JPH0238004Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a partial valve deactivation device for an engine valve train, which not only can reduce the external size, but also completely eliminates oil leakage and ensures smooth clutch operation. Provide something that can be used in and out.

[Prior art and its problems]

Generally, a part of the valve train is stopped operating in the following cases.

(1) One side of the double intake valve is stopped at startup to strengthen the swirl.

(2) One of the double intake valves is stopped at startup to suppress heat dissipation.

(3) Reduce energy loss by operating a multi-cylinder engine with fewer cylinders.

Therefore, as shown in FIG. 1, the basic structure of a device for stopping the valve operation is as follows: As shown in FIG. 5 are interlocked and connected, the clutch 4 is configured to be able to be turned on and off by a hydraulic cylinder 6, and the driving side rocker arm 3, the clutch 4, the driven side rocker arm 5 and the hydraulic cylinder 6 are provided so as to be externally fitted on a common rocker arm shaft 7,
The hydraulic oil chamber 11 between the cylinder body 8 of the hydraulic cylinder 6 and the piston 10 is connected to the outer peripheral surface 12 of the rocker arm shaft 7.
This is a type of structure in which an oil inlet/outlet 14 of a hydraulic oil chamber 11 is opened on the outer circumferential surface 12 of the rocker arm shaft 7.

In this type of conventional technology, a driving side rocker arm 5 is externally fitted onto a rocker arm shaft 7, and a piston is attached to a pressure receiving part of the rocker arm 5.
0 and the cylinder body 8 are sequentially fitted to the outside, and the cylinder body 8 is fixed to a sealing plate that completely closes the bracket side of the hydraulic oil chamber 11. If the hydraulic pressure flowing into the hydraulic oil chamber 11 is low, the pressing force of the piston 10 is small. When the clutch 4 is engaged, the clutch 4 is disengaged and the driving side rocker arm 3 is operated independently.If the oil pressure is high, the pressing force of the piston 10 becomes large and the clutch 4 is engaged, and the driving side and driven side rocker arms 3 and 5 are operated simultaneously. There is something.

However, in the above conventional technology, the piston 1
0 is oriented via the rocker arm shaft 7 and the driven rocker arm 5,
Since its outer circumferential surface is oriented via the cylinder body 8 caulked to the sealing plate, there is a difference in the direction of both circumferential surfaces of the piston, and the piston 10 is aligned with the rocker arm shaft 7.
In many cases, misalignment occurs due to the piston 10, and sliding is performed with uneven contact, which impedes the engagement and disengagement of the clutch 4. In addition, oil leaks from the gap between the piston 10, the sealing plate, and the cylinder body 8. There is a problem with it.

[Prior art and its problems]

Therefore, as a technology to eliminate this rattling of the piston, the present applicant has proposed Utility Application No. 60-66317 (Showa
(filed on May 2, 1960).

That is, in the prior art, as shown in FIG.
A piston 10 is slidably fitted into a thick and rigid cylinder body 8, and a sealing plate 70 is attached to a misalignment absorbing sealing member 71.
Since the piston 10 is attached to the rocker arm shaft 7 via the cylinder body 8, if the direction of the outer circumferential surface of the piston 10 is misaligned from that of its inner circumferential surface, the sealing plate 70 tilts appropriately to change the direction of the cylinder body 8 to the rocker arm shaft. 7, the piston 10 can slide smoothly without misalignment.

However, on the other hand, since the cylinder body 8 is formed of a thick member, the outer diameter of the hydraulic cylinder 6 becomes large, and the valve mechanism itself becomes large. Components surrounding the valve mechanism must be spaced apart, and the overall size of the engine is also becoming larger.

The technical problem of this invention is to make the outer diameter of a hydraulic cylinder compact.

[Means for solving problems]

Means for achieving the above object will be explained below using FIGS. 1 to 8.

That is, in the present invention, an extensible oil-tight cylinder membrane 15 is provided in the cylinder body 8 to surround the hydraulic oil chamber 11, one end 16 of the oil-tight cylinder membrane 15 is attached to the cylinder body 8, and the other end 17 is attached to the cylinder body 8. to the piston 10, and oil-tight fixing means 1 respectively.
8 and 20 are oil-tightly fixed.

[Effect]

When the oil pressure in the hydraulic oil chamber 11 increases, the piston 1
0 slides in the direction of engagement of the clutch 4 in response to this pressure, and the oil-tight cylindrical membrane 15 also extends its length and continues to surround the hydraulic oil chamber 11.

Conversely, when the oil pressure decreases, the piston 10 slides in the direction of releasing the clutch 4 due to the reduction in the received pressure, but as a result, the oil-tight cylindrical membrane 15 continues to surround the hydraulic oil chamber 11 while increasing its own length. Shorten and degenerate.

[Effect of idea]

Conventionally, a thick and rigid cylinder body was arranged to keep the outer peripheral surface of the piston oil-tight and to orient the piston, but in the present invention, the outer peripheral surface of the piston is made oil-tight with an oil-tight cylinder membrane. The cylinder body can be made thinner by bending a steel plate, so the stop device can be made smaller, and the parts around the valve mechanism can be moved closer to the locker arm shaft, making the entire engine more compact.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 and 2 are enlarged longitudinal sectional front views of the main parts around the hydraulic cylinder, Figure 3 is a right side view of the hydraulic cylinder, Figure 4 is its left side view, and Figure 5 is the V of Figure 3.
-V line sectional view, FIG. 6 is a longitudinal sectional front view around the rocker arm shaft, FIG. 7 is a plan view thereof, and FIG. 8 is a longitudinal sectional right side view of the main part of the diesel engine.

A cylinder 22 is provided at the center of a cylinder lock 21 of a diesel engine E, and a piston 23 is fitted therein so as to be vertically slidable.

The cylinder head 24 and head cover 25 are fixed in sequence above the cylinder block 21, two intake and exhaust ports 26 and 27 are opened in the cylinder head 24, and two double intake valves 28a and 28b are opened.
Double exhaust valves 29, 29 are made to face the two exhaust ports 27 so as to be openable and closable, respectively.

A plurality of brackets 30 are fixed to the end face of the cylinder head 24, a rocker arm shaft 7 is mounted on the brackets 30, and a driving side rocker arm 3 and a driven side rocker arm 5 for intake are fitted onto the rocker arm shaft 7 so as to be able to swing freely. , a meshing clutch 4 is formed on opposing end surfaces of both rocker arms 5, 3.

A valve drive camshaft 31 interlocked with the crankshaft is mounted on the left side of the cylinder block 21, and the valve drive camshaft 31 is interlocked with the drive side rocker arm 3 via a tappet 32 and a push rod 33.

The input part 34 of the driving side rocker arm 3 is connected to the upper end 33a of the push rod 33, and the output part 3
5 can be brought into contact with one side 28a of the double intake valve, and the output part 3 of the driven side rocker arm 5
6 so as to be able to come into contact with the other side 28b of the double intake valve.

Therefore, the rotational force of the valve train camshaft 31 is applied to the intake cam 2.
After the movement is converted into vertical movement, the drive side rocker arm 3
is transmitted to the intake valve 28a and swings the intake valve 28a.
Drive to open and close.

In this case, when the clutch 4 is engaged, the driven side rocker arm 5 also swings in accordance with the driven side, driving the other intake valve 28 so that it can be opened and closed (that is, both valves are driven), but when the clutch 4 is disengaged, the driven side rocker arm Since the side rocker arm 5 receives no input from the active side rocker arm 3, the other intake valve 28b is stopped, and only one intake valve 28a is operated as a single valve.

A hydraulic cylinder 6 for engaging and closing the clutch 4 is disposed in the gap between the left end of the driven side rocker arm 5 and the bracket 30, and is attached to the rocker arm shaft 7 so as to be externally fitted thereto.

The hydraulic cylinder 6 consists of a cylinder body 8, a piston 10, and an oil-tight cylinder membrane 15. An opening 37a is formed in the base wall 37 of the cylinder body 8, and this is inserted into the rocker arm shaft 7. From side peripheral wall 38
An oil-tight cylindrical membrane 15 that can be expanded and contracted is installed inside.

The oil-tight cylindrical membrane 15 consists of a base 40 and a bellows part 41 that meanders inwardly, and one end 16 of the cylindrical membrane 15 is oil-tightly fixed to the base wall 37 of the cylinder body 8 by an oil-tight fixing means 18, and other parts. The end portion 17 is oil-tightly fixed to the right half of the piston 10 by oil-tight fixing means 20.

The piston 10 has a cylindrical shape, and a pressure receiving part 46 formed at the left end of the driven rocker arm 3 is fitted into its inner circumferential surface 43, and a step engaging part 48 of the pressure receiving part 46 can be brought into contact with its right side surface 47. Let's face it.

The outer circumferential surface 45 of the piston is loosely fitted into the side circumferential wall 38 of the cylinder body 8.

Reference numeral 51 denotes a notch formed on the piston 10 side to prevent relative rotation of the piston 10 with respect to the cylinder body 8, and reference numeral 52 denotes a protrusion formed on the cylinder body side to prevent this relative rotation. By preventing
In addition to eliminating twisting of the oil-tight cylinder membrane and extending its life, as shown in FIG. .

The reference numeral 50 is an O-ring that seals the gap between the oil-tight cylinder membrane 15 and the rocker arm shaft 7, and the reference numeral 53 is a detent claw that prevents the cylinder body 8 from rotating relative to the bracket 30.

A lubricating oil passage 55 passes through the center of the rocker arm shaft 7, and the end of the oil passage is connected to a lubricating oil pump, and an oil feed passage 56 is branched from the lubricating oil passage 55, and its open end is used as an oil inlet/outlet 14 for the following operations. It communicates with the oil chamber 11.

Oil-tight cylinder membrane 15 and piston 10 of hydraulic cylinder 6
The area surrounded by the pressure receiving part 46 and the rocker arm shaft outer circumferential surface 12 becomes the hydraulic oil chamber 11, and the oil flowing from the oil feed passage 56 is filled in the oil-tight cylinder membrane 15, so to speak, and the left end of the piston 10 receives pressure. surface 57 and the left end pressure receiving surface 58 of the driven rocker arm pressure receiving portion 46
Press.

Note that an inclined notch 59 is provided on the left-end inner circumferential surface of the pressure-receiving portion 46 to facilitate the entry and exit of oil into the hydraulic oil chamber 11 and the oil feed path 56.

A compression spring 60 is fitted onto the driven side rocker arm 5, and its one end 61 is fixed to the driven side bracket 30, and the other end 62 is fixed to the rocker arm output portion 36, so that the driven side rocker arm 5 can be moved in the direction of releasing the clutch 4. That is, it is constantly biased in the direction of arrow P.

The functions of the hydraulic cylinder 8 will be described below.

(1) When the engine speed is low, the working oil pressure is low and the biasing force of the compression spring 60 overcomes and slides the driven side rocker arm 5 in the direction of arrow P, releasing the clutch 4 (see Fig. 1). ).

Therefore, only the main drive side rocker arm 5 swings independently, and only one of the double intake valves 28a is driven in a single-valve manner.

As a result, the intake port 2 on the side where one valve is driven
Intake air is concentrated at 6, which strengthens the swirl and improves combustion efficiency.

In this case, the inner circumferential surface of the piston 10 is oriented via the rocker arm shaft 7 and the driven rocker arm 5, but its outer circumferential surface is only restrained by the expandable oil-tight cylinder membrane 15.
Even if a deviation occurs in the direction of both circumferential surfaces, the elasticity of the oil-tight cylinder membrane 15 absorbs the misalignment, and the direction of the piston 10 can be easily aligned with that of the rocker arm shaft 7. Therefore, the clutch can be engaged and closed smoothly.

Further, the hydraulic oil chamber 11 is surrounded by an oil-tight cylindrical membrane 15, and both ends of the oil-tight cylindrical membrane 15 are oil-tightly fixed by oil-tight fixing means 18, 20, so that the oil in the hydraulic oil chamber 11 is kept oil-tight. It is reliably sealed by the cylindrical membrane 15. Therefore, oil leakage can be eliminated and oil pressure drop will not occur.

