DE1902122A1 - Converter for generating mechanical vibrations - Google Patents

Description

Patent attorneys Dipl. -Ing. R Weickmann, 1902122

Dipl.-Ing. H.Weickmann, Dipl.-Phys. Dr. K. Fincke Dipl.-Ing. F. A. Weickmann, Dipl.-Chem. B. Huber

JABM 8 MUNICH 27 DEN

MÖHLSTRASSE 22, CALL NUMBER 483921/22

IA ¹ I ¹ IOiUL RESEARCH DEVELOPMENT COKPOlLiTION, PO Box 236, Kingsgate House, 66-74- Victoria Street, London, SS 1.

England

converter for generating mechanical vibrations

The invention relates to a converter driven by hydraulic fluid is driven and generates mechanical vibrations «The term" liquid "is used herein as Generic term for liquids and gases that can be dripped!

Such a converter according to the invention has a relative to a cylinder reciprocating piston, one surface of which is a chamber in the cylinder limited, which is periodically pressurized with hydraulic fluid with the help of a valve and relaxed again is to generate the oscillating movement, wherein a controller is provided that a first position signal generated when the parts moving relative to each other (cylinder and piston) durchlauj'oü a first relative position, and outputs a second position signal when the 'i'eilo pass through a second relative' position; these

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Position signals are sent to a bistable element, which controls the valve in dependence on the position signals in such a way that the pressure fluid periods are in a predetermined phase relationship to the periods of the relative oscillation movement.

The term "relax" is intended to mean a much lower pressure than the process of "pressurization" prevails, but this much lower pressure need not necessarily be zero.

An arrangement can be made to at least one of the position signals by a logical To send circuit to the bistable element, the position signal as a function of a control signal lets through to the bistable G-song or blocks the passage.

The converter can have means to send each position signal through its own logic circuit, Each of these logic circuits receives its own control signal in the same way that only those first position signals are passed to the bistable element when passing through the first relative Position can be generated in one sense of the direction, and also only those second position signals reach the bistable element that when passing through the second relative position are generated in the opposite sense of direction.

3s a pressure meter can be provided, which shows the pressure in the chamber or a related pressure and controls signals to all logic circuits sends in the ..that the first position signals only .then are switched through to the bistable element when the.

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Chamber is pressurized and second position signals only when the chamber is relaxed.

There can also be another chamber, which is delimited by a further area of the piston, which is facing away from the first-mentioned piston surface, and that of the valve with a phase shift of about 180 opposite the first chamber is pressurized and relaxed. Accordingly, pressure measuring means can alternatively be used intended for the pressure in the first-mentioned and the further chamber or for pressures in relation thereto be, which send control signals to all logic circuits that operate so that the first position signals can only be passed to the bistable member when the first chamber is pressurized is, and the second position signals only reach the bistable element if the other chamber with Pressure is applied.

The valve can be a slide which is controlled by the bistable element with the aid of pressure fluid signals will.

One of the logic circuits can be intended to receive a control signal for switching the converter on and off. _: .

learner a suspension can be provided that the converter a resilient preload in the opposite direction to the relative 5chwinr.; ungsmotion granted. This suspension can consist of a chamber called a "liquid" leather contains effective volume of liquid, the pressure prevailing in this volume of liquid in the U-

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■ - 4 drove acts against another area of the carbene.

The invention is described in the form of an exemplary embodiment with reference to the accompanying drawings.

Fig. 1 shows an embodiment of an inventive Converter;

Figures 2a and 2b are graphs of the position signal pulses plotted against time;

Fig. 3 shows a further embodiment of the invention and

Fig. 4 shows yet another embodiment of the invention.

The terms "right" and "left" as used herein refer to those apparent from the drawings Directions.

In Fig. 1, a converter is shown which is driven by hydraulic fluid and generates mechanical vibrations and which has a piston IO, which supported in a cylinder 12 for sliding reciprocating movement of the two parts relative to one another is. The cylinder contains a first chamber 14 bounded by a working surface 16 of the piston. Further the cylinder closes a spring acting as a "liquid" Chamber 18, that of a further work surface 20 of the calving opposite to the work surface 16 is limited. The ^ chamber 18 contains a volume of liquid that forms a "liquid" spring which

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the calving 10 and the cylinder 12 to a predetermined relative position of the "two parts pushes and thereby the relative movement of the two [bearings is in the opposite direction.

