DE10046834A1 - Method for controlling the speed of a drive machine - Google Patents

Abstract

The invention relates to a method for regulating the speed of a drive motor during a starting process in a transmission line. Said drive motor comprises at least one starting element which can be connected to the drive motor in a rotationally fixed manner. The starting element is in the form of a hydrodynamic coupling, comprising a primary blade wheel and a secondary blade wheel which, together, form at least one torus-shaped working chamber. According to the invention, the speed of the drive motor is regulated according to the power which can be received by the hydrodynamic coupling. The power received can be controlled or regulated.

Description

The invention relates to a method for speed control Drive machine, in particular with the features from the preamble of Claim 1; further use of the method.

Method for regulating the speed of a drive machine, in particular during the start-up process, in a drive train, especially for the Use in vehicles, comprising at least one engine and one with this at least indirectly coupled starting element, are in one Many different designs with regard to the control process triggering quantities, d. H. the input variables of the control device, the Dependency of the controlled variables on other variables and the manipulated variables known. It is generally known that in drive trains of vehicles, comprising an internal combustion engine, in particular Otto or Diesel engine, and a mechanical or connectable with this hydrodynamic starting element, for speed control of the Drive machine as manipulated variable one, the adjustment of the Power actuator of the drive machine - throttle cap or injector - At least indirectly characterizing size is formed and thus the Actuator - throttle valve or injector - is controlled. Representative is "Diesel Injection Technology" from Bosch, VDI-Verlag 1993, pp. 162 ff. The time span of the Understand the operating time of the drive train, which is due to baptizing the starting unit from the start, d. H. the commissioning of the drive machine until changing to a higher gear while bridging the hydrodynamic starting element is characterized.

When using hydrodynamic couplings as a starting element in vehicles are designed such that a filling during the start-up process automatically, for example depending on the speed of the  Drive machine or with delay to this can be done. It has however, showed that the resulting transmission behavior, characterized by the clutch characteristic, characterized in that high Moments can only be transmitted at high engine speeds. However, this means when the drive machine is designed as Internal combustion engine that the consumption-optimized area in the Engine map and thus a low-pollution mode of operation is not achieved and furthermore always for the transmission of high moments Provision of a correspondingly high performance by the drive machine is required.

The invention is therefore based on the object of a method for To develop speed control of a prime mover such that the mentioned disadvantages are avoided and if necessary the part of Optimal energy balance, especially when using Driving machines in the form of internal combustion engines consumption-optimized areas in the map of the engine during of the starting process can be achieved. The solution according to the invention should be characterized by a low control and regulatory technology as well mark constructive effort.

The solution according to the invention is characterized by the features of claim 1 characterized. Advantageous embodiments are in the subclaims played. Advantageous uses are in the claims 12 to 15. The control and / or regulating device is in use 16 described.

A method for controlling the speed of a drive machine in a drive train, comprising at least one starting element in the form of a hydrodynamic coupling that can be connected in a rotationally fixed manner to the drive machine, is characterized in accordance with the invention in that the speed of the drive machine as a function of speed and torque as a function of the power that can be absorbed by the hydrodynamic clutch is set. This means that when a control deviation occurs between a variable that at least indirectly characterizes the rotational speed of the prime mover and an actual value of the variable that at least indirectly characterizes the rotational speed of the prime mover, a change in the rotational speed of the prime mover occurs

• a) control and / or
• b) Regulation of the power consumption, in particular the Torque recording at a certain speed of the hydrodynamic clutch

is achieved.

Under "the speed of the prime mover at least indirectly characterizing size "is either a size understood in is a proportionality ratio to the speed of the prime mover, so that determines the speed of the drive machine, in particular can be calculated or derived, or the speed of the Drive machine is determined directly.

The solution according to the invention has the advantage that in addition to a free Controllability more energy-efficient, when the drive machine is designed as Internal combustion engine consumption-optimized operating points in the map the drive machine is already transmitting high moments lower speeds is possible and the necessary deliverable power of the drive machine to be provided is kept low can be.

In a further aspect of the invention, the control and / or Regulation of the power consumption of the hydrodynamic clutch via the Control and / or regulation of the degree of filling of the hydrodynamic  Clutch. In the simplest case, control is sought. The The degree of filling is preferably controlled by the application an influencing pressure on a stationary medium, in particular that in the Framework of a resource supply facility in one Resource storage device adjusting resource level. Part of the equipment in the work area is used during the operation of the hydrodynamic clutch in a closed Circulation between at least one exit from the toroidal Working space between the pump wheel and turbine wheel and at least one Entry into the toroidal work space, the entrance with a closed pressure-tight to the environment Resource storage unit is coupled. When a Control deviation then becomes a manipulated variable for generating a Influence pressure on the resting in the resource storage unit Medium generated and the actuator controlled. The filling or Emptying then takes place until a pressure balance is set between the Resource level in the resource storage device and the rotating closed circuit.

