JP2001182505A - Variable valve train for V-type internal combustion engine - Google Patents

Abstract

(57) [Problem] To make valve lift characteristics and changes of intake and exhaust valves to which a variable valve mechanism is applied equal between left and right banks. SOLUTION: Left and right bank cylinder heads RH, LH
Are provided with variable valve mechanisms. Each of the variable valve mechanisms is configured such that the eccentric cam 12, the ring-shaped link 13, the rocker arm 16, the rod-shaped link 1
7. Open / close the intake valve 19 via the swing cam 18.
By rotating the control shaft 14, the control cam 15
The attitude of the rocker arm 16 is changed via the, and the valve lift characteristics are changed. When viewed in the same axis direction, drive shaft 1
The lift direction of the swing cam 18 and the rotation direction of the control shaft 14 with respect to one rotation direction are set to the same direction in the left and right banks.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve for variably controlling the opening / closing timing and operating angle (valve lift amount) of an intake valve and / or an exhaust valve (intake / exhaust valve) according to the operating state of an internal combustion engine. More particularly, the present invention relates to a variable valve apparatus applied to a V-type internal combustion engine in which cylinder heads of left and right banks and intake / exhaust valves thereof are set substantially symmetrically with respect to a bank center line.

[0002]

2. Description of the Related Art As is well known, in order to improve fuel efficiency and stabilize engine operation at low engine speed and low load, and to secure sufficient output by improving intake air charging efficiency at high speed and high load. In addition, various variable valve mechanisms that can change the opening / closing timing of intake / exhaust valves and the amount of valve lift according to the operating state of the engine have been conventionally proposed.

As an example, in a variable valve mechanism described in Japanese Patent Application Laid-Open No. 55-137305, a cam provided on a drive shaft that rotates in conjunction with an engine, and a suction valve provided on the outer periphery of a support shaft. The swing cam for driving the exhaust valve is linked to a rocker arm that is rotatably fitted to the outer periphery of an eccentric cam provided eccentrically to the control shaft. By controlling the rotation of the control shaft, the rocking center position of the rocker arm changes, and the lift characteristics of the intake and exhaust valves change.

[0004]

However, when such a conventional variable valve mechanism is simply applied to both the left and right banks of a V-type internal combustion engine, that is, the arrangement of the variable valve mechanism with respect to the rotation direction of the drive shaft. If no consideration is given to the above, the valve lift characteristics of the intake and exhaust valves may be different between the left and right banks.

One object of the present invention is to provide a variable valve operating system applied to a V-type internal combustion engine, in which the valve lift characteristics of the intake and exhaust valves to which the variable valve operating mechanism is applied are equal in the left and right banks. The object is to stably obtain the same valve lift characteristics in all cylinders.

[0006]

The invention according to claim 1 is
In a variable valve operating device of a V-type internal combustion engine in which a variable valve operating mechanism is provided in each of the left and right banks, each variable valve operating mechanism includes:
An eccentric cam provided eccentrically to a drive shaft that rotates in conjunction with an engine crankshaft, a swing cam that drives intake and exhaust valves, and a transmission mechanism that mechanically links the eccentric cam and the swing cam And a control mechanism for changing the attitude of the transmission mechanism, wherein the lift direction of the swing cam with respect to the rotation direction of the drive shaft is set to the same direction in the left and right banks when viewed in the same axial direction. I have.

[0007] Preferably, as in the invention according to claim 2,
The transmission mechanism includes a first link member externally rotatably fitted to an outer periphery of the eccentric cam, a rocker arm having one end relatively rotatably connected to a tip of the first link member, and another end of the rocker arm. And a second link member rotatably connected to the swing cam. The control mechanism extends substantially parallel to the drive shaft, and rotates at a predetermined angle in accordance with an operation state of the engine. It has a control shaft to be held and a control cam provided eccentrically to the control shaft, and the rocker arm is fitted on the control cam so as to be relatively rotatable.

According to a third aspect of the present invention, when viewed in the same axial direction,
The rotation direction of the control shaft with respect to the rotation direction of the drive shaft is set to the same direction in the left and right banks.

According to a fourth aspect of the present invention, when viewed in the same axial direction,
The variable valve mechanisms of the left and right banks are set to have substantially similar shapes with reference to the valve axis, and the rotation directions of the drive shafts of the left and right banks are set to the same direction.

According to a fifth aspect of the present invention, there is provided a variable valve operating apparatus for a V-type internal combustion engine in which a variable valve operating mechanism is provided in each of the left and right banks, wherein each variable valve operating rotates in conjunction with a crankshaft. A drive shaft, a control shaft extending substantially parallel to the drive shaft and rotated and held at a predetermined angle in accordance with the operation state of the engine; Oscillating cam for driving the eccentric cam, an eccentric cam provided eccentrically to the drive shaft, a first link member externally rotatably fitted to an outer periphery of the eccentric cam, and a control eccentrically provided to the control shaft. A cam, a rocker arm externally fitted to the outer periphery of the control cam so as to be relatively rotatable, and having one end connected to the tip of the first link member so as to be relatively rotatable; and the other end of the rocker arm and the rocking cam. To be rotatable relative to 2 link members, and the variable valve mechanisms of the left and right banks are set to be substantially similar to each other with respect to the valve axis when viewed in the same axial direction, and the rotation directions of the drive shafts of the left and right banks are set in the same direction. It is characterized by having been set.

According to the fifth aspect of the present invention, the swing cam for driving the intake / exhaust valve is rotatably fitted to the outer periphery of the drive shaft which rotates in conjunction with the engine. There is no possibility that the center of the swing cam is displaced with respect to the drive shaft, and the control accuracy is improved. Further, since it is not necessary to provide a support shaft or the like for supporting the swing cam separately from the drive shaft, it is possible to reduce the number of components and the arrangement space. Furthermore,
Since the connecting portions of the members are in surface contact, they have excellent wear resistance and are easy to lubricate.

By the way, if the drive shafts of the left and right banks rotate in the same direction and the variable valve mechanisms of the left and right banks are set to be symmetrical, the phase of the oscillating cam is changed with the rotation of the control shaft. With respect to the phase of the drive shaft, one bank side changes to the leading side, and the other bank side changes to the lag side. As a result, the change in the lift characteristics differs between the left and right banks.

Therefore, in the invention according to claims 4 and 5, each component of the variable valve mechanism of the left and right banks is connected to the drive shaft so that the change of the lift characteristic accompanying the rotation of the control shaft is equal in the left and right banks. The arrangement is substantially the same as viewed in the axial direction.

