DE102016213125A1 - Method for operating an electro-hydraulic valve control - Google Patents

Abstract

Proposed is an electrohydraulic valve control for variably actuating a gas exchange valve of an internal combustion engine, comprising: a pump, an actuator with a piston, an electrohydraulic switching valve including a 2-position solenoid valve actuator with transition control and a directional 2-position 4-way Control valve with three transition states includes - and an accumulator The valve control is to be operated in OCC mode.

Description

A hydraulic system for driving an inverse load has certain advantages over mechanical systems. In particular, in applications in the automotive industry, a variable control for implementation is very desirable with limited installation space. In such a situation, a mechanical system could be completely inappropriate.

One type of such systems is used to drive an inverse load, e.g. B. by a mechanical valve. Such a system is often referred to in the automotive industry as a valvetrain. In fact, the intake and exhaust valves in an internal combustion engine are driven by such a valvetrain. In the present case, a mechanical valve is used as a reverse load to explain the new hydraulic system. However, the use of the system is not limited to applications in valve trains.

• • Niedrige Effizienz: der Energiebedarf, um die gleiche Last anzutreiben, ist höher im Vergleich zu einem mechanischen Ventiltrieb;
• • Lüftung: die Steuerungspräzision ist in hohem Maß reduziert, weil sich im Öl des Systems Lufttaschen oder/Luftblasen befinden:
• • Befüllen/Nachfüllen der Hydraulikkammer: aus einem wenig benutzten System gibt es Ölleckagen; ein langsames Nachfüllen ist für den Endkunden nicht wünschenswert;
• • Niedrige Steuerungspräzision bei niedrigen Temperauren: wegen der hohen Viskosität des Öls verhindern bestimmte mechanische Bremssysteme eine rechtzeitige Reaktion des Systems.

A hydraulic valve train used in internal combustion engines has the following disadvantages, namely

• • Low efficiency: the energy demand to drive the same load is higher compared to a mechanical valve train;
• • Ventilation: the control precision is greatly reduced because there are air pockets or / air bubbles in the system's oil:
• • filling / refilling the hydraulic chamber: there is an oil leak from a less used system; Slow refilling is not desirable for the end user;
• • Low control precision at low temperatures: due to the high viscosity of the oil, certain mechanical brake systems prevent a timely reaction of the system.

• • Die im System verbrauchte oder nicht verbrauchte Energie optimal zu managen (oder recyceln), um die Energieeffizienz des Systems durch die Strategie des Energiemanagements zu steigern;
• • Das System rechtzeitig zu entlüften (Luftblasen und Lufttaschen zu entfernen), um die Entlüftung des Systems effektiv zu gestalten und den Energieverlust zu minimieren;
• • Die richtigen Stellen in den Bauteilen mit Hydrauliköl zu versorgen und ein schnelles und effektives Befüllen/und Nachfüllen des Systems zu ermöglichen;
• • Für das Ein-/Ausschalten des Ölpfads zum Bremsventil, Software zu verwenden, um bei niedriger Temperatur den Aktuator weniger (oder nicht) zu bremsen und bei hoher Temperatur stark zu bremsen.

In the following, a new hydraulic system is disclosed. The system is designed to

• • optimally manage (or recycle) the energy consumed or not consumed in the system to increase the energy efficiency of the system through the energy management strategy;
• • De-aerate the system in time (remove air bubbles and air pockets) to effectively vent the system and minimize energy loss;
• • supply the right parts in the components with hydraulic oil and allow fast and effective filling / refilling of the system;
• • To turn the oil path to the brake valve on / off, use software to slow (or not slow) the actuator at low temperature and to brake sharply at high temperature.

Under the name MultiAir from the company FIAT an electronically controlled hydraulic system for driving the intake or exhaust valves of an internal combustion engine is known.

The hydraulic system described in Patent MultiAir (Fiat) as a flexible valve train suffers from the disadvantages of high energy loss and difficulty in refilling which the present disclosure seeks to overcome.

• • Das System mit minimaler Energieverlust oder (Druckverlust) zu entlüften;
• • Schnelles Auffüllen/Nachfüllen des Systems mit Öl.

The novel system described herein is applicable to a hydraulic system where the mechanical load has a reversing motion. The system will reach:
Maximize energy return and minimize energy loss in the system;

• • vent the system with minimal energy loss or (pressure loss);
• • Fast filling / refilling of the system with oil.

The new system is presented as an engine load on the basis of an intake valve of an internal combustion engine and, as mentioned above, made into a valve train system. In order to provide a fluent explanation, no distinction is made in the designation between opening time and opening angle, because they can be interconverted by the rotational speed of the motor. The same applies to closing time and closing angle.

• 1) Ein 2-Positions-Magnetventil-Aktuator (SA) mit Übergangskontrolle;
• 2) Ein direktionales 2-Positions-4-Weg-Steuerventil (DVC) mit Übergangszuständen;
• 3) Druckspeicher (PA) mit Entlüftungsmechanismus;
• 4) Hydraulischer Aktuator (HA) mit einem einfachen Zylinder-Kolben-Aufbau für einen effizienten Antrieb des Einlassventils;
• 5) Mechanisches Bremsventil (BV), das während der letzten Phase des Aufsetzens des Ventils auf seinen Sitz aktiv ist (12) ;
• 6) Absperrventile für die Ölversorgung des hydraulischen Aktuators (4);
• 7) Absperrventile für die Ölversorgung der hydraulischen Pumpe (9);
• 8) Nocken mit speziell gestaltetem Profil und versetzt, um die Energierückführung sowie die Dynamik zu erleichtern;
• 9) Hydraulische Pumpe (HP);
• 10) Positionssensor zum Erkennen der Position des Kolbens des hydraulischen Aktuators oder des mechanischen Ventils (optional);
• 11) Einlassventil als mechanische Last des hydraulischen Aktuators;
• 12) Ventilsitz.

Shown in 1 is the arrangement of the system consisting of:

• 1) A 2-position solenoid valve actuator (SA) with transition control;
• 2) a directional 2-position 4-way control valve (DVC) with transient states;
• 3) accumulator (PA) with venting mechanism;
• 4) Hydraulic actuator (HA) with a simple cylinder-piston assembly for efficient intake valve drive;
• 5) Mechanical brake valve (BV) active during the last stage of seating the valve on its seat ( 12 );
• 6) shut-off valves for the oil supply of the hydraulic actuator ( 4 );
• 7) shut-off valves for the oil supply of the hydraulic pump ( 9 );
• 8) cams with specially designed profile and offset to facilitate energy return and dynamics;
• 9) hydraulic pump (HP);
• 10) position sensor for detecting the position of the piston of the hydraulic actuator or the mechanical valve (optional);
• 11) inlet valve as a mechanical load of the hydraulic actuator;
• 12) valve seat.

