"Module for pumping concrete"

Technical Field

The present invention relates to a module for pumping concrete and a vehicle comprising the module.

Prior Art

Stationary pumps (tracked or borne on a carriage) or truck pumps for pumping concrete are known. As well as being provided with a pumping group of the concrete, they also comprise a diesel engine or electric motor for dispensing power and an electrical and oil-dynamic plant for managing the whole machine. These machines are completely autonomous.

A drawback of these solutions is related to the high costs of equipment of this type. A further drawback of these constructional solutions is connected to the fact that these machines have significant dimensions and therefore require sufficiently large access paths and/or suitable spaces for stabilising the machinery (as in the case of truck pumps).

Aim of the invention

In this context, the technical task of the present invention is to provide a module for pumping concrete which obviates the drawbacks in the prior art as described above.

In particular, an object of the present invention is to provide a module for pumping concrete that enables the purchaser to optimise costs.

The defined technical task and the specified aims are substantially achieved by the module for pumping concrete, comprising the technical characteristics set out in one or more of the appended claims.

Brief description of the drawings

Further characteristics and advantages of the present invention will become more apparent from the following indicative, and hence non- limiting, description of a preferred, but not exclusive, embodiment of a module for pumping concrete as illustrated in the appended drawings, in which: - figure 1 is a schematic view of a system comprising a module for pumping according to the present invention;

- figure 2 is a circuit view of a system comprising a module for pumping according to the present invention;

- figure 3 is an alternative circuit to the circuit of figure 2.

Detailed description of preferred embodiments of the invention

In the accompanying figures, reference numeral 1 denotes a module for pumping concrete.

The module 1 comprises two pumping groups 2 for pumping the concrete. The module 1 further comprises a fluid-dynamic activating pathway 3 for activating the pumping groups 2 in which an operating fluid transits. The operating fluid is of the non-compressible type, preferably oil.

The pumping groups 2 of the concrete comprise a first and a second pumping piston 21 , 22 which come into contact with the operating fluid. The module 1 further comprises a first slide valve 25 which alternatively sends the operating fluid to the first and to the second pumping piston 21 , 22. Suitably, the first and the second pumping piston 21 , 22 do not come into direct contact with the concrete.

The pumping groups 2 further comprise a first and a second pumping member 23, 24 of the concrete activated respectively by the first and by the second pumping piston 21 , 22 and which come into contact with the concrete (in figure 3 these are explicitly illustrated while in figure 2 they are schematically represented by two rectangles). When the first pumping member 23 dispenses the concrete, the second pumping member 24 sucks concrete from a tank (typically a hopper); thereafter the second pumping member 24 will dispense the previously-sucked concrete and the first pumping member 23 will suck the concrete. The first and the second pumping member 23, 24 alternate a suction travel and a dispensing travel of the concrete.

Suitably, the module 1 is an additional module connectable to a machine provided with fluid-dynamic pump 102. The fluid-dynamic pump 102 is preferably, but not necessarily of the "automotive closed circuit" type (it might also be open-circuit as long as it is sufficiently powerful). The pump is a variable displacement pump. A variation of the displacement is obtained as a function of the rotating regime of an internal combustion engine. The power absorbed is limited on the basis of the displacement/pressure ratio. The fluid-dynamic pump 102 is suitably flanked by a boost pump 101 .

The module 1 comprises a collecting zone 41 of the operating fluid from said machine and a return zone 42 of the operating fluid to said machine Suitably, the module 1 comprises limiting means 6 of a pressure on the pumping groups 2. The limiting means 6 comprise at least a by-pass valve 60 of at least one of the pumping groups 2, said by-pass valve 60 opening on detecting a pressure that is greater than a predetermined threshold. This enables preventing dangerous increases of pressure which might compromise the correct functioning of the module 1 . This is particularly important as the fluid-dynamic pump of the machine that activates the module 1 might have pressure limits that are incompatible with those of the module 1 .

Suitably, the module 1 comprises two by-pass valves 60 which open on detecting a pressure greater than a predetermined threshold and reciprocally connect a supply/discharge conduit of the first pumping piston 21 with a supply/discharge conduit of the second pumping piston 22 (as a function of the position of the first slide valve 25 the same conduit will be the suction conduit or the discharge conduit). The two by-pass valves 60 are crossed over. In other words, they are one-way valves and enable passage of the fluid in two directions that are reciprocally opposite. Preferably, the predefined threshold determining the opening of the bypass valves 60 is adjustable. The valves limit the pressure in the high- pressure branch and discharge the operating fluid in excess into the low- pressure branch. The valves 60 are appropriately incorporated in a single steel body. Such by-pass valves 60 are of the "cartridge" type. This has a threefold advantage: modest dimensions, protection from impacts (thanks to the fact that they are incorporated in the body), large passage hole (with the possibility of discharging all the operating fluid flow rate into the low- pressure branch without overheating the operating fluid; this is useful for example in a case of obstruction of the concrete line with a consequent blocking of the pumping groups 2).