The piston 10 has two projecting parts 24, 26 with a relatively large diameter, which form a short groove 28 between them. The working surface 20 is formed by the transition between the diameter of the thick part 26 and a thinner part 30. The T _e il 50 is of an annular groove 31 into two sections. divided. It emerges from the cylinder 12 through a bore 32 and is designed to drive about a .Bohreinsatz or an agricultural grass mower, not shown.

The chamber 14 is operated by a valve 34 alternately with one under a practically constant pressure Pressure fluid source via a line 38 with a The low-pressure tank is connected via a line 40. The administration 38 contains a pressure accumulator 42 which serves to keep the pressure in the line constant.

"So when chamber 14 is pressurized, Pressurized fluid acts on the working surface 16 of the piston 10 and drives it to the right relative to the cylinder 12, the fluid in the chamber 18 is compressed. If the chamber 14 is relaxed, If the liquid contained in the chamber 18 drives the piston 12 to the left, an oscillating movement occurs on this basis of the piston relative to the cylinder.

D-in valve 34 has a spool 36 with two spaced apart Parts 44, 46, the end faces of which are chambers 48 and 50, respectively

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". To move the slide from one position to the To transfer others, pressure fluid is sent into one of the "two chambers 48 or 50" that is in the other Liquid present in the chamber can flow off through throttle points 52, 54 to an outlet 56 and 57, respectively. The slide 36 can assume two positions, depending on which of the two chambers 48, 50 with pressure is applied. 1 shows the first position in which the chamber 50 and the chamber 14 are under pressure is connected to the line 38. In the other, not shown slide position, the chamber 48 is under pressure acted upon and the chamber 14 is thereby connected to the line 40.

The projecting parts 24 ₅ 26 and the groove 31 of the piston 10 cooperate with spaced slots 58, 59, 61, 63 in the cylinder wall. The slots 58, 59 are connected to a line 60, which in turn is in communication with the line 38 and therefore contains pressure fluid. The slots 61, 63 are connected to the chambers 48 and 50 of the valve 34 via lines 62 and 64, respectively. The slot 59 lies opposite the slot 63 in the cylinder wall, so that these two slots briefly come into contact via the rage 28 during the relative oscillating movement. In the same way, the slots 59 and 61 are also arranged opposite one another and are briefly connected through the groove 31 during the to-and-fro movement. The slots 58, 59, 61, 63 and the grooves 28, 31 represent a control.

When the chamber 14 is pressurized, the Piston 10 pushed to the right until iüut 31 momentarily the slots 59, 61 connects with one another and thereby applies a short pulse of the pressure fluid that a

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represents the first position signal for the line 62. When the chamber 14 is depressurized, the movement of the piston 10 to the left causes a similar pulse to apply the pressure fluid which is a first position signal for the line 62. w ^r hen the chamber 14 relaxes, causing the leftward movement of the piston 10 has a similar short pulse of the pressure fluid, which is a second position signal, which is applied to line 64 when the! Tut 28 briefly, the slots 58, reveals' 64th

Lines 62 and 64 are associated with chambers 48 and 50, respectively Connected via a bistable element, for example a flip-flop 72. This one has a "memory" so that as soon as a short pulse of the pressure fluid is given on the line 62 or 64, the flip-flop 72 toggles and remains in this position until a pressure fluid pulse is applied to the other line.

The flip-flop can be a pure flow device, for example a so-called "all attachment element", or it can consist of two three-way valves with pistons in the manner of the so-called. "Fluidics" be formed. When a. "v / all attachment element" is used, are the throttle points 52, 54 and the drainage devices 56, 58 unnecessary because such are already built into the element.

