JP2955010B2 - Valve train for multi-cylinder engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an engine valve train, and more particularly to an engine valve train in which the opening characteristics of an intake valve or an exhaust valve are changed according to an operating state. About.

(Prior Art) In a valve operating device for an engine, a cam for operating an intake valve or an exhaust valve is switched according to an operating state, and a valve opening period, a valve lift amount, and the like are changed according to an operating state to vary the valve opening. Engine valve trains adapted to provide characteristics are known.

For example, Japanese Patent Application Laid-Open No. 63-147909 discloses an example of a valve train in which a cam is switched according to an operation state.

(Problems to be Solved) In the conventional apparatus, there is a problem that the operation of switching the cam to be used according to the operation state is not always smooth, and therefore, it is not always possible to obtain a good operation feeling.

Accordingly, it is an object of the present invention to provide a valve train for a multi-cylinder engine that is relatively compact and that can quickly switch valve opening characteristics.

(Means for Solving the Problems) That is, the valve train of the engine according to the present invention is at least arranged so as to include a set of cylinders whose ignition order is adjacent and a set of cylinders whose ignition order is not adjacent. A multi-cylinder engine comprising four cylinders, comprising: a camshaft; and an intake valve or an exhaust valve provided on the camshaft and selectively used to provide one cylinder of the engine. A first cam and a second cam that provide different valve-opening characteristics according to the first and second cams; a first rocker arm arranged to face the first cam to operate a stem of the valve; and a second rocker arm that does not interfere with the stem. A second rocker arm disposed opposite to the cam; and the first and second rocker arms are movable in the first and second rocker arms in the cylinder arrangement direction. And a selector pin member capable of taking a first position for engaging the two and a second position for releasing the engagement so that the first rocker arm operates independently of the second rocker arm. A lever mechanism that is engaged at one end so that the selector pin member takes the first position or the second position and controls the movement thereof; and a lever mechanism that is provided movably in the cylinder arrangement direction and engages with the other end of the lever mechanism. A moving pin member for actuating the lever mechanism, an elastic member for urging the moving pin member, and operation control means for controlling the operation of the moving pin member in accordance with an operation state, wherein the lever mechanism is a cylinder. It is located outside the first rocker arm and the second rocker arm in the arrangement direction, and is arranged to engage with one end of the selector pin member. The selector pin is provided for each cylinder. The moving pin member operates the selector pin members between cylinders whose ignition orders are not adjacent to each other at the same time, so that the operation timing of each selector pin member between cylinders whose ignition orders are adjacent is different. At least a set of cylinders in which the ignition order is not adjacent and a set of cylinders in which the ignition order is adjacent are provided, respectively, and the operation control means is configured to divide each of the moving pin members between the cylinders in which the ignition order is not adjacent. When the cam corresponding to each of the first and second rocker arms is at a rotational position that does not operate the valve, the selector pin member operates the first and second rocker arms in the coupling direction via the lever mechanism. And

In a preferred embodiment, the selector pin member, the lever mechanism, and the moving pin member are provided for each cylinder, and the operation control means is located between cylinder groups or cylinders in which the ignition order is not continuous in the cylinder arrangement direction. When the ignition sequence occurs in the order of 1-3-4-2 cylinders in the in-line four-cylinder engine, the operation control means is arranged between the second cylinder and the third cylinder. Further, in the V-type six-cylinder engine, since there is no continuous cylinder in the cylinder group of each adjacent bank, it is sufficient to provide one cylinder for each bank. Switching between the interlocking state and the non-interlocking state of the rocker arm is performed when the first and second rocker arms are engaged with the base circle portion of the cam, that is, while the valve is closed.

More preferably, the moving pin and the elastic member are provided in the cylinder head.

(Operation) According to the present invention, when the selector pin member is at the first position, the first rocker arm and the second rocker arm are connected to make the two rockers interlock. In this case, the second cam has a larger cam profile than the first cam.
Therefore, the first rocker arm is not affected by the cam profile of the first cam provided opposite thereto, and is moved by the operating force from the second cam transmitted through the second rocker arm. Therefore, the valve opening characteristic in this case is defined by the cam profile of the second cam.