According to a sixth aspect of the present invention, a straight line connecting the center of the drive shaft and the center of the control shaft is rotated by the same angle in the same direction in the left and right banks with respect to the valve axis of the intake / exhaust valve. It is characterized by having been set to.

According to a seventh aspect of the present invention, the distance from the center of the drive shaft to the center of the control shaft is set to be equal in the left and right banks, and the distance between the swing cam and the second link member at the time of the maximum lift is increased. The distance to the center of the drive shaft is set equal for the left and right banks, and for one bank,
The center of the control shaft on the other bank side is set to a position rotated by a predetermined angle in a predetermined direction around the drive axis with respect to the valve axis of the intake / exhaust valve, and
The connecting portion on the other bank side is set at a position rotated around the drive shaft by the same angle in the same direction as the control shaft with respect to a straight line connecting the center of the swing cam and the lift start position. Features.

According to an eighth aspect of the present invention, the connecting portions of the swing cam and the second link member at the time of the maximum lift are respectively provided on an extension of a straight line connecting the center of the control shaft of the left and right banks and the center of the drive shaft. It is characterized by being arranged.

The invention according to claim 9 is characterized in that the center of the drive shaft and the center of the control shaft are arranged on the valve axis of the intake / exhaust valve for both the left and right banks.

According to a tenth aspect of the present invention, the control shaft of one bank is set at a position rotated by a predetermined angle in a predetermined direction around a drive axis with respect to the valve axis of the intake / exhaust valve, while the other bank is set. Is set at a position rotated by the same angle in the direction opposite to that of the control axis of the one bank with respect to the valve axis.

According to an eleventh aspect of the present invention, the center of the control shaft and the connecting portion between the swing cam and the second link member at the time of the maximum lift are provided in at least one of the left and right banks by a valve as viewed in the axial direction. It is characterized by being arranged on the opposite side to the axis.

According to a twelfth aspect of the present invention, the center of at least one control shaft of the left and right banks is arranged closer to the center of the cylinder head than the valve axis of the intake / exhaust valve.

The invention according to claim 13 is applied to the intake side of a laterally mounted V-type internal combustion engine, and at least the center of the control shaft in the front bank of the vehicle is closer to the center of the cylinder head than the valve axis of the intake valve. It is characterized by being arranged in.

According to a fourteenth aspect of the present invention, when viewed in the same axial direction, the variable valve mechanisms of the left and right banks are set substantially symmetrically with respect to the bank center line, and the rotational directions of the drive shafts of the left and right banks are set. Are set in directions opposite to each other.

According to a fifteenth aspect of the present invention, the intake valves of the left and right banks are arranged inside the bank, the exhaust valve is arranged outside the bank, and the swing cam for driving the intake valve is arranged inside the bank, while the driving valve is arranged inside the bank. The shaft is disposed outside the bank, and the transmission mechanism is disposed from the outside of the bank to the inside of the bank.

The invention according to claim 16 has a first sprocket and a second sprocket that rotate in the same direction as the crankshaft, and a first reversing gear pulley and a second reversing gear pulley that mesh with each other and rotate in reverse. The first sprocket is fixed to one drive shaft of the left and right banks, the first reversing gear pulley is fixed to the second sprocket, and the second reversing gear pulley is fixed to the other drive shaft.

[0025]

According to the first and second aspects of the invention, the valve lift characteristics of the intake and exhaust valves to which the variable valve mechanism is applied can be made substantially equal between the left and right banks.

According to the third aspect of the present invention, it is possible to make the change in the valve lift characteristic accompanying the rotation of the control shaft substantially equal between the left and right banks.

According to the invention according to claims 4 to 6, in the V-type internal combustion engine in which the drive shafts of the left and right banks rotate in the same direction, the variable valve operating mechanisms of the left and right banks are referenced to the valve axis in the axial direction. Therefore, the change in the valve lift characteristic due to the rotation of the control shaft can be made substantially equal between the left and right banks, and the final valve lift characteristic can be made substantially equal between the left and right banks. In other words, it is not necessary to drive the drive shafts of the left and right banks in opposite directions, and it is possible to drive the drive shafts of the left and right banks in the same direction by a timing chain or a timing belt, as in a general V-type internal combustion engine. Become.

According to the seventh aspect of the present invention, the center of the control shaft on one bank and the position of the connecting portion of the swing cam with the second link member can be different from that of the other bank. This increases the degree of freedom in layout.

According to the invention of claim 8, the degree of freedom of the valve operating angle characteristic is improved.

According to the ninth and tenth aspects of the present invention, the drive shaft, the control shaft and the bearing brackets for supporting the drive shaft and the like can be substantially symmetrical in the left and right banks. In addition, there is an advantage that the bearing bracket and the like can be shared by the left and right banks.

In particular, in the invention according to claim 10, the center position of the control shaft and the phase of the swing cam can be made different between the left and right banks, and the degree of freedom in layout is increased.

According to the eleventh aspect of the present invention, the center of the control shaft and the connecting portion are disposed on the opposite sides with respect to the valve axis when viewed in the axial direction, as compared with the case where they are disposed on the same side. , While improving the bearing strength of the drive shaft and control shaft,
This is also advantageous in terms of layout and reliability.

According to a twelfth aspect of the present invention, when the center of at least one of the control shafts of the left and right banks is disposed closer to the center of the cylinder head than the valve axis of the intake / exhaust valve, the control shaft, the rocker arm, etc. Is tilted toward the center of the cylinder head, and the overall height of the entire variable valve mechanism can be effectively suppressed.

In particular, when applied to the intake side of a horizontally mounted V-type internal combustion engine as in the invention according to claim 13, the overall height of the variable valve mechanism of the front bank of the vehicle can be suppressed, This is advantageous for a vehicle hood line.

According to the fourteenth aspect of the invention, the variable valve mechanisms of the left and right banks are set to be substantially symmetrical to each other as in the case of the cylinder head or the like. Becomes possible. Also,
Since the rotation directions of the drive shafts of the left and right banks are set to be opposite to each other, the valve lift characteristics can be made equal between the left and right banks.

According to the fifteenth aspect, the drive shaft of the variable valve mechanism for changing the operation mode of the intake valve also serves as the camshaft of the exhaust valve. Part of the variable valve mechanism (mostly) can be arranged outside the bank (exhaust side) where there is relatively room for space, so that the overall height of the engine can be kept low and, consequently, the engine room of the vehicle can be kept low. The engine mountability can be improved.

