TWO-CYLINDER THICK PUMP

Description

[0001] The invention relates to a two-cylinder high-viscosity pump, in particular for a truck-mounted concrete pump, comprising at least one first hydraulic pump, two hydraulic drive cylinders driven in opposite directions by the at least one first hydraulic pump, which are provided for driving two delivery pistons, each of which runs in one of two delivery cylinders of the two-cylinder high-viscosity pump, wherein a high-viscosity delivery rate is adjustable by adjusting the delivery capacity of the at least one first hydraulic pump, comprising a second hydraulic pump and a switching hydraulic accumulator, wherein the second hydraulic pump is provided for charging the switching hydraulic accumulator, at least one switching hydraulic cylinder supplied from the switching hydraulic accumulator and a high-viscosity switching valve driven by the at least one switching hydraulic cylinder, which is provided for alternately connecting the two delivery cylinders to a high-viscosity delivery line.Furthermore, the invention relates to a method for operating such a two-cylinder viscous fuel pump.

[0002] A two-cylinder thick fuel pump mentioned at the beginning is known, for example, from DE 2 010 112 A.

[0003] Today, a truck-mounted concrete pump typically uses a hydraulic pump train consisting of several hydraulic pumps arranged in series, which drives the components of the concrete pump assembly, for example a concrete pump designed as a two-cylinder thick-slurry pump, the placing boom, the support and other components necessary for operation, on the construction site powered by a diesel engine of the truck chassis.

[0004] To reduce the emission of unwanted exhaust gases and climate-damaging carbon dioxide, it is desirable to also electrically power truck-mounted concrete pumps on construction sites.

[0005] There are now concepts for driving the hydraulic pump train of a truck-mounted concrete pump with an electric motor. However, with an electrically or hybrid (diesel- and electric) driven truck-mounted concrete pump, the problem is that the electrical power supplied by an on-board battery and / or a construction site power supply is generally insufficient to drive the truck-mounted concrete pump adequately or for a sufficiently long period of time for the concrete pumping / conveying process. A modern truck diesel engine typically has an output of approximately 300–500 kW, so there is always sufficient power reserve available to drive the truck-mounted concrete pump's components, which require a maximum drive power of 200–250 kW.

[0006] For design reasons, a truck-mounted concrete pump uses several hydraulic pumps arranged in series, a so-called hydraulic pump train, driven by the power take-off of the diesel engine. The diesel engine's speed should be kept as low as possible, but ultimately depends on the power requirements of the truck-mounted concrete pump assembly, especially the concrete pump itself, as this has the highest power demand during concrete delivery.

[0007] The simultaneous operation of all hydraulic pumps inevitably means that all hydraulic pumps, which drive not only the concrete pump but also the placing boom, the outriggers, the agitator, the concrete switching valve, and possibly other components of the system, are driven at an identical, generally constant, speed. This alone results in power losses because the available power of the hydraulic pumps is not drawn at a constant rate, even though some hydraulic pumps can be switched to idle operation by adjusting their delivery rate.

[0008] Due to the power losses described above when driving a hydraulic pump train, it is necessary to find ways to reduce these losses in order to use the available electrical drive power as effectively as possible.

[0009] One of the hydraulic pumps in the hydraulic pump train, the so-called accumulator charging pump, charges a hydraulic accumulator for switching the changeover valve of the two-cylinder thick fuel pump.

[0010] The changeover valve must be switched as quickly as possible (approx. 250-500 ms) using one or two hydraulic cylinders. This short switching time is necessary because, during the valve's operation, the delivery cylinders of the two-cylinder high-viscosity pump are short-circuited, resulting in a drop in delivery pressure, which should therefore be minimized. The accumulator charging pump is dimensioned so that, assuming a diesel engine speed of, for example, 1200 rpm, it fills the hydraulic accumulator quickly enough between switching operations to ensure that even at the two-cylinder high-viscosity pump's maximum delivery rate, the accumulator fills sufficiently for the switchover. At maximum delivery rate, the changeover valve switches approximately every two to two and a half seconds, meaning the hydraulic accumulator must be refilled in about two seconds.The accumulator charging pump features a simple control system: when the pressure of the hydraulic accumulator reaches a predetermined value, the pump switches to idle mode by reducing its flow rate. Alternatively, the hydraulic oil pumped by the accumulator is diverted into the hydraulic oil tank. During the actual charging process, the charging pump consumes a significant amount of energy. If a lower flow rate is required, for example, when the diverter valve switches only every five seconds, the charging pump is driven for approximately three seconds between switching operations without further charging the accumulator. This requires a corresponding amount of drive power even when idle.

[0011] It is therefore an object of the invention to provide a two-cylinder viscous material pump with which the described disadvantages are at least partially eliminated, or with which the available drive energy is used as effectively as possible for the conveying of concrete or viscous material.

[0012] This problem is solved by a two-cylinder thick-seal pump with the features of claim 1 and a method for operating a two-cylinder thick-seal pump according to claim 13.

