JPS59168207A - Valve driving mechanism for internal-combustion engine having function to render part of mechanism inoperative - Google Patents

Abstract

PURPOSE:To make the structue of a valve driving mechanism simple and compact, by supporting a cam follower and a rocker arm on a common shaft in the manner that they can be moved pivotally independently from each other, and enabling to interrupt the operative connection between the cam follower and the rocker arm according to the operational conditions of an engine. CONSTITUTION:In a valve driving mechanism, in which an intake (exhaust) valve 9 is opened and closed by a rocker arm 15 through rotation of a cam 23 by urging the valve 9 in its closing direction by the force of a valve spring 11, the rocker arm 15 is connected operatively with a cam follower 21 by a changeover means 29 selectively according to the operational conditions of an engine. Here, the changeover means 29 is so designed that, when an actuator 37 is rendered inoperative and a trigger lever 33 is moved pivotally by the cam follower 21 and disengaged from a groove 40, a rod 35 is retracted by a return spring 38 and a lock plate 53 is moved to its inoperative position by a shaft arm 42, a link arm 47, etc. In this state, the cam follower 21 is rendered freely movable, whereby the valve 9 is rendered inoperative.

Description

Detailed Description of the Invention The present invention operates in conjunction with a cam that rotates in synchronization with the rotation of the crankshaft of an internal combustion engine to open and close an on-off valve, that is, an intake valve or an exhaust valve. The present invention relates to a valve operating device for an internal combustion engine with a pause function that selectively pauses the opening/closing operation of the valve in accordance with the situation.

At least one of the intake valves and exhaust valves is provided in plurality for each cylinder of the engine, and in a low-speed or medium-speed rotation range, some of the plurality of intake valves and exhaust valves having the same function are stopped. An internal combustion engine is known in which all valves are operated in a high-speed rotation range to improve output over the entire operating range of the engine. Such an internal combustion engine is equipped with a valve gear with a shutdown function that selectively operates or shuts off only some of the valves depending on the operating state of the engine. A valve train that is satisfactory in these respects has not yet been developed.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a valve operating device with a shutdown function for an internal combustion engine that is simple, compact, highly reliable, and highly practical.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

First, in FIG. 1, inside the silicator 2 of the internal combustion engine 1,
A piston 3 is slidably held by a cylinder sleeve 4 and housed in a reciprocating manner, and a cylinder head 5 mounted on the cylinder 2 has a plurality of intake passages 6 and exhaust passages 7. It is formed. Multiple intake passages 6
A plurality of on-off valves, that is, an intake valve 9 and an exhaust valve 1o, are arranged at each opening end of the exhaust passage 7 to the combustion v8. At least one of the plurality of intake valves 9 and at least one of the plurality of exhaust valves 10 are configured to be able to selectively enter a rest state depending on the rotational speed of the engine 1. 1 shows an intake valve 9 and an exhaust valve 10 configured in this manner.

The intake valve 9 and the exhaust valve 10 are constantly biased in the direction of closing the openings of the intake passage 6 and the exhaust passage 7, that is, in the valve closing direction, by the elastic force of the corresponding valve spring 11, 12, respectively. Each rocker arm 1 is mounted on a rocker arm 15.16 pivotably supported by a corresponding rocker arm shaft 13.14.
When receiving an axial pressing force through an adjusting screw 19.20 fixed by a nut 17.18 at the tip of the valve spring 5.16, it moves in the axial direction against the elastic force of each valve spring 11.12. and open the valves respectively.

Each rocker arm 15.16 is connected to the rocker arm 15.16 via a cam follower 21.22 which is pivotally supported by a corresponding rocker arm shaft 13.14 independently of the rocker arm 15.16. is driven by cams 23 and 24. Cam 23.2/l
have a lower portion 25.26 formed by a circumferential surface on a reference circle, and a higher portion 27.28 that bulges radially outward from the reference circle, and these cams 23.24 They are configured to rotate in synchronization with the rotation of the engine 1 around mutually different axes.

Each rocker arm 15, 16 is connected to a cam follower 21, 22 which is selectively adapted depending on the operating state of the engine 1 by means of a corresponding switching device 29, 30 as described below.
is connected with. When these switching devices 29, 30 are in operation, the rocking movement of the cam followers 21, 22 driven by the cams 23, 24 is caused by the rocker arm 1.
5.16 and when the switching device 29.30 is inactive, the rocking movement of the cam follower 21.22 is not transmitted to the rocker arm 15.16.

