EP2640649A1

EP2640649A1 - Pressing system, refuse truck and method therefor

Info

Publication number: EP2640649A1
Application number: EP11788605.1A
Authority: EP
Inventors: Jan Paul Versteeg
Original assignee: Terberg Machines BV
Current assignee: Terberg Machines BV
Priority date: 2010-11-19
Filing date: 2011-11-16
Publication date: 2013-09-25
Anticipated expiration: 2031-11-16
Also published as: EP2640649B1; ES2951484T3; NL2005725C2; PL2640649T3; EP2640649C0; WO2012067506A1

Abstract

The invention relates to a pressing system (10) and refuse truck (4) and a method therefor. The pressing system (10) for compressing material in a collector (6) comprises : - a frame provided with coupling means mountable on the collector; - a pressing device (16,18) connected to the frame and comprising one or more hydraulic cylinders (54,56); - a drive system (32) operatively connected to the pressing (16,18) device, the drive system (32) comprising: - an energy supply (34) comprising an energy source; - an electric motor (48) operatively connected to the energy supply (34) and a motor control means (50) for controlling the electric motor (48); and - at least one hydraulic pump (44) drivable by the electric motor (48) for controlling the one or more cylinders (54,56) of the pressing device (16,18).

Description

PRESS ING SYS TEM , REFUSE TRUCK AND ME THOD THEREFOR

The present invention relates to a pressing system for a refuse truck. Such a pressing system is used particularly to compress the content of containers emptied into a refuse truck .

Containers filled with for instance waste, such as domestic refuse, waste paper or green waste, are usually collected from company and private premises using refuse trucks. Such refuse trucks are usually provided in practice with a loading system with which the containers can be lifted and emptied into the refuse truck with a pivoting movement. After a number of containers have been emptied, the content thereof is compressed using a pressing system. The refuse truck can hereby empty a greater number of containers in one journey. Refuse trucks known in practice drive the pressing system hydraulically via a so-called PTO pump powered from the fuel engine of the vehicle. The pressing system is therefore dependent on the fuel engine of the vehicle for its operation.

The present invention has for its object to provide a pressing system with which it is possible to allow the pressing system to function more independently of a vehicle. This object is achieved with the pressing system according to the invention in or on a collector, such as a refuse truck or large container. The pressing system comprises:

- a frame provided with coupling means mountable on the collector;

- a pressing device connected to the frame and comprising one or more hydraulic cylinders;

- a drive system operatively connected to the pressing device, the drive system comprising: - an energy supply comprising an energy source;

- an electric motor operatively connected to the energy supply and motor control means for controlling the electric motor; and

- at least one hydraulic pump drivable by the electric motor for controlling the one or more cylinders of the pressing device.

By providing a collector, preferably in the form of a collection container or a refuse truck, containers provided with refuse, including domestic refuse, green waste and paper, can be emptied into this collector. The container can be lifted, tilted and emptied in efficient manner by

preferably connecting the pressing system to a loading system. The material from the container is then compressed in the pressing system. Such a loading system can be

provided here with for instance two loading seats which operate synchronously for large four-wheel containers or independently for smaller two-wheel containers.

The pressing device compresses material so as to thereby reduce its volume. A refuse truck for instance can hereby transport more material. In the case of a refuse truck, material such as refuse is tipped out of containers into a hopper using a loading system at the rear of the refuse truck. The pressing device is activated once a determined quantity of material has been placed in the hopper. This can take place manually or automatically. The pressing cycle is started following activation of the press. The pressing plate is first opened here and subsequently performs a downward movement. This downward movement is realized by displacing the guide plate. The pressing plate is then closed and, by displacing the guide plate back again, the material is pressed against a pressing wall.

Other embodiments of the pressing device are also possible. The drive system of the pressing system according to the invention has an electric motor and control means therefor, including so-called motor control means or motor controllers. An efficient and effective loading system is obtained through the use of an electric motor. By providing the electric motor with control means the electric motor can be controlled on the basis of demand. Also achieved hereby is per se "clean" operation of the electrical drive during collection of for instance domestic refuse. In the case of a refuse truck provided with a pressing system according to the invention this means that, during collection of for instance domestic refuse, there is no emission of

contaminating substances in residential areas where the refuse is being collected. This is enhanced when use is also made of a loading system provided with an electrical or electro-hydraulic drive.

