JP2011169287A - Valve timing control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve timing control system capable of positively rotating a vane rotor to an optimal position at engine starting even when the vane rotor is not in a regulation position such as in unintended stopping. <P>SOLUTION: Relative rotation of a housing 12 and the vane rotor 14 can be regulated in an engine optimal start position by a stopper piston 30 provided so as to project with respect to the housing 12 from the vane rotor 14. At engine starting, an ECU 100 rotates the vane rotor 14 by a vane rotor rotating means such that the stopper piston 30 can fit together with the housing 12. At this time, the ECU 100 raises a pump passage oil pressure to a vane rotor rotating oil pressure by controlling a hydraulic control valve 24 by a holding control means, and it positively rotates the vane rotor 14 by the vane rotor rotating oil pressure. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a valve timing adjustment system that adjusts the opening / closing timing of at least one of an intake valve and an exhaust valve of an internal combustion engine (hereinafter referred to as “engine”).

  Conventionally, a vane that drives a camshaft through a housing that rotates together with an engine crankshaft and adjusts the valve timing of at least one of an intake valve and an exhaust valve by using a phase difference between the housing and the camshaft that rotate relative to each other. A valve timing adjustment device of the type is known. In such a valve timing adjusting device, the relative member of the vane rotor is restricted at the restricting position by restricting the relative rotation of the vane rotor with respect to the housing by projecting the restricting member accommodated in the vane rotor so as to protrude (see, for example, Patent Document 1). . This is because abnormal noise may occur when the vane rotor swings due to torque fluctuations of the camshaft, such as when the engine is not sufficiently supplied.

  As described above, the regulating member is used to regulate the relative rotation of the vane rotor at the time of starting the engine. Therefore, in general, the restriction position is an optimum position for starting the engine.

JP 2007-332957 A

  However, the engine may stop in a state where the restricting member is not fitted in the housing due to an engine stop unintentional by the driver, that is, a so-called engine stall. In this case, since the vane rotor is not held at the optimum position for starting the engine, it is necessary to rotate the vane rotor to the regulation position by the hydraulic oil supplied from the oil pump when starting the engine.

  However, in general, when the engine speed is low, the discharge hydraulic pressure when the oil pump discharges hydraulic oil is low. Therefore, when the engine is started at a low engine speed, there is a possibility that the hydraulic pressure required to rotate the vane rotor to the regulation position cannot be obtained. As a result, there is a concern that the rotation of the vane rotor to the optimum position for starting the engine is delayed, and the smooth start of the engine is hindered.

  The present invention has been made in order to solve the above-described problems. The purpose of the present invention is to set the vane rotor to the optimum position for starting the engine even when the vane rotor is not in the restricted position due to an unexpected engine stop or the like. An object of the present invention is to provide a valve timing adjustment system that can rotate reliably.

The valve timing adjustment system according to claim 1, which has been made to solve the above-described problem, includes a valve timing adjustment device, a hydraulic pump, a flow path switching valve, and a control unit.
The valve timing adjusting device is a device that changes the valve timing of at least one of the intake valve and the exhaust valve of the engine that is driven to open and close by the driven shaft by adjusting the phase of the drive shaft and the driven shaft of the engine.

  The valve timing adjusting device includes a housing that rotates together with one of the drive shaft and the driven shaft, a vane rotor that rotates together with the other of the drive shaft and the driven shaft, and is driven to rotate relative to the housing by the pressure of the working fluid, Member. The restricting member is accommodated in the vane rotor so as to be protrudeable, and protrudes from the vane rotor and fits into the housing, thereby restricting the relative rotational drive of the vane rotor with respect to the housing at the restricting position.

  The “restricted position” here refers to the position of the vane rotor with respect to the housing (hereinafter referred to as “the optimum engine start position”) that provides optimum valve timing when the engine is started. The “engine starting optimum position” is different in the detailed position depending on the engine configuration, but it is exemplified as the most advanced position, the most retarded position, or the intermediate position between the most advanced position and the most retarded position. Is done.

The hydraulic pump supplies the working fluid to the valve timing adjusting device from the working fluid reservoir that stores the working fluid.
The flow path switching valve switches the flow path for supplying the working fluid from the working fluid reservoir to the valve timing adjusting device. Control of the flow path switching valve is governed by the control unit.

