JP2003129813A - Valve unit for internal-combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve unit wherein it is related to improvements in a valve unit for an internal-combustion engine, and especially a twist or tilt is restrained in a plurality of rocker arms at whatever operating mode of a pair of valve provided at every cylinder. SOLUTION: The valve unit for 4-stroke cycle internal-combustion engine is equipped with a first rocker arm 32 and a second rocker arm 33 which come into contact with two adjoining valves among either one of a suction valve 10, 11 and an exhaust valve 12, 13 or both (hereafter referred to as a valve), a free rocker arm 34 driven by a cam having a larger lift amount that the one of the first and second rocker arm 32, 33, and a changeover mechanism 59, 60, 61 and 62 which switches between connection and non-connection of the rocker arm 32, 33 and 34 selectively. The above changeover mechanism 59, 60, 61 and 62 are the valve unit for the internal-combustion engine provided between the valve contacting section 57 and 58.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a valve operating system for an internal combustion engine, and more particularly, to a valve provided for each cylinder.
The present invention relates to a valve train in which a plurality of rocker arms are prevented from being twisted or tilted regardless of the operation mode of a pair of valves.

[0002]

2. Description of the Related Art In a conventional four-stroke cycle internal combustion engine, a pair of valves provided for each cylinder, in particular, a top end of an intake valve is provided with a tappet screw (a valve contacting end) of a pair of first and second rocker arms. (Corresponding to a portion), and a free rocker arm driven by a cam having a larger lift amount than the first and second rocker arms is interposed between the first and second rocker arms. A valve operating device provided with a switching mechanism for selectively switching between connection and non-connection of the second rocker arm, and also provided with a switching mechanism for selectively switching between the first, second and free rocker arms at the same time to connect or disconnect. , As disclosed in Japanese Patent Laid-Open No. 6-93820.

[0003]

The four-stroke cycle internal combustion engine disclosed in Japanese Patent Laid-Open No. 6-93820 is a SOHC internal combustion engine having a single camshaft, and cams are provided on the base end side of rocker arms 17, 18, and 19. A slipper 25 in contact with the shaft 16 is arranged, a tappet screw 28 abutting against the top end of the intake valve is arranged at the tip opposite to the camshaft 16 with the rocker shaft 16 interposed therebetween, and the tip side of the free rocker arm 18 is formed short. Then, the tip connecting arm 29 of the first rocker arm 17 bypasses the tip end of the free rocker arm 18 and extends laterally toward the tip end of the second rocker arm 19, and the first rocker arm tip side connecting arm 29. And the second rocker arm 19
First, which selectively switches between the connection and the non-connection.
A switching mechanism 30 is provided, and the rocker arms 17, 18, 19 are provided at the base end side thereof with the first, second, and free rocker arms 17, 18,
A second switching mechanism 31 was provided for selectively switching 19 or 19 simultaneously to connect or disconnect.

When the second switching mechanism 31 is switched to the non-coupling state and the first switching mechanism 30 is switched to the coupling mode, the low speed cam 21 having a higher cam peak than the rest cam 23 contacting the second rocker arm 19 is formed. As a result, the first rocker arm 17 is driven to swing up and down, and the second rocker arm 19 is also driven to swing up and down integrally with the first rocker arm 17 by the cam mountain 21b of the low-speed cam 21. Therefore, when both the intake valves V ₁ and V ₂ are opened, the intake valve V ₂
The spring reaction force of the valve spring 15 causes an upward resistance force to act on the portion of the tip connecting arm 29 of the first rocker arm 17 adjacent to the second rocker arm 19, and the first rocker arm 17 is twisted about its longitudinal direction. Occurs. Moreover,
The guide holes 35, 47 of the first switching mechanism 30 are located substantially at the centers of the longitudinal arm portions of the first rocker arm 17 and the third rocker arm 19 protruding from the rocker arm shaft 24, and the first rocker arm 17 and the third rocker arm 19 Flexural rigidity and strength decrease.

Therefore, the torsional force generated in the first rocker arm 17 and the bending rigidity and strength reduction of the first rocker arm 17 and the third rocker arm 19 reduce the first rocker arm 17 and the first rocker arm 17.
It is necessary to make the rocker arm 17 and the third rocker arm 19 thick, and it is difficult to reduce the size and weight of the first rocker arm 17 and the third rocker arm 19.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an improvement of a valve operating system for an internal combustion engine which solves the above-mentioned problems. The invention according to claim 1 is one of an intake valve and an exhaust valve. Alternatively, the rocker arms may be provided with first and second rocker arms that are provided on two adjacent valves in both of them, and a free rocker arm that is driven by a cam having a larger lift amount than the first and second rocker arms. In a valve operating system for an internal combustion engine, which is provided with a switching mechanism for selectively switching non-coupling, the switching mechanism is provided between valve contact portions.

According to the first aspect of the present invention, since the switching mechanism is disposed between the valve contact portions, the rigidity of the valve contact side portion of the rocker arms is improved when the rocker arms are connected to each other, and the rocker arms are twisted or tilted. One-sided contact and uneven wear are suppressed.

Further, since the switching mechanism is located on the side of the valve contact portion, when the valve opening force from one rocker arm is applied to the valve via the switching mechanism and the other rocker arm, Almost no bending load acts on the other rocker arm, and it is possible to reduce the size and weight of the rocker arm while maintaining the required strength and rigidity.

Furthermore, as described in claim 2, by making the switching mechanism installation location in the first and second rocker arms project from the free rocker arm, the contact portion of the free rocker arm with the cam is sufficiently wide, It is possible to reduce the distance between the valves while maintaining sufficient rigidity by sufficiently thickening the portion where the switching mechanism is provided.

Further, as described in claim 3, when the valve is driven to open and close by the cam contacting the free rocker arm, the first and second valve opening forces applied from the free rocker arm to the first and second rocker arms. By providing the oil passage at a location avoiding the outermost portions of the first and second rocker arms, which generate a large stress due to the torsional load acting on the rocker arm, it is possible to suppress the decrease in rigidity of the first and second rocker arms. The size and weight of the second rocker arm can be reduced.

