THICK FAT PUMP AND METHOD FOR OPERATING A THICK FAT PUMP

Description

Technical field

[0001] The present invention relates to a high-viscosity pump and a method for operating a high-viscosity pump. Description of the state of the art

[0002] A mobile high-viscosity pump, particularly a concrete pump, typically features a pre-assembled frame that is mounted on and connected to a truck chassis. This frame is designed to accommodate, among other things, a core pump with a material feed hopper or funnel and a drive unit for controlling the functional components. The core pump is usually a two-cylinder piston pump, comprising two pairs of interconnected hydraulic drive cylinders and delivery cylinders. The pistons of these cylinders are connected in pairs via a common piston rod that extends through a water reservoir and can be driven in opposite directions by a hydraulic control system. For this purpose, the drive cylinders are alternately pressurized with hydraulic oil at one end and hydraulically coupled to each other at the other end via a connecting line using so-called rocker oil.The concrete is fed via the hopper, in which a pipe diverter is arranged. The pipe diverter is alternately pivoted in front of the end openings of the two conveying cylinders on the inlet side and opens into a conveying line on the outlet side, which is guided over a distributor mast. Accordingly, the common piston rods with drive piston and conveying piston are moved back and forth in opposite directions along the longitudinal direction of the chassis during operation. Such an arrangement is described, for example, in DE 38 34 678 A1 and EP 2 867 531 B1. Summary of the invention

[0003] Based on this, a high-viscosity pump with the features of claim 1 and a method for operating a high-viscosity pump with the features of claim 6 are proposed according to the invention. Furthermore, a computer program with the features of claim 11 and a control device for a high-viscosity pump with the features of claim 12 are proposed according to the invention.

[0004] The invention is based on the insight gained of providing a cleaning operating mode for a high-viscosity pump of the type described above, in which the conveying cylinders jointly assume a hopper-side end position and the pipe diverter alternates between the two conveying cylinders. The invention includes a reverse pumping process for emptying the conveying cylinders and the conveying line. By draining (in the case of bottom-side drive of the drive cylinders) or supplying (in the case of rod-side drive of the drive cylinders) oscillating oil, the stroke of the conveying cylinders is shortened so that they can jointly assume the hopper-side end position.

[0005] Further advantages and embodiments of the invention will become apparent from the dependent claims, the description and the accompanying drawing.

[0006] The invention also relates to a computer program with program code means suitable for executing a method according to the invention when the computer program is executed on a computer. Both the computer program itself and the program stored on a computer-readable medium are claimed.

[0007] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0008] The invention is schematically illustrated in the drawing using an exemplary embodiment and is described in detail below with reference to the drawing. Brief description of the drawing

[0009] Figure 1The figure shows a schematic, partially cutaway perspective view of a thick material pump according to the invention, including a core pump and material feed container. Figure 2 shows a schematic representation of the slurry pump of the Figure 1 in a semi-transparent top view with bottom-mounted drive. Figure 3 The top view shows the Figure 2 more schematically. The Figures 4 to 6 Figure 3 illustrates the process of a cleaning operating mode according to the invention in a comparable representation. Figure 7 shows one variant of the representation of the Figure 3 with rod-side drive. Figures 8 to 10 illustrate the process of a cleaning operating mode according to the invention in the embodiment of the Figure 7 . Detailed description

[0010] Identical and similar features depicted in the individual figures are designated with the same reference symbols.

[0011] The Figures 1 and 2Figure 10 shows a high-viscosity pump according to the invention, comprising a core pump 12 and a material feed container or hopper 14. The core pump 12 has a first delivery cylinder 16 and a second delivery cylinder 18, the end-face openings 20, 22 of which open into the hopper 14 and are alternately connectable to a delivery line 22 via a pipe diverter 24 during the pressure stroke and are open towards the hopper 14 during the suction stroke, drawing in the material 24.