  The control unit includes an engine stall information storage unit, a vane rotor rotating unit, and a holding control unit. The engine stall information storage means stores engine stall information indicating whether or not an engine stall has occurred when the engine is stopped. The “engine stall” here refers to a phenomenon in which the engine stops regardless of the driver's intention.

When the engine stall has occurred based on the engine stall information stored by the engine stall information storage means, the vane rotor is rotated by the vane rotor rotating means so that the regulating member is fitted in the housing when the engine is started.
Here, particularly in the present invention, prior to such rotation of the vane rotor, the holding control means controls the valve timing from the hydraulic pump via the flow path switching valve so that the pump flow path hydraulic pressure rises to the vane rotor rotational hydraulic pressure. The flow path switching valve is held at a holding position where hydraulic fluid is not supplied to the adjusting device.

Here, the pump passage hydraulic pressure is the pressure of the hydraulic oil in the passage connecting the hydraulic pump and the passage switching valve. The vane rotor rotation hydraulic pressure is a hydraulic pressure at which the vane rotor can be rotated by the vane rotor rotation means.
That is, in the present invention, the flow path switching valve is controlled to increase the pump flow path hydraulic pressure to the vane rotor rotation hydraulic pressure, and the vane rotor is reliably rotated by the vane rotor rotation hydraulic pressure.

  Thus, in the present invention, even when the vane rotor is not in the restricted position due to an unintended engine stop or the like, the vane rotor can be reliably rotated to a position optimal for engine start. As a result, the engine is started smoothly.

  In the valve timing adjustment system according to claim 2, in order to determine whether or not engine stall has occurred based on the engine stall information stored by the engine stall information storage module, the control unit reads the engine stall information read module and the engine stall information determination module. It is illustrated having. When the engine is started, the engine stall information reading unit reads the engine stall information stored by the information storage unit. Based on the engine stall information read by the engine stall information reading unit, the engine stall information determination unit determines whether an engine stall has occurred.

  In the valve timing adjustment system according to the third aspect, the control unit includes a hydraulic pressure determination unit and a holding control release unit. The controller determines whether or not the pump passage hydraulic pressure has reached the vane rotor rotation hydraulic pressure by the hydraulic pressure determination means. Here, when it is determined that the pump flow path hydraulic pressure has reached the vane rotor rotation hydraulic pressure, the control unit releases the holding of the flow path switching valve by the holding control unit at the holding position by the holding control release unit.

  That is, after waiting for the pump passage hydraulic pressure to rise to the vane rotor rotation hydraulic pressure, the control for holding the flow passage switching valve in the holding position is released. Thus, even when the engine is started at a low engine speed, the vane rotor is reliably rotated by the vane rotor rotation hydraulic pressure. As a result, even if the vane rotor is not in the restricted position due to an unintended engine stop or the like, a smooth engine start is performed.

  In the valve timing adjustment system according to the fourth aspect, the control unit is exemplified to perform the rotation of the vane rotor by the vane rotor rotation unit after the release by the holding control cancellation unit. Thus, even when the engine is started at a low engine speed, the vane rotor is reliably rotated by the vane rotor rotation hydraulic pressure. As a result, even if the vane rotor is not in the restricted position due to an unintended engine stop or the like, a smooth engine start is performed.

Specifically, as shown in claim 5, the hydraulic pressure determination means detects the pump flow pressure, and the pump flow pressure reaches the vane rotor rotation hydraulic pressure based on the detected value of the pump flow pressure. It is exemplified to determine whether or not.
Further, as shown in claim 6, the hydraulic pressure determination means detects, for example, a holding time during which the flow path switching valve is held at the holding position by the holding control means instead of detecting the pump flow path hydraulic pressure, It may be determined whether or not the detected holding time is a certain time or longer.

By the way, the engine stall information storage means may determine the generation of the engine stall by any method. As an example, in the valve timing adjustment system according to the seventh aspect, when the engine is stopped, engine stall information indicating that an engine stall has occurred is stored only when the regulating member is not fitted into the housing.
Here, as an example, the engine stall information storage means includes a restricting member fitted into the housing when the vane rotor is held at the optimum engine start position based on a value detected by the cam angle sensor. It is exemplified that it is determined that they match.

