JPS6397808A - Valve system for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve reliability of each system, by a method wherein plural oil pressure feed passages are formed in a locker shaft and plural oil passages are formed in a locker arm, and each oil passage, serving as a different systems, is coupled to a hydraulic tappet and a coupling switching mechanism. CONSTITUTION:A pair of suction valves V1 and V2, mounted integrally to an engine body 1, is provided with a cam C, a locker arm 4, rockable about an axis extending in parallel to a cam shaft 2, and a switching mechanism 5, performing opening and closing motion by switching coupling and discoupling with and from the locker arm 4. The base part of the locker arm 4 is rockably supported on a locker shaft 10 secured to the engine body 1. In this constitution, an axially extending partition wall 36 is integrally molded in the locker shaft 10 to partition the interior of the locker shaft into plural oil pressure feed passages 37 and 38 by means of the partition wall. An oil passage 31 through which to intercouple a hydraulic tappet T2 and the one oil pressure feed passage 37 and an oil passage 58 through which to intercouple the switching mechanism 5 and the other oil pressure feed passages 38 are formed in the locker arm 4.

Description

Detailed Description of the Invention A6 Objective of the Invention Between the rocker arms, there is a connection switching device that can connect and disconnect each rocker arm using hydraulic pressure.

The present invention relates to a valve train for an internal combustion engine in which a valve train is provided.

(2) Prior Art Conventionally, such a valve train has been developed, for example, in Japanese Patent Application Laid-Open No. 61-815.
It is known from the publication No. 10.

(3) Problems to be Solved by the Invention In the above conventional technology, hydraulic pressure is supplied to the hydraulic tappet and the connection switching mechanism from a common hydraulic pressure supply path provided within the rocker shaft. However, when the hydraulic pressure is switched by the coupling switching mechanism, the hydraulic tappet is affected, so it is desirable to supply hydraulic pressure to the coupling switching mechanism and the hydraulic tappet separately.

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 system for an internal combustion engine that can independently supply hydraulic pressure to a connection switching mechanism and a hydraulic tappet.

B9 Structure of the Invention (Means for Solving Problem 11) According to the present invention, a first hydraulic pressure supply path and a second hydraulic pressure supply path are separated from each other in the rocker shaft via a partition wall extending in the axial direction. The rocker arm is provided with a first oil passage connecting the hydraulic tappet and the first oil pressure supply passage, and a second oil passage connecting the connection switching mechanism and the second oil pressure supply passage.

(2) Operation Hydraulic pressure is supplied to the hydraulic tappet from the first oil pressure supply path through the first oil path, and hydraulic pressure is supplied to the connection switching mechanism from the second oil pressure supply path through the second oil path. Ru.

(3) Examples Examples of the present invention will be explained below with reference to the drawings.
First, in FIGS. 1 and 2 showing a first embodiment of the present invention, a pair of intake valves Vl and V2 provided in an engine body l are shown.
The cam C is integrally provided on the camshaft 2 and is driven at a rotation ratio of 1/2 in synchronization with the rotation of the engine, and the first and second cams are swingable around an axis parallel to the camshaft 2.
Both intake valves V1 and V
The opening/closing operation is performed by switching between a state in which intake valve V2 is opened and closed, and a state in which only one intake valve V1 is opened and closed. The engine body 1 is also provided with a pair of exhaust valves (not shown), and these exhaust valves are also opened and closed in the same manner as the intake valves Vl and V2 described above.

The camshaft 2 is rotatably disposed above the engine body 1, and the cam C is integrally provided on the camshaft 2 at a position corresponding to one intake valve vl. Further, a concentric raised portion 6 is integrally provided on the camshaft 2 at a position corresponding to the other intake valve v2, and the radius of this raised portion 6 is set to be the same as the radius of the base circle 7 of the cam C. be done. Further, a cam slipper 8 that slides on the cam C is integrally provided at the upper center of the 10th latch arm 3, and a slipper 9 that can slide in sliding contact with the raised portion 6 is integrally provided at the upper center of the 20th latch arm 4.

The bases of each of the rocker arms 3 and 4 are slidably supported on a rocker shaft 10 fixed to the engine body 1 in parallel with the camshaft 2 so as to be able to swing freely.

At the end of each rocker arm 3.4 there is an intake valve Vl.