• • ein einfacher Aufbau der Zylinder-Kolbeneinheit des hydraulischen Aktuators zum Einsatz kommt. Folglich ist der zum Antreiben des hydraulischen Aktuators als auch des mechanischen Ventils viel niedriger;
• • der Entlüftungsmechanismus wird nur zum richtigen Zeitpunkt aktiviert und nicht während der gesamten Zeit;
• • Der Druckspeicher ist derart gestaltet, dass er eine hoch effiziente Energierückführung erreicht;
• • Das Nockenprofil und seine bezüglich der Mittellinie der Pumpe versetzte Anordnung (oder die Bewegungsrichtung eines anderen zwischen der Pumpe und dem Nocken angeordneten Bauteils (wenn vorhanden) werden optimiert, um die Energie nutzbar zu machen.

In addition to the energy management process implemented by the specially designed DCV, the overall energy demand of the system as a whole is also reduced because:

• • a simple design of the cylinder-piston unit of the hydraulic actuator is used. Consequently, it is much lower for driving the hydraulic actuator as well as the mechanical valve;
• • the venting mechanism is activated only at the right time and not during the whole time;
• • The pressure accumulator is designed so that it reaches a highly efficient energy return;
• • The cam profile and its offset relative to the pump centerline (or the direction of movement of another component between the pump and cam (if any) are optimized to harness the energy.

1 shows the structure of the hydraulic system (valve train) for an intake valve of an internal combustion engine. The solenoid valve actuator is controlled and driven by an electronic control unit (not shown in the figure). Two positions of the solenoid valve actuator are indicated by 1 and 2, with intermediate transition states. The 4 paths of the DCV are indicated by D for the accumulator path, B for the brake valve path, P for the pump path, and A for the hydraulic actuator path.

Operation of the system:

• 1. Position 1 (P1): die Leerlaufposition des DCV, das heißt, die Position, in der der Magnetventil-Aktuator nicht aktiviert ist;
• 2. Position 2 (P2): In dieser Position ist der Magnetventil-Aktuator vollständig aktiviert.

The key component of the system is the directional 4-way 2-position control valve ( 2 ). However, in addition to the two positions, ie, on and off positions of the DCV, there are three transition positions (states) therebetween. The two main positions of the DCV are:

• 1. Position 1 (P1): the idling position of the DCV, that is, the position in which the solenoid valve actuator is not activated;
• 2. Position 2 (P2): In this position, the solenoid valve actuator is fully activated.

• 1. Übergangsposition 1 (T1): die Schaltpositionen, in denen die Ölpfade sowohl der Ölpumpe (9) als auch des Druckspeichers ((3) verbunden sind;
• 2. Übergangsposition 2 (T2): die Schaltpositionen, in denen die Ölpfade der Ölpumpe (9) des Druckspeichers (3) als auch des Elektromagnet-Aktuators (4) verbunden sind;
• 3. Bremsposition (BK): die Pfadverbindung ist identisch mit der Übergangsposition 2 (T2), aber diese Position liegt sehr nah bei der Position 2 (P2). Folglich findet eine sehr starke Drosselungswirkung auf den Fluss statt, so dass der hydraulische Aktuator (4) wie auch das mechanische Ventil (11) im hohen Maße gebremst ist.

The three transitional positions (states) between the two main positions are:

• 1. Transition position 1 (T1): the switching positions in which the oil paths of both the oil pump ( 9 ) as well as the accumulator (( 3 ) are connected;
• 2. Transition position 2 (T2): the switching positions in which the oil paths of the oil pump ( 9 ) of the pressure accumulator ( 3 ) as well as the solenoid actuator ( 4 ) are connected;
• 3. Braking position (BK): the path connection is identical to the transition position 2 (T2), but this position is very close to position 2 (P2). Consequently, a very strong throttling action takes place on the flow, so that the hydraulic actuator ( 4 ) as well as the mechanical valve ( 11 ) is braked to a high degree.

These transition positions realize the energy management (mechanism for storing and releasing the energy) at T1 and T2. Furthermore, the transitional state BK promotes the early phase of the braking action on the mechanical load (in the present case the intake valve of the internal combustion engine).

Since the plunger of the solenoid valve actuator and the piston of the DCV are fixed together and move together, a position of the DCV also reflects the corresponding position of the plunger of the solenoid valve actuator.

Table 1 summarizes the various switching operations of the channels, the use and the resulting operations according to the DCV positions. Table 1: Hydraulic switch positions, their use and the resulting activities. DVC position channel connection application Behavior of the pressure accumulator P1 O, A, P, D Pump is at its lowest point: oil supply is channeled to the system and system filling / refilling is in progress. By a predetermined oil supply pressure, the vent can be triggered. Otherwise: if the mechanical valve is open, this position will cause the valve to close. For activating with energy management, the accumulator remains motionless, unless a predetermined pressure level is reached by the oil supply. In this situation, the venting is triggered. T1 P, D; A, D. P, D: facilitate the pumping of the oil to and the return of the oil to the PA later; block and prevent reopening of the valve due to the high oil pressure; A, D: release of the higher pressure oil, resulting in intense throttling by BV for the last braking phase of the valve. PA is filled or emptied by / to the pump in the cam start phase or the cam drain phase; Certain braking effect is caused by the spring of the PA. T2 P, A, D Rapid release of oil pressure from HA to PA. Replenishment of the PA by HP and HA begins; Venting is triggered at a predetermined displacement of the PA spring. BK A, D, P This is, in fact, the last phase of T2; Oil flow from HA is severely throttled to achieve a strong braking effect for the final closing phase of the valve. PA is mainly filled up by HP; Venting is triggered at a predetermined displacement of the PA spring. P2 P, A HP pumps oil into the hydraulic actuator; The valve starts to open. PA stops.

In order to describe the type of operation and the characteristics of the system for valve motor applications, it is often referred to a diagram of valve lift variation over time, similar to the diagram of FIG 2 resorted. In fact, all movements and their control result from the cam profile, which rotates on its own axis. Actually, the system converts the rotary motion of the cam into the desired stroke of the valve ( 11 ) around.

In 2 For example, the geometric character locations of the cam profile, established terms, and some lift profiles are defined based on various actuation modes that have been used throughout this text.

2 shows a typical cam profile for a valve train system. In this figure and also below, the dot-dash line represents the valve lift that can be achieved by using the complete cam profile; the solid line represents the valve lift achieved in an open-time control mode; the dashed line shows the valve lift, which is achieved in a control mode for the closing time.

Application of different modes and their control:

In different positions of the solenoid valve actuator ( 1 ) powered DCV ( 2 ), which actuator is precisely controlled by appropriate currents with good transient characteristics, Different actuation modes can be realized exactly even without the feedback signal of the hydraulic actuator from a position sensor.

However, in the case where the control precision of the solenoid valve actuator is limited, it becomes necessary to use a position sensor ( 10 ) for the hydraulic actuator or load (valve). With the information about the position of the load, a closed-loop control can be set up to correct inaccuracy caused by various components, including the solenoid actuator itself. This enables high-precision control with low-quality components.

