JPH0536612B2 - - Google Patents

Description

Detailed Description of the Invention A. Purpose of the Invention (1) Field of Industrial Application The present invention provides a hydraulic system that can switch the opening/closing operating characteristics of an intake valve or an exhaust valve by selecting according to the switching of a plurality of different cam hydraulic pressures. means for changing the valve operating characteristics of the formula;
The present invention relates to an internal combustion engine that includes an engine control operating means that controls control factors related to the combustion state of the engine other than valve operation.

(2) Prior Art Conventionally, an internal combustion engine in which the opening/closing operation characteristics of an intake valve or an exhaust valve are switched according to the operating state of the engine is known, for example, from Japanese Patent Laid-Open No. 19911/1983.

(3) Problems to be Solved by the Invention However, in the above-mentioned conventional engine, only the opening/closing operating characteristics of the intake valve or the exhaust valve are changed according to the operating state of the engine by means of a valve operating characteristic changing means. However, the combustion state of an engine is not determined only by the opening/closing characteristics of the intake valve or exhaust valve, but can also be determined by changing control factors such as ignition timing, fuel injection amount, and exhaust gas circulation amount. Therefore, from the viewpoint of improving engine operating performance and exhaust gas performance, it is desirable that these control factors also correspond to the operating characteristics of the intake valve or exhaust valve. Moreover, it is possible that the switching of the valve operating characteristics by the valve operating characteristic changing means is delayed for some reason. It is desirable to control the control factors by switching.

The present invention has been made in view of the above circumstances, and the operation characteristics of the intake valve or exhaust valve are completely switched according to the operating state of the engine, and other control factors are also controlled. It is an object of the present invention to provide an internal combustion engine whose driving performance, exhaust gas performance, etc. are improved in accordance with the characteristics of the engine.

B. Structure of the Invention (1) Means for Solving the Problems The internal combustion engine according to the present invention includes a pressure switch attached to the valve operating characteristic changing means to detect the end of the changing operation of the valve operating characteristic changing means by detecting the working oil pressure. and controlling the valve operating characteristic changing means to select a cam according to the operating state of the engine by hydraulic control, and also controlling the engine control actuating means in response to a signal confirming the end of the operation being output from the pressure switch. and control means for controlling the valve operating characteristic changing means to operate in a manner corresponding to the manner of operation.

(2) Effect According to the above configuration, by detecting a change in the hydraulic pressure in the valve operating characteristic changing means with the pressure switch, it is easily detected whether the operating characteristic of the intake valve or the exhaust valve has been completely changed. When the operating characteristics of the intake valve or exhaust valve are completely changed, the operating mode of the engine control operating means corresponds to the operating characteristics of the intake valve or exhaust valve. Since the operating characteristics of the valve and other control factors are matched to optimally suit the operation of the engine, operating performance, exhaust gas performance, etc. can be improved.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings. First, in FIGS. 1 and 2, a pair of intake valves 1, 1 provided in the engine body E are A low-speed cam 4, a high-speed cam 5, and a low-speed cam 4 integrally provided on the camshaft 2 which is rotatably driven at a reduction ratio of 1/2; 2nd and 3rd rocker arm 7, 8, 9
and the valve operation changing means 10 provided between each rocker arm 7 to 9 to open and close the valve.

The camshaft 2 is rotatably disposed above the engine body E, the low-speed cams 4 are integrated into the camshaft 2 at positions corresponding to both the intake valves 1, 1, and the high-speed cam 5 is integrated with the camshaft 2 at positions corresponding to both the intake valves 1, 1. It is integrated into the camshaft 2 between the low speed cams 4, 4. Both low-speed cams 4, 4 each have a high portion 4a having a relatively small amount of protrusion along the radial direction of the camshaft 2, and a base circular portion 4b. Further, the high-speed cam 5 has a protrusion amount along the radial direction of the camshaft 2 that is equal to the height of the high portion 4.
It has a high part 5a which is larger than 4a and has a center angle range wider than that of the high part 4a, and a base circular part 5b.