Contact portions 11 and 12 are provided for contacting the upper end of V2, respectively, and hydraulic tappets Tl and T2 are provided on these contact portions 11 and 12, respectively. These hydraulic tappets) TI and T2 basically have the same structure, and the structure of only one hydraulic tappet T2 will be described in detail below.

Hydraulic tank T2 is provided with a hydraulic chamber 15 at the back of a plunger 14 which is urged by a spring 13 in the direction of contacting the intake valve 2, and an oil reservoir chamber 16 which is constantly in communication with an oil supply source (not shown) and the above-mentioned hydraulic chamber 15. A check valve 17 is installed between the hydraulic chamber 15 and
is interposed.

A bottomed hole 18 that is open to the intake valve v2 side is bored in the contact portion 12, and a bottomed cylindrical plunger 14 with a spherical head 19 at the closed end is inserted into the bottomed hole 18. are slid together with the spherical head 19 facing the intake valve 2 side. Bottomed hole 1
A ring 20 is fitted on the inner surface of the open end of the plunger 8, and the ring 20 prevents the plunger 14 from falling out of the bottomed hole 18.

A cylindrical member 21 that defines an oil reservoir chamber 16 is slid into the plunger 14, and a hydraulic chamber 15 facing the back of the plunger 14 is defined between one end of the cylindrical member 21 and the plunger 14. will be accomplished.

A valve cage 22 pressed against a cylindrical member 21 by a spring 13 is housed in the hydraulic chamber 15, and a spherical check valve 17 is housed in a floating manner within this valve cage 22. Further, a valve hole 23 communicating with the oil reservoir chamber 15 is bored in one end of the cylindrical member 21 so that communication with the hydraulic chamber 15 is cut off by the check valve 17 .

An annular groove 2 communicating with the oil reservoir chamber 16 is formed on the outer surface of the cylindrical member 21.
A cylindrical member 2 is provided on the outer surface of the plunger 14.
An annular groove 25 is provided that communicates with the annular groove 24 regardless of the relative movement between the plunger 1 and the plunger 14. The other end of the cylindrical member 21 is urged by the spring force of the spring 13 to come into contact with the closed end of the bottomed hole 18.
A through hole 26 communicating with the oil reservoir chamber 16 is bored at the other end of the oil reservoir 1 . Further, an annular chamber 27 is defined by the bottomed hole 18, the plunger 14, and the cylindrical member 21.
In order to prevent the movement of the annular chamber 2 from being obstructed,
An open hole 28 is bored to open the interior of the housing 7 to the outside.

A partition wall 36 extending in the axial direction is press-fitted, fixed, or integrally molded into the rocker shaft 10 . Thereby, the partition wall 3.6 is interposed in the rocker shaft 10, and the first
A hydraulic pressure supply path 37 and a second hydraulic pressure supply path 38 are provided separately. These first hydraulic pressure supply path 37 and second hydraulic pressure supply path 3
8 are individually connected to corresponding hydraulic pressure supply sources (not shown), the first hydraulic pressure supply path 37 is supplied with relatively low pressure hydraulic pressure, and the second hydraulic pressure supply path 38 is supplied with relatively high pressure. of hydraulic pressure is supplied.

The 20th lever arm 4 is provided with an annular groove 39 surrounding the rocker shaft 10, and the rocker shaft 10 is provided with a communication hole 40 that allows the first hydraulic pressure supply path 37 to communicate with the annular groove 39.

Further, the 20th hook arm 4 is provided with a first oil passage 31 that connects the annular groove 39 and the annular groove 25 of the plunger 14 in the hydraulic tappet T2.
A diaphragm 32 is provided in the middle. That is, the oil reservoir chamber 16 of the hydraulic tappet T2 is always in communication with the first oil pressure supply path 37, and the throttle 32 functions to limit the oil supply speed from the first oil pressure supply path 37. At the upper part of the contact part 12, there is a diaphragm 3 that communicates with the through hole 26.
3 are bored and these throttles 32.3 serve to limit the speed of oil drainage from the oil sump chamber 16.
3 prevents the oil pressure in the oil reservoir chamber 16 from rapidly changing.

In FIG. 3, the tenth lever arm 3 is provided with an annular groove 41 that communicates with the first oil pressure supply path 37, and a first oil path 4 that connects the hydraulic tappet T1 and the annular groove 41.
2 is provided. A throttle (not shown) similar to the throttle 32 is provided in the middle of the first oil passage 42 .

