JPH09329009A - Control system of multi-degree-of-freedom valve system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a valve opening position, a valve closing period and a lift amount so that fuel consumption, an exhaust emission, and an output are set to an optimum level in accordance with a load and revolution number of an engine. SOLUTION: This system is provided with an internal combustion engine valve 3 which is driven between a valve opening period and a valve closing period by an oil pressure of a hydraulic system, a hydraulic control valve 1 which is incorporated in the hydraulic system and can be set to an opening position and a closing position, a valve system controller ECU8 which sends an open signal and a close signal to the hydraulic control valve 1, and a valve lift sensor 7 which detects that the valve 3 is in the valve opening position or valve closing position. Then a valve system controller ECU8 calculates time lag between the time sending an opening/closing signal and the time receiving a valve opening/closing position detection signal based on the time sending a signal to the hydraulic control valve 1 and the time receiving a valve opening/closing position detection signal from the valve lift sensor 7, and sends a valve opening signal or a valve closing signal to the hydraulic valve at the time at which a correction is made by the time lag at the subsequent valve opening and valve closing cycle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the opening timing and closing timing of an intake valve and an exhaust valve of a hydraulic valve operating system in an internal combustion engine, and the lift amount according to the engine usage condition, load and rotational speed. The present invention relates to a multi-degree-of-freedom valve train control system that is arbitrarily changed.

[0002]

2. Description of the Related Art Conventionally, as an example of a system for controlling a valve opening timing and a valve closing timing and a lift amount of an intake valve or an exhaust valve of a hydraulic valve system according to a demand for an engine and an operating condition of the engine, FIG. And a hydraulic valve operating system as shown in FIG. 4 is used.

The hydraulic valve system control system shown in FIGS. 3 and 4 is an intake valve of an internal combustion engine driven between an open position and a closed position by the hydraulic pressure supplied from an oil pump 102 of the hydraulic system. An exhaust valve 103, a hydraulic cylinder 104, a valve guide 105, and a hydraulic control valve 101 incorporated in a hydraulic system and having an open position and a closed position.
And the opening and closing of the hydraulic control valve 101
The valve opening timing and valve closing timing of the valve 103 and the lift amount are controlled via hydraulic pressure.

The oil pressurized by the oil pump 102 is sent to the hydraulic cylinder 104 when the hydraulic control valve 101 is closed, and as shown in FIG.
03 moves (falls) to the valve opening position. Hydraulic control valve 1
When 01 is open, the pressurized oil passes through the hydraulic pressure control valve 101 to release the hydraulic pressure, and the valve 103 moves (rises) to the closed position as shown in FIG.

In the hydraulic valve control system, the viscosity of the oil has a great influence on the valve opening timing and the valve closing timing. Therefore, the opening timing and the closing timing of the hydraulic control valve 101 are the actual values of the valve 103. It is corrected for a predetermined time according to the valve opening timing and the valve closing timing. The correction amount is determined according to the oil pressure or the oil temperature.

[0006]

However, in the hydraulic valve control system, there is a delay in oil transportation due to a change in oil viscosity, oil tightness between the hydraulic cylinder and piston, and sliding resistance between the valve guide and the valve. Change affects the valve opening and closing times and the lift amount.Therefore, changes in the amount of oil leakage due to wear of the hydraulic valve control system, wear of the valve seat, and oil Due to the inclusion of air, it becomes impossible to accurately grasp the valve opening timing and valve closing timing only by correcting the hydraulic pressure and the oil temperature, and it becomes difficult to control the hydraulic valve system.

In view of the above-mentioned problems, the present invention controls the valve opening and closing timings and the lift amount of a valve that optimizes fuel consumption, exhaust emission, and output according to the engine load and engine speed. An object of the present invention is to provide means for accurately grasping the relationship between the opening timing and closing timing of a hydraulic control valve and the valve opening timing and valve closing timing.

Further, according to the present invention, the valve lift sensor is used to constantly observe the lift amount of the valve, and the time difference between the actual valve opening timing and valve closing timing and the control target timing is feedback-corrected. An object of the present invention is to provide a means for performing optimum control that always brings the actual valve opening timing and valve closing timing closer to the control target timing regardless of the deterioration of the hydraulic valve system and the state of oil.

[0009]

As a means for solving the above-mentioned problems, the present invention provides a multi-degree-of-freedom valve train control system described in each of the claims.

