechanism.
[0071]
Further, in each of the above embodiments, the present invention is applied to the V-type multi-cylinder internal combustion engine having four cylinders in each of the left and right banks. However, the present invention is not limited to this, and a predetermined bank angle may be set along the axis of the crankshaft. With a V-type multi-cylinder internal combustion engine having at least one pair of cylinders arranged as described above, it is possible to obtain substantially the same effects as those of the above-described embodiments by applying the present invention. For example, a V-type multi-cylinder internal combustion engine having a total of two cylinders, one for each of the left and right banks, is also applicable to the present invention. Also, a so-called horizontally opposed multi-cylinder internal combustion engine in which the bank angle between the left and right banks is approximately 180 ° is also an object to which the present invention is applied.
[0072]
In each of the above embodiments, a configuration is adopted in which the rotational force of the crankshaft is transmitted so that the intake camshaft and the exhaust camshaft obtain the driving force. However, the present invention is not limited to this, and even if a configuration in which the intake camshaft or the exhaust camshaft obtains a driving force by another drive source (for example, an electric motor) is applied, the same effects as those in the above embodiments or effects similar thereto can be obtained. Can do it.
[0073]
【The invention's effect】
As described above, according to the present invention, in a multi-cylinder internal combustion engine in which at least a pair of cylinders arranged along the axis of a crankshaft forms a predetermined bank angle, the operation characteristics of intake and exhaust valves that are variably controlled. In addition, variations between cylinders and variations between left and right banks can be minimized.
[0074]
Further, in a multi-cylinder internal combustion engine provided with a mechanism for varying the operation characteristics of the intake valve or the exhaust valve provided in each cylinder of the left and right banks, the mountability thereof can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a multi-cylinder internal combustion engine according to an embodiment of the present invention.
FIG. 2 is a perspective view schematically showing a portion corresponding to a pair of cylinders in the power transmission mechanism.
FIG. 3 is a plan view schematically showing a portion of the power transmission mechanism corresponding to a pair of cylinders.
FIG. 4 is a schematic diagram showing a portion of the power transmission mechanism that transmits driving force to an exhaust valve provided in a right bank cylinder and a portion that transmits driving force to an intake valve provided in a right bank cylinder. .
FIG. 5 is a perspective view showing a swing mechanism provided on one swing support shaft and corresponding to a cylinder in a right bank, and another swing mechanism corresponding to a cylinder in a left bank.
FIG. 6 is an exploded perspective view showing various components of the swing mechanism in an exploded state.
FIG. 7 is a perspective view showing a swing mechanism together with a part of a swing arm and a roller arm and a swing cam removed from the swing mechanism;
FIG. 8 is a schematic diagram showing both a closed state and an opened state of the intake valve when the phase difference angle of the swing mechanism is set to a relatively small value.
FIG. 9 is a schematic diagram showing both a closed state and an opened state of the intake valve when the phase difference angle of the swing mechanism is set to a relatively large value.
FIG. 10 is a perspective view showing the external appearance of a variable valve timing mechanism provided at the tip of the intake camshaft, and a cross-sectional view showing the internal structure thereof.
FIG. 11 is a chart showing a change in the operating characteristics of the intake valve when the maximum lift of the intake valve is changed by using the variable lift amount mechanism.
FIG. 12 is a schematic view showing a part of a multi-cylinder internal combustion engine according to another embodiment of the present invention.
[Explanation of symbols]
1 engine (multi-cylinder internal combustion engine)
2 Crankshaft
3 cylinder row (left bank)
4 cylinder row (right bank)
3A, 3B, 3C, 3D, 4A, 4B, 4C, 4D cylinder
7 Intake camshaft
8 Exhaust camshaft
9 Variable valve timing mechanism (variable rotation phase difference mechanism)
9a Internal rotor
9aa convex part
9b Timing pulley
9bb convex part
10A Support pipe
10B control shaft
10a long hole
10b Lock pin
20, 30 Intake valve
21, 31 Intake cam
22, 32 arm support shaft (for intake valve)
23, 33 Rocker arm (for intake valve)
24,34 push rod (for intake valve)
25, 35 swing mechanism
26, 36 Swing cam
26a, 36a Nose
27, 37 Roller arm
27a, 37a roller
38 Slider gear
38a Small diameter part
38a Small diameter part
38b Roller arm side large diameter part
38c Oscillating cam side large diameter part
38d through hole
38d outer peripheral surface and hole
38e long hole
40,50 exhaust valve
41, 51 Exhaust cam
42,52 Arm support shaft (for exhaust valve)
43, 53 Rocker arm (for exhaust valve)
44,54 push rod (for exhaust valve)

Claims (6)