On the other hand, flange portions 34 and 35 are provided at the upper portions of both intake valves Vl and V2. Between these flanges 34, 35 and the engine body l, valve springs Sl, S2 surrounding the intake valves Vl, V2 are installed.
are interposed, and each intake valve Vl, V2 is urged in the valve closing direction, that is, upward, by valve springs Sl, S2.

The first and 20th rocker arms 3.4 are in sliding contact with each other, and have a connection switch that allows them to be switched between a state in which relative angular displacement is possible and a state in which both rocker arms 3 and 4 are integrally connected. A mechanism 5 is provided on the double-ended hook arm 3.4.

The connection switching mechanism 5 includes a piston 5 that is movable along an axis parallel to the rocker shaft 10 between a position where both rocker arms 3.4 are connected and a position where the connection state is released.
1 and a stopper 52 that restricts the movement of the piston 51.
and a spring 53 that biases the stopper 52 to move the piston 51 toward the disconnection position.

A first guide hole 54 that is open toward the 20th claw arm 4 and parallel to the rocker shaft 10 is bored in the 10th claw arm 3, and a stepped portion 55 is formed at the bottom of the first guide hole 54. A small diameter portion 56 is provided therebetween. The piston 51 is slidably fitted into the first guide hole 54, thereby defining a hydraulic chamber 57 between the piston 51 and the bottom surface of the first guide hole 54. Further, a second oil passage 58 communicating with the hydraulic chamber 57 is bored in the tenth lever arm 3, and this second oil passage 58 is connected to the rocker shaft 10 through a through hole 59 bored in the side wall of the rocker shaft 10. Second hydraulic supply path 3 inside
8 is always connected.

The axial length of the piston 51 is such that when one end thereof contacts the stepped portion 55, the other end is in the 20th position of the 10th lever arm 3.
It is set so that it does not protrude from the side facing the hookah arm 4 side.

The 20th claw arm 4 has a second guide hole 54 having the same diameter as the first guide hole 54 of the 10th claw arm 3.
A guide hole 60 is bored open toward the tenth fuser arm 3 side, and a disc-shaped stopper 5 is inserted into this second guide hole 60.
2 are rubbed together. A small diameter portion 62 is provided on the bottom side of the second guide hole 60 via a regulating step portion 61 . Furthermore, a small-diameter insertion hole 63 is formed in the 20th hook arm 4 between the bottom and the outer surface of the second guide 660, and is concentric with the second guide hole 60. A small-diameter guide rod 64 provided in is inserted into the insertion hole 63. Furthermore, a coiled spring 53 surrounding the guide rod 64 is provided between the stopper 52 and the bottom surface of the second guide 660.
is interposed.

In such a connection switching mechanism 5, the first and second guide holes 54,60 are such that the cam slipper 8 of the tenth latch arm 3 slides on the base circle 7 of the cam C, and the slipper 9 of the twentieth latch arm 4 is raised. While in sliding contact with section 6,
They are designed to be concentric.

Next, the operation of this embodiment will be explained. When the engine is operating at low speed, hydraulic oil is not supplied to the hydraulic chamber 57 of the connection switching mechanism 5. As a result, the stopper 52 is pushed toward the tenth lever arm 3 by the spring 53. , the piston 51 abuts against the stepped portion 55.

In this state, the contact surfaces of the piston 51 and the stopper 52 are at positions corresponding to the sliding surfaces of the first and twentieth claw arms 3 and 4. Therefore, the first and twentieth hook arms 3.4 are in sliding contact with each other, and the piston 51 and the stopper 52 are in sliding contact so that they can be relatively angularly displaced.

In such a disconnected state of the connection switching mechanism 5, the rotation of the camshaft 2 causes the tenth hook arm 3 to swing by the cam C, and one intake valve Vl is moved by the cam C.
It opens and closes with timing and lift amount depending on the shape of the door. On the other hand, the slipper 9 of the 20th hook arm 4 is in sliding contact with the raised portion 6, and the other intake valve V2 remains closed and open.

When operating the engine at high speed, the hydraulic chamber 5 of the connection switching mechanism 5
7 is supplied with relatively high pressure hydraulic oil.

As a result, the piston 51 is moved from the stopper 52 to the regulating step 61.
While contracting the spring 53 until it comes into contact with the second guide hole 6
0, and the piston 51 connects the first and twentieth claw arms 3.4.