The translator operates in the following manner: When the slots are in the positions shown in FIG. 1, the chambers 14 and 50 are pressurized and the piston 10 moves to the right when the piston 10 is "first" relative position "designated Ltell? overflows, in which the slots 59 and 61 connected with one another ^ ' ⁿ v: ird on the line 62 a first

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Position signal generated. This signal pulse causes the Plip-Irlop 72 to switch to a state in which it causes the chamber 48 to be pressurized and the chamber 50 to be relaxed, whereupon the slide 36 is moved into its second position. Sun relaxes the chamber 14 and the liquid in the chamber 18 acts on the piston to move it to the left. Due to its inertia, the piston 10 continues its movement to the right for a short time after the chamber 14 has been relaxed. If the piston then moves to the left, a redundant (superfluous) position signal is generated on the line 62 . However, since the flip-371op has already switched 72 to the previous position signal in line 62 _i he ignores the redundant first position signal. The left-hand movement of the piston is continued until the anger 28 releases the slots 58, 63 and thereby briefly connects the line 64 with the line 60. A second position signal is generated. A pressure fluid pulse is thereby brought into action on the working surface of the valve slide 36 which delimits the chamber 50 and returns the slide to its first position in which the chamber 14 is re-pressurized, with which the next cycle begins. Even if the chamber 14 is pressurized, the piston shoots slightly over the target and a redundant second position signal is generated in the same way as described above. This time, too, the ΐ'ΐορ ignores the redundant signal.

The relative positions of the slots 58, 59, 61 and 63 and the distance between the grooves 28, 31 determine together with the wetness of the piston 12 and the elasticity of the "liquidity" -l ^! edf; r 18 the frequency of the relative oscillation of the piston and the cylinder and the

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Phase difference between the cyclical application of pressure to chamber I4 and the relative oscillating movement.

The chamber 18 is via a line 66 which is a check valve 68 contains, supplied with refill liquid. The! Top-up liquid compensates for any leakage loss, for example, through the! Bore 32 " It can be taken from line 40 which is maintained at a relatively low pressure (e.g.

ρ ρ

100 lbf / in = 7 kg / cm versus a pressure of size-

2 ^

properly 1000 lbf / in = 70 kg / cm ' ^: "' in the line 38)

the! υπ falls.

ρ ρ

the! pressure in chamber 18 below 100 lbf / in "(7 kg / cm)

The described conversion can be done by means of a stop valve in;.; insr dor both lines 62 or 6A or by means of oinas stop valve in line VO, the hydraulic fluid feed line, being controlled. By closing a stop valve in line 62 or 64 comes the Piston on the right line of the cylinder to stop, while a stop valve in line 38 on closing the piston in an arbitrary position.

An alternative standard of control is shown in FIG indicated by dashed lines. The lines' 62 and 64 are connected to the logic circuits 74 "and 75, respectively ! Klip-Plop 72 connected. The logic circuits are Uli D-GIi ed er that depending on the presence or lack of control signals that are sent to the UiiD-Ü-lieder are placed via lines 77 and 78, the relative , 'ichwin.v.bev / eftung the piston and dos cylinder in G-ang network or stop. For example, if on the line there is no control signal, the hydraulic fluid is

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keitsimpuls from the line 64 not let through to the flip-flop, so that the slide 36 is not pushed into its first position. The piston 10 comes consequently at the left end of the cylinder 12 to rest.

The conduit 78 may also be a pulse-forming element 80 included so that any given to the conduction control signal is converted into a pulse whose pulse duration is shorter than the above _c hwingungsdauer a relative oscillating motion. It is assumed that a control signal is present in line 77 and that line 64 is under pressure. Then when such a pulse is applied to the line 78, only one cycle of the relative oscillating movement takes place before the piston comes back to the cows, because at the point in time, the line 64 is pressurized again, the control signal in the line 78 has already disappeared and the logic circuit 75 does not pass on a pressure fluid pulse in the line 64 to the Plip-ΙΊορ, - alternatively, the pulse-shaping element 780 can also be installed in the line 77.

The UjM D-GIi ed er and the pulse shaping element can pure Flow devices of a known type or they can be formed by piston valves. The UIfD members piston valves can be replaced by negated OR elements (in OK-GIi ed er), whereby the logical Behavior reverses.

When the converters are operated at high "frequency should, the transmission of the first and second position signals relative to the movement of the piston must be timed be advanced so that the periodic Druckbsaufschla-C'ung the chamber 14 with the correct phase difference

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happens to the vibrations of the piston.

This can be achieved by changing the distance between the mutes 28, 31 and the slots 58, 63, 59, 61.