According to the sixteenth aspect, the drive shafts of the left and right banks can be rotated in opposite directions with a relatively simple configuration.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the variable valve operating device according to the present invention will be described below with reference to the drawings.

FIG. 2 shows a cylinder head of a V-type internal combustion engine in which the variable valve apparatus according to the first embodiment of the present invention is applied to the intake valve side, and FIG. 1 is an enlarged view of a main part thereof. In the figure, RH indicates the cylinder head of the right bank, and LH indicates the cylinder head of the left bank. 1 and 2
Although the cylinder block mounting surfaces RHa and LHa of the left and right cylinder heads RH and LH are drawn on the same plane,
Actually, both mounting surfaces RHa and LHa are inclined with a predetermined bank angle. Further, in the following description, for the sake of simplicity, substantially the same parts in the left and right banks are denoted by the same reference numerals, and only the right bank and the left bank are required to be distinguished. Accordingly, a reference sign R indicating that it is a part of the right bank and a reference sign L indicating that it is a part of the left bank are added to the reference signs.

Each cylinder head RH, LH is provided with an intake valve along the inside of the V bank and an exhaust valve along the outside of the V bank. A single drive shaft 11 extending over a plurality of cylinders is provided above the intake valve in parallel with the exhaust camshaft that drives the exhaust valve to open and close. Each drive shaft 11 has a sprocket (not shown) at one end, and rotates in conjunction with the crankshaft together with the exhaust-side camshaft via a timing chain. That is, the pair of drive shafts 11 of the left and right banks are
Both rotate in the same direction (clockwise direction in FIGS. 1 and 2). A variable valve mechanism as shown in FIG. 3 is provided on the intake valve side for each cylinder of each bank.

Next, the above-described variable valve mechanism will be described in detail with reference to FIG. 3 (and FIGS. 4 and 5) are viewed in the axial direction opposite to those in FIGS. 1 and 2, and therefore, in FIGS. 3 to 5, the drive shaft 11 rotates counterclockwise. .

An eccentric cylindrical eccentric cam 12 which rotates integrally with the drive shaft 11 is fixed to the outer periphery of the drive shaft 11 by press-fitting or the like. Center (axis) of this eccentric cam 12
C2 is eccentric by a predetermined amount with respect to the center (axial center) C1 of the drive shaft 11. On the outer periphery of the eccentric cam 12, a large-diameter base portion 13a of a ring-shaped link (first link member) 13 is provided.
Are externally fitted so as to be relatively rotatable.

A control shaft 14 is provided obliquely above the drive shaft 11.
Extends over all cylinders in parallel with the drive shaft 11. The control shaft 14 is rotated and held in a predetermined rotation range in accordance with the operation state of the engine by an actuator (not shown) such as a motor and a hydraulic actuator connected to one end of the control shaft.

An eccentric ring-shaped control cam 15 that rotates integrally with the control shaft 14 is fixed to the outer periphery of the control shaft 14 by press-fitting or the like. Center (axial center) C of control cam 15
4 is eccentric by a predetermined amount with respect to the center (axial center) C3 of the control shaft 14. The center base of the rocker arm 16 is fitted around the outer periphery of the control cam 15 so as to be relatively rotatable. One end 16a of the rocker arm 16 and the tip 13b of the ring-shaped link 13 are rotatably connected via a connecting pin (connecting portion C5).

The other end 16b of the rocker arm 16
The rocking cam 18 and the rocking cam 18 are linked via a rod-shaped link (second link member) 17 disposed substantially along the vertical direction. That is, the one end 17a of the rod-shaped link 17 and the other end 16b of the rocker arm 16 are relatively rotatably connected via the connection pin (connection C7), and swing with the other end 17b of the rod-shaped link 17. The distal end of the moving cam 18 is connected via a connecting pin (connecting portion C6) so as to be relatively rotatable.

The drive shaft 11 and the control shaft 14
Is rotatably supported by the cylinder head via a bearing bracket 8 and bolts 9 shown in FIGS.

With this configuration, when the drive shaft 11 rotates in conjunction with the rotation of the engine, the ring-shaped link 13 moves via the eccentric cam 12, and the rocker arm 16 moves the center of the control cam 15 accordingly. The swing cam 18 swings around C4 as the swing center, and the swing cam 18 swings via the rod-like link 17. At this time, the cam surface 18c of the swing cam 18
The valve lifter 19 a slides on an upper surface 19 b of a valve lifter 19 a as a transmission member provided at an upper end of the intake valve 19.
By pressing a against the reaction force of a valve spring (not shown), the intake valve 19 opens and closes in conjunction with the rotation of the engine.

That is, the ring-shaped link 13, the rocker arm 16, and the rod-shaped link 17 constitute a transmission mechanism for mechanically linking the eccentric cam 12 and the swing cam 18.

The control shaft 14 according to the operating state of the engine
Is controlled, the rocking center C4 of the rocker arm 16 is controlled.
Is rotationally displaced with respect to the center C3 of the control shaft 14, and the intake valve 1
9 continuously changes. Specifically, the swing center C4 of the rocker arm 16 and the center C1 of the drive shaft 11
, The valve lift amount and the operation angle increase as the distance from the center C4 and C1 increases, and the valve lift amount and the operation angle decrease as the distance between the centers C4 and C1 increases.

That is, the control shaft 14 and the control cam 15
A control mechanism for changing the attitude of the transmission mechanism is configured.

As described above, the swing cam 18 for driving the intake valve 19 is rotatably fitted to the outer periphery of the drive shaft 11 which rotates in conjunction with the engine.
There is no danger of the shaft center misalignment with respect to the drive shaft 11
Control accuracy is improved. Further, since it is not necessary to provide a support shaft for supporting the swing cam 18 separately from the drive shaft 11, it is possible to reduce the number of components and the arrangement space. Furthermore,
Since the connecting portions of the members are in surface contact, they have excellent wear resistance and are easy to lubricate.

Then, as shown in FIGS. 1 and 2, each component 12, 13, 15 to 18 of such a variable valve mechanism.
Are substantially the same in the left and right banks as viewed in the axial direction of the drive shaft 11. That is, the variable valve mechanisms of the left and right banks are not arranged symmetrically like the cylinder head and the intake / exhaust valves, but are arranged in the valve axis 2 of the intake valve 19.
They are arranged in the same direction with reference to 0, and are substantially similar to each other when viewed in the same axial direction.