[0013] Because the delivery rate of the second hydraulic pump, which charges the hydraulic switching accumulator, can be adjusted depending on the set high-viscosity flow rate, the drive power of the second hydraulic pump can be reduced when a lower flow rate is required. This is particularly advantageous when the two-cylinder high-viscosity pump is driven by an electric motor whose drive power is lower than that of an internal combustion engine, which regularly results in a lower high-viscosity flow rate. Furthermore, peak power consumption of the second hydraulic pump is avoided, so that the available drive power can be better utilized for the actual high-viscosity conveying, i.e., for driving the conveying cylinders.

[0014] Advantageous embodiments and further developments of the invention are set forth in the dependent claims. It should be noted that the features listed individually in the claims can also be combined with one another in any technologically meaningful way, thus revealing further embodiments of the invention.

[0015] Preferably, the delivery rate of the second hydraulic pump is adjustable so that the switching hydraulic accumulator is completely filled immediately before a switching operation of the high-viscosity switching valve. This measure minimizes the maximum power consumption of the hydraulic pump that charges the switching hydraulic accumulator, depending on the required high-viscosity delivery rate, ensuring that the maximum possible drive power is always available for driving the delivery cylinders.

[0016] Advantageously, a control unit is provided to adjust the delivery rate of at least one first hydraulic pump and the delivery rate of the second hydraulic pump according to the set viscous material delivery rate. The control unit can optimally coordinate the delivery rates of the at least one first and second hydraulic pumps depending on the set viscous material delivery rate, and, if necessary, also take into account the available drive power for the hydraulic pumps, so that no short-term power consumption peaks occur that exceed the available drive power.

[0017] According to an advantageous embodiment, the delivery rate of the second hydraulic pump can be adjusted by changing the geometric delivery volume of the second hydraulic pump. This is particularly advantageous if the second hydraulic pump is, for example, designed as an axial piston variable displacement pump, whose geometric delivery volume can be very easily adjusted by changing the swivel angle of the swashplate, thus allowing the delivery rate of the second hydraulic pump to be very well adapted to the required flow rate of the viscous material.

[0018] In an alternative configuration, the delivery rate of the second hydraulic pump can be adjusted by changing the drive speed of the second hydraulic pump. This variant is particularly advantageous if the second hydraulic pump is a so-called constant flow pump, e.g., an inexpensive gear pump or a simple axial piston pump without adjustable flow rate. With this type of hydraulic pump, adjusting the drive speed allows for simple and cost-effective adjustment of the delivery rate.

[0019] In a further embodiment of the invention, a common drive motor drives the at least one first hydraulic pump and the second hydraulic pump, and the delivery rate of the at least one first hydraulic pump and the delivery rate of the second hydraulic pump can be adjusted by adjusting the speed of the drive motor. Particularly if the drive motor is an electric motor whose speed can be easily adjusted to the required flow rate of the viscous material without having to maintain a particularly efficient speed range as with an internal combustion engine, the delivery rate of the second hydraulic pump can be very easily adjusted to the required flow rate of the viscous material, with the correct ratio of the delivery rates of the two hydraulic pumps always being automatically established due to the common drive of both hydraulic pumps.

[0020] Alternatively, the first and second hydraulic pumps can advantageously be driven by separate drive motors. This makes it possible to easily adjust the delivery rate of the first and second hydraulic pumps to the respective delivery rate of the two-cylinder high-viscosity pump.

[0021] In a particularly advantageous embodiment, the second hydraulic pump and the drive motor that drives the second hydraulic pump are arranged close to the high-viscosity switching valve, and each of the at least one first hydraulic pump and the second hydraulic pump has its own hydraulic oil tank. This close arrangement of the second hydraulic pump and its drive motor at the high-viscosity switching valve, in conjunction with separate hydraulic tanks, reduces hydraulic power losses and, in particular, minimizes the length of the hydraulic suction hoses, which are difficult to accommodate and complex to install, leading to a centrally located hydraulic tank.

[0022] Preferably, the drive motor powering the second hydraulic pump drives another hydraulic pump designed to supply a hydraulic oil cooling and / or filter circuit. This additional hydraulic pump ensures a constant flow of hydraulic oil through the cooling and / or filter circuit, which is advantageous, especially since a hydraulic oil filter is sensitive to pulsating oil flow, such as that which naturally occurs in the drive circuit of the hydraulic switching accumulator.

[0023] In an advantageous embodiment, the geometric delivery volume of the second hydraulic pump is variable, and it has a leakage oil connection through which leakage oil can be fed into the hydraulic oil cooling and / or filter circuit. Particularly when the second hydraulic pump has its own hydraulic tank, this measure allows the typically very hot leakage oil to be used very easily for cooling the entire tank volume.

[0024] Preferably, an agitator in a feed hopper mixes the thick substance poured into the feed hopper, the speed of the agitator being adjustable depending on the set delivery rate of thick substance.

