Thick material pump

Abstract

The invention relates to a thick material pump having a first delivery cylinder, a second delivery cylinder and an additional cylinder. The additional cylinder serves for bridging a transition between the first delivery cylinder and the second delivery cylinder. The thick material pump comprises a movable tube portion which forms a connection between the first delivery cylinder and an outlet of the thick material pump in a first state and which forms a connection between the second delivery cylinder and the outlet of the thick material pump in a second state. The movable tube portion comprises a switchable closure which is arranged between an inlet end of the movable tube portion and the additional cylinder. The thick material pump according to the invention makes it possible for a uniform material flow to be delivered in the direction of the pump outlet.

Claims

1. A thick material pump having a first delivery cylinder (20), a second delivery cylinder (21) and an additional cylinder (22) for bridging a transition between the first delivery cylinder (20) and the second delivery cylinder (21), and having a movable tube section (24) which, in a first position, forms a connection between the first delivery cylinder (20) and an outlet (23) of the thick material pump, and which in a second position forms a connection between the second delivery cylinder (21) and the outlet (23) of the thick material pump, wherein the movable tube section (24) comprises a switchable closure (27) which is arranged between an inlet end (25) of the movable tube section (24) and the additional cylinder (22), wherein the movable tube section (24) comprises a first partial section which extends between the inlet end (25) and the closure (27) and a second partial section which extends between the closure (27) and the additional cylinder (22).

2. The thick material pump of claim 1, wherein the tube section (24) is rotatable about a rotational axis oriented concentrically with respect to an outlet end (23) of the tube section (24).

3. The thick material pump of claim 1, wherein the closure (27) comprises a gate valve which can be moved in a rotary fashion between an open position permitting flow from said inlet end (25) to said outlet (23), and a closed position preventing backflow through said movable tube section (24).

4. The thick material pump of claim 1, wherein the closure (27) is pivotable about a pivoting axis oriented coaxially with respect to a rotational axis of the movable tube section (24).

5. The thick material pump of claim 3 wherein the closure (27) is opened if a piston of one of the delivery cylinders (20, 21) is moving forward, and in that the closure (27) is closed while the movable tube section (24) is moved between said first and second positions.

6. The thick material pump of claim 5, wherein each delivery cylinder (20, 21) includes a piston which feeds material in an interior of the delivery cylinder (20, 21) toward said movable tube section (24) with forward movement of the piston and draws material into the interior of the delivery cylinder (20, 21) with rearward movement of the piston, and the delivery cylinder (20, 21) to which the movable tube section (24) is coupled after the switching over of the tube section (24) builds up a pressure with an initial forward movement of the piston before the closure (27) is moved from the closed position to the open position.

7. The thick material pump of claim 6, wherein the pistons of the delivery cylinders (20, 21) are at rest while the tube section (24) is moved between said first and second positions.

8. The thick material pump of claim 1, wherein the tube section (24) comprises a branch (26) which communicates with the additional cylinder (22).

9. The thick material pump of claim 8, wherein the additional cylinder (22) is arranged coaxially with respect to a rotational axis of the tube section (24).

10. The thick material pump of claim 1, wherein the movable tube section (24) extends through a pre-filling container (16) of the thick material pump.

11. The thick material pump of claim 10, wherein a drive for moving the tube section (24) is arranged on a first side of the pre-filling container (16), and a drive for moving the closure (27) is arranged on a second side of the pre-filling container (16) opposite said first side.

12. The thick material pump of claim 1, wherein a flow of material coming from the delivery cylinders (20, 21) and a flow of material coming from the additional cylinder (22) are combined at an angle of less than 90°.

13. The thick material pump of claim 6, wherein said additional cylinder includes a piston that feeds material in an interior of the additional cylinder toward said outlet (23) and forward movement of the piston of the additional cylinder (22) overlaps with the end of the forward movement of the piston of the one delivery cylinder (20, 21) and with the start of the forward movement of the piston of the other delivery cylinder (20, 21).

14. The thick material pump of claim 1, wherein the additional cylinder (22) is fed by a flow of material which is generated by the delivery cylinders (20, 21).

15. The thick material pump of claim 1, wherein the movable tube section (24) and the additional cylinder (22) are elements of one unit which is detachably connected to the thick material pump.

16. The thick material pump of claim 13, wherein said switchable closure (27) is closed while the piston of the additional cylinder (22) is moving forward.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be described by way of example below with reference to the appended drawings and by means of additional embodiments. In the drawings:

(2) FIG. 1 shows a vehicle which is equipped with a thick material pump according to the invention;

(3) FIG. 2 shows a schematic illustration of a thick material pump according to the invention;

(4) FIGS. 3 to 6 show a schematic illustration of various operating states of the thick material pump according to the invention; and

(5) FIG. 7 shows a clock diagram of various components of the thick material pump according to the invention.

