JP2000110527A - Variable valve timing control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the structure of a hydraulic fluid control system by simultaneously controlling an intake valve timing variable actuator and an exhaust valve timing variable actuator by use of one oil control valve. SOLUTION: An intake valve timing variable actuator 20 is mounted on the end part of an intake-side camshaft 19 to advance or delay the intake-side camshaft 17, whereby the opening and closing timing of an intake valve 17 is continuously changed. An exhaust valve timing variable actuator 22 is mounted on the end part of an exhaust-side camshaft 21 to advance or delay the exhaust-side camshaft 21, whereby the opening and closing timing of an exhaust valve 18 is continuously changed. One oil control valve 40 supplies a hydraulic fluid to each of the intake-side actuator 20 and the exhaust-side actuator 22 and properly controls the oil feed quantity at the same time. According to this, the oil passage structure of a hydraulic fluid control system can be simplified to moderate the limitation of the mounting space, and the system cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve timing control apparatus for an internal combustion engine for changing the opening / closing timing of both or one of an intake valve and an exhaust valve by a hydraulic actuator according to the operating conditions of the engine. .

[0002]

2. Description of the Related Art As a conventional variable valve timing control apparatus for an internal combustion engine, when a camshaft is driven by a timing pulley or a chain sprocket that rotates synchronously with the crankshaft of the engine, a vane type is interposed between the timing pulley and the camshaft. Alternatively, a helical piston type variable valve timing actuator is provided, and the variable shaft timing actuator is supplied with hydraulic oil from an oil pump via an oil control valve (hereinafter, referred to as OCV) to control the camshaft relative to the crankshaft. By rotating the camshaft relative to the rotation of the crankshaft to advance or retard the rotation of the camshaft relative to the rotation of the crankshaft, the opening and closing timing of the intake and exhaust valves is shifted with respect to the rotation of the engine to reduce exhaust gas and output. Improvement and aims to improve fuel efficiency and the like,
For example, Japanese Patent Application Laid-Open Nos. 7-139319 and 7-1
These are already known from JP-A-39320, JP-A-8-28219, JP-A-8-121122, JP-A-9-60507, JP-A-9-60508 and the like.

The actuator employed in such a conventional variable valve timing control apparatus for an internal combustion engine includes:
There are vane type, in which the rotor rotates and slides in the housing, and helical type, in which the helical piston rotates. The camshaft is advanced or retarded by supplying hydraulic oil from the OCV into the housing. It is.

[0004]

Since the conventional variable valve timing control apparatus for an internal combustion engine is constructed as described above, in order to control both the variable intake valve timing actuator and the variable exhaust valve timing actuator, Two OCVs for individually controlling the supply of hydraulic oil to those actuators are required, and the number of hydraulic passages corresponding to the two OCVs (that is, from the OCV to the intake valve timing variable actuator and the exhaust variable Hydraulic passages leading to the advance hydraulic chamber and the retard hydraulic chamber of the actuator are required,
For this reason, the configuration of the hydraulic oil control system of each of the actuators becomes complicated, and a space for mounting the hydraulic oil control system must be ensured, and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to simultaneously control both the intake valve timing variable actuator and the exhaust valve timing variable actuator with one OCV, and the hydraulic oil thereof is used. An object of the present invention is to provide a variable valve timing control device for an internal combustion engine that can simplify the configuration of a control system and reduce costs. In addition, the present invention provides one OC
It is an object of the present invention to provide a variable valve timing control apparatus for an internal combustion engine that can independently control only an intake valve timing variable actuator or an exhaust valve timing variable actuator with V. In addition, the present invention
An object of the present invention is to provide a variable valve timing control device for an internal combustion engine that can make a variable speed of an intake valve timing variable actuator and a variable speed of an exhaust valve timing variable actuator different with one OCV.

[0006]

A variable valve timing control apparatus for an internal combustion engine according to the present invention is provided on each of an intake camshaft and an exhaust camshaft whose rotational drive is controlled in synchronization with the rotation of the engine. Variable intake valve timing actuator and variable exhaust valve timing actuator for controlling the opening and closing timing of intake and exhaust valves of the engine; variable intake valve timing actuator and variable exhaust valve timing actuator; variable intake valve timing actuator; and variable exhaust valve A single oil control valve provided in a hydraulic passage for connecting an oil pump that supplies hydraulic oil to the variable timing actuator, and an electronic control unit that controls the operation of the engine according to an operating state of the engine. The oil control valve is switched and supplied to supply hydraulic oil from the oil pump to an advance hydraulic chamber of the intake valve timing variable actuator and a retard hydraulic chamber of the exhaust valve timing variable actuator, or It is controlled so as to supply the retarded hydraulic chamber of the variable valve timing actuator and the advanced hydraulic chamber of the exhaust valve timing variable actuator to simultaneously operate the variable intake valve timing actuator and the variable exhaust valve timing actuator. is there.

In the variable valve timing control apparatus for an internal combustion engine according to the present invention, the advance hydraulic chamber of the intake valve variable actuator and the retard hydraulic chamber of the exhaust valve variable actuator communicate with a common first oil passage. An oil control valve connected to the oil control valve, and a retard hydraulic chamber of the intake valve timing variable actuator and an advance hydraulic chamber of the exhaust valve timing variable actuator connected to the oil control valve through a common second oil passage; A flow control valve is provided in at least one of the first oil passage and the second oil passage.