Further, a straight line 21 connecting the center C1 of the drive shaft 11 and the center C3 of the control shaft 14 with respect to the valve axis 20 of the intake valve 19 is opposite to the rotational direction of the drive shaft 11 in both the left and right banks (counterclockwise). Drive shaft 1 by the same angle α in the clockwise direction)
It is set at a position rotated one turn. That is, the relative phase of the control shaft 14 with respect to the drive shaft 11 is set equally in the left and right banks. The center C1 of the drive shaft 11 is set on the valve axis 20.

FIGS. 4 and 5 show the dimensions of the variable valve mechanism shown in FIG. With the rotation of the engine, the center C2 of the eccentric cam 12 moves on a circle centered on the center C1 of the drive shaft 11. On the other hand, the arm length of the rocker arm 16 (length between C4 and C5) and the arm length of the ring-shaped link 13 (length between C2 and C5) are always constant. Therefore, as shown in FIG. 4, in the state where the rocking center of the rocker arm 16 is held at C4, the center C2 of the eccentric cam 12 changes from C2OPEN to C2 with the rotation of the drive shaft 11.
The range of CLOSE is moved, and the connecting portion C5 is moved to C5.
Move the range from MAX to C5S.

Here, the operation points C1, C2, and C5 are aligned on a straight line, that is, C2 and C5 are C2MA, respectively.
When the swing cam 18 is positioned at X, C5MAX,
Swings the most in the valve opening direction, and the valve lift becomes the maximum. On the other hand, at the start and end of the valve lift, the position of the center C2 of the eccentric cam 12 is different (C2OPE).
N, C2CLOSE) On the other hand, the connecting portion C5 is located at the same position C5.
It becomes S.

In order to change the lift characteristics (operating angle and valve lift amount) of the intake valve 19 from the control state shown in FIG. 4, the control shaft 14 is controlled to rotate counterclockwise, and the rocker arm 16 is controlled. When the center C4 is moved to C4 ', the dimension changes as shown by the broken line in FIG. That is, the position of the connecting portion C5 at which the valve lift becomes maximum changes from C5MAX to C5MAX '. Therefore, the center position of the eccentric cam 12 at the time of the maximum valve lift also changes from C2MAX to C2MAX '. Similarly, the rotation angle of the drive shaft 11 from the valve opening to the maximum lift also changes from θ1 to θ1 ′, and the rotation angle of the drive shaft 11 from the maximum lift to the valve close also changes from θ2 to θ2 ′.
Also, the change amount (θ1′−θ1) of the valve opening timing does not exactly match the change amount (θ2′−θ2) of the valve closing timing.

Therefore, if the left and right banks have the same rotational direction and the variable valve mechanisms of the left and right banks are bilaterally symmetric, the drive shaft 11
C5MAX, θ1, θ2, etc. change to the leading side with respect to the rotation direction of
Since X, θ1, θ2, etc. change to the delay side, the valve lift characteristics of the left and right banks are different from each other.

On the other hand, in the present embodiment, the respective components 12, 13, 15 to 18 of the variable valve mechanism in the left and right banks are arranged substantially in the same manner as viewed in the axial direction. On the other hand, since the straight line 21 connecting the drive shaft center C1 and the control shaft center C3 is set at a position rotated by the same angle α in the same direction in the left and right banks, the change in the lift characteristic due to the rotation of the control shaft 14 is not affected. The left and right banks can be equalized, and the same valve lift characteristics can be ensured in all cylinders. In other words, it is not necessary to drive the drive shafts of the left and right banks in opposite directions, and it is possible to drive the drive shafts of the left and right banks in the same direction by a timing chain or a timing belt, as in a general V-type internal combustion engine. Become.

FIGS. 6 to 8 show another embodiment of the present invention. In the following embodiments, substantially the same parts as those in the above-described first embodiment are denoted by the same reference numerals, and redundant description will be omitted as appropriate.

In the second embodiment shown in FIG. 6, both the left and right banks, when viewed in the axial direction, are connected to the swing cam 18 in the maximum valve lift state so that the degree of freedom (variation) of the valve lift characteristics is maximized. The connecting portion C6 with the rod-shaped link 17 is
It is arranged on an extension of a straight line 21 connecting the center C4 of the control shaft 14 and the center C1 of the drive shaft 11 and on the opposite side of the control shaft center C3 across the drive shaft center C1. That is, the control shaft center C3, the drive shaft center C1, and the connecting portion C6 are arranged on a straight line.

A straight line 21 connecting the drive shaft center C1 and the control shaft center C3 with respect to the valve axis 20 is set at a position rotated by an angle α1 in the direction opposite to the rotation direction of the drive shaft 11 on the right bank side. On the other hand, on the left bank side, the right bank is set at a position rotated by an angle α2 in the rotation direction of the drive shaft 11 from the straight line 21L ′ shifted in the reverse rotation direction of the drive shaft 11 by an angle α1. ing. In addition,
The distance from the drive shaft center C1 to the control shaft center C3 is set equally in the left and right banks.

A straight line 21 connecting the connecting portion C6 and the center C1 of the drive shaft to a straight line 22 connecting the drive shaft axis C1 and the valve lift start position 24 on the cam surface of the swing cam 18 is as follows. On the right bank side, it is set at a position rotated by an angle α3 in the direction opposite to the rotation direction of the drive shaft 11, whereas on the left bank side, as in the case of the control shaft 14 described above,
The position is set at a position rotated by an angle α2 in the rotation direction of the drive shaft 11 from a straight line C3L ′ shifted by an angle α3 like the right bank side. The distance from the swing cam center C1 to the connecting portion C6 is set to be equal in the left and right banks.

That is, with respect to the right bank side, the center position of the control shaft 14 on the left bank side and the rotational phase of the oscillating cam 18 have the same angle around the drive shaft 11 in the same direction (the rotational direction of the drive shaft 11). It is set at a position rotated by α2. As a result, the change in the lift characteristic due to the rotation of the control shaft 14 becomes equal between the left and right banks, and similar to the first embodiment,
The same valve lift characteristics can be ensured in all cylinders.

Further, in this embodiment, the center position of the control shaft 14 with respect to the drive shaft 11 and the initial phase of the swing cam 18 can be made different between the left and right banks, and the control shaft 14 and the Since the swing cam 18 and the like can be arranged, the degree of freedom in layout is increased.