In the multi-degree-of-freedom valve control system according to the first aspect, the opening and closing timings of the intake valve or the exhaust valve operated by opening and closing the hydraulic control valve are detected, and the required valve opening is performed. The deviation time of the actual valve opening timing with respect to the timing and the deviation time of the actual valve closing timing with respect to the required valve closing timing are calculated. Also, the opening delay time of the valve opening timing with respect to the timing when the opening signal is output to the hydraulic control valve,
The closing delay time of the valve closing timing with respect to the time when the closing signal is output to the hydraulic control valve is calculated, and the actual opening timing of the valve of the next cycle is requested to the opening timing of the valve and In order to correct and adjust the actual valve closing timing to the required valve closing timing, according to the calculated deviation time, valve opening delay time and valve closing delay time, an opening signal and The timing of the closing signal is changed.

In this case, even if the valve opening delay time and the valve closing delay time change due to changes in the usage status of the valve,
Since the valve and the hydraulic control valve of the next cycle are controlled based on the data detected and calculated in the previous cycle, the optimum valve opening timing and valve closing timing that are the target of the valve are always obtained.

In the multi-degree-of-freedom valve train control system according to the second aspect, air pressure is used instead of hydraulic pressure.
The part that supplies the air pressure can be made of a material having a lower rigidity than the part that supplies the hydraulic pressure, and the weight can be reduced as compared with the multi-degree-of-freedom valve train control system that uses the hydraulic pressure.

In the multi-degree-of-freedom valve control system according to the third aspect, the electromagnetic force of the electromagnetic circuit is used instead of the hydraulic pressure of the hydraulic system, and the electromagnetic coil is used instead of the hydraulic control valve. It can be made of a material having a rigidity lower than that of the portion that supplies the air pressure, and the weight can be reduced as compared with the multi-degree-of-freedom valve train control system that uses hydraulic pressure or air pressure.

In the multi-degree-of-freedom valve control system according to the present invention, the valve opening and closing timing of the intake valve or exhaust valve operated by opening and closing the hydraulic control valve, and the lift amount are detected, and the valve is The deviation time of the actual valve opening timing with respect to the required valve opening timing, the deviation time of the actual valve closing timing with respect to the required valve closing timing, and the deviation amount of the actual lift amount with respect to the valve required lift amount are calculated. In addition, the opening delay time of the valve opening timing with respect to the timing when the hydraulic control valve is issued and the closing delay time of the valve closing timing with respect to the timing when the closing signal is issued to the hydraulic control valve are Calculated, the actual valve opening timing of the next cycle is the required valve opening timing, the actual valve closing timing of the next cycle is the required valve closing timing, and the actual valve lift of the next cycle is In order to adjust and adjust the required lift amount to the required lift amount, the opening signal and the closing signal are sent to the hydraulic control valve in the next cycle according to the calculated deviation time, lift deviation, valve opening delay time, and valve closing delay time. The time when is issued is changed.

In this case, even if the valve opening delay time, the valve closing delay time, and the lift amount change due to changes in the valve usage condition, the next cycle is based on the data detected and calculated in the previous cycle. Since the valve and the hydraulic control valve are controlled, the optimum valve opening timing, valve closing timing, and lift amount that are the target of the valve can always be obtained.

In the multi-degree-of-freedom valve control system according to the present invention, the gap sensor continuously detects the gap between the valve stem and the valve stem which is partially tapered. It is possible to detect the valve opening timing, the valve closing timing, and the lift amount.

In the multi-degree-of-freedom valve control system according to the present invention, in order to continuously detect the change in the magnetic force line generated from a part of the valve stem magnetized by the pickup coil, the valve stem becomes dirty or dirty. Regardless of wear
It is possible to accurately detect the valve opening timing, the valve closing timing, and the lift amount.

In the multi-degree-of-freedom valve control system according to the present invention, a piezoelectric element mounted on a washer of a spring, the biasing force of which changes depending on the valve position, continuously detects the biasing force. Even when the engine room is magnetized, it is possible to detect the valve opening timing, the valve closing timing, and the lift amount.

In the multi-degree-of-freedom valve control system according to claim 8, the gap sensor has at least one discontinuous surface on the valve stem for detecting a gap with a part of the stepped valve stem. It is possible to detect the valve opening timing and the valve closing timing only by the presence of.