In the variable valve timing control apparatus for an internal combustion engine according to the present invention, the advance hydraulic chamber of the intake valve timing variable actuator and the retard hydraulic chamber of the exhaust valve timing variable actuator communicate with a common first oil passage. An oil control valve connected to the oil control valve, and a retard hydraulic chamber of the intake valve timing variable actuator and an advance hydraulic chamber of the exhaust valve timing variable actuator connected to the oil control valve through a common second oil passage; At least one of the first oil passage and the second oil passage is provided with a fluid resistance variable portion set so that the flow resistance of the hydraulic oil is different between the first oil passage and the second oil passage.

The fluid resistance variable section of the variable valve timing control apparatus for an internal combustion engine according to the present invention includes a variable intake valve timing actuator and a variable exhaust valve timing actuator in at least one of the first and second oil passages. And a throttle portion for reducing the flow rate of the hydraulic oil.

[0010] The fluid resistance variable section of the variable valve timing control device for an internal combustion engine according to the present invention includes an oil path length from an oil control valve to an intake valve timing variable actuator in at least one of a first oil path and a second oil path. The length of the oil passage from the oil control valve to the variable exhaust valve timing actuator is varied.

The fluid resistance variable section of the variable valve timing control apparatus for an internal combustion engine according to the present invention is characterized in that an oil passage cross-sectional area from an oil control valve to an intake valve timing variable actuator in at least one of a first oil passage and a second oil passage. And the oil passage cross-sectional area from the oil control valve to the exhaust valve timing variable actuator is made different.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a schematic sectional view showing a gasoline engine system provided with a variable valve timing control device for an internal combustion engine according to Embodiment 1 of the present invention. In the figure, reference numeral 1 denotes an engine having a plurality of cylinders, one cylinder of which is shown in the figure, 2 denotes a cylinder block forming a plurality of cylinders of the engine 1, 2 a denotes a cylinder block 2
3 is a cylinder head provided on the upper part of the cylinder block 2, 4 is a piston which reciprocates up and down in each cylinder of the cylinder block 2, and 5 is connected to a lower end of the piston 4. The crankshaft 5 is driven to rotate by the vertical movement of the piston 4.

Reference numeral 6 denotes a crank angle sensor disposed near the crankshaft 5, 7 denotes a signal rotor connected to the crankshaft 5, and 7a denotes a signal projection provided on the outer periphery of the signal rotor 7 at an angle of 180 °. Each time the signal projection 7a passes in front of the crank angle sensor 6, the crank angle sensor 6 outputs a pulse-like crank angle detection signal.

Reference numeral 8 denotes a combustion chamber for burning the air-fuel mixture, which is defined by the inner walls of the cylinder block 2 and the cylinder head 3 and the top of the piston 4. 9
Are spark plugs for igniting an air-fuel mixture in the combustion chamber 8;
Reference numeral 0 denotes a distributor connected to an exhaust-side camshaft 21 described later, and reference numeral 11 denotes an igniter that generates a high voltage. Here, each spark plug 9 is connected to a distributor 10 via a high-pressure cord (not shown), and the high voltage output from the igniter 11 is synchronized with the rotation of the crankshaft 5 by the distributor 10 so that each ignition plug 9 It is distributed to the plug 9.

Reference numeral 12 denotes a water temperature sensor provided in the cylinder block 2, and the water temperature sensor 12 is connected to the cooling water passage 2a.
The temperature of the cooling water flowing through is detected. 13 is an intake port provided in the cylinder head 3, 14 is the cylinder head 3
, An exhaust passage connected to the intake port 13, 16 an exhaust passage connected to the exhaust port 14, 17 an intake valve provided in the cylinder head 3 to open and close the intake port 13, 18 Is the cylinder head 3
The exhaust valve is provided in the exhaust port and opens and closes the exhaust port 14.

Reference numeral 19 denotes an intake side camshaft arranged above the intake valve 17, and 19a denotes an intake side camshaft 19
An intake side cam 19b is provided so as to be able to rotate synchronously and drives the intake valve 17 to open and close. An intake side signal rotor 19b connected to the intake side camshaft 19 has a plurality (for example, , 90 ° angle four) signal projections 19c.

Reference numeral 20 denotes an intake valve timing variable actuator (hereinafter, referred to as an intake actuator) mounted at an end of the intake camshaft 19. The intake actuator 20 advances or retards the intake camshaft 19. Thus, the opening / closing timing of the intake valve 17 is continuously changed, and its detailed configuration will be described later.

Reference numeral 21 denotes an exhaust camshaft disposed above the exhaust valve 18, 21a denotes an exhaust cam provided on the exhaust camshaft 21 for driving the exhaust valve 18 to open and close, and 21b denotes an exhaust camshaft 21. The exhaust-side signal rotor 21b is connected to the exhaust-side signal rotor 21b.
A signal projection 21c similar to that described above is provided.

Reference numeral 22 denotes an exhaust valve timing variable actuator (hereinafter referred to as an "exhaust actuator") mounted on an end of the exhaust camshaft 21. The exhaust actuator 22 advances or retards the exhaust camshaft 21. Thus, the opening / closing timing of the exhaust valve 18 is continuously changed, and its detailed configuration will be described later.

Reference numeral 23 denotes an intake-side timing pulley for transmitting rotational driving force to the intake-side actuator 20; 24, an exhaust-side timing pulley for transmitting rotational driving force to the exhaust-side actuator 22; And a timing belt for transmitting the rotational driving force of the crankshaft 5 to each of the exhaust pulley 24 and the exhaust side timing pulley 24.

