JPS6335173Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a multi-cylinder engine that can control the number of operating cylinders according to operating conditions.

Conventionally, for example, when idling or under low load, it is not necessary to operate all cylinders, so in order to save fuel consumption, the intake valves and exhaust valves of some cylinders are stopped to deactivate the cylinders, and the operating state is changed. A multi-cylinder engine that controls the number of operating cylinders has been proposed in which the intake valves and exhaust valves are operated again in response to the engine speed, so that all cylinders are operated.

By the way, if the exhaust valve is deactivated after the intake valve during one cycle of suction, compression, explosion, and exhaust, depending on the timing, the inhaled air or mixture or its combustion product gas may be exhausted. After that, the only gas left in the cylinder is the gas that fills the gap at the top dead center of the piston under the exhaust pipe pressure conditions.

When the piston descends from this state with the intake valve and exhaust valve remaining closed, the pressure inside the cylinder becomes negative pressure, and this negative pressure causes oil to be sucked into the cylinder. Afterwards, when the cylinder resumes operation, not only does the oil burn and oil consumption increases, but also problems such as carbon sludge buildup and an increase in harmful exhaust gas components occur.

Additionally, when returning from a cylinder-deactivated operating state to a normal operating state, if the exhaust valve is restarted after the intake valve, the gas trapped inside the cylinder will be blown back into the cylinder during the intake stroke immediately after the restart. Sufficient new air or air-fuel mixture is not sucked into the cylinder, resulting in incomplete operation of the cylinder, resulting in problems such as uneven operation, and an increase in harmful components in the exhaust gas.

The present invention aims to solve these problems, and uses a simple configuration to control the number of operating cylinders so that the exhaust valve can be given priority over the intake valve to stop and resume operation. The purpose is to provide a type multi-cylinder engine.

For this reason, the multi-cylinder engine with controlled number of operating cylinders of the present invention is provided with an intake valve side valve operating means and an exhaust valve side valve operating means that respectively operate in response to the lift of the cam that is generated in synchronization with the rotation of the engine. In addition, a valve driving plunger is slidably provided on each of the intake valve side valve operating means and the exhaust valve side valve operating means, and a valve driving plunger is provided on each of the above-mentioned both valve operating means to restrict sliding of the plunger. The cam is located between a plunger engaging position where the plunger engages to allow the opening and closing operations of the intake valve and the exhaust valve, respectively, and a plunger disengagement position where the plunger allows sliding and stops the opening and closing operations of the intake valve and the exhaust valve. a stopper that is movable during a period in which lift is not occurring; an actuator that moves the stopper from one position to the other position or vice versa between the engagement position and the disengagement position; A valve actuation stop mechanism is provided, which is a control means for detecting the phase of the cam and starting the movement of the stopper via the actuator immediately after the lift of the cam ends, and the cam is mounted between the two valve operating means. An exhaust valve priority actuation mechanism is provided for moving the stopper of the exhaust valve side valve operating means via the control means and actuator in response to the operation of the intake valve side valve operating means due to the lift of the exhaust valve. There is.

Below, an engine with controlled number of operating cylinders as an embodiment of the present invention will be explained with reference to the drawings. Fig. 1 is a schematic diagram thereof, and Fig. 2 is a partially cutaway view of the main part of the valve operation stop mechanism. Elevation showing,
Fig. 3 is a view in the direction of the - arrow in Fig. 2, Fig. 4 is a schematic diagram showing the outline of the exhaust valve priority operation mechanism, Fig. 5 is a schematic view seen in the direction of the arrow in Fig. 4, and Fig. 6 is a timing diagram for explaining the effect.

As shown in FIG. 1, the operating cylinder number controlled multi-cylinder engine according to this embodiment is shown as a four-cylinder engine having first, second, third, and fourth cylinders 1, 2, 3, and 4. . Each cylinder 1, 2, 3, 4
is communicated with the intake manifold 10 and the exhaust manifold 12, and the intake manifold 10 has an injector 14 of a fuel injection device near the connection part with each cylinder.
16, 18, and 20 are provided.

These injectors are then driven by output signals from an electrical control unit 22 which receives a number of signals representative of engine operating conditions.