Pur one operation "at very high frequencies, about 5000 periods / min, it can happen that the position signal must be advanced so much that the redundant first position signal, see above, occurs after the non-redundant second position signal, and accordingly that redundant second position signal after the non-redundant first position signal.

2a shows the time dependency of the occurrence of the first and second position _{signals P s} from a working with a mean frequency :! Converter is generated α, as it is in Tig. 1 is shown. It can be seen that the non-redundant first and second position _{signals P 1 and Pp, and the redundant first and second position signals P ^ 'and P 2} ¹ are generated in the following order: P 1, Ρ _χ ', P ,,, P ₉ 'Ρ _χ , P ₁ ', P ₂ , P ₂ »etc. ¹ Me dashed lines E ,, E, deuton the times rn, ^r 'u at which the piston 10 is at the right end of its "?"Above; the lines E ₉ , Ji ^ ₁ mark the point in time, see below. i de ·. ' Piston arrived at the left L-in-ie of its stroke -'st ... e--: Piston .10 of course changes its seal on

never, of its stroke and you can see that °. die-non-redundant en -ign.-ale Pη, P ₀ are fairly close in time to the change in direction of the pistons that they cause.

Tig. 2 b illustrates ^ -the time dependence of posi-

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tion signals in a converter operating at a very high frequency. Here you can see that the non-redundant signals P-,, P _? occur fairly well before the resulting change in direction of the piston. The signals are generated in the order P ₁ , P ₂ , P ₂ ', P ₁ ¹ , P ₁ , P ₂ , P ₁ ¹ , Ρ _χ and so on. As a result, the flip-flop 72 would treat some of the redundant position signals as effective signals, and vice versa. This would have the consequence that the pressure periods in the chamber 14 would get out of step. To avoid this, the converter is modified as described below.

In Fig. 3, a modified converter for operation at high frequencies is shown. Already with reference to Fig. Parts described in FIG. 1 have the same reference numerals.

The logic circuits 74 »75 receive control signals via lines 81 and 82, respectively. The lines 81, 82 are connected to a pressure gauge 84, which measures the pressure in the chamber 14 senses. In the drawing, the pressure gauge 84 is connected to the chamber 14 via a line 86; however, this line should be as short as possible and the pressure gauge is therefore preferably placed in the Wall of the chamber 14 installed. Of course, a can also be related to the pressure in the chamber 14 standing pressure can be measured, provided that the relationship is a unique function 84 works in such a way that. a control signal is given on line 81 only when the chamber 14 is pressurized, and a control signal is sent into line 82 only when the Chamber 14 is relaxed. ■

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The converter works as follows. It is assumed that the piston has moved to the right from its left limit position E and that the chamber 14 is pressurized. First, a non-redundant first position signal P i is generated on the line 62. Since the chamber 14 is under pressure, The UIfD-QIied 74 passes this first position signal to the flip-flop 72, which initiates the relaxation of the camera 14. As the next position ^{signal, a redundant second position signal Pp 1 is} generated in the line 64 when the I ^ ut 28 the Slots 58, 63. However, since the chamber 14 needs a finite time to relax, the pressure prevailing in the chamber at this point in time is still sufficient for the pressure gauge to send a control signal on line 81 and not on line 82 Pole, the AND gate 75 does not let the redundant signal through to the flip-flop 72. The piston 10 then reaches the end of its stroke at E, and begins to move in the opposite direction (to the left), now we d generates a non-redundant second position _{signal P 2} and at this point in time the chamber 14 is relaxed enough to allow the pressure gauge to generate a control signal in line 82 and not in line 81. Consequently, the UlTD element 75 switches this second position signal through to the flip-flop 72, which initiates the pressurization of the chamber 14.

While the iÖLben 10 continues its movement to the left, a redundant first position signal P-, 'is generated, but at this point in time the chamber 14 is still on a healed ice. If the pressure is low, ie it is still "relaxed", there is no control signal in the line U1 and the redundant first position signal is not passed on to the flip-flop 72. Then dor Jiolbon reaches the end of his stroke at Έ. and begins

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his movement to the right; at this point the pressure in chamber 14 is sufficient to activate the pressure gauge Control signal in line 81, and not in line 82, to be generated. The described cycle.

