JPH0550563B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve actuation control device installed in an internal combustion engine.

Some high-power internal combustion engines have multiple intake or exhaust valves per cylinder. This type of internal combustion engine has a large communication passage between the intake passage and the combustion chamber, which is opened and closed by multiple intake or exhaust valves, so it can take in a large amount of air-fuel mixture, and the engine can run at high revolutions and high output. suitable for driving.

However, operating these types of internal combustion engines at low speeds reduces the engine's output. This is because when the engine is operated at low speeds, the amount of intake air decreases, and this small amount of air is sucked into the combustion chamber through a wide communication path, further reducing charging efficiency. This is because intake air blow-through occurs in the rotation range, so if the exhaust valve opening area is large, the filling efficiency will decrease. In other words, in general, in an internal combustion engine, the air-fuel mixture is sucked by using the negative pressure and intake inertia generated in the combustion chamber during the engine's intake stroke, but during low-speed operation, the intake inertia weakens and Since intake air blow-by occurs, the engine output decreases as shown by the solid line in FIG. 1.

In order to eliminate such problems, there are various valve operation control devices, one example of which is to stop the operation of some of the plurality of intake or exhaust valves when the engine is operated at low rotation speeds, and to control the operation of some of the intake or exhaust valves. There are methods to narrow the area of the communication passage with the combustion chamber so that intake inertia can be used even during low-speed operation, and to reduce intake air blow-through.

The engine output characteristics when the operation of some of the plurality of intake or exhaust valves is stopped is as shown by the broken line in Fig. 1 at a predetermined engine speed N ₁
It intersects the output characteristic (solid line in FIG. 1) when there is no pause. This predetermined rotational speed _N1 is substantially constant regardless of the magnitude of the valve opening θth of the intake air amount throttle valve. Therefore, when the engine speed Ne is lower than a predetermined rotation speed N ₁ , the engine is operated with some of the valves in a rest state (hereinafter referred to as the "rest valve state"), and when it is higher than a predetermined rotation speed N ₁ , all valves are operated. When the engine is operated in this state, even in the above-mentioned type of internal combustion engine, it is possible to avoid a decrease in engine output during low-speed operation.

However, when operating an engine under no load, for example in a vehicle-mounted engine, the clutch is disengaged or the transmission is set to neutral to cut off power transmission between the engine's output shaft and the drive wheels. When driving, the engine performance will be satisfied as long as the engine output is as high as possible at the snap.

In such a case, it is sufficient to operate the engine with the valve inactive even if the engine speed is high. Furthermore, the engine speed rise response time at the no-load snap is very fast, so even if the valve actuation control device switches from the idle valve state to the full valve operation state when the predetermined engine speed _N1 is reached, the actual The engine rotational speed Ne at which this switching operation is performed may be higher than the predetermined rotational speed _N1 by α rotational speed.

The present invention has been made in view of the above-mentioned points, and the present invention maintains the valve operation mode suitable for the low speed rotation range of the engine by stopping the switching operation of the valve operation control device when the engine is operated in a no-load state. The purpose of this invention is to improve the durability of the valve operation control device and to prevent the engine output from becoming too high. To achieve this objective, the present invention selects two different valve operation modes for the operation of the plurality of intake or exhaust valves of an internal combustion engine having a plurality of intake or exhaust valves per cylinder depending on the operating state of the engine. In the valve operation control device, when a signal indicating the presence or absence of power transmission between the output shaft of the engine and the engine load indicates a cutoff state of the power transmission, the valve operation control device is switched to control the low speed rotation of the engine. The present invention provides a valve operation control device equipped with a control device that maintains a valve operation mode suitable for the region.

An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the valve operation control device according to the present invention is applied as a device for stopping the operation of a portion of the intake and exhaust valves.

FIG. 2 is a longitudinal sectional view of a 4-cylinder, 16-valve internal combustion engine equipped with a valve actuation control device according to the present invention. In the figure, a crankshaft 2 of an internal combustion engine 1
A piston 4, which is connected to the piston 4 via a connecting rod 3, is slidably fitted into a cylinder barrel 6 provided in a cylinder block 5.

The cylinder head 7 mounted on the upper part of the cylinder lock 5 is provided with an intake passage 9 and an exhaust passage 10 that communicate with a combustion chamber 8. (not shown) is connected to the downstream side of the exhaust passage 10.
is connected to an exhaust pipe (not shown).