In this specification, the intake valve being substantially in the closed state means that the intake valve is not opened / closed at all, or the intake valve is opened / closed with a slight valve opening lift amount. The amount of air that flows into the combustion chamber when the intake valve is opened is very small, and the air is opened and closed with a valve opening lift amount that does not affect combustion in the combustion chamber. Means the state of Further, when the intake valve is substantially opened / closed, the intake valve is opened / closed with a valve opening lift amount that is an amount that the air flowing into the combustion chamber at the time of opening the intake valve is involved in combustion in the combustion chamber. Means that.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the invention described in claims 1 and 2 of the present application shown in FIGS. 1 to 12 will be described below.

The internal combustion engine 1 shown in FIGS. 1 and 2.
Is a four-stroke cycle in-line multi-cylinder DOHC type internal combustion engine mounted on a passenger car (not shown), in which a cylinder head 3 is coupled above a cylinder block 2 of the internal combustion engine 1, and a cylinder 4 of the cylinder block 2 has a piston. 5 is swingably fitted, the piston 5 is connected to a crankshaft (not shown) through a connecting rod 6, and the crankshaft is rotatably pivoted between the cylinder block 2 and a crankcase (not shown) or a crankshaft holder. A crankshaft (not shown) rotates in response to the piston 5 moving up and down by the combustion of the air-fuel mixture in the combustion chamber 7 which is supported and is formed by the piston 5 in the cylinder 4 and the cylinder head 3. It is designed to be driven.

Further, the cylinder head 3 is formed with a pair of intake valve openings and a pair of exhaust valve openings that open into the combustion chamber 7 for each cylinder 4, and both intake valve openings are part of the cylinder head 3. It communicates with an intake port 8 which joins and opens on a side surface, and both exhaust valve openings communicate with an exhaust port 9 which joins and opens on the other side surface of the cylinder head 3, and the two intake valve openings are separately driven. A pair of intake valves 10 and 11 are provided so that they can be opened and closed, and a pair of exhaust valves 12 and 13 that are driven integrally at the same time are provided at the openings of both exhaust valves so that they can be opened and closed. . In addition,
An intake manifold (not shown) connected to the intake port 8 is connected to one side surface of the cylinder head 3, and an exhaust manifold (not shown) connected to the exhaust port 9 is connected to the other side surface of the cylinder head 3.

Further, the valve rods of the intake valves 10 and 11 and the exhaust valves 12 and 13 are slidably fitted to the valve guide 14, and the valve spring receiving portions 15 are fitted to the upper exposed portions of the valve guide 14, respectively. At the same time, the retainer 16 is integrally attached to the valve rod ends of the intake valves 10 and 11 and the exhaust valves 12 and 13, and the valve spring 17 is interposed between the valve spring receiving portion 15 and the retainer 16. By the spring biasing force of the valve spring 17, the intake valve opening and the exhaust valve opening are closed by the intake valves 10 and 11 and the exhaust valves 12 and 13, respectively. And, the valve operating device corresponding to the invention of claim 1 to claim 3 of the present application,
In this embodiment, it is an intake system valve operating device.

Furthermore, a spark plug 18 is provided in the combustion chamber 7.
A spark plug 18 is attached so as to penetrate the cylinder head 3 so that the electrodes of the above are exposed, and a guide cylinder 19 is loosely fitted so as to cover the spark plug 18, and the intake valves 10, 11 and the exhaust valves 12, 13 are attached. The guide cylinder 19 is sandwiched at a position slightly higher than the valve rod end, and the intake rocker arm shaft 20 and the exhaust rocker arm shaft 21 are parallel to each other and are supported through the rocker arm shaft holder 22. An intake camshaft 23 and an exhaust camshaft 24 which are located outside and above the exhaust rocker arm shaft 21 and are parallel to the intake rocker arm shaft 20 and the exhaust rocker arm shaft 21, respectively.
Is rocker arm shaft holder 22 and cam shaft holder
The rocker arm shaft holder 22 and the cam shaft holder 25 are rotatably sandwiched between the cylinder head 3 and the cylinder head 3 by four bolts 26 which are screwed to the cylinder head 3 by penetrating them from above to below. Is attached to. The intake camshaft 23 and the exhaust camshaft 24 are connected to a crankshaft (not shown) via a sprocket (not shown) and a chain, and the intake camshaft 23 and the exhaust camshaft 24 make one revolution each time the crankshaft makes two revolutions. Is driven to rotate.

As shown in FIG. 2, the intake camshaft 23 has a first low-speed intake cam 27 and a second low-speed intake cam 27 which is longer than the valve opening period and has a large lift amount.
A low speed intake cam 28 and a high speed intake cam 29 are integrally formed in the middle of the low speed intake cam 28, and one exhaust cam 30 is provided on the exhaust cam shaft 24.
Are integrally formed.

The intake system rocker arm 31 in the intake system valve operating apparatus according to the present invention is the first intake rocker arm 3
2, a second intake rocker arm 33 and a free intake rocker arm 34. As shown in FIG. 4, the first intake rocker arm 32 and the second intake rocker arm 33 are U-shaped in a plan view with their base ends open. Notches 32f and 33f are formed, and the first intake inner rocker arm 35 and the second intake inner rocker arm 36 are housed in the U-shaped notches 32f and 33f. The first intake inner rocker arm
35, sleeve shafts 38, 39 on the second intake inner rocker arm 36
The inner ends of the rollers are integrally fitted, and rollers 44, 45 are rotatably supported in a cantilever manner on the sleeve shafts 38, 39 via needle rollers 41, 42, respectively. Is the first
The low speed intake cam 27 and the second low speed intake cam 28 are brought into contact with each other. Between the first intake rocker arm 33 and the second intake rocker arm 34, the free intake rocker arm 34
Are arranged on the free intake rocker arm 34 and the sleeve shaft 40
Both ends of the roller are integrally fitted, and a roller 46 is rotatably supported by the sleeve shaft 40 via a needle roller 43. The roller 46 comes into contact with the high-speed intake cam 29. There is. In the intake system rocker arm 31, the first intake rocker arm 32, the second intake rocker arm 33, the free intake rocker arm 34, the first intake inner rocker arm 35, and the second intake inner rocker arm 36 are fitted to one intake rocker arm shaft 20. All the distances from the center line of the intake rocker arm shaft 20 to the center lines of the sleeve shafts 38, 39, 40 are set to the same size.

