JP2019157813A - Control device of variable capacity oil pump and control method - Google Patents

Abstract

To provide a control device of a variable valve mechanism in which an actual phase angle can be early converged to a target phase angle, and a control method.SOLUTION: When a target phase angle is changed, a control device of a variable valve mechanism acquires a deviation angle between the target phase angle and an actual phase angle, also when the deviation angle is larger than a prescribed first deviation angle threshold, the control device controls the discharge pressure of a variable capacity oil pump so as to be boosted, and when the deviation angle becomes smaller than a second deviation angle threshold, the control device controls the discharge pressure of the variable capacity oil pump so as to be lowered. By this constitution, when the deviation angle is large than the prescribed first deviation angle threshold, the control device controls the discharge pressure of the variable capacity oil pump so as to be boosted, also when the deviation angle becomes smaller than the second deviation angle threshold, the control device controls the discharge pressure of the variable capacity oil pump so as to be lowered, and an actual phase angle can be thereby early converted to the target phase angle.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a control device and a control method for a variable displacement oil pump used in an internal combustion engine, and more particularly to a control device and a control method for a variable displacement oil pump that supplies hydraulic oil to a variable valve mechanism.

  Conventionally, in a variable displacement oil pump as disclosed in Patent Document 1, the target discharge pressure of hydraulic oil is generally set lower as the rotational speed of the internal combustion engine is lower, and the target discharge of hydraulic oil is increased as the rotational speed increases. The pressure is set high. For example, the rotation speed range is divided into a low rotation speed area, a medium rotation speed area, and a high rotation speed area, and the target discharge pressure is set to low pressure, medium pressure, high pressure in each rotation speed area. Has been done.

  Further, since the hydraulic VTC mechanism is configured to operate in a wide range of the rotational speed of the internal combustion engine from the low rotational speed region to the high rotational speed region, the hydraulic oil having the target discharge pressure in each rotational speed region is generated. To be supplied. That is, as the rotational speed increases, low pressure, medium pressure, and high pressure hydraulic oil are sequentially supplied to the hydraulic VTC mechanism. This will be described in detail with reference to FIG.

JP 2014-159760 A

By the way, when the speed of the internal combustion engine is increased from a low speed to a predetermined speed by depressing the accelerator pedal, the target phase angle of the intake valve that is the engine valve is shifted to the advance side, and the hydraulic VTC mechanism is The hydraulic oil is controlled by the control valve so that the actual phase angle of the intake valve (hereinafter referred to as the actual phase angle) matches the target phase angle. In this case, the variable displacement oil pump is controlled so as to maintain the target discharge pressure in the low rotation speed region substantially constant.

  Therefore, when the target discharge pressure of the hydraulic oil discharged from the variable displacement oil pump is controlled in a low state corresponding to the current low speed, the hydraulic pressure is changed when the target phase angle of the intake valve is changed. A phenomenon occurs in which the actual phase angle obtained by the VTC mechanism cannot reach the target phase angle early.

  To cope with this, for example, when the target discharge pressure of hydraulic oil is changed to a high pressure state by a signal from an accelerator switch or the like, the hydraulic valve with high discharge pressure is supplied to the variable valve mechanism, and the target phase angle is changed. In addition, the actual phase angle exceeds the target phase angle to cause overshoot, and in order to converge this, the actual phase angle oscillates across the target phase angle, resulting in a phenomenon that the target phase angle cannot be settled early.

  The above phenomenon describes the case where the rotational speed is increased and the target phase angle is changed to the advance side. However, even when the rotational speed is decreased and the target phase angle is changed to the retarded side, the hydraulic pressure is changed. The same phenomenon occurs only by switching the hydraulic chamber of the VTC mechanism. This is particularly noticeable when the rotational speed transitions from a low rotational speed region to a direction in which the rotational speed rapidly increases or decreases.

  An object of the present invention is to provide a variable displacement oil pump capable of shortening the settling time to the target phase angle by suppressing the vibration of the actual phase angle at an early stage when the actual phase angle by the hydraulic VTC reaches the target phase angle early. A control device and a control method are provided.

  The feature of the present invention is that when the target phase angle is changed, the first target discharge pressure higher than the current target discharge pressure of the variable displacement oil pump is set, and the subsequent target discharge pressure is set higher first. The second target discharge pressure is lower than the first target discharge pressure.

  More specifically, when the target phase angle is changed, a deviation angle between the target phase angle and the actual phase angle is obtained, and when the deviation angle is larger than a predetermined first deviation angle threshold, the target of the variable displacement oil pump is determined. When the discharge pressure is set to a first corrected target discharge pressure that is higher than the current target discharge pressure and the deviation angle is smaller than a predetermined second deviation angle threshold value that is smaller than the first deviation angle threshold value, the first correction that has been set previously The second corrected target discharge pressure is lower than the target target discharge pressure.

  According to the present invention, the actual phase angle due to the hydraulic VTC reaches the target phase angle at an early stage, and the settling time to the target phase angle can be shortened by suppressing the vibration of the actual phase angle.

1 is a schematic configuration diagram of an internal combustion engine including a hydraulic VTC mechanism according to an embodiment of the present invention. It is a block diagram explaining the change method of the phase angle by the hydraulic VTC mechanism shown in FIG. It is a block diagram explaining the schematic structure of the variable capacity oil pump system in FIG. It is explanatory drawing explaining the pressure control of the hydraulic fluid by the variable capacity oil pump which becomes this embodiment. It is a flowchart figure explaining the first half of the control flow which becomes the 1st Embodiment of this invention. It is a flowchart figure explaining the second half of the control flow of FIG. 5A. It is explanatory drawing explaining the relationship between the pressure control of the hydraulic fluid by the variable capacity oil pump which becomes the 1st Embodiment of this invention, and the phase angle by a hydraulic VTC mechanism. It is a flowchart figure explaining the principal part of the control flow which becomes the 2nd Embodiment of this invention. It is explanatory drawing explaining the pressure control of the hydraulic fluid by the variable capacity oil pump which becomes the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and application examples are included in the technical concept of the present invention. Is also included in the range.

  FIG. 1 is a schematic configuration diagram of an internal combustion engine provided with a hydraulic VTC mechanism according to an embodiment of the present invention.

