DE1557701A1 - Method and device for regulating the penetration depth of a plow pulled by a tractor - Google Patents

Description

Patent attorneys · ·

.-ing. Linen weaver 13,238

Dipi.-ing. Carpenter

Munich 2, Rosental 7. - _rr "" _Λ "

Tel 2619 89 1557701

re: German patent application P 15 57 701.2-23

Alex. Friedmann limited partnership

in Vienna

Method and device for regulating the penetration depth a plow pulled by a tractor

When deep plowing a field, the greatest possible penetration depth of the plow should be used, but the penetration depth is limited by the power of the tractor. The soil is of different hardness in different places and, unless there is a special regulation of the penetration depth depending on the soil conditions, you can only work with a small penetration depth of the plow, at which the power of the tractor is not used. It is already known to regulate the penetration depth of the plow depending on the pulling resistance occurring on the plow. In order to raise and lower the plow depending on de! " Resistance which plow offers to _{carry out 9} ^ has already been made

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bs "a, No. I SaS: 3 des Knri ^, ^^. ^ ..". "_....

suggested the lifting movement of the plow as a function to be regulated by the pulling force occurring between the tractor and the plow. In these known embodiments, a spring is in the linkage in the manner of a Dynamometer switched on, the changes in length used to control the lifting movement of the plow will. If all or a large part of the pulling force is passed through the dynamometer, a great deal will result great forces, which require a heavy and complicated construction, plus the disadvantage that such large forces impair the sensitivity of the control. Only a small part of the pulling force is used used, the result is a distorted control and if the plow penetrates shallowly, the control system can become completely unusable.

It is also known to regulate the penetration depth of a tractor with an internal combustion engine to make trailed plow dependent on the injection quantity of the fuel injection pump.

The present invention aims to provide a method for regulating the penetration depth of one of a tractor with an internal combustion engine pulled, hydraulically controlled plow with the mediation of a to improve hydraulic control unit depending on the amount of fuel, the fuel supply to Injection pump takes place via a speed-dependent delivery feed pump. The invention consists in the essential in the fact that the amount of fuel delivered by the feed pump changes when the speed is changed recorded and from this the regulation of the penetration depth is derived. Such a speed-dependent feed pump feeds with a large excess, namely about ten times the consumption of the injection pump, so that there are considerable changes when the speed is changed in the amount of fuel supplied to the injection pump and

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so that considerable pressure changes are caused in a room downstream of the feed pump, which give a useful control variable. Due to the fact that such a large excess amount is conveyed, the schiiankende consumption of the injection pump is insignificant and therefore the control of the lifting movement of the plow is practically only from the amount of fuel delivered in the time unit of the speed-dependent conveying feed pump and therefore from the speed of the Machine derived. If the plow encounters too much resistance in the ground, the first consequence is that the driving speed of the tractor and thus the speed of the motor and the feed pump decrease and the pressure change resulting from this decrease in speed in a space downstream of the feed pump is used according to the invention to influence the regulation so that the plow is raised accordingly. ^ ~

According to a preferred embodiment of the invention, the control can also be known per se Way can be derived from the amount of fuel injected into the engine. If by increasing the resistance to the plow the driving speed of the tractor and thus the engine speed of the engine decreases, this results in an increase in the injection quantity in speed-controlled engines. This increase in the amount of injection has a greater one Fuel extraction from the pressure chamber of the feed pump result and it is thereby the pressure difference in the the space downstream of the feed pump in the same sense as by reducing the speed of this feed pump changes. The pressure difference available for regulation is thus determined by the measure, the control To make additionally dependent on the injection quantity supplied to the engine, increased, and it is thus the Control sensitivity increased.

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The pressure chamber of the feed pump can be limited by an overflow valve loaded by a progressive suspension and connected to the hydraulic control unit. Because the overflow valve is progressive, it is achieved that the change in the flow rate per unit of time, which occurs even with a small change in speed, brings about a significant change in pressure in this space, which is sufficient even with small changes in speed of barely 3% To let control of the plow respond.

If, as corresponds to a preferred embodiment of the invention, the overflow space with overflow control equipped injection pump is connected to the pressure chamber of the feed pump, the Pressure in the pressure chamber of the feed pump is additionally reduced when the injection quantity is increased and the for Control available pressure difference is increased.

