SWITCHING DEVICE FOR A CONCRETE PUMP

Abstract

A switching device for switching a hydraulic flow of a concrete pump, comprising a first connection component for connection to a hydraulic pump; a second connection component for connection to a drive cylinder; and a distribution unit which is arranged between the first and second connection components, wherein the first connection component has two fluid guides and the second connection component has a first fluid-guide pair and a second fluid-guide pair, and the distribution unit can be transferred reversibly between a first position, in which the fluid guides of the first connection component are connected fluidically to the first fluid-guide pair of the second connection component, and a second position, in which the fluid guides of the first connection component are connected fluidically to the second fluid-guide pair of the second connection component.

Claims

1. A switching device for switching a hydraulic flow of a concrete pump, comprising a first connection component for connection to a hydraulic pump; a second connection component for connection to a drive cylinder; and a distribution unit which is arranged between the first and second connection components, wherein the first connection component has two fluid guides and the second connection component has a first fluid-guide pair and a second fluid-guide pair, and the distribution unit can be transferred reversibly between a first position, in which the fluid guides of the first connection component are connected fluidically to the first fluid-guide pair of the second connection component, and a second position, in which the fluid guides of the first connection component are connected fluidically to the second fluid-guide pair of the second connection component, wherein the distribution unit is connected in a leak-tight manner to the first and second connection components.

2. The switching device of claim 1, wherein the distribution unit can be transferred between the first and second positions by way of rotation or translation.

3. The switching device of claim 1, wherein, when the distribution unit is transferred between the first and second positions, a position of the first and second connection components remains unchanged.

4. The switching device of claim 1, wherein the distribution unit has a first sealing surface for interaction with a sealing surface of the first connection component and/or has a second sealing surface for interaction with a sealing surface of the second connection component.

5. The switching device of claim 1, wherein the first and second connection components are connected to one another in a resilient manner.

6. The switching device of claim 1, wherein the first and second connection components are connected to one another via at least one releasable fastening means.

7. The switching device of claim 6, wherein the first and second connection components are connected to one another in such a way that no fluid can escape between the first or second connection component and the distribution unit when the at least one releasable fastening means is released.

8. The switching device of claim 1, wherein the first and second connection components are connected to one another via a resiliently mounted fastening element in such a way that the distribution unit is connected in a leak-tight manner to the first and second connection components.

9. The switching device of claim 6, wherein the fastening means and/or the resiliently mounted fastening element are/is configured as a guide aid for the transfer of the distribution unit between the first and second positions.

10. The switching device of claim 1, wherein the first and/or second connection component has a guide element for the transfer of the distribution unit between the first and second positions.

11. The switching device of claim 1, wherein the distribution unit has an operating lever for the transfer between the first and second positions, the operating lever preferably interacting with a guide element of the first or second connection component.

12. The switching device of claim 1, wherein the distribution unit has on a side which faces toward the second connection component at least four openings for connection to the first and second fluid-guide pairs.

13. The switching device of claim 1, wherein that fluid-guide pair of the second connection component which is in each case not connected fluidically to a fluid guide of the first connection component is short-circuited.

14. The switching device of claim 1, wherein two pressure hoses are mounted on the first connection component and/or four pressure hoses are mounted on the second connection component.

15. The switching device of claim 1, wherein the position determination of the distribution unit is realized using a sensor.

16. A concrete pump having a switching device of claim 1.

17. A method for switching a hydraulic-medium flow of a concrete pump using a switching device of claim 1, comprising the following steps: releasing a fastening means or resiliently mounted fastening element arranged between a first and a second connection component; transferring a distribution unit between a first and a second position; firmly tightening the fastening means or the resiliently mounted fastening element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Advantageous embodiments of the invention will be described by way of example below on the basis of the appended figures. In the figures:

[0038] FIG. 1 shows a system-based circuit diagram for rod/bottom-switching using a switching device according to the invention in a first embodiment;

[0039] FIG. 2 shows a three-dimensional schematic illustration of a switching device according to the first embodiment;