More specifically, if the center of the control axis on the left bank side is arranged at the same position C3L 'as the right bank side,
The rocker arm 16 and the ring-shaped link 13 project sideways, and if left untouched, the layout will interfere with the cylinder head and the like, which is not preferable. Therefore, in the present embodiment, the control axis center C3L on the left bank side is disposed at a position rotated by a predetermined angle α2 toward the center side (right side in FIG. 6) of the cylinder head around the drive shaft 11 with respect to the right bank side. I have. As a result, the variable valve mechanisms of the left and right banks are both arranged within the entire width of the cylinder head. As a result, the variable valve mechanism can be applied to and mounted on both the left and right banks without changing the entire width of the cylinder head.

Reference numeral 30 in FIG. 6 indicates a horizontal plane 30 corresponding to the total height of the variable valve mechanism on the right bank side when this variable valve apparatus is actually applied to the intake side of a V-type internal combustion engine. ing. As shown in the figure, the total height of the variable valve mechanism of the right bank is suppressed lower than that of the variable valve mechanism of the left bank.

Considering this point, in the variable valve operating mechanism of the right bank, in order to suppress the overall height, the center of the control shaft 14 is made large toward the cylinder head center side around the drive shaft 11 with respect to the valve axis 20 (FIG. Angle α1) It is set at a rotated position. In order to realize such a layout, in the swing cam 18R on the right bank side, the angle α3 between the connecting portion C6R at the time of the maximum lift and the lift start position 24R is much larger than that on the left bank side. ing.
Therefore, in the swing cam 18R on the right bank side, the cam lobe 28 provided with the connecting portion C6R is larger than the swing cam 18L on the left bank.

For example, when the variable valve train of this embodiment is applied to the intake side of a V-type internal combustion engine of a FF (Front Engine Front Drive) horizontal type, the variable valve train on the right bank side having a low overall height is used. Is applied to the bank on the front side of the vehicle, the overall height on the front side of the vehicle is suppressed relatively low, which is advantageous for the hood line of the vehicle.

FIG. 7 shows a third embodiment. Basically, the configuration is the same as that of the first embodiment shown in FIGS. 1 to 5, but in this embodiment, the angle α shown in FIG.
Set to degree. That is, the drive shaft center C1 and the control shaft center C3 are arranged on the valve axis 20 on both the left and right banks. According to the present embodiment, the components of the variable valve mechanism of the left and right banks including the swing cam can be shared, and the drive shaft 11 and the control shaft 1 of the left and right banks can be shared.
4 and its bearing bracket (8) and the like can be made symmetrical, so that its design and manufacture are easy.

FIG. 8 shows a fourth embodiment. Although the configuration is basically the same as that of the second embodiment, in this embodiment, the drive shafts 11 and the control shafts 14 of the left and right banks are arranged at symmetrical positions with respect to each other.

That is, a straight line 21 connecting the drive shaft center C1 and the control shaft center C3 with respect to the valve axis 20 is set at a position rotated by an angle β1 in a direction opposite to the rotation direction of the drive shaft 11 on the right bank side. On the other hand, in the variable valve mechanism of the left bank, the drive shaft 1 is shifted from the straight line 21L 'shifted in the reverse rotation direction of the drive shaft 11 by the angle β1 similarly to the right bank.
It is set at a position rotated by an angle β2 in the rotation direction 1. Here, the angle β2 is set to about twice the angle β1. That is, the center C3L of the control axis 14L of the left bank.
To the control axis 14R of the right bank with respect to the valve axis 20L.
The same angle β1 in the opposite direction (rotation direction of the drive shaft)
It is set to the rotated position only. The drive shaft center C
The distance from 1 to the control axis center C3 is set equally in the left and right banks.

The swing center C1 of the swing cam 18
Straight line 2 connecting the valve lift start position 24 on the cam surface
2, the straight line 23 connecting the swing center C1 of the swing cam 18 and the connecting portion C6 of the rod-shaped link 17 is shifted by an angle β3 in the direction opposite to the rotation direction of the drive shaft 11 on the right bank side. On the other hand, on the left bank side, from the position of the straight line C3L 'shifted by the angle β3 like the right bank side, the position is set to the position rotated by the angle β2 in the rotation direction of the drive shaft 11, as in the case of the control axis. Have been. The swing cam center C
The distance from 1 to the connecting portion C6 is set equally in the left and right banks.

That is, as in the second embodiment, the center position of the control shaft 14 on the left bank side and the rotation phase of the swing cam 18 are the same around the drive shaft 11 (the drive shaft 11 (Rotation direction) is shifted by the same angle β2. As a result, similarly to the second embodiment, the control shaft 1
The change in the lift characteristic accompanying the rotation of No. 4 becomes equal in the left and right banks, and the same valve lift characteristic can be ensured in all cylinders.

In addition, in this embodiment, since the drive shafts 11 and the control shafts 14 of the left and right banks are arranged symmetrically to each other, the layout on the cylinder head side on which the variable valve mechanism is mounted is substantially the same for the left and right banks. It can be made symmetrical, making its design and manufacture easy. In addition to the components of the variable valve mechanism, components on the cylinder head side such as the bearing bracket 8 can be shared by the left and right banks.

Further, in the first to third embodiments described above, the control shaft center C3 and the connecting portion C6 between the swing cam 18 and the rod-shaped link 17 at the time of the maximum valve lift are connected to each other.
They are arranged on opposite sides of the valve axis 20. Thereby, as compared with the case where the control shaft center C3 and the connecting portion C6 are arranged on the same side with respect to the valve axis 20, the bearing strength is improved and the layout and the reliability are advantageous.

FIGS. 9 and 10 show a fifth embodiment. Although the mounting surfaces RHa and LHa of the cylinder heads RH and LH on the cylinder block 31 (FIG. 10) are drawn on the same plane in FIG. 9, actually, as shown in FIG. LHas are mutually inclined with a predetermined bank angle.

In the fifth embodiment, the variable valve mechanisms of the left and right banks are substantially symmetrical with respect to the bank center line (center line of the left and right banks) 32 as viewed in the same axial direction as shown in FIG. You have set. It is to be noted that components substantially similar to those of the above-described embodiment are denoted by reference numerals obtained by adding 100, and redundant description will be omitted as appropriate.