The control of the quantity delivered in the unit of time can be much more effective realized the feed pump according to the invention be that the fuel drain from the space behind the overflow valve, which limits the pressure chamber of the feed pump, is throttled, the hydraulic Control unit is connected to the space between the overflow valve and the throttle. The one in excess of that Fuel delivered to the feed pump is fed entirely into the space between the overflow valve and the throttle and at A corresponding setting of the throttle can result in a deviation in the delivery rate from a predetermined delivery rate clearly established and effective to regulate from * - be enjoyed.

Here, too, in the case of injection pumps with overflow control, according to a preferred embodiment of the invention, the overflow space of the injection pump can be activated

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. the pressure chamber of the feed pump or the space between Overflow valve and throttle must be connected so that the pressure differences available for regulation are also reduced can be increased by changing the injection quantity.

A throttle with an unchanged throttle cross-section during operation is expediently selected, with this throttle cross-section can be determined empirically. But it is also possible through an additional one in operation adjustable throttle to influence the regulation, with this additional throttle a control in the Meaning of a lifting or lowering movement of the plow can be achieved. It can be through this additional throttle, if it is set to a constant value during operation will be determined, the furrow depth and it In the end, the plow can also use this throttle excavated or sunk deeper. It is also possible to use the constant throttle cross-section to replace a variable throttle cross-section and thus combining the effect of the constant throttle point with the effect of the variable throttle. However, such a measure brings difficulties in adjustment.

The hydraulic control unit, which is generated by the pressure in the pressure chamber of the backing pump or by the pressure is acted upon behind the overflow valve, is preferably an auxiliary control device, which in turn controls the inflow an auxiliary control medium to the pressure medium supply to the piston controlling spool or the like. regulates. In the drawing, the invention is explained schematically on the basis of exemplary embodiments.

Fig. 1 shows an embodiment of an inventive Device for regulating the penetration depth a plow pulled by a tractor. the

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FIGS. 2 and 3 show further exemplary embodiments of the invention Devices.

In all of the exemplary embodiments shown in the drawing, the fuel is conveyed from a fuel tank (not shown) via a line 1 by means of a feed pump 2 to the injection pump or pumps 3, through which the fuel is distributed to the injection nozzles k . In special cases it is expedient, in addition to the feed pump 2, to arrange a further backing pump connected into the line 1 between the fuel tank and the feed pump.

In the illustrated embodiments, the feed pump 2 is designed as a vane pump and has a speed-dependent pressure curve. The pressure chamber 5 of the feed pump, which from the to or the Injection pumps 3 leading line is limited by an overflow valve 6 through which a certain Pressure in the pressure chamber 5 is maintained.

In the embodiment shown in FIG. 1, this pressure relief valve 6 is loaded by a progressive spring 7. An auxiliary control device 8, which contains a membrane 9, which is also acted upon by the pressure in the line 5, is also connected to the line 5. The membrane 9 is connected via a plunger 10 to a valve disk 11 which is loaded by a spring 12 in the closing direction. The bias of the spring 12 can be changed by turning the spring plate 13, which is designed as a screw. The valve disk 11 controls the flow rate of an auxiliary control medium which is supplied and discharged through the lines Ik and 15.

This auxiliary control medium is known in Way a control slide or the like. pressurized which regulates the pressure medium supply to the reciprocating piston for lifting the plow.

0098U / 0178

The injection pump 3 is shown in FIG. 1 en embodiment designed as working with overflow control, single-flow injection pump, at which is the working chamber 16 of the injection pump piston 17 is completely filled with fuel during the suction stroke and the change in the amount of fuel injected as a result occurs that the suction opening 18 vonjeiner inclined groove of the Piston 17 is open and thus working space 16 is relieved of pressure. In this single-flow injection pump shown in FIG. 1, the flow therefore depends on the quantity of the fuel supplied to the injection nozzles or more less fuel back into the line 5, so that the The amount of fuel flowing back is a measure of the amount of fuel injected Represents amount of fuel.

; .--. If the driving speed of the tractor falls as a result of a harder ground, when driving uphill or as a result of increased friction conditions of the ground, and thus the speed of the Motpr and the feed pump driven by it, the pressure in the pressure chamber 5 of this feed pump _f also falls, whereby the the overflow valve 6 loading spring 7 is progressive, a pressure drop that can be used for a control is caused even with small changes in speed. This pressure drop has the effect that the valve disk 11 is moved in the closing direction by the spring 12, so that the pressure medium fed through the line 15 to the control slide is throttled. This causes a shift of the control slide, in the sense of an excavation movement of the plow. The pressure drop in the working chamber 5 of the feed pump is further assisted by the fact that when the driving speed of the tractor and thus also the speed of the engine drop, the controller ^ adjusts the injection pump to increase the injection quantity, so that less fuel flows back into line 5.