  The intake pipe 11 for introducing air into each cylinder of the internal combustion engine 1 is provided with an intake air amount sensor 12 for detecting the intake air flow rate QA of the internal combustion engine 1. As the intake air amount sensor 12, for example, a hot-wire flow meter that detects the mass flow rate of intake air can be used.

  The intake valve 13 opens and closes the intake port of the combustion chamber 14 of each cylinder, and is provided with a fuel injection valve 15 for each cylinder in the intake pipe 11 upstream of the intake valve 13. The fuel injected from the fuel injection valve 15 is sucked together with air into the combustion chamber 14 via the intake valve 13 and ignited and burned by spark ignition by the spark plug 16, and the pressure by this combustion causes the piston 17 to be applied to the crankshaft 18. The crankshaft 18 is rotationally driven by being pushed down. The crank angle sensor 27 detects the rotation angle of the crankshaft 18 and outputs a reference position signal REF and a unit angle signal POS of the crankshaft 18.

  Each of the spark plugs 16 is directly attached with an ignition module 19 that supplies ignition energy to the spark plug 16. The ignition module 19 includes an ignition coil and a power transistor that controls energization to the ignition coil.

  The exhaust valve 20 opens and closes the exhaust port of the combustion chamber 14, and the exhaust valve 20 is opened so that exhaust gas is discharged to the exhaust pipe 21. A catalytic converter 22 having a three-way catalyst or the like is installed in the exhaust pipe 21, and exhaust gas is purified by the catalytic converter 22. An air-fuel ratio sensor 23 is installed in the exhaust pipe 21 upstream of the catalytic converter 22 to detect the air-fuel ratio A / F based on the oxygen concentration in the exhaust.

  The intake valve 13 and the exhaust valve 20 operate in accordance with the rotation of the intake camshaft 24 and the exhaust camshaft 25 that are rotationally driven by the crankshaft 18. The intake valve 13 is opened and closed by a cam provided on the intake camshaft 24, and its phase angle (valve opening operating angle) is variable by the hydraulic VTC mechanism 26, so that the valve timing of the intake valve 13 is advanced, Be retarded. The hydraulic VTC mechanism 26 is configured to change the phase angle by switching the hydraulic passage by the solenoid valve 34.

  The cam angle sensor 28 detects a reference position signal (intake camshaft rotation angle signal) CAM from the intake camshaft 24. On the other hand, the exhaust valve 20 is driven to open and close by a cam provided on the exhaust camshaft 25.

  The water temperature sensor 29 detects the temperature (water temperature) TW of the cooling water of the internal combustion engine 1. The oil temperature sensor 33 detects the oil temperature TO of the working oil in the oil pan or in the circulation path of the working oil (engine oil). Further, the accelerator opening sensor 30 detects the amount of depression of the accelerator pedal 31 (accelerator opening ACC).

  The control device (control device: Engine Control Unit) 6 includes a microcomputer, and signals from various sensors provided in the internal combustion engine 1, for example, intake air flow rate QA, accelerator opening degree ACC, reference position signal REF, unit angle A signal POS, an air-fuel ratio A / F, a water temperature TW, an oil temperature TO, a rotation angle signal CAM, and the like are input.

  Further, the control device 6 receives a signal indicating the state of an ignition switch 32 that is a main switch for operating and stopping the internal combustion engine 1. Based on this information, the control device 6 performs arithmetic processing in accordance with a program stored in advance, calculates the operation amounts or control amounts of various devices such as the fuel injection valve 15, the solenoid valve 34, and the ignition module 19, and so on. A control signal is output to the device.

  The internal combustion engine 1 can be of various types such as a V type or a horizontally opposed type in addition to the illustrated serial type. Here, the fuel injection valve 15 injects fuel into the intake pipe 11 as an example, but a direct injection type internal combustion engine that injects fuel directly into the combustion chamber 14 may be used. Further, in addition to the intake side VTC mechanism 26, an exhaust side VTC mechanism that makes the opening / closing timing (valve timing) of the exhaust valve 20 variable may be provided.

  FIG. 2 shows an essential part extracted from the valve timing change by the hydraulic VTC mechanism 26 in FIG. The hydraulic VTC mechanism 26 is disposed at one end of an intake camshaft 24 (see FIG. 1) provided with an intake cam for opening and closing the intake valve 13. The hydraulic VTC mechanism 26 is configured by combining a sprocket 41 that rotates in synchronization with the crankshaft 18 of the internal combustion engine 1 and a rotor 42 that is rotatably connected integrally with the intake camshaft 24 so as to be relatively rotatable. ing. The sprocket 41 is connected to the crankshaft 18 of the internal combustion engine 1 by a timing belt (not shown), and rotates in synchronization with the crankshaft 18.

  The sprocket 41 is provided with a cylindrical housing 43 that accommodates the rotor 42. The housing 43 has a cylindrical shape in which both front and rear ends are formed, and the inner circumferential surface has a trapezoidal cross section, and partition walls 43a, 43b, and 43c provided along the axial direction of the housing 43 respectively protrude. It is installed. A plurality of vanes 42 a, 42 b, 42 c extending in the radial direction are formed on the outer periphery of the rotor 42, and accommodating portions 44 a, 44 b, 44 c for accommodating these vanes 42 a, 42 b, 42 c are formed on the inner periphery of the housing 43. Has been.

  Each of the vanes 42a, 42b, and 42c has a substantially inverted trapezoidal cross section, and the accommodating portions 44a, 44b, and 44c are separated in the front-rear direction in the rotational direction, and both sides of the vanes 42a, 42b, and 42c, and the partition wall portions 43a and 43b. , 43c are formed with advance side hydraulic chambers 45a, 45b, 45c and retard side hydraulic chambers 46a, 46b, 46c.

  The first hydraulic passage 47 supplies and discharges hydraulic pressure to the advance side hydraulic chambers 45a, 45b and 45c, and the second hydraulic passage 48 supplies and discharges hydraulic pressure to the retard side hydraulic chambers 46a, 46b and 46c. To do. A hydraulic oil supply passage 49 and drain passages 50 and 51 are connected to both the hydraulic passages 47 and 48 via a passage-switching solenoid valve 34, respectively.