When the selector pin member is at the second position, the engagement between the first rocker arm and the second rocker arm is released, and a non-interlocked state is realized. Thereby, the first
The rocker arm and the second rocker arm are independently moved by the first cam and the second cam, respectively. Therefore, in this case, the valve opening characteristic is defined by the cam profile of the first cam.

For example, when the ignition order occurs in the order of 1-3-4-2 in an inline four-cylinder engine, the operation control means is arranged between the second cylinder and the third cylinder in the cylinder arrangement direction. In this case, one cylinder group is a first cylinder and a second cylinder, and the other cylinder group is a third cylinder and a fourth cylinder. Not included. By doing this, first,
Immediately after the first cylinder closes, the selector pin member
When biased to the position, the first and second rocker arms of the first cylinder are in contact with the base circle of the cam,
It can move in the cylinder arrangement direction, and can be in the interlocked state by taking the first position.

At this time, since the rocker arm of the second cylinder is also in contact with the base circle, the rocker arm of the first cylinder can be interlocked with the rocker arm of the first cylinder. At this time, in the other cylinder group including the third cylinder and the fourth cylinder, the third cylinder opens after the first cylinder, so that the first position cannot be realized at this timing. But the third
When the cylinder closes the valve, the rocker arms of the third and fourth cylinders can simultaneously assume the first position. That is, according to the configuration of the present invention, the switching operation of the rocker arms of all the cylinders can be completed while the camshaft makes one rotation.

(Explanation of Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

Referring to FIG. 1, there is shown a plan view of an engine 1 according to one embodiment of the present invention with a cylinder head cover removed.

The engine 1 of this embodiment is an in-line four-cylinder engine, and includes a pair of intake valves 2 and a pair of exhaust valves 3 for each of the cylinders 1C, 2C, 3C, and 4C. In FIG. 1, a first cylinder 1C, a second cylinder 2C, a third cylinder
3C and the fourth cylinder 4C are arranged in this order.

Referring to FIG. 2, FIG. 3 and FIG. 4 together,
The intake camshaft 4 and the exhaust camshaft 5 are arranged so as to extend in the direction in which the cylinders are arranged. The intake camshaft 4 has a cylinder head 6 as shown in FIG.
And a journal portion constituted by a cam cap 8 fixed to the cylinder head 6 by bolts and nuts 7 so as to be rotatable. This journal portion is provided between each cylinder.

The exhaust camshaft 5 is composed of a cam cap 8a fixed to the cylinder head 6 by bolts and nuts 7a, and is rotatably supported by journals provided between the cylinders.

The intake camshaft 4 is provided with a pair of first cams 9 for each cylinder and a second cam 10 located between the first cams 9. The axial width of the first cam 9 is smaller than that of the second cam 10.

The first cam 9 is provided at a position corresponding to the position of the intake valve 2 in the axial direction of the camshaft 4. The second cam 10 is located between the two intake valves 2.

Referring also to FIG. 5, the intake camshaft 4
Below this, an intake rocker shaft 11 extends parallel to this. The rocker shaft 11 has a first cam 9
And a pair of the first
A second rocker arm 13 that is provided corresponding to the rocker arms 12A and 12B and the second cam 10 and swings in contact with the second cam 10 is attached.

Referring also to FIG. 3, the first rocker arm 12
A has a connecting portion 12a at the inner end of the rocker shaft 11 that comes into contact with the end of the valve stem 2a of the intake valve 2. The intake valve 2 is urged upward in FIG. 3 by a spring restraint 14 provided at the tip of the valve stem 2a and a valve spring 15 contracted between the cylinder head 6 and the upper surface. It is held in contact with the contact portion 12a of 12A. The first rocker arm 12A has a first cam 9
And a lightweight ceramic first roller 16 that makes rolling contact with the first roller 16. The first roller 16 rotates while being in rolling contact with the first cam 9 around the roller shaft 17.

