WO2008042622A1 - Dispositif de mise en phase de came pour réduction de durée d'ouverture de soupape variable (vedr) - Google Patents

Dispositif de mise en phase de came pour réduction de durée d'ouverture de soupape variable (vedr) Download PDF

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Publication number
WO2008042622A1
WO2008042622A1 PCT/US2007/079110 US2007079110W WO2008042622A1 WO 2008042622 A1 WO2008042622 A1 WO 2008042622A1 US 2007079110 W US2007079110 W US 2007079110W WO 2008042622 A1 WO2008042622 A1 WO 2008042622A1
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WO
WIPO (PCT)
Prior art keywords
phaser
valve
retard
chamber
control valve
Prior art date
Application number
PCT/US2007/079110
Other languages
English (en)
Inventor
James Sisson
Marty Gardner
Braman Wing
Original Assignee
Borgwarner Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Borgwarner Inc filed Critical Borgwarner Inc
Publication of WO2008042622A1 publication Critical patent/WO2008042622A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
    • F01L1/344—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
    • F01L1/3442—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear using hydraulic chambers with variable volume to transmit the rotating force
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/14—Tappets; Push rods
    • F01L1/16—Silencing impact; Reducing wear
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
    • F01L1/344—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
    • F01L1/3442—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear using hydraulic chambers with variable volume to transmit the rotating force
    • F01L2001/34423—Details relating to the hydraulic feeding circuit
    • F01L2001/34426—Oil control valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L2810/00—Arrangements solving specific problems in relation with valve gears
    • F01L2810/03—Reducing vibration

