DE1914669A1 - Method for specifying the target position of a piston as a function of the position of the rotor of a piston engine - Google Patents

Description

19H669

GRUNDIG E.M.V. Ftirth, September 1st, 3rd I. Electro-Mechanical Research Institute 788-Ba / Ku

Owner: M »x Grundig
85IO Fürth / Bavaria, Kurgartenstrasse 37 Kor. Tt5 <»

Method for specifying the target position of a piston as a function of the position of the Rotor of a piston engine

The invention relates to a method for specifying the target position of a piston as a function of the position of the rotor of a piston engine, in which the assignment between piston and rotor is hydraulic he follows. In such an engine, the connecting rods are an ordinary piston engine replaced by a system that does not guarantee a rigid assignment between piston and rotor », namely the hydraulics. In this case, the correct assignment only exists if the fill level the hydraulics is correct. When starting the engine. And because of leakage losses during the correct allocation must be adjusted when running.

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WAR®

19H669

The piston position is not linearly dependent on the angle of rotation of the rotor, but follows a sine-like curve with a constant change in the angle of rotation of the rotor. This relationship must therefore first be simulated in order to specify the target position of the piston.

According to the invention, this simulation as well as the setting and regulation of the piston position made possible by it is carried out by a transducer mapping the piston movement into the approximately linear section of its electrical output signal, which is sine-like as a function of the mechanical input variable, this section being smaller than half the periodicity range of the output signal, while an associated rotor transducer with a full piston play the full period of its sinusoidal electrical Ausgangesignals as a function of the rotation angle of the rotor to write, while further these two electrical output signals are compared in an evaluation circuit with each other and by a at a _f deviation of the signal · from each other or a plurality of valves be operated so that Je

009841/0632

OBlQlNAL INSPECTED

19H669

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after submitting and capitalizing the deviation more or less hydraulic oil tu- or abeapeiat and ao the piston is placed at the prescribed height. AIa transducers can be attached to the piston and rotor same transducers are used. Here ea is advantageous, al · transducer resolver ein-Buaataan. For this purpose, the piston moves back and forth with a lever arrangement transformed into a reciprocating rotary motion.

The resolvers are primarily acted upon by an alternating voltage. Dia amplitudes of aekundär Wechaelspannungen occurring, ie is Ausgangesignale, are each dependent upon represents Stallung daa K _o lbens or the rotor. Among other things, it is now necessary to be able to compare the output signals, it is advantageous to use only aina Phaaa of the swat or more secondary voltages of the Drahaalder and also to increase or reduce the primary or secondary voltage at the resolver so that the amplitudes of the output voltages on the rotor - and piston torque indicators are the same size in the corresponding positions. Latsterea iat necessary because yes the resolver on the piston and rotor door simulation of the non-linear Zuaaaaen-

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Reg. 1456

hanges are deflected differently between piston position and rotor rotation angle, and thus for the case that the resolvers are primarily fed with the same AC voltage - this is the case applied in practice - the maximum possible amplitudes of the output AC voltages are different are great.

To compare the output AC voltages, i. So to measure the deviation of the piston from its target position, it is advantageous to proceed so before that one subtracts the output signals of the piston and rotor torque, this difference signal phase-dependent rectified and by means of the resulting DC voltage the supply and drain valves controls. So are the output AC voltages the resolver is the same in size and phase, then the correct assignment of pistons and rotor reached.

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If the engine has several pistons running in phase, which is also the case in practice, then you need a resolver for each piston, but for all pistons running in phase Rotor only a single encoder.

The invention will now be explained in more detail with reference to drawings. To do this, show:

Fig. 1 shows the piston movement as a function the angle of rotation of the rotor,

Fig. 2 the amplitude of the output; alternation: voltage of the rotor speed indicator as a function of the angle of rotation of the rotor,

3 shows the amplitude of the alternating output voltage of the piston torque indicator depending on the piston position,

FIG. K shows the relationship between the output signal of the phase demodulator and the piston deviation from the target position and FIG