DETAILED DESCRIPTION

(6) A thick material pump 15 in the form of a concrete pump is arranged on the truck bed of a truck 14 which is shown in FIG. 1. The thick material pump 15 comprises a pre-filling container 16 into which the concrete is filled from a reservoir (not illustrated). The thick material pump 15 sucks the concrete out of the pre-filling container and feeds the concrete through a connection tube 17 which extends along a distributor mast 18. The distributor mast 18 is mounted on a live ring 19 and can be folded out by means of a plurality of joints, with the result that the end of the tube 17 can be moved into a position in which it is spaced apart from the truck 14. In this position, the concrete is discharged from the connection tube 17. Embodiments which are arranged on a stationary frame (not illustrated) are also included.

(7) According to FIG. 2, the thick material pump 15 comprises, adjacent to the pre-filling container 16, a first delivery cylinder 20, a second delivery cylinder 21 and an additional cylinder 22. A movable tube section 24 extends between the connection tube 17, which is connected to the outlet of the thick material pump, and the delivery cylinders 20, 21. The movable tube section 24 comprises an outlet end 23 which is arranged coaxially with respect to the connection tube 17 and is connected to the connection tube 17 by means of a rotary bearing. The rotary bearing defines a rotational axis about which the tube section 24 can be rotated.

(8) The inlet end 25 of the movable tube section 24 is spaced apart radially from the rotational axis. The position of the inlet end 25 is therefore changed if the movable tube section 24 is rotated about the rotational axis. In a first rotational position of the tube section 24, the inlet end 25 is aligned with the first delivery cylinder 20. In a second rotational position of the tube section 24, the inlet end 25 is aligned with the second delivery cylinder 21. The respective other delivery cylinder is accessible from the pre-filling container 16.

(9) In the state shown in FIG. 2, the first delivery cylinder 20 can suck concrete out of the pre-filling container 16 with a rearward movement of its piston. The second delivery cylinder 21 can feed, with a forward movement of its piston, concrete located in the interior of the delivery cylinder 21 into the connection tube 17 through the tube section 24. After the end of the forward movement of the second delivery cylinder 21, the movable tube section 24 is switched over, with the result that the inlet end 25 is connected to the first delivery cylinder 20, and that the second delivery cylinder 21 is open toward the pre-filling container 16. The first delivery cylinder 20 can then feed, with a forward movement, concrete into the connection tube 17 through the tube section 24, while the second delivery cylinder 21 sucks in concrete from the pre-filling container 16 with a rearward movement.

(10) During the switching over process, with which the movable tube section 24 is switched over between the two delivery cylinders 20, 21, neither of the two delivery cylinders 20, 21 can feed concrete into the tube section 24. In order to prevent an interruption in the flow of material in this phase, the thick material pump according to the invention is equipped with the additional cylinder 22. The additional cylinder 22 is connected to a branch 26 of the movable tube section 24, with the result that the additional cylinder 22 can feed, with a forward movement of its piston, concrete into the connection tube 17 through the tube section 24. The phase in which none of the delivery cylinders 20, 21 can feed concrete into the connection tube 17 is therefore bridged with the additional cylinder 22, with the result that in this phase it is also possible to maintain the continuous flow of material in the direction of the connection tube 17.

(11) In order to prevent the concrete which is fed with the additional cylinder 22 from flowing back in the direction of the delivery cylinders 20, 21, the movable tube section 24 is equipped with a gate valve 27. The gate valve 27 is arranged between the branch 26 and the inlet end 25 of the movable tube section 24. The gate valve 27 is switched in such a way that it clears the path through the tube section 24 when one of the delivery cylinders 20, 21 completes a forward movement, and that it closes off the path through the tube section 24 if switching over between the delivery cylinders 20, 21 is carried out. In this phase, concrete can be fed in the direction of the connection tube 17 with the additional cylinder 22.

(12) A possible method sequence when operating the pump according to the invention is explained below with reference to FIGS. 3 to 7. In FIG. 7A, the speed V of the movement of the first delivery cylinder 20 is plotted against the time T. FIGS. 7B and 7C correspondingly illustrate the movement of the second delivery cylinder 21 and of the additional cylinder 22. A forward movement is illustrated in FIG. 7A to FIG. 7C by means of a value above the zero line, and a value below the zero line corresponds to a rearward movement.

(13) In FIG. 7D, the movement of the gate valve 27 is shown, and in FIG. 7E the movement of the movable tube section 24. The illustration in FIGS. 7D and 7E is not direction-dependent; in each case both switching directions are illustrated by a value above the zero line.

(14) The state according to FIG. 3 corresponds to the phase 40 in FIG. 7. The piston of the first delivery cylinder 20 (FIG. 7A) carries out a forward movement, while the piston of the second delivery cylinder 21 (FIG. 7B) carries out a rearward movement. The gate valve 27 (FIG. 7D) is switched in such a way that the path through the tube section 24 is clear. The tube section 24 (FIG. 7E) is coupled to the first delivery cylinder 20.

