JPH034731Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a partial valve operating deactivation device for an engine valve operating system, and the present invention relates to a partial valve operating deactivation device for an engine valve operating system. To provide a device which can simplify the entire device by combining three functions of stopping a partial valve, securing a valve lift amount of a driven side rocker arm, and preventing position shift of an excessive return stopper of the rocker arm.

<Prior Art> Generally, a part of the valve train is stopped in the following cases.

(1) Swirl is strengthened by stopping one of the double intake valves during startup or low-speed operation.

(2) One side of the double exhaust valve is stopped at startup to suppress heat escape.

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

Therefore, the basic structure of a device for stopping a part of the valve train is shown in FIG. 1 or FIG. and a driven side rocker arm 5 are interlocked and connected via a clutch 4, and the clutch 4 is configured to be movable on and off by a hydraulic cylinder 6 and a coiled return spring 100, and the driving side rocker arm 3 and the driven side rocker arm 5 are connected to a common rocker arm shaft 7. It is of a type that is fitted externally.

The prior art of this type is
There is something related to No. 66317 (Figures 10 and 11)
(see figure).

That is, in the prior art, a meshing clutch is formed on the opposing surfaces of both the rocker arms 3 and 5 on the main shaft side and the driven side, and the return spring 1 is inserted in the circumferential direction of the clutch 4.
00 are attached to release the clutch 4, and when the hydraulic pressure of the hydraulic cylinder 6 is low, the clutch 4 is disengaged by the return force of the spring 100, and conversely,
When the oil pressure is high, the clutch 4 is configured to engage against the return force of the spring 100.

<Problems to be solved by the invention> In the above-mentioned prior art, a plurality of return springs 100 are attached in the circumferential direction of the clutch 4, and the return springs 100 are arranged in a so-called planetary shape on the outer periphery of the locker arm shaft 7. Therefore, the outer diameter of the hydraulic cylinder 6 becomes correspondingly larger, and not only does the valve train stopping device itself have to be made larger, but also the members around the valve train must be spaced apart from each other due to the increased size. This increases the size of the entire engine.

In addition, generally taking into consideration the manufacturing error of the meshing teeth of the driving side and driven side rocker arms 3, 5,
As shown in FIG. 12, the driven side rocker arm 5 is moved closer to the valve opening direction D by a safety gap B than the return end position A of the arm lift 80 of the driving side rocker arm 3 (if this gap B is not secured, the manufacturing If the engagement position 81 of the driven rocker arm 5 deviates from the engagement position 82 of the driving side in the valve closing direction F due to an error, the two rocker arms will not be able to engage.

Therefore, when the clutch 4 is engaged and both valves are driven, the driving side rocker arm 3 moves from the return end position A by the safety gap B, and then engages with the driven side rocker arm 5 to push it down in the valve opening direction D. .

In this case, the actual valve opening lift 83 of the driving side rocker arm 3 is the arm lift 80 minus the valve clearance C, and the valve opening lift 84 of the driven side rocker arm 5 is also the driven side arm lift 85.
However, for the above-mentioned reason, this driven side arm lift 84 is smaller than the driving side arm lift 80 by the safety gap B, so the driven side rocker arm 5 drives the intake valve to open. The time is shorter than that on the active side.

Moreover, the Rotsuka arm 3, which is driving both valves,
For example, when the clutch is released while pressing the intake valve, the driven side rocker arm 5 is flipped upward by the single pressure of the valve closing spring, and the upper limit stopper 5 limits the swinging of the rocker arm. There is a risk that the stopper may become misaligned during long-term use, causing the driven side rocker arm 4 to return too far in the valve closing direction F and not be able to engage with the driving side.

The technical challenge of this invention is to make a part of the valve train compact, to ensure the intake time area of the driven side rocker arm is the same as that of the driving side, and to prevent the upper limit stopper of the driven side rocker arm from shifting. do.

<Means for Solving the Problems> Means for achieving the above-mentioned problems will be described below with reference to FIGS. 1 to 8, which correspond to embodiments.