In a further aspect of the invention, additional functions can be implemented with the free controllability of individual points in the characteristic diagram of the drive machine by controlling the degree of filling, if necessary also taking additional parameters into account. This includes:

• a) the realization of a complete separation between engine and Working machine;
• b) the realization of a rigid connection between the engine and Working machine;
• c) the function of vibration damping via the setting of the Slip.

Preferably, the option of speed control throughout Starting process in a drive train, d. H. the duration of the operation the hydrodynamic coupling provided.

The method according to the invention is part of a further development the controlled system of a regulation for the power output of the drive machine. This offers the advantage of simply realizing an external regulation of the Power output of the drive machine without directly influencing the Drive machine, in particular without the required control of the Power actuator, resulting in a reduction in tax and control engineering effort leads.

In an advantageous embodiment based on this further development this method forms part of the control path for setting a constant and time-independent holding torque for the holding function a work machine. This special control task enables the conventional braking devices, for example while stopping of a vehicle on an incline.

Another option is to control the speed of the Drive machine in a scheme to set a constant, neither output speed dependent on time and engine speed, d. H. Speed on, Abrasion, for example to integrate a work machine.

Another major advantage of this method is that in order to implement the individual control and regulating tasks, only at least the following variables for the regulating process have to be taken into account:

• - The current actual speed of the prime mover;
• - The current actual speed at the output of the turbo clutch;
• - the direction of rotation of the output;  
• - A, a desired speed to be set Drive machine at least indirectly characterizing size and
• - Optional internal state variables to describe the How individual powertrain components work.

The effort for the provision of appropriate recording facilities can also be kept low or limited to detection devices already present in the drive train.

The solution of the speed control according to the invention, in particular the Setting the speed of the drive machine depending on the Degree of filling is not due to a specific configuration of the drive train limited with a hydrodynamic clutch as a starting element. You can the prime movers for example in the form of Internal combustion engines or electric motors. The Can be used in stationary systems or mobile facilities, preferably done in the vehicle.

The solution according to the invention is explained below with reference to figures. The following is shown in detail:

Figs. 1a and 1b illustrate schematically in a simplified representation based on block circuit Signalflußbildern and the basic principle of a method according to the invention for speed control and the construction of the control device;

Fig. 1c shows by way of, signal flow, an inventive method for speed control of the prime mover with integrated regulation of recordable power through the hydrodynamic coupling;

FIG. 2 illustrates the basic principle of the filling level control on the basis of a schematic representation of a hydrodynamic coupling and the associated equipment supply system;

Fig. 3 shows by means of the speed / torque characteristic map of an engine a comparison of the characteristic curve of the hydrodynamic coupling with conventionally operated starting elements;

Fig. 4 illustrates the possibility of using a signal flow of the control of the power output of the prime mover.

The Fig. 1a shows a schematically simplified representation of a block diagram based on the basic principle of an inventive method for controlling the speed of a prime mover 1 is in a drive train 2 during the starting process. The drive train 2 thereby comprises at least one, with the engine 1, at least indirectly couplable starting element 3, which is designed as a hydrodynamic clutch 4, comprising at least one functioning as a pump primary blade 5 and functioning as a turbine wheel secondary blade 6, which together form at least one toroidal working chamber 7, is. In the preferred use of the method according to the invention in vehicles, the drive machine 1 is preferably designed as an internal combustion engine. However, designs as an electric motor are also conceivable. The starting element is preferably integrated in a gear unit 8 .

According to the invention, the speed control of the engine 1 takes place as a function of the engine torque M depending on the possible recordable moment M _on through the hydrodynamic coupling. 4 That is, the amount of recordable by the hydrodynamic clutch 4 power P _in, in particular, the recordable torque which is substantially the deliverable by the engine 1 power P _ABM and this reduced corresponding to the power required for the drive of additional or ancillary components determined, thus, due to the characteristic relationship assigned to a certain degree of filling FG of the clutch between the resulting speed ratio n _T / n _{P of} the individual paddle wheels of the hydrodynamic clutch and the coefficient of performance, the transmissible torque M. The speed of the pump wheel n _P and then results from the power which can be absorbed thus the speed n _{M of} the drive machine 1 corresponding to this or at least proportional to it.