From the above it can be seen that non-redundant first Position signals only generated and demFlip-ITlpp are supplied when the piston is on its Vfeg to the right, whereas non-redundant second position signals only generated and forwarded to the Plip-Plp when the piston 10 moves to the left.

As in the embodiment of Fig. 1, lines 77, 78 intended for control signals. The logic circuits 74, 75 have three inputs, as can be established from the drawing. (Such a logic circuit can be made up, for example, of two logic circuits connected in cascade Create circuits with two inputs each).

In order to operate the converter, the lines 77, 78 are fed control signals. Then to stop the converter, when the piston is at a predetermined end of its stroke, the corresponding control signal (on line 77 or 78) removed. When the piston is always at a certain end of its stroke should stop only needs one of the two lines 77, 78 to be provided. Then the other logic circuit only needs two inputs.

If the converter functions in such a way that there is a noticeable difference in the duration of the piston movement to the left and to the right (for example, if the repeater works with a rapid decrease), it may be necessary to advance one of the position signals in time so that

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"Both non-redundant position signals appear when the piston moves in one direction. To make this possible, it must be ensured that the chamber pressurized faster than relaxed (or vice versa, depending on the exact piston movement). This can for example, by adjusting the ratio of the flow cross-sections on lines 33 and 40 reach.

In Fig. 4, a double-acting converter is shown schematically. Those parts that match the parts of the Fig. 1 and 3 match, have the same reference numerals and also work in the same way.

The converter is equipped with a further chamber 15, which is delimited by a further working surface 17 of the piston 10, which faces the working surface 16 is, Furthermore, a further, acting as a "Plüssigkeits-" spring chamber 19 is provided, which on a further The surface 21 of the piston 10 which is opposite to the surface 20 acts. The faces 20 and 21 are same size. The fluid pressures in chambers 13, 19 springs a movement of the piston in both clearings away.

The chambers 14 and 15 are periodically pressurized and relaxed, with a phase difference of 180 °. For this purpose, a modified control valve see 34 from GE, 37 rush a ^ cliieber with three broadened ", as well;. Rv ^r ei spaced outlets has connected to the Niederdruckleituiig 40, and two v / urther Auslässe-, via lines 90, 92 with the chambers 14 and 15 are connected.

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In the controller, instead of a single pressure gauge 84, two pressure gauges 94 »96 are provided, which the Sense pressure in the chamber 15 or in the chamber 14 or also functionally related to these Prints. In contrast to the pressure gauges 84, the pressure gauges 94, 96 have only one output line 98 or 100, on which corresponding control signals are generated when the chamber 14 or the chamber 15 is pressurized is.

Otherwise the converter works in the same way as the one in Pig. 3, with the exception that the AND gate 75 receives signals that indicate a high pressure in .of the chamber 15 instead of a low pressure in the chamber 14. This is feasible because the Pressure cycles in the two chambers have a phase shift of 180 °.

Alternatively, a control circuit, as shown in FIG. 3, can also be used for the double-acting converter of FIG. can be used, which has a single pressure gauge 84 which measures the pressure in one of the two chambers 14 or 15.

In both the single-acting and double-acting versions of the converter, the chamber 14 or chambers are grounded 14> 15 chosen so that they are compared to the as "Fluid" springs acting chambers 18 or 18, 19 · are small. The drawings are not to scale and say nothing about the proportions of the Chambers from.

In the case of the double-acting converter, the "liquid" springs also act on its own piston,

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which is in contact with the piston 10. Read in the description The term "piston" as used is intended to include such a construction. Chambers 14 and 19 For example, their position can be reversed and your own piston can then rush away from the thicker ones! '24, 26 be formed, which are then movable with respect to the rest of the piston and not shown shoulders for contact with the rest of the piston.

The size ratio of the working surfaces of the piston depend on whether a smooth movement or a continuous movement is to be emitted when shocks are exerted are aoll, the]> 'IcIien are chosen so that the piston has a tendency, from the anvil odor Bohreinsat: · ', wogsutritten.