In the multi-degree-of-freedom valve train control system according to the present invention, since the electric circuit conducts when the valve is in the closed position, an inexpensive electric circuit is used instead of an expensive sensor. The valve opening timing and valve closing timing can be detected.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The valve system control system of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 schematically shows the configuration of one embodiment of a valve train control system of the present invention. As shown in FIG. 1, a valve train control system according to an embodiment is an intake valve or exhaust gas for an internal combustion engine that is driven by a hydraulic pressure of a hydraulic system so as to reciprocate between a valve open position and a valve close position. The valve 3 and a hydraulic cylinder 4 which is fixed and drives the valve 3 by an internal hydraulic piston.
A valve guide 5 for holding and guiding the stem of the valve 3; a hydraulic control valve 1 which is incorporated in a hydraulic system and can take an open position and a closed position; and an open signal and a close signal for the hydraulic control valve 1. Valve control ECU (electronic braking device)
8, a position of whether the intake valve or the exhaust valve 3 is in the valve open position or the valve close position, and a valve lift sensor 7 for detecting the lift amount of the valve 3.

FIG. 2 shows an opening signal 91 and a closing signal 92 sent from the valve control ECU (electronic control unit) to the hydraulic control valve.
2 is a time chart showing a curve indicating the above, a valve opening timing 93 and a valve closing timing 94 of a valve detected by a valve lift sensor, and a lift amount 95. The valve opening delay time 96 is from the timing when the opening signal 91 is issued to the valve opening timing 93, and the valve closing delay time 97 is from the timing when the closing signal 92 is issued to the valve closing timing 94.

When signals of the engine load (accelerator opening) and the number of revolutions are input to an engine control ECU (not shown), the engine control ECU determines a predetermined value corresponding to an input value stored in advance in a memory. The required valve opening timing, the required valve closing timing, and a predetermined required lift amount are output to the valve control ECU 8 as target values.

Then, the valve control ECU 8 sends an opening signal to the hydraulic control valve 1 at a predetermined time, and sends a closing signal to the hydraulic control valve 1 after a predetermined time. The valve lift sensor 7 detects the time when the valve 3 is actually opened and closed and the lift amount of the valve 3, and sends the result to the valve operation control ECU 8.

The valve control ECU 8 determines the valve opening delay time of the intake valve or the exhaust valve 3 from the time when the opening signal is sent to the hydraulic control valve 1 and the time when the valve opening position detection signal is received from the valve lift sensor 7. According to the valve opening delay time and the valve opening speed of the previous cycle calculated from the output of the valve lift sensor 7, the following is calculated so that the timing of receiving the valve opening position detection signal is the target valve opening timing. Correct the timing to send the release signal in the cycle. Further valve control E
The CU 8 calculates the valve closing delay time of the intake valve or the exhaust valve 3 from the timing of sending the closing signal to the hydraulic control valve 1 and the timing of receiving the valve closing position detection signal from the valve lift sensor 7 to determine the valve closing position. According to the valve closing delay time and the valve closing speed of the previous cycle calculated from the output of the valve lift sensor 7, the valve closing signal is set in the next cycle so that the timing of receiving the detection signal becomes the target valve closing timing. Correct the sending time.

That is, when the valve opening timing detected by the valve lift sensor 7 is later than the required valve opening timing, the valve operation control ECU 8 advances the timing of sending the opening signal to the hydraulic control valve 1 to increase the valve lift. When the valve closing timing detected by the sensor 7 is later than the required valve closing timing, the timing for sending the closing signal to the hydraulic control valve 1 is advanced so that the valve opening timing detected by the valve lift sensor 7 is the required valve opening timing. When the timing is earlier than the timing, the timing of sending the opening signal to the hydraulic control valve 1 is delayed, and when the closing timing detected by the valve lift sensor 7 is earlier than the required closing timing, the hydraulic control valve 1 is controlled. It delays the timing of sending the closing signal. Further, when the lift amount detected by the valve lift sensor 7 is smaller than the required lift amount, the valve control ECU 8 lengthens the opening time of the hydraulic control valve 1 to request the lift amount detected by the valve lift sensor 7. When it is larger than the lift amount, the opening time of the hydraulic control valve 1 is shortened.

During engine operation, engine operating conditions are constantly changing. When the oil temperature of the hydraulic mechanism rises and the viscosity decreases, the oil flow becomes smooth, so the hydraulic control valve 1
The delay time of the valve opening timing or the valve closing timing of the valve 3 with respect to the timing when the opening signal or the closing signal is issued becomes short. or,
If the oil tightness of the hydraulic cylinder 4 deteriorates, the delay time becomes longer. When the sliding resistance of the sliding portion between the valve guide 5 and the valve 3 changes due to wear or thermal deformation, the delay time changes.