In a general V-type internal combustion engine, the left and right banks are inclined so as to fall to the outside of the engine, and the intake valves 119 and the like of the intake system are arranged inside the banks with respect to the cylinder axis 33 of each bank. An exhaust valve 62 and the like of the exhaust system are disposed outside the bank with respect to the cylinder axis 33. Accordingly, when the upper surface of the rocker cover 68 is set substantially parallel to the lower surface 34 of the hood, the space above the valve lifter 60 of the exhaust valve 62 located outside the bank is equal to the space above the valve lifter 119a of the intake valve 119 located inside the bank. There is more space than the space above.

Therefore, in the fifth embodiment, the intake valve 11
9 is a variable valve mechanism that changes the operation mode,
Most of the components of the variable valve mechanism are arranged on the exhaust side, that is, outside the cylinder axis 33 than the bank. As a result, the overall height of the engine can be suppressed low, and the mountability of the engine in the engine room of the vehicle can be improved.

More specifically, in this variable valve mechanism, the drive shaft 111 that rotates in conjunction with the crankshaft is used.
And an eccentric cam 1 eccentrically provided on the drive shaft 111.
A control shaft 114 which extends substantially parallel to the drive shaft 111 and is rotated and held at a predetermined angle in accordance with the engine operating state; A control cam 115 eccentrically provided on the control shaft 114 and a rocker arm 116 which is fitted to the control cam 115 so as to be relatively rotatable and has one end connected to the tip of a ring-shaped link 113 are formed by a cylinder as viewed in the axial direction. The plug post 66 is located outside the bank (exhaust side) of the plug post 66 along the axis 33.

On the other hand, in the variable valve mechanism, the intake valve 119
The swing cam 118 that opens and closes is located above the intake valve 119,
In other words, the rocker arm 11
The rod-shaped link 117 connected to the swing cam 118 and the swing cam 118 so as to be relatively rotatable is disposed from the outside of the bank (exhaust side) to the inside of the bank (intake side). That is, the rod-like link 117 has a shape crossing the cylinder axis 33.

A drive rotary cam 58 for pressing the valve lifter 60 of the exhaust valve 62 to open and close the exhaust valve 62 is fixed to the drive shaft 111. That is, the drive shaft 111
Are also used as the camshaft of the exhaust valve 62, and the configuration is simplified. This drive shaft 111
Are the lower bearing bracket 56a and the cylinder head RH,
The control shaft 114 is rotatably supported by the LH and the lower bearing bracket 56a and the upper bearing bracket 56b. Both brackets 56
A and 56b are fastened and fixed to the cylinder heads RH and LH by common bolts 56c, thereby simplifying the configuration.

The ring-shaped link 113 has a half-split structure in which the two members 113a and 113b are fastened and fixed to each other by the bolt 64 with the eccentric cam 112 interposed therebetween so that the ring-shaped link 113 can be assembled to the eccentric cam 112 later.

The swing cam 118 is fitted on the support shaft 52 so as to be swingable. The support shaft 52 is supported by the cylinder heads RH and LH via the bracket 50, and is parallel to the drive shaft 111. It extends in the cylinder row direction.

The basic operating principle of the variable valve mechanism of each bank is substantially the same as that described above with reference to FIGS. That is, when the control shaft 114 is rotated so that the maximum valve lift is reduced, a change occurs such as that the center position C2MAX of the eccentric cam 112 at the time of the maximum valve lift is advanced or retarded.

Here, since the variable valve mechanisms of the left and right banks are substantially symmetric, the drive shafts 11 of the left and right banks are temporarily
When the rotation directions of the first and second banks are set in the same direction, as described above, changes in valve lift characteristics of the left and right banks are different from each other, such as that C2MAX and the like advance in one bank and retard in the other bank. turn into.

Therefore, in this embodiment, the rotation directions of the drive shafts 111R and 111L of the left and right banks are set to be opposite to each other when viewed in the axial direction. That is, in the same axial direction shown in FIGS. 9 and 10, the rotation direction of the drive shaft 111R of the right bank is set counterclockwise, and the rotation direction of the drive shaft 111L of the left bank is set clockwise. Also, the control axes 114 of the left and right banks
The rotation directions of R and 114L are also set in opposite directions. That is, the control shaft 114 that reduces the valve lift amount
Are set clockwise on the right bank side 114R and counterclockwise on the left bank side 114L. In other words, for example, when the variable valve mechanism of the right bank is viewed from the back side of the paper of FIGS. 9 and 10, the layout is substantially the same as that of the variable valve mechanism of the left bank, and the rotation directions of the drive shaft and the control shaft are also changed. They are set to be substantially the same.

Therefore, while the variable valve mechanisms of the left and right banks are symmetrical with respect to the bank center line 32 in the same manner as the cylinder heads and the intake / exhaust valves, the valve lift characteristics and changes thereof are equal between the left and right banks. There is no possibility that a situation such as the reverse change of C2MAX or the like in the left and right banks will occur.

Next, a specific configuration for rotating the drive shafts 111R and 111L of the left and right banks in opposite directions will be described with reference to FIG.

A crank sprocket 70 attached to one end of a crank shaft (not shown) rotates clockwise in FIG. 10 together with the crank shaft. A chain 72 is wound around the crank sprocket 70, a first sprocket 74 provided on the left bank side, and a second sprocket (idler sprocket) 76 provided on the right bank side. Therefore, both sprockets 74, 7
6 rotates in the same direction as the crankshaft. The number of teeth and the like of both sprockets 74 and 76 are set so as to be reduced to half the rotational speed of the crank sprocket 70.

The first sprocket 74 is fixed to one end of a drive shaft 111L of the left bank, and rotates integrally with the drive shaft 111L. Therefore, the drive shaft 111L of the left bank
Rotates in the same direction (clockwise direction in FIG. 10) with respect to the crankshaft at a rotation speed of １ ／.

On the right bank side, there are provided a first reversing gear pulley 78 and a second reversing gear pulley 80 which mesh with each other and rotate backward at the same speed. The first reversing gear pulley 78 is coaxially fixed to the second sprocket 76 and rotates integrally with the second sprocket 76. The second reverse gear pulley 80 is fixed to one end of a drive shaft 111R of the right bank, and rotates integrally with the drive shaft 111R. Therefore,
The drive shaft 111R of the right bank rotates in a reverse direction (counterclockwise in FIG. 10) with respect to the crankshaft at a rotation speed of １ ／.

As described above, with a relatively simple structure, the drive shafts 111R and 111L of both banks can be rotated in opposite directions at a constant speed.

