JP2001329812A - Variable valve system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce driving noise in a variable valve system in starting an engine. SOLUTION: In this variable valve system, an operating fluid passage among a timing advance oil chamber 47, a timing a lag oil chamber 48 and an oil pump is changed over by an oil control valve 50, whereby the operating fluid is supplied from the oil pump to the timing advance oil chamber or the timing lag oil chamber through a check valve 63a provided on the downstream side of the oil pump and the upstream side of the oil control valve, and the operating fluid is discharged from the other oil chamber. In starting the engine, the operating fluid passage is changed over to supply the operating fluid to the timing lag oil chamber to contain the operating fluid in the operating fluid passage on the downstream side of the check valve or the lag oil chamber, thereby preventing driving noise due to collision between a vane 44 and a vane housing 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve operating device that changes the rotational phase of a camshaft relative to a crankshaft of an engine, and more particularly to a variable valve operating device that can reduce operating noise when starting an engine.

[0002]

2. Related Art A variable valve operating device is provided between a crankshaft and a camshaft of an engine to change the rotational phase of both shafts to variably adjust a valve overlapping period between an intake valve and an exhaust valve. It has been known. For example, an intake / exhaust valve drive control device described in Japanese Patent Application Laid-Open No. H11-153011 controls a control mechanism provided between a crankshaft and a camshaft to concentrically or eccentrically under the control of an operating mechanism. By changing the relative angular velocity of the crankshaft and the camshaft, a rotational phase difference is given to both shafts to control the operating angle of the intake valve. For this operating angle control, the operating mechanism includes a proportional solenoid type electromagnetic actuator and a controller for controlling the same, and switches the operating position of the switching valve and eventually the flow path of the hydraulic circuit by the electromagnetic actuator according to the engine operating state, Further, the rotational position of the control mechanism is controlled by a hydraulic cylinder that responds to a hydraulic pressure supplied from a hydraulic circuit.

[0003] In the above-described type of variable valve operating system, when the engine is restarted in a state where hydraulic oil leaks from the pressure receiving chamber of the hydraulic cylinder with the stop of the engine operation, the spring of the intake valve is applied to the cam of the camshaft. Positive and negative reaction forces may be transmitted to the piston of the hydraulic cylinder, causing the piston to slide violently in the hydraulic cylinder and generate operating noise.
In order to suppress such operation noise, in the above-described conventional device,
The drain passage of the hydraulic cylinder is located above the pressure receiving chamber, a check valve is provided in the hydraulic pressure supply path to prevent backflow of hydraulic oil, and all flow paths of the hydraulic circuit are switched by a switching valve when the engine is started. The electromagnetic actuator is controlled to be closed.

[0004] In the above-mentioned conventional apparatus, in a rotation position control of a control mechanism for controlling a rotation phase difference between a crankshaft and a camshaft, if an actual rotation phase difference deviates from a target value, an electromagnetic actuator is changed to a duty ratio. Drive at 0% or 100% to supply hydraulic pressure to one of the pressure receiving chambers of the hydraulic cylinder, and if the deviation is small, set the duty ratio to 50% to cut off the hydraulic pressure supply to both pressure receiving chambers. It has become something.

[0005]

The electromagnetic actuator is driven at a duty ratio of 50% even when all the flow paths are closed in order to suppress the operation noise at the time of starting the engine, so that the valve body of the switching valve is neutralized. To keep it in position. As described above, the conventional device is configured on the assumption that the switching valve can be held at the neutral position by setting the duty ratio to 50%.

However, when the duty ratio of the electromagnetic actuator is controlled in an open loop, it is actually difficult to accurately control the switching valve position by the duty control. That is, since the electromagnetic actuator and the switching valve have individual differences and change over time, it is necessary to accurately correspond to the neutral position of the switching valve in order to hold the switching valve in the neutral position when starting the engine and suppress the operation noise. It is necessary to determine the drive duty ratio of the electromagnetic actuator.

For this reason, generally, learning is performed to obtain the drive duty ratio of the electromagnetic actuator in a state where the actual phase difference is settled to the target phase difference during the rotational phase difference control as the duty ratio corresponding to the neutral position of the switching valve. At the time of starting the engine, the electromagnetic actuator is driven at the duty ratio thus learned to maintain the switching valve at the neutral position. However, in order to eliminate the deviation of the learning duty ratio from the appropriate value due to the aging of the electromagnetic actuator or the like, the learning needs to be performed periodically, which is complicated. In addition, even if learning is performed periodically, there may be a deviation in the duty ratio until learning is completed,
Operation noise may be generated.