With the position control of the DCV (see table 1) different modes for opening and closing the valve (see table 2) can be realized. In the following, the order of events for different actuation modes will be discussed in detail, in particular the behavior or reaction of each of the components in the course of the procedure will be discussed. Table 2: Valve Actuation Modes and Direction Control of Valve Positions No. Actuator control mode Order DVC control. description 1 OCE: opening control with power management. P1, T1, P2; T2, BK, T1, P1. Valve opening time is controlled and the closing time is determined by the mech. (eg cam profile) and hydr. Characteristics of the system determined; Full stroke is realized with this mode. 2 CCE: Close Control with Energy Management. P1, P2; T2, BK, T1, P1. Valve closing time is controlled and the opening time is determined by the mech. (eg cam profile starting point) and hydr. Characteristics of the system. 3 OCCE: opening and closing control with energy management. P1, T1, P2; T2, BK, T1, P1. Valve opening and closing times are both controlled. 4 ME: Multiple lift control with energy management. CCE and OCE, or OCCE and OCE This mode can also be used with appropriate modes without power management z. B. CC, OC and OCC modes are combined. 5 CSE: Cold start with minimal or minor braking, event. with energy management. P1, (T1), P2, T2, P1 It is often a full stroke without braking (no T1 state) or OCE with a desired earlier opening angle. (T1 state). 6 NE: zero stroke but with energy management. P1, T1, P1. Zero valve lift, filling and draining of PA by pump. 7 FE: refill mode / refill mode. P1. Top up the system at the beginning or top up the system after a long standstill. Oil supply at a predetermined pressure level to facilitate venting as well as refilling / refilling. 8th OC: opening control P1, P2; T2, BK, P1 Valve opening mode but without energy saving strategy. 9 CC: closing control P1, P2; T2, BK, P1. Valve closure mode but without energy saving strategy. 10 OCC: opening and closing control P1, P2; T2, BK, P1. Valve opening and closing mode but without energy saving strategy. 11 M: multiple stroke control CC and OC, or OCC and OC. Multi-stroke mode without energy saving strategy; this mode can be realized by combining CC and OC, or OCC and OC modes. 12 N: zero stroke P1. Zero-stroke and no energy saving strategy.

OCE mode

In the OCE mode, the opening time is desired, but the closing time is determined indirectly by the cam profile and the hydraulic system. The desired opening time must be between the cam start point and the time when the cam profile reaches its highest point.

The energy saving with accumulator strategy is activated.

• 1. Anfangspunkt: DCV ist an P1 Position, das System ist im Niedrigdruckzustand und das Ventil ist geschlossen;
• 2. Öffnungssteuerungsbefehl: Öffnungszeit;
• 3. Verfahren zum Energiemanagement: a. Hydraulikschalter aktiviert auf Position T1 bis zum Erreichen der Öffnungszeit; b. Pumpe drückt Öl in das System; c. Entlüftung: ausgelöst bei einer vorbestimmten Verschiebung der PA-Feder; d. Druckspeicher verwandelt den Druck in die potentielle Energie seiner Pumpe; e. Energie wird bis zum Erreichen der Öffnungszeit in den Druckspeicher geleitet;
• 4. Ventil öffnen: DCV wird in Position P2 bewegt;
• 5. Innerhalb der Ventilöffnungsspanne: Position P2 beibehalten;
• 6. Schließungssteuerungsbefehl: Schließungszeit (vorbestimmt durch Nockenprofil);
• 7. Verfahren zum Energiemanagement: a. Schnelles Schließen: DCV wird in Position T2 bewegt; b. Pumpe ist schon beim Runterfahren, HA drückt das Öl zurück in die Pumpe und auch PA entlädt seine Energie in die Pumpe; c. DVC Bremse: DCV wird in die Position BK bewegt, um eine moderate aber kontrollierbare Bremswirkung zu erzeugen; d. Mechanische Bremse: Bremsventil wird ausgelöst und hierdurch eine heftige Bremsung während der letzten Anlegephase des Ventils erzeugt; e. Hydraulischer Schalter wird in Position T1 bewegt, um Rückführung von Energie zu erleichtern; f. Pumpe setzt Runterfahren fort und PA pumpt weiterhin seine Energie in die Pumpe bis seine gesamte Energie geleert ist; g. Entlüftung: ausgelöst bei einer vorbestimmten Verschiebung der PA-Pumpe;
• 8. Endpunkt: DCV wird in Position P1 bewegt;
• 9. Nachfüllung des Systems: Nachfüllen für das nächste Ereignis beginnt.

The corresponding event sequence for the OCE mode is described as follows - see also 3 with OCE mode and the curve of the event time of its activation. The thin dotted vertical lines represent the times of valve opening and closing.

• 1. Start point: DCV is at P1 position, the system is in low pressure condition and the valve is closed;
• 2. Opening control command: opening time;
• 3. Energy management procedure: a. Hydraulic switch activated at position T1 until reaching the opening time; b. Pump pushes oil into the system; c. Venting: triggered by a predetermined displacement of the PA spring; d. Accumulator transforms the pressure into the potential energy of its pump; e. Energy is directed to the opening time in the pressure accumulator;
• 4. Open valve: DCV is moved to position P2;
• 5. Within the valve opening span: maintain position P2;
• 6. Closing control command: closing time (predetermined by cam profile);
• 7. Energy management procedure: a. Fast closing: DCV is moved to position T2; b. Pump is already on shutdown, HA pushes the oil back into the pump and also PA discharges its energy into the pump; c. DVC brake: DCV is moved to position BK to produce a moderate but controllable braking action; d. Mechanical brake: Brake valve is triggered causing heavy braking during the last application phase of the valve; e. Hydraulic switch is moved to position T1 to facilitate return of energy; f. Pump continues to shut down and PA continues to pump its energy into the pump until all of its energy has been drained; G. Venting: triggered by a predetermined displacement of the PA pump;
• 8. End point: DCV is moved to position P1;
• 9. Refilling the system: Refilling for the next event begins.

CCE mode

In CCE mode, the starting point of the cam profile is the opening time. The timing for the valve closing time is desirable and must be between the starting point of the cam profile and the end point.

The energy saving strategy with accumulator is activated.

• 1. Startpunkt: DCV ist an position P1, das System ist im Niedrigdruckzustand und das Ventil ist geschlossen;
• 2. Zum Öffnen des Ventils: DCV wird in die Position P2 bewegt;
• 3. Öffnungsspanweite: Position P2 beibehalten;
• 4. Schließungssteuerungsbefehl: Schließungszeit;
• 5. Verfahren zum Energiemanagement: a. Schnelles Schließen: DCV wird in die Position T2 bewegt; b. Entlüftung: ausgelöst bei einer vorbestimmten Verschiebung der PA-Feder; c. Pumpe ist immer noch aktiv und pumpt Öl in PA hinein, und HA führt Öl zurück in PA; d. DVC-Bremse: DCV wird in die Position BK bewegt, um eine moderate aber kontrollierbare Bremswirkung zu erreichen; e. Mechanische Bremse: Bremsventil wird ausgelöst, wodurch eine heftige Bremsung während der letzten Anlegephase des Ventils erzeugt wird; f. Hydraulischer Schalter wird in Position T1 bewegt, um Rückführung von Energie zu erleichtern; g. Pumpe setzt Herauffahren fort und pumpt Öl weiter in PA bis zum oberen Nockenpunkt; h. Pumpe fährt herab und PA lässt seine Energie in die Pumpe fließen; i. Entlüftung: ausgelöst bei einer vorbestimmten Verschiebung der PA-Feder;
• 6. Endpunkt: DCV wird in Position P1 bewegt;
• 7. Nachfüllung des Systems: Nachfüllen für das nächste Ereignis beginnt.