It is a mimetic diagram showing the valve timing adjustment system of one embodiment of the present invention. It is a flowchart which shows the process in the control part of the valve timing adjustment system of one Embodiment of this invention. It is a time chart which shows the process in the control part of the valve timing adjustment system of one Embodiment of this invention. It is a flowchart which shows the process in the control part of the valve timing adjustment system of other embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
A valve timing adjustment system according to this embodiment is shown in FIG. The valve timing adjustment system 1 of this embodiment is applied to a driving force transmission system.
The valve timing adjustment system 1 includes a hydraulic control type valve timing adjustment device 10 that uses hydraulic oil, a hydraulic control valve 24, a hydraulic pump 22, and an engine control unit (Engine Control Unit, hereinafter referred to as ECU) 100. Details will be described below.

  A housing 12 of the valve timing adjusting device 10 includes a sprocket 11 and a shoe housing 15. The sprocket 11 is rotatably supported by a camshaft (not shown) on the intake side or the exhaust side, and is fixed integrally with the shoe housing 15 by a bolt 19. A gear 8 is formed at the radially outer end of the sprocket 11, and the rotation of a crankshaft (not shown) is transmitted to the gear 8 via a chain (not shown). Thereby, the housing 12 rotates in synchronization with the crankshaft. The rotation of the crankshaft is transmitted to the camshaft via the housing 12.

  The housing 12 accommodates the vane rotor 14 in a relatively rotatable manner. The vane rotor 14 and the camshaft are fixed coaxially by a bolt 17. As a result, the vane rotor 14 and the camshaft are integrally rotatable relative to the housing 12 coaxially.

  Here, when the camshaft, the housing 12 and the vane rotor 14 are rotated to the right side of FIG. 1, that is, clockwise, this rotation direction is defined as an advance direction of the camshaft with respect to the crankshaft. On the other hand, when the camshaft, the housing 12 and the vane rotor 14 are rotated to the left side of the page, that is, in the counterclockwise direction, this rotation direction is set as a retard direction of the camshaft with respect to the crankshaft.

  The vane rotor 14 includes a cylindrical rotor 40 and vanes 41 to 44 arranged on the outer peripheral side of the rotor 40 at substantially equal intervals in the rotation direction. The interior of the housing 12 is divided into four vane accommodation chambers 50 that accommodate the vanes 41 to 44 so as to be relatively rotatable in the advance direction and the retard direction. Each vane storage chamber 50 is divided into advance hydraulic chambers 51 to 54 and retard hydraulic chambers 55 to 58 by the vanes 41 to 44.

  The vane 41 is provided with a stopper piston 30 for restricting relative rotation of the vane rotor 14 with respect to the housing 12 at an optimum engine start position. When the vane rotor 14 is positioned at the optimum engine start position, the stopper piston 30 can be fitted into the fitting hole 34 provided in the sprocket 11. The stopper piston 30 is fitted in the fitting hole 34, thereby restricting the phase of the camshaft to a predetermined optimum position for starting the engine. In this embodiment, the fitting hole 34 is formed at the most advanced angle position that the vane 41 can take as the optimum engine start position.

  The advance oil passage 25 is connected to each advance oil chamber 51 to 54 via an advance oil passage (not shown) formed in the sprocket 11, the vane rotor 14, and the camshaft. On the other hand, the retard oil passage 26 is connected to each retard hydraulic chamber 55 to 58 via a retard oil passage (not shown) formed in the sprocket 11, the vane rotor 14, and the camshaft. In FIG. 1, only the connection between the advance oil passage 25 and the advance hydraulic chamber 53 and the retard oil passage 26 and the retard hydraulic chamber 57 is schematically shown in order to avoid complication. .

The hydraulic pump 22 supplies the hydraulic oil from the oil tank 27 in which the hydraulic oil is stored to the valve timing adjusting device 10 via the advance oil passage 25 or the retard oil passage 26.
The connection between the oil tank 27 and the hydraulic pump 22, the advance oil passage 25 and the retard oil passage 26 is switched by a hydraulic control valve 24.

