DE1154965B - Hydraulic power lift system for agricultural tractors - Google Patents

Description

The invention relates to power lift systems of agricultural tractors for attached or trailed Soil cultivation equipment, preferably with a hydraulic power lift cylinder, its piston is usually applied on one side. The piston is frictionally connected to the implement by means of a lever and linkage tied together. The power lift system is provided with two or more control devices that control the The position of the piston in the cylinder determines the height or working depth of the device and the driver of the tractor can optionally be activated. One of these control systems speaks to changes the height of the device in relation to the tractor. Another control device responds to changes in the tensile force acting on the device or in the engine torque. A third of these mostly known control devices is of the processing depth of the device by means of a on the ground sliding or rolling button. In addition, there is often a fourth mode of operation of the Power lift in which a certain, possibly adjustable pressure is maintained in the cylinder, which, however, allows the device to move in a vertical direction.

The invention is based on the object, as far as possible, for control devices of the type mentioned a few links existing transmission linkage and the driver the operation to facilitate switching from one control device to another. Previously known power lift systems are too cumbersome in these relationships.

According to an older proposal, a power lift system with two optional traction and position control has addressable control devices for switching and working depth preselection suggested using a single hand lever. Here is the adjustment path of the hand lever divided into two adjacent swivel areas, one of which is different Tractive forces of the agricultural implement and the other different positions of the agricultural implement in relation to the tractor corresponds, with the position and working depth increasing from the limit position of the hand lever. Disadvantageous but has the effect of this known structurally complex power lift system that it is for the operating personnel not immediately recognizable in the border area of the two swivel areas is which regulation is in operation.

There is also a power lift system with an optionally switchable traction and position control known, in which also for switching and Ar-hydraulic power lift system
for farm tractors

Applicant:

Klöckner-Humboldt-Deutz Aktiengesellschaft, Cologne-Deutz

Hans Kagel, Bergisch Gladbach,
has been named as the inventor

A single hand lever, which has a cam-shaped attachment, is used for preselection of the working depth. The switchover takes place by transverse displacement of the hand lever on its axis, with the cam of the lever either on the lever of the control tool that transmits the tensile force pulses or the position pulses acts. However, this has the disadvantage that in the case when the lever of the adjusting tool on which the Switchover is to take place in the displacement range of the cam, this with simultaneous action on the control in operation must be turned until the lever is outside the cam contour which makes operation considerably more difficult.

There is also a power lift system with position and traction control that can be switched on as required become known, in which by means of a hand lever serving as a setpoint adjuster a to the way of Lever's proportional device position or pulling force is preselected and switching from one to the other control takes place by means of a second hand lever, which makes operation even more cumbersome has become.

The power lift system according to the invention is characterized by one on the movements of the Control processes participating operating lever, which optionally connects to the device for the position control and the device for the depth or Establish tension control and in its plane of movement lets you select the depth or traction to be regulated. The same operating lever has with it two functions, namely switching from one type of control to another and choosing which to

309 689/71

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regulating depth or traction. This results in a wise switch to other hydraulic motors,

a logical and simple operation. z. B. for a cutter bar drive and a loader

The operator control that transmits the control process.

The lever is preferably constantly connected to the control valve. The operating lever 15 is about an axis 16 of the power lift coupled and optionally pivotable with a 5, one on either side of the lever of two segments in different angular positions, segments 17 and 18 are mounted. The lever 15 against can be coupled, one segment of which holds an articulation point 19, which swivels right

Position control on a lever of the power lift, which is angled to the main plane of movement. These other segment on the measuring element for the tensile force pivoting serves to select either one of the two-

or the working depth is articulated. The respective Win- io side attached to the lever notches 20, 21 in a

The position of the coupling determines the choice of the front toothing 22, 23 of the segments

the depth or pulling force. 17, 18 insert. The relative chosen

The rod acting on one segment is angular position between the operating lever and

is designed in a development of the invention so that the segment in question corresponds to a preselection

that optionally the transducer for the tensile force 15 of the variable to be controlled.

or the measuring transducer for the working depth is articulated. The control slide 8 is connected via a rod 25.

can. articulately coupled to the operating lever 15. the

The same device is finally for an Ar-rod 25 includes an intermediate member 26 in the form

by way of the power lift with a constant or a weak preloaded spring, which during

z. B. creates a rigid connection with the tensile force variable pressure in 20 of the control processes,

Power lift cylinder suitable, in which the implement during actuation by the lever, however, a

is free to move in a vertical direction and allows evasion in both directions,

the proportion of the device weight corresponding to the pressure Segment 17, which controls the height

to increase the grip of the drive wheels position of the implement is transmitted via a

is transferred to the tractor: For this purpose, 25 rods 28 are attached to the power arm 3 of the power lift.

if the control lever is set to "lift" steers. The direction of rotation of the segment 17 is the

and counteracted with the segment for the position control of the operating lever 15, d. H.,

pelt. At the same time, a throttle or pressure relief valve is activated when the lever is swiveled clockwise

which is locked in the other regulations, the oil supply begins after the power lift cylinder,

a certain pressure is set or to the for this 30 and the implement is raised. The pole

provided control device connected. 28 moves to the left and swings it

In the drawing, the invention is illustrated segment 17 counterclockwise. Upon reaching

light. the desired altitude, the operating

Fig. 1 shows schematically a power lift system lever 15 returned to its central position and in

with the switchability according to the nomination; 35 the teeth of the segment engaged when the

Fig. 2 shows a modification of the operating altitude of the device by means of the control

elements for a mixed control; in spite of any leaks in the power lift cylinder

Fig. 3 and 4 are other ways one is to be maintained.