The corresponding event sequence for the CCE mode is described as follows - s. also 4 with CCE mode and the curve of the event time of its activation. The thin dotted vertical lines represent the times of valve opening and closing.

• 1. Starting point: DCV is at position P1, the system is in low pressure and the valve is closed;
• 2. To open the valve: DCV is moved to position P2;
• 3. Opening span: maintain position P2;
• 4. Closing control command: closing time;
• 5. Method for energy management: a. Quick Close: DCV is moved to position T2; b. Venting: triggered by a predetermined displacement of the PA spring; c. Pump is still active, pumping oil into PA and HA returning oil to PA; d. DVC brake: DCV is moved to position BK to achieve a moderate but controllable braking effect; e. Mechanical brake: Brake valve is triggered, causing a heavy braking during the last application phase of the valve; f. Hydraulic switch is moved to position T1 to facilitate return of energy; G. Pump continues to ramp up and continues to pump oil in PA up to the top cam point; H. Pump descends and PA lets its energy flow into the pump; i. Venting: triggered by a predetermined displacement of the PA spring;
• 6. End point: DCV is moved to position P1;
• 7. Refilling the system: Refilling for the next event begins.

OCCE mode

In this mode, both the opening time and the closing time are desired times. The time restrictions are the same as in OCE or CCE mode.

The opening time of the mech. Valve and the event sequence are realized in the same way as in the OCE mode during its opening phase; similarly, the closing time and the sequence of events are realized in the same way as in the CCE mode during its closing phase.

ME mode

• 1. CCE gefolgt von OCE, s. 5;
• 2. OCCE gefolgt von OCE.

In ME mode there are two alternatives ie

• 1. CCE followed by OCE, s. 5 ;
• 2. OCCE followed by OCE.

The energy saving strategy with accumulator is activated.

Similarly, in CCE mode, the starting point of the cam profile is the opening time; the closing time is a desired time and must be between the starting point and the end point of the cam profile. In OCE mode, the opening time is the desired time, but the closing time is indirectly determined by the cam profile and the hydraulic system. The desired opening time must be between the closing time of the previous CCE activation and the time when the cam profile reaches its upper point. Shown in 5 is a ME mode realized with the CCE and OCE modes. The corresponding event sequence is similar to CCE mode or OCE mode. Shown are the ME mode (CCE followed by OCE) and the curve of the event time. The thin dotted vertical lines represent the times of valve opening and closing.

CSE mode

In CSE (cold start energy management) mode, the opening time is a desired time, but the closing time is indirectly determined by the cam profile and the hydraulic system. The desired opening time must be between the starting point of the cam and the time when the cam profile reaches its upper point.

• • OCE-Modus mit wenig oder keiner Bremsung.
• • Vollständiger Hub mit wenig oder keiner Bremsung und ohne Energiemanagement;

The CSE mode is activated with the following features to prevent late closing of the valve:

• • OCE mode with little or no braking.
• • Complete stroke with little or no braking and no energy management;

• 1. Startpunkt: DCV befindet sich in Position P1, das System ist im Niedrigdruckbereich und das Ventil ist geschlossen;
• 2. Öffnungssteuerungsbefehl: Öffnungszeit;
• 3. Verfahren zum Energiemanagement: a. Hydraulischer Schalter ist bis Erreichen der Öffnungszeit in Richtung Position T1 aktiviert; b. Pumpe drückt Öl in das System hinein; c. Entlüftung: ausgelost bei einer vorbestimmten Verschiebung der PA-Feder; d. Druckspeicher verwandelt den Druck in die potentielle Energie seiner Feder; e. Energie wird bis zum Erreichen der Öffnungszeit in den Druckspeicher geleitet;
• 4. Ventil öffnen: DCV wird in Position P2 bewegt;
• 5. Innerhalb der Ventilöffnungsspanne: Position P2 beibehalten;
• 6. Schließungssteuerungsbefehl: Schließungszeit (vorbestimmt durch Nockenprofil);
• 7. Verfahren zum Energiemanagement: a. Schnelles Schließen: DCV wird in Position T2 bewegt; b. Pumpe ist schon beim Runterfahren, HA drückt das Öl zurück in die Pumpe und auch PA entlädt seine Energie in die Pumpe; c. Pumpe setzt Runterfahren fort und PA pumpt weiterhin seine Energie in die Pumpe bis seine gesamte Energie geleert ist; d. Entlüftung: ausgelöst bei einer vorbestimmten Verschiebung der PA-Feder;
• 8. Endpunkt: DCV wird in Position P1 bewegt;
• 9. Nachfüllung des Systems: Nachfüllen für das nächste Ereignis beginnt.

The corresponding event sequence in CSE mode with OCE feature is described as follows. 6 shows the CSE mode and the event time curve of its activation. The thin dotted vertical lines represent the times of valve opening and closing.

• 1. Starting point: DCV is in position P1, the system is in the low pressure range and the valve is closed;
• 2. Opening control command: opening time;
• 3. Method for energy management: a. Hydraulic switch is activated until reaching the opening time in the direction of position T1; b. Pump pushes oil into the system; c. Vent: triggered by a predetermined displacement of the PA spring; d. Accumulator transforms the pressure into the potential energy of its spring; e. Energy is directed to the opening time in the pressure accumulator;
• 4. Open valve: DCV is moved to position P2;
• 5. Within the valve opening span: maintain position P2;
• 6. Closing control command: closing time (predetermined by cam profile);
• 7. Energy management procedure: a. Fast closing: DCV is moved to position T2; b. Pump is already on shutdown, HA pushes the oil back into the pump and also PA discharges its energy into the pump; c. Pump continues to shut down and PA continues to pump its energy into the pump until all of its energy has been drained; d. Venting: triggered by a predetermined displacement of the PA spring;
• 8. End point: DCV is moved to position P1;
• 9. Refilling the system: Refilling for the next event begins.

The full lift CSE mode works in a similar way. Energy management is not needed.

NE mode

The zero stroke mode, but still provided with energy management, is again realized by using the T1 position of the DCV, through which the compressed oil from the pump is directed directly into the accumulator without diverting it into the hydraulic actuator during the upward movement of the cam. On the other hand, during the downward movement of the cam, the pressurized oil is directed out of the accumulator back into the pump. During this process, most of the energy extracted from the engine is transferred from the camshaft back to the engine in the form of positive torque; the event time curve for the NE mode can be determined from the 7 be removed. The thin dotted vertical lines represent the times of valve opening and closing.