The communication section between the intake passage 9 and the combustion chamber 8 is opened and closed by two intake valves 11 (only one is shown) arranged in parallel, and the communication section between the exhaust passage 10 and the combustion chamber 8 is also arranged in parallel. It is opened and closed by two exhaust valves 12 (only one is shown).

Since the activation/pause mechanism of the two intake valves 11 and the activation/pause mechanism of the two exhaust valves 12 are the same, a description of the activation/pause mechanism of the exhaust valves 12 will be omitted below. Only the activation/pause mechanism will be explained.

The two intake valves 11 that respectively open and close two valve seats 13 arranged in parallel in the communication portion between the combustion chamber 8 and the intake passage 9 are connected to an intake valve guide 14 (1).
(Only shown in the figure). At the upper ends of the two intake valves _11-1 and _11-2 , there is a rocker arm 1 on the normally operating side, as shown in FIGS. 3 and 4.
_5-1 and the respective ends of the rest side rocker arm _15-2 are in contact with each other.

In FIG. 3, the normally moving side rocker arm 15-
₁ and the rest rocker arm _15-2 are arranged side by side and are pivotally supported by a common intake rocker arm shaft 16.

A piston 17 is disposed inside the normally-moving side rocker arm _15-1 , and the hole 1 into which the piston 17 is slidably fitted is provided.
A back pressure chamber 18a formed at one end of the intake rocker arm shaft 16 communicates with an oil supply passage 16a formed at the axis of the intake rocker arm shaft 16 through oil holes 18b, 16b.

Stop side rocker arm _15-2 of piston 17
The end face of the side abuts the guide pin 19 disposed in the idle side rocker arm _15-2 , and the guide pin 1
Reference numeral 9 denotes a spring 2 disposed on the back of the guide pin 19.
The piston 17 is urged in the direction of the rocker arm _15-1 on the normally moving side with an elasticity of 0. Note that the reference numeral 21 is an air vent hole.

3 and 4, pressure oil is supplied to the oil supply passage 16a, the pressure oil flows into the back pressure chamber 18a through the oil holes 16b and 18b, and the piston 17 moves against the elasticity of the spring 20 to move the rest side rocker arm. _15-2 shows the state when it is fitted into the guide hole 22 of No. 15-2.
In this state, both Rocker arm 1 on the normally operating side and on the resting side
_5-1 and _15-2 are connected by the piston 17, and the rocker arm _15-1 on the normally moving side
When the surface of the intake side cam 24 slides into contact with the rocker arm cam slipper 23 formed on the upper part of the rocker arm cam slipper 23, the rocker arms _15-1 and _15-2 of the normally operating side and the idle side respectively
and swing around the shaft 16 based on the cam force and the elasticity of the valve spring 25, whereby the two intake valves _11-1 and _11-2 are simultaneously connected to the intake passage 9 and the combustion chamber 8. The communication is opened and closed simultaneously with the rotation of the crankshaft 2.

5 and 6, when the oil pressure in the oil supply passage 16a decreases, the piston 17 is pushed back into the hole 18 of the rocker arm 15-1 on the normally operating side by the elasticity of the spring 20, and the piston 17 is pushed back into the hole 18 of the rocker arm _15-1 on the normally operating side and the rest side. both rotscar arms 1
This shows a state in which the connection between _5-1 and _15-2 is disconnected. In this state, the cam force due to the rotational movement of the cam 23 is not transmitted to the rest rocker arm _15-2 .

Therefore, communication between the intake passage 9 and the combustion chamber 8 is opened and closed only by the intake valve _11-1 on the normally operating side.
The inactive valve _11-2 is in an inactive state and one of the valve seats 13 is closed.

FIG. 7 is a diagram showing an engine oil circulation system that operates the valve operation control device.

The engine oil that is force-fed from the oil pump 26 to the oil supply passage 28 via the filter 27 is supplied to the sliding and rolling parts 29 of each part of the engine, and the intake air that communicates with the back pressure chamber 18a on the intake side of each cylinder. Oil supply passage 16a in the side rocker arm shaft
and a refueling passage 16 in the exhaust-side Rockcar armshaft that communicates with the back pressure chamber 18a' on the exhaust side of each cylinder.
The oil is supplied to a' through an oil supply passage 30. The tip end 31 of each oil supply passage 16a, 16a' is formed in the shape of an orifice, and excess pressure oil is discharged into the cylinder head through the orifice 31.