6- Each switching device 29.30 is connected to a corresponding pivot shaft 31
．． 32, and each cam follower 2
1 to rigger levers 33 and 34 that swing in conjunction with the swinging motion of 1.
~ The drive rod 35 is moved by the action of the rig levers 33 and 34.
, 36 can be locked in their operating or non-operating positions. The switching device 29 on the intake valve 9 side and the switching device 30 on the exhaust valve 10 side basically have the same configuration and function, so the switching device 29 on the intake valve 9 side will be described in more detail below. d1 will be revealed.

In FIGS. 2(a), 2(c), the drive rod 35 is reciprocated in the axial direction by the actuator 37.
is constantly biased in the retracting direction (upward direction in FIG. 2(a)) by the elastic horn of the return spring 38, and when the acticoator 37 is activated, the acticoator 3
7 in the protruding direction (downward direction in FIG. 2 (ω)) and moves in the same direction against the elastic force of the return spring 38. When the acticoator 37 becomes inactive,
The drive rod 35 is moved in the retraction direction again by the resilient force of the return spring 38.

A valve weight notch groove 39 and a valve actuation notch groove 40 are sequentially formed in the drive rod 35 from its tip toward the base end on the actuator 3 side. On the base end side, there is an axial play X in one of the bifurcated legs 43a and 43b of the approximately dogleg-shaped shift 1 to arm 42, which are interlocking members that are swingably supported by a pivot @41. A notch engaging portion 44 is formed in such a manner that the engagement occurs. The other bifurcated leg 458 of the shift arm 42
．． A joint 46 is rotatably provided between 45b and a shaft 48 rotatably supported at one end of an arcuate link arm 47 in a pivot hole 46a of the joint 46.
is inserted, and a lock pin 719 that is engaged with a lock groove 46b formed in the peripheral wall of the joints 1 to 46 is fitted to the tip of the shaft 48 that has passed through the pivot hole 46a.

Further, referring to FIG. 3, the rocker arm 1
5 consists of a pair of arms 50 and 51 that are connected to each other under a predetermined pressure 111111II and are integrally molded in a substantially inverted U-shape. adjustment screws 19a, 1
a pair of intake valves 9 via at least one of the intake valves 9b.
A pair of intake valves 9a, including engaging portions 50b and 51b that engage with the top of at least one of arms 50 and 9b, and a flat portion 15a formed by the inner upper surface of each arm 50.51 and the upper surface of the connecting portion. , 9b can be activated or deactivated.

A pair of adjustment screws 19a, 19b are screwed into screw holes formed in each engaging portion 50b, 51b of arm 50.51, and screwed into each arm 50.51 by nuts 17a, 17b screwed together via spacer 52. Fixed against. The cam follower 21 is pivotally supported by the rocker arm shaft 13 so as to be located in a space 15b between the pair of arms 50, 51, and can freely move in and out of the rocker arm 15 in this space 15b.

On the flat portion 15a of the rocker arm 15, a plug-shaped lock plate 53 serving as a plate-shaped portion is provided so as to be movable in a direction perpendicular to the axis of the rocker arm shaft 13. The lock plate 53 is formed with a valve body notch 53a and a valve drive notch 53b. The valve driving notch 53b of the lock plate 53 has a fork portion 54a of the shift fork 54 as a swinging member.
The shifter 1 to the fork 54 are pivotably supported by a pivot shaft 55 supported by the lower projections 50c and 51c of the rocker arm 15.

The other end of the link arm 47 mentioned above is swingably supported on the downward protrusion 54b of the shift fork 54 via a pivot shaft 56. As shown in FIG. 2<b+, the one end shaft support on the shift arm 42 side and the point of action on the shift fork 54 side (the other end shaft support) in the link arm 47 are approximately parallel to the axis of the rocker arm shaft 13. They are arranged symmetrically.