In this embodiment, the second and third cylinders 2, 3 are configured to be able to be deactivated, and the operation or deactivation of the second and third cylinders is controlled by intake valve-side valve operation stopping mechanisms 24, 26 and exhaust valve-side valve operation stopping mechanisms 26, 30 which operate or stop the intake valves and exhaust valves (not shown) of these cylinders.

Each valve operation stop mechanism 24, 26, 28, 30 is a hydraulic type, and when supplied with hydraulic pressure from a hydraulic source 32 such as an engine oil pump, the intake valve
The exhaust valve is activated, and conversely, the hydraulic power source 32 is activated.
When the supply of hydraulic pressure from the engine is stopped, the intake valve and exhaust valve can be brought into a non-operating state.

The intake valve and intake valve-side valve operation stop mechanisms 24 and 28 of the second cylinder 2 are connected to a hydraulic power source 32 via a first hydraulic switching device 34, and the intake valve and exhaust valve side valve operation stop mechanisms of the third cylinder 3 26 and 30 are connected to a hydraulic power source 32 via a second hydraulic switching device 36. Each hydraulic switching device 34, 36 is a three-way solenoid valve that communicates the valve operation stop mechanism with the hydraulic source 32 or opens it to the atmosphere, and is activated by a hydraulic switching command issued from the control device 22 depending on the operating state of the engine. is controlled.

Although not shown in the drawings, the electrical control device 22 includes a determination device that determines a large number of signals from various sensors that detect the operating state of the engine and issues a valve operation stop signal or a valve operation signal, and a determination device that After receiving the ignition signal issued by the camshaft position sensor 38, which detects the ignition timing of each cylinder from the rotational phase of the camshaft, the ignition signal for cylinders 1 and 4, which are always operated, is identified and the ignition signal is activated. The engine is equipped with an ignition signal detector that counts the order of ignition signals for each cylinder based on the signals and provides a hydraulic pressure switching command to the hydraulic pressure switching devices 34 and 36. The ignition signals of the cylinders 2 and 3 that are deactivated are counted by the ignition signal detector and used to stop or restore fuel injection to the same cylinders by the injectors 16 and 18.

Next, with reference to FIGS. 2 and 3, the valve operation stop mechanism 2
4, 26, 28, and 30 will be explained in detail. Note that all of these valve operation stop mechanisms have the same structure.

The valve operation stop mechanism is provided in a rocker arm 40 that forms part of a valve train for driving intake valves and exhaust valves.
The arm on the right side of the figure is in contact with a cam with a camshaft of the valve train. A cylinder 42 is attached to the left arm portion of the rocker arm 40, and a bottomed cylindrical plunger 44 is slidably fitted into the cylinder 42.

Further, a spring 46 interposed between the cylinder 42 and the plunger 44 presses the plunger 44 downward in FIG. ing.

A plunger 44 is located on the cylindrical wall of the cylinder 42 at the lowest position relative to the cylinder 42 (the position shown).
Two elongated holes 48 are provided facing each other at positions adjacent to the upper end of the plunger 44 when the plunger is in the position.
As shown in FIG. 3, a stopper 50 having a forked left end portion is inserted into the elongated hole 48.

The bifurcated fork portion of the stopper 50 has an inner edge that is connected to the plunger 44 at the left portion (base end portion).
It has a cylindrical shape with a diameter slightly larger than the outer diameter of the plunger 44, and is spaced apart from the plunger 44 by a distance approximately equal to the inner diameter of the plunger 44 at its right portion (tip portion).

Further, a hook-shaped portion having a substantially C-shape is formed at the right end portion of the stopper 50.

A screw is formed on the upper outer surface of the cylinder 42, and a double nut 52 that guides the upper surface of the stopper 50 in order to smoothly slide the stopper 50 is screwed onto the screw. A presser spring 54 is interposed between them to prevent vertical vibration of the stopper 50.

Further, the valve operation stop mechanism includes a hydraulic actuator 6 that is composed of a cylinder 56, a piston 58 that slides inside the cylinder 56, and a return spring 60 that presses the piston into the inside of the cylinder 56.
2, and one end of a rod 64 is fixed to the piston 58. A connecting member 66 is fixed to the other outer end of the rod 64, and a connecting member 66 is fixed to the other end of the rod 64.
The hook-shaped portion surrounds the connecting member 66 with a gap 68 along the sliding direction of the piston 58, so that the stopper 50 and the rod 64 (piston 58) have a gap 68 between them. and will be connected.

