DE2330271A1 - HEIGHT COMPENSATION DEVICE FOR ONE UNIT - Google Patents

Description

DiPL.-INQ. Wilfrid RAECK

PATENT ADVOCATE 7 STUTTGART 1. MOSERSTRASSE 8 ■ TELEPHONE (0711) 244003

1 submitted)

♦ S 374.

Leon Claeysstraat 3A, CLAYSON N.V.

B-8210 Zedelgem / Belgium

Height compensation device for a mower unit

The invention relates to combine harvesters and similar agricultural machinery, are provided with a mower unit or a similar attachment for introducing crop · More specifically, the invention relates to improvements to an automatic Böhenverstellvorrichtung for mowing unit of such machines.

Height compensation devices for automatic adjustment 4 position of the mower or another attachment Above the ground or the timetable are known. Have conventional automatic control devices one or more floor sensors which are pivotably arranged on the mower unit and which are drive-coupled to the hydraulic lifting mechanism for the mower unit. The floor sensors

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determine elevations or depressions in the course of the ground and, depending on this, control the pressure oil supply or the oil drain from the corresponding lifting cylinders of the mower. The ground sensors are therefore coupled in one way or another to a hydraulic valve contained in the hydraulic circuit for the mower unit lifting device. This height compensation control works satisfactorily in itself and relieves the combine harvester driver of having to constantly check and readjust the height of the mower unit above the ground. However, this known automatic height control suffers from a number of considerable disadvantages, the most important of which is that the known device is rather complex in structure and therefore expensive. It is desirable to determine the course of the ground at a point in front of the cutter bar of the mower. This is done at the existing in that the floor sensors are provided under the stalk divider plates, which are arranged along the side edges of the mower unit and in front of it. As a result of such an arrangement of the floor sensors, however, obstacles occurring between the side edges of the mower unit would not be detected at all.

In another known proposal, the automatic height adjustment device for the mower unit is not so agile, while at the same time a weight compensation of the mower unit takes place. These adjustment devices are also known as compensating devices for mower units. In such compensation units, part of the weight of the mower unit is resiliently supported. Any devices can be used for this purpose, for example mechanical tension or compression springs or hydro-pneumatic means with a hydro-pneumatic memory. Operational

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the mower unit is lowered until it hits the ground with a touches a certain ground pressure and thus part of the weight of the mower unit is supported by the ground. In this Normal position establishes a state of equilibrium, in which the greater part of the weight is taken up by the balancing device, while the rest of the weight is supported on the ground. If a bump in the ground is encountered in a field while the machine is moving forward, the equilibrium is disturbed and an increased proportion of the weight of the .mower unit is then over the Ground supported. The balancing device has the task of restoring the state of equilibrium by the Mower unit is raised according to the size of the elevation causing the disturbance. If on the other hand a depression in the ground is encountered, the compensating device sets the crawling unit in the opposite direction after. You can therefore observe during operation that the mower floats or glides over uneven ground.

In summary, it can be stated that the known compensating devices for mower units work satisfactorily as long as the initial ground pressure remains precisely set. As already mentioned, such balancing devices have the advantage that they are not so complicated in construction and therefore also cheaper to manufacture than other balancing systems. Nevertheless, there is also an essential, important disadvantage with this compensating device. For proper operation, the operator must first set the mower unit iti to an optimal position. This means that initially the average ground pressure of the mower unit should neither be too large nor too small. If the average pressure on the ground is too high, the spring compensation device would be stretched too far and could then no longer lift the mower unit sufficiently if there is a bump on the ground. As a result, the mower unit would

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• I dig into the ground. If other ereraelta The initial ground pressure was set too low, so jjr operating the mower deck could make contact with the ground lose·

It is known from practice that it is very difficult and critical to bring about the required setting and that, in addition, the operation of the compensation device must be given constant attention finally requires an adjustment from tent to time.