Definitions

  • the invention pertains to the field of variable cam timing. More particularly, the invention pertains to a variable event duration reduction (VEDR) cam phaser.
  • VEDR variable event duration reduction
  • the performance of an internal combustion engine is improved by the use of dual camshafts, one to operate the intake valves of the various cylinders of the engine and the other to operate the exhaust valves.
  • one of the camshafts may be driven by the crankshaft of the engine, through a sprocket and chain drive or a belt drive, and the other of such camshafts would be driven by the first, through a second sprocket and chain drive or a second belt drive.
  • both of the camshafts are driven by a single crankshaft powered chain drive or belt drive.
  • Engine performance in an engine with dual camshafts can be further improved, in terms of idle quality, fuel economy, reduced emissions or increased torque, by changing the positional relationship of one of the camshafts, usually the camshaft which operates the intake valves of the engine, relative to the other camshaft and relative to the crankshaft, to thereby vary the timing of the engine in terms of the operation of intake valves relative to its exhaust valves or in terms of the operation of its valves relative to the position of the crankshaft.
  • VCT variable camshaft timing
  • Working hydraulic chambers are created by imposing either single or multiple vanes of a rotor attached to the camshaft into a cavity in a housing that is attached to the camshaft sprocket.
  • the circumferential length of the pocket or cavity in the housing determines the relative phase travel of the camshaft relative to the sprocket/housing.
  • the control is accomplished by exhausting fluid such as oil from one chamber while simultaneously filling the opposing chamber. This causes the variable camshaft timing mechanism to move the camshaft relative to the crankshaft manifested in a phase position.
  • the rate of change of the camshaft phasing is determined in part by how fast the oil can exhaust from the resisting or draining hydraulic chamber. As the rotor of the VCT reaches the end of its travel limited by the cavity of the housing, the rotor will impact the housing and cause undesirable noise. As can be seen, there is a need to reduce the noise at the end of travel of the vanes while maintaining a suitable rate of change in the phase position of the camshaft.
  • U.S. Patent No. 4,601,231 shows a rotary actuator that restricts oil flow to prevent leakage without using the sealing members of the vane and reduces the velocity of the vane as it approaches impact with the housing, thus cushioning the impact of the vane against the stops.
  • Multiple passages and switches are used to move oil to separate passages as the vane nears the stop.
  • the vane is used to block the primary passage and switch to the bypass circuit. Specifically, the vane blocks a main path and oil is supplied to a subpath. A small amount of oil flows into the bypath and the majority of the oil flows and pushes against a ball valve, which is in opposition to a spring.
  • U.S. Patent No. 5,002,023 describes a VCT system within the field of the invention in which the system hydraulics includes a pair of oppositely acting hydraulic cylinders with appropriate hydraulic flow elements to selectively transfer hydraulic fluid from one of the cylinders to the other, or vice versa, to thereby advance or retard the circumferential position of a camshaft relative to a crankshaft.
  • the control system utilizes a control valve in which the exhaustion of hydraulic fluid from one or another of the oppositely acting cylinders is permitted by moving a spool within the valve one way or another from its centered or null position.
  • the movement of the spool occurs in response to an increase or decrease in control hydraulic pressure, Pc, on one end of the spool and the relationship between the hydraulic force on such end and an oppositely direct mechanical force on the other end which results from a compression spring that acts thereon.
  • U.S. Patent No. 5,107,804 describes an alternate type of VCT system within the field of the invention in which the system hydraulics include a vane having lobes within an enclosed housing which replace the oppositely acting cylinders disclosed by the aforementioned U.S. Patent No. 5,002,023.
  • the vane is oscillatable with respect to the housing, with appropriate hydraulic flow elements to transfer hydraulic fluid within the housing from one side of a lobe to the other, or vice versa, to thereby oscillate the vane with respect to the housing in one direction or the other, an action which is effective to advance or retard the position of the camshaft relative to the crankshaft.
  • the control system of this VCT system is identical to that divulged in U.S. Patent No. 5,002,023, using the same type of spool valve responding to the same type of forces acting thereon.