  The hydraulic control valve 24 includes an electromagnetic solenoid 61 and a spool 63 that is pressed by a spring 62. The spool 63 moves against the pressing force of the spring 62 when the electromagnetic solenoid 61 is energized. The connection between the oil tank 27 and the hydraulic pump 22 and the advance oil passage 25 and the retard oil passage 26 is switched depending on the position of the spool 63 that has moved. Here, the position of the spool 63 is controlled by the value of the current supplied to the electromagnetic solenoid 61. The value of the current supplied to the electromagnetic solenoid 61 is controlled by duty ratio control by the ECU 100. As a result, the hydraulic control valve 24 adjusts the flow rate and direction of the hydraulic oil supplied to the valve timing adjusting device 10.

  Specifically, in the hydraulic control valve 24, a position where hydraulic oil pumped up from the oil tank 27 by the hydraulic pump 22 is supplied to the advance hydraulic chambers 51 to 54 according to the value of the current supplied to the electromagnetic solenoid 61, or The spool 63 can be moved to a position to be supplied to the retarded hydraulic chambers 55 to 58.

  Further, in the hydraulic control valve 24, the spool is set at a position where the supply of hydraulic fluid to any of the advance hydraulic chambers 51 to 54 and the retard hydraulic chambers 55 to 58 is blocked by the value of the current supplied to the electromagnetic solenoid 61. 63 can be moved. In the following, the position where the supply of hydraulic fluid to any of the advance hydraulic chambers 51 to 54 and the retard hydraulic chambers 55 to 58 is referred to as “holding position”.

  The ECU 100 controls the hydraulic control valve 24. That is, the ECU 100 controls the value of the current supplied to the electromagnetic solenoid 61 of the hydraulic control valve 24 by duty ratio control, and moves the spool 63 by controlling the value of the current supplied to the electromagnetic solenoid 61. Incidentally, since the current value for holding the spool 63 in the holding position is a value depending on the temperature or the like, the ECU 100 has a learning function for the current value for holding the spool 63 in the holding position. Hereinafter, when the ECU 100 energizes the electromagnetic solenoid 61 with such a value as to hold the spool 63 in the holding position with respect to the hydraulic control valve 24, this is referred to as “holding position control” of the hydraulic control valve 24 by the ECU 100.

The valve timing adjustment system 1 configured as described above operates as follows.
Here, during normal engine operation, the rotation of the crankshaft is transmitted to the housing 12, the rotation of the housing 12 is transmitted to the vane rotor 14 via the hydraulic oil, and the camshaft is rotationally driven. The ECU 100 controls the hydraulic oil pressure acting on the advance hydraulic chambers 51 to 54 and the retard hydraulic chambers 55 to 58 by energizing the hydraulic control valve 24, and rotates the vane rotor 14 relative to the housing 12. The displacement angle of the camshaft with respect to the crankshaft is changed. As a result, the valve timing of the intake valve or the exhaust valve changes.

On the other hand, when the driver stops the engine with the ignition key, the stopper piston 30 is fitted into the fitting hole 34 of the housing 12, and the vane rotor 14 is held at the engine start optimum position.
However, when an unintended engine stop such as a so-called engine stall occurs, the stopper piston 30 may not be fitted into the fitting hole 34 of the housing 12 and the vane rotor 14 may not be held in the engine starting optimum position. .

Here, in the present embodiment, particularly when the engine is started next time, the ECU 100 reliably rotates the vane rotor 14 to the optimum position for starting the engine even when the engine speed is low when the engine is started. The hydraulic control valve 24 is controlled.
Details will be described below.

  The ECU 100 has an information storage unit 300 inside. The information storage unit 300 is a storage device realized as, for example, a RAM. The ECU 100 is connected to an operating state detection unit 400 and a start / stop detection unit 410.

  The driving state detection unit 400 includes a crank angle sensor 401, a cam angle sensor 402, and a hydraulic pressure sensor 403. The crank angle sensor 401 can detect the number of rotations of the crankshaft. The cam angle sensor 402 can detect the phase of the rotating camshaft. The hydraulic sensor 403 can detect the hydraulic pressure of the pump flow path 28 that connects the hydraulic pump 22 and the hydraulic control valve 24. The start / stop detection unit 410 is a device that detects start and stop of the engine, and is realized as an ignition switch 411, for example.