An electromagnetic solenoid valve 32 is disposed between the oil supply passages 28 and 30, and a solenoid 33 of the electromagnetic solenoid valve 32 is electrically connected to the control device 4. As will be described in detail later, this control device 34 receives a signal from a clutch switch or neutral switch (not shown), controls on/off the current flowing through the solenoid 33, and controls the flow of pressure oil to the oil supply passage 30 side. do.

The structure of the valve mechanism of the electromagnetic solenoid valve 32 is shown in FIG. In FIG. 8, an electromagnetic solenoid 33 is disposed outside one end of a spool valve 38 that is slid into a valve hole 37 formed between the oil supply passage 30, the oil supply passage 28, and the leak hole 36. ing. A spring 39 is disposed at the other end of the spool valve 38.

When the electromagnetic solenoid 33 is energized, this spool valve 38 is moved to the right by electromagnetic force against the pressure of the spring 39, and as a result, the oil supply passages 28 and 30 are communicated with each other, and communication between the oil supply passage 30 and the leak hole 36 is cut off. be done. When the energization is stopped, the spool valve 38 moves to the left by the elasticity of the spring 39, and as a result, the communication between the oil supply passages 28 and 30 is cut off, and the oil supply passage 30 and the leak hole 36 are communicated with each other.

The oil supply passage 28 is provided with an accumulator chamber 42 in which a piston 41 that slides due to the differential pressure between the elasticity of a spring 40 and hydraulic pressure is disposed.

FIG. 9 is a block diagram showing one embodiment of the internal configuration of the control device 34.

The output terminal of the rotation speed sensor 40 is connected to the input terminal of a frequency-to-voltage converter (hereinafter referred to as "f-V converter") 41, and the output terminal of the f-V converter 41 is connected to the input terminal of a comparator 42. There is. The output terminal of the comparator 42 is connected to one input terminal of an AND circuit 43 and also to one input terminal of an arithmetic circuit 44 .

This rotational speed sensor 40 outputs an electric signal having a frequency proportional to the engine rotational speed and supplies this signal to an f-V converter 41, which converts the output signal of the sensor 40 in proportion to the engine rotational speed. The comparator 42 converts it into the voltage V _N
supply to. The comparator 42 compares the voltage V _N with a predetermined voltage value V ₁ corresponding to a predetermined engine speed (for example, 2000 rpm), and outputs a high level voltage when V _N ≧ V ₁ , that is, when the engine speed is higher than the predetermined speed. The voltage is output to the AND circuit 43, and when V _N <V ₁ , that is, when the engine speed is lower than the predetermined speed, a low level voltage is output to the AND circuit 43.

Neutral switch 48 is level correction circuit 4
The output terminal of the level correction circuit 49 is connected to one input terminal of the AND circuit 43 and to the input terminal of the arithmetic circuit 44.

This neutral switch 48 is a neutral switch for the transmission, and outputs an on signal when the neutral switch 48 is in the on state, that is, when the transmission is in the neutral position, and at this time, the level correction circuit 49 converts the on signal into a low level voltage. The level is corrected and output to the AND circuit 43. Further, when the neutral switch 48 is in the off state, that is, when the power transmission mechanism of the transmission is connected, an off signal is output, and at this time, the level correction circuit 49 corrects the level of the off signal to a high level voltage, and the AND circuit 43 outputs an off signal. Output to.

The clutch switch 50 is connected to an input terminal of a level correction circuit 51, and an output terminal of the level correction circuit 51 is connected to one input terminal of an AND circuit 43 and to one input terminal of an arithmetic circuit 44.

The clutch switch 50 outputs an on signal when the clutch is engaged, and at this time the level correction circuit 51 corrects the level of the on signal to a high level voltage and outputs it to the AND circuit 43. Further, when the clutch 50 is in the disengaged state, the clutch switch 50 outputs an off signal, and the level correction circuit 51 adjusts the level of the off signal to a low level voltage and outputs it to the AND circuit 43.