In addition, it must be taken into account that the hydraulic lifting system for the mower unit is designed in such a way that the mower unit can be raised and lowered fairly quickly. If the pre-setting to ensure a satisfactory compensating effect is very critical and, on the other hand, the mower unit via the hydraulic lifting devices is raised or lowered quickly, it is difficult for the operator to operate the hydraulic Stop the lifting device at the right moment. In other words, the actuation of the hydraulic lifting system The mower unit is often stopped too late, so that the mower unit is beyond its desired position emotional·

■ he invention is based on the task of taking measures meet, with which these Kachteile can be reduced or eliminated · According to the invention it is proposed for an agricultural machine with a mower unit and a hydraulic mower unit lifting device that From a blocking device and at least one sensing element are provided, the blocking device and the sensing element

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blocks the outlet of pressurized hydraulic fluid from the lifting cylinders as soon as the mower unit is connected to the Comes into contact with the ground.

The hydraulic lifting device for the mower unit comprises hydraulic lifting cylinders and a manually operable one Control valve with three main positions, namely a neutral position, a lifting position and a lowering position. The shut-off device is preferably between the manually operated control valve and the lifting cylinder connected. The shut-off device can, however, also be implemented by the manually operated control valve which is then designed so that it automatically returns to its neutral shut-off position when the mower unit comes into contact with the ground.

In the case of an independent shut-off device v / ini this preferably controlled by an electrical circuit comprising an actuating coil and an electrical switch has, which is drivingly assigned to the floor sensor. If the balancing device is more hydro-pneumatic The design is a hydro-pneumatic one between the shut-off device and the lifting cylinders for the mower unit Storage arranged.

When the machine, for example a combine harvester, is on is driving, at the beginning of the mowing operation, the driver first of all sets the manually operated control valve for actuates the lifting cylinder so that hydraulic fluid escapes from the cylinders and the mower unit moves accordingly can lower. As soon as the floor sensor comes into contact with the floor, the shut-off valve is activated and prevents further oil drainage, even if the manually operated control valve is still in the Lowered position should be held · From this point in time

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on the compensation device is effective, so that the mower unit slides over uneven floors.

An embodiment of the invention is shown below in Connection with the drawings explained in more detail. It shows

Fig. 1 is a schematic side view of a combine harvester according to the invention,

FIG. 2 shows an enlarged illustration of the section II outlined in FIG. 1,

FIG. 3 shows an enlarged section through the one outlined in FIG. 3 Section III,

4 shows a schematic overview of the embodiment shown in FIGS. 1-3,

FIG. 5 shows a schematic overview similar to FIG. 4, however for another embodiment and

6 shows a schematic overview similar to FIGS. 4 and 5, but for a third preferred embodiment.

According to FIG. 1, a combine harvester 1 comprises a main frame 2 with front drive wheels 3 and smaller rear steering wheels 4. On the main frame are the platform 5, threshing, separating and cleaning devices and a grain tank. In front of the machine, a mower unit 6 and an inclined elevator 7 are arranged in the usual design, the mower unit being pivotably articulated at point 8 on the frame 2 and being movable in an approximately vertical direction with the aid of extendable hydraulic cylinders 9 and a compensating device 10. The mowing unit 6 essentially consists of a transverse trough-shaped base unit 11 having an average rearwardly directed discharge opening in the direction towards the housing of the sloping elevator 7, further comprised of a arranged in the trough or the trough 11 transverse conveyor, a cutter bar 13 at the front edge of the base body 11

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and from a reel 14 supported on it.

When the combine harvester is moving forward in a field The mower unit is in its operating position directly above the bower, v / ira the crop with the mower 13 cut off immediately above the roots and fed from the reel 14 and the screw conveyor to the inclined elevator 7, which continues the mowed crop further back Further processing is carried in the threshing and separating units.

In the 6 preferred embodiment of FIGS. 1 to 4 are the hydraulic cylinders 9 at one end on the main frame 2 and with their ancate land on the right and left lobes 15 hinged with the aid of screw spindles 35. The February 15 are attached to a pivot shaft 16, which extends in the transverse direction under the: the housing of the inclined elevator and is rotatably held there. The pivot shaft 16 also carries second levers 17, into which spring springs 18 extending below the elevator housing are suspended. The other end of the tension springs 18 is held on the elevator housing.