  As described above, in this embodiment, when it is determined that engine stall has occurred at the time of engine start, the vane rotor 14 is controlled by the control of the hydraulic control valve 24 by the ECU 100 in order to fit the stopper piston 30 to the housing 12. It is characterized by being reliably rotated. The processing will be described based on the flowchart shown in FIG.

  In the first step S101 (hereinafter, “step” is omitted and simply indicated by the symbol “S”), the engine stall information is read. In reading the engine stall information, the engine stall information stored in the information storage unit 300 is read in response to the driver turning the ignition key. Here, cranking by the starter motor is started in parallel, triggered by the driver turning the ignition key.

  In subsequent S102, it is determined whether or not an engine stall has occurred based on the engine stall information read by the engine stall information reading. Here, a positive determination is made when the engine stall information indicates that an engine stall has occurred. If it is determined that an engine stall has occurred (S102: YES), the process proceeds to S103. On the other hand, when it is determined that the engine stall has not occurred (S102: NO), the subsequent processing is not executed and this processing is terminated.

  In S103, which is shifted to when it is determined that an engine stall has occurred, hydraulic control valve holding position control is performed. That is, the holding position control of the hydraulic control valve 24 is performed. As a result, supply of hydraulic fluid from the hydraulic pump 22 to any of the advance hydraulic chambers 51 to 54 and the retard hydraulic chambers 55 to 58 is interrupted, and therefore the hydraulic pump 22 and the hydraulic control valve 24 are connected. The hydraulic oil pressure increases in the pump flow path 28.

Next, in S104, the pump passage hydraulic pressure is read out. In the pump passage hydraulic pressure reading, the hydraulic pressure of the hydraulic oil in the pump passage 28 is detected by the hydraulic pressure sensor 403.
In subsequent S105, it is determined whether or not the pump passage hydraulic pressure read out by the pump passage hydraulic pressure readout has reached the vane rotor rotation hydraulic pressure. Here, an affirmative determination is made when the pump passage hydraulic pressure reaches the vane rotor rotation hydraulic pressure.

If it is determined that the pump passage hydraulic pressure has reached the vane rotor rotation hydraulic pressure (S105: YES), the flow proceeds to S106.
On the other hand, when it is determined that the pump passage hydraulic pressure has not reached the vane rotor rotation hydraulic pressure (S105: NO), the process proceeds to S103. That is, the holding position control of the hydraulic control valve 24 is performed until the pump passage hydraulic pressure rises to the vane rotor rotation hydraulic pressure. As a result, the hydraulic pressure of the pump passage 28 is increased to the vane rotor rotation hydraulic pressure.

In S106, which is shifted to when it is determined that the pump passage hydraulic pressure has reached the vane rotor rotation hydraulic pressure, the vane rotor phase is read out. In the vane rotor phase reading, the vane rotor phase detected by the cam angle sensor 402 is read.
In subsequent S107, the holding position control of the hydraulic control valve 24 is released.
Next, in S <b> 108, the vane rotor 14 is rotated so that the stopper piston 30 is fitted in the fitting hole 34 of the housing 12.

  Next, in S109, it is determined whether or not the engine has completely exploded. Specifically, when the engine speed detected by the crank angle sensor 401 exceeds a predetermined speed, an affirmative determination is made. Here, “complete explosion” refers to “a state in which the engine can maintain its rotation by itself after imparting an initial rotation (cranking) by a starter motor or the like”.

Here, when it is determined that the engine is completely detonated (S109: YES), the cranking is terminated and the present process is terminated.
On the other hand, when it is determined that the engine is not completely exploded (S109: NO), the process proceeds to S103. That is, the holding position control of the hydraulic control valve 24 is performed again, the hydraulic oil pressure in the pump passage 28 is increased to the vane rotor rotation hydraulic pressure, and the vane rotor 14 is rotated. These series of processes are repeated until the engine is completely detonated.

