DE102007024129A1 - Method and apparatus for oil circulation management in an internal combustion engine - Google Patents

Abstract

The present invention relates to a method and apparatus for oil circulation management in an internal combustion engine using at least one hydraulic component. In order to further develop a method and a device of the type mentioned while increasing efficiency and reliability, it is proposed that an oil pressure (p) and / or a delivery quantity (V) be pre-controlled as a manipulated variable as a function of a respective component to be controlled, carry out a setting process and then the Control variable can be returned to an original and necessary for operation level.

Description

The The present invention relates to a method and an apparatus for an oil circulation management in an internal combustion engine using at least one Hydraulic component. Without restriction their field of application, the present invention is only below with reference to the automotive sector and only to internal combustion engines received. The automotive and automotive sector is due the high system requirements combined with high cost pressure Due to the high sales figures, it is a very important economic factor Scope of application. Alternative fields of application in aircraft or power plant technology as well as on other fields are not excluded.

Also from this field of application is known that oil circuits, especially the engine oil circuits modern Gasoline engines, meanwhile not only serve for lubrication and cooling, but rather also the task of the pressure or energy supply for one Variety of hydraulic components. Exemplary hydraulic valve clearance compensation elements HVA at this point, hydraulically operated Camshaft phaser, hydraulic cam profiler plate, such as B. the UNIAIR variable valve actuation system, or hydraulic Ventilhubumschalteinrichtungen called.

A known hydraulic valve lift switching device, which is marketed under the system name Vario Cam Plus, will be described in more detail below. It is a two-stage valve lift switching system in which a locking element in a shift paddle or a rocker arm is actuated by oil pressure against a spring and can be switched between two different valve lift curves, as in 2 The accompanying drawing is shown by way of example and will be described below.

Around a flawless and timely clearly defined switching process to realize in such a device is the switching timing of great importance. Ultimately, it must be ensured that the switching process within of a specific engine work segment. Special meaning This process has for engines that are based on the principle of homogeneous Compression ignition work, where the combustion of a homogeneous mixture at the same time starts in the entire combustion chamber with the aim of reducing pollutant emissions. In such engines, under the designations Homogeneous Charge Compression Ignition or abbreviated as HCCI, or Controlled Auto Ignition or abbreviated CAI is known, with the valve lift switching at the same time linked a mode change.

It is therefore an object of the present invention, a method and a device of the type mentioned while increasing efficiency and reliability further education.

These The object is solved by the features of the independent claims. Further advantageous features of developments of the invention are the subject the respective subclaims.

Of the The present invention is based on the finding that it is at a motor oil circuit to a hydraulically actuated System is, in which a voltage applied to a locking element oil pressure, oil pressure curve and / or oil mass flow key sizes represent the switching. Based on embodiments will be below shown by certain energy and / or oil pressure management in the oil circuit to optimize the control while lowering the Energy requirement of one or more hydraulic components essential can be contributed.

Draws according to the invention a procedure for an oil circuit management in an internal combustion engine using at least one Hydraulic component characterized in that a manipulated variable in shape of oil pressure and / or delivery rate dependent on precontrolled each to be controlled component, a respective Stellvorgang performed and subsequently the oil pressure and / or the volume flow to an original and necessary level for operation to be returned.

A method according to the invention requires an oil supply system which, with regard to power, oil pressure or delivery flow, has a certain variability or flexibility with simultaneous good controllability. This can be z. B. be realized by an electrically driven and variable speed oil pump, which will be realized in future vehicles as standard. Alternatively, in a device according to the invention also a mechanically operated oil pump can be used, which is volume-controlled via an electrically operated blow-by valve. It is crucial that on the on the actuator, z. B. a switching valve or a locking bolt of the valve lift switching device applied pressure level and / or on the flow rate or a volume flow as a controlled variable by an inventive control in the form of a device influence is taken. It has been shown in experiments that adjusting operations usually run more reliably and safely, or even possible only when a certain oil pressure level and / or a flow on the actuator is because malfunction, such. B. by tilting, jamming or other technical sources of error, be significantly reduced. In addition, the switching time decreases, thereby reducing the impact on the overall switching timing, which in turn increases the reliability and safety of the actuating engagement. By the pressure and thus power limitation during the control engagement and the subsequent reduction reduces the energy demand and increases the efficiency, which ultimately comes to an associated engine in the form of a relatively lower CO ₂ emission to good.