  The hydraulic oil supply passage 49 is provided with a variable displacement oil pump 54 that pumps hydraulic oil in the oil pan 53, and the downstream ends of the drain passages 50 and 51 communicate with the oil pan 53. In the solenoid valve 34, an internal spool valve body 34b relatively controls switching between the hydraulic passages 47 and 48, the hydraulic oil supply passage 49, and the drain passages 50 and 51.

  The control device 6 controls the energization amount for the solenoid 34a that drives the solenoid valve 34 based on a duty control signal (operation amount) on which a dither signal is superimposed. In the hydraulic VTC mechanism 26, when an off control signal with a duty ratio of 0% is output to the solenoid 34 a, the hydraulic oil pumped from the variable capacity oil pump 54 passes through the hydraulic passage 48 and the retard side hydraulic chambers 46 a, 46 b, The hydraulic oil in the advance side hydraulic chambers 45 a, 45 b and 45 c is discharged from the drain passage 51 into the oil pan 53 through the hydraulic passage 47.

  As described above, when an OFF control signal with a duty ratio of 0% is supplied to the solenoid, the internal pressure of the retard side hydraulic chambers 46a, 46b, 46c increases while the internal pressure of the advance side hydraulic chambers 45a, 45b, 45c decreases. Thus, the rotor 42 rotates to the maximum retardation side via the vanes 42a, 42b, and 42c. As a result, the opening period of the intake valve 13 changes with a delay relative to the piston position. That is, when the energization to the solenoid 34a is cut off, the central phase of the valve operating angle of the intake valve 13 changes with a delay, and finally stops at the most retarded position.

  When an ON control signal with a duty ratio of 100% is output to the solenoid, the spool valve body 34b is driven in the direction of the arrow, and the hydraulic oil is supplied to the advance side hydraulic chambers 45a, 45b, 45c through the hydraulic passage 47. As the internal pressure increases, the hydraulic oil in the retarded-side hydraulic chambers 46a, 46b, 46c passes through the hydraulic passage 48 and the drain passage 50 and is discharged to the oil pan 53, where the retarded-side hydraulic chambers 46a, 46b, 46c The internal pressure is lowered.

Thus, when an ON control signal with a duty ratio of 100% is supplied to the solenoid 34b,
The rotor 42 rotates to the maximum advance side via the vanes 42a, 42b, and 42c, whereby the opening period of the intake valve 13 (the central phase of the valve operating angle) is advanced relative to the piston position. Change.

  Therefore, by changing the duty ratio of the control signal supplied to the solenoid 34b, the phase angle of the intake valve 13 can be controlled to an arbitrary position between the most retarded position and the most advanced position. Therefore, by adjusting the advance amount of the intake valve 13 according to the operating state of the internal combustion engine 1, the opening / closing timing, the valve overlap between the intake valve 13 and the exhaust valve 20, etc. can be changed.

  FIG. 3 shows a configuration example of a variable displacement oil pump 54 that variably controls the target discharge pressure of hydraulic oil in FIG. 2 in accordance with the rotational speed as shown in FIG.

  A suction port and a discharge port are provided on both sides of the pump housing 61, and a drive shaft 62 through which a rotational force is transmitted from the crankshaft 18 of the internal combustion engine 1 is disposed through substantially the center. Inside the pump housing 61, a rotor 64, which is coupled to a drive shaft 62 and holds a plurality of vanes 63 on the outer peripheral side so as to be able to advance and retreat in a substantially radial direction, is provided on the outer peripheral side of the rotor 64 so as to be able to swing eccentrically. The cam ring 65 in which the tip of each vane 63 is in sliding contact with the inner peripheral surface is accommodated. A pair of vane rings 72 are slidably disposed on both side surfaces on the inner peripheral side of the rotor 64.

  The cam ring 65 swings in a direction in which the amount of eccentricity is reduced around the pivot pin 69 in accordance with the discharge pressure introduced into the working chambers 67 and 68 that are separated by seal members 66a and 66b on the outer periphery. The coil spring 70 is configured to swing in a direction in which the amount of eccentricity is increased by the spring force of the coil spring 70 that presses the lever portion 65a that is integrally provided on the outer periphery thereof.

  In the initial state, the cam ring 65 is urged by the spring force of the coil spring 70 in the direction in which the amount of eccentricity is maximized to increase the discharge pressure. On the other hand, when the hydraulic pressure in the working chamber 67 exceeds a predetermined value, The discharge pressure is decreased by swinging in the direction in which the amount of eccentricity is reduced against the spring force of the coil spring 70.

  The working oil 67 is supplied from the oil main gallery 73 to the working chamber 67 of the variable capacity oil pump 54, and the working oil is supplied to the working chamber 68 via the oil control valve 71 including a proportional solenoid valve. Oil is supplied to the above-described hydraulic VTC mechanism of the internal combustion engine 1, an oil jet mechanism that cools the piston, a lubrication mechanism for a crank metal that is a bearing portion of the crankshaft, and the like. The oil control valve 71 is duty controlled.

  When the oil control valve 71 has a duty of 100%, the working chamber 67 communicates with the drain (oil pan 53) and enters a low pressure state. On the other hand, when the oil control valve 71 has a duty of 0%, hydraulic pressure is applied to the working chamber 67. Therefore, it will be in a high pressure state. The discharge pressure is adjusted by the adjusted duty value between 100% duty and 0% duty.

  The oil control valve 71 is supplied with a control signal (duty signal) from the control device 6 which is a control device, whereby the proportional solenoid 71 is driven to the instructed control position. Also. An oil pressure sensor 74 is disposed in the oil main gallery 73 and detects the discharge pressure of the variable capacity oil pump 54. The output of the hydraulic sensor 74 is input to the control device 6 and used for feedback control of the discharge pressure of the variable capacity oil pump 54 to the target discharge pressure. Of course, it can be used for other controls.

  In such a variable capacity oil pump 54, for example, a discharge pressure is set corresponding to the rotational speed. As shown in FIG. 4, the discharge pressure is set in association with the increase in the rotation speed, and the discharge pressure is within the range from the predetermined minimum rotation speed to the predetermined maximum rotation speed. The range is adjusted. The hydraulic oil discharge pressure can be adjusted by the duty ratio of the control signal applied to the oil control valve 71 (see FIG. 3).

  Therefore, if the duty ratio of the control signal is associated with the rotation speed, the target discharge pressure of the variable displacement oil pump 54 is basically variably adjusted according to the rotation speed, and further detected by the hydraulic sensor 74. The discharged pressure is feedback controlled to the set target discharge pressure.

