JPH0519002B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve 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 control devices, one example of which is disclosed in Japanese Patent Application Laid-Open No. 58-82033.
Techniques like No. 1 are known. This technology suspends the operation of some of the multiple intake or exhaust valves when the engine is operated at low speeds, narrowing the area of the communication passage between the intake or exhaust passage and the combustion chamber. This is also a method of making use of intake inertia and reducing intake 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.

On the other hand, a valve deactivation device that switches between a deactivated valve state and an all-valve operating state is a hydraulically actuated device that is incorporated into an engine oil circulation system and uses engine oil as hydraulic fluid. Therefore, when the engine oil temperature is low and the oil viscosity is high, the response of the valve deactivation device may be slow.

For this reason, the above-mentioned predetermined rotation speed N ₁ is, for example,
If it is set to 2000 rpm, the actual switching of the stop valve device will be at 2000 + α rpm, which is the addition of the error α due to oil viscosity.
When a vehicle is equipped with an engine equipped with such a valve deactivation device, it may cause discomfort to the occupants.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to appropriately operate a valve train control device according to the operating state of the engine and the temperature of the hydraulic oil, thereby preventing discomfort to the occupants. do. In order to achieve this object, the present invention provides a valve control device that can select two different valve operation modes for the operation of the intake or exhaust valves of each cylinder of an internal combustion engine depending on the operating state of the engine. When the engine oil temperature reaches a predetermined temperature or higher by exceeding a predetermined rotation speed and a parameter signal value representing the engine oil temperature indicates a predetermined value or higher, the valve control device is switched to a state suitable for a high speed rotation range of the engine. Select one valve operation mode,
A control device that switches the valve operating control device to select the other valve operation mode suitable for the low speed rotation range of the engine when the engine speed becomes less than the predetermined rotation speed or the parameter signal value becomes less than the predetermined value. The present invention provides a valve train control device characterized by the following features.

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

FIG. 2 shows a four-wheel drive system equipped with a valve control device according to the present invention.
FIG. 1 is a longitudinal cross-sectional view of a 16-cylinder internal combustion engine. In the figure, a piston 4 connected to a crankshaft 2 of an internal combustion engine 1 via a connecting rod 3 is slidably fitted into a cylinder barrel 16 provided within a cylinder block 5.

A cylinder head 7 mounted on the upper part of the cylinder block 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 1.
0 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 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 shaft 16 and an oil supply passage 16a formed at the axis of the shaft 16 communicate with each other via 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 on the normally operating side and the idle side respectively
- ₂ swing around the shaft 16 based on the cam force and the elasticity of the valve spring 25, and as a result, the two intake valves _11-1 and _11-2 are simultaneously connected to the intake passage 9 and the combustion chamber. 8 and crankshaft 2
Opens and closes in synchronization with the rotation of.

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 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 a control device 34. This control device 34
It is electrically connected to an engine oil temperature sensor 35 disposed in the middle of the solenoid 33, and controls on/off the current flowing through the solenoid 33 in response to signals of engine oil temperature and engine speed, as will be described in detail later. and controls the flow of pressure oil to the oil supply passage 30 side.

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. There is. A spring 39 is disposed at the other end of the spool valve 38.

When the electromagnetic solenoid 33 is energized, the spool valve 38 moves to the right against the pressure of the spring 39 due to electromagnetic force, and as a result, the oil supply passages 28 and 30 are communicated with each other, and the oil supply passage 30 and the leak hole 36 are communicated with each other. will be cut off. 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 brought into communication.

An accumulator chamber 42 is provided between the valve hole 37 of the oil supply passage 28 and the engine oil temperature sensor 35. The accumulator chamber 42 is provided with a piston 41 that slides due to the pressure difference between the elasticity of a spring 40 and the oil pressure.

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 "-V converter") 41, and the output terminal of the -V converter 41 is connected to the input terminal of a comparator 42. 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 a -V converter 41, which converts the output signal of the sensor 40 into a voltage proportional to the engine rotational speed. Convert to V _N and comparator 42
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.

Note that, instead of using a special sensor as the engine rotation speed sensor, for example, the ignition signal may be smoothed to extract a voltage proportional to the engine rotation speed, and this may be supplied to the comparator 42.

The output terminal of the engine oil temperature sensor 35 is connected to the input terminal of a comparator 45, and the output terminal of the comparator 45 is connected to one input terminal of an AND circuit 43 and to one input terminal of an arithmetic circuit 44. .