The output terminal of the AND circuit 43 is the switch circuit 52
is connected to the control terminal of the This switch circuit 52 is inserted and connected between a power source, for example, a battery 53, and the solenoid 33 of the electromagnetic solenoid valve 32 (Figs. 7 and 8) described above, and when the signal input to the control terminal is at a high level, Batsuteri 53
and the solenoid 33 are connected to energize the solenoid 33, and when the signal input to the control terminal is at a low level, this connection is cut off and the energization to the solenoid 33 is stopped.

An output terminal of an arithmetic circuit 44 to which signals from the comparator 42 and level correction circuits 49 and 51 are input is connected to an output terminal of an AND circuit 43.

The arithmetic circuit 44 maintains the voltage level applied to the control terminal of the switch circuit 52 at a high level when the signal from the neutral switch 48 indicates a predetermined change state as will be described in detail later, and controls the switch circuit 52. It is held in a closed state.

With the above configuration, when all the voltage levels applied to the input terminals of the AND circuit 43 become high level, that is, the clutch is engaged, the engine speed exceeds a predetermined speed, and the neutral switch is turned off. When this occurs, the AND circuit 43 outputs a high level signal and applies this signal to the control terminal of the switch circuit 52. At this time, the switch circuit 52 is closed, the solenoid 33 is energized, and the spool valve 3 of the electromagnetic solenoid valve 32 is energized.
8 moves to the right in the upper part of FIG.
a' (Figure 7).

As a result, pressure oil is supplied to each of the back pressure chambers 18a, 18a', and the piston 17 slides between the normally active rocker arm _15-1 and the rest rocker arm _15-2.
(Fig. 3) and the engine is operated with all valves in operation.

When the voltage level applied to any one of the input terminals of the AND circuit 43 (FIG. 9) is low level, the AND circuit 43 outputs a low level signal and applies the signal to the control terminal of the switch circuit 52. do. At this time, the switch circuit 52 is opened, the energization to the solenoid 33 is cut off, and the spool valve 38 of the electromagnetic solenoid valve 32 moves to the left in FIG. , 16a' (FIG. 7) is cut off.

As a result, the piston 17 (FIG. 5) is moved by the spring 20
is pushed back by the normally operating side rocker arm _15-1 , and the connection between the normally operating side rocker arm _15-1 and the idle side rocker arm _15-2 is severed, and the engine is operated in the idle valve state.

When the engine is operating with all valves in operation, that is, when high-level voltage is applied to all input terminals of the AND circuit 43, for example, when a gear change is performed, the neutral switch 48 is temporarily turned on. , and the output of the AND circuit 43 temporarily becomes low level. If this temporary change occurs in a high engine speed range and the valve actuation control device is switched, a shock will occur, which is unfavorable in terms of durability of the valve actuation control device. Moreover, such a shot will have a negative effect on the driving performance of the vehicle.

The arithmetic circuit 44 is provided to avoid the above-mentioned problem, and when the neutral switch 48 outputs an on signal and the output of the AND circuit 43 changes to low level while all valves are in operation, the AND circuit 43, a high level output voltage is applied to the control terminal of the switch circuit 52 for a predetermined period of time. Therefore, when the neutral switch 48 is temporarily turned on, if this on state is within the predetermined time, the closed state of the switch circuit 52 is not changed and all valves are maintained in the operating state.

In the above-mentioned control circuit 34, an example has been described in which the switching operation of the valve operation control device is performed when the engine speed exceeds a predetermined value, but if this predetermined value has a hysteresis characteristic, the switching operation can be made more stable. You can do it by doing this. For example, when the engine speed exceeds 2000 + 100 rpm, all valves are activated, and the engine speed decreases.
Adding a hysteresis circuit to the control circuit 34 that allows switching to the idle valve state when the engine speed drops below 2000-100 rpm avoids the problem of repeated switching operations of the valve actuation control device when the engine is operated at 2000 rpm. be able to.

FIG. 10 is an electrical circuit diagram of another embodiment of the control device 34.

In this embodiment, the switch 61 and the solenoid 33 of the relay circuit 60 are connected in series between the anode of the battery 53 and the ground, and the switches 70, 71, 72 and the relay circuit 60 are connected between the anode of the battery 53 and the ground. excitation coils 62 are connected in series.