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The soil conditions allow a greater penetration depth of the plow, the driving speed of the tractor and thus the speed of the The motor and the feed pump increase, which also results in a pressure increase in the pressure chamber 5, which is speed-dependent conveying feed pump 2, which acts on the membrane 9 and the valve disk 11 further from stands out from its seat. The amount of the control spool or the like. Auxiliary control medium supplied via line 15 is thereby enlarged, causing a displacement of the control slide in the sense of a lowering movement of the plow. Furthermore, by increasing the speed of the engine the controller adjusts the injection pump in order to reduce the injection quantity, whereby the quantity of the in the line 5 diverted fuel is increased. This measure also results in an increase in pressure in the pressure chamber 5, which shows the increase in pressure in this pressure chamber caused by the higher speed of the feed pump 2 additionally supported.

The plow is raised and lowered until the tractor returns to its previous speed or the engine has reached its earlier speed again, so that the original speed is again in the pressure chamber 5 Set the pressure conditions and the valve plate 11 of the auxiliary control device 8 back to its original Position, which corresponds to the neutral position of the control spool, arrives.

In the embodiment shown in Fig. 2, the pressure chamber 5 of the feed pump 2 is again through a Overflow valve 6 limited, but the spring 7 loading this overflow valve in this embodiment does not necessarily have to have a progressive characteristic. This overflow valve 6 controls in a known manner the fuel supplied in excess by the feed pump 2

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amount of substance in the return or in the suction chamber of the Feed pump 2 from * In the return line 19 behind the Overflow valve 6, a throttle 20 is switched on, and between the overflow valve 6 and the throttle 20 is from the return line 19 branches off a line 21 which opens into the working space 22 of an auxiliary control device 23. A membrane 24 is arranged in the working space 22 and is connected to a valve disk 26 via a plunger 25 and is loaded by a spring 27 in the closing direction of the valve disk 26. The valve disk 26 controls again the torque flow rate of an auxiliary control medium, which by the Lines 28 and 29 is supplied and discharged. The administration is with the working space of a control slide (not shown) or the like. connected, the pressure medium supply to the Controls reciprocating piston for the plow.

- ..; -, - The mode of operation of the device shown in FIG. 2 is similar to that shown in FIG Contraption. Sinks due to harder ground when driving uphill or as a result of increased friction, the speed of the motor and thus of the feed pump will decrease also the pressure between the overflow valve 6 and the Throttle 20 and thus in the working chamber 22 of the auxiliary control device 23 drop j the valve disk 26 is through the Feather. 27 shifted in the closing direction and thus the inflow of the auxiliary control medium is throttled through line 29 to the control slide. The control spool is thereby in the Moved in the sense of a lifting movement of the plow. Permit on the other hand, the soil conditions have a greater penetration depth of the plow, so the speed of the engine increases and thus the feed pump, the pressure in the working area also rises 22 of the auxiliary control device 23, the valve plate 26 is thereby shifted in the opening direction * so that the pressure of the auxiliary control medium in the control spool increases and this in the; Moves the meaning of a lowering movement of the plow. the Changes in pressure between the overflow valve 6 and the Throttle 20 and thus in the working space 22 of the auxiliary control device

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23 are again as in the embodiment shown in FIG by the pressure fluctuations in the line 5 as a result of the change in the controlled by the injection pump 3 Fuel amount supported. This Aushebebzw. The lowering process continues until the tractor its previous speed or the motor again has reached its previous speed.

The throttle 20 expediently has a throttle cross section which remains unchanged during operation and which is determined empirically will. In order to assign a certain lowering area of the plow to each engine operating area during operation can, another variable throttle 30 is provided, which is arranged parallel to the throttle 20 and another part of the overflowing fuel in the return or in the suction chamber of the feed pump 2 * But it is of course also possible, instead of the additional, variable throttle 30, the To make throttle 20 itself variable, but it must be taken into account that the throttle 20 in each set Location must have a certain passage cross section for the diverted amount of fuel.