=10- As is particularly clear from FIGS. 2(C) and 3, a spring 57 is disposed between a spring seat 15' formed on the rocker arm 15 side and a spring seat 21' formed on the cam follower 21 side. The elastic force of the spring 57 causes the adjustment screws 19a, 1! The slipper portion 21a is in contact with the top end surface of at least one of the intake valves 9a and 9b to such an extent that no gap is created between the end surfaces of the respective ends of the intake valves 9a and 9b, and the slipper portion 21a is in sliding contact with the cam 23 of the cam follower 21. The rocker arm 15 and the cam follower 21 are biased in a direction in which they repel each other so that the rocker arm 15 and the cam follower 21 are in constant contact with the cam surface of the cam 23 to such an extent that no gap is generated between the rocker arm 15 and the cam follower 21 .

When the trigger lever 33 has one end engaged with the engaging portion 21b of the cam follower 21, as the cam 23 rotates, the slipper portion 21a of the jy follower 21 engages the lower portion 25 of the cam 23.
While in contact with the drive rod 35, the drive rod 3
5 in the inoperative or activated position. Also,
When the slipper part 21a of the cam follower 21 comes into contact with the high part 27 of the cam 23, one end of the trigger lever 33 is pressed by the engaging part 21b of the cam follower 21, and the trigger lever 33 is moved as shown in FIG.
C) (When pulled, the drive rod 35 is swung in the cutting direction, and the drive rod 35 is locked by 1ft In2 L from the valve body notch groove 39 or the valve actuation notch groove 40 that were engaged with each other. Release.

Below, Figure 4 (a3 <b+, +c+ to Figure 8 (
a), City〉.

The switching operation of the two switching devices will be explained according to (C). First, Figure 4(a), mountain 1. In (C), the actuator 37 is activated and the cam follower 21 is in a state where the driving rod 35 receives a pressing force in the direction in which it protrudes.
When the slipper portion 21a contacts the high portion 27 of the cam 23, the rigger levers 1 to 33 swing clockwise in FIG. Release. The resulting drive rod 35
First, the notch engaging portion 44 and the bifurcated leg portion 43a of the shift arm 42.

43b moves by the axial play X between which. At this point, the shift arm 42 does not swing yet.

When the cam 23 rotates further and the contact position of the cam 23 against the slipper portion 21a of the cam follower 21 shifts from the high portion 27 to the low portion 25, the drive rod 3
5 further moves in the protruding direction, and in conjunction with this, the shift arm 42 swings clockwise in FIG. 4(a). The swing of the shift arm 42 causes the link arm 47 to shift to the fourth position.
Move in the direction of the arrow in figure (b) and shift fork 5
4 clockwise to move the lock plate 53 in the direction of the rocker arm shaft 13. When the slipper part 21a of the cam follower 21 comes into contact with the lower part 25 of the cam 23, as shown in FIGS.
The lock plate 53 moves from the non-operating position to the cam follower 21.
The trigger lever 33 slides on the flat portion 15a of the rocker arm 15 to the operating position where it can come into contact with the lower surface of the tip of the rocker arm 15, and the trigger lever 33 engages with the valve actuation notch 40 of the drive rod 35. After that, as shown in (C),
As the cam 23 rotates, the trigger lever 33 intermittently engages with the valve actuation notch 13-groove 40 to lock the drive rod 35 in the actuation position, while the rocker arm 15 is under the action of the lock plate 53. Since the cam 23 swings together with the cam follower 21 in response to the rotation of the cam 23, the movement of the cam 23 is transmitted to at least one of the intake valves 9a and 9b via the cam follower 21, the lock plate 53, and the rocker arm 15. As a result, at least one of the intake valves 9a and 9b opens and closes in synchronization with the rotation of the engine 1. When only one of the intake valves 9a, 9b is driven, the other may be driven by a conventionally known drive mechanism.

Next, when the actuator 37 is in the non-operating state in the operating state shown in FIG.
Although the slipper portion 21a of the cam follower 21 tries to move in the retraction direction due to the elastic force of the cam 23, the slipper portion 21a of the cam 23
5, it is locked in the operating position by the action of the trigger lever 33 and cannot be moved. Eventually, as shown in Figure 7 (C), the slipper portion 21a of the cam follower 21 is attached to the cam 23.
When the trigger lever 33 comes into contact with the high part 27 of the cam follower 21, the trigger lever 33 is pressed by the cam follower 21 and swings.As shown in FIG. 40 and unlock the drive rod 35. In this state, the rocker arm 15 is receiving the strong reaction force of the valve spring 11, so
A strong frictional resistance is generated in the lock plate 53 interposed between the rocker arm 15 and the cam follower 21, and the lock plate 53 is in the operating position, that is, the cam follower 21.
does not easily move from the position of contact with the lower surface of the tip. Therefore, the drive rod 35, which is under the action of the return spring 38, first engages the notch engaging portion 44 and the shift arm 4.
Axial clearance X between the two forked legs 4.3a and 43b
Move in the retraction direction by the amount of .