  • U.S. Patent Nos. 5,172,659 and 5,184,578 both address the problems of the aforementioned types of VCT systems created by the attempt to balance the hydraulic force exerted against one end of the spool and the mechanical force exerted against the other end.
  • the improved control system disclosed in both U.S. Patent Nos. 5,172,659 and 5,184,578 utilizes hydraulic force on both ends of the spool.
  • the hydraulic force on one end results from the directly applied hydraulic fluid from the engine oil gallery at full hydraulic pressure, P s .
  • the hydraulic force on the other end of the spool results from a hydraulic cylinder or other force multiplier which acts thereon in response to system hydraulic fluid at reduced pressure, Pc, from a PWM solenoid.
  • U.S. Patent No. 5,657,725 shows a control system which utilizes engine oil pressure for actuation.
  • the system includes a camshaft having a vane secured to an end thereof for non-oscillating rotation therewith.
  • the camshaft also carries a housing which can rotate with the camshaft but which is oscillatable with the camshaft.
  • the vane has opposed lobes which are received in opposed recesses, respectively, of the housing.
  • the recesses have greater circumferential extent than the lobes to permit the vane and housing to oscillate with respect to one another, and thereby permit the camshaft to change in phase relative to a crankshaft.
  • the camshaft tends to change direction in reaction to engine oil pressure and/or camshaft torque pulses which it experiences during its normal operation, and it is permitted to either advance or retard by selectively blocking or permitting the flow of engine oil through the return lines from the recesses by controlling the position of a spool within a spool valve body in response to a signal indicative of an engine operating condition from an engine control unit.
  • the spool is selectively positioned by controlling hydraulic loads on its opposed end in response to a signal from an engine control unit.
  • the vane can be biased to an extreme position to provide a counteractive force to a unidirectionally acting frictional torque experienced by the camshaft during rotation.
  • U.S. Patent No. 6,250,265 shows a variable valve timing system with actuator locking for an internal combustion engine.
  • the system consists of a variable camshaft timing system comprising a camshaft with a vane secured to the camshaft for rotation with the camshaft but not for oscillation with respect to the camshaft.
  • the vane has a circumferentially extending plurality of lobes projecting radially outwardly therefrom and is surrounded by an annular housing that has a corresponding plurality of recesses each of which receives one of the lobes and has a circumferential extent greater than the circumferential extent of the lobe received therein to permit oscillation of the housing relative to the vane and the camshaft while the housing rotates with the camshaft and the vane.
  • Oscillation of the housing relative to the vane and the camshaft is actuated by pressurized engine oil in each of the recesses on opposed sides of the lobe therein, the oil pressure in such recess being preferably derived in part from a torque pulse in the camshaft as it rotates during its operation.
  • An annular locking plate is positioned coaxially with the camshaft and the annular housing and is moveable relative to the annular housing along a longitudinal central axis of the camshaft between a first position, where the locking plate engages the annular housing to prevent its circumferential movement relative to the vane and a second position where circumferential movement of the annular housing relative to the vane is permitted.
  • the locking plate is biased by a spring toward its first position and is urged away from its first position toward its second position by engine oil pressure, to which it is exposed by a passage leading through the camshaft, when engine oil pressure is sufficiently high to overcome the spring biasing force, which is the only time when it is desired to change the relative positions of the annular housing and the vane.
  • the movement of the locking plate is controlled by an engine electronic control unit either through a closed loop control system or an open loop control system.
  • a phaser for an internal combustion engine having at least one camshaft comprising: a housing, a rotor and a control valve.
  • the housing has an outer circumference for accepting drive force.
  • the rotor connects to the camshaft coaxially located within the housing.
  • the rotor has a plurality of vanes separates a chamber formed between the housing and rotor into an advance chamber and a retard chamber.
  • the control valve has an advanced position, a retard position, and a valve event reduction position (VEDR).
  • VEDR valve event reduction position
  • In the advanced position fluid flows to the advance chamber to move the vane towards the advanced position.
  • the retard position fluid flows to the retard chamber to move the vane towards the retard position.
