GB2205179A

GB2205179A - Power control in an automotive machine

Info

Publication number: GB2205179A
Application number: GB08810612A
Authority: GB
Inventors: Gerd Bernhard; Andreas Oppitz; Reinhard Schaller; Gerhard Windisch; George Urban; Hansjorg Seiler
Original assignee: VEB Kombinat Fortschritt Landmaschinen Neustadt (Bestand)
Current assignee: VEB Kombinat Fortschritt Landmaschinen Neustadt (Bestand)
Priority date: 1987-05-26
Filing date: 1988-05-05
Publication date: 1988-11-30
Also published as: DE3810724A1; DD261298A1; IT8848006A0; IT1235577B; DK275988D0; FR2615904A1; GB8810612D0; DK275988A

Description

4 j 220 5179 POWER CONIROL IN AN AUTOMOTIVE MACHINE The present inventicn

relates to an automotive machine, especiallj a combine harvester, and has particular reference to regulation of the rotational speed of a driving engine of the machine and the rotat5 ional speeds of driven units of the machine.

In an automotive processing machine, the rotational speeds of its travel drive and processing elements are matched to the processing operations and are kept constant during these operations. Due to the wide var-ety of processing operations and possibilities of use, certain operating regimes arise in which the machine is not fully loaded for various reasons. Factors, which have influence on this are, for example, mowingthreshing of special crops, mass fluctuations according to hopper filling, beats deviating from the regular, turning operations and transport travel. Due to the lower engine loading at constant rotat- ional speed, which is necessary for the drive of the processing elements, the engine operates in a range of higher specific fuel consumption.

In principle, it is known to control rotational driving speed and engine torque to be in a favourable output range of the engine by way of a multistage gear. An arrangement for regulation of the rotational speed of an engine in dependence on load is described in DD 200 234. This arrangement concerns the most frequently arising cause of a load change, namely the transport state. In this case, the rotational speed of the engine is set below the nominal rotational speed by constrained coupling and the ratio of the transport gear is increased at the same time. It is disadvantageous that the engine speed can be regulated only for the transport state. This arrangement is therefore not applicable to automotive processing machines, in which each assembly has a specific rotational speed and an own component 9 - of Inc eng-lne torque.

221. In this A different arrangement is described in DE 2 50ú arrangeinen-f'., regulation of the engine speed takes place in dependence on the loading by the processing elements. In that case, the static pressure in the hydraulic system of the machine serves as a regulating magnitude and is detected by appropriate pressure-measuring equipment. This arrangement has the disadvantage of considerable complication. A further disadvantage is that rhange in the engina. speed does not take place automatically on load changes of the engine due to the processing elements.

It would thus be desirable to control the engine of an automotive machine in an output range of low specific fuel consumption, preferably by constantly monitoring engine load and controlling the engine towards lower speed when engine torque falls below a certain threshold while maintaining the rotational speeds of driven units at a substantially constant value.

According to the present invention there is provided an automotive machine comprising an engine, control means to control the speed of the engine, a plurality of driven units drivably coupled to the engine by way of speed and torque converter means, first sensor means to provide a first signal indicative of output torque or speed of the engine, second sensor means to provide a second signal indicative of output torque or speed of the converter means, evaluating means to evaluate the first signal for detection of change in engine torque and in response thereto to supply a control signal to the control means for change in the engine speed and to evaluate the second signal for detection of deviation of the driving speed of any one of the Q 1 a 3 - P1 driven units from a predetermined value and in response thereto to supply a control signal to the converter means for removal of that deviation, and threshold switch means to control delivery of the first signal to the evaluating means.

In'a preferred embodiment, a rotational speed torque measuring sensor for detection of instantaneous rotational speed as well as required torque is arranged at the engine of the machine and measuring sensors for detection of actual rotational speeds are arranged at the individual driven units or processing elements. All sensors are connected with a process computer which records and evaluates the signals from the sensors. The computer is connected by way of control lines with rotational speed torque converters upstream of the different processing elements and is connected with the engine by way of a further control line. When a predetermined deviation from a target value of required engine torque is exceeded, which is signalled by the sensor associated with the engine, the computer provides a pulse by way of the relevant control line to cause a regulator in the engine to respond. At the same time, the computer sends, by way of the other control lines, pulses to the sensors associated with the processing elements so that these keep the rotational speeds of the elements constant. In place of the individual rotational speed torque converters, a central rotational speed torque converter can be used, for example a multistage gear unit switchable under load. In order to stabilise the mode of operation of the arrangement, a threshold switch is arranged between the sensor associated with the engine and the computer.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a diagram of a first automotive machine embodying the invention; and Fig. 2 is a diagram of a second automotive machine embodying the invention.

