Mobile soil compaction system with working machine with electrically driven plate compressor

Abstract

An attachment tool (2) for mounting on a working machine (1) is specified, comprising a ground contact plate (19) for compacting soil, an unbalance exciter (18) acting on the ground contact plate (19) with unbalance forces, an electric drive for driving the unbalance exciter (18), a mechanical coupling device (14) for coupling the attachment tool to the working machine (1), and an electrical power interface (21) for coupling to an electrical power supply.

Description

[0001] The invention relates to a mobile soil compaction system according to claim 1, in particular a soil compaction system with a mobile working machine and an attachment tool for soil compaction.

[0002] Soil compaction devices such as vibratory plates or shaker plates are well known and are typically driven by combustion engines in construction sites to provide high performance independently of a power source from a power grid or a generator.

[0003] Mobile work machines are also known and can be used, for example, as wheel loaders, telescopic handlers, or excavators. Such work machines have a vehicle frame and a chassis that supports the frame for moving it. They also have a drive system, such as a hydraulic drive, which can serve both as a drive for travel and as a drive for working.

[0004] It is known to provide soil compaction devices for such machinery, enabling the machinery to also be used for soil compaction. These soil compaction devices are also known as attachment or plate compactors and are generally hydraulically operated. For this purpose, a hydraulic motor is provided on the attachment compactor, which serves as the implement. This motor is supplied by the machinery's hydraulic system and drives an unbalanced exciter belonging to the attachment compactor. The resulting centrifugal or vibrational forces are transmitted to a soil contact plate, which compacts the soil to be compacted. By moving the machinery, the soil can thus be compacted over a larger area.

[0005] Hydraulically driven compactors have poor efficiency and controllability. The frequent connecting and disconnecting of the hydraulic drive poses a risk of hydraulic oil leakage and environmental damage.

[0006] From EP 3 219 855 A1, an excavator with a detachably attached compactor is known. The compactor is hydraulically driven. Sensors or signaling devices of the compactor can be connected to the excavator's electrical system via electrical cables.

[0007] Other add-on compressors, which are permanently coupled to a chassis supporting the compressor and therefore cannot be detached without considerable assembly effort, are described in US 3 181 442 A, DE 18 43 591 U and GB 933 021 A.

[0008] The invention is based on the objective of providing an attachment tool and a soil compaction system utilizing the attachment tool, with which the disadvantages of the prior art can be overcome.

[0009] The problem is solved by a mobile soil compaction system according to claim 1, comprising a mobile work machine with an attachment tool for mounting on the work machine. Advantageous embodiments are specified in the dependent claims.

[0010] A tool attachment for mounting on a working machine is specified, comprising a ground contact plate for compacting soil, an unbalance exciter that applies unbalance forces to the ground contact plate, an electric drive for powering the unbalance exciter, a mechanical coupling device for connecting the tool attachment to the working machine, and an electrical power interface for connecting to an electrical power supply.

[0011] The attachment is essentially a soil compaction device, such as a plate compactor. The attachment is electrically driven by an electric drive, in particular an electric motor. The machine used is not part of the attachment and therefore not the subject of claim 1.

[0012] In particular, the electric motor drives the unbalance exciter. In one variant, the electric motor can drive the unbalance exciter directly, such that the motor shaft of the electric motor is directly coupled to an unbalance shaft of the unbalance exciter. In a further development of this variant, the motor shaft and the unbalance shaft can be a single component. Alternatively, it is also possible for the electric motor to drive the unbalance exciter indirectly, e.g., via a belt drive or a gearbox.

[0013] The unbalance exciter can have at least one unbalance shaft, which is driven by the electric drive. Alternatively, two unbalance shafts arranged parallel to each other can be provided, which can be driven in opposite directions. With such a design, it is possible for the horizontal components of the centrifugal forces caused by the rotation of the unbalance shafts to cancel each other out, while the vertical force components add up. In this way, a resulting force vector in the vertical direction can be generated, which allows for a strong compaction effect via the ground contact plate, while in the horizontal direction no or only slight forces act, which must be absorbed by the attachment and – if appropriately coupled to the driven machine – by the driven machine itself.