  • VEDR position fluid flows between the advance chamber and the retard chamber allowing the vane to oscillate.
  • Fig. Ia shows a schematic of the phaser of the present invention moving towards the retard position in cam torque actuated (CTA) mode.
  • CTA cam torque actuated
  • Fig. Ib shows a schematic of the phaser of the present invention moving towards the advance position in CTA mode.
  • Fig. Ic shows a schematic of the phaser of the present invention in the null position in CTA mode.
  • Fig. Id shows a side view of the phaser of the present invention in the null position in CTA mode.
  • Fig. 2a shows a schematic of the phaser of the present invention in valve event duration reduction (VEDR) mode.
  • VEDR valve event duration reduction
  • Fig. 2b shows a side view of the phaser of the present invention in VEDR mode.
  • Fig. 3 shows a schematic of the phaser of the present invention showing the VEDR cushion stop check valves.
  • Fig. 4a shows a side view of the VEDR cushion stop.
  • Fig. 4b shows a close up side view of the VEDR cushion stop.
  • Fig. 5 shows a schematic of an alternate embodiment of the phaser of the present invention in valve event duration reduction (VEDR) mode.
  • VEDR valve event duration reduction
  • Fig. 6 shows a flowchart of the control of the phaser between CTA mode and VEDR mode.
  • variable camshaft timing (VCT) mechanism use one or more "vane phasers" on the engine camshaft (or camshafts, in a multiple-camshaft engine).
  • VCT variable camshaft timing
  • the phasers have a rotor with one or more vanes, mounted to the end of the camshaft, surrounded by a housing with the vane chambers into which the vanes fit. It is possible to have the vanes mounted to the housing, and the chambers in the rotor, as well.
  • the housing's outer circumference forms the sprocket, pulley or gear accepting drive force through a chain, belt, or gears, usually from the crankshaft, or possible from another camshaft in a multiple-cam engine.
  • cam phasers are relatively slow acting devises and can advance or retard the camshaft, but to change between positions will take may engine cycles to accomplish, even at engine cranking speeds.
  • a cam torque actuated phaser may be actuated rapidly enough that during one valve event, the phaser is at a fully retarded position when the valve is opening and moving towards peak valve lift, and once the peak valve lift is reached, the phaser, through camshaft torque then rapidly moves to an advance position, reaching a fully advanced position before the valve closes. The net effect is retarding the valve opening and advancing the valve closing within one valve event, thus reducing the event duration, but not the valve lift.
  • the phaser of the present invention is preferably used at the lowest speed (engine cranking speed) during engine cold- starting.
  • the intake valve opening occurs after top dead center, resulting in a period of high air velocity past the intake valve seat as the valve is opening and the piston velocity is rising, enhancing fuel-air mixing and improving hydrocarbon emissions during the first several firing cycles of the engine.
  • the intake valve closing is preferably near the bottom dead center, maximizing the effective compression ratio, aiding combustion by maximizing the peak mixture temperature prior to ignition.
  • the CTA VEDR phaser is preferably used with V6, 13, single cylinder, 12, V-twin, boxer 4, and V-4 applications, since the valve events can not overlap on a given shaft.
  • the phaser of the present invention switches between two modes of function, a cam torque actuated mode (CTA) and a valve event duration reduction (VEDR) mode.
  • CTA cam torque actuated mode
  • VEDR valve event duration reduction
  • the housing 101 of the phaser has an outer circumference 100 for accepting drive force.
  • the rotor 105 is connected to the camshaft 126 and is coaxially located within the housing 101.
  • the rotor 105 has a vane 104 separating a chamber formed between the housing 101 and the rotor 105 into an advance chamber 102 and a retard chamber 103.
  • the vane 104 is capable of rotation to shift the relative angular position of the housing 101 and the rotor 105.
  • a phase control valve preferably a spool valve 109, includes a spool 111 with cylindrical lands Ilia, 11 Ib, and 111c slidably received in a sleeve 116 with a vent 122 that is received by a bore 121 preferably in the camshaft 126, although the bore 121 may also be in the rotor 105.
  • the spool 111 also has a central passage or spool bypass consisting of a closed end bore 11 Id with the open end blocked by a plug 11 Ie at the first end of the spool 111 in contact with the variable force solenoid (VFS) 107.
  • VFS variable force solenoid
  • the spool bypass also extends to the spool body 11 If between the first land Ilia and the second land 11 Ib and the spool body 11 Ig between the second land 11 Ib and the third land 11 Ic.