[0012] The conveying cylinders 16, 18 are driven in opposite directions by their respective first and second hydraulic drive cylinders 26, 28. For this purpose, the conveying pistons 34, 36 of the conveying cylinders 16, 18 are connected to the pistons 38, 40 of the drive cylinders 26, 28 via a common piston rod 30, 32. A water tank 42 is located in the area between the conveying cylinders 16, 18 and the drive cylinders 26, 28, through which the piston rods 30, 32 extend.

[0013] In the illustrated embodiment, the drive cylinders 26, 28 are alternately supplied with pressurized oil via pressure lines 44, 46 at their base, using a hydraulic pump. At their rod-side ends, the drive cylinders 38, 40 are hydraulically coupled to each other by a connecting line 48. During the alternating pressure and suction strokes of the pistons 38 and 40, the so-called rocking oil is pumped back and forth between the drive cylinders 26, 28 via this connecting line 48.

[0014] A 3 / 3-way valve 50 is connected to the connecting line 48, enabling controlled supply and discharge of rocking oil as described below. The inlet and outlet ports 52, 54 of the directional control valve 50 can be supplied with high pressure via a pump P or connected to a tank T at low pressure.

[0015] In the event of an incident, will the Figures 2 and 3In the conveying mode shown, pressurized oil is supplied to the first drive cylinder 26 via line 44 from the bottom (bottom-side drive), and the returning oil from the second drive cylinder 28 is returned to the low-pressure level or tank level via line 46. In this mode, the first piston assembly 34, 38 moves in the direction of arrow P1, and the piston assembly 32, 40 moves in the direction of the opposing arrow P2. Simultaneously, viscous material, particularly concrete, located in the first conveying cylinder 16 is conveyed in the direction of arrows P3 via the pipe diverter 24 under appropriate pressure into a conveying line 56, while material 58 is drawn from the hopper 14 into the second conveying cylinder 18 via the second conveying piston 36 in the direction of arrow P4.

[0016] After execution of the described pressure and suction stroke movement, the pressure application to the pressure lines 44, 46 is reversed and the pipe diverter 24 is switched to the front opening 22 of the second conveying cylinder 18, so that the previously drawn-in thick material from the second conveying cylinder 18 is conveyed via the second conveying piston 36 through the pipe diverter 24 under appropriate pressure into the conveying line 56 and material 58 from the hopper 14 can be drawn into the first conveying cylinder 16 by the first conveying piston 34.

[0017] After the pumping process has ended, not only the hopper 24, but also the conveying cylinders 16, 18 and their end-face openings 20, 22 and conveying pistons 34, 36 must be cleaned to prevent hardening of the remaining thick material. According to the invention, the operator can initiate a cleaning mode for this purpose, for example, by pressing a button provided on a control unit of the thick material pump. The sequence of the cleaning mode according to the invention is described in an exemplary embodiment in the Figures 4 to 6 illustrated.

[0018] In a first step, a reverse pumping action of the core pump is initiated. The connection of the pipe diverter 24 to the delivery cylinders 16 and 18 is operated asynchronously; that is, the pipe diverter 24 is assigned to or connected to the delivery cylinder that will next perform a suction stroke (instead of, as in regular pump operation, to the delivery cylinder that will next perform a pressure stroke). This situation is in the Figure 4 illustrated. The reverse pumping enables the emptying of the conveying cylinder (in the illustration of the figure the second conveying cylinder 18) which is still filled with thick material 58 from the last pumping process into the hopper 14, as well as the suction of thick material remaining in the pipe diverter 24 or the conveying lines 56 by the correspondingly other conveying cylinder (in the illustration of the figure the first conveying cylinder 16).

[0019] Simultaneously with the reverse pumping, rocking oil 60 is fed into tank T via the connecting line 48, e.g. via the one associated with the Figure 2 described directional control valve 50 (which is not shown in the illustration of figures 3 to 6 for the sake of clarity).