FIGS. 11 and 12 show a sixth embodiment.
The specific configuration and the basic operating principle of each variable valve mechanism are substantially the same as those in the first embodiment, and the same components are denoted by the same reference numerals and redundant description will be appropriately omitted. .

Also in the sixth embodiment, as shown in FIG. 12, the cylinder block mounting surfaces RHa, LHa of the cylinder heads RH, LH are inclined with a predetermined bank angle. In each of the cylinder heads RH and LH, an intake valve 19 is arranged inside the bank, and an exhaust valve 62 is arranged outside the bank. Above the exhaust valve 62, a valve lifter 60 is provided.
Camshaft 35 for driving the exhaust valve 62 to open and close by pressing
Are rotatably supported by the cylinder heads RH and LH via a bearing bracket 36 and a bolt 37.

In the sixth embodiment, similarly to the fifth embodiment, the variable valve mechanisms of the left and right banks are set substantially symmetrically with respect to the bank center line 32 when viewed in the same axial direction. . The rotation directions of the drive shafts 11R and 11L of the left and right banks are set to be opposite to each other, and the rotation directions of the control shafts 14R and 14L of the left and right banks are set to be opposite to each other. Therefore, the valve lift characteristic of the intake valve 19 to which the variable valve operating mechanism is applied and its change can be made equal between the left and right banks.

A variable valve mechanism for changing the operation mode of the intake valve 19 is disposed on the bank inner side (intake side) of the cylinder axis 33. Therefore, as compared with the configuration of the fourth embodiment, although the overall height of the engine cannot be suppressed so low, it is not necessary to dispose the variable valve mechanism from the exhaust side to the intake side, so that the structure is simplified. This is advantageous.

Next, a configuration for rotating the drive shafts 11R and 11L of the left and right banks in opposite directions will be described with reference to FIG.

A chain 72 is wound around a crank sprocket 70 that rotates clockwise together with the crankshaft and cam sprockets 84R and 84L in the left and right banks. These cam sprockets 84R, 84
The number L of teeth is set such that L rotates at half the rotational speed in the same direction with respect to the crank sprocket 70.
Each bank is provided with a first gear 86 and a second gear 88 that mesh with each other and rotate in the opposite direction at the same speed. Each first
The gear 86 is coaxially fixed to the cam sprocket 84 and rotates integrally with the cam sprocket 84.

In the right bank, the cam sprocket 84R is fixed to one end of the drive shaft 11R on the intake side,
The gear 88R is fixed to one end of the cam shaft 35R on the exhaust side. Therefore, the drive shaft 11R rotates at a speed of 1/2 in the same direction as the crankshaft, and the exhaust camshaft 35R rotates at a speed of 1/2 in the direction opposite to the crankshaft. On the other hand, in the left bank, the cam sprocket 84L
Are fixed to the exhaust side camshaft 35L, and the second gear 88
L is fixed to the drive shaft 11L on the intake side. Therefore,
The drive shaft 11L rotates at a half speed in the direction opposite to the crankshaft, and the camshaft 35L rotates at a half speed in the same direction as the crankshaft.

In the fifth embodiment, the drive shafts 11R and 11L and the camshaft 35 of the two banks are rotated in opposite directions at a constant speed with a simple structure that does not require the idler sprocket 76 and the like of the fourth embodiment. Can be done.

In FIGS. 1, 2, and 6 to 12, both banks are shown at the moment when the maximum lift is reached, but this is shown for convenience of explanation. is there. Actually, like the general multi-cylinder engine, the moment of the maximum lift comes sequentially, and a plurality of cylinders do not become the maximum lift at the same time.

As a configuration common to all the above-described embodiments, first, as viewed in the same axis direction, the lift direction of the swing cam with respect to the rotation direction of the drive shaft (the swing direction from the lift start position to the maximum lift position, Alternatively, the swing direction from the maximum lift position to the lift end position) is set to the same direction in the left and right banks. Therefore, the valve lift characteristics of the left and right banks can be made substantially equal.

Secondly, when viewed in the same axis direction, the rotation direction of the control shaft with respect to the rotation direction of the drive shaft is set to the same direction in the left and right banks. Therefore, the change of the valve lift characteristic accompanying the rotation of the control shaft can be made substantially equal between the left and right banks.

[Brief description of the drawings]

FIG. 1 is an enlarged view of a main part of FIG. 2 showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a left and right cylinder head to which the variable valve apparatus according to the first embodiment is applied.

FIG. 3 is a front view showing the variable valve mechanism alone.

FIG. 4 is an explanatory diagram showing dimensions of the variable valve mechanism.

FIG. 5 is an explanatory view showing dimensions of the variable valve mechanism.

FIG. 6 is a configuration diagram showing a variable valve apparatus according to a second embodiment of the present invention.

FIG. 7 is a configuration diagram showing a variable valve apparatus according to a third embodiment of the present invention.

FIG. 8 is a configuration diagram showing a variable valve apparatus according to a fourth embodiment of the present invention.

FIG. 9 is a configuration diagram showing a variable valve apparatus according to a fifth embodiment of the present invention.

FIG. 10 is a configuration diagram of an internal combustion engine to which the variable valve device of the fifth embodiment is applied.

FIG. 11 is a configuration diagram showing a variable valve apparatus according to a sixth embodiment of the present invention.

FIG. 12 is a configuration diagram of an internal combustion engine to which the variable valve apparatus of the sixth embodiment is applied.

[Explanation of symbols]

 11, 111 drive shaft 12, 112 eccentric cam 13, 113 ring-shaped link (first link member) 14, 114 control shaft 15, 115 control cam 16, 116 rocker arm 17, 117 rod-shaped link (Second link member) 18, 118: swing cam 19, 119: intake valve

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yoshihiko Yamada 1370 Onna, Atsugi-shi, Kanagawa Prefecture Inside Unisex Jex Co., Ltd. Term (reference) 3G016 AA08 AA10 AA19 BA19 BA21 BA23 BA28 BA33 BA34 BA36 BA40 BB04 BB11 BB25 CA06 CA08 CA09 CA10 CA21 CA25 CA34 CA47 DA08 FA29 GA00 3G018 AA07 AB05 AB07 AB17 BA02 BA06 BA09 BA17 BA19 BA24 BA32 DA01 DA13 DA DA15 DA19 DA70 DA77 DA85 EA24 EA31 EA32 FA01 FA06 GA02 GA04 GA06 GA07 GA14

Claims (16)