On the underside of the mower unit 6 skids 19 are arranged, which in operation with a certain pressure on the Rest on the ground so that part of the weight of the mower unit and the inclined elevator is supported on the ground. Another proportion of the weight of the milling unit and the Inclined elevator is via the hydraulic cylinder 9 and the Compensation device IO trimmed ,, during the remaining Weight fraction is absorbed by the upper pivot point 8. It is thus built in between the three supporting elements State of equilibrium, these elements from the The bottom consist of the hydraulic cylinders 9, the compensating device 10 and finally the upper pivot axis 8 on the main frame 2. In this equilibrium position

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the spring 18 is partially stretched by the forces acting on it.

During normal balancing operation, the lift cylinders 9 Oil is neither supplied to nor discharged from the mower unit, so that the cylinder length remains unchanged. However, the hydraulic cylinders 9 are extended or retracted, to raise the mower unit into the transport position or lower it into the operating position.

When driving forward across a field, the combine harvester encounters uneven ground. The mower unit is then located in their operating position, a larger proportion of the weight of the mower unit 6 and of the inclined elevator 7 pushes on the ground, so that consequently the force acting on the cylinders 9 and on the compensating device 10 decreases, with which the aforementioned state of equilibrium is completely disturbed. As a result, the whole moves System in a different position of equilibrium. The balance springs 18 contract while at the same time the length of the hydraulic cylinder 9 remains unchanged. These cylinders are pivoted upwards, and so is the pivot shaft 16 with the levers 15, 17 are raised accordingly and rotated about the axis of the pivot shaft. Accordingly the mower unit 6 and the inclined elevator 7 is also pivoted upwards, which reduces the ground pressure and the The mower unit is in the new equilibrium position on a higher level.

If the vehicle drives over a depression, it reacts entire system as above, but in the opposite direction. This means that the mower unit moves over uneven ground during operation slides away. However, the compensating device can not be in the favorable manner described above work unless the starting position of the mowing

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unit has been precisely adjusted.

Between the numerous juxtaposed sliding shoes 19, pivotable sensors 20 directed to the rear are arranged. The pivot shaft 21 (Fig. 3) of each BodenfUhler 20 is located slightly behind the cutter bar 13 and extends transversely to the longitudinal axis of the combine. The diode sensors 20 have approximately the same outline as the sliding shoes 19 and extend essentially over the entire width of the space between two adjacent sliding shoes 19. Line downward pivoting movement of the floor sensor 2O is prevented by stops 22, which are located behind the rear end of the sliding shoes 19 hook * the floor sensor 20 have upwardly extending side walls 23, which run past the shoes 19 and are disposed relationship with these in a more or less sealing be, to prevent that above the sliding blocks 19 and the floor sensor 20 dirt, waste material and the like . Electrical contacts 24 belong to a circuit 25 which contains an electrical coil of a hydro-electrical shut-off valve 27 and an additional electrical contact 28. The contacts 24 can be actuated by the floor sensors 20. The shut-off valve 27 is arranged in the hydraulic circuit 29 between the manually operated main control valve 30 on the one hand and the hydraulic cylinders 9 on the other hand. The type of electrical contact 24 and their relationship to one another is selected so that the actuation of the hydro-electrical shut-off valve 27 is ensured when at least one of the floor sensors is raised as a result of its contact with the ground. In the preferred embodiment of Figures 1 through 5, the electrical contacts 24 are normally closed and are opened by the floor sensors 20 when they are in their

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the lowest position. The j-ontacts are to each other arranged parallel and on the upper side ajn rearward. JLn & e of the sliding shoes 10 are arranged. Lie Podenfvhl ^ r 20 have rear extensions 33 via which they connect with aen electrical Kentakten 24 come into action.

The manually operated control valve 30 has a neutral blocking position, a raising and a lowering position. The valve 3C is connected to the pressure line 34 and to the return line 36. The hydraulic circuit also includes a conventional check valve 37 for the case when the main valve is in its neutral position and the mower unit 6 is not to be lowered by leakage oil from the main control valve 30. The check valve 37 is hydraulically opened when the main valve 37 is moved into its lowering position.

The shut-off valve 37 is normally open and is activated at ' Excitation of the magnet winding 26 shifted to its blocking position, so that no more oil flows out of the lifting cylinders 9 can. A check valve 38 is arranged parallel to the shut-off valve 27, which provides an oil inlet to the cylinders 9 allows when the shut-off valve 27 is in its shut-off position is located.

An articulated lever 39 according to FIG. 2 can be provided in order to contract the compensating springs 18 and a from it to prevent resulting lifting of the inclined elevator 7 when the mower unit 6 is separated from the inclined elevator 7.