[0040] FIG. 3 shows a three-dimensional schematic illustration of the switching device from FIG. 2 from another perspective;

[0041] FIG. 4 shows a schematic functional view of the switching device according to the first embodiment in a first position;

[0042] FIG. 5 shows a schematic functional view of the switching device from FIG. 4 in a second position;

[0043] FIG. 6 shows a three-dimensional schematic illustration of hydraulically driven drive cylinders of a concrete pump (not illustrated) with a switching device according to the first embodiment;

[0044] FIG. 7 shows a three-dimensional schematic view of a switching device according to the invention according to a second embodiment;

[0045] FIG. 8 shows a three-dimensional schematic illustration of hydraulically driven drive cylinders of a concrete pump (not illustrated) with a switching device according to the second embodiment;

[0046] FIG. 9 shows a schematic functional view of the switching device according to the second embodiment in a first position; and

[0047] FIG. 10 shows a schematic functional view of the switching device as per FIG. 9 in a second position.

DETAILED DESCRIPTION

[0048] FIG. 1 shows a schematic circuit diagram of two hydraulically driven conveying cylinders 20, 30 of a concrete pump (not illustrated). This is preferably a stationary concrete pump. The pistons 21, 31 of the conveying cylinders 20, 30 are moved back and forth by way of hydraulic drive cylinders 25, 35, whose pistons 26, 36 are connected via piston rods 23, 33 to the pistons 21, 31 of the conveying cylinders 20, 30. The displacement of the pistons 26, 36 of the drive cylinders 25, 35 is realized by way of alternating charging with pressure medium of the piston rod-side pressure chambers of the drive cylinders 25, 35 via the illustrated pressure-medium lines 27, 37. Those pressure chambers of the drive cylinders 25, 35 which face toward the full surfaces of the pistons 26, 36 are connected by pressure-medium lines 28, 38 in the manner of a hydraulic linkage. All the pressure-medium lines 27, 37, 28, 38 are led through a switching device 100, which switching device is illustrated in a highly simplified form in FIG. 1 to make the arrangement thereof clear.

[0049] As is indicated in the symbolic illustration of the switching device 100, a distribution unit 130 which is arranged between a first and a second connection component 110, 120 can be set in two positions by way of rotation about its axis through 180°. In a first position (as per FIG. 1), the pressure-medium lines 27, 37 are connected to pressure-medium lines 41, 42 which serve for supply of pressure medium and for discharge of pressure medium, while the pressure-medium lines 28, 38 are connected to form a hydraulic linkage (rod-side operation). In a second position (not illustrated in FIG. 1), the pressure-medium lines 28, 38 are connected to the pressure-medium lines 41, 42 for supply and discharge of pressure medium, while the pressure-medium lines 27, 37 are connected to form a hydraulic linkage (bottom-side operation). A switching valve 50 may be provided for the alternating application of pressure and relief of pressure of the pressure-medium lines 41, 42. In the case of a mobile concrete pump having free-flow hydraulics (FFH) control, such a switching valve 50 is not required, however. A pressure-medium pump is denoted by the reference sign 40.

[0050] FIGS. 2-6 and 7-10 respectively illustrate in detail a first and a second exemplary embodiment of the switching device 100 and 200, respectively.

[0051] FIGS. 2 and 3 show a three-part switching device 100 according to a first embodiment from two different perspectives. The switching device 100 comprises a first connection component 110 and a second connection component 120. A distribution unit 130 is arranged between the connection components 110, 120. The distribution unit 130 is clamped in a sandwich-like manner between the connection components 110, 210. All three components of the switching device are formed so as to be substantially plate-like with side edges of equal length, this however not being in any way imperative.

[0052] The first connection component 110 has visibly on its outer side two ports for pressure hoses 112a, 112b, which are connected to fluid guides (not illustrated) within the first connection component 110. The second connection component 120 has on its outer side four ports for pressure hoses 122a, 122b, 124a, 124b with so-called threaded elbow joints, which are likewise connected to fluid guides (not illustrated) in the second connection component 120. The fluid guides of the first and second connection component 110, 120 are separated from one another by the distribution unit 130, as is described in more detail below.