A further additional advantage, when use is made of an electrical drive, is that the noise production is also reduced. This is realized due to the absence of flow control valves, whereby the typical hissing sound associated therewith no longer occurs. Energy loss and heat generation are also reduced, since it is possible according to the invention to dispense with hydraulic flow control valves and/or splitter valves. Restrictions and resistances are hereby reduced significantly. This results in an energy- efficient system with an increased operational reliability due to the reduction of the number of components susceptible to malfunction. Surprisingly, it is also possible to reduce the energy consumption. This is realized in that the separate motor (s) of the pressing system can be adjusted to the specific loads from the pressing system, while the conventional system using the fuel engine must absorb a wider range of loads with this engine, this adversely affecting the effectiveness of the drive.

By using an electric motor according to the invention instead of a diesel engine it is further also possible to bring about more efficient operation of the hydraulic system. In contrast to a hydraulic pump, which in

conventional systems is driven by a diesel engine, whereby components must be located close to each other, the

components in the system according to the invention with the electric motor can be provided at any desired position.

After all, a mechanical connection to the diesel engine of the chassis need not be available. By more preferably providing a hydraulic pump with a continuously variable pump speed and torque in the hydraulic system the whole pressing system can be operated in more efficient manner using the associated hydraulics. Because less heat is generated in the hydraulic system, the oil tank can take a smaller form. The pump can operate at a higher rotation speed and also take a smaller form owing to the electrical drive. The hydraulic pump is preferably provided here with a fixed stroke volume and is also low-noise.

In an advantageous preferred embodiment according to the present invention the electric motor comprises a three- phase motor, and preferably a three-phase asynchronous motor.

An advantage of such three-phase motors is that, in contrast to DC motors, the three-phase motors do not display any significant switch-on peaks during startup under load. A kind of "soft" start is hereby obtained without a reduction of the oil flow being required as in conventional systems and with additional losses.

The asynchronous motor is preferably controlled in continuously variable manner here in order to thereby co-act effectively with the hydraulic pump which can preferably also be operated in continuously variable manner.

The three-phase motor is preferably a three-phase asynchronous motor without carbon brushes. Sparking and wear are hereby prevented. This increases the operational reliability.

In an advantageous preferred embodiment according to the present invention the motor control means for powering the at least one electric motor are operatively connected directly to the energy source.

The motors are preferably powered directly from the battery voltage via the motor controller, wherein a battery preferably functions as energy source. In a currently preferred embodiment such a battery forms part of the pressing system as separate component. Additionally or alternatively, a connection can be made to a battery already present in the vehicle. If additionally, extra energy can be utilized for the pressing system. If as alternative to a separate battery for the pressing system, the battery of the vehicle can for instance be used for small refuse trucks. No additional components are hereby required. By applying a battery, in the currently preferred embodiment a separate battery for the pressing system, an effective and robust system is obtained with which material can be compressed when a vehicle engine is switched off in the case of application in a refuse truck.

The connecting means of the pressing system connect the drive system during use to an internal and/or external energy source. A continuous connection to a power supply is realized by connecting the drive system of the pressing system via the connecting means to a battery, for instance of a refuse truck. Such a battery can be used in an

electrically driven refuse truck as well as in a fuel-driven refuse truck. A pressing system is hereby obtained which can be deployed in flexible manner and which can be employed irrespective of the type of drive of a refuse truck. In the case of an electrically driven refuse truck the pressing system is for instance connected to the traction battery.

The battery preferably comprises a battery with a relatively low voltage, preferably lower than 220 Volt, a so-called low-voltage battery. The battery voltage employed can thus amount for instance to 24 Volt or 80-100 Volt. This is the case in an embodiment in which the low-voltage battery is the battery of a refuse truck as well as in an embodiment in which the low-voltage battery is a separate battery in or for the pressing system. Hazardous situations for users and mechanics are avoided by making use of a low- voltage battery in a preferred embodiment according to the invention. Worker- friendly conditions are hereby realized. Such a low-voltage system can advantageously be provided, inter alia in a refuse truck driven by a combustion engine. Other voltages are of course also possible for the system according to the invention. When the pressing system according to the invention is for instance used in an electrically driven vehicle, the system can advantageously be provided operating at a different voltage.