The rocker shaft 6 is fixedly arranged below the camshaft 2. This locker shaft 6 includes a first locker arm 7 that is interlocked and connected to one intake valve 1, a third locker arm 9 that is interlocked and connected to the other intake valve 1, and a locker arm 9 that is interlocked and connected to the other intake valve 1. The second rocker arm 8 located in
are adjacent to each other and are respectively pivotally supported. Further, a cam slipper 11 that slides on the low-speed cam 4 is provided on the top of the first rocker arm 7, a cam slipper 12 that slides on the high-speed cam 5 is provided on the top of the second rocker arm 8, and a cam slipper 12 that slides on the high-speed cam 5 is provided on the top of the second rocker arm 8. A cam slipper 13 is provided that comes into sliding contact with the low speed cam 4.

On the other hand, a flange 14 is provided on the upper part of both the intake valves 1, 1, and a valve spring 15 is interposed between the flange 14 and the engine body E. 1 is biased toward the valve closing direction, that is, upward. Furthermore, tappet screws 16 that can come into contact with the upper end of the intake valve 1 are screwed into the tips of the first and third rocker arms 7 and 9 so as to be movable forward and backward.

Referring also to FIG. 3, the second rocker arm 8
is slightly extended from the lock shaft 6 toward both intake valves 1, 1, and this second lock shaft arm 8
is a spring biasing means 19 provided between the engine body E
is elastically biased in the direction of sliding contact with the high-speed cam 5.

The spring biasing means 19 includes a bottomed cylindrical lifter 20 whose closed end is in contact with the second rocker arm 8, and a lifter spring 21 interposed between the lifter 20 and the engine body E. is slidably fitted into a bottomed hole 22 bored in the engine body E.

In FIG. 4, a valve operating characteristic changing means 10 is provided between each rocker arm 7 to 9 to change the operating characteristic of the intake valves 1, 1 by making it possible to switch between connecting and disconnecting them.

The valve operating characteristic changing means 10 includes a first switching pin 2 that can connect the third and second rocker arms 9 and 8.
3, a second switching pin 24 that can connect between the second and first rocker arms 8, 7, a third switching pin 25 that restricts movement of the first and second switching pins 23, 24, and each switching pin 23. - 25 toward the disconnection side.

A bottomed guide hole 27 parallel to the rocker shaft 6 is bored in the third rocker arm 9 with its open end facing the second rocker arm 8, and the first switching pin 23 slides into this guide hole 27. A hydraulic chamber 29 is defined between the first switching pin 23 and the closed end of the guide hole 27 . Further, the third rocker arm 9 includes a communication passage 3 that communicates with the hydraulic chamber 29.
0 is bored, and a hydraulic pressure supply path 31 is bored inside the rocker shaft 6. Furthermore, the communication passage 30 and the hydraulic pressure supply passage 31 are always in communication through a communication hole 32 formed in the side wall of the rocker shaft 6 regardless of the swinging state of the third rocker arm 9.

A guide hole 33 having the same diameter corresponding to the guide hole 27 is bored in the second rocker arm 8 in parallel with the rocker shaft 6 between both sides thereof, and the second switching pin 24 slides into the guide hole 33. are movably fitted.

The first rocker arm 7 has a bottomed guide hole 34 having the same diameter that corresponds to the guide hole 33 and is parallel to the rocker shaft 6 and has an open end connected to the second rocker arm 8.
The third switching pin 25 is slidably fitted into the guide hole 34 . Moreover, a shaft portion 36 coaxially connected to the third switching pin 25 is movably inserted into a guide hole 37 formed at the closed end of the guide hole 34 . Further, the return spring 26 surrounds the shaft portion 36 and is interposed between the closed end of the guide hole 34 and the third switching pin 25, and the return spring 26 releases the switching pins 23 to 25 that are in contact with each other. ie, toward the hydraulic chamber 29 side.