Therefore, when the engine 1 is operating, the rotational driving force of the crankshaft 5 is transmitted to the intake-side timing pulley 23 and the exhaust-side timing pulley 24 via the timing belt 25, and the intake-side timing pulley 23 The rotational driving force of the exhaust-side timing pulley 24 is transmitted to the intake-side camshaft 19 and the exhaust-side camshaft 21 via the intake-side actuator 20 and the exhaust-side actuator 22, respectively. Therefore, the intake side cam 19a and the exhaust side cam 21a are rotationally driven,
When the intake valves 17 and the exhaust valves 18 are opened and closed by these cams 19a and 21a, the intake valves 17 and the exhaust valves 18
The engine 1 is driven at a predetermined opening / closing timing in synchronization with the rotation of the piston 1 and the vertical movement of the piston 4, that is, in synchronization with a series of four steps of the engine 1 including an intake step, a compression step, an explosion / expansion step and an exhaust step.

Reference numeral 26 denotes an intake-side cam angle sensor arranged near the intake-side camshaft 19. The intake-side cam angle sensor 26 detects the rotational position of the intake-side camshaft 19, and more specifically, , Intake side signal rotor 19b
Each time the signal projection 19c passes in front of the intake-side cam angle sensor 26, the sensor 26 outputs a pulse-like intake-side cam angle detection signal.

Reference numeral 27 denotes an exhaust cam angle sensor disposed near the exhaust cam shaft 21. The exhaust cam angle sensor 27 detects the rotational position of the exhaust cam shaft 21, and specifically, , Exhaust side signal rotor 21b
Each time the signal projection 21c passes through the front of the exhaust-side cam angle sensor 27, the sensor 27 outputs a pulse-like exhaust-side cam angle detection signal.

Reference numeral 28 denotes an injector for supplying fuel to the combustion chamber 8 of the engine 1, reference numeral 29 denotes a throttle valve disposed in the intake passage 15, reference numeral 30 denotes a throttle sensor for detecting an opening of the throttle valve 29, and reference numeral 31 denotes an intake passage. Fifteen
, An intake air amount sensor 31 disposed upstream of the throttle valve 29, and the intake air amount sensor 31 detects the intake air amount of the engine 1.

Reference numeral 40 denotes one oil control valve (hereinafter, referred to as OCV) for supplying hydraulic oil to each of the intake-side actuator 20 and the exhaust-side actuator 22 and appropriately controlling the amount of supplied oil at the same time.
40 will be described later.

Reference numeral 100 denotes an electronic control unit (hereinafter referred to as an ECU).
The ECU 100 calculates the crankshaft 5 and the intake camshaft 19 from the crank angle sensor 6, the intake cam angle sensor 26, and the exhaust cam angle sensor 27.
By inputting the actual rotation position detection signal of the camshaft 21 and the exhaust side, the optimal intake valve timing and exhaust valve timing for the operating state of the engine 1 are calculated,
A control signal adapted to the operating state of the engine is output to the OCV 40. The ECU 100 also receives detection signals from other sensors such as the water temperature sensor 12, the throttle sensor 30, and the intake air amount sensor 31, and based on the input signals, the intake air amount and the fuel injection adapted to the engine operating state. A control signal resulting from the calculation of the amount or the like is output to the injector 28.

FIG. 2 is a structural explanatory view showing a specific example of the variable valve timing control apparatus for an internal combustion engine in FIG.
The same parts as those described above are denoted by the same reference numerals, and redundant description will be omitted.
In the figure, reference numeral 50 denotes a housing of the intake-side actuator 20, and the housing 50 is rotatably attached to the intake-side camshaft 19. 51 is a plurality of equally spaced shoes protruding from the inner peripheral surface of the housing 50;
Is connected to the intake side camshaft 19 and
The rotor 52 is rotatable relative to the housing 50.
Reference numeral 53 denotes a plurality of vanes projecting from the outer peripheral surface of the rotor 52 and interposed between the shoes 51 at regular intervals, and 54 denotes a tip seal provided at the tip of the vane 53. It is in sliding contact with the inner peripheral surface of the housing 50. Reference numeral 55 denotes an advance hydraulic chamber for rotating the rotor 52 in the advance direction, and reference numeral 56 denotes a retard hydraulic chamber for rotating the rotor 52 in the retard direction. The hydraulic chamber 56 is provided between the housing 51 and the
And the vane 53.

Reference numeral 60 denotes a housing of the exhaust-side actuator 22, which is rotatably mounted on the exhaust-side camshaft 21. Since the other configuration of the exhaust-side actuator 22 is the same as that of the intake-side actuator 20,
Here, only the description of the same parts is given. That is, 61 is a shoe, 62 is a rotor, 63 is a vane, 64
Denotes a tip seal, 65 denotes an advance hydraulic chamber, and 66 denotes a retard hydraulic chamber.

70 is an oil pan, 71 is an oil pan 70
An oil pump having a suction side communicating therewith, a hydraulic supply passage 72 connecting the discharge port of the oil pump 71 and an A port (primary side port) 41 of the OCV 40, and an OCV 40
The first oil passage 73 is connected to a B port (secondary port) 42 of the intake side actuator 2.
An intake-side advance oil passage 73a communicating with the zero-advance advance hydraulic chamber 55;
It is branched to an exhaust-side retard oil passage 73b communicating with the retard hydraulic chamber 66 of the exhaust-side actuator 22. 74 is OCV
40 C port (secondary port) 43 connected to the second
The second oil passage 74 is an intake-side retard oil passage 74 a communicating with the retard hydraulic chamber 56 of the intake-side actuator 20.
And an exhaust-side advanced oil passage 74 b communicating with the advanced hydraulic chamber 65 of the exhaust-side actuator 22. 75 is O
A drain passage connected to the drain ports 44 and 45 of the CV 40 and leading into the oil pan 70.