The control means, such as the motor controller ( s ) , for controlling the one or more electric motors are preferably connected operatively and in direct manner to the battery. This means that the motor controller forming a substantial part of the motor control means is powered directly from the battery and that a converter need not therefore be provided which converts the battery voltage in use, for instance 80- 100 V, to a higher voltage for the purpose of the electric motor. This limits the number of parts, and therefore cost and complexity. In addition, safety is achieved by using a voltage which in a preferred embodiment is lower than 220 V as described above.

A further advantage of a direct coupling between motor controller and battery is that it is possible to dispense with hydraulic flow control valves and/or splitter valves. Restrictions and resistances in the system are hereby significantly reduced. Energy loss and heat generation are also reduced. This is a significant advantage of the motor controller applied according to the invention.

Reduction of energy loss and heat generation are further reduced in that, owing to the combination of motor with continuously variable speed, motor control means and pump with continuously variable adjustment, the maximum hydraulic pressure can be regulated without an overflow valve being required. Dispensing with overflow valves is possible by measuring the hydraulic pressure with which the engine speed is if necessary reduced. The critical limit, which is otherwise safeguarded with an overflow valve, is hereby not reached. By dispensing with overflow valves in normal operation no energy is lost when the maximum

operating pressure is reached. This further limits the number of parts. A flow control valve is therefore

preferably not provided in the pump feed.

In an advantageous preferred embodiment according to the present invention the cylinders in the pressing device are operatively connected to separate pumps.

Providing separate pumps per cylinder achieves that a modular pressing system can be obtained. The hydraulic fluid reservoir is preferably provided in the pressing system. The pressing system according to the invention therefore results in a combined electro-hydraulic drive. By providing a hydraulic fluid reservoir this drive operates independently of its setting, for instance a refuse truck provided therewith. This further achieves that the pressing system can function independently of the propulsion of such a refuse truck, i.e. independently of a fuel engine and/or electrical drive of the vehicle. The drive of the vehicle does not therefore have to remain active to allow the pressing system according to the invention to function. By using "internal" hydraulics the desired properties thereof are preserved for the pressing system. A fully modular system is hereby obtained. If use is made of a battery, a power supply cable has to be provided between this battery and the pressing device. Hydraulic couplings are not required .

An advantage of providing an oil reservoir in the pressing system is that it is possible here to suffice with a relatively small volume compared to conventional systems. This is achieved in that less heat generation occurs in the system. This is realized for instance through the use of a hydraulic pressure sensor instead of hydraulic safety valves .

In addition, the drive can be utilized in optimal manner through the use of electro-hydraulic driving of the pressing system according to the invention. In conventional drives, in which use is made of a fuel engine, this fuel engine will not operate in all cases at the optimal level of operation. The efficiency of the pressing system according to the invention can hereby be further increased. In the case of an electrically driven refuse truck a fully

electrically driven system is obtained with a pressing system according to the invention, since the hydraulic fluid for the pressing system remains wholly internal, preferably even wholly within the pressing system. This ensures that the advantages of a fully electrically driven system are realized, while retaining the properties of the hydraulic pressing system.

By providing the pressing system with coupling means it is also possible to for instance transfer a pressing system from a refuse truck provided with a fuel engine to a refuse truck provided with an electrical drive. Additional

advantages of providing a more independent pressing system according to the invention is that relatively few operations are necessary to connect the pressing system to a refuse truck, since no hydraulic connection need for instance be made. This has the further additional advantage that there is hereby also less risk of leakage of for instance the hydraulic fluid. Locating and subsequent repair of

malfunctions are also greatly simplified in that the different systems operate independently of each other.

An additional advantage is that it is also possible to exchange wholly filled pressing systems on for instance a refuse truck with an empty pressing system. The refuse truck can hereby be utilized in more efficient manner such that for instance the cost of collecting domestic refuse can be reduced.

The fluid reservoir is preferably also provided internally in one or more parts of the frame.

The independent operation of the pressing system of for instance the refuse truck is further enhanced by providing the pressing system according to the invention with a fluid reservoir. By providing the fluid reservoir in the interior of one or more parts of the profile, for instance in the interior of a tubular profile, a compact pressing system is obtained which also attains a great independence due to a reservoir being provided therein.

In an advantageous preferred embodiment according to the present invention the drive system is provided with system coupling means for coupling the drive system of the pressing system and a drive system of a loading system for emptying containers.

