Lifting and tipping device and waste collection vehicle with a lifting and tipping device

Description

[0001] The invention relates to a lifting and tipping device for a refuse collection vehicle having the features of claim 1 and to a refuse collection vehicle having the features of claim 9.

[0002] Electrification is also becoming increasingly widespread in the field of municipal vehicles. Therefore, it is advisable not only to design the drive for the vehicle itself with electric drive, but also to operate the superstructure at least partially electrically. DE 10 2019 131 986 A1 discloses a lifting and tipping device in which the pallet truck is driven by an electric motor. This has the advantage that the lifting and tipping device is no longer driven hydraulically, but can rely on the electrical power supply of the drive motor of a waste collection vehicle.

[0003] Document DE 10 2020 128034 A1 discloses a device according to the preamble of independent claim 1.

[0004] However, there are other components in the lift and tilt system that need to be moved. If these are to be driven hydraulically, as is currently the case, a connection to the hydraulic system of the refuse collection vehicle's body is required.

[0005] The object of the invention is to create a lifting and tipping device that does not require an additional connection to the hydraulic system of the body of the refuse collection vehicle.

[0006] This object is achieved by a lifting and tipping device having the features of claim 1. Particular embodiments of the invention are the subject of dependent claims 2 to 8. Furthermore, the object is achieved by a refuse collection vehicle according to claim 9 or 10.

[0007] The invention relates to a lifting and tipping device for a refuse collection vehicle having at least one electric drive, at least one electrically driven lifting carriage and at least one hydraulically operated consumer, wherein the at least one hydraulically operated consumer is supplied with a hydraulic fluid by an electro-hydraulic drive system, wherein the electro-hydraulic drive system has a pump which is operated by an electric drive and has a tank for the hydraulic fluid.

[0008] The at least one electric drive can be configured, for example, as an electric motor. The at least one electric drive can drive the lift truck and / or the electro-hydraulic drive system.

[0009] The hydraulically operated device can be, for example, a restraint device, a locking device for the lift truck, or a hydraulically movable chute. These devices are hydraulically driven via an electro-hydraulic drive system of the lift-tilt device itself. The entire required hydraulic system is provided on board the lift-tilt device. This eliminates the need to connect to the hydraulic system of a refuse collection vehicle itself. This significantly simplifies installation and maintenance, and the hydraulic system of the lift-tilt device can be tailored to the needs of the device(s). The individual components can be designed as needed. This simplifies the overall arrangement and saves weight and costs.

[0010] Preferably, the electro-hydraulic drive system has a pressure accumulator that can be filled with hydraulic fluid by the pump. A pressure accumulator can store hydraulic energy and release it to the hydraulic system as needed in the form of a volume flow. This allows peak demand to be absorbed, and the pump itself does not have to be designed for the consumer with the greatest demand.

[0011] It is further preferably provided that the at least one hydraulically operated consumer is supplied with hydraulic fluid from the pressure accumulator.

[0012] In particular, the accumulator flow rate generated by the accumulator in the hydraulic system is greater than the pump flow rate generated by the pump.

[0013] The consumer(s) do not need to be supplied with hydraulic fluid the entire time. For example, restraint devices or locking devices are only activated for a short time while a ton is being drained. This means that it is not necessary to operate the electro-hydraulic drive system at the full required flow rate. Instead, the pump can be designed smaller and fill the accumulator with a lower pump flow rate. If larger flow rates are required, for example to actuate a restraint device at the required speed, a larger accumulator flow rate can be generated from the accumulator. Furthermore, the pump does not need to be running the entire time, which saves energy and minimizes wear.

[0014] In one embodiment of the invention, a shut-off valve is provided between the electro-hydraulic drive system and the at least one hydraulically operated consumer. This shut-off valve can be opened to supply the at least one consumer with hydraulic fluid. A valve, for example, a solenoid valve, can be controlled easily and quickly, so that the consumers can be supplied when needed without significant time losses.

[0015] If the supply comes from the pressure accumulator, the required storage volume flow can be made available immediately after the shut-off valve is switched, without the need for additional generators, such as a pump.

[0016] A further advantageous embodiment of the invention provides that the electro-hydraulic drive system is designed to switch off the pump as soon as the pressure in the pressure accumulator exceeds an upper limit value and to switch the pump on as soon as the pressure in the pressure accumulator falls below a lower limit value.

[0017] The upper limit value is in particular between 70 and 90 bar, preferably between 75 and 85 bar, particularly preferably between 79 and 81 bar.

[0018] The lower limit value is in particular between 50 and 70 bar, preferably between 55 and 65 bar, particularly preferably between 59 and 61 bar.

