DE20210449U1 - Vehicle trailer with hydraulic reserve tank - Google Patents

Description

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Company Krampe Landtechnik and Metallbau GmbH, Bahnhofsallee 39, 48653 Coesfeld-Lette

"Vehicle trailer with hydraulic reserve tank" 5

The innovation relates to an agricultural vehicle trailer according to the preamble of claim 1.

In practice, trailers of this type are known in which a telescopic boom is used as a hydraulic unit.

cylinder is provided with the aid of which a trough used to receive the transported goods can be tilted in order to empty the trough.

It may be advantageous to use a telescopic cylinder,

which can be extended particularly far: for example, to be able to set the trough at a particularly steep angle, or with particularly large trailer dimensions, or to be able to attach the telescopic cylinder at a particularly great distance from the pivot point of the trough. Both for these particularly

For highly telescopic telescopic cylinders as well as other hydraulically operated units that may be provided on an agricultural vehicle trailer, it may be advantageous or necessary to operate them with a particularly large quantity of hydraulic fluid.

The problem may arise that certain towing vehicles, such as agricultural tractors, depending on their design or age, do not have a sufficient amount of hydraulic fluid to operate such an aggregate on

to be able to operate the agricultural vehicle trailer with the amount of fluid required for this unit. Retrofitting a larger fluid reservoir in the towing vehicle can be disadvantageous for cost reasons or difficult for space reasons.

The innovation is based on the task of enabling the use of hydraulic units even with a requirement for a very large quantity of hydraulic fluid on agricultural vehicle trailers, regardless of the quantity of hydraulic fluid in the towing vehicle.

This object is achieved by a trailer having the features of claim 1.

In other words, the innovation proposes to fill the missing

The trailer itself must be equipped with a reserve tank specifically designed for this purpose. It is therefore not necessary to convert the towing vehicles. The proposal also provides for a pumping device to be fitted on the trailer.

which pumps the hydraulic fluid from the reserve tank when the unit is operated and has the corresponding demand for hydraulic fluid.

The fluid can be fed directly to the unit,

if the pumping device is able to provide the required pressure. Alternatively, the fluid can be fed from the reserve tank via the return line into the storage tank of the towing vehicle, so that the latter has a virtually larger capacity.

Finally, according to the present proposal, a hydraulic circuit ensures that after operation of the hydraulic unit, when it is emptied, the hydraulic fluid flowing back is first used to refill the

reserve tank on the trailer itself and only then is the "excess" fluid fed to the towing vehicle. This prevents the tractor's fluid reservoir from being overfilled and potentially causing excess hydraulic fluid to be harmful to the environment.

This also ensures that the re-

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The vehicle trailer's serving container is always ready for use and optimally filled for the next use.

The pumping device advantageously does not require its own drive in the form of a pump unit, but

is advantageously designed as a mechanically actuated pump, whereby the movement of the hydraulic unit or a component moved by it actuates the trailer's hydraulic pumping device. This does not require a particularly high pumping capacity, since it is not necessary to draw from the reserve tank.

The unit does not have to be supplied directly with the corresponding hydraulic pressures, but the hydraulic fluid can be pumped from the reserve tank into the storage tank of the towing vehicle, so that it can be used as if it were a hydraulic tank with a correspondingly larger

Capacity can be used to supply the hydraulic pump of the towing vehicle in a conventional manner and to operate the unit on the vehicle trailer.

In the simplest and cheapest case, the pumping device

tion as a movable piston in the reserve tank.

An example of the innovation is explained in more detail using the drawing.

In it, an agricultural towing vehicle in the form of a tractor is designated with 1. The towing vehicle 1 has a reservoir (not shown) for hydraulic fluid and a hydraulic pump as well as a pressure line 2 and a corresponding

compared to pressureless return line 3.

A schematically indicated vehicle trailer 4 has its own pressure and return lines 2 and 3, as well as connections by means of which the tractor-side and the trailer-side

Pressure and return lines 2 and 3 can be connected to form continuous lines.