For adjusting a certain speed n _Msoll the drive machine 1 in dependence of recordable by the hydrodynamic clutch 4 power P _in is carried out according to Fig. 1a and the signal flow according to FIG. 1b by controlling or, preferably, regulating the power consumption of the hydrodynamic coupling 4, ie control of the recordable power _to P, as shown by a signal flow in FIG. 1c.

The size of the power P _{on that} can be absorbed is a function of the degree of filling FG of the hydrodynamic clutch 4 . The degree of filling FG is controlled.

For this purpose, the drive machine 1 is assigned a control and / or regulating device 9 , comprising at least one control and / or regulating device 10 , which has at least one comparison device 11 , in which at least one setpoint for a, the speed n _{M of} the drive machine at least indirectly, a variable describing the speed preferably n _Msoll, with an actual value of a, the speed of the engine at least indirectly characterizing, preferably the actual speed n _Mist compared. From the control deviation .DELTA.n _M between the target speed n _Msoll and the actual speed n _Mist of the driving machine 1 is formed a manipulated variable for the control of the hydrodynamic coupling 4, in particular the primary blade 5, recordable power P _on. In the case of the desired regulation of the absorbable power P _on , which is shown in FIG. _{1 c} , the desired variable P _{up is} formed from the manipulated variable and is continuously compared with the current actual variable P _up . In the simplest case, the detection of the actual _{value of the} power P _{upist which can be absorbed} takes place by recording the quantities torque mist and speed mist which at least indirectly describe the power, for which purpose corresponding detection devices should be provided. The deviation _AP then leads to a corresponding change of the manipulated variable γ. In order for the manipulated variable γ to take effect, the hydrodynamic clutch 4 is assigned a device for changing or influencing the power consumption 12 . This is integrated in the controlled system 13 of the speed control with regard to the action path. The device for changing and / or influencing 12 the power consumption comprises means 14 for changing the degree of filling during the starting process. The degree of filling change is preferably carried out by filling control by applying an external pressure to a stationary medium to produce a pressure balance between a closed rotating circuit and the stationary medium. The closed rotating circuit is pressure-tight, ie the inflow and outflow spaces from the working space of the hydrodynamic coupling and the line connection between them are made pressure-tight. This pressure, which is also referred to as influencing pressure p _B , is generated, for example, by means of a pressure control valve 15 , which is part of the means 14 for changing the degree of filling.

The principle of applying an external pressure to a stationary medium is reproduced in detail in FIG. 2 on the basis of a schematic illustration of a hydrodynamic coupling 4 and the equipment supply system 18 assigned to it. Part of the operating medium present in the toroidal working space 5 in the hydrodynamic coupling circulates in a closed circuit 19 . The closed circuit 19 is designed as a coolant circuit, that is to say, during the operation of the hydrodynamic coupling 4, operating resources are released in certain quantities from the working space 7 , in particular from the outlet 20 from the working space 7 , and via at least one entry 21 into the working space 7 guided. A line system 22 is provided for this. Means 23 for dissipating heat are arranged in this, for example in the form of a heat exchanger. The guidance of the operating medium from the working space 7 into the working space 7 in the closed circuit 19 serves mainly to cool the operating medium, in particular to generate a continuous flow of cooling medium. The equipment supply system 18 comprises a pressure-tight equipment storage device 24 , for example in the form of an equipment sump in a container or tank, which can be coupled to the closed circuit 19 in the region of the inlet 21 via at least one connecting channel 25 . The operating medium storage device 24 is arranged in such a way that the operating medium level 26 which is set up is preferably arranged below the toroidal working space 7 . An influencing pressure p _{B is} applied to the operating medium level 25 in order to change the degree of filling FG, which, when acting on the closed sump, admitted operating medium into the working circuit in the toroidal working space via connecting channel 25 until the pressure in the area of the inlet 21 after the heat exchanger Creates pressure equilibrium.

FIG. 1b shows the speed control in control of recordable power P _on the interaction of the individual elements in the Gesamtwirkungsweg 27 based on a signal flow. In terms of function, the control device 16 corresponds to the control and regulating device 10 . The controlled system 13 forms that part of the action path which represents the area of the drive train 2 to be influenced. The control device 16 influences the controlled system 13 via an actuator 17 , which is formed by the pressure control valve 15 . The pressure storage device 24 and the hydrodynamic clutch 4 act as further transmission elements. The _KP n of the receivable power P _as a function of the degree of filling FG corresponds to a particular moment M _KP and a certain speed, from which the deliverable by the engine 1 power P _ABM can be determined and, in dependence of the degree of filling FG associated torque the speed n _{M of} the engine 1 .