[0019] In particular, a pressure gauge can be provided that measures the pressure prevailing in the accumulator. This data is transmitted to a control system, which switches the pump on and off accordingly. This ensures that there is always a sufficient supply of hydraulic fluid in the accumulator to ensure the supply of hydraulic fluid to the consumers. At the same time, the pump is protected because it does not have to operate continuously.

[0020] In a further embodiment of the invention, the at least one electrically driven lift truck is driven by a first electric drive, and the pump is driven by a second electric drive. These can be electric motors, for example. This allows the first and second drives to be configured to the respective requirements of the at least one lift truck and the pump. Furthermore, the structural design of the electromotive movement is simplified. It is also possible to equip each lift truck with its own electric drive.

[0021] A further embodiment of the invention provides that the lifting and tilting device has a frame in which the components of the lifting and tilting device are arranged and which can be connected, in particular electrically connected, to a waste collection vehicle. This frame can be a housing and / or a framework to which the individual components are attached. These include the drive for the lifting truck, the lifting and tilting mechanism itself, the electro-hydraulic drive system, and the hydraulically operated loads. This allows the entire complex to be mounted in one piece, for example, on the body of a waste collection vehicle, which greatly simplifies commissioning and maintenance.

[0022] In particular, it can be provided that an electrical system of the lifting and tilting device is designed such that it can be supplied via one, in particular a single, electrical connection. This also simplifies assembly and maintenance, since, for example, only one plug connection needs to be established to establish the electrical supply to the lifting and tilting device. The electrical system comprises at least one electric drive, control system, cables, and the like. The electrical supply can be provided via an energy storage device and / or an energy generator. This is located on or in a waste collection vehicle.

[0023] In an alternative embodiment of the invention, the energy storage device and / or energy generator can be located on the lifting and tipping device itself. This allows the lifting and tipping device to be completely independent of a waste collection vehicle.

[0024] The invention also relates to a refuse collection vehicle with a lifting and tipping device as described above.

[0025] Advantageously, the refuse collection vehicle is designed such that the electrical system of the lifting and tipping device is connected to an energy storage device and / or energy generator located in or on the refuse collection vehicle and can be supplied with energy from this energy storage device and / or energy generator. The energy supply can be provided, for example, via a battery, accumulator, fuel cell, capacitor, and the like. In electrically powered vehicles, such an energy storage device and / or energy generator is already present and can easily be used to supply the lifting and tipping device.

[0026] Further features of the invention will become apparent from the exemplary embodiment presented in the figures. Figure 1 shows the electro-hydraulic drive system of a lifting and tilting device according to the invention, Figure 2 shows the electro-hydraulic drive system in an enlarged view, Figure 3 shows the electro-hydraulic drive system in a circuit diagram sketch.

[0027] In Figures 1 and 2 A part of a lifting and tilting device 1 according to the invention is shown. The first electric drives 2, which are designed as electric motors, are missing here, as they would otherwise obscure the view of the electro-hydraulic drive system 3. The electro-hydraulic drive system 3 has a pump 4, which is driven by a second electric drive 5, also an electric motor. In the illustration in Figures 1 and 2The pump 4 is arranged in the tank 6 and is therefore not visible. The pump 4 pumps hydraulic fluid from the tank 6 through a pressure accumulator line 8 into a pressure accumulator 7. The pump flow rate in this case is approximately 2 liters per minute. In a conventional system, in which the lifting and tipping device 1, and in particular the pallet trucks, are supplied by the hydraulic system of the refuse collection vehicle, the flow rate is approximately 40 liters per minute due to the greater demand. Within the scope of the invention, the pump 4 and second electric drive 5 can therefore be designed to be significantly smaller, lighter, and more economical, since the demand is significantly lower. The same applies to lines, couplings, and the like.

[0028] The consumers provided here are restraint devices 9 and the drive for a locking device 10. For the operation of the restraint devices 9 at the required speed, a volume flow of 6 liters per minute is required. In order to generate this volume flow and at the same time keep the pump 4 and the second electric drive 5 as compact and uncomplicated as possible, the pressure accumulator 7 is provided. This stores the hydraulic fluid. As soon as a pressure of approximately 80 bar is reached, the pump 4 is switched off. When a consumer, for example the restraint device 8, is to be actuated, a check valve 12 installed in a valve block 11 (see Figure 3) is opened. The hydraulic fluid flows at a storage volume flow of approximately 6 liters per minute into a supply line 13 and is guided to the retention device 9. From there, it flows back into the tank 6 via a return line 14. The pressure accumulator 7 makes it possible to temporarily provide more hydraulic fluid than the pump 4 alone is capable of. However, since the retention device 9 or the locking device 10 are only used briefly and not permanently, it is not advisable to operate the pump 4 permanently at the required volume flow.