At least one pair of cylinders arranged along the axis of the crankshaft,
A piston that reciprocates in each of the pair of cylinders, a connecting rod that converts the reciprocating motion of each of the pistons into a rotational motion of the crankshaft, and is provided in each of the pair of cylinders and displaced by itself to suck into the cylinder An intake valve that opens and closes a passage of air to be blown, and an exhaust valve that is also provided in each of the pair of cylinders and opens and closes a passage of exhaust gas that is discharged from the cylinder by displacing itself. In a multi-cylinder internal combustion engine in which the cylinder axis forms a predetermined bank angle,
For the pair of cylinders, at least one of an intake valve and an exhaust valve is a power transmission mechanism that transmits a driving force for displacing at a predetermined timing with respect to rotation of a crankshaft to each valve,
For a valve to which a driving force is transmitted by the power transmission mechanism, a displacement amount variable mechanism that changes a displacement amount of the valve with respect to a rotation amount of the crankshaft,
and,
A multi-cylinder internal combustion engine, wherein the displacement of each valve of the pair of cylinders is mechanically interlocked by the displacement variable mechanism. At least one pair of cylinders arranged along the axis of the crankshaft,
A piston that reciprocates in each of the pair of cylinders, a connecting rod that converts the reciprocating motion of each of the pistons into a rotational motion of the crankshaft, and is provided in each of the pair of cylinders and displaced by itself to suck into the cylinder An intake valve that opens and closes a passage of air to be blown, and an exhaust valve that is also provided in each of the pair of cylinders and opens and closes a passage of exhaust gas that is discharged from the cylinder by displacing itself. In a multi-cylinder internal combustion engine in which the cylinder axis forms a predetermined bank angle,
A power transmission mechanism that interlocks with rotation of the crankshaft and drives at least one of an intake valve and an exhaust valve for the pair of cylinders,
A main rotation shaft interlocked with the rotation of the crankshaft,
A cam provided on the outer periphery of the main rotation shaft,
A sub-rotation axis different from the main rotation axis,
A first input unit provided on an outer periphery of the sub-rotating shaft and swingable in conjunction with a cam of the main rotating shaft;
A first output unit that is also provided on the outer periphery of the sub-rotation shaft and that can swing in conjunction with the first input unit;
A first swing phase difference variable mechanism that varies a phase difference between the first input unit and the first output unit about the auxiliary rotation axis;
A first push rod that reciprocates in conjunction with the first output unit;
A first rocker arm that reciprocates a valve provided in one cylinder in conjunction with the first push rod;
A second input unit provided on the outer periphery of the sub-rotating shaft and swingable in conjunction with a cam of the main rotating shaft;
A second output unit that is also provided on the outer periphery of the auxiliary rotation shaft and that can swing in conjunction with the second input unit;
A second swing phase difference variable mechanism that varies a phase difference between the second input unit and the second output unit about the auxiliary rotation axis;
A second push rod that reciprocates in conjunction with the second output unit;
A second rocker arm that reciprocates a valve provided in one of the cylinders in conjunction with the second push rod;
A multi-cylinder internal combustion engine comprising a power transmission mechanism comprising: At least one pair of cylinders arranged along the axis of the crankshaft,
A piston that reciprocates in each of the pair of cylinders, a connecting rod that converts the reciprocating motion of each of the pistons into a rotational motion of the crankshaft, and is provided in each of the pair of cylinders. An intake valve that opens and closes a passage of intake air, and an exhaust valve that is also provided in each of the pair of cylinders and that opens and closes a passage of exhaust gas discharged from the cylinder by displacing itself. In a multi-cylinder internal combustion engine in which the axes of a pair of cylinders form a predetermined bank angle,
For the pair of cylinders, at least one of an intake valve and an exhaust valve is a power transmission mechanism that transmits a driving force for displacing at a predetermined timing with respect to rotation of a crankshaft to each valve,
A displacement amount varying mechanism that changes a displacement amount of the driven valve with respect to a rotation amount of the crankshaft, and
The power transmission mechanism corresponding to each of the pair of cylinders and the displacement amount variable mechanism corresponding to each of the pair of cylinders are driven based on the operation of a single camshaft. . At least one pair of cylinders arranged along the axis of the crankshaft,
A piston that reciprocates in each of the pair of cylinders, a connecting rod that converts the reciprocating motion of each of the pistons into a rotational motion of the crankshaft, and is provided in each of the pair of cylinders and displaced by itself to suck into the cylinder An intake valve that opens and closes a passage of air to be blown, and an exhaust valve that is also provided in each of the pair of cylinders and opens and closes a passage of exhaust gas that is discharged from the cylinder by displacing itself. In a multi-cylinder internal combustion engine in which the cylinder axis forms a predetermined bank angle,
A power transmission mechanism that interlocks with rotation of the crankshaft and drives at least one of an intake valve and an exhaust valve for the pair of cylinders,
A main rotation shaft interlocked with the rotation of the crankshaft,
A cam provided on the outer periphery of the main rotation shaft,
A first auxiliary rotation axis different from the main rotation axis;
A first input unit provided on an outer periphery of the first sub-rotating shaft and swingable in conjunction with a cam of the main rotating shaft;
A first output unit also provided on the outer periphery of the first sub-rotating shaft and swingable in conjunction with the first input unit;
A first swing phase difference variable mechanism that varies a phase difference between the first input unit and the first output unit about the first auxiliary rotation axis;
A first push rod that reciprocates in conjunction with the first output unit;
A first rocker arm that reciprocates a valve provided in one cylinder in conjunction with the first push rod;
A second sub-rotation axis different from any of the main rotation axis and the first sub-rotation axis;
A second input unit provided on an outer periphery of the second sub-rotating shaft and swingable in conjunction with a cam of the main rotating shaft;
A second output unit also provided on the outer periphery of the second sub-rotating shaft and swingable in conjunction with the second input unit;
A second swing phase difference variable mechanism that varies a phase difference between the second input section and the second output section about the second sub-rotation axis;
A second push rod that reciprocates in conjunction with the second output unit;
A second rocker arm that reciprocates a valve provided in one of the cylinders in conjunction with the second push rod;
A multi-cylinder internal combustion engine comprising a power transmission mechanism comprising: 5. The multi-cylinder internal combustion engine according to claim 2, wherein the main rotation shaft is disposed on a line segment that substantially bisects the bank angle. 5. The multi-cylinder internal combustion engine according to claim 2, wherein the main rotation shaft includes a rotation phase difference variable mechanism that changes a phase difference of the main rotation shaft with respect to a rotation phase of the crankshaft.

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