When the hydraulic pressure supplied to the hydraulic chamber 29 is released, each of the switching pins 23 to 25 has moved toward the disconnection side by the spring force of the return spring 26, and in this state, the first and second switching pins 23 and 24 are The abutment surface is between the third and second rocker arms 9, 8, and the abutment surface of the second and third switching pins 24, 25 is between the second and second rocker arms 9, 8.
and between the first rocker arms 8 and 7, and the rocker arms 7 to 9 are not connected. Furthermore, when high hydraulic pressure is supplied to the hydraulic chamber 29, each switching pin 2
3 to 25 move in a direction away from the hydraulic chamber 29 against the spring force of the return spring 26, and the first switching pin 2
3 fits into the guide hole 33, and the second switching pin 24 fits into the guide hole 34, thereby connecting the rocker arms 7 to 9.

The hydraulic pressure supply path 31 in the rock shaft 6 is connected to a hydraulic pressure supply source 42 via a control valve 41 that switches between an open state and a closed state by energizing and demagnetizing a solenoid 40 . When the control valve 41 opens, high hydraulic pressure is supplied to the hydraulic chamber 29 of the valve operating characteristic changing means 10, and when the control valve 41 closes, the hydraulic pressure in the hydraulic chamber 29 is released.

The solenoid 40 can be switched between excitation and demagnetization by a control means 43 such as a computer, and this control means 43 controls when the rotation speed input from a rotation speed detector 44 that detects the engine rotation speed exceeds a set value. and the control valve 41 is opened. Also connected to the control means 43 are a detector 47 for detecting intake negative pressure, a detector 48 for detecting engine temperature, and the like.

Further, the valve operation characteristic changing means 10 includes a pressure switch 45 for detecting whether or not the switching operation has been completed.
The pressure switch 45 is connected to the hydraulic chamber 29.
It is attached to the rocker shaft 6 to detect the oil pressure in the oil pressure supply path 31 leading to the oil pressure supply path 31. That is, when the oil pressure in the oil pressure supply path 31 becomes higher than a certain value, it is assumed that the oil pressure higher than the certain oil pressure is also supplied to the oil pressure chamber 29, and the valve operating characteristic changing means 10 is switched, and the pressure switch is set to a high level. The signal is input to the control means 43.

This internal combustion engine also includes electronic advance means 50 for determining the ignition timing and a fuel injection amount as an engine control operation means that controls control factors related to the combustion state of the engine other than the operation of the intake valves 1, 1. An electronic fuel injection means 51 for determining an exhaust gas circulation amount and an electronic exhaust gas circulation means 52 for determining an exhaust gas circulation amount are provided, and each means 50, 51, 52 is also controlled by a control means 43.
controlled by Moreover, the control means 43 has two types of maps that determine the ignition timing, fuel injection amount, and exhaust gas circulation amount depending on the engine speed and intake negative pressure, one for low-speed engine operation and one for high-speed engine operation. and the valve operating characteristic changing means 10
In response to confirming with the pressure switch 45 that the changing operation of the valve operating characteristic changing means 10 has been completed when the valve operating characteristic changing means 10 performs a switching operation according to the operating state of the engine,
The control means 43 includes an electronic advance means 50, an electronic fuel injection means 51, and an electronic exhaust gas circulation means 52.
is controlled in a manner corresponding to the operating manner of the valve operating characteristic changing means 10.

Next, to explain the operation of this embodiment, when the engine speed is below the set value, the control means 4
3 outputs a signal for demagnetizing the solenoid 40. When the solenoid 40 is demagnetized, the control valve 41 is closed and the hydraulic pressure in the hydraulic chamber 29 is released, so the valve operating characteristic changing means 10 is in a disconnected state, and the intake valves 1, 1 are connected to the low speed cam. 4,4
It opens and closes with timing and lift amount depending on the shape of the door. Moreover, at this time, the electronic advance angle means 50,
The configuration of the electronic fuel injection means 51 and the electronic exhaust gas circulation means 52 is also compatible with low engine speeds, so that the ignition timing and ignition timing suitable for low speed operation of the engine are adjusted.
It operates based on fuel injection amount and exhaust gas circulation amount.