(2) As the engine speed increases, the hydraulic pressure increases, which overcomes the biasing force of the compression spring 60 and slides the sliding rocker arm 5 in the direction of arrow Q, connecting the clutch 4 (see Figure 2). .

Therefore, both the rocker arms 5, 3 on the driving side and the driven side swing, and the double intake valves 28a, 28
b drives both valves.

As a result, intake air flows through the two intake ports, improving air utilization and combustion efficiency.

In this case, the oil-tight cylinder membrane 15 extends its inward reciprocating meandering portion and slides in the Q direction, but as shown in FIGS. The end side is bent inward at 90 degrees to form a stopper 65, and this stopper 65 receives the protruding peripheral wall 66 of the piston 43, so that the movement of the piston 10 in the Q direction is within the width of the side peripheral wall 38 of the cylinder body. Stay.

Thereafter, the left end pressure receiving surfaces 58 of both driven rocker arms 5 receive hydraulic pressure, and the driven rocker arms 5 are brought closer to the driving rocker arms 3 to connect the clutch 4.

The reason why the piston 10 and the driven rocker arm 5 are arranged in two stages is that when the oil pressure increases, the initial force is mainly applied to the piston 10, thereby preventing the driven rocker arm 5 from moving suddenly and making smooth movement. This is to enable the clutch 4 to be engaged and disengaged.

As described above, in the present invention, the oil-tight cylinder membrane 15 is provided in the cylinder body 8 of the hydraulic cylinder that drives the rocker arm, and the hydraulic oil chamber 11 is surrounded by this cylinder membrane 15. The present invention may be applied to an intake valve train as in the above, but it may also be applied to a double exhaust valve train or a cylinder reduction movement mechanism as described above.

[Brief explanation of drawings]

1 to 8 show an embodiment of the present invention. FIG. 1 is an enlarged longitudinal sectional front view of the main parts around the hydraulic cylinder showing the clutch in the released state, and FIG. 2 is an enlarged longitudinal sectional front view showing the clutch in the engaged state. Figure 1 is a diagram equivalent to Figure 1. Figure 3 is a right side view of the hydraulic cylinder, Figure 4 is its left side view, Figure 5 is a cross-sectional view taken along the line V-V in Figure 3, and Figure 6 is a vertical front view around the rocker arm shaft. 7 is a plan view thereof, FIG. 8 is a vertical right side view of the main part of the diesel engine, and FIG. 9 is a view corresponding to FIG. 1 showing the prior art. 1... Valve train, 2... Valve drive cam, 3... Drive side rocker arm, 4... Clutch, 5... Driven side rocker arm, 6... Hydraulic cylinder, 7... Locker arm shaft, 8... Cylinder body , 10...piston,
11... Hydraulic oil chamber, 12... Outer peripheral surface of 7, 14...
...11 oil inlet/outlet, 15...oiltight cylinder membrane, 16...
One end of 15, 17...the other end of 15, 18,2
0...Oil-tight fixing means, E...Engine.

Claims (1)

[Scope of utility model registration request] A driven side rocker arm 5 is interlocked and connected to a valve driving cam 2 of a valve train 1 of an engine E via a driving side rocker arm 3 and a clutch 4, and the clutch 4 is configured to be able to be turned on and off by a hydraulic cylinder 6, and the driving side rocker arm 3, The clutch 4, the driven side rocker arm 5, and the hydraulic cylinder 6 are provided so as to fit around a common rocker arm shaft 7, and the hydraulic oil chamber 11 between the cylinder body 8 of the hydraulic cylinder 6 and the piston 10 is connected to the outer peripheral surface of the rocker arm shaft 7. 12, and the oil inlet/outlet 14 of the hydraulic oil chamber 11 is located on the outer peripheral surface 12 of the rocker arm shaft 7.
In a partial valve operation deactivation device for an engine valve train configured with a gap between One end 16 is attached to the cylinder body 8, and the other end 17 is attached to the piston 10, respectively, with oil-tight fixing means 1.
8. A partial valve train deactivation device for an engine valve train, characterized in that the parts 8 and 20 are oil-tightly fixed.