Fig. 5 shows the basic structure of the control device,

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In Fig. 1, the middle curve 1 represents the piston movement with the correct amount of oil in the hydraulic system, while there is too much oil in the upper curve 2 and too little oil in the lower curve 3. The working area A of the piston is located within the displacement area V. When the engine is to be started, the rotor, the position of which is plotted on the abscissa in Fig. 1 and Fig. 2 in angular degrees a, initially has any angular position b. For the engine to work properly, piston position 4 is required. Before starting, the piston must therefore be set to point k. When the engine is running, the piston automatically moves through the middle curve (i). Because of the oil loss due to leakage while running, the piston movement must now be adjusted to curve 1. The basic structure of the control device is shown in FIG. The resolvers 7 and 8 are primarily supplied with the same alternating voltage U ". The amplitude U. of the AC output voltage of the rotor bodice 7 i * t of the angular position a of the rotor · shown in FIG. 2 dependent, while the dependence of 'Amplitude IL, the Ausgangawechaelspannung the piston resolver 8 from the Kolbenateilung r ^ in FIG. J dargeatellt iat. When the Rotordrehaelder 7 runs

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the amplitude is on the curve U, whereas with the piston rotary indicator 8 it is on the curve U, whereby this can only be changed between points 5 and 6. However, these curves must be adapted to one another in such a way that the maximum amplitudes that occur at U. and U_ are the same, since the non- linear relationship between piston position r. and Uotordrehwinkel a according to Fig. 1 can be produced only for this case . The adaptation is carried out by a divider 9. The adapted curve in FIG. 2 is denoted by U_.

The evaluation of the output signals from the piston and hotord sensors is carried out by first calculating the difference by switching them against each other. This differential voltage is then freed of harmonics by means of a filter element 10 and then rectified in a phase-dependent manner in a phase modulator 11 and rotor is to be reached. The comparison phase 12 is the phase of the alternating voltage U, from which the rotary indicators are primarily acted upon. Ae output 13 of the circuit is then the DC voltage U. to

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BATH ORIGINAL

Available, the sign and size of the deviation τ. of the piston is directly proportional from the target position to a certain range (see Fig. 4). The output signal U. at the demodulator 12 is “a measure of whether and how much oil is to be fed in or out.

In Fig. 5 it is also indicated that in an engine with several pistons running in phase, a corresponding measuring device, again consisting of a piston transducer 8 ', a voltage divider 9', a filter element 10 'and a phase modulator 11', is required for each additional piston , while a single resolver 7 is sufficient to obtain the comparison signal from the rotor for the in-phase pistons.

009841/0632

Claims (3)

- 9 - 'Keg. Claims ί ΐ · Λ « / learn about the target position specification of the piston as a function of the position of the rotor of a piston engine, in which the assignment between piston and Ho tor takes place hydraulically, characterized in that a transducer maps the Kolbcii movement into the approximately linear part tuck (U ,.) of its sine-like electrical output signal as a function of the mechanical input variable (γ ..), this part being smaller than the ha.lbt * periodicity range of the output signal while a transducer assigned to the rotor emits the full period of its sine-like electrical output signal (U _o ) as a function of the rotation angle (a) of the rotor with a full piston play, that these two electrical output signals are also compared with one another in an evaluation circuit (10, 11) and that if the signals differ from one another, one or more valves are operated in such a way that, depending on the sign and size of the deviation, more or less hydraulic oil is fed in or discharged and the piston is set to the pre-gas level. - ¹⁰ - ORIGINAL BATHROOM 9841/0632 19H669 - 10 - lie fr. 14th 2. The method according to claim 1, characterized in that as a transducer on the piston and rotor-like transducers can be used. 3. The method according to claim 1; characterized in that resolver as a transducer (7,8) can be used. k. Process according to claims 1 and 3i characterized in that of the two or more
Secondary voltages of the resolver (7 τ 8) is used only one phase, and that the primary or secondary voltages of the resolver are increased or reduced in such a way that the amplitudes of the output
The voltages on the rotor and the piston torque indicator (U., U_) are the same for the corresponding positions. 5 * Method according to claims 1 , 3 and k _t characterized in that to measure the deviation of the piston from its target position, the output signals of the piston and rotor torque are subtracted, this difference signal is rectified depending on the phase and controlled by means of the resulting DC voltage {*? &} & £ · inlet and outlet valves will © ii 009841 / 0S32 Blank page