  In addition, since it is possible to perform so-called feedforward control in which the actual discharge pressure is controlled only by the target discharge pressure without performing feedback control, both controls can be applied in this embodiment.

  As described above, when the speed of the internal combustion engine is increased from a low speed to a predetermined speed in the low speed range by depressing the accelerator pedal, the target phase angle of the intake valve is shifted to the advance side, The hydraulic VTC mechanism controls the hydraulic oil by the control valve so that the actual phase angle of the intake valve matches the target phase angle. However, when the target discharge pressure of the variable displacement oil pump is controlled to be low, the actual phase angle obtained by the hydraulic VTC mechanism reaches the target phase angle early when the target phase angle of the intake valve is changed. The phenomenon that it is not possible occurs.

  To cope with this, when the target discharge pressure of hydraulic oil is changed to a high pressure state, hydraulic oil with a high discharge pressure is supplied to the variable valve mechanism, and when the target phase angle is changed, the actual phase angle becomes the target phase. Overshoot occurs beyond the angle, and the actual phase angle oscillates, resulting in a phenomenon that the target phase angle cannot be settled early.

  Therefore, in the first embodiment of the present invention, when the target phase angle is changed to the advance side, a first target discharge pressure that is higher than the current target discharge pressure of the variable displacement oil pump is set, and thereafter A configuration is proposed in which the target discharge pressure is reset to a second target discharge pressure that is lower than the first target discharge pressure that is set high.

  More specifically, when the target phase angle is changed to the advance side, the deviation angle between the target phase angle and the actual phase angle is obtained, and if this deviation angle is larger than a predetermined first deviation angle threshold, the variable capacity When the target discharge pressure of the oil pump is set to the first corrected target discharge pressure that is higher than the current target discharge pressure, and when the deviation angle is smaller than the predetermined second deviation angle threshold value that is smaller than the first deviation angle threshold value, it is set higher first. A configuration is proposed in which the second corrected target discharge pressure is set lower than the first corrected target discharge pressure.

  First, before describing the present embodiment, the characteristics of the target discharge pressure of the variable capacity oil pump will be described. As shown in FIG. 4, three types of rotation speed region and target discharge pressure are set. Corresponding to the increase in the number of revolutions, the range from the number of revolutions (N1) that is the low number of revolutions to less than the number of revolutions (N2) is set as the first pressure control region, ) From the above to less than the rotational speed (N3) is set as the second pressure control region, and the rotational speed (N3) which is the high rotational speed region is set as the third pressure control region. Here, the rotational speed has a relationship of N1 <N2 <N3.

  The first pressure control region is set to the first target discharge pressure (P1), the second pressure control region is set to the second target discharge pressure (P2), and the third pressure control region is set to the third target discharge pressure (P1). P3). In this case, the control duty of the oil control valve 71 is set to 80% for the first target discharge pressure (P1), 40% for the second target discharge pressure (P2), and the third target discharge pressure (P3). ) Is set to 0%, and the target discharge pressure increases as the control duty value decreases. Here, the target discharge pressure has a relationship of P1 <P2 <P3.

  Thus, the reason why the target discharge pressure is set stepwise with respect to the increase in the rotational speed is to reduce the pump drive loss as much as possible and improve the fuel efficiency of the internal combustion engine. For example, if proportional control is performed from the first pressure control region to the third pressure control region, extra work must be performed by the difference from the characteristic of FIG. 4, but if the control is performed as in the present embodiment, the above-described difference is reduced. This is because the output of the internal combustion engine can be saved as a result.

  Further, each target discharge pressure is set corresponding to a hydraulic auxiliary mechanism provided in the internal combustion engine, and the first target discharge pressure (P1) corresponds to the hydraulic VTC mechanism, and the second target discharge pressure ( P2) corresponds to the oil jet mechanism, and the third target discharge pressure (P3) corresponds to the crank metal lubrication mechanism.

  For this reason, the hydraulic VTC mechanism is driven by hydraulic oil having a target discharge pressure in the first pressure control region, the second pressure control region, and the third pressure control region, and the oil jet mechanism is driven by the second pressure control region and the third pressure control region. The crank metal lubrication mechanism is driven by hydraulic oil having a target discharge pressure in the third pressure control region. Since the oil jet mechanism and the crank metal lubrication mechanism are well-known structures, description thereof is omitted.

  Next, a control flowchart according to the first embodiment will be described with reference to FIGS. 5A, 5B, and 6. This control flow is a control flow of the variable displacement oil pump, and a target phase angle of the hydraulic VTC mechanism. And the hydraulic VTC mechanism drive control based on this calculation is executed by another VTC control flow. However, the VTC phase angle information such as the target phase angle and the actual actual phase angle is obtained by the VTC control flow and stored in a well-known work area (RAM). From step S10 in FIG. It has been read.

  This control flow is started at the start timing every 10 ms cycle, and the start timing is generated by a compare match interrupt of a timer function built in the microcomputer. Then, the following control steps are executed upon arrival of the activation timing.

  Further, the following control steps are executed based on a program of the microcomputer, but these control steps can be replaced with a control function executed by the control means (microcomputer).

  Here, when the target phase angle of the intake valve is changed, the phenomenon that the actual phase angle obtained by the hydraulic VTC mechanism cannot reach the target phase angle early occurs mainly because the rotational speed of the internal combustion engine is low. Since this is the first pressure control region, the following description will be given assuming this first pressure control region. Therefore, the target discharge pressure is basically controlled to the first target discharge pressure (P1).

<< Step S10 >>
In step S10, the rotation speed is detected by the crank angle sensor 27, the oil temperature of the hydraulic oil is detected by the oil temperature sensor 33, the discharge pressure of the hydraulic oil is detected by the hydraulic sensor 74, and these detected parameters are And temporarily stored in the work area of the microcomputer. It should be noted that any other necessary parameters may be detected as appropriate. When a necessary parameter is detected, the process proceeds to step S11.

  Although not described here, in the VTC control flow of the hydraulic VTC mechanism, the target phase angle is obtained according to the rotational speed and load, and the actual actual phase angle is detected and stored in the work area of the RAM. ing. Therefore, in this control step, the VTC phase angle such as the target phase angle and the actual phase angle is read from the work area. The hydraulic VTC mechanism performs the operation shown in FIG. 2 based on the VTC control flow.

