SE463007B - HYDRAULIC SYSTEM FOR OPERATING A SPREADER - Google Patents

Description

465 ÛÛ7 2 spreaders. The line 17 goes to a single-acting hydraulic cylinder 19, which opens and closes the spreading funnel of the manure spreader. From the hydraulic motor 18 a return line 21 goes to the container. From this line a line 22 is branched, which through a node A opens into the line 17. a line 23 further emanates from the line 17 before the node A, which likewise again opens into the line 22. In the line 23 an adjustable pressure relief valve 24 is arranged. Its outlet opens into the line 23. Between the outlet point 23 of the line 23 in the line 22 and its outlet point A in the line 17, a choke 25 is arranged.

Between the line 16 and the line 22 runs a line 27. which contains a non-return valve 28 with low opening pressure (approx. 50 kPa). which can open in the direction from line 22 to line 16. In line 21 there is also a biased non-return valve 29 (approx. 300 kPa). which - seen in the flow direction of the outlet from the hydraulic motor - is located after the mouth of the line 22 in the line 21. This non-return valve 29 can open in the direction of the container 12.

The three-way flow control valve 15 is so designed. that a constant adjustable flow of pressure medium flows through the line 16 to the hydraulic motor 18 and the residual flow flows through the line 17 to the working cylinder 19. Through the constant flow, the hydraulic motor 18 obtains a constant speed and drives the spreading disc.

To influence the working cylinder 19 against its load (opening of the spreading funnel) a pressure between 3 and 4 MPa is required. which is achieved if a certain pressure medium flow passes through the throttle 25. The pressure relief valve 24 is set to said pressure between 3 and 4 Mæa. The pressure medium flowing into the line 17 thus reaches at the node A into the branch line 22 and flows through the choke 25 and then further through the non-return valve 29 in the return line 21. The opening pressure of the pressure relief valve 24 is set when the above-mentioned determined pressure medium flows through the choke 25. in front of the choke 25 such a dynamic pressure. which opens the hydraulic cylinder 19. 10 15 20 25 3 465 G97 If the directional valve 14 is brought to its position II, the pressure medium fed by the pump flows directly back to the container 12. The hydraulic motor 18 is now no longer a pressure medium from the pump 10 but continues to rotate time due to the mass of the spreading disc. In order to avoid negative pressure, the hydraulic motor 18 must be able to aspirate pressure medium. This is achieved through the non-return valve 28 in combination with the non-return valve 29 acting as a bias valve. that the pressure medium flowing away from the hydraulic motor 18 in the line 27 and via the non-return valve 28 (approx. 50 kPa bias voltage) and the line 16 is returned directly to the inlet side of the hydraulic motor 18. The hydraulic motor therefore always remains filled with pressure medium. which is a prerequisite for it to start before the hydraulic cylinder 19 moves.

It is advantageous to arrange the three-way flow control valve 15 near the inlet of the hydraulic motor 18. since this only requires a short line part 16.

Conveniently, the described device may. i.e. the flow control valve 15. the pressure relief valve 24. the throttle 25 and the non-return valves are assembled in a block 30 and are mounted directly on the inlet side of the hydraulic motor 18. On the opposite side there is a connection block 31. and the two blocks 30. 31 are connected to each other by a tolerance equalizing plug pipe 32. In this way a very compact drive unit with minimal piping is obtained, which unit can be easily adjusted and tested in a workshop.

Claims (5)

Patent claims 1. Hydraulic system for operating a spreader. in particular a manure spreader, with a pump (10) driven by a vehicle engine, which supplies a constant flow of pressure medium through a three-way flow control valve (15) connected to the pump to a spreader plate driving hydraulic motor (18) and supplies a residual flow via a branch line (17) to a hydraulic cylinder (19) acting on the spreading funnel, characterized in that a throttle (25) is connected parallel to the branch line (17), the pressure difference generated by this throttle being effective at a pressure relief valve (24); which determines and limits the pressure affecting the hydraulic cylinder (19). Hydraulic system according to Claim 1, characterized in that two lines (22, 23) are branched off from the branch line (17). which are connected to each other and lead to the return line of the hydraulic system (21). and that the pressure relief valve (24) is arranged in a first (23) of these two lines while the throttle (25) is arranged in the second (22). Hydraulic system according to Claim 1 and / or 2, characterized in that a prestressed non-return valve (29) is opened in the return line (21) in the direction of the pressure medium container (12) and is located in one place after said second line. (22) mouth in the return line (21). seen in the flow direction of the outlet from the hydraulic motor (18). Hydraulic system according to any one of claims 1 - 3. characterized in that in a branch line (27), which connects said second line (22) to the pressure medium supply line (16) of the hydraulic motor (18), there is a non-return valve (28 ) arranged. Hydraulic system according to one of Claims 1 to 4, in which hydraulic blocks (30, 31) intended for the pressure medium circuit are arranged on either side of the hydraulic motor (18). FEATURES - THAT THE HYDRAULIC BLOCKS (30, 31) ARE COMMUNICABLE WITH EACH OTHER THROUGH A TOLERANTS COVERING PLUG CONNECTOR (32).