Further, in the above-mentioned conventional apparatus, the check valve is provided in the hydraulic pressure supply path to prevent oil leakage while the drain passage is disposed above the pressure receiving chamber to prevent oil leakage during a long-term stop. ing. However, if the drain passage cannot be located above the pressure receiving chamber due to engine layout restrictions, or if the neutral position of the switching valve is shifted, oil in the hydraulic oil chamber may leak, and there is still room for improvement. .

Now, as a variable valve operating device whose operation principle is basically the same as that of the above-mentioned conventional device, there is provided a rotating member capable of rotating synchronously with a crankshaft, for example, a housing member provided integrally with a pulley, and a camshaft. 2. Description of the Related Art A hydraulic vane-type variable valve apparatus including a vane member rotatably provided with a vane member is known. In this device, rotation of a camshaft with respect to a crankshaft is performed by supplying and discharging hydraulic oil to a retard oil chamber and an advance oil chamber formed between a vane of a vane member and a housing member that accommodates the vane. It changes the phase.

[0010] Even in such a vane-type variable valve apparatus, the vane easily swings largely in the housing when the engine is started, which is a factor of generating operation noise. That is, generally, immediately after the engine is started, the hydraulic oil flow path is switched to the advanced side so as to advance the variable valve operating device. Is not sufficiently supplied. On the other hand, the valve spring of the intake valve or the exhaust valve acts in a direction that hinders rotation of the camshaft when the valve is opened, and acts in a direction that encourages rotation of the camshaft when the valve is closed. That is, the vane directly connected to the camshaft receives the reaction force of the valve spring in the retard direction before going over the cam hill, and receives the spring reaction force in the advance direction after going over the cam hill. For this reason, the vane moves to the advance side (retard oil chamber side) in the housing immediately after climbing over the cam hill, and the hydraulic oil in the retard oil chamber connected to the drain passage is discharged (see FIG. 4). . Immediately before going over the next cam mountain, the vane moves to the retard side (advancing oil chamber side) while sucking the air in the drain passage into the retard oil chamber, but the amount of hydraulic oil in the advance oil chamber is reduced. Due to the small number, the vane may move greatly and collide with the housing to generate abnormal noise (FIG. 5
See).

In the vane type variable valve apparatus, when the switching valve position is controlled by using an electromagnetic actuator when supplying and discharging hydraulic oil, the switching valve is held at a neutral position as described in Japanese Patent Application Laid-Open No. 11-153011. It is conceivable to prevent the supply and discharge of hydraulic oil by controlling the duty of the electromagnetic actuator to suppress operating noise.In this case, as described above, it is not only necessary to learn the duty ratio, Until the learning is completed, the generation of driving noise cannot be prevented.

It is an object of the present invention to provide a vane control system for controlling the switching valve position using an electromagnetic actuator whose duty is controlled without learning the duty ratio corresponding to the neutral position of the switching valve. It is an object of the present invention to provide a variable valve actuation device capable of preventing the generation of operation noise due to the striking sound.

[0013]

According to a first aspect of the present invention, there is provided a variable valve operating apparatus, comprising: a hydraulic oil supply means provided between an advance oil chamber and a retard oil chamber defined by a vane member and a housing member; The hydraulic oil flow path is switched by the switching means, and the hydraulic oil supply means is connected to the advance oil chamber or the retard oil chamber via a check valve provided downstream of the hydraulic oil supply means and upstream of the switching means. Hydraulic oil is supplied to one of the oil chambers, and the hydraulic oil is discharged from the other oil chamber. Rotation of a crankshaft to which one of the vane member and the housing member is connected and a camshaft to which the other member is connected. The phase changes. And
When the engine is started, the hydraulic oil flow path is switched so that the hydraulic oil is supplied to the retard oil chamber.

Preferably, for example, when the engine speed reaches the advance switching speed and the pressure of the operating oil supplied from the operating oil supply means reaches the advance switching pressure, the hydraulic oil is supplied to the advance oil chamber. The hydraulic oil flow path is switched by the switching means so that the supply is performed. The advance switching pressure, for example, the advance switching speed, is set to a higher value as the parameter representing the operating oil temperature, for example, the engine water temperature is higher. Further, the switching means includes:
Immediately before the engine operation is stopped, the hydraulic oil flow path is switched so that hydraulic oil is supplied to the retard oil chamber. The switching means may include an electromagnetic actuator whose duty is controlled, and a switching valve having a valve element such as a spool that is drivingly connected to the electromagnetic actuator.

According to the variable valve operating device of the present invention, at the time of starting the engine, the hydraulic oil flow path is switched so that the hydraulic oil is supplied to the retard oil chamber. After the engine is started, while the hydraulic pressure on the hydraulic oil supply means side is lower than that on the retard oil chamber side in the hydraulic oil flow path, the communication between the hydraulic oil supply means and the switching means is shut off by the check valve. You. Therefore, while the operating oil from the operating oil supply means is at a low pressure, the operating oil is confined in the operating oil flow path or the retard oil chamber downstream of the check valve. For this reason, when the camshaft takes the rotation position just before climbing over the cam hill and receives the spring reaction force in the retard direction with the rotation of the engine, the vane member is generally at the most retarded position, and moves in the retard direction. do not do. Immediately after climbing over the cam hill, a spring reaction force in the advance direction is applied to the camshaft, but since the communication between the retard oil chamber and the drain passage is interrupted, the hydraulic oil is not discharged from the retard oil chamber. The movement of the vane member in the advance direction (toward the retard oil chamber) is hindered by the hydraulic oil in the retard oil chamber.

Particularly, in a preferred embodiment in which the hydraulic oil flow path is switched so that the hydraulic oil is supplied to the retard oil chamber immediately before the engine operation is stopped, the hydraulic oil is retarded from the time the engine is stopped until the time the engine is restarted. Since the engine is confined in the oil chamber and the working oil flow path around the oil chamber, the operation noise at the time of restarting the engine is reliably suppressed. As described above, according to the present invention, the hydraulic oil is confined in the hydraulic chamber and the surrounding hydraulic oil flow path by a simple method of switching the hydraulic oil flow path to the retarded oil chamber side at the time of starting the engine, and Function as cushioning material,
The movement of the vane member in the housing member and the collision of the vane member with the housing member are prevented, and the operating noise in the variable valve gear at the time of starting the engine is suppressed. The variable valve train of the present invention is equipped with a vehicle in which the engine is frequently started and stopped during vehicle operation, for example, a traveling motor is mounted and a traveling engine or a power generating engine for charging a battery is mounted. It is particularly suitable for a hybrid vehicle.

In a preferred embodiment of the present invention, for example, when the engine speed reaches the advance switching speed, it is determined that the hydraulic oil pressure has reached the advance switching pressure, and the hydraulic oil flow path is advanced from the retard oil chamber side. The valve is switched to the square oil chamber side, whereby the variable valve gear is advanced, for example, to increase the engine output.
When the hydraulic pressure reaches the advance switching pressure in this way, the vane member and the housing member can be firmly connected via the hydraulic oil, and the vane member does not move undesirably in the housing member. In other words, the hydraulic oil flow path is maintained on the retard side until the advance switching pressure is reached, thereby preventing the movement of the vane member.

In a preferred embodiment of the present invention, the higher the temperature parameter value is, the higher the advance switching pressure, for example, the advance switching speed is set. In this case, the start timing of the advance operation of the variable valve operating device at the time of starting the engine depends on the temperature parameter value. In other words, when the temperature parameter value is low and the hydraulic oil viscosity is high, and therefore the hydraulic oil buffering function is high, noise is generated due to the movement and collision of the vane member even if the retard operation is released earlier. Is less likely to
The advance operation is started earlier. On the other hand, when the temperature parameter value is high and the hydraulic oil viscosity is low, the release of the retarding operation holding is delayed to prevent the operation noise due to the movement of the vane member.

The present invention is applicable to a variable valve actuating device provided with a switching means for switching the valve element position of a switching valve by an electromagnetic actuator whose duty is controlled. In this type of apparatus, in order to accurately maintain the valve body in the neutral position so as to shut off the supply and discharge of hydraulic oil to and from the oil chamber in order to reduce operating noise when starting the engine, it is necessary to drive an electromagnetic actuator corresponding to the valve body neutral position. Although it is necessary to learn the duty ratio and the operation noise is generated until the learning is completed, when the present invention is applied to this type of variable valve operating device, the valve body takes the retarded position when the engine is started. In addition, there is no need to learn the duty ratio for maintaining the valve element at the neutral position, and the switching valve control is simplified as a whole.

Further, the switching valve can be configured so as to take a valve body position that enables communication between the hydraulic oil supply means and the retard oil chamber when the electromagnetic actuator is not energized (drive duty ratio is 0%). In this case, the hydraulic oil is confined in the retard oil chamber and the hydraulic oil flow path therearound even during parking, for example, when the energization control of the electromagnetic actuator is not performed, and operating noise at the time of starting the engine after restarting vehicle operation is prevented. You.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a variable valve operating device according to an embodiment of the present invention will be described with reference to the drawings. The variable valve train of the present embodiment is a hydraulic vane type, for example, a series type hybrid vehicle equipped with a motor and an engine as a driving source for driving and a parallel type hybrid vehicle equipped with a power generating engine together with a driving motor. Will be installed. Since this type of hybrid vehicle is conventionally known and is not directly related to the present invention, the description thereof is omitted. The basic configuration of the hydraulic vane type variable valve apparatus is conventionally known, and a detailed description thereof will be omitted below.

The variable valve apparatus according to the present embodiment is variably controlled in a phase of an opening period of an intake valve with respect to crankshaft rotation, which is attached to a camshaft on an intake side of an engine. However, the variable valve apparatus can be arranged on both the exhaust side and the intake / exhaust side of the engine. The engine equipped with the variable valve gear includes an intake-side camshaft 10 rotatably supported by a cam journal (not shown), and a cam formed on the camshaft contacts an intake valve via a rocker arm. It has become something. The crankshaft (not shown) of the engine is provided with a toothed belt 20.
is connected to the cam pulley 20 on the intake side via a.
The cam pulley 20 includes a disk-shaped main body and a toothed belt 2.
0a and a toothed flange that meshes therewith. FIG. 1 shows only the peripheral wall portion of the cam pulley main body.

The variable valve apparatus has a vane housing 30 rotatable integrally with the cam pulley 20, and a vane rotor (vane member) 40 fixed to an end face of the camshaft 10 and rotatable integrally with the camshaft. . The vane rotor 40 has, for example, four vanes 44 provided on a peripheral surface of a cylindrical main body. Vane housing 30
Has a housing body having the same number of partitions as the number of vanes, and a housing end wall fixed to the housing body.
FIG. 1 shows only the partition wall of the housing body. The housing main body forms a housing member together with the housing end wall and the cam pulley, and also defines a vane housing chamber for housing the vane 44. The vane storage chamber is divided by a vane 44 into an advance oil chamber 47 and a retard oil chamber 48.

Next, the supply and discharge of pressure oil to and from the oil chambers 47 and 48 will be described. As shown in FIG. 1, the oil control valve (OCV) 50 includes a spool 50a. One end of the spool 50a is constantly urged to the retard side by a spring 50b, and the other end is electromagnetically driven by an electromagnetic solenoid 50c. Are combined. Therefore, when the electromagnetic solenoid 50c is in a non-energized state (in the present embodiment, when driven at a drive duty ratio of 0%), the spool 50a assumes the retard position shown in FIG. When the electromagnetic solenoid 50c is in the energized state (drive duty ratio 100%), the spool 50a takes the advanced position against the urging force of the spring 50b.

The OCV 50 is, for example, driven by an engine and pressurizes oil from an oil tank by driving first and second outlet ports respectively connected to an advance oil passage 15a and a retard oil passage 15b formed in a cam journal. It has an inlet port connected to an oil supply pipe 63 communicating with an oil pump (not shown), and first and second drain ports connected to a return pipe. As viewed in the longitudinal direction of the spool 50a, the inlet port is provided between the first and second outlet ports, and the drain port is provided outside the outlet port. The spool 50a is provided with two lands at substantially the same intervals as the first and second outlet ports.

The oil supply pipe 63 constitutes a working oil supply means together with an oil pump. The oil supply pipe 63 is formed in the advance oil passage 15a, the retard oil passage 15b, the camshaft 10, the vane rotor 40 and the like, and both oil passages 15a, A hydraulic oil passage is formed together with other oil passages (not shown) for communicating the oil passage 15b with the advance oil chamber 47 and the retard oil chamber 48. The oil supply pipe 63 is provided with a check valve 63a.

When the spool 50a takes the retarded position due to the deenergization of the electromagnetic solenoid 50c, the inlet port communicates with the first outlet port, and the communication between the first outlet port and the first drain port is interrupted. The second outlet port and the second drain port communicate with each other, so that hydraulic oil from the oil pump can be supplied to the retard oil chamber 48. On the other hand, the electromagnetic solenoid 5
When the power is supplied to the spool 50a and the spool 50a assumes the advanced position, the inlet port communicates with the second outlet port, the first outlet port communicates with the first drain port, and the second outlet port communicates with the second outlet port. The communication with the second drain port is cut off, and the supply of the pressurized oil to the advance oil chamber 47 is performed.

In the present embodiment, the energization time to the electromagnetic solenoid 50c of the OCV 50 is duty-controlled by the controller 80 to obtain a desired cam phase. The controller 80 incorporates, for example, an engine speed / duty ratio map, reads a duty ratio corresponding to the engine speed detected by the engine speed sensor 81 from this map, and performs duty control. When the engine is started, the variable valve operating device is operated at the most retarded angle under the control of the controller 80, and when the engine speed exceeds the advanced angle switching judgment rotational speed, the variable angle device is advanced from the most retarded position.

In this embodiment, the advance switching speed is set to a low speed as the engine coolant temperature decreases, and when the viscosity of the hydraulic oil is large, the timing of releasing the most retarding operation is advanced. In connection with the phase control when starting the engine,
An engine water temperature sensor 82 is connected to the controller 80, and an engine water temperature / advance angle switching determination rotation speed map is stored in a memory (not shown) of the controller 80.

Hereinafter, the operation of the variable valve apparatus according to the present embodiment will be described with reference to FIG. The controller 80 of the variable valve apparatus periodically executes a control routine shown in FIG. 2 when its operating power is turned on. In this control routine, it is determined whether or not the ignition key is at the ON position (step S1). If the result of this determination is negative, the control processing in the current control cycle is ended.

On the other hand, if the ignition key is turned on in step S1, the output of the engine coolant temperature sensor 82 is read (step S2), and then it is determined whether or not the engine has been started (step S3). If the engine has not been started, that is, if the engine is stopped, the controller 80 performs the most retarding control so as to cause the variable valve device to perform the most retarding operation (step S7).

In this most retarded control, the drive duty ratio of the electromagnetic solenoid 50c of the OCV 50 is set to 0%,
The electromagnetic solenoid 50c is driven at the duty ratio of 0%. That is, the electromagnetic solenoid 50c is deenergized.
As a result, the spool 50a of the OCV 50 assumes the retard position shown in FIG. While the engine is stopped, the supply of pressure oil from the oil pump is not performed.

In the present embodiment, the duty ratio is set to, for example, 0% in order to control the cam phase to the most retarded position in order to stabilize the engine rotation by performing the engine operation in the extremely low speed range immediately before the engine operation is stopped. From the oil pump via the OCV 50 at the retard position.
Pressure oil. While the engine is stopped, the most retarded control is performed in step S7. For this reason,
After the engine stops, the pressure oil supplied until immediately before the engine stops is confined in the hydraulic oil flow path or the retard oil chamber 48 on the downstream side of the check valve 63a as shown in FIG.
In FIG. 3, dark shaded portions indicate a hydraulic oil flow path and a retarded oil path 15b and a retarded angle inside the OCV defined by a sleeve of the OCV 50 and two lands of the spool 50a downstream of the check valve 63a. The hydraulic oil in the oil chamber 48 is shown, and a thin hatched portion is the first oil from the advance oil passage 15a.
Represents air in the hydraulic oil flow path to the outlet port.

When the engine is started with the ignition key turned on, for example, to start accelerating the hybrid vehicle, the start of the engine is determined in step S3 of the control cycle immediately after that. The advance switching speed is determined from an engine water temperature / advance switching speed map (not shown) based on the engine water temperature read in step S2 of the control cycle (step S4).
It is determined whether or not the engine speed read from the engine speed sensor 81 exceeds the advance switching speed (step S5). If the result of this determination is negative, that is, if the advance switching speed has not been reached, In step S7, the most retarded angle control is performed. At this time, unlike when the engine is stopped, pressure oil is supplied from the oil pump. However, since the check valve 63a is provided between the oil pump and the retard oil chamber 48, the pressure supplied from the oil pump is reduced. While the pressure of the oil is lower than the pressure of the pressure oil confined in the downstream side of the check valve 63a or in the retard oil chamber 48, the pressure oil from the hydraulic pump is
does not flow downstream of a. That is, by providing the check valve 63a, the backflow of the pressure oil due to the operation supply of the low oil pressure as well as the stop is prevented.