  • the position of the spool 111 is influenced by spring 115 and a variable force solenoid (VFS) 107 controlled by the ECU 106. Further detail regarding control of the phaser is discussed below in regards to Figure 6.
  • the position of the spool 111 controls the motion, (e.g. to move towards the advance position or the retard position) of the phaser and moving the phaser into the VEDR mode.
  • VEDR valve event duration reduction
  • Makeup oil is supplied to the phaser from supply S to make up for leakage and enters line 119 and moves through inlet check valve 118 to the spool valve 109. From the spool valve 109, fluid enters line 114 through either of the check valves 108, 110, depending on which is open to the chambers 102, 103.
  • Figure Ib shows the phaser moving towards the advance position in CTA mode.
  • the force of the VFS 107 was increased and the spool 111 was moved to the right by the VFS 107, until the force of the spring 115 balanced the force of the VFS 107.
  • the solenoid's 107 duty cycle for the CTA mode is limited so that the travel of the spool 111 of the spool valve 109 is also limited. From the null position the spool 111 travels within a set distance range that allows the spool to actuate the phaser from a null position to an advance position through cam torque actuation and from a null position to a retard position through cam torque actuation.
  • VEDR valve event duration reduction
  • spool land 11 Ib blocks line 112 and lines 113 and 114 are open.
  • Camshaft torque pressurizes the retard chamber 103, causing fluid to move from the retard chamber 103 and into the advance chamber 102 and the vane 104 to move in the direction indicated by arrow 130.
  • Fluid exits from the retard chamber 103 through line 113 to the spool valve 109 between spool lands 111b and 111c and recirculates back to central line 114 and line 112 leading to the advance chamber 102.
  • Fluid will also fill the central passage 11 Id, however fluid will only flow out of the spool valve 109 to the central line 114, since fluid is blocked from exiting the spool 111 by the plug 11 Ie and by the sleeve 116.
  • Makeup oil is supplied to the phaser from supply S to make up for leakage and enters line 119 and moves through inlet check valve 118 to the spool valve 109. From the spool valve 109, fluid enters line 114 through either of the check valves 108, 110, depending on which is open to the chambers 102, 103.
  • Figures Ic and Id show the phaser is a null position. In this position the force of the VFS 107 on one end of the spool 111 equals the force of the spring 115 on the opposite end of the spool 111.
  • the lands 11 Ib and 111c block the flow of fluid to lines 112 and 113 respectively.
  • Makeup oil is supplied to the phaser from supply S to make up for leakage and enters line 119 and moves through inlet check valve 118 to the spool valve 109. From the spool valve 109, fluid enters line 114 and through either of the check valves 108, 110 to lines 112 and 113 leading to the advance and retard chambers 102, 103 respectively. Fluid will also fill the central passage 11 Id, however fluid will only flow out of the spool valve 109 to the central line 114, since fluid is blocked from exiting the spool 111 by the plug 11 Ie and by the sleeve 116.
  • FIGS 2a through 4b show the phaser of the present invention in valve event duration reduction (VEDR) mode.
  • VEDR valve event duration reduction
  • the duty cycle of the VFS 107 is increased to or decreased to move the spool beyond the travel used to actuate the phaser to an advanced position in CTA mode or to actuate the phaser to a retarded position in CTA mode.
  • the VFS duty cycle required to actuate the phaser in CTA mode to an advanced or retarded position may for example be 0% to 50% and for VEDR mode 100%.
  • the force of the VFS 107 on the one side of the spool 111 is greater than the force of the spring 115 on the opposite side of the spool 111, such that the spool 111 is moved to a position in which the spool 111 is all the way in the sleeve 116, beyond the travel of necessary to actuate the phaser to an advanced or retarded position in CTA mode, the spring 115 is compressed, spool land 111b partially blocks both lines 112 and 114, spool land 111c partially blocks line 113, and the central passage 11 Id within the spool 111 is open to fluid to and from all of the lines.
  • line 112 is open to the central passage 11 Id at a port 11 If of the spool body between the first land Ilia and the second land 11 Ib and lines 114 and 113 are open to the central passage 11 Id at port 11 Ig of the spool body between the second land 11 Ib and the third land 11 Ic.
  • the central passage 11 Id open to all lines, oil may flow freely from the advance chamber 102 to the retard chamber 103 and vice versa.
  • the oil circuit created between the two chambers 102, 103 and through the central passage 11 Id of the spool 111 essentially bypasses the high pressure check valves 108 and 110.