By a suitable number of the shape of the outlets in the Control valve 34 and the shape of the protruding KolbonteilG the waveform of the periodically applied pressure can be influenced. As described, the waveform is basically a square wave. T / enn der Umrjetzsr does not serve to generate impacts, can but other wave forms may also be useful.

The resilient element can £ iiistelle the "liquid" spring described at all, usführungsformeia boiopiels- • 'UISE a mechanical Toder, a magnetic or when the Arbeitsmittol The more dcr, a droppable liquid, be a pneumatic spring. I _n this case, the chamber would be inexpensive by a flexible diaphragm into two 'to divide, one of which would contain in contact with the working surface 20 of a pressurized gas and the other the working fluid. In the case of the double-acting embodiment, the chamber 19 would be in the same way

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to subdivide.

The invention has been described using an exemplary embodiment "in which the piston 10 is seen relative to the cylinder emotional. But one can also use a construction in which the reverse movement takes place, and instead of linear oscillations, too Torsional vibrations are generated with the help of an analog device, which a rotatable Vie lie an oscillating Torque granted.

- patent claims -

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Claims (10)

- 19 -. Claims 1. Converter which, driven by hydraulic fluid, generates mechanical vibrations and has a piston which is "movable" relative to a cylinder, one surface of which delimits a chamber in the cylinder which is periodically pressurized and relaxed via a valve by hydraulic fluid in such a way that The oscillating movement of the piston relative to the cylinder occurs, characterized by a control (28,31,58,59,61,63) which generates a first position signal when the piston and cylinder (10,12) move through a first relative position to one another move, and a second position signal, v / hen the piston and cylinder move through a second relative position, and through lines (62,64) which feed the position signals to a bistable member (72) which the valve (34) after i ^v iaßgabe the position signals controlled such that the uruckflüssigkeitsperioden are in a predetermined phase relationship with the periods of relative vibratory movement. 2. converter according to claim 1, characterized in that that at least one of the position signals is fed to the bistable element (72) via a logic circuit (74, 75) which, depending on a control signal, blocks the passage of the position signal to the bistable element or releases. 3. Converter according to claim 2, characterized in that each; 3 of the two position signals by its own logic circuit (74,7L-) is sent and both logic circuits from its own control signal in the way that only those first po- - 20 909836/0930 position signals to the "bistable element passed that during the relative movement of the piston and cylinder in a certain direction through the first relative position are generated, and only those second position signals to the bistable member (72) passed v / earth generated by the relative movement of the piston and cylinder in the opposite direction will. 4. converter according to claim 2 or 3, characterized by a pressure-responsive device (84), which senses the pressure in the chamber (14) or a pressure related to it and control signals the logic circuits (74,75) in such a way that the first position signals only then to the bistable Member (72) are allowed to pass when the chamber is pressurized and the second position signals only when the chamber is relaxed. 5. Converter according to one of claims 1 to 4, characterized by a further chamber (15) which is delimited by a further working surface (17) of the piston which faces away from the first surface (16) and is delimited with the aid of the Valve (34) with a phase shift of about 180 ° compared to the first-mentioned chamber (14) is pressurized and relaxed. ■ 6. converter according to claim 3 and 5, characterized by pressure-responsive devices (94,96), which is related to the pressure in the first-mentioned chamber (14) and in the further chamber (15) Sense pressures and send control signals to the logic circuits (74,75) built in such a way - 21 909836/0930 that they first position signals only to the "bistable Allow member (72) to pass through, v / cnn the first-mentioned chamber is acted upon by pressure, and a wide position signals only if the further combing: is under pressure. 7. Converter according to one of the preceding claims, characterized in that 'dan valve (34) is a slide valve which is controlled by the bistable element (72) by means of J-v-uckiliiolgkeitssignale. In that the logic circuit receives the following claims, characterized in that a control signal for starting and stopping of the converter: 8. A converter according to claim 2 or any AEEI. 9. Converter according to one of the preceding claims, characterized by a Peder element (13) whose PederlcvH.rt in the opposite direction to the relative oscillation int. 10. Converter according to claim 9, characterized in that o.aß el:;. O peder element acting as a liquid spring Comb or- (IS) is that of a further surface (19) of the Piston (10) is limited and receives a liquid which forms a liquid spring. 9 0 9 8 3 6/0930