<< Step S11 >>
In step S11, the current rotational speed (Np) detected in step 10 is compared with the previous rotational speed (Np-1), and the current rotational speed (Np) is compared with the previous rotational speed (Np). -1) Judge whether it is larger. This determination determines whether or not the current rotational speed of the internal combustion engine is increasing (accelerated state). If the rotational speed of the internal combustion engine is increasing, the target phase angle (θt) is changed and the process proceeds to step S12. If the rotational speed of the internal combustion engine is decreasing, the process returns to the return and the next start timing Prepare for the arrival of .

<< Step S12 >>
Since it is determined in step S11 that the current rotational speed of the internal combustion engine is increasing (acceleration state) and the target phase angle (θt) may be changed, in step S12, step 10 The deviation angle (Δθ: θt−θa) between the target phase angle (θt) detected in step (b) and the actual phase angle (θa) is calculated. This deviation angle (Δθ) is updated to a smaller value every control period of 10 ms as the actual phase angle (θa) approaches the target phase angle (θt). When the deviation angle (Δθ) is obtained, the process proceeds to step S13.

<< Step S13 >>
In step S13, it is determined whether or not “1” is set in the first discharge pressure change flag. When "1" is set in the first discharge pressure change flag, it indicates that control steps S14, S15, and S16 described below have been executed. On the other hand, when the first discharge pressure change flag is set to “0”, the following control steps S14, S15, and S16 are not executed, and the target phase angle (θt) is changed to a predetermined angle or more for the first time. Is detected to indicate that the target discharge pressure of the variable displacement oil pump is changed.

  The first discharge pressure change flag will be described in steps S15 and S16. If “1” is set in the first discharge pressure change flag, the process proceeds to step S17. If “0” is set in the first discharge pressure change flag, the process proceeds to step S14.

<< Step S14 >>
In step S14, it is determined whether the deviation angle (Δθ) obtained in step S12 is larger than a first deviation angle threshold value (θshd1) from the target phase angle (θt). As shown in FIG. 6, when the rotational speed of the internal combustion engine increases, the target phase angle (θt) is changed, but the deviation angle (Δθ) between the current actual phase angle (θa) and the target phase angle (θt) is changed. If it is smaller than the predetermined first deviation angle threshold value (θshd1), the delay of the actual phase angle does not matter so much.

  On the other hand, when the deviation angle (Δθ) between the current actual phase angle (θa) and the target phase angle (θt) is larger than a predetermined first deviation angle threshold value (θshd1), the actual phase angle (θa) becomes the target phase angle. It takes a long time to reach (θt), resulting in a phenomenon that the actual phase angle obtained by the hydraulic VTC mechanism cannot reach the target phase angle early.

  Therefore, if it is determined in step S14 that the deviation angle (Δθ) is smaller than the predetermined first deviation angle threshold value (θshd1), the process returns to the return and prepares for the next start timing. On the other hand, if it is determined in step S14 that the deviation angle (Δθ) is larger than the predetermined first deviation angle threshold value (θshd1), the process proceeds to step S15.

  As shown in FIG. 6, this determination corresponds to time t1, and the deviation angle (Δθ) between the target phase angle (θt) and the actual phase angle (θa) at this time is the first deviation angle threshold value. The state is larger than (θshd1). From this time t1, the operation of the hydraulic VTC mechanism based on the VTC control flow, that is, the change in the relationship between the actual phase angle (θa) and the target phase angle (θt) is monitored. If it is determined that the deviation angle (Δθ) is larger than the first deviation angle threshold (θshd1), the process proceeds to step S15.

<< Step S15 >>
In step S15, the first correction target discharge pressure (Pf) is obtained by adding the first correction pressure value (ΔPf) to the current target discharge pressure (P1). As shown in FIG. 4, the current target discharge pressure of the variable displacement oil pump is the first target discharge pressure (P1) with a duty of 80%, but the first correction pressure value (ΔPf) is set to a duty of 10%. The first corrected target discharge pressure (Pf) has a duty of 70%, and a control signal having the duty of 70% is given to the oil control valve 71 of the variable displacement oil pump. Therefore, as shown in FIG. 6, the target discharge pressure (P1) is set to the first corrected target discharge pressure (Pf) at time t1, and the variable displacement oil pump is controlled based on this. When the first corrected target discharge pressure (Pf) is set, the process proceeds to step S16.

<< Step S16 >>
In step S16, “1” is set to the first discharge pressure change flag indicating that the first corrected target discharge pressure (Pf) has been set in step S15. This prevents steps S14, S15, and S16 from being executed again at the next startup timing. In this state, the state where the target discharge pressure is set to the first corrected target discharge pressure (Pf) is continued until the determination in step S18 described below. When “1” is set in the first discharge pressure change flag, the process returns to the return and prepares for the next start timing.

<< Step S17 >>
When the next activation timing arrives, “1” is set in the first discharge pressure change flag in step S13, so that the process proceeds to step S17 and this control step is executed.

  In step S17, it is determined whether or not “1” is set in the second discharge pressure change flag. When “1” is set in the second discharge pressure change flag, it indicates that control steps S22 and S23 described below have been executed. On the other hand, when the second discharge pressure change flag is “0”, the following control steps S22 and S23 are not executed, and the target discharge pressure is set to the first corrected target discharge pressure (Pf). Indicates that it continues.

  The second discharge pressure change flag will be described in steps S20 and S21. If “1” is set in the second discharge pressure change flag, the process proceeds to step S22. If “0” is set in the second discharge pressure change flag, the process proceeds to step S18.

<< Step S18 >>
In step S18, it is determined whether the deviation angle (Δθ) obtained in step S12 is larger than a second deviation angle threshold value (θshd2) from the target phase angle (θt). Here, the deviation angle (Δθ) changes to a small value because the actual phase angle (θa) approaches the target phase angle (θt) as time passes. Note that the second deviation angle threshold value (θshd2) is set to a value smaller than the first deviation angle threshold value (θshd1).

  The second deviation angle threshold (θshd2) is used to determine that the actual phase angle (θa) has approached the target phase angle (θt). As shown in FIG. 6, the current actual phase angle (θa) approaches the target phase angle (θt) over time. In this control step, the current phase angle (θt) is between the target phase angle (θt) and the actual phase angle (θa). Is determined to be larger than a predetermined second deviation angle threshold (θshd2).