FE mode

If not used for a long period of time, a hydraulic system could drain. In this situation, a quick refill is important.

• 1. Startpunkt: P1 (Motor bleibt im Stillstand);
• 2. Ölversorgung: Druckhöhe festgelegt innerhalb eines vorbestimmten Niveaus, um den Entlüftungsmechanismus im Druckspeicher zu aktivieren;
• 3. Auffüllen/Nachfüllen beginnt, und gleichzeitig findet die Entlüftung statt;
• 4. Endpunkt: erst wenn das System aufgefüllt ist und die Entlüftung beendet ist.

If a system is provided with an electric oil pump, which can be activated before the start of the rotational movement of the internal combustion engine, no valve lift will be possible. Here, the following event time curve is used for refilling / refilling. 8th shows the FE mode and the event time curve for cases with an electric oil pump.

• 1st starting point: P1 (engine stops at standstill);
• 2. oil supply: pressure level set within a predetermined level to activate the venting mechanism in the accumulator;
• 3. filling / refilling starts, and at the same time the venting takes place;
• 4. End point: only when the system is filled up and the venting is completed.

• 1. Startpunkt: P1: (Zündschlüssel ist in Betrieb und der Motor rotiert.);
• 2. Ölversorgung: das Öldruckniveau muss höher sein als der Öldruck im hydraulischen System, wenn die Ölpumpe sich auf dem Nockengrundkreis befindet;
• 3. Ventilaktivierung: mit N-Modus (kein Hub vorhanden), so dass die Ölpumpe den Druckspeicher PA laden und entladen kann. Wenn sich der Öldruck während des Pumpens eine Höhe innerhalb eines vorbestimmten Druckniveaus erreicht hat, wird die Entlüftung ausgelöst;
• 4. Endpunkt: erst wenn das System aufgefüllt, entlüftet und ein normaler Ventilhub möglich ist.

In the case of a system provided with only a mechanical pump driven by the internal combustion engine itself, a valve lift is possible. Here, the following event time curve is used for refilling / refilling ie

• 1. Starting point: P1: (Ignition key is in operation and the engine is rotating.);
• 2. Oil supply: the oil pressure level must be higher than the oil pressure in the hydraulic system when the oil pump is on the cam base circuit;
• 3. Valve activation: with N-mode (no stroke present) so that the oil pump can charge and discharge the accumulator PA. When the oil pressure has reached a level within a predetermined pressure level during pumping, venting is initiated;
• 4. End point: only when the system is filled, vented and a normal valve lift is possible.

OC mode

In the OC mode, the definitions and limitations of the opening time and the closing time are exactly the same as those of the OCE mode.

The energy saving strategy with the accumulator is not activated. However, the inherent features of the system allow a limited power saving process to occur. Strictly speaking, the entire hydraulic chamber is used to conduct energy into the accumulator and let it out of the accumulator even with the oil path of the hydraulic actuator.

• 1. Startpunkt: DCV ist in Position P1, das System befindet sich im Niedrigdruckzustand und das Ventil ist geschlossen;
• 2. Öffnungssteuerungsbefehl: Öffnungszeit;
• 3. Eingeschränkter Energiesparvorgang: a. Pumpe drückt Öl in das System hinein bis zum Erreichen der Öffnungszeit; b. Entlüftung: ausgelost bei einer vorbestimmten Verschiebung der PA-Feder; c. Druckspeicher verwandelt den Druck in die potentielle Energie seiner Feder; d. Energie wird bis zum Erreichen der Öffnungszeit in den Druckspeicher geleitet;
• 4. Ventil öffnen: DCV wird in Position P2 bewegt;
• 5. Innerhalb der Ventilöffnungsspanne: Position P2 beibehalten;
• 6. Schließungssteuerungsbefehl: Schließungszeit (vorbestimmt durch Nockenprofil);
• 7. Eingeschränkter Energiesparvorgang: a. Schnelles Schließen: DCV wird in Position T2 bewegt; b. Pumpe ist schon beim Runterfahren, HA drückt das Öl zurück in die Pumpe und auch PA entlädt seine Energie in die Pumpe; c. DVC-Bremse: DCV wird in die Position BK bewegt, um eine moderate aber kontrollierbare Bremswirkung zu erzeugen; d. Mechanische Bremse: Bremsventil wir aktiviert, so dass sich für die letzte Anlagephase ein heftige Bremswirkung ergibt; e. Hydraulischer Schalter wird in die Position P1 bewegt, um eine Rückführung der Energie zu erleichtern; f. Pumpe setzt Runterfahren fort und PA pumpt weiterhin seine Energie in die Pumpe bis seine gesamte Energie geleert ist; g. Entlüftung: ausgelöst bei einer vorbestimmten Verschiebung der PA-Feder;
• 8. Endpunkt: Die gesamte Energie ist aus dem Druckspeicher herauslassen;
• 9. Nachfüllung des Systems: Nachfüllen für das nächste Ereignis beginnt.

The corresponding event sequence in CC mode is described as follows. 9 shows the OC mode and event time curve of its activation. The thin dotted vertical lines represent the times of valve opening and closing.

• 1. Starting point: DCV is in position P1, the system is in low pressure and the valve is closed;
• 2. Opening control command: opening time;
• 3. Limited energy saving process: a. Pump pushes oil into the system until it reaches the opening time; b. Vent: triggered by a predetermined displacement of the PA spring; c. Accumulator transforms the pressure into the potential energy of its spring; d. Energy is directed to the opening time in the pressure accumulator;
• 4. Open valve: DCV is moved to position P2;
• 5. Within the valve opening span: maintain position P2;
• 6. Closing control command: closing time (predetermined by cam profile);
• 7. Limited energy saving process: a. Fast closing: DCV is moved to position T2; b. Pump is already on shutdown, HA pushes the oil back into the pump and also PA discharges its energy into the pump; c. DVC brake: DCV is moved to position BK to produce a moderate but controllable braking action; d. Mechanical brake: Brake valve is activated so that a strong braking effect results for the last conditioning phase; e. Hydraulic switch is moved to position P1 to facilitate return of energy; f. Pump continues to shut down and PA continues to pump its energy into the pump until all of its energy has been drained; G. Venting: triggered by a predetermined displacement of the PA spring;
• 8. End point: The entire energy is let out of the accumulator;
• 9. Refilling the system: Refilling for the next event begins.

CC mode

In the CC mode, the definitions and limitations of the opening time and the closing time are exactly the same as those of the CCE mode.

The energy saving strategy with the accumulator is not activated. However, the inherent features of the system allow a limited power saving process to occur. Strictly speaking, the entire hydraulic chamber is used to conduct energy into the accumulator and let it out of the accumulator even with the oil path of the hydraulic actuator.