There a pressure or delivery flow range, the oil pump - and more precisely consider the entire oil pressure system - cover is capable of operating point-dependent, is in a training the invention take a differentiation. So z. B. mechanically driven oil pumps build only relatively low pressures during engine idle. For the control intervention Here the full potential is exploited. But you are in operating areas where a high or even excessively high pressure level is called up you can not fully exploit this. One limits oneself to pressure and / or volumetric flow rates at which a flawless Control intervention can be realized. Under certain circumstances, there is no increase necessary.

It is in one embodiment The invention provides each subsystem its own independent circuit within which a method according to the invention is applied. A practical solution But rather looks like that an aggregate network in a cycle summarized and is supplied by a common oil pump, as follows still referring to the drawing on the basis of an overview image will be shown.

Further Features and advantages of the invention will be described below of exemplary embodiments with reference to the figures of the drawing. In the Drawing show in schematized form:

1 : a basic structure of a controlled system in the form of an oil circuit one V12 gasoline engine with cylinder deactivation as an overview image;

2 a three-dimensional view of a known shift cup tappet;

3 a flow chart of an oil circuit manager according to the invention;

4 : a basic approach to modeling additional consumers in a hydraulic circuit using a diagram;

5 : a basic approach to modeling manipulated variable loading from switching frequency on the basis of a diagram;

6 : a diagram for a prophylactic Stellgrößenbeaufschlagung;

7 : a diagram for the quick implementation of a driver's request and

8th : a block diagram illustrating a control loop using the example of an oil pressure regulator.

About the various embodiments and figures will hereafter be given the same reference numerals and names for same function or assemblies and process steps used.

1 shows a basic structure of a controlled system 1 in the form of an oil circuit one 12-cylinder gasoline engine with cylinder deactivation as overview. This complex aggregate network is summarized in a circuit that is in a primary circuit of a common oil pump 2 using a regulator 3 is supplied according to the present invention.

2 shows a known Hydra- or Schalttassenstößel 4 as stated in a device according to 1 is inserted in a three-dimensional view. This hydraulic valve lift switching device operates in two stages by a locking element 5 in the shift rod plunger by an oil pressure p against a spring 6 is pressed. So you can switch between two different valve lift curves, as in 2 indicated.

To switch a located in the oil circuit solenoid valve is energized, which then opens. The oil pressure p builds up, and the locking element 5 moves as soon as the on the locking bolt 5 acting force greater than the force of the spring 6 is. With the locking of the locking bolt 5 the switching process is completed. If the voltage at the changeover valve is switched off, the valve closes and the oil pressure p breaks down. If the pressure p falls below a holding pressure, the locking bolt returns 5 actuated by the force of the spring 6 back to its starting position. The switch-back process is completed.

It is crucial that on the on the actuator, here so the bolt as a locking element 5 the valve lift switching device, applied pressure level p and / or on the flow rate or a volume flow V as a controlled variable by a he inventive regulation is influenced in the form of a device. By applying a certain oil pressure level and / or a flow on the actuator malfunction, such. B. by tilting, jamming or other technical sources of error, significantly reduced in their occurrence.

3 shows a flowchart of a controller 3 as an embodiment of the invention in the form of an oil circuit manager. In order to avoid disturbances due to interactions of the individual subsystems with each other during a control intervention, it is advantageous in the prior art to switch off consumers as far as possible for the duration of a control intervention or to freeze them in their current state. Alternatively or additionally conceivable in this context is a limitation of the dynamics or actuating speed and thus of the energy consumption. If this is not allowed, because z. B. during the valve lift and the associated activation z. B. a CAI combustion process, a camshaft phase adjustment must be made, the power requirement, respectively, an associated pressure loss of the components or units involved is to be considered and compensated accordingly. This known procedure is as far as in the flowchart according to 3 been recorded, as indicated by the dashed bordered area.