(15) In the phase 40, the first delivery cylinder 20 feeds concrete to the connection tube 17 through the tube section 24. The second delivery cylinder 21 sucks concrete out of the pre-filling container 16, with the result that the interior of the second delivery cylinder is filled with concrete. The piston of the additional cylinder 22 is forced to the rear by the pressure present within the tube section 24. The additional cylinder 22 therefore carries out a rearward movement (FIG. 7C) and therefore also takes up concrete into its interior.

(16) In the phase 41, the first delivery cylinder 20 (FIG. 7A) is just before the end of its forward movement, and the speed of the forward movement is reduced to half. The flow of material which is fed with the first delivery cylinder 20 is decreased. At the same time, the additional cylinder 22 (FIG. 7C) is given a forward movement with a reduced speed, with the result that the flow of material in total remains the same.

(17) At the end of the phase 41, the gate valve 27 is activated, with the result that in phase 42 it closes off the path through the tube section 24. The forward movement of the first delivery cylinder 20 ends, and the first delivery cylinder 20 remains at rest in phase 42. The additional cylinder 22 (FIG. 7C) is moved forward with an increased speed in phase 42, with the result that said additional cylinder 22 alone maintains the desired flow of material. In phase 42, the movable tube section 24 (FIG. 7E) is switched over from the first delivery cylinder 20 to the second delivery cylinder 21. FIG. 4 shows the state just before the switching over of the tube section 24 in which the gate valve 27 is already switched over, but the tube section 24 is still connected to the first delivery cylinder 20.

(18) After the tube section 24 is switched over to the second delivery cylinder 21, the forward movement of the second delivery cylinder 21 starts in phase 43 (FIG. 7B). This state of the pump in which the forward movement of the second delivery cylinder 21 starts, but the gate valve 27 is still closed, is illustrated in FIG. 5. As soon as the second delivery cylinder 21 has built up a first pressure, the gate valve 27 (FIG. 7D) is activated, with the result that it clears the path through the tube section 24 again. The second delivery cylinder 21 and the additional cylinder 22, which are both moved forward at a reduced speed, together generate the desired flow of material in the direction of the tube 17.

(19) In phase 44, the second delivery cylinder 21 moves forward at full speed, whereby the additional cylinder 22 is given a rearward movement. At the same time, with a rearward movement the first delivery cylinder sucks in concrete from the pre-filling container 16, see FIG. 6. The phase 44 therefore corresponds to the phase 40, wherein the states of the first delivery cylinder 20 and of the second delivery cylinder 21 are interchanged.

(20) The forward movement of the second delivery cylinder 21 ends in phase 45 in which the piston of the second delivery cylinder 21 is moved forward at a reduced speed. At the same time, the additional cylinder 22 is moved forward at a reduced speed, with the result that the flow of material is maintained unchanged. At the end of the phase 45, the gate valve 27 is activated, with the result that in phase 46, in which the two delivery cylinders 20, 21 are at rest, the tube section 24 can be switched over again to the first delivery cylinder 20. The sequence starts from the beginning after the gate valve 27 is opened again.

(21) This sequence is based on the following design of thick material pump according to the invention. The branch 26, leading to the additional cylinder 22, of the tube section 24 is arranged coaxially with respect to the rotational axis of the tube section 24. The additional cylinder 22 is arranged as a prolongation of the branch 26. The tube section 24 is supported by a first rotary bearing which is arranged at the outlet end 23 of the tube section 24, and by a second rotary bearing which is arranged between the branch 26 of the tube section 24 and the additional cylinder 22. The tube section 24 extends between the two rotary bearings, through the pre-filling container 16. The gate valve 27 is supported by a further rotary bearing which is coaxial with respect thereto. The rotary bearing of the gate valve 27 is connected to the branch 26 of the tube section 24, with the result that the position of the gate valve 27 in the tube section 24 remains unchanged when the tube section 24 is rotated.

(22) The activation of the tube section 24 is carried out by means of a drive which is arranged in a housing part 28 of the pre-filling container. The drive comprises, according to FIGS. 3 to 6, two hydraulically activated cylinders 29, 30 which act on a lever of the tube section 24. The tube section 24 is rotated about the rotational axis by the one cylinder moving out and the other cylinder moving in. The drive 29, 30 is arranged in the direction of the rear of the vehicle when viewed from the pre-filling container 16.

(23) The drive for the gate valve 27 is arranged on the other side of the pre-filling container 16. The drive also comprises two hydraulically activated cylinders 31, 32 which act on a lever of the gate valve 27. The hydraulically activated cylinders 31, 32 are moved along passively when the tube section 24 is rotated. Active activation of the cylinders 31, 32 causes the gate valve 27 to be moved relative to the tube section 24. The drive 31, 32 is arranged in the direction of the front of the vehicle when viewed from the pre-filling container 16.

(24) The housing part 28 of the pre-filling container 16 forms one unit, together with the movable tube section 24, the gate valve 27, the two drives 29, 30, 31, 32 and the additional cylinder 22, which unit can be detached in its entirety from the thick material pump. This permits easy cleaning and maintenance of the pump.