[0014] In one variant, the unbalance exciter can have at least two exciter units which together form the unbalance exciter and, in particular, through their interaction enable the compaction effect described above, but also the compensation of forces in the horizontal direction.

[0015] Each excitation unit can have an unbalanced shaft that can be driven directly by an electric motor. This means that each excitation unit can have its own electric motor. By appropriately controlling or synchronizing the electric motors, the desired compression effect in the vertical direction can be achieved, especially with opposing directions of rotation.

[0016] The electric motor and the unbalance shaft can form a single unit, in that the unbalance shaft and the motor shaft coincide. The unbalance mass provided on the unbalance shaft can thus be located directly on the motor shaft. For example, the unbalance mass can be located at one end of the motor shaft or at both ends. In the latter case, the actual electric motor, with its rotor and stator, is positioned between the two unbalance masses at its shaft ends.

[0017] When integrating a motor shaft and an unbalanced shaft, the motor shaft itself may also be asymmetrically constructed, resulting in an imbalance effect.

[0018] In one embodiment, two excitation units can be arranged in the direction of travel of the machine. The unbalanced shafts of the excitation units can rotate in opposite directions, so that the centrifugal or unbalanced forces cancel each other out in or against the direction of travel. Instead, there is only one direction of action in the vertical direction, i.e., upwards or downwards. It has been found that no mechanical coupling or electronic control is required to achieve synchronization of the two unbalanced shafts. Rather, synchronization occurs automatically through self-synchronization.

[0019] Instead of or in addition to synchronization, a targeted phase shift of the rotational positions of the two unbalanced shafts is also possible, so that forces in or against the direction of travel result, or the resulting centrifugal forces acquire a horizontal component.

[0020] The imbalance agent can also have more than two agent units in order to achieve higher performance.

[0021] The unbalance exciter and its excitation units can all be provided and installed on the attachment. In this case, only a power supply from the machine to the attachment is necessary (especially direct current). Special converters to provide a suitable current for the electric motors of the excitation units are not required on the machine. The converters and control units can all be located on the attachment, particularly on its upper mass (explained below) to protect against vibrations on the lower mass.

[0022] The electrical power supply for the electric drive can be provided externally, in particular by the working machine via the electrical power interface, as will be explained below.

[0023] A signal interface may be provided for transmitting control data between an external operating device and the electric drive. "External" in this context means that the operating device is physically separate from the attachment. Signal transmission between the operating device and the electric drive can be wired or wireless, e.g., via radio or Bluetooth.

[0024] The control data can switch the electric drive, and thus the unbalance exciter, on or off. Furthermore, the control data can also allow for the adjustment or modification of the speed or frequency of the electric drive and the unbalance exciter.

[0025] It is also possible to switch the electric drive on or off directly via the power interface, in particular by interrupting or disconnecting the power supply provided by the electrical power supply.

[0026] The attachment tool can have an upper mass to which at least one component of the mechanical coupling device can be arranged, wherein the unbalanced exciter and the ground contact plate form a lower mass, and the lower mass can be movable relative to the upper mass. A vibration decoupling device can be arranged between the lower mass and the upper mass. This principle of a vibratory plate compactor is known per se and has proven its worth in many applications.

[0027] A mobile soil compaction system is described, comprising a mobile working machine and an attachment tool of the type described above, wherein the working machine has a vehicle frame, a chassis supporting the vehicle frame for moving to the vehicle frame, a drive motor for driving the chassis, an electrical energy storage device, and a tool holding device held on the vehicle frame, wherein the attachment tool is detachably held on the tool holding device, and wherein the electric drive of the attachment tool is supplied with electrical energy by the electrical energy storage device.

[0028] The mobile work machine can be, in particular, a wheel loader, a telescopic handler, an excavator, or similar equipment. Articulated loaders are also suitable as loading vehicles. The drive motor can be an internal combustion engine or an electric motor.

[0029] The chassis can have wheels, which are arranged particularly on two or more axles. At least one wheel can be driven to make the machine mobile. Likewise, an entire axle or several axles can be driven. It is also possible for the chassis to have a chain drive, which is powered by the drive motor.