FIG. 1c illustrates _the interaction of the individual elements in the Gesamtwirkungsweg the speed control 28 at the recordable power P control based on a signal flow. Called the action path for the control of recordable power P _on it with the 29th Otherwise, the controlled system 13 corresponds to that described in FIG. 1b, which is why the same reference numbers are used for the same elements.

The solution according to the invention makes it possible to set the speed n _{M of} a drive machine 1 in such a way that optimal behavior of the drive machine with regard to the starting process can be achieved. Each individual operating point in the characteristic diagram of the drive machine 1 can be approached separately or stationary, that is, set. This takes place depending on the control or regulation of the power that can be absorbed by the hydrodynamic clutch.

An essential criterion for the speed control is the load-free start-up of a drive machine 1 , in particular in the case of designs for use in vehicles when it is designed in the form of an internal combustion engine, and the emission-optimized operation. Since the power consumption of the starting element, in particular the hydrodynamic coupling, is dependent on this itself and not on a working machine connected to it at least indirectly on the output side, when installing such an element between the driving machine 1 and the output, it must be taken into account that for each load condition there must also be a state of equilibrium with regard to the torque and the speed between the drive machine 1 and the hydrodynamic clutch. In the rarest case, the power that can be output by the drive machine is entirely available to the gear unit downstream of the starting element, and thus to the hydrodynamic component during the starting process. The services for auxiliary machines, such as fans, alternators, pumps, etc., which are arranged in front of the starting element, must be deducted from the available drive power. During the start-up process at low speeds, in order to operate the drive machine as far as possible in the consumption-optimized range, it is necessary to transmit the greatest possible torque even at very low speeds. Such behavior can be achieved by changing the degree of filling. The power that can be absorbed via the hydrodynamic clutch causes a change in the speed of the drive machine 1 . Fig. 3 a illustrates another possible starting characteristics compared with different Start-4 a- c 4 and according to the invention during the start on the possible power controlled or regulated turbo coupling 4 in the speed / torque characteristic diagram of the drive machine 1. The torque line of the drive machine is designated II. The following indications are assigned to the individual starting characteristics:

• 1. Trilok converter - I _4a
• 2. Trilok converter with bypass - I _4b
• 3. Hydrodynamic clutch with lock-up - I _4c
• 4. Hydrodynamic clutch controlled according to the invention - I ₄ .

From the characteristic curves it can be seen that the solution according to the invention enables controlled and load-free startup of the engine 1 and operation in the emission-optimized area of the engine, in particular the internal combustion engine. Furthermore, the transferability of high torques is increasingly being shifted to lower engine speeds.

In a further aspect of the invention, the speed control of the drive machine is integrated in a control 31 of the power output of the drive machine 1 without directly influencing the output. This is illustrated by a control device 32 for comparing a target value for the output P _abMsoll with an actual value P _abMist . The power P _abM that can be output is determined, inter alia, by the speed n _M. The speed is regulated with regard to the consideration with regard to the effect in the context of the controlled system 33 of the regulation 31 .

The free controllability of the filling level of the hydrodynamic coupling also allows the setting with appropriate control a constant, time-independent, load-dependent holding torque for Holding functions, for example when inserting into vehicles, holding of a motor vehicle on an incline.  

LIST OF REFERENCE NUMBERS

1

prime mover

2

powertrain

3

starter

4

hydrodynamic clutch

5

primary blade

6

secondary blade

7

toroidal work space

8th

transmission unit

9

Control and regulating device

10

Control and regulating device

11

comparator

12

Device for changing and influencing the recordable performance

13

controlled system

14

Means for changing the degree of filling

15

Pressure control valve

16

control device

17

actuator

18

Working fluid supply system

19

closed circle

20

exit

21

entry

22

line system

23

Heat removal means

24

Equipment storage

25

connecting channel

26

Operating medium level

27

Gesamtwirkungsweg

28

Gesamtwirkungsweg

29

action path

30

regulation

31

Regulation of the power that can be output by the drive machine

32

control device

33

controlled system
n _Msoll

Target speed
n _crap

Actual speed
P _on

recordable performance
P is _up

Actual value of the absorbed power
P _should

Target value of the absorbed power
ΔP _on

power deviation
P _abist

Actual value of the output power of the drive machine
P _absoll

Setpoint of the output power of the drive machine
p _B

influencing pressure
γ manipulated variable

Claims (16)