However, in the valve operating system as the embodiment of the present invention shown in FIG. 1, the feedback control of the hydraulic control valve 1 with respect to the output from the valve lift sensor 7 is continued during the operation of the engine. Thus, the optimum valve opening timing and valve closing timing of the valve 3 and the lift amount can always be obtained. It should be noted that the opening signal and the closing signal of the hydraulic control valve 1 should be set earlier in consideration of the actual valve lift amount and the delay time between the valve opening timing and the valve closing timing.
It is sent from U8.

In this preferred embodiment of the invention, the valve opening and closing times and the lift amount are detected,
In another preferred embodiment, it is possible to detect only one of the valve opening timing and valve closing timing and the lift amount depending on the purpose.

Further, in this preferred embodiment of the present invention, hydraulic pressure is used as the drive source of the valve, but not shown in the drawings, but in another preferred embodiment, pneumatic pressure or electromagnetic force is used instead of hydraulic pressure. It is also possible to be done. If pneumatic pressure is used instead of hydraulic pressure, pneumatic control valves are used instead of hydraulic control valves. When electromagnetic force is used instead of hydraulic pressure, electromagnetic coils are used instead of hydraulic control valves.

FIGS. 5 to 9 are enlarged views of the valve 3 and the valve lift sensor 7 of FIG. 3, each showing a plurality of preferred embodiments of the present invention.

The valve lift sensor shown in FIG. 5 is a so-called gap sensor 31, which is attached to the valve guide 5 and detects a gap with a taper portion formed by machining a part of the valve stem 30 to intake air. The time when the valve or the exhaust valve 3 is arranged at the valve opening position and the valve closing position and the lift amount of the intake valve or the exhaust valve 3 are detected.

The valve lift sensor shown in FIG. 6 is a pickup coil 43, which is attached to the valve guide 5 and is generated from a magnetized portion of a portion of the valve stem 30 or a permanent magnet 40 attached to that portion. The change in the line of magnetic force is detected, and the timing at which the intake valve or the exhaust valve 3 is placed at the valve opening position and the valve closing position and the lift amount of the intake valve or the exhaust valve 3 are detected. In the structure shown in FIG. 6, the permanent magnet 40 is attached to the stem 30 of the valve 3, and the pickup coil 43 is attached to the valve guide 5 so that the pickup coil 43 is positioned closest to the permanent magnet 40 when the valve 3 is closed. ing.

The valve lift sensor shown in FIG. 7 is a piezoelectric element 52, which is attached to a washer of a spring 6 for urging the intake valve or the exhaust valve 3 toward a closed position and is supported by the washer. The urging force is electrically detected to detect the time when the intake valve or the exhaust valve 3 is at the valve opening position and the valve closing position and the lift amount of the intake valve or the exhaust valve 3.

The valve lift sensor shown in FIG. 8 is also a gap sensor 31, which is attached to the valve guide 5 and detects the gap with the stepped portion 61 formed in a part of the valve stem to detect an intake valve or an exhaust valve. The time when 3 is located in the valve opening position and the valve closing position is detected. The stepped portion 61 of the stem is arranged so as to be closest to the gap sensor 62 when the valve is closed.

In the embodiment shown in FIG. 9, when the intake valve or the exhaust valve 3 is in the valve closing position, the electric circuit 73 is formed to be conductive, and when the valve is in the valve opening position, the electric circuit 73 is cut off to form the electric circuit. By forming the switch that opens, the timing when the intake valve or the exhaust valve 3 is placed in the valve opening position and the valve closing position is detected. That is, since the valve seats provided on the valve 3 and the cylinder head 72 are electrically conductive, if these are used as contacts, an electrical circuit is conducted when the valve 3 is seated on the valve seat of the cylinder head 72, and Detects that the valve 3 is in the closed position.

[Brief description of drawings]

FIG. 1 is a schematic diagram of one embodiment of a valve train control system of the present invention.

2A and 2B are curves showing an open signal and a close signal output from a valve control ECU to a hydraulic control valve, a curve showing a valve opening timing and a valve closing timing detected by a valve lift sensor, and a curve showing a lift amount. It is a graph showing.

FIG. 3 is a schematic diagram of a conventional valve train control system showing a state in which a valve is arranged in an open position.

FIG. 4 is a schematic diagram of a conventional valve train control system showing a state in which a valve is arranged in a closed position.

5 is an enlarged view of the valve and valve lift sensor of FIG.