Next, as the cam 23 rotates, the contact position of the cam 23 with respect to the slipper part 21a of the cam follower 21 shifts from the high part 27 to the low part 25, and the cam follower 21 swings, causing the valve spring 11 to react. As the force weakens and the frictional resistance against the lock plate 53 also decreases, the drive rod 35 is retracted by the elastic force of the return spring 38, and in conjunction with this, the shift arm 42 moves counterclockwise as shown in FIG. swing in the direction. Due to the swinging of the shift arm 42, the link arm 47 moves to the seventh position.
Move in the direction of the arrow in figure (b) and shift fork 5
4 in the counter-time cutting direction, as shown in Fig. 8 (ω).

The lock plate 53 is retracted from the operating position to the non-operating position as shown by the arrow. At the same time, trigger lever 3
3 engages with the valve weight notch groove 39 of the drive rod 35, as shown in FIGS. 8(a) and 8(C). After that, as shown in Fig. 2+b+, (C), the cam 23
As the cam follower 2 rotates, the trigger lever 33 swings and intermittently engages with the valve weight notch 39 to lock the drive rod 35 in the non-operating position.
1 moves in and out of the space 15b of the rocker arm 15, the rocking motion of the cam follower 21 is not transmitted to the rocker arm 15, and therefore at least one of the intake valves 98.9b is at rest.

In the transition from the operating state to the rest state, the rocker arm 15 is swinging in the operating state, and as a result of this swinging, the link arm 47 installed on the rocker arm 15 is
Since the position of the point of application (shaft 56) of the link arm 47 also swings, there is a concern that a force that attempts to move the fixed point of effort (shaft 718) of the link arm 47 may act on it. However, in the valve train according to the present invention, the link arm 47 is formed so as to bypass the rocker arm shaft 13, and the point of force and the point of action of the link arm 47 are approximately symmetrical with respect to the axis of the rocker arm shaft 13. As shown in FIG. 9, the rocker arm 1
A swing trajectory P centered on the axis of the rocker arm shaft 13 at the point of application (axis 56) accompanying the swing of No. 5 and a swing trajectory Q centered on the force point (axis 48) at the point of application. The deviation ∆p that occurs between the two is minute within the range of swing of the point of application, and the force acting on the point of effort as the point of action swings becomes so small that it can be ignored. Therefore, the force point of the link arm 47 can be driven by the shift arm 42 without any problem, and by moving and covering the force point, the swinging rocker arm 15
The upper lock plate 53 can be moved reliably, so that the transition from the operating state to the rest state can be carried out smoothly.

The valve train according to the present invention configured as described above can operate and deactivate two valves at the same time, so that in a high-speed multi-cylinder internal combustion engine having two intake valves and two exhaust valves per cylinder, By being used to drive two valves in the same cylinder, the engine can be made into a cylinder body stop type engine in which the operation of only a predetermined cylinder is suspended. Further, in the case where at least one of the intake valve and the exhaust valve is two or more valves, it is also possible to apply the valve operating device according to the present invention to only a single valve, and furthermore, it is possible to apply the valve operating device according to the present invention to only a single valve. In the case where one valve has three or more valves, it is also possible to apply the valve train according to the present invention to only two valves.