A notch 70 is formed in the middle of the cylindrical wall of the piston 58.
is provided, and one end of the timing plate 72 can engage with the notch 70.

The timing plate 72 is the Rotsuka arm 40
It is rotatably supported on a shaft 74 attached to the cylinder 56, and slides in a groove 76 provided above the outside of the cylinder 56 to the outer end of the piston 58 (left side in FIG. 2) and the notch 70. They can be engaged with each other.

Further, the timing plate 72 is biased by a spring in the piston engagement direction, and is rotated clockwise when the substantially cylindrical timing cam follower 80 is moved upward in FIG. It is designed to be disengaged.

Timing cam follower 80 is Rotsuka arm 4
According to the rocking motion of the rocker arm 40, the rocker arm 40 is configured to follow a timing cam 84 formed by scraping a part of the outer peripheral surface of the rocker shaft 82 along its circumferential direction. Alternatively, when the cam lift is at or near the maximum (the cam lift is at or near the maximum), the timing cam follower 80 can be largely slid outward in the radial direction of the camshaft 82.

Note that the cylinder 56 of the actuator 62 is
Regardless of the rocking of the rocker arm 40, the oil passage 86 provided in the rocker arm and the rocker shaft 8
It is constantly in communication with an axial oil passage 90 of the rocker shaft via a radial oil passage 88 provided in the rocker shaft.

Further, the oil passage 90 is communicated with one of the hydraulic switching devices 34 or 36.

By the way, as shown in FIGS. 4 and 5, between the intake valve side valve operation stop mechanisms 24, 26 and the exhaust valve side valve operation stop mechanisms 28, 30, the valve operation stop and valve operation return are controlled more than the intake valve. An exhaust valve priority operation mechanism 78 is provided to give priority to the exhaust valve.

That is, the intake valve side valve operation stop mechanism 24, 26
A fixed roller 92 is provided on the rocker arm 40 of the intake valve side valve operation stop mechanism 24, 26 by the action of a cam 94.
When the shaft rotates clockwise in FIG. 4 around the rock shaft 82, the driven portion 98a is ejected by the fixed roller 92 as shown by the chain line in FIG. 4 and rotates around the fixed support shaft 96. A lever-like cam 98 is provided. In other words, this lever-like cam 98
can respond to the intake valve-side valve operation stop mechanisms 24 and 26.

Further, the timing plate 72 of the exhaust valve-side valve operation stop mechanism 28, 30 includes a cam follower 10 that abuts a cam portion 98b of a lever-like cam 98 that is positioned across a fixed support shaft 96 with respect to the driven portion 98a.
0 is provided, thereby lever-like cam 9
8 is ejected by the fixed roller 92 as described above, the cam follower 100 is also ejected following the cam 98, and as a result, the timing plate 72
The engagement with the piston 58 is released by rotating clockwise in the figure.

Therefore, the exhaust valve side valve operation stop mechanism 28, 3
The timing plate 72 of 0 is disengaged from the piston 58 in the section indicated by the symbol α in FIG. The timing plate 72 of the exhaust valve side valve operation stop mechanism 28, 30 is disengaged from the piston 58, and the section where the timing plate 72 of the exhaust valve side valve operation stop mechanism 28, 30 is disengaged from the piston 58 is the section where the timing plate 72 of the exhaust valve side valve operation stop mechanism 28, 30 is disengaged from the piston 58. The timing plate 72 of the piston 58 will necessarily overlap with the area where it is out of place.

Note that the symbol E in FIG. 6 indicates the part where the rocker arm 40 of the exhaust valve valve operation stop mechanism 28, 30 swings in accordance with the lift amount of the cam 94', and the symbol I indicates the part where the valve operation stop mechanism for the intake valve is stopped. A portion in which the rocker arms 40 of the mechanisms 24 and 26 are oscillated in accordance with the lift amount of the cam 94 is shown.