  When the actual phase angle (θa) is smaller than the second deviation angle threshold value (θshd2), it indicates that there is a possibility of overshooting if the current first corrected target discharge pressure (Pf) is maintained. On the other hand, if the actual phase angle (θa) is larger than the second deviation angle threshold (θshd2), the actual first corrected target discharge pressure (Pf) is maintained and the actual phase angle (θa) obtained by the hydraulic VTC mechanism is The target phase angle (θt) is reached early.

  Therefore, if it is determined in the control step S18 that the deviation angle (Δθ) is smaller than the predetermined second deviation angle threshold value (θshd2), the process proceeds to step S20, while the deviation angle (Δθ) is the predetermined second deviation angle. If it is determined that the value is larger than the threshold value (θshd2), the process proceeds to step S19.

<< Step S19 >>
Since it is determined in step S18 that the actual phase angle (θa) is larger than the second deviation angle threshold value (θshd2), in step S19, the current first corrected target discharge pressure (Pf) is maintained and the hydraulic VTC mechanism is maintained. The actual phase angle (θa) obtained by (1) reaches the target phase angle (θt) at an early stage. Therefore, as shown in FIG. 6, the state in which the target discharge pressure is set to the first corrected target discharge pressure (Pf) from time t1 is continued. If the setting of the first corrected target discharge pressure (Pf) is maintained, the process returns to the return and prepares for the next start timing.

<< Step S20 >>
Since it is determined in step S18 that the actual phase angle (θa) is smaller than the second deviation angle threshold value (θshd2), in step S20, the second corrected pressure value (ΔPs) is set to the current target discharge pressure (P1). The second corrected target discharge pressure (Ps) is obtained by addition. Here, the second correction pressure value (ΔPs) is set to a value smaller than the first correction pressure value (ΔPf), and in the present embodiment, the second correction pressure value (ΔPs) is the first correction pressure value. The value is set to 1/2 of (ΔPf).

  Therefore, as shown in FIG. 4, the current target discharge pressure of the variable displacement oil pump is the first target discharge pressure (P1) with a duty of 80%, but the second correction pressure value (ΔPs) is set to a duty of 5%. Then, the second corrected target discharge pressure (Pf) has a duty of 75%, and a control signal with this duty of 75% is given to the oil control valve 71 of the variable capacity oil pump.

  Therefore, as shown in FIG. 6, the target discharge pressure (P1) is set to the second corrected target discharge pressure (Ps) at time t2, and the variable displacement oil pump is controlled based on this. Since the target discharge pressure of the variable displacement oil pump is set low from the first correction target discharge pressure (Pf) to the second correction target discharge pressure (Ps), the actual phase angle (θa) becomes the target phase angle (θt). The phenomenon that causes overshoot beyond the range is suppressed. As a result, the phenomenon that the actual phase angle (θa) vibrates across the target phase angle (θt) and cannot be settled to the target phase angle (θt) at an early stage can be avoided. Therefore, it is possible to suppress the vibration of the actual phase angle (θa) and shorten the settling time to the target phase angle (θt).

  Thus, from time t1 to time t2, the first corrected target discharge pressure (Pf) is set, and after time t2, the second correction target discharge pressure (Ps) lower than the first correction target discharge pressure (Pf) is set. Is set. When the second corrected target discharge pressure (Ps) is set, the process proceeds to step S21.

<< Step S21 >>
In step S21, “1” is set to a second discharge pressure change flag indicating that the second corrected target discharge pressure (Ps) has been set in step S20. This prevents steps S18 to S21 from being executed again at the next startup timing. In this state, the state where the target discharge pressure is set to the second corrected target discharge pressure (Ps) is continued until the determination in step S22 described below. When “1” is set in the second discharge pressure change flag, the process returns to the return and prepares for the next start timing.

<< Step S22 >>
When the next start timing arrives, “1” is set in the first discharge pressure change flag in step S13, and “1” is set in the second discharge pressure change flag in step S17, and the process proceeds to step S22. Thus, this control step is executed.

  In step S22, it is determined whether or not the deviation angle (Δθ) obtained in step S12 has reached an allowable deviation angle threshold value (θmgn) from the target phase angle (θt). Here, the allowable deviation angle threshold value (θmgn) is set to a value smaller than the second deviation angle threshold value (θshd2). ) Is almost reached.

  As shown in FIG. 6, the current actual phase angle (θa) approaches the target phase angle (θt) over time. In this control step, the current phase angle (θt) is between the target phase angle (θt) and the actual phase angle (θa). It is determined whether the deviation angle (Δθ) is greater than a predetermined allowable deviation angle threshold value (θmgn).

  When the actual phase angle (θa) is smaller than the allowable deviation angle threshold value (θmgn), the static settling time may be increased if the current second corrected target discharge pressure (Ps) is maintained. . On the other hand, if the actual phase angle (θa) is larger than the allowable deviation angle threshold value (θmgn), the current second corrected target discharge pressure (Ps) is maintained, and the actual phase angle (θa) obtained by the hydraulic VTC mechanism is over. The target phase angle (θt) is approached without shooting.

  Accordingly, when it is determined in step S22 that the deviation angle (Δθ) is larger than the predetermined allowable deviation angle threshold value (θmgn), the process proceeds to step S23, while the deviation angle (Δθ) is determined to be the predetermined allowable deviation angle threshold value (θmgn). If determined to be smaller than (), the process proceeds to step S24.

<< Step S23 >>
Since it is determined in step S22 that the actual phase angle (θa) is larger than the allowable deviation angle threshold value (θmgn), in step S23, the current second corrected target discharge pressure (Ps) is maintained and the hydraulic VTC mechanism is maintained. The actual phase angle (θa) obtained by the above is prevented from overshooting. Therefore, as shown in FIG. 6, the state in which the target discharge pressure is set to the second corrected target discharge pressure (Ps) from time t2 is continued. If the setting of the second corrected target discharge pressure (Ps) is maintained, the process returns to the return and prepares for the next start timing.

<< Step S24 >>
On the other hand, since it is determined in step S22 that the actual phase angle (θa) is smaller than the allowable deviation angle threshold (θmgn), that is, the actual phase angle (θa) has reached the target phase angle (θt), it is shown in FIG. At the passing time t3, the current target discharge pressure (P1) is set. When the target discharge pressure (P1) is set, the process proceeds to step S25.