Also, outer and inner wall side portions 32a, 32b, 33 of the first intake rocker arm 32 and the second intake rocker arm 33.
Piston holes 32c, 32d, 33c and 33d having the same diameter as the inner diameters of the sleeve shafts 38 and 39 are formed in a and 33b, and are integrated with the piston holes 32c and 32d of the first intake rocker arm 32 and the first intake inner rocker arm 35. In the center hole of the sleeve shaft 38 of
The connecting pins 47, 48, 49 are slidably fitted and
The connecting pins 50, 51, 52 are slidably fitted in the piston holes 33c, 33d of the second intake rocker arm 33 and the central hole of the sleeve shaft 39 integrated with the second intake inner rocker arm 36, and the connecting pin 49 and the first pin The return coil spring 53 is interposed between the intake rocker arm 32 and the bottom of the piston hole 32d of the inner wall 32b, and the connecting pin 52 and the second intake rocker arm 33 are provided.
The return coil spring 54 is interposed in the bottom of the piston hole 33d of the inner side wall 33b of the intake air rocker arm shaft 20 and the outer side wall 32a of the first intake rocker arm 32 and the outer side wall 33a of the second intake rocker arm 32. Oil passages that communicate with the piston holes 32c and 33c from the fitting holes of
55, 56 are formed, and when the pressure oil is not supplied to the oil passages 55, 56, the connecting pins 47, 48, 49 and the connecting pin 5 are caused by the spring biasing force of the return coil springs 53, 54.
0, 51, and 52 move outward, and the first intake inner rocker arm 35 is integrally connected to the first intake rocker arm 32, and the second intake inner rocker arm 36 is integrally connected to the second intake rocker arm 33. When the pressure oil is supplied to 55, 56, the connecting pins 47, 48, 49 and the connecting pins 50, 51, 52 move inward, respectively, and the first intake inner rocker arm 35, the second intake inner rocker arm 35. 36 is the first
The intake rocker arm 32 and the second intake rocker arm 33 can freely swing relative to each other.

Further, tappet screws 57 and 58 are respectively screwed to the tip ends of the first intake rocker arm 32 and the second intake rocker arm 33 so as to be capable of advancing and retreating, respectively, and substantially in the middle of the tappet screws 57 and 58, and the tappet screw 57, 58. The first intake rocker arm 32 and the second intake rocker arm 33 have piston holes 32e, 33e located on the same plane passing through the screwed portion to which 58 is screwed.
And a piston hole 32 of the first intake rocker arm 32 is formed.
e and the piston hole 33e of the second intake rocker arm 33 between the free intake rocker arm 34 and the piston through hole.
34a is formed, and connecting pins 59, 60, 61 are slidably fitted in the piston holes 32e, 33e and the piston through hole 34a, respectively, and the connecting pin 60 and the second intake rocker arm 33 are formed.
The return coil spring 62 is interposed in the tip piston hole 33e of the above, and the inner side wall portion 32b of the first intake rocker arm 32 is
An oil passage communicating from the fitting hole of the intake rocker arm shaft 20 to the bottom of the piston hole 32e of the first intake rocker arm 32.
When the pressure oil is not supplied to the oil passage 63, the connecting pins 59, 60, 61 are connected to the first intake rocker arm 32 by the spring biasing force of the return coil spring 62.
When the first intake rocker arm 32, the second intake rocker arm 33, and the free intake rocker arm 34 have their tip portions unconnected and pressure oil is supplied to the oil passage 63, the first intake rocker arm 32, the first intake rocker arm 32, 2 intake rocker arm 33
Further, the tip portion of the free intake rocker arm 34 is integrally connected.

Furthermore, the intake rocker arm shaft 20
In the three oil passages, as shown in FIG.
Oil passages 64, 6 communicating with 55, 56, 63 respectively
5, 66 are formed, and the oil passages 64, 65, 66 are connected to an oil pump via a control valve (not shown), and the oil is controlled by an operation control means (not shown) that operates by receiving an operation control command signal. The control valves provided in the passages 64, 65, 66 are selectively opened and closed.

In addition, spring receiving portions 34b, 34b are provided on the lower surfaces of the free intake rocker arm 34, the first intake inner rocker arm 35, and the second intake inner rocker arm 36, respectively.
35b and 36b are formed, and the lost motion spring receiving portion 67 formed on the cylinder head 3 and the spring receiving portion
A lost motion spring 68 is interposed between 34b, 35b, and 36b, and the first motion of the first intake rocker arm 32 is caused by the spring urging force of the lost motion spring 68.
Roller 44 of intake inner rocker arm 35 and roller 45 of second intake inner rocker arm 36 of second intake rocker arm 33
The roller 46 of the free intake rocker arm 34 is always in contact with the first low speed intake cam 27, the second low speed intake cam 28 and the high speed intake cam 29 of the intake camshaft 23.

Further, as shown in FIGS. 1 and 2, the exhaust rocker arm 37, which is fitted on the exhaust rocker arm shaft 21 so as to be vertically swingable, is of a one-body type.
The tappet screw 69 is screwed into the left and right ends of the exhaust rocker arm 37 so that the tappet screw 69 can abut the valve rod top ends of the two exhaust valves 12 and 13, and one tappet screw 69 provided on the exhaust camshaft 24 is provided. The exhaust cams 30 drive the exhaust valves 12 and 13 to open and close simultaneously.

Since the first embodiment of the present application described above is configured as described above, the following operation can be performed.