That is, in the present invention, the coiled return spring 100 is attached to the rocker arm shaft 7 in an externally fitted manner, and the spring wire tip 105 of the fixed side end 104 of the coiled return spring 100 and the spring wire tip of the movable side end 110 are connected to each other. Part 11
1 and 1 are aligned along the axial direction S of the rocker arm shaft 7 and are oriented in opposite directions to each other, so that the spring wire tip 105 on the fixed side does not move relative to the axial direction and rotational direction of the rocker arm shaft 7. The coiled return spring 100 biases the driven side rocker arm 5 in the sliding direction for intermittent switching operation of the clutch 4, and also in the swinging direction toward the valve opening side. This is characterized in that the tip end portion 111 of the spring wire on the movable side is engaged with the output end portion 36 of the rocker arm 5 on the driven side.

<Function> The coil return spring 100 is always biased in the direction of releasing the clutch 4, and when the hydraulic pressure of the hydraulic cylinder 6 is low, the elastic force of the spring 100 overcomes and the clutch 4 is released, and only the drive side rocker arm 3 is released. It will be driven independently.

On the other hand, when the oil pressure of the hydraulic cylinder 6 becomes high, this oil pressure overcomes the elastic force of the spring 100, and the clutch 4 is connected to drive both the driving side and driven side rocker arms in parallel.

Moreover, since the driven side rocker arm 5 is elastically biased in the valve opening direction by the coiled return spring 100, when the clutch 4 is engaged, as shown in FIG. In this state, it will mesh with the locker arm 3 on the driving side.

Therefore, even if the driven side rocker arm 5 does not have the safety gap B as described in the prior art section, it is pushed down at least by the distance of the valve clearance C in the valve opening direction D, so the driving side rocker arm 3 The meshing position 82 is the driven side position 81
Since the clutch 4 is located higher up, the clutch 4 can be smoothly engaged.

As a result, at the moment when the drive-side rocker arm 3 is pushed down by the amount of the valve clearance C and the intake valve opens after the clutch 4 contacts, the clutch 4
is fully engaged, the driven side rocker arm 5 is pushed down, and the driven side intake valve is opened at the same time.

Therefore, although the arm lift 85 of the driven rocker arm 5 is smaller than the arm lift 80 on the driving side, its valve opening lift amount 85 is equal to the lift amount 83 on the driving side.
Therefore, the time for the driven side rocker arm 5 to drive the intake valve to open can match that of the driven side.

Furthermore, even if the clutch 4 is disengaged, the driven-side rocker arm 5 is urged against the valve shaft head, so it will not be pushed up by the elastic force of the valve-closing spring. The arm never hits.

As a result, it is possible to prevent the upper limit stopper from shifting its position.

<Effects of the invention> Since the coiled return spring that urges the hydraulic cylinder in the direction of resistance is attached to the rocker arm shaft in an external fit, the wire portion of the spring is wound around the rocker arm shaft in the circumferential direction, so that the rocker arm shaft Compared to the conventional technology in which a plurality of return springs are arranged in a planetary manner around the center, the outer diameter of the hydraulic cylinder is smaller, the valve train stop device itself can be made smaller, and the entire engine can be made more compact.

In addition, a coiled return spring is used to combine the three functions of partially stopping the valve train, ensuring the valve opening lift amount of the driven side rocker arm, and preventing the upper limit stopper from shifting. can be simplified.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

Fig. 1 is a plan view of the rocker arm shaft and its surroundings, Fig. 2 is a cross-sectional view taken along the - line in Fig. 1, Fig. 3 is a right side view of the coiled return spring, Fig. 4 is a plan view of the same spring, Fig. 5 6 is a longitudinal sectional front view of the rocker arm shaft and its surroundings, FIG. 7 is an enlarged longitudinal sectional front view of the hydraulic cylinder periphery, and FIG. 8 is a longitudinal sectional right side view of the main parts of the diesel engine.

Diesel engine E cylinder block 21
A cylinder 22 is formed in the center of the cylinder 22, and a piston 23 is fitted inside the cylinder 22 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 the double intake valves 28a and 28b are connected to the two intake ports 26 and 27. Further, double exhaust valves 29, 29 are arranged to face the two exhaust ports 27 so as to be openable and closable, respectively.