[0053] In this embodiment, the switching device 100 has four fastening means 140 arranged in the corners that are in the form of screws. The fastening means 140 connect the first and second connection components 110, 120 to one another and can be tightened to such an extent that the distribution unit 130 is clamped in a secure or tight manner between the connection components 110, 120. The switching device 100 additionally has a centrally arranged, resiliently mounted fastening element 142. The fastening element 142 is designed as a combination of a screw and a spring and has the effect that, even after partial loosening of the fastening means 140, the first and second connection components 110, 120, by way of the force of the spring, continue to be pressed together. In this way, a fluid, such as a hydraulic medium, cannot undesirably escape from the switching device 100.

[0054] In order for the distribution unit 130 to be transferred from a first position into a second position, it is firstly necessary for the fastening means 140 to be loosened slightly, so that the distribution unit is no longer fixed between connection components 110, 120. The distribution unit 130 has an operating lever 148 on its side facing toward the first connection component 110. Instead of a mechanical actuation of the distribution unit 130, an electrical, hydraulic or pneumatic actuation is also possible. The operating lever 148 can be guided along a guide element 146 which is formed as part of one of the connection components 110, 120. By way of the movement of the operating lever 148 along the guide element 146, the distribution unit 130 can be rotated through up to 180°.

[0055] FIGS. 4 and 5 show the switching device 100 in a first position and a second position. The different orientation of the distribution unit 130 is indicated in particular by the different position of the operating lever 148 too. FIGS. 4 and 5 show the fluid guides arranged in the interior of the connection components 110, 120 and of the distribution unit 130. The first connection component 110 has fluid guides 111a and 111b which are connected to the ports for pressure hoses 112a, 112b. The second connection component 120 has four fluid guides 121a, 121b, 123a, 123b which are connected to the ports for pressure hoses 122a, 122b, 124a, 124b. The fluid guides 121a, 121b and 123a, 123b are in each case referred to as a fluid-guide pair. The fluid guides 111a, 111b, 121a, 121b, 123a, 123b extend as bores in the interior of the connection components 110, 120.

[0056] In this embodiment, the distribution unit 130 has three fluid guides 131a, 131b, 133c which, according to the position of the distribution unit 130, bring about fluid connections between different fluid guides of the first and second connection component 110, 120. In this exemplary embodiment, the fluid guides of the distribution unit are formed as bores which are suitable for transporting a pressure medium. In addition, the fluid guides 131a, 131b, 133c are equipped with sealing rings on the outer side of the distribution unit 130.

[0057] Fluid guide 131a of the distribution unit 130 connects fluid guide 122b of the first connection component 110 to fluid guide 123b of the second connection component 120. Fluid guide 131b of the distribution unit 130 connects fluid guide 112a of the first connection component 110 to fluid guide 123a of the second connection component 120. The fluid guides 123a, 123b belong to a fluid-guide pair. Fluid guide 131c connects the fluid guides 121a and 121b of the second connection component 120 and thereby short-circuits the fluid-guide pair 121a, 121b.

[0058] If an operator moves the operating lever 148 illustrated in FIG. 4 along the guide element 146 of the first connection component 110, the setting illustrated in FIG. 5 is obtained. In this case, the distribution unit 130 performs a rotation of 180° about its own axis. This central axis is determined in this embodiment by the resiliently mounted fastening element 142, which is guided through a cutout in the distribution unit 130. In this setting, the fluid guide 131c connects that fluid-guide pair of the second connection component 120 which is formed by the fluid guides 123a and 123b, while the fluid guides 131a and 131b each connect a fluid guide 112a, 112b of the first connection component 110 to a fluid guide 21a, 121b of the second connection component 120. Consequently, the transfer of the distribution unit 130 from the first position into the second position makes it possible to switch the type of operation between the fluid-guide pairs. In this way, an operator can switch the machine from rod-side operation to bottom-side operation, or from bottom-side operation to rod-side operation, without significant outlay in terms of assembly and in a short period of time.