A. When starting, both intake valves 10 and 11 operate
State (see FIGS. 5 and 6) When the internal combustion engine 1 is started while the internal combustion engine 1 is stopped, the oil passages 64, 6 in the intake rocker arm shaft 20 are generated by the control signal based on the start command signal.
Since the control valves related to 5 and 66 are shut off, as shown in FIG. 5, the connecting pins 47, 48 and 49 are moved to the outside of the first intake rocker arm 32 by the spring biasing force of the return coil spring 53 ( Pushed downward)
The intake inner rocker arm 35 is integrally connected to the first intake rocker arm 32, and the connecting pins 50, 51, 52 are pushed outward of the second intake rocker arm 33 (upward in the drawing) by the spring biasing force of the return coil spring 54. Has been
The second intake inner rocker arm 36 is the second intake rocker arm
33, and the connecting pins 59, 60, 61 are pushed toward the first intake rocker arm 32 side (downward in the drawing) by the spring biasing force of the return coil spring 62, and the free intake rocker arm 34 becomes the first intake rocker arm 34. 32 and the second intake rocker arm 33 are not connected.

Therefore, when the crankshaft (not shown) is cranked by the starter motor (not shown), the intake camshaft 23 and the exhaust camshaft 24 are rotationally driven, and the intake valves 10 and 11 have the first low speed intake cam.
The exhaust valves 12 and 13 are driven to be opened / closed by the exhaust cam 30 while being driven to be opened / closed by the 27 and the second low speed intake cam 28, respectively, so that the internal combustion engine 1 can be operated at a low speed.

B. Cylinder idle operation state (see Fig. 7 and Fig. 8)
When any one of the plurality of cylinders 4 is deactivated in the operating state of the internal combustion engine 1, the deactivated cylinder 4 receives the control signal based on the cylinder deactivation command signal from the inside of the intake rocker arm shaft 20. Oil passage 64,65
Since the control valve related to is opened, as shown in FIG. 7, the connecting pins 47, 48, 49 are pressed by the pressure oil introduced into the piston hole 32c of the first intake rocker arm 32,
Overcome the spring biasing force of the return coil spring 53 and inside the first intake rocker arm 32 (upward in the drawing)
When the first intake inner rocker arm 35 is unconnected to the first intake rocker arm 32, the connecting pins 50, 51, 52 are pressed into the piston hole 33c of the second intake rocker arm 33. By return coil spring
The second intake inner rocker arm 36 is decoupled from the second intake rocker arm 33 by being pushed inward (downward in the drawing) of the second intake rocker arm 33 by overcoming the spring biasing force of 54, and the oil passage Since the control valve associated with 66 is closed, the connecting pins 59, 60, 61 are pushed toward the first intake rocker arm 32 side (downward in the drawing) by the spring biasing force of the return coil spring 62, and the free intake rocker arm 34. Is not connected to the first intake rocker arm 32 and the second intake rocker arm 33.

Therefore, in the idling operation, the internal combustion engine 1 is changed depending on the cylinder operating state in the other cylinder 4.
Even when is in the operating state, the cylinder 4 described above is in the idle state, so that the fuel supply amount is greatly reduced and the fuel efficiency is improved.

C. Intake valve 11 is paused
The first low speed operation in which only 10 is operated by the first low speed intake cam 27.
Rotation state (see FIG. 9) In the operating state of the internal combustion engine 1, when the intake valve 11 is stopped, based on the stop command signal of the intake valve 11,
The control signal causes the control valve associated with the oil passage 64 in the intake rocker arm shaft 20 to be shut off, so that the connecting pins 47, 48, 49 have springs of the return coil spring 53 as shown in FIG. The first intake inner rocker arm 35 is integrally connected to the first intake rocker arm 32 by being pushed outward by the force (downward in the drawing) of the first intake rocker arm 32. Since the related control valve is opened, the piston hole 33c of the second intake rocker arm 33 is opened.
The pressure oil is supplied to the connecting pins 50, 51, 52 by this pressure oil.
Overcomes the spring biasing force of the return coil spring 54 and is pushed inward (downward in the drawing) of the second intake rocker arm 33 so that the second intake inner rocker arm 36 moves to the second position.
The intake rocker arm 33 is not connected, and
Since the control valve associated with the oil passage 66 in the intake rocker arm shaft 20 is shut off, pressure oil is not supplied to the piston hole 32e of the first intake rocker arm 32, and the connecting pins 59, 60, 61 are returned to the return coil spring. The spring urging force of 62 pushes the second intake rocker arm 33 toward the inner force (downward in the drawing), so that the free intake rocker arm 34 is disconnected from the first intake rocker arm 32 and the second intake rocker arm 33.

Therefore, since only the intake valve 10 is opened / closed by the first low speed intake cam 27 having a cam lobe lower than that of the second low speed intake cam 28, the operating state suitable for the lowest operation is obtained.

D. Intake valve 10 paused and intake valve
Second low speed operation in which only 11 is operated by the second low speed intake cam 28
In the operating state of the internal combustion engine 1, when the intake valve 10 is deactivated, based on the deactivation command signal of the intake valve 10,
The control signal causes the control valve associated with the oil passage 65 in the intake rocker arm shaft 20 to be closed, so that the connecting pins 50, 51, 52 are provided with springs of the return coil spring 54 as shown in FIG. Second by power
The second intake inner rocker arm 36 is integrally connected to the second intake rocker arm 33 by being pushed outward of the intake rocker arm 33 (upward in the drawing), but a control valve related to the oil passage 64 in the intake rocker arm shaft 20. Is opened, so the piston hole 32c of the first intake rocker arm 32
Pressure oil is supplied to the connecting pins 47, 48,
49 overcomes the spring biasing force of the return coil spring 53 and is pushed inward (upward in the drawing) of the first intake rocker arm 32 so that the first intake inner rocker arm 35 moves to the first position.
It is not connected to the intake rocker arm 32, and further,
Since the control valve associated with the oil passage 66 in the intake rocker arm shaft 20 is shut off, pressure oil is not supplied to the piston hole 32e of the first intake rocker arm 32, and the connecting pins 59, 60, 61 are returned to the return coil spring. The spring urging force of 62 pushes the second intake rocker arm 33 inward (downward in the drawing), so that the free intake rocker arm 34 is disconnected from the first intake rocker arm 32 and the second intake rocker arm 33.