At the start of operation, the driver pushes the main valve 30 into the lowered position so that it is in the open position Stop valve 27, oil escapes from cylinders 9

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unQ thus the mower unit is lowered. Sofcal «: at least ε a probe 2.0 on the surface of the floor occurs una pivoted relative to the mower unit 6, The corresponding electrical contact 24 closes, with which the winding 26 actuates the wire and thus the shut-off valve 27 reaches its shut-off position / due to the inertia inherent in the system, the mower unit does not work stopped immediately when the floor sensor 20 touched the floor surface Makes contact, but continues to descend for a short distance. Still, one more has left of the valve 30 in its lowered position has no effect on the setting of the mower unit. Touch in this position the sliding shoes 19 hit the ground with a certain pressure, and the compensating device 10 is described in the above Way effective.

To move the cutting unit to its transport position upwardly, the driver shifts the Kauptventil 3O in the lifting position, so Dafi pressurized Ul the lift cylinders 9 is supplied via the check valve 33 ·

By opening the normally closed contact 28, which is connected in series with the contacts 34 , the driver can lower the mower unit 6 further via the normally correct operating compensation position. This is particularly advantageous, for example, when the mower unit is placed on a trailer for transport purposes or when the mower unit is placed on the ground.

In the embodiment of FIG. 5, the mechanical compensating device 10 is replaced by a hydro-pneumatic compensating device 40 which has a hydro-pneumatic accumulator 41, which at a point between the shut-off valve 37 and the lifting cylinders, 9 via a rotary valve 4 2, a throttle 43 and a check valve 44 to the

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hydraulic circuit 29 connected 1st. The shut-off valve 27 works in the same way as in the arrangement according to FIGS. 1 to 4. The compensation process using the hydro-pneumatic system is known per se and therefore does not need to be described in detail.

In the embodiment according to FIG. 6, the same compensating device 40 is used as according to FIG. 5. The main valve 3ü is, however, replaced by a solenoid-operated control valve 45 which has a lifting magnet 46 for lifting and a lifting magnet 48 for lowering. In the electrical circuit 32 of the lifting magnet 46 there is also a normally open contact 47, while the circuit 25 for the lowering magnet contains a normally open contact 50, a group of normally closed contacts 51 actuatable by the floor sensors 20 and a normally open contact. The contacts 50, 51 are connected in series with one another, while the contact 49 is parallel thereto. The ground sensors 20 take effect and open the contacts 21 when they are raised with respect to the mower unit 6 as a result of touching the ground. During operation, the driver closes the contact 50 in order to lower the mower unit 6. When at least one of the floor sensors 20 has touched the floor surface and is raised relative to the mower unit, the corresponding contact 51 opens so that the further excitation of the lowering magnet 48 is switched off, even if the driver continues to hold the contact 50 actuated. The downward movement of the mower unit 6 is thus interrupted, the compensating device 40 operating in this position as described above. A further lowering of the mowing device, for example to suspend the mower unit from the inclined elevator 7, is only possible if the contact 49 is actuated. The lifting of the mower unit can be achieved through

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Actuation of contact 47.

It goes without saying that modifications and further developments are possible c. the above-described exemplary embodiments are possible without departing from the scope of the invention. For example, the hydraulic shut-off valve 27 according to FIGS. 4 and 5 can be replaced by a pneumatic, electromagnetic, mechanical or other shut-off valve of any kind. Also the Eodenflihler 20 and the sliding shoes 19 below the trough-shaped base part 11 can be replaced by a single flexible sliding shoe which extends essentially over the entire width of the mower unit and like the others described Facilities as a floor sensor works. Finally, the floor sensors 20 below the trough 11 can also be used by others Feelers are replaced, e.g. by movable devices for lifting flat crops, by movable ones Sensing elements in the fixed stalk dividers, through sensing devices in the supply line that respond to the hydraulic pressure 29 to cylinders 9 and so on.