18- As explained above, according to the present invention, the cam follower and the rocker arm, which can swing independently from each other, are pivotally supported by a common pivot shaft (rocker arm shaft), and the cam follower and the rocker arm are The cam follower is provided to perform rocking motion on the same side with respect to the pivot shaft, and the rocker arm is selectively driven to transmit or not transmit the rocking motion of the cam follower to the rocker arm depending on the operating state of the engine. Since the stop drive mechanism is provided on the opposite side of the cam follower and rocker arm with respect to the pivot shaft, the mechanism structure is simple and compact, and the valve drive with a stop function for internal combustion engines is highly reliable and highly practical. The device is obtained.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the main part of an internal combustion engine equipped with a valve train with a valve shutting function according to the present invention, and Fig. 2 is a cross-sectional view of the main part of the valve train in a valve resting state. is shown in Figure 2 (A of ω
2(C) is a sectional view taken along line A-B of FIG. 2(al), FIG.
a) is a cross-sectional view of the main parts of the valve train at the start of switching from the valve rest state to the operating state, and the 4th appearance is the Δ of Fig. 4 (a).
- A sectional view taken along the line A, FIG. 4(C) is a sectional view taken along the A-B line in FIG. 4(a), and FIG. Partial sectional view, 5th issue> is a sectional view taken along line A-A of FIG. 5(a), and FIG. 5(C) is a sectional view of FIG.
Fig. 6 (ω is a sectional view of the main part of the valve train in the valve operating state, in Fig. 6) is a sectional view taken along line A-B of a).
Figure 6 (C) is a cross-sectional view taken along line A-A of Figure 6 (a).
7(a) is a sectional view of the main part of the valve train at the start of switching from the operating state to the rest state of the valve; 7th line) is the A-A in FIG. 7(a) 7(C) is a sectional view taken along line A-B in FIG. 7(a), and FIG. 8(a) is a main part of the valve train at the completion of switching from the valve operating state to the rest state. Sectional view, 8th issue) is Fig. 8 (cross-sectional view of ω line 8-A,
FIG. 8(C) shows A-Bli! of FIG. 8(a)! The cross-sectional view, FIG. 9, is a view showing the swing locus of the point of application relative to the point of force of the link arm that goes into the valve train. Explanation of symbols of main parts 1...Internal combustion engine 9.9a, 9b...Intake valve 10...Exhaust valve 13.11...Rocker arm shaft 15 ．．
16...Rocker arm 21.22...
・Cam follower 23.24...Cam 29.30...Switching device 33.34...Trigger lever 35.36...
... Drive rod 42 ... Shift arm 47 ... Link arm 53 ... Lock plate 54 ... Shift fork - Applicant Honda Motor Co., Ltd. Agent Patent Attorney Motohiko Fujimura 21- No. 4 S No. 5 Fig.-45- Fig. 5 (b) Fig. 8-47- Fig. 8 Fig. 1 (b)

Claims (1)

[Scope of Claims] (1) The on-off valve is driven to open and close in conjunction with a cam that rotates in synchronization with the rotation of the crankshaft of the internal combustion engine, and the on-off valve is selectively opened and closed according to the operating state of the engine. A valve operating device with a pause function for an internal combustion engine that pauses an opening/closing operation, the cam follower being swingably supported by a pivot shaft and swinging in accordance with the rotation of the cam, and the cam follower being independent of the cam follower. a rocker arm that is swingably supported by the pivot shaft and that swings to drive the on-off valve; a switching mechanism that can selectively transmit the swinging motion of the cam follower to the rocker arm; The cam follower and the rocker arm are provided on the same side with respect to the pivot shaft, and the drive mechanism switches between the cam follower and the rocker arm with respect to the pivot shaft. A valve operating device with a shutdown function for an internal combustion engine, characterized in that the rocker arm is installed on the opposite side of the rocker arm. It consists of a pair of arms pivotally supported by a support shaft, and is configured such that one end of the pair of arms can drive the on-off valve, and the cam follower swings in the space between the pair of arms. A valve operating device with a stop function for an internal combustion engine according to claim 1. (3) The switching mechanism includes a plate-like member movable on the rocker arm between an operating position in which the rocking motion of the cam follower is transmitted to the rocker arm and a non-operating position in which the rocking motion is not transmitted, and the rocker arm. a swinging member that is swingably supported by and has one end engaged with the plate member;
2. The valve operating device with a stop function for an internal combustion engine according to claim 1, further comprising a link member that transmits the driving force of the drive mechanism to the other end of the swinging member. (4) The drive mechanism includes a drive rod that has two volumes corresponding to the operating position and non-operating position of the front plate-like member and is movable in the axial direction between the operating position and the non-operating position. , an interlocking member that drives the link member in conjunction with the moving movement of the drive rond, and an interlocking member that swings in conjunction with the swinging movement of the cam follower and engages intermittently with either one of the two grooves. 4. A valve operating device with a function for an internal combustion engine body 1 according to claim 3, further comprising a trigger lever for locking said drive rod in an operating position or a non-operating position.