[0029] When the pressure in the pressure accumulator 7 falls below approximately 60 bar, the second electric drive 5 is switched on again and hydraulic fluid is pumped into the pressure accumulator 7. The pressure is measured by a pressure sensor 15, and the pump 4 is switched accordingly via a control system.

[0030] Should the pressure in the pressure accumulator 7 rise above a specified limit, here 85 bar, a safety valve 17 is provided to direct the hydraulic fluid back into the tank 6.

[0031] In addition, a throttle valve 16 is provided to manually release the pressure in the pressure accumulator 7.

[0032] The entire hydraulic circuit is located on board the lifting and tipping device 1. It is therefore not necessary to establish a connection to the hydraulic system of a waste collection vehicle (not shown in detail here). Together with the fact that the lifting carriages of the lifting and tipping device 1 are also electrically operated, this means that, in addition to connections for a control system and the like, only an electrical connection, e.g., via a plug connection, needs to be established between the lifting and tipping device 1 and the waste collection vehicle in order to connect the lifting and tipping device 1 to a power source and / or power generator on board the waste collection vehicle. This makes the lifting and tipping device 1 independent of the waste collection vehicle's hydraulic system, which is oversized for the consumers. The electro-hydraulic components can be designed to meet actual requirements, saving weight and costs.On the other hand, assembly and maintenance of the lifting and tilting device 1 are greatly simplified, which reduces the associated effort.

[0033] This is particularly advantageous if all components of the lifting and tipping device 1 are arranged in a frame 18, partially shown here. This frame can be connected to the body of a refuse collection vehicle by screwing or welding. A plug connection can also be provided there to electrically connect the electrical system of the lifting and tipping device 1 to a power source on or in the refuse collection vehicle. Reference symbol

[0034] 1Lift-tilt device 2First electric drive 3Electro-hydraulic drive system 4Pump 5Second electric drive 6Tank 7Accumulator 8Accumulator line 9Retaining device 10Drive for a locking device 11Valve block 12Locking valve 13Forward line 14Return line 15Pressure gauge 16Throttle valve 17Safety valve 18Frame

Claims

1. Lifting and tipping device (1) for a refuse collection vehicle, comprising at least one electric drive (2,5), at least one electrically driven lifting truck and characterized in that the lifting and tipping device has at least one hydraulically operated load (9, 10) which is supplied with a hydraulic fluid by an electrohydraulic drive system (3), the electrohydraulic drive system (3) having a pump (4) which is operated by an electric drive (5) and having a tank (6) for the hydraulic fluid.

2. Lifting and tipping device (1) according to claim 1, characterized in that the electrohydraulic drive system (3) has a pressure accumulator (7) which can be filled with hydraulic fluid by the pump (4).

3. Lifting and tipping device (1) according to claim 2, characterized in that at least one hydraulically operated load (9, 10) is supplied with hydraulic fluid from the pressure accumulator (7).

4. Lifting and tipping device (1) according to at least one of the preceding claims, characterized in that a shut-off valve (12) is provided between the electrohydraulic drive system (3) and the at least one hydraulically operated load (9, 10), which shut-off valve can be opened to supply the at least one load (9, 10) with hydraulic fluid.

5. Lifting and tipping device (1) according to any of claims 2 to 4, characterized in that the electrohydraulic drive system (3) is designed to switch off the pump (4) as soon as the pressure in the pressure accumulator (7) exceeds an upper limit, and to switch on the pump (4) as soon as the pressure in the pressure accumulator (7) falls below a lower limit.

6. Lifting and tipping device (1) according to at least one of the preceding claims, characterized in that the at least one electrically driven lifting truck is driven by a first electric drive (2) and the pump (4) is driven by a second electric drive (5).

7. Lifting and tipping device (1) according to at least one of the preceding claims, characterized in that it has a frame (18) in which the components of the lifting and tipping device (1) are arranged and which can be connected, in particular electrically connected, to a refuse collection vehicle.

8. Lifting and tipping device (1) according to at least one of the preceding claims, characterized in that an electrical system of the lifting and tipping device (1) is designed such that it can be supplied via an electrical connection.

9. Refuse collection vehicle having a lifting and tipping device (1) according to at least one of the preceding claims.

10. Refuse collection vehicle according to claim 9, characterized in that the electrical system of the lifting and tipping device (1) is connected to an energy storage device and / or energy generator arranged in or on the refuse collection vehicle and can be supplied with energy therefrom.