In addition, however, a power requirement in the form of a pressure loss and / or a volume flow of the respective individual components is additionally reproduced as a function of the operating point, as in FIG 4 indicated by way of example. These individual values then flow into the control as model variables, see 3 , The power, oil pressure or volumetric flow control is now handled by an oil circuit manager, which is integrated into the functional structure of the engine control. It has all the necessary information such as TQI, engine speed N, oil pressure POIL, oil temperature TOIL, condition and number of other components, etc. available. The oil circulation manager 3 assumes control of the components that are relevant for the level of performance indicated by oil pressure p and / or volumetric flow V. This is how the oil circulation manager controls 3 in this embodiment, an electric oil pump 2 at.

In a particularly advantageous embodiment, the oil circulation manager 3 in other words prophylactically, as in 6 outlined. If z. For example, when the engine is operated in a valve lift switching relevant area, the oil pressure level is prophylactically raised depending on the current operating point. If the changeover is then requested, one hardly loses time to build up the pressure, so that the switching process can be carried out quickly and safely. If no changeover is expected, the pressure level will be maintained at the minimum necessary for engine operation.

At At this point a further differentiation is carried out: Ist one far away from the switching limit, it is sufficient to ensure the minimum the manipulated variable. among them one understands that z. B. lubrication and cooling of the engine are reliably met. Switching components is not possible in this state. Approaching the switching limit, the manipulated variable is raised so far that the principle switchability is given. Just before switching the manipulated variable is set in such a way that an optimal switching can take place. This can be special embodiment also manually from the driver z. B. by switch.

Parallel a driving profile or a driver behavior is analyzed, evaluated and taken into account. Rating size is here as switching frequency z. B. a number of valve lift switching within a specific Observation period. Demands the driver behavior a very frequent switching, will that be available standing performance level moved up, so the switching process be done with little or no preparation time can. On the other hand, if you notice that switching is very rare or in extreme cases at all is not required, the performance level is lowered. This Condition requires more preparation time in case of a switchover request, which makes the switching longer takes and the motor dynamics is limited. On the other hand, that is Energy consumption thereby reduced to a minimum. Not in one further illustrated embodiment provided in this regard that the driver himself this Mode z. B. over activity an economy button is activated.

• • Stufe 1 = Versorgungsminimum,
• • Stufe 2 = Schalten ist prinzipiell möglich,
• • Stufe 3 = optimales Schalten, d. h. schnell und sicher.

In the simplest case, the switching frequency is subdivided into the two groups "frequent" and "rare". This classification can be refined as desired. It offers the classification in three stages:

• • level 1 = supply minimum,
• • Level 2 = switching is possible in principle,
• • Level 3 = optimal switching, ie fast and safe.

In a further advantageous embodiment, the driver's request is observed, analyzed and interpreted. If there is a changeover urgency, the immediate release for switching is granted, irrespective of the current manipulated variable value, as shown in the drawing 7 as a flow chart. This one runs the risk that it is at the Um circuit to complications, such as B. jerking, comes, but by the simultaneous retrieval of the manipulated variable maximum is ensured in this way that the switching can be done as quickly as possible.

und die folgende Abfrage durchlaufen:
If (Fehlerhäufigkeitsindex > Schwellwert)
Then (Stellgröße = Stellgröße + 10%) In a further step, the long-term behavior of the system is analyzed and taken into account. If it is determined during a certain observation period that there has been a certain number of faulty operations, the power or pressure level is categorically over the entire operating range by a definable value, eg. B. 10% raised. For this an error frequency index is defined to:

and go through the following query:
If (Error Frequency Index> Threshold)
Then (manipulated variable = manipulated variable + 10%)

causes can z. As in system aging, wear, increase in leakage, oil aging or oil dilution lie. Is the oil condition, in the present embodiment by means of an oil quality sensor is determined, main reason for that change System behavior, can reset the additional level after a successful oil change become. For this purpose, a reset is performed.