1. Method for regulating the speed of a drive machine ( 1 ) during a starting process in a drive train ( 2 ), comprising at least one starting element ( 3 ) in the form of a hydrodynamic clutch ( 4 ), which can be connected in a rotationally fixed manner to the drive machine ( 1 ), comprising a primary blade wheel ( 5 ) and a secondary paddle wheel ( 6 ), which together form at least one toroidal working space ( 7 ), characterized in that the speed of the drive machine ( 1 ) is dependent on the power that can be absorbed by the hydrodynamic clutch ( 4 ), in particular the torque that can be absorbed at a specific speed is set. 2. The method according to claim 1, characterized in that when a control deviation occurs between a variable that at least indirectly characterizes the rotational speed of the prime mover and an actual value of the variable that at least indirectly characterizes the rotational speed of the prime mover, a change in the rotational speed of the prime mover ( 1 ) by the controller and / or regulation of the power consumption of the hydrodynamic coupling ( 4 ) takes place. 3. The method according to claim 2, characterized in that the control and / or regulation of the power consumption of the hydrodynamic coupling ( 4 ) by means of a control and / or regulation of the degree of filling of the hydrodynamic coupling ( 4 ) is achieved. 4. The method according to claim 3, characterized by the following features:

• 1. 4.1 part of the equipment is during the operation of the hydrodynamic coupling ( 4 ) in a closed circuit between an outlet from the toroidal working space ( 7 ) between the impeller ( 5 ) and turbine wheel ( 6 ) and an entry into the toroidal working space ( 7 ) guided;
• 2. 4.2 the inlet is coupled to an operating medium storage unit which is closed in a pressure-tight manner with respect to the surroundings;
• 3. 4.3 that when a control deviation occurs, a manipulated variable for generating an influencing pressure on the medium at rest in the operating medium storage unit is generated and the actuating device is actuated.

5. The method according to claim 4, characterized in that the influencing pressure via a drive motor ( 1 ) driven gear pump. 6. The method according to claim 1 to 5, characterized in that the Speed control at least during the entire start-up process is carried out in a drive train. 7. The method according to any one of claims 1 to 6, characterized in that this part of the controlled system of a control for power output of the prime mover ( 1 ). 8. The method according to any one of claims 1 to 6, characterized in that that this part of the control path for setting a constant and time-independent holding torque for the holding function of a Working machine is. 9. The method according to any one of claims 1 to 6, characterized in that this part of the controlled system of a regulation for setting a constant, neither time nor engine speed dependent Output speed is used.   10. The method according to any one of claims 1 to 9, characterized in that at least the following variables are taken into account for the control process:
the current actual speed of the drive machine;
the current actual speed at the output of the turbo coupling, the direction of rotation of the output;
a, at least indirectly characterizing a desired speed of the drive machine to be set and
Optional internal state variables to describe the functioning of individual components of the drive train. 11. The method according to any one of claims 4 to 10, characterized characterized in that the manipulated variable is parameter-dependent. 12. Use of a method according to one of claims 1 to 11 in a drive train ( 2 ) with a drive machine ( 1 ) in the form of an internal combustion engine. 13. Use of a method according to one of claims 1 to 11 in a drive train ( 2 ) with a drive machine ( 1 ) in the form of an electric motor. 14. Use of a method according to claim 12 or 13 in one Vehicle. 15. Use of a method according to claim 12 or 13 in one stationary plant.   16. Control and / or regulating device ( 9 ) for carrying out the method according to one of claims 1 to 11, characterized by the following features:

• 1. 16.1 with a control and / or regulating device ( 10 ); at least one comparison device ( 11 ) for comparing a setpoint value of a variable that at least indirectly describes the speed of the drive machine with an actual value;
• 2. 16.2 the control and / or regulating device ( 10 ) is connected to a device for detecting the actual value of a variable describing the speed of the drive machine, at least indirectly, and a device for specifying a target value for the speed of the drive machine;
• 3. 16.3 the control and / or regulating device ( 10 ) comprises at least one comparison device ( 11 ) for comparing a setpoint value of a variable that at least indirectly describes the speed of the drive machine with an actual value; and a device for forming a target value for the degree of filling of the hydrodynamic clutch;
• 4. 16.4 the control and / or regulating device ( 10 ) comprises at least one beginning, which is coupled to an actuator for influencing the degree of filling of the hydrodynamic coupling.