When the engine speed exceeds the set value, the control means 4
3 outputs a signal that excites the solenoid 40, thereby opening the control valve 14. Therefore, high oil pressure is supplied to the hydraulic chamber 29, the valve operating characteristic changing means 10 is switched to the connected state, and each rocker arm 7 to
9 are connected. Therefore, the intake valves 1, 1 are opened and closed at timing and lift amount depending on the shape of the high-speed cam 5. Moreover, when it is confirmed by the pressure switch 45 that the switching operation of the valve operating characteristic changing means 10 has been completed, the control means 43 controls the electronic advancing means 50, the electronic fuel injection means 51, and the electronic exhaust gas circulation means 52. is switched to a mode compatible with high-speed operation of the engine.

In this way, as the operating characteristics of the intake valves 1, 1 are changed according to the operating state of the engine, the ignition timing, fuel injection amount, and exhaust gas circulation amount are also controlled to correspond to the operating state of the engine, The operating performance and exhaust gas performance of the engine can be improved.
Moreover, the electronic advance angle means 50, the electronic fuel injection means 51, and the electronic exhaust gas circulation means 52 can switch their operating modes in response to the completion of the changing operation of the valve operating characteristic changing means 10. By matching the operating mode of No. 1 with the ignition timing, fuel injection amount, and exhaust gas circulation amount, driving performance and exhaust gas performance can be improved more reliably.

In the above embodiments, a valve operating device for an intake valve has been described, but the present invention can also be applied to a valve operating device for an exhaust valve. Further, according to the present invention,
At least one of the ignition timing, the fuel injection amount, and the exhaust gas circulation amount as control factors other than the valve operation may be changed and controlled in synchronization with the end of the changing operation of the valve operation characteristic changing means 10.

C. Effects of the Invention As described above, the internal combustion engine according to the present invention includes a pressure switch attached to the valve operating characteristic changing means to detect the end of the changing operation of the valve operating characteristic changing means by detecting the working oil pressure, and a pressure switch that is attached to the valve operating characteristic changing means to detect the end of the changing operation of the valve operating characteristic changing means by detecting the operating oil pressure. The valve operating characteristic changing means is controlled to select a cam corresponding to the engine by hydraulic control, and the engine control actuating means is changed to the valve operating characteristic changing means in response to a signal confirming the end of the operation being outputted from the pressure switch. Since it includes a control means for controlling the operation in a manner corresponding to the operating mode, the valve operating characteristic changing means changes the operating characteristics of the intake valve or exhaust valve by changing the hydraulic pressure. By changing the operating mode of the engine control operating means in response to confirmation of the completion of the switching operation of the valve operating characteristic changing means, the operating characteristics of the intake valve or exhaust valve can be easily detected, and changes other than valve operation can be easily detected. It is possible to reliably match and control the control factors related to the combustion state of the engine, and it is possible to reliably improve driving performance, exhaust gas performance, etc.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a plan view of a valve train, and FIG.
A line sectional view, Figure 3 is a - line sectional view of Figure 1,
FIG. 4 is a sectional view taken along the line -- in FIG. 2. 1... Intake valve, 10... Valve operation characteristic changing means,
43...control means, 45...pressure switch, 50
. . . Electronic advance means as an operating means for engine control, 51 . . . Electronic fuel injection means as an operating means for engine control, 52 . . . Electronic exhaust gas circulation means as an operating means for engine control.

Claims (1)

[Claims] 1 Hydraulic valve operating characteristic changing means 10 capable of switching the opening/closing operating characteristic of the intake valve 1 or the exhaust valve by selection according to the oil pressure switching of a plurality of different cams 4 and 5
and engine control actuation means 50, 51, 52 that govern control factors related to the combustion state of the engine other than valve operation.
In an internal combustion engine, the pressure switch 45 is attached to the valve operating characteristic changing means 10 in order to detect the end of the changing operation of the valve operating characteristic changing means 10 by detecting the working oil pressure, and the cam 4 according to the operating state of the engine. 5 by hydraulic control, and in response to a signal confirming the completion of the operation being output from the pressure switch 45, the engine control operating means 50 to 52 are changed to change the valve operation characteristics. An internal combustion engine characterized in that it includes a control means 43 for controlling the operation in a manner corresponding to the operation manner of the means 10.