An essential advantage of the method described above is that by a temporary power intervention, such. B. the pressure level increase described before the switching, on the one hand, the conditions for a control action to be improved, whereby the level of security intervention is increased, on the other hand by the increased control or switching speed of the influence on the entire switching timing decreases. This minimizes another uncertainty factor of known devices and methods. Coordinating the power requirements of the individual components on the part of the oil circuit manager ensures safe engine operation even during a control intervention. In addition, the power requirement of the overall system is kept low, which contributes to CO ₂ reduction. Advantageous embodiments of the described principle lead to a system adaptation to a respective driver behavior. The required control actions are carried out by a manager who has all the necessary information available, this manager being implemented in the example structure presented in the functional structure of the engine control system. 8th shows a corresponding block diagram illustrating a control loop on the example of an oil pressure regulator. Here is the pump 2 is controlled by the sum of two pulse width modulated signals PWM and ΔPWM to control the oil pressure p to a default value p_soll.

1

Oil circuit a 12V gasoline engine as a controlled system

2

oil pump

3

regulator

4

hydro- or switch board ram

5

locking element

6

feather

p

oil pressure

V

flow or flow rate

TOIL

oil temperature

POIL

oil pressure

p

print

.delta.t

time

Claims (17)

Method for an oil circuit management in an internal combustion engine using at least one hydraulic component, characterized in that an oil pressure (p) and / or a flow rate (V) as a control variable in response to a component to be controlled in each case, carried out a positioning process and then the manipulated variable to an original and the level necessary for operation. Method according to claim 1, characterized in that that the variation of the manipulated variable in dependence is performed from a respective operating point. Method according to one of the two preceding claims, characterized characterized in that a current power requirement in addition during the control intervention activated consumer is determined and compensated. Method according to the preceding claim, characterized characterized in that an additional Power requirement during Activation of activated consumers by operating point-dependent modeling is determined. Method according to one of the preceding claims, characterized characterized in that it is in service area relevant operating areas the manipulated variable prophylactic and depending varies from the current operating point and in particular is raised. Method according to one of the preceding claims, characterized characterized in that evaluates a driving profile or a driver behavior and the manipulated variable accordingly the assessment is tracked. Method according to the preceding claim, characterized characterized in that the evaluation takes place in at least two stages. Method according to one of the two preceding claims, characterized in that the evaluation takes place in three stages, in which Level 1 the reliability of the engine z. B. in shape of lubrication and cooling ensuring Stage 2 is a fundamental switching of the components allows and Stage 3 realized the switching optimum. Method according to one of the three preceding claims, characterized characterized in that the rating based on a switching frequency carried out becomes. Method according to one of the four preceding claims, characterized characterized in that over a certain period of time (Δt) the switching error frequency determined and the manipulated variable level is raised if a certain error rate is exceeded. Method according to one of the five preceding claims, characterized characterized in that a driver is active on the result of the rating Influence, in particular by pressing an economy button. Method according to one of the preceding claims, characterized characterized in that an accelerator pedal value is analyzed and more urgent Switch request the immediate release for switching takes place and the manipulated variable maximum is requested. Method according to one of the preceding claims, characterized characterized in that an actuating increase after a successful oil change reset if the oil quality is the cause for the Malfunction represented. Contraption ( 1 ) for an oil circulation management in an internal combustion engine, characterized in that the device is designed to implement a method according to one or more of the preceding claims, that it is designed to vary and regulate manipulated variable, which influence a control behavior of at least one component, and means are provided for the precontrol of a manipulated variable as a function of a respective components to be controlled, for carrying out a setting operation and for returning the manipulated variable to an original and necessary for operation level. Device according to the preceding claim, characterized characterized in that the means formed in the form of logic are those with a mechanically operated oil pump and / or an electric actuated Blow by valve are connected. Device according to one of the two preceding Claims, characterized in that the means in the functional structure the engine control are implemented. Device according to one of the three preceding claims, characterized characterized in that the oil circulation is subdivided into subsystems and each subsystem as its own independent cycle a corresponding sub-device is assigned.