<< Step S25 >>
Since it is determined in step S22 that the actual phase angle (θa) by the hydraulic VTC mechanism has reached the target phase angle (θa), in step S25, the first discharge pressure change flag and the second discharge pressure change flag described above. Is cleared to “0”. Then, return to return and prepare for the arrival of the next activation timing.

  By executing the control steps as described above, it is possible to control the target discharge pressure as shown in FIG. 6, and as a result, the actual phase angle (θa) of the intake valve is the target as shown by the solid line. The phase angle (θt) can be reached early, and the vibration of the actual phase angle (θa) can be suppressed to shorten the settling time to the target phase angle (θt).

  The broken line simply shows the case where the target discharge pressure is increased. When the target phase angle (θt) is changed, the actual phase angle (θa) exceeds the target phase angle (θt) and an overshoot occurs. In order to converge this, the actual phase angle (θa) oscillates across the target phase angle (θt), resulting in a phenomenon that the target phase angle (θt) cannot be settled early.

  In the first embodiment described above, in step S18, the deviation angle (Δθ) is compared with the second deviation angle threshold value (θshd2). Instead of the second deviation angle threshold value (θshd2), the deviation angle is changed. It can also be configured to determine whether or not the angle (Δθ) has reached a predetermined ratio of the first deviation angle (Δθ). In other words, when the deviation angle (Δθ) is obtained in step S12, the deviation angle (Δθ) is multiplied by a predetermined ratio, and this is set as a threshold value to be compared in step S18. “1/3”.

  Accordingly, in step S18, the threshold value obtained by the calculation of “(Δθ) × 1/3 in step S12” is compared with the current deviation angle (Δθ) that is changing. The subsequent control steps are the same as in the first embodiment, and the same operational effects can be obtained.

  Next, a second embodiment of the present invention will be described with reference to FIGS. The basic concept is the same as that of the first embodiment, but the setting characteristics of the second corrected target discharge pressure are different between time t2 and time t3 shown in FIG. In the first embodiment, as shown in FIG. 6, the second corrected target discharge pressure (Ps) smaller than the first corrected target discharge pressure (Pf) is simply set at time t2, but in the second embodiment, As shown in FIG. 8, the second correction target discharge pressure is continuously set to be small as time elapses.

  In FIG. 7, when “1” is set in the second discharge pressure change flag in step S <b> 17, control of the target discharge pressure after time t <b> 2 is executed as shown in FIG. 8. If the actual phase angle (θa) does not reach the target phase angle (θt) in step S22, the second corrected target discharge pressure (Ps) is controlled between time t2 and time t3. The setting of the second corrected target discharge pressure (Ps) is performed in step S26. In the present embodiment, every time the control flow is executed, in other words, the second corrected target discharge pressure (Ps) is calculated so as to continuously decrease with time.

  Therefore, as shown in FIG. 8 in accordance with the progress of the control cycle, the correction pressure value for obtaining the second correction target discharge pressure becomes smaller as ΔPs1⇒ΔPs2⇒ΔPs3, and in step S22, the actual phase If it is determined that the angle (θa) has reached the target phase angle (θt), the process proceeds to step S24 as in the first embodiment. As described above, since the second corrected target discharge pressure (Ps) is continuously reduced, overshoot can be further suppressed and the settling time can be shortened.

  Here, in step 26 shown in FIG. 7, the second correction target discharge pressure (Ps) is decreased by executing the control flow once, but the second correction target discharge pressure is passed after a plurality of control cycles. It is also possible to reduce (Ps).

  In the above-described embodiment, the case where the rotation speed is increased and the target phase angle is changed to the advance side is described, but even when the rotation speed is decreased and the target phase angle is changed to the retard side, It is possible to apply similarly.

  In the above-described embodiment, the case where the pressure characteristic of the variable displacement oil pump has a step-like characteristic as shown in FIG. 4 has been described. However, the pressure characteristic varies proportionally from the first pressure control region to the third pressure control region. Even in the case of characteristics, if the same problem as in the present invention occurs, it can be similarly applied.

  As described above, when the target phase angle is changed to the advance side, the present invention sets the first target discharge pressure higher than the current target discharge pressure of the variable capacity oil pump and sets the subsequent target discharge pressure. The second target discharge pressure is set to be lower than the first target discharge pressure that has been previously set higher. More specifically, when the target phase angle is changed to the advance side, the target phase angle and A deviation angle of the actual phase angle is obtained, and when this deviation angle is larger than a predetermined first deviation angle threshold, the target discharge pressure of the variable displacement oil pump is set to a first corrected target discharge pressure higher than the current target discharge pressure. When the deviation angle is smaller than a predetermined second deviation angle threshold value that is smaller than the first deviation angle threshold value, the second correction target discharge pressure is reset to be lower than the first correction target discharge pressure that was previously set higher. It is.

  According to this, the actual phase angle by the hydraulic VTC reaches the target phase angle at an early stage, and furthermore, the oscillation of the actual phase angle can be suppressed and the settling time to the target phase angle can be shortened.

  In addition, this invention is not limited to above-described embodiment, Various modifications are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 6 ... Control apparatus, 26 ... Variable valve mechanism (hydraulic VTC mechanism), 29 ... Water temperature sensor, 33 ... Oil temperature sensor, 34 ... Solenoid valve, 34a ... Solenoid, 54 ... Variable capacity oil pump, 71 ... oil control valve.