As shown in FIG. 2, the second rocker arm 13 also has a second roller 18 in the form of a steel needle roller which makes rolling contact with the second cam 10.
Has a structure in which a plurality of needles 20 are arranged around a roller shaft 19.

The second rocker arm 13 has a contact portion 13a that contacts the urging member 21 below the second roller 18, and the urging member 21 is compressed into a recess formed at the top of the cylinder head 6. Urged upward by the spring 22
As a result, the urging member 21 is maintained in a state of being urged upward in FIG. 2 while always in contact with the second rocker arm 13.

Referring to FIGS. 6 to 8 together, a switching device 23 for switching whether or not the first rocker arms 12A and 12B and the second rocker arm 13 are interlocked is provided. The switching device 23 includes a first rocker arm.
The first rocker arm 12 is accommodated in a through-hole 24 provided in the rocker arm 12A in a non-interlocking state in which the second rocker arm 13 swings independently, and the first rocker arm 13 is slidable in the axial direction of the camshaft 4.
The selector pin 25 is accommodated in the second selector pin 27 slidably accommodated in the through hole 26 of the second rocker arm 13 and the recess 28 of the first rocker arm 12 in the non-interlocked state. A spring 29 is provided to abut one end of the second selector pin 27 to urge the first and second selector pins 25 and 27 downward in FIG.

Further, the switching device 23 is provided with first and second sliding pins 30 and 31 provided for each cylinder slidably disposed in the cylinder head 6 in the axial direction of the camshaft 4, and the pins 30 and 31. And a spring 32 for urging the pins 30 and 31 away from each other. Further, the switching device 23 has a lever 34 pivotally attached to a shaft member 33 attached to the cylinder head 6.
As shown in FIG. 6, the selector pin 25 and the sliding pin 30
Or, to engage both 31, the pivot of lever 34 is inclined. One arm 34a of the lever 34 has an L-shaped bent shape, and the tip of the arm 34a is in contact with one end of the first selector pin 25. This switching device 23
Is provided for each of the cylinders 1C, 2C, 3C and 4C. As shown in FIG. 1, a drive mechanism 35 for driving the switching device 23 for operating the switching device 23 is provided between the second cylinder 2C and the third cylinder 3C in the axial direction of the camshaft 4. Provided. In this case, the switching device 23 for switching between the first cylinder 1C and the second cylinder 2C includes the third cylinder 4C and the fourth cylinder 4C.
Are arranged in a symmetrical relationship with respect to the drive mechanism 35.

Therefore, the switching device for the first cylinder 1C and the fourth cylinder 4C
23 has a symmetrical structure, and the other arm 34b of these levers 34 is in contact with the end surface of the first sliding pin 30 on the side surface near the drive mechanism 35 in the axial direction of the camshaft 4. Switching device for the second cylinder 2C and the third cylinder 3C
23 has a symmetrical structure with respect to a drive mechanism 35, and the other arm 34b of these levers 34
The first sliding pin on the side near the drive mechanism 35 in the axial direction of
It is in contact with 30 end faces. The side surface farther from the drive mechanism 35 is in contact with the end surface of the second sliding pin. That is, the other arm 34b of the switching device 23 for the second cylinder 2C and the third cylinder 3C is the first arm 34b in the axial direction of the camshaft 4.
And the second sliding pin.

The drive mechanism 35 includes a support portion formed on the cylinder head 6.
A rotary shaft 36 extending parallel to the camshaft 4 rotatably supported by 6b is provided, and a fan-shaped urging member 37 is fixed to the rotary shaft 36 as shown in FIG. . The urging member 37 swings in a plane orthogonal to the axis of the camshaft 4 as the rotating shaft 36 rotates around an axis parallel to the camshaft 4. On both sides of the urging member 37,
The distal ends of the second sliding pins 31 of the switching device 23 for the second cylinder 2C and the third cylinder 3C are pressed against each other by the elastic force of the spring 32.