[0025] Furthermore, the present invention relates to a method for operating a two-cylinder high-viscosity pump, wherein the two-cylinder high-viscosity pump has at least one switching hydraulic cylinder supplied from a switching hydraulic accumulator for driving a high-viscosity switching valve, which is provided for the alternating connection of two delivery cylinders of the two-cylinder high-viscosity pump to a high-viscosity delivery line. According to the invention, in particular, the charging rate at which the switching hydraulic accumulator is charged with hydraulic oil between the switching operations of the high-viscosity switching valve is adjustable depending on a predetermined high-viscosity delivery rate.The adjustable charging speed allows, in particular, the maximum power consumption for charging the switching hydraulic accumulator to be reduced when the viscous material delivery rate is reduced, by better distributing the power consumption over time, thereby freeing up drive power for driving the delivery cylinders.

[0026] Further features, details, and advantages of the invention will become apparent from the following description and the drawings, which show exemplary embodiments of the invention. Corresponding objects or elements are provided with the same reference numerals in all figures. The figures show: Figure 1: View of a two-cylinder piston pump according to the invention. Figure 2: Drive diagram of a truck-mounted concrete pump according to the prior art. Figure 3: Drive diagram according to the invention in a first embodiment. Figure 4: Drive diagram according to the invention in a second embodiment. Figure 5: Drive diagram according to the invention in a third embodiment. Figure 6: Drive diagram according to the invention in a fourth embodiment. Figure 7: Drive diagram according to the invention in a fifth embodiment. Figure 8: Detailed view of a hydraulic drive unit according to the invention in a first variant. Figure 9: Detailed view of a hydraulic drive unit according to the invention in a second variant. Figure 10: Detailed view of a hydraulic drive unit according to the invention in a third variant.

[0027] In the Figure 1Figure 1 shows a truck-mounted concrete pump 100 with a two-cylinder high-viscosity pump 111 according to the invention. The truck-mounted concrete pump 100 has a truck 102 driven by an internal combustion engine 103, with a chassis 104 on whose frame 105 a concrete pump superstructure 101 is arranged. The concrete pump superstructure 101 essentially comprises a concrete pump base 127 with a support 108 with hydraulically driven support cylinders 109 and foldable or extendable support beams 121, as well as a hydraulically driven two-cylinder high-viscosity pump 111 for conveying or pumping concrete. The concrete pump base 127 carries a feed hopper 116 for liquid fresh concrete at its rear end, in which an agitator 113 driven by a hydraulic motor mixes the fresh concrete, which is, for example, filled from a truck mixer.In the lower part of the feed hopper 116, a hydraulically driven thick-material switching valve 112, for example in the form of a pipe diverter (see above), is located in an upwardly open housing 144. Fig. 3 ) arranged. Instead of a pipe diverter 112 (e.g., an S-pipe or a so-called rock gate valve), the high-viscosity switching valve 112 could, for example, also be constructed from one or more rotary or flat gate valves. The concrete pump substructure 127 also includes the hydraulic pumps 115, 119, 117, and 118 (see Fig. 3) for driving the units 111, 107, 108, 113 of the concrete pump superstructure 101. The concrete pump base 127 is connected via a turntable 106 to a placing boom 107, the individual boom segments 126 of which are connected to each other via articulated joints 125. The placing boom 107, or each of the articulated joints 125, is actuated by means of hydraulic cylinders 110 or other suitable articulated drives 110. The hydraulic pressure for driving the hydraulic cylinders 110 of the placing boom 107 and the support 108 is provided by the hydraulic pump 119.

[0028] The Figure 2Figure 1 shows a drive scheme of a hybrid, i.e., diesel / electrically driven, truck-mounted concrete pump 100 with a two-cylinder high-viscosity pump 111, according to the prior art. An internal combustion engine 103 drives the chassis 104 for travel via a transmission 134. The outriggers 108, the placing boom 107, the agitator 113, and the two-cylinder high-viscosity pump 111 are hydraulically driven by hydraulic pumps 115, 119, 117, and 118, which are grouped into a hydraulic pump train 128. An electric motor 122 drives the hydraulic pump train 128. The electric motor 122 obtains its electrical energy from an electrical supply unit 166. The electrical supply unit 166 can, for example, obtain electrical energy for driving the electric motor 122 from a construction site power supply 133, an external accumulator 120 on a transporter 136 or a trailer, from an on-board accumulator 120 or from a generator 132.The electric motor 122 typically rotates at a constant speed so that all units 107, 108, 111, 113 of the concrete pump assembly 101 can be supplied with pressurized oil and driven at all times via the hydraulic pumps 115, 119, 117, 118. Two hydraulic drive cylinders 147, driven in opposite directions by the two first hydraulic pumps 115, are provided for driving two delivery pistons 149, each of which runs in one of two delivery cylinders 148 of the two-cylinder high-viscosity pump 111, the high-viscosity delivery rate being adjustable by adjusting the delivery capacity of at least one first hydraulic pump 115. The delivery capacity of the hydraulic drive cylinders 147, and thus the delivery rate of thick solids, is usually changed by adjusting the swivel angle of the hydraulic pumps 115, which are designed as axial piston pumps, and the switching of the delivery cylinders 148 is carried out via the switching device 163.The hydraulic pump 117, which can also be called a storage charging pump, always charges the switching hydraulic accumulator 146 for switching the thick-substantiation switching valve 112 so quickly that even with the thick-substantiation delivery rate set to the maximum, the switching hydraulic accumulator 146 is filled at the switching time of the thick-substantiation switching valve 112.