Therefore, since only the intake valve 10 is opened / closed by the second low speed intake cam 28 having a cam mountain higher than that of the first low speed intake cam 27, the operating state is suitable for operating in the second lowest operating state. .

E. Intake valve 10 and intake valve 11
1st low speed intake cam 27 and 2nd low speed intake cam 28
In the operating state of the internal combustion engine 1 in each of the medium speed operation states in which they operate (see FIGS. 5 and 6) , based on the medium speed operation command signal, the control signal causes the intake rocker arm shaft 20 to move in the same manner as the start command signal. The control valves associated with the oil passages 64, 65, 66 are all closed, the first intake inner rocker arm 35 is integrally connected to the first intake rocker arm 32, and the second intake inner rocker arm 36 is connected to the second intake rocker arm 33. And the free intake rocker arm 34 is integrally connected to the first intake rocker arm 32 and the second intake rocker arm 32.
Since the intake rocker arm 33 is not connected to the intake rocker arm 33, the intake valve 10 and the intake valve 11 are opened and closed, and the operating state is more suitable for the medium speed operation higher than the second low speed operation.

F. Both intake valve 10 and intake valve 11
The high-speed operation state that operates from the high-speed intake cam 29 (Fig. 11,
(See FIG. 12) In the operating state of the internal combustion engine 1, the intake rocker arm shaft is controlled by the control signal based on the high speed operation command signal.
Since the control valves related to the oil passages 64, 65, 66 in 20 are all opened, the piston hole 32c of the first intake rocker arm 32 and the piston hole 33c of the second intake rocker arm 33 are opened.
And pressure oil is supplied to the piston holes 32e of the first intake rocker arm 32, respectively, and the connection pins 47, 4 are supplied by this pressure oil.
8, 49, connecting pins 50, 51, 52 and connecting pins 59, 60, 61
Overcome the spring biasing forces of the return coil springs 53, 54 and the return coil spring 62, respectively, and the piston hole 32d of the first intake rocker arm 32, the piston hole 33d of the second intake rocker arm 33, and the second intake rocker arm 33.
The first intake inner rocker arm 35 is disengaged from the first intake rocker arm 32 by being pushed toward the piston hole 33e side of the second intake inner rocker arm 36.
Becomes unconnected to the second intake rocker arm 33,
Moreover, the first intake rocker arm 32 and the second intake rocker arm 33 are integrally connected to the free intake rocker arm 34. As a result, the first intake rocker arm 3 is contacted with the free intake rocker arm 34 that abuts against the high-speed intake cam 29 and swings up and down.
2. Since the second intake rocker arm 33 integrally swings up and down, the intake valves 10 and 11 are in an operating state suitable for high speed operation.

As described above, in this embodiment, the intake air can be supplied to the cylinder 4 in the intake state suitable for the five kinds of operation modes, so that the combustion chamber 7 can be properly operated in the entire operation region. Combustion is performed, exhaust gas properties are good, and fuel consumption is improved.

The first part of the intake system rocker arm 31
The connecting pins 59, 60, 61 for integrally connecting the intake air rocker arm 32, the second intake rocker arm 33 and the free intake rocker arm 34 to each other are provided with tappet screws 57, 58 at the tips of the first intake rocker arm 32 and the second intake rocker arm 33. Since it is arranged between the intake rocker arm shaft 20 and the tappet screws 57, 58, the distance from the intake rocker arm shaft 20 to the connecting pins 59, 60, 61 is substantially equal,
When the first intake rocker arm 32, the second intake rocker arm 33 and the free intake rocker arm 34 are connected by the connecting pins 59, 60 and 61, when the downward swinging force is transmitted from the free intake rocker arm 34 to the tappet screws 57 and 58, The bending moment hardly acts on the tip of the 1 intake rocker arm 32 and the 2nd intake rocker arm 33, and the torsion torque is small,
As a result, the inclination and swing of the first intake rocker arm 32 and the second intake rocker arm 33 are suppressed.

Further, the width of the tip portion of the free intake rocker arm 34 is narrower than the width of the central portion pivotally supporting the roller 46, and the first intake rocker arm 32 and the second intake rocker arm 33 are provided.
Since the inner side of the tip of the roller protrudes toward the free intake rocker arm 34, the width of the roller 46 that abuts against the high speed intake cam 29 is secured, and the connecting pin in the first intake rocker arm 32 and the second intake rocker arm 33 is secured. The space between the tappet screws 57 and 58, that is, the space between the intake valves 10 and 11 can be shortened while ensuring the space for housing the 59 and 60, and the internal combustion engine 1 can be made compact.

Furthermore, the roller 46 contacts the high speed intake cam 29, that is, the free intake rocker arm 34, the first intake rocker arm 32, and the second intake rocker arm 33 are integrated to form the first intake rocker arm 32, the second intake rocker arm 32, and the second intake rocker arm 32. Intake rocker arm
Since the first intake inner rocker arm 35 and the second intake inner rocker arm 36 are separated from the first intake rocker arm 32 and the second intake rocker arm 33 when the 33 is vertically swung by the free intake rocker arm 34, The inertial mass of the first intake rocker arm 32 and the second intake rocker arm 33 is reduced by the inertial mass of the first intake inner rocker arm 35, the second intake inner rocker arm 36, the needle rollers 41, 42 and the rollers 44, 45.

Moreover, the inner and outer side walls of the first intake rocker arm 32 and the second intake rocker arm 33 at the substantially central portions in the longitudinal direction are
Piston holes 32c, 32d, 33 of connecting pins 47, 49, 50, 52
c and 33d are blind holes, and the piston holes 32c, 32d and 33
Since the openings of c and 33d are not exposed on the outer side surface and the inner side surface, the first intake rocker arm 32 and the second intake rocker arm 33
The decrease in rigidity of the inner and outer walls of the is suppressed.

The piston holes 32e, 33e of the connecting pins 59, 60 are blind holes in the outer wall of the tips of the first intake rocker arm 32 and the second intake rocker arm 33.
Since the openings of e and 33e are not exposed on the outer side surface, the rigidity of the outer wall at the tip of the first intake rocker arm 32 and the second intake rocker arm 33 is less deteriorated.