This temperature sensor 35 converts the temperature of engine oil, which is the hydraulic oil of the valve control device, into a corresponding voltage V _T and supplies it to a comparator 45 . The comparator 45 compares the voltage V _T with a predetermined voltage value V ₂ corresponding to a predetermined engine oil temperature, and when V _T ≧V ₂ , that is, when the oil temperature is higher than the predetermined temperature and it is determined that the oil viscosity is low. High level voltage AND circuit 4
3, and when V _T <V ₂ , that is, when it is judged that the oil temperature is lower than the predetermined temperature, the oil viscosity is high, and the delay in the operation response of the valve control device is large, a low level voltage is sent to the AND circuit 43. Output.

Note that the temperature sensor 35 does not need to directly detect the engine oil temperature. For example, a sensor that detects the temperature of the engine itself such as the cylinder or cylinder head, or a sensor that detects the valve opening of the choke valve, the position of the choke lever, etc. is installed, and the parameter signal values output from these sensors are used to determine the oil temperature. It may also be supplied to the comparator 45 as a function value.

The output terminal of the AND circuit 43 is the switch circuit 5.
It is connected to the second control terminal. 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 5
3 and solenoid 33 to connect solenoid 33.
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.

The output terminal of the arithmetic circuit 44 to which the signals from the comparators 42 and 45 are input is connected to the base of the transistor 54. The collector of the transistor 54 is connected to the output terminal of the AND circuit 43, and the emitter is grounded.

The arithmetic circuit 44 makes the transistor 54 conductive when the signal from the temperature sensor 35 shows a predetermined change state as will be described in detail later, and the voltage applied to the control terminal of the switch circuit 52 regardless of the output of the AND circuit 43. The switch circuit 52 is kept in an open state by setting the level to a low level.

With the above-described configuration, when the voltage levels applied to both input terminals of the AND circuit 43 both reach a high level, that is, when the engine rotation speed exceeds a predetermined rotation speed and the engine oil temperature exceeds a predetermined temperature, the AND circuit is activated. 43 outputs a high level signal and applies the 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 38 of the electromagnetic solenoid valve 32 moves to the right in FIG.
Engine oil pumped from the oil pump 26 is supplied to the oil supply passages 16a, 16a' (FIG. 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 32 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.

Even if the engine rotation speed exceeds the predetermined rotation speed when the engine oil temperature is below the predetermined temperature, the output voltage of the AND circuit 43 remains at a low level. When the engine warms up and the oil temperature exceeds a predetermined temperature at a high engine speed, the output voltage of the AND circuit 43 changes to a high level. However, the engine speed at the time of this change may be very high, and in such a case, the change in the output of the AND circuit 43 causes the valve control device to change from the idle valve state to all valve operation. When the state is switched, the shock at the time of switching is large, which is unfavorable in terms of operational performance and equipment durability.

The arithmetic circuit 44 operates the comparators 42 and 4 when the above change occurs, that is, when the oil temperature exceeds the predetermined temperature when the engine speed is higher than the predetermined rotation speed.
This state is detected by the output signal of the switch circuit 52, and a control signal is output to the base of the transistor 54 to make the transistor 54 conductive, thereby maintaining the voltage applied to the control terminal of the switch circuit 52 at a low level.
Therefore, in such a case, the valve control device is maintained in the valve inactive state and no changeover to the normal state in which all valves are operated is performed.

The maintenance of the inactive valve state by the arithmetic circuit 44 is canceled when the engine speed once drops below a predetermined speed and then exceeds the predetermined speed again, and the valve is switched to the all-valve operating state.

In the above-mentioned control circuit 34, an example has been described in which the switching operation of the valve control device is performed when the engine speed and oil temperature each exceed a predetermined value, but these predetermined values may have hysteresis characteristics. This allows for more stable switching operations.
For example, when the oil temperature is above a predetermined temperature, when the engine speed exceeds 2000 + 100 rpm, the valve is switched to the all-valve operating state, and when the engine speed decreases to below 2000-100 rpm, the valve is switched to the idle valve state. If a hysteresis circuit is added to the control circuit 34, the engine speed will be increased to 2000rpm.
It is possible to avoid the problem of repeated switching operations of the valve control device when operating the valve control device. The same applies to the predetermined temperature.

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

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

Switch 70 is closed when the engine speed is above a predetermined rotation speed, and switch 71 is closed when the engine oil temperature exceeds a predetermined temperature.

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

With this configuration, when switches 70 and 71 are both closed, current flows through excitation coil 62, which closes switch 61 and energizes solenoid 33.