[0029] The Figure 3 Figure 1 shows a drive diagram of a two-cylinder high-viscosity pump 111 according to the invention in a first embodiment. The design of the two-cylinder high-viscosity pump 111 with respect to the arrangement of the hydraulic drive cylinders 147, the delivery pistons 149, the delivery cylinders 148 and the high-viscosity switching valve 112 corresponds to the design shown in Figure 1. Figure 2The two-cylinder high-viscosity pump 111 has at least one, in this case two, first hydraulic pumps 115, two hydraulic drive cylinders 147 driven in opposite directions by the two first hydraulic pumps 115, which are provided for driving two delivery pistons 149, each of which runs in one of two delivery cylinders 148 of the two-cylinder high-viscosity pump 111, wherein the high-viscosity delivery rate is adjustable by adjusting the delivery rate of the two first hydraulic pumps 115. The two-cylinder high-viscosity pump 111 also has a second hydraulic pump 117 and a switching hydraulic accumulator 146, wherein the second hydraulic pump 117 is provided for charging the switching hydraulic accumulator 146.Furthermore, the two-cylinder high-viscosity pump 111 has a switching hydraulic cylinder 145 supplied from the switching hydraulic accumulator 146 and a high-viscosity switching valve 112 driven by at least one switching hydraulic cylinder 145, which is provided for the alternating connection of the two delivery cylinders 148 to a high-viscosity delivery line 164. The delivery rate of the second hydraulic pump 117 is adjustable depending on the set high-viscosity delivery rate. That is, the charging rate at which the switching hydraulic accumulator 146 is charged with hydraulic oil between the switching operations of the high-viscosity switching valve 112 is adjusted depending on a predetermined high-viscosity delivery rate.

[0030] The viscous material delivery rate or the stroke rate of the hydraulic drive cylinders 147, which ultimately determines the viscous material delivery rate, is specified, for example, by an operator at an input unit 143, for example in the form of a remote control 143, and transmitted to the control unit 142. The control unit 142 adjusts the swivel angles of the first hydraulic pumps 115, which are designed, for example, as axial piston pumps with swivel discs, via an output unit and the control line 141, so that the desired viscous material delivery rate or stroke rate of the two-cylinder viscous material pump 111 is achieved.Furthermore, the delivery rate of the second hydraulic pump 117, which charges the switching hydraulic accumulator 146, is also adjusted depending on the set high-viscosity delivery rate. This is achieved by adjusting the delivery rate of the second hydraulic pump 117, for example, by adjusting the geometric delivery volume, such as by changing the swivel angle of the hydraulic pump 117, if it is designed as an axial piston pump 117 with a swivel disc. The control unit 142 and the second hydraulic pump 117 are connected to each other via the control line 135. This means that the control unit 142 is configured to adjust the delivery rate of at least one first hydraulic pump 115 and the delivery rate of the second hydraulic pump 117 according to the set high-viscosity delivery rate.

[0031] In the exemplary embodiment according to Figure 3The hydraulic pumps 115, 119, 117, and 118 are combined into a hydraulic pump train 128 and are jointly driven by an electric motor M1. The hydraulic pump train 128 could also be driven by an internal combustion engine 103, for example, the drive system of the truck 102.

[0032] Hydraulic oil from the second hydraulic pump 117 is pumped via a check valve 151 into the changeover hydraulic accumulator 146, thus charging it. At the moment when the delivery pistons 149 reach their respective end positions in the delivery cylinders 148, the directional control valve 150, which controls the changeover hydraulic cylinder 145, is switched. This causes the high-viscosity changeover valve 112 in its housing 144 to switch abruptly, connecting the other delivery cylinder 148 to the high-viscosity delivery line 164 for conveying high-viscosity material. Simultaneously, the other delivery cylinder 148 opens to the interior of the housing 144, allowing it to draw high-viscosity material or concrete from the housing 144.The delivery pistons 149 then move in the opposite direction in the delivery cylinders 148, while the switching hydraulic accumulator 146 is charged so that it is completely filled immediately before the next switching operation of the high-viscosity switching valve 112. This means that the switching hydraulic accumulator 146 is filled to such an extent that the volume and pressure are sufficient to switch the switching hydraulic cylinder(s) 145 and thus the high-viscosity switching valve 112. It should be noted that even during the switching operation, the second hydraulic pump 117 continues to run, providing hydraulic pressure for switching the high-viscosity switching valve 112, in addition to the hydraulic pressure of the switching hydraulic accumulator 145. A pressure relief valve 152 ensures that any excess pressure in the switching hydraulic accumulator 146 is released into the hydraulic oil tank 153.This case could occur, for example, with a jammed high-viscosity switching valve 112. In this embodiment, all hydraulic pumps 115, 117, 118, 119 draw the hydraulic oil from the common hydraulic oil tank 153.

