FI106710B - Hydraulic control device for rope winches - Google Patents

Description

106710

Hydraulic steering equipment for rope winches - Hydraulisk styranord-Ning för repvinschar

The invention relates to a control apparatus for rope winches.

5 Rope winches for lifting and lowering loads are used, for example. mobile devices, such as portal loaders, which in most cases operate on internal combustion engines.

Lifting requires a certain amount of power, taking into account the overall efficiency; the same power minus the prevailing lowering rate for the resistors, but with the winch rotating in the opposite direction.

In most cases, so-called. closed circuits in which the flow directions are reversed, which belong to both the primary and secondary sides of the fluid motor in the winch and, for example, to the inlet and outlet sides of the control pump, must flow the same amounts of hydraulic oil for lifting and lowering operations.

Even in open circuits, where the rotary direction of the winch's fluid motors is reversed by 4/3-way valves, the amount of hydraulic oil required on the secondary side of the fluid motor must always be at least the same outflow as the hydraulic pump supplies. Further, these quantities 20 must be subjected to a certain pressure, the so-called. against "feed pressure" to avoid cavitation on the inlet sides of the pump and liquid motor.

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M ··; .1. The result of the required quantities and feed pressure provides the power that • · ·: the drive motor for the mobile unit must also develop.

• 1 • ♦: The throttling during load calculation is controlled in most cases by • · 1:25. by means of downward stop valves, and by controlling the throttle cross-section in accordance with successive quantities of hydraulic oil. Hydraulic oil quantities supplied: '1 1: thus determines the lowering speeds.

• · «*: · 'The disadvantage of this is that, even when lowering, where the load is: pulled, the drive motor of the mobile device must always rotate at the same speed and up to:: 1: 30 slower speed.

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♦ · ♦ • · * »2 106710

It is an object of the invention to provide a hydraulic control apparatus for rope winches which enables the drive motor of a mobile device to rotate at idle speed even at the highest winch load lowering speed.

The object is achieved by a hydraulic control apparatus comprising a hydraulic oil reservoir and a fluid motor for a rope winch, and a pump for the fluid motor, a pressure relief valve, a pressure switch, and a fluid connection to and from the fluid motor. wherein the oil return line has a pressure relief valve coupled to the proportional-10 choke.

The amount of hydraulic oil supplied to the winch's fluid motor is determined by the current speed of the drive motor of the device, at least its idle speed.

So long as vintturinkuorman decrease the speed of the motor and thus the fluid flowing out of the hydraulic oil 15 is less than derived through the pump, it is ensured that there is a pressure differential between the post and the secondary side fluid motor suhteellisuuskuristimen vastapai-Neen. arranged between the pressure side liitosjoh-toon-return valve remains in each case closed. In this mode of operation, the proportional throttle throttled and thus heated hydraulic oil flows to change the oil reservoir to 20 o'clock, while the fresh hydraulic oil is pumped from the oil reservoir by means of a pump to a circulation circuit.

Short-circuiting of the hydraulic oil flow would cause heating and, consequently, risk of hydraulic oil decomposition. If now the winch load-; as a result of the known lowering speed, the amount of hydraulic oil flowing out is • «·: 25 higher than the amount coming from the pump;

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The invention ensures that, due to reversed pressure conditions: "1: Hydraulic oil can be re-fed through a non-return valve to the connecting line. · * · 'The oil is drained from the oil tank.

• · • · · • «· · 3 106710

An advantage of the invention is that, in addition to the lower power required to supply the hydraulic oil, the engine speed is reduced, which significantly reduces fuel consumption and noise levels when the winch load is lowered.

The invention will be explained in more detail by means of a schematic diagram of the connection shown in simplified form in the drawing.

By switching on the main switch (not shown here) and controlling the lowering incident, the hydraulic oil initially flows from pump 1, which is driven by idle engine, through line 3 to secondary side B of liquid engine 5, to approximately 40 bar by biasing valve 8 through that the feed pressure is at a predetermined value. The retaining brake 9 is vented and the driving load 10 rotates the winch 11 and thus also the fluid motor 5. The load is resting hydraulically on the proportional throttle 12 still closed.

Opening the proportional throttle 12 controls the winch load lowering operation and the controlled hydraulic oil flows along the line 13 and through a biased valve to the oil tank 7 when opening the proportional throttle 12, the lowering speed of v> n can be adjusted to a maximum value.

If the amount of hydraulic oil derived from the stern supplied by pump 1 becomes smaller than the amount controlled by the proportionality choke 12, the supply pressure in the conduit 4 is lost and a pressure drop from conduit 13 to conduit 4 then results in opening of the conduit 16: · The throttle valve 15 and the missing amount of hydraulic oil flows into line 4 and secures; thus supplying the motor 5 with hydraulic oil under all operating conditions, and up to the current pressure value of ···: 25 13.

• o • ♦: This ensures that in the proportionality choke 12 the hydraulic oil that has been warmed by the throttle action ♦ · is returned to the oil tank 7 for change and cooling, and only then the fraction is passed through the check valve 15: *** to the pump volume 5 the hydraulic oil outflow becomes * ": 30 greater than the amount of hydraulic oil supplied by the pump 1 corresponding to the rotational speed of the drive motor 2.

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Claims (2)

4 106710 Claim Hydraulic control apparatus for rope winches comprising a hydraulic oil reservoir and a fluid motor for a rope winch and a pump in the line leading to the fluid motor, pressure relief valve, pressure switch, and oil in / out, 15) and that the oil return line is provided with a pressure relief valve (14) after the proportionality choke (12). 10 Hydraulisk styranordning för repvinschar, innefattande en behällare för hydraulisk oil och en fischer motor för en repvinsch samt en pump i en ledning som leder account fischer, en tryckgränsventil, en tryckkopplare och en proportionalitetsdrossel i en frän vätskem and account oljereturledningen via en returventil (15) och att olje-15 returledningen har en tryckgränsventil (14) kopplad efter proportionalitetsdrosseln (12). I «· I ·« • «· · · · ········································································ Reporting • · 1 »·· * · * · <e <*« * «« «· 1 · · • · * · • · I