  In S101 described above, the engine stall information is read from the information storage section 300, but the engine stall information is stored in the information storage section 300 as follows. That is, the engine stall information storage unit stores engine stall information indicating that engine stall has occurred only when the stopper piston 30 is not fitted into the housing 12 when the engine is stopped. Here, the engine stall information storage unit determines that the stopper piston 30 is fitted in the housing 12 when the rotation angle of the vane rotor 14 is the same as the optimum engine start position.

  Note that the ECU 100 in this embodiment constitutes “engine information storage means”, “vane rotor rotating means”, and “holding control means”. Further, S101 in FIG. 4 corresponds to the processing as the function of the “entist information reading unit”, S102 corresponds to the processing as the function of the “entist information determination unit”, and S103 as the function of the “holding control unit”. S105 corresponds to the processing as the function of the “hydraulic pressure judging means”, S107 corresponds to the processing as the function of the “holding control releasing means”, and S108 as the function of the “vane rotor rotating means”. S109 corresponds to the processing as a function of the “complete explosion determination means”.

  Here, the above process will be described with reference to FIG. FIG. 3 shows the engine rotation speed, the current value for the hydraulic control valve 24, the pump passage hydraulic pressure, the phase of the vane rotor 14 and the time until the engine is normally operated after an unintended engine stop such as an engine stall occurs. It is a figure which shows how the state of the stopper piston 30 changes.

  After an unintended engine stop such as an engine stall has occurred, the stopper piston 30 is not fitted in the fitting hole 34 of the housing 12, and for example, the vane rotor 14 is positioned at the most retarded position. . In the hydraulic control valve 24, for example, when the current value is 100 mA, the spool 63 is located at a position where the hydraulic oil is supplied to the advance hydraulic chambers 51 to 54 by the hydraulic pump 22, and when the current value is 550 mA, When the spool 63 is held at the holding position and the current value is 1000 mA, the spool 63 is located at a position where the hydraulic oil is supplied to the retarded hydraulic chambers 55 to 58 by the hydraulic pump 22. In addition, when the engine speed detected by the crank angle sensor 401 exceeds 700 rpm, it is determined that the engine has completely exploded.

  At time t <b> 1, the engine stall information stored in the information storage unit 300 is read, triggered by the driver turning the ignition key. Further, cranking by the starter motor is started in parallel. At this time, the engine speed is 200 rpm (S101).

  Subsequently, based on the engine stall information read from the information storage unit 300, it is determined whether an engine stall has occurred (S102). Here, it is determined that an engine stall has occurred (S102: YES), energization of the hydraulic control valve 24 is started at 550 mA, and the spool 63 is held in the holding position (S103). As a result, the pump passage hydraulic pressure gradually increases after time t1.

  At time t2, it is determined that the pump passage hydraulic pressure detected by the hydraulic sensor 403 has reached the vane rotor rotation hydraulic pressure (S104, S105: YES).

  Here, the vane rotor phase detected by the cam angle sensor 402 is read (S106). Based on the read vane rotor phase, the direction and phase for rotating the vane rotor 14 to the optimum engine start position are determined. The value of the current to be supplied to the hydraulic control valve 24 is determined from these values. Here, since the vane rotor 14 is located at the most retarded position, the value of the current supplied to the hydraulic control valve 24 is changed from 550 mA to 100 mA in order to rotate the vane rotor 14 to the advance side. Thereby, the holding position control of the hydraulic control valve 24 is released (S107).

  By changing the current value to 100 mA, the spool 63 is positioned at a position where the hydraulic oil is supplied to the advance hydraulic chambers 51 to 54 by the hydraulic pump 22. As a result, hydraulic oil is supplied to the advance hydraulic chambers 51 to 54, and the vane rotor 14 is rotated to the advance side by the vane rotor rotation hydraulic pressure at times t2 to t3 (S108).

At time t <b> 3, the vane rotor 14 is positioned at the engine start optimum position, and the stopper piston 30 is fitted into the fitting hole 34 of the housing 12.
At time t4, the engine rotation reaches 700 rotations, and it is determined that the engine has completely exploded (S109: YES), normal operation of the engine is started, and normal control of the valve timing adjustment system 1 is performed.