In the above description, the OCV 40 has the primary A port 41, the secondary B port 42 and the C port 42 as described above.
The electromagnetic spool valve has a port 43 and drain ports 44 and 45. The OCV 40 has a first switching position connecting the A port 41 and the B port 42 and connecting the C port 43 and the drain port 44, a connecting position connecting the A port 41 and the C port 43, and connecting the B port 42 and the drain port. A second switching position for connecting port 45, and A port 4
1 and the drain ports 44 and 45 are switched to the neutral position where the B port 42 and the C port 43 are shut off,
The switching is performed by a control signal from the ECU 100. Therefore, in the first switching position, the operating oil from the oil pump 71 is
The hydraulic oil from the oil pump 71 is supplied to the advance hydraulic chamber 55 and the retard hydraulic chamber 66 of the exhaust side actuator 22 at the second switching position.
, And the advanced hydraulic chamber 65 of the exhaust-side actuator 22.

Next, the operation will be described. ECU 100
Control signal from OCV40 causes A port 41 and B
When the position is switched to the connection position with the port 42, the hydraulic oil supplied from the oil pump 71 to the A port 41 of the OCV 40 flows from the B port 42 of the OCV 40 to the first oil passage 73.
, And is supplied to the advance hydraulic chamber 55 of the intake-side actuator 20 and the retard hydraulic chamber 66 of the exhaust-side actuator 22, respectively. Here, the operating oil pressure supplied to the advance hydraulic chamber 55 of the intake side actuator 20 causes the rotor 52 inside the intake side actuator 20 to advance the intake side camshaft 19 (clockwise direction in FIG. 2). It operates, and the retard hydraulic chamber 6 of the exhaust side actuator 22
The rotor 62 inside the exhaust-side actuator 22 operates in the direction of retarding the exhaust-side camshaft 21 (counterclockwise direction in FIG. 2) by the operating oil pressure supplied to 6.
At this time, the hydraulic oil staying in each of the retard hydraulic chamber 56 of the intake-side actuator 20 and the advance hydraulic chamber 65 of the exhaust-side actuator 22 passes through the OCV 4 from the second oil passage 74.
The oil is returned from the drain passage 75 to the oil pan 70 via the C port 43 and the drain port 44.

When the OCV 40 is switched to the connection position between the A port 41 and the C port 43 by a control signal from the ECU 100, the intake-side actuator 20 and the exhaust-side actuator 22 perform the reverse operation. That is, the operating oil from the oil pump 71 passes through the A port 41 and the C port 43 of the OCV 40 and from the second oil passage 74 to the retard hydraulic chamber 56 of the intake actuator 20 and the advance hydraulic chamber 65 of the exhaust actuator 22. By being supplied, the rotor 52 inside the intake side actuator 20 retards the intake side camshaft 19 and the rotor 62 inside the exhaust side actuator 22 advances the exhaust side camshaft 21. Operate.

Therefore, the intake-side actuator 20 and the exhaust-side actuator 22 operate in opposite directions. That is, when the intake side actuator 20 is advanced, the exhaust side actuator 22 is retarded, and when the intake side actuator 20 is retarded, the exhaust side actuator 22 is advanced.

According to the first embodiment described above, both the intake-side actuator 20 and the exhaust-side actuator 22 can be simultaneously controlled and operated in the opposite direction by one OCV 40, so that one OCV 40 can control the intake-side actuator. As described above, only two hydraulic passages, the first hydraulic passage 73 and the second hydraulic passage 74, are used to connect the hydraulic actuator 20 and the exhaust-side actuator 22, so that the configuration of the hydraulic oil control system can be simplified, and the mounting space is restricted. Can be reduced, the system cost can be reduced, and the engine output can be improved, as will be apparent from the experimental results described later, and the exhaust gas can be made cleaner.

FIG. 3 is a table showing the relationship between the engine speed and the torque based on the experimental results of the gasoline engine system provided with the variable valve timing control device for the internal combustion engine according to the first embodiment. 2 shows the torque characteristics when the intake-side and exhaust-side actuators 20 and 22 in FIG. 2 are not operated, and the solid line B shows the torque characteristics when the intake-side and exhaust-side actuators 20 and 22 are operated. In this experiment, the intake valve 1 in FIG.
7, the intake-side actuator 20
Was advanced to a crank angle of 40 °, and the exhaust side actuator 22 was retarded to a crank angle of 40 ° as the opening / closing timing of the exhaust valve. As described above, when the intake-side actuator 20 (intake valve 17) and the exhaust-side actuator 22 (exhaust valve 18) are operated in the opposite directions by the same amount of angle, the engine speed is substantially reduced, as is apparent from FIG. In the rotation range of 4000 r / m or less, the result that the engine output was greatly improved was obtained as shown by the hatched portion in FIG. In the high-speed rotation region where the engine speed is 5000 r / m or more, when the intake valve 17 is advanced, the intake valve 17 opens early and the combustion gas flows back to the intake passage 15 more than necessary. The efficiency of charging the air-fuel mixture in the combustion chamber 8 is reduced, and the engine output is reduced. Therefore, in this experiment, when the engine speed is 5000 r / m or more, FIG.
The operation of the variable valve timing control device for an internal combustion engine was stopped.