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Claims (1)

DiPL.-lNG. Wilfrid RAEOK PATENT ADVOCATE
7 STUTTGART 1, MOSERSTRASSE 8 ■ TELEPHONE (0711) 244003 CLAYSOU NV,
Zedelgem / Belgium Protection claims 1. Height compensation device for a: iM: unit, especially on "ILhdreschern, r, \ it a lifting device for the mowing unit, characterized by a shut-off valve (27) uiy at least one Fühlolieu (20) , which are coupled to each other to the ALfIuP of hydraulic shut off uruckül from the lifting device for aas mower when the mower unit touches the ground surface. 2. Apparatus according to claim 1, characterized in that a weight compensation device for the mower unit (6) is also provided. 3. Apparatus according to claim 2, characterized in that. the counterbalancing unit is of mechanical design and Contains balancing springs (10). 4. Apparatus according to claim 2, characterized in that the compensating device is of a hydropneumatic type and has a hydropneumatic collector (41) which is connected to the hydraulic supply line (29) of the lifting device for the mower unit (6). 5. Device according to one of the preceding claims, characterized in that each floor sensor has a sensing element (20) which is connected to the shut-off device (27) cooperates and when the floor sensor engages with the The floor surface moves the shut-off device into its shut-off position, 409882/0123 - / - BATHROOM 0RK3INAL S 374 - 15 - 6. Device according to part 5, characterized in that the floor sensing element extends substantially over the entire Third of the mower unit (6) extends. 7. VoxrLchtung according to one of claims 5 or 6, characterized characterized in that each floor sensor (20) is inclined backwards and downwards and at the bottom of the the front end of the mower unit (6) is arranged. 8. Apparatus according to claim 5, characterized in that Fixed sliding shoes (19) are attached to the mower unit (6, 11) between the adjacent floor sensors (20), and that the floor sensors (20) extend much deeper than the stationary sliding shoes and have upright side walls (23) which extend around the sliding shoes. 9. Device according to one of claims 5 to 8, characterized characterized in that stop means (22) are provided, around the downward swiveling movement of the floor sensor (20) to limit. 10. Device according to one of claims 5 to 9, characterized in that an electrical circuit with electrical contacts is provided which the shut-off device (27) is assigned in terms of drive, and that the floor sensors (20) actuate the electrical contacts when the floor is touched and thereby the shut-off device (27) in their Move shut-off position. IX, provision according to one of claims 1 to 4, characterized in that the floor sensor (20) has a pressure-sensitive element which is arranged in the actuation line of the mower unit lifting device and is drive-connected to the shut-off device (27) in order to prevent the mower unit from being touched to move the shut-off device into its shut-off position with the floor surface » 409882/0123 - / - 12. Device according to one of the preceding claims, characterized in that daP. the M-unit lifting device a main control valve (3U) with connected M-unit lifting cylinders (9), and that the shut-off device (27) is a hydro-electric shut-off valve, that is connected to the feed line (29) of the lifting cylinder (9) and in terms of drive connection with the Eode sensors to be pushed into the shut-off position by the mower unit when the soil is touched. 13. The apparatus according to claim 12, characterized in that the shut-off valve (27) has a check valve (38) in such a way is connected in parallel that in the blocking position of the shut-off valve (27) hydraulic pressure oil to the lifting cylinders (9) can flow. , 14. Device according to one of claims 1 to 11, characterized in that the blocking device (27) is a hydraulic control valve and is connected to the ground sensors (20) to move when touching the mowing unit (6) with the ground surface in a neutral locking position to will. 15. The device according to claim 14, characterized in that the hydraulic control valve (45) is a solenoid valve , an electrical circuit for the first magnet (46), an electrical contact (47) for lifting the mower unit (6) and an electrical circuit ( 25) for the second lifting magnet (48) has an electrical contact (50) for lowering the mower unit (6), and that the electrical circuit (50) has a first electrical contact for actuating the valve in the lowered position and at least one second electrical contact (49), which is drivingly assigned to the floor sensors (20) , to when actuated by 409882/0123 S 374 - 17 - to overrun the first contact with the floor feeler Move the valve (45) into its neutral shut-off division. 16. Device according to one of the preceding claims, characterized in that aer a shut-off device Overriding or overflowing electrical contact is assigned in terms of drive to the in their ALsrerrstellung to move the shut-off device in its open position. 17. The device according to claim 1, characterized in that that the shut-off device (27) pneumatic, electromagnetic or mechanical design. ßAD ORfGINAL 409882/0123