  In the valve timing adjustment system 1 of the present embodiment, the stopper piston 30 corresponds to a “regulating member” in the claims, the hydraulic oil corresponds to “working fluid” in the claims, and the advance oil passage 25. And the retarded oil passage 26 corresponds to the “flow path” in the claims, the hydraulic control valve 24 corresponds to the “flow path switching valve” in the claims, and the oil tank 27 corresponds to “ It corresponds to a “working fluid reservoir”.

According to the valve timing adjustment system 1 of the present embodiment configured as described above, the pump flow passage hydraulic pressure is increased to the vane rotor rotational hydraulic pressure by controlling the hydraulic control valve 24, so that the engine start with a low engine speed is performed. Even in this case, the vane rotor 14 can be reliably rotated by the vane rotor rotation hydraulic pressure.
Accordingly, even when the vane rotor 14 is not in the restricted position due to an unintended engine stop or the like, the vane rotor 14 can be reliably rotated to the optimum position for starting the engine, and as a result, the engine can be started smoothly. Is done.

As mentioned above, this invention is not limited to the said form at all, In the range which does not deviate from the meaning of invention, it can implement with a various form.
(A) In the above embodiment, the hydraulic pressure determination means determines whether or not the pump flow hydraulic pressure has reached the vane rotor rotation hydraulic pressure based on the value of the pump flow hydraulic pressure detected by the hydraulic sensor 403. Instead of this, the hydraulic pressure determination means may determine whether or not the holding time during which the hydraulic pressure control valve 24 is held by the holding control means is equal to or longer than a predetermined time. Specific processing will be described based on the flowchart of FIG.

  In FIG. 4, the processing of S201 to S203 and S206 to S209 is the same as the processing of S101 to S103 and S106 to S109 in FIG. That is, in the present embodiment, only the processing of S204 and S205 is different from the processing shown in the flowchart of FIG. Hereinafter, only the processing of S204 and S205 in FIG. 4 will be described.

In S204, the holding time is read. In the holding time reading, the time during which the hydraulic control valve 24 is in the holding position control is detected.
In subsequent S205, it is determined whether or not the holding time read in the holding time reading is equal to or longer than a predetermined time T. Here, an affirmative determination is made when the holding time is equal to or longer than the predetermined time T.

  If it is determined that the holding time is equal to or longer than the predetermined time T (S205: YES), the process proceeds to S206. On the other hand, when it is determined that the holding time is less than the predetermined time T (S205: NO), the process proceeds to S203. That is, the holding position control of the hydraulic control valve 24 is performed until the holding time becomes equal to or longer than the predetermined time T. The fixed time T is a time required for raising the hydraulic pressure of the pump passage 28 to the vane rotor rotation hydraulic pressure by holding position control by the hydraulic control valve 24. Thereby, the hydraulic pressure of the pump flow path 28 can be increased to the vane rotor rotation hydraulic pressure.

  This embodiment is the same as the above configuration in that the pump passage hydraulic pressure is increased to the vane rotor rotation hydraulic pressure by controlling the hydraulic control valve 24. As a result, the same effects as in the above embodiment are produced.

(B) In the above embodiment, the complete explosion determining means determines that the complete explosion has occurred when the engine rotational speed detected by the crank angle sensor 401 exceeds a predetermined rotational speed. It may be determined that a complete explosion has occurred when the phase of the camshaft detected by 402 is equal to the optimum engine start position.
(C) In the above embodiment, the optimum engine start position is the most advanced angle position that the vane 41 can take, but the optimum engine start position may be the most advanced angle position that the vane 41 can take. Alternatively, it may be an intermediate position between the most advanced position and the most retarded position that the vane 41 can take.