When one or both of the switches 70 and 71 is opened, that is, when the engine speed is below a predetermined speed or the oil temperature is below a predetermined temperature, the excitation coil 62 is de-energized and the switch 61 is opened.
is opened and power to the solenoid 33 is cut off.

In this way, the energization of the solenoid 33 of the electromagnetic solenoid valve 32 is controlled, and switching control of the valve 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 a solenoid of an electromagnetic solenoid valve as a switching mechanism of a valve control device has been described.
The present invention is not limited to this, and if the valve train control device is configured with another switching mechanism, it is sufficient that the switching mechanism is controlled based on the engine speed and oil temperature.

Further, in the above embodiment, the valve control device is applied to a valve stop device that stops operation of a part of the intake and exhaust valves, but the present invention is not limited to this, and the valve control device is applied to a valve control device that stops operation of a part of the intake and exhaust valves. The present invention may also be applied to a device that performs a substantial pause or cancellation of a pause by a minute lift, a change in valve lift timing, etc. as the operating modes of two different valves to be selected.

As explained above, in the present invention, in a valve control device that can select two different valve operation modes for the operation of the intake or exhaust valve of each cylinder of an internal combustion engine depending on the operating state of the engine, the engine speed is changed. When the engine oil temperature reaches a predetermined temperature or higher by lowering the engine speed to a predetermined rotation speed and a parameter signal value representing the engine oil temperature to a predetermined value or higher, the valve control device is switched to a control device suitable for the high speed rotation range of the engine. One valve operation mode is selected, and when the engine speed becomes less than the predetermined rotation speed or the parameter signal value becomes less than the predetermined value, the valve control device is switched to the other valve operation mode suitable for the low speed rotation range of the engine. Equipped with a control device that selects the valve operating mode, it prevents the valve control device from switching the valve operating mode when the engine oil temperature is low to prevent discomfort to the occupants when switching, and improves durability. It is possible to improve the

[Brief explanation of the drawing]

Fig. 1 is a graph showing the engine output characteristics of an internal combustion engine equipped with a valve control device, Fig. 2 is a longitudinal sectional view of an internal combustion engine equipped with a valve control device according to the present invention, and Fig. 3 is a graph showing the normally operating side. Figure 4 is a side view of the Rocker arm when all valves are in operation, and Figure 5 is a cross-sectional view of the Rocker arm showing the connection between the Rocker arms on the normally operating side and the idle side. Figure 6 is a side view of the Rocker arm in the idle valve state, Figure 7 is a hydraulic circuit diagram of the hydraulic oil system of the valve control device, and Figure 8 is the hydraulic circuit diagram of the valve control device. FIG. 9 is a cross-sectional view of a valve mechanism of an electromagnetic solenoid valve that switches the pressure oil path of hydraulic oil, FIG. 9 is a block diagram of an electric circuit showing an embodiment of the control device of the valve train control device according to the present invention, and FIG. FIG. 3 is an electrical circuit diagram of another embodiment of the control device. DESCRIPTION OF SYMBOLS 1... Internal combustion engine, 2... Crankshaft, 4... Piston, 8... Combustion chamber, 9... Intake passage, 11-1... Normal operation side intake valve, _{11-2 ...} Dormant side intake valve,
_15-1 ...Normal operation side Rocker arm, _15-2 ...Stopping side Rocker arm, 16a...Oil supply passage, 18a...
Back pressure chamber, 20... Spring, 23... Cam slipper, 26
...oil pump, 32...electromagnetic solenoid valve,
33... Solenoid, 34... Control device, 35... Temperature sensor, 38... Spool valve, 40... Rotation speed sensor, 43... AND circuit, 52... Switch circuit, 5
3... Battery, 60... Relay circuit, 70, 71...
Switch.

Claims (1)

[Claims] 1. In a valve control device that can select between two different valve operation modes for the operation of the intake or exhaust valves of each cylinder of an internal combustion engine depending on the operating state of the engine, when the engine speed reaches a predetermined speed or higher and the engine oil When a parameter signal value representing temperature indicates a predetermined value or more and the engine oil temperature reaches a predetermined temperature or more, the valve control device is switched to select one valve operating mode suitable for the high speed rotation range of the engine; A control device that switches the valve control device to select the other valve operation mode suitable for the low speed rotation range of the engine when the engine speed becomes less than the predetermined rotation speed or the parameter signal value becomes less than the predetermined value. A valve control device characterized by comprising: