JP2001140663A - Valve timing control device and power output device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimumly control closing timing of an intake valve at the stop and start of an internal combustion engine and to attain smooth and quick starting of the internal combustion engine. SOLUTION: In this valve timing control device to be used for a power output device provided with a timing adjusting mechanism capable of adjusting closing timing of an intake valve of an internal combustion engine within a prescribed adjusting angle range, a stopping time control means for setting closing timing of the timing adjusting mechanism to a foremost advancing angle position when a stopping of the internal combustion engine is requested, a stopping history determining means for determining whether a stopping operation (an IG.OFF operation, for instance) based on the will of a driver exists or not between starting of previous time and starting of this time when a starting of the internal combustion engine is requested and a starting time control means for setting closing timing of the timing adjusting mechanism to a foremost lag angle position when the internal combustion engine is started.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power output device having a valve adjustment mechanism capable of adjusting a closing timing of an intake valve within a predetermined adjustment angle range, and a valve timing control device used for the power output device. About.

[0002]

2. Description of the Related Art Hitherto, there has been proposed a power output apparatus provided with a timing adjusting mechanism for changing a closing phase of an intake valve by changing a rotation phase of a camshaft with respect to a crankshaft of an internal combustion engine (Japanese Patent Laid-Open No. 10-1998). 22723
6).

[0003] The timing adjustment mechanism includes a housing that rotates in synchronization with a crankshaft, a vane that is coupled to the camshaft and that is rotatable within a predetermined adjustment angle range with respect to the housing, and an inflow of oil. An advancing chamber that expands its own volume to advance the rotational phase of the vane with respect to the crankshaft, and a retard chamber that expands its own volume by inflow of oil to retard the rotational phase of the vane with respect to the crankshaft. ing.

Therefore, by controlling the inflow of oil into the advance chamber and the retard chamber, the rotational phase of the camshaft for driving the intake valve with respect to the crankshaft is made variable, whereby the closing timing of the intake valve is set to (open). (Including timing).

[0005] In a power output device provided with such a timing adjustment mechanism, there are cases where the internal combustion engine cannot be started properly. In general, the closing timing of the intake valve of the internal combustion engine is controlled by the rotation angle after the bottom dead center of the crankshaft in the intake stroke, that is, on the retard side, in order to fill the cylinder with as much air-fuel mixture as possible using the inertia of the intake air. However, if the cold internal combustion engine is started in this state, the starting pressure may be insufficient due to insufficient compression pressure at the start. On the other hand, if the warmed internal combustion engine is started with the intake valve closing timing being early (advanced side state), the compression pressure may become too high and large vibrations may occur at the time of starting.

In order to solve such a problem, in a timing adjusting mechanism disclosed in Japanese Patent Application Laid-Open No. H10-227236, a lock pin biased toward a housing by a spring is provided on a vane.
There has been proposed a structure in which a lead-side engaging hole that can be engaged with the lock pin when the vane is at the most advanced position is formed on the housing side. Therefore, this timing adjustment mechanism can fix the closing timing of the intake valve to the most advanced angle side regardless of the hydraulic pressure state.

FIGS. 10 and 11 of Japanese Patent Application Laid-Open No. Hei 10-227236 propose a method of controlling the above-mentioned timing adjusting mechanism both when the internal combustion engine is stopped and when it is started. The outline of a certain part will be described.

The control of the timing adjustment mechanism is applied to a hybrid vehicle that can be driven by a motor and can automatically stop and start the internal combustion engine by an electric control unit (ECU) even during driving. When a request to stop the internal combustion engine is issued, the request to stop
It is determined whether the vehicle is stopped due to the driver's intention (stop by turning off the ignition key). Where E
In the case of an automatic stop request by the CU, the next start is also EC
Considering that the internal combustion engine is automatically started by U, the internal combustion engine is predicted to be in a warm state at the next start, and the internal combustion engine is stopped at the most retarded closing timing of the intake valve. On the other hand, in the case of a stop request based on the driver's intention, if the internal combustion engine temperature (determined by cooling water) is high, it is set to the most retarded side, and if the internal combustion engine temperature is low, it is fixed to the most advanced side. To stop the internal combustion engine.

After stopping the internal combustion engine as described above,
When a start request occurs, first, the start request
It is determined whether the request is an automatic start request by U or a start request based on the driver's intention (ignition key ON operation). Here, in the case of automatic start by the ECU,
The previous stop was also an automatic stop by the ECU, and the closing timing of the intake valve was set to the most retarded side, and the internal combustion engine is still assumed to be in a warm state. Start the internal combustion engine. on the other hand,
When the start request of the internal combustion engine is based on the driver's intention, it can be considered that the last stop of the internal combustion engine was a stop based on the driver's intention, and the temperature state of the internal combustion engine is determined again. This is because even when the internal combustion engine is stopped with the intake valve closing timing set to the most retarded side because the temperature was high, the internal combustion engine is already turned on at the next start of the internal combustion engine after the ignition key is turned off. It is based on the idea that the situation where the temperature is falling is probably present. As a result of the determination, if the temperature of the internal combustion engine at the time of the current start is high, it is obvious that the temperature of the internal combustion engine at the time of the previous stop was obviously high. Start the internal combustion engine as it is. On the other hand, when it is determined that the temperature of the internal combustion engine is low, the closing timing is set to the most retarded side because the temperature of the internal combustion engine was high at the previous stop, and Therefore, an operation (control) for fixing the closing timing of the intake valve to the most advanced side is performed once, and the engine is started.

According to the above-described control, when the internal combustion engine is started in a cold state, it can be started with the closing timing of the intake valve being on the most advanced side, thereby preventing insufficient compression pressure at the time of starting. It can be started reliably. In addition, when the internal combustion engine is started during a warm period, the internal combustion engine can be started with the closing timing being on the most retarded side, and vibration and abnormal noise at the time of starting can be prevented.

[0011]

According to the timing adjusting mechanism described above and the valve timing control at the time of stopping and starting the internal combustion engine, the above-mentioned advantages can be obtained in a certain situation. However, on the other hand, there are aspects in which the characteristics (actual situation) of the hybrid vehicle and the like are not necessarily sufficiently reflected.

More specifically, the above control is performed by the EC
It is assumed that the automatic start of the internal combustion engine by U is automatically started by the ECU, and the stop of the internal combustion engine by the operation of turning off the ignition key is always started by the operation of turning on the ignition key. ,
Actually, after the automatic stop of the internal combustion engine by the ECU, the “power output device (for example, a vehicle)” including the motor itself is stopped by the driver's operation of turning off the ignition key, and the internal combustion engine is turned on by the next operation of the ignition key. The engine may be started. Conversely, after the internal combustion engine is stopped by the driver turning off the ignition key, the internal combustion engine is not started at the next operation of turning on the ignition key, the vehicle is driven by the motor for the time being, and then the ECU as necessary. In some cases, the internal combustion engine is automatically started.

In consideration of the above, for example, when the internal combustion engine is stopped by turning off the ignition key, the closing timing is set to the most retarded side because the temperature of the internal combustion engine is high, and after a long time, the ignition key is turned off. By turning on the vehicle, the vehicle runs on "motor only", and then the EC
Considering the case where the internal combustion engine is automatically started by U, even though the internal combustion engine is sufficiently cooled through turning on and off the ignition key, the closing timing is reset for automatic start by the ECU. In some cases, the engine may be started on the most retarded side, and vibration and abnormal noise such as knocking may occur.

Further, according to the above control, when the internal combustion engine is started by turning on the ignition key when the engine is cold, the crankpin of the internal combustion engine is reversely rotated by a predetermined angle by the motor at all times to release the lock pin. Since it is necessary to perform the operation of engaging and fixing the closing timing of the intake valve to the most advanced side, there is a possibility that the start of the internal combustion engine is delayed and the driver feels discomfort. Especially when driving ECU
When the internal combustion engine is started by turning on the ignition key of the driver,
The start of the internal combustion engine is delayed against "the driver's intention", which gives the driver a strong sense of discomfort.

The present invention has been made in view of the above-mentioned problems, and even when applied to a so-called hybrid vehicle or the like, the internal combustion engine can be started quietly and reliably. It is an object of the present invention to obtain a valve timing control device capable of preventing a driver from feeling uncomfortable.

[0016]

SUMMARY OF THE INVENTION The present invention comprises an internal combustion engine,
A timing adjustment mechanism capable of adjusting a closing timing of an intake valve of the internal combustion engine within a range of a predetermined adjustment angle. When there was
A stop control means for setting the closing timing of the timing adjustment mechanism to the most advanced position, and when a request for starting the internal combustion engine is issued, the driver's intention is determined between the previous start and the current start of the internal combustion engine. A stop history determining means for determining whether or not a stop operation of the power output device has been performed, and if the stop operation has not been performed, the closing timing of the timing adjustment mechanism is reset to the most retarded position when the internal combustion engine is requested to start. The above object is achieved by providing a start-up control means.

This valve timing control device always sets the closing timing of the intake valve to the most advanced side when the internal combustion engine is stopped, and stops and waits with the priority given to the startability. At the time of the next start, control is performed so as to determine whether to start with the most advanced position or reset to the most retarded side depending on the situation. Therefore, if the internal combustion engine at the time of startup is cold, there is no need to reset the valve timing (since the closing timing is always set to the most advanced side when the engine is stopped), and the internal combustion engine can be started quickly. Therefore, it is possible to prevent the driver from feeling uncomfortable due to a delay in starting. Further, even when the internal combustion engine is started in a warm state, when the closing timing is reset from the most advanced side to the most retarded side, for example, the crankshaft of the internal combustion engine is "forward-rotated" by a motor or the like. Therefore, the valve timing can be changed simultaneously with the start of the internal combustion engine using a so-called cranking operation. Therefore, there is almost no delay in starting the internal combustion engine due to the change in the valve timing.

Further, the valve timing control device comprises:
Whether or not it is necessary to reset the closing timing at the time of the start request of the internal combustion engine is determined between the previous start of the internal combustion engine and the current start,
It is configured to determine whether or not "stop operation of the power output device" based on the driver's intention, such as the driver's operation of turning off the ignition key. This “stop operation of the power output device” does not only mean a stop operation of the internal combustion engine, but also includes a case where the power supplied to the motor or the like is stopped while the internal combustion engine is already stopped. That is, the power output function of the power output device (regardless of motor or internal combustion engine)
It is almost synonymous with stopping.

If such a stop operation of the power output device is present between the previous start of the internal combustion engine and the present start, it takes a time from the previous "stop" of the internal combustion engine to the present start. It can be determined that the elapsed time has passed to the extent that the internal combustion engine is sufficiently cooled, and if there is no such operation to stop the power output device, the previous “stop” of the internal combustion engine was performed.
It can be determined that the time taken from the start to the current start is short, and it is still warm. Therefore, it is possible to reliably determine the temperature state of the engine in consideration of the characteristics of the hybrid vehicle or the like while using a very simple method of determining whether such an operation history exists.

As a result, if this valve timing control device is applied to a power output device such as a hybrid vehicle,
It is possible to achieve both the smoothness of starting by accurately judging the temperature condition and the like of the internal combustion engine and the prevention of a start delay problem caused by resetting the valve timing.

In the above invention, when an electric motor (motor) is connected to the crankshaft of the internal combustion engine, when the internal combustion engine is stopped, the crankshaft is reversely rotated by the electric motor to advance the closing timing of the intake valve most. You may make it set to a corner position. In the case of stop, even if the valve timing is set by rotating the crankshaft in the reverse direction, the driver hardly feels discomfort or the like.

Further, in the case where the crankshaft is reversely rotated by the electric motor as described above, when a power disconnecting means such as a clutch is disposed between the internal combustion engine and the drive wheels, the power disconnection is performed. Preferably, the means is such that reverse rotation of the crankshaft is not transmitted to the drive wheels. With this configuration, the driving shock transmitted to the driving wheels due to the reverse rotation of the crankshaft is prevented, so that the driver can be prevented from feeling uncomfortable.

When the crankshaft is reversely rotated by the electric motor, the reverse rotation angle is preferably set to an angle for rotating the timing adjustment mechanism by a predetermined adjustment angle or more, and as described above. In the case where the crankshaft is reversely rotated by the electric motor and the request for stopping the internal combustion engine is made at the same time as the operation of stopping the power output device based on the driver's intention, until the reverse rotation is completed (reverse rotation). It is preferable to maintain the energized state of the electric motor.

Further, a rotation speed control means for controlling the reverse rotation speed of the crankshaft by the electric motor is provided, and when the reverse rotation of the crankshaft is completed, the closing timing of the timing adjustment mechanism is shifted to the retard side by inertia force. It is preferable to control the rotation speed within a range that does not exist. This is because despite the fact that the closing timing of the intake valve shifted to the most advanced side during the reverse rotation of the crankshaft, for example,
Because the reverse rotation of the crankshaft suddenly stopped,
The timing of closing the timing adjustment mechanism may be shifted to the retard side due to the rotation inertia force of the camshaft or the like acting on itself, and such a shift is prevented by controlling to the optimal reverse rotation speed.

While the above description has been made mainly of the case where the closing timing of the intake valve is set to the most advanced side by reversing the crankshaft when the internal combustion engine is stopped, the present invention is not limited to this. An internal combustion engine stop delay unit that sets the closing timing of the timing adjustment mechanism to the most advanced position by the stop control unit while maintaining the operation of the internal combustion engine, and stops the internal combustion engine after the completion of the setting of the closing timing. It may be. With this configuration, since the internal combustion engine is in the operating state, the closing timing can be changed to the most advanced side by normal control using hydraulic pressure or the like, and the reverse rotation operation of the crankshaft by the electric motor is not required, and the smooth operation is possible. The engine can be stopped.

Further, the timing adjusting mechanism may be provided with a hydraulic pressure generating device capable of adjusting the closing timing by hydraulic pressure and capable of generating hydraulic pressure even when the internal combustion engine is stopped. With this configuration, it is not necessary to reversely rotate the crankshaft even after the internal combustion engine is completely stopped, and it is possible to set the closing timing to the most advanced side by hydraulic pressure.

Further, when the power output device includes a transmission employed in the vehicle, when the transmission is in the running position, the most advanced control of the closing timing by the stop control means is prohibited. You may do so. By doing so, it is possible to predict that the internal combustion engine is automatically started immediately afterwards, especially in the case of an automatic stop request of the internal combustion engine by the ECU or the like in the traveling position. The next start can be smoothly performed by prohibiting the control in particular.

Also, the power output device is provided with state detecting means for detecting the environmental state, and the stop time control means is adapted to advance the closing timing of the timing adjusting mechanism in accordance with the environmental state detected by the state detecting means. It is also preferable that the state can be variably set to less than the most advanced angle. In this way, the state of the next start of the internal combustion engine is predicted, for example, in accordance with the temperature state of the internal combustion engine, and the closing timing is set to the optimum advance state, instead of always setting the maximum advance angle. And the next smooth start of the internal combustion engine can be achieved. In this case, it is also preferable to reset the closing timing of the intake valve to an optimum state by using the detection information by the state detecting means even at the time of starting the internal combustion engine. By the combination, an optimal valve timing state can be obtained in a short time when the internal combustion engine is started.

In the above invention, the timing adjustment mechanism may include an engagement means for fixing the closing timing of the intake valve in a cold state by a shape change based on a change in temperature of the timing adjustment mechanism. This makes it possible to fix the advancing state or the retarding state in a cold state with a simple structure, and furthermore, in a warm condition, the closing timing of the intake valve is automatically maintained in a variable state. The above-described control device is adapted to enable smooth control. The fixing force by the engagement means is preferably set so as not to be displaced by the rotational resistance of the camshaft when the internal combustion engine is started. On the other hand, a mechanism for adjusting the closing timing of the intake valve by hydraulic pressure or the like is preferable. In the case of combination, it is preferable to set the pressure weaker than the adjusting force generated by the hydraulic pressure or the like.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a configuration of a hybrid vehicle 1 as a power output device to which a valve timing control device according to a first embodiment of the present invention is applied. The hybrid vehicle 1 has an engine 10 that is an internal combustion engine.
A generator 12 connected to an output shaft of the engine 10 via a gearbox 18; a motor 14 arranged in series with the generator 12 via a clutch 16; In addition, a drive wheel 24 connected via a reduction gear (or transmission) 20 and a differential gear (diff) 22 and an electric control unit (ECU) for controlling the generator 12 and the like are provided. The clutch 16 is a power disconnecting means. In a disengaged state, the shaft of the generator 12 and the output shaft of the motor 14 can rotate independently of each other, and in an engaged state, both rotate integrally.

Further, the generator 12 and the motor 14 are provided with inverters 26 and 28, respectively. The generator 12 and the motor 14 can function as a generator and an electric motor irrespective of their names, and when functioning as a generator, the inverter 26,
The battery 30 connected to the battery 28 is charged by receiving supply of charging power from the generator 12 and / or the motor 14. On the other hand, when functioning as an electric motor, the battery 30 supplies driving power to the generator 12 and / or the motor 14 via the inverters 26 and 28.

An electric control unit (ECU) 32 controls the engine 10, the generator 12, and the like collectively. Therefore, the ECU 32 receives an input of an accelerator opening indicating an acceleration request, a brake pedal force indicating a deceleration request, an engine brake switch state indicating an engine brake request, and the like from the driver. Further, the ECU 32 controls the rotation speeds of the generator 12 and the motor 14 by rotation speed sensors 34 and 36, the state of charge (SOC) of the battery 30 by the SOC sensor 38, and various information of the engine 10 by various sensors. (This point will be described in detail later), respectively.

The ECU 32 determines whether the generator 12 and the motor 14 function as a generator or a motor, and controls the inverters 26 and 28 to reduce the torque of the generator 12 and the motor 14. Control. Also, in combination with this, the engagement state (on, off) of the clutch 16 is also controlled.

Since the hybrid vehicle 1 is configured as described above, (1) a so-called series hybrid traveling mode (hereinafter referred to as an SHV mode), which can also be called an electric vehicle with an engine generator (2) The engine 10 and each electric motor Thus, a so-called parallel hybrid traveling mode (hereinafter referred to as PHV mode) in which the wheels 24 are directly driven can be switched according to the traveling state.

In the SHV mode, the clutch 16 is released by the ECU 32, the power of the engine 10 is input to the generator 12 via the gearbox 18, and the power output of the generator 12 is After that, it is converted again into AC through another inverter 28 and supplied to the motor 14. When the power output generated by the generator 12 is larger than the power supplied by the motor 14, part of the power is used to charge the battery 30. Conversely, when the required power of the motor 14 is larger than the power output of the generator 12, the battery 30 makes up for the shortage of power.

In the PHV mode, the clutch 16 is engaged (on) by the ECU 32, and the power of the engine 10 is directly transmitted to the drive wheels 24. EC
U32 calculates the required output torque required by the hybrid vehicle 1 from the accelerator opening and the like, and when the power of the engine 10 is less than the required output torque, the generator 12 and the motor 14 are made to function as electric motors and the shortage is calculated. Conversely, when the power of the engine 10 is excessive with respect to the required output torque, the generator 12 and the motor 14 are made to function as a generator, and the excess is converted into electric power and stored in the battery 30.

The SHV mode and the PHV mode described above are switched mainly based on a predetermined threshold value of the vehicle speed.
In the low speed range, the mode is set to the SHV mode in which the high torque motor 14 is used, and in the high speed range, the mode is set to the PHV mode in which the power of the engine 10 is actively used. As a result, the engine 10
Can be used only in a limited rotational speed range that outputs the most efficient and high torque, so that the hybrid vehicle 1 achieves higher fuel efficiency and lower emissions than existing gasoline engine vehicles. ing.

Next, a partial configuration of the engine 10 of the hybrid vehicle 1 and a timing adjustment mechanism capable of adjusting the closing timing of the intake valve of the engine 10 within a predetermined adjustment angle range are described with reference to FIG. And will be described in detail.

As shown in FIG. 2, the timing adjustment mechanism 1
Eleven vane type pulleys 111A (details will be described later)
A driven gear 122 is installed adjacent to the shaft end of the intake-side camshaft 112 of the engine 10. Further, a timing pulley 124 is connected to the exhaust side camshaft 123. This driven gear 1
22 and the timing pulley 124
68 is driven by a crank pulley 168A attached to the end of the crank pulley 168 via a timing belt 127, and the timing pulley 124 and the driven gear 122 are set to a gear ratio of 1: 2 with respect to the crank pulley 168A. When the shaft 68 rotates twice, the timing pulley 124 and the vane type pulley 111
A makes one rotation.

Also, the intake and exhaust camshafts 11
A total of four pairs of cams 120 are formed on the reference numerals 2 and 123, respectively, and the upper ends of the intake and exhaust valves 162 and 164 provided for each cylinder of the engine 10 are in contact with each cam 120. Therefore, when the cam 120 rotates integrally with the intake and exhaust camshafts 112 and 123, the intake and exhaust valves 162 and 164 are opened and closed. An oil pump 115 is connected to the crankshaft 168 adjacent to a crank pulley 168A.
The generator 12 is connected via a gearbox (not shown) indicated by.

Next, the timing adjustment mechanism 111 will be described in detail.

The timing adjustment mechanism 111 is, as shown in an enlarged view in FIG. 3, an oil pumped by an oil pump 115 as a separate body from a vane type pulley 111A attached to an end of the intake side camshaft 112. An oil control valve 116 for changing the oil passage of
An electronic control unit 32 (this is the ECU 32 shown in FIG. 1).

The intake camshaft 112 is connected to the engine 1
0 is rotatably supported by an upper end surface of the cylinder head 118 and a semi-cylindrical bearing cap 119. A wide-diameter portion 121 is formed on the tip side (left side in FIG. 3) of the intake-side camshaft 112, and external teeth 122A are formed on the outer circumference of the wide-diameter portion 121 on its own outer circumference. A cylindrical driven gear 122 is installed so as to be slidable and rotatable in the circumferential direction. This driven gear 1
A vane-type pulley 111A, which will be described later, is connected to the end of the intake-side camshaft 112.

The vane type pulley 111A includes a hollow cylindrical housing 128 and a vane 129 rotatably housed inside the housing 128. Specifically, as shown in FIGS. 4 and 5, four protrusions projecting toward the axis of the intake-side camshaft 112 at intervals of about 90 ° in the circumferential direction, as shown in FIGS. 133
Are formed, and a tapped hole 1 is provided at the center of each projection 133.
30A are formed. Therefore, this tap hole 130
A with housing 130
Are coaxially connected to the driven gear 122.

The vane 129 has a bolt hole 1 at the center position.
40 is formed, and is coaxially connected to the shaft end of the intake side camshaft 112 by a mounting bolt 141 penetrating the bolt hole 140. The shape of the vane 129 when viewed axially is as shown in FIGS.
The pressure receiving part 1 is shaped like a cross, and each projection receives hydraulic pressure.
32.

Accordingly, 4 formed on the housing 128
Four convex parts 133 and four pressure receiving parts 132 of the vane 129.
For example, four advanced hydraulic chambers 113 (see FIG. 4)
And two retard hydraulic chambers 114 (see FIG. 5). Note that a disc-shaped cover 138 is attached to the end surface of the housing 128 using the end of the bolt 130 shown above in order to seal each hydraulic chamber (see FIG. 3).

An outer circumferential groove 135 is formed on the outer circumferential surface of each pressure receiving portion 132 in the axial direction of the camshaft. Inside the outer circumferential groove 135, a housing 1 is provided by a leaf spring 137.
The seal member 136 urged toward the inner peripheral surface side of the seal member 28 is disposed. Therefore, the seal 136 seals the advance hydraulic chamber 113 and the retard hydraulic chamber 114 so that they are independent spaces.

The sealing member 136 is made of a bimetal, and is set so as to bend outwardly when cold to increase the sealing force. Further, when warm, the bending degree is weakened, and a sealing force is generated to such an extent that the vane 129 can slide smoothly against the housing 128 while maintaining the sealing state.

Since the vane 129 is rotatably housed in the housing 128, the
8 can be slid from the state shown in FIG. 4 to the state shown in FIG. 5, and the vane 129 has a rotational phase difference with respect to the housing 128 by the rotation angle. This rotation phase difference is synonymous with that for the crankshaft 168 in consideration of the fact that the housing 128 rotates in synchronization with the crankshaft 168. Therefore, the sizes of the advance hydraulic chamber 113 and the retard hydraulic chamber 114 are reduced. By adjusting the hydraulic pressure, the rotation phase of the intake camshaft 112 with respect to the crankshaft 168 can be changed.

According to the timing adjusting mechanism 111 configured as described above, the closing timing of the intake valve 162 is adjusted from the bottom dead center of the crankshaft 168 as illustrated in the valve timing diagram shown in FIG. Within the range of the adjustment angle sandwiching the position delayed by about 90 ° (range between the most advanced position α1 (= 80 °) and the most retarded position α2 (= 120 °) with respect to the bottom dead center). Can be set variably. The reason why the closing timing of the intake valve 162 is greatly retarded in this way is to take into account the characteristics of the hybrid vehicle 1 that can constantly operate the output torque and the rotation speed of the engine 10 in an efficient state. Intake valve 1
When the closing timing of the cylinder 62 is set to the retard side, the intake valve 162 is still open even in the compression process, so that a part of the air-fuel mixture once sucked into the combustion chamber of the engine 10 flows back to the intake manifold. That is, the actual compression step can be shortened.

Next, a structure for adjusting the sizes of the advance hydraulic chamber 113 and the retard hydraulic chamber 114 will be described.

As shown in FIG. 3, an advance-side oil passage P1 and a retard-side oil passage P2 are formed inside the intake-side camshaft 112, and the advance-side oil passage P1 is advanced. Hydraulic chamber 113
Further, the retard side oil passage P2 is always connected to the retard hydraulic chamber 114. Specifically, the advance-side oil passage P1 penetrates through the inside of the intake-side camshaft 112 and continues to the center of the vane 129, and from the root of each pressure-receiving portion 132 of the vane 129 to the advance-side hydraulic chamber 113. It is always open towards. That is,
Part of the advance side oil passage P1 is integrated with the vane 129. On the other hand, the retard side oil passage P2 is
2 and continues to the outer periphery of the wide-diameter portion 121, further reaches the side end of the convex portion 133 of the housing 128 from the outer periphery of the wide-diameter portion 121, and always opens to the retard hydraulic chamber 114. ing. That is, a part of the retard side oil passage P2 is integrated with the housing 128.

As shown in FIG. 3, the advance side and the retard side oil passages P1 and P2 penetrate the inside of the cylinder head 118, and pass through an oil control valve 116, an oil filter 155, and an oil pump 115. To the oil pan 157. Note that, as already shown in FIG. 2, the oil pump 115 is driven by the crankshaft 168 to generate a predetermined oil pressure.

The oil control valve 116 is provided as shown in FIG.
As shown in FIG.
70 and the spool 17
6 is provided with an electromagnetic solenoid 178 that drives the motor 6 in the axial direction, and a spring 179 that constantly biases the spool 176 toward the electromagnetic solenoid 178 side. The casing 170 has an advance port 171 to which the advance oil path P1 is connected.
And an advance-side drain port 172 for discharging the oil flowing from the advance-side oil passage P1 to the oil pan 157, a retard-side boat 173 to which the retard-side oil passage P2 is connected, and a retard-side oil passage P2. A drain port 174 for discharging the oil flowing from the oil pan to the oil pan 157 and an inflow port 175 into which the oil supplied by the oil pump flows are formed. Therefore, the oil control valve 116 can: (1) connect the inflow port 175 and the retard port 173, and connect the advance port 171 and the advance drain port 172, thereby forming a retard oil passage; Oil is supplied to the retard hydraulic chamber 114 via P2 and the advance hydraulic chamber 11
A state in which the oil is discharged from 3 through the advance-side oil passage P1 and the vane 129 is rotated to the retard side (hereinafter referred to as a retard state). (2) The inflow port 175 and the advance-side port 171 communicate with each other. By connecting the retard port 173 to the retard drain port 174, oil is supplied to the advance hydraulic chamber 113 via the advance oil passage P1, and the retard hydraulic chamber 11
The state in which the oil is discharged from the valve 4 through the retard side oil passage P2 to rotate the vane 129 to the advance side (hereinafter referred to as a retard state) can be switched. This spool 17
6 can control its position by duty-controlling the voltage applied to the electromagnetic solenoid 178. Therefore, the inflow amount and the discharge amount of the oil can be more finely controlled, and the closing timing of the intake valve 162 can be positioned at an arbitrary position between the most advanced position α1 and the most retarded position α2.

E for controlling the electromagnetic solenoid 178 and the like
The input ports of the CU 32 include, for example, an intake pressure sensor 80 for detecting the load of the engine 10 and a rotational speed and a rotational speed of the crankshaft 168, as shown in FIG. A rotation speed sensor 81 and a crank angle sensor 82, a cam angle sensor 83 for detecting a rotation angle of the intake side camshaft 112, a water temperature sensor 84 for detecting a water temperature of the engine 10, and turning on / off an ignition key
An ignition switch 85 for detecting the OFF state is connected.

Next, the control at the time of stopping and starting the engine 10 by the valve timing control device applied to the hybrid vehicle 1 described above will be described in detail.

FIG. 6 shows a flowchart of the valve timing control when the engine 10 is stopped. First,
When there is a request to stop the engine 10 (regardless of an automatic stop request by the ECU 32 or a stop request by the driver turning off the ignition key), in step 200, the case where the hybrid vehicle 1 is in the PHV mode is considered. Then, the clutch 16 is released by the ECU 32,
Next, the routine proceeds to step 202, where the engine 10 is stopped. After the oil control valve 116 is advanced in step 204, the crankshaft 16 of the engine 10 is
8 is reversely rotated by a predetermined angle. The reason why the oil control valve 116 is advanced in the step 204 is that the hydraulic pressure is still generated immediately after the stop command of the engine 10 is issued, so that the retard side hydraulic passage communicating with the retard hydraulic chamber 114 is provided. This is because P2 is set to the drain state and the vane 129 is smoothly rotated to the advance side by the residual pressure. The predetermined angle at which the crankshaft 168 is rotated in the reverse direction by the generator 12 is set so that the housing 128 of the timing adjustment mechanism 111 can rotate more than the adjustment angle, and more specifically, is twice the adjustment angle. It is set above.

At step 206, the crankshaft 168
Is completed in step 208, if the request for stopping the internal combustion engine is simultaneous with the stop operation of the hybrid vehicle 1 based on the driver's intention (turn-off operation of the ignition key) in step 208, After the control is completed, the power supply state to the generator 12 is cut (the vehicle is stopped).

According to the above control, the rotation of the intake camshaft 112 is suppressed by the influence of the cam 120 urged by the intake valve 162.
While the rotation of the vane 129 is suppressed, the housing 12
Only 8 rotates, and the closing timing of the intake valve 162 is set to the most advanced position.

Next, control by the valve timing control device at the time of starting the engine 10 will be described.

FIG. 7 shows a flowchart of the valve timing control when the engine 10 is started. If there is a request to start the engine 10, step 250
In the above, between the previous start of the engine 10 and the present start, it is determined whether or not the ignition key has been turned off (the hybrid vehicle 1 has been stopped). If the result of the determination is positive, that is, if there is a history of turning off the ignition key, the temperature of the engine 10 is sufficiently cooled, and the closing timing is set to the most advanced position by the seal member 136 made of bimetal. It is determined that it is fixed, and the routine proceeds to step 252, where the engine 10 is started as it is.

On the other hand, if the result of the determination in step 250 is negative,
That is, if there is no history of the ignition key turning-off operation, the previous ECU in the running state of the hybrid vehicle 1
32, the engine 10 is automatically stopped, and it is determined that the automatic
Since it is expected that the temperature of 0 is still sufficiently high, the process proceeds to step 254 to set the oil control valve 116 to the retarded state, and then proceeds to step 252 to start the engine. Since the engine 10 is sufficiently warm, the sealing force of the seal member 136 made of a bimetal is such that the vane 129 and the housing 128 can rotate smoothly relative to each other. Thus, the engine 10 is started while the closing timing of the intake valve 162 is smoothly changed to the retard side.

With the above control, when the engine 10 is stopped, the closing timing of the intake valve 162 is always set to the most advanced side, so that the next time the engine 10 is started in the cold state, the advanced state is set. The engine can be started quickly as it is. On the other hand, even when the engine 10 is started during warm weather, the cranking force that rotates the crankshaft 168 in the “positive direction” by the generator 12 is used,
Since it is possible to smoothly change from the most advanced state to the most retarded state, it is possible to rationally achieve a quick and reliable start in a cold state and a smooth and quiet start in a warm state.

Further, according to the above control, the engine 10
Can be determined by a very simple method called "history of the driver's operation of turning off the ignition key", so that a complicated configuration and control are not required. However, the determination of the presence or absence of the history sufficiently reflects the characteristics of the hybrid vehicle 1 and the like, and the temperature state of the engine at the time of starting can be more reliably determined.

The above-mentioned temperature conditions (environmental conditions)
May be determined including the temperature of the engine (by the water temperature sensor 84 or the like).
It can be started very smoothly by checking the temperature state of 0.
Further, the elapsed time from the turning-off operation of the ignition key may be measured by the timer 86, and the closing timing at the start may be reset in consideration of the elapsed time.

In particular, the timing adjusting mechanism 111 configured as described above is provided with a bimetallic sealing member 136.
By this, the valve timing can be naturally set to a state where the valve timing is fixed at the time of cold, and to a state where the valve timing can be changed smoothly at the time of warmth. Despite the structure, reliable starting of the engine 10 is achieved.

The engagement means for fixing the closing timing of the intake valve is not limited to the above case.
For example, as shown in FIG. 8, a protrusion 150 made of a bimetal may be provided on the inner peripheral side of the housing 128 so as to engage with the pressure receiving portion 132 at a cold time to fix the valve timing. In addition to using the bimetal as described above, the housing 128 and the vane 129 are made of different materials, and the difference in the coefficient of thermal expansion causes the vane 1 to be in the cold state.
29 may be tightened by the housing 128, and the closing timing of the intake valve may be fixed by the tightening force. Alternatively, fixing by a known lock pin (for example, JP-A-10-227236) may be employed. I do not care.

In the above control, the engine 10
After stopping the operation, the closing timing is set to the most advanced side by the generator 12, but the present invention is not limited to this, and the closing timing is set by the normal hydraulic control while the engine 10 is operating. The engine may be set to the most advanced side, and then the engine may be quickly stopped.

Immediately after the engine stop command is issued, since the hydraulic pressure still remains, a command to advance the engine is first issued, and then the engine is shifted to the most advanced state by delaying the engine stop command only for a short time. Can be done.

In the above-described embodiment, the timing adjustment mechanism is exemplified only in the case of the vane type. However, a predetermined member helically meshed with the intake side camshaft is pivoted by hydraulic pressure, a solenoid or the like. The valve timing control device of the present invention can also be applied to a helical type in which the closing timing is adjusted by moving in the direction.

[0072]

According to the power output apparatus and the valve timing control apparatus of the present invention, even when applied to a so-called hybrid vehicle or the like having an engine having a valve timing adjusting mechanism, the internal combustion engine can be started quietly and reliably. In addition, it is possible to quickly start the vehicle and prevent the driver from feeling uncomfortable.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration of a hybrid vehicle to which a valve timing control device according to an embodiment of the present invention is applied.

FIG. 2 is a perspective view showing a part of an engine and a timing adjusting mechanism of the hybrid vehicle.

FIG. 3 is a partial cross-sectional view showing a configuration of the timing adjustment mechanism.

FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3, showing a state in which the closing timing is in the most advanced state.

FIG. 5 is a cross-sectional view taken along the line AA in FIG. 3, showing a state in which the closing timing is the most retarded state.

FIG. 6 is a flowchart showing valve timing control when the engine is stopped by the valve timing control device according to the embodiment of the present invention;

FIG. 7 is a flowchart showing valve timing control at the time of engine start by the valve timing control device;

FIG. 8 is a sectional view showing another configuration example of the timing adjustment mechanism.

FIG. 9 is a valve timing diagram illustrating opening and closing timings of an intake valve and an exhaust valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Engine 12 ... Generator 14 ... Motor 16 ... Clutch 26, 28 ... Inverter 32 ... ECU 111 ... Timing adjustment mechanism 111A ... Vane type pulley 112 ... Intake side camshaft 113 ... Advanced hydraulic chamber 114 ... Delay hydraulic chamber 116 ... oil control valve 123 ... exhaust side camshaft 124 ... timing pulley 128 ... housing 129 ... vane 132 ... pressure receiving part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F01L 1/34 F02D 29/00 C F02D 29/00 29/02 D 29/02 321A 321 41/06 320 41 / 06 320 41/12 320 41/12 320 B60K 9/00 E (72) Inventor Toshifumi Takaoka 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Takashi Suzuki Toyota Town, Toyota City, Aichi Prefecture No. 1 Inside Toyota Motor Corporation (72) Daibun Okada, Inventor Daiichi Hatsachi 1-1, Ikeda-shi, Osaka F-term inside Daihatsu Industries Co., Ltd. 3G092 AA11 AC02 DA01 DA09 DF04 DF09 DG02 DG05 DG09 EA03 EA04 EA13 EA14 EA16 EA17 EA28 EA29 FA31 GA01 GA10 HA05Z HA13X HA13Z HE01Z HE03Z HE08Z HF01X HF01Z HF02Z HF08Z HF12Z HF15X HF19Z HF20Z HF25Z HF26Z 3G093 AA07 AA16 BA21 B A22 CA00 CA01 DA01 DA03 DA05 DA07 DA12 DA13 DB11 DB23 EA15 EB09 EC04 FB01 FB02 FB04 3G301 HA01 HA19 HA26 KA01 KA28 LA07 LC08 NE11 NE12 NE17 NE19 NE21 NE23 PA07Z PE01Z PE03Z PE08Z PE10A PE10Z PF05Z PF06 PF05Z PF06 PF05Z PF06Z PU22 PU24 PU25 PU26 PU27 PV07 PV09 QN12 RB08 RE01 RE07 SE04 SE05 SJ12 TB01 TE08 TI01 TO05 TO21

Claims (11)

[Claims] 1. A valve timing control device used in a power output device including an internal combustion engine and a timing adjustment mechanism capable of adjusting a closing timing of an intake valve of the internal combustion engine within a predetermined adjustment angle range. A stop control means for setting the closing timing of the timing adjustment mechanism to the most advanced position when a request to stop the internal combustion engine is provided; and Between the previous start and the current start of the power output device based on the driver's intention whether there is a stop history determining means, and if the stop operation does not exist, A valve timing control device comprising: a start-time control unit that sets the closing timing of the timing adjustment mechanism to a most retarded position when the internal combustion engine is started. 2. The internal combustion engine according to claim 1, wherein an electric motor is connected to a crankshaft of the internal combustion engine, and the stop-time control means reversely rotates the crankshaft by the electric motor to adjust the closing timing of the intake valve. A valve timing control device, wherein the valve timing control device is set to a most advanced position. 3. The power cutoff device according to claim 2, wherein a power disconnection means capable of cutting off the transmission of the rotational power is disposed between the internal combustion engine and a drive wheel to which the rotational power of the internal combustion engine is transmitted. A valve timing control device, wherein when the electric motor rotates the crankshaft in a reverse direction, the power disconnecting means makes a state in which the rotation of the crankshaft is not transmitted to the driving wheels. 4. The crankshaft according to claim 2, wherein a reverse rotation angle of the crankshaft by the electric motor is set to an angle by which the timing adjustment mechanism rotates the intake camshaft of the internal combustion engine by the adjustment angle or more. A valve timing control device characterized by the above-mentioned. 5. The electric motor according to claim 2, wherein the request for stopping the internal combustion engine is made simultaneously with the stop operation of the power output device based on the driver's intention. A valve timing control device comprising: an energization stop delay unit that maintains an energization state of the electric motor until the reverse rotation of the crankshaft is completed. 6. A rotation speed control means for controlling a reverse rotation speed of the crankshaft by the electric motor, wherein the motor is driven by an inertia force when the reverse rotation of the crankshaft is completed. A valve timing control device, wherein the rotation speed is controlled so that the closing timing of the timing adjustment mechanism does not shift to the retard side. 7. The internal combustion engine according to claim 1, wherein the internal combustion engine is maintained in an operating state during the adjustment of the closing timing of the timing adjustment mechanism by the stop time control means, even if a request for stopping the internal combustion engine is issued. And an internal combustion engine stop delay means for stopping the internal combustion engine after the adjustment of the closing timing is completed. 8. The power output device using the valve timing control device according to claim 1, wherein the timing adjustment mechanism adjusts the closing timing by a hydraulic pressure, and the internal combustion engine is stopped. A power output device comprising a hydraulic pressure generating device capable of generating hydraulic pressure. 9. The power output device according to claim 1, wherein the power output device includes a transmission employed in the vehicle, and the control of the closing timing by the stop time control means is prohibited when the transmission is in a running position. A valve timing control device, comprising: a stop-time control prohibiting unit that performs the control. 10. The power output device according to claim 1, further comprising: state detecting means for detecting an environmental state of the power output device, wherein the stop-time control means controls the timing according to the environmental state detected by the state detecting means. A valve timing control device, wherein an advance state of the closing timing of the adjustment mechanism is changed to less than a maximum advance angle. 11. The power output device using the valve timing control device according to claim 1, wherein the timing adjustment mechanism adjusts a closing timing of the intake valve at a cold time by a shape change based on a temperature change of the timing adjustment mechanism. A power output device comprising a lockable engagement means.