The urging member 37 has a shape whose thickness changes in the swing direction. That is, it has a thick portion 37a and a thin portion 37b. Therefore, when the urging member 37 swings, the contact position of the tip of the second sliding pin 31 between the thick portion 37a and the thin portion 37b changes. For this reason, the second sliding pin 31 of the switching device 23 for the second cylinder 2C and the third cylinder 3C is provided with an urging member.
When the 37 is swung, the camshaft 4 is displaced in the axial direction.

The swing of the second sliding pin 31 of the switching device 23 for the second cylinder 2C and the third cylinder 3C is caused by the spring 32 and the first sliding pin 30 of the switching device 23 for the second cylinder 2C. And transmitted to the second cylinder 2C lever 34 via the second cylinder 2C.
Is transmitted to the lever 34 for the first cylinder 1C via the second sliding pin 31, the spring 32 and the first sliding pin 30 of the switching device 23 for the first cylinder 1C.

On the other hand, it is transmitted to the lever 34 for the third cylinder 3C via the spring 32 and the first sliding pin 30 of the switching device 23 for the third cylinder 3C, and further transmitted to the switching device 23 for the third cylinder 2C. Lever 34, the second switching device 23 for the fourth cylinder 4C
The power is transmitted to the fourth cylinder 4C lever 34 via the sliding pin 31, the spring 32 and the first sliding pin 30.

Thus, the swing of the urging member 37 of the drive mechanism 35 is
When transmitted to the lever 34 of the switching device 23 for 1C, 2C, 3C and 4C, the first selector pin 25 abutting on the tip of one arm 34a of the lever 34 is connected to the first rocker arm 12A.
In the axial direction of the camshaft 4, thereby achieving the non-interlocking state or the interlocking state of the first and second rocker arms 13.

In this case, referring to FIGS. 9A and 9B, in the state of FIG. 9A, the first selector pin 25 and the second selector pin 27
And the spring 29 are connected to the first rocker arm 12 respectively.
A, the first rocker arm 13 is housed inside the second rocker arm 13 and the first rocker arm 12B.
12 shows a state in which the second rocker arm 13 and the second rocker arm 13 are not linked. In this state, the flange portion formed at the end of the first selector pin 25 engaging with the tip of one arm 34a of the lever 34
25a is located leftward in the figure from the entrance of the hole 24 of the first rocker arm 12A. The first selector pin 25 is formed at a boundary between a small diameter portion 25b formed at an end opposite to the flange portion 25a and a large diameter portion 25c formed between the flange portion 25a and the small diameter portion 25b. And a step 25d. In the state of FIG. 9A, the small diameter portion of the first selector pin 25
25b is separated from the reduced diameter portion 26a formed at one entrance of the hole 26 of the second rocker arm 13, and the step 25d is separated from one entrance of the hole 26 of the second rocker arm 13. ing.

In the state shown in FIG. 9B, the lever 34 is in a position where the spring 29 is compressed and rotated counterclockwise from the state shown in FIG. 9A, and the first selector pin 25 is
a is engaged with one entrance of the hole 24 of the first rocker arm 12A, and its small diameter portion 25b enters into the reduced diameter portion 26a of the entrance of the hole 26 of the second rocker arm 13. , Step 25d
Abuts its entrance end. In this state, the first rocker arms 12A and 12B and the second rocker arm 13 are linked.

In FIG. 7, in order to facilitate understanding, the first cylinder
1C and the second cylinder 2C, the second sliding pin 31 abuts the thin portion 37b of the urging member 37 and is not interlocked, and in the third cylinder 3C and the fourth cylinder 4C, the second sliding pin 31 is thick. Abuts part 37a,
Although in an interlocked state, in actual operation, the contact portion to the urging member 37 does not differ among the cylinders 1C, 2C, 3C, and 4C.