In this way, in the state where the first and 20th linker arms 3.4 are integrally connected, both the first and 20th linker arms 3, 4 swing according to the rotation of the cam C, and both the intake valves Vl, Both V2 are operated to open and close.

During the connection operation of the connection switching mechanism 5, when both the intake valves Vl and V2 are closed, the tenth hook arm 3 is moved so that the cam slipper 8 moves to the base circle of the cam C due to the action of the hydraulic tappets Tl and T2. The 20th hook arm 4 is biased in the direction in which the slipper 9 comes into sliding contact with the raised portion 6, and in the direction in which the slipper 9 comes into sliding contact with the raised portion 6. Therefore, since the axes of the first and second guide holes 54 and 60 are aligned, the piston 51 moves smoothly and the connection switching mechanism 5 is reliably connected.

In this way, relatively low pressure hydraulic pressure is supplied to each hydraulic tappet Tl, T2, and relatively high pressure hydraulic pressure is supplied to the connection switching mechanism 5, so that the hydraulic tappets Tl, T2 and the connection switching mechanism 5 Each will operate with appropriate hydraulic pressure.

FIG. 4 shows a second embodiment of the present invention, and parts corresponding to those of the first embodiment described above are given the same reference numerals.

In this second embodiment, the connection switching mechanism 5 is disposed across the middle of the first oil passage 42' that connects the hydraulic tappet (Tl) of the tenth lever arm 3 and the first oil pressure supply passage 37. In this case, an annular groove 65 that always surrounds the piston 51 in the connection switching mechanism 5 is provided in the tenth lug arm 3, and the first oil passage 42' is connected to the annular groove 65 at its intermediate portion to the tenth lug arm 3. provided.

FIG. 5 shows a third embodiment of the present invention, in which the first and twentieth claw arms 3.4 are rotatably supported by a rocker shaft 10 at their intermediate portions. Further, one end of both rocker arms 3.4 has a hydraulic tappet T1. which abuts on the intake valves Vl and V2. A cam slipper 8 that slides on the cam C is provided at the lower end of the 10th claw arm 3, and a slipper 9 that slides on the raised portion 6 is provided at the lower end of the 20th claw arm 4. Further, a connection switching mechanism 5 is provided on both rocker arms 3.4 on the other end side of the rocker shaft 10.

In this case, within the rocker shaft 10 there is a second hydraulic pressure supply path 38 on the side of the connection switching mechanism 5, and both hydraulic pressure tubes) T1. A first hydraulic supply path 37 on the T2 side is formed on both sides of the partition wall 360,
The second oil pressure supply path 38 and the connection switching mechanism 5 are connected by a second oil path 58, and both hydraulic tappets Tl, T2 and the first oil pressure supply path 37 are connected by separate first oil paths 42, 31. tied together.

FIG. 6 shows a fourth embodiment of the present invention, in which the connection switching mechanism 5 is connected to the hydraulic tappet Tl rather than the rocker shaft 10.
, are provided on the first and twentieth hook arms 3 and 4 on the T2 side.

In this case, the nozzle ffl communicating with the first hydraulic pressure supply path 37 side
Condition 141. 39 surrounds the rocker shaft 10 and the first
And installed on the 20th hook arm 3, 4, hydraulic pressure 9 pesos) TI, T2 ring? a41. 39 is an individual first
Connected by oil passage 42.31. In addition, the connection switching mechanism 5
It is connected to the second hydraulic pressure supply path 38 via an oil path 58 .

FIG. 7 shows a fifth embodiment of the present invention, in which the cam C
A single intake valve V is brought into contact with a hydraulic tab (T) provided on a rocker arm 3 that is swing-driven by a rocker arm 3, and a connection switching mechanism 5 is provided between the rocker arm 4 and the rocker arm 3 that are in sliding contact with a raised portion 6. provided. Moreover, one rocker arm 3
A first oil passage (not shown) connected to the hydraulic tube T and a second oil passage (not shown) connected to the connection switching mechanism 5 are provided.

FIG. 8 shows a sixth embodiment of the present invention, which shows a pair of rocker arms 3, 4 with a connection switching mechanism 5 disposed between them.
For example, one of the fork arms 4a is provided with a hydraulic tappet (not shown) that abuts a pair of intake valves (not shown), respectively.