The system coupling means achieve that a combined drive , is realized, preferably a combined electro-hydraulic drive for the pressing system according to the invention. A drive for these sub-systems can hereby be realized in efficient manner and with a minimum of system components.

In an advantageous preferred embodiment according to the present invention the pressing device is operatively connected to one or more detectors of a loading system of a refuse truck for the purpose of activating the pressing device .

The activation of the pressing can for instance be performed automatically by operatively coupling the pressing device to detectors of the loading system. The pressing device can thus be activated fully automatically after for instance four two-wheel containers have been emptied.

Alternatively or additionally, a detector can also be provided in the hopper of the pressing system so as to thereby activate the pressing as soon as a determined guantity of material has been introduced into the hopper. The number of pressing actions are in these ways adapted to the actual requirement, and no unnecessary pressing actions are performed. This contributes toward an energy-efficient system.

The invention further relates to a refuse truck provided with the pressing system as described above.

Such a refuse truck provides the same effects and advantages as those stated in respect of the pressing system. The pressing system has been found to be

particularly advantageous here in combination with an electrically driven refuse truck, wherein no fuel engine is present .

It has been found that such a refuse truck according to the present invention can advantageously be combined with the modular embodiment of the pressing system as described above. The system can hereby be operatively connected to the vehicle by connecting preferably only a power supply cable between system and vehicle. The vehicle can hereby be provided in relatively simple manner with another pressing system. This further increases the flexibility of both the system and the vehicle.

In an advantageous preferred embodiment according to the present invention the refuse truck comprises a second pressing system as described above.

Providing a second pressing system makes it possible to collect separated refuse simultaneously using a single refuse truck. This further improves the efficiency of collecting material such as domestic refuse.

In a further advantageous preferred embodiment

according to the present invention the refuse truck

comprises a pressing system of the modular type, preferably in combination with a modular embodiment of the loading system. The vehicle can hereby be provided with another pressing system and/or loading system in relatively simple manner by connecting preferably only a power supply cable to the vehicle between one or more drive systems of the pressing system and/or the loading system. This further increases the flexibility of both the individual systems and the vehicle.

The invention further also relates to a method for compressing material, comprising of providing a pressing system as described above. Such a method provides the same effects and advantages as those stated in respect of the pressing system and the refuse truck.

Further advantages, features and details of the invention are elucidated on the basis of the diverse preferred embodiments thereof, wherein reference is made to the accompanying drawings, in which:

- figure 1 shows a view of a refuse truck according to the invention;

- figures 2-5 shows schematic views of the pressing cycle with the pressing system according to the invention;

- figure 6 shows a view of a refuse truck provided with the pressing system of figures 2-5; and

- figure 7 shows a schematic representation of the drive of the pressing system of figure 6.

A refuse truck 2 (figures 1 and 6) comprises a truck 4 provided with a bin or container 6, wherein a loading system 8 is provided on the rear side. A pressing system 10 is provided between bin 6 and loading system 8. Refuse 14 is carried into a hopper 12. In the shown embodiment this takes place using loading system 8. Pressing system 10 comprises a pressing plate 16 and guide plate 18. Refuse 14 from hopper 12 is hereby compressed to form pressed waste 20 using pressing wall 22 and carried into collection space 24 of bin 6. Bin 6 further has a rear loader 26 with a pushing mechanism 28 with which wall 22 is slidable in a direction A and back. Refuse 20 can hereby be pushed out of bin 6 at for instance the offloading location. Loading system 8 is used to empty containers. Containers are, among others,

containers of the type EN 840-1, -2, -3 and -4 with

respective volumes of 80-360 litres, 500-1200 litres, 770, 1100 and 1300 litres, and 750-1700 litres. In addition, it is also possible using the shown refuse truck 2 to place refuse bags therein. The containers are emptied into loading opening 30.

Once sufficient refuse 14 has been placed in hopper 12 from insertion opening 30, a pressing cycle is started. This cycle is started by opening pressing plate 16 in a direction B (figure 2) . A downward movement is then made with guide plate 18 in a direction C (figure 3) . This is followed by pressing plate 16 being closed in a direction D (figure 4), wherein refuse 14 is as it were scooped out of hopper 12. Finally, guide plate 18 shifts upward in a direction E

(figure 5) in order to obtain pressed waste 20. Waste 20 is pressed here against pressing wall 22. Pressing wall 22 is optionally displaced to some extent in the case of

sufficient pressure. It will be apparent that variants of the described approach for compressing refuse 14 are also possible .