The second cam 10 has a larger cam profile than the first cam 9, and when the first and second rocker arms 13 are in the interlocked state, the opening characteristic of the intake valve 2 is as follows.
Controlled by the cam profile of the second cam 10, the first cam 9
It is not affected by the cam profile.

That is, in this case, the valve opening characteristic of the intake valve 2 is the second
Determined by the cam profile of cam 10. Also, the first
And when the second rocker arm 13 is in the non-interlocked state, the first rocker arm 12 is
Independent of 13, it swings according to the cam profile of the first cam 9. In this case, the valve opening characteristics of the intake valve 2 are:
The valve profile is not affected by the cam profile of the second cam 10. In this case, the second rocker arm 13 swings in contact with the urging member 21 in a floating state regardless of the opening / closing operation of the intake valve 2.

A lever 38 is attached to one end of a rotation shaft 36 of the drive mechanism 35, and the lever 38 is connected to an operation rod 41 of an actuator 40 via a ring 39. The actuator 40 has a diaphragm (not shown) mechanism inside. An intake negative pressure downstream of the throttle valve is introduced into the pressure chamber via a communication pipe 42 in one of the diaphragm mechanisms. ing. When an intake negative pressure is introduced, the operating rod 41 is displaced in its axial direction, and this displacement is
To rotate the rotation shaft 36 of the drive mechanism 35 and swing the urging member 37.

When the load increases and the intake negative pressure decreases, the urging force of the diaphragm weakens and the operating rod 41 is returned by the elastic force of the spring.

The release of the negative pressure can also be performed by a solenoid (not shown) for controlling communication of the pressure chamber with the atmosphere. In this case, when the solenoid is activated,
The pressure chamber is released to the atmosphere, and the operating force due to the negative pressure of the intake air is eliminated, and the diaphragm is returned to the original state by a spring (not shown) for urging the other side of the diaphragm.

The exhaust camshaft 5 includes a pair of cams 45 corresponding to the respective exhaust valves 3. Exhaust camshaft 5
A rocker shaft for exhaust 46 rotatably supported by the cylinder head 6 is provided below the rocker shaft 46. A rocker arm 47 abutting on each cam 45 is attached to the rocker shaft 46. The rocker arm 47 has an abutting portion 47a that abuts on the distal end thereof with the distal end of the valve stem 3a of the exhaust valve 3.
And a roller 48 that comes into rolling contact with the surface of the cam 45. The roller 48 has the same material and structure as the second roller 18 described above.

The exhaust valve 3 is provided with a spring holder 49 and a valve spring 50 in the same manner as the intake valve 2. This elastic force causes the distal end of the valve stem 3 a to be connected to the rocker arm 47.
, Whereby the roller 48 and the cam face of the cam 45 are always kept in contact with each other.

The valve opening characteristics of the exhaust valve 3 are determined by the shape of the cam profile of the cam 45.

As shown in FIGS. 2 and 3, a part of an intake passage 51 and a part of an exhaust passage 52 are formed in the cylinder head 6, and intake air is supplied to a combustion chamber 53 formed by the cylinder block 52 and the cylinder head 6. It communicates via the valve 2 or the exhaust valve 3.

As shown in FIGS. 1 and 2, a cylinder head 6 is provided through a mounting hole 56 such that a spark plug 54 protrudes into a combustion chamber 53 for each cylinder 1C, 2C, 3C and 4C. Can be installed.

A cylinder head cover 57 is attached to the cylinder head 6 to cover the upper part of the valve gear.

Explaining the lubrication system of this valve gear, oil passages 58 and 59 extending along the central axis are formed inside the camshafts 4 and 5, respectively.
As shown in FIG. 4 and FIG. 4, each of the journal portions is provided with a camshaft 4,
5 are provided with radial oil passages 60, 61 leading to the outer surface. This lubricates the journal. In the structure of this embodiment, rocker shafts 11 and 46 are provided below the camshafts 4 and 5, and lubricating oil from the journals of the camshafts 4 and 5 is supplied to the rocker shafts 11 and 46 and the rocker arms 12 and 13. Lubricating the sliding contact part.