FIG. 4 is a table showing the effect ratios on torque, THC and NOx of the experimental results obtained by operating the internal combustion engine valve timing variable control device of FIG. 2 at an engine speed of 2000 r / m. In FIG. 4, A shows the torque characteristics when the intake-side and exhaust-side actuators 20 and 22 are not operated, and B shows the intake-side actuator 20 and the exhaust-side actuator 22 operated in the opposite direction to a crank angle of 20 °. C shows the torque characteristics in the case where the intake side actuator 20 and the exhaust side actuator 22
9 shows the torque characteristics when is operated in the reverse direction up to a crank angle of 40 °. A ′ is the two actuators 2
THC in exhaust gas when 0,22 is not operated
B ′ indicates the THC content in the exhaust gas when the intake-side actuator 20 and the exhaust-side actuator 22 are operated in the opposite direction to a crank angle of 20 °,
C ′ indicates the THC content in the exhaust gas when the intake-side actuator 20 and the exhaust-side actuator 22 are operated up to a crank angle of 40 ° in opposite directions. A "indicates the NOx content in the exhaust gas when both actuators 20 and 22 are not operated, and B" operates the intake-side actuator 20 and the exhaust-side actuator 22 in opposite directions to a crank angle of 20 °. N in the exhaust gas
4 shows the Ox content, and C ″ shows the NOx content in the exhaust gas when the intake-side actuator 20 and the exhaust-side actuator 22 are operated in the opposite direction up to a crank angle of 40 °. As is apparent from FIG. By operating both actuators 20 and 22 in the opposite direction by the same amount of angle, not only can the engine output be improved, but THC and NOx contained in the exhaust gas from the engine can be significantly reduced, and the exhaust gas can be greatly reduced. The result obtained was that it could greatly contribute to the cleanliness of the product.

Embodiment 2 FIG. 5 is an explanatory diagram showing a configuration of a variable valve timing control apparatus for an internal combustion engine according to Embodiment 2 of the present invention. The same parts as those in FIG. In FIG. 5, 81 is the first
A first flow control valve provided in the middle of the oil passage 73,
This is a second flow control valve provided in the middle of the oil passage 74, and these flow control valves 81 and 82 are controlled to open and close by a control signal output from the ECU 100 in accordance with the operation state of the engine 1 (FIG. 1). It has become so. The first and second flow control valves 81 and 82 perform continuous or stepwise control of the flow rate and perform opening and closing control, such as a solenoid valve, a needle valve, a poppet valve, a gate valve, and a rotary valve. Or whatever it is. That is, in the second embodiment, the first and second flow control valves 81 and 82 stop the operation of the intake side actuator 20 and operate only the exhaust side actuator 22 alone, or the first and second flow rate control valves 81 and 82 operate the exhaust side actuator 22 alone. The operation speed with the side actuator 22 can be changed.

Here, when the intake side actuator 20 is advanced in the high speed rotation region of the engine 1, the combustion gas in the combustion chamber 8 is opened by the rapid opening of the intake valve 17, as described in the above-mentioned experimental example. And the engine output drops.

Therefore, in the second embodiment, when the engine 1 is rotating at a high speed, the first flow control valve 81 or the second flow control valve 82 is closed by a control signal from the ECU 100, whereby the OCV 40 The hydraulic oil is not supplied to the intake side actuator 20 but is supplied only to the exhaust side actuator 22. Therefore, the operation of the intake side actuator 20 is stopped, and the operation of the exhaust side actuator 2 is stopped.
Only 2 operates alone. In other words, in detail, when only the exhaust-side actuator 22 is to be retarded, if the first flow control valve 81 is closed, the operating oil from the OCV 40 is discharged from the exhaust-side retarded oil passage 73b of the first oil passage 73. The supply to only the retard hydraulic chamber 66 of the side actuator 22 causes only the exhaust actuator 22 to independently perform the retard operation. Further, when only the exhaust-side actuator 22 is advanced, the second flow control valve 82 is closed.
Hydraulic oil from the CV 40 flows from the exhaust-side advance oil passage 74 b of the second oil passage 74 to the advance-side hydraulic chamber 65 of the exhaust-side actuator 22.
To the exhaust side actuator 2
Only 2 operates independently. Thus, engine 1
By operating only the exhaust-side actuator 22 alone at the time of high-speed rotation, the backflow of the combustion gas from the combustion chamber 8 to the intake passage 15 can be prevented, and the engine output can be improved.

Further, depending on the operating condition of the engine 1, E
It is also possible to make the respective valve openings of the first and second flow control valves 81 and 82 different from each other by a control signal from the CU 100. In this case, by controlling the valve opening of the two flow control valves 81 and 82, it is possible. The operation speeds of the intake-side actuator 20 and the exhaust-side actuator 22 can be variably controlled.

That is, during operation of the engine 1, the intake side camshaft 19 and the exhaust side camshaft 21 apply a cam load to the intake side timing pulley 23 and the exhaust side timing pulley 24 in the direction opposite to the rotational direction. Due to this cam load, an actuating force (reaction force) in the retard direction is applied to both the intake-side actuator 20 and the exhaust-side actuator 22, so that both of the actuators 20, 22 are in the retard direction. Since the operating speed is inevitably faster and the advance speed of the exhaust-side actuator 22 becomes slower, in order to prevent this, the advance speed of the exhaust-side actuator 22 is made faster than the retardation speed of the intake-side actuator 20. There is a need.

Therefore, in the second embodiment, the OCV4
0 from the second oil passage 74 through the retard hydraulic chamber 56 of the intake side actuator 20 and the exhaust side actuator 22.
When controlling the supply to each of the advance hydraulic chambers 65, the valve opening of the second flow control valve 82 is reduced, so that the operating hydraulic pressure supplied to the retard hydraulic chamber 56 of the intake-side actuator 20 is on the exhaust side. The operating hydraulic pressure supplied to the advance hydraulic chamber 65 of the actuator 22 increases. For this reason, the advance angle speed of the exhaust-side actuator 22
And the delay of the advance angle of the exhaust-side actuator 22 caused by the cam load can be eliminated.