The module 1 further comprises a flow switcher 4 located downstream of the collecting zone 41 . In a first configuration the flow switcher 4 directs the operating fluid towards at least one of the pumping groups 2 and in a second configuration by-passes the pumping groups 2, placing the collecting zone 41 in communication with the return zone 42.

The flow switcher 4 is preferably elastically retro-activated by elastic means 40 which push the flow switcher 4 into said second configuration. The flow switcher 4 is fluid-dynamically piloted (the operating fluid for the piloting thereof is suitably collected from the boost pump mentioned in the foregoing). The flow switcher 4 in the preferred solution is a 6-way piloted flow switcher 4

As illustrated by way of example in the accompanying figures, the module 1 comprises a pumping structure 20 comprising the concrete pumping groups 2. The module 1 further comprises an interfacing structure 400 with a machine external of the module; the interfacing structure 400 comprises the flow switcher 4 and advantageously also the collecting zone 41 and the return zone 42 of the operating fluid. In the second configuration of the flow switcher 4, the collecting zone 41 and the return zone 42 are in fluid communication without involving conduits external of the interfacing structure 400 (which defines a common casing).

Suitably, the module 1 comprises a casing containing the collecting zone 41 , the return zone 42 of the operating fluid, the flow switcher 4, while it does not contain a pumping member of the operating fluid.

The casing suitably comprises two fluid-dynamic connecting mouths with the external machine (for enabling the linking of the zone 41 and the zone 42 with the fluid-dynamic pump). Suitably, this casing is mechanically removably connectable to the external machine.

The pumping structure 20 is separate and can be located in a remote position with respect to the interfacing structure 400.

Furthermore, the module 1 comprises conduits 5 of the operating fluid that connect the pumping structure 20 with the interfacing structure 400 for enabling fluid-dynamic connection of the flow switcher 4 and the pumping groups 2. The conduits 5 are advantageously of a flexible type. The conduits 5 are removably connectable to the pumping structure 20 and to the interfacing structure 400.

The module 1 further comprises quick couplings 50 of said conduits 5 with the pumping structure 20 and/or the interfacing structure 400. The quick couplings 50 keep the pipes of the pumping structure 20 full due to the retaining function. This is essential because usually the machines to which the module is applied are not able to withstand large volume increases in which the operating fluid can circulate (or leaks of the operating fluid). The first pumping piston 21 advantageously separates a first and a second chamber 26, 27 destined to contain the operating fluid.

The second pumping piston 22 separates a third and a fourth chamber 28, 29 destined to contain the operating fluid. The module 1 comprises a first conduit 201 which places the first slide valve 25 in communication with the first chamber 26 of the first pumping piston 21 . The module 1 further comprises a first conduit 202 which places the third chamber 28 in communication with the first slide valve 25. The module 1 further comprises a third conduit 203 which places the second chamber 27 in communication with the fourth chamber 29. In a first position of the first slide valve 25, the operating fluid supplies the first chamber 26, causing a displacement of the first pumping piston 21 to which an expansion of the first chamber 26 and a reduction of the second chamber 27 are associated. The fluid exiting from the second chamber 27 via the third conduit 203 flows into the fourth chamber 29, causing an expansion thereof and a reduction of the third chamber 28. The operating fluid exiting from the third chamber 28 is directed towards the flow switcher 4 (this will suitably newly be collected by the fluid-dynamic pump of the machine and re-cycled).

In a second position of the first slide valve 25, the operating fluid supplies the third chamber 28, causing a displacement of the second pumping piston 22 which determines an exit of the operating fluid from the fourth chamber 29 and the inlet thereof into the second chamber 27 through the third conduit 203. This determines an expansion of the second chamber 27 with respect to the first chamber 26 from which the operating fluid exits and is directed towards the flow switcher 4 (then to be sent on into the machine and recycled via the pump).

The module 1 suitably comprises a delivery conduit 8 (visible in figures 1 and 3) of the concrete which in a first position is located downstream of the first pumping member 23 and which in a second position is located downstream of the second pumping member 24. This conduit 8 enables pumping the concrete to a dispensing line of the concrete. In the technical field the conduit 8 is known as an "S-valve" or "concrete shuttle valve". The module 1 further comprises displacing means 80 of the delivery conduit between the first and the second position.

The displacing means 80 comprise two fluid-dynamic pistons 81 , 82 which respectively displace the delivery conduit 8 from the first to the second position and from the second position to the first position. The displacing means 80 comprise a second slide valve 83 which directs the operating fluid alternatively to one or to the other of said two fluid-dynamic pistons

81 , 82.

Synchronising means 9 are also present, which activate said first and second slide valve 25, 83 as a function of a position assumed by the pumping groups 2 and in particular by the fluid-dynamic pistons 81 , 82. The synchronising means 9 comprise pilots. In figure 2 these are of the fluid-dynamic type and are indicated with broken lines. In figure 3 these are of the electrical type. For example when the first and the second pumping piston 21 , 22 reach a first end stop, the pilots modify the position of the second slide valve 83 and activate the two fluid-dynamic pistons 81 , 82 so as to induce a displacement of the delivery conduit 8 from the first to the second position. When the fluid-dynamic pistons 81 , 82 reach a first end stop, the pilots activate the first slide valve 25 for inverting the travel of the first and the second pumping piston 21 , 22 In turn, when the first and the second pumping piston 21 , 22 reach a second end stop, the pilots act on the second slide valve 83 to cause a displacement of the fluid-dynamic pistons 81 , 82 for returning the delivery conduit 8 into the first position. When the fluid-dynamic pistons 81 , 82 reach a second end stop, the pilots activate to displace the first slide valve 25 to determine a fresh displacement of the first and the second pumping piston 21 , 22. These movements are then iteratively repeated.