[0020] The reverse pumping according to the invention is carried out over several alternating piston strokes until, through the reduction of the amount of rocking oil 60 located in the cylinders 26, 28, a short stroke, i.e. a shortening of the possible stroke of the drive cylinders 38, 40, has been achieved, as is the case in Figure 5This is illustrated. At this moment, the pump is switched off. The size of the short stroke, to which the reverse pumping movement of the delivery pistons 16, 18 is set (i.e., stopped), can be parameterizable, i.e., adjustable or predefined. In this situation, the difference or offset between the two cylinder positions is significantly smaller, and the oscillation volume is already considerably reduced.

[0021] In a next step, rocking oil 60 is further pumped into tank T until both conveying pistons 34, 36 come to rest in a funnel-side end position, i.e., near their end-face openings 20, 22, as shown in the illustration of the Figure 6 This illustrates the point.

[0022] After the conveying pistons 34, 36 reach the described funnel-side end position, the pipe diverter 24 is reactivated, so that it switches back and forth between the two end-face openings 20, 22. This is in the Figure 6This is illustrated by the two pipe diverter positions superimposed with dashed lines. According to the invention, the activation of the pipe diverter 24 can be time-controlled, whereby the duration of the switching intervals can be parameterized, i.e., adjusted or predefined.

[0023] During this time, the operator can clean the conveying cylinders, for example, by spraying the end-face openings and the cylinder interior between the end-face openings and the conveying pistons with sufficiently pressurized water. These openings are alternately released by the pipe diverter at a controlled time. According to the invention, due to the end-position of the conveying pistons, only a very small space behind the end-face openings needs to be cleaned, thus saving time and water and also ensuring optimized cleaning of the conveying piston ends.

[0024] After cleaning is complete, the operator can stop the cleaning mode by pressing a corresponding button or by pressing the button already pressed to initiate the cleaning mode again, whereupon rocking oil 60 is fed back in via the inlet port 52 until the regular counter-rotating piston positions are reached again.

[0025] The Figures 7 to 10 illustrates a variant embodiment of the invention with rod-side drive.

[0026] According to the in Figure 7In the illustrated embodiment, the drive cylinders 26, 28 are alternately supplied with pressurized oil via rod-side pressure lines 44, 46 by means of a hydraulic pump. At their bottom end, the drive cylinders 38, 40 are hydraulically coupled to each other by a connecting line 48. During the alternating pressure and suction stroke movements of the pistons 38 and 40, the hydraulic oil is pumped back and forth between the drive cylinders 26, 28 via this connecting line 48.

[0027] A directional control valve (not shown) is connected to the connecting line 48, enabling the controlled supply and discharge of rocking oil as described below. The inlet and outlet connections of the directional control valve can be supplied by a pump, connected to a tank, or connected to the rod-side pressure lines 44 and 46.

[0028] Figure 7Figure 1 shows the high-viscosity pump 10 in conveying mode with the first conveying cylinder 16 in a hopper-side end position, after it has previously conveyed the high-viscosity material contained therein via the pipe diverter 24 under appropriate pressure into a conveying line 56, while the conveying piston 36 of the second conveying cylinder 18 has drawn material 58 from the hopper 14. Next, in this position, the pipe diverter 24 (associated with the first conveying cylinder 16) switches from the position shown in Figure 16 to the other position shown in Figure 16. Figure 7 position shown in the Figure 8 Position shown, in which the pipe switch 24 is assigned to the second conveying cylinder 18 filled with material 58.

[0029] Subsequently, in conveying mode, pressurized oil is supplied to the first drive cylinder 26 via line 44 on the rod side (rod-side drive), and the returning oil from the second drive cylinder 28 is returned to low-pressure level or tank level via line 46. The first piston assembly 34, 38 moves in the direction of arrow P5, and the second piston assembly 32, 40 moves in the direction of the opposite arrow P6. Simultaneously, material 58 is drawn from the hopper 14 into the first conveying cylinder 16 via the first conveying piston 34, while the viscous material in the second conveying cylinder 18 is conveyed under appropriate pressure via the pipe diverter 24 into a conveying line 56 (see end position of the Figure 8 ).