A tipping trough 5 can be tipped using a telescopic cylinder 6 with a very long stroke. The telescopic cylinder 6 is extended,

by supplying it with hydraulic fluid via the pressure line 2. This telescoping movement of the cylinder 6 causes the trough 5 to pivot about a pivot point 7. Its underside thereby moves away from a frame 8 of the trailer 4.

A cable 9 is attached to the trough 5 and runs around a pulley 10 to a piston rod 11, which is connected to a piston 12. The piston is arranged in a reserve tank 14, which contains hydraulic fluid. In the drawing, the position of the piston 12 within the reserve tank is shown.

reservoir 14 is shown purely schematically. A reserve line 15 leads from the reserve reservoir 14 to the return line 3.

When the trough 5 is raised, the piston 2 is moved in the reserve tank 14 via the cable pull 9 and presses the hydraulic fluid contained therein via the reserve line 15 and the pressure line 3 into the storage tank of the towing vehicle 1. The hydraulic pump provided on the towing vehicle 1 can therefore supply the telescopic cylinder 6 with a larger amount of fluid than can be accommodated in the storage tank of the towing vehicle 1.

so that a virtually larger storage container is created than the one the towing vehicle 1 actually has.

By means of appropriate valve arrangements known to the hydraulics expert, a hydraulic priority circuit is created which, when the trough 5 is lowered, initially leads the hydraulic fluid flowing back from the telescopic cylinder 6 via the reserve line 15 into the reserve tank 14. Due to the weight of the trough 5, sufficient pressure is built up in the hydraulic fluid when the telescopic cylinder 6 is lowered, so that

the piston 12 reliably in a deep into the reserve tank

14 can be moved back to its original position, especially since the cable 9 is relaxed during the lowering movement of the trough and this piston movement enables it. As soon as the piston 12 has taken up its original position, the further lowering movement of the trough 5 leads to a pressure

rose in the hydraulic line system, so that a hydraulic shut-off valve can then clear the flow path of the returning hydraulic fluid through the return line 3 into the storage tank of the towing vehicle.

It can be provided that the storage tank of the towing vehicle is first almost emptied until the cable 9 is tightened and hydraulic fluid is pumped from the reserve tank 14 into the storage tank of the towing vehicle. Alternatively, it can be provided that when the Mul

de 5 Hydraulic fluid is pumped from the reserve tank 14 into the storage tank of the towing vehicle and continuously fills it. In the second case, the hydraulic priority circuit is designed so that when the telescopic cylinder is lowered, the reserve tank 14 is always filled to the extent that

such that the piston 12 can move into the reserve tank 14 and that excess hydraulic fluid is pumped into the reservoir of the towing vehicle.

The trailer 4 shown can, for example, carry a hydraulic

lic cylinder 6 with an oil requirement of 80 l, whereby the maximum withdrawal quantity in the towing vehicle 1 can be, for example, 40 l. The reserve tank 14 can provide the required additional 40 l and thus despite using the intrinsically too low withdrawal quantity of the towing vehicle 1

enable reliable operation of the telescopic cylinder 6.

Claims (3)

1. Agricultural vehicle trailer,
with a hydraulically operated unit, such as a telescopic cylinder for tipping a trough,
and with a hydraulic supply and return line to a towing vehicle,
marked by
a reserve tank with hydraulic fluid, and by a pumping device which is in turn actuated by the operation of the unit,
wherein the pumping device pumps hydraulic fluid from the reserve tank into the unit and 1 or into the return line leading to the towing vehicle,
and by a hydraulic circuit which initially feeds the fluid flowing back from the unit to the reserve tank and only when the reserve tank is full directs further fluid flowing back from the unit via the return line to the towing vehicle. 2. Trailer according to claim 1, characterized in that the pumping device is designed as a piston movable in the reserve container. 3. Trailer according to claim 1 or 2, characterized in that the pumping device is mechanically connected - such as by means of a rod or cable - to a movable part of the unit or to a component of the trailer moved by the unit.