[0030] The electrical energy storage device can be supported by the vehicle frame. In particular, it can be a battery located in the rear part of the vehicle frame, opposite the tool holder with respect to the vehicle's longitudinal axis, thus forming a stabilizing counterweight to the tool holder and the attached tool.

[0031] The tool holding device can be designed for the detachable coupling of the mechanical coupling device of the attachment tool, and thus for the detachable coupling of the attachment tool to the machine. The detachable coupling process makes it possible to equip the machine with various tools, of which the soil compaction attachment according to the invention is merely one alternative.

[0032] A detachable electrical power interface may be provided for the releasable connection of the attachment's electric drive to the electrical energy storage system of the machine. Accordingly, the power interface may include components present on the attachment as well as components present on the machine.

[0033] When the power interface is disconnected, the attachment and the machine can be moved completely independently of each other, as the respective components remain attached to the attachment and the machine. Only when connected is the power interface closed, enabling the desired power transmission.

[0034] It may be advantageous if the power interface is provided in the area of ​​the tool holding device or in the vicinity of the tool holding device, in order to be able to establish the electrical connection when the attachment tool is coupled.

[0035] The drive motor of the machine is an electric motor, which is supplied with electrical energy by the machine's electrical energy storage system. In this case, a complete electrical supply for the machine and the attachment is possible.

[0036] An operating device may be provided for setting parameters for the electric drive and thus for the vibratory exciter driven by the electric drive. The operator has the option, via a suitably designed operating device, for example with levers, buttons and indicators or a touch-sensitive display, to switch the vibratory exciter on and off as desired or to change the vibration parameters of the vibratory exciter, in particular the rotational frequency of the electric drive.

[0037] The control unit can be located in a driver's cab mounted on the vehicle frame. This makes it very convenient for the operator, who is in the cab and operating the machine, to directly control the unbalance exciter on the attachment. Signal transmission can be wired or wireless (e.g., via radio, such as Bluetooth).

[0038] A control unit may be provided to control the electric drive and thus the unbalance exciter, whereby the control unit can be controlled by the operating device. The control unit can accordingly be arranged on the machine or on the attachment. It serves to receive control commands from the operating device and to control the electric drive or electric motor at the unbalance exciter in a machine-compatible manner.

[0039] In a mobile soil compaction system according to the invention, the attachment tool can be pushed and moved over the soil to be compacted by the working machine. In addition to the mechanical coupling, the attachment tool is connected to the working machine via a detachable interface, which may include an electrical power interface and / or a signal interface.

[0040] The electrical energy storage device in the machine can include overcurrent and short-circuit protection. A control device, e.g., in the form of a control unit, can be provided on the tool and / or machine side.

[0041] The electrically driven mobile soil compaction system allows for significant energy savings compared to conventional systems, especially compared to systems with hydraulically driven vibratory exciters. Furthermore, the electric drive of the vibratory exciter enables better controllability and simpler, cleaner connections, eliminating the risk of leakage of contaminants (hydraulic oil).

[0042] These and other advantages and features of the invention are explained in more detail below using an example and the figure. The figure shows: Fig. 1 schematic side view of a mobile soil compaction system according to the invention; Fig. 2 In perspective view, an excitation unit of an unbalance exciter for the soil compaction system; and Fig. 3 a vertical section through the excitation unit of Fig. 2 .

[0043] The mobile soil compaction system comprises a mobile working machine 1 and an attachment tool 2 carried by the working machine 1.

[0044] The work machine 1 could be, for example, a wheel loader (as in Fig. 1 The wheel loader (shown) could be a telescopic handler or an excavator. It may have a steerable axle. It could also be an articulated loader. The excavator could be wheeled or tracked.

[0045] The work machine 1 has a vehicle frame 3, which is supported by a chassis 4. The chassis 4 has two wheel axles 5, each carrying wheels 6, at least one of which is driven to move the chassis 4 and thus the work machine 1. The off-road capability of the work machine 1 is increased by driving several wheels 6 or, if necessary, all wheels 6.

[0046] A driver's cab 7 is built on the vehicle frame 3, which protectively encloses a driver's seat 8.

[0047] A drive motor (not shown) is provided for powering the working machine 1 and is arranged in the vehicle frame 3. The drive motor can be an internal combustion engine or an electric motor.