[0030] As described above, after the pumping process has ended, not only the hopper 24, but also the conveying cylinders 16, 18 and their end-face openings 20, 22 and conveying pistons 34, 36 must be cleaned to prevent hardening of the remaining thick material. According to the invention, the operator initiates a cleaning mode for this purpose, for example by pressing a button provided on a control unit of the thick material pump.

[0031] The sequence of the cleaning operating mode according to the invention with rod-side drive is shown in the illustration of the Figures 8 to 10 illustrated.

[0032] In a first step, a reverse pumping action of the core pump is initiated. The connection of the pipe diverter 24 to the delivery cylinders 16, 18 is operated asynchronously, i.e., the pipe diverter 24 is assigned to or connected to the delivery cylinder that will next perform a suction stroke (instead of, as in regular pump operation, to the delivery cylinder that will next perform a pressure stroke), thus in the situation shown... Figure 8 the second conveying cylinder 18.

[0033] The reverse pumping allows the conveying cylinder, which is still filled with thick material 58 from the last pumping operation (i.e., in the representation of the Figure 8 the first conveying cylinder 16) into the hopper 14 and the emptying of any thick material remaining in the pipe diverter 24 or the conveying lines 56 by the correspondingly other conveying cylinder (in the illustration of the Figure 8 the second conveying cylinder 18).

[0034] Simultaneously with the reverse pumping, rocking oil 60 is supplied via the connecting line 48, e.g. via a directional control valve 50 (not shown). For this purpose, the directional control valve can be connected to a tank with a rocking oil reservoir, or the supply can be effected by connecting the connecting line 48 to the pressure lines 44, 46 (as is generally known to those skilled in the art and is described, e.g., in EP 2 867 531 B1).

[0035] The reverse pumping according to the invention is carried out over several alternating piston strokes until, through the increase in the quantity of rocking oil 60 located in the cylinders 26, 28, a short stroke, i.e. a reduction of the possible stroke of the drive cylinders 38, 40, has been achieved, as is the case in Figure 9This is illustrated. At this moment, the pump is switched off. The size of the short stroke, to which the reverse pumping movement of the delivery pistons 16, 18 is set (i.e., stopped), can be parameterizable, i.e., adjustable or predefined. In this situation, the difference or offset between the two cylinder positions is significantly smaller, and the oscillation volume is already considerably reduced.

[0036] In a next step, rocking oil 60 is fed further into the drive cylinders 26, 28 until both conveying pistons 34, 36 come to a funnel-side end position, i.e., near their end-face openings 20, 22, as shown in the illustration of the Figure 10 This illustrates the point.

[0037] After the conveying pistons 34, 36 reach the described funnel-side end position, the pipe diverter 24 is reactivated, so that it switches back and forth between the two end-face openings 20, 22. This is in the Figure 10This is illustrated by the two pipe diverter positions superimposed with dashed lines. According to the invention, the activation of the pipe diverter 24 can be time-controlled, whereby the duration of the switching intervals can be parameterized, i.e., adjusted or predefined.

[0038] During this time, the machinist can, as described above, in connection with the Figure 6 The cleaning of the conveying cylinders was described.

[0039] After cleaning is complete, the operator can stop the cleaning mode by pressing a corresponding button or by pressing the button already pressed to initiate the cleaning mode, as described above. As a result, the 60 sloshing oil is drained back out via the inlet until the regular counter-rotating piston positions are reached again. Reference symbol list

[0040] 10 Thickness pump 12 Core pump 14 Material feed hopper or hopper 16 First delivery cylinder 18 Second delivery cylinder 20 First front opening 22 Second front opening 24 Pipe diverter 26 First hydraulic drive cylinder 28 Second hydraulic drive cylinder 30 Common piston rod 32 Common piston rod 34 First delivery piston 36 Second delivery piston 38 Piston of first drive cylinder, drive piston 40 Piston of second drive cylinder, drive piston 42 Water tank 44 Pressure line 46 Pressure line 48 Connecting line, rocking oil line 50 3 / 3-way valve 52 Inlet connection 54 Outlet connection 56 Delivery line 58 Material, thickness 60 Rocking oil Pump P1 Arrow P2 Arrow P3 Arrows P4 Arrow P5 Arrow P6 Arrow Tank