[0059] FIG. 6 shows the switching device 100 with fixedly connected pressure-medium lines 27, 37, 28, 38 in the form of pressure hoses. The pressure hoses connect the pressure-hose ports 122a, 122b, 124a, 124b of the second connection component 120 to the rod side or bottom side of the drive cylinders 25, 35 (see also FIG. 1), the structure of the switching device 100 otherwise being as described above. The switching device 100 may be arranged at any position of the machine, for example at any position along the drive cylinders 25, 35.

[0060] FIG. 7 shows a three-part switching device 200 according to a second exemplary embodiment of the invention. The switching device 200 comprises a first connection component 210, a second connection component 220 and a distribution unit 230 arranged between the first and second connection components 210, 220. The switching device 200 differs from the switching device 100 in that the reversible transfer of the distribution unit 230 between a first position and a second position is carried out by lateral displacement of the distribution unit 130. The displacement of the distribution unit 130 can likewise be realized via an operating lever 248.

[0061] The first and second connection components 210, 220 each have ports for pressure hoses 212a, 212b, 22a, 22b, 224a, 224b. The first and second connection components 210, 220 are moreover connected to one another via fastening means 240 in the form of screws and have in addition a resiliently mounted fastening element 242 in the form of a combination of a spring and a screw. The fastening means 240 are arranged in slots of the first and second connection component 210, 220, which slots serve as guide elements 246 during a displacement of the distribution unit 130. The distribution unit 230 is situated in the first and second positions in each case fully between the first and second connection components 210, 220 and is clamped therebetween.

[0062] FIG. 8 shows the switching device 200 with pressure hoses which are connected fixedly to the pressure ports 222a, 222b, 224a, 244b at the second connection plate 230. The pressure hoses connect the pressure ports 222a, 222b, 224a, 244b to the rod side or bottom side of the drive cylinders 25, 35. The switching device 200 may be arranged at any desired position at the machine, for example along the drive cylinders 25, 35.

[0063] FIGS. 9 and 10 show the switching device 200 in a first position and a second position. The different position of the distribution unit 130 is characterized in that the distribution unit 130 is displaced in the direction of the pressure ports 212a, 212b in a substantially horizontal direction. In the setting shown in FIG. 9, a first fluid guide 211a of the first connection component 210 is connected via fluid guide 231b of the distribution unit 230 to fluid guide 223b of the second connection component 230, and a second fluid guide 211b of the first connection component 210 is connected fluidically via fluid guide 231c of the distribution unit 230 to fluid guide 223a of the second connection component 220. The fluid guides 221a and 221b of the second connection component 220 are both in contact with fluid guide 231d of the distribution unit 230 and are thereby short-circuited via the distribution unit 230 (hydraulic linkage). The fluid guides 223a and 223b belong to a fluid-guide pair.

[0064] In the setting illustrated in FIG. 10, the fluid guide 211a of the first connection component 210 is connected fluidically via the fluid guide 231b of the distribution unit 230 to fluid guide 221b of the second connection component 220. The second fluid guide 221b of the first connection component 210 is connected fluidically via fluid guide 231c of the distribution unit 230 to the fluid guide 221a of the second connection component 220. All the fluid guides are formed as bores, wherein the fluid guides 211a, 211b of the first connection component have branches with multiple mutually offset exits. This, however, is not a problem since the connection components 210, 220 are, via the resiliently mounted fastening element 240 and any seal elements (not illustrated), at all times held together in such a way that the switching device 200 is leak-tight.

[0065] For carrying out the method for switching a hydraulic flow of a concrete pump by way of a switching device 100, 200, firstly the fastening means 140, 240 (or the resiliently mounted fastening element 142, 242) are (is) unscrewed slightly, without however releasing the connection between the first and second connection components 110, 120, 210, 220. This enables the distribution unit 130, 230 to have a sufficient amount of play to allow a rotation or translation between the connection components. As soon as the final position of the distribution unit 230 has been reached, the fastening means 140, 240 (or the resiliently mounted fastening element) are (is) screwed tight again by an operator before the switching device 100, 200 can be used during operation.