According to the second embodiment described above, the OC
From V40, the advance hydraulic chamber 55 of the intake side actuator 20
And a first flow control valve 81 in a first oil passage 73 which is a hydraulic oil supply system to the retard hydraulic chamber 66 of the exhaust side actuator 22.
And a second flow control valve 82 in a second oil passage 74 which is a hydraulic oil supply system from the OCV 40 to the retard hydraulic chamber 56 of the intake-side actuator 20 and the advance hydraulic chamber 65 of the exhaust-side actuator 22. Since the first and second flow control valves 81 and 82 are controlled to open and close by a control signal from the ECU 100, the flow control valves 81 and 82 can be controlled to open and close according to the operating condition of the engine 1. Thus, for example, during high-speed operation of the engine 1, the operation of the intake-side actuator 20 can be stopped and only the exhaust-side actuator 22 can be operated alone, thereby improving the engine output. Further, by controlling the valve opening of the flow control valves 81 and 82, the hydraulic oil supply flow rate from the OCV 40 to the intake side actuator 20 and the hydraulic oil supply flow rate to the exhaust side actuator 22 are variably controlled. In addition, the operating speed of the exhaust-side actuator 22 can be variably controlled, whereby the delay of the advance angle speed of the exhaust-side actuator 22 caused by the cam load can be eliminated.

By variably controlling the valve opening of the first and second flow control valves 81 and 82 described in the second embodiment, the operating speeds of the intake-side actuator 20 and the exhaust-side actuator 22 can be varied. The variable speed means may include the advanced hydraulic chamber 55 and the retard hydraulic pressure of the intake-side actuator 20 in addition to the first and second flow control valves 81 and 82 according to the second embodiment. As means for making the fluid resistance of the working oil supplied to the chamber 56 larger than the fluid resistance of the working oil supplied to the advance hydraulic chamber 65 and the retard hydraulic chamber 66 of the exhaust-side actuator 22, the first oil passage 73 and the second oil path A fluid resistance variable section may be provided on at least one of the oil passages 74.

One of the fluid resistance variable portions is provided between the intake-side advance oil passage 73a and the exhaust-side retard oil passage 73b in the first oil passage 73 and / or the intake air in the second oil passage 74 in FIG. It comprises a throttle (not shown) such as an orifice provided between the side retard oil passage 74a and the exhaust side advance oil passage 74b. Thus, by providing the throttle portion such as the orifice in the first oil passage 73 and / or the second oil passage 74, the advanced hydraulic chamber 55 of the intake-side actuator 20 and the exhaust oil from the OCV 40 through the first oil passage 73 are provided. When hydraulic oil is supplied to the retard hydraulic chamber 66 of the side actuator 22, the flow rate of hydraulic oil flowing through the first oil passage 73 and flowing to the intake-side advance oil passage 73 a (advance hydraulic chamber 55) is reduced by the aforementioned flow rate. By being throttled by a throttle unit such as an orifice, the operating oil pressure supplied to the retard hydraulic chamber 66 becomes larger than the operating oil pressure supplied to the advanced hydraulic chamber 55. For this reason, the retardation speed of the exhaust-side actuator 22 becomes faster than the advancement speed of the intake-side actuator 20.
The combustion gas can be prevented from flowing backward from the intake passage 15 to the intake passage 15, and the engine output can be improved. In addition, from the OCV 40 to the second oil passage 7
4 and the retard hydraulic chamber 56 of the intake side actuator 20
Also, when hydraulic oil is supplied to the exhaust-side actuator 22 and the advancing hydraulic chamber 65 of the exhaust-side actuator 22, the hydraulic oil flows through the second oil passage 74 to the intake-side retarded oil passage 74a (the retarded hydraulic chamber 56). When the flow rate of the oil is reduced by the throttle section, the operating oil pressure supplied to the advance hydraulic chamber 65 becomes larger than the operating oil pressure supplied to the retard hydraulic chamber 56, and the retard of the intake-side actuator 20 is retarded. Since the advance angle speed of the exhaust-side actuator 22 becomes faster than the angular speed, in this case, it is possible to prevent a delay in the advance angle speed of the exhaust-side actuator 22 due to the cam load.

Another one of the fluid resistance variable units is as follows.
In the first oil passage 73 and the second oil passage 74 in FIG.
V40 to the intake side actuator 20 and O
The length from the CV 40 to the exhaust-side actuator 22 is different. To describe a specific example, in FIG. 2, the first oil passage 73 is provided between the OCV 40 and the retard hydraulic pressure of the exhaust-side actuator 22 as compared with the hydraulic oil supply stroke from the OCV 40 to the advance hydraulic chamber 55 of the intake-side actuator 20. The hydraulic oil supply stroke up to the chamber 66 is short, and even in the second oil passage 74, similarly, compared to the hydraulic oil supply stroke from the OCV 40 to the retard hydraulic chamber 56 of the intake-side actuator 20. Thus, the working oil supply stroke from the OCV 40 to the advance hydraulic chamber 55 of the exhaust side actuator 22 is shortened. As described above, if the hydraulic oil supply process from the OCV 40 to the exhaust-side actuator 22 is set shorter than the hydraulic oil supply process from the OCV 40 to the intake-side actuator 20, the hydraulic oil from the OCV 40 becomes smaller than the intake-side actuator 20. By being supplied earlier to the exhaust-side actuator 22, the advance or retard speed of the exhaust-side actuator 22 can be made faster than the retard or advance speed of the intake-side actuator 20. Therefore, it is possible to improve the engine output and prevent the backflow of the combustion gas from the combustion chamber 8 to the intake passage 15 at the time of high-speed operation of the engine, thereby preventing the engine output from decreasing.