Coupling of the operating lever with the segment stops 30, 31 are provided on segment 17,

outlines reproduced; 40 the the path of the piston 2 to an acceptable level

Fig. 5 shows the application of a depth control limit when it is z. B. with disengaged rest 20

with feeler wheel; move in against the operating lever. The attack

Fig. 6, finally, another adjustability 30 (possibly also the stop 31) is useful.

the control sensitivity as shown in Fig. 1. moderately in a manner not shown within limits

In the scheme of Fig. 1, the power lift cylinder is 1, 45 adjustable to the circumference of the segment. The load

whose piston 2 over the power arm 3 and one or arm 5 does not only come in its lowest position,

two load arms 4 carries the tillage device. but in the selected working depth of the device

Fig. 5 shows, for example, a well-known four-bar system to a standstill,

chain with which the device is attached to the tractor. Instead of the lever 15 in the manner described

A pump 6 conveys the pressure medium from a 50 to operate, one can use the catch 20 from the outset

Place container 7 over the control slide 8 (in the right one in one of the gaps in the segment toothing,

Position) when lifting through the line 9 according to what is caused by the aforementioned spring member 26

Power lift cylinder 1. In the indicated middle position is possible. The power lift then reaches the

of the control slide, the pump delivers to the desired position, which continues to be controlled by the control slide

Jaufleitung 10 in the container 7. In the left position 55 is maintained.

The control element is the pump and the force at the extreme end of the piston stroke

Lift cylinder connected to the return line, so power lift before the system is shut down

that under the weight of the implement pressure by means of a pivoting lock 33 in known

means pushed out of the power lift cylinder 1 to be secured against lowering,

and the implement is lowered. A the pressure 60 The segment 18 for the traction control is over

Line 9 with the return line 10 connecting a rod 35 coupled to the traction generator.

Valve 11 is in a known manner on one This consists in a known manner of one in both

desired dynamic pressure in the line 9 adjustable, directions of movement yielding spring 36 and

if a wheel load increase on the tractor through a coupling eye 37 for attacking one with the

part of the device weight is to be achieved. 65 connected boom part, the one

For the regulations described below, the respective soil resistance is proportional

the valve 11, however, is completely blocked. The compressive force is transmitted to the tensile force transmitter. The traction

Line also contains a control element 12 for an optional action here on rod 35 from left to right.

Smaller fluctuations in the tensile force are compensated for by a spring 38 in the rod 35 balanced. To prevent segment 18 from participating in high-frequency movements and thereby transfers unnecessarily many control pulses to the control slide 8, there is also an on the segment 18 attacking oil damper39 provided.

The linkage parts described here transmit the control impulses corresponding to the respective tensile force on the control slide 8, which in turn raises when the ground resistance fluctuates and lowering the implement causes. The scheme works in a known manner so that essentially a constant tensile force is maintained. Depending on the locking position of the operating lever 15 opposite the segment 18 the tensile force is more or less large, i. i.e. the average working depth of the device can be selected by means of the detent position.

The right end of the rod 35 is in a radial arcuate slot 40 of the segment 18 by means an angle lever 41 adjustable. By changing the size of the transferred to the control slide 8 Distance pulses can be used in this way to increase the sensitivity of the regulation to the respective fluctuations adjust the hardness and bumps as required. When working on the plane a coarse sensitivity will be preferred, since soil hardening then has a smaller influence exercise on the working depth. In undulating terrain and for lighter maintenance work, a more sensitive one Regulation appropriate.

The rod 35 carries a stop 50 which, when an insurmountable ground resistance occurs A spring-loaded valve 52 pushes open via an angle lever 51 in a manner known per se and Pressure oil from the power lift cylinder into the container? can flow back. This will make the The tractor's driving wheels depend on the weight of the device and any vertical component of the Ground resistance is relieved so that the wheels slip and the tractor cannot rear up.

In Fig. 1, below the rod 35 engaging the traction force transducer 36 is another rod 42 for the attack of a transmitter intended for the depth control. This rod 42 is preferably behind the The spring 38 is articulated to the rod 35. Fig. 5 shows, for example, a jockey wheel 43 as a transmitter, the pivot lever of which is connected to the rod 42 via a Bowden cable 44. Here are accordingly Variations in the working depth 45 of the plow

46 transmitted as control pulses to the control slide 8. According to Fig. 5, you can optionally the transmitter for the depth control to the rod 42 or the transmitter for the tension control to the Connect rod 35. The latter happens z. B. in the usual way by connecting the upper link

47 of the four-link chain with the coupling 37 of the traction generator.