Claims (10)

An internal combustion engine comprising: a hydraulically driven variable valve mechanism that controls at least an opening timing (hereinafter referred to as a phase angle) of an engine valve; and a variable displacement oil pump that supplies hydraulic oil to the variable valve mechanism A variable displacement oil pump control device comprising control means for variably controlling a target discharge pressure of hydraulic oil used in the variable displacement oil pump,
The control means includes
When the target phase angle by the variable valve mechanism is changed, the first target discharge pressure higher than the current target discharge pressure of the variable displacement oil pump is set and the subsequent target discharge pressure is set first. A control apparatus for a variable displacement oil pump, comprising a function of resetting to a second target discharge pressure lower than the first target discharge pressure. An internal combustion engine comprising: a hydraulically driven variable valve mechanism that controls at least an opening timing (hereinafter referred to as a phase angle) of an engine valve; and a variable displacement oil pump that supplies hydraulic oil to the variable valve mechanism A variable displacement oil pump control device comprising control means for variably controlling a target discharge pressure of hydraulic oil used in the variable displacement oil pump,
The control means includes
When the target phase angle by the variable valve mechanism is changed, a deviation angle between the target phase angle of the engine valve and the current actual actual phase angle is obtained, and the deviation angle is a predetermined first deviation angle threshold value. If larger, the function of setting the target discharge pressure of the variable displacement oil pump to a first corrected target discharge pressure higher than the current target discharge pressure;
When the deviation angle becomes smaller than a predetermined second deviation angle threshold value smaller than the first deviation angle threshold value, a function of resetting to a second corrected target discharge pressure lower than the previously set first correction target discharge pressure is provided. A control device for a variable capacity oil pump. A control device for a variable displacement oil pump according to claim 2,
The control device for a variable displacement oil pump, wherein the engine valve is an intake valve, and the target phase angle is set to an advance side with respect to the actual phase angle. An internal combustion engine comprising: a hydraulically driven variable valve mechanism that controls at least an opening timing (hereinafter referred to as a phase angle) of an intake valve; and a variable displacement oil pump that supplies hydraulic oil to the variable valve mechanism A variable displacement oil pump control device comprising control means for variably controlling a target discharge pressure of hydraulic oil used in the variable displacement oil pump,
The control means includes
According to the rotational speed of the internal combustion engine, at least a first pressure control region corresponding to a predetermined first rotational speed range and a second pressure control corresponding to a predetermined second rotational speed range higher than the first rotational speed range. A predetermined first target discharge pressure is set in the first pressure control region, and a predetermined second target discharge pressure higher than the first target discharge pressure is set in the second pressure control region. The function to set,
When the target phase angle by the variable valve mechanism is changed to the advance side while being controlled in the first pressure control region,
A deviation angle between the target phase angle of the intake valve and the current actual actual phase angle is obtained, and when the deviation angle is larger than a predetermined first deviation angle threshold, the target discharge pressure of the variable displacement oil pump is A function of setting the first corrected target discharge pressure higher than the first target discharge pressure;
When the deviation angle is smaller than a predetermined second deviation angle threshold value that is smaller than the first deviation angle threshold value, a second correction that is lower than the previously set first correction target discharge pressure and higher than the first target discharge pressure. A control device for a variable displacement oil pump, which has a function of resetting to a target discharge pressure. A control device for a variable displacement oil pump according to claim 2 or claim 4,
The control means includes
A control apparatus for a variable displacement oil pump, comprising a function of setting a target discharge pressure lower than the second corrected target discharge pressure when the actual phase angle approaches the target phase angle. A control device for a variable displacement oil pump according to claim 2 or claim 4,
The control means includes
A control apparatus for a variable displacement oil pump, comprising: a function for obtaining the second deviation angle threshold by multiplying a first ratio by a predetermined ratio when the target phase angle is changed. A control device for a variable displacement oil pump according to claim 2 or claim 4,
The control means includes
A control apparatus for a variable displacement oil pump, comprising a function of sequentially setting the second correction target discharge pressure to be smaller as time elapses.
An internal combustion engine comprising: a hydraulically driven variable valve mechanism that controls at least an opening timing (hereinafter referred to as a phase angle) of an engine valve; and a variable displacement oil pump that supplies hydraulic oil to the variable valve mechanism A variable displacement oil pump control method comprising a control means for variably controlling a target discharge pressure of hydraulic oil used in the variable displacement oil pump,
The control means includes
When the target phase angle by the variable valve mechanism is changed,
Setting a first target discharge pressure higher than the current target discharge pressure of the variable displacement oil pump;
A control method for a variable displacement oil pump, wherein the target discharge pressure after being set to the first target discharge pressure is reset to a second target discharge pressure lower than the first target discharge pressure. An internal combustion engine comprising: a hydraulically driven variable valve mechanism that controls at least an opening timing (hereinafter referred to as a phase angle) of an engine valve; and a variable displacement oil pump that supplies hydraulic oil to the variable valve mechanism There is used a control method for a variable displacement oil pump, comprising a control means for variably controlling a target discharge pressure of hydraulic oil of the variable displacement oil pump,
The control means includes
When the target phase angle by the variable valve mechanism is changed,
Obtaining a deviation angle between the target phase angle of the engine valve and a current actual phase angle;
If the deviation angle is greater than a predetermined first deviation angle threshold, the target discharge pressure of the variable displacement oil pump is set to a first corrected target discharge pressure that is higher than the current target discharge pressure,
When the deviation angle becomes smaller than a predetermined second deviation angle threshold value smaller than the first deviation angle threshold value, a second correction target discharge pressure lower than the previously set first correction target discharge pressure is reset. Control method of variable displacement oil pump. An internal combustion engine comprising: a hydraulically driven variable valve mechanism that controls at least an opening timing (hereinafter referred to as a phase angle) of an intake valve; and a variable displacement oil pump that supplies hydraulic oil to the variable valve mechanism A variable displacement oil pump control method comprising a control means for variably controlling a target discharge pressure of hydraulic oil used in the variable displacement oil pump,
The control means includes
According to the rotational speed of the internal combustion engine, at least a first pressure control region corresponding to a predetermined first rotational speed range and a second pressure control corresponding to a predetermined second rotational speed range higher than the first rotational speed range. A predetermined first target discharge pressure is set in the first pressure control region, and a predetermined second target discharge pressure higher than the first target discharge pressure is set in the second pressure control region. Set,
When the target phase angle by the variable valve mechanism is changed to the advance side while being controlled in the first pressure control region,
Obtaining a deviation angle between the target phase angle of the intake valve and the actual actual phase angle;
If the deviation angle is greater than a predetermined first deviation angle threshold, the target discharge pressure of the variable displacement oil pump is set to a first corrected target discharge pressure that is higher than the current first target discharge pressure,
When the deviation angle is smaller than a predetermined second deviation angle threshold value that is smaller than the first deviation angle threshold value, a second correction that is lower than the previously set first correction target discharge pressure and higher than the first target discharge pressure. A control method for a variable displacement oil pump, characterized by resetting to a target discharge pressure.

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