Since the first intake inner rocker arm 35 and the second intake inner rocker arm 36 pivotally support the rollers 44 and 45 in a cantilever manner, the first intake inner rocker arm 35,
The width of the second intake inner rocker arm 36 has been greatly reduced,
The width of the intake system rocker arm 31 as a whole is significantly reduced, and the intake system rocker arm 31 as a whole can be made smaller and lighter.

Even if the roller 44 is cantilevered on the first intake inner rocker arm 35, if the first low speed intake cam 27 drives the first intake rocker arm 32 to swing up and down, Since the roller 44 is supported at both ends by the first intake inner rocker arm 35 by the connecting pins 47, 48, 49,
The roller 44 can be firmly and stably pivoted on both side walls of the first intake rocker arm 32. Similarly, the roller 45 can be firmly and stably pivoted on both side walls of the second intake rocker arm 33.

The first intake rocker arm 32, the second intake rocker arm 33, and the free intake rocker arm 34 are connected to the first through the needle rollers 41, 42, 43 and rollers 44, 45, 46.
Low speed intake cam 27, second low speed intake cam 28, high speed intake cam 29
Since it is in contact with, the power loss for rotating the first low speed intake cam 27, the second low speed intake cam 28, and the high speed intake cam 29 is small, and the durability is high.

Further, the first and second intake rocker arms 32,
The bottoms of the piston holes 32e, 33e provided in the 33 are
Since the second intake rocker arms 32, 33 are provided within the widths of the inner wall side portions 32b, 33b of the second intake rocker arms 32, 33 in the axial direction of the rocker shaft, it is possible to suppress deterioration in rigidity due to the provision of the piston holes 32e, 33e.

Furthermore, the first and second intake rocker arms
First and second intake inner rocker arms provided at 32 and 33
By providing the first and second intake rocker arms 32, 33 on the tip side of the notches 32f, 33f of the 35, 36, the notches 32f, 33f
It is possible to suppress a decrease in rigidity when forming the.

In the embodiment illustrated in FIGS. 1-12,
The roller 44 is rotatably supported by the first intake inner rocker arm 35 of the first intake rocker arm 32, and the roller 45 is rotatably supported by the second intake inner rocker arm 36 of the second intake rocker arm 33. And the roller 46 is rotatably supported by the free intake rocker arm 34,
Although 44, 45 and 46 were in contact with the first low speed intake cam 27, the second low speed intake cam 28 and the high speed intake cam 29, respectively.
21 to 21, a first intake rocker arm is provided.
The first intake inner rocker arm 74 of 71 and the second intake inner rocker arm 75 of the second intake rocker arm 72 are integrally formed with slippers 76 and 77, respectively, and the free intake rocker arm 73 is integrally formed with the slipper 78. The intake system rocker arm 70 may be configured so that the slippers 76, 77, 78 are brought into contact with the first low speed intake cam 27, the second low speed intake cam 28, and the high speed intake cam 29.

In the second embodiment shown in FIGS. 13 to 21, the internal combustion engine 1, the cylinder block 2 and the exhaust cam 30 in the first embodiment shown in FIGS. 1 to 12 are provided.
The same parts as those of the oil passages 64, 65, 66 are designated by the same reference numerals.

Intake system rocker arm in the second embodiment
70 is a first intake rocker arm 71, a second intake rocker arm
72 and a free intake rocker arm 73, and the first intake rocker arm 71 and the second intake rocker arm 72 have slippers that contact the first low speed intake cam 27 and the second low speed intake cam 28.
A first intake inner rocker arm 74 and a second intake inner rocker arm 75 having 76 and 77 are accommodated, and slippers 76 and 77 are integrally formed on the first intake inner rocker arm 74 and the second intake inner rocker arm 75, and are free. A slipper 78 is formed integrally with the intake rocker arm 73, and tappet screws 79 and 80 are screwed to the tip ends of the first intake rocker arm 71 and the second intake rocker arm 72 so as to be able to move back and forth.

The first intake rocker arm 71 and the second intake rocker arm 71
Outer and inner wall portions 71a, 71b, 72a, 72 of the intake rocker arm 72
Piston holes 71c, 71d, 72c, 72d of the same diameter are formed in b, and the center line of the first intake inner rocker arm 74 has the same diameter as the piston holes 71c, 71d of the first intake rocker arm 71. The piston hole 74a is formed, and the second intake inner rocker arm 75 is formed with a piston hole 75a having the same diameter as the piston holes 72c and 72d of the second intake rocker arm 72 and having its center line aligned with the first intake rocker arm 71. Connecting pins 81, 82, 83 to the piston holes 71c, 71d of No. 1 and the piston hole 74a of the first intake inner rocker arm 74.
Is slidably fitted, and the connecting pins 84, 85, 86 are slidably fitted in the piston holes 72c, 72d of the second intake rocker arm 72 and the piston hole 75a of the second intake inner rocker arm 75. There is. A return coil spring 87 is interposed between the connecting pin 82 and the bottom of the piston hole 71d of the inner wall portion 71b of the first intake rocker arm 71, and the connecting pin 85 and the piston of the inner wall portion 72b of the second intake rocker arm 72 are provided. A return coil spring 88 is interposed at the bottom of the hole 72d.

The outer wall portion 71a of the first intake rocker arm 71 and the outer wall 72a of the second intake rocker arm 72 are
Oil passages 89, 90 communicating from the fitting hole of the intake rocker arm shaft 20 to the piston holes 71c, 72c, respectively.
Is formed and the pressure oil is not supplied to the oil passages 89 and 90, the connecting pins 81, 82 and 83, the connecting pin 84, the connecting pin 85 and the connecting pin 86 are generated by the spring biasing force of the return coil springs 87 and 88. And the first intake inner rocker arm 74 to the first intake rocker arm 71,
The second intake inner rocker arm 75 is the second intake rocker arm
In the state where the oil is connected to the 72 integrally and the pressure oil is supplied to the oil passages 89 and 90, the connecting pins 81, 82 and 83 and the connecting pins 84 and 8
5 and 86 move inward, respectively, and the first intake inner rocker arm 74 and the second intake inner rocker arm 75 can swing freely relative to the first intake rocker arm 71 and the second intake rocker arm 72, respectively. You can do it.