[0033] In the second embodiment according to Figure 4The hydraulic pump train 128 of a truck-mounted concrete pump 100 is divided into two sub-trains 128a and 128b, each driven separately by electric motors M1 and M2. Electric motor M2, connected via inverter 160a to the DC intermediate circuit 130 (which, for example, has a constant DC voltage of 600 volts), drives the placing boom 107 or the support 108 via hydraulic pump 119, and the agitator 113 via hydraulic pump 118. Electric motor M2 is operated at a constant speed, for example, as long as the hydraulic consumers 107, 108, and 113 are in operation. However, the speed of electric motor M2 could also be controlled via inverter 160a. An optional accumulator 120 and an inverter 158 are also connected to the DC intermediate circuit 130.Instead of or in addition to the accumulator 120, a fuel cell for generating electrical energy, a supercapacitor, or similar electrical devices could also be used. The inverter 158, for example, is an on-board charger (OBC) that receives the alternating current from the construction site power supply 133 via one or more mains connection plugs 159 and converts it into direct current for the DC link 130. The accumulator 120 can be charged via the DC link 130 and can also provide direct current to drive the electric motors M1 and M2, enabling them to operate for a limited time when the construction site power supply 133 is unavailable. Furthermore, when the construction site power supply 133 is present and connected, the accumulator 120 can absorb power peaks that could overload the construction site power supply 133.

[0034] The first two hydraulic pumps 115 for driving the hydraulic drive cylinders 147 of the two-cylinder high-viscosity pump 111, and the second hydraulic pump 117 for charging the switching hydraulic accumulator 146, together form the hydraulic pump train 128a and are driven by the common drive motor M1, in this case an electric motor M1. The delivery rate of the first two hydraulic pumps 115 for the hydraulic drive cylinders 147 and the delivery rate of the second hydraulic pump 117 for charging the switching hydraulic accumulator 146 can be adjusted by adjusting the speed of the drive motor M1. The speed of the electric motor M1 is controlled, for example, by an inverter 160b. The inverter 160b draws the current for the drive motor M1 from the DC intermediate circuit 130.The inverter 160b is also connected to the control unit 142 via the control line 135, which, based on the high-viscosity conveying rate set at the input unit 143, adjusts the speed of the drive motor M1 via the inverter 160b. The delivery rate of the second hydraulic pump 117 is also controlled in this embodiment. Figure 4 so that it is adjusted depending on the set viscous material delivery rate, whereby the delivery rate of the at least one first hydraulic pump 115 and the delivery rate of the second hydraulic pump 117 can be adjusted by adjusting the speed of the drive motor M1.

[0035] The exemplary embodiment according to Figure 5Figure 1 shows a drive scheme in a third embodiment with a hybrid-driven truck-mounted concrete pump 100, that is, the concrete pump assembly 101 of the truck-mounted concrete pump 100 can be driven either by several electric motors M1 / G, M2, M3 or by the combustion engine 103 of the truck 102 or by a mixture.

[0036] The electric motor M1 / G, which in this embodiment drives, for example, the two first hydraulic pumps 115 for driving the hydraulic drive cylinders 147 and the hydraulic pump 119 for driving the distributor mast 107 and the support 108, also functions as a power generator in this embodiment. That is, the shaft of the motor / generator M1 / G can be mechanically connected to the power take-off 123, or to the auxiliary drive 123, via the decoupling device 165, for example, a switchable clutch or a freewheel.The auxiliary drive 124 of the internal combustion engine 103 is coupled so that, via the auxiliary drive 123 of the internal combustion engine 103, the hydraulic pumps 115 and 119 are driven, and the electric motor M1 / G generates electrical current which is supplied via the inverter 160a to the DC intermediate circuit 130, for example, to charge the accumulator 120 and / or to drive the electric motors M2 and M3 via their inverters 160b and 160c. Thus, in this embodiment, the concrete pump assembly 101 can be driven by the internal combustion engine 103 even if the accumulator 120 has insufficient capacity and / or there is no on-site power supply 133. In this embodiment, the electric motor M3 directly drives the agitator 113. This has the advantage that hydraulic losses through a hydraulic circuit with hydraulic pump and hydraulic motor are avoided.Furthermore, the independent operation of the agitator 113 via the electric motor M3 allows the speed of the agitator 113 to be adjusted to the delivery rate of the two-cylinder slurry pump 111, thereby reducing the drive energy for the agitator 113 when the delivery rate is reduced. The principle of direct drive by an electric motor can also be applied to other components of the concrete pump assembly 101 that do not necessarily require hydraulic drive, such as a high-pressure cleaner.