Switch 70 is closed when the engine speed is above a predetermined speed, switch 71 is closed when the clutch is engaged, and switch 72 is closed when the transmission is in a position other than neutral.

The switch 61 of the relay circuit 60 is the excitation coil 6
2 is closed when energized.

With such a configuration, each switch 70, 71, 7
2 are all closed, and the excitation coil 62 has a battery 5.
Current flows from the switch 3, which closes the switch 61 and energizes the solenoid 33.

When the clutch is disengaged or the transmission is in the neutral position and the power transmission path is disconnected, or the engine speed is below a predetermined speed, that is, at least one of the switches 70, 71, and 72 is activated. When is opened, the excitation coil 62 is de-energized, the switch 61 is opened and the solenoid 33 is de-energized.

In this way, the energization of the solenoid 33 of the electromagnetic solenoid valve 32 is controlled, and the switching control of the valve operation control device is performed in the same manner as described above.

In each of the above-mentioned embodiments, a control device for controlling energization of the solenoid of an electromagnetic solenoid valve as a switching mechanism of a valve operation control device has been described, but the present invention is not limited to this. If the control device is constituted by another switching mechanism, it is sufficient that the switching mechanism is controlled based on the connection/disconnection state of the power transmission path.

As explained above, in the present invention, two different valve operation modes are selected for the operation of the plurality of intake or exhaust valves of an internal combustion engine having a plurality of intake or exhaust valves in one cylinder depending on the operating state of the engine. In the valve operation control device, when a signal indicating the presence or absence of power transmission between the output shaft of the engine and the engine load indicates a cutoff state of the power transmission, the valve operation control device is switched to control the low speed rotation of the engine. Equipped with a control device that maintains the valve operation mode suitable for the region, the switching operation of the valve operation control device can be stopped when the engine is operated with no load, improving the durability of the valve operation control device. can be achieved.

[Brief explanation of the drawing]

Figure 1 is a graph showing the engine output characteristics of an internal combustion engine equipped with a valve operation control device.
The figure is a longitudinal sectional view of an internal combustion engine equipped with the valve actuation control device according to the present invention, FIG. 3 is a cross-sectional view of the rocker arm showing the connection of both the rocker arms on the normally operating side and the idle side, and FIG. 4 is a complete view of the rocker arm. A side view of the Rocker arm when the valve is in operation. Figure 5 is a cross-sectional view of the Rocker arm showing the disconnection of the Rocker arms on the normally operating side and the rest side. Figure 6 is a side view of the Rocker arm when the valve is in the idle state. ,
Figure 7 is a hydraulic circuit diagram of the hydraulic oil system of the valve operation control device, Figure 8 is a cross-sectional view of the valve mechanism of the electromagnetic solenoid valve that switches the hydraulic oil path of the valve operation control device, and Figure 9 is the main A block diagram of an electric circuit showing one embodiment of the control device 34 of the valve operation control device according to the invention, FIG. 10 is an electric circuit diagram of another embodiment of the control device 34. 1...Internal combustion engine, 2...Crankshaft, 4...
...Piston, 8...Combustion chamber, 9...Intake passage, 1
_1-1 ...Normal operation side intake valve, _11-2 ...Non-operation side intake valve, _15-1 ...Normal operation side Rocker arm,
_15-2 ...Rotsker arm on the rest side, 16a...
Oil supply passage, 18a... Back pressure chamber, 20... Spring, 2
3...Cam slipper, 26...Oil pump, 3
2... Electromagnetic solenoid valve, 33... Solenoid, 34... Control device, 38... Spool valve, 4
0... Rotation speed sensor, 43... AND circuit, 48
... Neutral switch, 50 ... Clutch switch, 52 ... Switch circuit, 53 ... Battery, 60 ... Relay circuit, 70, 71, 72 ...
Switch.

Claims (1)

[Claims] 1. A valve operation control device capable of selecting two different valve operation modes for the operation of the plurality of intake or exhaust valves of an internal combustion engine having a plurality of intake or exhaust valves in one cylinder according to the operating state of the engine. When a signal indicating the presence or absence of power transmission between the output shaft of the engine and the load of the engine indicates a cutoff state of the power transmission, the valve operation control device is switched to maintain a valve operation mode suitable for the low speed rotation range of the engine. 1. A valve operation control device characterized by comprising a control device for controlling the valve operation.