  • VEDR mode in this embodiment, it is possible for the phaser to be at a fully retarded position when the valve is moving towards peak valve lift, and once peak valve is reached, camshaft torque will rapidly fully advance the camshaft 126 before the valve closes, having the net effect of retarding the valve opening and advancing the valve closing within one valve event, thus reducing the valve event duration, and modulating the valve lift slightly.
  • At least one chamber formed between the housing 101 and the rotor 105 is fully restricted at least a number degrees before the mechanical stop or the housing walls 101a, 101b in both directions by using hydraulic cushioned stops.
  • the number of degrees at which the at least one chamber formed between the housing 101 and the rotor 105 is fully restricted is preferably 5 degrees, but may be more or less depending on the application, spool travel, and tolerances.
  • the hydraulic cushioned stops eliminate the impact force of the vane 104 with the advance wall 101a and the retard wall 101b of the chamber formed between the housing 101 and the rotor 105 housing the vane 104.
  • a pad 152 is present along at least a portion of either side 104a, 104b of the vane 104 for contacting the advance and retard walls 101a, 101b of the housing 101, but still allowing a small amount of fluid to be present between the vane walls 104a, 104b and the advance or retard wall 101a, 101b depending on the position of the phaser.
  • the fluid present or trapped between the vane walls 104a, 104b, the pads 152, and the housing walls 101a, 101b provides the hydraulic cushioning.
  • the fluid trapped between the vane walls 104a, 104b, the pads 152 and the housing walls 101a, 101b is allowed to leak out from the chambers through clearances.
  • the clearances may be adjusted to either increase the leak rate or slow the leak rate down. Depending on the clearances chosen and the resulting leak rates, the damping rate of the phaser may be altered.
  • the port to the advance or retard line 112, 113 is restricted and then blocked and rotated under the housing 101 at the degree of cushion stop chosen.
  • the port to the advance or retard line 112, 113 rotates under the housing 101 until aligned with axial cushion stop check valves 151a, 151b in the housing 101 and a hydraulic cushion is formed between the vane walls 104a, 104b and pads 152 and the walls 101a, 101b of the housing 101, defining the chamber which receives the vane 104.
  • the fluid of the hydraulic cushion will leak out through clearances.
  • the phaser may be held in the fully retarded position or the fully advanced position with the port of the advance and retard lines 112, 113 when the lines are aligned with the cushioned stop check valves 151a, 151b, by moving the spool 111 from the position shown in Figures 2a, 2b, and 3 to the spool position shown in Figure Ic.
  • phaser may be rapidly actuated in the opposite direction once peak valve lift is achieved.
  • the movement will be described for a phaser moved to a fully retarded position and then rapidly actuated to a fully advanced position.
  • cam torque pressurizes the retard chamber 103, causing fluid in the retard chamber 103 to move to the advance chamber 102. Fluid exits the retard chamber 103 through line 113 and to the spool valve 109. In the spool valve 109, fluid moves to the port 11 Ig in the spool body between the second land 11 Ib and the third land 111c through the spool bypass 11 Id and out through the port 11 If of the spool body between the first land Ilia and the second land 111b leading to the advance line 112.
  • the advance line 112 is open to filling the chambers 102, 103, and aids in filling the advance chamber 102 with the cushion stop check valves 151a, 151b and the hydraulic cushioning, allowing a rapid switch between a fully retard position and a fully advance position, at peak valve lift.
  • the VEDR mode of the phaser may be used at engine startup. To position the spool valve 109 correctly, the VFS 107 would be commanded to a duty cycle equivalent to VEDR mode before engine cranking to move the spool beyond the travel used to actuate the phaser to an advanced position in CTA mode or to actuate the phaser to a retarded position in CTA mode.
  • the spool 111 moves to the position shown in Figures 2a through 4, and then the cam may be set to the fully retarded position prior to peak valve lift and then at peak valve lift the cam is then moved to the fully advanced position, reaching the fully advanced position prior to the valve closing. The net effect is retarding the valve opening and advancing the valve closing within one valve event, thus reducing the event duration, but not the valve lift.
  • the valve lift is modulated when the phaser is in VEDR mode.
  • the spool lands 211a, 211b, 211c do not partially block any of the lines 112, 113, 114, allowing uninhibited flow between the chambers 102, 103 through the spool valve 209.
  • the duty cycle of the VFS 107 is increased or decreased to move the spool beyond the travel used to actuate the phaser to an advanced position in CTA mode or to actuate the phaser to a retarded position in CTA mode.