[Claims] In a variable valve operating apparatus for a V-type internal combustion engine in which a variable valve operating mechanism is provided in each of right and left banks, each variable valve operating mechanism is biased to a drive shaft that rotates in conjunction with a crankshaft of the engine. The eccentric cam provided with the center
A swing cam that drives the exhaust valve, a transmission mechanism that mechanically links the eccentric cam and the swing cam, and a control mechanism that changes the attitude of the transmission mechanism. A variable valve train for a V-type internal combustion engine, wherein a lift direction of a swing cam with respect to a rotation direction of a drive shaft is set to the same direction in right and left banks. 2. The transmission mechanism according to claim 1, wherein the first link member is rotatably fitted to the outer periphery of the eccentric cam, and a rocker arm having one end connected to the tip of the first link member so as to be relatively rotatable. A second link member rotatably connected to the other end of the rocker arm and the swing cam, wherein the control mechanism extends substantially parallel to the drive shaft, and is provided in accordance with an operation state of the engine. A control shaft rotated and held at a predetermined angle;
A control cam provided eccentrically to the control shaft,
2. The variable valve operating apparatus for a V-type internal combustion engine according to claim 1, wherein said rocker arm is fitted to said control cam so as to be relatively rotatable. 3. The V-type internal combustion engine according to claim 2, wherein the rotation direction of the control shaft with respect to the rotation direction of the drive shaft is set to be the same in the left and right banks when viewed in the same axial direction. Variable valve device. 4. The variable valve mechanism of the left and right banks is set to have substantially similar shapes with reference to the valve axis, and the rotation directions of the drive shafts of the left and right banks are set in the same direction when viewed in the same axial direction. The variable valve train for a V-type internal combustion engine according to any one of claims 1 to 3. 5. A variable valve mechanism for a V-type internal combustion engine in which a variable valve mechanism is provided in each of the left and right banks, wherein each variable valve mechanism includes a drive shaft that rotates in conjunction with a crankshaft, and a drive shaft that rotates the drive shaft. A control shaft that extends substantially parallel to the shaft and is rotated and held at a predetermined angle in accordance with the operation state of the engine; and a swing cam that is fitted to the outer periphery of the drive shaft so as to be relatively rotatable and drives an intake / exhaust valve. An eccentric cam provided eccentrically to the drive shaft, a first link member externally rotatably fitted to the outer periphery of the eccentric cam, a control cam eccentrically provided to the control shaft, and the control cam A rocker arm that is rotatably fitted to the outer circumference of the first link member and has one end connected to the tip of the first link member so as to be relatively rotatable; and a rotatably connected to the other end of the rocker arm and the swing cam. A second link member, In the same axis direction, the variable valve mechanisms of the left and right banks are set to have substantially similar shapes based on the valve axis, and the rotation directions of the drive shafts of the left and right banks are set to the same direction. A variable valve train for a V-type internal combustion engine. 6. A straight line connecting the center of the drive shaft and the center of the control shaft with respect to the valve axis of the intake / exhaust valve is set at a position rotated by the same angle in the same direction in the left and right banks. The variable valve apparatus for a V-type internal combustion engine according to claim 5, wherein 7. The distance from the center of the drive shaft to the center of the control shaft is set equally in the left and right banks, and the distance from the connecting portion between the swing cam and the second link member during the maximum lift to the center of the drive shaft is set. The distance is set equal for the left and right banks, and the center of the control shaft of the other bank is rotated by a predetermined angle in a predetermined direction about the drive axis with respect to the valve axis of the intake / exhaust valve with respect to one bank. And the connecting portion on the other bank side in the same direction as the control axis with respect to the straight line connecting the center of the swing cam and the lift start position with respect to the one bank side. 6. The variable valve operating apparatus for a V-type internal combustion engine according to claim 5, wherein the variable valve operating apparatus is set at a position rotated around the drive shaft by an angle. 8. A connecting portion between the swing cam and the second link member at the time of the maximum lift is arranged on an extension of a straight line connecting the center of the control shaft of the left and right banks and the center of the drive shaft. The variable valve train for a V-type internal combustion engine according to claim 5 or 7, wherein 9. The center of the drive shaft and the center of the control shaft,
6. The variable valve train for a V-type internal combustion engine according to claim 5, wherein both the left and right banks are arranged on the valve axis of the intake and exhaust valves. 10. The control axis of one bank is set at a position rotated by a predetermined angle in a predetermined direction around a drive axis with respect to the valve axis of the intake / exhaust valve, while the control axis of the other bank is set to a valve position. 8. The variable valve apparatus for a V-type internal combustion engine according to claim 7, wherein the control valve is set at a position rotated by the same angle in a direction opposite to that of the control axis of the one bank with respect to the axis. 11. At least one of the left and right banks, the center of the control shaft, the swing cam during the maximum lift, and the second
The connecting portion with the link member is disposed on the opposite side to the valve axis when viewed in the axial direction.
The variable valve train for a V-type internal combustion engine according to any one of claims 10 to 10. 12. The center of at least one of the control shafts of the left and right banks is disposed closer to the center of the cylinder head than the valve axis of the intake / exhaust valve.
The variable valve train for a V-type internal combustion engine according to any one of the preceding claims. 13. The invention is applied to an intake side of a laterally mounted V-type internal combustion engine, wherein at least a center of a control shaft in a vehicle front bank is arranged closer to a center of a cylinder head than a valve axis of an intake valve. The variable valve train of a V-type internal combustion engine according to claim 12, wherein 14. The variable valve mechanisms of the left and right banks are set substantially symmetrically with respect to the bank center line when viewed in the same axial direction, and the rotation directions of the drive shafts of the left and right banks are set opposite to each other. The variable valve train for a V-type internal combustion engine according to any one of claims 1 to 3, wherein: 15. The left and right bank intake valves are disposed inside the bank, the exhaust valve is disposed outside the bank, the swing cam for driving the intake valve is disposed inside the bank, and the drive shaft is disposed outside the bank. The variable valve train of a V-type internal combustion engine according to any one of claims 1 to 3, wherein the transmission mechanism is disposed from the outside of the bank to the inside of the bank. 16. A first sprocket and a second sprocket that rotate in the same direction as the crankshaft, and a first reversing gear pulley and a second reversing gear pulley that mesh with each other and rotate in the opposite direction, and the first sprocket is divided into left and right banks. The V-type internal combustion engine according to claim 15, wherein the first reverse gear pulley is fixed to the second sprocket, and the second reverse gear pulley is fixed to the other drive shaft. Variable valve device.