Claims

1. A high-density solids pump (10) with two conveying cylinders (16, 18), the conveying pistons (34, 36) of which are each rigidly connected to a drive piston (38, 40) of an associated drive cylinder (26, 28) via a common piston rod (30, 32), wherein a conveying operating mode is provided in which the conveying cylinders (16, 18) are driven in push-pull operation, in order to convey high-density solids (58) via a diverter valve (24) alternately connected to the conveying cylinders (16, 18) from a hopper (14) into a conveying pipe (56) (50), and characterized in that a cleaning operating mode is provided in which the conveying cylinders (16, 18) jointly adopt an end position on the hopper side and the diverter valve (24) is alternately switched between the two conveying cylinders (16, 18).

2. The high-density solids pump (10) according to claim 1, wherein, to initiate the cleaning operating mode, reverse pumping takes place with an asynchronous alternating assignment of the diverter valve (24) to the conveying cylinders (16, 18) in comparison to the conveying operating mode.

3. The high-density solids pump (10) according to claim 2, wherein, parallel to the reverse pumping process, the strokes of the conveying cylinders (16, 18) are shortened until the conveying pistons (34, 36) are in an end position on the hopper side.

4. The high-density solids pump (10) according to claim 3, wherein the drive cylinders (26, 28) are in communication with one another via a rocking-oil line (48) arranged on the rod side, so as to exchange rocking oil (60), and the strokes of the conveying cylinders (16, 18) are shortened by withdrawing rocking oil (60).

5. The high-density solids pump (10) according to claim 3, wherein the drive cylinders (26, 28) are in communication with one another via a rocking-oil line (48) arranged on the bottom side, so as to exchange rocking oil (60), and the strokes of the conveying cylinders (16, 18) are shortened by supplying rocking oil (60).

6. A method for operating a high-density solids pump (10) with two conveying cylinders (16, 18) (70, 80), the conveying pistons (34, 36) of which are each rigidly connected to a drive piston (38, 40) of an associated drive cylinder (26, 28) via a common piston rod (30, 32), wherein in a conveying operating mode the conveying cylinders (16, 18) are driven in push-pull operation in order to convey high-density solids (58) via a diverter valve (24) alternately connected to the conveying cylinders (16, 18) from a hopper (14) into a conveying pipe (56), and in a cleaning operating mode the conveying cylinders (16, 18) are brought jointly into an end position on the hopper side and the diverter valve (24) alternately opens the conveying cylinders (16, 18).

7. The method according to claim 6, wherein, to initiate the cleaning operating mode, reverse pumping is carried out with an asynchronous alternating assignment of the diverter valve (24) to the conveying cylinders (16, 18) compared to the conveying operating mode.

8. The method according to claim 7, wherein, parallel to the reverse pumping, the strokes of the conveying cylinders (16, 18) are shortened until the conveying pistons (34, 36) are in an end position on the hopper side.

9. The method according to claim 8, wherein rocking oil (60) is drained off to shorten the strokes of the conveying cylinders (16, 18) when the drive cylinders (26, 28) are in communication with one another via a rocking-oil line (48) arranged on the rod side, so as to exchange rocking oil (60).

10. The method according to claim 8, wherein rocking oil (60) is supplied to shorten the strokes of the conveying cylinders (16, 18) when the drive cylinders (26, 28) are in communication with one another via a rocking-oil line (48) arranged on the bottom side, so as to exchange rocking oil (60).

11. A computer program with program code means for carrying out all steps of a method according to any of claims 6 to 10 when the computer program is run on a computer or a corresponding computing unit, in particular a control device of a high-density solids pump (10).

12. A control device for a high-density solids pump (10), in particular according to any of claims 1 to 5, which is designed to carry out a method according to any of claims 6 to 10, or in which a computer program according to claim 11 is saved in a manner suitable for execution.