[0048] The vehicle frame 3 also supports an electrical energy storage device 10, e.g., a battery or accumulator. A protective device 11 is provided to protect the electrical energy storage device against overcurrent and short circuits. The energy storage device 10 can serve to supply electrical energy to the attachment 2, which will be described in detail later. Likewise, the electrical energy storage device 10 can provide energy for the drive motor of the working machine 1 if it is designed as an electric motor.

[0049] A lifting device 12 is provided in the front area of ​​the machine 1 in a known manner. The lifting device 12 can be configured in various ways and has a tool holding device 13 at its front end. In particular, the lifting device 12 can include hydraulic cylinders, electric or pneumatic actuators, linear drives, struts, and joints to achieve the desired mobility of the lifting device 12 so that a tool attached to the tool holding device 13 can be moved and guided in the manner intended for operation.

[0050] The tool holder 13 holds the attachment tool 2. For this purpose, the attachment tool 2 has a mechanical interface 14 serving as a mechanical coupling device, which can be coupled to the tool holder 13.

[0051] The attachment tool 2 is an electrically driven plate compactor for soil compaction.

[0052] The attachment tool 2 has an upper mass 15 and a lower mass 16. The lower mass 16 is held movable relative to the upper mass 15 and is connected to the upper mass 15 by vibration decoupling elements 17, e.g., rubber buffers.

[0053] On the base 16, an unbalance exciter 18 with two counter-rotating unbalance shafts is arranged. The unbalance exciter is mounted on a ground contact plate 19, which also belongs to the base 16. When the unbalance exciter 18 is in operation, vibration forces are generated by the centrifugal forces of the unbalance shafts in a known manner. These vibration forces can be transmitted into the ground contact plate 19 and thus into the soil to be compacted.

[0054] At least one electric motor (not shown) is provided to drive the unbalance exciter 18, in particular to drive the counter-rotating unbalance shafts. It is also possible to drive both unbalance shafts 18 separately by their own electric motors. Furthermore, an unbalance exciter 18 can be used with only one unbalance shaft or with more than two. For example, in a large plate compactor, it is possible to arrange and operate four unbalance shafts in parallel.

[0055] The electric motor for the unbalance exciter 18 can be mounted directly on the unbalance shafts or drive them directly. Alternatively, the electric motor can be mounted on the upper mass 15 and its torque transmitted to the unbalance exciter 18 via a belt drive.

[0056] The upper mass 15 is coupled to the mechanical interface 14 via a swing arm or boom 14a, so that the attachment tool 2 is attached to the tool holding device 13 at its upper mass 15.

[0057] An electrical line 20 is provided for transmitting electrical current from the electrical energy storage device 10 of the machine 1 to the electric motor in the attachment 2. The electrical line 20 can be disconnected at an electrical power interface 21. This makes it possible to detach the attachment 2 from the machine 1 not only mechanically by disconnecting the mechanical interface 14 from the tool holder 13, but also electrically by disconnecting the electrical power interface 21.

[0058] Furthermore, a signal line 22 can be provided for transmitting control commands to the attachment tool 2, in particular to its electric motor, as well as for providing feedback of signals from the attachment tool 2, e.g. from the unbalance exciter 18. For this purpose, corresponding sensors or transducers can be provided on the attachment tool 2.

[0059] The signal line 22 can be routed to an operating unit 23 located in the driver's cab 7, via which the operator can control the attachment 2, in particular the electric motor and the unbalance exciter 18 provided therein. Information about the attachment 2 can also be transmitted to the operator via the operating unit 23.

[0060] The signal line 22 can also be disconnectable to allow the attachment tool 2 to be detached. For this purpose, the electrical power interface 21 can also be configured as a signal interface 24. In particular, the electrical power interface 21 and the signal interface 24 can also be provided in a common physical unit and, for example, use the same housings (e.g., with plug and socket).

[0061] Instead of the wired signal line 22 and the signal interface 24, it is also possible to provide a wireless connection, in particular a radio connection such as Bluetooth.

[0062] The corresponding control units or line connections can be provided on the upper mass 15 at a connection device 25.

[0063] On the tool or machine side, a control unit 26 can be provided with which the commands from the operating device 23 can be converted or transmitted in a suitable manner for the drive motor of the working machine 1 or for the electric motor of the attachment tool 2.