Referring now to the drawings, there is shown in Fig. 1, in schematic block form, drive and control components of an automotive processing machine, in particuar an engirie 1 cl-riiected by way of stepless mechanical rotational speed torque converters 6 with different driven units such as a threshing drum 8, a travel drive 7 and other processing elements 9. The converters 6 provide differentiated transmission of the engine speed to the driven units. Arranged at the engine 1 is a rotational speed/torque sensor 2, which detects the actual rotational speed as well as the required torque of the engine 1. The signal provided by the sensor is conducted to a computer 3 and is evaluated by the computer. A threshold switch 12 is arranged between the sensor 2 and the computer 3. The threshold switch 12 responds only to certain changes defined in magnitude and duration so that brief small fluctuations of the engine torque are not passed onto the computer 3. The necessary stability of the entire arrangement is ensured by the threshold switch 12. When the required torque reduces as a consequence of change in the operating regime, then this is recorded by the sensor 2. If the change has a value which exceeds or falls below the value set by the threshold switch 12, the change is detected by the computer 3 and evaluated. The computer 3 sends a control pulse to a regulator of the engine 1, which is connected with the computer by way of a control line 4, and this pulse so influences the regulator that this - 5 either reduces or increases the speed of rhe engine '].

The computer 3 is also connected by way of control lines 5 with rotational speed/torque converters 0, arranged downstream of which a 1 re the travel drive 7, the drive of the threshing drum 8 and the drives of the other processing elements 9. A respective rotational speed sensor 10, which is connected in turn with the compu.ter 3, is disposed between the converters 6 and the travel drive 7, the drive of the threshing drum 8 and the drive of the other, processing elements 9. If, for example, the engine torque falls, then engine speed is reduced by the computer 3 in the described manner. This has the consequence that a falling below the required rotational speed is recorded by the sensors 10 at the travel drive 7, the drum 8 and the other processing elements 9 and corresponding signals are sent by the sensors 10 to the computer 3. The converters 6 are controlled by way of the control lines 5 from the computer 3 so that the rotational speed deviations are corrected correspondingly. Correction is also provided of rotational speed deviations due to slip, different V-belt bias and wear.

In the machine, also illustrated in schematic block form, of Fig. 2, in place of the individual converters 6, a central rotational speed/torque converter 11 is used, for example a multi-stage gear unit switchable under load. This central converter 11 is connected with the computer 3 by way of a control line 5 and is drivingly coupled with all the driven units 7, 8 and 9. The manner of operation of this arrangement is similar to that of Fig. 1. Changes in the required driving torque are detected by the sensor 2. The signal resulting from this is passed, in the case of appropriately large - - 6 - deviation, on to the computer 3 and evaluated by the computer. BY way of the control line 4, the regulator of the engine 1 receives a pulse for changing the rotational speed, while by way of the contrcl line 5 the computer 3 delivers a further pulse to the converter 11.

Thereby, the converter 11 corrects the driving rotational speeds for the travel drive 7, the threshing drum. 8 and the other processing elements 9. The maintenance of the required constant rotational speed is monitored hy the single reLotional speed setiso.,- 10 and s-ignalle to the computer 3. In this embodiment, the rotational speed adjustment of the engine 1 is stepped according to the transmission ratio of the gear unit 11.

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Claims

1 An automotive machine comprising an eng,ne, control means to control the speed of the engine, a plurality of driven units drivably coupled to the engine by way of speed and torque converter means, first sensor means to provide a first signal indicative of output torque or speed of the engine, second sensor means to provide a second signal indictive of output torque or speed of the converter means, evaluating means to evaluate the first signal for detection of change in enailne torque and in respinsc thereto to supply a 1-ortrcl signal to the control means for change in the engine speed and to evaluate the second signal for detection of deviation of the driving speed of any one of the driven units from a predetermined value and in response thereto to supply a control signal to the converter means for removal of that deviation, and threshold switch means to control delivery of the first signal to the evaluating means.

2. A machine as claimed in claim 1, the evaluating means comprising a computer.

3. A machine as claimed in either claim 1 or claim 2, the converter means comprising a respective speed and torque converter coupling each driven unit to the engine.

4. A machine as claimed in either claim 1 or claim 2, the converter means comprising a central gear unit coupling all of the driven units to the engine.

5. A machine as claimed in claim 4, the control means being operable - 8 to step adjustment of the speed -.f the engine in dpppndence on trans. mission ratios of the gear unit.

6. An automotive machine substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

7. An automotive machine substantially as hereinbefore described with reference to Fiq. 2 of the accomDinying d-axilnqs.

1 Pubhshed 1988 at The Patent Office, State House, 66.171 High Holborn, London WCIR 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3P.D. Printed by Multiplex techniques ltd, St Maz7 Cray, Kent. Con. 1187.

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