In such a situation, when the hydraulic oil flow path is switched to the advance side in order to advance the variable valve operating device, the vane 44 moves in the advance side (retard angle) in the housing 30 immediately after passing over the cam hill. (The oil chamber 48 side) and the hydraulic oil in the retard oil chamber 48 (shown with dark hatching in FIG. 4) is discharged to the drain passage, and the air in the drain passage is immediately before passing over the next cam mountain. (Shown with thin hatching in FIG. 5)
The vane 44 is sucked in and the vane 44
Side) and may collide with the housing 30.

On the other hand, in the variable valve apparatus of the present embodiment, as described above, the hydraulic oil supplied from the oil pump during the stop of the engine and after the start of the engine is such that the hydraulic oil is supplied to the retard oil chamber 48 side. While the pressure is lower than the operating pressure, the hydraulic oil is supplied to the hydraulic oil flow path or the retarded oil chamber 4 downstream of the check valve 63a.
8 confined. For this reason, when the camshaft 10 assumes the rotational position immediately before climbing over the cam hill and receives the spring reaction force in the retard direction, the vane 44 does not move in the retarding direction, and the camshaft 10 immediately after climbing over the cam hill. When the spring reaction force in the advance direction is applied to the vane 44, the operating oil in the retard oil chamber 48 causes the vane 44 to advance in the advance direction (the retard oil chamber 48).
Side) is obstructed. That is, the hydraulic oil confined in the retard oil chamber 48 and in the hydraulic oil flow path around it functions as a cushioning material, preventing the vane 44 from colliding with the housing 30 and suppressing operating noise.

If it is determined in step S5 of the control routine of FIG. 2 that the engine speed has exceeded the advance switching speed, it is determined that the pressure of the hydraulic oil supplied from the oil pump has reached the advance switching pressure. Then, the advance angle control in which the electromagnetic solenoid 50c is driven at, for example, a duty ratio of 100% is performed (step S6), and the operating oil from the oil pump is returned to the check valve 63
The fluid flows into the advance oil chamber 47 via a or the like, whereby the variable valve apparatus performs the advance operation. At this time, since the hydraulic pressure has reached the advance switching pressure, the vane 44 and the housing 30 are connected via the hydraulic oil, and the vane 44 is
Does not move undesirably.

In this embodiment, as the engine water temperature is higher, the advance switching speed is set to a higher speed, so that the start timing of the advance operation of the variable valve apparatus at the time of engine start is determined by the engine water temperature and, hence, the operating oil. It will be compatible with viscosity. That is, at low engine water temperature, the advance operation is started earlier because the advance switching speed is low, but at low engine water temperature, the viscosity of the hydraulic oil is high and the hydraulic oil buffer function is high, Even if the holding of the retard position of the OCV 50 is released earlier, there is little possibility that noise is generated due to the movement and collision of the vane 44. On the other hand, at a high engine water temperature, the timing of starting the advance operation is delayed because the advance switching speed is high. As a result, the vane 44 easily moves and collides undesirably at a high engine coolant temperature, but this problem can be prevented beforehand by delaying the start of the advance operation.

Further, in this embodiment, since the OCV 50 is held at the retard position when the engine is started to reduce the operating noise, the electromagnetic solenoid 50c which is indispensable in the method of holding the OCV 50 at the neutral position to reduce the operating noise. Learning of the duty ratio is unnecessary, and the OCV control can be simply performed as a whole. Furthermore, in the case of the present embodiment, when the electromagnetic solenoid 50c is not energized (drive duty ratio is 0%),
Since the CV 50 is in the retard position, the electromagnetic solenoid 50c
Hydraulic oil is confined in the retard oil chamber and the surrounding hydraulic oil flow path even during parking, for example, when power is not supplied to the
Driving noise when starting the engine after restarting the vehicle operation is prevented.