• 1. Startpunkt: DCV befindet sich in Position P1, das System ist im Niedrigdruckbereich und das Ventil ist geschlossen;
• 2. Ventilöffnung: DCV wird in die Position P2 bewegt;
• 3. Öffnungsspanne: Position P2 beibehalten;
• 4. Schließungssteuerbefehl: Schießungszeit;
• 5. Eingeschränkter Energiesparvorgang: a. Schnelles Schließen: DCV wird in die Position T2 bewegt; b. Entlüftung: ausgelost bei einer vorbestimmten Verschiebung der PA-Feder; c. Pumpe ist noch beim Herauffahren und pumpt Öl in PA hinein und HA drückt das Öl zurück in PA; d. DVC-Bremse: DCV wird in die Position BK bewegt, um eine moderate aber kontrollierbare Bremswirkung zu erzeugen; e. Mechanische Bremse: Bremsventil wird aktiviert, so dass sich für di0e letzte Anlagephase eine heftige Bremswirkung ergibt; f. Pumpe setzt Herauffahren fort und pumpt Öl in PA hinein bis zum Erreichen des oberen Nockenpunkts; g. Pumpe ist beim Herunterfahren und PA entlädt seine in die Pumpe hinein; h. Entlüftung: ausgelöst bei einer vorbestimmten Verschiebung der PA-Feder;
• 6. Endpunkt: die gesamte Energie ist aus dem Druckspeicher herausgelassen;
• 7. Nachfüllung des Systems: Nachfüllen für das nächste Ereignis beginnt.

The corresponding event sequence for the CC mode is described as follows. 10 shows the CC mode and the event time curve of its activation. The thin dotted vertical lines represent the times of valve opening and closing.

• 1. Starting point: DCV is in position P1, the system is in the low pressure range and the valve is closed;
• 2. Valve opening: DCV is moved to position P2;
• 3. Opening span: maintain position P2;
• 4. Close control command: shooting time;
• 5. Limited energy saving process: a. Quick Close: DCV is moved to position T2; b. Vent: triggered by a predetermined displacement of the PA spring; c. Pump is still pumping up and pumping oil into PA and HA pushing oil back into PA; d. DVC brake: DCV is moved to position BK to produce a moderate but controllable braking action; e. Mechanical brake: Brake valve is activated, resulting in a strong braking effect for the last conditioning phase; f. Pump continues to ramp up and pumps oil into PA until reaching the top cam point; G. Pump is shut down and PA discharges its into the pump; H. Venting: triggered by a predetermined displacement of the PA spring;
• 6th end point: the entire energy is released from the accumulator;
• 7. Refilling the system: Refilling for the next event begins.

OCC mode

In this mode, both the opening time and the closing time are desired times. The time restrictions are the same as in OC or CC mode.

The opening time of the mechanical valve and the sequence of events are realized in the same way as in the OC mode during its opening phase; similarly, the closing time and the sequence of events are realized in the same way as in the CC mode during its closing phase.

M mode

The system realizes the normal multi-stroke mode by simply replacing the position T1 with the position P1 for DCV, as compared with the ME mode. 11 shows the M-mode and event time curve of its activation. The thin dotted vertical lines represent the times of valve opening and closing. The control of the DCV is simplified.

Since the position T1 is defined for energy recovery, without T1 the effectiveness of the system to store unused energy into the accumulator is reduced and it may be possible to over-energize (pressurize) the reactivation of the hydraulic actuator and the mechanical valve ) are released.

N mode

The system realizes the N (zero-stroke) mode simply by leaving the DCV in the P1 position, similar to the FE mode.

In this mode, due to the intrinsic feature of the system, there is no active but only passive energy recovery. The oil pump pushes the oil into the system and into the accumulator during the upward movement of the cam, and the accumulator spring forces the oil back into the system and into the pump during the downward movement of the cam. There is only a limited recovery of energy because the pressure in the system is low and because some venting will consume some of the pressure / energy.

A new hydraulic system for driving an inverse load has been created. With this system, the energy consumption has been optimally reduced, the ventilation in the hydraulic paths is handled effectively and the filling / refilling of the system can be realized quickly.

• 1. Mit dem in 1 beschriebenen Aufbau besteht das System selbst aus folgenden Hauptbauteilen: 1) 3-Positions-Magnetventil-HydraulikAktuator; 2) 3-positions-4-Weg-DCV; 3) Druckspeicher mit Entlüftungsmechanismus; 4) Hydraulischer Aktuator; 5) Mechanisches Bremsventil; 6) Absperrventile von der Ölversorgung zum hydraulischen Aktuator; 7) Absperrventile von der Ölversorgung zur Pumpe; 8) Nocken; 9) Hydraulische Pumpe; 10) (optional) Ein Positionssensor, um die Position des Kolbens des mechanischen Ventils des hydraulischen Aktuators zu erkennen; 11) Mechanische Last für den Aktuator (z. B. ein Einlassventil);
• 2. Die verschiedenen Bauteile des Systems werden wie in 1 gezeigt miteinander verbunden werden;
• 3. Nockenversatz und Nockenprofil werden optimal durch die benötigte Dynamik für den Nocken mit seinen mechanischen Bauteilen insbesondere Pumpe und hydraulischem System bestimmt; 1) Erleichterung einer schnellen und leichtgängigen Bewegung der mechanischen Last; 2) Stets einen Kontakt zwischen Bauteilen in der Kette der mechanischen Teile von Nocken bis zum Pumpenkolben halten. 3) Die Beanspruchung durch den Kontakt muss innerhalb der erlaubten Grenzen bleiben; 4) Zusammenwirkung mit anderen Bauteilen des Systems, um das positive Drehmoment nutzbar zu machen und das negative Drehmoment zu reduzieren;
• 4. Die Bauteile und die Einlassstellen der Ölversorgung werden derart im System positioniert, dass sie das Entfernen von Lufttaschen/-blasen maximieren, und zwar durch: 1) Anordnung des Druckspeichers (Entlüftungsfunktion) an einer höheren Stelle als das DCV, der hydraulische Aktuator und die Pumpe; 2) Anordnung des hydraulischen Aktuators und der Pumpe mit den Einlasspunkten ihrer Ölversorgung an niedrigeren Stellen in den Bauteile; 3) Tote Ecken und scharfe Kanten in den Öldurchfluss-Pfaden vermeiden, um das Entfernen von Lufttaschen/-blasen zu erleichtern und auch, um örtliche Flussverluste zu vermeiden;
• 5. Der Ölversorgungsdruck wird reguliert 1) mit ausreichender Stärke, um ein normales Nachfüllen des Systems zwischen den Aktivierungsvorgängen zu ermöglichen; 2) innerhalb eines geeigneten Bereiches, in dem der Entlüftungsmechanismus ausgelöst wird, in einer Situation, in der das System leer oder teilweise entleert ist; 3) auf schwankende Weise, um zu ermöglichen, dass der Druck immer wieder diesen Druckbereich überschreitet, um den Entlüftungsmechanismus mehrmals während der Dauer des Auffüllens/Nachfüllens auszulösen;
• 6. Ein DCV besitzt die Funktionen, 4 Kanäle mit 2 Positionen von P1 und P2 für die An- und Ausfunktionen zu schalten, aber mit drei zusätzlichen, in Tabelle 1 definierten Übergangspositionen T1, T2 und BK, um 12 verschiedene, in Tabelle 2 definierte Aktuationsmodi zu ermöglichen, genauer gesagt, müssen die Übergangspositionen Folgendes ermöglichen: 1) eine Trennung der Kanäle der hydraulischen Pumpe und des hydraulischen Aktuators, um die unverbrauchte Energie von der Pumpe an den Druckspeicher maximal umzuleiten; 2) eine durch Software gesteuerte Bremswirkung, um die mechanische Last zu verlangsamen.
• 7. Ein Entlüftungsmechanismus ist in dem Druckspeicher integriert, der den Entlüftungsvorgang während des Betriebs innerhalb eines kleinen Niedrigdruckbereichs ermöglicht;
• 8. Ein mechanisches Bremsventil (5) wird verwendet, um ein sanftes Anlegen in der letzten Etappe der Stopp-Phase der mechanischen Last zu erleichtern.