With the above-described configuration, for example, in order to restore the operation of the valve from the cylinder deactivation state, pressure oil is supplied to the actuator 62, but this supply is performed at the sixth
No matter which part is marked E or I in the figure, while the timing plate 72 of the intake valve stop mechanism 24, 26 is removed from the piston 58, the exhaust valve stop mechanism 28,
The timing plate 72 of No. 30 has come off the piston 58, and since this timing plate 72 has already come off the piston 58 before that, the cam lift that occurs after this time will definitely cause the exhaust valve to take priority over the intake valve. A restoration will take place.

This provides advantages such as smooth operation and prevention of increase in harmful exhaust gas components.

It also stops valve operation (puts the cylinder in a dormant state).
In this case, the supply of pressure oil to the actuator 62 is stopped and the return spring 60 is operated. As in the case of restoring valve operation, the operation of the exhaust valve is stopped first.

This has the advantage of reducing the amount of carbon sludge deposited and preventing an increase in harmful exhaust gas components.

Furthermore, a case in which the operation of the intake and exhaust valves is restored from the cylinder deactivation state will be described in detail.

In the initial state (inactive state), no hydraulic pressure is supplied to the actuator 62, and the piston 5
8 is located at the right position in FIG. 2 due to the pressing force of the spring 60, and the engagement between the plunger 44 and the stopper 50 is released, and the plunger 44 is able to slide, and the intake/exhaust valve (not shown) Valve is deactivated. From this state, when the electric control device 22 controls the hydraulic switching devices 34 and 36 according to the operating state of the engine and supplies hydraulic pressure to the actuator 62, the piston 58 is pushed to the left by the hydraulic pressure. During a period in which cam lift is not occurring, the timing plate 72 is engaged with the left end of the piston 58, so the piston 58 does not slide to the left. Next, when the cam lift occurs and reaches the maximum value or near it, the rocker arm 40 swings and the timing cam follower 80
follows the timing cam 84 and the camshaft 8
2, the timing plate 72 slides greatly toward the outer radial direction of the timing cam follower 80.
The piston 58 is ejected, moves upward, disengages from the left end of the piston 58, and the piston 58 slides to the left due to hydraulic pressure. However, in this state, the cam lift occurs as described above, the rocker arm 40 is swinging, and the plunger 44 is sliding inward of the cylinder 42, so the stopper 50 abuts against the cylindrical wall surface of the plunger 44. It does not slide. Therefore, the piston 58 slides by the size of the gap 68 provided at the connection portion with the stopper 50, and reaches a position where its left end does not engage with the timing plate 72. Thereafter, when the cam lift is completed, the plunger 44 is slid downward outside the cylinder 42 by the pressing force of the spring 46, and its upper end is below the elongated hole 48, so that the stopper 50 can slide, and the piston 58 As the stopper 50 is moved to the left by hydraulic pressure, the stopper 50 enters the elongated hole 48 and comes into contact with the upper end of the plunger 44, thereby stopping the plunger 44 from sliding. As a result, the next time a cam lift occurs and the rocker arm 40 is swung, the plunger 44 will not slide, so the intake and exhaust valves will be operated.

In this valve operating state, the timing plate 72 engages with the notch 70 of the piston 58 when no cam lift is occurring.

Next, a case in which the operation of the intake and exhaust valves is stopped from a state in which the intake and exhaust valves are in operation will be described in detail.

From the valve operating state, the electric control device 22 controls the hydraulic switching devices 34 and 36 to stop the operation of the intake and exhaust valves according to the operating state of the engine, and when the hydraulic pressure in the actuator 62 is discharged, the spring 60 Therefore, the piston 58 is pushed to the right, but since the timing plate 72 is engaged with the notch 70 of the piston 58 during a period in which cam lift is not occurring, the piston 58 does not slide to the right. Next, when the cam lift occurs and reaches or is close to the maximum value, the timing plate 72 and the notch 70 of the piston 58 are disengaged, and the piston 58 is moved to the right by the pressing force of the spring 60. However, in this state, the locker arm 40 swings and operates the valve before the engagement is released, so the stopper 50 is placed between the upper end of the plunger 44 and the upper surface of the elongated hole 48 due to the valve spring load. Instead of being clamped and not sliding, the piston 58 slides by the distance of the gap 68 provided at the connecting portion with the stopper 50, and reaches a position where the notch 70 and the timing plate 72 do not engage.
Thereafter, when the cam lift is completed, the stopper 50 is released from the valve spring load and becomes slidable, and as the piston 58 is moved to the right by the spring 60, it is pulled out of the elongated hole 48 and the plunger 44 is moved. Sliding becomes possible. As a result, even if a cam lift occurs next time and the rocker arm 40 is swung, the plunger 44 will slide, so the intake and exhaust valves will not be operated.