[0037] For the hydraulic control of the switching hydraulic cylinder 145, in the exemplary embodiment according to Figure 5A separate hydraulic drive unit 161 is provided, comprising, for example, the electric motor M2, the second hydraulic pump 117, a hydraulic oil cooling and / or filter circuit 137 with a hydraulic oil filter 155 and a hydraulic oil cooler 156, and a hydraulic oil tank 154. These elements thus form a self-contained hydraulic drive unit 161, which can be positioned at a suitable location, i.e., as close as possible to the hydraulic consumer, in this case the high-viscosity switching valve 112 with the switching hydraulic cylinder 145. In this embodiment, the electric motor M2 of the hydraulic drive unit 161 drives, in addition to the second hydraulic pump 117, which charges the switching hydraulic accumulator 146, a hydraulic pump 157, which continuously delivers hydraulic oil from the hydraulic oil tank 154 to the hydraulic oil filter 155 and hydraulic oil cooler 156 in order to filter and cool the hydraulic oil of the hydraulic drive unit 161.The second hydraulic pump 117 and the hydraulic pump 157 can, for example, be combined as a tandem pump. In this embodiment, the delivery rate of the second hydraulic pump 117 is adjusted by adjusting the geometric delivery volume of the second hydraulic pump 117, as already described in connection with the... Figure 3described via control line 135. In order to determine the quantity of viscous material conveyed by the hydraulic drive cylinders 147 more precisely and to optimally adjust the delivery rate of the second hydraulic pump 117 based on this, the hydraulic oil flow rate to the hydraulic drive cylinders 147 is measured at the outlet of the first hydraulic pump 115 and signaled to the control unit 142 via the flow measurement signal line 131. Based on this, the control unit 142 sets the optimal delivery rate for the second hydraulic pump 117 so that the switching hydraulic accumulator 146 is completely filled immediately before a switching operation of the viscous material switching valve 112. Because in the embodiment according to Figure 5Since the main hydraulic pumps are designed as variable displacement pumps, the electric motors M1 / G, M2, and M3 can operate at constant speeds. However, the speeds of motors M1 / G, M2, and M3 could also be adjusted to the respective flow rate / power requirements of the concrete pump assembly 101 or the two-cylinder slurry pump 111.

[0038] The one in Figure 6 The fourth embodiment shown differs from the embodiment according to Figure 5This is achieved in particular by adjusting the delivery rate of the second hydraulic pump 117 via the speed of the electric motor M2. That is, a control line 135 runs from the control unit 142 to the inverter 160b to adjust the speed of the electric motor M2. This has the advantage, for example, that with reduced delivery rate, the hydraulic pump 157 also drives the hydraulic oil cooling and / or filter circuit 137 at a lower power, thereby reducing hydraulic losses.

[0039] The fifth embodiment of the Figure 7Figure 1 shows a drive scheme for a truck-mounted concrete pump 100 with a two-cylinder high-viscosity pump 111 according to the invention, in which both the truck chassis and the concrete pump superstructure 101 are fully electrically driven. This means that an electric drive motor MF is also provided for the drive of the truck-mounted concrete pump 100. The electric motor M1 drives the two first hydraulic pumps 115 for driving the hydraulic drive cylinders 147 and the hydraulic pump 119 for driving the placing boom 107 and the support 108. The second hydraulic pump 117, driven by the electric motor M2, charges the switching hydraulic accumulator 146, whereby the delivery rate of the second hydraulic pump 117 is adjusted as a function of the set high-viscosity delivery rate by adjusting the drive speed, for example by the inverter 160b controlled by the control unit 142. In the illustration, the accumulator 120 supplies the Figure 7Both the drive motor MF and the electric motors M1, M2, and M3 are supplied with electrical energy. During concrete pumping on the construction site, the mains connection plug(s) 159 are primarily used to supply the electric motors M1, M2, and M3 with electrical power. In this case, the battery 120 serves, for example, to provide additional electrical power to the construction site power supply 133 during peak power consumption of the concrete pump assembly 101, such as during a high delivery rate of viscous material from the two-cylinder viscous material pump 111. Conversely, the construction site power supply 133 can be used to charge the battery 120 when the electrical power consumption of the concrete pump assembly 101 is low, for example, during pumping breaks. The battery 120 can also be a drive battery assigned to the truck chassis 104.The concrete pump assembly 101 can also have a separate accumulator 120 or be fully powered via the external mains connection plug(s) 159 with electrical power from one or more site power supplies 133 if a drive battery of the truck chassis 104 cannot be used for the electrical operation of the concrete pump assembly 101.

[0040] In the exemplary embodiments of Figures 4 to 7 Inverters 158, 160a, 160b, and 160c are shown as separate modules connected to each other via the DC link 130. In principle, inverters 158, 160a, 160b, and 160c can also be combined to form an electrical supply unit 166, practically as in Figure 2The information shown can be summarized. Because the inverters 158, 160a, 160b, 160c generally require cooling during operation, a common air or liquid cooling system for the inverters 158, 160a, 160b, 160c can be provided, for example.

[0041] In Figure 8Figure 161 shows a variant of the hydraulic drive unit in which the geometric delivery volume of the second hydraulic pump 117 is variable and it has a leakage oil connection through which leakage oil can be supplied to the hydraulic oil cooling and / or filter circuit 137. In particular, hydraulic pumps with a variable geometric delivery volume, e.g., axial piston pumps with a swiveling disc, typically have such a leakage oil connection 162, so that the hydraulic oil exiting via the leakage oil connection 162 is supplied to the hydraulic oil cooling and / or filter circuit 137 and cooled, and optionally also filtered via the hydraulic oil filter 155, which is located upstream of the hydraulic oil cooler 156.