The features and functionalities of the system are summarized as follows:

• 1. With the in 1 The system itself consists of the following main components: 1) 3-position solenoid valve hydraulic actuator; 2) 3-position 4-way DCV; 3) accumulator with venting mechanism; 4) hydraulic actuator; 5) Mechanical brake valve; 6) shut-off valves from the oil supply to the hydraulic actuator; 7) shut-off valves from the oil supply to the pump; 8) cams; 9) hydraulic pump; 10) (optional) A position sensor to detect the position of the piston of the mechanical valve of the hydraulic actuator; 11) mechanical load for the actuator (eg, an inlet valve);
• 2. The various components of the system will be as in 1 be shown connected to each other;
• 3. cam offset and cam profile are optimally determined by the dynamics required for the cam with its mechanical components, in particular pump and hydraulic system; 1) facilitating a quick and smooth movement of the mechanical load; 2) Always maintain contact between components in the chain of mechanical parts from cams to the pump piston. 3) The stress from the contact must remain within the permitted limits; 4) interaction with other components of the system to harness positive torque and reduce negative torque;
• 4. The components and inlet ports of the oil supply are positioned in the system to maximize the removal of air pockets / bubbles by: 1) placing the accumulator (venting function) at a higher position than the DCV, the hydraulic actuator and the pump; 2) placing the hydraulic actuator and the pump with the inlet points of their oil supply at lower points in the components; 3) Avoid dead corners and sharp edges in the oil flow paths to facilitate the removal of air pockets / bubbles and also to avoid local flow losses;
• 5. The oil supply pressure is regulated 1) with sufficient strength to allow a normal refilling of the system between the activation processes; 2) within a suitable range in which the venting mechanism is triggered, in a situation where the system is empty or partially depleted; 3) in a wavering manner to allow the pressure to repeatedly exceed this pressure range to trigger the venting mechanism several times during the refilling / refilling period;
• 6. A DCV has the functions to switch 4 channels with 2 positions of P1 and P2 for the on and off functions, but with three additional transition positions T1, T2 and BK defined in Table 1, by 12 different, defined in Table 2 To enable actuation modes, more specifically, the transition positions must allow for: 1) a separation of the hydraulic pump and hydraulic actuator channels to maximally divert the unused energy from the pump to the accumulator; 2) a software controlled braking action to slow the mechanical load.
• 7. A venting mechanism is incorporated in the accumulator which allows the venting operation during operation within a small low pressure range;
• 8. A mechanical brake valve ( 5 ) is used to facilitate a smooth application in the last stage of the mechanical load stop phase.

The present patent application relates mainly to a new concept relating to the system.

However, the specially designed components of the system together play a critical role in realizing the defined functions of the system. In the following sections these components are briefly described for the sake of completeness of the description of the system.

The control strategies and procedures for the system are also further explained in later sections.

Solenoid valve actuator

Solenoid Valve Actuator (SA) has 2 precise steady state positions, i. H. On and off state. In addition, the SA has the property of bringing the DCV to certain transitional positions.

• • Den Kolben präzise an 5 Positionen zu bringen; im Moment scheint dieses nicht einfach zu sein;
• • Die Schaltzeit muss sehr kurz sein;
• • Er hat einen langen Hub;
• • Was wenn eine falsche Position oder eine nicht präzise Position zu einer Wiederöffnung des Ventils führt?

We expect the following challenges:

• • to bring the piston precisely to 5 positions; At the moment this does not seem to be easy;
• • The switching time must be very short;
• • He has a long stroke;
• • What if a wrong position or position does not reopen the valve?

Directional Control Valve (DCV)

• • D: zum/vom Druckspeicher;
• • B: zum Bremsventil;
• • P: zur/von der hydraulischen Pumpe;
• • A: zum/vom hydraulischen Aktuator.

mit 2 Dauerzustands-Positionen,

• • An;
• • Aus;

plus 3 Kategorien von Übergangszuständen, nämlich

• • T1: zum Trennen vom Aktuator und Energiespeicherungskanälen;
• • T2: zur schnellen Freigabe von Öl im Aktuator;
• • BK: für eine Bremswirkung durch eine heftige Drosselung im DCV.

Actuated by the solenoid valve actuator, the DCV controls 4 flow paths namely

• • D: to / from accumulator;
• • B: to the brake valve;
• • P: to / from the hydraulic pump;
• • A: to / from the hydraulic actuator.

with 2 steady-state positions,

• • At;
• • Out;

plus 3 categories of transitional states, viz

• T1: for disconnecting the actuator and energy storage channels;
• • T2: for quick release of oil in the actuator;
• • BK: for a braking effect due to severe throttling in the DCV.

Please refer 13 - 18 for DVC positions and the corresponding flow directions.

• • Für die Steuerung des Ganzen hat der Kolben des DCV 5 verschiedene Positionen. Was ist der maximale und der minimale Hub, der realisiert werden kann und der gleichzeitig ein richtiges Gleichgewicht erreichen kann von – Hub ist kurz genug, um durch seinen Magnetventil-Aktuator angetrieben zu werden, und lang genug, um zwischen den 5 Reihen von Löchern (Wegen) zu unterscheiden; – Schnelles und genaues Schalten; – Langzeitige Abnutzung; – Leckage;
• • Was wenn ein Ungleichgewicht des Öldrucks das DVC vollkommen unkontrollierbar macht;

We expect the following challenges:

• • For the control of the whole, the piston of the DCV has 5 different positions. What is the maximum and minimum lift that can be realized and that can at the same time achieve a proper balance of - Hub is short enough to be driven by its solenoid valve actuator, and long enough to travel between the 5 rows of holes ( Because of) to distinguish; - Fast and accurate switching; - long-term wear; - leakage;
• • What if an imbalance in oil pressure makes the DVC completely uncontrollable?

12 is an overview of different positions of the DVC.