As described in detail above, the engagement and release of the plunger 44 and the stopper 50 for activating or stopping the intake and exhaust valves starts immediately after the cam lift ends in synchronization with the cam phase. The engagement and disengagement operations are completed until the next cam lift occurs, and the next cam lift will not occur with the engagement and disengagement incomplete. Therefore, the electric control device 22 controls the hydraulic pressure switching devices 34 and 36 to supply and stop hydraulic pressure to the actuator in order to switch between activation and deactivation of the intake and exhaust valves according to the operating state of the engine. Regardless of whether the operation is stopped at the part marked E or I in FIG. 6, the exhaust valve is always shut down in priority to the intake valve.

Note that even if the timing plate 72 of the exhaust valve-side valve operation stop mechanisms 28 and 30 is not disengaged from the piston 58 before the above-mentioned overlap section, and even if it is made to have only the above-mentioned overlap section, the exhaust valve It is possible to stop and resume operation with priority over the intake valve. In this case, the timing cam follower 80 of the exhaust valve-side valve operation stop mechanism 28, 30 is not required.

Figures 7 and 8 show a multi-cylinder engine with controlled number of operating cylinders as another embodiment of the present invention.
The figure is a cross-sectional view showing the main part, and FIG. 8 is a cross-sectional view taken along the - arrow in FIG.
The same reference numerals as in the figure indicate substantially similar parts.

The above embodiment concerns a multi-cylinder engine with a cross-flow type intake/exhaust valve arrangement structure, but this embodiment applies to a multi-cylinder engine with a turn-flow type intake/exhaust valve arrangement structure. It is something.

In the engine of this embodiment, the exhaust valve preferential operation mechanism 78' is constructed as follows.

That is, the intake valve side valve operation stop mechanism 24, 26
The locking arm 40 of is provided with a cam 102 having a shape as shown in FIG. Even when the rocker arm 40 of the exhaust valve stop mechanism 28, 30 rotates around the rocker shaft, the cam follower 104, both of which is ejected by the cam 102, will control the timing of the exhaust valve stop mechanism 28, 30. It is provided on the plate 72.

Note that the timing plate 72 of the intake valve-side valve operation stop mechanism 24, 26 is moved at the base end of the timing plate 72 only when the rocker arm 40 of the intake valve-side valve operation stop mechanism 24, 26 rotates around the rocker shaft 82. Cam follower 106 with parts
is removed from the piston 58 by being ejected by another cam 108.

Therefore, the exhaust valve side valve operation stop mechanism 28, 3
As in the case of the above-mentioned embodiment, the timing plate 72 of 0 is disengaged from the section piston 58 indicated by the symbol α in FIG.
The timing plates 72 of the exhaust valve side valve operation stop mechanisms 28 and 30 are disengaged from the piston 58 only in the section indicated by the symbol β in FIG.
The area where the piston 58 is separated from the timing plate 7 of the intake valve-side valve operation stop mechanism 24, 26
2 will necessarily overlap with the area where piston 58 is out of place.

With the above-mentioned configuration, for example, in order to restore the valve operation from the cylinder deactivation state, pressure oil is supplied to the actuator 62, but this supply is performed at either of the parts marked E or I in FIG. Even if the intake valve side valve operation stop mechanism 2
The timing plates 72 of 4 and 26 are the piston 5
8, the timing plate 72 of the exhaust valve stop mechanism 28, 30 is always removed from the piston 58, and the timing plate 72 has already been removed from the piston 58 before that. The cam lift that occurs after this time always causes the exhaust valve to return to operation in preference to the intake valve.

As in the case of the above-mentioned embodiment, this provides advantages such as smooth operation and prevention of increase in harmful exhaust gas components.

Further, in order to stop the valve operation, the supply of pressure oil to the actuator 62 is stopped and the action of the return spring 60 is performed. Even if this is done, the operation of the exhaust valve is stopped first in the same way as in the case of restoring the valve operation described above.