  1: valve timing adjustment system, 6: camshaft, 8: gear, 10: valve timing adjustment device, 11: sprocket, 12: housing, 14: vane rotor, 15: shoe housing, 17: bolt, 19: bolt, 22: Hydraulic pump, 24: hydraulic control valve (flow path switching valve), 25: advance oil path (flow path), 26: retard oil path (flow path), 27: oil tank (working fluid reservoir), 30: Stopper piston (regulating member), 34: fitting hole, 40: rotor, 41-44: vane, 50: vane accommodating chamber, 51-54: advance hydraulic chamber, 55-58: retard hydraulic chamber, 100: ECU (Control unit, engine stall information storage means, vane rotor rotating means, holding control means, engine stall information reading means, engine stall information determining means, oil pressure determining means, holding control releasing means, vane rotor Motion means, complete explosion determining means), 300: information storage unit, 400: operating condition detecting unit, 401: crank angle sensor, 402: a cam angle sensor, 403: pressure sensor, 410: start stop detection unit, 411: Ignition switch

Claims (8)

A housing that rotates with one of a drive shaft and a driven shaft of an internal combustion engine, a vane rotor that rotates with the other of the drive shaft and the driven shaft, and is driven to rotate relative to the housing by the pressure of a working fluid; and A regulating member which is accommodated in the vane rotor so as to be projectable, and projects from the vane rotor and fits into the housing, thereby restricting relative rotational driving of the vane rotor with respect to the housing at a regulating position; and the drive shaft and the driven A valve timing adjusting device that adjusts the opening / closing timing of at least one of the intake valve and the exhaust valve of the internal combustion engine driven to open / close by the driven shaft by adjusting a phase with the shaft;
A hydraulic pump that supplies the working fluid from the working fluid reservoir in which the working fluid is stored to the valve timing adjusting device;
A flow path switching valve for switching a flow path for supplying a working fluid from the working fluid reservoir to the valve timing adjusting device;
A control unit for controlling the flow path switching valve;
A valve timing adjustment system comprising:
The controller is
Engine information storage means for storing engine information indicating whether or not an engine stall has occurred when the internal combustion engine is stopped;
Vane rotor rotating means for rotating the vane rotor so that the regulating member fits into the housing;
When it is determined that engine stall has occurred based on the engine stall information stored by the engine engine information storage means at the time of starting the internal combustion engine, the hydraulic pressure is applied before the vane rotor rotation mechanism rotates the vane rotor. The pump passage hydraulic pressure, which is the pressure of hydraulic oil in the flow passage connecting the pump and the flow passage switching valve, is increased to the vane rotor turning hydraulic pressure at which the vane rotor can be turned by the vane rotor turning means. Holding control means for holding the flow path switching valve at a holding position where hydraulic fluid is not supplied to the valve timing adjusting device from the hydraulic pump via the flow path switching valve;
A valve timing adjustment system comprising: The controller is
Engine information reading means for reading the engine information stored by the engine information storage means when starting the internal combustion engine;
2. The valve timing adjustment system according to claim 1, further comprising an engine stall information determination unit configured to determine whether engine stall has occurred based on the engine stall information read by the engine stall information reading unit. The controller is
Oil pressure judging means for judging whether or not the pump passage oil pressure has reached the vane rotor rotation oil pressure;
When it is determined that the pump passage hydraulic pressure has reached the vane rotor rotation hydraulic pressure, holding control release means for releasing the holding at the holding position of the passage switching valve;
The valve timing adjustment system according to claim 1, wherein: The controller is
4. The valve timing adjusting system according to claim 3, wherein the vane rotor is rotated by the vane rotor rotating means after being released by the holding control releasing means.   The hydraulic pressure determination unit detects the pump flow path hydraulic pressure, and determines whether the pump flow path hydraulic pressure has reached the vane rotor rotation hydraulic pressure based on a detection value of the pump flow path hydraulic pressure. The valve timing adjustment system for an internal combustion engine according to claim 3 or 4.   The hydraulic pressure determination means detects a holding time in which the flow path switching valve is held at a holding position by the holding control means instead of detecting the pump flow path hydraulic pressure, and the detected holding time is a fixed time. 6. It is determined whether or not the pump flow path hydraulic pressure has reached the vane rotor rotation hydraulic pressure by determining whether or not the above is true. Valve timing adjustment system for internal combustion engines.   2. The engine stall information storage unit stores engine stall information indicating that an engine stall has occurred only when the regulating member is not fitted in the housing when the engine is stopped. The valve timing adjustment system as described in any one of -6.   8. The valve timing according to claim 7, wherein the engine information storage unit determines that the restricting member is fitted in the housing when the rotation angle of the vane rotor is the same as the restricting position. Adjustment system.

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