13 : DVC off position (P1). Here and below D indicates the accumulator, B the brake valve, P the hydraulic pump and A the hydraulic actuator.

14 : DVC on position (P2). All the oil from the hydraulic pump is diverted to the hydraulic actuator to open the mechanical valve.

15 : DVC first transient position (T1). Flow paths of the pump to / from the pressure accumulator are separated from the hydraulic actuator. Flow from the pump to the accumulator: energy storage; Flow from accumulator to pump: Energy release.

16 : DVC second transition position (T2). Rivers from pump and actuator are diverted to the storage. This also allows pressurized oil to be released to the pump to recover the stored energy in a limited manner.

17 : First brake position (BK). Flow comes back from the hydraulic actuator and the fierce throttling action to brake the actuator. The backward pressure in the DVC chamber (connected to the pump-pump path) also causes the braking effect (throttling).

18 : Second brake position (BK). Flow comes back from the hydraulic actuator and the fierce throttling action to brake the actuator. The backward pressure in the DVC chamber (connected to the pump-pump path) also causes the braking effect (throttling)

brake valve

• • Herstellbarkeit, auch bei der Kugelform;
• • Kann sie die Bremsaufgabe des DVC insgesamt übernehmen, um die Bremswirkung zu realisieren?

We expect the following challenges:

• • manufacturability, also with the spherical form;
• • Can she take over the braking task of the DVC as a whole in order to realize the braking effect?

19 shows an ideal brake valve with minimum loss (a) and the other with better manufacturability (b).

accumulator

• • Ein großer Durchmesser speichert mehr Energie bei niedrigem Druck aber mit hoher Verschiebung der Feder, und umgekehrt. Es ist günstig, eine Wiederöffnung zu vermeiden, aber eine hohe Dynamik des Speichers könnte den Ölfluss schnell genug verhindern, um ein positives Drehmoment beim Herunterfahren zu generieren.
• • Ein kleiner Durchmesser speichert einen hohen Druck, und eine kleine Verschiebung der Feder setzt ihre Energie schnell frei, um die Pumpe beim Herunterfahren nach unten zu schieben. Aber eine Wideröffnung ist leicht zu realisieren;
• • Was wenn das weiche Teil der Feder Resonanz induziert mit Schwankung des Öldrucks in der Hochdruckkammer?
• • Wo liegt ein gutes Gleichgewicht zwischen einer guten Dämpfung für NVH und, gleichzeitig einer guten Rückgewinnung der Energie?
• • Was wenn wenig Nuten der heftigen Lüftung nicht gewachsen sind aber zu viele Nuten einen großen Druckverlust verursachen?

We expect the following challenges:

• • A large diameter stores more energy at low pressure but with high displacement of the spring, and vice versa. It is beneficial to avoid re-opening, but high dynamics of the accumulator could prevent the flow of oil fast enough to generate positive shutting-down torque.
• • A small diameter stores high pressure, and a small shift in the spring quickly releases its energy to push the pump down when it shuts down. But a reopening is easy to realize;
• • What if the soft part of the spring induces resonance with fluctuation of the oil pressure in the high pressure chamber?
• • What is the right balance between good damping for NVH and, at the same time, good energy recovery?
• • What if a few grooves of heavy ventilation are not equal but too many grooves cause a large pressure loss?

Hydraulic accumulator with a spring with variable stiffness

20 shows various forms of variable stiffness springs for the pressure accumulator. All of these springs have two features: damping of the sudden pressure change caused by the high pressure chamber containing the softer part of the spring; Storage of high pressure energy (also higher than 30 bar!) With the hard part of the spring.

Ventilation mechanism for a hydraulic system integrated in the pressure accumulator

21 shows the position of the piston in the pressure accumulator and the triggering of the venting mechanism with the thin grooves on the inner surface of the cylinder

Method for optimizing the cam profile and offset for energy efficiency

• • Bedarf an Energie von der Nockenwelle (in Form eines negativen Drehmoments) während des Anlaufs des Nockens zu reduzieren;
• • Erhöhung des positiven Drehmoments an die Nockenwelle während des Nockenablaufs.

The offset, camshaft and cam profile are optimized to accommodate the new system with the following objectives:

• • reduce the need for energy from the camshaft (in the form of a negative torque) during cam start-up;
• • Increasing the positive torque to the camshaft during the cam run.

Control strategies and procedures

• • Ein 2-Positions 4-Wege direktionales Steuerungsventil mit Übergangszuständen
• • Auffüll-/Nachfüllstrategie für ein hydraulisches System
• • Steuerung der Bremswirkung für einen hydraulischen Aktuator basierend auf seinem Positionssignal
• • Verfahren zur Integrierung von durch Software gesteuerten und mechanischen Bremseffekten
• • Steuerung der Übergangszustände eines Mehrpositions-Aktuators mit Magnetventil
• • Steuerung der Bremswirkung für einen hydraulischen Aktuators basierend auf seinem Antriebsstrom
• • Steuerung der Bremswirkung für einen hydraulischen Aktuators basierend auf seiner Position

The following control strategies and procedures need to be developed before the system can be put into practice:

• • A 2-position 4-way directional control valve with transient states
• • Refilling / refilling strategy for a hydraulic system
• • Control of the braking effect for a hydraulic actuator based on its position signal
• • Method of integrating software controlled and mechanical braking effects
• • Control of the transient states of a multi-position actuator with solenoid valve
• • Control of the braking effect for a hydraulic actuator based on its drive current
• • Control of the braking effect for a hydraulic actuator based on its position

The new system can be considered as an alternative to the hydraulic valve train, with more advantages over today's UniAir system. Some components from the new system can be immediately transferred to the UniAir system.

Further, the application of the alternative system can be extended to areas where precise control of a mechanical load in a reciprocating motion is needed, such as in other areas of automotive industries, medical equipment, power engineering, mechanical engineering, and chemical industries

• • Hoher Energieverlust;
• • Lüftungsprobleme;
• • Schwierigkeiten beim Nachfüllen;
• • Niedrige Präzision in der Kontrolle im kalten Zustand.

A new hydraulic system has been created to overcome certain disadvantages of existing systems, ie

• • high energy loss;
• • ventilation problems;
• • difficulty refilling;
• • Low precision in cold control.

• • Potential zum Reduzieren von NVH im System;
• • Potential zum Reduzieren der Anzahl von mechanischen Bauteilen im System.

Furthermore, the new system also has some additional advantageous features, ie

• • potential to reduce NVH in the system;
• • Potential to reduce the number of mechanical components in the system.

Claims (1)

Method for operating an electro-hydraulic valve control for the variable actuation of a gas exchange valve ( 11 ) of an internal combustion engine, comprising: - a pump ( 9 ) - an actuator ( 4 ) with a piston - an electrohydraulic switching valve ( 2 ) comprising a 2-position transient control solenoid valve actuator (SA) and a 2-position 4-way directional control valve (DVC) with three transient states (T1, T2, T3) and a pressure accumulator (Fig. 3 ), wherein the valve control is operated in OCC mode.

Images