Further, another one of the fluid resistance variable sections is compared with an oil passage cross-sectional area from the OCV 40 in the first oil passage 73 in FIG. 2 to a branch portion of the exhaust-side retard oil passage 73b.
The oil passage cross-sectional area before the branch portion (on the intake side advance oil passage 73a side) is set to be small, and similarly, from the OCV 40 in the second oil passage 74 to the branch portion of the exhaust side advance oil passage 74b. The cross-sectional area of the oil passage from the branch portion to the intake-side retarded oil passage 74a is set smaller than the cross-sectional area of the oil passage. Thus, by setting the oil passage cross-sectional area on the intake side actuator 20 side smaller than the oil passage cross-sectional area from the OCV 40 to the exhaust side actuator 22 in the first oil passage 73 and the second oil passage 74, the OCV 40 The flow resistance of the hydraulic oil supplied to the intake-side actuator 20 is larger than the flow resistance of the hydraulic oil supplied to the exhaust-side actuator 22 from the valve. Therefore, in this case, the exhaust-side actuator 22 operates earlier than the intake-side actuator 20, thereby improving the engine output and preventing the backflow of the combustion gas from the combustion chamber 8 to the intake passage 15 during high-speed operation of the engine. Thus, it is possible to prevent the engine output from lowering.

[0048]

As described above, according to the present invention, one oil control valve is provided in the hydraulic passage between the intake valve variable actuator and the exhaust valve variable actuator and the oil pump. A single oil control valve controls the supply of hydraulic oil to the variable intake valve timing actuator and variable exhaust valve timing actuator, so a single oil control valve controls both the variable intake valve timing actuator and the variable exhaust valve timing actuator simultaneously. Therefore, the oil passage configuration of the hydraulic oil control system connecting one oil control valve and the two actuators can be simplified, the restriction on the mounting space can be eased, and the system cost can be reduced. There is an effect that can be achieved.

According to the present invention, the advance hydraulic chamber of the variable intake valve timing actuator and the retard hydraulic chamber of the variable exhaust valve timing actuator are connected to the oil control valve by communicating with the common first oil passage. The retard hydraulic chamber of the variable intake valve timing actuator and the advanced hydraulic chamber of the exhaust valve timing variable actuator are connected to the oil control valve through a common second hydraulic passage, and are connected to the oil control valve. Since the flow control valve is provided on at least one of the oil passages,
By controlling the opening and closing of the flow control valve, one oil control valve can simultaneously control both the intake and exhaust valve timing variable actuators and independently control only the intake or exhaust valve timing variable actuators according to the operating condition of the engine. There is also an effect that you can also. It is also possible to control the valve opening of the flow control valve in accordance with the operating condition of the engine, and the valve opening control controls the operation speed of the intake valve variable actuator and the exhaust valve variable actuator. Variably controlled, thereby preventing a decrease in engine output due to a rapid opening of the intake valve during high-speed operation of the engine, and eliminating a delay in the advancement speed of the variable exhaust valve timing actuator due to a cam load. Has the effect.

According to the present invention, the advance hydraulic chamber of the variable intake valve timing actuator and the retard hydraulic chamber of the variable exhaust valve timing actuator are connected to the oil control valve through a common first oil passage. The retard hydraulic chamber of the variable intake valve timing actuator and the advanced hydraulic chamber of the exhaust valve timing variable actuator are connected to the oil control valve through a common second hydraulic passage, and are connected to the oil control valve. At least one of the oil passages is provided with a fluid resistance variable portion that is set so that the flow resistance of the hydraulic oil is different between the first oil passage and the second oil passage. Variable hydraulic oil flow supplied from the oil control valve to the variable intake valve timing actuator and variable exhaust valve timing Due to the difference in the hydraulic oil flow supplied to the actuator, for example, the operating speed of the exhaust valve timing variable actuator can be increased as compared to the operating speed of the intake valve timing variable actuator. The engine output can be prevented from lowering due to the early opening, and the delay of the advance angle speed of the exhaust valve timing variable actuator caused by the cam load can be eliminated.

According to the present invention, the throttle for reducing the flow rate of the hydraulic oil is provided in the oil passage between the variable intake valve timing actuator and the variable exhaust valve timing actuator in at least one of the first oil passage and the second oil passage. The variable throttle valve portion allows the flow rate of hydraulic oil supplied to the variable intake valve timing actuator and the variable hydraulic oil flow supplied to the variable exhaust valve timing actuator to differ from each other. The operating speed of the exhaust valve timing actuator and the operating speed of the exhaust valve timing actuator can be varied, thereby preventing a decrease in engine output due to the early opening of the intake valve during high-speed operation of the engine. Eliminates delay in advance speed There is any effect.

According to this invention, the oil path length from the oil control valve to the intake valve timing variable actuator in at least one of the first oil path and the second oil path, and the oil path from the oil control valve to the exhaust valve timing variable actuator. Because the path length is different, the hydraulic oil flow supplied from the oil control valve to the variable intake valve timing actuator and the hydraulic oil flow supplied from the oil control valve to the variable exhaust valve timing actuator differ. The valve timing and the exhaust valve timing can be variably controlled, so that the engine output can be prevented from lowering due to the early opening of the intake valve during high-speed operation of the engine, and the exhaust valve timing variable actuator caused by the cam load can be prevented. There is an effect, such as can be eliminated the delay of the advance speed of data.