This has the advantage of reducing the amount of carbon sludge deposited and preventing an increase in harmful exhaust gas components.

Note that even if the timing plate 72 of the exhaust valve stop mechanism 28, 30 does not come off the piston 58 before the above-mentioned overlap section, even if it has only the above-mentioned overlap section, the exhaust valve It is possible to stop and resume operation with priority over the intake valve. In this case, the right half of the cam 102 in FIG. 8 becomes unnecessary.

As described in detail above, according to the multi-cylinder engine that controls the number of operating cylinders of the present invention, the cam responds to the intake valve stop mechanism, and the exhaust valve stop mechanism responds to the intake valve stop mechanism. The simple configuration includes an exhaust valve priority operation mechanism consisting of a cam follower installed at Advantages such as reducing the amount of components and smooth operation can be obtained.

[Brief explanation of drawings]

Figures 1 to 6 show a multi-cylinder engine with controlled number of operating cylinders as an embodiment of the present invention. Figure 1 is a schematic diagram of the engine, and Figure 2 is a schematic diagram of the main part of its valve operation/stopping mechanism. Elevation view showing the section broken away, No. 3
The figure is a - arrow view of Figure 2, Figure 4 is a schematic diagram showing the outline of the exhaust valve priority operation mechanism, and Figure 5 is a view of the
FIG. 6 is a schematic diagram as seen from the direction of the arrow in the figure, and FIG. 6 is a timing diagram for explaining the operation.
Fig. 8 shows a multi-cylinder engine with controlled number of operating cylinders as another embodiment of the present invention, Fig. 7 is a cross-sectional view showing the main parts thereof, and Fig. 8 is a cross-sectional view taken along the - arrow in Fig. 7. It is. 1 to 4...Cylinder, 10...Intake manifold, 1
2...Exhaust manifold, 14, 16, 18, 20
... Injector, 22 ... Electrical control device, 2
4, 26... Intake valve side valve operation stop mechanism, 28, 3
0... Exhaust valve side valve operation stop mechanism, 32... Hydraulic source, 34, 36... Hydraulic switching device, 38... Camshaft position sensor, 40... Rocker arm, 4
2...Cylinder, 44...Plunger, 46...
Spring, 48...long hole, 50...stopper,
52...double nut, 54...presser spring, 56...cylinder, 58...piston, 60
... Return spring, 62 ... Actuator,
64...Rod, 66...Connecting member, 68...Gap, 70...Notch, 72...Timing plate, 74...Shaft, 76...Groove, 78, 78'...
Exhaust valve priority operation mechanism, 80... Timing cam follower, 82... Lock shaft, 84... Timing cam, 86, 88, 90... Oil path, 92...
...Fixed roller, 94, 94'...Cam, 96...
Fixed support shaft, 98... lever-shaped cam, 98a... driven part, 98b... cam part, 100... cam follower, 102... cam, 104, 106... cam follower, 108... cam.

Claims (1)

[Scope of utility model registration request] The intake valve side valve operating means and the exhaust valve side valve operating means are provided with an intake valve side valve operating means and an exhaust valve side valve operating means that respectively operate in accordance with the lift of the cam generated in synchronization with the rotation of the engine. a plunger for driving a valve, which is slidably provided on each of the means, and a plunger that is provided on each of the two valve operating means and restricts sliding of the plunger to permit opening and closing operations of the intake valve and the exhaust valve, respectively; a stopper that is movable during a period in which the cam is not lifted between the engagement position and the plunger detachment position that allows the plunger to slide and stops the opening/closing operation of the intake valve and the exhaust valve; an actuator that moves the stopper from one position to the other position or vice versa between the engagement position and disengagement position; and an actuator that detects the phase of the cam and moves the stopper immediately after the cam finishes lifting. A valve actuation stop mechanism is provided, comprising a control means for starting the movement of the stopper via an actuator, and is installed between the two valve operating means and responsive to the operation of the intake valve side valve operating means due to the lift of the cam. characterized in that an exhaust valve priority actuation mechanism is provided for moving the stopper in the exhaust valve side valve operating means via the above control means and actuator;
Multi-cylinder engine with controlled number of operating cylinders.