A bracket 30 is attached to the upper end surface of the cylinder head 24.
A rocker arm shaft 7 is mounted on the bracket 30, and a driving-side rocker arm 3 and a driven-side rocker arm 5 for air intake are fitted onto the rocker arm shaft 7 so as to be able to swing freely. A meshing clutch 4 is formed on the opposite end surface.

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 is configured to be able to come into contact with the other 28b of the double intake valve.

Therefore, the rotational force of the valve drive camshaft 31 is converted into vertical movement by the intake cam, and is then transmitted to the main drive side rocker arm 3 via the tappet 32 and push rod 33 to swing it, thereby causing one intake valve 28a to move. 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 The rocker arm 5 loses the input from the driving side rocker arm 3, stops the other intake valve 28b, and performs single-valve drive with only one intake valve 28a.

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 is made up of a cylinder body 8, a piston 10, and an oil-tight cylinder membrane 15, and a hydraulic oil chamber 11 surrounded by the oil-tight cylinder membrane 15 has a lubricating oil penetrating through the center of the rocker arm shaft 7. An oil feed hole 56 branched from the hole 55 is communicated with the oil feed hole 56 so that oil can be pumped from the lubricating oil pump of the engine E to the hydraulic oil chamber 11.

On the other hand, a coiled return spring 100 is fitted onto the outermost cylinder body 8 of the hydraulic cylinder 6 so that it is always directed against the hydraulic cylinder 6, that is, in the direction of disengaging the clutch 4. energize.

As shown in FIGS. 3 to 5, the return spring 100 is a left end portion 10 of a single-turn coil 108.
8a is extended rightward to form a fixed side end 104,
The tip portion is folded back in a V shape along a horizontal plane to form a spring wire tip portion 105, and the tip portion 1
05 in a straight line to the right (see Figure 5, which is a front view).

Further, the right end portion 108b of the coil 108 is folded back in a V shape while along the vertical plane, and the movable end portion 1
10, the spring wire tip 111 of the movable side end 110 is oriented along the expansion/contraction direction S of the coiled return spring 100, and is folded back into a U shape to connect the spring wire tip 111 and the fixed side. and the spring wire tip 105 are positioned opposite each other.

On the other hand, a chevron-shaped spring receiving part 104 is formed above the bracket 30, and a spring wire insertion hole 103 is formed in the spring receiving part 104 along the spring expansion/contraction direction S, that is, the longitudinal direction of the rocker arm axis.

Then, the spring wire tip 105 of the coiled return spring 100 is inserted from the left side of the spring wire insertion hole 103, and the tip 105 is oriented in the longitudinal direction S of the rocker arm axis (i.e., the direction of expansion and contraction of the spring 100). At the same time, the adjustment screw 101 is screwed into the insertion hole 103 from the right side, and the tip of the screw 101 is brought into contact with the spring wire tip 105.

A spring wire insertion hole 112 is formed in the output portion 36 extending forward of the driven rocker arm 5 along the direction of expansion and contraction of the spring 100, and the U-shaped spring wire tip 111 on the movable side of the spring 100 is inserted into the spring wire. Insertion hole 112
Insert and suspend.

In this case, the coiled return spring 100 has the spring wire tip 105 on the fixed side and presses the movable end 110 to the right more than in the natural state (see Fig. 4 and Fig. 1). In an attempt to return the movable end portion 110 to its original position, the output portion 36 is simultaneously pulled back in the direction of arrow P (sliding direction on the side that disengages the clutch 4).

Therefore, the return spring 100 always works in the direction of releasing the clutch 4, and by screwing in the adjustment screw 101, the urging force of the spring 100 is increased, and the screw 101
The biasing force can be reduced by loosening the .

The on/off operation of the clutch 4 will be described below.

(1) When the engine speed is low, the hydraulic pressure is low and the biasing force of the return spring 100 is overcome and the driven rocker arm 5 slides in the direction of arrow P,
Release clutch 4 (see Figure 1).

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

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.

(2) As the engine speed increases, the hydraulic pressure increases, overcoming the biasing force of the return spring 100 and sliding the driven rocker arm 5 in the direction of arrow Q;
Connect clutch 4 (see Figure 2).