Fig. 2 optionally shows an axially displaceable bevel pinion mounted on the operating lever 15 55, which engages in counter-toothing of the segments 17 and 18 in the position shown. In order to there is a mixed control of position and tension control or depth control, which under certain Conditions is advantageous.

Fig. 3 shows a friction clutch of the operating lever 15 with the segments 17, 18. A handle 56 of the lever 15 is articulated with this and carries an eccentric 57 between parallel A fork 58 of the lever is guided so that when the handle is pivoted in the one or the other direction of the lever 15 pressed against one of the friction linings 59, 60 of the segments 17, 18 will.

In Fig. 4 another friction clutch is shown: A two-armed coupling piece 62, which is on the operating lever 15 is mounted in a pendulum manner, is supported by a front cam attached to one side of a handle 64 pivoted by turning the handle about the lever axis in one or the other direction and pressed against the periphery of one of the segments 17,18. A compression spring 65 determines it the size of the contact pressure.

According to Fig. 6, the adjustment of the sensitivity takes place at a different point than in Fig. 1: The rod 35 engaging the encoder is firmly hinged to the segment 18. The rod 25 engaging the operating lever is displaceable at its other end in a longitudinal slot of an intermediate lever 66 , which in turn engages the control slide 8. The shift is carried out by means of an angle lever 67. Because of the short distances of the control slide 8, the intermediate lever 66 is less inclined than the slot 40 in the segment 18 according to FIG. 1 and, as a result, there are practically no changes in the working depth when the setting is changed.

It should also be noted that a control lever participating in the movements of the control processes, which enables a coupling in different angular positions with a segment within the meaning of the invention, can also be advantageous if only a single segment is present. It is also conceivable to Place the two segments that can be optionally coupled, three such segments with encoder rods acting on them to be provided and to train them optionally to be coupled with the operating lever.

Claims (12)

PATENT CLAIMS: 1. Power lift system of agricultural tractors for attached or attached soil cultivation equipment, with a hydraulic power lift cylinder, which contains two optionally switchable control devices that respond to changes in the height and the cultivation depth or the tractive force, characterized by an operating lever that participates in the movements of the control processes (15 ), which can optionally establish a connection with the device (3, 28, 17) for the position control and the device (35, 36, 18) for the depth or tension control and can preselect the depth or tension to be controlled in its plane of movement. 2. Installation according to claim 1, characterized in that the transferring the control process The operating lever (15) is constantly coupled to the control valve (8) of the power lift (1 to 4) and can optionally be coupled with one of two segments (17, 18) in different angular positions, one of which is a segment (17) for position control on a lever (3) of the power lift (1) and the other segment (18) is hinged to the transducer (36, 43) for the tensile force or depth is. 3. Plant according to claim 1 or 2, characterized in that the segment (17) for the Position control has end stops (30, 31) for limiting the angular positions of the operating lever (15) with respect to the segment (17, 18). 4. Plant according to claim 3, characterized in that the end stops (30, 31) of the segment (17, 18) for position control and / or depth control attached to the segment so as to be adjustable are. 5. Plant according to one of claims 1 to 4, characterized in that the segment (18) the high-frequency movements of the transducer for traction or working depth control compensating damper (39) attacks. 6. Installation according to one of claims 1 to 5, characterized in that in which the segment (18) for the traction or working depth control with the transducer (36, 43) connecting rods (35) a spring (38) responsive to tension and compression is included. ao 7. Installation according to one of claims 1 to 6, characterized in that the point of the rod attack for the traction or working depth control on the associated segment (18) in the radial direction, preferably in a curved guide (40), is adjustable. 8. Installation according to one of claims 1 to 6, characterized in that the connecting rod (25) between the operating lever (15) and the control valve (8) can be adjusted in its longitudinal direction on an intermediate lever (66) (Fig. 6). 9. Installation according to one of claims 1 to 8, characterized in that the connecting rod (25) of the operating lever (15) with the Control valve (8) of the power lift (1) a member (26) that yields elastically in both directions contains, which is preferably a rigid connection by biasing during the control process and only yields when the preload force is exceeded. 10. Plant according to one of claims 1 to 9 with a relief valve, which is excessive Soil resistance is pushed up by the linkage for the draft control, characterized in that that the rod (35) connecting the tensile force transmitter (36) to the associated segment (18) actuates the relief valve (52). 11. Installation according to one of claims 1 to 10, characterized in that on the operating lever (15) is mounted with the axis in the longitudinal direction of a bevel pinion (55) which optionally brought into engagement with opposing teeth of the segments (17, 18) or is disengaged by axial displacement. 12. Plant according to one of claims 1 to 11, characterized in that a known blow-off valve (11) downstream of the control valve (8) is arranged, the setting of a selectable cross-section or the clamping force of a Closing spring transfers part of the implement weight to the tractor and allows it to be used a regulation of the power lift can be completely shut off. Considered publications:
German Auslegeschrift No. 1082 442;
French patents No. 1127 870,
366. 1 sheet of drawings © 309 689/71 9.63