 The operation of the valve train having the above structure will be described.

When the engine 1 is started, intake air starts to be introduced through the intake passage 51.

When the engine load is small, a large intake negative pressure is generated because the throttle opening is small. When the intake negative pressure is large, the operating rod 41 moves in the lower left direction in FIG. 8, thereby rotating the lever 38 counterclockwise in FIG. 8 to achieve the state shown by the broken line in the figure.

As a result, the rotating shaft 36 rotates counterclockwise, and the fan-shaped urging member 37 swings in a direction orthogonal to the axial direction of the camshaft 4. As a result, the tip of the second sliding pin 31 changes from a state in which it contacts the thin portion 37b of the urging member 37 to a state in which it contacts the thick portion 37a of the urging member 37. In this case, the second
The sliding pin 31 has a thin-walled portion as the urging member 37 swings.
The contact position is changed along the inclined surfaces formed on both side surfaces of the urging member 37 so that the thick portion 37a continues from the thick portion 37a, and finally comes into a state of contact with the thick portion 37a.

That is, the second sliding pin 31 is displaced in the axial direction of the camshaft 4, and the interlocking state of the first rocker arm 12 and the second rocker arm 13 shown in FIG. 9B is realized.

In the interlocking state of the first rocker arm 12 and the second rocker arm 13, the valve opening characteristics are determined by the second cam 10,
The valve opening characteristics of the cam 9 according to the cam profile are not reflected in the actual operation of the intake valve 3.

In the in-line four-cylinder engine of this example, the ignition order is 1-3
It occurs in the order of 4-2. In this configuration, one cylinder group divided by the drive mechanism 35 is a first cylinder and a second cylinder, and the other cylinder group is a third cylinder and a fourth cylinder. Further, none of the cylinder groups includes a cylinder whose ignition order is continuous. In this configuration, immediately after the first cylinder 1C is closed, when the first selector pin 25 is urged toward the interlocked state by the lever 34, the first and second rocker arms 12, 13 of the first cylinder become Since the cams 9 and 10 are in contact with the base circles, the cams 9 and 10 can move in the cylinder arrangement direction, and are interlocked.

At this time, the first and second rocker arms 12, 13 of the second cylinder 2C are also in contact with the base circle.
The first and second rocker arms 12 and 13 of 1C can be interlocked. At this time, the third cylinder 3C and the fourth cylinder 3C
In the other cylinder group composed of the cylinders 4C, the third cylinder 3C opens after the first cylinder 1C, so that the interlocking state cannot be realized at this timing. But the third
At the same time when the intake valve 2 of the cylinder 3C is closed, the first and second rocker arms 12, 13 of the third cylinder 4C and the fourth cylinder 4C can be in an interlocking state. That is, according to the configuration of the present invention, the switching operation of the rocker arms of all the cylinders can be completed while the camshaft 4 makes one rotation.

Thereafter, when the engine load increases, the throttle opening increases, so that the intake negative pressure decreases, and the operating rod 41 of the actuator 40 is returned to the position shown by the solid line in FIG. 8 by the elastic force of the spring. Along with
The contact position of the second sliding pin 31 of the second cylinder 2C and the third cylinder 3C with the urging member 37 also changes from the thick portion 37a to the thin portion 37b, and the non-interlocking state shown in FIG. 9A is established. As a result, the second rocker arm 13 does not contribute to the operation of the intake valve 2 that swings in the free state. Therefore, the intake valve 2 operates with a valve opening characteristic according to the cam profile of the first cam 9.

In the above description, the present invention is limited to the example in which the present invention is applied to the intake valve 2. However, the present invention can be applied to a valve train of the exhaust valve 3. In this case, the overlap period becomes longer, a relatively large amount of residual unburned components is obtained, and the combustibility can be improved by the contribution of this component to combustion.