FIG. 6 is an enlarged view of the valve and valve lift sensor of FIG. 3 showing another preferred embodiment of the present invention.

FIG. 7 is an enlarged view of the valve and valve lift sensor of FIG. 3 showing another preferred embodiment of the present invention.

FIG. 8 is an enlarged view of the valve and valve lift sensor of FIG. 3 showing another preferred embodiment of the present invention.

FIG. 9 is an enlarged view of the valve and valve lift sensor of FIG. 3 showing another preferred embodiment of the present invention.

[Explanation of symbols]

 1 ... hydraulic control valve 2 ... high pressure pump 3 ... valve 4 ... hydraulic cylinder 5 ... valve guide 6 ... spring 7 ... valve lift sensor 8 ... valve control ECU (electronic control unit)

Claims (9)

[Claims] 1. An intake valve or an exhaust valve of an internal combustion engine which is driven between a valve opening position and a valve closing position by a hydraulic pressure of a hydraulic system, and a hydraulic pressure which is incorporated in the hydraulic system and can take an open position and a closed position. In a multi-degree-of-freedom valve train control system including a control valve and a control unit that sends an opening signal and a closing signal to the hydraulic control valve, the intake valve or the exhaust valve electrically coupled to the control unit is A valve lift sensor for detecting whether the valve is located at the valve opening position or the valve closing position is provided, and when the control unit sends the opening signal to the hydraulic control valve and the valve lift sensor. From the time when the valve opening position detection signal is received, the deviation time between the time when the valve opening position detection signal is received and the time when the valve opening position detection signal is received is calculated. In the closing cycle, the opening signal is sent to the hydraulic control valve at the time corrected by the deviation time, and the control unit sends the closing signal to the hydraulic control valve and the valve. From the time when the valve closing position detection signal is received from the lift sensor, the deviation time of the time when the valve closing position detection signal is received with respect to the time when the valve closing signal is sent is calculated, and the next opening / closing cycle of the hydraulic control valve is calculated. In this case, a multi-degree-of-freedom valve operating system control system is characterized in that a closing signal is sent to the hydraulic control valve at the time when the deviation time is corrected. 2. The multi-degree-of-freedom valve operating system control system according to claim 1, wherein air pressure is used instead of hydraulic pressure. 3. The multi-degree-of-freedom valve train control system according to claim 1, wherein an electromagnetic force of an electromagnetic circuit is used in place of the hydraulic pressure of the hydraulic system, and an electromagnetic coil is used in place of the hydraulic control valve. A multi-degree-of-freedom valve train control system. 4. The multi-degree-of-freedom valve according to any one of claims 1 to 3, wherein the valve lift sensor is further capable of detecting a lift amount of the intake valve or the exhaust valve. System control system. 5. The valve lift sensor is attached to a valve guide as a gap sensor to detect a gap with a valve stem that is partially processed into a taper shape, and the intake valve or the exhaust valve detects the opening position and 5. The multi-degree-of-freedom valve operating system control system according to claim 4, wherein it is possible to detect a time when the valve is in the closed position and a lift amount of the intake valve or the exhaust valve. 6. The valve lift sensor is attached to a valve guide as a pickup coil to detect a change in a magnetic line of force generated from a part of a magnetized valve stem, and the intake valve or the exhaust valve detects the opening position and 5. The multi-degree-of-freedom valve operating system control system according to claim 4, wherein it is possible to detect a time when the valve is in the closed position and a lift amount of the intake valve or the exhaust valve. 7. The valve lift sensor, which comprises a piezoelectric element, is attached to a washer of a spring that biases the intake valve or the exhaust valve toward the closed position, and the valve lift sensor is supported by the washer. The urging force is detected, and the time when the intake valve or the exhaust valve is in the valve opening position and the valve closing position and the lift amount of the intake valve or the exhaust valve are detected. The multi-degree-of-freedom valve train control system described in. 8. The valve lift sensor is attached to a valve guide as a gap sensor to detect a gap with a part of a stepped valve stem, and the intake valve or the exhaust valve detects the open position and the open position. The multi-degree-of-freedom valve operating system control system according to any one of claims 1 to 3, wherein the timing at the valve closing position is detected. 9. An electric circuit is formed when the intake valve or the exhaust valve is in the valve closing position to detect when the intake valve or the exhaust valve is in the valve opening position and the valve closing position. The multi-degree-of-freedom valve system control system according to claim 1, wherein the multi-degree-of-freedom valve system control system is provided.