  • the VFS duty cycle required to actuate the phaser in CTA mode to an advanced or retarded position may for example be 0% to 50% and for VEDR mode be 100%.
  • the force of the VFS 107 on the one side of the spool 211 is greater than the force of the spring 115 on the opposite side of the spool 211, such that the spool 211 is moved to a position in which the spool 211 is all the way in the sleeve 216, beyond the travel of necessary to actuate the phaser to an advanced or retarded position in CTA mode, the spring 215 is compressed, all lines, 112, 114, and 113 are open to receiving fluid.
  • Fluid in lines 114 and 113 cannot directly flow to line 112, since spool land 211b is present between lines 112 and 114. Instead, fluid is fluid flows to and from lines 113 and 114 to and from line 112 through central passage 21 Id within the spool 211, which is open to fluid from all of the lines.
  • line 112 is open to the central passage 21 Id at a port 21 If of the spool body between the first land 211a and the second land 21 Ib and lines 114 and 113 are open to the central passage 21 Id at port 21 Ig of the spool body between the second land 21 Ib and the third land 211c.
  • the central passage 21 Id open to all lines, oil may flow freely from the advance chamber 102 to the retard chamber 103 and vice versa.
  • the oil circuit created between the two chambers 102, 103 and through the central passage 21 Id of the spool 211 essentially bypasses the high pressure check valves 108 and 110.
  • VEDR mode it is possible for the phaser to be at a fully retarded position when the valve is moving towards peak valve lift, and once peak valve is reached, camshaft torque will rapidly fully advance the camshaft 126 before the valve closes, having the net effect of retarding the valve opening and advancing the valve closing within one valve event, reducing the valve event duration, but not valve lift.
  • a hydraulic locking pin is not present since the VEDR operation preferably occurs prior to the phaser having engine oil pressure. To ensure the phaser is kept full of oil during engine shutoff, seals or a sealing feature are present within and on the phaser.
  • FIG. 6 shows a flowchart of control of the phaser 160.
  • the ECU 106 will command the phaser 160 to either a VEDR mode or a mode that changes the phase of the phaser through a phaser controller 178.
  • the phaser controller includes a normal mode controller 168, a valve event reduction (VEDR) controller 162, and a switch 170. If the ECU 106 commands the phaser 160 to VEDR mode, an "on" command 166 is sent to the VEDR controller 162. From the VEDR controller 162, a VEDR command equivalent to the corresponding duty cycle 164 set to VEDR mode, is sent to a switch 170.
  • the ECU 106 also sends a switch logic signal 174 controlling where the command signal will be received from.
  • the % duty cycle 164 from the VEDR controller 162 is inputted into the a proportional valve 107, shown as a VFS, and the VFS moves the position of the spool 111, 211, aiding in moving the phaser 160 to VEDR position and mode.
  • a phase setpoint signal 172 is not sent to the normal mode controller 168 when VEDR mode is given an "on" command signal 166 from the ECU 106.
  • the position of the phaser 160 is sent to the normal mode controller 168 in a phaser position feedback loop 176.
  • a phase setpoint signal 172 is sent to the normal mode controller 168 and an "off" command 166 is sent to the VEDR controller 162.
  • a % duty cycle equivalent to spool position, other than VEDR mode is sent to switch 170.
  • the ECU 106 also sends a switch logic signal 174 controlling where the command signal will be received from.
  • the % duty cycle 163 from the normal mode controller 168 is inputted into the proportional valve 107, shown as a VFS, and the VFS moves the position of the spool 111, 211, aiding in moving the phaser 160 to the phase setpoint 172 established by the ECU 106.
  • the position of the phaser 160 is sent to the normal mode controller 168 in a phaser position feedback loop 176.
  • position feedback may also be used by the controller when the phaser is in VEDR mode.
  • VEDR control may not be on/off control, but instead the VEDR controller 162 may control the upper duty cycle range and the normal mode controller 168 may control the lower duty cycle range or vice versa depending on what % duty cycle is established as equivalent to the moving the phaser to VEDR mode.
  • a sensor 180 providing engine input such as rpm may be connected to switch 170, and based on whether the rpm exceed a predetermined value, either the normal mode controller 168 or the VEDR controller 162 sends a signal to switch 170, which them commands the proportional valve 107 to move the spool to the appropriate position.
  • the phaser controller 178 may be incorporated into any vehicle regardless of the ECU.
  • the cushion stop check valves may axial or radial and may also be reed type check valves.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve Device For Special Equipments (AREA)