4b, and each arm portion 4a, 4b has a first oil passage 31 provided in the rocker arm 4 across the connection switching mechanism 5.
Also, second oil passages 31a and 31b are provided which connect the first oil passage 31 and each hydraulic tappet. Further, the other rocker arm 3 is provided with a second oil passage 5 connected to the connection switching mechanism 5.

FIG. 9 shows a seventh embodiment of the present invention, in which rocker arms 71.7 swing in sliding contact with cams (not shown).
2 are provided with hydraulic tappets that abut the respective intake valves, and a rocker arm 73 that slides into contact with a protrusion provided on the camshaft is disposed between both rocker arms 71 and 72.

Moreover, rocker arm 71.73 questions and rocker arm 7
A connection switching mechanism 5' is provided between 2 and 73, respectively.

The double-ended hook arms 71 and 72 are provided with first oil passages 74 and 75 connecting the hydraulic tappet and the first supply oil passage 37, respectively, across each connection switching mechanism 5', and the rocker arm 73 is provided with each connection switching mechanism. 5'' to the second hydraulic supply path 38
A pair of second oil passages 76 are provided.

FIG. 10 shows an eighth embodiment of the present invention, in which a rocker arm 71 is provided with a first oil passage 74, a rocker arm 72 is provided with first and second oil passages 75. A second oil passage 77 is provided.

As shown in each of the above embodiments, in the present invention, the first and second oil passages can be arranged in accordance with the number of valves and the arrangement of the rocker arm and connection switching mechanism, which differ depending on the control mode. 2 in order to be able to control it in three stages.
The second oil passages of the system can also be provided independently of each other.

Effects of C0 Invention As described above, according to the present invention, in the rocker shaft,
A first oil pressure supply passage and a second oil pressure supply passage are separated via a partition wall extending in the axial direction, and the rocker arm has a first oil passage connecting the hydraulic tappet and the first oil pressure supply passage, a connection switching mechanism, and a second oil pressure supply passage. Since a second oil passage is provided to connect the oil pressure supply passage,
Appropriate operation can be performed by using a separate hydraulic pressure supply system for the hydraulic tappet and the connection switching mechanism.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a plan view, FIG. 2 is a sectional view taken along the line ■-n in FIG.
FIG. 3 is a cross-sectional view taken along line mm in FIG. 2, FIG. 4 is a cross-sectional view corresponding to FIG. 3 of the second embodiment of the present invention, and FIGS.
The figure is a sectional view corresponding to FIG. 2 of the third and fourth embodiments of the present invention, FIG. 7 is a plan view corresponding to FIG. 1 of the fifth embodiment of the present invention, and FIGS. 8 and 9. and FIG. 10 are sectional views corresponding to FIG. 3 of the sixth, seventh and eighth embodiments of the present invention. 3.4,71,72.73...Rocker arm, 5°5
'...Connection switching mechanism, 10...Rocker shaft, 3
1.31a, 31b, 42.42'-first oil passage, 36
... Bulkhead, 37... First oil pressure supply path, 38... Nose 2 oil pressure supply path, 58, 76.77... Second oil path Tl,
T2... Hydraulic shaft, Vl, V2... Intake valve Fig. 3 Fig. 4 Fig. 5 Fig. 7 Fig. 8 Fig. 10 Fig. 9

Claims (4)

[Claims] (1) A plurality of rocker arms, including a rocker arm equipped with a hydraulic tappet that contacts the intake valve or exhaust valve, are pivotally supported by a rocker shaft, and between each rocker arm, the connection and disconnection of both rocker arms can be switched by the action of hydraulic pressure. In a valve train for an internal combustion engine provided with a connection switching mechanism, a first hydraulic pressure supply path and a second hydraulic pressure supply path are separated from each other in the rocker shaft via a partition wall extending in the axial direction, and the rocker arm includes A valve train for an internal combustion engine, characterized in that a first oil passage connects a hydraulic tappet and a first oil pressure supply passage, and a second oil passage connects a connection switching mechanism and a second oil pressure supply passage. (2) The second hydraulic pressure supply path is supplied with a higher hydraulic pressure than the first hydraulic pressure supply path.
1) A valve train for an internal combustion engine according to item 1). (3) The connection switching mechanism includes a piston that is movable between a position where each rocker arm is connected and a position where the connection is released depending on the action of hydraulic pressure. ) or (2) above. (4) Claim 1(1), characterized in that the connection switching mechanism is disposed across a part of the second oil passage;
The valve train for an internal combustion engine according to item (2) or item (3).