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

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

On the other hand, the coiled return spring 100
As shown in FIG. 3 and FIG. 3, the fixed side end 1
04 and the movable end 110, the movable end 110 can be rotated about the fixed end 104 in the direction of arrow R (i.e., the side that brings the driven rocker arm 5 into contact with the valve 28b). It will be biased in the direction.

Therefore, the driven side rocker arm 5 is always connected to the intake valve 2.
8b is biased by the valve shaft head 60 (however, this biasing force is weaker than the valve closing force of the valve closing spring 70).

As a result (1) there is no valve clearance between the driven side rocker arm 5 and the intake valve shaft 60, which prevents the driven side rocker arm 5 from wobbling;
The rocker arm 5 on the driven side has the same swing angle as the rocker arm 5 on the driving side, so that the lift amount can be made equal.

(2) Even if the clutch 4 is released while the locker arms 3 and 5 on the driving side and the driven side are driving both valves and pressing the intake valves 28a and 28b, the biasing force of the return spring 100 is Since it is acting on the driven side rocker arm 5, the same rocker arm 5
The upper limit stopper will not bounce upward, eliminating any misalignment of the upper limit stopper.

As described above, in the present invention, the coiled return spring 100 that resists the on/off action of the hydraulic cylinder is attached to the rocker arm shaft 7 in an externally fitted manner, thereby partially stopping the valve operation and elastically biasing the driven side rocker arm 5. Therefore, it may be applied to a double intake valve train as in the above embodiment, but it may also be applied to a double exhaust valve train or a reduced cylinder operation mechanism as described above.

[Brief explanation of the drawing]

1 to 8 are drawings showing an embodiment of the present invention, and FIG. 1 is a plan view around the rocker arm shaft;
Figure 2 is a cross-sectional view taken along the - line in Figure 1, Figure 3 is a right side view of the coiled return spring, Figure 4 is a plan view of the spring, Figure 5 is its front view, and Figure 6 is the rocker arm shaft. 7 is an enlarged longitudinal sectional front view of the vicinity of the hydraulic cylinder, FIG. 8 is a vertical sectional right side view of the main parts of the diesel engine, FIG. 9 is a schematic explanatory diagram of the locker arm showing the engaged state of the clutch, 10
The drawings are a diagram corresponding to FIG. 6 showing the prior art, FIG. 11 is an enlarged longitudinal sectional view of the vicinity of the clutch showing the prior art, and FIG. 12 is a diagram equivalent to FIG. 9 showing the prior art. DESCRIPTION OF SYMBOLS 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, 36... 5... Output end, 100...
Coiled return spring, 102...Spring receiver, 10
3... Spring wire insertion hole, 104... Fixed side end of 100, 105... Spring wire tip end of 104, 110
...The movable side end of 100, 111...The tip of the spring wire of 110, E...Engine, S...The direction of expansion and contraction of 100.

Claims (1)

[Scope of Claim for Utility Model Registration] A driven side rocker arm 5 is interlocked and connected to a valve driving cam 2 of a valve driving device 1 of an engine E via a driving side rocker arm 3 and a clutch 4, and the clutch 4 is connected to a hydraulic cylinder 6 and returned in a coiled manner. In a partial valve train deactivation device for an engine valve train, which is configured to be turned on and off by a spring 100 and in which a driving side rocker arm 3 and a driven side rocker arm 5 are externally fitted onto a common rocker arm shaft 7, a coiled return spring is provided. 100 is fitted onto the rocker arm shaft 7, and the spring wire tip 105 of the fixed end 104 of the coiled return spring 100 and the spring wire end 111 of the movable end 110 are connected to the rocker arm shaft 7, respectively. The coiled return spring 100 is aligned along the axial direction S and oriented in opposite directions to each other, and the fixed side spring wire tip portion 105 is supported by the spring receiving portion 102 that does not move relative to the axial direction and rotational direction of the rocker arm shaft 7. The spring wire on the movable side is set so that the driven side rocker arm 5 is elastically biased in the sliding direction for the intermittent switching operation of the clutch 4, and is also elastically biased in the swinging direction toward the valve opening side. A partial valve operating stop device for an engine valve operating system, characterized in that a tip end 111 is engaged with an output end 36 of a driven side rocker arm 5.