Abstract

La présente invention concerne un dispositif de mise en phase pour moteur à combustion interne comportant au moins un arbre à cames, lequel dispositif de mise en phase comprend: un logement, un rotor et une soupape de commande. Le logement présente une périphérie extérieure pour accepter une force motrice. Le rotor est relié à l'arbre à cames coaxialement placé à l'intérieur du logement. Le rotor comporte une pluralité de palettes divisant une chambre formée entre le logement et le rotor en une chambre d'avance et une chambre de retardement. La soupape de commande peut se mettre en position avancée, en position de retardement ou en position de réduction de durée d'ouverture de soupape (VEDR). En position avancée, le fluide s'écoule vers la chambre d'avance pour déplacer la palette en direction de la position avancée. En position de retardement, le fluide s'écoule vers la chambre de retardement pour déplacer la palette en direction de la position de retardement. En position de réduction de durée d'ouverture de soupape, le fluide s'écoule entre la chambre d'avance et la chambre de retardement, permettant ainsi à la palette d'osciller.
PCT/US2007/079110 2006-09-29 2007-09-21 Dispositif de mise en phase de came pour réduction de durée d'ouverture de soupape variable (vedr) WO2008042622A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US82746206P 2006-09-29 2006-09-29
US60/827,462 2006-09-29
US90901207P 2007-03-30 2007-03-30
US60/909,012 2007-03-30

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Publication Number Publication Date
WO2008042622A1 true WO2008042622A1 (fr) 2008-04-10

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Application Number Title Priority Date Filing Date
PCT/US2007/079110 WO2008042622A1 (fr) 2006-09-29 2007-09-21 Dispositif de mise en phase de came pour réduction de durée d'ouverture de soupape variable (vedr)
PCT/US2007/079107 WO2008042621A1 (fr) 2006-09-29 2007-09-21 Dispositif de réduction de la durée d'ouverture d'une soupape avec amortissement

Family Applications After (1)

Application Number Title Priority Date Filing Date
PCT/US2007/079107 WO2008042621A1 (fr) 2006-09-29 2007-09-21 Dispositif de réduction de la durée d'ouverture d'une soupape avec amortissement

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Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008037997B4 (de) 2008-08-16 2019-08-22 Schaeffler Technologies AG & Co. KG Vorrichtung zur variablen Einstellung der Steuerzeiten von Gaswechselventilen einer Brennkraftmaschine
CN102144079B (zh) * 2008-09-19 2014-03-05 博格华纳公司 在一个凸轮轴或多个同心凸轮轴中内装的相位器
DE102013207615B4 (de) * 2013-04-26 2021-05-12 Schaeffler Technologies AG & Co. KG Nockenwellenverstelleinrichtung mit einer Mittenverriegelung
DE102014214610B4 (de) * 2014-07-25 2017-05-18 Schaeffler Technologies AG & Co. KG Nockenwellenverstellvorrichtung für eine Brennkraftmaschine
JP2019027435A (ja) 2017-07-31 2019-02-21 ボーグワーナー インコーポレーテッド ｅ−位相器クッション止め部

Citations (4)

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Publication number Priority date Publication date Assignee Title
US5172659A (en) * 1989-10-16 1992-12-22 Borg-Warner Automotive Transmission & Engine Components Corporation Differential pressure control system for variable camshaft timing system
JP2004108370A (ja) * 2002-09-19 2004-04-08 Borgwarner Inc 可変カムシャフトタイミング機構
US6745732B2 (en) * 2002-06-17 2004-06-08 Borgwarner Inc. VCT cam timing system utilizing calculation of intake phase for dual dependent cams
US6883481B2 (en) * 2001-08-14 2005-04-26 Borgwarner Inc. Torsional assisted multi-position cam indexer having controls located in rotor

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5172659A (en) * 1989-10-16 1992-12-22 Borg-Warner Automotive Transmission & Engine Components Corporation Differential pressure control system for variable camshaft timing system
US6883481B2 (en) * 2001-08-14 2005-04-26 Borgwarner Inc. Torsional assisted multi-position cam indexer having controls located in rotor
US6745732B2 (en) * 2002-06-17 2004-06-08 Borgwarner Inc. VCT cam timing system utilizing calculation of intake phase for dual dependent cams
JP2004108370A (ja) * 2002-09-19 2004-04-08 Borgwarner Inc 可変カムシャフトタイミング機構

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