Further, the first intake rocker arm 71 and the second intake rocker arm 72 are located substantially in the middle of the tappet screw 79 at the front end of the first intake rocker arm 71 and the tappet screw 80 at the front end of the second intake rocker arm 72. Piston hole 71
e and 72e are formed, and the piston hole 71e of the first intake rocker arm 71 and the piston hole 72e of the second intake rocker arm 72 are formed.
A piston through hole 73a is formed at the tip of the free intake rocker arm 73 sandwiched between the piston holes 71e and 72e.
The connecting pins 91, 92, 93 are slidably fitted in the e and the piston through hole 73a, and the connecting pin 92 and the second intake rocker arm are
A return coil spring 94 is inserted in the tip piston hole 72e of 72, and the inner wall 71b of the first intake rocker arm 71 is
An oil passage 95 is formed so as to communicate from the fitting hole of the intake rocker arm shaft 20 to the bottom of the piston hole 71e of the first intake rocker arm 71, and when the pressure oil is not supplied to the oil passage 95, the spring of the return coil spring 94 is formed. The connecting pins 91, 92, 93 are first intake rocker arms due to the biasing force.
After moving to the 71 side, the first intake rocker arm 71, the second intake rocker arm 72 and the free intake rocker arm 73 have their leading ends unconnected, and when the pressure oil is supplied to the oil passage 95, the first intake rocker arm 71, Second intake rocker arm 7
2. The tip of the free intake rocker arm 73 is integrally connected.

Then, the three oil passages 89, 90, 95
Respectively communicate with the oil passages 64, 65, 66 formed in the intake rocker arm shaft 20 respectively, and by turning on / off the control valve interposed in the oil passages 64, 65, 66, The pressure oil flows through the oil passages 89, 90,
The passages 95 are respectively supplied or stopped.

A tappet screw 97 is screwed to the tip of an exhaust rocker arm 96 which is vertically rocked by the exhaust cam 30 so as to be able to move back and forth.

In the embodiment shown in FIGS. 13 to 21, slippers 76, 77 and 78 are provided in place of the rollers 44, 45 and 46, so that the first low speed intake cam 27 and the second low speed intake cam 28 are provided. , The frictional resistance between the high speed intake cam 29 and the rollers 44, 45, 46 is slightly large, but the sleeve shafts 38, 39, 40 and the needle rollers 41, 42, 43 are not required, so the number of parts is reduced. Therefore, the cost can be reduced by simplifying the structure.

Also in the second embodiment, similarly to the first embodiment, even if the pressure oil is not supplied at the time of starting, the intake valves 10 and 11 are both in the operating state and the starting is smoothly performed. At the same time, a cylinder idle operation state in which the required cylinder is inactive, a first low speed operation state in which the intake valve 11 is inactive and only the intake valve 10 opens and closes, and an intake valve 10 is inactive and only the intake valve 11 opens and closes 2nd low-speed operation or intake valve 10 intake valve 11 1st low-speed intake cam 27
Also, it is possible to perform a medium speed operation in which both the second low speed intake cam 28 operates and a high speed operation in which both the intake valve 10 and the intake valve 11 operate by the high speed intake cam 29.

In the first embodiment, the oil passages 55 and 56 for supplying the pressure oil to the switching mechanism of the first intake rocker arm 32 and the second intake rocker arm 33 are provided with the outer walls of the first intake rocker arm 32 and the second intake rocker arm 33. In the second embodiment, the oil passages 89 and 90 for supplying pressure oil to the switching mechanism of the first intake rocker arm 71 and the second intake rocker arm 72 are provided outside the first intake rocker arm 71 and the second intake rocker arm 72. Although provided on the wall, the inner wall portions 32b, 33 of the first intake rocker arm 32 and the second intake rocker arm 33 are provided as in the third embodiment of the invention described in claim 4 shown in FIGS. 22 and 23.
b may be provided with oil passages 98, 99, and switching mechanisms 32e, 33e for switching the first intake rocker arm 32, the second intake rocker arm 33 and the free intake rocker arm 33 to the connection or non-connection.
Oil passage 10 for supplying pressure oil to 34a, 59, 60, 61
0 may be provided on the inner side wall portion 32b of the first intake rocker arm 32, and the oil passage 98 may be arranged above the oil passage 100.

Furthermore, when the intake valves 10 and 11 are driven to open and close by the high speed intake cam 29 that abuts on the free intake rocker arm 35, the valve opening applied to the first and second intake rocker arms 32 and 33 from the free intake rocker arm 35. First by force
First and second intake rocker arms 32, 33 that generate a large stress due to a torsional load acting on the second intake rocker arms 32, 33
By providing the oil passage in a position avoiding the outermost portions 32a and 33a of the above, it is possible to suppress the decrease in rigidity of the first and second intake rocker arms 32 and 33, and to reduce the size of the first and second intake rocker arms 32 and 33.
The weight can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view of essential parts of an internal combustion engine of a first embodiment of the invention according to claims 1 to 3 of the present application.

FIG. 2 is a plan view of FIG.

3 is a plan view of the intake system rocker arm of FIG. 1. FIG.

FIG. 4 is an exploded plan view of FIG.

FIG. 5 is a cross-sectional plan view of the intake system rocker arm at the time of starting and in a medium speed operation state according to the first embodiment.

FIG. 6 is a front view of FIG.

FIG. 7 is a cross-sectional plan view of the intake system rocker arm in the cylinder deactivated operation state in the first embodiment.

8 is a front view of FIG. 7. FIG.

FIG. 9 is a cross-sectional plan view of the intake system rocker arm in the first low speed operation state according to the first embodiment.

FIG. 10 is a cross-sectional plan view of the intake system rocker arm in the second low speed operation state according to the first embodiment.

FIG. 11 is a cross-sectional plan view of the intake system rocker arm in the high speed operation state according to the first embodiment.

FIG. 12 is a front view of FIG. 11.