The electro-hydraulic drive system 32 (figure 7) is supplied with power from a battery/dynamo 34 in vehicle 2 (figure 6) . In the shown embodiment battery 34 is a low- voltage battery. Between vehicle 2 and pressing system 10 a coupling is provided to battery 34. Pressing system 10 is operatively connected to refuse truck 2 via the coupling in a manner such that it can be uncoupled, and for instance be exchanged, in simple and efficient manner. Controller or microprocessor 36 is provided with a control panel 38.

Controller 36 is connected to one or more position sensors 40, as shown schematically in the figure. Hydraulic pressure sensor 42 realizes a safety in the case where the maximum hydraulic pressure is reached. Such a safety system has the advantage over the use of conventional valves that no unnecessary energy loss occurs.

Also using motor speed sensor 46, hydraulic pump 44 is controlled by motor 48, wherein motor 48 is provided with motor controller 50. In the shown embodiment motor

controller 50 is powered directly from battery 34. System 32 is further provided with valve block 52 and comprises an assembly of electrically driven switch valves. In the shown advantageous embodiment it is possible to dispense with choke valves. System 32 realizes the movement of cylinder pair 54 for pressing plate 16, cylinder pair 56 for guide plate 18, cylinder pair 58 for opening loading system 8 and cylinder 60 for pressing wall 22. A connection 62 is also provided for a hydraulic container loading. System 32 further comprises an oil reservoir 64. In the shown

embodiment of system 32 according to the invention reservoir 64 takes a considerably smaller form compared to

conventional systems, among other reasons because of the limited heat generation. Controller 36 is preferably operatively connected to motor controller ( s ) 50 via a CAN communication connection 66.

Charging of battery 34 can be carried out in one or more of the following ways: using a dynamo on the basis of the fuel engine of vehicle 2, from a charging station, using solar panels, for instance on the roof of bin 6, and via braking energy. Other methods are also possible. It will be apparent that diverse variants of diagram 32 are possible within the scope of the present invention.

In a currently preferred embodiment refuse truck 2 is provided with a loading system 8 and a pressing system 10 with drive system 32. The separate drives for systems 8, 10 are preferably operatively connected in order to further limit the number of parts.

An experiment with refuse truck 2 has shown that the fuel consumption at a comparable load is about 12% lower than in conventional refuse trucks. The present invention is by no means limited to the above described preferred embodiments thereof. The rights sought are defined by the following claims, within the scope of which many modifications can be envisaged.

Claims

1. Pressing system for compressing material in a collector, comprising:

- a frame provided with coupling means mountable on the collector;

- a drive system operatively connected to the pressing device, the drive system comprising:

- an energy supply comprising an energy source;

2. Pressing system as claimed in claim 1, wherein the electric motor comprises a three-phase motor, and preferably a three-phase asynchronous motor.

3. Pressing system as claimed in claim 1 or 2, wherein the motor control means for powering the at least one electric motor are operatively connected directly to the energy source.

4. Pressing system as claimed in claim 1, 2 or 3, wherein cylinders in the pressing device are operatively connected to separate pumps.

5. Pressing system as claimed in one or more of the claims 1-4, wherein the hydraulic fluid reservoir is provided in the pressing system.

6. Pressing system as claimed in claim 5, wherein the fluid reservoir is provided internally in one or more parts of the frame.

7. Pressing system as claimed in one or more of the foregoing claims, wherein the drive system is provided with coupling means for coupling the drive system of the pressing system and a drive system of a loading system for emptying containers .

8. Pressing system as claimed in one or more of the foregoing claims, wherein the pressing device is operatively connected to one or more detectors of a loading system of a refuse truck for the purpose of activating the pressing device .

9. Pressing system as claimed in one or more of the claims 1-8, wherein the energy source comprises a battery.

10. Pressing system as claimed in claim 9, wherein the battery comprises a low-voltage battery.

11. Refuse truck provided with a pressing system as claimed in one or more of the claims 1-10.

12. Refuse truck as claimed in claim 11, wherein the refuse truck is an electrically driven refuse truck.

13. Refuse truck as claimed in claim 11 or 12,

comprising a second pressing system.

14. Method for compressing material, comprising of providing a pressing system as claimed in one or more of the claims 1-10.