[0042] The Figure 9Figure 161 shows another alternative embodiment of a hydraulic drive unit 161, which drives the high-viscosity switching valve 112 and the agitator 113. The hydraulic drive unit 161 has two hydraulic pumps 117 and 118, which are provided for the hydraulic oil supply to the two working devices 112 and 113 in hydraulic circuits and draw hydraulic oil from a hydraulic oil tank 154. For example, hydraulic pump 117 drives the high-viscosity switching valve 112 and hydraulic pump 118 drives the agitator 113. Both the high-viscosity switching valve 112 and the agitator 113 are arranged in or on the feed hopper 116 of the concrete pump 100; therefore, the hydraulic drive unit 161 is located close to the working devices 112 and 113.The hydraulic circuit of the agitator drive, in which a hydraulic motor drives the agitator shaft, is also used here to cool the hydraulic oil of the hydraulic drive unit 161. The hydraulic oil is supplied by the hydraulic pump 118 to the agitator 113, or rather to the hydraulic motor for driving the agitator 113. From the agitator 113, the return line leads through the hydraulic oil filter 155 and the hydraulic oil cooler 156 back to the hydraulic oil tank 154. Thus, the hydraulic pump 118 simultaneously acts as a cooling circuit pump, and the return line also fulfills the function of the hydraulic oil cooling and / or filter circuit 137.In this embodiment, the hydraulic oil cooled by the hydraulic oil cooler 156 is also used for liquid cooling of the electric motor M2. The hydraulic oil is routed to the electric motor M2 via a line, then flows through the motor housing of the electric motor M2, cooling it in the process, and is then routed via another line to the hydraulic oil tank 154. Alternatively, in this exemplary embodiment, the hydraulic pumps 117 and 118 could be combined into a single hydraulic pump that simultaneously drives both the high-viscosity switching valve 112 and the agitator 111. However, this requires a suitable hydraulic circuit to adjust the hydraulic oil pressures for the two working units 112 and 113.This variant offers a particular advantage: the shared drive motor M2 of the agitator 113 and the switching hydraulic accumulator 146 allows the speed of the agitator 113 to be adjusted to the flow rate of the second hydraulic pump 117 by adapting the charging process of the switching hydraulic accumulator 146 to the flow rate of the second hydraulic pump 117, depending on the set high-viscosity flow rate. This means that by adjusting the flow rate of the second hydraulic pump 117 to the set high-viscosity flow rate, the speed of the agitator 113 is automatically adjusted to the high-viscosity flow rate, thus saving drive energy for the concrete pump 100, especially at low high-viscosity flow rates.

[0043] The Figure 10Figure 161 shows a variant of the hydraulic drive unit 161 in which the second hydraulic pump 117, whose delivery rate is regulated in this case by the drive speed of the electric motor M2, switches to pressureless circulation when the required accumulator fill pressure for switching the high-viscosity changeover valve 112 is reached. This is achieved by the directional control valve 138 opening the hydraulic oil cooling and / or filter circuit 137. The remaining time until the changeover hydraulic accumulator 146 is emptied can thus be used to cool and filter the hydraulic oil of the hydraulic drive unit. After a set hysteresis is reached, the directional control valve 138 is closed again and the changeover hydraulic accumulator 146 is refilled.

[0044] The embodiments shown here relate to the hydraulic drive of the hydraulic drive cylinders 147 of the two-cylinder high-viscosity pump in a so-called open hydraulic circuit. The invention can readily be transferred to the hydraulic drive of the hydraulic drive cylinders 147 in a closed hydraulic circuit with so-called reversing pumps, in which the hydraulic switching of the high-viscosity switching valve 112 is possible in the same way as presented here. Reference symbol list

[0045] 100 Truck-mounted concrete pump 101 Concrete pump superstructure 102 Truck 103 Truck combustion engine 104 Chassis 105 Truck frame 106 Turntable 107 Distributor mast 108 Outrigger 109 Support cylinder 110 Articulated joint drive 111 Two-cylinder high-viscosity pump 112 High-viscosity diverter valve 113 Agitator 115 First hydraulic pump for hydraulic drive cylinder 116 Feed hopper 117 Second hydraulic pump for diverter hydraulic accumulator 118 Hydraulic pump agitator 119 Hydraulic pump mast / outrigger 120 Accumulator 121 Support beam 122 Electric motor (St.dT) 123 Power take-off (PTO) 124 Power take-off gearbox 125 Articulated joint 126 Mast segments 127 Concrete pump substructure 128 Hydraulic pump train 130 DC intermediate circuit 131 Flow measurement signal line 132 Power generator (St.dT)133 Construction site power supply 134 Transmission drive 135 Control line delivery rate second hydraulic pump 136 Transporter with electric energy storage 137 Hydraulic oil cooling and / or filter circuit 138 Directional control valve 139 Power line 140 Hydraulic control line cooling circuit 141 Control line delivery rate 142 Control device 143 Input unit 144 Housing high-viscosity changeover valve 145 Changeover hydraulic cylinder 146 Changeover hydraulic accumulator 147 Hydraulic drive cylinder 148 Delivery cylinder 149 Delivery piston 150 Directional control valve 151 Check valve 152 Pressure relief valve 153 Hydraulic oil tank 154 Hydraulic oil tank - drive unit 155 Hydraulic oil filter 156 Hydraulic oil cooler 157 Cooling pump 158 Inverter 159 Mains connector 160 Inverter 161 Hydraulic drive unit 162 Leakage oil connection 163 Hydraulic drive cylinder switch 164 Thick substance delivery line 165 Decoupling device 166 Electrical supply unit M; M1; M2; M3: Electric motors MG: Electric motor / generator.