Suitably, the first and the second slide valve 25, 83 and possibly the bypass valve 60 are integrated in a valve block.

The first slide valve 25 comprises an H-shaped spool. This facilitates maintaining the minimum pressure required by the low branch during the switching of the first slide valve 25 between the first and the second position (defined previously). In particular the first slide valve 25 has a geometry such that during the switching thereof between the first and the second position the first and the second conduit 201 and 202 are placed in mutual communication (the switching however lasts only a fraction of a second).

Likewise the second slide valve 83 also comprises an H-shaped spool. In this case, during the switching of the second slide valve 83 the following are placed in communication:

-a portion connecting the second slide valve 83 and one of the two fluid- dynamic pistons (denoted by reference numeral 81 in figure 2 or 3);

-a portion connecting the second slide valve 83 and the other of the two fluid-dynamic pistons (denoted by reference numeral 82 in figure 2 or 3) The module 1 suitably comprises a fluid-dynamic motor for activating a mixer located in a hopper. The module 1 preferably further comprises an oil-dynamic cylinder activatable by using a manual pump for activating an opening hatch of a hopper.

With reference to the appended figures the module 1 comprises a control valve 43 of the flow switcher 4. The control valve 43 is electrically activated (preferably at 12 V). The valve 43 is suitably activatable by means of a two-handed activation on a user interface. Consequently this enables minimising the risk of involuntary activations. When changing configuration the control valve 43 enables modifying the pathway of the operating fluid so as to pilot the flow switcher 4. The module 1 further comprises an accumulator 7 of the operating fluid.

The accumulator 7 comprises dispensing means 70 of the operating fluid in a portion comprised between the flow switcher 4 and the first and/or the second slide valve 25, 83 if the pressure value falls below a calibration value of the accumulator 7. This can happen for example in a case in which the first and/or the second slide valve 25, 83 change position. A check valve 71 (for example preloaded to 0.5 bar) is suitably positioned between the accumulator 7 and the portion which connects the flow switcher 4 and the first slide valve 25. Likewise an additional check valve 72 is positioned between the accumulator 7 and the portion which connects the flow switcher 4 and the second slide valve 83. When the pressure along the portion comprised between the flow switcher 4 and the first slide valve 25 falls to below a predefined threshold, the check valve 71 opens, enabling an exit of the operating fluid present in the accumulator

70. When the pressure along the portion comprised between the flow switcher 4 and the second slide valve 83 falls to below a predefined threshold, the additional check valve 72 opens, enabling an exit of the operating fluid present in the accumulator 70.

A further object of the present invention is a system comprising a vehicle

10. The vehicle 10 comprises a fluid-dynamic pump 102. The fluid- dynamic pump 102 has the characteristics already described in the foregoing. As already illustrated, the pump 102 also has a boost pump 101 . The system further comprises movement means 103 of at least a part of the vehicle 10 which are activated by the pump 102. The means 103 comprise particularly displacement means of the vehicle on the ground surface, for example wheels, tracked means, etc.

Furthermore, the vehicle 10 comprises a module 1 for the concrete pumping having one or more of the characteristics indicated in the foregoing. In particular, in the second configuration, the flow switcher 4 directs the operating fluid towards the movement means 103 of the vehicle 10. Instead, in the first configuration of the flow switcher 4 the functioning of the pumping groups 2 of the concrete is possible. The operation of the pumping groups 2 is alternative to the operation of the movement means 103. The traction means further comprise a motor (typically an internal combustion engine) for activating the pump 102. In the first configuration of the flow switcher 4 the flow rate variation of the concrete takes place by modifying the regime of the internal combustion engine. In this regard the vehicle 1 comprises a potentiometer which advantageously acts on an electric servo cylinder located in proximity of a vehicle fuel pump. Additionally, the engine speed can be controlled by a pedal of the vehicle accelerator 10.

The invention as it is conceived enables achieving multiple advantages. Firstly it enables minimising costs by providing a module for pumping concrete which can be supported by existing machines (for example known-type telescopic lifting machines such as telehandlers) without any need to modify the original adjustments, calibrations and safety guards. In this way, the purchasing costs of the concrete pump are reduced, as already-existing vehicles can be used, all of which therefore make the invention even more versatile. A further important advantage is related to a simpler logistical management as well as a reduction in maintenance costs. The invention as it is conceived is susceptible to numerous modifications and variations, all falling within the scope of the inventive concept characterising it. Further, all the details can be replaced with other technically-equivalent elements. In practice, all the materials used, as well as the dimensions, can be any according to requirements.