In this case, it is desirable to slightly change the load region of the engine in which the interlocking state is realized and electrically control the operation of the switching device 23 using a solenoid. In this case, it is necessary to perform load detection by electrical means, but this means can be performed by using any known means. It can be used arbitrarily, and this technique does not constitute a feature of the present invention.

Further, the valve train according to the present invention can be provided in both the intake system and the exhaust system.

(Effects of the Invention) According to the present invention, the selector pin and the lever mechanism for switching the rocker arm between the interlocking state and the non-interlocking state, and the operation control means for driving this switching are also provided on the cylinder head, so that the apparatus is compact. Can be

In addition, the above switching operation can be performed promptly, and the driving feeling can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a valve gear of an engine to which the present invention can be applied, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a sectional view taken along line BB of FIG. FIG. 4 and FIG.
FIG. 5 is a plan view of the valve gear of FIG. 1, particularly around the rocker shaft, and FIG. 6 is D- of FIG. 1.
D sectional view, FIG. 7 is an EE sectional view of FIG. 6, FIG. 8 is an FF arrow view of FIG. 1, FIG. 9A, FIG. 9B is an operation state of the switching device. FIG. DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Intake valve, 3 ... Exhaust valve, 4 ... Intake camshaft, 5 ... Exhaust camshaft, 6 ... Cylinder head, 9 ... First cam, 10 ... No. 2 cam, 11 ... rocker shaft for intake, 12 ... first rocker arm, 13 ... second rocker arm, 16 ... first roller, 18 ... second roller, 21 ... urging member, 22 ... ... Spring, 23 ... Switching device, 25 ... First selector pin, 27 ... Second selector pin, 30, 31 ... First and second sliding pins, 32 ... Spring, 34 ... Lever.

Claims (3)

(57) [Claims] 1. A multi-cylinder engine comprising at least four cylinders arranged so as to include a set of cylinders whose ignition order is adjacent and a set of cylinders whose ignition order is not adjacent, comprising: a camshaft; A first cam and a second cam which are provided on the top and selectively provide different valve opening characteristics according to an operation state to an intake valve or an exhaust valve provided for one cylinder of the engine, A first rocker arm disposed opposite to the first cam to actuate the stem of the valve; a second rocker arm disposed opposite to the second cam at a position not interfering with the stem; A first position movable in the second rocker arm in the cylinder arrangement direction and engaging the first and second rocker arms so that the first and second rocker arms are interlocked with each other; A selector pin member capable of taking a second position for disengaging the two so as to operate independently of the arm; and an end engaged at one end so that the selector pin member takes the first position or the second position. A lever mechanism for controlling the movement of the lever mechanism; a movable pin member movably provided in the cylinder arrangement direction to engage the other end of the lever mechanism to operate the lever mechanism; and bias the movable pin member. An elastic member, and operation control means for controlling the operation of the moving pin member in accordance with an operation state, wherein the lever mechanism is located outside the first rocker arm and the second rocker arm in the cylinder arrangement direction, The selector pin member is disposed so as to engage with one end of the selector pin member. The selector pin is provided for each cylinder, and the moving pin member is a cylinder whose ignition order is not adjacent to each other. Are operated at the same time, and at least a set of cylinders whose ignition order is not adjacent and a set of cylinders whose ignition order is adjacent so that the operation timing of each selector pin member between cylinders whose ignition order is adjacent is different. The operation control unit is configured to rotate the moving pin members such that cams respectively corresponding to the first and second rocker arms between cylinders whose ignition orders are not adjacent to each other do not operate valves. Wherein the selector pin member causes the first and second rocker arms to move in the coupling direction via the lever mechanism at the time of (1). 2. The apparatus according to claim 1, wherein said selector pin member, lever mechanism, and moving pin member are provided for each cylinder, and said operation control means is located between cylinder groups or cylinders whose ignition order is not continuous in the cylinder arrangement direction. The valve train of a multi-cylinder engine according to claim 1, wherein: 3. A valve train for a multi-cylinder engine according to claim 2, wherein said movable pin member and said elastic member are provided in a cylinder head.