The embodiment shown in Fig. 3 differs differs from the embodiment shown in Fig. 2 only in that a double-flow injection pump 3 'is used, in which the control of the overflowing fuel is not in the intake chamber, but in a separate overflow space 31 takes place. This overflow space is in the embodiment shown in FIG. 3 Connected via a line 32 to the return line 19 between the overflow valve 6 and the throttle 20. Sinks as a result of harder ground conditions or the like. If the speed of the motor decreases, there is not only a lower delivery through the feed pump 2, but it is also through the Regulator that controls the injection nozzles 4 through the injection pumps 3 The amount of fuel supplied is increased, so it becomes less

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Fuel is controlled in overflow space 31, so that) d, he pressure between the "overflow valve 6 and the throttle 20 drops and thus the valve disk 26 by the spring 2? is moved in the closing direction. As already mentioned, this causes a shift of the control slide in Meaning of a lifting movement of the plow. In the opposite case, namely od .. the like in softer soil conditions. the speed of the motor increases, whereby on the one hand the feed pump promotes 2 meters and on the other hand through the Regulator more of the fuel supplied to the injection pump 3 is diverted into the overflow chamber 31. the end These two facts result in a pressure increase between the overflow valve 6 and the throttle 20 and thus in the Working space 22 of the auxiliary control device 23, from which a shift of the control slide in the sense of a lowering movement of the plow results.

Claims;

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Claims (7)

Claims 1. Method for regulating the penetration depth of a tractor with an internal combustion engine trailed, hydraulically controlled plow with the mediation of a hydraulic control device as a function on the amount of fuel, the fuel supply to Injection pump takes place via a speed-dependent feed pump, characterized in that the when the speed is changed, the amount of fuel delivered by the feed pump is detected and thereof the Regulation of the depth of penetration is derived. 2. The method according to claim 1, characterized in that the regulation is also known per se Way is derived from the amount of fuel injected into the engine. 3. Apparatus for performing the method according to claim 1 or 2, characterized in that the Pressure chamber (5) of the feed pump (2) through an overflow valve (6) loaded by a progressive suspension (7) limited and connected to the hydraulic control unit (8), the overflow space (18) of the expedient injection pump equipped with overflow control (3) is connected to the pressure chamber (5) of the feed pump (2). 4. Apparatus for performing the method according to claim 1, characterized in that the pressure chamber (5) the feed pump (2) is limited by an overflow valve (6) that the fuel outflow from the room (l9) is throttled behind the overflow valve (6) and that the hydraulic control unit (23) to the space between the - 12 new underlay- n w99i $ i $ M £ Q ¹ 7 $ * ■ ou-. j uij Ander ui ^ jsfles. v. 4. 9.1967J The overflow valve (6) and the throttle (20) are connected, in the case of injection pumps (3, 3 V) with overflow control, the overflow space (18, 31) of the injection pump is preferred to the pressure chamber (5) of the feed pump (2) or to the space between the overflow valve (6). and throttle (20) connected. ii.st. . .; ■ ■ \ - - ... - - ■ "- 5. Device according to claim 4. » thereby-identified-; shows that an invariable throttle cross-section (21) is provided for throttling the fuel outflow from the space (19) behind the overflow valve (6). ¹ 6. Device according to claim k or 5, characterized in that in addition to the constant throttle cross-section (21) a variable throttle (30) for di.e regulation of the outflow of the fuel from the room. (19) is provided behind the overflow valve (6) or that the unchangeable cross-section is replaced by a variable throttle device. 7. Device according to one of claims 3 to 6, characterized in that · that the hydraulic control device "(8y ~ 23), which is controlled by the pressure in the pressure chamber (5) of the feed pump (2) or by the pressure behind the overflow valve (6 ;. "-; is beaufsehlagt), a Hilfssteuergerat is ^ which, in turn, the inflow of an auxiliary control Medi Unis a di ^ pressure medium supply to the reciprocating controlling ^'; spool ödidgl.-regulates. . ■: ■■. - ^ SJ ** -. _r * ^ - ^:: "'■ -" ■ 13 I -'"/ 11/27/69 / hr 009814/0178 Neue Unterläösn ia * 7 ■ ;, ^. _{2 IJr} ., ^ _{3 d} ^ _{5ndefu (iii} _ _{v Λ n} , "_ Blank page