According to the present invention, the cross-sectional area of the oil passage in at least one of the first oil passage and the second oil passage from the oil control valve to the intake valve timing variable actuator, and the oil passage cross-sectional area from the oil control valve to the exhaust valve timing variable actuator. Since the cross-sectional area of the oil passage is different, the hydraulic oil flow supplied from the oil control valve to the variable intake valve timing actuator differs from the hydraulic oil flow supplied from the oil control valve to the variable exhaust valve timing actuator. In addition, the intake valve timing and the exhaust valve timing can be variably controlled, so that the engine output can be prevented from lowering due to the early opening of the intake valve during high-speed operation of the engine. There is an effect, such as can be eliminated the delay of the advance speed of over data.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a gasoline engine system including a variable valve timing control device for an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is a configuration explanatory view showing a variable valve timing control device for an internal combustion engine in FIG. 1;

FIG. 3 is a table showing a relationship between an engine speed and a torque based on an experimental result of a gasoline engine system including the variable valve timing control device for an internal combustion engine according to the first embodiment of the present invention.

4 is a table showing the effect ratios on torque, THC, and NOx of experimental results obtained by operating the variable valve timing control apparatus for an internal combustion engine shown in FIG. 2;

FIG. 5 is a configuration explanatory view showing a variable valve timing control device for an internal combustion engine according to a second embodiment of the present invention.

[Explanation of symbols]

1 engine, 17 intake valve, 18 exhaust valve,
19 intake side camshaft, 20 intake valve timing variable actuator, 21 exhaust side camshaft, 2
2 Exhaust valve timing variable actuator, 40
OCV (oil control valve), 71 oil pump, 73 first oil passage, 74 second oil passage, 81, 82
Flow control valve.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 13/02 F02D 13/02 G F-term (Reference) 3G013 AA06 AA07 BC26 CA05 EA03 3G015 AA06 AA07 CA04 CA12 CA19 FA02 3G016 AA02 AA08 AA12 AA19 BA22 BA28 CA24 CA33 CA36 CA37 CA46 CA48 DA05 DA06 DA22 DA27 GA00 3G065 AA04 DA04 GA00 GA05 GA09 GA10 GA41 KA33 3G092 AA11 DA03 FA09 GA05 GA06 GA16 HA01Z HA06Z HA13X HA13Z HE01Z HE03Z

Claims (6)

[Claims] 1. An intake valve timing variable actuator which is provided on each of an intake camshaft and an exhaust camshaft whose rotational drive is controlled in synchronization with rotation of an engine, and controls opening / closing timing of an intake valve and an exhaust valve of the engine. And an exhaust valve timing variable actuator, and a hydraulic passage connecting the intake valve timing variable actuator and the exhaust valve timing variable actuator, and an oil pump supplying hydraulic oil to the intake valve timing variable actuator and the exhaust valve timing variable actuator. A single oil control valve provided, and the electronic control unit switches and controls the oil control valve in accordance with the operating state of the engine to operate the oil pump. Hydraulic oil is supplied to the advance hydraulic chamber of the intake valve variable actuator and the retard hydraulic chamber of the exhaust valve variable actuator, or the retard hydraulic chamber of the variable intake valve actuator and the exhaust valve variable. A variable valve timing control device for an internal combustion engine, wherein the variable valve timing control device is supplied to an advanced hydraulic chamber of an actuator so as to simultaneously operate the variable intake valve timing actuator and the variable exhaust valve timing actuator. 2. An advanced hydraulic chamber of an intake valve timing variable actuator and a retard hydraulic chamber of an exhaust valve timing variable actuator are connected to a common first oil passage to be connected to an oil control valve, and the intake valve timing is variable. The retard hydraulic chamber of the actuator and the advance hydraulic chamber of the exhaust valve timing variable actuator communicate with a common second oil passage and are connected to the oil control valve. At least one of the first oil passage and the second oil passage The variable valve timing control apparatus for an internal combustion engine according to claim 1, wherein a flow control valve is provided on one side. 3. An advanced hydraulic chamber of an intake valve timing variable actuator and a retard hydraulic chamber of an exhaust valve timing variable actuator are connected to a common first oil passage and connected to an oil control valve. The retard hydraulic chamber of the actuator and the advance hydraulic chamber of the exhaust valve timing variable actuator communicate with a common second oil passage and are connected to the oil control valve. At least one of the first oil passage and the second oil passage On the other hand,
2. The variable valve timing control device for an internal combustion engine according to claim 1, wherein a fluid resistance variable section is provided such that the flow resistance of the hydraulic oil is different between the first oil passage and the second oil passage. 4. A variable fluid resistance section is provided between the intake valve timing variable actuator and the exhaust valve timing variable actuator in at least one of the first oil path and the second oil path, and controls the flow rate of the hydraulic oil. 4. The variable valve timing control apparatus for an internal combustion engine according to claim 3, further comprising a throttle section for narrowing down. 5. The variable fluid resistance unit includes: an oil path length from an oil control valve to an intake valve timing variable actuator in at least one of a first oil path and a second oil path; and an oil path length from an oil control valve to an exhaust valve timing variable actuator. 4. The variable valve timing control apparatus for an internal combustion engine according to claim 3, wherein the oil passage lengths of the internal combustion engine and the internal combustion engine are different. 6. The variable fluid resistance unit includes an oil passage cross-sectional area from at least one of a first oil passage and a second oil passage from an oil control valve to an intake valve timing variable actuator, and an oil control valve to an exhaust valve timing variable actuator. 4. The variable valve timing control apparatus for an internal combustion engine according to claim 3, wherein the variable cross-sectional area is different from that of the oil passage.