Claims

1. Two-cylinder thick-matter pump (111), in particular for a truck-mounted concrete pump (100), comprising - at least one first hydraulic pump (115), - two hydraulic drive cylinders (147) driven in opposite phase by the at least one first hydraulic pump (115), which are provided to drive two delivery pistons (149) which each run in one of two delivery cylinders (148) of the two-cylinder thick-matter pump (111), wherein a thick-matter delivery quantity is adjustable by adapting the delivery rate of the at least one first hydraulic pump (115), - a second hydraulic pump (117), - a switching hydraulic accumulator (146), wherein the second hydraulic pump (117) is provided to charge the switching hydraulic accumulator (146), - at least one switching hydraulic cylinder (145) supplied from the switching hydraulic accumulator (146), - a thick-matter switching valve (112) driven by the at least one switching hydraulic cylinder (145), which is provided for alternately connecting the two delivery cylinders (148) to a thick-matter delivery line (164), characterized in that the delivery rate of the second hydraulic pump (117) is adaptable as a function of the set thick-matter delivery quantity.

2. Two-cylinder thick-matter pump (111) according to claim 1, characterized in that the delivery rate of the second hydraulic pump (117) is adaptable such that the switching hydraulic accumulator (146) is completely filled in each case immediately before a switching operation of the thick-matter switching valve (112).

3. Two-cylinder thick-matter pump (111) according to claim 1 or 2, characterized by a control device (142) which is configured to adapt the delivery rate of the at least one first hydraulic pump (115) and the delivery rate of the second hydraulic pump (117) in accordance with the set thick-matter delivery quantity.

4. Two-cylinder thick-matter pump (111) according to one of claims 1 to 3, characterized in that the delivery rate of the second hydraulic pump (117) is adaptable by setting the geometric displacement volume of the second hydraulic pump (117).

5. Two-cylinder thick-matter pump (111) according to one of claims 1 to 3, characterized in that the delivery rate of the second hydraulic pump (117) is adaptable by setting the drive speed of the second hydraulic pump (117).

6. Two-cylinder thick-matter pump (111) according to one of claims 1 to 3, characterized by a common drive motor (M1) which drives the at least one first hydraulic pump (115) and the second hydraulic pump (117), wherein the delivery rate of the at least one first hydraulic pump (115) and the delivery rate of the second hydraulic pump (117) are adaptable by setting the rotational speed of the drive motor (M1).

7. Two-cylinder thick-matter pump (111) according to one of claims 1 to 6, characterized in that the at least one first hydraulic pump (115) and the second hydraulic pump (117) are driven by separate drive motors (M1, M2).

8. Two-cylinder thick-matter pump (111) according to claim 7, characterized in that the drive motor (M2) driving the second hydraulic pump (117) is an electric motor.

9. Two-cylinder thick-matter pump (111) according to claim 7 or 8, characterized in that the second hydraulic pump (117) with the drive motor (M2) driving it is arranged spatially close to the thick-matter switching valve (112) and that the at least one first hydraulic pump (115) and the second hydraulic pump (117) are each assigned their own hydraulic oil tank (153, 154).

10. Two-cylinder thick-matter pump (111) according to one of claims 7 to 9, characterized in that the drive motor (M2) driving the second hydraulic pump (117) drives a further hydraulic pump (157) which is provided to supply a hydraulic oil cooling and / or filter circuit (137).

11. Two-cylinder thick-matter pump (111) according to one of claims 7 to 9, characterized in that the geometric displacement volume of the second hydraulic pump (117) is variable and it has a leakage oil connection (162) via which leakage oil can be supplied to the hydraulic oil cooling and / or filter circuit (137).

12. Two-cylinder thick-matter pump (111) according to one of the preceding claims, characterized in that an agitator (113) in a feed hopper (116) mixes the thick matter introduced into the feed hopper (116), wherein the rotational speed of the agitator (113) is adaptable as a function of the set thick-matter delivery quantity.

13. Method for operating a two-cylinder thick-matter pump (111), wherein the two-cylinder thick-matter pump (111) has at least one switching hydraulic cylinder (145) supplied from a switching hydraulic accumulator (146) for driving a thick-matter switching valve (112), which is provided for alternately connecting two delivery cylinders (148) of the two-cylinder thick-matter pump (111) to a thick-matter delivery line (164), characterized in that a charging speed with which the switching hydraulic accumulator (146) is charged with hydraulic oil between the switching operations of the thick-matter switching valve (112) is adapted as a function of a predetermined thick-matter delivery quantity.