FIG. 13 is a longitudinal cross-sectional speed view of essential parts of the internal combustion engine according to the second embodiment of the invention of claims 1 to 3 of the present application.

14 is a plan view of the intake system rocker arm of FIG. 13. FIG.

FIG. 15 is a cross-sectional plan view of the intake system rocker arm at the time of starting and in a medium speed operation state according to the second embodiment.

16 is a front view of FIG.

FIG. 17 is a cross-sectional plan view of the intake system rocker arm in the cylinder deactivated operation state according to the second embodiment.

FIG. 18 is a front view of FIG. 17.

FIG. 19 is a cross-sectional plan view of the intake system rocker arm in the first low speed operation state according to the second embodiment.

FIG. 20 is a cross-sectional plan view of the intake system rocker arm in the second low speed operation state according to the second embodiment.

FIG. 21 is a cross-sectional plan view of the intake system rocker arm in the high speed operation state according to the second embodiment.

22 is a front view of FIG. 21. FIG.

FIG. 23 is a cross-sectional plan view of an intake system rocker arm according to a third embodiment of the invention of claim 4 of the present application.

24 is a vertical cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Cylinder block, 3 ... Cylinder head, 4 ... Cylinder, 5 ... Piston, 6 ... Connecting rod, 7 ... Combustion chamber, 8 ... Intake port, 9 ... Exhaust port, 10 ... Intake valve, 11 ... Intake valve, 12 ... Exhaust valve, 13 ... Exhaust valve, 14 ... Valve guide, 15 ... Valve spring receiving part, 16 ... Retainer, 17 ... Valve spring, 18 ... Spark plug, 19 ... Guide cylinder, 20 ... Intake rocker arm shaft, 21 ... Exhaust rocker arm shaft, 22 ... Rocker arm shaft holder, 23 ... Intake cam shaft, 24
... Exhaust camshaft, 25 ... Camshaft holder, 26 ... Bolt, 27 ... First low speed intake cam, 28 ... Second low speed intake cam,
29 ... High-speed intake cam, 30 ... Exhaust cam, 31 ... Intake system rocker arm, 32 ... First intake rocker arm, 33 ... Second intake rocker arm, 34 ... Free intake rocker arm, 35 ... First intake inner rocker arm, 36 ... Second intake air Inna Rocca Arm, 37
Exhaust rocker arm, 38 ... Sleeve shaft, 39 ... Sleeve shaft, 40 ... Sleeve shaft, 41 ... Needle roller, 42 ... Needle roller, 43 ... Needle roller, 44 ... Roller, 45 ... Roller, 46 ... Roller, 47 ... Connecting pin , 48 ... connecting pin, 49 ... connecting pin, 50 ... connecting pin, 51 ... connecting pin, 52 ... connecting pin,
53 ... Return coil spring, 54 ... Return coil spring, 55 ... Oil passage, 56 ... Oil passage, 57 ... Tappet screw, 58 ... Tappet screw, 59 ... Connecting pin, 60 ... Connecting pin,
61 ... Connecting pin, 62 ... Return coil spring, 63 ... Oil passage, 64 ... Oil passage, 65 ... Oil passage, 66 ... Oil passage, 67 ... Lost motion spring receiving part, 68 ... Lost motion spring, 69 ... Tappet screw, 70 Intake system rocker arm, 71 ... 1st intake inner rocker arm, 72 ...
Second intake inner rocker arm, 73 ... Free intake inner rocker arm, 74 ... First intake inner rocker arm, 75 ... Second
Air intake inner rocker arm, 76 ... slippers, 77 ... slippers, 78 ... slippers, 79 ... tappet screws, 80 ... tappet screws, 81 ... connecting pins, 82 ... connecting pins, 83 ... connecting pins, 84 ...
Connection pin, 85 ... connection pin, 86 ... connection pin, 87 ... return coil spring, 88 ... return coil spring, 89 ... oil passage, 90 ... oil passage, 91 ... connection pin, 92 ... connection pin,
93 ... Connection pin, 94 ... Return coil spring, 95 ... Oil passage, 96 ... Exhaust rocker arm, 97 ... Tappet screw, 98 ...
Oil passage, 99 ... Oil passage, 100 ... Oil passage.

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[Procedure amendment]

[Submission date] November 1, 2001 (2001.11.
1)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

SUMMARY OF THE INVENTION The present invention relates to an improvement of a valve operating system for an internal combustion engine which solves the above-mentioned problems. The invention according to claim 1 is one of an intake valve and an exhaust valve. Or valve abutment that abuts two adjacent valves of both (hereinafter referred to as valve)
First and second rocker arms provided with a portion, and the first and second rocker arms .
First between the Kkaamu, and a free rocker arm driven by the lift amount of larger cam than the second rocker arm, the dynamic of the internal combustion engine connected, with a switching mechanism that an unbound selectively switches the rocker arm In the valve device, the switching mechanism is the same as the valve contact portion between the valve contact portions.
It is characterized by being provided on one plane .

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3G016 AA08 AA19 BA03 BA06 BA18                       BA28 BA36 BA42 BA43 BB13                       BB22 CA29 GA00                 3G018 AA05 AB04 AB17 BA07 BA14                       CA19 CB02 DA12 FA03 FA06                       FA07 GA00

Claims (3)

[Claims] 1. A first and a second rocker arm which are provided to two adjacent valves of either one or both of an intake valve and an exhaust valve (hereinafter referred to as valves), and the first and second rocker arms. In a valve operating system of an internal combustion engine, comprising a free rocker arm driven by a cam having a larger lift amount than a rocker arm, and having a switching mechanism for selectively switching connection / disconnection of the rocker arm, the switching mechanism includes a valve contact. A valve operating system for an internal combustion engine, characterized in that it is provided between the parts. 2. The valve operating system for an internal combustion engine according to claim 1, wherein a portion of the first and second rocker arms where the switching mechanism is provided protrudes toward the free rocker arm side. 3. The supply oil passage for applying hydraulic pressure to the switching mechanism is provided on a free rocker arm side wall of the first and second rocker arms. Valve drive for internal combustion engine.