[0064] In one variant, the imbalance pathogen 18 can, for example, in two Fig. 2 The units 18a shown are constructed similarly to an external vibrator and can be used on the attachment tool 2. The number of units 18a can be varied depending on the application or dimensions of the attachment tool 2.

[0065] The Figuren 2 and 3 show an example of a unit 18a (pathogen unit) of such an imbalance pathogen 18.

[0066] The unit 18a has a housing 30 which can be attached to the ground contact plate 19 by means of screw connections 31 in order to effectively use the vibrations generated by the unbalance exciter 18 for soil compaction through the ground contact plate 19.

[0067] How Fig. 3 As shown, an unbalanced shaft 32 is arranged inside the housing 30, which is rotatably mounted in the housing 30 by means of bearings 33.

[0068] An electric motor 34 is arranged between the two bearings 33. The electric motor 34 has a rotor 35 and a stator 36. The rotor 35 is suitably attached to the unbalanced shaft 32, for example by press-fitting. Thus, the unbalanced shaft 32 also serves as the motor shaft of the electric motor 34. The stator 36 is pressed into the interior of the housing 30. In this way, the electric motor 34 with the unbalanced shaft 32 can be installed inside the housing 30 in a very simple manner.

[0069] Partial unbalance masses 37 are arranged at each end of the unbalance shaft 32. The total effect of the partial unbalance masses 37 can correspond to the unbalance effect of a single unbalance mass.

Claims

1. Mobile ground compaction system, comprising - a mobile working machine (1); and - an attachment tool (2); wherein the working machine (1) has - a vehicle frame (3); - a chassis (4), which supports the vehicle frame (3), for moving the vehicle frame (3); - a drive motor for driving the chassis (4); - an electrical energy storage device (10); and - a tool holding apparatus (13) which is held on the vehicle frame (3); wherein the attachment tool (2) has - a ground contacting plate (19) for compacting the ground; - an unbalance exciter (18) which applies unbalance forces to the ground contacting plate (19); - an electric drive for driving the unbalance exciter (18); - a mechanical coupling apparatus (14) for coupling the attachment tool to the working machine (1); and - an electrical power interface (21) for coupling to an electrical energy supply; wherein - the attachment tool (2) is detachably held on the tool holding apparatus (13); - the electric drive of the attachment tool (2) is supplied with electrical energy by means of the electrical energy storage device (10); - the drive motor of the working machine (1) is an electric motor; and wherein - the electric motor is supplied with electrical energy by means of the electrical energy storage device (10).

2. Mobile ground compaction system as claimed in claim 1, wherein a signal interface (24) is provided for transmitting control data between an external operating device (23) and the electric drive.

3. Mobile ground compaction system as claimed in claim 1 or 2, wherein - an upper mass (15) is provided, on which at least one component of the mechanical coupling apparatus (14) is arranged; - the unbalance exciter (18) forms together with the ground contacting plate (19) a lower mass (16); - the lower mass (16) is movable relative to the upper mass (15); and wherein - a vibration decoupling device (17) is arranged between the lower mass (16) and the upper mass (15).

4. Mobile ground compaction system as claimed in any one of the preceding claims, wherein the tool holding apparatus (13) is designed to detachably couple the mechanical coupling apparatus (14) of the attachment tool (2) and thus to detachably couple the attachment tool (2) to the working machine (1).

5. Mobile ground compaction system as claimed in any one of the preceding claims, wherein a separable electrical power interface (21) is provided for detachably connecting the electric drive of the attachment tool (2) to the electrical energy storage device (10) of the working machine (1).

6. Mobile ground compaction system as claimed in any one of the preceding claims, wherein an operating device (23) is provided for specifying parameters for the electric drive and thus for the unbalance exciter (18) by an operator.

7. Mobile ground compaction system as claimed in claim 6, wherein the operating device (23) is arranged in a driver's cabin (8) arranged on the vehicle frame (3).

8. Mobile ground compaction system as claimed in claim 7, wherein - a control device (26) is provided for activating the electric drive and thus for activating the unbalance exciter (18); and wherein - the control device (26) can be activated by means of the operating device (23).

Images