Following the OCV control at the time of starting the engine, OCV control for cam phase control is performed. For example, during the operation of the engine, the controller 80 reads the output of the engine speed sensor 81 to detect the current engine speed, and then responds to the engine speed by referring to an engine speed / duty ratio map (not shown). The duty ratio of the power supply to the electromagnetic solenoid 50c of the OCV 50 is controlled based on the duty ratio so that the cam phase matches the engine speed. In this duty control, the energization time (duty ratio) is increased to advance the cam phase in a high rotation range, and the energization time is reduced to delay the cam phase in a low rotation range.

The device of the present invention is not limited to the above embodiment, but can be variously modified. For example, in the above embodiment, the variable valve device mounted on the hybrid vehicle has been described. However, the present invention is also applicable to a variable valve device mounted on a normal vehicle using only the engine as a driving source. is there. Further, the present invention can be suitably used for a variable valve operating device having no lock mechanism for locking the vane to the housing, but the present invention is also applicable to a variable valve operating device having a lock mechanism. It is. The lock mechanism may include a spring that urges the lock pin in the locking direction, or may not include such a spring.

In the above-described embodiment, the description has been given of the four-vane type variable valve apparatus. However, the number of vanes is not limited to four.
Further, details of the device can be variously modified.

[0043]

According to the variable valve operating device of the present invention, the switching means for switching the hydraulic oil flow path between the advance oil chamber and the retard oil chamber defined by the vane member and the housing member and the hydraulic oil supply means. Through a check valve provided downstream of the hydraulic oil supply means and upstream of the switching means to supply hydraulic oil from the hydraulic oil supply means to either the advance oil chamber or the retard oil chamber. Supply and discharge the hydraulic oil from the other oil chamber,
At the start of the engine, the hydraulic oil flow path is switched so that the hydraulic oil is supplied to the retard oil chamber, so when the engine is started, the hydraulic oil is confined in the retard oil chamber and the surrounding hydraulic oil flow path, and the hydraulic oil is It can function as a buffer, so as to prevent the movement of the vane member in the housing member and the collision of the vane member with the housing member, thereby suppressing the operation noise in the variable valve gear at the time of starting the engine.

[Brief description of the drawings]

FIG. 1 is a schematic partial sectional view showing a variable valve operating device according to an embodiment of the present invention.

FIG. 2 is a flowchart of an oil control valve control routine executed by the controller shown in FIG. 1;

3 is a schematic diagram showing a state in which pressure oil is confined in a hydraulic oil flow path or a retard oil chamber downstream of a check valve of the variable valve operating device of FIG. 1 when the engine is started or stopped.

FIG. 4 is a schematic diagram showing vane movement at the time of climbing over a cam hill immediately after engine start in a conventional variable valve apparatus.

FIG. 5 is a schematic view showing a collision between a vane and a housing immediately before the vehicle climbs over a cam mountain in a conventional apparatus.

[Explanation of symbols]

 Reference Signs List 10 camshaft 15a, 15b retard oil passage 30 vane housing 40 vane rotor 47 advance oil chamber 48 retard oil chamber 50 oil control valve 63a check valve 80 controller

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Nobuaki Murakami 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation F-term (reference) 3G018 AA14 BA09 BA33 CA18 DA57 DA59 DA70 DA72 DA73 DA74 EA02 EA17 EA21 EA31 EA32 FA16 GA32 3G092 AA11 AC02 DA01 DA02 DA09 DF04 DF09 DF10 DG02 DG05 DG09 EA04 EA11 EA13 EA28 EA29 EC08 FA06 FA14 GA01 GA10 HE01Z HE08Z HF19Z

Claims (1)

[Claims] A vane member that is drivingly connected to one of a camshaft that drives an intake valve or an exhaust valve of an engine and a crankshaft of the engine; and a vane member that is drivingly connected to the other of the camshaft and the crankshaft. Hydraulic oil can be supplied to an accommodating member that is drivingly connected and rotatable relative to the vane member, and an advancing oil chamber and a retarding oil chamber respectively formed between the vane member and the accommodating member. Hydraulic oil supply means, and hydraulic oil is supplied from the hydraulic oil supply means to the other oil chamber while allowing the hydraulic oil to be discharged from one of the advance oil chamber and the retard oil chamber. Switching means for switching a hydraulic oil flow path so that the hydraulic oil is supplied to the retard oil chamber at least when the engine is started; and Downstream and variable valve device, characterized in that it comprises a non-return valve from the arranged is and the switching means on the upstream side to prevent back flow of hydraulic fluid to the hydraulic oil supply means of the switching means of means.